US2657368A

US2657368A - Twisted plug-cord connector

Info

Publication number: US2657368A
Application number: US170421A
Authority: US
Inventors: Francis C Cooke
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-06-26
Filing date: 1950-06-26
Publication date: 1953-10-27
Anticipated expiration: 1970-10-27

Description

Oct. 27, 1953 F. c. COOKE 2,657,368

TWISTED PLUG-CORD CONNECTOR Filed June 26, 1950 26 Enventbr d A wigw/w WMES Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE 2,657,368 TWISTED PLUG-CORD CONNECTOR Francis Cooke, East Hampton, Conn. Application June 26, 1950, Serial No; 170,421

2 Claims. 1

This invention relates to connectors for electric cables, cords or the like, and more particularly to a connector to be applied to the end of such a cord to make an electrical connection with an exposed contact member which carries a current.

In using a number of appliances, such as a floor sander and similar tools which are operated by electricity, it is customary to connect the appliance to a source of current within a fuse box or similar device within the building, as sufiicient current cannot usually be obtained from the usual wall plugs. These wall plugs are protected by fuses of relatively low capacity so that the passage through the fuse of a sufficient current to operate the appliances will often result in the blowing of the fuse.

The connection of the terminals of the cord or cable leading to the appliance is often very inconvenient in that it usually requires the cutting off of the current to the building while such connection is being made. Also it often is time consuming in that screws must be removed and replaced in order that a secure connection be made.

According to the present invention, I provide a flat terminal on each of the conductors of the cable, which terminals project from the cable so that they are exposed'for contact with a current-carrying member in a fuse block or the like. In addition, the cords or cables which carry the conductors (the latter being usually in pairs) are clamped tightly together at a point spaced a short distance from the exposed ter'- minals so that these cords or cables offer considerable resistance to being twisted and when distorted by being twisted against this resist ance tend to return to their normal positions. The exposed terminals or contact members con' nected to the cords may for this reason be readily placed in contact with the fixed current carrying members or contacts of a fuse block and on account of this tendency, after being twisted, to twist or turn ina reverse direction will make a good contact and at the same time be automatically held in place against accidental detachment.

One object of the present invention is to pro vide a new and improved terminal connector for electric cords or the like.

A further object of the inventionis to provide a plural conductor electric cord of such construction that it may be readily connected to an exposed contact member of a fuse block or the like without the use of tools.

Still another object of the invention is to provide a two-wire electric cord or cable with exposed terminal or contact blades and to clamp the two cords firmly together at a point spaced from the terminal blades so that while twisting of the two conductors beyond. the clamping means is permitted, there will be considerable resistance to such twisting and a relatively strong torsional force tending to return them to their original positions.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

1n the accompanying drawings:

Fig. 1 is a perspectvie view of a fuse block having connected thereto a plural wire electric cord provided with my invention;

Fig. 2 is an elevational view of the improved connector;

Fig. 3 is a sectional view on line 3-3 of Fig. 2; and

Fig. 42 is a sectional view on line 44 of Fig. 2.

To illustrate a preferred embodiment of my invention I have shown in Fig 1 of the draw--' ings a fuse block H) of conventional form,- this block being provided with fuse sockets H and terminals or contact members I2 which carry the current to the fuse sockets, these contacts I2 being supplied with current by the wires l3 and it in the usual manner.

As will be apparent, there is no socket provided upon such a device into which the blades of the ordinary cord plug or blades secured upon conductors can be plugged. In order, therefore; for a connection to be made to the terminals I2 it would be necessary to remove the screws and in some manner fasten the terminals of the cord to the contacts I2 by such screws. Usually the fuse block H1 is of porcelain or some insulating material and the contact members l2 are set in recesses l5 so that shoulders l6 are provided adjacent the contact members [2. I make use of these shoulders in securing the blades oi. my improved connecting device in place as will be hereinafter explained.

{Ihe improved connector is shown in Fig. 2 oi the drawings wherein I. have illustrated an electric cable consisting of the two insulated wires I8 and I9 separately enclosed in insulat: ing covers 20 and 2| illustrated

blades

22 and 23 are connected electrically with the wires l8- and i9 respectively, these blades protruding fromthe insulating covers 20 and 2| so as to be exposed for connection to any available con;- tact member such as the contact members [2 shown in Fig. l. The ends of the cords 20 and 2| may be bonnd with

ferrules

24 and 25 of a suitable plastic material. the outer surface of these ferrules being substantially flush with the outer surface of the cords 20 and it so that there will be no rough or projecting edges. Also these ferrules 24 and 2'5 will secure the blades 22 and 2.3- firmlyin placein the cords 20' and 2| so that no relative movement will be permitted between the blades and the cords and there will be no likelihood of the blades becoming detached. At a point spaced from the ends of the cords 20 and 2t I provide a clamping: member 26. This clamping member is at a point approximately four to six inches from the free ends of the cords and may consist of a metal ring or collar which embraces both of the cords and, as shown in Fig. 3, the metal of this ring or band is displaced inwardly at 21 and 28 so that it is clamped rigidly and tightly upon the cords holding them against relative movement at this point.

I may also provide the

blades

22 and 23 adjacent their ends with

recessed portions

29 and 30 so as to provide a narrow neck adjacent the end of each blade to facilitate its connection with a terminal member and provide for a more secure connection of the blade with the terminal member and thus reduce the likelihood of accidental detachment.

As the cords 20 and 2| are relatively heavy and stiff, and as they are held tightly and securely together by the embracing band 26, it will be apparent that they will normally stand in the position shown in Fig. 2. Each of the cords may be twisted to some extent about its own axis but as this twisting must be confined to that length of the cord between the free end and the band 26 the inherent stiffness of the cord will offer considerable resistance to such twisting and there will be a strong tendency of the cord to return to its original position. This tendency of each of the cords to return to it original position may be made use of to secure them in place in engagement with the contact members l2 of the fuse box H], as shown in Fig. 1.

To make an electrical connection between the cords or rather the

blades

22 and 23 thereof and the terminals 12, each of the cords is twisted from its normal position through a considerable angle until the blade will enter fiatwise between one of the terminals [2 and an adjacent shoulder or other projecting part of the fuse box to, such as the shoulder I6. After the end of one of the blades has been inserted in this space, the cord is released and the tendency of the latter to return to its original position will cause the blade to bind tightly between the terminal l2 and the shoulder, and thus automatically secure itself against detachment. If the parts are arranged as shown in Fig. 1 of the drawings, the edge of the contact member [2 will enter one of the recesses 3|] and thus form a lock which will effectually prevent accidental detachment of the connectors.

While I have described the

connectors

22 and 23 as being fiat blades, the invention is not limited in this respect, although these members will normally be non-circular and have one dimension greater than the other in order that they may have a fiat side to be introduced into the space between the contact member [2 and the adjacent shoulder and thereafter by returning or untwisting toward their original position present the larger dimension between these two elements so as to be wedged tightly between the contact member and the adjacent shoulder.

It is this wedging action due to the tendency of the cords to return to their original position that holds the contact members in place. This tendency of the cords to resist twisting and to return to their original positions can be regulated in amount to some extent by the position of the clamping band 26 with respect to the ends of the cords. That is, the nearer the band 26 is placed to the end of the cords the less twisting will be permitted so that the position of the band 26 will depend to some extentupon the stiffness or rigidity of the cords 20 and 2|.

While I have shown and described a preferred 4 embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. An electrical connector comprising a pair of cords for connection to an electrical appliance and each having a conductor and a rubber insulating cover, a pair of substantially fiat blades, each of the blades being electrically connected to one of the conductors and extending outwardly from the cover thereof, the blades having recessed side edges, and a clamp disposed over the cords and clamping the cords together, the clamp being located a short distance from the blades and preventing twisting movement of the cords at that point, the cords being free for independent twisting movement, and movement toward and away from each other, between the clamp and the adjacent ends of the cords, twisting movement of the cords being resisted by the inherent resilience of said rubber covers, said cords being adapted to be twisted from their normal positions between said clamp and their adjacent ends, whereby each of said blades may be engaged by one of a pair of inlet terminals in a fuse block, the block being provided with two recesses, each bounded in part by one of the inlet terminals and a shouldered lportion, each of said blades extending into one of the recesses and having the recessed side edges thereof engaging the terminal and the shouldered portion respectively, and the inherent resilience of the cords maintaining firm engagement between said blades and the inlet terminals.

2. An electrical connector comprising a pair or" cords for connection to an electrical appliance and each having a conductor and a rubber insulating cover, a pair of substantially flat blades, each of the blades being electrically connected to one of the conductors and extending outwardly from the cover thereof, the blades having recessed side edges, a clamp disposed over the cords and clamping the cords together, the clamp being located a short distance from the blades and preventing twisting movement of the cords at that point, the cords being free for independent twisting movement and movement toward and away from each other, between the clamp and the adjacent ends of the cords, twisting movement of the cords being resisted by the inherent resilience of said rubber covers, and a fuse block provided with two inlet terminals, said block also being provided with two recesses each bounded in part by one of the inlet terminals and a shouldered portion, said cords being adapted to be twisted from their normal positions between said clamp and their adjacent ends, whereby each of said blades may be engaged by one of said inlet terminals, each of said blades extending into one of the recesses in the block and having the recessed side edges thereof engaging the terminal and the shouldered portion respectively, and the inherent resilience of the cords maintaining firm engagement between said blades and the inlet terminals.

FRANCIS C. COOKE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,180,643 Hubbell Apr. 25, 1918 1,706,158 Hendricks Mar. 19, 1929 2,478,570 Crehan Aug. 9, 1949