US2927297A - Top wired electrical cap and connector - Google Patents

Description

March 1, 1960 H, HUBBELL 2,927,297

TOP WIRED ELECTRICAL CAP AND CONNECTOR 2 Sheets-Sheet 1 Filed Feb. 4, 1957 INVENTOR %%M ATTORNEYS,

March 1, 1960 H. HUBBELL 2,927,297

TOP WIRED ELECTRICAL CAP AND CONNECTOR 2 Sheets-Sheet 2 Filed Feb. 4, 1957 ATTORNEYS TOP WIRED ELECTRICAL CAP AND CONNECTOR Harvey Hubbell, Southport, Conn, assignor to Harvey Hubbell, Incorporated, Bridgeport, Conn, a corporation of Connecticut Application February 4, 1957, Serial No. 637,979

4 Claims. (Cl. 339196) This invention relates to electrical wiring devices and particularly to a top wired electrical cap and connector, and has for an object to provide an improved means for connecting the lead wires to the contacts in the cap and the connector.

Another object is to provide such a connecting means which consists of a top wired means of connecting the lead wires to the contacts without the use of binding screws. Another object is to provide such a connector for the lead wires to an electrical contact in which each wire is firmly clamped between two metal plates which are parts of the contact to efiect a better electrical connection between the lead wires and the cap or connector contact, and also to secure a better grip for the lead wires.

Another object is to provide a construction in which the lead wires are clamped between upper and lower plates forming a part of the cap or connecting contacts, wd in which the upper plate is pivotally connected to the contact in such a way that it may be shifted upwardly from the lower plate and yieldingly held in this position to permit insertion of the bared end of the conductor wire between them, with means for drawing together the two sections of the insulating body member in which they are mounted to clamp the wire between the plates.

With the foregoing and other objects in view, I have devised the construction illustrated in the accompanying drawings forming a part of this specification. It is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In these drawings:

Fig. 1 is a partial side elevation and partial section of an electrical cap connector embodying this invention;

Fig. 2 is a transverse section thereof substantially on line 2--2 of Fig. l and showing a portion of one clamping plate broken away;

Fig. 3 is a detail section showing the parts in position just before the final clamping operation, the section being substantially on line 33 of Fig. 2;

Fig. 4 is a detail section of a portion of the lower section of the body showing the upper portion of the contact with the top clamping plate raised to permit insertion of the lead wire;

Fig. 5 is a side view of a contact removed from the body member;

Fig. 6 is an edge view thereof looking from the right of Fig. 5;

Fig. 7 is a top plan view with a portion of the top plate broken away;

Fig. 8 is a bottom view of the cap of Fig. 1 on a reduced scale;

Fig. 9 is a bottom view of the upper section of the cap on a reduced scale;

Fig. 10 is a partial side elevation and partial section of a connector for use with the cap of Fig. 1, or any other similar cap showing how this improved top wiring can be applied thereto;

hire States atent Fig. 11 is a transverse section substantially on line 11-11 of Fig. 10, with a portion of the top clamping plate of one contact broken away;

Fig. 12 is a detail section substantially on line 12-12 of Fig. 11;

Fig. 13 is a section through an upper portion of the lower body section showing the upper end of a contact in elevation and wtih the top clamping plate raised to permit insertion of a lead wire;

Fig. 14 is a side view of the receptacle contact of Fig. 10 removed from the body member;

Fig. 15 is an edge view looking from the right of Fig. 14;

Fig. 16 is a top plan view of this contact with a portion of its upper clamping plate broken away;

Fig. 17 is an end view of the connector of Fig. 10 looking toward the bottom thereof and on a reduced scale, and

Fig. 18 is a view on a reduced scale looking toward the bottom of the upper section of the body member.

Referring first to the cap form of this connecting means as shown in Figs. 1 to 9, this is a cap portion of a connector for connecting two conductor cables or cords, such, for example, as used for connecting an electrical attachment such as an electrically operated machine of some kind to an outlet receptacle in a house or shop wiring system, and also called an attachment plug cap, which may be plugged either into the outlet direct or to a so-called connector connected to a cable connected at its other end to a cap plugged into the outlet, such, for example, as the connector shown in Figs. 11 to 18. The cap shown comprises a body of insulating material composed of two sections 1 and 2 which, for the purposes of identification will be called respectively the upper and lower sections, and they are placed one above the other in a protective metal casing or shell 3 which is in the form of a cupped member having side walls 4 enclosing the sections of the body member, and a top or upper end wall 5 extending over the top of the upper body section 1. The two body sections and the cap or shell are connected together by any suitable means, preferably by screws 6 passing through the two sections 1 and 2 and threaded into the top wall of the shell, as indicated at 17. The lower section 2 is slidable in the shell. A strain relief or cord grip comprising two clamping members 3 may be provided to clamp the opposite sides of the insulated conductor cord 9, and each is provided with a laterally extending foot 10 mounted to slide in a radially extending groove 11 in the top of section 1 of the body and under the top wall 5 of the shell, and provided with clamping screws 12 by which they may clamp the opposite sides of the cord 9.

Mounted in the body member, and particularly the lower section 2 thereof, is a pair of electrical contacts 13, in this case including contact blades 14 projecting from the lower side of the section 2 for insertion in the entrance slots of an outlet receptacle or a connector in an extension cable to engage the receptacle contacts therein for completing the circuit. These contacts include at their upper end a widened portion 15 including a series of teeth 16 on its opposite edges having downwardly and inwardly inclined lower edges 17 and horizontal upper edges forming sharp corners 18, and above this widened portion the contact is bent laterally to provide a laterally extending top wall or lower clamping plate 19. The contacts are mounted in the lower section 2 of the body by inserting the blades 14 from the top of the section through elongated slots or openings 20 in the lower face of the section 2 with the opposite edges of the widened portions 15 having the teeth 16 sliding down into channels 21 in the upper portion of the section 2 and leading downwardly from the top surface thereof, but closed at their lower ends by the shoulders 22. The contact is inserted from l 3 the. top of the section 2 to the position shown .in Fig. 1, with the laterally extending wall or plate 19 lying on the top surface of the section 2 of the body member. The distance betweenthe bottoms or outer walls of the opposed channels 21 isslightly less than thewidth between the free edges of the teeth 16, so that although these teeth maybe slid down into these channels due-to their inclined lower walls 16, their sharp free edges 18 will embed themselves somewhat in the insulating material at the bottoms of these channels to efiectively and securely hold the contacts against withdrawal from or outward movement in these channels or from the position of Fig. 1. This does away with anchoring screws or rivets for the contacts.

An upper clamping plate 23 is also provided as a part or each contact 13. This plate is pivotally secured to the body portion of the contact to lie above the top of the lower plate or wall 19. For this purpose it is provided with a downwardly extending portion 24 at one edge, and a laterally extending lower end portion 25 at the lower end of this downwardly extending portion, which is a flat portion extending through a rectangular opening 25 in the lat: body portion of the contact 13.. This end portion 25 is slotted for a portion of its length, as shown at 27, communicating with a vertical slot 28 in the upright portion 24., This-provides a spring efiect of the sides of the pora tions24 and on the opposite'sides of-these slotsand of a a. width to. firmly grip the: opposite vertical edges of the opening 26 when the clamping plate is in the position of Figs. 5, 6 and 7 to yieldingly retain this plate in this position. This connection, however, will permit the plate 23 to berswung upwardly to the position of Fig. 4, to thus position the plate '23 well above the lower clamping plate 19 to permit insertion of a lead wire between them. Theporti0ns'24' and 25 tend to spring outwardly from the contracted condition of Fig. 5, so that when this plate is swung'tothe'position of Fig. '4, the portions on the opposite sides of the slots 27 and 28 will spread outwardly to a width substantially that of the diagonal of the opening 26, and thus wider than the width of the opening 26, as shown in Fig. 4, to thus yieldingly retain the upper clamping, plate 23 in the raised inclined position of Fig. 4 to facilitate insertion of the lead wire between the plates 19 and 23, as .will presently bedescribed,

' The two contacts-including their clamping plates 19 and 23, are separated by an upwardly extending cross wall 29, as shown in Figs. 2 and 3, to electrically separate the plates of the respective contacts 13 and also the lead wires connectedthereto. a

The upper-body section 1 is provided with an entrance passage or opening 30'for the lead wires 31 from the conductor cord 9 to permit the bared or stripped ends 32 of thesewires to be connected to the contacts 13 by means of the: clamping plates 19 and 23. In. efiecting this connection, the hated ends of the lead wires are passed through. the passage 30 and inserted between the clamping plates 19 and. 23 of the contacts while the lower body section 2' is removed from shell 3 and while the upper plate 23 is swung to the upper position, as shown in Fig. 4. When the plate is in'this position plenty of space is provided for insertion of the conductor wire between theplates, and as'previously described this plate is yield ingly;v held in this upper position by coaction of the spring portions of the sections 29 and 25 with the diagonal corners of the opening 26. After the lead wires are inserted to a position'betweenthe plates of the respective contacts 13 the'upper plate. 23 of each contact is swung down to the position of Figs. 5 to 7 on top of thewire 32 between the'plates. To secure more efiective grip on the wire the opposed surfaces of the plates 19 and 23 may be grooved,

as indicated at 33 and 34 respectively, and the surfaces of these grooves roughened such as by knurlingor providing narrow transverse grooves 35. After these plates '23 are swung down to this position on the conductors leading to the contacts they will each be held in this position by the pressure of the sides of the portions'24 and25 'against'the retain the contacts in position, thesame as described in' vertical sides of the opening 26. The lower section 2 of the body with these contacts and the lead .wires so positioned can now be inserted in the lower portion of the shell 3 against the under side of the top section 1. Then the two screws are inserted in the top of the shell and tightened up, thus drawing the two body sections 1 and 2 together, and this action by pressing on the'under side of the plate 19 and top side of the plate 23 between the top wall of the lower section and the lower wall of the top section, will tightly clamp the lead wires between the plates 23 and 19 with a firm and strong grip, without the use of any binding screws or other securing means. A veryefi'ective and improved electrical connection is secured between the lead wires and the contacts 13 because these wires are each clamped between two metal and therefore electrically conducting plates which are parts of the contact. After the body members are secured by the screws, the strain relief or clamps 8 may be firmly clamped against the cord 9 by setting up the screws 12.

The same effective means may be employed for securing the conductor wires to the receptacle contacts enclosed in the connector of Figs. 10 to 18. This connector comprises an insulating body composed of upper and lower sections 36 and 37, the upper section 36 being the same as the upper section 1 of the cap in Figs. 1 to 9. The lower section 37 is longer so as to project further from the lower end of the protective shell or casing- 3, which is the same as-that used in the cap of Fig. 1. This lower: section 37 is provided with chambers 38 therein to the lower ends of which lead the inlet slots 39 in the lower end wall of the section 37 for entrance of the blade contacts 14 of the cap to engage the receptacle contacts 40in this connector. These contacts, as shown in Figs. 13 and 16, each comprise a pair of fiat metal strips 41 and 42 side by side portion 15 and the teeth 16 of the cap contacts 13. The

upper ends of these members 41' and 42 are bent laterally to form the lower clamping plate'49 corresponding to theclamping plate 19 of the cap contacts. The body portion is also provided witha rectangular opening 50 corresponding with the opening 26 in the cap, and the upper clamping plate 23 above the plate '49 is the same asthat of Figs. 1 to 9 and comprises the same parts and is mounted in the opening,53' for pivotal connection with the contacts 4d, the same as in the first form. The contacts 40 are mounted in the lower section 37 of the body'by inserting them downwardly from the top thereof into the chambers 38 with the opposite toothed edges of the widened portion 47 passing into opposed channels 54 with the teeth 48 gripping the bottoms of these channels, to

connection with the contacts 13. This positions the lower clamping plates or walls 49 at the top of the lower section 37. a

In making the'connection of the lead wides 32 to these contacts, they are inserted through the opening 30 of the top section 35, and with the'lower body section 37 removed from shell 3 these wires are inserted between the plates 23 and 49 while the plate 23 is raised toits upper position of Fig. 13, and held thereby the spring side portions 2d and 25 in the diagonal corners of the opening 59. After the conductors are inserted between these plates the upper plate 23 of each contact is swung down onto the conductor and is retained in this position by the spring side walls .24 and 25 gripping the vertical side edges of the opening 5% while the lower body section 37 is inserted'in the lower open side or the shell or casing '3 to bring its top surface against the under surface of the top section 36. Then by inserting the screws 55 in the top wall of the shell 3 and tightening them up, the two clamping plates 23 and 49 of each contact are tightly clamped against opposite sides of the conductor wire 32 between the bottom surface of the upper section 36 and the top surface of the lower section 37 the same as described in connection with the cap of Figs. 1 to 9, to effect a good electrical connection between the conductor wires and the contacts 40 and also a good tight mechanical grip of the conductor wires. Then the cord strain relief or clamps 8 may be set against the opposite sides of the insulated cord 9 by setting up the clamping screws 12.

It will be seen from the above that this construction forms a simple and effective means for connecting the lead wires to the contacts without the use of binding screws, and which provides a metal contact on both sides of the conductor wire by means which are parts of the receptacle contacts for a more efiective electrical connection between the wire and the contact; that the wires are firmly and etfectively clamped to the contacts by merely setting up and tightening the screws connecting the two sections of the body together and to the enclosing shell, and that this same connection may be used for connecting the lead wires to the blade contacts of the cap section and the receptacle contacts of the connector section. In both forms the top section 1 or 36 of the body is provided with similarly shaped recesses 23a (Figs. 9 and 18) in its lower surface in which the clamping plates 23 are located and by which they are enclosed and retained against shifting laterally out of position.

Having thus set forth the nature of my invention, I claim:

1. A contact for an electric wiring device comprising a body portion and a transverse upper portion, a clamp ing member located over the transverse portion, and means pivotally connecting the clamping member to the body portion including a rectangular opening in the body portion, and the clamping member includes a downwardly extending portion having a laterally extending lower end portion in said opening with said downward and lateral portions provided with a longitudinal slot forming spring portions on the opposite sides thereof to yieldingly engage the opposite side edges of the opening and retain the clamping member in either its raised or lowered position.

2. The electrical contact according to claim 1 in which the clamping member and the transverse upper portion comprise upper and lower plates provided on their opposed surfaces with gripping means to engage and hold the wire inserted between them.

3. In an electric wiring device, a body composed of upper and lower sections of insulating material, electrical contacts mounted in the lower section each including a body portion and a transverse portion at its upper end located at the upper side of the lower section, a clamping member on each contact extending over said transverse portion, means pivotally mounting the clamping member on the contact for movement toward and from said transverse portion comprising a rectangular opening in the body portion and the clamping member includes a downwardly extending portion with a laterally extending lower end portion in said opening forming the pivotal connection, said downward and lateral portions provided with a longitudinal slot forming yieldable spring portions on opposite sides thereof cooperating with side edges of the opening to yieldingly retain the clamping member in either a raised position spaced above the transverse portion to permit insertion of a lead wire between them or a lowered position immediately over the inserted wire, said upper body section provided with passage means for the lead wires, and means connecting the body sections adapted to draw them together to clamp the wires between the clamping members and transverse portions by pressure of the opposed surfaces of said sections on opposite sides thereof.

4. A contact for an electric wiring device comprising a body portion and a transverse upper portion, a clamping member located over the transverse portion, means pivotally connecting the clamping member to the body portion including resilient means to yieldingly retain the clamping member spaced above the transverse portion for insertion of a lead wire to a clamping position between them and to also hold the clamping member against the inserted wire to retain the wire between the transverse portion and the clamping member, and said clamping member and the transverse upper portion comprise upper and lower plates provided on their opposed surfaces with gripping means to engage the wire inserted between them.

References Cited in the file of this patent UNITED STATES PATENTS Webster Oct. 15,

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