US2255215A - Regulating means - Google Patents

Description

Sept. 9, 1941 I J. HEINRICH- REGULATING MEANS l0 Shets-Sheet 1 Filed Oct. 22, 1938' IIIIIIIII IIIIIIIIIIII/IIIHIIG! INVENTOR JoHANNHEINRIC BY @4344 %a ORNEYS ATT S P 1941- J. HEINRICH 2,255,215

REGULATING MEANS Filed 001;. 22, 1938 10 Sheets-Sheet 3 lNVE TOR JOHANN, IIEIEINRIC'H ATTONEY P 1.941- V J. HEINRICH 2,255,215

REGULATING MEANS Filed Oct. 22, 1958 1o Sheets-Sheet 4 ism:

INVENTOR JOHANN HEINRICH P 1941- J. HEINRICH 2,255,215

REGULATING MEANS Filed Oct. 22, 1938 10 sheets-sheet 5 INVENTOR JOHANN HEINRICH ATTORNEYS Sept. 9, 1941. J. HEINRICH 2,255,215

REGULATING MEANS Filed 001;. 22, 1938 10 Sheets-Sheet 6 Sept. 9, 1941. J. HEINRICH REGULATING MEANS Filed Oct. 22. 1958 10 Sheets-Sheet 8 m 3 m n m N W n I L i Sept. 9, 1941. J. HEINRICH REGULATING' MEANS Filed Oct. 22, 1938 Fig. 18. 131

Sheets-Sheet 10 Fig. 13. 131

g i I 120 123 F150 2 I; w 7 0 asp c2 c0 A\L\Y\\ I 55-+ -48 66-1 I INVENTOR L I i l I JOHANN HEINRICH l I 67,6169 B I 152 E W2 ATTORNEYS Patente d Sept. 9, 1941 REGULATENG MEANS Johann Heinrich, Berlin-'Iegel, Germany, as- Signor, by mesne assignments, to Maschinen- Und Metallwaren-Handelsgesellschaft m. b. H., Berlin, Germany, a limited liability company of Germany Application October 22, 1938, Serial No. 236,398 In Germany May 12,1938

Claims.

This invention relates to means for regulating gradually, exactly and without steps the amount of the medium compressed by piston-compressors.

The present application is a continuation-inpart of the co-pending patent application of Heinrich and Spilger, Serial No. 299,938, filed May 25, 1938.

In the said patent application piston-compressors are described which are provided with a suction valve through which the medium is introduced into a compression cylinder, and an outflow valve through which the compressed medium is removed from that cylinder. The amount of the compressed medium is regulated by keeping the suction valve open during a part of the compression stroke, so that a portion of the medium sucked into the compression cylinder is removed therefrom through the same suction valve by the motion of the compression piston. When the suction valve is closed, the medium remaining in the compression cylinder is compressed to the final pressure by the piston and is removed through the outflow valve.

The suction valve is operated by an auxiliary piston which during each reciprocation of the compression piston is subjected to a certain pressure, preferably, the pressure of the medium which has just been compressed. This pressure medium is supplied to the auxiliary piston through a rotary valve which may be connected with the main shaft of the compressor or may constitute a part of that shaft. The suction valve is closed when the pressure within the compression cylinder becomes greater than the pressure upon the auxiliary piston. The time of the closing of the suction valve depends upon the time required by the pressure medium to flow away from the auxiliary piston through a throttle valve.

It was found that in certain instances, for example, in the case of large single or doubleoperated compressors the use of a rotary valve which constitutes a part of the compressor shaft, or is directly driven thereby, is not altogether satisfactory.

It was further found that the adjustment is comparatively inexact whenever the regulation of the amount of the pressure medium supplied to the auxiliary piston and of the time of its flow is carried out by hand. Considerable variations and changes in the cooling temperatures then take place and this rise and fall in temperature is sometimes furthered by varying operating conditions. It is well known, however, that variations in the temperature of a cooling plant are undesirable and are often detrimental.

An object of the present invention is the provision of an efiectively operating regulating device for piston-compressors by means of which the amount of the compressed fluid can be very minutely and exactly regulated.

Another object is the provision of a device by means of which the amount of the compressed medium is adapted in a completely automatic manner to the cold requirements of a cooling plant, so that the evaporation temperatures are maintained constant, or practically constant.

A further object is the provision of an automatically operable device for regulating the supply of the pressure medium to the auxiliary piston depending upon the temperatures in the evaporating device of a refrigeration plant.

Other objects of the present invention will be apparent in the course of the following specification.

The objects of the present invention may be realized by substituting the rotary valve with a swinging or oscillating valve comprising a sleeve or cylinder which is caused to carry out a reciprocatory turning movement by some of the reciprocating parts of the compressor. The cylinder is provided with an opening which may coincide with an opening provided in another cylinder. One of these openings is in communication with a source of the pressure medium,-

while the other opening is in communication with the auxiliary'piston, so that the pressure medium is caused to flow to the auxiliary piston when the two openings are in communication with each other. The second-mentioned cylinder is adjustable in relation to the first-mentioned cylinder, so that the amount of the pressure medium supplied to the auxiliary piston and/or the time when a certain pressure will be exerted upon the auxiliary piston may be varied.

In accordance with one modification of the present inventionthis adjustment of the two cylinders is carried out by hand.

In accordance with another modification of the present invention the adjustment is carried out automatically, for example, by utilizing the evaporation pressure of a medium which is responsive to temperature variations, such as ammonia. This pressure which changes with the changes in the cold output of the refrigeration plant, is caused to vary the pressures of another medium, such as a liquid, the pressure of which is not affected by temperature variations to any substantial extent. The liquid is caused to 0perate a device which regulates the admission of the pressure medium to the auxiliary piston; this device may be used, for example, to adjust the position of the second-mentioned cylinder.

The ammonia may be contained in a flask suspended in the evaporation chamber of the refrigeration plant. Its pressure may be transmitted to the liquid which is used for lubricating the compressor and a part of which is supplied under constant pressure by a special pump.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing, by way of example, preferred embodiments of the inventive idea.

In the drawings:

Figure 1 shows in side elevation a compressor having a swinging or oscillating valve;

Figure 2 is atop view of the compressor shown in Figure 1;

Figure 3 is a section along the line 3--3 of Figure 2;

Figure 4 is a section along the line 4.4 of Figure 1.

Figure 5-shows in detail the mechanism which operates the swinging valve of the compressor;

Figure 6 is a section along the line 6--6 of Figure 5;

Figure 7 is a View along the line l'! of Figure 6;

Figure 8 is a section along the line 8-8 of Figure 6 and shows the position of the swinging valve when the compressor is running empty.

Figure 9 is similar to Figure 8 and shows the position of the swinging valve when the compressor is operating at full load;

Figure 10 illustrates a straight-current singleacting compressor having a swinging valve regu- Figure 11 shows in side elevation a compressor provided with automatically operating regulating means;

with a. separate auxiliary piston 44, which is reciprocated in an auxiliary cylinder 45. The interior of the cylinders 45 is connected by means of the branch pipes 52 with a pipe 53 which leads to the swinging valve 55 (Figures 1 and 2). Pipes I9 which constitute a continuation of the pipe 53, carry throttle valves 54 and are connected to the main suction pipe 55 of the compressor. The medium to be compressed is supplied through the suction pipe 55 to a space situated behind the suction valves 5a and flows Figure. 12 is a top view of the compressor shown in Figure 11;

Figure 13 is a section along the lines I.3l3 of Figure 15 and shows the automatic regulating means when the compressor is running empty.

Figure 14 is similar to Figure 13 and shows the. automatic regulating means when the compressor is operating at full load;

Figure 15 shows the automatic regulating means partly in side elevation and partly in section;

Figure 16 is a section along the lines |5-l5 of Figure 15 and shows the servo-motor when the compressor is running empty;

Figure 17 is a section along the lines l'l-I'! of Figure 15 and shows the oscillating valve when the compressor is running empty;

Figure 18 is similar to Figure 18 and shows the position of the device when the compressor is operating under full load; and

Figure 19 is similar to Figure 17 and shows the position of the device when the compressor is operating under full load.

The compressor shown in Figures 1 to 9 of the drawings is a double-operating one, and com prises a piston (Figure 3), which is reciprocated in a cylinder 4| and which is connected by a piston rod. 42 with a crosshead 43. Each side of the cylinder is provided with three suction valves. and a corresponding number of compression valves 5!, so that there are in all six suction valves 58 and six compression valves 5i. Each of the suction valves 50 is connected into the interior 45 of the cylinder 41 when the suction valves are open.

. The medium compressed in the cylinder 46 is removed through the compression valves 5| and the main pressure conduit 58 which is connected with the pipe 53 through the intermediary of the pipe 5'! and the swinging valve 56.

The swinging valve or the regulating device 56 comprises two swinging sleeves 66 (Figures 8 and 9), each of which regulates the amount of the compressed medium flowing to the suction valves 55 situated at one side of the main piston 40.

Each of the sleeves 60 is hollow and is carried within a regulating sleeve 6| which is provided with an opening 52 for the introduction of the compressed medium. The opening 62 co-operates with the edges 53 of an opening 69 provided in the hollow sleeve 56.

As shown in Figure 6, the interior 6'! of each sleeve 65 is connected by means of openings 64 with a separate chamber 65formed within the valve casing 56. The pipe 51, which is connected with the pressure conduit 58 of the compressor, is in communication with the annular chambers 65. When the opening 69 of a sleeve 60 and the opening 62 of the sleeve 6| are in communication with each other, a connection is established between the interior 6'! of the sleeve 60 and an annular chamber 10 formed in the casing 66. As shown in Figures 8 and 9 passages 48 connect the chambers 10 with the pipe 53 by means of which the compressed medium is caused to flow through the branch pipes 52 and behind the auxiliary pistons 44.

The crosshead 43 of the compressor actuates thesleeve 60 by means of the lever system 41. As shown in Figure 5, this lever system comprises a fork it, which is movably mounted upon the pin of the crosshead 43 and which is linked with the bearing spindle ll of each sleeve 60 by means of the links 74 and I5 and the levers 16. As shown in Figure 6, each of the levers 16 is mounted upon the projecting end of the spindle H which is integral with the sleeve 65. The levers 16 are firmly connected with the spindle 11 by the bolts 49. Due to this connection, each sleeve 65 carries out an oscillatory turning movement in the course of the reciprocation of the crosshead 43.

In this construction, the moment at which the compressed medium begins to flow into the interior of the auxiliary cylinders 45 behind the auxiliary pistons 44 is determined by manually adjusting the regulating sleeves 6 I.

Each of the sleeves BI is integral with a bearing spindle which is supported in the casing 65. Each spindle 86 carries a crank 8| provided with a pin 82. The pins 82 are situated within openings 35- formed in the plates 83 which are carried by a yoke 85. The yoke 85 is adjustable by means of a spindle 84 which is operated by a hand-wheel 31. thus shifting or adjusting the yoke 85, the po- By turning the wheel 3|, and

sition of the openings 62 of the sleeves 6| is changedwith reference to the edges 63 of the openings 69 provided in the sleeves 66, thereby changing the time at which the compressed me dium situated inthe chamber 61 is out ofi from the annular chamber 16, the pipe 53, and the suction valves 59. p

The device operates as follows:

The medium compressed in the interior 46 of the cylinder ll causes the compression valves to open and flows into the compression conduit 58. A part of the compressed medium flows through the pipe 5! to the chambers 65 provided in the valve casing 66. The compressed medium fills the interior Bl of the sleeves 66 by means of the opening 64.

At a time when the opening 69 of the sleeves 60 are in communication with the openings 62 of the sleeves 6|, the compressed medium will flow through these openings, the chambers and the passages 48 and into the pipe 53, reaching the auxiliary cylinders 55 behind the auxiliary pistons 44.

Due to the pressure of the compressed mediumexerted upon the auxiliary pistons 44, the suction valves 59 will remain open during a part of the compression stroke. This pressure diminishes gradually and continually since the compressed medium in the cylinders 45 will gradually fiow through the pipes i9 and the throttle valves 54 to the suction conduit 55. The suction valves 5|] will close when the pressure exerted upon the auxiliary pistons 34 becomes smaller than the pressure of the medium situated within the cylinder 4| and acting upon the operative surfaces of the suction valves 50.

Figure 8 shows the position of the sleeves 6| at the time when the compressor is operated without performing any useful work. Then, the suction valves 59 are never closed throughout the reciprocation of the main piston ill. Throughout the reciprocation of the sleeves 66 caused by the crosshead 43 and the lever system 41, the openings 69 provided in the sleeves 60 are in communication with the openings 62 provided in the sleeves 6|.

Thus, in this position, the compression conduit 56 always remains in connection with the space behind the auxiliary pistons 34 through the pipe 51, the valve 56 and the pipes 53 and 52. The auxiliary pistons 44 are always subjected to the pressure of the compressed medium, so that th suction valves 56 will not close.

The position at which the compressor is operated at full capacity is illustrated in Figure 9. In this position, the openings 62 of the sleeves 6| are so located in relation to the openings 69 of the sleeves 69 that they will never establish a connection with each other in the course of the reciprocation of the sleeves 66, so that the compressed medium situated within the chambers 6'! cannot reach the auxiliary cylinders 45.

Therefore, in this position pistons 44 of the suction valves 56 will not be subjected at any time to any pressure operating in the opposite direction to the pressure prevailing within the interior 46 of the main cylinder 5|, so that the suction valves 59 will close right at the beginning of the compression stroke.

Of course, the sleeves 6| may assume any number of positions which lie between the extreme positions illustrated in Figures 8 and 9. Depending upon these positions, the period of time at which the suction valves 56 will be closed will be changed depending upon how soon the supply of the compressed medium to the auxiliary cylinders 45 is interrupted. V

The adjustment of the sleeves 6| may be easily supervised by providing a scale 33 (Figure 7) around the adjusting spindle 84 and by providing a pointer or indicator 86 upon the yoke 85, which is adjustable by means of the spindle 84.

Single-acting compressors also can be regulated in the described manner. A compressor of this type is illustrated in Figure 10 of the drawings, said compressor operating upon the uniform flow principle and being provided with a suction valve 25 which is carried by the main piston 34. The cylinder 35 carries a compression valve 36, and a part of the compressed medium flows through a pipe 3'! toward the regulating device 56, which is of the same type as the one illustrated in Figures 6, 8 and 9. The pipe 31 communicates with the interior 6'! of the sleeve 60 which is provided with an opening 69. The opening 69 may coincide with the opening 62 provided in the sleeve 6|. The opening 62 communicates by means of the chamber 16 with the passage 48 which is connected to a pipe 38 leading to the interior 39 of an auxiliary cylinder 20. The auxiliary piston 2| situated within the cylinder 20 is connected by means of a rod 22 with an auxiliary valve 25.

The position of the sleeve 6| is adjusted man ually in the same manner as that already described by operating the wheel 3|. The sleeve 66 is reciprocated by means of a crank 23 which is connected to an oscillating lever 24. The lever 24 is connected to the flywheel 21, which is connected by the piston rod 28 with the piston 34.

The return flow of the compressed medium from th auxiliary cylinder 20 to the main cylinder 35 is regulated by providing a branch pipe carrying a throttle valve 29.

In compressors of this type, the regulation of the amount of the compressed medium is carried out by means of the auxiliary valve 25.

As already mentioned, a portion of the compressed medium is caused to flow through the v pipe 31 and into the regulating device 56. If the manually operable regulating wheel 3| is so set that at certain times a connection is established between the openings 69 and 62, then at those times the compressed medium will flow through the pipe 38 and into the chamber 39, exerting a pressure upon th auxiliary piston 2|, so that the auxiliary valve 25 will remain open during a part of the compression stroke. Due to the provision of a branch pipe carrying the throttle valve 29, the compressed medium in the chamber 39 will gradually return to the main cylinder 35 through the throttle valve 29, so that the pressure within the chamber 39 will gradually drop until it will be overcome'by the pressure prevailing within the cylinder 35. At that time the auxiliary valve 25 will close. This moment of closing of the auxiliary valve 25 can be easily adjusted by regulating the throttle valve 29.

In the construction illustrated in Figures 11 to 19, a double-acting compressor is shown wherein the adjustment of the regulating device 56 is carried out automatically.

The plant comprises an evaporator (Figures 11 and 12) which is influenced in the customary manner by the compressed medium. A flask or container 9|, which is partly or totally filled with ammonia, is suspended within the evaporator 90.

A pipe 92 carrying a valve 93 connects the con- A diaphragm 95 i situated within the chamber 94 and is carried by the casing 96. The diaphragm 95 is in engagement with a member 91 having the form of a mushroom and provided with a stem 98 which is in contact with one arm of an angular lever 99. suspended at I within a casing IOI.

A diaphragm valve I02, which is also situated within the casing IOI, comprises a valve casing I03 having an inner wall I04 which separates the interior of the diaphragm valve I02 into two chambers I and I06. These two chambers are in communication with each other through an opening I01, which may be closed by a valve body I08 integral with the valve stem I09. A diaphragm H0 is situated within the chamber I05 and is connected with the valve stem I09 by the nut III. A diaphragm I I2 situated within the chamber I06 is connected by similar means with the valve stem I09. The valve stem I09 presses against the lower arm I i3 of the angular lever 99. A coil spring I I4 situated within the chamber I05 presses against the diaphragm I I0 and thus exerts a pressure upon the valve stem I99 which is connected with the diaphragm I I0. The pressure of the spring H4 may be adjusted by means of the bolt H5.

The chamber I 05 of the diaphragm valve I02 is in communication with the pipe II6, the opposite end of which is connected to a pump II'I, shown in Figure 11. This pump which is illustrated diagrammatically in the drawings, is used for transmitting some of the lubricating medium under a constant pressure through the pipe II6 and into the chamber I05 of the diaphragm valve I02. The pump II? is preferably driven by the compressor itself. It is advisable to utilize for this purpose the usual pump used for the circulation of the lubricating liquid which is situated in a container of the customary type (not shown).

As shown in Figure 15, the pipe I I6 is provided with a branch pipe IIS carrying a valve H9. The branch pipe H8 is used for the removal of a part of the lubricating liquid flowing through the pipe H6 and the valve I I9 may be adjusted to vary the pressure imparted to the lubricating liquid by the pump I I1.

Another pipe I (Figure 15) connects the chamber I05 of the diaphragm valve I02 with a servo motor I26, which is shown in greater detail in Figures 16 to 19 of the drawings.

The servo motor I 29 comprises a casing I27 having a passage I28 which is in communication with the pipe I20. A piston I 29 is reciprocable within the casing I27 and is subjected to the pressure of a coil spring I30. The position of the piston I29 within the casing I2'I may be adjusted manually by turning the hand wheel I3I which is connected with the disc I50.

The piston I29 is in communication by means of a rod I32 with the device used for adjusting the positions of the sleeves 6| of the valve 56.

As shown in Figure 13, a pipe I34, which is used for the removal of the lubricating liquid, is in communication with the chamber I06 of the diaphragm valve I02. The oil or lubricating fluid removed from the chamber I06 is preferably returned to the crosshead support.

A coil spring I35 is movable along with a disc I36 which presses against the vertical arm II3 of the angular lever 69. The opposite end of the spring I35 is adjustable by means of a disc I31 which is connected with a threaded guide I38. The adjustment of the spring I95 is carried out by means of a hand-wheel I39, which is connected with a sleeve I40. Due to this arrangement, the

The lever 99 is pivotally by the yoke 85.

pressure transmitted by the diaphragm 95 may be varied at will; This adjustment which depends upon the flexibility of the coil spring I35 may be used to regulate the operations of the compressor from no load to full load within temperature variations of 1 C. of the liquid cooled in the evaporator 99.

The regulating device 56 is similar to those described and comprises a separate sleeve 60 for each side of the main piston. Each of the hollow sleeves 60 is carried in a sleeve BI provided with an opening 62. When the openings 69 of the sleeves 50 coincide with the openings 62 of the sleeves 6I, the compressed medium is caused to flow to the auxiliary pistons connected with the suction valves 50. The openings 54 of the sleeves 60 connect the interiors of these sleeves with annular chambers 65 which are formed in the casing 66 and which are connected with the conduit 51 supplying a part of the compressed medium to the valve 56. The leverage system 41 which is attached to the crosshead 43 is used for causing the sleeves 60 to carry out a reciprocatory turning movement.

The position of the sleeves 6| determines the time when the compressed medium situated within the chambers 61 is allowed to reach the auxiliary pistons 44.

As shown in Figure 15, the sleeves BI are integral with spindles which is supported by the casing 66. Each of the spindles 80 of the sleeves 6I carries a crank 8|, shown in Figures 16 and 18, which carries a pin 82. The pins 82 are situated within the slots 30 of plates 83, which are carried The yoke 85 is movable along with the rod I32 of the servo motor I25.

The device is operated as follows:

Assume that the temperature of the liquid to be cooled is increased within the evaporator (Figures 11 and 12). Then the pressure upon the diaphragm in the chamber 94 (Figures 13 and 14) is increased, and the diaphragm 95 moves the member 91 downwards. The stem 98 of the member 91 exerts a greater pressure on the angular lever 99 and swings this lever around its pivot I00 in the direction of the arrow I46, shown in Figure 13. Then the valve stem I09 moves to the right (looking in the direction of Figures 13 and 14) under the influence of the spring H4, and the valve body I08 diminishes the operative cross-sectional area of the opening I01 situated between the chambers I05 and I66 of the diaphragm valve I02. Due to this diminishing of the opening I07, less liquid is caused to flow from the chamber I05 to the chamber I105, so that the pressure in the chamber I05 is increased. The liquid collected in chamber I05 flows through the pipe I20 (Figure 15) to the servo motor I26 (Figures 16 to 19) and this increased pressure is transmitted to the piston I29 of the servo motor. The piston I29 is then moved downward under the influence of this increased pressure, thereby compressing the spring I30 and moving downwardly the piston rod I32. The yoke 85 moves downwardly along with the rod I32 and the cranks BI are turned or rotated along with the spindles 80 and the sleeves SI. The openings 09 and 62 of the sleeves 60 and 6!, are so disposed that after this shifting of the sleeves 6|, the compressed medium will reach the auxiliary pistons earlier than it did before, so that the suction valves 50 will also close earlier. Thus, the amount of the medium compressed by the compressor is increased, and

any further increase in temperature in the evaporator SEI is avoided.

The greater the pressure exerted upon the diaphragm 95, the less will be the operative crosssectional area of the opening IQ'I connecting the chambers I 65 and m6 of the diaphragm valve I02. Therefore, in that case the pressure transmitted by the pipe IZl'i to the servo motor E25 will be also increased.

Figures 13, 16 and 17 show the positions of l.

the lever 99, the piston I29 and the sleeves GI, respectively, when the compressor is operating without performing any useful work. Then the interior 3'! of the sleeves 89 is always in connection with the passages 18 of the casing 68; so

that the auxiliary pistons i l of the suction valves 50 are always subjected to the pressure of the compressed medium and the suction valves 58 do not close at all.

Figures 14, 18 and 19 show the positions of the lever 99, the piston I29 and the sleeves 6|, respectively, when the compressor is operating at full load. Then the compressed medium within the chambers 61 can never reach the auxiliary pistons 44 of the suction valves 59, since the openings 82 and the openings 69 are so located that they will never coincide. Then the suction valves 50 of the compressor operate in a normal manner and are closed at the beginning of the compression stroke.

Obviously, there can be many intermediate positions between these two extreme positions, and the sleeves 6| may assume any intermediate position depending upon the temperature in the evaporator 99.

As soon as the compressor is stopped, the auxiliary pump III stops as well, and then the lubricating oil does not exert any pressure at all upon the piston I29 of the servo motor I26. Then the spring I30 presses the piston I29 upwardly and the piston rod I32 and the yoke 85 are moved upwardly along with the piston, thereby turning the cranks BI, the spindles 80, and the sleeves SI until the regulating device 56 is brought to its no-load position. This has the advantage that when the operation of the compressor is resumed, it begins by operating at no load.

As shown in Figures 13 to 15, a manometer I48is connected with the chamber 94 enclosing the diaphragm 95. This manometer may indicate the temperature of the liquid to be cooled.

The device may be also provided with an indicator or pointer I 49 (Figure which indicates the position of the sleeves SI upon a scale I5I which is carried by the casing I52.

It is apparent that the specific illustrations shown above have been given by way of illustration and not by way of limitation, and that the structures above described are subject to wide variation and modification without departing from the scope or intent of the invention, all of which variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A regulating device for a compressor having a cylinder, a main piston reciprocable within said cylinder, a valve communicating with the interior of said cylinder, an auxiliary piston operatively connected with said valve and a condenser for storing the compressed fluid; said regulating device comprising an oscillatory member controlled by said main piston and forming a passage for the pressure medium, a regulatory member controlled by the condenser pressure for controlling said passage, m ans for supplying the pressure medium to said passage and means for conveying said medium from said passage to said auxiliary piston.

2. A regulating device for a compressor having a cylinder, a main piston reciprocable Within said cylinder, a valve communicating with the interior of said cylinder, an auxiliary piston operatively connected with said valve and a condenser for storing the compressed fluid; said regulating device comprising a pair of telescoping and individually oscillatory sleeves, one of said sleeves being controlled by said main piston and forming a passage for the pressure medium, the other one of said sleeves being controlled by the condenser pressure and having an opening for regulating said passage, means for supplying the pressure medium to said passage and means for conveying said medium from said passage to said auxiliary piston.

3. In a regulating device for compressors, a pressure-actuated member, a valve controlled by said pressure-actuated member in accordance with the pressure exerted upon said member, an oscillatory member controlled by the compressor and constituting a passage for the pressure medium, a regulatory member for controlling said passage, a servo-motor for controlling said regulatory member and means connected with said valve and said servo-motor for causing a flow of the liquid operating said servo-motor through said valve and to said servo-motor.

l. In a regulating device for compressors, a

r pressure-actuated member, a valve controlled by said pressure-actuated member in accordance with the pressure exerted upon said member, manually operable means for adjusting said valve, an oscillatory member controlled by said compressor controlled by the operation of the compressor constituting a passage of the pressure medium, a regulatory member for controlling said passage, a manually adjustable servo-motor for controlling said regulatory member and means connected to said valve and to said servomotor for causing a flow of the liquid operating said servo-motor through said valve and to said servo-motor.

5. A regulating device for a compressor having a cylinder, a main piston reciprocable within said cylinder, a valve communicating with the interior of said cylinder, an auxiliary piston operatively connected with said valve and a condenser for storing the compressed fluid; said regulating device comprising a pair of oscillatory sleeves, one of said sleeves being controlled by said main piston and forming a passage for the pressure medium, the other one of said sleeves having an opening for regulating said passage, means supplying the pressure medium to said passage, means for conveying said medium from said passage to said auxiliary piston and means controlled by the condenser pressure for operating said other sleeve, said last-mentioned means comprising a pressure-actuated member, a valve controlled by said member according to the pressure exerted upon said member and a servomotor operatively connected with said other sleeve and means connected with said pressureactuated member and said servo-motor for causing a flow of the liquid operating said servomotor through said valve to said servo-motor.

JOI-IANN HEINRICH.

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