DE2059421C - Set button to actuate contact spring - Google Patents

Description

The invention relates to a button for actuating sets of contact springs, in particular for telephone sets with touch dial, with a push button against the force of a return spring between two is movable by stops certain positions and sits on a feeler pin that is longitudinally displaceable is guided in a hollow probe body, which has breakthroughs through which a switching ball is inserted] extends, each of which lies on one of the switching curves of the feeler pin, through which the switching balls be Pressing the button in the breakthroughs can be moved outwards and thereby actuate the contact springs.

With such a (but not for telecommuting, since as with the first mentioned besp-echapparate) known key (see German Known Key (see German utility model utility model 1786069) the contact spring sets 1786069) are also here the contact spring sets the vertical to the direction of movement of the pushbutton and the dimensions of the button are arranged transversely to the direction of movement, so that the button determines an extremely large transverse deflection of the pushbutton,
In addition, an electrical pressure switch has been reported especially for telephones with touch dialing (filing date: March 23, 1970, cf. interpreting diameter of not greater than the Tastknopfs see Laid-Open Patent 2013 779), consisting of an outer diameter of Tastzapfens from which the actuating member ia and the switching contacts ent-push button is an integral extension. In the case of the holding switch housing there is, with an H-förser known key, is further disadvantageous that the moderate connecting part with elastically resilient Schen push button crown a relatively small area is not provided, which is paired on the actuator; an enlargement of the button crown to the supply organ and held on the switch housing easier operation would accordingly be 15; more precisely, an enlargement of the dimensions of the Tastzap- a flange with at least two opposite, fens and the feeler body is on the actuator. If Iran wanted to increase the T-shaped recesses on its outer circumference measurements only of the button crown, if available, in which the upper T-shaped formed the production including the assembly of these and preferably beveled legs of the unknown button would be very difficult, because then ao binding part intervene while the lower Schenz. B. the feeler are designed to be divided kel this connection part with two after inmusste. _NEN directed projections that are longer than the Fs is therefore the object of the invention to improve the button of the leg width in a correspondingly trained type mentioned so that their and arranged recesses of the switch housing-Gf office dimensions engage transversely to the direction of movement 25 ses.

of the push button is reduced, but the dimensions. The actuator of the last-mentioned switch

of the pushbutton at right angles to its direction of movement can be done by simply pulling it (possibly after loosening

increased to make the button easier to operate to an externally accessible nut) from the

can, however, a simplified assembly of the legs can be separated again, what for many

Button without aids or tools ensures 30 purposes is undesirable, so z. B. with touch pads

should be. of telephone sets with touch dialing, where against

This object is achieved by preventing unauthorized interventions.

Tactical springs approximately parallel to the direction of movement of the In a further development of the invention, it is

Tasiknopfs are arranged and that a similar advantageous on the easier assembly that the button

Tasizapfen seated hollow cylindrical center piece 35 body has an inner annular projection below, which

of the push button on its inner circumference a push button when pushing in from above the push button in the

stop ring has, when the feeler is pushed on, two at the lower end of the feeler pin

button on the upper end of the feeler pin of the provided resilient locking jaws to each other presses.

sem presses two resilient locking jaws towards each other, which then snap apart and become

which then snap apart and attach to 40 by the force of the return spring on the lower edge

Place the upper edge of the locking stop ring while the ring projection is in place.

rend the lower edge of the center piece on the upper It is also useful that the feeler pin ar edge a compared to the upper end of the feeler its thicker step with a longitudinal pin thicker step of the feeler pin is supported. The guide rib engages in a corresponding guide due to the slit of the probe body achieved by the invention,
easy assembly of the button can be the tactile. The guide rib is initially an additional button after the electrical test of the key guidance of the probe pin in the probe body. They are mounted. can also be dimensioned so that they are together which acts on a fixed feeler pin. In addition, the guide prevents the, massive tactile button guide core is provided, rungsrippe a rotation of the tactile pin Gegei on almost the entire length of a hollow cylindrical the tactile body and thus also a side view formed button slidably placed and schung during assembly. The latter is important because a return spring of the switching balls, which is arranged at the bottom of the lower section of the switching curves of the sensing pin for the actuation of the sensing button guide core, has a different course supported. The push button has about halfway ben in order to achieve different switching sequences for the length of a breakthrough through which a single individual switching balls actuated Kontaktfedersälzi switching ball extends, which also on a switching curve.

of the push button guide core is applied, so that at 60 Furthermore, it is advantageous that the lower edge de

Pressing the push button the switching ball to the outside outer shell of the push button when the Ta is not actuated

is shifted to ste through stronger exit from below the level of the contact rivets of the con

Your breakthrough lies in the pushbutton, the associated external tension springs and the switching balls.

to actuate the contact springs for making contact. This feature allows good stick protection;

run. 65 for the contact springs and balls, while de;

This known key also requires the balls unc

Lots of space, especially when contact springs are practically exposed for easier operation. Also for-

tion the button crown a certain minimum area changes the relatively large length; of the outer

Sheath of the pushbutton mutual support of the pushbuttons when several keys form a pushbutton unit are summarized.

The grip of the button for the tactile finger of the operator is increased by the fact that the outer Coat of the button is tapered upwards over a paragraph to a Taslknopfkrone and that the The top surface of the button crown has a recess.

Another advantageous embodiment of the invention is expressed in the fact that in the recess of the Tastknopfkrone a transparent panel and underneath a non-rotatable character insert are arranged.

Any characters such as numbers or letters can be created by choosing the appropriate character insert can be displayed in a wide variety of colors. On the other hand, if the signs were injected, special tools would be required in each case.

For a better mutual guidance of the keys in a key unit and for a better one Dust protection also helps that the outer jacket of the push button has a rectangular cross-section.

It is recommended that the probe body of the probe pin, the push button and the switching balls made of plastic exist.

Polyacetal is preferably used as the plastic. This plastic is characterized by high strength, good dimensional stability and high Abrasion resistance.

For a firm holding of the contact springs and thus for maintaining an exact contact spring spacing with regard to precise, reproducible switching sequences by pressing the button it is It is expedient that the contact springs each have a bead on their lower section, which is supported by a retaining groove is recorded, either from the probe body and longitudinal webs extending therefrom or from the Longitudinal webs and a cross web connecting these is limited.

The attachment of the beads in the contact springs also allows the retaining grooves to have certain minimum dimensions to give, so that the components delimiting the retaining grooves advantageously by injection molding can be produced.

Production is further simplified in that the retaining grooves are the same for all contact springs are great.

To secure the contact springs in the assembled state against longitudinal displacement, it is useful to that the longitudinal webs each have a horizontal projection whose distance from one another is greater or smaller than the width of the upper or lower section of the contact springs.

For defined distances between the individual contact springs and thus precise switching sequences also ensures that the contact springs are biased with their upper section on the probe body or crossbar prop up.

In particular, it can be provided that the contact springs have a substantially at their upper end have a right-angled elbow, by means of which they are supported in a pretensioned manner on the probe body in the rest position.

If the longitudinal webs have the horizontal projections already mentioned, this is easy possible, for assembly also those with a right-angled Push the contra-angle provided contact springs into the button from below.

If the key according to the invention is intended exclusively for telephones with touch dialing, it is advisable that the switching curves of the feeler pin each have an inclined section that is a pronounced maximum of the key actuation pressure force causes a minimum key actuation time to guarantee.

Such a minimum key press time is required so that the user can press the key transmitted dialing information can be reliably recognized in the switching device.

The effect of the pressure point is essentially due to the inclined sections of the switching curves the further advantage that there are no additional forces for resetting the key by the resetting spring required are.

Several of the keys according to the invention can be combined to form a key unit in such a way that that the probe body, transverse webs and longitudinal webs are integrally connected to form a tactile block, which also hold all contact springs.

The key pad ensures that the individual keys are precisely aligned with one another, so that the individual probe pins are only pushed into the individual probe bodies of the keypad will need (without additional adjustment work to maintain certain distances between the keys). As a result, relatively small tolerances for the center distances can also be achieved of the keys can be provided with a large number of completely separate keys compared to the assembly. In this way, when there is a large number of keys, the space requirement of the key unit can be proportionate can be kept small.

The invention is explained with reference to the drawing, in which an embodiment of an au «· several keys according to the invention existing key unit according to the invention is shown. It shows

F i g. 1 shows a partial view of the pushbutton unit in longitudinal section along 1-1 in FIG. 3,

2 shows a partial view, partly in cross section along H-II of FIG. 1,

F i g. 3 shows a plan view of the key unit, partly in cross section along III-III of FIG. 1, and un;

F i g. 4 shows the relationship between key actuation pressure force and key travel of a single Ta of the pushbutton unit.

F i g. 1 shows a total of three keys, of which the right key is only partially shown, while The middle button is in the rest position and the left button is in the actuation position Similarly, in FIG. 2 the right key to the idle position, while the left key, from the nui the push button can be seen, pressed isL It should first the structure of a single key can be described.

A base plate 1 made of insulating material, which is used, for example, as a printed circuit board of a printed circuit, carries several, essentially strip-shaped contact springs 2 for each key, the ones shown in FIG. Way via a broken through a base plate 1 α extending flag Id to an electrical circuit, z. B. the circuit board or base plate 1, are connected. The lugs Id of the individual contact springs 2 are expediently offset from one another (see FIG. 2). The contact springs 2 are arranged on both sides of a sensing element 3, which is also supported by the base plate 1, for the middle key of Fi e. 1 three cons

έ,

clock springs on the left and two contact springs on the right of the probe body 3. The contact spring assembly shown here is only an example, it can be varied depending on the intended use.

Parallel to the probe body 3, strip-shaped transverse webs 3 'extend from the base plate and are connected to the probe body 3 by longitudinal webs 3 ″ (cf. in particular FIG. 3). The longitudinal webs 3 ″ have mutually facing projections 3 ″ o (cf. FIG. 3) so that holding grooves 3'a are delimited by the longitudinal webs 3 ″ on the one hand and the feeler 3 or cross web 3 'on the other hand. The retaining grooves 3'a hold particular provided with substantially hemispherical beads la contact springs 2 fixed at its lower portion, which promotes the adherence to the defined distances between the individual contact springs. 2

As Fig.2 shows, the contact springs2 are through the projections 3 "a of the longitudinal webs 3" are also secured against upward displacement. "O

All retaining grooves 3'a have reached in the present embodiment, the same dimensions, therefore, by suitable dimensioning of the beads la for different sheet thickness of the contact springs 2, a fixed seat. * 5

The Anb-ingen the beads la at the contact springs lends itself to manufacturing reasons, there may not be undercut in the manufacture by injection certain minimum dimensions of grooves.

For defined distances of the individual Kontaktfedem2 from each other and thus precise switching sequences also ensures that the contact springs 2 on the upper section are either biased against the probe body 3 or the transverse web 3 'so that they rest against the probe body 3 or transverse web 3' in the rest position, or by means of a right-angled upper angle piece Ic, are supported in a pretensioned manner on the probe body 3 (cf. in FIG. 1 the contact springs 2 of the middle button).

How particularly well the right button of Fig. 1 shows, the probe body 3 is an internally hollow cylindrical cuboid, which has two diametrically opposite openings 3a for receiving one switching ball 4 each, which can be pushed radially outward by a probe pin 5 guided longitudinally by the probe body 3, as more precisely will be explained, so that the contact springs 2 adjacent to the switching balls 4 press with their two contact rivets Ib against each associated contact rivets 2 6 of the next contact spring 2 and thus establish the desired electrical connection. The pushbutton pin 5 is actuated by a pushbutton 6 connected to it, as will be explained in detail below.

The diameter of the Dutch breaks 3 a corresponds to the diameter of the switching balls 4, so that they can be moved freely in the openings 3 o to the outside when the feeler pin 5 is moved.

The sensing pin 5 has on its sides directed towards the switching balls 4 switching cams 5 a, through which the movement of the switching balls 4 when pressing and releasing the button 6 and thus the sensing pin 5 is controlled. It is readily apparent that by appropriate shaping of the switching curves 5 α the timing of the switching of the contact springs 2 can be determined as desired, also for the two contact spring sets *: different, which will be explained in more detail. The section of the feeler pin 5 lying below the switching curve Sa is stepped (cf. 3 e is surrounded. Between a flange 5 at the lower end b of the switching curves 5a and the annular projection 3e of the feeler 3 is a restoring spring? arranged in the form of a helical spring, which is compressed when the sensing pin 5 is pressed (see. The left button in Fig. 1) and when the button 6 is released, the sensing pin S returns to its rest position (see. Middle button in Fig. 1). To securing the Tastzapfens 5 on the annular projection 3 e and will be discussed in detail at the probe body. 3

If the key is provided for a telephone with touch dialing, it must be ensured in general with regard to the switching inertia of the existing telephone exchanges that a certain minimum time, z. B. 40 msec, for pressing the key is not fallen below, otherwise when the keys are pressed one after the other, the switching indicators generated by them get into the exchanges in too fast a sequence. Therefore, the switching curves 5 α of the feeler pin 5 together with the return spring 6 should be designed so that this minimum actuation time of the key is observed. For this purpose, the method shown in FIG. 4 dependency of the key actuation pressure force on the key stroke, which with the from F i g. 1 apparent course of the switching curves 5 α is linked as follows.

If the in F i g. 1, the middle key shown in the rest position is pressed, the switching balls 4 initially roll on the vertical, straight section of the switching cams 5 a, so that the mechanical resistance to be overcome by the pressing force of the key is essentially determined by the compression of the return spring 7. This stage of key operation, during the, so the contact rivet 2 has not yet b of a contact spring 2 contact with the contact rivets Ib give another Kontaktfeder2, is yet to take place no electrical switching operations in F i g. 4 labeled "Vorhub".

However, as soon as the switching balls 4 are pressed against an inclined section 5 a 'when the button is pressed again reach, the key actuation pressure increases understandably, especially since that on each Switching ball 4 abutting contact spring 2 first against its own bias and then against the the remaining contact springs 2 must be pushed away. The electrical switching operations by dk The phase of button actuation that triggers the desired contacting of the contact springs 2 is the “working stroke” (see FIG. 4) with a pressure point.

Due to the pressure point of the working stroke, the key operator is forced to exert such a great pressure point that after overcoming the pressure point: the key actuation cannot be aborted arbitrarily, but the key is pressed further through the inertia of the Hanc, so that the Schaltku gel4 on the upper vertical , straight section of the sound curves 5 a as with the left button ii F i g. 1 unroll until the lower edge 6 c of the hollow cylindrical middle piece 6 a of the push button 6 strikes the top edge 3d of the feeler body 3. This"

Phase of key actuation that corresponds to the work stroke contact made unchanged forms the "post stroke" (see FIG. 4). The post stroke guaranteed with the required minimum pressing time of the key.

The effect of the pressure point essentially through the inclined sections 5 a 'of the switching curves hai the further advantage that to reset the Button by the return spring 7 no additional forces are required.

The feeler pin S has two diametrically opposite guide ribs 5 c above the switching cams 5 a at a relatively thick step 5 g. which are each guided in a Fühningsschlitz 3 c of the probe body 3. In Fig. 1 shows only the front guide rib 5c for the left and middle button and only the guide slot 3c for the rear guide rib (not shown) for the right button. In this way, a rotation lock of the feeler pin 5 is achieved.If for each key instead of two only * o a guide rib with a single Fühningsschlitz is provided, a side reversal of the feeler pin 5 when it is inserted into the probe body 3 is prevented, which is desirable if - as already mentioned - The switching curves 5 a for the individual switching balls 4 have different shapes in order to achieve a different timing of the switching of the left and right contact springs.

The connection of the upper end of the feeler pin 5 with the pushbutton 6 is most clearly shown in FIG. 2 shown. The upper end of the feeler pin 5 is essentially a fork 5 d with a locking jaw Se on each fork half. Each locking jaw Se has an outer lead-in bevel 5 /. The securing of the push button 6 on the feeler pin 5 is made by pushing the push button 6 with a hollow cylindrical center piece 6 α from above onto the locking jaws 5 e so that they are pressed towards each other and finally snap apart again, with the adjacent section of the respective half of the yoke 5d to a Rastanschiagring 6 b bear against the inside of the hollow-cylindrical middle part 6 of a Tastknopfs. 6 At the same time, the lower edge 6 c of the center back 6 a is supported on the upper edge of the step Sg , which is thicker than the upper end of the feeler pin 5, including the guide rib 5 c, so that the push button 6 is secured against longitudinal displacement on the feeler pin 5

Conveniently 5 similar forked shaped like the upper end above the lower end of Tastzapfens and therefore also with two locking jaws Se '(see. Fig. 1) provided to be pressed when mounting the Tastzapfens 5 in the sensor body 3 by the ring projection 3e to each other and then snap apart so that the feeler pin 5 is secured against being pulled out of the feeler body 3

The remaining free part of the lower edge 6 c of the hollow cylindrical center piece 6 a of the push button 6 when the button is pressed, it hits a corresponding stop surface 3d * of the feeler body 3 (see left button in Fig. 1) in order to limit the stroke of the pushbutton 6 and thus of the pushbutton pin 5.

The push button 6 has a relatively deeply drawn outer jacket 6d, the lower edge 6e of which in the rest position of the push button 6 is below the height. in which the switching balls 4 and the contact rivets 2 b of the contact springs 2 are located. This arrangement provides effective dust protection for the components just mentioned, which makes the key according to the invention very reliable. The dust protection can be further improved by a rectangular cross section of the push button shell 6d if several keys are arranged next to one another, since the space between the individual push button shells is reduced compared to a circular cross section.

The push button casing 6 d is tapered upwards over a shoulder 6 / to a push button crown 6 g, as can be clearly seen from the drawing. The tapered button button crown 6 g facilitates the actuation of the buttons by reducing the risk of unintentional actuation of a neighboring button.

The button crown 6 g has a circular recess 6 A, which initially converges downwards and then has a constant diameter. The convergent course at the beginning largely prevents the operator's fingers from slipping while keying. The bottom half of the recess 6 ή has a circular character insert 8, ζ on its base. B. made of paper, on the z. B. a number or a letter is shown and a transparent also circular aperture 9, z. B. is made of plastic. The replaceable character insert 8 ha the advantage that it can be printed according to the respective needs, while special production tools would be required in you push button crown 6 g injected characters.

An advantageous development of the invention bc is that several keys according to the invention to a key unit, in particular for a Fen speakerphone with Tasi selection. are summarized in such a way that the base plate 1 is common for all keys and accordingly all probe bodies 3 'Quci webs 3'. Longitudinal webs 3 "and contact springs 2 for the individual keys. Here, the Tastkö 'per 3, the transverse webs 3' and the longitudinal webs 3" all keys form a unit that can be manufactured as a one-piece Ta «- ¹ , block 10 by injection molding .

First of all, the feeler pins are required for assembly. with the return spring 7 in the associated Tastki-: locked by 3 by means of the locking jaws 5 <- '. Then the switching balls 4 are inserted into the openings 3 and now the contact springs 1 are pushed in from below via the holding grooves 3'a and the space between the projections 3 "e (the upper section of the contact springs 2 is somewhat narrower than this space), until the lower section de KGntaktfedem with its upper edge on the Voi jumps 3 "a of the longitudinal webs as in Fig get through the associated Gnmdplatte openings 1. After connecting the keypad 1 to the grand plate 1 by several arbitrarily arranged screws 12 (see. Fig. 1 and 3), the buttons 6 are placed on the TastaapfenS, from which they snap in the manner already explained. After the electrical connection of the flags 2 <fz1 by dip soldering, the pushbutton unit is ready for operation.

The entirety of the pushbuttons 6 of the push-button unit extends through a recess in a housing wall 11 (cf. Fi g. I) with as little spacing as possible

of the latter in order to prevent the ingress of dust as much as possible.

If , in contrast to the invention, to create a key unit, the keys would be attached individually to the base plate 1, the keys would have to be

aligned with each other and in this context larger tolerances of the center distances c individual keys are provided, which especially with a large number of keys the Platzbed Tactile unit would increase.

1 sheet of drawings

Claims (17)

Patent claims: 1. Button for actuating contact spring sets, especially for telephones with touch dialing, a push button being movable against the force of a return spring between two positions determined by stops and sitting on a feeler pin which is guided longitudinally in a hollow probe body which has openings each extending a switching ball, which is located on one of the switching curves of the sensing pin, through which the switching balls are moved outward when the button is pressed in the openings and thereby actuate the contact springs, characterized in that the contact springs (2) approximately parallel to Direction of movement of the pushbutton (6) are arranged and that a hollow cylindrical center piece (6 a) of the pushbutton (6) sitting on the pushbutton pin (5) has a push-button stop ring { 6b) on its inner circumference, which when the pushbutton is pushed open ( 6) on the upper end (Sd) of the sensing pin (5) of this two resilient locking jaws (5 e) to each other d moves, which then snap apart and rest on the upper edge of the locking stop ring (6 b) , while the lower edge (6 c) of the center piece (6 α) on the upper edge of a step (5) that is thicker than the upper end of the feeler pin (5) g) the feeler pin (5) is supported. 2. Button according to claim 1, characterized by two openings (3 a) which are diametrically opposite. 3. Button according to one of the preceding claims, characterized in that the probe body (3) at the bottom has an inner annular projection (3 e) which, when the probe pin (5) is pushed in from above, into the probe body (3) has two at the lower end of the probe pin ( S) provided resilient locking jaws (5e ') pushes each other, the subsequently snapping apart and create by the force of the return spring (7) at the lower edge of the annular projection (3 e). 4. Key according to one of the preceding claims, characterized in that the feeler pin (S) engages at its thicker step (S g) with a longitudinal guide rib (Sd) in a corresponding guide slot (ic) of the feeler body (3). 5. Button according to one of the preceding claims, characterized in that the lower edge (6e) of the outer jacket (6d) of the push button (6) when the button is not pressed below the level of the contact rivets (2 b) of the contact springs (2) and the switching balls ( 4) cherishes. 6. Button according to one of the preceding claims, characterized in that the outer jacket (6 d) of the push button (6) is tapered upwards over a shoulder (6 /) to a push button crown (6 g) and that the top surface of the push button crown ( 6 g) has a recess (6 h) . 7. Button according to claim 6, characterized in that in the recess (6 h) of the push button crown (6 g) a transparent panel (10) and underneath a non-rotatable character insert (11) are arranged. 8. Button according to one of the preceding claims, characterized in that the outer jacket (6d). of the push button (6) has a rectangular cross section. 9. Button according to one of the preceding claims, characterized in that the probe body (3), the feeler pin (5), the pushbutton (6) and the switching balls (4) are made of plastic. 10. Button according to claim 9, characterized in that the plastic is polyacetal. 11. button according to one of the preceding claims, characterized in that the contact springs (2) each have one at their lower section Have bead (2 a), which is held in place by a retaining groove (3'a), which is either from the feeler body (3) and longitudinal webs (3 ") proceeding therefrom or from the longitudinal webs (3") and one connecting them Cross web (3 ') is limited. 12. Button according to claim 11, characterized in that that the retaining grooves (3Ό) for all contact springs (2) are the same size. 13. Button according to claim 11 or 12, characterized in that the longitudinal webs (3 ") each one have horizontal projection (3 "a) whose distance from each other is greater or smaller than that Width of the upper or lower section of the contact spring ^ (2) is (F i g. 2). 14. Button according to one of the preceding claims, characterized in that the contact springs (2) preloaded with its upper section on the probe body (3) or crosspiece (3 ') prop up. 15. Button according to one of the preceding claims, characterized in that the contact springs have a substantially right-angled elbow (2 c) at their upper end, by means of which they are supported in a pretensioned manner on the probe body (3) in the rest position. 16. Key according to one of the preceding claims for telephones with touch dial, characterized in that the switching curves (Sa) of the feeler pin each have an inclined section (5 a ') which has a pronounced maximum of the key actuation pressure force (pressure point in F i g. 4) caused to ensure a minimum key actuation time. 17. Key according to one of claims 11 to 16, characterized in that it is combined with several keys of the same type to form a key unit can be in that the probe body, transverse webs and longitudinal webs are integrally connected to form a tactile block, which also includes all Holds contact springs.