US2983803A - Load interrupter housed fuse cutouts - Google Patents

Description

May 9, 1961 MccLQUD 2,983,803

LOAD INTERRUPTER HOUSED FUSE CUTOUTS Filed Feb. 3, 1959 6 Sheets-Sheet 1 INVENTOR.

GEORGE R. M CLOUD ATTORN EY G. R. M CLOUD LOAD INTERRUPTER HOUSED FUSE CUTOUTS May 9, 1961 6 Sheets-Sheet 2 Filed Feb. 3, 1959 INVENTOR. GEO RGE Rv M CLOUD ATTORNEY May 9, 1961 G. R. MccLouD 2,983,803 LOAD INTERRUPTER HOUSED FUSE CUTOUTS Filed Feb. 3. 1959 s Sheets-Sheet s INVENTOR. GEORGE R. M CLOUD ATTORNEY y 9, 1 G. R. MCCLQUD 2,983,803

LOAD INTERRUPTER HOUSED FUSE CUTOUTS Filed Feb. 3, 1959 6 Sheets-Sheet 5 a O l 3? INVENTOR. 57 GEORGE R. MQCLOUD ATTORNEY May 9, 1961 G. R. MCCLOUD 2,983,803

LOAD INTERRUPTER HOUSED FUSE CUTOUTS Filed Feb. s, 1959 e Sheets-Sheet e INVENTOR. GEORGE R. M -CLOUD ATTORNEY United States Patent ()fifice Patented May 9, 1961 LOAD INTERRUPTER HOUSED FUSE CUTOUTS George R. McCloud, South Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Feb. 3, 1959, Ser. No. 790,850

8 Claims. (Cl. 200-114) This invention relates to new and useful improvements in a load interrupter fuse cutout and more particularly to fuse cutouts of the housed type wherein provision is made for mechanically breaking the fusible elements subject to a load current in an electric circuit.

The usual practice is to provide, in an electrical system, a fuse for interrupting a circuit under overload conditions and in series therewith, a circuit breaker which may be manually operated to open the circuit operating under normal load conditions.

Theoretically, the fuse can be used as a circuit breaker. However, the fuse contacts are not designed to withstand the destructive effects of arcing when the contacts are separated under load.

The principal object of this invention is to provide a fuse cutout having a fuse link which will interrupt the circuit under overload conditions and including manually operable means for breaking the fuse link when it is desirable to interrupt the circuit under normal loads, thus dispensing with the use of the circuit breaker in series with the fuse cutout permitting the operation of the fuse cutout to open circuit position without producing injurious arcing between the fuse contacts.

Another object of the invent-ion is to provide a housed fuse cutout wherein the link break mechanism for rupturing the fuse link is selectively actuated only when it is desired to operate the link break means.

A further object of this invention is to provide a housed fuse cutout which is selectively actuated by a link break tool which may be attached to a hook stick or the like, said link break tool being adapted to impart rotative mo tion to a link break means which is fixed to the door assembly of the cutout, said rotational motion in turn being changed with an increased mechanical advantage to translational movement to break the fuse link.

A further object of the invention is to provide a housed fuse cutout which needs 'no latching means to maintain the fuse tube means in circuit bridging relation in the cutout during operation of the link break means, since the rotative motion of the link break tool imparts a moment of force in the same direction as the door closing direction.

A further object of this invention is to provide a housed fuse cutout which has no projecting electrically live parts extending beyond the confines of the insulating housing for dangerous engagement by a lineman.

A further object of the invention is to provide 'a'housed fuse cutout with a link break mechanism which is exceedingly simple to operate, requires an absolute minimum of parts, and is otherwise well adapted for the purposes for which it was designed.

The novel features which are characteristic of the invention areset forth with particularity in the appended claims. The invention, itself, both as to its organization and its method of operation, together with additional objects and advantages thereof will best be understood by the following description of specific embodiments when read in connection with the accompanying drawings in which:

Fig. 1 is a side view, a portion of which is in section, showing one embodiment of the inventive concepts;

Fig. 2 is a front elevational view of the device shown in Fig. 1;

Fig. 3 is a fragmentary sectional view of the lower right hand portion of Fig. 1, the parts being shown when the fuse link is in non-ruptured operative position in the assembly;

Fig. 4 is a sectional view of the same parts shown in Fig. 3 immediately after operation of the link break means rupturing the fuse link;

Fig. 5 is a perspective view of the type of tool which may be manually or hook stick operated to cause rotative motion of a portion of the link break means;

Figs. 6 and 7 are semidiagrammatic views showing the relative positions of the parts of Figs. 1 to 4 during the sequential link breaking operation;

Fig. 8 is a view, a portion of which is in section, of an alternative embodiment of the invention having subs-tantially similar inventive concepts;

Fig. 9 is a reduced scale, full line, front view of the cutout shown in Fig. 8;

Figs. 10 and 11 are schematic views similar to Figs. 6 and 7 showing the sequential operation and position of the parts of the embodiment shown in Figs. 8 and 9;

Fig. 12 is a fragmentary sectional view of a third embodiment of the invention having substantially similar inventive concepts;

Figs. 13 and 14 are views similar to Figs. 6 and 7 and 10 and 11 showing the operative position of the parts on the third embodiment shown in Fig. 12.

Returning now to Fig. 1 of the drawings, this embodiment of the invention comprises a porcelain housing H for a housed fuse cutout having an open front and bottom and a door D made of insulating material for closing the open front of the housing. The housing H has a top 15, back portion 16, and side portions 17 and 18 which define the aforementioned open front and bottom. It is to be noted that some embodiments of housed cutouts are designed for use with a double vented fuse and in this type of cutout the housing is formed with a large aperture in the top of the cutout (not shown) or with no top portion at all. Mounted in the rear wall 16 of the housing, intermediate the top and bottom of the cutout and facing outwardly therefrom is a hanger 19 by which the cutout may be conveniently mounted to a crossarm or the like.

Interiorly of the housing H and on the inside of the back wall 16 are a pair of spaced terminal means, the upper terminal means being denominated 22 and the lower terminal means being denominated 23, both being adapted for receipt of electrical conductors 20 and 21, respectively, which are here shown semidiagrammatically.

The upper terminal means includes the upper contact assembly 24 which has generally U-shaped side contacts 25 and a spring top contact member 26, whereas the lower terminal means 23 includes the lower contact means 27 which comprises side contact blades 28 which are generally U-shaped in configuration. The foregoing is conventional and well understood in the art.

A closure assembly 30 comprises the door D which is pivotally mounted on pins 29 which project inwardly from the side walls 17 and 18 near the bottom of housing H. A pair of cooperating trunnions 31 are conveniently formed on the outside of a hollow box-like contact sleeve 32, the latter being fixedly mounted to the door D by means of mounting screws 33, or the like. Thus, pins 29 and trunnion 31 afiord the positioning of the door D and the entire closure assembly 30 in operative position in the housing of the fuse cutout.

A fuse is normally disposed to electrically bridge the upper and lower contact terminals 22 and 23 and as here shown generally comprises the fuse tube 34 which the link 37 causing the latter to rupture.

is open at its lower end and closed at its upper end by a metallic contact cap 35 which frictionally engages the upper contacts 25, 26 of the upper contact means 24.

Near the lower portion of the closure assembly 30 is the aforementioned generally box-like contact sleeve 32 which is formed of metal and the outer portion of which is configured to electrically engage the lower contact means 27 when the door assembly is closed. The top surface of contact sleeve 32 is for-med of an aperture for receiving the tube 34 therethrough, there being a through pin 36 which locates and retains the tube 34 in fixed relation to the contact sleeve 32.

A fuse link 37 is normally disposed within the fuse tube 34 in conventional fashionand has a rupturable thermally responsive portion intermediate the ends there of. The end or tail of the fuse link 37 is securably mounted to the contact sleeve 32 by means of a manually 'tightenable mounting means 38 located on the inwardly facing (to the left as viewed in Fig. 1) portion of the contact sleeve 32 to electrically bridge terminals 22 and 23. Spring loaded flipout lever means (as shown in Figs. 3 and 4) and denominated with reference to numeral 40 may be disposed at the bottom of the contact sleeve 32 adjacent to and engaging the fuse link 37. The purpose of the fiipout lever means 40 is to flip the severed fuse link from within the fuse tube upon rupture of the fusible portion 37-a in accordance with standard procedure.

It will be noted that the door D is formed with a conventional pull ring 39 on the outside thereof at its upper extremity, said door being operative to rotate the fuse means and contact sleeve 32 about pins 29 and trunnions 31 to remove the entire assembly from the housing as desired.

Means 41 for breaking the link are comprised of components associated with the closure assembly 30. More particularly, these components comprise a link break member 42 which is generally cylindrical in shape and is surroundingly disposed to the lower portion of the fuse tube 34, said member 42 being formed with a depending lip 43 which engages fuse link 37. As perhaps best shown in Figs. 3 and 4, the right hand side of the link break member 42 is formed with a rack portion 44 which is engageable by a pinion 45 which is operatively mounted closely thereto and which will be described in more detail hereinafter.

A pair of pins or cars 48 are firmly attached to and extend transversely of link break member 42 and are adapted to ride in a pair of elongated guide slots 49 formed in the side walls of the contact sleeve 32. It will be noted that slots 49 are in axial alignment with fuse 'tube 34 and serves to prevent twisting action of the rack 44 when a load is imposed by the pinion 45.

Pinion 45 is generally cylindrical in shape and formed with teeth which engage rack 44. The pinion 45 is further formed with a reduced diameter portion 46 extending through a suitable bearing aperture 32-a formed in a rearward depending portion of the contact sleeve 32. A square aperture 47 is for-med in the center of the pinion 45 to receive a tool 50 (shown in Fig. having generally square keyed portions 51 which extends transversely from handle 52 and are adapted to fit within the square aperture 47 of the pinion.

The sidewalls of the lower portion of the door D are formed with suitable apertures 30-a and 30-11 which are in alignment with aperture 47. It is thus seen that the tool 50 may be inserted from either side of the door of the housing into aperture 47 and is operable such that movement of the tool will cause pinion 45 to rotate in a counterclockwise direction. This, in turn, imparts a mechanical advantage by virtue of the rack 44 to the link break member 42 which moves downwardly and depending lip portion 43 puts an extreme stress upon It will be noted that the counter-clockwise movement of pinion I M2,983,803 i 45 also imparts a moment of force to the entire door assembly 30 in a door closing direction and thus no latching mechanism is necessary to hold the closure assembly in operative position during link break operation.

The link break tool 50 is made with an elongated handle portion 52 which may be manually actuated. The end portion of the handle section 52 is f rther formed with an aperture 54 for movement by a ,onvention hook stick, or the like. A raised portion of the handle near the square tool section 51 is formed with a keyed slot 53 which is adapted to be handled by a hook stick to alford entry of the tool portion 51 within the apertures 47 of the pinion when the operator is located at a position spaced a considerable distance from the cutout.

It will be observed that the foregoing described mechanism affords an exceedingly simple to operate link break mechanism wherein the job of exerting some 200 pounds of force upon, for example, a amp. link 37 is done with a very minimum of parts and with no latches or other complicated mechanism to hold the door in place during operation of the link break means. Further, since the link break means is selectively actuated, there'is no need to rupture the link 37 on opening of the cutout when there is no load current across the upper and lower terminals of the cutout and, thus, no danger of arcing.

The embodiment shown in Fig. 8 of the drawings is substantially similar to the embodiment hereinbefore de scribed except for location of the link break means 61 which is on the left side of the closure assembly (as viewed in Fig. 8). To afford entry of the link break tool 50, the side walls 17 and 18 of the housing H are formed with apertures 67 (shown in Fig. 9) therein. This construction afiords a standard door D rather than the modified door shown in Fig. 1.

More particularly, this second embodiment is constructed such that the link break member 62 is substantially longer than link break member 42 shown in the earlier embodiment so that the rack portion 64 may be conveniently placed at the top thereof. It will be noted that the rack faces inwardly i.e., to the left as viewed in Fig. 8 and the pinion 65 is disposed in a rotative position in suitable apertures in the contact sleeve 32.

As shown in Figs. 10 and 11, when the tool 50 is inserted within square pinion aperture 66, clockwise movement of pinion 65 causes rack 64 to move downwardly thereby causing link break member 62 to impose a stress upon link 37 causing rupture thereof, thereby rupturing the link within the confines of the fuse tube. There is no need for latching mechanism in this embodiment since the closure assembly 30 cannot move outwardly because the tool 50 would engage the side wall of the apertures 67, of the housing side walls 17 or 18.

The third embodiment (shown in Figs. 12 through 14) of the drawings is substantially identical in principle to the foregoing embodiments, the difierence being mainly in the type of lnk break means 71 for imparting a mechanical advantage to a link break member 72 having depending lip 74 in engagement with the fuse link 37. More particularly, the link break means 71 comprises a rotatably disposed square bar 78 having a square central bore 77 and a pair of annular shoulders 76 for hearing rotative engagement with suitable apertures formed in the contact sleeve 32. A pair of load imposing lever members 75 are formed with a square aperture 78 to fit over and engage the square bar 78. In spaced position to square aperture 78' on lever member 75 is an enlarged circular aperture 81 which is adapted to surround and engage pins 73 which are projecting from the top portion of the cylindrical member 72. Circular apertures 81 are of suflicient size that there is no binding of pins 73 on downward motion of member 72 in the translation of the rotative counter-clockwise movement of lever arm 75 about shoulders 76 into downward movement of link break member 72.

It will be noted that the back edge portion 79 (to the right as viewed in Fig. 12) of lever member 75 is curvilinear and is adapted to engage and coact with a backing bearing plate 80. This provides a bearing surface so as to eliminate excessive stress upon the shoulder bearings 76 in the side walls of the housing 32. As is quite apparent from drawings 13 and 14, the tool 50 is adapted to be inserted in square aperture 77 such that counter-clockwise movement of the bar 78 causes lever arm 75 to impart downward movement to link break member 72 causing the link 37 to rupture. This action is similar to the first embodiment.

Although specific embodiments of the invention have been shown and described, it is with full awareness that many modifications thereof are possible. The invention, therefore, is not to be restricted except as insofar as 18 necessitated by the prior art and by the spirit of the appended claims.

What is claimed as the invention is:

1. A housed fuse cutout comprising, in combination, a housing, closure means for said housing, means for releasably pivoting said closure means on said housing, first and second electrical terminal means disposed within said housing, fuse means fixedly mounted on said closure means electrically bridging said first and second terminal means when said closure means is in closed position including a fuse tube and a mechanically rupturable fuse link therewithin, means for mechanically rupturing said fuse link including motion translating means comprising a cylindrical rack member disposed in surrounding relation to a portion of said fuse tube and engagmgsard fuse link and movable axially of said fuse tube 1n a direction to rupture said fuse link, and a pinion member mounted for rotation about its axis and operably engaging said rack member, said pinion membenhavmga rotatable shaft portion accessible from the exterior of said housing, detachable, manually operable tool means having an elongated portion extending radially of the axis of said shaft portion, and releasable interlocking, rotation-transmitting means between said shaft portion of said pinion and said tool means, said elongated portion, constituting force-multiplying lever means, whereby rotation of said tool means actuates said link break means to rupture said fuse link and imparts a force to said closure means in a direction to urge it toward closed position.

2. A housed fuse cutout comprising, in combination, a housing having at least a back portion and a pair of side portions, a support member, interengaging trunnion and bearing means releasably pivoting said support member on said housing, closure means for said housing fixedly attached to said support member, first and second electrical terminal means disposed within said housing, fuse means fixedly mounted on said support member for normally electrically bridging said first and second terrmnal means, said fuse means including a fuse tube and a mechanically rupturable fuse link therewithin, means for mechanically rupturing said fuse link including motion translating means comprising a first member dlsposed in surrounding relation to a portion of said fuse tube and movable axially of said fuse tube in a direction to rupture said fuse link, and a second member mounted on said support member for rotation about its axis and operatively engaging said first member, said second member having a rotatable shaft portion provided with releasable tool interlocking means, one of said side portions of said housing having an aperture in alignment with said shaft portion, detachable tool means adapted to be d1sposed in said aperture and having a first portion complementary to and adapted to engage said interlocklng means and a second elongated portion extending radially of the axis of said shaft portion, whereby arcuate motion of said tool means actuates said link break means to rupture said fuse link and the walls defining said aperture in said side portions of said housing cooperates with said tool means to prevent said closure means from opening during link break operation.

3. A housed fuse cutout comprising, in combination, a housing, a support member, interengaging trunnion and bearing'means releasably pivoting said support member on said housing, closure means for said housing fixedly attached to said support member, first and second stationary contact means disposed within said housing, fuse means fixedly attached to said support members for electrically bridging said first and second contact means While said closure means is in closed position, said fuse means including a fuse tube and a mechanically rupturable fuse link therewithin, means for mechanically rupturing said fuse link including motion multiplying means comprising a first member disposed in surrounding relation to a portion of said fuse tube and movable axially of said fuse tube in a direction to rupture said fuse link, a second member mounted on said closure means for rotation about its axis and provided with releasable tool-interlocking means accessible from the exterior of said housing, means operatively engaging said first member and said second member for translating rotational motion of said second member into rectilinear motion of said first member, detachable, manually operable tool means having a first portion complementary to and engaging said releasable tool-interlocking means on said second member and a second elongated portion extending radially of the axis of said second member, whereby arcuate movement of said tool means incident to a force imparted to said second portion as a lever arm actuates said link break means to rupture said fuse link and exerts a force on said closure means tending to urge said closure means toward closed position.

4. A housed fuse cutout comprising, in combination, a housing, closure means for said housing pivotally mounted thereon, first and second electrical terminal means disposed within said housing, fuse means disposed within said housing electrically bridging said first and second terminal means including a fuse tube and a mechanically rupturable fuse link within said fuse tube, means for mechanically rupturing said fuse link including motion translating means having, a first member mounted on said closure means and engaging said fuse link and movable in a direction to rupture said fuse link and a second member operatively connected to said first member and mounted on said closure means for rotation about its axis and having a rotatable shaft portion accessible from the exterior of said housing provided with noncircular tool engaging means, and a tool having a noncircular first portion complementary to and adapted to engage said last-named means to couple said tool and said second member for rotation and an elongated second portion extending radially of the axis of said shaft portion and providing an elongated lever arm.

5. A housed fuse cutout comprising, in combination, a housing, a member, interengaging trunnion and bearing means pivotally mounting said member on said housing, closure means for said housing fixedly attached to said member, first and second electrical contact means disposed within said housing, fuse means fixedly mounted on said closure means for electrically bridging said first and second contact means when said closure means is in closed position, said fuse means including a fuse tube and a mechanically rupturable fuse link therewithin, means for mechanically rupturing said fuse link including motion translating means, said motion translating means including a cylindrical member disposed in surrounding relation to a portion of said fuse tube engaging said fuse link and movable axially of said fuse tube in a direction to rupture said fuse link and a member mounted on said closure means for rotation about its axis and engaging said cylindrical member, said rotatably mounted member having a rotatable shaft portion accessible from the exterior of said housing provided with noncircular tool engaging means thereon, detachable,

manually operable tool means having a noncircular first portion complementary to and adapted to engage said last-name means for transmission of rotary motion therebetween and an elongated second portion extending radially of the axis of said shaft portion, whereby arcuate motion of said tool means having said elongated radially extending second portion as a lever arm actuates said link break means to rupture said fuse link.

6. A housed fuse cutout comprising, in combination, a housing, closure means for said housing, means for releasably pivoting said closure means on said housing,

first and second electrical terminal means disposed within said housing, fuse means fixedly mounted on said closure means and disposed within said housing electrically bridging said first and second terminal means when said closure means is in closed position, said fuse means including a fuse tube and a mechanically rupturable fuse in a direction tending to rupture said fuse link, and a second member operatively connected to said first member and mounted on said closure means for rotation about its axis, said second member having means thereon accessible from the exterior of said housing and rotatable independent of movement of said closure means for actuating said first member to rupture said fuse link.

7. A housed fused cutout comprising, in combination, a housing, closure means for said housing, means for releasably pivoting said closure means on said housing, first and second electrical terminal means disposed within said housing, fuse means fixedly mounted on said closure means and disposed within said housing electrically bridging said first and second terminal means when said closure means is in closed position, said fuse means including a fuse tube and a mechanically rupturable fuse link within said fuse tube, means for rupturing said fuse link including motion translating means having a first member mounted on said closure means and movable in ond member operatively connected to said first member and mounted on said closure means for rotation about its axis and being provided with releasable tool-interlocking means accessible from the exterior of said housing, rotation of said second member in a direction to rupture said fuse link tending to hold said fuse means in said circuit bridging position.

8. A housed fuse cutout comprising in combination, a housing, closure means for said housing pivotally mounted on said housing, first and second electrical contact means disposed within said housing, fuse means fixedly mounted on said closure means and disposed within said housing normally electrically bridging said first and second electrical contact means, saidfuse means including a fuse tube and a mechanically rupturable fuse link within said fuse tube, means for rupturing said fuse link including rack means slidably mounted on said closure means and adapted to engage said fuse link and movable in a direction to'rupture said fuse link, and rotatable pinion means operatively engaging said rack means and having releasable tool-interlocking means accessible from the exterior of said housing, rotation of said pinion means actuating said rack means in a direction to rupture said fuse link and also exerting a force againstsaid closure means in a direction to urge it toward closed position.

References Cited in the file of this patent UNITED STATES PATENTS 2,400,850 Steinmayer et al. May 21, 1946 2,672,539 Steinmayer Mar. 16, 195.4 2,680,171 Curtis et al. June 1, 1954 2,820,868 McCloud Jan. 21, 1958 2,835,764 Earle May 20, 1958 2,836,681 Bracey May 27, 1958 2,843,704 Wood July 15, 1958

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