US2054542A - Refrigerating machine indicator - Google Patents

Description

Sept. 15, 1936. v w. HOELLE 2,054,542

' RPilFRIGERAT ING MACHINE INDICATOR I Filed June 21, 1954 2 Sheet s-Sheet 1 air 1 'Sept. 15, 1936. L v 2,054,542

REFRIGERATl [NG MACHINE INDICATOR Filed June 21, 1934 2 Sheets-Sheet 2 unuunnnm Patented Sept. 1 1936 UNITED. STATES PATENT. OFFICE 3 Claims.

The purpose of this invention is to provide an improved arrangement of. indicating devices responsive to abnormal conditions on the high and low pressure sides of a refrigerating machine'for 5 indicating the necessity of attention or repairing and to locate failures of individual cooling'coils operated-in multiple from a single compressor unit.

The purpose of the invention is accomplished by means of an arrangement as illustrated in the drawings in which: I

Figure 1 is a diagrammatic view of a refrigerating machine shown, as having connections with distantly located cooling coils and arranged to operate indicating lights on a central panel according to the operative condition of the machine. The cooling coils also have separate connections to the indicating panel.

Fig. 2 is an enlarged detail partly in section, showing an expansion motor operated switch for the compressor motor and contact elements for the indicator which discloses normal or abv normal operation.

Fig. 3 is an enlarged detail partly in section of an expansion motor with indicator control contacts and for use in connection with cooling coils.

In the work of servicing refrigerator machines, it is found that much needless expense is occasioned the owners thereof due to delays in learning of failures of the machines. For instance, a compressing unit may be locatedin a basement while the cooling coils are on upper floors, and failure of a machine to operate correctly is only learned through observation of conditions in the refrigerators. Needless losses are occasioned due to the lack of a means for indicating at a convenient location normal or abnormal conditions in the system.

Dangerous conditions also result from use of refrigerating equipment, as at present manufactured, from many unforeseen possibilities having an immediate eifect upon-'either'the' high or low pressure sides of the machine. Utilization of the pressure conditions is made in the improved I arrangement for indicating normal or abnormal operation. e

To accomplish the purposes of the invention,

there is provided a central indicating panel having lights wired to pressure responsive devices on the high and low pressure sides of the refrigerating machine. Some of the lights are also connected with pressure responsive switches at the individual cooling coils. The contacting devices, for these lights indicating the condition of the refrigerating machine, are-arranged to' send a momentary signal for each normal operation of the control switch for the compressor motor and to continuously signal a failure of the machine. 1 5

Figure 1 shows diagrammatically a refrigerating machine including a compressor I having the usual connections to a condenser 2 and individual refrigerating coils 3 arranged in multiple. Control switch 4 for the circuit 5 of the 10 compressor motor 6 is subject for operation upon the action of an expansion motor -1 having conduit connections 8 with the low pressure side of the compressor.

-The expansion device 1 operates a lever 9 piv-'l5 oted at ID and carries the lever ll linked to the switch 4. The lever H coacts with a resilient quick-throw member l2.

The operation of the lever 9 is in accordance with pressure conditions on'the low pressure side of the compressor and the throwing of switch 4 is nicely regulated to occur at some exact pre-" determined pressure by an adjustable spring 13 bearing down upon a plunger I4, resting upon the end of the lever. When the plunger 14 is pressed upwardly against the action of spring l3, it contacts with-the lower end of a screw l5 when the switch is swung to closing position a by action of member I2. 'This sets'the compressor in operation and there is an immediate drop in the pressure within the expansion motor I and the lever 9 moves slightly downward, permitting spring actuated plunger M to move out of contact with screw IS.

The momentary engagement of plunger 14 with screw l5 serves to ground a circuit throughlamp l6 and causes the illumination of the lamp for that short interval. Thus anindication is made of the normal operation of the switch.

7 Screw I5 is carried by an insulator l1 and the conductor [8 leads from the screw to lamp i6 and the circuit is from there completed through conductor l9 to one of the power lines 20. 4 In case the switch 4. is closed by a rising pressure inthe expansion device I and the motori fails or the compressor I fails tocause a drop in pressure'on the low pressure side thereof, the lever 9 is-held in its uppermost position and plunger I4 is held in contact with screw 15 and lamp i6 is continuously illuminated, thereby indicating failure. of the refrigeration machine.

If an undue pressure occurs on the high pres--- sure side for any reason, such as lack of circulation or failure of the cooling fluid, an expansion motor 2| connected by conduit 22 to the high 66 pressure side of the compressor lifts a plunger 23 carried by the motor into contact with screw 24. This screw is secured to the insulator guide 25 for plunger 23 and through the conductor 2% is connected with an indicating lamp 21. The

circuit of the lamp is thus closed through grounding on the plunger 23.

The cooling coils 5 control the operation of signal lamps 29 and 30 and the lamps are lighted upon undue rise in temperature of these coils. For this purpose associated with each coil is an expansion motor M as illustrated in Figure 3. The motor contains an expansible fluid and mm municates with a closed tube or bulb 32 filled with the fluid and clamped to the coil 3.

A rise in temperature of the coil ii causes heat to be conducted. to the expansible fluid. and at a predetermined rise in temperature plunger 33 is lifted into engagement with contact screw 36. The screw is carried by the insulator 35 within which the plunger is slidable. Screw 35 is connected with a conductor 36 leading to one side of the power line and when contact m made the current may flow through the conductor 36, screw 34, plunger 33, the irame of the expansion device and by means of conductor 3? through an indicating lamp back to the opposite side of the line.

In the operation oi the arrangement illustrated, the lamps 29, 3t and 21 are normally not illuminated. Also lamp it under normal conditions is only momentarily illuminated when the switch 4 is thrown to the on position. This is due to the periodical increase in pressure in the expansion device '5 at which time the lever d is lifted far enough to engage plunger M with contact screw l5; and as a consequence lamp i6 is illuminated but only until a. drop in pressure on the low pressure side of the compressor, due to the operation-of the compressor. The arm-is thus drawn downwardly slightly and disengages plunger M from screw i5. But if the compressor fails to operate, the expansion device I remains expanded and illumination of lamp it continues.

In case of an undue rise in pressure in the high pressure side of the compressor, expansion device 25 moves plunger 23 into contact with screw 24 and lamp 2'! is illuminated. In case of an undue rise in temperature of one of the cooling coils 3, the heat therein is communicated to the bulb 32 and the expansion of the fluid therein operates the thermostatic motor 3|, causing a closing of one of the circuits for lamps 29 or 30, thus indicating what cooling coil is failing to function properly.

.Although but one specific embodiment of this invention is herein shown and described, it is to be understood that details as set forth may,

be altered or omitted without departing from the spirit of the invention as defined by the following claims.

I claim:

1. A refrigerating machine including a compressor and a condenser, a. motor for driving said compressor, a switch mechanism for the motor including a switch, an operating lever and an. expansion motor for oscillating said lever and thereby opening and. closing the switch, said expansion motor having conduit connections with the low pressure side of the compressor, a separate contact device associated with said lever for operation thereby to make contact each time the lever comes in position for closing the switch,

said lever bemg subject to decreased pressure upon the starting of the compressor to release f said contact after the closing of the contact and to finally open the switch upon a continued decrease in pressure, said lever and xpwsionmeans also being arranged to hold said contact in contacting position during continued high pressure in the expansion device irrespective of the position of the switch operated thereby, an

.motor operated by said expansion motor, an expansion motor connected with the high pressure side of the compressor,'contact devices operated by each of said expansion motors, and indicating means with circuit connections to said contact devices.

3. In a system of the class described, a refrigerating machine and a plurality of separate cooling units connected therewith, said refrigerating machine comprising a compressor and an electric motor for driving the compressor, a pressure operated switch for said motor, said switch being subject to the pressure on the low pressure side of the compressor, a contact device associated with said pressure-operated switch, said contact device being arranged to momentarily move to closing position each time the pressure operated switch is closed, an indicating circuit connected with said contact device and including a lamp; a circuit including an indicating lamp for each cooling unit, means for controlling each cooling unit circuit according to the temperature of the corresponding cooling unit; a circuit including a contact device and an indicating lamp for indicating the condition of the high pressure side of the refrigerating machine, and expansion means for operating said contact device, said expansion means being in communication with the high pressure side of said refrigerator.

WILLIAM HOELLE.

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