US3223798A - Variable timer switch - Google Patents

Description

14, 1965 E. c. ARMENTROUT ETAL 3,223,793

VARIABLE TIMER SWITCH Filed April 18, 1963 4 Sheets-Sheet l IF Il l L F n C r r Evere rmen rou I 4 BY Josf S. Sucro ZMX Their A Horney VARIABLE TIMER SWITCH Filed April 18, 1965 4 Sheets-Sheet 2 INVENTORS Everett C.Armemrouf BY Josf S. Sucro Their Afforney 14, 1965 E. c. ARMENTROUT ETAL 3,223,793

VARIABLE TIMER SWITCH 4 Sheets$heet 5 Filed April 18, 1963 INVENTORS Everett C. Armenfrouf BY Josi S.Sucro (4,408. Thelr Affarney United States Patent ()filice' 3,223,798 Patented Dec. 14, 1965 3,223,798 VARIABLE TIMER SWITCH Everett C. Armentrout, New Carlisle, and Just S. Sucro,

Dayton, Ohio, assignors to General Motors Corporati'on, Detroit, Mich., a corporation of Delaware Filed Apr. 18, 1963, Ser. No. 274,039 10 Claims. (Cl. ZOO-61.69)

This invention relates to electrical switches and more particularly to the type of switch that is operated after any of several predetermined intervals.

Certain electrical devices, especially refrigeration units, require periodic cycling of components to insure proper functioning of the main unit. For example, refrigeration apparatus requires defrosting from time to time. Existing timer switches can be set to anticipate one set of climatic conditions but they cannot be varied as a unit is moved into a different environment.

It is an object of this invention to provide a timer switch whose interval of operation can ve varied.

It is a further object of this invention to provide a variable cycle electrical switch which will reset itself by the stimulus of a shunt heater.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIGURE 1 is a size;

FIGURE 2 is a side elevation size;

FIGURE 3 is a bottom view of the invention in actual size;

FIGURE 4 is a side elevation of the invention in actual size;

FIGURE 5 is, an end view size;

FIGURE'6. is an enlarged sectional view taken along line 6-6 of FIGURE 4;

FIGURE 6A illustrates the amount of pawl movement at the setting in FIGURE 6;

FIGURE 7 is an enlarged sectional view taken along line 6-6 of FIGURE 4 illustrating another position of the variable cycle control; 7

FIGURE 7A illustrates the amount of pawl movement at the setting in FIGURE 7;

FIGURE 8 is an enlarged sectional view taken along line 8-8 of FIGURE 1;

FIGURE 9 is an enlarged sectional view taken along line 9-9 of FIGURE 3 showing in partial section the switch driver mechanism;

FIGURE 10 is a sectional view taken along line 10-10 of FIGURE 4;

FIGURE 11 is an enlarged perspective view of the shunt lead strip and a portion of the shunt heater with parts broken away;

FIGURE 12 is an enlarged perspective view of the control pawl;

FIGURE 13 is an enlarged sectional view taken along line 13-13 of FIGURE 2 showning the switching mechanism in a position it would assume after having been struck by the driver pin and the variable cycle switch in a typical operating environment of a refrigeration circuit;

FIGURE 14 is an enlarged sectional view taken along line 13-13 of FIGURE 2 which shows the switching mechanism in the normal position;

FIGURE 15 is an enlarged sectional view taken along line 15-15 of FIGURE 1.

\ Referring now to the drawings and more specifically to plan view of the invention in actual of the invention in actual of the invention in actual FIGURE 10, the switch body is generally designated by numberal 10 wherein are contained three compartments. The variable cycle control compartment 12 is disposed immediately above and adjacent to the temperature responsive switch compartment 14 and the switch driver compartment 16. The variable cycle control compartment 12 is enclosed by cover 18 as shown in FIGURE 5. The screws 20 hold the variable cycle control compartment cover 18 in firm attachment to the switch body 10. The temperature responsive switch compartment 14 is enclosed by cover 22 as. shown in FIGURE 4. The switch driver compartment 16 is enclosed by cover 24 as shown in FIGURE 2. FIGURE 14 illustrates the method of attaching the temperature responsive switch cover and the driver mechanism switch cover to the switch body. In the temperature responsive switch cover 22 and in the driver cover 24 are recesses 30. Holding screws 26 cooperate with the recesses 30 in the temperature responsive switch cover 22, pass through the switch body 10 and engage the holding nuts 28 embedded permanently at the base of the recesses 30 of the driver cover 24.

Referring now to FIGURE 6, the plunger 32 enters the variable cycle control compartment through an outwardly disposed port 34. Plunger 32 has a plunger cam portion 36 which cooperates with a control pawl 38 to turn a ratchet wheel 40. FIGURE 8 clearly illustrates the mounting of the ratchet wheel 40 on the switch body 10. The switch body 10 has a raised portion 44 around which is mounted a soft metal ratchet wheel bearing 46. Disposed within the center of the raised portion 44 is a recess which carries a metal pin bearing 42. Referring now to FIGURE 12, the control pawl 38 is mounted around the metal pin bearing 42 at 38c and the portion 38a is biased to the surface of the ratchet wheel 40 by a spring 48. The control pawl 38 engages the ratchet wheel 40 at surface 38a for forward movement and has a portion 38e which engages the ratchet wheel 40 to prevent any backlash. Portion 38f keeps the control pawl in biased engagement with the variable cycle control compartment cover 18 as more clearly seen in FIGURE 7. The extension 38h returns the portion 38b to a position adjacent to the plunger cam portion 36 and maintains the control pawl in readiness for the next actuation due to its normal resiliency. The spring 48 is kept partially depressed by the variable cycle control cover 18.

Referring now to FIGURE 9, a plunger 32 has an extension 50 which carries a lug 52. This plunger extension 50 extends into a recess portion 53 of the variable cycle control compartment 12. The plungerextension 50 is biased against the far wall of a recessed portion 53 by means of a spring 54.

FIGURE 9 is substantially an inversion of FIGURE 8 with parts broken away to illustrate more clearly the connection between the variable cycle control compartment 12 and the switch driver compartment 16. The switch driver compartment 16 is connected to the variable cycle control compartment 12 through a hole 58. The drive spring strip 60 has an extension 62 which protrudes through the hole 58 and cooperates with a ratchet wheel cam 56 carried on the underside of the ratchet wheel 40. A driver spring strip 60 is held in firm engagement with the switch body by virtue of the pressure exerted upon it by a cover 24 which is in turn held in place by holding screws 26 in their engagement with the temperature responsive switch cover 22. The switch driver compartment 16 is connected to the temperature responsive switch compartment 14 through a hole 70. In hole is disposed a driver pin 64. At one end the driver pin 64 is in contact with a driver spring strip 60 and at the other end is in contact with a polymetallic element 72. As illustrated in FIGURE 8, a double throw contact blade 76 is disposed around the perimeter of and connected to the polymetallic element 72 by a toggle spring 74. The polymetallic element 72 is held in operative position by being wedged between an insulator block 61 and the insulator block 77 while the double throw contact blade 76 is wedged between the contact blade lead strip 90 and the insulator block 61.

FIGURE 14 clearly shows the tiered arrangement of parts by which the holding screws 26 hold the various portions of the switch together. Disposed on one end of the double throw contact blade 76 is a double throw contact 86. FIGURE 14 illustrates the double throw contact in electrical contact with the normal cycle contact 82. FIGURE 13 illustrates the double throw contact 86 in electrical contact with a defrost cycle contact 78. The normal cycle contact 82 is mounted on the normal cycle lead strip 94. The defrost cycle contact 73 is mounted on the defrost cycle lead strip 92. The defrost cycle lead strip 92 is held in firm engagement with the switch body 1% by pressure exerted on it by an insulator block 93. The normal cycle lead strip 94 in turn is held in firm engagement with the insulator block 93 by a toggle block 84. The shunt heater 86 is held on one end by a shunt heater mounting flange 85 and on the other end by a shunt heater mounting flange 87 which is a portion of an insulator block 77. A toggle lip 83, a portion of a toggle block 84, acts as a resting point for the polymetallic element 72 while the switch is in the defrost cycle. A heater lead strip 88 is held in firm engagement with the insulator block 77 and a shunt heater lead strip 96 is held in firm engagement with the toggle block 84 by the temperature responsive switch cover 22.

FIGURE 12 illustrates, in a perspective projection, the control pawl 38 and its operative surfaces. FIGURE 11 illustrates, in a perspective projection, the shunt heater lead strip 96 in a typical form and the shunt heater 86 with parts broken away. As previously illustrated, the shunt heater lead strip 96 is held in firm engagement with the toggle block 84 by means of pressure exerted by the holding screws 26, one of which passes through the hole 96a of the shunt lead strip. Portion 96c holds the shunt heater 86 in firm engagement with the shunt heater mounting flange 85 while portion 96b acts as an external lead. The shunt heater 86 is composed of any common insulator material with the resist material 86a applied in any conventional fashion known in the printed circuit art.

In operation, the variable timer switch is activated by a door 98 moving to a position designated by the dotted numeral 98 on the hinge 97 as illustrated in FIGURE 9. As the plunger 32 moves into the switch body, the plunger cam portion 36 makes contact with portion 38b of the control pawl and causes the control pawl to rotate the ratchet wheel 40 due to engagement of the ratchet wheel teeth with portion 38a of the control pawl as best illustrated in FIGURES 6 and 7.

Referring to FIGURES 6 and 6A, the lines A and B indicate the amount of travel of the control pawl with the portion 38g of the control pawl in the notch 35a. The amount of rotary movement induced into the ratchet wheel 40 by the control pawl can be varied by moving the portion 38g of the control pawl into any of the notches 35a, 35b, 35c or 35d as shown in FIGURES 6 and 7. FIGURE 7 illustrates the portion 38g of the control pawl in the notch 35d and the consequent change in movement is indicated by the lines A and C extending from the center of the ratchet wheel.

The FIGURES 6A and 7A illustrate clearly the contact of the plunger cam portion with the control pawl and the consequent movement induced in either of the positions 35a or 35d to the ratchet wheel 40. The spring 54 causes the plunger 32 to return to its fully extended position after each actuation. As the ratchet wheel 40 is turned a predetermined amount with each actuation of the plunger, the cam portion 56, as illustrated in the portion of the drawing with parts cut away in FIGURE 14, advances in the direction indicated by the arrow. The

4 portion 56, after having been in sliding contact with portion 62 of the driver spring strip 60 for several intervals of movement, passes its point of farthest contact with the extension 62 and causes the driver spring strip 60 to go off the edge of the cam at point 56:: as illustrated in FIGURE 13.

The linear plane alignment of these parts is more clearly shown in FIGURE 9. As the extension 62 of the driver spring strip 66 reaches the point 56a of the cam 56, the driver spring strip 69, being normally biased in the direction of the switching compartment 14, is caused to snap into contact with the driver pin 64 and move into a position illustrated in FIGURE 13.

As the driver pin 64 moves in the hole 70, it makes contact with the polymetallic element '72 and causes it to go in the direction of the normal cycle contact 82 with the consequent overtravel of the toggle spring 74. The polymetallic element '72 is driven downward until it comes into contact with the toggle lip 83 of the toggle block 84, thus limiting its movement. Overtravel of the toggle spring 74 causes the double throw contact blade contact to move into contact with the defrost cycle contact 78 as shown in FIGURE 13. This energizes a circuit through the defrost cycle lead strip 92 to a defrost heater switch 106 to a defrost heater 102, thus initiating the defrost cycle. The defrost heater switch 106 during the refrigeration cycle is in the closed position. This defrost heater switch is responsive to the temperature of the defrost heater 162 and, when the temperature in this area reaches approximately 50 F., this switch will be caused to open.

This opening of the defrost heater switch 1% shunts the current through the shunt heater lead strip 6 into the shunt heater 86 and through heater lead strip 38 to the defrost heater 102. This current flow through the shunt heater will cause it to heat the polymetallic element 72, thus causing it to move in the direction of the switch driver compartment 16. This movement causes an overtravel of the toggle spring 74 and allows the double throw contact blade 76 to move downward in the direction of the normal cycle contact 82. This movement of the double throw contact blade contact it into engagement with the normal cycle contact 82 reinitiates the refrigeration cycle and ends the defrost cycle.

It is apparent from the foregoing description that this invention has utility as an improved control system for automatically actuating the defrost cycle of a domestic refrigerator as well as providing a method whereby this automatic actuation of the defrost cycle can be varied to accommodate different temperature and climatic conditions.

While the description of this invention as set forth in the specification presents a preferred form of the invention, it is understood that minor modifications could be made by one skilled in the art without departing from the spirit of this invention.

What is claimed is as follows:

1. In control apparatus, an electrical switch, said switch comprising a body, a temperature responsive multiple position switching means disposed within said body, a cycle control having means for applying a mechanical impulse to said temperature responsive multiple position switching means for moving said switching means from a first position to a second position, said switching means including a bimetallic element and a heater therefor, said switching means responsive in said second position to a temperature change for movement of said switching means from said second position to said first position in response to movement of said bimetallic element by said heater.

2. In control apparatus, an electrical switch, said switch having a body, a cycle control and a temperature responsive switching means having a first and second position disposed within said body, said cycle control including a ratchet wheel, a cam carried by said ratchet wheel, means for advancing said ratchet wheel, and means including said cam for applying a mechanical impulse to said temperature responsive multiple position switching means for moving said switching means from a first position to a second position, said switching means including a bimetallic element and a heater therefor, said switching means responsive in the second position to a temperature change for movement of said switching means from said second position to the first position.

3. In control apparatus, an electrical switch, said switch having a body, a cycle control and a multi-position temperature responsive switching means disposed within said body, said temperature responsive switching means including a bimetallic element, said cycle control including a ratchet wheel, means for operating said ratchet wheel, means operated by said ratchet wheel for imparting a mechanical impulse to said temperature responsive multiple position switching means thereby moving said switching means from a first to a second position, and electrical heating means associated with said bimetallic element for heating said bimetallic element and moving said temperature responsive switch from a second position to a first position in response to the resulting temperature change.

4. In temperature control apparatus, an electrical switch, said switch having a body, a cycle control and a temperature responsive multiple position switching means disposed within said body, said cycle control including a ratchet wheel, a cam carried by said ratchet wheel, a spring metal control arm piloting said ratchet wheel, and a cycle control actuating plunger, said temperature responsive multiple position switching means including a double throw contact blade, a pair of contacts carried on either side of one end of said contact blade, a strip of polymetallic material connected to said contact blade by a toggle spring, heater means connected to said polymetallic material, and external lead strips extending through the switch body into the switching area, said lead strips carrying contacts disposed on either side of said contact blade mounted contacts, said polymetallic material being responsive to said heater means and operatively associated with said cycle control to provide control of said apparatus at certain predetermined intervals.

5. In temperature control apparatus, an electrical switch having a body, a variable cycle control and a temperature responsive multiple position switching means disposed within said body, said variable cycle control including a pin, a ratchet wheel carrying said pin, a cam carried by said ratchet wheel, a spring metal arm for controlling said ratchet wheel, said arm having an irregularly formed periphery, portions of said arm serving to advance, rotate, and position said ratchet wheel, said arm being rotatably mounted on said pin providing thereby a variable advancing motion to said ratchet wheel, said switch body having an outwardly disposed port with notches on one side thereof, said arm having an extension cooperating with said notches to fix said spring metal arm in any of several positions, and a variable cycle control actuating plunger, said temperature responsive multiple position switching means including a double throw contact blade, a pair of contacts carried on either side of one end of said contact blade, a strip of polymetallic material connected to said contact blade .by a toggle spring, and external lead strips extending through the switch body into the switching area, said lead strips carrying contacts disposed on either side of said contact blade mounted contacts, said cycle control having means for applying a mechanical impulse to said temperature responsive multiple position switching means for moving said switching means from a first position to a second position, said switching means being responsive in the sec ond position to a temperature change for movement from said second position to the first position.

6. A control including a ratcheting device, said control comprising: a body; a control device carried by said body and operated by said ratcheting device, an operating means slidably carried by said body for advancing said ratcheting device, and a selector means carried at least partially externally of said body and integral to said ratcheting device for selecting a plurality of rates of advancement between said operating means and said ratcheting device.

7. An adjustable ratchet device comprising a gear having a plurality of teeth and a pawl means to advance said gear, said pawl having an irregular outer periphery with portions of said periphery having means for advancing said gear means for rotating said pawl means, and means for holding said gear in the advanced position, and an actuating means having a cam for engaging the irregular outer periphery at different points, in accordance with rotational movement of said pawl means and operating said means for advancing said gear.

8. An adjustable ratchet device comprising a gear having a plurality of teeth and a pawl to advance said gear, said pawl having an extension and being rotatably mounted on said gear, and having a plurality of positions of rotation in an arcuate path around said gear for varying the number of teeth the gear is advanced on each actuation, and integral means for holding said extension in any one of a plurality of selected positions and for holding said gear in an advanced state.

9. In a ratcheting device including a ratchet gear rotatably mounted on a pin bearing, said gear rotated by a control means, and a plunger cam cooperating with said control means, a control pawl comprising, an irregularly shaped member of spring steel material having a plurality of contoured surfaces and a fiat plate area, said fiat plate area having an aperture disposed in the center thereof cooperating with said pin bearing to hold the ratchet gear in its operative position and allowing the rotation of said control pawl, said plurality of surfaces including a cam follower portion for actuation of said ratcheting device, a hooked portion disposed in peripheral engagement with said ratchet gear to move said gear around said pin bearing, and a ratchet gear holding portion for preventing backward rotation of said ratchet gear, said control pawl having an extension providing a manually rotatable means for said control pawl causing said control pawl to move a variable peripheral distance around said ratchet gear as the plunger cam is actuated.

10. In control apparatus, an electrical switch, said switch comprising a body, a temperature responsive multiple position switching means disposed within said body, and a cycle control having means for applying a mechanical impulse to said temperature responsive multiple position switching means for moving said switching means from one position to another position, said switching means including a polymetallic element responsive in one position to a temperature change for causing a movement of the switching means from a first position to a second position, said cycle control having means for advancing said cycle control, and selector means integral to the cycle control means and cooperating with said advancing means and cycle control for selecting a plurality of rates of advancement.

References Cited by the Examiner UNITED STATES PATENTS 2,459,083 1/1949 McCloy 62-153 2,569,917 10/ 1951 Bergman 314-77 2,595,967 5/1952 McCloy 62-153 X 2,737,025 3/1956 Soreng et al. 62-153 2,788,640 4/1957 Newberry 62153 X 2,990,462 6/1961 Dietz 200-405 3,055,188 9/1962 Syfert 62-267 3,169,179 2/ 1965 Lennon 200- FOREIGN PATENTS 680,227 8/ 1939 Germany. 566,777 1/1945 Great Britain.

BERNARD A. GILHEANY, Primary Examiner. ROBERT A. OLEARY, Examiner.

Claims (1)

1. IN CONTROL APPARATUS, AN ELECTRICAL SWITCH, SAID SWITCH COMPRISING A BODY, A TEMPERATURE RESPONSIVE MULTIPLE POSITION SWITCHING MEANS DISPOSED WITHIN SAID BODY, A CYCLE CONTROL HAVING MEANS FOR APPLYING A MECHANICAL IMPULSE TO SAID TEMPERATURE RESPONSIVE MULTIPLE POSITION SWITCHING MEANS FOR MOVING SAID SWITCHING MEANS FROM A FIRST POSITION TO A SECOND POSITION, SAID SWITCHING MEANS INCLUDING A BIMETALLIC ELEMENT AND A HEATER THEREFOR, SAID SWITCHING MEANS RESPONSIVE IN SAID SECOND POSITION TO A TEMPERATURE CHANGE FOR MOVEMENT OF SAID SWITCHING MEANS FROM SAID SECOND POSITION TO SAID FIRST POSITION IN RESPONSE TO MOVEMENT OF SAID BIMETALLIC ELEMENT BY SAID HEATER.

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