US 3596232 A
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United States Patent Joseph Medley 6, Llantarnam Close, Cwmbrnn, Monmnuthshire, Wales 786,314
Dec. 23, 1968 July 27, 197 1 Dec. 29, 1967 Great Britain lnventor Appl. No. Filed Patented Priority ELECTRICAL CONNECTORS 12 Claims, 5 Drawing Figs.
US. Cl. 339/99 Int. Cl r H01! 11/20 Field of Seal-claw; 339/97-99  References Cited UNITED STATES PATENTS 2,717,365 9/1955 Greenbaum 339/99 2,764,748 9/1956 Heller 339/99 3,162,501 12/1964 Mahl 339/98 Primary Examiner-Marvin A. Champion Assistant Examiner-Joseph H. McGlynn Att0mey Kemon, Palmer and Estabrook ABSTRACT: A plug has a cover hinged to a base. Terminals are provided with cutting tools which are mounted on the base.
Channels in a block support wires with their ends projecting from a face of the block. When the cover and base are brought together about the hinge the cutting tool moves in front of the fact stripping insulation from the ends of the wires and clamping them against the face.
I I 23 I2 21 PATENTEU JULZY 197:
SHEET 3 [IF 3 The present invention relates to electrical connectors for establishing contact between conductors and wires covered with a sheath of insulating material, and is concerned particularly, but not exclusively, with electrical connectors in the form of multipin plugs for use in domestic pIug-and-socket connectors.
Since the advent of electricity for domestic use the provision of plugsand-socket connectors which are satisfactory both electrically, and from the point of view of safety to the user, has presented problems. The different approaches to the solutions of these problems are clear from the abundance of different designs of plug-and-socket connectors provided over this time. The continuing development of the use of electricity in the home calls for plug-and-socket connectors which can readily and safely be assembled and put into use by persons other than electricians.
It is an object of the present invention to provide an improved electrical connector, such as a multipin plug, in which the insertion, stripping and connection of wires is facilitated.
According to the present invention an electrical connector comprises two parts hinged to one another, one part including a block for supporting a wire, the block having a wire-supporting channel therein, and the other part including a cuttingand-clamping tool arranged upon relative rotation of the two parts about the hinge to move in front of a face of the block at which the channel terminates, the arrangement being such that, in operation, with a sheathed wire supported in the chan nel and projecting beyond the said face, the tool in a single movement relative to the block removes insulation from the wire and clamps the wire against the said face.
Thus a connector is provided which does not require wires to be stripped of insulation before they are insertedin it and does not require terminal screws and nuts for clamping the bared wire.
Embodiments of the invention will be described by way of example, with reference to the accompanying drawings, of which:
FIG. 1 shows an exploded view of the embodiment which is in the form of a plug for use with a socket,
FIG. 2 shows a vertical cross-sectional view of the embodiment through a pin and with a wire inserted in a channel of a wire-support,
FIG. 3 shows a cross-sectional view corresponding to FIG. 2
with two hinged parts relatively rotated,
FIG. 4 shows a cross-sectional view also corresponding to FIG. 2 with the hinged parts rotated further relative to one another, and I FIG. 5 shows a perspective view of another embodiment in the form of a plug.
Referring to FIG. 1, this shows a plug according to the invention. The plug comprises a base 11 and a cover 12 which are hinged together by a hinge pin 13. Two terminals in the form of contact pins 14 are mounted in holes in the base 11 which are so positioned that the plug will fit into a standard domestic socket.
The cover 12 consists of a flat rectangular piece of synthetic plastics material on which is moulded a raised portion 15 also of synthetic plastics material. The raised portion 15 extends towards the hinged end in a projecting portion 16 through which a hole 17 passes.
The base 11 has a cavity 18 around which walls 19 of the base 11 extend. The walls at the end of the base nearer the hinge are thicker than the sidewallsand holes 20 pass through the walls at this end. Here there is a gap in the wall in order that it can receive the projecting portion 16. The hinge pin 13 passes through the holes 20 and the hole 17 connecting the cover to the base. The ends of the walls 19 and the end of the projecting portion 16 are rounded to allow hinged movement of the base 11 and the cover 12 relative to each other.
The raised portion 15 which constitutes a wire-support has a substantially rectangular middle portion which provides two laterally extending shoulders or blocks 21. Each shoulder has a channel 22 passing through it andthe end of the channel nearer the hinge is reinforced by an insert of metal tubing 23.
Each contact pin 14 carries at its inner end a cutting' tool in the form of a chisel 24, which, when the base and cover are closed together is brought down beside the face of the corresponding shoulder 21 which is nearer the hinge. In this position the face of the chisel is approximately one-half mm away from the face of the shoulder.
In the rectangular flat piece of the cover 12 between the said face and the edge nearest the hinge there is a small depression 25.
In the wall at the end of the base that is remote from the hinge there is a notch 26 through which a lead can pass from the exterior to the cavity 18. At this end the base 11 also has a hole 27 to receive a screw. There is corresponding hole 28 in the cover 12 such that when the base and cover are brought together a screw can be inserted to hold them in position.
To insert a lead of two insulated wires into the plug the base and cover are opened as shown in FIG. 2 and the two wires 29 of the lead are inserted in the two channels 22 in such a manner that their ends project beyond the faces nearest the hinge of the blocks. The base and cover are then brought together. The chisels bite into the insulating sheaths of the wires and the ends of the wires are bent, as shown in FIG. 3. As the chisels move down the faces of the shoulders, they carry part of the insulating sheath before them, each chisel paring a strip off one side of each insulating sheath or stripping the end of the wire completely according to the nature of the insulating material. The displaced insulating material is accommodated by the depressions 25. However, the chisels do not sever the wires because of the small clearances between the faces of the shoulders and the chisels and the flexibility of the wire. When the movement of the base and cover, each towards the other, is completed, a screw 30 is inserted through the hole 27 into the hole 28. The sides of the chisels clamp the stripped wires against the shoulders 21 and a good electrical contact is made between each chisel and its associated wire. The wires each having been bent through a right angle and clamped are securely held in the plug.
In this way, aplug is provided which can be fitted with leads without having to strip the insulating sheath from the wires beforehand. Nor are there any screws needed to anchor or clamp the wires. Thus this construction simplifies the operation of fitting leads to a plug.
FIG. 5 shows another plug according to the invention. A base 41' is connected to a cover 42 by a hinge pin 43. A terminal 44 is mounted on the base 4] and a terminal 45 is mounted on the cover 42.
Moulded on the cover 42 is a block 46 in which there are two channels 47. Each channel is in the form of an open channel at one end anda tunnel at the other end. The tunnels terminate at two faces 48 of the block. At foot of these faces are two small depressions 49 in the cover 42.
The-faces 48 are separated by a portion 50 projecting from the block and through which a hole passes to receive the hinge pin 43. The base 41 has a cavity 52 around which extend sidewalls 53 and an end wall 54. There are holes in the sidewalls 53 which are aligned with the hole in the portion 50. There is a gap in the end wall 54 into which the projecting portion 50 fits and the hinge pin 43 passes through the holes in the base and the hole in the cover.
An upstanding boss 56 is mounted on the'cover 42 in a recess in the block 46. The boss 56 is externally threaded and has a transverse slot as shown. A collar 57 is internally threaded, has a knurled outer surface and can be screwed on the boss 56. In front of the boss 56 there a hole 70 through the cover and inclined to the cover at an angle of 30.
Two metal chisels 58 and 59 are mounted in the base 41 against the end wall 54. The chisel 58 is in electrical and physical contact with the terminal 44. A plate 60 located against one of the sidewalls is in electrical and physical contact with the chisel 59. A small domed projection 61 0.0l5" high is formed on the inner face of the plate 60.
The terminal 45 is mounted on the side of the block 46 which is cut away behind the inner end of the terminal to allow it to flex inwardly. A small dimple 62 is formed near the one end of the terminal in the outwardly directed face. The upper and outer edge of the terminal 45 is radiused as is the lower inner edge of the plate 60.
To insert a lead of two insulated wires into the plug, the two wires are insertedthrough the hole 70 and fitted in the transverse slot in the boss 56. The end portions of the two wires are laid respectively in the two channels 47 their extremities projecting from the faces 48. The collar 57 is screwed on the boss 56 to grip the wires in the slot. The base 41 is then lowered to the cover 42, pivoting about the hinge pin 43. The chisel edges move down the faces 48 and as they meet the projecting extremities of the wires they bend them over and bite into the insulation. The clearance between the faces 48 and the chisels is so arranged that the chisels do not sever the strands forming the conducting cores of the wires but merely displace insulation, pushing it before them and into the depressions 49. When the movement of the base 41 towards the cover 42 is completed and they lie one against the other, the chisels are clamping the ends of the wires against the faces 48 and the bared cores of the wires are in contact with the chisels. In this position also the projection 61 is located in the dimple 62, the inner end of the terminal 45 having flexed inwardly to allow the stud to pass over its outer surface during the closing of the plug. The passage of the plate 60 outside the end of the terminal 45 is facilitated by the outer upper edge of the terminal and the inner lower edge of the plate being radiused.
Electrical connection between the bared wire through the chisel 59 and plate 60 to the terminal 45 is provided by the projections 61 accommodated in the dimple 62.
The plug cannot be opened when the terminals are inserted in the holes of a socket. However a screw may be provided if desired to hold the plug closed when the terminals are not inserted in the holes of a socket.
Although the invention has been described with reference to a plug for a plug-and-socket it will be understood the invention can be applied to other forms of connecting devices. It will also be appreciated that the hinge could alternatively be arranged along an axis at 90 to that shown. Furthermore the faces of the shoulders can be given a slight rake so that the gap between the chisels and the faces gets narrower as the relative movement of the base and cover is completed.
The invention can also be applied to electrical devices to facilitate the connection of leads to them. For example, a fuse .box or a cutout of a motor car can have a hinged cover embodying cutting tools. The supply leads are located on wire supports and stripped and clamped in electrical contact with the fuse box or cutout, by the cutting tool when the cover is closed.
1. An electrical connector comprising:
hinge means connecting said two parts to one another for relative rotation from an initial open position to a final closed'position;
a block on one of said parts, having a wire supporting channel therein, said channel being open at each end thereof to permit an insulated wire to be inserted in one end and pushed completely through to extend beyond the other end, said other end terminating in a face of said block; and
a tool having a cutting edge and a clamping surface so mounted on the other of said parts that when said parts are rotated from their initial open position to their final closed position, said tool first contacts the wire adjacent said face of said block where said channel terminates, bends the wire downwardly parallel to said face, strips the insulation therefrom and finally firmly clamps the 'thus bared end of the wire between the clamping surface. of
said tool and said face, the distance between said face and said clamping surface in the final closed position of the parts being approximately equal to the diameter of the bare wire.
2. A connector according to claim 1 wherein the said channel is a tunnel of substantially circular cross section.
3. A connector according to claim 1 wherein the cutting tool includes a straight cutting edge which is parallel to the axis of the said hinge means.
4. A connector according to claim 1 wherein the axis of the said channel is in a plane substantially normal to the part of the path of travel of the cutting edge of the cutting tool nearest the channel.
5. A connector according to claim 1 wherein the said one part includes a cover on which the block is provided and wherein the said other part includes a base on which the cutting tool is mounted, the cover and the base together surrounding the cutting tool and the end of the wire when a wire is clamped against the said face of the block by the cutting tool.
6. A connector according to claim 1 including a terminal provided on the said one part and on the other said part a conductor in electrical contact with the cutting tool to make contact with the said terminal when the two parts are brought together about the hinge means.
7. A connector as defined by claim 1 wherein said hinge means is located in front of said face of said block.
8. A connector according to claim 1 wherein the cutting tool is in the form of a chisel.
9. A connector according to claim 8 including a terminal, the chisel being provided on the said terminal.
10. An electrical connector comprising:
hinge means connecting the said two parts to one another;
a block provided on one of said parts for supporting wires;
two wire-supporting channels in the said block;
two cutting-and-clamping tools on the other of said parts arranged upon relative rotation of the two parts about the hinge means to move in front of a face of the block at which the channels terminate and to remove insulation from the ends of wires supported in the channels and projecting beyond the said face and to clamp the wires against the said face a first terminal provided on the said one part,
a second terminal provided on the other said part and connected electrically to one of said cutting tools,
and a conductor connected electrically to the other of said cutting tools and provided on the said other part to make contact with the first terminal when the two parts are brought together.
11. A connector according to claim 10 and including a projection and a dimple which are provided on the conductor and the first terminal and which engage one another when the saidtwo parts are brought together.
12. A connector according to claim 11 wherein the block is cut away behind the end of the first terminal nearer the hinge to allow it to flex inwardly.