US1611499A - Electrical installation assemblage and conductor clamp - Google Patents

Description

Dec. 21 1926.

H. F. VAUGHN ET AL ELECTRICAL INSTAULATION ASSEMBLAGE AND CONDUCTOR CLAMP Filed May 6, 1926 W W QM fifFVauykn Jifi. jv em z'nj Patented Dec. 21, 1926.

UNITED STATES PATENT OFFICE.

HERMAN IE. VAUGHN AND RAYMOND R. TERPENING, OF SCHENECTAIDY, NEW YORK.

ELECTRICAL INSTALLATION ASSEMBLAGE AND CCNDUCTOR CLAMP.

Application filed May is,

In electrical construction work, when clamping conductors to switch boxes, outlet boxes, and other receptacles,-it is customary -to .pass said conductors through relatlvely large openings in the receptacle and secure them by means of a screw-operated clamp within the receptacle. The form of clamp heretofore employed leaves gaps'between'the conductors and the edge. walls of the openings through which they pass, which gaps are contrary to regulations covering electrical installation, and constitute a dangerous lire hazard. It is the principal object of our invention to provide a new .and improved electrical installation assemblagedncluding a clamp which is so constructed as'to close the gaps of the openings, heretofore left by the form of clamp previously employed.

Another object of the invention 1s to provide a clamp which will not only etfectlvely close the portion of the knockout hole not occupied by the conductor armor, but whlch may be used to efiectlvely grlp and hold any of the several sizes of flexible metallic armored cables as. well as the non-metallic sheathed cables. and the flexible tubingsnow 1n use.

Other objects are to provide a combined cable clamp and lmockout-hole-closure of almost universal application tothe standard switch and outlet boxes, which may bemanufactured at small cost, which may be easily and quickly installed, and which W111 be strong and highly effective 1n use.

With the foregoing in view, the IIIVQIltlpD. resides in the novel subject matter hereinafter described and, claimed, the descript on being supplemented by the accompanymg drawing.

showing the improved clamp in usefor securing two conductors to sald box.

Figure 2 is a transverse 'sectlona'l new on line 2-2 of Fig. 1.

line 33ofFig.2.. v Figure 4 is a perspective view of the 1mproved clamping member.

m 1n the drawing above briefly described,

Figure 1 is an elevation of aswitch box Figure 3 is an enlarged detail section connecting the numeral 5 designates a receptacle which,

1926. Serial No. 107,189.

for the purposes of this specification, may be considered as any of the well known cabinets, switch boxes, outlet boxes, or other enclosures or receptacles commonly used in electrical installation. The term receptacle'will hereinafter be used with this understanding in view. I

The receptacle 5 isformed with the usual continuous-walled openings or knockout holes 6 through which the conductors 7 and Q their protecting armors 8 pass and in which they are held .by our improved clamping member 9. The latter serves the double function of closing the unoccupied portions of the knockout holes and of holding one or 65 two of the armored cables that enter the receptacle. This improved clamp comprises essentially a closing portion or plate shaped to slide against the inner wall of the receptacle, arched clamping portions rigid with the plate at an angle thereto and braced by itso that they will securely grip and hold either one or two conductors, and suitable means for holding these parts inoperative position.

In the present showing, the member 9 comprises two arched clamping portions 10 to engage the armors 8, said clamping por tions being integrall .connected by a con-- necting portion' 11 aving an opening 12 which receives a clamping screw 13 suitably engaged with an opening in the receptacle, this opening being in a wall of the receptacle at right angles to the wall in which the openings 6 are formed. The member 9 is 35 disposed adjacent the inner side of one wall of the receptacle 5 and its inner edge is preferably provided, in the clam-ping portions 10, with inwardly stamped lugs '14 to anti-slippingly engage the armors -8, regardless of the nature of the latter, that is, whether said armors be of flexible metal tubing, tubing formed from helically wrapped stripping, or tubing formed from. woven or other nonmetallic material. The outer edge of the member 9 is provided with an integral plate 15 in a plane at right angles to that of the portion 11, said plate being adapted to slidably engage the inner side of the receptacle wall, as shown- In this 1 9 stamped metal construction illustrated the drawing, it willbe seen that the arched clamping portions 10 and the connecting portion 11 form a relatively long and narrow continuous flange along the edge of the plate 15 so that these parts brace or strengthen each other to provide a strong clamp with the use of the minimum amount of metal; and at the same time the clamping portions 10 have sufficient bearing on the cables or conductors to prevent the tilting of the plate 15 away from the wall of the receptacle when i the clamping screw is tightened. The shape and size of the clamping portions 10 may of course be varied but they project substantially at right angles from plate 15 and follow the contourof arched edges or seats in said plate 15. Thus, when the clamping member is moved rectilinearly to clamping position by the screw 13, this plate covers the gaps which would otherwise exist between the relatively small conductor armors and the edges of the comparatively large openings 6. By closing these gaps, the assembly is broughtwell within the realm of standard requirements regarding electrical installation, and. the fire hazard is greatly reduced.

In the present showing, both conductors 8 pass through one end of the receptacle 5 and are held by the single clamp 9, but one of these clamps may if desired be provided at each end of the receptacle, in which case, one conductor could be located at one end and the other conductor at the other end of said receptacle,'only half of each clamp being then effective. It is, of course, understood that the receptacle is provided with knockouts, anyofwhich may be removed, according to the manner in which the conductors must be arranged.

In the standard switch and outlet boxes the knockouts are of one size which is slightl v larger than the diameter of the largest size flexible armored cable; and it will be readily observed that the plate 15 is of such size that when the smallest size cable is used or when the smaller flexible tubing or the nonmetallic sheathed-cable is used, the portion of the knockout hole not occupiedby the conductor or conduit will be effectively closed against the possibility of sparks or flame leaving the box through such hole. The one clamp is therefore usable with all of the sizes of these several kinds of cables or conductors now in general use; and it may be used in the smallest size of the standard switch box where the interior space is limited. In actual use, it has been found in all of these different uses to be very effective in securely holding the cable or conduit without injury or short-circuiting as well as in safely closing the unoccupied-portions of the knockout .holes.

The device is exceptionally simple and 1nexpensive, may be easily manufactured, may be applied or released with ease, and is generally advantageous. While it is intended primarily for use in connection with electrical work, it might in some instances be used in other fields.

On account of existing advantages for the details disclosed, they are preferably followed. Howeven within the scope of the invention as claimed, variations may of course be made.

What is claimed is:

1. An electrical installation assemblage comprising an electrical receptacle having two walls at an angle to each other, one of said walls having two openings to receive conductors while the other of said walls is formed with a screw receiving opening whose axis is between the axes of said conductorreceiving openings, a plate contacting slidably with the inner side of said one wall and having an edge disposed at the edge port1ons of said conductor-receiving openings remote from said other wall, said plate being provided with a lateral relatively long and narrow flange along said edge projecting into the receptacle in spaced relation with said other wall, said flange being provided with arched ends to engage the conductors and having a screw-receiving opening between said arched ends and near said plate, this opening being alined with the aforesaid screw-receiving opening, and a headed screw 4 passing through said screw-receiving open- .1ng and having its head contacting with the flange, said screw being threaded into the screw-receivin opening of said other wall and when tightened serving to draw the aforesaid plate and its flange rectilinearly toward said other wall to clamp the conductors in place, said plate then serving to close portions of the conductor-receiving openings remote from said other Wall.

aforesaid plate contacting with the apertured receptacle wall, a screw may be passed through said opening to secure the arched ends of the flange against conductors passing through the wall apertures, said plate then serving to close portions of the apertures unoccupied by the conductors.

3. A combined conductor clamp-and closure for the unoccupied portions of conductor-receiving apertures in an electrical receptacle, com rising a plate having arched seats, arched 0 am ing portions projectin laterally from said p ate at said seats an followin the contour thereof, and a ortion artures, said late then servin to close g P P 8 having an opening, whereby upon sposal portions of the apertures unoccupied by the of the article within a. receptacle with the conductors. 10 plate in slidable contact with the apertured In testimony whereof we have hereunto wall thereof, a screw may be passed through aflixed our si atures.

said opening to clamp the arched flanges HE MAN F. VAUGHN.

against conductors passing through the wall 1 RAYMOND R. TERPENING.

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