US2066172A - Fuse cut-out - Google Patents

Description

R. S. BENNETT FUSE CUT-OUT Filed March l5, 1936 Dec. 29, 1936.

Inventor: Ralph S. Bennett bg His ttorrwe Patented Dec. 29, 1936` UNITED STATES PATENT OEE-ICE I' 2,066,172 y FUSE cU'r-ou'i` Ralph S. Bennett, Pittsfield, Massi., assign'or to General Electric Company, av corporation New York ofv Application March 13, 1936, serial No. 68,701

10 Claims.

The present invention relates to electric fuse cutoutsv and an object of the invention is the provision of an improved arrangement for mounting the fuse holder of an expulsion fuse in a cutout to prevent impairment of the operating parts and supporting structure of the cutout upon operation of the fuse.

A further object of the invention is to improve type disclosed in the copending application of Benjamin R. Hermann, Serial No. 65,994, led February 2'7, 1936, and assigned to the assignee of the present invention.

Other objects and the details of the construction and operation of an illustrative example of an enclosed fuse cutout embodying the present invention willy become apparent from the following description taken in conjunction with the accompanying drawing in which Fig. 1 is a `sectional side elevation of an enclosed fuse cutout showing the parts thereof in the positions they assume when the fuse unit is latched in its normal connected position and the fuse link is intact, and Fig. 2 ls a sectional side elevation of the cutout showing the parts in the positions which they assume immediately after operation of the fuse.

Referring to the drawing, I designates a housing of porcelain or similar insulating material having an open front and bottom and formed with an electric creepage barrier I0' on its rear wall. A pair of stationary contacts II and I2 are mounted in the housing respectively on opposite sides of barrier I0' and are adapted to have line, conductors fastened thereto. A removable cover I3 is provided for the open front of the housing and is arranged to be mounted on' the fuse unit I4 of the cutout by means of projections or bosses I5 and I6 of insulating material formed integrally with the cover and having `openings I5 and I6 Qfsumcient size to provide `nected to contact cap I8 and the lower end con,

Vnected to a conductor 2li extending out from the bottom of the fuse holder.

When the fuse unit I4 is in its normal connected position illustrated in Fig.' l, contact cap I8 isarranged to engage a contact linger 2l carried by the upper stationary contact I I and is backed up by a spring strip 22 to provide the desired contact pressure. The contact finger is formed-with a downwardly facing concave seat 23 which serves as a latch to prevent outward swinging ofthe upper. endy of the fuse. Also,

(Cl. Zoll-114) when the fuse is in its normal connected position, cover I3, which is carried by the fuse holder I1, is arranged to close the open front of housing I0. As will be seen from the drawing, the front rim of the housing is provided with a flanged recess 24 into which the rim of the cover is arranged to seat, as indicated at 25, in suiilciently close cooperative Erelation with the housing to prevent; the entrance of rain, snow and sleet to the interior of the housing and thus protect the parts of the cutout from damage by adverse4 weather conditions. I y

In the exemplary embodiment illustrated, f use unit I4 and the cover I3 carried thereby are sup.- ported in the housing I0 by means of a toggle mechanism, one lever arm or element 26 of which is hingedly supported on hinge pins 2l carried by the housing, and the other arm or element 28 of which is pivotally connected to the element 26 as indicated at 30. A tension spring 3| is connected between thetwo arms 26 and 28 and tends to effect collapse of the'toggle mechanism. The details of the construction of this supporting toggle mechanism, which form no part of the present invention, are fully set forth in the previously referred to copending application of Benjamin R. Hermann and hence there will be described herein only sufilcient of the mechanism to insure a proper understandingv of the present invention.

Toggle arm or element 26 is provided with slots 32 and 33 for the slidable engagement therewith of pins or studs 34 and 35, respectively, carried by a member 36 which is rigidly fastened to the fuse holder Il, thereby providing a pivotal and slidable connection between the fuse and the toggle mechanism. As best shown in Fig. 2, member 36 is formedV with two arms 3l and 38 which have bores for the accommodation of the fuse holder. The rigid fastening of the member 36 to the fuse holderA is effected by means of a screw 46 which engages openings in the arm 31 and is arranged to seat tightly in a groove 4I formed in one side of the fuse holder. Due to the loose fit of fuse holder Il within the openings I5 and I6 of bosses I5 and I 6 on the cover, arms 31 and 38 of member 36 are free to move to a limited extent between the boss I6 and a boss 42 formed integrally With the cover and having a groove 43 in which the fuse holder may slide. e Arm 3l has a shoulder or abutment 44 and interposed between this shoulder and the boss 42 is a compression spring 45 which acts normally to maintain the cover in an elevated position with respect to the fuse holder andthe housing so that boss I6 contacts with arm 38 and the top of the cover seats ina goodweathertight manner in the upper portion of recess24 as indicated at 25.

The hinged element or lever arm 26 of the fuse unit supporting toggle mechanism is provided with a strap 46 and, as best shown in Fig..1,rthe lower end of fuse holder I1 is latched normally in rigid engagement with the strap by means of conductor 20 which is securely clamped to the strap vto a contact 50 carried by element 28 of the i7og' gie. vThis strip serves toinsure good electricy connection between that contact 5|! and the lower end of the fuse unit and to minimize current flow f through spring 3i and the elements of the toggle mechanism. L

To the back of the housing I0 there is secured a mounting bar, partially indicated at 5I, for the attachment of the cutout to a suitable supporting structure, not shown. For manual operation of the cutout, cover I3 is provided with a handle 52 which may be grasped manually or engaged by a suitablefform of switch stick 'to swing the fuse unit and door assembly inwardly and outwardly about the hinge pins 21. i

When the cutout is closed, fuse unit I4 then, being connected between fixed contacts I I and I2 and door I3 closing the front of housing lIII as illustrated in Fig. l, elements 26 and 28 of the supporting toggle mechanism are Amaintained in the extended relation shown by the pressure of contact 50 ,againstthe bearing surface of contact I2. Under these circumstances spring 3i tends to effect collapse of the toggle mechanism as fully described in the previously referred to Hermann application, to cause outward movement of the fuse unit and door assembly. However, the combined action of seat 23 and resilient backing strip 22 serves to latch contact cap Il in. engagement with contact finger 2| and to prevent the upper end of this assembly from swinging outwardly about hinge pins 21, while the toggle mechanism and the lower` end of the fuse unit and door assembly are latched by means of conductor 2li and clamping screw 41. The lower latch remains operative as long Nas the fuse link remains intact and the fuse unit is maintained thereby in its inward position connected between fixed, contacts II and I2, the connection at the upper end being through contact nnger 2i to contact cap I8 and at the lower end through contact 5II and strip 48-to conductor 2li. While the Vfuse unit is in this connected position,` cover I3 eiIectively closes the front of housing III, as previously pointed out, to prevent the entrance oi' rain, sleet and snow to the interior of the housing. If it is desired to open the cutout while the fuse link remains intact, this may be .done by 'grasping the handle 52 on the cover, either manually'or by means of a; suitable switch stick, and pulling outwardly with sumcient force to disengage contact cap I8 from seat 23 ofcontact finger 2i. The fuse holder, door and toggle assem- 4"bly can then be swung outwardly and downwardly as a unit to a position at which the fuse unit is disconnected from the stationary contacts. On the other hand, operation of fuse unit I4, when it is in .its normal connected position shown in Fig. l, results in automatic operation of the cutout. Only suiiicient of the operation asis necessary for a full understanding of the present invention will be given herein, and reference may be had, if desired, to the previously' identied Hermann application for the details of the complete automatic operation. The first step in the operation of the'cutout is the expulso that the toggle mechanism can become etlective to operate 'the cutout. At the same time. the downwardly directed expulsion action of the fuse unit produces a violent upwardly directed Vrecoil of 'the fuse holder since there is present usually some slack in the various connections ofthe parts of the fuse supporting mechanism. In previous constructions wherein the door has been mounted on the Lfuse holder with little or no provision made 'for relative movement between the fuse holder and the door, this recoil of the fuse holder, though partially absorbed by the fuse supporting structure and by the upper contact backing strip, still has been transmitted to the door to a sufiicient extent to produce a violent upward movement of the door. As a result of this violent upward movement the upper rim of the door frequently strikes the front of the porcelain housing with sufiicient force to cause chipping or complete breaking of the door or the housing or both. An expedient for preventing such damage has been to provide a wide clearance between the door and the housing at the point designated 2l onthe drawing. Under certain weather conditions,VV this wide clearance has permitted the entrance of rain, sleet and snow into the housing. Inthe cutout constructed in accordance with my present invention, the normal action of spring 4l maintains the upper rim of the door in a re.la-`V tively close weathertight relation with respect to the wall of `recess 24 so that it is impossible for rain, sleet and snow to enter the housing to impair the parts of the cutout, while my improved' the fuse holder and the door so that insuiilcient of the force oi the recoil is transmitted to the doonto cause damage tio the housing or to the VVdoor itself. Furthermore, the cushioning action of the spring in combination with the inertia of the door produces a shock absorbing eii'ect which tends to relieve the fuse holder supporting structure of some of'the shock of the recoil. The positions of the parts of the cutout immediately subsequent to rupture of the fuse link are 'illustrated in Fig. 2 wherein the fuse holder is shown as having4 moved upwardly in the loose fitting openings I5. and Ii' of thebosses I5 and II. respectively, of the cover, and arm 3l is shown as having moved away from the boss Il while spring 45 is shown as being compressed between the shoulder 44 of arm 31 and the lower face of the boss 42.l j y From the foregoing description, it will be evi'- dent that my improved arrangement for mounting the door of the enclosed cutout on the fuse holder makes it possible to adequately protect the parts of the cutout from all sorts oi.'r adverse weather conditions and at the same time protects do so, the details of the invention may be sultu ably modiiied for' incorporation in other forms of fuse cutouts without departing from the true spirit and scope of the invention as dened in the appended claims. Y

yWhat I claim as new and desire to secure by Letters Patent of the United States is:

1. In an electric cutout, the combination of a housing having an opening in a side thereof and having a movable door for closing the opening to protect the interior of the housing from adverse weather conditions, an expulsion fuse unit mount` edv and electrically connected within the housing,

' and means supporting the door on said fuse unit vfili with the rim of the door in closely cooperative substantially weathertightrelation with respect to the rim of said opening and'operative upon recoil of the fuse unit incident to fuse operation for minimizing the transmission of shock through the door to the rim of the housing opening.

2. In an electric cutout, the combination of a housing having an opening, in a side thereof, a door for closing the opening to protect Athe in'- terior of the housing from adverse weather conditions, an expulsion fuse unit mounted and electrically connected within the housing,`means for supporting the door on the fuse unit with the rim of the door in relatively close relation to the rim of the housing, and shock absorbing means operative to minimize the transmission of the recoil force from the fuse unit to the door upon operation o! the fuse unit.'

3. In an electric cutout, the combination of a housing having an opening in a side thereof, an expulsion fuse unit, means for mounting and electrically connecting the fuse unit within the housing, a door for closing said opening to protect the interior of the housing from vadverse weather conditions, and means for movably mounting the door on the fuse unit with the rim of the door in cooperative weathertight relation with respect to the rim of said opening including a shock absorbing device operatively connected between the door and fuse unitv for minimizing the transmission to the door of the recoil force of the fuse unit incident to fuse operation to thereby prevent damaging impact of the door against the rim of the housing opening.

4. In an electric cutout, the' combination of a housing having an open-side, a door for closing said open side, an expulsion fuse unit mounted and electrically connected in lthe housing,

means for supporting the door on the fuse unit with the rim of the door in relatively close engagement with the rim of said open side of the housing, and shock absorbing meansl operative to prevent damaging impact of the door rim against the rim of the housing upon recoil of the fuse unit incident to fuse operation.

' 5. In an electric cutout, the combination of a housing having an open side and a flanged recess extending around the rim of the top and at least a portion of the sides of said open side, an expulsion fuse unit mounted and electrically connected in the housing and having a downwardly directed gas discharge opening, a door arranged to seat in said flanged recess to close the opening, and means for supporting the door on the fuse unit operative normally for maintaining the top edge of the door substantially in engagement with the top wall of said ilanged recess and operative upon recoil'of the fuse unit incident to fuse operation for preventing damaging impact of the door against said top wall ot the iianged recess.

6. In an enclosed fuse cutout, the combination of a housing having an opening in a side thereof, spaced contacts mounted in the housing, an expulsion fuse unit, means for supporting the fuse unit in the housing connected between the contacts, a door, means for mounting the door slidably on fuse unit in position to close said opening when the fuse unit is in connected position, a boss rigidly carried by the door, a second boss rigidly carried by the fuse unit and a. spring operatively connected between said two bosses for the transmission to the door of the recoil of the iuse unit upon fuse operation.

7. In an electric cutout, the combination of a housing having an open side, an expulsion fuse unit mounted and electrically connected within the housing, a door for closing said open side, means for motuiting the dooron the fuse unit including bosses carried by the door and having openings for the relatively loose slidable accommodation of the fuse unit, means providing an abutment rigidly carried by the door, means pro-l viding an abutment rigidly'carried. by the fuse unit and a spring operatively disposed between said abutments for maintaining the top of said door in relatively close engagement with the top Vsaid housing opening, means for siidably mounting the door on the fuse unit with the rim of the door seated'in said ilanged recess of the housing, and spring means operatively connected between the door and fuse' unit for maintaining the top of the door in substantially weathertight relation with respect to the top portion of said flanged recess, said spring being operative also upon recoil of the fuse -unit incident to fuse .operation for absorbing at least part fof the force of such recoil and preventing damaging impact between the top of the door and the housing.

9. In an electric cutout, the combination of spaced contacts, an expulsion fuse unit, means for supporting the fuse unit connected between the contacts, and an inertia element movably and resiliently mounted on the fuse unit for absorbing at least part of the shock of the fuse unit recoil incident to fuse operation to thereby minimize the strain to which said supporting means is subjected due to such recoil.

10. In an electric cutout, the combination of spaced contacts, an expulsion fuse unit, means for connecting the fuse unit between the contacts, means for supporting the fuse unit removably in a connected position, an element mounted slidably on the fuse unit and a spring connected between said element and the fuse unit to provide a cushioning action therebetween upon recoil of the fuse unit incident to fuse operation, said element having suiiicient inertia upon recoil of the fuse unit to cause said spring to act as a shock absorber to relieve said lfuse supporting means of a portion of the shock of such recoil.

. RALPH s. BENNETT.

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