US2185107A - Refrigeration control - Google Patents

Description

F. P. PEISERICH El AL REFRIGEIfiATION CONTROL 2 Sheets-Sheet 1 Filed F913. 8, 1937 INVENTOR Frederick P. Peiserich (Ian-Z F. Bidenber BY W 7 ATTORNEYS 19394 F. P. 'PEISERICH ET AL 07 REFRIGERATION CONTROL Filed Feb. 8, 1937 2 Sheets-Sheet 2 INVENTOR Frederick .P. Peiserirflv,

Earl F. Biel'enber BY 7 ATTORNEYS Patented Dec. 26, 1939 I REFRIGERATION CONTROL Frederick P. Peiserich, Bettendorf, and Carl F.

Bielenberg,

Davenport, Iowa,

assignors to Micro-Westco, Inc., Bettendorf, Iowa, a corporation of Delaware Application February a, 1931, Serial No. 124,536

12 Claim.

This invention relates to automatically controlled refrigerating systems and particularly to such a system for use in connection with wrapping machines for cooling the overlapped portions of a wrapped article to effect an efllcient seal thereof.

An object of the invention is to provide a sys- I tern for the control of a refrigerating apparatus which will automatically operate to maintain the pressure in the evaporator or refrigerant plates and related parts below a predetermined pressure whether the system is idle or in use to seal wrapped articles in order that such elements of the system will not be likely to rupture or burst.

Another object is to provide such a control in which the refrigerant circulation may be put into or out of operation by a single switch which switch may be arranged to be operated at more than a single station.

A further object is to provide a control of this character in which a signal lamp indicates when the refrigerant is circulating.

Another object is to provide an improved arrangement of refrigerating members and refrigerant conduits for carrying refrigerant to and from the refrigerating members which will more efliciently chill the overlapped portions of the wrapper of a wrapped article.

Other objects and advantages will become apparent from the following detailed description made with reference to the accompanying diagrammatic illustrations of systems constructed according to the present invention.

Figure 1 is a diagrammatic illustration of a refrigeration system embodying a control constructed according to the present invention; and

Fig. 2 is a modification of the control illustrated in Fig. l and showing a preferred arrangement of and connections for the refrigerating plates.

In Fig. 1, a compressor l, belt driven from an electric motor 2, is designed to receive a suitable gaseous refrigerant such as methyl chloride from a low pressure conduit or line 3 and deliver it in a compressed condition to a condenser 4 over which a current of air may be directed by a fan 5 carried on the motor shaft. After being cooled in the condenser the refrigerant flows into the reservoir 6.

A high pressure line I conducts the liquid refrigerant to the bottom evaporator or refrigerant plates 8 and 9 and side evaporator plates Ill and H, the flow of the refrigerant through the high pressure line being controlled by an electromagnetic or solenoid valve l2 and expansion valves I3 and I4.

It will be seen that beyond the solenoid valve l2 the high pressure line I divides at [5 into two branches l6 and II, the flow of the refrigerant through the branch i6 being regulated by the expansion valve I3 and the flow of the refrigerant through the branch I! being controlled by the expansion valve I 4. The refrigerant conduit branch l6 includes expansion valve l3, evaporator plates or tanks 9 and II, and connecting tubular conduits. The conduit from the expansion valve I3 is connected to the under side of the bottom evaporator plate 9 and the refrigerant, after flowing through the evaporator plate 9, is directed through the conduit l8 into the lower portion of the side evaporator plate II which is thus connected in series with the bottom evaporator plate 9. In a similar manner the refrigerant in branch I! which includes expansion valve l4, evaporator plates or tanks 8 and I0, and tubular connecting conduits fiows through bottom evaporator plate 8 and side evaporator plate It. The two branches l6 and II join again at H! and the refrigerant flows from this point to the compressor I through the low pressure conduit or line 3, after which the cycle may be repeated.

The motor 2 receives its energy from an electric power line having sides and 2| and controlled by the magnetic switch 22. One pole 23 of the -magnetic switch is connected to the side 2| of the power line and provided with an overload cut-out 24 arranged to break the circuit in case of excessive load on the motor and compressor in order to prevent damage thereto. The other pole 25 of the magnetic switch is connected to the side 20 of the power line and is tied into the side 2| of the power line through the series circuit 26 consisting ofv an electromagnet 21 which operates armature 28 of the magnetic switch, and a pressure actuated switch 29. The pressure switch 29 is connected to the low pressure line 3 of the refrigerant circuit, and is arranged to open the series electric circuit 26 when the pressure in the line 3 is reduced to a predetermined value and to close the circuit 26 when such pressure is raised to a predetermined value. In this manner the circuit 26, controlled by the pressure switch 29, will actuate the armature 28 of the magnetic switch 22 and close or open motor circuit 30 solely in response to the pressure of the refrigerant in the low pressure line 3 and independently of other controls.

A control switch 3lhaving a start button 32 and a stop button 33 is provided to place the refrigerating mechanism into or out of operation. The start button has a pigtail 34 tied into the side 2| of the power line so that pressure on the start button 32 shunts the circuit 26 across the pressure switch 29, thereby energizing the magnet 21 of the magnetic switch 22 and starting the motor 2.

The electromagnetic or solenoid valve 12 in the high pressure line I isarranged to open and permit the flow of refrigerant when energized and to close-the high pressure line when de-energized.

Its circuit 35 consists of a direct connection to the side 20 of the power line and indirect connection to the side 2! thereof through a single pole relay 36. Armature 31 of the relay 36 is actuated by electromagnet 39 energized through a circuit 39 comprising a tie to the side 20 of the power line through a remote control stop switch and a tieto the stop button 33 of the control switch 3|. When the start button 32 of the control switch is pressed the current from the side 2| of the power line carried thereby through the pigtail 34 is shorted into-the circuit 39 as well as the circuit 26, thereby energizing the electromagnet 38 of the relay 36 and closing the circuit 35 which opens the solenoid valve I2 to permit the flow of high pressure refrigerant to the expansion valves l3 and I4. A pigtail 4| on the armature 31 is also tied to the relay circuit 39 so that the electromagnet 38 will remain energized, after the start button 32 is released. In this case the current from the side 2| comes from the armature 31 and is carried through the stop button 33. Thus, the solenoid valve l2, when once opened by pressing start button 32, remains open until the relay circuit 39 is broken either by actuating the stop button 33 orwrapping machine and inadvertently leave the refrigerating mechanism in operation. In the present invention this is accomplished by providing the remote control switch40 which may be situated so that it is automatically operated simultaneously with the turning off of the wrapping machine.

As a further precaution and in order that an operator may readily determine when the refrigerating system is operative a pilot orsignal light 42 is provided. This light is connected in series with'a suitable resistance 43 to the side 20 of the power line and a contact of the relay 36 so that it is energized only when the armature-31 closes the relay.

Accordingly, when the relay 36 is energized to close the circuit 35'of the electromagnetic valve l2, the signal lamp 42, which is connected in parallel with the solenoid coil of the valve I2, is illuminated and indicates to the attendant that the valve I2 is open. The attendant is thus informed that refrigerant is being supplied to the evaporators and the system is operative to cool articles, the maintenance of a sufficiently low pressure in the evaporators by the compressor i being automatically controlled as previously explained. It is apparent that without the signal lamp 42, the operator would be unable to determine, without an extensive investigation, whether the system is in condition to chill a series of wrapped articles because the compressor may or may not be in operation when the valve I2 is open and may even operate when such valve is closed. The operation of the system is as follows:

Assuming that the motor is idle and the evappressure refrigerant into the branches l6 and ll of the refrigerating mechanism. This refrigerant is-throttled' through the expansion valves l3 and I4 and enters the bottom evaporator plates 9 and 9 at a low pressure.

The refrigerant partially vaporizes in the evaporator plates 9 and 9, thereby absorbing heat from the same to give them an efficient chilling effect so as to withdraw heat from the bottom of a wrapped article. From the bottom of the evaporator plates the low pressure refrigerant, part of which is vaporized, flows into the bottom of the side evaporator plates l6 and l I through the conduits 18, where it is further vaporized with the absorption of heat, so that the ends or sides of the wrapped article positioned between the vside evaporator plates are'prope'rly chilled.

As will be seen in the drawings, the evaporator or cooling plates are so. arranged that wrapped articles to be sealed, such as loaves of bread, may be passed successively over the bottom plates 8 and 9 and between the side plates l0 and II. The article to besealed may have its bottom portion engaged directly with plates 8 and 9 and its ends engaged with plates I0 and II respectively, or if desired, suitable conveyors or plates may be interposed between the cooling plate and wrapped article to be sealed.

After the start button 32 is released the circuit 39 is not broken, since the armature 31 of the relay 36 has been closed and the side 2| of-the power line is tied to the circuit 39 through the pigtail 4|. However, the motor circuit 30 is dependent upon the magnetic switch 22 and upon release of the start button 32 the circuit 26 controlling the armature 28 of the magnetic switch will be broken unless the pressure in the low pressure conduit 3 is high enough to close the pressure switch 29, in which event, of course, the circuit 26 W11 remain closed and the motor and compressor continue in operation.

Assuming, however, that the pressure in the low pressure line 3 is insuflicient to close the switch 29, the circuit 26 is therefore broken, opening the circuit 30, and stopping the motor and'compressor. In this case the refrigerant continues to flow through the expansion valves l3 and I4 and vaporize in the evaporator plates. This vaporization, of course, gradually builds'up the pressure in the evaporator plates and low pressure line 3 until it is sufiicient to actuate the switch 29 and close the circuit 26, whereby the magnet 21 is energized to close the magnetic switch 22 and start the motor and compressor, which reduces the pressure in the low pressure line 3 and evaporator plates until it'reaches the predetermined pressure at which the switch 29 opens to break the circuit 26, thereby stopping the motor and compressor.

when it is desired to stop the operation of the refrigerating mechanism either the stop button 33 or the remote control switch 40 is pressed, 7;

thus breaking the circuit. 99 to open the relay 98 which breaks the circuit 99, thereby closing the electromagnetic or solenoid valve l2 and also turning off the signal lamp 42. However, as pointed out above, the circuit 29 is independent of the stop button 99 or remote control stop switch 49 so that if the pressure in the low pres-. sure line 9 is high enough to keep the pressure switch 29 closed the motor and compressor will continue in operation until such pressure is reduced sufllciently to open the switch 29. If, however, continued'vaporization of refrigerant remaining in the evaporator plates should build the low pressure setting of the pressure switch 29.

In Fig. 2 is diagrammatically illustrated a modified refrigerating system for cooling the overlapped portions of the wrapper of a wrapped article. In this drawing the parts which correspond to parts described in connection with Fig. 1 have been indicated by the same numerals of reference.

It is to be observed that in this modification the refrigeration control system has been considerably simplified from that shown in Fig. 1. The magnetic switch 22, control switch 3|, relay 36, and remote stop switch 40 have been replaced by a single control switch 44. This switch may be simply a snap type and is arranged to make and break the solenoid circuit 45, which corresponds to the circuit 35 described in connection with the control mechanism of Fig. 1. This circuit is energized from the power lines having sides 20 and 2|. means of switch 44 the solenoid valve I2 opens the high pressure line 1 from the refrigerant reservoir 6 and permits the liquid refrigerant to flow into and through the refrigerating members or plates, as will be hereinafter described.

The motor 2 is automatically controlled by the pressure switch 29, connected in series with the motor and the side 20 and side 2| of the power line. I

Normally the motor circuit just described and indicated by the numeral 46 is at all times connected to the power line. Consequently, energization of this circuit to actuate the motor 2 is dependent upon the pressure switch 29. Thus, regardless of whether the refrigerating unit or system is being used to cool the overlapped portions of the wrapper of a. wrapped article or whether it is standing idle, the pressure in the low pressure line 3, and consequently in the evaporator plates 8, 9, l and II, will be automatically maintained within a predetermined range by the operation of the pressure switch 29. This operation of the pressure switch 29 to maintain the pressure in the low pressure line 3 within a predetermined range is similar to the operation'previously described in connection with the system illustrated in Fig. 1.

Refrigerant admitted to the high pressure line 1 through the opening of the solenoid valve l2 divides at l5 into the two branches I 6 and I1 of the high pressure line and is then throttled through the expansion valves 41 and 48. Each branch of the high pressure line 1 is provided with a separate expansion valve which is ther- Upon closing the circuit by mostatically controlled by means of bulb 49 110- sitioned against the refrigerant outlet line of the refrigerant circulating branch for which the particular expansion valve is a control. The bulb 49 of the expansion valve 41 is positioned against the outlet line 5|, through which is drawn the.

spent refrigerant from the refrigerant circulating branch comprising the tanks 9 and II and adjacent the joint [9 where the several outlet lines are combined to form the single low pressure refrigerant line 9. Thus the flow of refrigerant through this branch is separately regulated by means of its individual thermostatically controlled expansion valve 41. In a similar manner the expansion valve 49 regulates the flow of refrigerant through the branch comprising the tanks 9 and ill by means of the thermostatic bulb 49 positioned adjacent the outlet line 58 through which is drawn the spent refrigerant from this branch. Expansion valves 41 and 48 are of the type which are arranged to permit a greater rate of flow of refrigerant when the thermostatic bulbs 49 are at an elevated temperature than when such bulbs are at a lower temperature. Consequently the temperature of the refrigerant leaving the cooling plates of the respective branches through the conduits 50 and 5| will control the rate of flow through the respective branches, and if each of a series of wrapped articles has one end which is heated to a higher degree than the opposite end, a refrigerating system constructed according to the present invention is adapted to furnish sufficient refrigerant to adequately cool both ends without excessively cooling one end and insufliciently cooling the other. That line or branch of the refrigerating system which is arranged to cool the ends of the articles elevated to the higher temperature will automatically adjust itself to the greater demand for refrigerant.

A pair of spaced parallel vertically disposed refrigerating plates or tanks, previously identi fied by the numerals l0 and l I each receives refrigerant from one of the expansion valves 41 and 48. These tanks define the sides of a cooling zone through which the wrapped articles are passed in the direction indicated by the arrow A in order to chill the overlapped portions of the wrapper. The bottom refrigerating members or tanks 8 and 9 form the bottom of the cooling zone which is in the nature of a trough. It is to be understood that wrapped articles are to be passed through the cooling zone in any suitable manner well known in the art. This may be accomplished by one or more endless conveyors having one lap arranged to ride over one or more of the refrigerating members and carry the articles through the cooling zone by frictional engagement therewith. Another contemplated method is to have a succession of articles pushed through the cooling zone trough by some suitable means exterior of the cooling zone, such as a flight conveyor or other pusher means. In such a construction the wrapped articles could be arranged to have direct contact with the refrigerating members 8, 9, I0 and II. However, the particular means used to advance the wrapped articles through the cooling zone forms no part of the present 'in-' vention and accordingly has not been shown in the drawings. As shown, fresh refrigerant enters each of the side cooling plates or refrigerant tanks at the top of the end thereof adjacent the discharge end of the cooling zone. Intermediate conduits 52 carry the refrigerant from the side or vertically disposed refrigerant tanks to the bottom refrigerant tanks. The refrigerant is drawn off from the top of the end of each vertically disposed refrigerant tank which end is disposed adjacent the entering end of the cooling zone and intermediate conduits I52 introduce such refrigerant to the end of a bottom refrigerant plate which end is positioned adjacent the discharge end of the cooling zone. Each intermediate conduit 52 conducts the refrigerant ,from

. a side heater plate to a bottom heater plate which 3. The refrigerant is preferably made to take a circuitous path through the refrigerant tanks or cooling plates by means of baffles 53. These baffles may be in the form of webs or partitions which extend between the walls of the refrigerant chambers and form openings 54 to permit the refrigerant to flow from one side of the baiiie to the other. As shown by the sectioned parts of the drawings, the vertically disposed or side evaporator plates have the baiiles arranged vertically in the refrigerant circulating chambers with the openings 54 at alternate ends of successive baflles so that refrigerant is directed in an up and down path progressively through the refrigerant chambers. In this manner the wall 55 of the side refrigerant plates which is disposed toward the cooling zone has its internal surface swept over a plurality of times by the refrigerant passing through the refrigerant chamber. This back and forth sweeping action of the refrigerant over the inside surface of the evaporator'plates is progressive from the end thereof adjacent the discharge end of the cooling zone toward the inlet end of the cooling zone. Consequently the refrigerant which has a lower temperature when entering the refrigerant tank than when leaving tends to maintain the wall 55 thereof coldest at the discharge end of the cooling zone with a progressive increase in temperature toward the entering end of the cooling zone. In a similar manner the bottom evaporator plates or refrigerant tanks 8 and S are each provided with baflles to direct the refrigerant in a back and forth motion across the inner surface of the wall 56 thereof which is disposed towards the coo ing zone. The bottom cooling or refrigerating plates are tapered in plan view so that the wide end of one plate is positioned adjacent the narrow end of the other plate. Consequently the space or slot 51 which separates the two bottom refrigerant plates 8 and 9 is disposed at an angle to the direction of movement of wrapped articles over such plates. Thus there is no portion of the bottom of a wrapped article which is not in contact with a chilling plate during a substantial portion of its travel through the cooling zone. In each branch of the refrigerant system which forms a portion of the cooling zone, the freshest or coolest refrigerant entering each particular cooling or refrigerating plate does so at the end of such plate which, is adjacent the discharge end of the cooling zone. In this manner the warmest portion of each of the respective refrigerating plates is positioned adjacent the entering end of the cooling zone and the coldest portion thereof is positioned adjacent the discharge end of the cooling zone so that wrapped The spent refrigerant is drawn from articles being passed in continuous succession through the cooling zone are first subjected to the warmest portion of the cooling zone and then finally to the coldest portion of the cooling zone to provide an efficient and effective chilling action thereon.

It is of considerable advantage to have the cooling system arranged in branches as previously mentioned so that in the event each of a succession. of wrapped articles has one end at a higher temperature than the opposite end, the system will be able to adjust itself so that adequate cooling will be furnished the ends of the articles which have been elevated to the higher temperature without excessively cooling the ends of the articles which were not so highly heated. Accordingly, this invention provides a cooling zone-through which articles may be advanced to chill overlapped portions of the wrappers of wrapped articles, and which zone includes a plurality of refrigerating members each having itscolder end disposed adjacent the discharge end of the cooling zone and which refrigerating members are arranged in a plurality of thermostatically controlled branches, each branch arranged to chill the same relative portion of each of a series of wrapped articles. Furthermore, the flow of refrigerant through each branch is automatically controlled so that the portion of each article cooled by such branch is chilled the proper amount regardless of the temperature of another portion of the article cooled by a separate branch, and articles may be uniformly chilled which enter the cooling zone. with different portions of their wrappers at diiferent temperatures. It will thus be seen that the present invention provides a control system for a refrigerating mechanism in which the evaporator plates are protected against excessive pressures, so that they will be less likely to burst or become ruptured with a resultant loss of refrigerant. Furthermore, the invention provides a control of this character in which a means is provided for remotely controlling the stopping of the apparatus and in which a signal lamp is arranged to indicate to the operator when the mechanism is operative.

It is to be understood that-this invention is not limited to the specific arrangement herein shown or suggested, since the invention is adapted to different conditions according to the judgment of one familiar with the art, nor are the particular types and forms of control media shown and described herein essential, since they may be varied to suit difl'erent conditions.

We claim as our invention:

1. In a refrigerator having a circulating re-'- frigerant, a compressor, a condenser, an evaporator, conduits for carrying refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, a second valve in the conduit which carries refrigerant to the evaporator, valve operating means, a manually to the compressor and for stopping the compressor at a predetermined pressure in said last named conduit, said starting and stopping means being operative independently of the starting and pping buttons, whereby the pressure in the evaporator is continuously controlled.

2. In a refrigerator having a circulating refrigerant, a compressor, a condenser, an evaporator, conduits for carrying refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, a second valve in the conduit which carries refrigerant to the evaporator, valve operating means, a manually operable starting button, a manually operable remote control button, and a manually operable stopping button, said operating means being responsive to said starting button for opening said second valve, said starting and stopping buttons being disposed adjacent one another and said manually operable remote control button being removed from the starting button, said valve operating means being responsive to both said stopping button and said remote control button for closing said second valve, and means for starting the compressor at a predetermined refrigerant pressure in the conduit which carries refrigerant from the evapoator to the compressor and for stopping the compressor at a predetermined pressure in said last named conduit, said starting and stopping means being operative independently of the starting, remote control and stopping buttons, whereby the pressure in the evaporator is continuously controlled.

3. In a refrigerator having a circulating refrigerant, a compressor, a condenser, an evaporator, conduits for carrying refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, a second valve in the conduit which carries refrigerant to the evaporator, valve operating means, a manually operable starting button, a manually operable stopping button, said operating means being responsive to said starting button for opening the second valve in the conduit which carries refrigerant to the evaporator and responsive to said stopping button for closing said last named valve, 2!. signal lamp connected to said valve operating means and arranged to indicate when said last named valve is admitting refrigerant to the evaporator, and means for starting the compressor at a predetermined refrigerant pressure in the conduit which carries refrigerant from the evaporator to the compressor and for stopping the compressor at a predetermined pressure in said last named conduit, said starting and stopping means being operative independently of the starting and stopping buttons, whereby the pressure in the evaporator is continuously controlled.

4. In a refrigerator having a circulating refrigerant, a compressor, a condenser, an evaporator, conduits for carrying refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, a valve in the conduit which carries refrigerant to the evaporator, valve operating means, a manually operable "when said second valve is admitting refrigerant to the evaporator, and means for starting the compressor at a predetermined refrigerant pressure in the conduit carrying refrigerant from the evaporator to the compressor and for stopping the compressor at a predetermined pressure in said last named conduit, said starting and stopping means being operative independently of the starting, remote control and stopping buttons, whereby the pressure in the evaporator is continuously controlled.

5. In a refrigerator having a circulating refrigerant, a compressor, an electric motor for operating the compressor, a condenser, an evaporator, conduits for carrying refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, an electromagnetic valve positioned in the conduit which carries refrigerant from the compressor and condenser to the expansion valve, valve operating means, a manually operable start button and one or more manually operable stop buttons, said operating means being responsive to said start button for opening said electromagnetic valve and responsive to one of said stop buttons for closing said electromagnetic valve, a magnetic switch for opening and closing the electric circuit which energizes the motor, and a switch responsive to the pressure in the conduit which carries refrigerant to the compressor for controlling the magnetic switch, whereby said pressure is maintained within a. predetermined range.

6. In a refrigerator having a circulating refrigerant, a compressor for compressing the refrigerant, an electric motor for operating the compressor, a condenser, an evaporator, conduits for carrying the refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, an electromagnetic valve positioned in the conduit which carries refrigerant from the compressor and condenser to the expansion valve, valve operating means, a manually operable start button, one or more manually operable stop buttons, said valve operating means being responsive to said start button for opening said electromagnetic valve and responsive to one of said stop buttons for closing said electromagnetic valve, a magnetic switch for opening and closing the electric circuit which energizes the motor, and a switch responsive to the pressure in the conduit which carries refrigerant to the compressor for controlling the magnetic switch, whereby said pressure is maintained within a predetermined range, and said start button arranged to energize the magnetic switch to Start the motor and compressor simultaneously with the opening of the electromagnetic valve regardless of said pressure.

7. In a refrigerator having a circulating refrigerant, a compressor, an electric motor for operating the compressor, a condenser, an evaporator, conduits for carrying refrigerant from the compressor to the condenser, from the condenser to the evaporator and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator, an electromagnetic valve for opening and closing the conduit which carries refrigerant from the compressor to the expansion valve, valve operating means, a manually operable start button, one or more manually operable stop buttons and a magnetic relay, said electromagnetic valve being actuated by electric current controlled by said magnetic relay, said operating means being responsive to said start button for opening and one of said stop buttons for closing said electromagnetic valve, a magnetic switch for opening and closing the electric circuit which energizes the motor, and a switch responsive to the pressure in the conduit which carries refrigerant to the compressor for controlling the magnetic switch, whereby said pressure is maintained within a predetermined range.

8. In a refrigerator having a circulating re frigerant, a compressor for compressing the re-.

frigerant, an electric motor for operating the compressor, a condenser in which the refrigerant gives off heat, an evaporator member in which the refrigerant absorbs heat, conduits for carrying the refrigerant from the compressor to the condenser, from the condenser to the evaporator member and from the evaporator to the compressor, and a control system comprising an expansion valve for regulating the flow of refrigerant into the evaporator member, an electromagnetic valve for opening and closing the conduit carrying refrigerant from the compressor to the expansion valve, valve operating means, a manually operable start button, one or more manually operable stop buttons, a magnetic relay, said electromagnetic valve being actuated by electric current controlled by said magnetic relay, said valve operating means being responsive to said start button for opening and one of said stop buttons for closing said electromagnetic valve, an electric signal lamp connected in parallel with the electromagnetic valve to indicate when said valve is open, a magnetic switch for opening and closing the electric circuit energizing the motor, and a switch responsive to the pressure in the conduit carrying refrigerant to the compressor for controlling the magnetic switch, whereby said pressure is maintained within a predetermined range, and said start button being arranged to energize the magnetic switch to start the motor and compressor simultaneously with the opening of the electromagnetic valve regardless of said pressure.

9. In a refrigerating system for chilling wrapped articles, a plurality of bottom refrigerating members and a plurality of side refrigerating members, a refrigerant compressor, an electric motor for actuating said compressor, a condenser, a refrigerant reservoir, refrigerant conduits arranged so that refrigerant may be circulated through said system, and means for controlling the said circulation including valve operating means, .a remote manually operable electric aismoz being'responsive to said remote manually operable switch, expansion valves positioned in thesystem between the magnetic valve and the refrigerating members for admitting refrigerant to the members, a magnetic switch in the electric motor power circuit for stopping and starting said motor, and a switch responsive to the pressure of the refrigerant on the suction side of the compressor, said pressure responsive switch arranged to energize the magnetic switch and close the motor circuit when the pressure inthe refrigerating members exceeds a predetermined range and open the motor circuit when the pressure falls below said range independently of the state of the magnetic valve.

10. In a refrigerating system for chilling wrapped articles, a plurality of bottom refrigerating members and a plurality of side refrigerating members, a refrigerant compressor, an electric motor for actuating said compressor, a condenser, a refrigerant reservoir, refrigerant conduits arranged so that refrigerant may be circulated through said system, and means for controlling the said circulation including valve operating means, a remote manually operable switch, a magnetic valve for controlling the admission of compressed refrigerant to the refrigerating members, said valve operating means being responsive to said remote manually operable switch, expansion valves positioned in the system between the magnetic valve and the refrigerating members for admitting refrigerant to the members, a magnetic switch in the electric motor power cir-. cuit for stopping and starting said motor, and a switch responsive to the pressure of the refrigerant on the suction side of the compressor, said pressure responsive switch arranged to energize the magnetic switch and close the motor circuit when the pressure in the refrigerating members exceeds a predetermined range and open the motor circuit when the pressure falls below said range, and a manually operable switch arranged to simultaneously energize the magnetic switch to close the motor circuit and to energize the magnetic valve to admit refrigerant to the refrigerating members.

11. In a refrigerating system for chilling wrapped articles, a pair'of vertical, spaced, parallel refrigerating members and a plurality of horizontal refrigerating members arranged to cooperate with the first mentioned members to define a channel having an entering end and a discharge end for the passage of wrapped articles, the vertical members disposed at the sides of the channel and the horizontal members disposed at the bottom of the channel, a refrigerant compressor, an electric motor for actuating the compressor, a supply conduit for carrying refrigerant from the compressor, branch conduits for carrying refrigerant from the supply conduit to the top portions of the vertical members substantially at the ends thereof disposed at the discharge end of the channels, a return conduit for carrying refrigerant from the refrigerating members to the compressor, outlet conduits for carrying refrigerant from portions of horizontal refrigerating members substantially at the entering end of the channel to the return conduit, intermediate conduits for carrying refrigerant from the vetical refrigerating members to the horizontal refrigerating members, an electromagnetic valve for controlling the admission of refrigerant to the refrigerating members, a switch responsive to the pressure of refrigerant in the return conduit and operable independently of the electromagnetic valve for controlling the electric motor independently of the electromagnetic valve, and manual means for controlling the energization of the electromagnetic valve.

12. A refrigerating system comprising a plurality of evaporator members, a motor driven compressor unit, conduits for carrying .refrigerant to the evaporator members from the compressor unit and from the evaporator members to the compressor unit, said evaporator members being connected in parallel with one another, an expansion valve for each of said evaporator members and arranged to individually manually operable means for controlling the opening and closing of said valve whereby the flow of refrigerant to all of said evaporator members can be simultaneously started or arrested at will; and pressure responsive control means for starting and stopping the motor of the compressor unit, said control means being connected to the conduit through which refrigerant returns to the compressor unit from the evaporator members and arranged to start said motor upon the pressure in the last mentioned conduit falling to a predetermined value and to stop said motor upon the pressure rising to a'predeterregulate the flow of refrigerant into said mem-- mined value. 15 bers, valve means interposed in the conduit carrying refrigerant to the evaporator members,

FREDERICK P. PEISERICH. CARL 1". BIEIENBERG.

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