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Publication numberUS1646622 A
Publication typeGrant
Publication dateOct 25, 1927
Filing dateJul 3, 1925
Priority dateJul 3, 1925
Publication numberUS 1646622 A, US 1646622A, US-A-1646622, US1646622 A, US1646622A
InventorsMason Ralph K
Original AssigneeTrumbull Vanderpoel Electric M
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Knock-out-type electrical inclosing box
US 1646622 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

1,64 2 Oct. 25,1927. R. MASON 6,6 2


Ila-E- is localized at the auxiliary RALPH K. MASON, OF BANTAIVI, CONNECTICUT, ASSIGNOR,- BY- DIREC'I AND MESNE AS- srenmnnrs, rornn TRUMBUL'L-VANDER-POEL ELECTRIC maa uracrunme cor/r- PANY, or BANTAM; connncrrcu'r, A conrone'rron or CONNECTICUT.


Application filed July 3, 1925. Serial a... 41,324.

( On practically all electrical inclosing boxes, it is customary to provide a number of knock-out portions to form Openings at desired locations, for the introduction of bushings, loom, conduits, troughs, or other conductors or conductor inclosures, or for the introduction within the inclosure of de vices such as meters, fuse holders, etc. These knock-out? portions are partly cut from the wall of the box or casing and one or more of them is knocked out to form the-desired opening or openings. Difficulty is often encountered in removing these knock-out portions and there is danger of injuring the parts inclosed by the box or casing, even when a chisel is used to effect complete severing of the knock-outs from the wall. I have however provided anovel construction, whereby each knock-out is partly severed from the wall and a plurality of auxiliary knock-outs are provided adjacent the periphery of each main knock-out, so that the strain when forming an opening in the wall,

knock-outs when they are first removed, and removal of them serves to permit easy removal of the main knock-out. In the preferred form of construction, the main knock-out is partly severed from the wall of the box or casing by an interrupted out, each interruption of the out leaving an integral neck which connects the knock-out with the wall, a-portion of this wall, adjacent the pe-- wall and used as means for breaking the neck, to facilitateremoval of the knockout.

Different ways of carrying the invention into effect, are disclosed in the accompany ing drawing, forininga part of this specification.

Figure 1 is an elevation of a box provided withthe invention. I

Figures 2 and 3 are sectional views 011 lines 2-2 and-33 of Fig. 1.

Figures 4, 5, 6 and 7 are elevations show ing slight dilferences of construction.

In the drawing" above briefly described,

which illustrates the preferred details, the numeral 1 designates a wall of a malleable, stamped metal-box or casing for inclosing'an electrical contrivance, said wall having a knock-out portion 2. of any desired configuration, partly cut therefrom by aninterrupted out 3, each interruption of said out leaving a neck or bridgejl which integrally joins the knock-out or main cut portion 2 to the surrounding-portion of the wall 1. In most instances, I prefer that each reach of the interrupted cut 3, shall entirely sever a portion of the knock-out 2, from the adjacent part of, the wall 1, and preferably the knock-out is laterally stamped into offset relation with the remainder of the wall as shown in Figs. 2 and 3, so as to later I facilitate its removal. 7

A portion of the wall 1 adjacent each neck 4, or any desired number of-the latter, is formed with a tongue 5 partly out therefrom by a'sub'sidiary cut 6 which preferably extends entirely'through the wall, as shown in Fig. 2. This cut may either be uninterrupted from end to endas shown in Figs. 1, 2 and 6, or it may be an interrupted cut, as disclosed in Fig. 7. In eitherinstance, each tongue or subsidiary cut portion 5 is left integrally joined to the bridge or neck 4. By preference, each cut 6 is formed in the knock-out or main cut portion as shown, so that the tongues or auxiliary cut portions 5 are within the confines of this knock-out and will not cause notches in the edge of the opening, when the main and subsidiary cut portions or knockouts are removed. This, however, is not essential. In forms of boxes such as those disclosed 1n Figs. 1,6 and 7, in which the knock-out has one of its edges formed by an edge of the wall 1, the invention may be carried out in numerous ways as will be clear from a comparison of these views. In this connection, however, it maybe stated that the form of tongue shown in Fig. 7 is not restricted to a knock-out which extends entirely to an edge ofthe wall 1, but may be of course employed in connection with a knock-out of any other type, for instance, such as shown 1n Figs. 4 and 5 Moreover, it will be understood that the shape of the tongue 5 is immaterial. Each tongue. 5 constitutes an auxiliary knock-out at the periphery of the main knock-out 2, and it is an easy ,matter to iliary knock-out forming an opening entlrely through the wall. If desired, any opening thus formed may be used to receive the end of a screw driver, a pair of pliers or some other adequate tool which may be effectively used in entirely dislocating the main knock-outfrom the wall, without the necessity of excessive. hammering and requiring no chiseling. When punching the auxiliary knock-outs laterally from their normal positions, only a slight force is necessary and this force is so localized that there is no danger of injuring parts within the. box or casing, and in the forms of construction shown, it will be seen that when any tongue 5 is forced laterally, it may be efiec-.

separate the main knock-out? from the wall,

and in other cases (Fig. 1 for instance), the connection between the knock-out and the wall is at least so weakened that. said knockout may be easily removed without trouble and without danger of injuring any parts within the casing or box. At this p'oint ,.it-

may be explained that the tongues or auxiliaryknock-outs f Fig. 1 are so located that they may be-easily gripped with a pair of pliersand wrenched-or twisted loosel If,

' mere lateral forcingof any'of the other tongues or auxiliary knock-outs "does not break them loose from the wall, they may either be worked back and forth or gripped with a pair of pliers and twisted. In the' form of construction shown in Fig. 7, either end of the tongue 5 may be forced laterally in one direction and this will cause opposite '1 movement of its other end, so that it will easily twist off.

Byen ploying any form of construction herein disclosed or any analogous form, in which a mam -knock=out and an auxiliary knock-out or a pl urahty of them, are: associated in substantially the unique manner disclosed, a marked advance is made, as not only is the difficulty of renuiving the kneels outs reduced, butthere is no danger whatever of injuring any parts inclosed by, the box or casing. In the preferred construclClOI1, several species 'of which have been shown, the auxiliary knock-outs form the s'ole means of connecting the-main knock out? with the box orthe like, but this is not in all instances necessar as even if the cuts 3 did'not entirely extend through the .wall

1, removal of the auxiliary knock-outs would form openings to fetl'ectively. weaken the connection between the main knock-out.

and the wall, sothat said main knock-out could be easily removed.

It is to be understood that the term knock-out does not necessarily have the restricted meaning of a portion which is actually knocked out by a blow or blows, but this term is used in a sufficiently broadsense to be applicable to a portion which is twisted out,'pried out or otherwise removed.

I claim: v

1 A metal electrical inclosing box having a main cut portion to provide an opening when removed, said main cut portion being normally retained in place by an uncut bridge, and a subsidiary out portion contiguous to the uncut bridge and providing .means for breaking said bridge before removing the main cut portion.

2. A metal electrical inclosing box having a main cut portion to provide an opening when removed, an uncut supporting portion normally connectingsaid main out portion with the adjacent portion of the box, and a 8'5 subsidiary out partly surrounding said uncut supporting portion, providing a t-wistably removable portion for severing said uncut portion by a localized twisting-operation.

3. A metal electrical inclosing box having a main cut portion positioned to form a notch in an edge of the inclosure when removed, an' uncut supporting portion normally connecting said main cntportion with the adjacent portion of the box, and a subsidiary. cut partly surrounding said uncut supporting portion, providing a twistably removable portion for severing said uncut portion by a localized twisting operation.

4. An electrical inclosing box having a 109 knock-out portion partly severed from one of its walls by an interrupted cut, the interruption of said cut leaving a narrowneek integrally connecting the knock-out portion with the contiguous portion of the wall, said all having a restricted tongue partly cut therefrom and integral with said neck, the ends of the tongue-forming-cut being disposed substantially at opposite sides of said neck and substantially at the peripheral edge of said knock-out portion.

5. An electrical inclosing box having a knock-out portion partly severed i'ronuone of its walls by an interrupted cut, the interruption of said cut leaving a narrow neck integrally connecting the knock-out poi tion with the contiguous portion of the wall, said knock-out portion having a. restricted tongue partly cut therefrom and integral with said neck, the ends of the tongue-ferns 12 ingcut' being disposed substantially at opiposite sides of said neck and substantially at the peripheral edge of said knock-out portion. p .In testimony whereof I have hereunto aflixed my signature.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4758180 *May 9, 1986Jul 19, 1988Ncr CorporationMultiple size connector panel and method for constructing
US5125527 *May 28, 1991Jun 30, 1992LegrandBox with knock-outs for build-in equipment, in particular electrical equipment
U.S. Classification220/266
International ClassificationH02G3/08
Cooperative ClassificationH02G3/085
European ClassificationH02G3/08B1K