US2762414A - Crimping device - Google Patents

Description

p 1956 H. w. DEMLER 2,762,414

CRIMPING DEVICE Filed NOV. 3, 1953 THEN. T1

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INVENTORI /%-/m=r W 55/1115? ATTORN 5.

United States Patent CRIMLPING DEVICE Henry W. Demler, Lebanon, Pa., assignor to Aircraft- Marine Products, Inc, Harrisburg, Pa., a corporation of New Jersey Application November 3, 1953, Serial No. 389,983

7 Claims. (Cl. 153-1) This invention relates to tools for crimping electrical connectors or terminals onto wire conductors, and more particularly to a universal crimping device adaptable by a single easily made adjustment to crimp a range of sizes of connectors and wires. A die assembly including a plurality of spaced dies is turned to different positions enabling a single device to be used to crimp various sizes 1 crimping operation is, driventoward a second rotatable die assembly which carries several dies of different sizes each arranged at spaced angular positions about a rotatable pivot member coupled to the second die assembly. Any one of these spaced dies may be turned-so as to oppose said first die assembly. The device is quickly adjusted for diflerent sizes of wires and connectors by positioning the rotatable die assembly about'the rotatable member so as to present a difl'erent die surface-to the first die assembly.

Among the advantages of the described device is the fact that the rotatable die assembly is backed up by an arcuate abutment member against which the die assembly lies during crimping operation and which acts to relieve the pivot member of the strain caused by the relatively large forces developed during a crimping operation.

Advantageously, the first die assembly may include a die piece of the so-called universal type whereby it can be operated with all of the diiferent'dies in the second die assembly.

Among the objects of the present invention are to provide a relatively simple rugged universal crimping device and ,to provide one which is quickly and easily adjusted.

A further object of the present invention is'to provide a handy crimping head which is adapted for use on various sizes of conductors and connectors, and which holds the dies in accurately opposed position so as to produce connections having a high mechanical strength and good electrical conductivity. Another object of the invention is to enable rotatably adjustable die assemblies to be used for crimping large sizes of wires and connectors wherein the forces used during a crimping operation are large.

The present invention is described as embodied in a universal crimping tool head adapted to be actuated by hydraulically or pneumatically developed force. For example, the universal headdescribed is adapted for use on hand-operated tools of the pump up type such as used by linemen and is adapted for use on crimping machines in fixed installations such as used for production. Also, it will be understood that the invention maybe embodied in a universal crimping head adapted to be actuated by a mechanical force-multiplying leverage system, such as a hand tool of the toggle-action type.

Various other aspects and advantages of the present invention will be in part pointed out and in 'part ap parent from the following description considered in conjunction withthe accompanyingdrawings, inwhich:

Figure 1 -is-a side elevational view of a universal crimping head embodying the present invention, with portions broken away to show the construction;

Figure 2 is a cross sectionalview taken along the ir regular line 2-2 in Figure 1; and

Figure 3 is a fragmentary view of the adjusting knob and side of the tool adjacent the knob.

The embodiment of the tool head 10, as illustrated, includes dies of the type for forming electrical connections by crimping a ferrule portion 11 of a connector around a bared portion 12 of an electrical conductor. This head 10 has a first movable die assembly 13 shown in fully retracted position in Figure 2 and including a die piece 14 and a die-holding piston ram 15. During crimping action therdie piece is driven by the ram 15 toward a 'secondrotatable die assembly 16 mounted by a pivot shaft 18 in a 'latchable jaw portion, generally indicated at 19,-an'd extending across the top of the head in the path of the first die assembly.

Jaw portion 19 is pivoted by a pin hinge 21 on one side so as to-swing open for handy insertion of the connector and conductor, and alatch 22 on the other side holds the jaw closed after the work is inserted. This hinge 21 and the latch 22 together with the jaw portion 19 in effect form a yoke which is astride the'path of die assembly 15. Thus, as the die piece 14 is driven against themetaLof the ferrule 11 and wire 12, the thrust exerted on die assembly 16 is distributed to both sides of the yoke and is borne about equally by hinge 21 and latch 22 so that die assembly 161's held firmly and accurately in a properly centered-position with respect to the advancing die piece 14. The resulting crimp obtains optimum cross sectional formand optimum strength and electrical conductivity.

As seen in side elevation in Figure 1, the frame of the jaw portion 19 has an inverted U-shape and includes two side plates 24 joined at the top by a cross piece 26 so as toform a pocket in which the rotatable die assembly 16 is held in firmly aligned position. In effect this U-shape of the jaw frame forms a second yoke, further strengthening the head structure and acting to center accurately .the :transverseposition of the die assembly 16 with respect'to dieassembly 13.

The die assembly 16 is keyed to its shaft 18 by a suitable locking means 28, such as a set screw, and the ends of the shaft extend through bearing holes in the side plates 24. One end is headed by an upset portion 30, and on the other end is a knurled knob- 32 fastened to the shaft by locking means 34 such as a set screw. By twisting'this knob the die assembly is quickly and easily rotated to any one of its three operating positions.

To :hold die assembly 16 accurately positioned in any one ofits three operation positions and 'to enable quick adjustment three spring-loaded locating pins 36 are provided, resting in equally spaced'holes in side plate 24 adjacentknob 32. The inner ends of pins 36 are rounded and cooperate with three recesses 38 located in one side of die assembly 16 equally spaced about pivot shaft 18. An actuating spring 40 for the locating pins surrounds the shaft 13 and .is housed in the hollow underside of knob 32. Spring 40 presses a washer 42 against the outer ends .of these three locating pins to provide the spring bias.

As'shoWnin Figure 3, in order to aid in the quick adjustment of the rotatable die assembly, knob 32 may include a suitable index mark 43 such as an etched arrow, and :the outer face '44 of the jaw frame plate 24 may have three equally spaced numerals indicating-the various sizes of dies in die assembly 16 and the position to which it should be turned to place the corresponding die in operating position opposite die piece 14.

As shown, the rotatable die assembly is of a generally disk shape and includes three nest dies 45, 46, and 47 formed in its cylindrical periphery 48 at equally spaced points and in the head shown here are of sizes to accommodate, respectively, an American Wire Gauge N0. 2, No. 4 or No. 6 wire and the corresponding size of connector ferrule.

Each of these nest dies includes a concave die surface having cylindrical bottom surface 50 and a mouth formed by a pair of outwardly divergent planar side walls 51 tangent to the bottom surface with a pair of flat clearance surfaces or shoulders 52 adjacent the mouth of the die, which act as bottoming stops for die assembly 13 to limit the extent of entrance of the protuberances 49 on die piece 14 into each of the nest dies. When die assembly 13 has reached its fully extended or fully crimped position, the shoulders on die piece 13 adjacent protuberances 49 abut against stops 52. The radial depth between the respective bottoms 50 of nest dies 45, 46 and 47 and these stops 52 differs with each size nest, being approximately proportional to the size of the mouth of the nest, in order to accommodate the various amounts of metal in the cross sections of the various sizes of wires and connector ferrules. Advantageously, the stops 52 automatically provide the proper amount of cold working and axial extrusion of this metal and act to stop the die piece 14 at the desired position regardless of which of the nest dies 45, 46, or 47 is turned to operative position opposite the die assembly 13. Thus, optimum crimp shape, strength and conductivity are obtained. Also, with this stop arrangement the operator can see and be certain that die piece 14 is fully bottomed against die assembly 16 before ceasing the crimping operation.

The arcuate lengths of the portions of the cylindrical periphery 48 of the die assembly between adjacent nest dies are approximately the same in spite of the different sizes of the mouths of the nest dies because the lengths of the flat stop surfaces 52 are approximately inversely proportional to the widths of the mouths of the die surfaces. Thus, substantially the same amount of load bearing peripheral surface 48 is available diametrically opposite each of the concave die surface 45, 46, and 47, which is important as explained below.

Thus, for example, as shown in Figure 2, with the largest die 45 in the die assembly turned to operative position opposite die piece 14, a load-bearing surface 48 rests against the arcuate face of an abutment 53 formed by a pillow block fastened to the cross piece 26 so as to back up die assembly 16. When the die assembly is turned to another position, a corresponding peripheral surface 48 lies against the cylindrical face of abutment 53 to transfer to the abutment the thrust from die assembly 13. The cross piece 26 extends directly across the path of the die assembly 13 at right angles thereto so that the thrust of the die assembly 13 is equally distributed to the two jaw frame side plates 24. Abutment pillow block 53 is secured to cross piece 26 by fastening means 54 shown as a machine screw and lock washer.

In order to provide the desired axial length (i. e. length parallel to shaft 18) of the nest dies 45, 46, and 47 both sides of the disk are milled oif to the same extent near each nest die along segments spanning the full width of each of the nest dies. This milling operation leaves an equilateral triangular area in the center of the die assembly as seen in Figure 2. The milled segments (only one is seen in the drawing) spanning both ends of the smallest die 47 are deepest, leaving die 47 with the shortest axial length. The milled segments spanning die 46 are of intermediate depth, and the segments spanning die 45 are quite shallow, as seen in Figure 1, leaving the greatest axial length for nest die 45.

The die piece 14 has a die surface of the so-called universal W-crimp indenter shape, which is adapted for use with any one of the three nest dies 45, 46, and 47. This type of indenter is more fully described in the copending application of Kerchner et al., Serial No. 250,840, filed October 11, 1951, and assigned to the same assignee as the present application. It will be understood that by using a die assembly 13 with a different sized die piece and by using a rotatable die assembly 16 with a diflerent range of sizes of nest dies, a tool head such as shown is then adapted for a different range of sizes of connectors and wires.

A latch spring 58 urging latch 22 toward closed position is inserted between a spring socket 60 in one side of the abutment block 53 and a socket 62 in the top end of the latch 22. As indicated by the invisible line (Figure 2) and as seen in Figure 3, the jaw side plates 24 each have rounded triangular projections 64 on the latch side of the jaw. The latch 22 fits between these projections 64 and has a latch pivot pin 66 passing through them. Thus, latch 22 and pin 66 anchor firmly both sides of the second yoke described above as formed by sides 24 and cross piece 26, also anchoring one side of the yoke formed by latch 22, jaw portion 19 and hinge 21.

To provide a stop and to widen the area of engagement of the latch hook 68 with the corresponding hook 70 on the head of the tool, thus more firmly aligning the die assemblies when the jaw is closed, the bottom end of latch piece 22 is widened just below the side projections 64, forming a shoulder stop 72 which acts to prevent latch piece 22 from swinging too far inwardly when jaw 19 is swung open about its hinge 21. As seen in Figure 2, the hook portion of the latch extends down below hinge 21 so that as the jaw swings closed, latch hook 68 tends to follow an arcuate path so as to swing inward ly toward the outer face of hook 70, which strikes the face of hook 68, allowing book 68 to slide down and spring in to engaged position. Thus, both hooks are enabled to have flat outer surfaces, providing greater strength because a greater amount of metal is positioned behind each of the engaged hooked surfaces than is the case if either outer hook face is inclined. Yet this arrangement provides automatic latching upon closure of the jaw. The top of latch 22 near spring 58 projects out beyond jaw sides 24, providing a tab so the operator can readily unlatch the jaw by depressing this tab.

On the opposite side of jaw 19 from the latch, a pair of hinge plates 74 project down and engage jaw hinge 21. Plates 74 extend down between a pair of supporting members 76 upstanding from the body 77 of the head of the tool and anchoring both ends of pin 21. Thus, supports 76, hinge 21, and plates 74 anchor both sides of the inverted U-shaped yoke described above an anchor one side of the first yoke formed by latch 22, jaw portion 19 and hinge 21. An inclined recess 78 between supporting members 76 provides a stop when the jaw is swung fully open.

During operation, hydraulic fluid is pumped through an inlet 79 into a ram chamber 80 within a cylinder wall 81. This fluid acts on the bottom face of the piston ram 15, driving it upwardly and forcing die piece 14 toward the opposed nest die, here shown as die 45. Die piece 14 is held on ram 15 by a stem 82 which slides into a hole 83 in the ram wherein a spring-biased detent 84 engages a groove in the stem. The die piece is prevented from turning in ram 15 by its rear surface which engages a channel 86 extending across the front of the ram. The whole die assembly 13 is prevented from turning by a pm key 88 engaging a slot in the side of ram 15 as shown 1n F gure l. A spring 90 returns die assembly 13 to its starting or retracted position when a crimping operation 1s complete and the fluid pressure is released.

A pair of leather washers straddling an O-ring 92 in a groove around the ram 15 provide a seal against cylinder wall 81 to prevent the passage of fluid. Another O-ring 93 in inlet 79 provides a seal with a mating nipple portion of a source of hydraulic pressure such as hand tool or machine with a gland nut into which the threads on neck 94 of the head can be screwed.

As shown in Figure 2, the body portion 77 of head is screwed down into threads 95 inside the top of cylinder wall 81 until the body binds against the top edge of cylinder wall 81, forming a unitary head structure. It will be understood by a person skilled in the art that the described head 10 may be connected to the handles of a hand tool also by use of the threads 95 instead of those on neck 94. For example, threads 95 of body 77 may be screwed into the collar 112 of the crimping device shown in Figure 3 of the copending application, Serial No. 315,059, filed October 16, 1952, in the name of Herbert C. Stoltz, and assigned to the same assignee as the present invention. With this assembly the piston ram has the grooved portion holding O-ring 92 reduced in diameter to fit within the cylinder 21 shown in the Stoltz application.

I claim:

1. A crimping device including a first die assembly movable along a path, a second die assembly,.a plurality of spaced dies carried by said second die assembly, each of said spaced d ies having a different angular position about said second die assembly, a rotatable mounting for said second die assembly, whereby said second die assemblycan be turned into various angular positions with respect to the path of said first die assembly to present various ones of said spaced dies toward said path, said second die assembly having a plurality of load-bearing surfaces intermediate said spaced dies, an abutment member adjacent said second die assembly, locating means arranged to hold said second die assembly in said various angular positions with various ones of said dies toward saidyath and with various ones of said load-bearing surfaces adjacent said abutment member, whereby during crimping operation said rotatable mounting is relieved of a portion of the forces exerted by said first die assembly on said second die assembly, and force-exerting means arranged to move said first die assembly along said path to bring said die assemblies together.

2. In a tool for crimping connectors onto wire wherein a first and a second die assembly are driven along a path toward one another during a crimping operation, apparatus enabling the tool to be used with a range of sizes of wires and connectors comprising: a first die assembly, a yoke-shaped frame member, a second die assembly rotatably mounted within said frame member in position to straddle the path along which said die assemblies are driven toward one another, whereby to hold said second die assembly firmly and accurately in said path, force-exerting means coupled at least to one of said die assemblies to drive them together, said second die assembly incuding a plurality of die surfaces angularly arranged with respect to its center of rotation, stop means for said first and second die assemblies effective to limit to a predetermined distance the relative movement of said first die assembly toward each said die surfaces upon being turned toward said path and locating means associated with said frame member and said rotatable die assembly and arranged to lock said rotatable die assembly in any one of a plurality of positions in each of which positions one of said die surfaces on said rotatable die assembly is presented to said first die assembly and held in opposed relationship thereto when said die assemblies are driven toward one another.

3. A crimping device adapted to be used for crimping various sizes of wires and connections including first and second die assemblies, a plurality of spaced dies of graduated sizes on said second die assembly, said second die assembly having a generally circular configuration, a rotatable mounting for said second die assembly whereby said second die assembly can be turned to various angular positions to present various ones of said spaced dies toward said first die assembly, said second die assembly having a plurality of arcuate load-bearing surfaces of thesame curvature, eachof said load-bearing surfaces corresponding withone of said spaced dies, load-bearingabutment means having an arcuate surface also of the same curvature associated with said second die assembly, locating-means to hold said second die assembly in said various angular positions with various ones of said spaced dies facing said first die assembly and with corresponding .ones of saidarcuate load-bearing surfaces adjacent the arcuate surface of said load-bearing abutment means, and forceexerting means to bring said first and second die assemblies toward each other with said abutment means behind said second die assembly.

.4.,In a .tool for crimping connectors onto wire wherein afirst and,. a second die assembly are driven along: a path toward one anotherduring a crimping operation, app ratus enabling the tool to be used with a range of sizesof wires and connectors comprising; a first die assembly, a yoke-shaped frame member straddling the path along whichsaid die assemblies are driven toward one another, a senor 1d die assembly mounted within said frame member whereby said yoke member holds said second die assembly firnily and accurately in saidpath, force-exerting means coupled at least to one of said die assemblies to drive them together, a plurality of spaced dies of graduatedsizes on said second die assembly, said second die assemblyhaving a generally circular configuration, said second die assembly being rotably mounted within said frame member .whereby said second die assembly can be turned to various angular positions to present various ones ofsaid spaced dies toward saidpath, saidsecond die assembly having a pluralityof arcuate load-bearing sur' faces of the same curvature, each of said loadebearing surfacescorresponding with one of said spaced dies, loadbearing abutment means in said frame member on the oppositesigle of said second die assembly from said path, said abutment means having an arcuate surface also of the same curvature adjacent said second die assembly, and locating means to hold said second die assembly in said various angular positions with various ones of said spaced dies facing said path and with corresponding ones of said arcuate load-bearing surfaces adjacent the arcuate surface of said load-bearing abutment means.

5. In a tool for crimping connectors onto wire wherein a first and a second die assembly are driven along a path toward one another during a crimping operation, apparatus enabling the tool to be used with a range of sizes of wires and connectors comprising: a body, a first die assembly carried by said body, a double-yoke-shaped frame member including first and second yokes extending across said path at right angles to each other, a second die assembly rotably mounted within both of the yokes in said frame member whereby said member holds said second die assembly firmly and accurately in said path, force-exerting means coupled at least to one of said die assemblies to drive them along said path toward one another, a plurality of spaced dies of graduated sizes on said second die assembly, said second die assembly having a generally circular configuration, said second die assembly being rotable whereby said second die assembly can be turned to various angular positions to present various ones of said spaced dies toward said path, said second die assembly having a plurality of arcuate load-bearing surfaces of the same curvature, each of said load-bearing surfaces corresponding with one of said spaced dies, load-bearing abutment means within both of the yokes in said frame member on the opposite side of said second die assembly from said path, said abutment means having an arcuate surface also of the same curvature adjacent said second die assembly.

6. In a tool for crimping wires or connections wherein first and second die assemblies are driven along a path toward one another during a crimping operation, apparatus enabling the tool to be used with a range of sizes of wires and connections comprising: a body, forcegenerating means, a first die assembly coupled to said force-generating means to be driven from an initial position in said body along a path during crimping operation, a yoke-shaped frame member extending across said path, a hinge for said frame member on one side of said path connecting said yoke to said body, a hook-ended latch pivotally mounted on the other side of said frame member from said hinge, with said latch in closed position the hook end of said latch reaching in a direction parallel to said path further toward said initial position than the position of said hinge, a hook on the opposite side of said body from said latch, said hook having a first lip and a pair of flat faces each face extending parallel with said path and facing away from said path, and the hook end of said latch having a second lip and a pair of fiat faces, which faces in closed latch position abut against the respective faces of said hook with said first and second lips engaging, a second die assembly rotatably mounted on said frame member and held in the path of said first die assembly when said latch is closed, said second die assembly including a plurality of die surfaces angularly arranged with respect to its center of rotation.

7. In a tool for crimping connectors onto wire wherein a first and a second die assembly are driven along a path toward one another during a crimping operation, apparatus enabling the tool to be used with a range of sizes of wires and connectors comprising: a body, a first die assembly movably carried by said body, force-exerting means adapted to drive said first die assembly along a path, a yoke-shaped frame member, a hinge for said frame member, hinging it to said body on one side of said path, a latch for said frame member adapted to latch it in a position extending across said path, a second die assembly, a pivot shaft rotably mounting said second die assembly within said frame member whereby said member when latched holds said second die assembly firmly and accurately in said path, a plurality of spaced dies of graduated sizes on said second die assembly, said second die assembly having a generally circular configuration, a control member on said shaft for rotating said second die assembly, whereby said second die assembly can be turned to various angular positions to present various ones of said spaced dies toward said path, an indication scale associated with said control member to show the angular positions of said spaced dies, said second die assembly having a plurality of arcuate load-bearing surfaces concentric around said pivot shaft, each of said load-bearing surfaces corresponding with one of said spaced dies, load-bearing abutment means within said frame member on the opposite side of said second die assembly from said path, said abutment means having an arcuate surface of the same curvature adjacent said second die assembly, and locating means to hold said second die assembly in said various angular positions with various ones of said spaced dies facing said path and with corresponding ones of said arcuate load-bearing surfaces adjacent the arcuate surface of said load-bearing abutment means.

References Cited in the file of this patent UNITED STATES PATENTS 866,505 Naysmith Sept. 17, 1907 1,563,941 Wickmann Dec. 1, 1925 1,715,496 Faure June 4, 1929 2,113,087 Jensen Apr. 5, 1938 2,662,574 Franck Dec. 15, 1953 2,693,216 Kerchner Nov. 2, 1954 FOREIGN PATENTS 431,954 France Nov. 24, 1911 172,272 Austria Aug. 25, 1952

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