US2009410A - Refrigerating apparatus - Google Patents

Description

.July so, 1935.

G. C. PEARCE ET AL REERIGERATING.APPARATU S Filed April 28, 1952 5 Sheets-Sheet INV NTORS 5f J2 y 30, '1935- G. c. PEARCE ET AL 2,009,410

RE FRIGERAI I NG APPARATUS Filed April 28, 1932 3 Sheets-Sheet 2 g INVEWRS'T 1/ ATTORNEYS July 3 1 G. c. PEARCE ET AL 2,009,41fi

REFRIGERATING APPARATUS Filed April 28-, 1932 3 Sheets-Sheet s ATTORN EYE:

clearance for one desiring to operate the manual operating means to grasp the dial firmly and rotate it conveniently. The removable top wall portion is. provided with insulation 38 which is held between upper and lower sheet metal walls 3d and 3d. A rubber sealing bushing til is provided for the opening through the upper.

sheet metal wall 3d through which the manual operating means 35 projects, and a similar rubber bushing 62 is provided for the opening in the lower sheet metal wall dd. These rubber sealing bushings prevent the access of air and moisture to the insulation 38 between the upper and lower sheet metal walls as and so and in this way the insulation is protected.

Referring now more particularly to Fig. '2, th r i shown it... atically, a complete reiiigerating system including the control means,

all of which are mounted on the removable top wall portion 2d of the cabinet 2@ without any connection to any other. portion of the refrigerator cabinet, sothat this top wall portion together with all of the portions of the refrigerating apparatus including a control means may be removed without disurbing any of the fluid or electrical connections or any other part of the apparatus. The sealw unit 2% contains a compressor 55 of any suitable type for compresuid refrigerant under reduced pressure absorbs heat from the food compartment 20 and vaporizes, which vapor is returned to the compressor through the return conduit 39.

The compressor 35 is preferably driven by an electric motor 5t also located within the sealed unit 28, which motor has a squirrel cage rotor 56 directly connected to the compressor 65. The motor 58 is provided with a running winding 52 and a starting winding 53. The motoris also preferably provided with a separate exciting winding 56 for actuating the starting relay which is necessary in single phase induction motors.

Bic elements of our improved switch are also shown in Fig. 2. These elements comprise a thermostatic switch actuated by a thermo= static bulb 58 located in the food compartment 25 adjacent the evaporator 86. For protecting the windings of the motor 5d there is provided a compensated bimetallic overload means 511 having a pivoted bimetallic strip to which is heated by a heater 59 through. which the current to the motor Eli passes. The bimetallic strip 5d holds the contact arm to in closed circuit position normally, but when an excessive amount of current fiows'through the heater 5d, the bimetallic strip 58 will trip outwardly to release the contact arm 6t) and to separate the contacts to open the motor circuit. A second bimetallic strip at is connected to the strip did at one end and is held static by an adjustment device 62 at its other end. This second bimetallic strip iii compensates the overload device for changes in room temperature.

A starting relay, generally designated by the reference character E38, comprising a contact arm dd, an armature 6 and a relay coil lid, is pro= vided for opening'and closing the starting 51.. l ne circuit. 7 One of the power lines or is nected so that the current will flow through the heater 59, thence through the contact arm'fill and through the overload contacts of the overload relay '51? to the thermostatic switch 55. From thence the current flows through an electrical conductor 58 which conducts the electric current to the conductor 59 which leads to the contacts of the starting relay 63 from which the electric current flows through an electric conductor it to 'the starting winding 53 which is con heated to the other wire it of the power line. mother electrical conductor ii is connected to the conductor 58 and conducts electric current to the main winding 52 which is also connected to the wire ll nects the conductor @8 to the relaycoil $6 and another'electrical conductor ll connects the relay coil it with the relay exciting coil 5 located in the motor windings. The relay coil Ed is also connected to the electrical conductor 712 within the sealed unit 2%. The relay exciting circuit comprising the relay coil 66, the relay exciting A. branch electrical conductor 73 concoil 56 and the electrical conductors is, ll and i2 v may be entirely separate from the motor circuit but a portion of the motor circuit, namely the electrical conductor 12 has been used as a part of this circuit in order to eliminate one lead-in bushing to conduct the electric current through the housing of sealed unit 28.

Referring now more particularly to the figures showing the practical embodiment of our improved control switch, there is shown particularly in Fig. 5, a generally U-shaped supporting bracket 8%, which is mounted upon the platform 33 and surrounds a bellows 8i which is expanded the flanges $3. The follower 32 has a downwardly projecting pin which engages the" upper closed end of the thermostatically operated bellows 80. The free end of the follower 82 is provided with a notch which receives an upwardly A extended portion iii of the U-shaped bracket to, which portion is provided with abutment means for limiting the movement in either direction of the free end of the follower 82.

On top of the follower 82 there is supported a spring retainer 88 which supports the lower end of an adjusting spring 8%. The upper end of the adjusting spring @9 is supported by a knurled spring retainer to threaded upon a short threaded pin 9!! which is riveted to an adjustment hinge 92 provided with ears d3 at its opposite end and pivoted by means of a pin dd to the upper end of the flanges 8d. The tension of the adjusting spring may be varied by rotating and thus moving upwardly or downwardly the knurled spring retainer d@ to change the tension of the adjusting spring. The cars are located on the outside oi the. flanges d5). Pivoted to the flanges 83 by means of the pin dd is a main operatingarm or lever 95 of a general inverted L-shaped form as shown in Fig. 3. This arm extends around the outside of the flanges 83. This arm is connected to the bellows follower 82 by being resiliently held against an ear which extends from the-bellows follower 32. The operating -of lever 95 is resiliently held in engagement with the ear 96 by means of a hook 9'! which engages the lower side of the operating arm 95 and which passes through the ear 96 and is provided with a coil spring 98 of the compression type which presses against a washer 99 and a cotter pin I which is'held by the upper end of the hock 91. In this way the arm 95 is held in normal engagement with the ear 96 of the follower 82 so that the arm will normally follow the movements of the bellows follower82.

The free end of the operating arm of lever 95 is connected to a toggle switch mechanism. For this purpose, a member of a suitable moulded insulating material IOI is fastened to the free end of the operating arm 95 by a bolt I02, This member I 0| of insulating material is provided with a pair of notches I03, best shown in Fig. 6, which support the knife edges at the forked end of a flat wishbone shaped secondary lever I04 in order that this secondary lever may be pivoted to the operating arm or primary lever 95. In order to control the movement of the free end of the wishbone-shaped secondary member, a stop member I05 is provided with a U-shaped portion I06 with which a rubber bumper I0'I, held in the end of the secondary lever I04, engages to limit the movement of the free endof the secondary lever.

The secondary lever I04 is connected by means of a tension coil spring I08 to an upwardly extending arm I09 of a pivoted switch contact member H0. The switch contact member He has at its other end another upwardly extending arm iii which is pivoted to the member Hi5 by having in wardly projecting prongs I I2 extending into apertures in the opposite sides of the member I05. 0n its underside, the contact member M0 has a leaf spring I I3 which is riveted at I It to a projecting end portion of the switch contact member 6 it. The leaf spring I I3 has a switch contact M5 riveted to its free end. The switch contact member I I0 is provided with an aperture directly above the switch contact I I5 to receive the upper riveted portion of this contact. The leaf spring H9 is limited in its downward movement by the stop member II It which passes through an aperture in the leaf spring I I3 and is riveted to the sw tch contact member I 10. The leaf spring I is is ten= sioned so as to resiliently press against the stop member II6. By this spring mounted construc-- tion of the contact II5, a more sudden and rapid engagement and disengagement of this contact is obtained with the stationary contact II? with which it cooperates. In this double toggle switch mechanism, when the pivot point I03 crosses the center line of the coil spring I08, the stationary lever I04 is tripped from one of its limiting positions to another oi its limiting positions, and thereby the coil spring I08 will throw or pull the switch contact member I I0 from one of its limiting positions to another of its limiting positions. The movement of-the switch contact member I I0 is limited in moving to closed circuit position by the set of switch contacts 'I I6 and Iii which engage each other and compress the leaf spring II3 against the switch contact member IIO. In the opposite direction or opening movement of the tacts and the closing of the switch contacts is determined by the position of the free end of the secondary lever I04. Inasmuch as the rubber bumper is subject to some wear and is somewhat plastic, it follows that under some conditions this wear might cause a change in the differential oi. the switch after a period of use. In order to avoid such a possibility we have provided tripping pins I20 and I2I which form part of the abutment member I06. It will be understood that the angularity of the secondary lever I04 is greatest immediately after tripping from one position to another, and is the least when the secondary lever is ready to trip from one position'to another. In this way, when the secondary lever I04 is tripped, the rubber bumper I01 will engage the abutment member I06, and in this way the contact of the secondary member with the abutment member will be silenced. By reason of the greater angulaizlty when the secondary lever comes into contact with the abutment member, only the rubber bumper I0'I will contact with the abutment member m6 and the secondary lever I04 will not at this time come into engagement with one of the stopping pins I20 or I2I.' However, as the toggle mechanism approaches tripping position and the secondary lever I04 approaches in alignment with the coil spring I08, the angularity of the secondary lever i04 is reduced and the secondary lever will engage one of the stopping pins I20 or I2i, whicheverthe case may be, and these stopping pins will hold the secondary lever I04 in proper position to be tripped. At this time the rubber bumper will be lifted free from the abutment member 805 so that the position of the free end of the secondary lever at;this time is entirely dependent on the location of the stopping pins. Inasmuch as the stopping pins are made of metal and are not subject to any impact, they will maintain their shape indefinitely and the free end of the secondary lever will always be held at the proper time in proper position for tripping.

In order to provide an adjustment for changing the diflerential of the switch mechanism, there is provided-a tension coil spring I23, connected at its lower end to a pin I24 fixed to the platform 33 and connected at its upper end to a threaded adjusting pin I25, which is provided with a nut H26 threaded thereon which normally rests upon a supporting arm I2'I extending from the upwardly extending portion 81 of ,the U-shaped supporting bracket 80. The nut I26 has a downwardly extending portion I28 which is adapted to engage an ear extending from the bellows follower 82 when the bellows follower 02 is in its upper position. When the bellows follower 82 is in its lower position, as shown'in Fig. 5, the bellows follower 82 is not in engagement with the abutment portion I28. In this way, by exerting a force upon one limit of the movement of the bellows follower 82 and not upon the other limit, the temperature or pressurediiferentiazl may be increased, or if the force is reduced, the differ ential is reduced. A range adjustment is also provided by varying the. tension of the coil spring 89 by raising or lowering the threadedly ver I33, which is pivoted by means of the pin I 34 to the overload supporting bracket I 35 which is,

mounted upon a sub-base I36 which is preferably.

' of some suitable moulded insulating material.

The pivoted lever I33 is normally held in its uppermost position with its contact I38 in engagement with the contact I32 by means of a bimetallic strip I39, mounted upon a block of insulating material I40 which is pivoted by means of a pin I II to a bracket I42 mounted on the subbase I36. Also fixed to the block I I0, but separate from the bimetallic strip I39, is a second bimetallic strip I43 which compensates for variations in room temperature. The bimetallic strip I43 is held at its free end by a screw I63 which is threaded into a strip of metal I35 which projects from the end of the bracket I 32. A small coil spring I46 holds the free end of the bimetallic strip I43 in engagement with the head of the screw I44.

A heater I41 of nickel-chromium wire formed into a serpentine shape is riveted to the bimetal strip I39 and is thereby held at a fixed distance therefrom. This heater M'I corresponds to the heater 59 shown in Fig. 2. When an excessive amount of current flows through the heater I II, the bimetal strip I39 will be bent suificiently out from under the lever I33 to allow the lever I33 to fall downwardly and to separate the overload contacts I32 and I38 to break the motor circuit. Inasmuch as the strip I53 always compensates the room temperature, the strip I39 will be always responsive to the heating action of the current flowing through the motor and in this way injury to the motor 50 will be prevented thereby.

In order to provide a convenient way of indicating the tripping of the overload switch as well as to provide a convenient way for resetting the same, an arm or lever I56, pivoted by means of the screw II to the supporting bracket I35, is provided with pins I53 and I52 on either side of the lever I33. The lever I55 has a metal strip I54'connected thereto which is connected by means of a pivotpin I55 to a collar I56 (see Fig. 1) which is held in place on a vertical rod I 5i by means of a set screw I58. The vertical rod I51 extends downwardly through the center of the hollow shaft 35 and has a red button I53 at its lower end, a small portion of which is exposed beneath the manual operating dial 36. When the overload mechanism is tripped, the lever I33 will fall, engaging the lower pin I53 mounted on the lever I56 and the weight of the shaft I57 and the lever I50 will cause the shaft I57 to drop until stopped by the spacing members I 66 so that a considerable length of the red button I59 will appear beneath the manual operating dial 36, indicating that the overload mechanism has tripped. In order to resetthe overload mechanism, the red button is pushed upwardly, lifting the lever I53 which causes the lower pin I53 to raise the lever I33 and allow the bi-metal strip I39 to spring back to its position beneath the lever I33. In this way a convenient mechanism is provided for resetting the overload mechanism.

- double thread is mounted on the threaded portion I66 of the collar I62, and seats upon the bottom portion of a tilted U-shaped I 63 cover is secured to the platform 33 by a nut I38,

(see Figs.1 and 4). The top portion of the oshaped link I6'I connects with an arm I68 extending from the adjustment hinge 92. This arm I68 extends through an aperture ..l69 in the side of the link I6'I and has a turnedzup end of the link I67.

By rotating the shaft 35, the double threaded which extends into. an aperture I It in the top screw I66 raises or lowers the double threaded nut I66 which is held 1 from rotation by the bracket I6? (as shown in Fig; 1), thus raising or loweringthe adjustment hinge 92 to decrease or increase the tension upon the range adjusting coil spring 39 to provide a cold control; efiect.

The bushing I62 is provided with acollar-III which is riveted thereto to hold the bushing in position. This collar III is provided with an up the tension of the spring 98. In this way the.

operating arm is moved independently of the bellows'8I or the bellows follower 82 in order to hold the switch contacts II 6 and III separated for defrosting purposes. 1

The starting relay is mounted upon the sub-= base I36 which is preferably made of molded insulating material. The starting relay is provided with an L-shaped member I86 of magnetic material which supports an electro-magnet I8I. At the upper end of the L'-shaped member I80 there is pivotally mounted a tilting armature I82. The tilting armature I82 is normally held in extreme counter-clockwise position away from the electro-magnet I8I and against a stop I83 of insulating material by a coil spring I8 6. The coil spring I85 is connected at its lower end to a pin I35 fixed to the L-shaped bracket I86 and is connected at its upper end to a threaded pin I36 provided with a nut I B'I which rests upon the upper surface of the tilting armature I82. When the armature I62 is rotated in a clockwise direction by the electro-magnet IBI, an ear I86 at one end engages a leaf spring I83 (see Fig. 3) to separate a set of relay contacts, one contact I33 of which is riveted to the end of the leaf spring I33 and the other contact IIII of which is? riveted to a bracket I 92 which is provided at its lower end with binding screws I93. When the compressor motor is idle, the relay contacts I96 and I 3I will be in closed position. When the thermostatically controlled switch contacts are closed to close the circuit, very little electric energy is generated within the separate winding 53. AS the motor speeds up, the generation of the electric energy by the Winding 53 increases rapidly and finally becomes sufficient in amount to cause the electro-magnet I3I to attract the armature I32 against the tension of the coil spring I65 to open the relay contacts I36 and I3I. The tension of the spring I 83 is so'calibrated that the relay contacts I36 and I3I will'be opened at the desired tripping speed.

The switch is enclosed by a metal cover I35 which has its lower edge engaging the flange I96 surrounding the edge or the platform 33. The

threaded upon a long vertical pin l99'which has its lower end riveted to the platform 33.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of-the claims which follow.

What is claimed is asfollows;

1. Refrigerating apparatus including an insulated refrigerator cabinet having an insulated removable wall portion supporting a refrigerating apparatus, and control means mounted upon one side of said removable wall portion for controlling the operation of the refrigerating apparatus, said control means having manual operating means for selectively varying the operation thereof, said manual operating means having a portion extending through said removable wall portion and having a manipulating portion connected to said extending portion and exposed on the other side of said removable wall portion.

2. Refrigerating apparatus including an insu lated refrigerator cabinet having an insulated removable wall portion, a refrigerating apparatus supported thereon, a food compartment adjacent the removable wall portion, control means mounted upon one side of said removable wall portion for controlling the operation of the refrigerating apparatus, rotatable shaft means extending from said control means through said removable wall portion, sealing means between said shaft means and said removable wall portion, and a manually operable dial upon the end of said shaft means exposed within the food compartment for selectively varying the operation of said control means.

3. Refrigerating apparatus including an insulated refrigerator containing a food compartment provided with an insulated removable wall portion supporting a refrigerating system, said system including control means mounted outside of said food compartment upon one side of said removable wall portion, said control means having manual regulating means extending through the removable wall portion into the food compartment and provided with manual manipulating and indicating means at the end thereof within the food compartment, said control means having means controlled by said manual manipulating means for controlling the starting and stopping of the refrigerating system and for varying the average temperature within the food compartment.

4. Refrigerating apparatus including an insulated refrigerator cabinet having an insulated removable horizontal wall portion supporting a refrigerating apparatus, and control means mounted upon one side of said removable horizontal wall portion for controlling the operation of the refrigerating apparatus, said control means having manual operating means for selectively varying the operation thereof, said manually operating means having a vertical shaft extending through said removable horizontal wall portion and having a manipulating means connected to said vertical shaft and exposed on the other side of said horizontal removable wall portion.

GEORGE C. PEARCE. DONALD FORD ALEXANDER.

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