US1990953A - Electrical cut-out - Google Patents

Description

Feb. 12, 1935. R, w. E. MOORE I ELECTRICAL CUT-OUT Filed Jan. 11, 1934 INVENTOR fiafi WE M00219 M A ORNEYS Patented Feb. 12, 1935 UNITED STATES PATENT OFFICE ELECTRICAL CUT- OUT Application January 11, 1934, Serial No. 706,202

Claims.

This invention relates to electrical cutout organizations and particularly to cutout organizations of the type which protect circuits with plug fuses.

5 The electrical supply for buildings (for example) is customarily distributed from a distributing-cabinet in which are located fuses for protecting the "various electrical circuits individually. Frequently this cabinet is also provided with manually operable switches for cutting circuits in and out. To minimize tampering, the distributing cabinets in residences and many otherinstallations are so arranged as to give the consumer no more access to the wiring and electrical circuits than is necessary. This means that the elements are all permanently enclosed except'that the fuse plug elements themselves are accessible forreplacement andthat the handles ofswitches are accessible for operation of the m switches. Even this degree of accessibility permits'more or less easily accomplished tampering whichmay endanger the circuitswith resultant fireand-personal-hazard. For example, the conaumermay replace a burned out fuse with a fuse having a rating .higher than the safe carrying capacity of the-circuit; Or, when a fuse burns tout the consumer may bridge the fuse socket with a coin, wire, or tin foil thus leaving the icircuit "completely unprotected.

object of the 'presentinv'ention is to pro- -vide a permanent cutout and/or controlling organization which will make it very difilcult indeed for a consumer to so tamper with the distributing cabinet' as toleave a circuit unprotected.

. Another object of the invention is to provide a permanent cutout and/or controlling organiza- "tion which 'will prevent the insertion of fuses having ratings higherthan the safe carrying capacity of the respective circuits. Fig.1 is a'view with parts'broken away showing'a typical distributing cabinet installation emhodying the present invention. Considering the box as mounted on a wall the view is an ele- LVation.

Fig. 2 is an approximately full sized figure showing a fuse receptacle of the present-inven- ..tion,. the figure being a plan view if the recep- 150 tacle be. considered as being in a horizontal .position.

- Fig. 3 is an enlargedvertical section taken vapproximatelvon the line 3-3 of Fig. 2.

" Fig. 4 is a fragmentary view showing the end of aiuse plug in-the position it occupies when being advanced for insertion into the socket shown in Fig. 3.

Reference will first be had to Fig. 1. Screwed, or otherwise secured to the bottom (or back) of a metal distributing cabinet 10 are a plurality 5 of fuse receptacle blocks such as 11, 12 and 13. Blocks such as 11 are adapted to receive two fuses which may be used (for example) to fuse one side of two separate circuits, the other side of each circuit being unfused and connected to 10 a grounded neutral bar 9. Blocks such as 12 are adapted to receive four fuses for fusing (for example) both sides of two individual circuits. Blocks such as 13 are adapted to receive four fuses for fusing four wives as desired, and in series with each of the fuses is a manually operable single pole snap-switch controlled by a handle 14. The connection to the center contact of each of the fuse sockets is made by bus bars 15 (four shown) which pass beneath the fuse blocks; and connection to the shell contact of each of the fuse sockets is made by suitable wiring 1'7. Covering the wiring and fuse blocks is a rigidly secured cover plate which is merely provided with suitable apertures through 25 which the fuses can be inserted into the fuse sockets and through which the handles 14 of the switches project for actuation. At its top the cover plate 18 may have a separately removable section 18" to give an electrician access to 0 the terminals of bus bars 15 and to the grounded .neutral bar. Hinged to the trim 19 is a metal door 19 which closes over the fuses and switch handles.

Reference will now be had to Figs. 2 and 3 which show the structural details of the fuse receptacles, a receptacle such as 11 being specifically shown to avoid needless duplication of similar parts. An insulating base 20, of suitable molded material such as a phenol condensation product or porcelain, is provided with leg portions 21 and 22 which are adapted to contact with the bottom of the distributing cabinet; and between these leg portions extends one of bus bars 15, threaded into which is a screw 24. A flat metal terminal member 25 lies in the bottom of cuplike depression 26 and extends through aperture 2'7, beyond which it is provided with a screw 28 for making wiring connection to the cutout base. The terminal member 25 is secured in place in the insulating base by screws 29-29. Secured to terminal member by several screws 30 (one shown) is a sheet metal threaded screw socket 31 which preferably is of smaller diameter than a standard shell so it will. reject the plug fuses which have heretofore been in common use. Screwed into the socket 31 is a fuse selector 32 7 made of suitable molded insulating material such as a phenol condensation product. This fuse selector 32 is provided with a spring barb 33, the point of which engages the surface of shell 31 and prevents removal of the fuse selector 32. This barb is of the same general type as barb 35 shown in Fig. 2 of my copending application Serial No. 699,652, filed November 25, 1933. Within the fuse selector 32 is a movable circuit mak v ing andbreaking plug 34 provided at one end with a head 35, and at the other end with a washer 36, held in place by riveting as-at 37. Member 34' is normally biased into the position shown in the drawing by helical spring 38; and when the member 34 is reciprocated, washer 36 moves back and forth in a recess 39. Holes 40 are provided to receive screws for securing the cutout base in the service box; and vertically extending insulating partitions 41 separate wiringv connections 7 28 one from another.

The receptacle is adapted. to receive a fuse of the type fullydisclosed in my copending application Serial No. 699,652, filed November 25, 1933, but Fig. 4 of the present drawing shows the portion of the fuse which is received by and cooperates with' the present fuse receptacle. The fuse body of suitable molded insulating material has adepending central portion 45 from which projects a 'metalcontact member:46. Surrounding and spaced from the central member 45 is an e v V annular space about wall 43, and hence such into the shell 31.

annular skirt 47 outside of which is a screwthreaded sheet metal thimble 48 adapted to screw A fuse link, located inthe upper portion of the fuse, connects central contact 46 with shell 48; and when the fuse blows,

shown at 49." g r g V 1 The fuse 'is installed in the base merely by screwingit inplace in the shell 31 in an obvious manner. Center fuse contact 46 engages circuit gases escape through ports, one of which is makingfand breaking member 34, advancing it of such dimensions that it telescopes into the,

annular space about outer wall 43 of the fuse selector 32. The outer vertical wall of the fuse Iselector 32 is provided with grooves 44 which perinit the escape of gases issuing from the fuse.

{In fuses of diiferent rating the skirt 47 has different' thicknesses, with the thicker skirts- 47 'being assigned to the fuses of higher rating; Fuse port 49 in "selector 22 is so sized as to receive a'fuse of the rating which the circuit is designed to carry.

:Fuses of lower rating are of course harmless and may be inserted in the circuit since the skirt 47 .will be of less thickness than'the width of the space around wall 43. But fuses having a rating higher than the safe carrying capacity of the circuit have a skirt 47 which is thicker than the fuses of higher rating are rejected by thefuse selector 32:.and cannot be insertedin the receptacle." 7

It will be apparent that the circuit cannot be bridged by the insertioin of coins and the like because when a fuse is removed the circuit is automatically broken by the outward movement of circuit making and breaking member 34.- Shell 31 may extend to such a small height above the tually prevents unauthorized and ill advised persons from over fusing the circuits or bridging blown out fuses. The invention may of course be embodied in various specific forms and hence the foregoing disclosure is merely illustrative in compliance with the patent statutes, and the invention is not to be limited except by the scope of the appended claims.

I claim: r

1 A fuse receptacle comprisingga base of insulating material, thefbase being formed with a socket having a bottom and a recess extending below the center portion of'the bottom; a cuplike fuse-receiving contact positioned' in said socket; the bottom of the cup formation being adjacent to the bottom of said socket and having .an aperture overlying said recess; a center current-carrying contact positioned in said recess below the bottom of said socket; a fuse selector oi insulating material positioned in the lower portion of said fuse-receiving contact; and a circuit breaker carried by said fuse selector and cooperable with said center contact, the circuit breaker being normally biased into open position but being automatically movable intoengagement with said center contact by the insertion of a fuse.

2. A fuse receptacle comprising: -a base of insulating material, the base being formedwith a socket having a bottom and a recess extending below the center portion of the bottom; an'annular' fuse receiving contactlining said socket; a center current-carrying contact positioned in said recess below the 'bottom' ofsaid socket;

a fuse selector of insulating material positioned k in the lower portion of said'fuse-receiving contact, said selector receiving fuses up to a given rating and rejecting fuses of higher rating; and a circuit breakencarried by said fuse selector and cooperable with; said .centerflcontact, the circuit breaker'being normally'biased into open position but being automatically movable into engagement with said. center contact bytheinsertion of a fuse.

3. A fuse receptacle comprising: a base of insulating material, the base being formed with 5' lower portion of said fuse-receiving contact,said

fuse selector having an annular extension of insulatingmaterial projecting through the aperture in the'bottom of said fuse-receivingconvtact; and a circuit breaker carried by said fuse selector and cooperable with said center contact,

4. A fuse receptacle comprising:" a base of insulating material, the base being formed with a socket having a bottom and a recess extending below the center portion of the bottom; a threaded cup-like fuse-receiving contact positioned in said socket, the bottom of the cup formation being adjacent to the bottom of said socket and having an aperture overlying said recess; a center current carrying contact positioned in said recess below the bottom of said socket; a fuse selector of insulating material screwed into and permanently secured in the lower portion of said fuse-receiving contact; and a circuit breaker carried by said fuse selector and cooperable with said center contact, the circuit breaker being normally biased into open position but being automatically movable into engagement with said center contact by the insertion of a fuse.

5. A fuse receptacle comprising: a base of insulating material, the base being formed with a socket having a bottom and a recess extending below the center portion of the bottom; an annular fuse-receiving contact lining said socket; a center current-carrying contact positioned in said recess below the bottom of said socket; a fuse selector of insulating material positioned in the lower portion of said fuse-receiving contact, the fuse selector having a single centrally located cylindrical extension projecting upwardly within the fuse-receiving contact and acting to receive fuses of various ratings up to a certain rating and reject fuses of higher rating; and a circuit breaker carried by said fuse selector and cooperable with said center contact, said circuit breaker comprising a reciprocatory vertical member biased upwardly by a spring and adapted to be depressed by the insertion of a fuse.

RALPH W. E. MOORE.

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