US3028776A - Crimping tool with adjusting means - Google Patents

Description

Aprll 10, 1962 H. KELLER ETAL 3,023,775

CRIMPING TOOL WITH ADJUSTING MEANS Filed June 4, 1959 INVENTORS HERMAN KELLER CLIFFORD R. WALDRON ATTOR Ns United States PatentO 3,028,776 CRIMPING TOOL WITH ADJUSTING MEANS Herman Keller, Sidney, and Clifford R. Waldron, Unadilla, N.Y.,,assignors to The Bendix Corporation, a corporation of Delaware Filed June 4, 1959, Ser. No. 818,068 2 Claims. (Cl. 81-15) This invention relates to a tool for indenting a ferrule; such tool is useful, for example, in the fastening of a cable or wire to a lug or contact.

The invention has among its objects, the provision of a novel improved indenting tool of the type described, which is characterized by the accuracy and uniformity of the indented products produced thereby.

A further object of the invention lies in the provision of an improved indenting tool having an indentor advancing cam means pivotally mounted with respect to the indentor mounting and guiding means.

Still a further object of the invention lies in the provision, in a tool of the type indicated immediately above, of means for adjusting the inner terminal position of the indentors corresponding to the final, inner angular position of the indentor advancing and indentor guiding means relative to each other.

Yet another object of the invention lies in the provision of an indenting tool of such character, that after the indentors have once been advanced forcibly to contact a workpiece such as a ferrule, the indentors can not thereafter be retracted to release the workpiece before they have completed the full path of their operative stroke.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits ofthe invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a view in side elevation of a preferred embodiment of indenting tool in accordance with the invention, the indentors of the tool being shown in their fully advanced, inner position with the operating arms of the tool advanced into their inner, most nearly adjacent position; 7

FIG. 2 is a fragmentary view in vertical section generally through the axis of the head of the indenting tool, the section being taken generally along the line 2-2 of FIG. 1, FIG. 2 showing a pin contact of a separable electrical connector within the tool and in the condition in which the ferrule of such contact has been fully clenched upon a lead vw're connected thereto;

FIG. 3 is a fragmentary view in vertical section through the tool head shown in FIG. 2, the section being taken generally along the line 3--3 of FIG. 2, certain of the parts being shown in elevation, the indentors being shown in their inner, fully advanced position;

FIG. 4 is a fragmentary view in vertical section similar to FIG. 3 but with the indentors, and the indentor moving arms, occupying their outer, fully opened positions, the figure also showing, in phantom lines, an intermediate position of the parts wherein the indentors and the indentor-operating arms are prevented from outward movement;

FIG. 5 is a view in vertical section through the indentor mounting element of the head of the tool, the section being taken along the line 5-5 of FIG. 2;

FIG. 6 is a view in vertical section through the tool showing the upper end of an indentor-operating arm, the section being taken along the line 6-6 of FIG. 2;

FIG. 7 is an enlarged view in end elevation of the serrated ring member designed to interfit between the serrated surfaces of the portions of the apparatus shown in FIGS. 5 and 6 whereby to effect a fine angular adjustment between such parts; I

FIG. 8 is a view in side elevation of one embodiment of connector contact and wire leading thereto, which may be assembled by one embodiment of the indenting tool of the present invention; and

FIG. 9 is a view in elevation of a second embodiment of contact and lead wire assembly which may be made by a further embodiment of the indentor tool of the present invention. I

The indentor tool of the invention in the embodiment thereof shown herein is particularly adapted for assembling connector contacts, such as those shown in FIGS. 8 and 9, upon their lead wires. Such connectors are adapted for use in separable electric connectors of the type disclosed and claimed in application Serial No. 808,611, filed April 24, 1959, by George I. Swanson. In such contact assembly, theclenching or indentingof a ferrule on the contact upon the lead-wire extending therei-nto is relied upon for both the sole mechanical and sole electrical connection between the wire and the contact ferrule. In order'that-such connections shall have'the desired mechanical strength and electrical conductivity, both initially and after long periods of arduous service, the connecting ferrule of the contact must be held to close tolerances in machining, and the clenching or indenting operation must closelycontrolledj Thus, if the degree of indention of the ferrule upon the wire should be inadequate, the resulting joint will not only lack the desired mechanical strength, but it will leave a somewhat open structure within the indented ferrule, assuming the wire is of the multi-strand type, in which the strands are only loosely packed, thereby allowing the. markedingress of air into the joint. If, however, the degree of clenching or indention of the ferrule wall is too great, either on one or all sides thereof, the side wall of the ferrule will be locally drawn, reducedin gauge, and thereby weakened or in some cases evenzpunctured. It will be seen, therefore, that the ferrule indenting operation must be carried out with care, and with precision apparatus, if such manner of connection of electrical fittings and lead wires thereto is to be satisfactory.

The embodiment of indenting tool shown herein has proved to be particularly satisfactory for use by work-' men engaged in installing in situ electrical connectors in cables. It will be understood, however, that in some instances it may be desired to mount the headof an indenting tool made in accordance with the invention on a fixed support, and to rotate the mainparts of the head relative to each other as by power means rather than by handles as shown.

The head of the clenching or indenting tool of'thc invention in theembodiment shown is generally designated by the reference character 10. In describing the tool and the parts which form it, the horizontal direction to the right in FIG. 2 will be termed the forward direction, and

' ing element 12 has an annular flange 17 fitting within a} similarly shaped seat in the wall of cam housing 11. A split spring ring 19, snapped into the seat at the rear of flange 1 7,-retains element 12 within the cavity in cam housing 11.

As shown more particularly in FIGS. 3 and 4, element 12 has four equally angularly spaced radially directed guideways 20, lying at the forward end of element 12 adjacent wall 15 thereof. Radially reciprocable in guideways 20 are four clenching or indenting tools 21, each indentor 21 being very accurately guided in its respective guideway. The outer ends of tools 21 are partially circular cylindrical, as shown at 22, ends 22 having sliding engagement with the respective ones of the four cam surfaces 24 on the inner periphery of cam housing 11. Between the radially innermost end of each of cam surfaces 24 and the radially outermost end of the next adjacent cam surface, there is located a part circular cylindrical pocket 25 which accurately receives the outer end 22 of its respective indenting tool 21 when such tools are retracted into inoperative position, as shown in solid lines in FIG. 4. Indenting tools 21 are constantly urged outwardly into engagement with the cams 24 and/or the pockets 25 by a split spring ring 26, which fits within slots 27 in the forward faces of the indentors as shown in FIGS. 3 and 4. The spring ring 26 is of such relaxed configuration that it constantly tends forcibly to expand radially outwardly of the position shown in FIG. 4.

The cam housing 11 of the head of the tool has an extension 29 integral therewith, there being a handle extension 30, conveniently formed of bent sheet metal, attached thereto by bolts 31. Adjustably secured to inden tor-mounting element 12 is a second, handle-forming arm, composed of an upper, centrally apertured portion 32 having an extension handle 34 connected thereto as bolts 35. The upper apertured end portion 32 of the second handle is snugly but rotatably received over a central hollow trunnion-like member 36 which projects rearwardly from element 12. Portion 32 is adjustable angularly with respect to member 36, and thus with respect to element 12, by the following mechanism. The rear face of element 12 is serrated as shown more clearly in FIGS. and 7. Such serrations, which are designated 37, are equally angularly spaced about the axis of element 12; conveniently there may be 24 serrations 37. Fitting accurately over member 36 and rotatable thereon is a serrated adjusting ring 39 having serrations 41, on its forward surface, which mesh accurately with serrations 37, that is, there are 24 equally spaced serrations on the forward face of ring 39. The rear face of ring 39 has a plurality of equally angularly spaced serrations 40 thereon, such serrations differing slightly in number from serrations 37 and 40. Conveniently there may be 23 serrations 40 on ring 39. The forward face of element 32 is provided with a plurality of serrations 42 of the same shape, serrations 42 being equal in number and complementary in shape to serrations 41. After adjustment of the parts, in the manner to be described, elements 32, 39, and 12 are maintained tightly together with their serrated surfaces in mesh by means of a nut 44 threadedly engaged with the threaded outer end of element 36, and by a spring washer 45 interposed between nut 44 of the rear surface of element 32. In the embodiment disclosed, spring washer 45 is laminated and in relaxed condition is bent or dished somewhat along one diameter.

The tool head has a connector-locating means in the form of a stud 46 having the forward end thereof provided with a forwardly open axial bore 47. Stud 46 accurately fits within the central axial bore 49 in member 36, and is held accurately by means of a flange 50 on member 46, and a nut 51. As shown, flange 50 engages the end of member 36; the nut 51 has an annular rear flange thereon overlying flange 50 and thrusting member 46 forwardly. The axial length of bore 47 in member 46 is such that when a contact such as that shown at 52 in FIG. 2 is placed with its operative end in engagement with the inner end of bore 47, the ferrule on the contact is positioned in the proper transverse plane axially of the head of the tool to be operated upon by the inner ends 54 of tools 21. It will be obvious that contacts of different effective lengths may be operated upon by the tool by the substitution of another locator member 46 having a bore 47 therein of the diiferent required length.

The position of nearest approach of handles 30 and 34 of the tool relative to each other is determined by the adjusted position of a stop stud 55, which is threaded into a bore 56 in handle portion 29, as more clearly shown in FIG. 1. Preferably, as in the construction shown, the slotted outer end of stud 55, by which it is adjusted, lies hidden beneath the upper part of handle extension 30, thereby to prevent tampering with the adjustment of the stop.

The embodiment of tool shown is provided with a means whereby, once the indentors have been advanced into firm engagement with a ferrule, the tool can not be again opened until the indentors have completed their operative stroke. In the illustrative embodiment, such means takes the form of a pawl 57, which is pivotally mounted upon arm 32 by means of a pivot pin 59. Pawl '57 is constantly urged into the position shown in full lines in FIG. 3 and in phantom lines in FIG. 4 by means of a coil tension spring 60 having the bottom end thereof attached to arm 32 at 61 and the upper end thereof attached to the lower end of pawl 57 at 61. In such position the upper, pointed operative end 64 of pawl lies in the central longitudinal plane of arm 32.

The end 64 of the pawl selectively cooperates with three downwardly extending serrations 65, 66, and 67, the point 64 of the pawl, when the tool is open as shown in FIG. 4, lying to the left of serration 65, and, when the tool is fully closed, lying to the right of serration 67. When arm 32 is swung to the right from its full line position shown in FIG. 4, the upper end 64 of pawl 57 snaps into the valley between serrations 65 and 66 or if such motion is continued, into the valley between serrations 66 and 67. In either of such two latter positions, the pawl 57 is swung counterclockwise, as shown in phantom lines in FIG. 4, so that the pawl 57 now effectively prevents or blocks retrograde movement of arm 32. It is only when the arms 30 and 34 have been swung together sulficiently to cause point 64 of the pawl to clear serration 67, as shown in FIG. 3, that the arms 30 and 34 again become free to be moved apart.

The arms of the tool are constantly urged apart into tool-open position by the spring 69 acting therebetween, as shown in FIG. 1. The arms of the tool must be fully open to accept the largest diameter of the ferrule or other part being crimped. Undue separation of the arms, should the arms be allowed to spring apart under the action of spring 69, is prevented by a cross-pin 70 engaging bent tang portion 71 on the lower end of spring 69.

In FIGS. 8 and 9 there are shown alternative connectors which may be operated upon by the embodiment of the tool shown. In FIG. 8 the contact is that shown at 52 in FIG. 2, such contact having one ferrule 72 engaging the end of the lead wire 73. Thus the inner, operative ends 54 of the indentors 21 need have indenting surfaces lying generally in one head transverse to the axis of head 10. In FIG. 9, on the other hand, the contact 74 has two ferrules, one, shown at 75 engaging the forward end of wire 76, and the second, shown at 77 being larger and clenched upon the end of the insulation 79 on the wire 76. In forming the assembly shown in FIG. 9, the embodiment of tool shown will have its indentors provided with two clenching zones, the rear zone clenching ferrule 75 upon the wire 76, and the forward zone clenching ferrule 77 upon the insulation 79.

The described construction of the tool, including the adjustable stop 55 and the adjusting means including serrated ring 39 acting between arm 32 and element 12, permit the tool to be accurately adjusted, when necessary, to compensate for the wearing of the elements of the indenting tool, including the outer end surfaces 22 on the indentors 21 and cam surfaces 24 on cam housing The indentcrs 21 and the spring 26 are assembled in guide element 12, and such assembly is installed in cam housing 11, being retained therein by snapping the split Spring ring 19 into the cavity rearwardly of element 12.

The pawl 57 and spring 6% are then mounted upon arm 32. Adjusting ring 39 is then telescoped over element 35, ring 39 being placed so that its teeth 41 mesh with teeth 37 on the rear face of element l2. Arm 32 is now telescoped over element 36, and is positioned so that it forms an angle of about 28 with handle portion 29. With arms 2? and 32 held in such position relative to each other, the curved spring washer 45 is installed over element 36 and is held in place by the nut 44, which is tightened finger-tight at this time. The adjustable stud 55 is now installed, and is screwed inwardly so that its inner end lies spaced a distance of .062 to .004 inch from arm 32 when the point 6 of pawl 57 just barely snaps past the last tooth or serration 67 on the body of cam housing 12.

This can best be done by first adjusting stud 55 so that the arm 32 can not be closed enough for the pawl 57 to snap past the last tooth 57. Then, holding the tool closed, the operator slowly backs out the stud 55 until the pawl 57 snaps clear of tooth 67. The adjustment is checked by inserting a .904 inch feeler gauge between the screw 55 and arm 32 and then closing the tool. The pawl should not snap clear of tooth 67. The same operation is repeated using a .002 inch feeler gauge. The pawl should now snap clear of tooth 67. The tool should then be opened and closed several times and rechecked to make sure that its action is consistent.

After a justment of the set screw 55 is completed, a piece of masking tape is attached over the pawl 57 to prevent it from contacting the teeth 65, 66, and 67 on arm 32 while the indentors are adjusted. The indentor setting is now checked, and the distance between the inner ends of the indentors is measured with the tool closed. it such dimension is greater than the desired setting, nut 44 is loosened and the adjusting ring 39 is turned one click relative to arm 32 and element 12. While holding ring??? in its new position, nut 44 is re tightened, after which the distance between the inner ends of the indentors 2:1 is checked with the tool closed. It will be understood that such turning of adjusting ring 39 one click relative to arm 32 and element 12 will have adjusted the terminal position of element 12 relative to cam housing 11 through an angle approximately equal to 39 minutes, that is, the difference between of 360 and of 360.

Cam surfaces 24 are so designed that when arms 39 and 3d are moved one tooth in either direction of the adjusting ring the effective result is a movement of the indentors equal to .0026 inch. If, however, the distance between the inner ends of the indentors, with the tool closed, is less than the desired dimension, nut 44- is loosened and the arms 3% and 34 of the tool are closed and en opened one tooth each way on the adjusting ring 39 for each .0026 inch the distance between the inner ends of indentors is below the desired setting.

When the desired setting is obtained, nut 44 is tightened to a predetermined degree as by using a torque wrench thereon. The masking tape is now removed from pawl 57, and the assembly of the tool head is completed by installing the contact locator 46 and the nut 51. Handles 3t) and 34 are now attached to arms 29 and 32 of the tool; the tool is now completely assembled and ready for use. The tool may be readjusted, when necessary, to compensate for wear on the indcntors, cam ring, etc., whereby to restore the tool to its initial accurately adjusted condition.

Although only one embodiment of the invention has been illustrated in the accompanying drawings and only two embodiments thereof have been described in the foregoing specification, it is to be especially understood that various changes, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those sltilled in the art.

W rat is claimed is:

l. A tool for crimping a ferrule upon a wire, comprising a tool head carrying a plurality of ferrule-indenting tools for movement inwardly toward and outwardly away from each other, a cam means rotatable with respect to the tool head for advancing the tools inwardly in a working stroke, means for drivingly rotating one of the cam means and the tool head with respect to the other, and means for adjusting the angular relationship between the driven element and the driving means therefor, said last means comprising a ring member interposed between the driven element and the driving means, opposite sides of the ring member carrying a plurality of uniformly spaced teeth, the teeth on the two sides of the ring memher being different in number, teeth on the driven element and the driving means meshing with the teeth on the respective sides of the ring member, and means for holding the driving element, the ring member, and the driven element together in driving relationship.

2. A pliers-type tool for crimping a ferrule upon a wire, comprising a circular tool head carrying a plurality of generally oppositely disposed ferrule-indenting tools for movement inwardly toward and outwardly away from each other, a barrel means disposed about the periphery of the tool head and carrying cam ramps cooperating with the outer ends of the tools, the barrel means being rotatable with respect to the tool head about the axis thereof for advancing the tools inwardly in a working stroke, levers constituting handles connected to the tool head and the barrel means, stop means acting between the levers for determining the terminal positions of the levers when thetools are in their innermost position,

' and means for adjusting the angular relationship between one of the elements consisting of the barrel means and the tool head and its respective lever, said last-named means comprising a ring member interposed between the i References Cited in the file of this patent UNITED STATES PATENTS 918,065 Low Apr. 13, 1909 1,262,621 Beacham s Apr. 16, 1918 2,086,400 Brenizer July 6, 1937 2,696,747 Bergan Dec. 14, 1954 2,753,742 Buchanan July 10, 1956 OTHER REFERENCES I American Machinist, pages l689, Jan. 22, 1931.

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