Crimping Tool

Abstract

A tool for crimping tubular or sleevelike connectors onto electrical conductors and comprising relatively fixed die means adapted to operatively support a connector during a crimping operation, first and second relatively movable die means adapted to independently cooperate with the fixed die means to crimp a connector therebetween, explosive means for moving the relatively movable die means from deactuated to actuated positions, means for detonating the explosive means, and means for biasing the relatively movable die means toward their respective deactuated positions.

Description

BACKGROUND OF THE INVENTION

It has heretofore been proposed to secure tubular or sleevelike connectors fabricated, for example, of aluminum or a similar electrically conductive material, onto electrical conductors or wires by means of crimping dies which are actuated by an explosive force. Typical examples of heretofore known and used devices are shown in U.S. Pat. No. 2,968,043, for Hand Tool For Crimping Electrical Conductors, and No. 3,062,260 for Explosively Actuated Press. Although such prior art crimping devices have been found to operate satisfactorily when crimping two wires of substantially the same diameter or gage, the effectiveness of such devices has been doubtful when they have been used to connect wires of different sizes, due primarily to the fact that a common crimping die was used to crimp a connector sleeve into operative engagement with each of the different size wires. Such heretofore known and used crimping devices have also been objectionable from the standpoint that they were frequently of a relatively complicated and bulky construction, thereby preventing convenient manipulation, actuation and storage thereof.

Generally speaking, the present invention is directed toward a new and improved crimping tool which overcomes the above undesirable features of similar-type tools known in the prior art. More particularly, the crimping tool of the present invention is characterized by the provision of a pair of independently movable crimping devices that are actuable in response to an explosive force to move toward and into engagement with the electrical connector to be crimped. .By virtue of the fact that the aforesaid dies are independently movable, each end of the connector is compressed to the limit of the force applied, regardless of the force applied to the opposite end thereof. Accordingly, a positive and effective electrical connection is achieved between each end of the connector and the associated electrical conductor, even though the two conductors may be of different sizes. The crimping tool of the present invention is further characterized by an extremely simple design which renders itself to economical manufacture, convenient assembly and a minimum amount of maintenance, with the result that the tool is desirable not only from the standpoint of being effective in operation, but also by having a long and durable operational life and being economical to commercially produce.

SUMMARY OF THE INVENTION

This invention relates generally to crimping tools and more particularly, to a new and improved crimping tool of the type adapted to crimp tubular or sleevelike metallic connectors to electrical conductors.

Accordingly, it is a general object of the present invention to provide a new and improved crimping tool.

It is another object of the present invention to provide a crimping tool of the above-described type that is lightweight and compact in size so as to permit use thereof in relatively confined areas.

It is a more particular object of the present invention to provide a crimping tool of the above-described type which utilizes a blank explosive cartridge as a source of power, thereby eliminating the use of physical strength, long and bulky handles and/or hydraulic or electrical actuating mechanisms.

It is another object of the present invention to provide a crimping tool which is extremely fast acting so as to produce a cold welding effect between the electrical conductors and the connectors being crimped thereto, with the result that an effective electrical connection is provided therebetween.

It is still another object of the present invention to provide a crimping tool which utilizes a pair of independently movable pistons which provide for effective crimping of the associated connector to wires of different diameters.

It is a further object of the present invention to provide a crimping tool of the above-described type wherein the crimping device functions to confine the explosive actuating means so as to assure complete ignition thereof.

It is another object of the present invention to provide a new and improved crimping tool which utilizes a novel spring clip arrangement for positively securing the electrical conductors to the tool during a crimping operation so as to prevent inadvertent movement of the wires relative to the tool.

It is still another object of the present invention to provide a crimping tool of an object extremely simple design, and which is therefore economical to manufacture and easy to assemble.

Other objects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of a crimping tool in accordance with a preferred embodiment of the present invention;

FIG. 2 is a cross-sectional view of the crimping tool illustrated in FIG. 1, as taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is an end elevational view of the crimping tool shown in FIGS. 1 and 2 ;

FIG. 4 is a side elevational view of a modified form of the spring clip means utilized to secure electrical conductors to the crimping tool during a crimping operation, and

FIG. 5 is an exploded perspective view of an electrical connector and a pair of conductors which may be secured together via the connector upon operation of the crimping tool of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

For purposes of clarity, the terms "inwardly," "outwardly" and derivatives thereof will have reference to the geometric center of the crimping tool of the present invention and the various component parts thereof. Similarly, the terms "forwardly," "rearwardly" and the like will have reference to the present invention and the component parts thereof shown in FIGS. 1 and 2, with the forward end of the tool being located at the right side of these Figures.

Referring now in detail to FIG. 1 of the drawings, a crimping tool 10, in accordance with a preferred embodiment of the present invention, is shown as comprising a longitudinally extending annular or tubular housing 12 which defines a generally cylindrical-shaped cavity 14 therewithin. The forward and rearward ends of the housing 12, around the inner periphery thereof, are threaded, as seen at 16 and 18, respectively, and the housing 12 is formed with a series of radially outwardly extending vent apertures, generally designated 20, around an intermediate portion thereof. An annular shroud or shield member 22 extends around the outer periphery of the housing 12 at a position longitudinally aligned with the apertures 20. As illustrated, the shield 22 comprises a mounting section 24, which may be secured by any suitable means around the periphery of the housing 12, and a longitudinally extending sleeve section 25 that is spaced radially outwardly from the periphery of the housing 12 and defines an annular passageway 26 therewith which communicates with the apertures 20, for reasons later to be described.

The rearward end of the housing 12 is provided with a breechblock 28 which comprises an annular, externally threaded section 30 adapted to be threadably mounted within the threaded portion 16 of the housing 12. The breechblock 28 also comprises a rearwardly extending, reduced-diameter, externally threaded support section 32 that is arranged coaxially of the section 30 and defines a longitudinally extending bore 34 therewith. The rearward end of the bore 34 is counterbored, as seen at 36, and is adapted to have a suitable explosive cartridge 38 such as, for example, a 0.22 caliber rimfire blank cartridge or the like, disposed therein, with the cartridge rim being received within the counterbore 36, as illustrated.

The support section 32 of the breechblock 28 is adapted to function in operatively supporting an elongated receiver member 40 upon the tool 10. As best seen in FIG. 1, the receiver 40 comprises an annular collar section 42 that is internally threaded and is adapted to be threadably mounted upon the support section 32 of the breechblock 28. The receiver 40 also comprises a rearwardly extending firing pin support section 44 that defines a longitudinally extending cylindrical bore 46 therewithin. The forward end of the bore 46 is communicable with the rearward end of the counterbore 36 by means of a longitudinally extending slot 48 formed in the receiver 40 intermediate the sections 42, 44 thereof. Disposed within the bore 46 is a reciprocable firing pin, generally designated 50, that comprises an annular guide section 52 which is designed to be slidably received within the bore 46. Extending forwardly from the guide section 52 and integrally connected thereto is a cartridge engaging pin section 54 which is adapted to slide longitudinally within the slot 48 and engage the rim of the cartridge 38 located in the breechblock 28. Extending rearwardly from the guide section 52 of the firing pin 50 is a longitudinally projecting actuating section 56 which projects out the rearward end of the receiver 40 and is provided with a manually engageable, externally serrated knob 58. An actuating spring 60 extends circumjacent the firing pin section 56 interjacent the rearward side of the guide section 52 and a retaining nut 62 that is threadably mounted within the rearward end of the bore 46. Briefly, in operation of the crimping tool 10, the operator grasps the firing pin 50 by the knob 58 thereof and pulls the pin 50 rearwardly against the resistance of the spring 60. Thereafter, the operator will release the knob 58 and the firing pin will be biased forwardly under the influence of the spring 60, with the result that the section 54 thereof will engage the rim of the cartridge 38 to effectuate ignition thereof.

The forward end of the crimping tool 10 of the present invention is provided with a female die member, generally designated 64, which comprises a longitudinally extending section 66 that terminates at its forward end in an arcuately upwardly extending section 68 defining a semicylindrical recess 70 that extends transversely to the longitudinal axis to the tool 10. The recess 70 is defined by a radius which is the same or slightly larger than the radius of the connectors which are to be crimped upon operation of the tool 10 , whereby the connectors may be received within the recess 70 in the manner shown in FIG. 1. The end of the die section 66 opposite the section 68 is integrally connected to an annular mounting section 72 which is externally threaded and is thereby adapted to be threadably mounted within the threaded section 18 of the housing 12, as illustrated, whereby to secure the die member 64 to the tool 10. The mounting section 72 is formed with a pair of longitudinally extending, spaced parallel bores 74 which function in a manner hereinafter to be described.

The crimping tool 10 is provided with a pair of male die members which are preferably identical in construction and generally designated by the numeral 76. Each of the die members 76 comprises a generally cylindrically shaped, longitudinally extending section 78 adapted to be slidably received within one of the bores 74. Each of the die members 76 also comprises a head section 80 on the forward end thereof, the sections 80 being slightly larger in diameter than the die sections 78 and defining laterally aligned arcuate face portions 82 which are of a generally complementary shape with respect to the electrical connectors which are to be crimped during operation of the tool 10.

As best illustrated in FIG. 2, the rearward ends of the male die sections 78 are operatively connected to a pair of piston members, generally designated 84, which are longitudinally slidably disposed within the cavity 14. Means in the form of suitable connecting pins or the like 86 are preferably utilized in securing the die members 76 to the piston 84 against relative movement therebetween. By virtue of the above-described construction, longitudinal movement of the piston members 84 within the cavity 14 will result in simultaneous movement in the same direction of the die members 76 toward and away from a connector located in the recess 70 of the female die member 64.

The piston members 84 and male die members 76 are adapted to be normally retained in a deactuated or retracted position, as seen in FIGS. 1 and 2, by means of a plurality of return springs, generally designated 88, that extend longitudinally within the cavity 14. The rearward ends of the springs 88 are received within suitable longitudinally extending bores 89 formed in the forward ends of the pistons 84, and the forward ends of the springs 88 are mounted circumjacent the rearward ends of a plurality of guide pins 90 fixedly mounted on the rearward side of the mounting section 72 of the female die member 64. In operation of the tool 10, the pistons 84 and die members 76 move forwardly against the resistance of the springs 88 to provide the desired crimping action on a suitable connector mounted within the recess 70, and upon completion of the crimping operation, the springs 88 function to bias the pistons 84 and male die members 76 rearwardly to a position wherein the rearward sides of the pistons 84 abuttingly engage the forward side of the breechblock section 30. A particular feature of the above construction resides in the fact that the rearward sides of the pistons 84 function to close or confine the forward end of the bore 34 within which the cartridge 38 is operatively mounted. This assures that the cartridge 38 will be confined within a relatively small volume upon initial ignition thereof so as to provide for complete and efficient combustion of the powder charge contained therein.

Mounted on the opposite sides of the female die member 64 and projecting outwardly therefrom is a pair of spring clip members, generally designated by the numeral 92. Each of the members 92 is of a generally U-shaped configuration, as seen in FIG. 3, and comprises a pair of spaced parallel leg sections 94, 96 and an intermediate section 98 extending therebetween. The members 92 are fixedly secured to the laterally outer sides of the female die member 64 by means of a plurality of inwardly projecting mounting screws, generally designated 100, which extend through the intermediate sections 98 of the members 92 and are received within suitable interiorly threaded bores 102 in the die member 64. The leg sections 94, 96 of the spring clip members 92 are cut away , as best seen at 103 in FIGS. 2 and 3, whereby to define a pair of arcuately inwardly converging conductor-engaging sections 104 between which suitable wire conductors may be inserted and positively retained preparatory to and during a crimping operation. By virtue of the arcuate configuration of the sections 104, once a wire conductor has been inserted therebetween, it will be positively retained in place during the crimping operation, thereby assuring against any relative movement of the conductor with respect to the electrical connector during the crimping operation.

FIG. 4 illustrates an alternate embodiment of the spring clip means shown in FIGS. 1 through 3 for securing wire conductors to the crimping tool 10 of the present invention. More particularly, FIG. 4 illustrates a spring clip means, generally designated 108 and comprising a generally laterally extending support member 110 adapted to be secured to the female die member 64 by any suitable means. Extending upwardly from the support member 110 is a securing block member 112 which carries a plurality of conductor-engaging fingers 114 that are pivotably mounted at one end, as seen at 116 to the block 112. Fingers 114 are adapted to be resiliently biased into engagement with the end of a conductor, which is to be secured during a crimping operation, by means of associated spring means 118 which act against the fingers 114 through suitable plungers 120, with the spring means 118 being suitably mounted upon the support member 110 and an inwardly extending member 122 which is spaced above the member 110 and connected to the block 112 through suitable screw means 124. It will be seen that when the end of a conductor is inserted between the inner ends of the fingers 114, the fingers 114 will be biased apart against the resistance of the spring means 118, and that the fingers 114 will be resiliently biased into engagement with the periphery of the conductor through the spring means 118 and plungers 120 so as to resist outward movement of the conductor with respect to the tool 10 during a subsequent crimping operation.

In operation of the crimping tool 10 of the present invention, a typical tubular or sleevelike connector shown in FIG. 5 and designated by the numeral 126 is inserted within the recess 70 of the female die member 64. Thereafter, the pair of wire conductors, shown in FIG. 5 and designated by the numerals 128 and 130, which are to be secured by means of the connector 126, are inserted through the spring clip members 92 and into the opposite ends of the connector 126. The clip members 92 will be seen to prevent any lateral movement of the conductors 128, 130 relative to the connector 126 during the subsequent crimping operation, as above described. The receiver 40 may be unscrewed from the section 32 of the breechblock 28 and a suitable blank cartridge 38 be inserted into the bore 34. Thereafter, the receiver 40 may be reassembled preparatory to actuating the tool 10. At such time as it is desired to effect a crimping operation, the firing pin 50 is retracted rearwardly, thereby compressing the spring 60. The firing pin 50 may be released when desired, with the result that the spring 60 will bias the pin 50 forwardly, resulting in the pin section 54 engaging the rim of the cartridge 38 to effect ignition thereof. The explosive gas generated by ignition of the cartridge 38 will force the piston members 84 and male die members 76 carried thereon forwardly, resulting in the face portions 82 impinging against the side of the connector 126 opposite the recess 70, thereby effecting the desired crimping action which results in the conductors 128, 130 being secured to the connector 126. The aforesaid explosive gases produced by the cartridge 38 are communicated or vented through the apertures 20 and then forwardly through the passageway 26 defined between the housing 12 and shield 22, thereby preventing such gas from injuring the operator. As the piston members 84 thus move forwardly, the return springs 88 are compressed, which springs 88 therefore cause the pistons 84 and die members 76 to be moved rearwardly upon completion of the crimping operation. Once the crimping operation has been completed, the entire assembly consisting of the connector 126 and conductors 128 and 130 may be removed from the tool 10 by sliding the assembly rearwardly so that the connector 126 clears the recess 70 and the conductors 128, 130 are disengaged from the spring clip members 92, thereby preparing the tool 10 for a subsequent operational cycle.

A particularly important feature of the crimping tool 10 of the present invention will be seen from the fact that the male die members 76 and pistons 84 are free to move independently of one another during a crimping operation. This allows each end of the connector being crimped to be compressed to the limit of the force required, regardless of the force applied to the opposite end of the connector. This feature permits one end of the connector to be crimped a greater amount than the other end thereof in the event conductors of two different diameters are being secured to one another. Such an action is not possible wherein a single die is used to crimp each end of the connector, and accordingly, the crimping tool 10 of the present invention assures for positive electrical connection between a pair of conductors and an associated connector, regardless of whether or not the conductors are of the same size. Another feature of the present invention will be seen from the small, lightweight construction thereof, which permits the tool to be used in confined and difficult locations. By using an explosive cartridge as a source of power, physical strength is minimized to the extreme, as is the need for ancillary mechanical-type tools requiring long and bulky handles, or alternatively, hydraulic or electrically energized power means. The fast action of the tool in effecting a crimp will have an extremely beneficial cold welding effect between the wires and the connector, thereby providing for effective electrical connections. The tool 10 is designed to have sufficient power so that harder alloy crimping connectors may be used, thereby permitting the use of smaller size connectors, while still providing the strength and current-carrying capacity of much larger connectors heretofore required.

While it will be apparent that the preferred embodiments illustrated herein are well calculated to fulfill the objects above stated, it will be appreciated that the present invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

Claims

I claim:

1. In an electrical-connector-crimping tool for operatively connecting first and second wire elements,

relatively fixed die means adapted to operatively support a connector during a crimping operation,

first and second independently movable die means cooperable with said fixed die means to crimp a connector therebetween,

piston means for applying an explosive force to said movable an die means, whereby said movable die means will be biased independently toward said connector supported on said fixed die means and thereby exert independent compressive forces against said connector to secure said connector to said first and second wire elements regardless of whether or not said elements are of the same cross-sectional size, and

means for detonating an explosive device adjacent said piston means for producing said force.

2. A tool for crimping electrical connectors as set forth in claim 1 which includes first and second reciprocable piston means cooperable with said relatively movable die means.

3. A tool for crimping electrical connectors as set forth in claim 1 wherein said means for detonating an explosive device comprises firing pin means and spring means for resiliently biasing said firing pin means toward said explosive device.

4. A tool for crimping electrical connectors as set forth in claim 1 wherein said relatively fixed die means comprises a female member adapted to operatively support a connector, and wherein said first and second relatively movable die means comprises first and second male dies adapted to independently move toward and away from said female die to crimp a connector therebetween.

5. A tool for crimping electrical connectors as set forth in claim 4 which includes first and second spring means for biasing said first and second male dies toward deactuated positions.

6. A tool for crimping electrical connectors as set forth in claim 1 which includes spring clip means for positively securing at least one of said wire elements to which a connector is to be crimped in a preselected position relative to said fixed die means.

7. A tool for crimping electrical connectors as set forth in claim 6 wherein said spring clip means comprises a pair of opposed spring clip members each having portions adapted to positively engage said one wire element to which a connector is to be crimped, whereby to resist movement of the element relative to the tool during a crimping operation.

8. A tool for crimping electrical connectors as set forth in claim 6 wherein said spring clip means includes wire-engaging finger means and spring means resiliently urging said finger means toward a position engaging the wire element to which a connector is to be crimped.

9. A tool for crimping electrical connectors as set forth in claim 2 wherein said piston means acts to confine the explosive force to effect efficient ignition said explosive device.

10. A tool for crimping electrical connectors as set forth in claim 1 wherein said first and second relatively movable die means comprises first and second male dies adapted to independently move toward and away from said relatively fixed die means to crimp a connector therebetween, which includes first and second reciprocable piston means cooperable with said relatively movable die means, which comprises firing pin means and spring means for resiliently biasing said firing pin means toward said explosive device, wherein said relatively fixed die means comprises a female member adapted to operatively support a connector, which includes spring clip means for positively securing the wire elements to which a connector is to be crimped in a preselected position relative to said female member, and wherein said piston means acts to confine said explosive force to effect efficient ignition of said explosive device.