US897852A

US897852A - Safety-fuse.

Info

Publication number: US897852A
Application number: US37441507A
Authority: US
Inventors: Joseph Sachs
Original assignee: SACHS Co
Current assignee: SACHS Co
Priority date: 1907-05-18
Filing date: 1907-05-18
Publication date: 1908-09-01
Anticipated expiration: 1925-09-01

Description

PATENTED SEPT. 1, 1908.

J. SACHS. SAFETY FUSE. APPLICATION FILED MAY 18, 1907.

q-N E5 5 E5 Hi5 TTY UNITED sTAtrEs PATENT OEFICE.

JosEPn SACHS, OF HARTFORD, CONNECTICUT, AssIcNoR TO THE SACHS COMPANY, or HARTFORD, CON ECTICUT, A CORPORATION OF CONNECTICUT.

SAFETY-FUSE. I

Specification of Letters Patent.

Patented Sept. 1, 1908.

Application as May 18, 1907. Serial No. 374,415.

' To all whom it may concern:

Be it known that I, JOsEPH SACHS, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented an Improvement in Safety-Fuses, of which the following is a specification.

My present invention relates to excess electric current protective devices or safety fuses, and the object thereof is the provision of an electric safety fuse or protective device which is so constructed as torupture electric currents of large volume without an are or flash. I

Heretofore electro thermal protective devices have been provided in which a fusible conductor is inclosedin a casing of insulating material and is surrounded by a filling material in a loose condition. In these socalled iuclosed fuses the arcing upon rupture of the fuse strip is checked or eliminated due tothe fact that the gases or other products of combustion from the ruptured fuse strip are permitted to pass into and though the interstices of the filling surrounding the fuse strip and are thus broken up and cooled with the resultant loss of disruptive pressure and breaking up of the are. As heretofore constructed however, each inclo'sed fuse device is a self-contained structure and therefore after being ruptured must be returned to the manufacturer for the )urpose of being properly re-loaded and re-filled, and moreover as it is difficult to construct such inclosed safety fuse devices with very large ampere capacities without using tubes or casings and other parts of large dimensions, the re-loading or re-filling of such safety fuse devices is necessarily relatively expensive.

The safety fuse or electric current protect ive device comprising my present invention is ofthe thermal type, that is to say, its operation depends on the heating and fusing of a conductor, and I am enabled by the peculiar construction and combination of elements which I employ to produce a safety fuse in which the rupture of the fusible element is practically'free from' are and consequently 1n the employment of this device the circuit even at large current values may be opened practically without an arc and at the same time the structure is such that the destructible element of this improved safety fuse may be readily and inexpensively renewed.

As is well understood, the arcing in an electric circuit is dependent upon the conduction of the media etween the separated electrodes, and that if it were possible to practically eliminate the separation of minute particles of the conductor material from the electrode points at the instant of initial rupture, or if it were possible to reduce the amount of metal in each of the separated electrodes to a mimimum, the resultant arcing would be eliminated or reduced proportionately. For example, when a single fusible conductor carrying say 1000 amperes is ruptured due to an excess current, the arcing is exceedingly severe because Of the large amount of metal acted upon by the current and between which the arc is formed. Should however, 1000 conductors be taken, each capable of carrying one ampere and each separated from the others by a suitable insulating medium, the arcing upon the ru ture of such a multiple fuse device would e very muclr reduced in view of the fact that ingly reduced conducting material, and furthermore, if ach of these one ampere fusible conductors were independently located in an insulating sheath into which they were tightly fitted and under tension, upon the rupture of the fusible conductors each one would be pulled asunder and out of the hole or recess in the insulating sheath and the arcs created u on rupture would be further reduced or e iminated, due to the fact that they could not follow through the very small aperture after the fusible conductors were withdrawn.

In carrying out my present invention, I preferably employ a sheathing of insulating material, a pair of electrodes between which the said sheathing of insulating material is located, a multiplicity of fusible conductors connected to and extending between the said electrodes and passing through the said sheathing, terminals connected respectively to the said electrodes and means for effecting a tension on said conductors to draw the separated portions of the same apart immediately upon being disrupted, as will be hereinafter more particularly described.

In the drawing, Figure 1 is an elevation of the safety fuse comprising my present invention. Fig. 2 is a plan and partial section, the section being taken on line y, y, Fig. 1. Fig.

the others.

3 is a central section of an inclosed safety fuse comprising my present in- Fig el is an end view of the fuse.

vention. device shown inFig. 3 and Fig. 5 is asection taken at line as, x, of Fig. 3.

Referring to the drawing and particularly to Figs. 1 and 2, a designates a sheathing par titionwhich is preferably made of asbestos sponge, or other similar suitable insulating material having the requisite elastic properties to efiect the purpose and perform the function of this element of my present invention. I) c designate electrodes made of any suitable conductive material and preferably provided centrally with screw threaded stud members 10 11 respectively. Extending be tween the electrodes 6 c and electrically connected therewith and passing through the sheathing partition a I employ a multiplicity of fusible conductors indicated at f. As will be understood, these fusible conductors may be made of any suitable material and in pass ing through the said sheath 0. each one of the same is independently insulated from all of (i represents a head adapted to be connected to. the electrode b by being screwed down on the stud 10, and similarly e is a head adapted to be electrically connected to anelectrode c by being screwed down on the stud 11; d e 'are helical springs, re

. spectively connected at one end with the head members (i e and at the opposite ends. "with terminals (Z 6 respectively. The terminals d 0 may be of any desired construction'and are adapted to be connected to terminals d e mounted on a suitable base a, and the sheathing of insulating material a of relatively large dimensions is preferably secured to this base a by pins a being passed through the sheathing and made fast in the said base in any desired manner.

It will be understood that the hereinbefore described protective device is secured to the base with the spring members under tension and that immediately upon the fusible conductors being disrupted the se arated parts of each conductor will be entirely withdrawn from the sheathing partition by the action of the springs in drawing apart the said electrodes, and that the are formed by the blowing of each conductor cannot follow not only because of the smallness of the aperture in which each conductor is insulated, but because on account of the elastic nature of the sheathing partition; the apertures in which the C'ldUCtOI'S normally he will be self closing immediately upon the withdrawal of the fusible conductors.

trated my present invention as embodied in an inclosed fuse device, g represents the easing made of fiber or other insulating material as is customary, and preferably tubular. The ends of the casing g are provided with end caps 7 adapted to fit over the extremities thereof and to. be secured thereon by meansof set screws 12 or otherwise. Centrally each end-ca -h isprovided with an inwardly extending s 'ghtly conical or tapering wall indicated at '1', and this wall i terminates in an internal flange indicated at k and provided with a central opening through which either the terminal (1 or the terminal 0 may be passed.

In providing the destructible element of the fuse device according to my present invention, in an inclosed fuse device, I prefer to em loy a tubular lining 13 fitting closely wit the tubular casing g and a disk which may also be made of insulating material indicated at 14; the disk 14 being adapted 'to abut against the inner face of the flange 76 of each end cap it and the tubular lining 13 to extend between the disk 14 and the sheath member 7 a, to maintain the same, together with the parts constituting the destructible element, in a fixed positionwithin the cas- II? this structure as illustrated, I prefer to provide the terminals (1 e with head members 15 16 respectively, which are of such a diameter as to create a slight wedge action in being passed into the recess formed by the conical walls 1, and within the conical wall 71 of each each fusible conductor member be inter rupted and broken by not being able to follow the parted conductor memberout of the sheathing, but the sheathing being made of insulating material of a spongy consistency will from its elasticity close the hole or space formerly occupied by a fusible conductor and thereby insure the extinguishing of any are which is formed in the rupture of the fusible members.

I claim as my invention: 1

1. A safety fuse comprising a plurality of separately insulated and sheathed conductors connected in multiple to common electrodes, and means for effecting a tension to separate the said conductors immediately l upon the same becoming disrupted. Referring to Fig. 3 wherein I have illus- 2. A safety-fuse comprisinga plurality of conductors, electrodes common to all of said conductors, a sheathing partition between the said electrodes and in which the said consaid conductors and theelectrodes immedi-' ately upon the said conductors becoming disrupted.

3. A safety fuse comprising a plurality of conductors, electrodes common to all of the said conductors, a stationary sheathing partition of suitable and insulating material between the said electrodes and through which each of the said conductors passes and means for effecting a tension to separate the said electrodes immediately upon the conductors becoming disrupted to entirely withdraw the parted ortions of the said conductors from the sai sheathing partition.

4. A safety fuse'comprising a casing, end caps therefor and a sheath member within said casing, electrodes on the opposite sides of said sheath, fusible conductors connected to the said electrodes extending between the same and passing through the said sheathing, means for connecting the said electrodes with the said end caps, means for maintaining the said sheathing in position within the said casing and means for moving the said elec trodes away from one another immediately upon the rupture of the said conductors.

5. A safety fuse comprising a casing, end caps therefor and a sheath member within said casing, electrodes on the opposite sides of said sheathing, fusible conductors connected to the said electrodes extending between the same and passing through the said sheathing, means for connecting the said electrodes with the said end caps, and means for creating a tension on the said. fusible conductors.

6. A safety fuse comprising a casing, end caps therefor, an inwardly extending wall in each of the said endcaps, an internal flange at the inner end of each of the said walls, a sheathing, electrodes on the opposite sides of the said sheathing, terminals connected with,

each of the said electrodes and adapted to pass through the flanges at the inner extremities of the said inwardly extending walls and to make'electrical connection with the said end caps, a plurality of fusible conductors each electrically connected with the said electrodes and passing through and insulated in said sheathing and means for moving one electrode and its terminal from the other electrode and its terminal immediately upon the rupture of the said fusible conductors to entirely withdraw the parted portions of the same from the said sheathing.

7. A safety fuse comprising a tubular cas ing, end caps therefor, an inwardly extending wall in each of said end caps, a flange at the inner extremity of each of the said inwardly extending walls, a sheathing, electrodes on the opposite sides of the said sheathing, a multiplicity of fusible conductors connected to the said electrodes extending between the same and passing through the said sheathing, terminals electrically connected to the said electrodes and adapted to pass through the said flanges at the inner ends of the said inwardly extending walls of the end caps, a head at the outer end of each of the said terminals adapted to enter and contact with the side of the recess formed by the said inwardly extending walls, and springs extending between the said head of the terminal and the said flanges at the inner ends of the said inwardly extending walls.

8. A safety fuse comprising a tubular casing, end caps therefor, an inwardly extending wall entering each of said end caps, a flange at the inner extremity of each of the said inwardly extending walls, a sheathing, electrodes on the opposite sides of the said sheathing, a multiplicity of fusible conductors con-' nected to the said electrodes extending between the same and passing through the said sheathing, terminals electrically connected to the said electrodes and adapted to pass through the said flanges at the inner ends of the said inwardly extending walls of the end caps, a head at the outer end of each of the said terminals adapted to enter and contact with the sides of the recess formed by the said inwardly extending walls, springs extending between the sald heads of the terminals and the said flanges at the inner ends of the said inwardly extending walls, a disk of insulating material surrounding each of the said terminals and adapted to abut against the flange of the adjacent end cap and a cylindrical lining adapted to fit within the said casing, and to extend between the said insulating disk members and the said sheath.

Signed -by me this 12th day of April 1907.

JOSEPH SACHS.

' Witnesses:

" GEo. T. PINGKNEY,

E. ZACHARIASEN.