US1539870A

US1539870A - Electric cut-out

Info

Publication number: US1539870A
Application number: US389567A
Authority: US
Inventors: Sandin Maurits Jerome
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1920-06-17
Filing date: 1920-06-17
Publication date: 1925-06-02
Anticipated expiration: 1942-06-02

Description

WITNESSES:

M J. sANDlN I ELECTRIC CUT-OUT vFiled June 17, `1920 "lulu/111 www INVENTOR M60/'ifs Jerome Sand/'n j ATTORNEY Patented June 2, 1925.

UNITED STATES 1,539,870 PATENT OFFICE.

MAURITS JEROME SANDIN, 0F WILKINSBURG, IENNSYLVANIA, ASSIGOR T0 WEST- INGHOUSE ELECTRIC &; MANUFACTURING SYLYANIA.

COMPANY, A CORPORATION or PENN- ELECTRIC CUT-OUT.

Application led June 17, 1920. Serial No. 389,567.

To all whom t may concern:

Be it known that I, MAUR'rrs JEROME SANDIN, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electric Cut-Outs, of which the following is a specification.

My invention relates to electrical protective devices and particularly to cut-Outs ha'Vingtime-limit characteristics for intel rupting circuits in response to predetermined overloads.

One object of my invention is to provide a device ofV the .above indicated' Character that shall be simple and durable in Construction and effective in operation.

'Another object of my invention is to provide an economical, renewable, thermalresponsive element for an electric cut-out that shall embody-fusible means for interrupting a circuit and heating means for the fusible means, thereby eliminating the necessity Of having,` as a permanent member of the device, a heating coil that is subject to damage.

In electric circuits wheremotors'or other devices may be subjected 'to slight overloads for a Certain lengthlof timeit is desirable to provide a protective device having a time-limit Characteristic. may be accomplishedl by providing a thermal-responsive.circuit-interrupting member that, on an overload of short duration, does not heat sufliciently to interrupt the circuit but which will interrupt the circuit when. an overload continues for a considerable period of time. In cut-out of relatively small capacity, a heating coil of relatively small cross-sectional area and, therefore, likely to damage, is usuallyemployed.

In practicing my invention, I provide a Container or casing having suitable terminals and a resiliently biased member, connected to one of the terminals, disposed therein. A renewable thermal-re Onsive element comprises a relatively short eating Conductor of relativelyv high resistance provided, at one end, with a head or enlarged portion, .secured -in position by fusible means, that is separated from the conductor in response to a certain temperature.. The renewable element is attached, at one end, to one of the casing terminals and is placed under tension by the co-Operation of its headed end with the resiliently biased member.

In response to a predetermined temperature in the heating Conductor, the head of the element 1s moved quickly away from the heating conductor to interrupt the circuit.

Figure 1 of the accompanying drawings is a plan view, partially in section and par tially elevation, of a cut-out embodying ing my 1nvent1on.

Fig. 2 is a sectional side View ofthe de- A cut-out of the plug type embodying my invention may comprlse, in general, an insulating container or casing 1, a bottom terminal member 2, a side screw-sleeve terminal. member 3, a renewable termal-responsive element 4, a movable conducting member 5, a spring 6, a transparent window or f disk 7 and a screw cap member 8. The casing 1, as shown in Figs. 1 and 2, is providedwith a main chamber 9 having a frusto-conical upper portion 10 and a cylindrical lower portion 11. into which a sleeve' portion 12 projects from the lower portion of the casing 1. An opening 13, of relatively small diameter, extends through the sleeve portion 12 to the lower end of the casing 1 where it is provided with an Outwardly-fiaring or countersunk portion 14.

T he bottom terminal member 2, of substantially hollow-sleeve formation and iitted into an apertured disk or Washer 15, is provided, aty its inner end, with an annular liange 16 disposed in the opening 14' for `holding it in position in the disk 15 and,

at its outer end, with a headed rtion 17 having a transverse slot 17. is held against the bottom of the casing 1 by a flange. 1 8 on the terminal member 3.

The spring 6, Connected at one end 19 tothe sleeve terminal member 3,'is wound e disk 15 helically about the sleeve portion 12 and is in compression between the bottom of the chamber 9 and the movable conducting member 5. The member constitutes substantially a washer having an opening 19l disposed over the opening 13 on the s eeve portion 12.

The renewable thermalresponsive element`4 comprises a portion 20 of relatively thin conducting wire or otherconductor, preferably of relatively high resistance, to which a bead er ball 21 of solder or suitable alloy is secured at one end. The wire 2() is embedded in the bead 21 and, therewith, constitutes a renewable element comprising the source of heat by which it is actuated.

The mass or the bead 21 is such as to absorb a considerable amount of the heat from the wire 20, thereby furthering the timelimit characteristic caused by the construction of the element .and by the fact that the actuating heat is generated mainly in the wire.

The portion 2O of the element 4 is .placed through the openings 19a and 13 and the washer 5 is depressed to compress the spring 6, after which one end of the portion 20 is bent back into the slot 17 a of the terminal 2 and wrapped around the outer surface of the latter under the head 17. The bead 21, being larger in diameter than the opening 19, will hold the washer 5 in depressed position.

Upon the occurrenceof an overload o f suiiieient duration to heat the element 4 and the bead 21 to a predetermined degree, the

l bead 21 will be separated from the conductor 20 to interrupt the circuit.

As shown in Fig. 7, any of the renewable elements 4 may be provided with an insulating coating 22 to prevent deterioration and to conserve .the heat in the element.'

In Figs. 3 and 4, the chamber 9 is of substantially cup-shape and, instead of the helical spring 6 and the washer 5, a composite member 23 serves to hold the bead 2l and to separate it from the element 4. The heating conductor 20 may be provided with a few helical turns 24 or be otherwise arranged to increase its heating capacity without altering the -length or function of the element. The member 23 may be provided with a slot 28 extending from the opening 19n to one edge thereof to receive the element and thus permit the coil 24 to be larger, if

desired, than the opening 19a. Also, in this form, the bottom terminal member 2 may be secured to a bottom wall 25 of the easing 1. In Fig. 5, a washer 26 takes the placefof the beads 21 in Figs. 1 to 4 and is secured to the end of the heating conductor 20 by a body of solder or alloy 27.

While Iv have shown and described particular forms of my invention, changes may be effected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as my invention:

1. An electric cut-out device comprising a heating conductor, a body of fusible material adhering' directly thereto, and conducting'means biased against said body to complete a circuit and to interrupt' the circuit in response to a predetermined temperature.

2. A thermal-responsive device comprising a terminal member, a relatively short heating conductor-of relatively high resistance detachably connected to the terminal, a body of fusible material adhering thereto, and a separate conducting member movable with respect to the heating conductor .and normally yieldingly held against movement by said body and adapted to be released to interrupt a circuit in response to a predetermined temperature.

3. A thermal-responsive device comprising a terminal member, a heating conductor, a body of fusible material adhering to one end thereof, and a conducting member movable with respect to the heating conductor and normally yieldingly held against movement by engagement withsaid body and adapted to be released to interrupt a circuit in response to a predetermined temperature.

4. In an electric cut-out device, the combination with a casing, contact yterminals therefor, and a movable conducting member connected to one of said terminals, of a separate thermal-responsive elementv comprising a relatively short length of heating conductor detaehably connected to the other of said terminal members, and fusible means adhering io the conductor for releasably engaging the movable member and for holding the said element in circuit relation to the terminals and for releasing the same to open the circuit in response to a predetermined temperature.

5. In an electric cnt-ont device, the combination with a casing and contact terminals therefor, of an apertured movable conducting member connected to one of said terminals, a thermal-responsive element comprising a heating conductor connected to the other of said terminal members, and a body of fusible material adhering to the heating conductor and disposed in said aperture for holding the movable'member in circuit relation to the terminals and for releasing the lflfl movable member to open the circuit in respense to a predetermined temperature.

6. A thermal-responsive device comprisf ing a body of fusible material, a hea-ting conductor having a portion embedded therein, a movable conducting member' having an aperture by which it embraces the heating conductor and resilient means for biasing the movable member against said body.

7. In' an electric cut-out device of the plug-type, the combination with side' and bottom contact terminals therefor, of a resiliently biased conducting member operatively connected to the side terminal, a renewable,thermal-responsive element comprising a heating conductor connected to the bottom terminal, and a body of fusible material adhering to the heating conductor normally disposed to hold the conducting member in circuit relation to the terminals and to release the conducting member toopen the circuit in response to predetermined circuit conditions.

8. In an electric lcut-out, the combination` with a casing and terminal members therefor, of a renewable thermal-responsive device comprising a heating conductor detachably secured at one end to a terminal'and havin an enlarged head of fusible material adhermgthereto by means of which the conductor 1s releasably attached to the other terminal.

9. In an electric cut-out, the-combinaton with a casing havin relatively movable terminals therefor an a 4thermal-responsive link' for connecting the terminals comprising a heating conductor detachably secured to one terminal and having a fusible portion adhering thereto for engaging the other terminal and forl retaining it 1n operative relation with the conductor.

10. In an electric cut-out, a support, a pair of relativel movable' terminals, oney of which is. movab e with respectv to the support, and a renewable thermal-responsive ink for connecting the terminals comprising a heating conductor detachably securedjat `fusib1e portion for engagin terminal and holding it in one end tothe one conductor and having a straight portion provided with an adherent the flexible and which is moved longitudinally of the conductor and separated therefrom when the tem erature of the conductor has reached a pre etermined degree.

11. In an electric cut-out, a casing having a relatively small perforation therethrough and having a chamber communicating therewith, a terminal secured to the casing and havin an opening therein registered with the said perforation, a second terminal with* in the chamber movable toward and away from the first terminal and provided with an opening, and a thermal-responsive device comprising a heating conductor adapted to Abe inserted through the openings in the terminals and -attached at one end to the first terminal and rovided at the other end with an adherent usible head for engaging the movable terminal and for retaining it in operative relation with the said conductor.

'12. In an electric cut-out, a/ asing having a chamber 'therein and |'aire atively long and narrow perforation. extending therethrough, a ilexible terminal in the chamber,

exed position a terminal adjacent one end of the perforation and a heating conductor in the perforation in the casing having a fusible head for releasably attaching the conductor to the movable terminal. I n testimony whereof, I have vhereunto subscribed m'y name 1. MAURITS JEROME SANDIN.

this 14th day of June