US2115078A - Circuit controlling device - Google Patents

Description

April 26, 1938. H 2,115,078

CIRCUIT CONTROLLING DEVICE Filed June 9, 1933 2 SheetsSheet l 51 5o 45 ea 15 17 1a 60 64 59 70 63 .5 77 6? 66 76 '11 Q4 10 Mk5 0 O 7 9 k 13 I O 7 69 I April 26, 1933- c. w. KUHN 2,115,078

CIRCUIT CONTROLLING DEVICE Filed Jun 9, 1933 2 Sheets-Sheet 2 v a .11 777 d? 76 11169 7175 r Patented Apr. 26, 1938 CIRCUIT CONTROLLINGDEVICE Clarence W. Kuhn, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation Y of Delaware This invention relates to Application June 9, 1933, Serial No. 675,011

9 Claims.

electric circuit consome instances this device has been found objectionable due to the fact that it is necessary to employ a signal lamp to indicate tripping of the overload mechanism.

The present invention has among its objects to provide a refrigerator controller having a manual control adapted to indicate tripping of the overload mechanism, and adjustable to effect temperature control, defrosting and overload reset.

Another object is to provide a control device of the aforementioned character having a rotatable temperature control knob which is moved axially out of a given normal position to indicate tripping of the overload mechanism and which is returnable to such position to effect resetting of the overload mechanism.

Another object is to simplify and generally improve the construction and operation .of refrigerator control devices and to provide improved manual control means therefor.

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of modiflcation without departing from the spirit and scope of the appended claims.

In the drawings,

Fig. 1 is a plan view of a control device embodying the invention, a cover for the enclosing casing of the device being removed;

Figs. 2, 3 and 4 are sectional views taken substantlally on lines 2-2, 3-3 and 4-4, respectively, of F18. 1;

Fig. 5 is a fragmentary sectional view similar to that shown in Fig. 2, but illustrating certain of .the operating parts in another position:

Fig. 6 is a sectional view on line 6-6 of Fig. 2;

Fig. 7 is a sectional view on line 1-4 of Fig. 8 is an isometric view of a movable switch element associated with the I'lg. 1;

switch unit shown in Fig. 9 is an isometric view of the complete switch unit together with a diagrammatic showing of the circuit connections therefor;

Fig. 10 is a sectional view on line Ill-10 of Fig. 1, and

Fig. 11 is a sectional view illustrating a modifled form of manual control embodying the invention.

The controller illustrated in Figs. 1 and 2 includes an elongated box-shaped housing I hav- 10 ing a switch unit 2 and a fluid condition responsive unit 3 mounted therein. As hereinafter set forth, the switch unit 2 is controlled by the fluid condition responsive unit 3 to effect starting and stopping of the refrigerator and the unit 15 3 is shop adjusted to provide predetermined normal cycles of operation of the refrigerator and is also adjustable by rotation of a knob 4 mounted on the housing I to provide for modification of such cycles. Also as hereinafter set forth the switch unit 2 has an overload mechanism associated therewith which is responsive to effect stopping of the refrigerator and the knob 4 is movable axially to control such mechanism and to also indicate response thereof under overload conditions.

The switch unit 2 includes an insulating block 5 having stationary contacts 6 and I mounted upon the front end thereof to be bridged by a pair of cooperating movable contact members 8 w and 9. As shown in Fig. 9 one end of movable contact 8 cooperates with stationary contact 6 and the opposite end thereof is pivotally mounted at l0 upon an inverted L-shaped supporting member I l which is secured to the upper face of 5 insulating block 5 by a screw l2. Also as shown in Fig. 9, the movable contact 9 is mounted upon an insulating support l3 and one end thereof cooperates with stationary contact I while the opposite end thereof cooperates with movable con- 40 tact 8 at a point to the right of pivot III.- Insulating support I3 is slidable within a recess 14 in the underside of insulating block 5 and contact 9 is mounted between spaced upwardly projecting lugs 15 and it on the front end of said support. 4.5 As shown in Figs. 6 and-8, contact 9 has a stirrup II secured to the rear face thereof which straddles lug i6 and a coil spring I8 held under compression between the inner end of said stirrup and said lug serves to bias said contact towards said lug. Insulating support I3 has an overload responsive mechanism associated therewith for normally holding the same in the position shown in Fig. 6 against the action of a spring I! which engages an upwardly projecting lug 20 on the rear end of said support. As is apparent, with the support 13 held in the position shown in Fig. 6 spring l8 acts to yieldingly hold movable contact 9 in engagement with stationary contact l and movable contact ll and to also yieldingly hold the latter contact in engagement with stationary contact 5.

The overload responsive mechanism associated with insulating support i3 includes a spring latch 22 secured to said support and arranged to cooperate with an electro-thermal device 23 mounted upon insulating block 5. Electro-thermal device 23 includes an electric heater 24 of helical form arranged within a recess in the upper face of insulating block 5, a tubular member 25 fixed within an opening in said block and having its upper end surrounded by said heater and a ratchet pin 25 located within said tubular member. The upper end of ratchet pin 26 is connected to tubular member 25 by a solder connection 2? and the lower end of said pin is supported upon a plate 28 fixed to base 5 by a screw 29 and is provided with an enlarged toothed head 35 which cooperates with latch 22 to normally hold the insulating support l3 in the position shown in Fig. 6 against the action of spring I9. As shown in Fig. 9, the heater 24 has one terminal connected to contact 6 and the other terminal thereof is connected to a terminal plate 3! fixed to the upper face of insulating base 5 by a rivet 32 shown in Fig. 2. A line terminal 33 is also mounted upon the upper face of insulating base 5 and contact I is secured to base 5 and connected to said terminal by a screw 35.

The refrigerator motor is illustrated at M in Fig. 9 and the supply circuit therefor is indicated by lines L L Line L is connected to terminal 33 and one terminal of motor M is connected to terminal plate 3| while the opposite terminal thereof is connected directly to line L With the insulating support l3 latched in the position shown in Fig. 6 the motor circuit is normally established from line L to terminal 33'through screw 34 to stationary contact I through movable contacts 9 and 8 to stationary contact 5 and through heater 24 and terminal plate 3| to one terminal of the motor M. Upon given overload conditions in the motor circuit, heater 24 acts to fuse the solder connection 21 of the electrothermal device 23, and as is apparent the toothed wheel 39 of said device is then released and insulating support I3 is moved forwardly under the action of spring I9 to move contact 9 out of engagement with stationary contact I and movable contact 8 for interruption of the motor circuit. As will now be set forth, the knob 4 is adjustable'axially to effect resetting of the aforedescribed overload responsive mechanism and to also effect tripping thereof at will for defrosting of the refrigerator.

As shown in Fig; 2, the knob 4 is arranged within a ring projection 35 on the front end of housing I and is slidably mounted upon a sleeve 35 supported within an opening in the front wall of said housing. A pin 3] swiveled to the knob 4 by a screw 38 is arranged within the opening in sleeve 35 and a spring 39 held under compression between a shoulder formed on the interior of said sleeve and an enlarged head 40 on the rear end of said pin serves to yieldinglyhold said head in engagement with the front end of insulating support l3. The insulating base 5 of switch unit 2 is secured to the bottom wall of housing I by screws 4| and 42 (Fig. 1) and is so located that under normal conditions knob 4 is held in the insulating support l3.

armors position shown in Fig. 2 under the action of spring 39. As hereinbefore set forth, upon response of the above described overload mechanism the insulating support i3 moves forwardly under the action of spring l9, and as is apparent pin 31 moves therewith and causes knob 4 to move forwardly with respect to the ring projection 35 on housing I to indicate response of said overload mechanism. Upon inward movement of knob 4 into the position shown in Fig. 2 insulating support [3 is moved inwardly by the pin. 31 to effect resetting of the overload mechanism.

Knob 4 is also provided with means for manually tripping the aforedescribed overload mechanism to effect defrosting of the refrigerator. Such means comprises an insulating trip member 44 reciprocably mounted upon insulating support l3 and secured to the inner end of pin 31. As shown in Figs. 2 and 8, the trip' member 46 has a projection 45 on the inner end thereof which is located to the left of spring latch 22. (Fig. 6) and is guided within a recess 45 in the upper face of Upon forward movement of knob 4 out of the position shown in Fig. 2 the projection 45 on trip member 4 engages the spring latch 22 to release the same from the toothed head 35 and insulating support I3 then moves forwardly under the action of spring [9 to cause contact 9 to effect interruption of the motor circuit for defrosting of the refrigerator.

As hereinbeforeset forth the energizing circuit for the driving motor of the refrigerator extends through stationary contact 5 and movable contact B, and as will now be set forth the fluid condition responsive unit 3 acts upon said movable contact to effect cyclic operation of the refrigerator.

The fluid condition responsive unit 3 includes a bellows 48 secured to the rear wall of housing 5 and having a communicating pipe extension 49 on the rear end thereof. The pipe 49 may be connected to the low pressure side of the refrigerator to provide for operation of the bellows by pressure in that part of the apparatus, or it may contain an expansible gas and be arranged at a point contiguous to the refrigerating apparatus where the temperature and consequently the pressure within the pipe and the. bellows varies in accordance with operations of. the refrigerator. The front end of bellows 48 cooperates with a pivoted lever 50 having an adjustable spring 5| associated therewith which opposes expansive movements of the bellows, and said lever has a snap operating mechanism associated therewith for effecting operation of the movable contact 8.

More specifically lever 55 is pivotally mounted upon a pin 52 carried by a U-shaped bracket 53 fixed to the bottom wall of housing I by screws 54. Said lever has a stirrup 55 fixed to the rear face thereof which bears against the outer end of bellows 48 and carries a snap operating mechanism comprising a pair of oppositely arranged U-shaped members 55 and 51 operatively connected by a tension spring 58. As shown in Figs. 2, 4 and 5, the side arms of members 55 are pivoted at 59 upon spaced legs 55-50 associated with stirrup 55, while the side arms of member 51 are pivoted at 5| upon spaced legs 52-52 associated with said stirrup. Also as shown in these figures the side arms of bracket 53 are each provided with a pair of spaced pins 53-43 for engaging member 51 on opposite sides thereof and said bracket is also provided with a fixed stop 54 for limiting movement of member 55 in' one direction and an adjustable stop 55 for lim-' iting movement thereof in an opposite direction. The free end of member 56 cooperates with an insulating strip 66 slidably mounted within a slot in the upper face of insulating base 5, and as shown in Fig. 9 the front end of said strip is operatively connected to contact 6 at 61.

The operation of the aforedescribed fluid condition responsive unit will now be more fully described. With lever 56 in the position shown in Fig. 2 member 51 is held in a position wherein the axis of spring 56 is located to the left of the pivot 56 of member 56 and said spring thus acts to hold member '56 in engagement with its associated stop-65. With member 56 in this position movable contact 6 engages its cooperating stationary contact 6 to establish an energizing circuit for the refrigerator driving motor as hereinbefore set forth. With the driving motor in operation the temperature within the refrigerator ,decreases and upon a predetermined temperature drop determined by the degree of compression of spring 5| bellows 48 permits lever 50 to move inwardly under the action of said spring towards the position shown in Fig. 5. During such inward movement of lever 56 the pins 63 on bracket 53 cause the member 51 to assume a position wherein the axis of spring 56 is located to the right of the pivot 59 of member 56, andsaid spring then acts to move member 56 with a snap action from the position shown in Fig. 2 into the position shown in Fig. 5. Upon movement of member 56 into the position shown in Fig. 5 insulating strip 66 is moved forwardly to disengage movable, contact 6 from stationary contact 6 for stopping of the refrigerator. The temperature within the refrigerator then increases and upon a predetermined temperature increase bellows 46 moves lever 56 forwardly against the action of spring 5| into a position wherein the pins 63 on bracket 53 cause member 51 to assume a position wherein the axis of spring 58 is located to the left of the pivot 56 of member 56. Spring 58 then returns member 56 with a snap action into the position shown in Fig. 2 and contact 6 reengages stationary contact 6 to effect restarting of the refrigerator.

As will now be set forth, spring 5| has a shop adjustment and a user's adjustment associated therewith for determining the temperature values at which the refrigerator is started and stopped. As shown in Fig. 2, the front end of spring 5| engages a nut 66 which is threaded into one leg of a U-shaped bracket 66 slidably mounted within a channel 16 in the bottom wall of housing I. The other leg of. bracket 66 has a threaded opening therein for receiving an enlarged screw threaded portion II on the inner end of sleeve 36 which abuts a washer I2 mounted in the front wall of housing As hereinbefore stated, knob 4 is movable axially upon the sleeve 36, and as shown in Fig. 10 said sleeve is provided with flat side faces which engage within the opening in knob 4 to lock said sleeve and said knob against relative rotation. Also as shown in Figs. 2 and 10, the inner face of knob 4 is provided with a channel 13 for receiving a projection 14 on the front face of housing and a stop 15 within said channel cooperates with the projection 14 to limit rotation of said knob in opposite directions. As is apparent from the foregoing, the degree of compression of spring 5| may be varied by adjusting nut 66 with respect to bracket 63, and in practice this nut is shop adjusted with sleeve 36 in a given angular position to provide for starting and stopping of the refrigerator at predetermined temperature values to effect what may be termed normal cycles of operation of the refrigerator. By rotating knob 4, the screw H on sleeve 36 varies the position of bracket 66, and the degree of compression of spring 5| is thus changed to vary the temperature values at which the refrigerator is started and stopped, or to effect what may be termed non-normal cycles of operation of the refrigerator.

As shown in Fig. 2, the biasing spring i6 associated with insulating support I3 is held under compression between said support and a thimble 16 fixed within an opening in nut 66. Also as shown in Fig. 2, the aforedescribed mechanism is enclosed within the housing by a cover 11 which is secured to said housing by a screw 16.

Referring now to Fig. 11, the same illustrates a modified form of manual control means including a knob 76 fixed to the sleeve 36,and a knob 86 fixed to the pin 31. As is apparent, knob I9 -when rotated serves to adjust the sleeve 36 to vary the temperature values at which the refrigerator is started and stopped. On the other hand, the pin 31 is movable axially by the knob 66 to effect control of the switch unit 2 in the manner hereinbefore set forth, and to also indicate tripping of the aforedescribed overload mechanism.

What I claim as new and desire to secure by Letters Patent is:

1. In a controller for electric refrigerators, in combination, a circuit controlling device, fluid condition responsive means for effecting cyclic operation of said device, thermal overload means responsive to effect circuit opening operation of said device, and a manual control element rotatable to vary the operating characteristic of said first mentioned means and movable axially to effect resetting of said thermal overload means upon response thereof.

2. In a controller for electric refrigerators, in combination, a circuit controlling device having thermal overload means associated therewith responsive to efiect circuit opening operation thereof, fluid condition responsive means for effecting cyclic operation of said device and a manual control element rotatable to vary the operating characteristic of said fluid condition responsive means, said manual control element being also movable axially to effect operation of said device independently of said fluid condition responsive means and to effect resetting of said thermal overload means upon response thereof.

3. In a controller for electric refrigerators, in combination, a circuit controlling device having thermal overload means associated therewith responsive to effect circuit opening operation thereof and having fluid condition responsive means associated therewith for effecting cyclic operation thereof, and a manual control element rotatable to vary the operating characteristic of said last mentioned means, said control element being also movable axially out of a given normal position upon response of said overload means and being adapted upon return to said normal position to reset said overload means.

4. In a controller for electric refrigerators, in

of said refrigerator, and movable axially to efiect resetting of said overload protective means- 5. In a controller for electric refrigerators, in combination, a circuit controlling device having thermal overload means associated therewith responsive to effect circuit opening operation thereof, fluid condition responsive means for effecting cyclic operation of said device, said means having a manual control element associated therewith rotatable to vary the operating characteristic thereof, and means for moving said manual control element into a given position to indicate response of said thermal overload means and for also eiiecting resetting of said thermal overload means by movement of said manual control element out of such position.

6. In a controller for electric refrigerators, in combination, an enclosing casing, a circuit controlling device mounted within said casing and having thermal overload means associated. therewith for effecting circuit opening operation thereof, a fluid condition responsive device also mounted within said casing and associated with said circuit controlling device to effect cyclic operation thereof, and a pair of concentrically arranged adjusting parts mounted upon said enclosing casing, one of said adjusting parts being associated with said fluid condition responsive device and being rotatable to vary the operating characteristic thereof and the other of said adjusting parts being associated with said circuit controlling device and being movable axially to trip said thermal overload means and to effect resetting thereof.

7. In a controller for electric refrigerators, in combination, a circuit controlling device, thermal overload means associated therewith responsive to effect circuit opening operation thereof, fluid condition responsive means for effecting cyclic operation of said device and adjusting means inarmors eluding a manual control element movable in a given plane to vary the operating characteristic of said fluid condition responsive means, said control element being also movable in another plane to effect operation of said device independently of said fluid condition responsive means and to eifect resetting of said thermal overload means upon response thereof.

8. In a controller for electric refrigerators, in combination, a circuit controlling device, thermal overload means associated therewith responrsive to efiect circuit opening operation'thereof, fluid condition responsive means for efiecting cyclic operation of said device and a pair of concentrically arranged adjusting parts, one of said adjusting parts being movable in a given plane to vary the operating characteristics of said fluid condition responsive means and the other of said adjusting parts being movable in a different plane to effect operation of said device independently of said fluid condition responsive means and to also effect resetting of said thermal overload means upon response thereof. 9. In a controller for electric refrigerators, in combination, a circuit controlling device, thermal overload means associated therewith responsive to efiect circuit opening operation thereof, fluid condition responsive means for effecting cyclic operation of said device and adjusting means for varying the operating characteristic of said fluid condition responsive means, said adjusting means including a manual control element movable into a given position to effect circuitopening operation of said device at will, said element being also movable into said given position to indicate response of said thermal overload means and being movable out of such position to effect resetting of said thermal overload means. CLARENCE W. KUHN.

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