US2529133A

US2529133A - Junction box

Info

Publication number: US2529133A
Application number: US777219A
Authority: US
Inventors: Harold L Bush
Original assignee: Crouse Hinds Co
Current assignee: Crouse Hinds Co
Priority date: 1947-10-01
Filing date: 1947-10-01
Publication date: 1950-11-07
Anticipated expiration: 1967-11-07

Description

Q 7, v1950 I H. L. BUSH ,529,133

JUNCTION Box I Filed Oct. 1, 1947 I 2 Sheets-Sheet 2 N VEN TOR.

Patented Nov. 7, 1950 JUNCTION BOX Harold L. Bush, North Syracuse, N. Y., assignor to Grouse-Hinds Company, Syracuse, N. Y., a corporation of New York Application October 1, 1947., Serial No. 777,219

Claims.

This invention has to do with a junction box for electrical conductors and particularly an explosion proof junction box wherein branch circuit conductors are taken off from feed circuit conductors, the latter consisting of conductors of unusually large cross section.

The invention has as an object a junction box ofthe type referred to embodying a structure whereby'the branch circuit conductors can be quickly and conveniently connected to the heavy feed circuit conductors, the connector terminals being readily adapted for various sizes of conductors,,both on the branch and feed circuits.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed,

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a vertical sectional view of a junction box embodying my invention.

Figure 2 is a top plan view of the structure shown in Figure 1 with the closure cap removed and a portion of the top insulating shield broken away.

Figure 3 is a top plan view of one of the feed conductor terminal blocks.

The invention consists of a metallic housing 9 formed with apertured hubs III, II, to receive conduits enclosing the conductors. The housing is provided with an opening in the top wall thereof which, in the structure illustrated in the drawings, is commensurate in size to the interior of the housing 9. In this case, the housing is of cylindrical form, and the opening is internally threaded to receive an inverted cup-shaped closure cap I2 which, when threaded into the opening, forms a flame tight closure for the opening.

A plurality of feed conductor terminal blocks I3 are mounted in the housing on the base wall I4 thereof, the blocks being mounted upon an insulating panel I5 secured to the bottom wall of the housing, as by screws I6, and the blocks I3 are secured to the panel in either one of two positions by screws I'I shown in dotted outline, Figure 1. The blocks I3 are formed with a transversely extending rectangular groove I8, and with a groove I9 of V formation extending at right angles to the groove I8. The corner portions of the blocks are provided with threaded apertures to receive the mounting screws IT.

A terminal bar 22 is mounted upon each of the blocks I3 and extends upwardly therefrom and outwardly through the opening in the top of the housing. The lower end of each of the bars 22 is formed with a jaw portion 24 adapted to be positioned in the grooves I8, I9, the bars being detachably secured to the blocks by tightening means in the form of screws 26 which also thread into the apertures 20 of the blocks I3. The jaws 24, in conjunction with the blocks I3 and the tightening means 26, form a clamp for clamping the large feed conductors 28. Branch conductor terminals 29 are mounted upon opposite sides of the bars 22 on the outwardly extending portions thereof.

With this arrangement, the housing is mounted upon the wall, or other surface, by bolts, lag

screws, or the like, extending through apertured' feet SI. The conduit lines are attached to the hubs I0, II, and the conductors pulled through the conduits.

The feed conductors 28 are of large size rang-, ing from 1/0 to 500 circular mills. To connect these heavy conductors, it is only necessary to de-insulate a short portion of each conductor and drop it into one of the connector blocks I3. The terminal bars 22 are then secured to the blocks respectively, and this operation results in the heavy conductor being clamped between the block and its associated connector bar 22.

The branch circuit conductors may be then conveniently attached to the terminals 29 inasmuch as they are fully exposed outside of the housing. These branch conductors may range in size from No. 14 Wire to 4/0 wire. However, there is no difficulty in connecting the larger size branch conductors inasmuch as the branch connectors are positioned outside of the housing and the workman is in no way hampered, or obstructed, in making the connections. After the branch circuit conductors have been attached to the terminals 29, the closure cap I2 is screwed into position.

An insulating plate 36 may be detachably mounted over the ends of the terminal bars 22. As shown, blocks 31 of insulating material are detachably secured to the two outer terminal bars, as by screws 38, and the top plate 36 secured to the blocks 31, as by screws 40. Shields 4I may be mounted on the under side of the plate 36 to effectively prevent any arcing or short circuit between the terminal bars and likewise, a U- shaped shield 43 may be employed in connection with the mounting of one or more of the blocks I3.

In Figure 1, the left and center terminal block I 3 is positioned to receive the feed conductors 28 in the V slots I9. The right hand block is positioned to receive the conductor in the rectangular slot l8. This slot is to accommodate conductors of the smaller sizes, while the slots 19 accommodate conductors of larger size.

What I claim is:

1. An explosion proof junction box for electrical conductors comprising a housing formed with conduit receiving apertures and having an opening in the top wall, a plurality of feed conductor terminal blocks mounted in the housing on the bottom wall thereof, a terminal bar detachably secured to each of said terminal blocks and extending outwardly through said opening, the lower ends of said bars being cooperable with said terminal blocks respectively to clamp conductors thereto, branch terminal connectors carried on the outer ends of said bars, and a closure cap enclosing the outwardly extending portions of said bars and forming a flame tight/closure for said opening.

trical conductors comprising a housing for con- 4 ing position, a closure cap enclosing the outwardly extending portion of said bars and forming a flame tight closure for said opening.

4. An explosion proof junction box for electrical conductors comprising a housing formed With conduit receiving apertures and having an opening in the top wall, a plurality of feed'conductor terminal blocks mounted in the housing on the bottom wall thereof, a terminal bar extending outwardly from each of said blocks through said opening and being provided at its outer end with branch terminal connectors, each of said bars having a jaw member which, in conjunction with its associated terminal block and tightening means, forms a clamp for a feed conductor, a closure cap enclosing the outer porduit receiving apertures and having an opening in the top wall, a plurality of terminal blocks mounted in the housing on the bottom wall thereof, a terminal bar extending outwardly from each of said blocks through said opening, and said bars being provided at their outer ends with branch terminal connectors, the lower ends of s'aid'terminal bars and said blocks forming conductor clamp jaws, means operable to detachably secure the terminal bars to said blocks respectively, and. to contract said clamp jaws on a conductor, a closure cap enclosing the outwardly extending portions of said bars and forming a flame tightjclosure for said opening.

v 3. An explosion proof junction box for electrical conductors comprising a housing formed with conduitjreceiving apertures and having an opening in the top wall thereof, a plurality offeedcondu'ctor terminal blocks mounted in the housing on the bottom wall thereof, a terminal bar extending outwardly from each of said blocks through said opening and being provided at their outer ends with branch terminal connectors, the lower end of each terminal bar having a jaw member cooperable with said block in one relation, to form a clamp for a feed conductor, and in another relation to form a clamp for a conductor of different size, means operable to detachably secure the terminal bars to said blocks respectively, and to move said jaw into conductor clamption of said bars and forming a flame tight closure for said opening.

5. An explosion proof junction box for electrical conductors comprising a housing formed with conduit receiving apertures and having an opening 'in the top wall thereof substantially commensurate with the interior of the housing; a plurality of U-shaped terminal blocks mounted in the housing on the bottom wall thereof, a branch terminal bar extending outwardly from each of said blocks through said opening and being provided at its outer end with branch ter-' minal connectors, each of said terminal bars being formed at its lower end with a conductor clamp jaw mounted between the leg portions of said U shaped terminal block, means operableto detachabl'y' secure the terminal bar to the block and to cause said jaw to clamp a feed conductor to the block, a closure cap enclosing the upwardly extending portions of said terminal bars and forming. a flame tight closure for said opening.

HAROLD L. BUSH. f

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 2,208,558 Appleton July 23, 1940 FOREIGN PATENTS Number Country Date 2 Great Britain Nov. 25, L899 WWW.