US1691705A - Protector - Google Patents

Description

Nov. 13, 1928; 1;691,705

I w. L. (300K I PROTECTOR Filed Nov. 29, 1926 Patented Nov. 13,

UNITED STATES 1,691,705 PATENT oFFlcE.

WALLACE L. COOK, OF CHICAGO, ILLINOIS, ASSIGNOR TO RELIABLE ELECTRIC '00., OF

' CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS. i

rnorncron.

Application filed November 29, 1926. Serial No 151,422.

My invention relates to thermal protective devices adapted to be inserted in an electric circuit for breaking the circuit when an excessive amount of current passing through a portion of the device heats the same above a predetermined temperature.

It is a purpose of my invention to provide a thermal protective device having electrodes held in electrical engagement by heat responsive material with means for causing a wide separation of said electrodes upon heating said material termined temperature.

It is a further purpose of my invention to provide means whereby the electrodes of the thermal protective device may be reset after separation upon softening the heat responsive means.

Another purpose of my invention is to provide an enclosing casing for the thermal protective device and indicating meansprojecting outside said casing to indicate whether the protective device is in open or closed circuit position and to aid in resetting said device in closed position after it has opened the circuit. 1

ther objects and advantages will appear as the description proceeds when taken in above a predeconnection with the accompanying drawing.

However, I wish it to be understood that I do not intend to limit myself to the exact details shown and described but that I intend to avail myself of all such modifications'as would occur to one skilled in this art and would fall within the scope of the claim. Q

In the drawings,

Fig. 1 is a sectional view taken longitudi- Fig. 1.

why through my improved thermal protector; and

Fig. 2 is a section on the line 2-2 of Referring now in detail to the drawings, the numeral 3 represents an elongated tubular casing which has on opposite ends thereof the terminal members 4' and 5, made of any suitable metallic material, and which a are held on the tube 3 by means of punched- .51-m1y'ho1d the terminals in place.

in portions such as illustratedoat 6 and 7. The tube 3 is made of an insulating composition which is sufliciently soft to permit the portions 6 and 7 to enter thereinto zlt rlld e terminal is further provided with inwardly extending portions 8 and 9 which hold the disk 10 againstone end of the tube 3 for a purpose which will presently appear. The terminal 5 has soldered thereto a conductor' member 11 which extendsinwardly through an opening in the insulating disk 10 and is coiled around the member 12 inside the tube 3. .This member 12 has the. outerlend thereof extending through the disk 10, as shown clearly in Fig. 1,-and the end 14 of the conductor 11 is soldered to the end of the member 12 by means of a. comparatively hard solder which is capable of withstanding considerable heat. The portion of the conductor 11 that is coiled around the member 12 serves as a heat coil adapted on the, passage of current therethrough to heat the member 12 and soften the solder shown at 15 to permit release of the elecmember 12 inside the tube and in close proximity to the solder 15. The opening in the member 12 which accommodates the solder 15 and the electrode 16 should be sufiiciently large to permit the use of a considerable amount of solder so as to avoid any danger of binding between the electrodes 12 and 16'when the solder is softened under heat. The electrodelfi has a portion 17 consisting of a long rod which projects lengthwise throughthe tube 3 and out through the end of the terminal 4. This rod 17 serves as 'an indicator to show whether or not the electrodes 12 and 16 are in. contact with each other, and serves a further purpose which will presently appear.

Secured to the electrode 16, as at 18, is a spring member 19 which surrounds the rod 17 and has its free end soldered to the terminal 4 at 20. This spring is adapted to be under tension when the electrodes 12 and 16 are in contact. so that upon undue heating of the electrode 12 due to a current flowing from terminal 5 through conductor 11, electrode 12, electrode 16 spring 19 and terminal 4, the spring will serve to pull the electrode 16 away from the electrode 12 and create a wide break between the two elec-.

trodes, thus breaking the circuit in which the protector is'inserted and separating the electrodes for enough apart to prevent any due to the action of the spring 19 and the softening of the solder 15 the device may be reset by epplyine" suiiiclent heat thereto to soften the comparatively soft solder 15 and pushing the rod 1? inwardly so as to cause the electrode-.16 to extend down into the electrode 12. The parts may be then held in this posit-ion until the solder cools enough to hold the electrodes 12 and 1:6 together. In some cases it might happen that the spring 19 would break, and this would not interfere with the resetting of the device; but, as is clearly apparent, if the member 17 were not insulated from the terminal 4 the protector would beuseless, since the spring would be out of commission and there would be no means for creating agap by separating the members l2-and 16 when the solder was melted by the heat. In this way it might happen that a protector would be reset and installed without any one becom ing aware of the fact that it could not open the circuit because the spring was broken. By use of the insulating tube 21, I make the spring 19 the only electrical connection between electrode 16 and terminal4, so if the spring breaks, even though it is not visible from the outside, resetting of the two electrodes 12 and 16 will not complete the circuit between terminals 4 and 5, and there I will be no danger of the tube being inserted in a circuit unless it can serve it purpose as a rotector.

From the a ove description it will be seen,

that I have provided a thermal protector wherein the solder heated by the heat coil to release the electrodes cannot be contaminated by the inferior solder used for securing the conductors, and one wherein a wide separation of the electrodes is obtained, to-

get-her with means for resetting and indi- I claim and desire to secure by Letters Patent. is:

A thermal protector of the character described comprising a pair of electrodes, heat responsive means for normally retaining said electrodes in electrical engagement and adapted upon undue increase in heat to permit separation of said electrodes, a spring normally under stress adapted to cause a wide separation of said electrodes upon softening of said heat responsive means, means for again setting said electrodes into operative position upon re-softoning of said heat responsive means, an enclosing shell housin said electrodes, heat responsive means an spring, and indicating means projecting from said shell for indicating the relative osition of said electrodes with respect to eac other.

In witness whereof, I hereunto subscribe my name' this 4th day of November, A. D.,

WALLACE L. 000K.

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