US2137728A - Refrigerator control switch - Google Patents

Description

Nov. 22, 1938. E. c. RANEY 2,137,728

REFRIGERATOR CONTROL SWITCH v Filed Feb. 1, 1934 8 Sheets-Sheet l Nov. 22, 1938. E. c. RANEY REFRIGERATOR CONTROL SWITCH Filed Feb. 1, 1954 8 Sheets-Sheet 2 25 fie C.-

TTc Sign C] No: nu 1 Nov. 22, 1938. E. c. RANEY 2,137,728

REFRIGERATOR CONTROL SWITCH Filed Feb. 1, 1954 8 Sheets-Sheet 3 H616 34 48 as 6 6 {39.

Nov. 22, 1938. E. c. RAN EY REFRIGERATOR CONTROL SWITCH Filed Feb. 1, 1934 8 Sheets-Sheet 4 Nov. 22, 1938. E. c. RANEY REFRIGERATOR CONTROL SWITCH V Filed Feb. 1, 19 34 8 Sheets-Sheet 5 Nov. 22, 1938. c RANEY 2,137,728

REFRIGERATOR CONTROL SWITCH Filed Feb. 1, 1934 8 Sheets-Sheet 6 WlDE CYCLE Eqil Nov. 22, 1938. E. RANEY 2,137,728

REFRIGERATOR CONTROL SWITCH Filed Feb. 1, 1934 8 Sheets-Sheet"? DEFQOST SINGLE -cxrcu: FAST FQEEZE mas-r posmm Hqd Nov. 22, 1938. E. c. RANEY 2,137,728

' REFRIGERATOR CONTROL SWITCH Filed Feb. 1, 1954 8 sheets-sheet 8 o L r :L 34

' I :35 smeu-z CYCLE g FAST FREEZE 8 s 56 556mm POSITIQN o T IlC e 14 L- 60 5 9 51 l-zs 5s 66 6a 95 j 0 O '75 67 as 52 es 1 77 54 l 46 78 18 57 :89 11 1,0 0 Y I 45 $.5 34 CONTINUOUS 90 22 2o o FAST FREEZE 19 5.

TTc 18 O Patented Nov. 22, 1938 PATENT OFFICE REFRIGERATOR CONTROL SWITCH Estel C. Raney, Columbus, Ohio, assignor to Ranco Incorporated, Columbus, Ohio, a corporation of Ohio Application February 1, 1934, Serial No. 709,384

26 Claims.

This invention provides a switch thatis particularly adapted for the control of a refrigerating apparatus to produce a wide variety of operating characteristics which enables the user of the refrigerator to obtain a greater degree of service from the apparatus with more convenience and accuracy than could be obtained by switches heretofore used.

The switch is provided with an adjusting member by which the user of the refrigerator may adjust, within certain limits, the temperatures at which the cooling unit of the refrigerating apparatus is normally maintained. The adjusting member may also be set so that extremely low temperatures are produced in the cooling unit for freezing substances rapidly and maintaining low temperatures as long as the user desires. Also, the adjusting member may be set to produce cycles of operation having a wide temperature differential in the cooling unit so that on each cycle of operation of the refrigerating apparatus the temperature of the cooling unit will rise to a point above the melting point of ice, after which the temperature is lowered to a degree well below the freezing point of water before the refrigerating part of the cycle is discontinued.

The switch is also provided with a control member that the user of the refrigerator may move from a normal position to a second position to permit the temperature of the cooling unit to rise above the melting point of ice to a predetermined temperature regardless of the adjustment of the adjusting member, to defrost the unit, whereupon the member is automatically returned to its normal position and refrigeration is resumed according to the adjustment of the adjusting member.

On the other hand, if the user of the refrigerator wishes to freeze a substance rapidly but does not wish to have the cooling unit maintain low fast freezing temperatures, the control member may be moved from its normal position to a third position which will cause the refrigerating apparatus to operate until a predetermined low tem perature is reached in the cooling unit regardless of the temperature adjustment of the adjusting member, whereupon the control member is automatically returned to its normal position and refrigeration is resumed according to the adjustment of the temperature adjusting member.

The electric switch is preferably operated by a gas filled bellows which may be connected to the cooling unit either for heat or pressure trans mission to cause its expansion or contraction to operate the switch in accordance with the temperatures of the cooling unit.

A plurality of springs are employed to selectively place various loads upon the bellows in order to, cause the refrigerating apparatus to produce the desired refrigerator operating characteristics described above. One of the springs is operatively connected .to the bellows to produce switch operations at abnormally low temperatures in the refrigerating apparatus. A second spring, the tension of which may be readily adjusted within limits by the user to vary the load on the bellows for producing desired normal refrigerating temperatures, is arranged so that its loading effect on the bellows may be removed to permit unaffected operation of the various other springs in performing their particular functions. A third spring is also used for loading the bellows and operates to produce a high switch closing temperature, while the other limit is dependent upon the adjustment of the second spring described above and thus produces a continuous wide cycle of operation of the refrigerating apparatus as measured by the difference between the switch closing and opening temperatures. The

third spring is maintained ineffective during all other operations of the control device. A fourth loading spring is also provided and maintained ineffective until used for producing a fixed defrosting temperature limit. It is automatically rendered ineffective when the defrosting temperature limit has been reached.

The particular object of this invention is to provide means whereby the various springs mentioned above may be rendered operative in their effect to load the thermically responsive bellows according to the operating characteristics of the refrigerating apparatus that is desired to be produced.

Another object of the invention is to provide a refrigerator control switch having means for setting the control elements of the switch to cause the refrigerator motor circuit to remain closed until a predetermined low temperature is reached in the refrigerator and whereby the control switch is automatically reset for normal operation of the refrigerator by the expansion of the bellows during the rise in temperature of the cooling unit following the cessation of the refrigerating operation that produces said predetermined low temperature.

The invention may be contained in structures of different forms and to illustrate a practical application of the invention, I have selected a switch mechanism as an example of the various structures in which the invention maybe em- I bodied, it being understood that variations in the details of the structure selected as an example may be made without departing from the spirit of the invention, and, also, that certain features of the structures selected may be used without the use of the other features and still contain the substance of the invention as claimed in the claims and structures that contain the invention may be used for controlling apparatuses of different forms.- The particular structure selected as an example is shown in the accompanying drawings and is described hereinafter.

Fig. 1 illustrates a view of a section of the switch selected as an example of various embodiments of my invention. Fig. 2 illustrates a face plate having suitable indicating material for indicating relative positions of controlling members whereby the refrigerating apparatus to which the switch may be connected may be caused to operate to produce desired characteristics of operation. Fig. 3 illustrates a section of the control, showing the mechanism also illustrated in Fig. 1 but on the side reverse to that shown in Fig. 1. Fig. 4 illustrates one end view of the mechanism and a section of the enclosing shell. Fig. 5 illustrates the other end view of the mechanism. Fig. 6 illustrates a top view of the mechanism shown in Fig. 1. taken on a plane of the line 'I-'I indicated in Fig. 1. Fig. 8 is a view of a part of the mechanism and illustrates a lever that carries a dog disposed in a position to which it is forced by a manual control member. Figs. 9, 10, 11, and 12 illustrate in each case related parts of the mechanism. Fig. 9 illustrates a pair of levers and a manually operating member for setting the levers. Fig. 10 illustrates means for adjusting parts of the mechanism by adjustment of certain springs, the springs not being shown. Fig. 11 illustrates a view similar to that shown in Fig. 9, certain of the elements being disposed in a position different from that shown in Fig. 9. Fig. 12 illustrates means for adjusting one of the levers by adjustment of a spring and particularly illustrates a means for rendering the spring ineffective in its operation on the lever. Figs. 13, 14, 15, 16 and 17 are diagrams indicating generally relative positions and cooperative functions of parts, the parts illustrated in the diagrams being distorted in order to enable clarity of presentation of their functions as distinct from the details of their structures. They are, however, marked with the same identifying reference numerals given to the corresponding parts in the other figures. Fig. 13 illustrates diagrammatically the relation of parts when the control device is set to produce normal refrigerating operations. Fig. 14 illustrates diagrammatically wherein a. manual control device may be set to produce refrigeration cycles having wide temperature limits so that defrosting and refrigerating temperatures are produced in each cycle. Fig. 15 illustrates diagrammatically the relation of the parts of the mechanism when a control member is set to cause defrosting of the cooling unit while the apparatus is producing normal refrigerating cycles. Fig. 16 illustrates diagrammatically the relative positions in which certain parts of the control mechanism is set when it is desired to modify the operations of the refrigerating apparatus to produce a single fast-freezing cycle. Fig. 1'7 illustrates positions that parts of the mechanism assume at the conclusion of a fast freeze cycle, just prior to resumption of normal operation. Fig. 18 illustrates diagrammatically a modified form of the structure illustrated in the figures described Fig. '7 illustrates a .view of a section above wherein a manual control member may be set to cause a refrigerating apparatus to produce repeated fast freeze cycles.

The mechanism of the switch may be enclosed in a pair of shells I and 4 connected to a suitable base 2 on which the greater part of the mechanism is mounted by means of a suitable frame I.

In the form of construction shown, the bellows 6 is connected to a tube I4 that terminates in a bulb '5 and encloses a liquid having a low boiling point such as sulphur dioxide. The bulb 5 is secured in high heat conductive relation with the cooling unit I so that the pressure of the volatile liquid will vary substantially as the temperature of the cooling unit varies and, hence, the bellows 6 will operate as a thermostatic element by means of which the control mechanism may be made thermally responsive to the temperatures produced in the refrigerating apparatus.

By its contraction and expansion movements, the bellows 6 operates a lever I8 to open and close a switch 8 in the manner well known in the art. The switch 8 is located in the circuit 9 of an electric motor ID that operates a compressor I I to draw the refrigerant from the cooling unit I and direct it into the condenser I3 in the manner well known in the art.

When the refrigerating apparatus is idle, the cooling unit becomes warm which increases the gas pressure within the bellows which will then expand to close the switch 8 and initiate operation of the refrigerating apparatus, and as the cooling unit becomes chilled due to the operation of the apparatus, the gas pressure decreases within the bellows 8 until the bellows contracts to a point which permits the switch to open producing, thereby, a cycle of operation of the refrigerating apparatus. To vary the temperatures at which the switch is operated, the bellows is subjected to various loads so that greater or lesser gas pressures will cause the bellows to open and close the switch at various temperatures according to the load upon the bellows. The reater the resistance that the bellows is subjected to, the greater will be the pressure and temperatures required to close and open the switch.

The temperatures at which the switch 8 will be operated by the bellows may be varied by the variation in the tension of an adjusting spring, or by the addition of loads by connecting one or more springs to the lever I8 and removing the adjusting spring load from the lever to produce operation of the switch at substantially definite temperatures independently of the adjusting spring. Thus, by the inter-control through manually operated members, I have provided a mechanism whereby desired operating characteristics of the refrigerating apparatus may be produced with great accuracy.

As shown in Figs. 1 and 13, the bellows 6 enages a lever I8 to move the lever about its pivot to operate the toggle switch 8 in response to the temperature changes in the cooling unit of the refrigerating system. For normal operation of the refrigerating apparatus, the lever I8 is loaded to resist the expansion of the bellows by two springs 90 and I9. The spring 90 is connected to a depending lug 9| on the lever I8 and the other end is closely coiled to engage the threads of a pin 92, supported by the frame 3, whereby the tension of the spring may be properly adjusted and fixed at the factory. The spring 90 has a relatively light tension and is connected to the lever .I8 during all operations of the ther 2,187,728 mostat. The spring is exerts a load upon the 1 lever l8 by means of a slotted stirrup 20 (Figs.

' 3, Land 12) which rests on the bevelled edge of the lug 2i extending at right angles from the lever I 8, one end of the spring l9 being connected to the lower part of the stirrup and the other end to an adjusting plate 23. The adjusting plate is threaded on the rod 24 so that it may be raised or lowered by rotating the rod by means of an ence to the dial 21, positions in which it may be placed by the user of the refrigerating apparatus to produce variations in the temperature caused by the adjustment of the tension of the spring Hi to produce desired food preservative temperature in the food chamber of the refrigerator. The adjusting member '25 is preferably limited in rotation to maintain the operations of the refrigcrating apparatus within a relative narrow term perature range by means of suitable steps, such as the finger 26 which protrudes into a slot formed in the base of the adjusting member 25. The finger 26' is connected to a suitable plate having a projecting finger 29. The plate 25 is connected to the rod 24, and when the rod is rotated to the right or the left, the finger 29 engages the stop 30 formed on the shell I as illustrated in Figs. 1 and 5 and as in the manner described in my copending application Ser. No. 680,689, filed July 17, 1933. Also, the temperature differential between switch opening and closing temperatures is relatively small during normal refrigerating operations and during continuous fast freezing, which produces a more constant temperature in the food chamber than where the cycles extend over a greater differential between the cut in" and cut out temperatures of the motor and the compressor.

When it is desired to cause the refrigerating apparatus to perform continuously cyclic operations by which a wide temperature difierential is produced in the cooling unit to enable defrosting of the unit and yet maintain the food chamber at food preservative temperatures, the adjusting member 25 is turned,-as indicated in Fig. 14, so as to locate the pointer 25 within the colored area 32 (Fig. 2) which increases the tension of the spring is by-the movement of the plate 23, and moves a cam 33 located on the rod 24.

The cam- 33 has a flat surface l5, as shown in Figs. 6, 12, and 13, and 16 and is engaged by a finger 45 on a pivoted arm 34 that is spring pressed by means of a spring 35 sothat when the cam 33 is rotated to the position described,

the fiat surface IE will release the finger and permit the end of the lever 34 to drop until the stop screw 48 threaded in the lever 34, rests against the bar 38. The lever will then lie in close juxtaposed relation to a laterally extending lug 45 located on the lever l8 and will be en-- gaged by the lug 45 as the lever i8 is raised by the bellows to close the switch. 1

When the lever i8 engages the lever 34 the additional load of the spring 35 prevents closure of the switch until a higher than normal pressure is produced in the bellows 5, thereby raising the switch closing temperature above normal while maintaining the switch opening-pressure subject only to the load of the spring l9 and the fixedly connected spring 90. There will thus be produced a wide cycle characteristic operation of the apparatus.

The spring 35 may be adjusted at the factory by means of a suitable threaded pin 36 and nut 31. The pin 35 is connected to a stop bar 38 that has limiting lugs for determining the amount of upward travel that is required of the lever l8 beforethe switch 8 is closed, and ex tends upward through the lever 34. The spring 35 is located intermediate the adjusting nut 31 and the lever 34 whereby the pressure of the spring 35 on the lever 34 may be adjustably varied by rotation of the nut 31. The position of the stop bar 38 may be adjusted to produce the desired switch cutin and cut out" temperature differential by means of a screw 4! that ex-- tends into the base 2, the stop bar being held against the head of the screw by means of the spring 42. The spring 35 is adjusted to raise the temperature at which the switch is closed to a sufiiciently high point to enable the cooling unit to defrost during each cycle of operation of the apparatus while the low temperature, determined by the'adjustment of the :spring i9, is such as to maintain the food chamber at aneflicient food preserving temperature notwithstanding the alternate production of the defrosting temperature in the cooling unit. Consequently, a food preservative temperature may be maintained in the food chamber. When, therefore, the adjusting member 25 is turned to cause the wide cycle characteristic operation of the refrigerating apparatus, the apparatus may be left indefinitely without care as to defrosting, and will produce an exceedingly economic operation of the apps.- ratus and maintain it in agood working condition since it prevents the rise in the temperature of the apparatus to atmospheric temperatures which will cause deleterious effects when maintained a considerable length of time due to the high pressure of the refrigerant that is produced at atmospheric temperatures.

When it is desired to produce defrosting of the to have the defrosting period automatically terminated, a control member 55- may be rotated to the right as shown in .Fig. l by means of the part 5! of the member. As shown diagrammaticaliy and for convenience of illustration, in Fig. 15, the part 5! is moved to the left to produce defrosting. The manually operable member ispivotally supported on the shell I at 41 and is movable relative to a latch member 52. The latch member 52 is pivotally supported adjacent one end thereof on the frame 3 and carries a pivoted dog and a roller The dog 55 is provided with a pin 54 which extends through a slot 58 formed in the latch member. As shown in Fig. 8, a light coiled spring 51 acting on the pin 54 and frame 3, normally biases the pin 54 against the upper end of the slot 58, thereby tending to rotate the latch member clockwise. The control member 50 has a slot 53 that engages the pin 54 so that the latch member 52 may be rotated about its pivot in either direction by the movement of the part 5i. When the manualy operable part 5! is moved to the right 'as viewed in Fig. 1, it rotates the latch member 52 counterclockwise, or to the left towards the fulcrum of a lever 58. The lever 58 is provided with a cam surface 59 so that as the member 52 is rotated, the roller 50 will bemoved along the cam cooling unit ofthe refrigerating apparatus, and

surface 53 of the lever 58 and engage the end of a defrosting lever 85 that has a circular recess 55. The levers 58 and 85 are supported parallel to one another and pivoted on the frame 3. The lever 55 is spring pressed by a relatively heavy defrosting spring "ll. The roller 55 is sufficiently wide to engage the recess 55 and the cam surface 59 so that the lever 58 will be raised and at the same time the lever 85 will be displaced from its stop 61 formed by the adjusting nuts 52 located on the threaded pin 18. The edge of the recess 86 is formed to extend beyond the vertical line passing through the center of the roller; and downwardly to form a detent for preventing the member 52 from being returned to its vertical position by the slight returning action produced by the cam surface 53 due to a slight spring load on the lever 58 provided by the coiled spring 15 acting between the lever 58 and the frame 3. When the roller 60 raises the arm 58, the tension of the adjusting spring 19 is removed from the lever: 13. The stirrup 20 to which the spring I3 is connected is raised from the laterally extending lug 2! by means of the strap 61 which is connected to the lever 58 by means of a bolt 58 and a nut 59 (Fig. 12). The bolt 58 extends through 0. lug 1!) formed on the lever 53 and allows free play of the stirrup 20 with reference to the lever 58 to enable the production of the normal cycle of operation without interference between the connection of the stirrup 20 with the lever 53. The latch member 52 is provided with a laterally extending lug 33 (Figs. 1, 9, and 11) that engages the lug 4-5 formed on the lever l8 and operates to prevent upward movement of the lever 18 until the latch 52 is rotated to the right, as viewed in Fig. 1, by the raising of the lever i8, so that the roller Si! is dislodged from the notch 85. This necessitates raising the lever 55 against the pressure of the spring ll, thereby placing an additional load on the bellows for preventing closing of the, switch until the cooling unit reaches a temperature sufficiently high to defrost the unit. The roller is then moved by the cam surface 59 and the pressure of the spring 15 to the normal positions maintained by the roller and latch member. When the latch member is rotated to its normal position, the cam 5! permits the lever 53 to be lowered and the stirrup 20 will therefore TE-BStflbllSh the connection of the normal adjusting spring is with the lever l3, whereupon the normal refrigerating cycles will be restored.

When it is desired to produce an abnormal low temperature in the cooling unit such as to produce fast freezing by a single cycle, the manually operated control part 5! is thrown to the left when in the position shown in Fig. 1. In the diagrams of Figs. 16 and 17, it is shown as moved to the right. This causes the slotted part of the control member to throw the dog outward to clear a laterally protruding lug 89 formed on the lever 18 and move the pin 54 against the left end of the slot 51 as shown in Figs. 8 and 11 and rotate the latch member 52 to the right, as viewed in Fig. 1, from its normal position, until the roller ill raises the lever 58 and nests in a shallow recess 83 formed in the lever 58.v When the lever 58 is raised, the stirrup 20 re eases the lever l3 from the tension of the adjusting spring 13. The lever ll now being free from the effect of the normal adjusting spring [9, is subject'only to the pressure of the spring 90 which has, relatively speaking, but a slight resilient pressure on the lever i8 and produces a light effective pressure on the bellows B.

The relatively light effective pressure of the spring 90 will, when the member 51 is operated, cause the switch to close if open, and produce operation of the compressor. In the fast freezing operation, the lever l8 descends as the cooling unit decreases in temperature, and in so doing, it moves the lug 88 below the end of the dog 55 before the switch has opened. Since the dog 55 is spring pressed by the spring 51 in a direction counter to that which it was moved by the operation of the manually operated member 50, the spring 51 will drawthe end of the dog 55 toward the body' of the latch member until the pin 55 is drawn against the right end of the slot 56 as viewed in Fig. 8. Thus after the lever 18 has been depressed sufficiently to open the switch due to the low temperature produced in the cooling unit, and the lever II begins to raise by reason of the expansion of the bellows due to the warming of the cooling unit, until the lug 55 engages the end of the dog 55 and thereby rotates the latch member 52 so as to move the roller 50 out of the shallow recess 88 and restore, by the pressure of the spring 15 on the cam surface 58, the latch to its normal position with reference to the lever 58. The lever 58 will thereby be lowered and the stirrup 20 will at the same time be lowered to permit reconnection of the normal adjusting spring I! to the lever 18 so that the refrigerating apparatus will again produce normal refrigerating temperature according to the adjustment of the spring I! made by the operation of the adjusting member 25. The fast freezing temperature thus produced will be determined by the factory adjustment of the spring 80 which may be a factory adjustment. Thus the normal positions of the control elements are automatically reestablished after the low or fast-freezing temperature has been reached and the switch has opened and the temperature of the control unit has begun to rise. Thus, the low switch opening temperature that produces the fast-freezing is in nowise affected by mechanical friction in the automatic resetting of the control elements to produce normal refrigeration. The switch opening temperature upon production of the fast-freezing temperature must be definite and unaffected by any uncertain resistance in view of the fact that the desired fastfreezing temperature is ordinarily very close to the refrigerating capacity limit of household refrigerators, and hence, llmiting'mechanlsm that produces normal refrigerating temperatures is restored in its control during the rise in temperature from the said low, fast-freezing temperature, but in advance of the normal refrigerating switch closing temperature.

The spring 30, being a light weight spring, is permanently connected to the lever I! while the spring l9 when connected to the-lever I 8, is the normal adjusting spring and the combined action of the springs l9 and 9D cooperate to resist the expansion movement of the bellows to produce normal refrigerating cycles of the operation of the refrigerating apparatus. Also, there is the cooperation between the spring 90 and the spring 11 when the manual control member 5i is operated to produce engagement with the roller 50 of the latch 52 to produce a. defrosting temperature. Thus, where it is desired to produce temperatures above that which is produced by the spring 90 when acting alone, the spring I9 in one case or the spring H inthe other case, add

their effective pressure to the spring to control the temperatures.

When it is desired to produce continuous fast freezing in the refrigerator the control member 25 is rotated, as indicated in Figs. 12 and 18, to position the pointer 25 within the colored area 86 shown in the face plate 3| which disposes a cam 93 located on the rod 24 in a position that the cam 93 engages and raises the arm 58 so that the stirrup 20 connected by means of the strap 61 to the arm 58, will release the lever l8 from the efiect of the spring IS. The bellows will then be subject to the load-of the relatively light fast freeze spring 90 which lowers the pressures and consequently the temperatures at which the.

means for adjusting the thermic means and having means for limiting the adjustment of the thermic means to produce switch operations within a desired range of temperatures, a resilient means adapted to control the temperature at which the switch is opened by the thermic means, a second resilient means adapted to control the closing temperature of the switch, and means operable for selectively rendering either of the resilient means effective.

2. In a thermo-responsive switch, a thermic means for operating the switch, a resilient means for controlling the thermic means to produce a desired pre-determined switch operating temperature, a second resilient means effective to produce a switch operating temperature below that produced by the first named resilient means, a third resilient means effective to produce a switch operating temperature above that produced by the first named resilient means, means for selectively rendering the first named resilient means ineffective and the second or third means effective.

3. In a thermo-responsive switch, a thermic means for operating the switch, a resilient means for yieldingly resisting the operation of the thermic means, an adjusting means for adjusting the said resilient means and having means for limiting the adjustment of the thermic means to produce switch operations within a desired range of temperatures, a second resilient means operatively connected to the thermic means for yieldingly resisting the operation of the thermic means and operative to lower the switch operating temperature below that of the said range of temperatures when the first named resilient means is rendered inefi'ective, a third resilient means cooperatively effective with the said second resilient means for raising the switch operating temperature above the said range of temperatures and means for selectively rendering the first named resilient or the said third resilient means ineffective.

4. In a thermo-responsive switch, a thermic means for operating the switch, a pair of resilient means, each of said resilient means operative to yieldingly resist the operation of the thermic means to produce a desired predetermined switch operating temperature, a third resilient means for yieldingly resisting the operation of the thermic means, means for selectively rendering one of the said pair or the said third resilient means effective and the other ineffective or both ineffective to resist the operation of the thermic means to produce any one of three materially different substantially predetermined temperatures.

5. In a thermo-responsive. switch, thermic means for operating the switch; adjusting means for adjusting the thermic means between predetermined high and low limits; means for tem-. porarily modifying one of the temperature limits of operation of the switch; means for temporarily modifying theopposite limit of temperature of operation of the switch and for rendering the adjusting means inoperative; and means responsive to the completion of either of the modified operations of the switch for restoring the operation of the thermic means to the first mentioned adjusting means.

6. In a thermo-responsive switch, a thermic means for operating the switch, a resilient means for yieldingly resisting the operation of the thermic means, an adjusting means for adjusting the said resilient means and having means for limiting the adjustment of thethermic means to produce switch operations within a desired range of temperatures, a second resilient means operatively connected to the thermic means for yieldingly resisting the operation of the thermic means and operative to lower the switch operat ing temperature below that of the said range of temperatures when the first named resilient means is rendered ineffective, .a third resilient means cooperatively effective with the said second resilient means for raising the switch operating temperature above the said range of temperatures, means for selectively rendering the said first named resilient means ineffective or the said third resilient means effective, and automatic means for rendering the first named resilient means effective upon the completion of the operation of the switch in response to the said second resilient means when operating alone or upon completion of the operation of the switch in response to'the cooperation of the said second resilient means and said third resilient means.

'7. In a thermo-responsive switch, a thermic means for operating the switch, a resilient means for yieldingly resisting the operation of the thermic means, an adjusting means for adjusting the resilient means and having means for limiting the adjustment of the resilient means to produce switch operations within a desired range of temperatures, a second resilient means for lowering the switch operating temperature below that of the said range of temperatures, a third resilient means for raising the switch operating temperature above the said range of temperatures, and meansfor selectively rendering the first named resilient means ineffective and rendering the second or third resilient means effective.

8. In a thermo-responsive switch, a thermic means for alternately opening and closing the switch, a resilient means for resisting the switch operative movements of the thermic means, an adjusting means for adjusting the resilient means and having means for limiting the adjustment of the thermic means to produce switch operations within a limited range of temperatures, a second resilient means for producing opening of the switch below that of the said range of temfperatures, a control means for rendering the first named resilient means inefi'ective at will, and automatic means for rendering the first named resilient means effective upon the completion of the operation of the said second resilient means, a third resilient means for producing a high switch closing temperature, a control means for rendering the said third resilient means effective at will, and automatic means for rendering the third resilient means ineffective upon the completion of the operation of the said third resilient means.

9. In a thermo-responsive switch, a thermic means for alternately opening and closing the switch, a resilient means operatively connected to the thermic means for yieldingly resisting the operation of the thermic means to produce switch operations at a relatively low temperature, a second resilient means, an adjusting means for adjusting the said second resilient means and having means for operatively connecting the said second resilient means to the thermic means and having means for limiting the adjustment of the said second resilient means to produce switch opening and closing operations of the switch within a desired range of temperatures materially above the temperature produced by the first named resilient means, a third resilient means and means operated by the adjusting means for operatively connecting the said third resilient means to the thermic means for raising the switch closing temperature above the said range of temperatures while producing switch opening temperature as determined by the adjustment of the said second resilient means during the continuous opening and. closing of the switch by the thermic means.

10. In a thermo-responsive switch, a member expansible in response to temperatures for ac tuating the switch, an adjustable resilient means for resisting the expansion of the said member, means operable to render saidresilient means ineffective to resist expansion of the said member, and means whereby the resistance of the resilient means to the expansion of the said member is restored by expansion of the expansible member to asubstantially predetermined point subsequent to the operation of the said second named means.

11. In a refrigerator control switch, means for operating the switch in response to definite desired temperatures produced in the refrigerator including an expansible thermo-responsive member, a pair of resilient members for loading said thermo-responsive member during normal operation of the switch, means for removing the loading efiect of one of the resilient members to permit modified operation of the switch in accordance with the loading effect of the second resilient member, and means for automatically restoring the loading efiect of the first resilient member to the thermo-responsive member subsequent to the said opening of the switch.

12. In a thermo-responsive switch, a pressure responsive element for operating the switch whereby the closing pressure of the switch is greater than the opening pressure of the switch, a resilientmember operative to control the opening and closing pressure of the switch, an adjustable resilient member operable to coact with the first named resilient member to vary the switch opening and closing pressures within a fixed range, means for rendering the adjustable resilient member inoperative and means for automatically rendering said adjustable resilient member operative by an increase of pressure in the pressure responsive element after the switch has operated at the pressure as determined by the said first resilient member.

13. In a thermo-responsive switch, a thermic element for operating the switch, a resilient member operative to control the opening and closing temperatures of the switch, an adjustable resilient member operable to coact with the first named resilient member and to vary the temperatures at which the switch is opened and closed within a fixed range, a third resilient member operative to coact with the said first named resilient member to control the closing temperature of the switch, means for rendering said adjustable resilient member inoperative and said third resilient member operative, and means for automatically rendering said adjustable member operative and the said third resilient member inoperative upon operation of the switch as determined by the effect of the first named resilient member when operating alone, or the said third resilient member when operating with the said first named resilient member.

14. In a switch, in combination; a movable actuating member; means for yieldingly affecting movement of said member; adjustable means for varying the eflect of the yielding means on the actuating member between predetermined limits; a second means being adapted to yieldingly affect movement of said member; a device adapted to render the first named yielding means ineffective and said second yielding means eilective; and means for rendering the device operative and inoperative.

15. In a switch, in combination; a movable actuating member; means for yieldingly afiecting movement of said member; adjustable means for varying the efi'ect of the yielding means on said actuating member between predetermined limits; a second means being adapted to yieldingly affect movement of said actuating member; a device adapted to render the first named yielding means ineffective and said second yielding means effective; and means for automatically restoring the eifect of the first yielding means to said member and for rendering the second yielding means inefl'ective upon operation of the switch.

16. In a switch, in combination, a movable actuating member; means for yieldingly afiecting movement of said member; adjustable means for varying the eifect of said yielding means between predetermined limits; a device having a normal position and being movable to either of two other positions for either increasing or decreasing the effect of said yielding means; said device, when moved to one of said twolast mentioned positions, rendering the adjustment means inoperative; and means for rendering the device operative and non-operative.

17. In a switch, in combination. a movable actuating member; means for yieldingly afiecting movement of said member; adjusting means for varying the eiiect of said yielding means between predetermined limits; a device having a normal position and being movable to either of two other positions for increasing or decreasing the effect of said yielding means; said device, when moved to either of said two last mentioned positions, rendering the adjusting means inoperative; and means for rendering said device operative and non-operative.

18. In a switch, in combination, a movable'actuating member; means for yieldingly affecting movement of said member; adjustable means for varying the efl'ect of said yielding means between predetermined limits; a device having a normal position and being movable to either of two other positions for increasing or decreasing the effect a of said yielding means, said device, when moved to one of said two last mentioned positions, rendering the adjustable means inoperative, means for rendering the device operative, and means operated by subsequent operation of said actuating member for relieving the device of its control and for restoring the effective control of the adjustable means.

19. In a switch, in combination, a movable actuating member; means for yieldingly affecting movement of said member; adjustable means for varying the effect of said yielding means between predetermined limits; a device having a normal position and being movable to either of two other positions for increasing or decreasing the effect of said yielding means; said device, when moved to either of said two last mentioned positions, rendering the adjusting means inoperative; means for rendering the device operative; and means operated by a subsequent operation of said actuating member for relieving the device of its control and restoring the effective control of the yielding means to the adjustable means.

20. In a switch, in combination, a movable actuating member; means for yieldingly affecting movement of said member; adjustable means for varying the effect of said yielding means between predetermined limits; a device having a normal position and being movable to either of two other positions for increasing or decreasing the effect of said yielding means; said device, when moved to one of said two last mentioned positions, supplanting the control of the adjustment means; and means for rendering the device operative and non-operative.

21. In a switch, in combination, a movable actuating member; means for yieldingly affecting movement of said member; adjustable means for varying the effect of said yielding means between predetermined limits; a device having a normal position and being movable to either of two other positions for increasing or decreasing the effect of said yielding means; said device, when moved to one of said two last mentioned positions, supplanting the control of the adjustment means; means for rendering the device operative; and means operated by a subsequent operation of said actuating member for relieving the device of its control and for restoring the eifective control 01' the yieldable means to the adjustable means.

22. In a switch, in combination,,a movable actuating member; means for yieldingly aflecting movement of said member; adjustable means for varying the effect of said yielding means between predetermined limits; a device operable for rendering the adjustable means inoperative and for simultaneously imposing either an increased or decreased predetermined yielding effect upon said actuating member; and means for rendering said device operative and. non-operative.

23. In a switch, in combination, a movable actuating member; means for yieldingly affecting movement of said member; adjustable means for varying the efiect of said yielding means between predetermined limits; a device operable for rendering the adjustable means inoperative and for simultaneously imposing either a predetermined setting of an increased value or a predetermined setting of a decreased value upon said actuating member; means for rendering said device operative; and means for relieving said device of its control and for restoring the effective control of said actuating member to said second means.

24. In a switch, in combination, a movable actuating member; means for yieldingly afiecting movement of said member; adjustable means for varying the effect of said yielding means between predetermined limits; a device operable for rendering the adjustable means inefiective and for simultaneously imposing either an increased or decreased yielding efiect upon said actuating member; means for rendering the device operative; and means operated by a subsequent operation of said actuating member for relieving the device of its control and for restoring the effective control of said actuating member to the second mentioned means.

25. In a switch, in combination; a movable actuating member; means for yieldingly affecting movement of said member for causing operation of the switch between predetermined limits; means operable for causing operation of .the

switch at a temperature other than provided by the yielding means, said last means when rendered efiective, supplanting the effect of the yielding means on the actuating member; and means for rendering the second mentioned means effective and ineffective.

26. In a switch, in combination; a movable actuating member; means for yieldingly affecting movement of said member for causing operation of the switch between predetermined limits; means operable for causing operation of the switch at a temperature other than provided for by the yielding means, said last means when rendered effective supplanting the effect of the yielding means on the actuating member; and means responsive to a subsequent operation of the switch for rendering the yielding means efl'ective and the second mentioned means inefiective.

ESTEL C. RANEY.

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