Gould Inc.

Other

The Chase-shawmut Company

Gould Inc. Electric Fuse Division

Gould Inc., Electric Fuse Div.

Richard A Belcher

Frederick J Kozacka

Robert J Panaro

An electric fuse is provided with heat dam elements interconnecting the fusible element and the fuse end terminals, which are provided with one or more raised ribs integrally formed therein. The heat dams include a plurality of planar sections and interconnecting bends to which the ribs impart a high degree of stiffness and dimensional stability.

Electric fuse heat dam element having stiffening ribs

An electric fuse having a support for helically wound fusible element or elements. The support includes a plurality of rods which are supported at their opposite ends adjacent the fuse end terminal by rod supports each of which is made from a pair of angularly arranged sheet-metal channels. The channels have a U-shaped cross-section and are arranged with their open ends facing the center of the fuse housing. Centrally positioned sections of the channels are flattened to facilitate rigid attachment of the channels to one another. The ends of the rods are received in and attached to interior portions of the U-shaped channels. A sub-assembly comprising the rods, rod supports and the wound fusible elements is pre-assembled and, when placed in a fuse housing, the ends of the channels cooperate with the inside walls of the housing to properly position the entire assembly.

Support arrangement for a helically wound fusible element

A blade type fuse whose blades project through the end surfaces of the caps which close the tubular casing. Thus the blade contacts project from the outside of the casing into the inside thereof. There are a plurality of fusible elements inside the casing, all having substantially the same resistance. Some of the fusible elements inside the casing that interconnect the aforementioned blade contacts have a relatively small spacing from the plane defined by the pair of blade contacts. Others of the fusible elements that interconnect the aforementioned blade contacts have a relatively large spacing from the plane defined by the pair of blade contacts. All fusible elements are approximately equally distributed across the cross-section of the casing. This involves for some of the fusible elements a relatively large, and for others of the fusible elements a relatively small, spacing from the plane of the blade contacts to which their ends are attached. To compensate for this difference in spacing the resistance of the connector means is approximately inversely proportional to the spacing of the fusible elements from the plane defined by the pair of blade contacts. Thus the resistance of all fusible elements is equalized, irrespective of their position across the cross-section of the casing of the fuse.

Electric fuse having terminal caps and blades projecting through said

An electric fuse having a fuse tube or casing into the ends of which plug terminals are plugged. The plug terminals are conductively interconnected by a plurality of fusible elements, the number of which may change depending upon the desired current-carrying capacity of the fuse. Each plug terminal is provided with a recess in the center thereof. Each recess receives an insert member having a wide flange at right angles to the longitudinal axis of the insert member. A small gap is left between the axially outer end surfaces of the pair of flanges and the axially inner end surfaces of the plug terminals. The fusible elements are held in position by radial slots in the aforementioned flanges into which they are inserted, and their ends are bent 90 degrees and inserted into the aforementioned gap. A solder joint is placed in each slot containing a fusible element conductively connecting the bent ends of the fusible elements, the aforementioned flanges and the plug terminals. One or more additional solder joints may be used for connecting the flanges to the plug terminals.

Electric fuse

A fuse for elevated circuit voltages having a blown fuse indicator. The fuse is characterized by its great simplicity of design. Virtually all its components, or constituent parts, form a sub-assembly capable of being inserted as a unit into the fuse tube or casing. One terminal of the fuse is formed by a plug contact that defines a heating chamber for heating one end of the restraining wire for the blown fuse indicator above all other points thereof. The other terminal of the fuse is formed by a ferrule, or terminal cap, conductively connected to a perforated metal disk, or metal plate, arranged immediately adjacent thereto. That disk or plate performs four functions, namely (1) to help support insulating rods around which the fusible element is helically wound, (2) to form one of the terminals of the fusible element and of the restraining wire for the blown fuse indicator, and (3) to provide a large aperture through which the fuse is easily filled with arc-quenching filler.

Electric fuse for elevated circuit voltages

An electric fuse having plug terminals. The fusible elements are connected to the plug terminal by the intermediary of metal strips having three sections. One section is inserted into the grooves of the plug terminals and conductively connected with the latter. Another section is arranged in a plane parallel to, but spaced from, the plane defined by said first mentioned section. A third section of the metal strips conductively interconnects the first section and the second section thereof. The aforementioned strip, if of sufficient length, greatly increases the flexibility of the fusible-element-and-strip-unit, minimizes the voltage drop across the fuse if the strip is considerably thicker than that of the fusible element of the fuse, and permits an arrangement of the fusible elements within the casing of the fuse that does not depend on the arrangement of the grooves on the axially inner end surfaces of the plug terminals and allows the pulverulent arc-quenching filler to exert a maximal arc-quenching action.

Electric fuse having plug terminals

An electric fuse the fusible element of which is arranged off-center of the casing. The fuse casing is closed by caps through the end surfaces of which the knife blade contacts project into the casing. The spacing of the end surfaces of the caps to the axially inner ends of the blade contacts is substantially equal. Each of the axially inner ends of the blade contacts is conductively connected to the fusible element by the intermediary of a flexible metal strip having a smaller cross-section than each of the blade contacts. This imparts a relatively great flexibility to the unit including the blade contacts, the flexible metal strips and the fusible element.

Electric fuse having off center fusible element

An electric fuse including blade contacts projecting through the terminal caps into the casing. The axially inner ends of the blade contacts are conductively connected by electroconductive elements to the axially outer ends of the fusible element. The electroconductive elements each comprise a first planar arm conductively affixed to one end of the fusible element, a second planar arm arranged parallel to and spaced from said first planar arm and conductively affixed to one end of the blade contact, and tie means integral with said first and said second arm conductively connecting the axially outer end of said first arm to the axially inner end of said second arm.

Fuse terminal connector for one or more electric fuses

A sub-assembly for electric fuses comprising a perforated fusible element having a pair of ribbon ends. The ribbon ends are bent around the rims of the casing from the inside to the outside of the casing. In fuses including such a sub-assembly one of the ends may be pre-bent, i.e. bent prior to insertion of the fusible element and its pair of ends into the casing. The other end or non-pre-bent end, must be bent around one of the rims of the tubular casing to the outer surface thereof preparatory to the mounting of the terminal caps, or ferrules, on the casing. This bending operation may involve great difficulties, particularly if the pair of ends have great dimensional stability, and the perforated fusible element portion is relatively frail, and tends to be twisted and/or otherwise deformed when one of the pairs of ends is bent around the rim of the casing to the outer surface thereof. According to this invention the casing of the fuse is provided with a slot extending axially inwardly from one of its rims and has a sufficient length to allow insertion of the fusible element into said casing with both of its ends pre-bent. The pre-bent ends are angularly displaced relative to the slot in the casing which allowed the fusible element to be inserted into the casing with both ends thereof pre-bent. Also described herein is a sub-assembly having a pair of longitudinal slots rather than but one.

Electric fuse and method of manufacturing the same

An electric fuse having a support for the helically wound fusible element or elements. The support includes a plurality of rod-like supports each made of one uniform material. Some of the plurality of rod-like supports consist solely of a non-gas-evolving material, while at least one of the plurality of rod-like supports consists solely of a gas-evolving material.

Electric fuse having composite support for fusible element

A time-lag fuse of the type including a fusible element proper, and heat dams formed by strips of sheet metal folded in a direction transversely to the direction of the fusible element proper impeding the axially outer heat flow from said fusible element proper. The fusible element proper has several straight edges extending parallel to the axis of the casing of the fuse. Points of the heat dams engage the inner surface of the casing of the fuse and thus ensure correct positioning of the fusible element proper, i.e. in such a way that its edges extend always parallel to, and are equidistantly spaced from, the axis of the casing. The heat dams engage the inner surface of the casing at discrete points only, to minimize the area of engagement between said heat dams and the inner surface of the casing and to thus minimize direct heat flow from one to the other.

Electric fuse having heat retaining means

An electric fuse suitable for motor-starting, i.e. having a considerable time-lag in the range of motor starting currents, and at the same time having a current-limiting action in the high fault current range, characterized by extremely small peak let-through currents and extremely small clearing I.sup.2.multidot. t values. To be more specific, fuses emboyding this invention have considerably smaller maximum peak let-through currents and considerably lower clearing I.sup.2.multidot. t values than Underwriter Laboratories Class RK5 fuses, and meet the maximum acceptable peak let-through current values and clearing I.sup.2.multidot. t values of Underwriter Laboratories Class RK1 fuses. This is achieved by combining specific time-lag means involving a minimum of mass with parallel current paths of greatly increased number and greatly decreased size.

An electric fuse has helically wound fusible element means which are supported by a mandrel made up of insulating plates. The latter engage grooves provided in terminal plugs of the fuse. The mandrel-forming plates are locked in position inside said grooves by cooperating abutment means. These abutment means are formed by recesses in the mandrel-forming plates, and by projections formed by displaced portions of the metal of which the plug terminals of the fuse are made, which portions enter into said recesses in said mandrel-forming plates and preclude relative movement of the latter and the plug terminals.

Electric fuse with plate-supported fusible element

A fuse for elevated circuit voltages, e.g. 4-34 kv, has a tubular insulating casing closed on both ends thereof by means of plug terminals. The latter are provided with blind bores of which each receives one end of a fusible element, a spring means for clamping said end of said fusible element against the lateral wall of said blind bore, and a solder joint conductively interconnecting said end of said fusible element and one of said plug terminals.

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Hampton Falls, NH, United States of America

Richard A Belcher