US2968043A - Hand tool for crimping electrical connectors onto conductors - Google Patents

Description

H. W. DEMLER Jan. 17, 1961 HAND TOOL FOR CRIMPING ELECTRICAL CONNECTORS ONTO CONDUCTORS Filed May 19, 1959 2 Sheets-Sheet l Jan. 17, 1961 w, DEMLER 2,968,043

HAND TOOL FOR CRIMPI'NG ELECTRICAL CONNECTORS ONTO CONDUGTORS Filed May 19, 1959 2 Sheets-Sheet 2 fi I 22, I

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:b i" INVENTOR. Henry M flem/er BY FM United States Patent HAND TOOL FOR CRIMPING ELECTRICAL CONNECTORS ONTO CONDUCTORS Henry W. Dernler, Lebanon, Pa., assignor to AMP Incorporated, Harrisburg, Pa.

Filed May 19, 1959, Ser. No. 814,339

Claims. (Cl. 1-215) Electrical connectors of the ferrule type may be cold forged onto conductors in various ways including actuation of crimping dies by explosive force. An application filed in the name of William F. Broske (CMS 123114-A), Serial No. 806,093, filed April 13, 1959, teaches the concept of actuating connector crimping dies by firing an explosive cartridge internally, i.e. with a primer located inside the cartridge.

It is an object of this invention to provide a tool such as referred to above which is compact, light-weight, and easily operated. It is also an object of this invention to provide such a tool having a firing mechanism which is spring loaded during the firing cycle, but is so designed that the spring loading mechanism is inactive during the crimping stroke. In previously known tools, the explosive force operates the dies so as to place the spring in tension and cause fatigue. The tool illustrated by the present invention is designed so that the spring is inactive during the crimping or explosive cycle.

It is a further object of this invention to provide such a tool wherein the tool can only be actuated by positive operation. In many of the explosive tools shown in the prior art, the tool may be placed in a cocked position before it is fired. Thus the possibility exists that the operator may cock the tool and then lay it down in this cocked position. However, in the tool shown in this application, the operator cannot cook the tool and leave it lying around, since the motion to put the tool into firing position must automatically cause the tool to be fired or else the spring means will cause it to return to its inactive position.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detaileddescription when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings;

Figure 1 is a perspective view of a tool embodying principles of this invention;

Figure 2 is a fragmentary View similar to Figure 1, partially broken away;

Figure 3 is a plan view taken along plane 3--3 of Figure 1;

Figure 4 is a sectional view taken along plane 4-4 of Figure 3;

Figure 5 is a sectional view taken along plane 5--5 of Figure 3.

As shown in the drawings, the basic unit of the tool comprises a O-shaped head 10, preferably a metal of ade- 2,968,043 Patented Jan. 17, test quate strength, with a pistol-grip type of handle 12 secured thereto (or integral therewith) at an angle to the longitudinal axis of the frame. Located in one bight of the inside surface of the head is a fixed die 14. An opening 16 in the head opposite the fixed die accommodates a slidable ram 18 with a movable die 20 on one end thereof. The dies 14 and 20 are thus operatively disposed and relatively movable to deform an electrical connector C placed therebetween (note Figure 3).

The opening 16 may be counter bored as to accommodate a firing chamber 21. Although the firing chamber 21 could be integral with the head 10, the preferred embodiment shows it as a separate piece from the frame so it may be made of material more suitable for a firing chamber, e.g. stainless steel. A lock nut 22 retains the firing chamber 21 in the frame. A threaded cap 24 fits over the end of the firing chamber 21, and has a spring loaded locking latch 26 pivoted thereto with a hook 27 on one end which fits into a detent 28 on the cap 2 t to form a releasable locking means. The internal bore of the firing chamber 21 accommodates an internally fired cartridge 30. This cartridge is described in a patent application filed February 17, 1959, in the name of William F. Broske, Serial No. 793,814. As set forth in the application, the cartridge assembly includes an internal plug 32, an explosive charge: 34 and a primer 36 located within the internal plug 32.

As shown in the drawings, the ram 18 is disposed internally of the cartridge 30. A detonating pin 38 is carried on the free end of the ram whereby movement of the ram in a direction toward the priming means causes the detonating pin to strike the primer 36 and thus detonate the cartridge.

An opening 40 in the head 10 (parallel to the opening 16) contains a shaft 42 slidably disposed therein. The shaft 42 has a pair of handles 44, 46 (Figure 1) projecting from one end thereof at right angles to the shaft. These handles may be used to grip the shaft in moving it back and forth. A hollow section 48 in the frame 10 accon1- modates a pair of levers 50 and 52. Lever St is pivoted at one end to the frame at 54 with its opposite end projecting into the path of the movable die 20. In its operative position, one side of the lever bears against the opening in the frame and the opposite side bears against the movable die 20. The second lever 52 is also pivoted within the frame at an intermediate point on the lever by means of a pivot pin 56. In its operative position, the point 58 of the lever bears against a shoulder 69 in the nonworking or rearward face of the movable die. As shown in Figure 3, these levers cooperate releasably to lock the die 20 in its contact or pro-fired position.

A first spring 62 is secured between the first lever 5i) and the tube 42 and is at rest in the position shown in Figure 3. A second spring 64 is secured between the pivot pin 54 and the bottom part of the lever 52 and is at rest when the levers 5d and 52 lock the die 2 in place. A tab 66 projects from the shaft d2 to provide an actuating means for the second. lever 52. As seen in Figure 4, a slot 67 in the tube 42 forms a track for the lever 50. Thus the tab 66 does not affect the lever but trips the lever 52 when moved rearwardly with the tube 42. A housing 68 is secured to one end of the C-shaped frame and has a pair of pivoted handles 79, each operating a pivoted arm 72 which grip the conductor and hold it in position during the crimping operation.

0perati0n.A connector C is inserted between the relatively movable dies 14 and 20. A conductor is inserted therein and hooked into place by the arms 72 on the housing 68. The cartridge 30 is inserted into the firing chamber 21 so that it encompasses one end of the ram 18. The cap 24 is threaded. and locked onto the back of the firing chamber. The die 20 is manually moved forwardly until it is locked between the levers 50 and 52. The tool is now ready to be fired.

In firing, the operator grips the handles 44, 46 in one hand and the piston grip 12 in the other. Pulling the handles rearwardly causes the shaft 42 to move in a direction away from the fixed die 14. With the lever 52 looking the movable die 20 against rearward action and the movable die 20 holding the lever 50 against rearward action, the motion of the shaft 42 serves to extend the spring 62 and place it in tension. When the spring as is fully extended, the tab 66 trips the bottom portion of the lever 52 and causes it to rotate counter-clockwise. When the lever 52 is rotated counter-clockwise, the ram 18 and movable die 20 is released. The spring contacts moving the lever 50 against the die 20 to drive the die 2% and ram 18 in a rearward direction toward the primer 36. The lever 50 moves clockwise out of the path of travel of the die 29. Rearward travel of the die 20 and the ram 18 causes the detonating pin 38 to be impacted against the primer 36. This explodes the primer and, in turn, combustion of the charge 34 drives the ram 18 and die 20 forwardly toward the conductor and the connector to crimp them together by cooperation of the die 14 and the die 20. It is noted that in the forward travel of the ram, both levers t} and 52 are out of the path of the die. The connector and conductor are then removed from the die and the spent cartridge is also removed.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. A tool for crimping electrical connectors including: a first die, a second relatively movable die cooperating with the first die to crimp a connector therebetween, explosive means for operating said relatively movable die, means for detonating said explosive means including a first pivoted lever adapted to urge the movable die toward the explosive means, a ram on said movable die adapted to strike the explosive means with the necessary detonating force, a spring means for urging said lever against said die in a direction calculated to drive the die and the ram against the explosive means, and releasable means for restraining the die until the spring is loaded to a predetermined amount.

2. A tool of the character described having an explosive means therein, including a movable member capable of moving longitudinally in one direction to accomplish work, and in the opposite direction to detonate the explosive means, means for urging said member in a direction to detonate the explosive means, said means including a pivoted lever bearing against the movable member, spring loaded means for actuating the lever in a direction calculated to drive the member in the explosive detonating direction, and releasable locking means for retaining said movable member in fixed position until the spring is sufiiciently loaded so as to drive the member into the explosive detonating position with sufficient force to detonate the explosive.

3. A device for firing an internally fired cartridge operated tool having a pair of cooperative, relatively movable dies including: a lever pivoted at one end, the free end of the lever bearing against the movable dies, a second lever pivoted intermediately of its ends with one end bearing against the opposite side of the movable die, a spring biased lever with one end projecting into the path of said die, a spring-loaded member movable longitudinally toward the spring-biased end of the lever, means on said member for causing actuation of the second lever into a position wherein it is displaced from the path of the movable die, and spring means on the said movable member between the movable member and the first lever, said spring means adapted to be stretched to a predetermined degree to cause the first lever to actuate the movable die after the second lever has been displaced from the path of the movable die.

4. An explosively-operated device for performing useful work including a frame member, a handle on said frame, a pair of relatively slidable dies positioned in said frame, means in said frame for generating an explosive force, one of said dies having a ram secured thereto with a detonating pin on the free end of the ram, said ram movable toward said means for generating an explosive force, and means for driving said die in a direction whereby the detonating pin is driven against the means for generating an explosive force to detonate it at the end of the stroke, said means for driving said die being inoperative unless actuated with sutficient force to cause the die and ram to be driven rearwardly to the full extent of their stroke.

5. A tool for crimping electrical connectors onto conductors, including a C-shaped frame, a handle secured to said frame, a pair of relatively movable dies within the C of the frame, a ram on at least one of said dies, said ram extending into the frame, a detonating chamber in said frame adapted to receive one end of said ram and to permit said ram to slide longitudinally therein as to the die is moved longitudinally, means for actuating said movable die including a pair of levers, said first lever pivoted at one end with the opposite end bearing against the working face of the die, said second lever pivoted intermediate its ends with one arm bearing against the nonworking face of the movable die and spring-biased into the path of the die, a spring means secured intermediate the ends of said first lever, the other end of said spring being secured to a spring operating means, said spring operating means actuatable to place the spring under a predetermined tension, and means on said spring operating means for tripping the second lever after the spring operating means has placed the spring under the predetermined tension, whereby the spring operating means loads the spring means to the predetermined degree, and the second lever is swung out of the path of the die to release the die for rearward travel, thus causing the spring means to pivot the first lever against the movable die to drive the movable die toward the detonating means.

No references cited.

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