US2038292A - Junction box - Google Patents

Description

p 1936- I J. w. HOOLEY 2638,22

JUNCTION BOX Original Filed Jan. 28, 1955 INVENTOR ATTORNEY Patented Apr. 21, 1936 UNITED STATES PATENT OFFICE Divided and this application January 15, 1936, Serial No. 59,167

2 Claims.

- This invention relates to electrical fixtures in general and. more especially to junction boxes and the like, constituting a division. of my copending application, Serial No. 3,695 filed January 28th, 1935.

Among the objects of the present invention, it is aimed to provide an improved junction box of the type specified composed. of cast metal having a wall structure of uniform thickness throughout to prevent distortion during the stresses and strains that might occur during the metal treating process to which the box may be subjected in the course of manufacture.

It is still another object of the present invention to provide an improved junction box of the type specified composed of cast metal having a wall structure of uniform thickness throughout provided with internally threaded openings to be associated with discs composed of moldable substance such as soft metal to be filled into the openings readily removable when desired and otherwise effective to close up such openings to obstruct the admission of water, vapor, gas or the like. vantagesof the invention will appear from the subjoined detail description of specific embodiments thereof illustrated in the accompanying drawing in which Figure 1 is a vertical section of a floor forming structure equipped with one embodiment of the present invention; and

Fig. 2 is a vertical section showing the several parts of the junction box including its cover, anchoring ring and moldable opening closures before being installed in a job.

In the embodiment shown in Fig. 1, the wall structure I composed as an instance of concrete is typical of any wall structure whether a lateral wall, floor or ceiling of a room although in the present instance for the purpose of this description, it will be assumed that the wall structure I illustrates a floor section in the process of formation with the form board or plate 2 still secured in place. In the process of constructing a floor before the concrete filling forming the structure I is introduced, the junction box 3 or the like is secured to the form board 2 and connected to the conduits 4 and 5.

The junction box 3, see Fig. 2, is preferably composed of cast metal having a conical lateral wall 6 and a base I integral with one another and preferably of a uniform thickness throughout to prevent distortion from any stresses or strains that might occur during the metal treat- These and other features, capabilities and. ad-

ing process to which the box 3 may be subjected in the course of manufacture. The conical wall 6 as clearly shown in Fig. 2, tapers inwardly as it recedes from the base I.

In the lateral wall 6, there are formed one or more openings 8, the edge of each of which is provided with a screw thread 9. After the box 3'is so manufactured and preparatory to shipping the same to a job, each of the openings 8 is preferably completely sealed with a disc Ill composed of a moldable substance, such as aluminum, white metal or the like. The disc H], see Fig.- 2, before being inserted into an opening 8 preferably has convex faces II so that the disc after being inserted into an opening may have its faces ll engaged by a pressing tool or the like to squash the disc so that its periphery will flow into intimate engagement with the thread 9 and thereby effectively seal the opening 8. The disc ID at the left of the box 3 in Fig. 2 is shown before being inserted into the opening 8 while the disc ID at the right of the box 3 in Fig. 2 is shown squashed into sealing position as above described.

After the box 3 is so equipped with the discs 10, it is then ready to act' as a container to receive the fittings to be associated with it on a particular job whereupon before shipment the box preferably is closed by a cover l2 preferably composed of spring metal. The cover 12, see Fig. 2, has a flexible disc portion l3 with or without a central opening l4, an annular rim l5 at the periphery of the disc portion [3 and a flange l6 extending outwardly from the edge of said rim IS. The rim I5 is preferably tapering as shown in Fig. 2 to facilitate insertion into the open end of the box 3. After being inserted into the open end of the box 3, the disc portion I3 is pressed inwardly into the position shown in Fig. 1, where the outer face of the rim l5 will snugly engage and. frictionally anchor the cover l2 to the open end of the box 3 as shown in Fig. 1.

In order to secure the box 3 to the form board 2 as shown in Fig. 1, there is preferably provided an annular ring I! having a cylindrical portion i8, an outwardly extending annular flange I9 and a number of bendable fingers 20 extending from the free end of the cylindrical portion l8. The flange I9 is preferably provided with a plurality of openings to receive bolts or screws, such as the screws 2"! illustrated in Fig. 1.

The inner periphery of the ring I! is preferably greater than the outer periphery of the wall 6 at its open end but less than the outer periphery of the wall 6 adjacent the base 1 so that the box 3 with its open end may with facility be passed into the ring I! until the ring I I approaches the base 1.

After the ring approaches the base 1 into the position shown in Fig. 1, the fingers 2|] will preferably be bent over into engagement with the base I and the ring I! thus securely anchored to the box 3 without requiring the provision of any screw openings in the box 3 for securing the ring ll thereto. The ring I! may also be secured to the box 3 in the aforesaid manner before the box 3 is shipped to a job if desired.

After the ring I! is so secured to the box 3, the box 3 is then ready to have one or more conduits according to the specification of the jobunder consideration, such as the conduits 4 and 5, connected to the wall 6.

In the present instance, the discs ID in the openings 8.to which the conduits 4 and 5 are to be connected are first removed by a tool or the like to clear the threads 9 of such openings and then each opening 8 provided with a bushing 2 I, such as disclosed in my copending application, Serial No. 3,694 filed January 28, 1935. The bushing 2|, preferably has an external threaded formation 22 to engage the thread 9. The bushing 2| also has an internal; screw threaded formation and an enlargement 24. 7

The bushing 2| is introduced from the inside of the box into an opening 8. and after being positioned so that its external thread is ready to engage the thread 9 of the opening 8 and its internal thread 23 is in position to engage the external thread of the conduit 4 or 5 as an instance, the enlargement 24 is engaged by a wrench or tool and the bushing turned simultaneously to connect the conduit 4 or 5 and the box 3 to the bushing 2| and in turn to one another.

After the conduits and box are so connected and the electrical conductors are or are not passed through the conduits 4 and 5 to terminate in the box 3, see the end of the conduit 31 in Fig. l, the box is ready again to receive the cover l2 and the fastening means, as for instance the structure I after it has been set to anchor thebox 3 against accidental displacement.

It will be seen from the foregoing that a construction of a junction box 3 free from openings except those closed by the discs l0 and connected to the conduits 4, 5 by the bushings 2] and in turn anchored to a form board 2 will not only produce in association with the conduits, such as the conduits 4 and 5 a mechanically and electrically connected system constituting an uninterrupted electrical conductor but will further provide a mechanically and electrically bonded job including joints that are vapor-proof, gasproof and water-proof, eliminating necessity for bonding jumpers and the like.

I claim:

1. The combination with a metal junction box having an opening and an internal screw thread cut in the periphery of said opening, of a seal composed of moldable metal softer than the metal of the box and forced into said opening effective to seal the same before use, whereby the screw threads are protected during shipment and the likeand in turn the sharp edges of the threads serve to anchor the seals against accidental displacement.

2. The combination with a junction box having a base and a lateral wall composed of cast metal with a uniform thickness throughout, there being openings in said lateral wall and screw threads cut in said openings, of seals composed of moldable metal softer than the metal of the box and squeezed into said openings into intimate engagement with said screw threads effectively to seal the openings, whereby the screw threads are protected during shipment and the like and in turn the sharp edges of the threads serve to anchor the seals against accidental displacement. JOHN W. HOOLEY.

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