US3354692A

US3354692A - Electrical connector contact crimping tool

Info

Publication number: US3354692A
Application number: US422686A
Authority: US
Inventors: James E Morris
Original assignee: General Dynamics Corp
Current assignee: General Dynamics Corp
Priority date: 1964-12-31
Filing date: 1964-12-31
Publication date: 1967-11-28
Anticipated expiration: 1984-11-28

Description

NOV. 28, 1967 J. E. MORRIS ELECTRICAL CONNECTOR CONTACT CRIMEING TOOL JAMES E. N10/221s. BY ai W KM A T TOIZNE Y.

ELECTRICAL CONNECTOR CONTACT CRIMPING TOOL Original Filed Aug. 27, 1958 l 3 Sheets-Sheet 2 lliilHln INVENTOR JAMES E. MORRIS fm/ da,

ATTORNEY Nov. 2s, 1967 J. E. Mop-ms 3,354,692

ELECTRICAL CONNECTOR CONTACT CRIMPING TOOL Original Filed Aug. 27, 1958 5 Sheetsheet 5 1N V EN TOR. JA MES E Mom/5.

A T TOQNE Y United States Patent O 3,354,692 ELECTRECAL CONNECTR CONTACT CRIMPING TL .lames E. Morris, Fort Worth, Tex., assigner to General Dynamics Corporation (Convair Division), San Diego, Calif., a corporation of Delaware Application Feb. 9, 1962, Ser. No. 172,195, which is a division of application Ser. No. 757,514, Aug. 27, 1958, now Patent No. 3,159,511, dated (let. 23, 1962. Divided and this application Dec. 31, 1964, Ser. No. 422,686

5 Claims. (Cl. 72-402) ABSTRACT OF THE DISCLQSURE This connector crimping tool has a ratchet that holds the handles of the tool in position during closure until the handles 'have been completely closed. This assures complete crimping of each connector. An overload release device or a clutch limits the amount of crimping pressure applied to the connector to compensate for complete closing of the handles in each crimping operation.

This application is a division of applicants co-pending application, Ser. No. 172,195 tiled Feb. 9, 1962, now Patent No. 3,172,211, which application and patent was a division of application Ser. No. 757,514, filed Aug. 27, 1958, now Patent No. 3,059,511.

Heretofore crimping tools have been used for making crimps in a connector barrel to secure it to an electrical conduct-r. This provides for physical and electrical contact without the necessity of soldering. However, care must be exercised to insure that a crimp of sufficient depth has been made to prevent accidental disengagement of the connector with the conductor. Also, if excessive pressure is applied, the connector barrel becomes distorted and its walls may become cut or broken. Since the connector has a barrel portion to receive the conductor and a pin portion extension which will not receive the conductor, the position of the crimp along the connector axis must be accurate in order to insure crimping action with the conductor. Additional crimping of the connector to the insulation on the conductor for greater strength is sometimes desirable, requiring a second crimping spaced along the connector axis from the rst crimp. While a length adjustment attachment for crimping tools is currently available, it requires that a connector well nut be manually adjusted until the centerline of the nut is properly set. This requires continuous adjustment in placing more than one crimp axially along the connector.

The -connector contact crimping tool comprising the present invention provides for a ratchet mechanism to prevent withdrawal of the connector from the punch holder until the handles 0f the tool have been completely closed to insure suicient crimping action regardless of the size of the wire and connector being crimped. An overload release mechanism is provided to limit the crimping pressure applied against the connector so that excessive pressure will not break, cut or unduly distort the connector, irrespective of its size. This is done by stopping further inward movement of the punches against the connector with continued inward movement of the handles. A depth selector with a positive stop is provided to accommodate various lengths of connector pins and barrels. For connectors requiring a secondaxial crimp, a trigger mechanism is provided to readily permit a positive predetermined axial spacing of the second crimp from the lfirst. Once the tool is set for crimping of a certain depth no further adjustment is necessary and connectors Patented Nov. 28, 1967 ICC and conductors may be crimped together in a speedy mass production manner without adjustment to provide for their size.

lt is therefore an object of the present invention to provide for a new and improved crimping tool.

Another object is the provision of a crimping tool which automatically applies a uniform pressure to connectors and conductors irrespective of their various sizes.

Another object is the provision of a crimping tool wherein a predetermined minimum crimping pressure must be applied before the tool punches may be withdrawn from contact with the connector being crimped to its associated conductor.

Another object is the provision of a crimping tool wherein lexcessive pressure will operate an overload release mechanism to prevent crimping too deeply, thereby cutting, ybreaking or unduly distorting the connector being crimped.

Another object is the provision of a crimping tool having a plurality of quickly adjustable positive stops for axially positioning the crimping of a connector at predetermined distances from its tip.

Another object is the provision of a crimping tool having a stop release to permit the crimping of a connector in axial spaced relation from a first crimp.

Another object is the provision of a crimping tool which automatically applies a pressure within predetermined minimum and maximum limits to all sizes of connectors and conductors within wire sizes #28 through #10 without manual adjustment for crimping indentations.

Other objects and features of the present invention will be readily apparent to those skilled in the art from the following specication and appended drawings wherein is illustrated a preferred form of the invention, and in which:

FIGURE 1 is a side elevational view with portions thereof broken away to better illustrate tool operation,

FIGURE 2 is an elevational view of the top handle before assembly with the bottom handle and with a side plate removed,

FIGURE 3 is an elevational view ofthe bottom handle with rack attached,

FIGURE 4 is a perspective view of the overload release plate,

FIGURE 5 is atop plan View showing the depth selector mounting, and f FlGUR-E 6 is an exploded perspective view of the depth selector mechanism. y

This invention relates generally to an improved crimping tool of the type having two relatively movable handle members 11 and 12 adapted to be pivotally connected at one of their extremities. Handle member 11 is generally U-shaped in section formed by a Vbody portion 13 and a pair of

side plates

14, 16 which have enlarged sections 17 at the pivotal extremity. These plates have aligned open ings 18 for receiving the connector to be crimped. Slotted openings 19 are arranged symmetrically about and spaced radially from the central opening 18 and are designed to accommodate fastening units 21 such as bolts, rivets or the like when the component parts of the tool are assembled. Handle member 12 has a structural conguration similar to that of handle member 11 except that it is preferably constructed of solid material, such as cast iron for example, and its enlarged extremity 22 is adapted to lit between

plates

14, 16. This enlarged extremity 22 has an enlarged opening 23 whose center is in axial alignment with the center of opening 18 in the

plates

14, 16. This opening 213 in handle member 12 has a series of cam surfaces 24 about its periphery.

A cylindrical punch holder 26 is adapted to rotate within the enlarged opening 23.`This punch holder 26 also has a central opening 27 in axial alignment with the other opening 18 to accommodate the connector inserted therein. Extending radially from the central opening 27 of the punch holder 26 and intermediate the side walls thereof are a series of passageways 28, preferably four in number spaced at ninety degree intervals. These passageways 28 are preferably circular in section and contain a shoulder 29 delined by the juncture between an inner constricted portion 31 and an outer larger portion 32. Disposed in the passageways 28 are forming punches 33, each having an enlarged head portion 34 that engages cam surface 24 on handle member 12 and a cylindrical body portion 36 integrally connected with the head portion 34 and being provided with a connector engaging tip 37. A spring member 38 located between the bottom surface of head portion 34 and the shoulder 29, urges the forming punch 33 into contact with the cam surface 24. It may be readily appreciated that rotation of the punch holder 26 ina clockwise direction will cause the cam surfaces 24 to force the forming punches 33 inwardly against the action of spring member 38. The punch holder 26 is caused to rotate clockwise as handles 11 and 12 are brought together because of its connection with the top

handle side plates

14, 16 and overload release plate 39 positioned therebetween on both sides of the punch holder 26. This rotation is directly related to handle movement until an excessive force is applied, after which the overload release mechanism permits further handle movement without further punch holder rotation. Overload release plate 39 consists of a pair of rotatable faces 41 riveted, bolted or otherwise secured to punch holder 26 by fastening means 21 so as to rotate therewith and to prevent relative rotation therebetween. The two faces 41 extend toward the handle ends of the tool and terminate with an integral transverse connector 43 upon which rollers 44 ride. Fastening means 21 extend outwardly from the faces 41 of the clutch plates and engage slots 19 in the top

handle side plates

14, 16. Normally the fastening means 21 will engage the clockwise end 4S of the slots 19 and the overload release plate 39 and punch holder 26 will rotate in direct response to movement of handle 11 relative to handle 12. However, forces in excess of the desired crimping force on the punch tips 37 permit continued clockwise rotation of handle 11 without further rotation of the punch holder 26 or clutch plates 39. When this happens the fastening means 2-1 engages the counterclockwise end 47 of the slots 19.

`When a connector exerts a force against the punch tips 37, as when a larger size connector is being crimped, the frictional force between punch head 34 and cam surface 24 is too great to permit further relative movement therebetween, and prevents further rotation of the punch holder 26 and overload release plate 39. This xes the position of the transverse connector 43 upon which roller 44 is adapted to move. The roller 44 is mounted at the pivotal connection 49 between bar 51, which is pivotally mounted to the top handle 11 at a point 52 slightly forward (to the left as shown in FIGURE 1) of the pivotal connection 49, and aplunger 53. This plunger 53 is telescopically engageable with a sleeve 54 which is pivotally seated in a socket 56 in the end of the top handle 11. An overload release rentention spring 57 urges the sleeve 54 and plunger 53 apart and thus roller 44 forward to the position shown in the drawing. This retains the transverse connector 43 in its downwardmost position and the overload release plates 39 in clockwise position. The fastening means 21 connecting the overload release plates 39 and punch holder 26 to the top

handle side plates

14, 16 are thus retained against the clockwise end 48 of the slots 19, all of which is substantially as shown in FIG- URE 1. When the connector pressure against the punch tips 37 execeeds a predetermined amount and the punch holder 26 and overload release plates 39 cease clockwise rotation, further closing of the handles 11, 12 may still be accomplished. This is done by the force of the transverse connector 43 on the overload release plates 39 against the rollers 44, causing rearward telescopic movement of plunger 53 against the force of spring 57. This rotates bar 51 counterclockwise about pivot 52 to a less vertical position, permitting further closing of the handles to the position where the fastening means 21 abut the counterclockwise ends 47 of the slots 19.

A feature of the present invention is that the handles must fully close before the connector being crimped can be released from the punch tips 37 and withdrawn from opening 18. This insures that a predetermined minimum crimping effect has taken place to securely connect the connector and its conductor together. A ratchet -mechanism is provided for this purpose. Rack 53 has an arcuate inner surface 59 with notches 61 thereon and is pivotally mounted on lower handle 12. A pawl assembly 62 is pivotally mounted on fastener 63 to the top

handle side plates

14, 16. This assembly includes a triangular pawl 64 engageable with the notches 61 on rack 53 ,and a rearward extension 66 to which one end 67 of pawl assembly positioning spring 63 is attached. This spring 68 is of the compression type and, having its other end 69 fastened to the upper handle, continually urges rotation of the pawl assembly 62. When the rearward extension 66 is below pivot point 63, the spring `63 urges clockwise rotation of the assembly, freeing pawl 64 from engagement with the notches 61. This happens only when the handles 11 and 12 are completely closed and pawl 64 is urged upwardly by contact with dat face 71 on the closed end of rack 58. When this is done the handles may again be separated, causing counter rotation of the punch holder 26 and withdrawal of the punch tips 37 from engagement with the connector. When the handles are separated the flat surface 72 on the open end of rack 53 engages pawl 64 to cause counterclockwise rotation to lift the pawl extension 66 above pivot point 63. Spring 68 then urges further counterclockwise rotation to engage pawl 64 with the rack notches 61 for the next crimping operation.

Another feature of the present invention is the novel manner in which the crimping indentations `are positioned along the axis of the connector. Positive stops are provided to limit inward movement of the connector into opening 18 for the various desired positions of the indentations along the axis. This is done with the connector depth selector mechanism 73 mounted on the other side of the opening 18 as shown in FIGURE 5. Here a knurled knob 74 is rotated until the proper color, designating the desired length, appears in the opening 76 in housing 77. A trigger 73, pivotally mounted on one of the top handle side plates 14, is actuated by a trigger thumb press 79 urged downwardly by the operator to permit an additional .adjustment for a second crimp in axial spaced relation to the rst crimp. This is more fully explained with reference to FIGURE 6.

The depth selector mechanism 73 shown in exploded form in FIGURE 6 provides for a depth selector plunger 31 with a plurality of recesses 82 of predetermined depth extending from its inner lface 83. This depth selector plunger 31 rotates about plunger pin 84 so that the selected recess will become aligned with opening 18, shown in FGURE 1, to receive the connector to be crimped. The depth of the selected recess determines how far the connector may be inserted, which in turn determines the axial spacing of the crimping indentations on the conductor. The plunger 81 consists of a cylinder having flats 86 on four sides to provide indices for alignment of the recesses 82 with the connector opening 1S. These ilats are also color coded with proper nomenclature on the outside of the depth stop housing 77 to identify the type of connector to be used for the various positions of the plunger 61. The colored ats may be seen through a suitable opening 76 in the housing 77.

A depth selector plunger guide 87 retains the plunger 81 in its selected position. This guide is preferably of cylindrical configuration and is mounted on the tool in.

such manner that a central opening 88 in the guide is in axial alignment with the connector opening 18, shown in FIGURE 1. A transverse keyway 89 extends across the outer portion of the guide to receive the depth selector plunger 81 in non-rotatable condition, the keyway walls 91 being spaced substantially the thickness of the plunger 81 between opposing tlats 86. The guide 81 is counterbored on its inner surface 92 to receive a plunger pin trigger plate 93 for axially spacing a second crimp as will be more fully described. A suitable aperture 94 spaced from the central opening 88 in the selector plunger guide 87 is for the purpose of receiving the depth selector plunger pin 84 for pivotal and axial movement. A selector knob 74 is engageable through oifset opening 96 in the face of the stop housing 77 with the stem 97 on the outer surface of the plunger 81. A spring 98 over the stem 97 abuts the outer surface of the plunger 81 and the inner wall of the housing 77 to urge the plunger 81 into the keyway 89 in the plunger guide 87 and the plunger pin 84 into contact with the outer surface of trigger plate 93. To make the proper depth selection the knob 74 is pulled outwardly to free the plunger 81 from engagement with the keyway 89. The knob 74 is then rotated (pin 84 in aperture 94 is in axial alignment with the knob 74) until the proper color appears in opening 76, whereupon the knob is released and spring 98 again seats the plunger 81 in keyway 89 to prevent further rotation.

The trigger 78 and trigger plate 93 provide for axial spacing of a second crimp as in the case of crimping coaxial cable wherein it is desired to crimp the connector to both the conductor and the insulator portion. The trigger plate 93 consists of a circular disc with a hole 101 in the center and a wedge-shaped cut 102 radiating out from the hole. A small aperture 103 is placed the same distance from the center as the pin receiving aperture 94 in the plunger guide 87. Trigger tip 104 fits within the wedge-shaped cut 102. A suitable recess 106 is provided in the plunger guide 87 to permit movement of the trigger tip 104 therein for aligning aperture 103 in the trigger plate 93 with the aperture 94 in the plunger guide 87 to permit the plunger pin 84 to be urged therein by spring 98. This moves the connector in an axial direction in an amount equal to the thickness of the trigger plate 93 so that a second crimp may be made. As previously pointed out with reference to FIGURE 5, the trigger 78 is pivotally mounted and actuated by pressing the trigger thumb press 79 downwardly to rotate the trigger plate 93 until its aperture 101 is in alignment with the aperture 94 of the plunger guide.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

I claim:

1. Means for assuring a predetermined minimum crimping action has been applied to a connector comprising a crimping tool having handles for eifecting crimping upon closure thereof, ratchet means interconnecting said handles, said ratchet means permitting closure of said handles but not opening thereof until said handles have been completely closed, said ratchet means permitting opening of said handles upon complete closure thereof, said ratchet means comprising a rack mounted on one of said handles with notches on the surface thereof and an abutting face at each end of said notches, a pawl assembly pivotally mounted on the other of said handles and having a pawl engageable with said notches and said abutting faces, said pawl being pivotally disengaged from said notches upon abutment with one of said faces, resilient means maintaining said pawl out of engagement with said notches until said pawl abuts the other of said faces, said resilient means thereafter maintaining said pawl in engagement with said notches until said pawl again abuts said one of said faces.

2. Means for assuring a predetermined minimum crimping action has been applied to a connector comprising a crimping tool having handles for effecting crimping upon closure thereof, ratchet means interconnecting said handles, said ratchet means permitting closure of said handles but not opening thereof until said handles have been completely closed, said ratchet means permitting opening of said handles upon complete closure thereof, said ratchet means comprising an arcuate rack mounted on one of said handles with notches on the inner surface thereof and an abutting face at each end of said notches, a pawl assembly pivotally mounted on the other of said handles and having a pawl engageable with said notches and said abutting faces, said pawl as` sembly having an extension rearwardly of said pivotal mounting, resilient means urging said extension forwardly, one of said abutting faces contacting said pawl to move said extension upwardly to cause counterclockwise rotation of said assembly by said resilient means to free said pawl from engagement with said notches, the other of said faces contacting said pawl to move said extension downwardly to cause clockwise rotation of said assembly by said resilient means to urge said pawl into engagement with said notches.

3. Overload release means for preventing crimping pressures greater than a predetermined amount to be exerted on a connector being crimped by inwardly moving punches thereon, said means comprising an overload release plate releasably rotatable with one of said handles and operable to urge inward movement of said punches upon rotation of said plate, compression means releasably connecting said overload release plate to said handle whereby said handle may be moved without further rotation of said overload release plate when said crimping pressure on said connector has exceeded a predetermined amount to thereby limit further inward movement of said punches.

4. Overload release means for preventing crimping pressures greater than a predetermined amount to be exerted on a connector being crimped by moving punches thereon, said means comprising an overload release plate releasably rotatable with one of said handles and operable to urge inward movement of said punches upon closing of said handles, said overload release plate ceasing rotation when said crimping pressure on said connector has exceeded a predetermined amount to limit further inward movement of said punches, means releasably connect'mg said overload release plate to said handle comprising a bar pivotally connected to said handle and eX- tendmg downwardly, compression means yieldably urging said bar forwardly into operable engagement with said plate to thereby urge rotation of said overload release plate with said handle, sand compression means permitting rearward pivoting of said bar upon non-rotation of said overload release plate to thereby permit closure of said handle.

5. Overload release means for preventing crimping pressures greater than a predetermined amount to be eX- erted on a connector being crimped by radially moving punches thereon, said means comprising an overload release plate releasably rotatable with one of said handles and operable to urge inward movement of said punches upon rotation of said plate, compression means releasably connecting said overload release plate to said handle whereby said handle may be moved without further rotation of said overload release plate when said crimping pressure on said connector has exceeded a predetermined amount to limit further inward movement of said punches, said compression means comprising a bar pivotally connected to said handle and adapted to extend downwardly and slightly rearwardly, a telescopic plunger pivotally :onnected to said bar and adapted to resiliently urge said bar forwardly into engagement with said overload release plate to thereby urge rotation of said overload release plate with said handle, said plunger permitting rearward pivoting of said bar upon non-rotation of said overload release plate to thereby permit closure of said handle.

i *e References Cited UNITED STATES PATENTS 8/1965 Holmes et al. 72-410 8/1965 Holmes et al. 72-410 RICHARD I. HERBST, Primary Examiner.

R. D. GREFE, Assistant Examiner.

Claims

1. MEANS FOR ASSURING A PREDETERMINED MINIMUM CRIMPING ACTION HAS BEEN APPLIED TO A CONNECTOR COMPRISING A CRIMPING TOOL HAVING HANDLES FOR EFFECTING CRIMPING UPON CLOSURE THEREOF, RATCHET MEANS INTERCONNECTING SAID HANDLES, SAID RATCHET MEANS PERMITTING CLOSURE OF SAID HANDLES BUT NOT OPENING THEREOF UNTIL SAID HANDLES HAVE BEEN COMPLETELY CLOSED, SAID RATCHET MEANS PERMITTING OPENING OF SAID HANDLES UPON COMPLETE CLOSURE THEREOF, SAID RATCHET MEANS COMPRISING A RACK MOUNTED ON ONE OF SAID HANDLES WITH NOTCHES ON THE SURFACE THEREOF AND AN ABUTTING FACE AT EACH END OF SAID NOTCHES, A PAWL ASSEMBLY PIVOTALLY MOUNTED ON THE OTHER OF SAID HANDLES AND HAVING A PAWL ENGAGEABLE WITH SAID NOTCHES AND SAID ABUTTING FACES, SAID PAWL BEING PIVOTALLY DISENGAGED FROM SAID NOTCHES UPON ABUTMENT WITH ONE OF SAID FACES, RESILIENT MEANS MAINTAINING SAID PAWL OUT OF ENGAGEMENT WITH SAID NOTCHES UNTIL SAID PAWL ABUTS THE OTHER OF SAID FACES, SAID RESILIENT MEANS THEREAFTER MAINTAINING SAID PAWL IN ENGAGEMENT WITH SAID NOTCHES UNTIL SAID PAWL AGAIN ABUTS SAID ONE OF SAID FACES.