US 761675 A
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PATENTED JUNE 7, 1904.
W. J. HARTWIG. ELECTRIC CUT-OUT.
APPLIOATIQN HLBD'PEB. 29, 1904.
163mm MMM. hisk Wouw different styles of terminals.
UNITED STATES Patented June f7, 1904.
l ELECTRIC CUT-OUT.
SPECIFICATION forming part of Letters Patent No. 761,675, dated June 7, 1904.
Application filed February 29, 1904. Serial No. 195,786. (No model.)
T0 @ZZ U17/1,0777, it may concern:
Be it known that I, WILLIAM J. HARTWIG, a citizen of the United States, residing at Def treit, in the county of Wayne and State of Michigan, have invented a new and Improved Electric Cut-Out, of which the following is a specification.
This invention relates to automatic circuit interrupters or cut-outs, often termed cfuses, and is intended to produce an instant interruption of the current and of the arc formed by the action of the fuse in opening` the circuit.
rIhe objects of my invention are to provide a fuse-strip that may be easily and quickly replaced, to provide a housing that will prevent the fiame of the arc caused by the disruption of the fuse from escaping, to provide means for instantly breaking the arc inside the housing, and to provide a cut-out that is simple, cheap, and durable. I attain these objects by the construction illustrated in the accompanying drawings, in which` A Figure 1 is a detail of the arc-breaking means. Fig. 2 is a viewv of the fuse-strip. Fig. 3 is a longitudinal cross-section of the fuse-holder. Fig. 4 is an end view of the head for the housing. Fig. 5 is a View of the cut-out, the housing being in section. Fig. 6 isa plan of the cut-out provided with a different style of terminal. y Figs. 7, 8, and 9 are end views of the cut-out provided with Fig. 10 is a side View o f a modified terminal, and Fig.. 11` is a detail of the arc-breaking means.
Similar Vreference characters refer tolike parts throughout the several Views.
The housing 1 of the cut-out is shown to be around tube of iireproof insulating material, such as guttapercha or vulcanite, although it may be of any other desirable cross-section or material. In the ends of theV housing are two split heads 2, held in place by the screws 3, which heads may be of metal or any other desirable material. Between the heads is the fuse-holder 4, a split tube of insulating mfterial, having heads 5, of any desirable cementitious insulating material, a mixture of plaster-of-paris and asbestos being preferred. The fusible conductor-strip 6 passes through the heads 2 and 5 and projects beyond the ends of the housing. In Figs. 2, 3, and 5 I have shown the ends-of the strip bent down to form brackets to be engaged by the ordinary terminal binding-posts. In Fig. 8 I have shown the ends of the'strip straight and provided with fiat strengthening-plates 14, preferably of copper, secured on each side, so that the fuse may be placed between spring terminals or clips `similar to those used in knife-switches.
The conductor-strip has enlarged ends 8, having shoulders 17 and a straight portion 7, which is of the same length as the fuse-holder 4. Intermediate the shoulders, preferably in the middle of 7, the conductor-strip is reduced in cross-sectional area to a size that will depend upon the amount of current under which it is desired that the strip shalldisrupt. The thickness ofV this strip and the width at the point 9 can be precisely measured, and therefore the disrupting-current predetermined with great accuracy.
When a heavier current than desired passes over the conductor 6, the small portion at 9 will be softened and melted. To extinguish the arc forming when the fuse breaks, I provide two springs 11, the outer ends of which are embedded in the heads 5. The inner ends of the springs are provided with notched plates of insulating material, mica preferred, which rest on the strip 6 at 9, as shown. These springs are of little strength, but are suficient to aid in disrupting the softened conductor and to press the plates 13 against each other, thus placing a barrier of insulation material in the path of the are. The springs may be of crimped fiber, as shown, or a fiat piece of mica of suificient length may be secured in the heads in a mannerto be under tension. v A strip of paper 12 is pasted around the fuse-holder 4 and holds tlie conductor in place.
When it is desired to replace a fusible strip 6, the cut-out is removed from its terminals and the screws 3 taken out, allowing the heads 2 and the fuse-holder to be withdrawn from the housing. The heads 2 are slipped oif and the paper 12 is removed from the fuse-holder, permitting the parts of the strip 6 to be taken TOO out. The material of the fuseeholder may be sulliciently flexible to permit the slit to be opened 'far enoug'h to permit the insertion of the strip and of a thin blade to separate the plates 13. A new paper 12 is then pasted on, the heads 2 put in position, and all are slipped into the housing and secured by the screws 3. IVhen brackets, such as shown in Fig. 2, are 'formed on the ends of the fuse-strip, one may be bent atril'le to permit it to pass through the housing'.
Instead of plates 14, which are soldered or riveted to the fuse-strip, a U-shaped piece 15 may be secured thereto by means of screws 16, as shown in Fig. l0, a construction that is preferable where the spring-terminals are of large size. In this construction, as well as in that of Figs. 2 and it will be noticed that no soldering is required. IVhile I prefer to 'form the fusible conductor of aluminium, any other desirable substance may be used. In many other ways the details of this cut-out may be changed b v those skilled in the art without departing' from the spirit of my invention.
Having' now explained my improvement, what I claim as my invention, and desire to secure by Letters Patent, is
l. In an electric cut-out, the combination of a tubular housing of lireproo'f insulating' material, a fuse-holder comprising a split tube of insulating material having heads of insulating substances, a fiat fusible strip extending through said housing', slotted heads in thev ends of said housing', and screws securing the strip in said heads and the heads in the housing.
2. In an electric cut-out, the combination of the tubular housing' of insulating' material, slotted heads removably secured in the ends of said housing, a tubular fuse-holder within the housing extending between the heads, and a fuse-strip removably secured within the slots in said heads and extending through said fuseholder, said strip being' reduced at a point intermediate the ends of the 'fuse-holder to form the fusible part of the cut-out.
3. In an electrical cut-out, the combination of a tubular housing of insulating' material, a split inner tube within the housing', a fuse passing through said inner tube and said housing, means to close the opening' in the side of the inner tube and slotted heads secured in the ends of said housing to hold the innery tube and the fusible strip in place.
LI. In an electric cut-out, the combination of a tube of insulating material having' heads, a
fuse passing' through the tube and the heads and having' a reduced portion, and plates of insulating material tensionally positioned at the reduced portion so as to contact with each other upon the rupture of the fusible strip.
5. In an electric cut-out, the combination of a tube of insulating material having' insulating-heads, a fusible strip extending' through said tube and heads and having a reduced portion intermediate said heads, springs secured in said heads, and insulators secured to said springs and so positioned as to contact with said strip at the reduced point, and under such tension of the springs that they will contact and form a barrier of insulating' material across the path of the arc and extinguish the same at the rupture of the fusible strip under an overloading current.
6. In an electric cut-out, the combination of a tubular housing, an inner tube within the housing', a fusible strip passing' through said housing' and having' projecting' terminals, copper plates secured to the sides of said terminals, and slotted heads secured to said strip and in the ends of said housing'.
T. In an electric cut-out, the combination of a tubular housing', an inner tube within the housing, a iiat strip of aluminium of uniform width and thickness and reduced in width in the middle by having circular segments cut out of the sides of the straight portion thus forming the fusible portion of the strip, this strip passing through said housing and having projecting terminals,and slotted heads secured to said strip and in the ends of the housing.
8. In an electric cut-out, the combination of a tubular housing', an inner tube within the housing', a flat strip of aluminium of uniform width and thickness and reduced in width in the middle by having' circular segments cut out of the sides of the straight portion thus 'forming the Afusible portion of the strip, this strip passing through said housing' and having projecting' terminals, slotted heads secured to said strip and in the ends of the housing', and enlarging-plates secured to the sides of the ends of the strip for enlarging' and strengthening the same for contact with thc spring-terminals of electric circuits.
In testim ony whereof I have signed my name to this specification in the presence of two subscribing witnesses.
WVU. J. HARIIVIG.
EDWARD N. IAGuLsnN, A. F. IVILcOx.