DE8711110U1 - Contacting device - Google Patents

Description

15

The invention relates to a contacting device for test devices according to the preamble of claim 1.

20 25 30

Such test devices are used to test electrical or electronic test objects, such as circuit boards, integrated circuits and switches or similar, for electrical faultlessness. Known spring contact pins of this type (e.g. KRÜGER, "Test device for electrical testing of circuit boards for watches", Yearbook of the German Society for Chronometry, Volume 30, 1979, pp. 269-276; DE-OS 35 07 464) have a cylinder in which the round cross-section, solid piston of the piston member is mounted so that it can slide axially. This piston is loaded by a separate, pre-tensioned helical compression spring, against the force of which it is moved by the test objects when the test object is tested. Despite the small size of such spring contact pins, the spring must be able to exert relatively large contact forces, usually around 50 - 300 cN. The

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Electrical contact resistances between the parts of these spring contact pins increase the electrical resistances and these generally increase with the number of load changes. The piston member and the cylinder of the known spring contact pins are manufactured by machining, for example on lathes and the coil spring on spring winding machines. Depending on the specific application, the parts are then galvanized and assembled in hand-operated devices or on machines. Even if the individual production stages are carried out on machines, the costs of producing such high-quality spring contact pins are relatively high.

It is therefore an object of the invention to provide a contacting device of the type mentioned above, which can be manufactured very cost-effectively and

is easy to install and, in the case of several or many spring contact pins, corresponding to the normal fail, can also allow particularly small center distances between adjacent points on test objects that are to be contacted simultaneously by such spring contact pins.

To solve this problem, the invention provides a

Contacting device according to claim 1 is provided. 30

Since the spring and the piston member are formed by a single, single-piece sheet metal part, the rod can be manufactured extremely cost-effectively from a sheet metal, for example by producing the sheet metal blanks by punching, etching or the like and, if necessary, by forming the sheet metal without cutting, such as bending, embossing or the like.

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its punching, etching or similar and, if necessary, chipless
If necessary, the rod only needs to be deformed
still deburred and if necessary with at least one
chemically or galvanically applied coating
to be provided, e.g. nickel-plated* gold-plated
or similar. One or more such
Coatings can also be applied to the sheet
be provided before cutting for the
relevant Stöo of inrn by punching, etching or
etc. Multi-layer coatings
or coatings are in spring contact pins
As is well known, this is of course possible.

The thickness of the sheet from which the preferably

e flat rod is to be produced, can be very low §

be, e.g. often appropriate at least 0.05 mm, §

in particular 0.1 to 1 mm, preferably 0.2 to |

0.4 mm, often appropriately about 0.25 j

up to 0.35 mm. Other sheet thicknesses are also possible depending on ^!

Design in question. For example, in the case of rods that \

from the plane of the original sheet metal cut |

are deformed, particularly low sheet thicknesses | should be provided, e.g. approx. 0.09 to 0.25

mn. The maximum width of the bar can be appropriately *

larger, preferably several times larger than the s

Thickness of the sheet metal forming it. This maximum j

Width can be at least 2 times, ^preferably at least 3 times larger than the thickness

of the» sheet, preferably about 4 to &iacgr; 20 times, particularly useful often about 4 to

10x. f

The longitudinal direction of the bar can include

the spring should preferably be straight.

Although it is a contact device for

simultaneous scanning of a large number of ,

•

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Contact points by means of spring-loaded sensing elements for telecommunications systems* inserted in a grid pattern in a support block, in particular for sensing the contact points of printed circuit boards, known (DE-PS 1 790 052), in which the sensing elements are designed as flat springs bent in a meandering shape in one plane, which are guided in holes in the bearing body and in openings in the cover plates in pairs with their flat sides lying against one another and on both sides of the support block with their straight-running (' spring ends to form sensing tips on the one hand

and connecting lugs on the other hand protrude beyond the support block. These

However, the contacting device is structurally relatively complex, simply because two springs are arranged next to each other in each bore of the bearing body and two sensing elements emerge from each opening of the cover plate adjacent to the test object.

protrude. The springs, which are in contact with each other with their flat sides, can interfere with each other and the size of the contact forces that arise when testing test objects, which force the two probe tips to the same

■ Contact point of a test subject, uncontrolled

fluctuate and, accordingly, the test current conducted by them together. Also, precise guidance of the probe tips is not guaranteed because the probe elements do not have straight pistons. The center distances of adjacent points to be contacted on each test object must be arranged in a relatively large grid because the paired arrangement of the probe elements designed as springs does not allow for very small grid dimensions. It is indeed possible with this contact device to

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&Igr; Springs of a spring pair through the two legs

of a U-shaped bent part, the free

\ Leg ends form the probe tips, but forms

Such a bent part is not a rod, but is similar to a hairpin and attached to the

This does not change the disadvantages mentioned above.

In contrast, spring contact pins according to the invention have a simpler, more cost-effective design, precise guidance of the piston elements, allow extremely small center distances between adjacent spring contact pins in the contacting device, allow the desired contact forces to be achieved very precisely and allow a variety of rod designs to adapt to different requirements.

If a section of the rod forms a spring, at least this spring section of the rod must have spring-elastic properties. For this purpose, the sheet metal of the rod can be made of steel, copper-iron, nickel-beryllium, bronze, metallic composite materials or other

. 25 suitable metals or metal alloys and, if necessary, also be provided with a single or multi-layer metallic coating or coatings throughout or in certain areas, preferably made of metals or metal alloys.

30

It is also possible that the rod forming

Sheet metal is punched or similar while still in a non-elastic state and possibly deformed, such as bent and/or embossed or similar, and only then is it tempered to obtain spring-elastic properties,

hardened or otherwise treated. For example, the sheet may initially be soft copper-beryllium

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and the rod made from it is then heat treated for 1 hour at approx. 300° C. Or only the section of the rod that forms the spring is given the spring-elastic properties necessary for the spring by tempering, hardening or the like, and the remaining areas of the rod have completely or largely different properties.

2Q appropriate treatment or non-treatment. For example, when manufacturing the rod from sheet steel, the piston member can be treated so that it has a structure with the most rigid properties possible, e.g. by hardening without subsequent

j ₅ Tempering, whereby the section forming the spring is tempered after hardening in order to achieve the best possible elastic spring properties, e.g. is subjected to a suitable temperature treatment.

The spring can preferably be a flat spring or a leaf spring. The spring can be particularly useful in a serpentine shape and/or have at least one opening. However, other designs are also possible.

As mentioned, the ^rods can be provided with chemical or galvanic or other applied coatings or coatings

₃ q, which further improve their desired properties, e.g. providing the highest possible wear resistance of the pistons of the piston members, etc. For this purpose, for example, hard nickel plating is advantageous and, if necessary, coatings or

o ₅ Coatings made of precious metals or precious metal alloys, or electrically insulating coatings may also be used in certain areas

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be provided, etc.

In order to perform the function to be performed, the metal c rod must be a good electrical conductor. Here it is an advantage that the spring together with the piston element forms a one-piece component, so that there is no longer any electrical contact resistance between the spring and d<3m piston element. The electrical conductor connecting the spring contact pin to the test device can then be connected directly to the rear end of the rod. For example, an electrical conductor wire can be soldered or

,_ be welded, or the rear end of the rod can be elastically pressed against a connection contact, or a connection contact can be clamped to it, etc. This also increases the electrical resistance of this

Spring contact pin no longer with the number 20

the load change.

In the simplest case, the spring contact pin can only consist of the one-piece rod or the rod and a separate contact head attached to it. This also makes it possible to achieve particularly small center and side distances between adjacent spring contact pins, which enables contacting of correspondingly closely spaced

Test points of test items to be tested. 30

The sliding guide for the piston of the piston member can then be formed by a slot forming a channel in a plate arrangement, a plate or another object.

into which this Fedor contact pin is inserted |

I

This plate arrangement or similar can then

have several or very many such slots, %

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in which such spring contact pins are or can be inserted, and in which the springs of the rods can preferably also be arranged, so that the springs are thereby secured against lateral buckling and also guided in a simple manner. These springs can be arranged completely in the slots or, if necessary, protrude slightly beyond them. The plate, plates or the like can be made of electrically insulating material, preferably plastic, so that the spring contact pins themselves do not require electrically insulating coatings or the slots have to be provided with insulating coatings.

Since the spring contact pins in the contacting device are arranged individually in separate channels or similar

2Q and are electrically insulated from each other and each consist of only one rod or have only one rod, they also result in more uniform contact with the test objects and more uniform volume resistances than the touch elements lying next to each other in pairs according to DE-PS 17 90 052.

When testing test objects, the individual spring contact pin according to the invention conducts a test current which is or can be independent of the test currents individually conducted by the other spring contact pins of the contacting device in question.

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The spring contact pin according to the invention can therefore due to the possible extremely small center and side distances between adjacent

Spring contact pins also open up areas of application where conventional spring contact pins could not be used. They can allow extremely small grid dimensions for the points to be contacted on test objects,

especially in the case of only individual

'■ Rows of contact points arranged on

V test objects, e.g. the pads of chips.

The assembly of this inventive

Spring contact pins are extremely simple, as no separate assembly of the spring is required, but only the rod must be inserted into the relevant, preferably flat, sliding guide or similar.

In many cases, the spring contact pin can be provided with a separate sliding guide that is assigned only to it.

/ 25 can preferably also be made from sheet metal by punching, etching or similar and bending or similar, but can also be made from other materials such as plastic, ceramic or similar. This sliding guide of the spring contact pin can then be inserted into a contacting device, for example into a test adapter or similar of a test device, for example into a front panel of a test adapter, normally together with several or many such spring contact pins.

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It is also particularly advantageous if the two longitudinal end regions of the rod are formed by the two longitudinal end regions of the sheet metal blank from which the rod is made.

The following definitions are given:

The width b of the bar is parallel to the

geometrical broad longitudinal center plane of its piston member and perpendicular to its

^ Direction of movement and thus perpendicular to its

Measured longitudinally.

The height h of the rod, including the height of its spring, is measured perpendicular to the geometrical width-longitudinal center plane of the piston member and perpendicular to its direction of movement and thus perpendicular to its longitudinal direction.

The geometric longitudinal center plane of the piston link is parallel to its width and runs at half the maximum / 25 height of the piston link.

The cross-sectional width (x) of each cross-section of the sheet metal forming the spring is the width parallel to the bending force present during normal operation.

QQ neutral fiber (=stress »iu 11 i η i e ) (77) measured cross-sectional dimension and the cross-sectional height (y) of the relevant cross-section is the

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vertically measured cross-sectional dimension (y), as shown in Figures 2C and 24.

This cross-sectional width and height do not need to be

to match the width and height of the spring.

Preferably, it can be provided that the maximum width of the piston member is greater, preferably at least twice as large as its maximum ^height and/or that the maximum width of the spring is greater, preferably at least twice as large as its maximum height. Particularly expediently, ^r

( it must be ensured that the maximum width of the bar

larger, preferably at least 2 times larger than its maximum height.

In a preferred embodiment, which results in a particularly high fracture resistance of the spring, it is provided that the sheet metal area of the sheet metal part of the rod forming the spring does not run parallel to the geometrical wide longitudinal center plane of the piston member at least in part, ₄ preferably is inclined to it and/or is directed approximately perpendicularly (Fig.

17,19,20), whereby the non-parallel region or at least one non-parallel region may be curved and/or flat or otherwise bent out of the plane of the originally flat sheet metal blank.

The drawing shows embodiments of the invention. They show:

5881-2

&bull;it

ti f

-ZO-

Fig. 1 is a partial top view of a plate arrangement of a contact opening (not shown in further detail) of a test adapter of a test device for testing electrical or electronic test objects, such as circuit boards or the like.

Fig. 2A is a section through the plate arrangement according to Fig. 1, seen along the section line 2-2,

Fig _t 2B a side view of the narrow side of the flat rod according to Fig. 2A ₁

Fig. 2C is a section through the spring of the rod according to Fig. 28, seen along the section line 2C-2C

Fig. 3 a variant of Fig. 2A,

Fig* 4 shows a variant of Fig. 2A in a partial representation,

Fig. 5 is a front view of the spring contact pin forming a flat rod of Fig. 4,

Fig. 6A Variants of the flat bar according to Fig. 5, and 6B also seen in frontal view,

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Fig. 7 a side view of a

Spring contact pin according to another

Embodiment of the invention, 5

Fig. 8 is a section through Fig. 7 taken along section line 8-8,

Fig. 9 a bottom view of the spring contact pin

% 10 according to Fig. 7,

Fig. 10 is a section through the spring contact pin according to Fig. 7, seen along the section line 10-10j
15

Fig. 11 a side view of a

Spring contact pin according to another embodiment of the invention,

\ 20 Fig. 12 Sections through the spring contact pin according to

and Fig. 11, seen along the

Cutting lines 12-12, 13-13 or 14-14,

a Fig. 15 a variant of Fig. 2A.

Fig. 16 is a view of a flat rod with a flat spring consisting of a row of rings according to another embodiment of the invention ₄

Fig. 17 is a diagrammatic view of a flat

35

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Rod of a spring contact pin, the sliding guide of which is indicated by dash-dotted lines,

7»

Fig. 18 the flat lead blanks from which the rod and the sliding guide forming a sleeve according to Fig. 17 are made by bending,

Fig. 19 shows a variant of the rod shown in Fig. 17 and 20, also in a schematic view,

Fig. 21 the flat sheet metal blank from which both

the rod according to Fig. 19 as well as the one according to Fig. 20 can be produced by bending ,

Fig. 22A Variants of test specimens of the pistons of

to 22G rods as shown in Fig. 17, 19 and 20 to approximately equalize the height of the pistons to that of the springs,

Fig. 23 a section through the spring according to Fig. 20, seen along the cutting line

Fig. 24 a cross section through the sheet metal of the

Spring according to Fig. 2.&Oacgr; , seen along the section line 24-124.

In Fig. 1, a partial plan view ac ^; .,ne contacting device 13 is shown, which has a block-forming plate arrangement 10, which has a

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A plurality of channels or slots 11 with a rectangular cross-section, with a single spring contact pin designed as a flat rod being inserted into each such slot in the manner shown in Fig. 2A. This flat rod 12, which forms a one-piece, single-layer sheet metal part, has a constant thickness and is flat and its longitudinal axis is straight. Instead of the plate arrangement 10, a one-piece plate or another object which has slots 11 serving to guide the flat, straight rods 12 can also be provided. The flat rods 12 are inserted with their lower feet 16 with a rectangular cross-section into a support plate 14 made of

Plastic is used, which has «graduated through holes 15, on whose respective steps the rear ends of the flat rods 12 sit, whereby the axial position of these rear ends of the

upright flat bars 12. These slot-shaped openings 15 of the support plate 14 can be so narrow that these rear ends 16 of the flat bars 12 are held in them with friction. The plastic of the

° Support plate 14 is electrically insulating, just like the two plates 17 and 18 of the plate arrangement 10.

The plate 18 of the plate arrangement ¹⁰ has on one side the rectangular slots 11 which are machined parallel to one another and which are connected on this side by a

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attached flat plate 17 are closed, so f

that the rectangular through-slots 11 are thereby formed in a simple manner in terms of production. Such a plate arrangement 10 with inserted spring contact pins 12 and support plate 14 forms a contacting device 13, which can form a test adapter or a module of a test adapter, or such a module or a number or a large number of such modules can be arranged on a test adapter. Such a module can also have two rows of such slots without any problem with the same manufacturing method. This &

I

^v Module or this plate arrangement 10 is attached to a

Carrier or frame of the test adapter is fixed together with the support plate 14. The test adapter can be electrically connected in a known manner to a test device of the test device, see KRÜGER, as above, and its spring contact pins 12 can be used for simultaneous contacting of points of the respective test

2Q lings. The elongated metallic flat rod 12 is made from a flat sheet, preferably by stamping, the thickness of which can preferably be 0.2 to 0.4 mm, often particularly expediently 0.25 to 0.35 mm. Such sheet thicknesses are also often advantageous for other rods. It is completely flat and has a constant thickness d, see Fig. 2B, so that the geometrical wide longitudinal center plane 61 of its piston member 2U, which in Fig. 1 and 2B runs perpendicular to the image plane, is a plane of symmetry of the rod 12, in which its longitudinal center axis 69 (Fig. 2A) also falls. Its length L is much greater than its maximum width b (Fig. 2A), preferably at least 10 times greater, particularly expediently at least 25 times greater. This maximum width b is in turn significantly larger than its thickness d< It is designed with plain bearing clearance in the relevant

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Slot 11 is mounted and secured against rotation by its shape. It has the shape shown in jjj Fig. 1 to 2B.

5, it has, as shown, a wave-shaped or serpentine shape in the plane of the &iacgr; flat rod 12

ji extending flat spring 19, which in relation to the

Longitudinal axis 69 in the plane of this flat bar 12

] is transversely corrugated and which looks like

&Igr;&iacgr;&ogr; clearly a curved bending spring

with serpentine coils. This spring 19
^ closes the short straight foot part 16 and

The flat piston member 20 forms both the straight piston member 20 which is slidably mounted in the slot 11 with sliding bearing clearance and has a rectangular cross section of constant width.

Piston 21, which can also be referred to as a flat piston, and in this embodiment the contact tip 22 which is used for contact with test objects such as circuit boards or the like, of which a section is shown in dash-dotted lines at 23 in Fig. 4. The piston 21 is «··■■ 25, i.e. here the area of the piston member 20 which has a constant width and which can be slid through it in the relevant slot 11. A further electrical QQ conductor wire 40 is soldered to the foot part 16 which has a rectangular cross-section. Each rod 12 forms a

electrical conductors, and these rods 12 are individually electrically insulated from each other.

The serpentine flat spring 19 has a straight longitudinal axis that coincides with the longitudinal axis of the rod 12, so that this rod 12 is a rod with a straight longitudinal axis 69. The spring 19 is not pre-tensioned in this embodiment and so

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dimensioned so that it cannot get stuck in the slot 11 during the stroke movements of the piston member 20 in the direction of the double arrow A when testing test objects. For this purpose, its width b2 (Fig. 2A) can be the same size or, if necessary, slightly smaller than that of the piston 21. Its thickness corresponds to that of the piston member 20 and is therefore significantly smaller than its width. The flat spring 19 is therefore also guided in the slot 11, which forms a straight channel with a constant clear cross-section, and cannot buckle transversely to its longitudinal direction, but can only spring axially.

When testing test specimens, the test specimen is simultaneously pressed against the contact slots 22 of the triangular, flat contact heads 26' of the flat rods 12 of the contacting device or devices and presses them downwards against the spring forces of the springs 19. After the test has ended, the test specimen is removed and the piston members 20 thereby return to their starting positions.

If it is desired to reinforce the upper end portion of the flat rod 12 which projects upwards beyond the slot 11, this can be achieved in a simple manner by

gO the part forming this flat rod has two tabs 24 punched out at the sides, which are then bent by 180° as shown in Fig. 4 and 5. They can also be bent by less than 180°, for example by 90° each to the same side (Fig. 6A) or to opposite sides (Fig. 6B). Other stiffenings of the flat rod 12

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° are possible. 8For example, one or more impressions can be provided for this purpose, which may also be in the

Straight guidance can be extended as shown in Figures 11 to 14 in an example embodiment.

As mentioned, the flat rod 12 can also be provided with at least one chemical or galvanic or applied in another way coating or covering, which further improves its desired properties, for example, resulting in the lowest possible electrical contact resistance or high wear resistance of the piston of the piston member, etc.

In this spring 19 of the rod 12, the cross-sectional width x measured parallel to the neutral fiber present during axial compression of the spring, as 77, corresponds to each of its sheet cross-sections (Fig.

² ^ 2C) of the thickness d of the sheet metal forming it. The cross-sectional height y of each such cross-section, measured perpendicularly to this, is greater than d in this flat spring 19 in the embodiment. The thickness d here corresponds to the height of the spring and the cross-sectional height y is therefore perpendicular to this thickness d. The maximum width b2 of this spring 19 here runs parallel to the cross-sectional height y.

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The spring 19 forms a transverse, "standing" wave train, whose "oscillation plane" is referred to as the "wave plane" to make it clear that this wave train does not oscillate transversely. The wave plane is the one

"Vibration plane" which runs halfway up the transversely waved spring 19. In this embodiment according to Figures 1 to 2C this wave plane corresponds to the geometric width-longitudinal center plane 61.

The contacting device 13 according to Fig. 3 differs from that according to Fig. 2A essentially in that the foot 16 of the spring contact pin forming

flat bar 12, which can also be described as a flat bar with a straight longitudinal axis, has a recess 26 into which a plate 27 engages in a form-fitting manner to secure the axial position of this foot 16. This plate 27 is attached to the plate 18 having the slots 11. This plate 18 as well as the plate 17 can correspond to the plates 17 and 18 according to Fig. 1 and 2, but no support plate 14 is required here, so

that the contact device is structurally very special 30

simple and inexpensive. It normally has several or many such rods 12 forming spring contact pins, each of which is used for the simultaneous contacting of separate test or contact points

of the respective test item for testing purposes and to 35

separate conduction of test specimens during testing

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are electrically insulated from each other by the test currents that occur.

If it is desired to limit the stroke of the piston member 20 of the flat rod 12, which here has a longer area 28 tapered in width, a dash-dotted

jQ shown plate 3ü can be attached to the top of the plate arrangement 10, which engages in one of the two recesses 31 forming the tapered area 28. This tapered straight area 28 forms a flat shaft of the

per piston member 20, which integrally connects its flat piston 21 with its widened, also flat contact head 26'. In the presence of such a plate 30, which extends over the length of the respective plate 18 to all slots 11 of this

OQ plate can extend simultaneously (which also applies to the plate 27) , it can also be provided that the serpentine transversely corrugated spring 19, the wave plane of which corresponds to the geometrical wide longitudinal center plane of the

2g of the piston member 20, is permanently pre-tensioned by being so long that it presses the piston 21 against the plate 3Q under pre-tension. This must therefore also be a curved plate with a straight longitudinal axis.

·

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Bending spring forming spring 19 correspondingly long

The foot part 16 can then be omitted and the serpentine flat spring 19

rest only on plate 27. 5

In the embodiment example according to Figures 7 to 10, the spring contact pin 50 consists of a flat rod 12 with a straight longitudinal axis and

&ogr;&igr;&pgr;&ogr;&tgr;»&agr;&Lgr;&agr; nactr\r\*4i%-v*±r*o Toi 1 aiionah^ 1 called im/i only»

**""»-&mdash;&mdash;"&mdash;' ^a - &mdash;- &mdash;"

associated metallic, straight

Sliding straight guide 34. This sliding straight guide 34 ( can be used together with the sliding straight guides 34 of a

A plurality of such spring contact pins 50 in a dash-dot

_: Front plate 38 of a contact device

15

direction forming a test adapter, in which it is secured against axial displacement downwards or is otherwise held in a predetermined position. This front plate 38 can have a separate

; 20

have a slot in which the relevant

Sliding straight guide 34 is inserted in a form-fitting manner and is held immobile. Or such a contacting device forms a module of a test adapter or the like.

This sliding guide, which forms a straight rod ( 25
^v 34, which essentially consists of a profile bar C-shaped

cross-section, is made from a single piece of sheet metal of rectangular shape by bending this sheet metal into the shape shown in Fig. 8.

C-shaped shape and thus a straight 30

Channel forming straight guide slot 11 for

Straight guide of the piston 21 of the straight piston member 20, which slot 11 through the flat broad side 51 and the two

Space 52 between bent

35

L-shaped leg 53 of the straight guide 34 limited

The rod 12 is also made of sheet metal cut to size to match its shape.

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The zigzag-shaped, flat flat spring 19 is connected to this piston member 20 in one piece at the bottom and, as shown, runs transversely in the same plane as the piston member 20 and the foot 16' and whose wave plane corresponds to the geometrical width-longitudinal plane of the piston member 20. The wave- or serpentine-shaped flat spring 19, which also forms a curved bending spring with a straight longitudinal axis, can advantageously be flat here and therefore run in the same plane as the associated piston member 20 and the foot 16'. This

Plane runs in the longitudinal direction of the flat bar

12 parallel to its broadside. The entire

flat rod 12 is in this embodiment flat and has a constant thickness, so that it can be a stamped part. The

One-piece foot 16' sits with a

Shoulder 35 on two in the bottom view of the figure

9, which are angled obliquely inwards and which thus protrude from the lower end area of the straight guide 34 from the

bent areas of this straight guide

2 B
( forming sheet by correspondingly stronger

Bending. This foot 16' also expediently forms a piston in this embodiment, in that its

Gie &igr;tgeradführung 34 located above the

The area of constant, rectangular cross-section located on the tab 36 forms a piston 39 which is axially movably mounted with Gl &rgr;. 111 bearing spit 1 in the guide wheel 34 and thus the lower, narrower end area 16' of the flat rod 12 is also guided in a gersdö manner, which

Overall guidance of the flat bar 12 improved.

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Also from another one, located above, |

A narrow tab 36* leading obliquely inwards is also formed in the correspondingly strongly bent, short section of one of the bent areas of the straight guide 34, which fits into a recess 31* of the piston 21 of the upper

piston member 20 and a stop for |

the highest position of the lower with I

Plain bearing play guided area 37 of the piston 21, against which this area 37 is pressed by the pre-tensioned spring 19, as long as the piston member 20 of the flat rod 12 is not pressed downwards against the action of the spring 19. This spring 19 is guided in the straight slot 11 forming a channel to prevent it from buckling sideways.

The piston area 37 together with the

Distance above it further f

Piston area 37' the axial guidance of the massive |

Piston member 20 in the C-shaped cross-section sliding straight guide 34. The flat single-layer rod 12 is one-piece including its triangular flat contact head 26' of the flat rod 12. The piston 21 here thus has the straight guided areas 37, 37' and the narrower connecting them, through

Indentations 31', 31" form a strip-shaped central region 33. The piston 21 is therefore the region of the piston member 20 that can be in a straight guide 34 at the maximum immersion depth. |

In this embodiment, the foot 16' of the flat rod 12 projects downwards over the sliding straight guide 34 and can, for example, be supported by the spring 19

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elastically to a in a dash-dotted

*-' indicated connection plate 42 arranged

The contact contact 41 for electrically connecting this 5 flat rod 12 to a further conductor Sj 40 must be constantly pressed. This contact force can

by the spring 19 by the connection

plate 42 on the contacting device 13, which has a test

f. adapter or part of a test adapter, so

high so that it lifts the shoulder 35 from the lobes 36.

In the embodiment according to Figures 11 to 14, a straight longitudinal

A separate, triangular contact head 22' of constant thickness is welded to the upper end of the rod 12 having the axis 69, which contact head consists, for example, of a harder and/or more wear-resistant material than the sheet metal of the flat rod 12, so that the overall rod 60 consisting of the parts 12 and 22' is in two parts.

This straight spring contact pin 50 in turn has a rod-shaped, C-shaped cross-section, separate, preferably made of sheet metal by punching . 25 and bending, flat, straight

The piston 21 of the straight piston member 20 of this flat rod 12 is guided in a straight channel 11 in an axially sliding manner. A shaft 27 of reduced width is connected in one piece to the top of the flat piston 21 of the flat piston member 20, which shaft carries the contact head 22*, so that here, as shown, the piston 21 is always completely within the sliding guide 34. The flat flat spring 19 is connected to the bottom of the piston 21 and ends in a flat base part 16', which also has a

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The spring 19, whose wave plane runs parallel to the geometric width/longitudinal center plane of the piston member 20, can be prestressed, since it can press the shoulder 44 of the flat rod 12 present at the upper end of the piston 21 onto two tabs 36' formed from the sheet of the sliding guide 34, which are also bent diagonally inwards as shown in Figure 13. These tabs 36' are only bent inwards after the piston 21 has been inserted into the sliding guide 34 and thus hold the flat rod 12 together with the tabs 36 in the sliding guide 34. When test pieces are tested, these contact the tip of the contact head 22' and press the piston member 20 downwards against the force of the spring 19. When the respective test piece is removed ^{, this} spring 19 then presses the piston member 20 upwards again until its shoulder 44 rests against the tabs 36'. The rod 12 - as well as the entire rod 60 - can also be referred to as a flat rod 12 or ( overall flat rod 60) due to its flat design.

The positive guidance of the piston 21 is visible from Fig.

^ In this embodiment, the piston member 20 of the rod 12, which has a substantially rectangular cross-section, has a straight embossing beginning at the contact head 22' and extending to just before the lower end of the piston 21.

which is on the side of the

5881-2 - 35 -

Piston member 20 forms a flat groove 47 and on the other flat side of the piston member a corresponding flat bulge 48, which however does not widen the maximum thickness of the spring contact pin 50, since the elevation 48 in the area of the sliding straight guide 34 protrudes into the gap 52 between the longitudinal edges 45 of the legs 43. This embossing can also extend over

VIJ.O yaiiaxs t.oiit£t7 uoo iiauncii ubauca xc oiouxooncfi 10

or otherwise longer or shorter than shown. The width of the slot 11 of this sliding guide 34 is, as can be seen from Figures 12 to 14, so large that the piston 21 is mounted in a straight line in this slot 11 with only a small sliding bearing side play. This embossing of the piston member 20, which forms the groove 47 and the bulge 48, allows the piston to be moved practically without

&iacgr; Additional effort whose stiffness increases

j its maximum height h (Fig. 13),

■ on ^ma

However, the increase in height does not

j in an increase in the clear height h3 of the

j Straight guide 34 and the maximum height of this

spring contact pin.

j ty c

( In this example, the electrical

j Connection of this spring contact pin 50 to the

j Test device on its metallic

A further conductor is connected to the sliding straight guide 34. It is actually more advantageous to connect such a further conductor directly to the flat bar, as shown in the other embodiments, since then the electrical contact resistance between the flat bar 12 and the sliding straight guide 34 plays no role. This electrical contact resistance is

stressed by compressing their rings more or less. The rod 12 according to Fig. 16 can, for example, be flat and have a constant thickness and its piston 21 and the foot 16' supported at 42 can be guided in a straight line in a form-fitting manner.

In Fig. 15, a variant of a one-piece flat rod 12 according to Fig. 2A is shown. In Fig. 15, the foot 16' of the flat rod, which is connected to the flat spring in one piece, forms a second flat piston 39 in addition to the piston 21, which is located in the slot 11

5881-2 - 36 -

However, the design example is small due to the construction shown.

Instead of the illustrated sliding straight guide 34 with a C-shaped cross-section, it can also be designed as a flat sleeve by making the two bent legs 53 and 43 of the relevant sheet so wide that they touch and 30 ulcäc nüläc βgr;&idigr;&Pgr;&Egr;&Pgr;�iacgr;&iacgr;&idigr;&Tgr;&idigr;&idiagr;. SHy 53&bgr; it xy y S3 Ciix GS &Xgr;&THgr;&Pgr;&THgr;&Ggr;&iacgr;

*0 Channel, preferably approximately rectangular in cross-section, for guiding the piston and the spring. The legs of such a sleeve can then be firmly connected to one another by spot welding at least in one place to stiffen it, if desired.

Instead of forming the flat spring 19 in a wave-like or serpentine shape, it can also have other configurations, e.g. as a ring or a straight row of integrally connected rings 57, as is the case with the rod shown in Fig. 16, which rings 57 are round here and thus have round openings 56. The spring 19 in Fig. 16 is also designed to bend in the longitudinal direction during operation

X&Lgr;-

5881-2 - 37 -

&iacgr; of the plate arrangement 10 also with

The sliding bearing play is axially slidably guided straight. This also means that the lower end region 16' of the flat rod 12 B, which has a straight longitudinal axis, is guided straight and the overall guidance of the flat rod 12 is particularly good. This foot 16', which has the second piston 39, is pointed at the lower end and rests with its tip 46 on an electrical connection contact 41 inserted into a connection plate 4?, onto which this tip 46 is pressed by the dead weight of the flat rod 12 and, when testing test objects, also by the spring force exerted by the transversely corrugated flat spring 19. In this embodiment, the conductor is therefore not connected to the flat rod 12, but rather to the contact 41, as in the embodiment according to Fig. 7. The contact head 26' of the one-piece rod 12, which is used for coming into contact with test objects such as 23, is designed as a trident. Other designs of the contact head 26' are of course also possible.

For the springs of such rods 12, high resistance to fracture is desired so that they can withstand as many load changes as possible without the risk of fracture. In the case of the springs 19 of the rods 12 according to Figures 1 to 16, if the spring 19 is flat, its thickness d is equal to its maximum height «, since both sizes are identical here. The fracture resistance of these springs 19 is greater the greater the ratio of the cross-sectional width x (Fig. 2C) of the cross-section or sections of the sheet metal forming the springs 19 that are most at risk of fracture to the vertical cross-sectional height y of the cross-sections in question.

5881-2 - 38 -

If this ratio is made relatively large for the springs according to Figures 1-16 for the fracture resistance, e.g. 1:1 or larger, this can cause problems in terms of stamping technology and also lead to unfavorably flat spring characteristics or disadvantageously require large sheet thicknesses.

The fracture resistance of the spring 19 can be increased particularly easily by making the ratio of the cross-sectional width x to the cross-sectional height y of the cross sections of the sheet metal forming the spring 19 or at least of its cross sections most at risk of fracture at least 1:1, preferably greater than 2:1. According to a further development of the invention, this can be achieved in a simple manner with sheet metal cuts that are favorable in terms of stamping technology and thus increase the fracture resistance of the spring 19, wherein very small center distances in the contacting device of adjacent ⁴ spring contact pins can also be achieved by the area of the sheet metal part of the rod 12 forming the spring 19 at least partially not running parallel to the geometric wide longitudinal center plane 61 (Fig. 22D) of the piston member 20, preferably at an angle, preferably being angled by approximately. Such a spring therefore has at least one area which is bent out of the plane of the sheet metal blank from which this rod is formed, whereby the entire spring can also be bent out of this plane of the sheet metal blank. Preferably, it can be provided that the area of the sheet metal part of the rod 12 forming the spring 19 is corrugated and rotated by approximately ⁹⁰ ° about an axis parallel to the direction of movement of the piston. It can be expediently provided that the maximum width b2 of the

5881-2 - 39 -

FeiJer 19 greater than its maximum height h2 and this

greater than the thickness d of the spring 19 forming *

Sheet metal. Examples of such bars J'

are shown in Fig. 17 to 24. ;

t

The result of a curved bending spring with \

The axially resilient rod 12 according to Fig. 17 can be made of a flat, preferably punched,

Sheet metal blank 62 according to Fig. 18 by bending,

by cutting the sheet metal 62 fe

adjacent to its flat region forming the piston member 20 as shown a <_;

rectangular narrow elongated strips

&bull;c 66, from which the spring 19 is formed by bending and whose straight longitudinal axis 69' coincides with the straight longitudinal axis 69 of the piston member in this embodiment, but depending on the embodiment, it can also be provided parallel to the position shown in Fig. 18 and slightly offset to the side. The front longitudinal end region 75 and the rear longitudinal end region 76 of the sheet metal blank 62 form the front end region 75 and the rear longitudinal end region 76 of the finished rod 12.

2J, rear end region 76. The thickness d of the sheet metal of the rod 12 can preferably be very small here, particularly expediently about 0.1 to 0.25 mm. The spring 19 of the rod 12 of Fig. 17 can preferably be formed from this strip 66 by

_O( _ by first shaping the strip 66 into the shape of a

corrugated sheet is bent in a serpentine manner transversely to its longitudinal direction. Then this wave-shaped or corrugated sheet-shaped leather 19 is bent in the whole at the transition to the piston 21 of the piston member 20 by |

_ot . one in the direction of movement (double arrow A) of the *

piston member 20 extending 'geometric axis around

588J-2 - 40 -

approximately 90° into the position shown in Fig. 17. The width b2 of this spring 19, which corresponds to its maximum width, then runs parallel to the width of the piston 21, so that the width b2 of the spring can easily correspond to the width bl of the piston member 20 or, if desired, can also be smaller or larger, since there are no restrictions on the size of the width b2 due to the corrugation of the spring transversely to its longitudinal direction. The ratio of the maximum cross-sectional width x of its sheet metal area, which here corresponds to the maximum height h2 of the spring 19 and runs perpendicular to the geometric width-longitudinal center plane of the piston member 20 and is rotated by 90° to the plane of the blank 62, to the cross-sectional height y, which here corresponds to the sheet metal thickness d, can thus easily be greater than 1:1 in terms of punching technology, preferably significantly larger.

The springs 19 of the rods 12 according to Figures 19 and 20 also have ratios of the cross-sectional widths x to the cross-sectional heights y at the peaks of their waves that are most at risk of breakage, which are preferably larger, preferably significantly larger than 1:1 and are nevertheless also problem-free in terms of punching technology.

In the spring 19 according to Figure 17, the sheet metal area forming the spring runs, as shown, essentially perpendicular to the geometrical width-longitudinal center plane of the piston member 20, i.e., the two broad sides of the strip 66 from which the spring 19 is bent run perpendicular to the geometrical width-longitudinal center plane of the piston member 20, since the edge of the spring 19 is directed perpendicular to the said width-longitudinal center plane almost over its entire length.

5881-2 - 41 -

is.

Preferably, in such piston members which are at least partially bent or angled out of the geometrical wide longitudinal center plane of the "

Springs 19, the ratio of the maximum height h2 of the spring 19 to the thickness d of its sheet should be greater than 1.2:1, particularly expediently at least 2 :1, often advantageously at least 4:1. Ratios of h2:d of approximately 3:1 to 8:1 have proven to be particularly advantageous. The maximum value of the ratio x:y can preferably be greater than 1:1, preferably greater than 2:1, particularly advantageously greater than 4:1.

*5 It is also expedient in these embodiments, as in other rods according to the invention, that the maximum width b2 of this spring 19 is larger, preferably significantly larger, than its maximum height h2. The ratio of the maximum width b2 to the maximum height h2 of the spring 19 can preferably be at least 2:1, particularly expediently at least 3:1, and 2.5:1 to 5:1 is particularly favorable.

j ( 25 The thickness d of the sheet of the blank 66 and thus also the thickness d of the sheet of the spring 19 can preferably be 0.05 to 1 mm, particularly expediently 0.09 to 0.4 mm. The maximum height h2 of the spring 19 can particularly expediently be 0.2 to 2 mm, particularly advantageously 0.4 to 1 mm.

The piston member 21 is flat in the embodiment according to Fig. 17 and its thickness hl corresponds to the thickness d of the sheet of the blank ^g ß and thus also to the thickness d of the sheet forming the spring 19. Accordingly, in this

5881-2 - 42 -

embodiment, the thickness hl of the piston member 20 and thus the thickness of its piston 21 is considerably smaller than the maximum height h2 of the spring 19. \

In Fig. 22D the geometric ;

The wide longitudinal center plane 61 of the piston member there is shown. In Fig. 17, this wide longitudinal center plane runs parallel to the flat upper side 70 of the piston 21 at half the maximum height of the piston member 20 and thus here at h .*..',· above the height of the flat piston 21. In this wide longitudinal center plane, the strip 66 of the cut 62 has therefore been appropriately first corrugated transversely and then, after this corrugation, rotated by 90° as a whole around an axis parallel to the straight longitudinal axis 69 of the piston member 20 or aligned with this longitudinal axis 69, so that the height h2 of the spring 19 corresponds to the width of the strip 66 of the still flat cut 62, designated h2 in Fig. 18, and the spring 19 in its final position is parallel to the wide longitudinal center plane de·«; piston member is transversely corrugated, as Figure 17 clearly shows. The transverse corrugations of the spring also run transversely to the straight longitudinal axis of the rod 20.

The rod 12 can again be arranged in any suitable manner on the contact device that supports it so that its piston 21 is mounted in a channel guided in a straight line by it. The spring 19 can be supported on the straight line or on any other suitable part in such a way that it when moving the piston member 21 with reference to Fig.

3g 17 is compressed to the right by a test specimen or is compressed more strongly

5881-2 - 43 -

and the tip 22 of the rod 12 thereby exerts the contact force required for secure contact with the test object. For example, this rod 12 can be shown in a dot-dash line

&dgr; indicated sleeve 34', which can be formed from the blank according to 62' (Fig. 18) by bending. The bending lines 63 of the ·

The dimensions of the blank 62' are shown in Fig. 18 in dot-dash lines ', ': Since the KolDen 2i in this

If the embodiment is flat and only has the thickness hl of the sheet metal forming it and is not profiled its straight guide must have a correspondingly low clearance height, which can be compensated for by sliding bearing play |

slightly larger than hl. ^To this end, the 1

forming a sliding linear guide for the piston 21 |

and the spring 19 also taking up |

Sleeve 34' has a front section 64 which

can be closed on the circumference and whose clear cross-section corresponds to the cross-section of the piston 21 |

with the j required for low plain bearing clearance

This ·; area 64 is followed by a the same width, but for

the accommodation of the spring greater clearance <. longitudinal section 65 of the sleeve 34*, in

where the spring 19 is located, whereby it is located at the i

rear end of this section 65 at a |

stop or similar. The piston 21 |

can be placed in this interior space which accommodates the spring 19 *

when moving the piston member 20 to the right

more or less far under compression of the
Spring 19, but its
Straight guidance in area 64 still fully preserved
The spring 19 can be pre-tensioned and
its front end at an edge of the transition

from area 64 to area 65 of sleeve 34'

Section 65 may appropriately contain the same

5881-2 - 44 -

have the same width as section 64.

10

C

The spring 19 forms in this embodiment a corrugated leaf spring which extends in the direction of the longitudinal axis 69 of the piston member 20 and thus in its direction of movement as shown and forms transverse waves to the longitudinal axis 69, the half-height of which

&ogr;&bgr;&ogr;&iacgr;&udigr;&bgr;&idiagr;&iacgr;"ischs Wsllsnsbsns dsr ^o SGcnstri5 wide longitudinal center plane of the piston member 2Q or can run parallel or approximately parallel to it, preferably at only a small distance.

20

25

30

35

In some cases it is also possible to provide that the corrugated spring 19 is not rotated with respect to the piston member 20, i.e. that the wave plane of its transverse waves then runs approximately perpendicular to the geometrical broad longitudinal center plane of the piston member 20.

In the embodiments according to Fig. 19 and 20, the spring 19 is not rotated by 90° as a whole relative to the wide longitudinal center plane of the piston member 20, which is also flat here, but rather it has angular, serpentine turns which can run essentially in this plane of the piston member 20 and thus of the piston 21 or at an angle to this plane, but are angled at the vertices of the approximate braided half-waves to rectangular tabs 67, 67' by approximately 90° to the plane of the piston 21. For this purpose, the spring 19 in the flat sheet metal blank 62" (Fig. 21) has the serpentine course shown, with the bends of the spring at the transition from the respective crossbar 71 to the tab 67 or 67'

5881-2 - 45 -

each be almost 90°. These bends can also be 90° or more or less than Sü*. Each rectangular tab 67,67' extending in the longitudinal direction of the rod 12 is straight and flat and these tabs are formed by bending along the bending lines 63 shown in dotted lines in Fig. 21. These bending lines 53 can be suitably provided so that the width b2 (Fig. 19);""i

Hot· CdHot 1Q iinnoföhr Hur Hrn-ito hl riaa l^nlKono 91

&mdash; » « · w « w βgr; « &ngr; w»*£ywe«a**a W w « «v B «» Mt «» «« w « w &ngr; «» ·««»»■*·«««■«« a* ^; The tabs 67 and 67,67' are connected by crosspieces 71 of the respective spring 19. These crosspieces 71 can be used expediently for geometric width in the embodiment \ according to Fig. 19.

be parallel to the longitudinal center plane of the piston 21, preferably falling into it. The crossbars 71 and

The lobes 67, 67' can be straight as shown or, if desired, can have a different shape, e.g. be curved.

In the rod 12 according to Fig. 19, all tabs 67 are angled from the crossbars 71 to the same side. Their maximum height measured on the outside corresponds

) which here is the maximum cross-sectional width x of the

The maximum height ti2 of the sheet metal forming the spring 19 corresponds to the maximum height ti2 of this spring 19, whereby this height h2 is in turn significantly greater than the thickness d of the sheet metal forming this spring 19 and the piston member 20. For the tabs 67, 67', x=h2 and y=d apply here, see Figure 24.

The following applies to the spring web 71 of the spring 19 according to Figure 19: (whereas x=d and y corresponds to their width. The maximum width b2 of the bending spring, which is essentially subjected to bending during axial compression and thus forms a curved bending spring with a straight longitudinal axis extending in the direction of movement of the piston member 20.

5881-2 - 46 -

Spring 19 can again suitably correspond approximately to the maximum width bl of the piston 21 or the piston member 20 and be larger, preferably significantly larger than the height h2 of the

B spring 19. The shaft plane of the spring 19 runs parallel or approximately parallel to the geometric longitudinal center plane of the piston member 20.

The rod 12 according to Fig. 20 differs from the rod according to Fig. 19 essentially in that on one side of the spring 19 the flat tabs 67 are angled upwards and on the other side the flat tabs 67' are angled downwards by approximately 90° or possibly by a little more or a little less than 90°. It can be particularly expedient that in this spring 19 according to Fig. 20 the crossbars 71 do not fall into the geometrical wide longitudinal center plane of the piston member 20, but are inclined to this plane in such a way that the tabs 67 and 67' are opposite each other at the same height and thus the maximum height h2 of this spring 19 corresponds to the height h2 measured on the outside of any of the tabs 67, 67' and not to twice the tab height. This results in a lower structural height of the rod 12 with the same breaking strength and other structurally identical properties of the spring, i.e. practically only half the structural height as if the crossbars 71 were to run parallel to the plane of the piston 21. Each section of the spring 19 leading through a web 71 according to the section line 23-23 in Fig. 20 then has a Z-shaped configuration, as Fig. 23 clearly shows. In Fig. 23, the geometric wave plane of this spring 19, which runs halfway up the height of the spring 19, is marked with 79.

5881-2

- 47 -

and it runs parallel or approximately parallel to the geometrical longitudinal center plane of the piston member and can preferably correspond to this longitudinal center plane.

Also in these rods 12 according to Figures 19 and 20, the maximum width bl of the piston member 20, which corresponds approximately to b2, is larger, preferably substantially larger, than the maximum height h2 of the rod 12.

In the springs 19, which are curved bending springs with straight longitudinal axes and are subjected to bending stress at maximum compression, according to the exemplary embodiments shown in Fig. 19 and 20, the apex of the serpentine turns of the respective spring 19 are the areas most at risk of breaking. As the height h2 of these tabs 67, 67' is greater, preferably significantly greater than the thickness d of the sheet, the resistance to breakage of each of these springs 19 is significantly increased. The height h2 here is also the maximum height of these rods 12.

In many cases it is desirable and expedient that the maximum height hl of the piston 21 and, if applicable,

of the entire piston member 20 corresponds approximately to the maximum height h2 of the spring 19, preferably equal to this height h2 or slightly greater than this height h2, since this makes it possible to adjust the clear height of the channel guiding the piston 21 or the like.

to be provided in accordance with the clearance height for the spring 19, so that the clearance cross-section of the sliding guide or another cardan provided for the positive piston guide, slot or the like.

not only in the area where the piston is guided,

5881-2

- 48 -

but also in the area where the spring 19 is arranged, over the length of the area receiving and guiding the piston 21 and the spring 19 or almost over this length. For this purpose, it can preferably be provided that the piston 21 and possibly also further length of the piston member 20, possibly the entire piston member 20, are provided with a profile having the maximum height hl (Fig. 22A), where hl is greater than the thickness d of the sheet metal forming the piston member 20. Some suitable profiles for this are shown in Fig. 22A to 22G. In Fig. 22A this profile is U-shaped, in Fig. 22B Z-shaped, in Fig. 22C U-shaped with a recessed bottom,

in Fig. 22G S-shaped, in Fig. 22E W-shaped, in Fig. 22 U-shaped with a raised middle base area and in Fig. 22G M-shaped. For the ratio of the maximum width bl of the piston 21 formed by such a profile to its maximum height hl, approximately the same values can then apply as for the ratio of the maximum width b2 to the maximum height h2 of the spring 19 in question, whereby hl can preferably correspond approximately to h2 and bl approximately to b2. Rods 12 with such piston profiles can then be inserted, for example, into slots 11 of a plate arrangement according to Fig. 1 or 3 or into the channel or slot 11 of a sliding straight guide 34 according to Figs. 11 to . Other possibilities also exist. The rods 12 can also form the contact tip η here or separate contact heads can be attached to them.

In general, it is particularly expedient to provide that the maximum width of the bar 12

5881-2 - 49 -

larger, preferably at least twice as large as its maximum height. Preferably, this maximum width can be at least 3 times larger, preferably 4 to 8 times larger than the maximum height of the rod 12.

Also, in general, the maximum length of the rod 12 can be much greater than its maximum width, preferably this maximum length can be at least 10 times, particularly expediently at least 25 times, particularly preferably approximately 30 to 120 times greater than its maximum width.

In all embodiments, the rods 12 are made of sheet metal by punching and, if necessary, by bending or

Embossing of the preferably punched sheet metal blank |; and each have straight longitudinal axes.

The front and rear free longitudinal end areas 75,76 of these bars 12 are defined by the front and rear longitudinal end areas

75,76 of the sheet metal blanks from which they consist or are formed, which is particularly advantageous in terms of construction and function, among other things. Each rod 12 is arranged in a channel / 25 11 assigned only to it. Between its spring 19 and its front end there is only a single piston 21, which can have a constant width throughout (e.g. Fig. 2A) or at least one indentation that reduces its width in certain areas (Fig.7).

Instead of guiding the piston 21 of the piston member 20 straight in a single channel, it can also be provided that it is guided straight in several aligned channels or in another straight guide. The guidance of the piston 21 of the piston member 20 can

It is particularly useful if it is provided in a form-fitting manner in the at least one channel or other straight guide.

5881-2 - 50 -

In each such channel or the like, only a single rod 12 is arranged, so that in the respective contacting device, adjacent rods 12 do not touch each other.

The movement of the piston member 20 of the relevant rod 12 during testing of test specimens takes place in the direction of its straight longitudinal axis.

IO

At least when the maximum height of the rod is smaller than its maximum width, as is preferably provided, the rod can be referred to as a flat rod or flat bar. Each rod 12 is also positively secured against rotation in the guide that guides it due to its non-circular shape.

The rods 12 according to Fig. 17 to 24 can be easily stamped to achieve a high degree of resistance to breakage of their springs with favorable spring characteristics and yet small transverse dimensions and are particularly well suited, among other things, for contacting devices which serve to simultaneously contact all pads of chips in which the pads are arranged in a straight row along all four sides of the chip, whereby the rods 12 contacting such a row of pads or spring contact pins having such rods 12 can be expediently arranged in such a way that the wide longitudinal center planes of these rods are parallel to one another, which easily enables particularly small center distances between adjacent rods with high spring resistance and favorable spring characteristics. The contact device can be used to simultaneously contact the pads of a chip or to simultaneously contact several or many such chips.

Claims (1)

35 &bull;··&bgr;· ·· m 5881-2 Protection claims Contacting device for test devices for testing electrical or electronic test objects, such as printed circuit boards, integrated circuits or the like, which ·.; Contacting device at least one {. Spring contact pin, preferably many L spring contact pins, which correspond to the Contacting test subjects and 15 are electrically conductive, whereby the Spring contact pin has a piston member whose piston is guided straight in a channel or the like, which piston member is arranged downstream in the exial direction by a spring serving its spring load, characterized in that the piston member (20) and the spring (19) of the spring contact pin (12;50) are jointly connected by a single, one-piece, made from a sheet metal blank formed sheet metal part which has a ( 2b axially spring-loaded rod (12) bildot. 2. Contacting device according to claim 1, characterized 30 5881-2 - 2 - characterized in that the piston member (20) of the rod (12) is a flat piston member, preferably the entire rod (12) is a flat scab. 3. Contacting device according to claim 1 or 2, characterized in that the spring (19) !O and/or the piston (21) of the rod (12) forms or form a flat area of this rod (12), preferably the entire rod (12) is flat. 4. Contacting device according to one of the preceding claims, characterized in that the longitudinal direction of the rod (12) is straight. 5. Contacting device according to one of the preceding claims, characterized in that the spring (19) is transversely corrugated with respect to the longitudinal direction of the rod 6. Contacting device according to one of the preceding claims, characterized in that the sheet metal area of the sheet metal part of the rod (12) forming the spring (19) is at least partially adapted to the geometric Wide longitudinal center plane (61) of the piston member (20) does not run parallel, preferably inclined to it and/or approximately perpendicular 5881-2 - 3 - (Fig. 17,19,20). 7. Contacting device according to claim 5 or 6, characterized in that the wave plane (61; 79) of the transversely waved spring (19) is parallel or substantially parallel to the geometric wide longitudinal center plane (61) of the piston member (20), preferably corresponds to it. 8. Contacting device according to claim 7, characterized ( characterized in that the spring (19) forming Sheet of the rod (12) at least substantially approximately perpendicular to the geometric
wide longitudinal center plane of the piston member (20) (Fig. 17). 9. Contacting device according to one of claims 5 to 7, characterized in that the vertices 20 the transverse waves of the spring (19) by lobes, preferably flat lobes (67;67') are formed are those arising from the connection between them Crossbars (71) defined plane preferably | are angled approximately at right angles, whereby ( 25 ', these flaps preferably for geometric \ Width-longitudinal center plane (61) of the piston member ' j (20) are approximately perpendicular. \ .Contacting device according to one of the 'i preceding claims, thereby characterized in that the rod (12), preferably its piston member (20), at least one of its 5881-2 -α deformation serving to stiffen, preferably at least one bend (24) and/or embossing (47,48) and/or the rod (12) has a foot connected to the spring (19) (16;16 ¹ ), which preferably also has a piston. Aa 4/-k_ a. _ L. .i. .! &mdash;._.*.·.&mdash;.&mdash; ä JtUi. .·.. ...&igr;, &mdash; J « am «J ««* «jcinuriwunuxoi &tgr;&ugr;&igr;&khgr; xuituuiiu nuuii &ugr;&khgr; 11« &pgr;&igr; uoa preceding claims, thereby characterized in that the spring contact pin (50) has a straight, separate sliding guide (34), preferably made of sheet metal, in which the piston (21) of the piston member (20) is axially slidably mounted and in which preferably also the spring (19) is arranged and that preferably the spring contact pin (50) only or essentially consists of the sliding straight guide (34) and the rod (12) 20 exists. .Contacting device according to claim 11, characterized in that the separate sliding guide (34) forms or has a straight rod with ( 25 C-shaped cross-section or a sleeve. 13.Contacting device according to claim 11 or 12, characterized in that the separate sliding guide (34) has at least one stop (36; 36') for the rod (12), preferably stops between which 5881-2 - 5 - the spring (19) of the rod is located, wherein this spring (19) is preferably pre-tensioned be kfenrt, 14. Contacting device according to one of the preceding claims, characterized in that on the rod (12) a Horn Tnl/nnfal/f l/nmman m-i 4* Hon D &tgr;* &Ggr;&igr; f 1 &eeacgr;&eegr;&eegr;&ogr;&eegr;&EEgr;-&igr;&agr;&pgr;&agr;&pgr;&Pgr;&agr;·*« Contact head (22 ¹ ) is attached as a separate part or that the contact head (26 ¹ ) of the spring contact pin which serves to come into contact with the test objects is formed by the sheet metal part forming the one-piece rod (12). 15.Contacting device according to one of the Claims 1 to 10 or 14, characterized in that it comprises a block, a plate or another object (10) in which a plurality of channels (11) are arranged, the walls of which serve as sliding guides for the pistons (21; 21, 39) of the
they serve the rods (12) inserted therein and in which the springs (19) of the rods are preferably also arranged. 16.Contacting device according to claim 15, characterized in that the one-piece rods (12) alone or if attached to the rods (12) contact heads (22 ^f ) designed as separate parts are arranged, these rods 5881-2 - 6 - together with these contact heads form the spring contact pins. &Idigr;7.Contacting device according to one of the preceding claims, thereby / characterized in that the maximum width of the Piston member (20) larger, preferably .;- 10 is. ■' 18.Contact device according to one of the s preceding claims, thereby characterized in that the maximum width of the spring (19) is greater, preferably at least 2-fold greater than its maximum height. 19.Contacting device according to one of the preceding claims, characterized ; characterized in that the maximum width of the 1, 20 rod (12) larger, preferably at least 2 times larger than its maximum height. "-, 20 .Contacting device according to one of the Claims 17 to 19, characterized &iacgr; 25 characterized in that the maximum width of the rod (12) larger, preferably at least twice as thick, particularly useful is at least 3 times greater than the thickness of the sheet metal that forms it. 30 .Contacting device according to claim 20, characterized in that the maximum width ';, 35 5881-2 - 7 - of the rod (12) approx. 4 to 20 times, preferably ^ approx. 4 to 10 times larger | than the thickness of the sheet metal forming it. <j - 22.Contact device according to one of the
preceding claims, thereby
characterized in that the spring is a flat spring (19) which has at least one opening (56) ■ preferably forms a row of rings. ( 23.Contacting device according to one of the | preceding claims, characterized in that ' characterized in that the spring (19) of the rod (12) in a guide (11;34)
which preferably also forms a sliding wheel guide for the piston (21) of the piston member (20). .Contacting device according to claim 12, characterized in that the rod (12) has a recess in the C-shaped cross-section between the two legs (43) Sliding straight guide (34) existing gap &igr; 25 protruding embossing (48). 25.Contact device according to one of the
preceding claims, since characterized in that the 30 Sheet metal part by punching and possibly bending and/or embossed sheet metal part. 5881-2 26. Contacting device according to one of the preceding claims, characterized in that at least the piston member (20) of the rod (12) is solid. 27. Contacting device according to one of the preceding claims, characterized in that the thickness of the sheet metal forming the rod (12) is approximately 0.05 to 0.4 mm, preferably approximately 0.09 to 0.25 mm. 28. Contacting device according to one of the preceding claims, characterized in that the ratio of the cross-sectional width (x) to the cross-sectional height (Y) of the cross-section of the sheet metal forming the spring (19) is greater than 1:1, preferably greater than 2:1, at least at the cross-sections most subject to bending stress. 29. Contacting device according to one of the preceding claims, characterized in that the two longitudinal end regions (75, 76) of the rod are formed by the two longitudinal end regions (75, 76) of the sheet metal blank from which the rod is formed and/or that the rod (12) is the only rod (12) arranged in the relevant channel (11) or the like.