US1654523A - Refrigerator control mechanism - Google Patents

Description

Jan. 3, 1928.

W. E. BIHL REFRIGERATOR CONTROL MECHANISM Filed 'June 8. 1923 2 Sheets-'Sheet 1 Illi- LPM Jan. 3, 1928.

, 1,654,523 W. E. BIHL REFRIGERATOR CONTROL MECHANISM Filed June 8, 1923 2 Sheets-Sheet 2 fi@ 5,

fia/ W R1 G/ f/ A l :x E i l 4`/ H 6 if @f ff 777 W a QM Patented Jan.l 3, 11928.

UNITE-D STAT-Es y, ,51,654,523 PATENT OFFICE.

WILLIAM IERICK BIHL, OIF CHICAGO, ILLINOIS, ASSIGNOR T IRON MOUNTAIN COM- PANY, A CORPORATION OF ILLINOIS.

. REFRIGERATOR CONTROL MECHANISM.

Appiicationinea June s., 1923.l serial No. 644,129.

The present invention relates to refrigerator control mechanism.

In domestic, portable and other types of refrigerators employing an 'electric motor for driving the refrigerator' compressor, considerable diiiiculty has been encountered in providing a I switch operating element which will be suiciently accurate and sensitive in its operation, under the very slight changes of 'pressure incident in the heating and cooling of the'refrigerator; land which will give sufficient amplitude of movement for actuating the circuit controlling member under the very slight change of pressure available for its operation.

Considerable d-'iiiiculty has also been encountered in providing a vcircuit interrupter which will operate successfully on the very small actuating movement available from the switch operating element without injurious arcing and binding of the vswitch contacts. Reliability and positiveness of operation, and the ability to give continued service without repair are practically essential to the commercial success of these domestic and portable refrigerators, because ofthe continuous duty ofthe refrigeratorand the expense of rendering service to refrigerators scattered over a. large area of the coun# try. Y

It is the fundamental object of the present invention to provide improved temperature responsive switch operating meais which will be positive and reliable in operai with the accompanying drawings, in which tion, and which will give the maximum range of switch operating 4movement fora given pressure variation; also to provide in co-operation therewith anA improyed circuit interrupting member which will require only a very small amount of actuating movement to insure a positive, clean make or break of the motor circuit without the possibility of arcing Vor'binding of the contacts. Other objects will be apparent from the following description taken in connection I have illustrated a preferred embodiment of my invention.

In the drawings: 'i Fig. 1 is an assembly view of the compressor unit and the brine tank isolatedfrom the remainder of the refrigerator structure. y

Fig. 2 is a fragmentary side elevational View of thev `control switch, with the cover` plate of the switch housing removedfand' Fig. `3 is a horizontal sectional view through the switch "housing, l

Referring toFig. 1, the compressor-unit 5 comprises anelectric motor 6 and a compressor 7' mounted upon.l a common baseplate. A belt drive 9 connects the motor 6 with a driving wheel 11 on the compressor.

A crank 12 is driven from the drive wheel 11 and reciprocates a piston .or diaphragml in the compressor cylinder. This compressor cylinder is not shown, being disposed substantially centrally in a condensing Lor cooling'chamber 13. The' compressor cylinder dischargesintothis chamber 13', and after'being condensed or cooled therein the refrigerant is discharged -through pipe 14; into the cylindrical receiver 15 which is mounted on the base plate 8 between the motor and compressor. The refrigerant is cooled or condeiised-in the chamber 18 by. coming into contact with ahold water cooling coil in the chamber. The-cold water inlet is through/a pipe 18 which opens into a valve 19', and fro-in this valve the cold water is conducted through pipe 2O to the inlet end. of the cooling coil. Thev outlet from the coil is indicated at 21. The cold `water controlling valve 19 is subject to autoconducted through a valve fitting 16-and I through a pipe`17 to an expansion valve 30. This expansion valve discharges into a cooling chamber 22; in the indirect expansion installation shown, this expansion occurring into a series of coils contained in the chamber or tank 22. These cool-ing coils consist of a multiplicity of sinuated coils 23 extending between lieaders 24 and 25 in the top and bottom of the brine tank. These several coils 23 are submerged in a body ofl brine whichfsubstantially fills ythe tank 22v and which surrounds cooling chambers 26 extending transversely through the tank'22. The refrigerating fluid is withdrawn from the lower header 25 througha pipe 27 which extends down to the compressor unit 'and has connection with the compressor cyl# inder through the intake connection 28.

The circuit controlling mechanism for the electric motor 6 is assembled in unit form upon a mounting plate or bracket 31 of angular form, this plate or bracket being secured by bolts 32 to standards or uprights 33 on the main mounting base 8. Mounted on this bracket 31 is a central standard 34 which carries a pivot pin or shaft 35 for pivotally supporting oppositely extending levers 36 and 37. Both levers have individual metallic bellows for imparting a tilting lever 36, and has connection through its lower standard portion with a pipe 43 which connects with the condensing chamber 13. The expansion of the bellows 38 is opposed by a tension sprin 44 which has connection at one end aroun a pin 45 secured to the lower part of the mounting bracket 31, and

at its upper end'is connected with a screw eye 46 having adjustable attachment to the lever 36, whereby the tension of the spring 44 can be readily adjusted. When an excessive pressure is generated in the condensing chamber 13,l this pressure is effective through the bellows 38 to rock the lever 36 upwardly. This lever has an extending end carrying vv,an adjusting screw 47 which is adapted to strike in the bottom of the channel-shaped. lever 37 after the lever 36 has moved a predetermined amount. The extentl of movement of the lever '36 before actuation of the lever 37 can be varied by adjusting the screw 47. The initial'part'of the upward movement of the lever 36, upon an undesirable increase in pressure in the condensing chamber 13, operates through the adjustable rod 40 to open the cold`water valve 19 toa greater extent. If the` increased condensation resulting from the greater flow of cold water through'the cooling coil vdoes not result in stopping the 'undesirable -increase in pressure, the continued expansion ofthe bellowsI 38 will rockr the screw 47 down against the lever 37 and open the motor circuit by depressing the rod 41. f

The bellows 39vhas' engagement with its lever 37, similarly to the engagement between the bellows 38 and lever-36, such as by a pin or stud 48 engaging in'an opening in the bottom of the lever. A tension spring 49 is secured toa transverse pin 51 carried in the mounting bracket 31, and at its upper end this spring has connection with an eye bolt 52 passing up through the bottom of the channel-shaped lever 37. An adjusting screw or nut 53 threads down over the bolt 52 and rovides an adjustment for increasing or ecreasing the tension of the spring 49. The tension spring 44 for the other bellows may. have an adjustment similar to the adjustment 52-53. e

The bellows 39 is intended to be responsive to the rise and fall of temperature in the brine tank 22, and to this end is connected tank. Extending downwardly from this TV connection is a tube56, the lower end of which is hcrmetically sealed, and whichis submerged in the body of brine permeating between the tubes 23. The temperature responsive Huid, which is a refrigerating liquid, is contained in this sub-merged tube 56. In the assembly of this control mechanism, a preferred practice is to pump a vacuum ot`as high as 30 inches on the line 56, 554and 54 and the bellows 39, and then seal tliis line or chamber. rThe line or chamber is then charged with a predetermined amount of refrigerating liquid to a pressure of approximately 10 pounds. The bulk of this liquid will condense in the coldest porreverse action' takes place, the fall of pres- 1 sure in the bellows 39 causing the motor switch to open. i

' Referring toFigs. 2 and 3, the expansion or contraction of the bellows 39, or the expansionof the bellowsI 38, operates through the rod 41 to tilta mercury tube 58. This mercury tube comprises a horizontally extendingglass tube having upturned terminal ends supporting contact terminals 61 and 62. Theterminal 61 is supported in the left-hand end of the tube by a wire 63 extending downwardly therein, and the terminal 62 supported in immediate lproximity to the terminal 61 by a wire 64 which is extended down from the other end of the mercury tube and is then bent horizontally to dispose the terminal 62 adjacent the terminal 61. The tube contains a quantity of mercury 65 of just sufficient volume to immerse the lower ends of both terminals 61 .and 62 when the left-hand end ofthe tube is tilted downwardly, but suiiiciently small in quantity as to leave these terminals dry and connect through external wires 66 and 67 with connecting terminals 68 and 69 terminal block 71. ,n

The mercury tube 58 is snapped between the sides or jaws of a spring-clip 72, which is fastened by a screw or bolt 7 3 to a rotatable hub 74. The screw 73 extends through an upright standard 75 and aords a bearing support therein for the hub 74. An arm 76 extends laterally from the hub 74 and has pivotal connection at 77 With the slotted end of a sleeve coupling 78, into which the lower end of the rod 41 threads. The ends o'l the rod 41 are threaded for adjustable reception in the coupling members of the 7 8 and 7 9, whereby the eti'fective length of the rod 41 can be lengthened or shortened.

The supporting member 75 is screwed to the insulating connector block 7l, and the latter is supported on the vertical wall of the mounting bracket 31 by screws 81 extending through suitable spacing sleeves 82.- The housing 42 encloses the mercury tube 58 and connector block 71, this housing having a removable cover for affording ready access to v the mercury tube and. its connections. The

circuit wires 84 and 85 for the electric motor pass through the housing 42, the wire 84 being interrupted for connection with the connector terminals 68 and 69 to include the mercury tube 58 in circuit.

IVidespread use of refrigerators embodying the present motor control apparatus over a considerable period o f time has demonstrated the reliability and durability of the combination of the bellows and-the gas-filled tilting mercury tube. The extreme sensitiveness of the bellows to variations in pressure results in a sharp positive operation with only a change of a few `degrees in the brine tank 22. /The bellows is substantially immune to leakage, and isy capable of operating under a high degree of pressure o`r exhaustion. An. exceedingly small movement of the bellows 3S) is operative to tilt the mercury tube 58, this mercury tube interposing substantially no inertia to this movement of the bellows. A very slight tipping of the mercury tube. 5 is operative ,to` roll the mercury into or out of contact with the terminals 61 and 62. 'lhere appears to be no tendency to draw an are when the mercury breaks contact with tbe terminals, and consequently there are relatively few service replacements or repairs compared to those necessary with a conventional knife switch.

I claim l. In a switch of the class described, the

combination of a relatively long second class Y lever having fixed pivotal support at one end, a mercury bulb having pivotal mounting in substantially horizontal position in proximity to the free end of said lever and independently of and remote from the pivotal support for said lever, means connecting the free end of the lever with the bulb mounting for tilting the bulb by angular movement of said lever, said bulb having contacts at one end and mercury therein for connecting and disconnecting said contacts by the tilt` ing of the bulb, a temperature responsive bellows eo-operable directly with the lever between its pivot-ed and free ends to swing the lever in a direction to tilt said bulb so that the mercury therein will connect said bulb contacts upon a rise in ytemperature and a spring independent of the pivotal mounting of the lever and connected with said lever to swing same in a direction to open the mercury connection between said contacts.

2. In a switch of the class described, the` combination of a switch housing having an overlying substantially horizontal supporting plate, an upright bracket member mounted upon said platebeyond the ends of the housing, a relatively long second class lever having fixed pivotal support on said bracket member at one end, a mercury bulb having pivotal mounting in substantially horizontal position in the switch housing and in proximity to the free end of said lever, the pivotal mounting for said bulb being independentof and remote from the pivotal'support for said lever, an actuating rod pivotally connected to the free end of the lever and extending down through the supporting plate into the switch housing and connected with the bulb mounting within the housing for tilting the bulb by angular movement of the lever, said bulb having-contacts at one end and mercury therein for connecting and disconnecting said YQcontacts` by the tilting o'l the bulb, a temierature responsive bellows mounted upon the supporting plate between the upright bracket and the actuating rod and co-operable directly with the lever between its pivoted and free ends to swing the lever in a direction to tilt said bulb so that the mercury therein will connect said bulb contacts upon a rise in temperature and a spring independent of the pivotal mounting of the lever and connected with' said lever to swing same in a direction to open the mercury connection between said contacts.

In witness whereof, I hereunto subscribe4 th day of May, 1923.

my name this WILLIAM ERICK BIHL.

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