US 3739448 A
A semi-automatic hand tool for extruding electrical connectors in order to connect a wire to a post of an integrated circuit panel includes extruding means which are actuated by an air-operated actuating means, and which includes means for feeding the electrical connectors to the extruding tip. The operation of the extruding means, the actuating means, and the feeding means are coordinated by a multi-valve control system which is air operated. In addition, a sensing means is provided in conjunction with the extruding means for insuring that the hand tool does not recycle prematurely.
Claims available in
Description (OCR text may contain errors)
United States Patent 1 Garner SEMI-AUTOMATIC HAND TOOL FOR EXTRUDING ELECTRICAL CONNECTORS Peter Garner, Bernardsville, NJ.
Thomas & Betts Corporation, Elizabeth, NJ.
Filed: Oct. 18, 1971 Appl. No.: 189,994
US. Cl. 29/203 H Int. Cl H0lr 43/04 Field of Search 29/203 H, 203 D,
29/203 HC, 212 D References Cited UNITED STATES PATENTS Harris 29/203 HC June 19, 1973 Primary Examiner-Thomas H. Eager Att0rneyDavid Teschner  ABSTRACT A semi-automatic hand tool for extruding electrical connectors in order to connect a wire to a post of an integrated circuit panel includes extruding means which are actuated by an air-operated actuating means, and which includes means for feeding the electrical connectors to the extruding tip. The operation of the extruding means, the actuating means, and the feeding means are coordinated by a multi-valve control system which is air operated. In addition, a sensing means is provided in conjunction with the extruding means for insuring that the hand tool does not recycle prematurely.
11 Claims, 13 Drawing Figures PAIENTEDJUN 19 ms SHEEI20F4 INVENTOR.
47 7' ORA E Y SEMI-AUTOMATIC HAND TOOL FOR EXTRUDING ELECTRICAL CONNECTORS The present invention relates to hand tools, and more specifically, a semi-automatic hand tool for extruding extrusible electrical connectors to form gas tight, reliable connections between the electrical elements.
The hand tool of the subject invention is adapted for use with an improved type of ductile connector for providing a mechanical and electrical interconnection between a conductor and, for example, a small terminal post of the type normally found in computers and other complex and miniaturized electrical and electronic equipment. The use of a ductile connector is particularly suitable for forming a gas tight connection and for providing mechanical strain relief for the wires of the small insulated conductors by gripping a portion of the insulation. The type of extrusible electrical connector which is referred to is disclosed in U.S. Pat. application Ser. No. 113,833, filed Feb. 9, 1971 by Francis A. O- Loughlin and entitled Extrusible Electrical Connector and Connection Method, which application is assigned to the same assignee of the present invention.
In the field of miniaturized electronic equipment, it has heretofore been known to secure conductors to terminal posts and the like either by mechanically wrapping the wire of the conductor about a terminal post, or by soldering the connector to the post or affixing the stripped wire to the post by means of a small resilient clip. In the case of standard conductor wires, soldering is usually employed because of the fragile nature of the strands of the small gauge wire (for example A. W. G. No. 30) are often ruptured if the connection operation is performed by automatic equipment. While soldering provides a secure electrical connection to the post, there are several disadvantages, the primary one of which is that soldering can only be used where the components immediately surrounding the connection can withstand the eHects of the local heat required to make the soldered joint. Furthermore, soldering is generally more expensive than other methods of electrical con nection, and requires adequate preparation of the terminal posts and the conductor by chemical cleaning in order to insure a reliable soldered connection. One further disadvantage is that soldering does not permit removal of the wire, as does a crimped connection, without again applying heat to the terminal post or subjecting the terminal post to relatively high tensile loadings which may cause damage to the terminal post.
In the techniques as heretofore known, a distinct disadvantage common to all techniques is that the wire, if subjected to constant deflection or fatigue loading, may become weak and break due to its low fatigue resistance. Usually the breakage occurs immediately adjacent the point where the wire is held rigidly at the terminal post, although breakage also occurs in wrapped joints if, for example, even momentary tension is applied to the conductor during automatic wrapping. In those instances where miniature resilient clips are employed, a gas tight connection is not readily achieved, and also the clips do not normally work satisfactorily with terminals having round, as opposed to rectangular, geometries.
Based on this background, a suitable electrical connection as fully disclosed in the above-identified application, which is incorporated herein by reference, has been developed in order to form a gas tight electrical and mechanical connection between a wire and a post,
and which, at the same time, provides strain relief for the wire conductor by gripping the conductor insulation.
The present invention is directed to a hand-operated tool for attaching extrusible electrical connectors of the type mentioned above to achieve an electrical and mechanical connection between a stripped wire, whether stranded or solid, and a terminal post of an integrated circuit panel. The hand tool has several advantages, one of which is that it includes extrusion means which are coordinated with feeding means so as to insure the rapid installation of the connector, as well as a unique wire inserting and sensing device for insuring that the wire is inserted within the tool to the proper degree in the extrusible connector prior to the connector being placed over the post. The sensing mechanism additionally functions to insure that, after the extrusible connector has been extruded to form an electrical connection between the wire and post, the hand gun is not recycled until the tool is completely removed from the post, thereby obviating the possibility of jamming or malfunction of the hand tool.
The hand tool has the additional! feature of providing the extruding means, the actuating means, the sensing mechanism and feeding means, in a small compact hand tool, which is light in weight and is readily operated by unskilled labor, while being highly reliable.
In accordance with the invention, the foregoing and other objects are met by a hand tool generally in the form of a hand gun which is trigger operated, and which includes an extruding means operatively connected to an air operated actuating cylinder that, in turn, is operatively connnected to a valve control means. In addition, the hand tool is provided with feeding means, including an internally mounted cartridge for holding a plurality of extrusible electrical connectors, with the operation of the feeding means being co ordinated with the extruding means. In addition, the hand tool is provided with a wire inserting and sensing device mounted internally of the extruding means for gauging the proper positioning of the wire in the electrical connector prior to the extrusion operation, and additionally for insuring the proper cycling of the hand tool.
For a better understanding of the invention, reference should be made to the following detailed description and to the drawings, in which:
FIG. 1 is a side view of the semi-automatic hand tool of the present invention shown in partial cross-section;
FIG. 2 is a front view of the hand gun;
FIG. 3 is a partial horizontal sectional top view of the hand gun of the subject invention;
FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;
FIG. 5 is a sectional view taken along 5-5 in FIG. 1;
FIG. 6 is a detailed sectional view of the front portion of the hand tool;
FIG. 7 is a view similar to FIG. I but illustrating the position of the components of the semi-automatic hand tool of the subject invention at the completion of the extrusion cycle of operation;
FIG. 8 is a view similar to FIG. 1 but illustrating the position of the components of the [hand tool during the recycling operation; and
FIGS. 9A-9E illustrate in the sequence of operation of the hand tool in forming an extruded electrical connection between an electrical conductor, a wire, and a post.
Referring to FIGS. 1 through 8, the semi-automatic hand tool of the subject invention is basically in the form of a pistol-like device comprising an outer housing 12 made of two molded, hollow plastic pieces enclosing an extruding means 14, actuating means 16 for actuating the extruding means 14, feeding means 118 for providing extrusible electrical connectors to the extruding means 14, and a control means 20 for coordinating the operation of the extruding means 14, feeding means 18 and actuating means 16.
The actuating means 16 generally comprises a tandem arrangement of a double acting sleeve cylinder 22 and a plunger cylinder 24. As detailed in FIG. 6, the sleeve cylinder 22 includes an elongated sleeve 26 which extends forwardly along the axial length of the elongated portion of the housing 12. Disposed concentrically with and internally of said sleeve 26 is a plunger sleeve 28 which is slideably mounted within said cylinder sleeve 26 and extends through the double acting sleeve cylinder 22 for connection to the piston 30 of the plunger cylinder 24. The plunger sleeve 26 is hollow and has slideably mounted therein a wire stop and sensing mechanism 32, to be more fully described hereinafter. The lower portion of cylinder sleeve 26 is connected to or formed integral with the pistons 34 and 36 of the double acting sleeve cylinder 22. The latter is divided by an intermediate wall 38 having an O-ring seal 40 for preventing communication between the chambers 42 and 44 of said sleeve cylinder 22. The purpose of providing a double-acting sleeve cylinder is to minimize the space required for the actuating means 16, and to achieve the required force necessary for extrusion of the ductile electrical connectors for forming an electrical connection between a terminal post and a wire.
The extruding means 14 is mounted on the forward end of the cylinder sleeve 26, and includes an extruding tip 50 threadedly connected as at 52 to said cylinder sleeve 26, and having a reduced diameter portion 54 at its forward end. The latter is provided with a key-hole cut-out 56 (see FIGS. 2 and 6) for accepting a wire conductor, as more fully described hereinafter. The extruding tip 50, being threadedly connected to the cylinder sleeve 26 moves rearwardly therewith relative to the plunger sleeve 28 thereby extruding and effectively reducing the outer diameter of an electrical connector C disposed in the extruding tip 50.
The wire stop and sensing mechanism 32 includes a small diameter rod 60 (see FIG. 4) disposed within the reduced diameter portion 54 of the plunger sleeve 28, which rod 60 is connected to a larger diameter rod 62 (see FIG. 5) that extends through the major portion of the plunger sleeve 28 and terminates at a seal 64. A spring 66 is provided to bias the rod assembly 68 and 62 forwardly, and the spring 66 bears against the piston 30 of plunger cylinder 24. By this arrangement, the wire stop and sensing mechanism 32 is slideably mounted within the plunger sleeve 28 and is constantly biased in a forwardly direction by the action of spring 66.
Feeding means 18 of the hand tool 110 includes a tubular cartridge 70 for accommodating the extrusible electrical connectors C, one end of the cartridge being connected to a source of pressurized air (not shown), while the opposite end thereof is connected to an escapement mechanism 72.. The escapement mechanism 72 (see FIG. 6) includes a channel track 74 through which the electrical connectors C are fed, and a pair of spring fingers '76 and 78 each of which is cantilevered from the upper structure of the escapement mechanism 72 and is adapted to project into the channel track 74. Projecting of the spring finger 76, 78 into the channel track 74 is accomplished by movement of the plunger sleeve 28 in that the latter, in the vicinity of the spring finger 76 and 78, includes an external cam surface suitably configured to cause the spring fingers to be alter natively projected into the channel track 74. (see FIGS. 1 and 5) By this arrangement, the spring fingers 76, 78 function to maintain one electrical connector C is a ready position intermediate the two spring fingers 76, '78, while the remaining connectors C are held in the track channel 74 downstream of the rear-most spring finger 78. The electrical connectors C are forced to move toward the extruding tip 50 by means of the constant source of compressed air provided at the opposite end of the cartridge 70. The forwardmost portion of the track channel 74 is obstructed by a moveable spring tongue 80 (see FIG. 6) which is self-biasing toward the open position (i.e., to allow an electrical connector to pass from track channel 74 to the extrud ing tip 50), but is maintained in the closed position, as shown in FIG. 1, by the abutting surface of the forward end of the plunger sleeve 28 when the latter is in its forward-most position.
Turning to FIG. 3, the hand tool 10 also includes a pair of locking pins 82, 82, slideably mounted in the housing 12 transverse to the elongated, concentric sleeves 26, 28. Each locking pin 82 is spring biased by means of a spring 84 toward the center of the concentric sleeves 26, 28. In addition, each locking pin 82 includes a tapered portion 83 terminating in a tip 86, with the tapered portion 83 being accommodated in a slot formed in the cylinder sleeve 26,.and with the tip 86 being of suitable dimensions so as to project beyond the thickness of the clyinder sleeve 26 and into a suitable cut-out 28' in the plunger sleeve 28. Lock pins 82, 82, are biased to the locking position, as shown in FIG. 3, when the plunger sleeve 28 is being held at a fixed position by the operation of the plunger cylinder 24 during an extrusion operation, and said lock pins 82, 82 operate to aid the plunger cylinder 24 in maintaining the fixedposition of the plunger sleeve 28, to be more fully described hereinafter.
The control means 20 includes a four-way valve 90 having a pilot actuator 592 provided for controlling in a sequential manner the operation of the extruding means 14, the actuating means 16, and the feeding and escapement mechanism means 18. Valve 90 is conventional construction and includes an inlet 94 to which a supply hose 96 of high pressure air is connected, and two exhaust outlets 98 and 98' open to the atmosphere. Valve 90 also includes manifold ports A and B, while the pilot actuator 92 includes an inlet port 102.
The interconnections between the various ports of the four-way valve 90 and its associated pilot valve 92 and the actuating means 18 of the hand tool 10 will now be described. Extending from manifold port A are three tubes at 1110, 112, and 114; tube being connected to port Ill leading to the chamber 42 forwardly of piston 34; tube 112 being connected to port P2 leading to chamber 44 forwardly of piston 36; and tube 1 14 being connected to port P3 leading via conduit 116 to an opening 118 in the hollow center of the plunger sleeve 28 in the region of spring 66 of the wire stop and sensing means 32. As illustrated in F161. l, the slideable seal 64 is located in the vicinity of opening 116 and, is slideable to a sufficient degree so as to be positioned on either the upstream or downstream side of the opening 1 18. When seal 64 is positioned upstream or forwardly of the opening 118 (as shown in lFlGS. 11 and 7), the air pressure entering port P3 is directed through opening 116, thence to the hollow center of the plunger sleeve 28 and through a suitable opening 120 provided in said plunger sleeve to the chamber 25 of the plunger cylinder 24 forwardly of the piston 36. At such time, the air pressure entering the plunger cylinder 24 will cause the piston 36 to be actuated rearwardly. On the other hand, when the seal 64 is disposed downstream or rearwardly of the opening 118 (see FIG. 8), the pressurized air entering port P3 is conducted in the annular space defined between the rods 60, 62 of the wire stop and sensing mechanism 32 and the plunger sleeve 28 to a suitable port 122 disposed in the plunger sleeve 28. After leaving port 122, the pressurized air is exhausted via a suitable opening (not shown) in the hand gun. Further discussion relative to air entering port P3 is described hereinafter.
Extending from port B of valve 96 are three tubes 130, 132, and 134. Tube 130 is connected to a port P4 located in the chamber 42 rearwardly of piston 34; tube 132 being connected to port P5 leading to chamber 44 rearwardly of piston 36; and tube 134 being connected to port P6 which is in communication with a conduit 136 extending into the chamber 25 of plunger cylinder 24 rearwardly of piston 30. Also disposed in the wall of plunger cylinder 24 is a port P7 spaced from the rear wall of said plunger cylinder 24 a distance greater than the width of the piston 30, which port P7 is in communication via a tube 140 with the inlet port 102 of pilot actuator valve 92.
Operation of the actuating means 16 of the hand tool is achieved in a semi-automatic manner by the manual depressing of a slidably mounted trigger 156 which cooperates with the plunger 91 of the four-way valve 96, with said trigger 150 being biased toward its unactuated position (see P16. 1) by trigger return spring 152.
The operation of the hand tool 10 of the subject invention will now be described. As previously mentioned, the hand tool 10 of the subject invention is intended for forming an electrical and mechanical connection between a wire W and a terminal post T by means of extruding a ductile electrical connector C in such manner as to form a gas-tight connection between the stripped portion W of the wire W and the post T, and to form a frictional connection between the insulated portion of the wire W and the post T thereby providing a strain relief for the electrical connection.
Turning to FIGS. 9A 91E, the first step is the position of the hand tool 10 above a terminal post T with the longitudinal axis of the concentric sleeves 26, 28 being aligned with the longitudinal axis of the post T. The next step in the operation is the manual insertion of a wire W into the extuding tip 36 of the gun tool 16 so as to pass axially through the center of the ductile electrical connector C which is disposed in the extruding tip 50 between the reduced diameter portion 54 of the extruding tip 50 and the plunger sleeve 28. The wire W is inserted into the connector C until the forward end thereof contacts the small diameter rod 60 of the wire W stop and sensing means 32. The insulated portion of the wire W is then forced into the key hole slot 56 thereby preventing the inadvertent withdrawal of the wire from the extruding tip 50 of the hand tool 10 (see FIG. 9B).
FlG. 3C illustrates the next step in the operation of the subject hand tool 10. At such time the hand tool Ml is placed axially down over the terminal post T to a-sufficient degree to cause the post T to move the wire stop and sensing mechanism 32 rearwardly, thereby depressing the spring 66 to a sufficient degree such that the seal 64 is disposed rearwardly of the opening 118. Accordingly, any pressurized air entering port P3 will be conducted to the annular space defined between the rods 60, 62 of the wire stop and sensing mechanism 32, and the plunger sleeve 28 and thence through the port 122 disposed in the plunger sleeve 28, and exhausted to the atmosphere. Furthermore, the position of the seal 65 prevents the introduction of pressurized air via the port P3 from entering the plunger cylinder 24. Accordingly, the piston 36 of the plunger cylinder 24 is held in a stationary position thereby providing a constant biasing force for maintaining the plunger sleeve 28 in position during the extrusion operation.
FIG. 9D illustrates the position of the concentric sleeves at the completion of the extrusion cycle at which time the electrical connector C forms an electrical connection between the wire W and the terminal post T. In order to actuate the hand tool 10, the trigger T50 is actuated rearwardly thereby enabling pressurized air from the inlet 94 of valve to enter manifold port A, and via tubes 110, 112 and 1 14 to pass to ports P1, P2 and P3. Air entering the latter port is exhausted to atmosphere as described above due to the position of the seal 64 being downstream of opening 118. On the other hand, pressurized air entering ports P1 and P2 cause the pistons 34 and 36 of the sleeve cylinder 22 to be forced rearwardly thereby moving the cylinder sleeve 26 relative to the plunger sleeve 26. Accord ingly, the extrusion tip Fall is likewise forced rearwardly relative to the plunger sleeve 28, which is held in place by the piston 36, so as to extrude the ductile electrical connector C about the terminal post T and wire W. The operation of the loclting pins 82, 282 also aids in maintaining the plunger sleeve in a fixed position during the extrusion operation. More particularly, at a designated point in the rearward travel of the cylinder sleeve 26, the corresponding openings in the cylinder sleeve 26 and plunger sleeve 28 are aligned so as to enable the tips 86, 66 of said locking pins 82, 82 to be projected into the cut-outs 26', 28' in the plunger sleeve 23 under the action of springs 64, 84. The interaction of the locking pins and the plunger sleeve 28 provides a me chanical loci; for maintaining the plunger sleeve'23 in position, which mechanical lock functions in conjunction with the pneumatic pressure acting on the back portion of the piston 30 in plunger cylinder 24 to maintain the plunger sleeve 26 in a rigid position during the final portion of the extrusion operation. it is at this time that the forces acting on the plunger sleeve 23 are the greatest.
Upon completion of the extrusion cycle, even though the pistons 34 and 36 are moved to their fully retracted position, and the connector C has been fully extruded about the post T and wire W, and hand tool ill will not recycle because of the by-pass created through the ports P3 and 122 to the atmosphere. As previously mentioned, this by-pass is created by virtue of the position of the seal 64 of the wire stop and sensing mechanism 32. In order to effect the recycling of the hand tool 10, seal 64 must be moved to a position upstream or forwardly for the opening 118, and this can only be accomplished by the manual removal of the hand tool from its position down over the post T. In other words, the wire stop and sensing mechanism 32 provides a means for preventing the inadvertent recycling of the hand tool 10 while the latter is still positioned over the terminal post T. The arrangement of the elements of the hand tool 10 at this time is illustrated in FIG. 8.
Recycling of the hand tool 10 to its initial ready position is achieved by removing the hand tool 10 from the terminal post T, as is shown in FIG. 9E. At such time, the wire stop and sensing mechanism 32 returns, under the action of return spring 66, to its initial position, whereat the seal 64 is disposed forwardly of inlet 118. As the seal 64 moves forwardly of the inlet 118, pressurized air entering port P3 is conducted to the opposite side of the seal 64 through the hollow center of the plunger sleeve 28 and through opening 120 in said plunger sleeve 28, to the chamber 25 of the plunger cylinder 24 forwardly of the piston 30. The pressurized air acting on the forward face of piston 30 causes the latter to move rearwardly thereby retracting the plunger sleeve 28 and causing the flow of air pressure contained rearwardly of the piston 30 to pass through port P7 and via tube 140 to the inlet port 102 of the pilot actuator valve 92. As the plunger sleeve 28 is retracted, the cam surfaces of the plunger sleeve 28 cause a cycling or recriprocal motion of the spring fingers 76, 78 so as to allow an electrical connector C to be conducted via the channel track 74 to the extruding tip 50. The leading connector C is allowed to pass from the track channel 74. Upon full retraction of the plunger sleeve 28, the spring tongue 80 is positioned as illustrated in FIG. 8 where it provides a psssageway leading from the track channel 74 to the extruding tip 50. At such time the rearmost spring finger 78 is fully depressed, thereby preventing the remaining electrical conductors C from going beyond the forwardmost spring finger 76.
The input of high pressure air to the pilot valve 92 causes, in turn, switching of the main valve 90 whereby high pressure air is directed from the inlet 96 through the manifold port B, instead of the manifold port A. Pressurized air thus flows through tubes 130 and 132 to the chambers disposed adjacent the rearmost faces of the pistons 34, 36 of the sleeve cylinder 22 so as to cause the sleeve cylinder to return to its initial position. At the same time, pressurized air is caused to flow through tube 134 via port P6 to the rearmost face of the piston 30 of the plunger cylinder 24. Movement of the piston 30 forwardly causes a corresponding movement of the plunger sleeve 28. Upon completion of the movement of the respective pistons, and a corresponding movement of the trigger 150 due to the reaction of spring 152, the hand tool is returned to its initial position as illustrated in FIGS. 1 and 7.
Accordingly, there is provided a semi-automatic hand tool 10 for extruding electrical connectors C onto a terminal post T, which hand tool 10 includes extruding means 14, feeding means 18, actuating means 16 and a control means 20 for coordinating the operation of the extruding means 14 and the feeding means 18, and, in addition, a sensing mechanism 28 for insuring that the hand tool 20 does not recycle prematurely.
As is readily apparent, various modificiations and changes may be incorporated in the hand tool without departing from the scope of the invention. For example, the double cylindrical sleeve cylinder 22 may be in the form of a single piston arrangement, and other forms of control systems may be provided in lieu of the valve arrangement 90, 92. Similarly, other forms of cartridge means for holding the extrusible electrical connectors may be provided within the hand tool, and an electrical system may be employed in lieu of the pneumatic pressure system as shown in the preferred em bodiment of the subject invention.
Although the preferred embodiment of the invention has heretofore been described, it is to be recognized that other modifications and variations thereof may be made without departing from the spirit and scope of the invention.
What is claimed is:
1. A semi-automatic hand tool for extruding a ductile electrical connector to form an electrical connection comprising: a housing; extruding means disposed in said housing; said extruding means comprising an actuating means operative in response to a manually oper ated trigger movably mounted in said housing; feeding means disposed in said housing and operatively associated with said extruding means for feeding electrical connectors to said extruding means; and a control means for coordinating the operation of said extrusion means and said feeding means.
2. A semi-automatic hand tool as in claim 1 wherein said extruding means includes two concentric sleeve members, the outer sleeve of which is movable relative to the inner sleeve so as to extrude an electrical connector.
3. A semi-automatic hand tool as in claim 1 wherein said actuating means comprises a tandem arrangement of two actuating cylinders, the pistons of which are respectively connected to said two concentric sleeves, the inner sleeve being a plunger which is held fast while the outer sleeve comprises an extruding sleeve which is moved relative to said plunger during an extrusion operation.
4. A semi-automatic hand tool as in claim 1 wherein the actuating means and the control means are pneumatically operated.
5. A semi-automatic hand tool as in claim 1 further including wire stop and sensing means for preventing the recycling of the extrusion means prior to the removal of the hand gun from the extruded connection.
6. A semi-automatic hand tool for extruding a ductile electrical connector so as to form an electrical connection between a wire and a post comprising:
extruding means including two concentric sleeves,
the inner sleeve of which is maintained in a stationary position during an extrusion operation while the outer sleeve is moved relative thereto;
said extruding means including a pneumatically operated actuating device;
feeding means for providing electrical connectors to said extruding means; and
control means for coordinating the operation of said extruding means, including the actuating device, and the feeding means.
7. A semi-automatic hand tool as in claim 6 further including wire stop and sensing means for preventing the recycling of the semi-automatic hand tool after an electrical connection has been performed, but prior to the removal of the hand tool from said post.
8. A semi-automatic hand tool as in claim 7 wherein said wire stop and sensing means is disposed concentric with and internally of the inner sleeve of said concentric sleeves, and is controlled by said control means.
9. A semi-automatic hand tool as in claim 6 wherein said control means includes a main valve and a pilot the hand tool.
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