US2021052A - Refrigerating apparatus - Google Patents

Description

Nov. 12, 1935. E. DlcKEY 2,021,052

REFRGERA-T ING APPAR ATU S Original Filed March 25, 1929 5 Sheets-Sheet l Nov. 12, 1935. E, DICKEY 2,021,052

IREFRIGERATING APPARATUS Original Filed March 25, 1929 5 Sheets-Sheet 2 hlillllllmml v 1*/ Nov. l2, 1935.

Original Filed March 25, 1929 E. DICKEY REFRIGERATI NG APPARATUS 5 Sheets-Sheet' 3 Nov. 12, 1935. E. DICKEY REFRIGERATING APPARATUS 5 sheets-Smale 4 Original Filed March 25, 1929 Nov. 12, 1935. E, DlcKEY 2,021,052

REFRIGERATING APPARATUS Original Filed March 25, 1929 5 Sheets-Sheet 5 4 We fag Alamented Nov. 12, 193.5

UNITED STATES PATENT OFFICE REFRIGERATIN G APPARATUS Application March 25, 1929, Serial No. 349,796 Renewed July 9, 1932 14 claims. (chez-115) The present invention relates to refrigerating systems and particularly to that, type of system formaintaining a plurality of chambers at different refrigerating temperatures. This application is a continuation in part of my copending application for Refrigerating apparatus S. N. 1,090, filed January 7, 1925.

The present invention is particularly applicable to systems for soda fountain purposes requiring that ice cream be maintained in a frozen state and that drinks be maintained cool but not frozen.

The present invention is also particularly applicable to systems supplying refrigeration for several chambers to be cooled such as several.

cabinets, as in apartment houses and the like, in such al manner as to permit each individual user to regulate the temperature of the chambers or cabinets thus supplied with refrigeration and to control lthe rate of freezing in ice trays and the like which are generally providedin systems of this character.

Refrigerating systems of the above type are generally installed at places where the attendant, such as the clerk, in case of a soda fountain installation, or such as a maid or housewife,l in case of an apartment installation, is unskilled in the mechanical problems of refrigeration. One of the objects of the present invention is to provide for individual control ,of temperatures of one or various refrigerating compartments by the use of a readily accessible and readily adjustablevalve handle, in which the movement thereof is limited to prevent movement of the Valve beyond temperature controlling positions normally desirable, and to provide indicia for indicating the position of the valve.

Further objects and' advantages of the present invention will be-apparent from. the following description, reference `being had. to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings: i

Fig. 1 is a diagrammatic view of a refrigerating Fig. 6 is a view somewhat similar to Fig. 5 showing a further modification of the system;

Fig. 7 is a cross sectional view taken along the line 1-1 of Fig. 8 of a valve adapted to regulate the temperature in the cooling unit; 1 5

. Fig. 8 is a front view of a cooling unit adapted to be used in the systems herein described; and

Fig. 9 is a side elevation somewhat diagrammatic of a cooling unit embodying features of this invention.

All of the refrigerating systems herein described may be provided with means to cause circulation of a cooling medium such as a device generally designated 'throughout the drawings as 40. Preferably this device may include means for receiving evaporated refrigerant, liquefying said refrigerant and delivering the liquefied refrigerant. Connected to this device may be provided a cooling medium circulation system preferably comprising a liquid refrigerant distributing line generally designated throughout the drawings as 41 and an evaporated refrigerant collecting line generally designated throughoutA the drawings as 45. The device for circulating the cooling medium may be provided with an automatic controller for controlling the operation of the device, and this has been generally designated throughout the drawings as B0. 1n all of the systems there may be provided a plurality of chambers to be cooled, such as chambers 26, 32 and 32a. Each of the chambers may be provided with cooling units, such as evaporators shown in the patent to R. G. Osborn, Patent No. 1,556,708, patented Oct., 13, 1925, or such as is disclosed and shown in the copending application of Jesse G. King 4S. N. 670,357, filed October 23, 1923, now Patent 1,805,700, granted May 19, 1931. Some or all of the cooling units or evaporators may be provided with valves for controlling the flow of cooling medium within the cooling units to thus control the temperature of the cooling units or of the chambers within which the cooling units are placed. These valves have been generally designated throughout the drawings as 50, 50a and 50h. 45

Throughout the drawings, the means l0 to cause circulation of the cooling medium may, if desired, comprise a compressor generally designated as l00' which is adapted to deliverl refrigerant to a condenser 0E. The condenser lili is adapted to deliver liqueed refrigerant through the liquid refrigerant distributing line lil, and may be provided with a liquid refrigerant receiver fila, as shown in Figs. 5 and 6', which stores the liquefied refrigerant for.' use in the liquid @5 peratures.

distributing une. After `passing through the various cooling units the evaporated refrigerant again through the cycle.

The liquid refrigerant distributing line may be provided with branches 28, 35, 35a, 35h, 35o and 35e leading to the variouscooling units yor -evaporators or as in the case of 35h, leading to other distributing branches 35e. The evaporated refrigerant collecting line may be provided with collecting branches 29, 36, 36a, 36h, 36o and 36d leading to the various cooling units or evaporators or, as in the case in the branch 36, leading to further collecting branches 36e.

The cooling medium in the system or in part thereof preferably is maintained within certain temperature imparting limits. For instance, in this embodiment the refrigerantv may be maintained within certain pressures or potential tem- Thus as indicated in the drawings, the collecting side of the system may be maintained within certain predetermined temperature or pressure limits. As a specific embodiment, the evaporated refrigerant collecting lines 45 may be connected to the expansible bellows 84 by means of a pipe 85 with :the'collecting line 4|5.V The expansible bellows 84 is adapted to operate a snap switch 86 which is adapted to control the starting and stopping of ,the electric motor 4|, for instance, through the medium of the contacts 8| and '82 which make and break the lead 83. The motor 4| may drive through the medium of pulleys 42 and 44 and the belt 43 the compressor 00.

'I'he various cooling units 25, 3|, 3|a and 31h preferably are provided with means for mainbranches to vthe collecting line 45 Yand thus to Lthe valves 50a of Fig. 5.

the compressor |00. Any or all of the cooling units or evaporators may thus be maintained, if desired, at the lowest temperature which the device 40 is capable of imparting to the units. The device 40, through the control 80, preferably is set to maintain a potential temperature suiciently low for the lowest temperature demanded in the system. Thus, as shown in Fig. 1, means 40 may be set to maintain a temperature sufciently low for the requirements in chamber 26. In Fig. 6, the control for device 40 may be set slightly lower than any possible demand in any of-the refrigerating chambers 32a for a purpose hereinafter to be more fully described. Any or all of the cooling units or evaporators may be provided with a valve adapted to maintain a temperature within the evaporator at any temperature edual to or higher than that for which the circulating. means 40 is set. Thus the cooling unit or evaporator 3|, of Fig. 1, may be provided with the valve 50 for this purpose, the cooling units 3|a, of Fig. 5 may be provided with valves 50a and the cooling units 3|b, of Fig. 6,.may be provided with valves 50a substantially the same as more fully described, these -various valves are adapted to maintain, automatically. predeterthe evaporator 3|.

As hereinafter to ber mined temperatures equal to or higher than that for which the circulating means 46 is set.

In the embodiment disclosed in Figs. 1 to 4 inclusive, features of the invention have been adapted particularly to the Irequirements pre- 5 vailing inv soda fountains and the like, and, as applied to this particular art, the invention is described in its special relation to soda fountains. Thus referring to the drawings, and particularly to Figs. 1l to 4 inclusive there is shown for the 10 purpose of illustration a cabinet 20 for cooling ice cream contained in can 2|, and a cabinet 22 for cooling drinks, fruit syrups, etc. The liquids y which refrigerant medium is conducted to and 20 from said evaporator. As shown in the drawings, I prefer the type of evaporator comprising a header forming areservoir for liquid refrigerant and having depending loops or conduits normally filled with liquid refrigerant, all as more fully 2.5 A

disclosed in the patent heretofore referred to, of my colleague, Robert B. Osborn, No. 1,556,708.' issued October 13, 1925 to the assignee of this application, such evaporators being commonly known in the art as hooded evaporators. 30

Cabinet 22 is provided with an evaporator 3| which is submerged in Water 32 which covers the coil 23 which is spaced a substantial, distance from evaporator 3l for a purpose to be described. Evaporator 3| is similar to evaporator 35 25 `and includes couplings 33 and 34 connected respectively with pipes 35 and 36 for conducting refrigerant to and from the evaporator. The refrigerating system also includes a compressor 40 which is driven by a motor 4| through 40v belt and pulley connections 42, 43-and 44. The refrigerant from evaporators 25 and 3| is conducted through a pipe 45 into the compressor 40 where it is compressed and forced into a condenserA 4B from where it is conducted by pipe 41 to a 4--T 48 45 i which also connects pipes 28 and 35 leading to the evaporators 25 and 3| respectively.

A valve 50 is interposed between pipe 36 and pipe 45 for impeding the ilowof refrigerant from Valve 50 includes `a bocLv 5| 50 having a passage 52 which is unobstructed and through which the refrigerant passes when being withdrawn from evaporator 25. The body 5| also includes a hollow boss 53 the interior of which provides a passage 54 connecting with the pipe 3 6 55 leading to evaporator 3| and to a passage 55 extending transversely to passage 52. The passage 55 includes a reduced portion 66, and a seat 51 for a valve 58. The top of body 6| carries a metal bellows 60, the interior of which is in communica- 60 tion with the passage 55. The top wall 6| of the bellows 60 carries the valve 56. An inverted U- shaped member 63 is secured to the body 6| by screws 63a and the horizontal portion 64 of member 63 extends above the bellows 60. Portion 64 is 65 apertured at 65 to receive a stem 66. Stem 66 is formed as a continuation of valve 58 and is sealed to the top wall 6| of bellows 60. The portion 64 of member 63 is provided with tapped holes 68 and 69 either of which are adapted tc 70 receive a threaded stud 10. 'I'he upper end of stem 66 is screw threaded to, cooperate with an adjusting nut 1| having an arm 12 which is adapted to engagev the stud 10 whereby the movement of said nut is limited. A spring 13 is interposed be- 75,

tween the part 64 and the top 6| of the bellows 60 and normally tends to collapse said bellows and to hold the valve,58 upon the seat 51. A spring 14 is interposed between the part 64 and the nut 1| and normally tends to force the valve 58 upwardly. The springs 13 and 14 are adjusted in such a manner that when a predetermined pressure is present within the bellows 60 the bellows will expand causing the valve 58 to be moved away from the seat 51.

When the compressor 40 is operating, the refrigerant medium will be pumped from theevapo- Y rator 25 through the pipe 29, passage 52 of valve 58 and pipe 45. Likewise, refrigerant medium will be pumped from evaporator 3| through the pipe 36, passages 54, 55, 56 and 52 of valve 50 into the pipe 45. When the pressure within the evaporator 3| and likewise within the bellows 60 falls to a predetermined degree, the spring 13 acting upon thetop wall 6| will force the valve 58 upon the seat 51 and thereby cut off the flow of refrigerant `between pipe 36 and pipe 45 to impede the flow of refrigerant from the said evaporator 3| Valve 50 is adjusted so that itwill shut 01T the connection between pipes 36 and 45 when the temperature of the liquid 32 inthe cabinet 22 has been decreased to such a degree that a cake of ice is formed around the evaporator 3|. This ice may be considered as a large temperature reducing member for maintaining the liquid 32 substantially at freeing temperature for a relatively long time whereby the liquid may be maintained at substantially freezing temperature without operating the compressor at frequent intervals.

The water in the cabinet 22 will remain substantially at 32 while the cabinet is only partly filled with ice. Since the ice enclosing the evaporator is a relatively poor heat transferring medium, it is apparent that the ice is not formed in direct proportion to the temperature of refrigerant within the evaporator. It will be apparent that the pressure within the evaporator can be reduced to relatively low amount before the ice block enclosing the evaporator will extend to the coil 23. Therefore, the allowable range of valve adjustment is relatively wide, andthe valve may be easily made more reliable than one adjustable only within a narrow range.

It is to be seen that the valve50 may be adjusted to maintain any desired refrigerant ternperature in evaporator 3| and that it may be adjusted so that no ice is formed thereon.

The starting and stopping of the compressor 40 is controlled by a controller 80 including contacts 8| and 82 for opening and closing a circuit 83 to the motor 4|. The controller 86 includes a metal bellows 84 connected by pipe 85 to the pipe4 4 5 and is therefore responsive to the pressure upon the low pressure side of the refrigerating system.

Bellows 84 operates a snap switch 86 includingy ent system, one type being shown in the copending application of Jesse G. King, Serial No. 670,357 led October 23, 1923, now Patent 1,805,700.

During the operation of the system, the compressor will reduce the pressure in the evaporators 25 and 3 and, when the pressure within evaporator 3| has been reduced to cause a certain amount of ice to be formed upon the evaporator, the valve 50 will stop flow from pipe 36 to pipe 45. However, since the outlet pipe 29 is unobstructed, reduction of pressure continues in the evaporator 25, the controller 80 being adjusted so that the compressor will not be stopped until the evaporator 25 is reduced to a degree low enough to maintain the brine 26 at a, lower temperature than the water 32.

Since the controller is responsive to the pressure on the low pressure side of the refrigerating system, an increase in temperature above a certain degree and consequently a certain increase in pressure within either of the evaporators 25 and 3|, will cause the controller to operate Vto start the refrigerating cycle.

During the time when the compressor is idle, or4 when the compressor temporarily lacks suflicient capacity to exhaust both evaporators at the same time because of undue refrigeration loads, refrigerant vapor from evaporator or cooler 3| passes the valve 50 when its pressure has increased to a certain extent and. is condensed in the evaporator 25 because of the relatively low temperature of evaporator 25. Thus the evaporator 25 together with the cabinet 20 and the brine 26a form a cold accumulator into which the cooler 3| periodically exhausts. 'I'he accumulator thus formed includes the insulating casing of the cabinet-20 which'has two chambers, the chamber or evaporator 25 containing a volume of refrigerant and the other chamber containing brine 26a which is a medium for storing cold, the depending ducts of the chamber 26 forming passageways for the refrigerant through the brine or medium.

The adjustable 'nut 1| and spring 14 provide means whereby the valve 50 vcan be readily adjusted. When installing the valve 50, the stud 10 is removed andthe spring 14 is adjusted by the nut 1| so that the valve 58 will close when a certain amount of ice has formed upon the evaporator. After the valve has been adjusted, the stud 10 is inserted into hole 68 or hole 69 whereby the stud 10 will be in such a position that the arm 12 of nut 1| can be rotated vsubstantially one-half revolution in either direction. In this manner', the attendant can increase or decrease the tension of spring 14 to vary the adjustment of the valve 50, in order to increase or decrease the amount 'of ice formed, the stud 10 providing a stop for limiting the movement of nut 1| whereby the attendant can not unrestrictedly vary the adjustmentfof the valve.

When features of this invention are applied to the requirements of apartment houses and the like, it is desirable to provide means for regulating the temperature within each cooling unit or chamber to be cooled, and the means thus provided includes preferably some easily actuated manual control provided with indicating means having a normal setting such as markers showing other settings for quick freezing and the like which may be desirable for short periods of time. Thus, in Fig. 5, the cabinet 20 may embody features substantially like those described with reference to Figs. 1 to 4 inclusive and for this purpose need not, but may beprovided with such easy adjustment. However, the cooling units 3|a preferably are provided with valves 50a which permit the users of the chambers 32a to be cooled to obtain various desired temperatures. For this purpose valves 50a may be provided. These valves are more particularly shown in Figs. 7

and 8. Thus the cooling units 3| a receive liquefied refrigerant through the branches 35a and are maintained in a substantially flooded condition in accordance with the disclosure in the pat-- ent to Osborn, or in the application S. N. 670,357, and the evaporated refrigerant is adapted to reiurn through a fitting |02 through the'valve 50a and thus to the collecting branches 36a. The valve 50a may be provided with a closing valve member 58a having a seat 51a. The valve member 58a is adapted to be actuated by a metallic bellows or diaphragm 60a which'is responsive to the pressures prevailing within the inlet Ill2a or the fitting |02 of the evaporator 3| a, for instance, by providing the passage 55a around theV valve stem. Springs 13a and 14a may be provided adapted to operate in the same manner as heretofore described with relation to Figs. 1 to 4. The A nut lla, however, preferably is provided with. an opening through whch the stud or bolt 12a is adapted to pass in order to provide a more or less permanent adjustment. The means for providing the individual adjustment at the apartment may include any desired easy manual adjustment. Thus an indicating disk III) may be placed over the member 63a, and disk IIO may be .provided with a spirally shaped cam I I I. A manually movable member II2 may be provided with a cooperating spiral cam I I3 which, with the cam III, is adapted to change the tension of .the spring 74a. The member H2 is thus part of the means adapted to have a normal setting for instance by placing it in position I. 'This normal setting may be provided with means for adjusting the tensions in the valve? independently of the normal'setting device so that any desired temperature may be obtained at this normal setting.

Thus, by means of the nut 1Ia vand the stud or ing within the trays IM, the individual user mayv This move member H2 to another position. varies 'the tension of the spring Ila and causes a f lower evaporating pressure within the evaporator Bla and consequently a lower temperature.

The stud 12a thus limits the adjustment of the valve so that the unskilled attendant can move the adjusting handle of the valve only a certain ydistance and therefore cannot move the .valve out of its'normally desirable positions.

It sometimes happens when. refrigerating :systems are installed in large apartment houses, particularly where there are long horizontal runs for the distributing and collecting lines, that the evaporators at the ends of the lines most Vremote Y from the circulating device do-not obtain the proper temperatures. 'I'his occurs probably because of internal frictional resistance in the lines which causes variations in the pressures obtainable at these points. In order to overcome this diiliculty, as shown in Fig. 6, valves 50h, similar to valve 50 shown in Figs. 1 to 4 inclusive, may be provided in the refrigerant collecting line 45 of Fig. 6.V Collecting branches or risers b con- Y' 'nectd to the valves 50h in the same manner in which the branch 36 is connected to the valve 5i!l in Figs. 1 to 4 may receive the' refrigerant from part of the evaporators in the system; Thus, in Fig. 6, the collecting line really comprisesthe horizontal portion 45 and the risers Bib and 36e'. The risers 36h and 36e are adapted to be connected by means of the collecting branches 38e 5 with the various evaporators in the chambers 32a to be cooled. Because of a slight resistance imposed between the risers 36h and the line I5 by means of the valves 50h it is possible to obtain a sufiiciently low pressure in the riser 36e so that 10 the evaporators in the vertical row at the right of Fig. 6 obtain sufiiciently low temperatures for the requirements of the users. Obviously the valves 50h' would not have a tension adjustment to pro.

vide as big pressure differential in this case as in 15 the case disclosed in Figs. 1l to 4; but a suiilcient differential would be provided in order to compensate for the frictional resistance or loss within the collecting line 45 so that a suilciently low pressure may be obtained throughout the system. 20 The cooling units 3 lb may be provided, if desired, with individual temperature controls 50a similarly to the embodiment shown in Fig. 5.

The valves 50a are substantially like the valves 50 described with respect to Figs. 1 to 4 with they;

exception of the indicator and easy adjustment before described is provided. Also the valve 50a need not be provided with three branches since it is adapted to be placed where there is no necessity for the three branches. 30

While the form of embodiment of the present 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. 35

What is claimed is as follows:

1. 'I'he combination in a mechanical refrigerating system of a relatively high temperatine evaporator, a refrigerant liquefying unit for delivering l a volume of refrigerant thereto, a relatively low temperature evaporator having an evaporated refrigerant connection with said liquefying unit with substantially unrestricted iiow toward saidunit and into which connection the relatively high temperature evaporator exhausts, said low temperature evaporator comprising a casing providing a chamber for a volume of refrigerant, and a valve operable to connect the chamberto the liquid supply of said refrigerant liquefying unit when the quantity of refrigerant in the chamber w falls below a predetermined point to preserve the balance of the system. Y

2. In combination ina mechanical refrigerating system including a. relatively high temperature evaporator and a refrigerant liquefying unit u for supplying avolume of refrigerant thereto, of a relatively low temperature 'evaporator' an evaporated refrigerant connection with said liquefying unit with substantially unrestricted tlow toward said un'it and into-which connection 50 said high temperature evaporator exhausts, saidlow temperature evaporator comprising an insu. lating casing having two chambers, lone of said chambers containing a volume of refrigerant and the other of said chambers providing a medium 05 for storing cold, and means providing eways for the refrigerant through said medium.

3. The combination in a mechanical refrigerating system of a refrigerant liquefying unit, a relatively high temperature evaporator; a relatively low temperature' evaporator having an evaporatedrefrigerant connection with said liquefying unit with substantially unrestricted iiov'v toward said unit and into which' connection the high temperature evaporator is adapted to ex- 15 haust automatically upon reach-ing a predetermined temperature, and means for maintaining the low temperature evaporator normally at a lower temperature than the high temperature evaporator.

4. That method of mechanically refrigerating a relatively high temperature evaporator which comprises delivering'the refrigerant to the evaporator, periodically exhausting the refrigerant from the evaporator into an evaporated refrigerant zone having a substantially unrestricted re frigerant flow between a relatively low temperature evaporator and a refrigerant liquefying zone for a substantial volume of refrigerant when the first named evaporator temperature rises above a desired point, and maintaining the relatively low temperature evaporator at a lower temperature than the relatively high temperature evaporator.

5. In refrigerating apparatus, the combination of means for liquefying gaseous refrigerant comprising a compressor and a condenser; an evaporator having an inlet for liquid refrigerant and an outlet for gaseous refrigerant; a conduit connecting the said inlet to the discharge of the condenser; a second conduit connecting the said outlet of the evaporator to the inlet of the compressor; a valve for controlling the flow of gaseous refrigerant through the second conduit and adapted automatically to cut off said flow when the temperature in the evaporator falls below a predetermined point and toreestablish the flow when the temperature again rises above said point; a chamber for refrigerant substantially unrestrictedly communicaty ing with the second conduit between the said valve and the compressor, and automatic means adapted to start the compressor when the pressure in the second conduit rises above a predetermined value below the vapor pressure corresponding to the predetermined maximum temperature of the evaporator and to stop the compressor when the refrigerant pressure in the said second conduit between the said valve and the compressor falls below a predetermined value below the pressureat whichsaid valve operates and substantially lower than `the pressure at which the compressor starts.

6. In refrigerating apparatus, the combinaition of means for liquefying gaseous refrigerant comprising a compressor and a condenser; an evaporator having an inlet for liquid refrigerant and an outlet for gaseous refrigerant; a conduit connecting the said inlet to the discharge of the condenser; a second conduit connecting the said outlet of the evaporator to the inlet of the compressor; a container for liquid to be cooled comprising a metal section having its wall in contact on one side with liquid refrigerant in the evaporator, whereby heat ows directly from the liquid to be cooled through said wall into the liquid refrigerant; a valve for controlling the flow of gaseous refrigerant through the second conduit and adapted automatically to cut oi said ow when the temperature in the evaporator fallsA below a predetermined point and to re-establish the flow when the temperature again rises above said point; a chamber for refrigerant substantially unrestrictedly communicating with the second conduit between the said valve and the compressor; and automatic means adapted to start the compressor when the pressure in the second conduit rises above a predetermined value below the vapor pressure corresponding to the predetermined maximum temperature of the evapora-,-

tor and to stop the compressor when the refrigerant pressure in the second conduit between the aforesaid valve and the compressor falls to a predetermined value below the pressure at which said valve operates and substantially lower than the pressure at which the compressor starts.

of gaseous refrigerant through the second con- 15 duit and adapted automatically to cut off said flow when the temperature in the evaporator falls below a predetermined point and to re-establish the flow when the temperature again rises above 20 said point; a chamberfor refrigerant substantially unrestrictedly communicating` with the second conduit between the said valve and the compressor; and adjustable means adapted automatically to start the compressor when the pressure in the second conduit rises above some predetermined value within a range below the vapor pressure corresponding to the predetermined maximum temperature of the evaporator and to stop the compressor when the refrigerant pressure in the said second conduit between the said valve and the compressor falls below a, predetermined value Within a pressure range below' the pressure at which the said valveoperates.

8. In refrigerating apparatus, the combination of means for liquefying gaseous refrigerant comprising a compressor and a condenser; an evaporator having an inlet for liquid refrigerant and an outlet for gaseous refrigerant; a conduit connecting the said inlet to the discharge of the condenser; a second conduit connecting the said heat Hows directly from the liquid to be cooled 5 through said wall into the liquid refrigerant; a valve for controlling the flow of gaseous refrigerant through the second conduit and adapted automatically to cut off said ow when the temo perature in the evaporator falls below a predetermined point and to re-establish the flow when the temperature again rises above said point; a chamber for refrigerant substantially unrestrict edly communicating with the second conduit between the said valve and the compressor; and adjustable means adapted automaticallyt to start the compressor when the pressure in the second conduit rises above some predetermined value` within a. range below the vapor pressure corresponding to the predetermined maximum temperature of the evaporator and to stop the compressor whenvthe refrigerant pressure in the saidsecond conduit -between the said valve and the compressor falls below a predetermined value within a pressure range below the pressure at which the said valve operates.

conditions, a valve for use in such system for controlling the pressure within an evaporator of the system for regulating the temperature of the evaporator, said valve having a readily yaccessible and readily adjustable handle, means associated with the handle for preventing movement 'of the valve beyond temperature controlling positions normally desirable, and indicating means associated with the handle for indicating the adjusted position of the handle.v

10. In a refrigerating system of the type suitable for a plurality of refrigerating compartments in which individual temperatures are desirable in each compartment and in which' regulation is to be limited to the normal desired conditions, a valve in the exhaust conduit oi.' an evaporator of the system for controlling the pressure and therefore for regulating the tempera` ture of the evaporator, said valve having a readily accessible and readily adjustable handle, means associated with the handle for preventing movement of the valve beyond temperature controlling positions normally desirable, and indicating means associated with the handle for indicating .the adjusted position of the handle.

' 11. In a refrigerating system of the type suitable for a plurality of refrigerating compartments in which individual temperatures are desirable in each compartment and in which regulation is to be limited to the normal desired conditions, a valve for use in such system for controlling the Vpressure within an evaporator of the system 4for regulating the temperature of the evaporator.

said valve having a readily accessible and readily adjustable handle, means associated with the handle for preventing movement of the valve beyond a predetermined high temperature and a predetermined low temperature, and indicating means associated with the handle? for indicating the adjusted position of thehandle.

12. In a reirigerating system of-the type suitable for a plurality of refrigerating compartments in which individual temperatures are desirable in each compartment and in which regulation is to be limited to the normal desired conditions, a valve for use in such system for controlling .the pressure within an evaporator ofv the system for regulating the temperature of the evaporator, said valve having a flexible diaphragm adapted to be exed by pressure existing in the evaporator, a valve member carried by the diaphragm for controlling the flow of refrigerant from the evaporator, a spring for resisting movement of the diaphragm, a readily accessible and readily adjustable handle for varying the effectiveness of said spring, means associated with the handle for preventing movement of the valve beyond temperature controlling positions nor- 5 mally-desirable, and indicating means associated with the handle for indicating the adjusted position of the handle.

13. In a refrigerati'ng apparatus, a plurality of cooling units each comprising a reservoir for 10 liquid refrigerant, common nmeans forsupplylng refrigerant medium to, and, withdrawing same from said units, said means includingv a plurali ity of exhaust conduits, means for controlling the pressure in one unit independentlypf the 15 pressure' in another, said means comprisinga valve member in the corresponding exhaust conduit, said valve member including a valve body lcontaining a valve seat, a valve cooperating with said seat, a device responsive to the pressure of 20 refrigerant medium in said unit to be controlled, for operating said valve, a spring tending to seat said valve, and a spring tending to unseat said valve, said second-named spring being adjustable, and means for limiting the adjustment 25 of said spring.

14.3In a refrigerating apparatus, a plurality of cooling units each comprising a reservoir for liquid refrigerant, common means for supplying" refrigerant medium to, and withdrawing same 35 from said units, said means including a' plurality of exhaust conduits,'means` for controlling .the pressure in one unit independently of the pressure in another, said means comprising a valve member in the corresponding exhaust con- 35 duit, said valve member including a valve body containing a valve seat, a valve cooperating Awith said seat, a device responsive to the pressure of refrigerant medium in said unit to be controlled for operating -said valve, a U-shaped member attached to said valve body, a stem for said valve,

.said stemI projecting through an opening in said U-shaped member, a spring interposed between said U-shapedmember and said bellows, a spring resting on said U-shaped member and surround- 45 ing and projecting part of said valve stem, means for vadjusting the tension of said second-named spring, and means for hunting the movement of said adjusting means. v

' ERNEST DrCKEY; 50

Images