US2735080A

US2735080A - Terminal connecting device

Info

Publication number: US2735080A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb. 14, 1956 w. I. I I'r'rMAN 2,735,080

TERMINAL CONNECTING DEVICE Filed March 20. 1953 Fig.3.

F|g 5 I3 Fig 6 Y I3 I4 INVENTOR 7" f n |2 YE "555 I Iom. Itmon. L7 |4 B f ATTORNEY United Statesl Patent O TERMINAL CONNECTING DEVICE William I. Littman, New Windsor, N, Y., assigner to The :Bryant Electric Company, Bridgeport, Conn., a corpm ration of Connecticut Application March 20, 1953, Serial No. 343,704

9 Claims. (Cl. 339-269) `My invention relates, generally, to terminal connecting devices and, more particularly, to devices for making terminal connections to electrical apparatus, `such as switches, receptacles, sockets and the like.

In the installation of many electrical devices, particularly those which are used in large quantities, the time required for attaching wires to a device by means of a terminal connector is an important factor in the installed cost of the device, particularly when it is desired to obtain a secure connection without the necessity of preforming the wires.

An object of my invention is to provide a terminal connector for an electrical device to which a wire may be quickly and easily attached.

Another object of my invention is to provide a connector which shall securely hold a wire attached thereto.

A further object of my invention is to provide a connector particularly suitable for attaching a stranded wire to the connector.

Still another object of my invention is to provide a terminal connector which does not require preforming of the wire end before making the connection.

A more general object of my invention is to provide a terminal connector which shall be simple and efficient in operation and which may be economically manufactured, installed and used.

Other. objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of my invention, a recess or well is provided in the base of an outlet receptacle, or other electric-al device, adjacent to one edge of the metal terminal plate for receiving the end of a wire, with the recess or well extending toward the plate and beneath the surface ofthe plate to which the main portion'of the wire is secured so that the wire must then be substantially reversely bent an angle greater than 90 to lie on the surface of .the plate to which it is secured. A tang may be bent upwardly from the terminal plate, and the well and the tang are so llocated that the wire is looped substantially entirely around the shank of the terminal screw prior to the tightening of the screw head against the wire.

For a better understanding of rthe nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a view, in elevation, of an outlet receptacle embodying the principal features of the invention;

Fig. 2 is a view, in bottom plan, of the receptacle, portions being broken away for clearness;

Fig. 3 is a view, in plan of a fluorescent lampholder having a terminal connector embodying the invention;

Fig. 4 is a view, in elevation, of the lampholder, a portion being broken away for clearness, and

Figs. 5 and 6 are views, in section, of simplified structures embodying the invention.

Referring to the drawing, and particularlyto Figs. 1 and 2, the outlet receptacle shown therein comprises an insulating base 10, a mounting bracket 11 and two oppositely disclosed terminal plates 12 having two terminal screws 13 in each plate for connecting wires 14 to the plate. The base 10 may be molded from a suitable insulating material. rThe mounting bracket 11 may be formedfrom sheet steel and, as shown, is generally of a U-shape having a lateral extension 15 on each leg of the U provided with an opening 16 therein for attaching the bracket to an outlet box (not shown). The bracket 11 may be attached to the base 10 by means of a screw or rivet 17. A sheet of insulating material 20 is disposed underneath the bracket 11.

Each terminal plate 12 has integrally formed contact iingers 1S and 19 for engaging Contact prongs or stabs on a plug (not shown) which may be inserted into the receptacle in the usual manner. As shown, two sets of contact fingers are provided on each terminal plate so that the receptacle is of the duplex type accommodating two plugs which may be attached to extension cords for conducting power to electrical apparatus.

As explained hereinbefore, the connecting of the wires 14 to the terminal plates 12 has heretofore required a considerable portion of the total time required for installing the receptacle in an outlet box. In order to reduce the time required for connecting the wires 14 and at the same time provide for connecting the wires in a secure manner, I have provided a recess or well 21 in the molded base 10 for receiving the end of each wire 14. As shown in Fig. 2, the recess 21 is located behind each terminal plate 12.

As shown in Fig. l, the end of the wire enters the well Z1 through a notch 22 in the sheet 20. Tangs 23 are bent upwardly from the terminal plate 12 and are disposed adjacent to the head of the screw 13. As shown, the recess 21 and the tangs 23 for each terminal screw 13 are so disposed that the Wire 14 is wrapped substantially entirely around the shank of the screw 13.

ln securing a wire 14 to the connector, the bared end of the wire 14 is iirst inserted in the recess 21, the wire i's then bent over the edge of the terminal plate 12 towards the plate 12 and then placed between the tangs 23 and the shank of the screw 13, and thereafter bent around the shank of the screw. After this the head of the screw may be tightened against the wire, thereby securely holding the wire in position between the head of the screw and the plate 12. rl`he tangs 23 prevent the wire from coming out from under the head of the screw as the screw is tightened.

The bend in the wire over the edge of the terminal plate 12 is substantially in excess of 90, being on the order of -l80, and serves to substantially increase the holding power of the connection, thereby making it more ditlicult to loosen the connection by pulling on the wire 14. Also, wrapping the wire substantially entirely around the screw 13 further increases the holding power of the connection.

As explained hereinbefore, a recess 21 is provided for each terminal screw 13. Thus, two recesses are provided for each terminal plate 12 since each terminal plate has two terminal screws 13 therein. Since the recesses 21 are in the molded base 10, they do not require any increase in the size of the terminal plate.

In the modification of the invention shown in Figs. 3 and 4, the lampholder shown therein comprises an insulating base 3i) having a downwardly extending portion 31 thereon foi-'receiving one end of a fluorescent lamp, and terminal plates 32 disposed in the top of the base for connecting conductors 14 thereto. Each terminal plate 32 has a terminal screw 33 threaded into the terminal plate.

.A groove 34 is provided in the base 30 and extends away from one edge of each terminal plate.

As shown most clearly in Fig. 4, a recess or well 35 is provided in the base 10 and is disposed at the end of the groove 34 adjacent to the edge of the terminal plate 32. The recess 35 is so disposed at the edge of the terminal plate thatrin making the connection the end of the conductor 14 is irst inserted `into the well 35 underneath the terminal plate, and the conductor then bent over the terminal plate and wrapped around the shank of the screw with a portion of the conductor then lying in the groove adjacent to the portion which is inserted into the recess 35. The screw 33 may then be tightened against the looped portion of the conductor, thereby completing the terminal connection.

It will be noted that upwardly extending portions or

projections

36 and 37 on the base 10 are disposed adjacent opposite sides of the head of the screw 33 to retain the conductor underneath the head of the screw as it is being tightened. Furthermore, the sides of the groove 34 function to prevent the conductor from coming out from under the screw while it is being tightened.

ln the simplied form of the invention shown in Fig. 5 the recess 21 is so disposed in one edge of the base 10 that the wire 14 is bent over a portion of the base and then wrapped around the shank of the screw 13.

In the structure shown in Fig. 6 the terminal plate l2 is of sueient thickness that the recess 21 can be located in one edge of the plate. The wire M- is bent over the edge of the plate and then wrapped around the shank of the screw 13.

From the foregoing description, it is apparent that I have provided a terminal connector which is simple in construction and to which a conductor may be quickly attached. No preforming of the end of the bare conductor is necessary and the snubbing action due to the reverse bend in the conductor permits a strong pull on the conductor when it is wrapped around the binding screw. ln fact, it is very ditiicult to pull the conductor from under the screw head even without the head being tightened against the conductor. The connector is particularly suitable for stranded wire conductors, but may be utilized with solid wires. The wire may be connected to the terminal plate in a relatively short time, thereby effecting a saving in the time and cost of installing electrical devices.

Since numerous changes may be made in the above described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

l claim as my invention:

l. In a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, a recess in said base at an edge of the plate for receiving the end of the conductor, said recess being disposed at the edge of the plate over which the conductor lies when it is wrapped around the shank of the screw and said recess being disposed to make it necessary to bend the conductor more than 90 over the edge of the plate prior to wrapping the conductor around the shank of the screw.

2. ln a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, a recess in said base at an edge of the plate for receiving the end of the conductor, said recess being disposed at the edge of the plate over which both portions of the looped conductor lie when the conductor is looped around the shank of the screw and said recess being disposed to make it necessary to bend the conductor more than 90 over the edge of the plate prior to looping the conductor around the shank of the screw.

3. In a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, upwardly extending projections disposed adjacent to the head of the screw, said base having a recess therein at an edge of the plate for receiving the end of the conductor, said recess being so disposed on a line between said projections that the conductor lies adjacent to the recess after the conductor is wrapped around the shank of the screw and disposed between the shank and said projections, and said recess being disposed to make it necessary to bend the conductor more than 90 over the edge of the plate prior to wrapping the conductor around the shank of the screw.

4. In a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, a groove in said base extending away from one edge of the plate, a recess in said base at the end of the groove adjacent to the edge of the plate for receiving the end of the conductor, said groove and said recess being disposed to direct said end of the conductor toward the shank of the screw.

5. In a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, a groove in said base extending radially from the shank of the screw, a recess in said base underneath said plate, and an entrance into said recess at the end of the groove adjacent to the edge of the plate, said entrance being disposed to direct the end of the conductor toward the shank of the screw when the conductor is inserted into the recess.

6. In a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw threaded therein, upwardly extending projections on the terminal plate adjacent to and at opposite sides of the head of the screw, said base having a recess therein at an edge of the plate, said recess being disposed on a line extending from the shank of the screw between said projections to direct the end of the conductor toward the shank of the screw when the conductor is inserted into the recess.

7. in a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, said base having an opening therein adjacent to an edge of the plate for receiving the end of the conductor, the opening in said base being shaped to direct the end of the conductor toward the shank of said screw, said opening being so disposed that the portion of the conductor leaving the screw after being looped around the screw is adjacent to the portion entering said opening.

8. `In a terminal assembly for securing a conductor, in combination, an insulating base, a terminal plate disposed on the base and having a terminal screw therein, said base having a recess therein behind the plate for receiving the end of the conductor, the recess in said base being shaped to direct the end of the conductor toward the shank of the screw, said recess being so disposed that the portion of the conductor leaving the screw after being looped around the screw is adjacent to the portion entering said recess.

9. A terminal assembly for securing a conductor wire thereto comprising, a terminal having a terminal screw in one side thereof for clamping a wire to said one side of the terminal beneath the head of the screw, a recess beneath said one side of the terminal extending generally radially from a point adjacent the axis of said screw and having its outer end open to receive the end of a wire, said recess being shaped to direct the end of the con- 5 ductor toward the shank of the screw, so that after a wire is inserted in said recess it must be reversely bent to extend around the shank of said screw before the screw is tightened.

References Cited in the ijle of this patent UNITED STATES PATENTS 778,681 Krantz Dec. 27, 1904 6 Gates Oct. 21, 1941 Hubbell Apr. 27, 1943 Bellek Feb. 28, 1950 FOREIGN PATENTS Great Britain June 11, 1952