US1872208A - Thermoresponsive apparatus - Google Patents

Description

Aug. 16, 1932. D, wool, 1,872,208

'I'HBRIORESPOHSIVE APPARATUS Filed July 1. 1927 II I LL-LJ lllllllllll VIIIIIV'I'I fiver-(hark Patented Aug. 16, 1932 UNITED STATES PATENT. OFFICE JOSEPH D. WOOD, OF WOLLASTON, MASSACHUSETTS, ASSIGNOR 1'0 GON'DIT ELEG'IBICAL MANUFACTURING CORPORATION, OF SOUTH BOSTON, MASSACHUSETTS, A CORPORA- I'HERMORESPONSIVE APPARATUS Application filed Jul 1, 1927. Serial no. 202,940.

This invention relates to electrically actuated thermo-responsive devices especially adapted to effect the opening of an electric switch upon overload in the switch circuit, although not necessarily restricted to such use.

An object of the invention is the provision of a thermo-responsive device as a unitary piece of apparatus adapted for many different purposes.

A further object is the provision of a thermo-responsive apparatus having a spring tensioned actuating member with means governed by the thermo-responsive elements to hold said member in set condition and to release it for movement under the action of its spring to effect the tripping of the switch or the control of some suitable circuit or device, combined with means to efiect the manual resetting of the actuating member after it has been operated.

A further object of the invention is a novel form of thermo-responsive apparatus having a spring tensioned actuating member normal 1y held in set position in readiness for operation and a plurality of thermo-responsive elements each adapted independently and all conjointly to eil'ect the release of the actuating element for operation.

A further object is generally to improve the construction and operation of electrically actuated thermo-responsive apparatus.

The device embodying this invention is described in my co-pending application Serial No. 202.950 filed-July l. 1927.

Fig. 1 is a side elevation of the thermoresponsive apparatus embodying the invention.

Fig. 2 is an end view of the apparatus of Fig. 1.

Fig. 3 is a perspective view of the tripping frame.

Fig. i is an end view partly in section of one of the theme-responsive devices.

Fig. 5 is a longitudinal sectional view taken along line 55 of Fig. 4.

tended between the holding frame and the thermo-responsive devices.

Fig. 8 is a section diagram illustrating the manner in which a thermo-responsive de-- vice can be connected in an electric circuit.

The thermo-responsive apparatus embodying this invention comprises a supporting frame having the spaced integral upstanding side walls 10 and 12 and the bottom connecting wall 14. A tripping frame comprising a pair of closely spaced plates 16 and 18 is pivotally mounted on a bolt 20 extended between and carried by the upper portions of the side walls. Said plates 16 and 18 are riveted together at appropriate points and are provided with flat upper faces 22 which are adapted to strike against the latch 24 of a switch 26 to effect the opening of the switch; or to actuate some other appropriate mechanism. A tensile spring 28 is disposed between said plates 16 and 18 and has its upper end connected with a pin 30 of the tripping frame and its lower end connected with a pin 32 carried by the side walls 10 and 12 in the lower portion thereof. Said spring is disposed at one side of the pivotal center of the tripping frame and so biases the frame for rotation in a counter-clockwise direction as viewed in Fig. 1. i

The frame is normally held in the set position illustrated in Fig. 1 by a holding frame 36 which has spaced side walls 38 pivoted on the pin 32 and upstanding ears 40 between which a roller 42 is journalled. Said roller is adapted to overlie a roller 44 carried between the plates 16 and 18 of the tripping frame to hold the tripping frame in set position. A compression spring 46 is disposed under the holding frame and serves normally to hold it in the elevated position shown in Fig. I, and in engagement with the tripping frame.

When the tripping frame is released, it is adapted to move upward under the action of the tensile spring 28 and is'adapted to remain in elevated position until reset. The frame is adapted to be reset by a resetting pin 48 which may be manually operated and which works in an arcnate slot 50 in the side wall 10 of the supporting frame and is adapted to engage 9. depending car 52 of the plate 16 of the tripping frame. thus to move it in a clockwise direction into re-engagcmcut with the holdin frame.

Figs. 4 and 5. The thermo-responsive desg pisive elements are received.

vices are identical and but one needs to be described. Each device is carried by a bracket 53 having spaced ears 54 at the end provided with slots 56 in which the tbermo-re- A screw 58 ing an enlarged head 60 is received in one of the cars 54 and an insulating bushing, (32 is received in the other car. A screw (54 is extended through said bushing coaxially with o the screw )8 and is held in location by the nut 66. A heater element comprising a spiral coil 68 of suitable resistance material is extended between and is secured electrically to the screws. A cylindrical metal tube 70 surrounds the heating element and is rotatable on the enlarged head 60 of the screw 58 and upon the head of the bushing 62. A spiral therino-responsive member 72 of tubular or helical formation formed of a strip of thermostatic metal composed of two metals having dissimila expansion COQfll(i8nlS. as copper and iron fixedly united together, is received within the tube 70 and has one end thereof fixed to the tube by the rivet 74. The other and free end 76 is extended freely through an opening 77 in the side of the tube and has an outwardly projecting tongue 78. The supporting brackets for the thcrmo-rcsponsive elements are secured one above the other to the side wall 12 of the supporting frame and the tongues 78 are received in vcrtically elongated slots 80 of a vertical connecting member 82. the lower end of which is connected loosely with a pin 84 carried by the holding frame 36.

The heater elements are. adapted to be heated by current from some appropriate source a currentset up in the secondary winding of a current transformer 83. 8. which is included in series with the circuit 85 of the switch 26. As thus arranged. the spiral thermostatic elements 'i'L are adapted to expand when sufficiently heated and to more the free ends 76 thereof i'lownwarilly. thus moving the holding frame .lfi downwardly against the action of thispring 4i and releasing the tripping frame 16 which is thus free to move upwardly and trip the switch open. The time and current scttiuirs of the thcrino-rcsponsivc element n? lvaried by rotating the tubes Tl") :i ml 2h ing the positions of the free ends of the lliii'- niostatic elements in the slots oi the con: ing strip 82. For this purpose plates (1 V A; secured to said tubes at similar ends the; mi

and are pivotally connected with a vertical adjusting rod 88, the upper end of which extends through an ear of the side Wall 12 of the supporting bracket and has a screw threaded nut 9:2 thereon. It is apparent that by rotating the nut 92, the rod 88 may be raised and lowered, thus to rotate the tubes 70 about their axes and change the adjustment of the thermo-responsive elements.

Preferably the thermostatic element 72 is arranged close to the inner face of the tube 70 with the material of least expansion outermost. Thus, in Fig. 6, the copper section 720*. of the thermostatic element is innermost and the iron section 72?) outermost. This arrangement, combined with the heat absorbing and dissipating characteristics of the metal tube 70, provides a device which is sensitive to sudden overloads so that it can trip the switch open rapidly without the usual long delay provided by devices of this character. It will be apparent that upon sudden heating of the heating element, the copper section of the expansible element 72 will become heated and will expand while the iron section will be kept cool by its proximity to the metal enclosing tube 70 so that quick ex pansion of the device will result. On lower or more gradually applied overloads, the two metals of the spiral thermostatic element will heat more or less uniformly, however.

While I have shown my device associated with an electric switch for purposes of illustration. the device can be used for other purposes with little or no modification as will be apparent.

I claim:

1. In a thermo-responsive apparatus, the combination of a movable holding member, a. plurality of thermo-responsive devices having means whereby they can be initially set to operate in accordance with any one of a plurality of predetermined conditions, means connecting said devices with said holding member by which all thermo-responsive devices conjointly and also each thermo-responsive device independently of the others can actuate said llfilfllllfl' member. and means for simultaneously varying the settings of said thermo-responsive devices.

2. In a thermo-rcsponsivc apparatus. the combination of a plurality of .thermomespom sire members having independent and fixed supports on which they are separately adjustable. actuating means controlled by said members singly and also in unison. and means to effect the simultaneous adjustment of all said members on their several Fll]')]')lf)I'tS in the some [lira-lion.

fl. In a thcrmo-rcsponsive apparatus. the ciunliinzllimi of a plurality of separately- :ufing adjustable thermo-responsive members which are res 'mnsivc to diii crent conditions having individual adjustment elements, means separately and also conjointly controlled by said members, and means to effect the simultaneous adjustment of said I118lll hers relatively to said controlled means ineluding an adjustment-member having connections with said adjusting elements of all said thermo-responsive members by which said thermo-responsive members can act separately and also conjointly on said controlled means.

4. In a thermo-responsive device, the combination of a thermally expansible member having a free end, a fixed end, a rotatable support for the fixed end and a fixedly supported heating element for said expansible member extended lengthwise thereof and located within said rotatable support.

5. In a thermo-responsive device, a thermally expansible element of helical formation having a fixed end and. a tree end, means to vary the setting of said expansible element including means to rotate said element, and a fixedly supported heating element extended through said rotatable expansible elei uent.

6. In a thermo-responsive device, a thermally expansible element of helical formation having a fixed end and a free end, a rotatable support for the fixed end generally coaxially disposed with the axis of said helical element, and a heating element having fixed supporting means therefor extended through said helical element.

7. In a thermo-responsive device. a thermally expansible element, an enclosing tube surrounding said element, said element having one end fixed to said tube and a free end extended outwardly through a wall of said tube intermediate its ends, said tube characterized by being rotatable about its axis, means to hold said tube in any rotated position thereof. and an electric heating element extended through said tube and said expansible element.

8. In a therIno-responsive device. a. thermally expansible element of helical formation. an enclosing tube surrounding said element. said element having one end fixedto said tube and a free end extended outwardly of said tube, said tube characterized by being rotatable about its axis, means to rotate said tube. means to hold said tube in any rotated position thereof. and an ele tric heating element extended tl'irough said tube and said expansible element.

9. In a thermo-responsive device, a tube of substantial length. supports for the ends of said tube on which said tube is rotatable. a thermally expansible element of generall helical formation disposed within said tide and having one end thereof fixed thereto and having the other end t'reely extended outwardly of said tube, and a heating member to beat said expansible helical element located therein.

10. In a thorniii-responsive device. a supporting bracket having a pair of spaced coaxial shoulders, a cylindrical tube having its open ends encircling and journalled upon said shoulders, and a thermally expansible element of helical formation received within said tube having one end fixed to said tube intermediate its ends, and means to hold said tube against rotation on its journals in any one of a plurality of angularly related positions and having its other end freely extended outwardly of said tube.

11. In t1tllQIlllO-lCSpOIlE-IVE device, the combination of a rotatably supported tube, an electric heating element located within said tube, a thermally expansible element disposed alongside said heating element within and rotatable with and having one end fixed to said tube and having a radially-extended free end, means operated by said free end, and means to fix said tube against rotation on its support in any one of a plurality of positions.

12. In a thermo-responsive device. the combination of a supporting bracket, a sore w having an enlarged cylindrical head carried by said bracket at one end, an insulating bushing carried by said bracket at the other end. a tube loosely received on said bushing and the head of said screw and rotatable on both, a thermally expansible element. received within said tube and having one end fixed to said tube and having its other end extended freely outwardly of said tube, and a heating element extended within said tube adjacent said expansible element having one end thereof conneeted electrically with said screw and having an electrical connection at its other end extended through said bushing.

13. In a thermo-responsive device the combination of a cylindrical heat-absorbing metal tube, a generally cylindrical thermally expansible member composed of two sections having different coefficients of expansion received within said tube and having its most expansible section innermost and its least expansible section closely adjacent and in heattransferring relation with said metal tube and a heater element disposed within said tube adjacent said most expansible section.

14. In a thermo-responsive device, the combination of a U-shaped supporting frame having spaced upstanding side walls. a pivotally supported tripping frame disposed adjacent one of said side walls, a spring urging said frame for rotation about its pivot, a holding frame disposed beneath said tripping frame and normally engageable therewith to hold it from engagement, and a thcrmoresponsivc device carried by the other wall of said supporting frame at one side of said holding frame having an operative connection with said holding frame and arranged to move it to release said tripping frame.

15. In a thermo-responsive device, a bracket having spaced parallel arms,

aligned confronting cylindrical supports carried by said arms, one of which supports is connected electrical with and the other is insulated from sai bracket, a tube extended between said arms and rotatable on said supports, a helical thermo-expansible member located within said tube and having one end fixed thereto and the other end extended freely laterally through an opening in the side wall of said tube, and a heating member extended through said helical member having one end connected to said electrically-connected sup ort and its other end extended through sai insulated sup ort.

16. A thermo-res onsive device aving the combination 0 a tripping frame, a spring urging said frame for movement into an operated position, a holding frame normally holding said tripping rame in an inoperated position against the action of said spring, a plurality of thermally-expansive members each having a fixed end and a movable free end, said free ends having independent lost-motion connections with said holding frame by which each thermally-expansive member independently can operate said holding frame, and adjusting means connected with all of the fixed ends of said thermally-expansible members are arranged to move said ends in unison.

17. A thermo-responsive device having the combination of a supporting frame having an upstanding wall, a tripping frame having a pivotal suport on said supportin frame and located on one side of said wal a spring urging said tripping frame for movement to an operated position, a holding frame having a pivotal support on said supporting frame and located on the same side of said well with said tripping frame and arranged to hold said tripping frame normally in an unoperated position, thermoresponsive means to depress said holding frame and to move it out of holding relation with said tripping frame, and a resetting member located mainly on the side of said wall opposite said tripping frame having an extension which is extended through an opening in said wall and is normally free from said tripping frame and is movable into engagement therewith in a direction to return it to the engagement of said holding frame.

18. A thermo-responsive device having the combination of a U-shaped supporting frame, a tripping frame comprising a pair of spaced plates having a pivotal connection with said supportin frame, a roller journalled between said p ates, a spring engaging said tripping frame urging it toward an operated position, a holding frame comprising a pair of spaced L-shaped members having a pivotal connection at one end with said supporting frame and having a roller located between the other ends there- Patent No. 1,872,208.

CERTIFICATE OF CORRECTION.

August 16, 1932.

JOSEPH D. WOOD.

it is hereby certified that error appears in-the printed specification of the above numbered patent requiring correction as follows: Page 3, line 71, claim 10, beginning with the word "intermediate" strike out all to and including the word "positions" in line 74, and line 75, same claim, after the word "tube" insert the words intermediate its ends, and means to hold said tube against rotation on its journals in any one of a plurality of angularly related positions; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of November, A. l) i932.

M. J. Moore,

(Seal) Acting Commissioner of Patents.

Images