US3273786A - Flow regulator for piston-equipped cylinder - Google Patents

Description

2 Sheets-Sheet l mg? M Sept. 20,` 1966 A. B. NEWTON FLOW REGULATOR FOR PISTON-EQUIPPED CYLINDER Filed Feb, l, 1963 Sept. Z0, 1966 A. B. NEWTON FLOW REGULATOR FOR PIfSTON'EQUIPPED CYLINDER 2 Sheets-Sheet 2 Filed Feb. 1, 1963 U aww@ JQZ f t/ @vga/@ww ander 5 United States Patent 3,273,786 FLOW REGULATR FR PISTON-EQUIPPED CYLINDER Alwin B. Newton, 136 Shelbourne Drive, York, Pa. Filed Feb. 1, 1963, Ser. No. 255,491 4 Claims. (Cl. 2311-23) This invention is a continuation-impart of my copending application, Serial No. 760,995, filed September 15, 1958, now patent No. 3,076,593.

This invention relates to a flow regulator for a pistonequipped cylinder, and, more particularly, to a flow regulator for the gas intake line for a compressor.

In certain applications of air conditioning, the compressor is operated irrespective of whether refrigeration is called for. One prime example `is in automotive refrigeration. There, the compressor piston is `directly coupled to the crankshaft and reciproc-ates whether refrigeration is needed or not. This operation is currently justified, since automobiles are overpowered and the power utilized in the refrigeration -compressor does not seriously affect the engine performance. It would be desirable, however, to provide means which would regulate the amount of compression effected by the compressor as a function of the refrigeration load. It would further be desirable to provide means to reduce the capacity of the compressor during periods when little or no compression is required. These, then, form some -of the objectives of this invention.

Another objective is to provide a novel flow regulator for a piston-equipped cylinder. Still another object is to provide means in t-he gas intake to la piston-equipped cylinder that regulates the flow of gas thereto. Yet another object is to provide means cooperating with the piston of a piston-equipped cylinder that regulates the degree of capacity or unloading of the cylinder and thereby correlates the compression developed by the cyl inder to the load requirements.

A further object of the invention is to provide a novel structure of the character indicated in which a flow fitting or port member is sealingly and positionably mounted in the gas intake to a piston-equipped cylinder with the piston being movable into engagement with the fitting or port to close the same. A still further object is to provide in the apparatus described in the object immediately preceding, means for positioning the fitting or .port member which is responsive to a thermal signal. A yet further object is to provide, in the apparatus just described, time delay means which postpones the imposition of all or part of the load on the compressor until it has started up. `Other objects and advantages of this invention can be seen in the details of construction and operation set down in this specification.

This invention will be described in conjunction with the accompanying drawing, in which- FIG. 1 is a fragmentary elevational view, partly in section, of apparatus embodying the teachings of this invention;

FIG. 2 is a cross-sectional View, taken along the line 2-2 of FIG. 1;

FIG. 3 is a view similar to FIG. 1 but showing a plurality of cylinders in the inventive compressor;

FIG. 4 is Ia sectional View taken along the line 4-4 of FIG. 3;

FIG. 5 is a fragmentary sectional view of apparatus such as is seen in FIG. 3 and showing a modified form of controlling the positionable element for varying the degree of unloading in the inventive construction; and

FIG. 6 is a perspective view of the movable element of FIGS. 1 and 2.

In the illustration given in FIG. l, the numeral 10 designates generally a cylinder provided las part of a frame F which has a piston slidably mounted therein and which 3,273,786 Patented Sept.. 20, 1966 is reciprocated by a piston rod 12 coupled to piston 11 through a wrist pin 13 in a conventional fashion.

The cylinder 10 is equipped with an outlet port .14 communicating with an outlet manifold 15, the manifold supporting an exhaust check valve 16. The foregoing arrangement is well known, and therefore details have been omitted as unnecessary, i.e., spring mountings, etc. for check valves. An inlet check valve 17 is provided in conjunction with the inlet manifold 18, each of the check valves 16 and 17 operating in conjunction with 'a suitable port as at 14 -and 19, respectively.

The inlet manifold 18 is equipped with a second flow port 20 which communicates with the interior of an integral supplemental housing generally designated 21. Slidably positioned within the supplemental housing 21 is a flow fitting or element generally designated 22 and which functions in the invention to vary the degree of compressor loading. For this purpose, the element 22 is hollow as at 23 and is equipped with a notched-out bottom portion as at 24., conforming as at 22a to the piston, i.e., being ground to the radius of the piston. Thus, the element 22 provides at least a portion of the cylinder wall.

From the foregoing, it will be seen that a path for the liow of refrigerant gas alternative to port 19 is provided via the port 20, the hollow interior 23 of the element 22, and the notched-out portion 24, so as to communicate with the head space 10a in the cylinder 10. In the position of element 22 shown in FIG. l, the compressor is fully loaded, i.e., as the piston 11 rises, there is no return of the refrigerant gas to the intake manifold 18. However, the compressor can be fully unloaded by elevating the element 22 so that during the entire upstroke of the piston 11, there is provided a by-pass around the inlet check valve 17. `In this connection, it is noted that the upper sur-face of the piston 11 is relieved as at 11a to accommodate the inlet check valve 17.

The position of the element 22 is regulated by means of a solenoid 25. The solenoid acts against a coiled spring 26 interposed between the top wall 27 of the housing 2'1 and a spider 28 provided interiorly of the element 22. Extending axially of the spring and into the solenoid 25, is a rod 29. Thus, as the solenoid is energized, the rod 29 is moved upwardly to the position designated 29 (in dotted line) to move the element 22 to a position of unloading the cylinder 10. A suitable seal as at 30 may be interposed where the rod 29 extends upwardly outwardly of the housing 21.

For the purpose of energizing the solenoid 25, an electrical circuit as at 31 may be employed which includes a switch 32 for manual operation, a time delay switch 33, and a thermostatic switch 34.

Operation In the operation of the apparatus just described, and in conjunction with an automobile refrigeration system, the intake manifold 18 is connected to a condenser (not shown) while the outlet manifold 15 is connected to the usual expansion valve and evaporator (also not shown). In such a case, the piston 11 is energized from the engine crank shaft through the piston rod 12. The manual and safety switch is provided as part of the ignition switch, while the thermostat 34 is responsive to the temperature within the passenger space of the automobile. When the automobile is started, switch 32 is closed, along with the time-delay switch 33. If the thermostatic switch 34 is in the position shown, this will energize solenoid 25 to raise` the fitting or element 22 to its upper limit of travel and` thus have the compressor completely unloaded.

Thus, no compression is provided and the refrigerant is merely drawn into the cylinder 10 through the port 19 and the passage made up of port 2li, hollow interior 23, and notched portion 24, and discharged through the same passage. The cylinder now acts as a compressor in a completely unloaded condition (i.e., with its capacity to pump reduced to zero). A short time after start-up, the time-delay switch 33 opens, breaking the supply of electrical current to the solenoid 25, and the spring 26 forces the tting 22 to the position shown. The compressor is then loaded. Under the operation just discussed, the thermostatic switch 34 is in the position in which refrigeration is called for. Should the switch be in the alternative position, corresponding to no demand for refrigeration, the solenoid will be continuously energized and the cylinder 10 will remain in an unloaded condition.

This invention provides a number of advantages over prior art structures employed for the same purposes. The invention here, when employed in conjunction with a compressor, does more than merely unload the compressor, as was the case with prior art devices. Here, it is possible to reduce the capacity of the compressor cylinder. In a multi-cylinder compressor, it is possible to reduce the capacity of all cylinders an equal amount. In contrast to this, many conventional unloading means for cylinders permit only complete unloading, one by one. This results in unequal torque and damages some drive means. Such a conventional unloader is described in my prior Patent No. 2,761,616, issued September 4, 1956. In contrast to this, the invention here permits a smooth reduction of capacity. Furthermore, in conventional systems, it is usual to unload all but 20430% of the cylinders in a multi-cylinder compressor, as to unload all of them would result in cessation of flow of gas and therefore of cylinder cooling. By keeping at least one or two cylinders cool by continuing their ow, it was hoped that the rest would be cool also. In the inventive device, at least a minimum ow can be provided for each cylinder through restricting the upward position of the element 22, irrespective of the number of cylinders, thereby attaining cooling of each.

It is to be appreciated that the flow member 22 can be positioned intermediate two adjoining cylinders, thus varying the capacity of eachor a plurality of such members can be employed, each operating from a common shaft, so that each cylinder is unload to the same degree. In a form of invention where one port member as at 122 is slidably mounted in the intake 115 common to both cylinders 110 and 210, a port member 122 is positioned by means `of a connecting rod 129 connected to an eccentric 129a. For individual port members for each cylinder, the shaft 129b to which the eccentric 129a is attached can be arranged in parallel to the crankshaft 212e instead of transverse, as shown. In this manner, each of a number of positioning rods such as 129 can be simultaneously positioned. The crankshaft 21251 is seen to be connected in conventional fashion to the pistons 111 and 211 by means of piston rods 112 and 212, respectively.

The rod 129 is seen to be connected to a solid portion 122 of the member 122, thev member 122 also having a hollow interior as at 123 and notched-out portions as at 124 and 224, communicating, respectively, with the interior head spaces 110:1 and 210a of the cylinders 110 and 210, respectively.

With the construction of FIG. 3, it will be seen that the sides of the pistons 111 and 211 contact the movable element 122 at all times in order to keep it in position and to cooperate with the upper lip of the pistons 111 and 211 as they move up and down.

The embodiment of FIGS. 3-4 permits positioning of the flow element 122. This permits variation of the cornpressor loading. Normally, a refrigeration compressor, or, for that matter, most any compressor, operates at a fairly constant compression ratio and pressure level as load, speed, or both, vary. One of the features of the inventive construction is that for a given capacity, i.e., compression ratio and pressure level, the time for gas to enter the cylinder is fairly constant. For example, at 18 r.p.s. and a 60 portion of the stroke corresponding to the port or notch 124 being open, the time the port is open is 0.0093 of a second. At r.p.s. with the port being open three-fourths of the stroke, i.e., 270, the time the port is open is 0.0083 second.

As seen in FIG. 4, the element 122 has a pair of oppositely-disposed, arcuate side walls as at 122er and 222a, thereby providing portions of the cylinder walls. In the event it is desired to operate the construction of FIGS. 1 and 3 independently of the rods 29 and 129, the construction in FIG. 5 can be employed.

In FIG. 5, the numeral 310 designates generally the upper portion of the cylinder units wherein a flow element 322 is mounted for positionable movement much the same as the element 122 in the showing in FIG. 3. The intake is designated by the numeral 31S and connects to a suction line as at 315a.

Provided as .an upward projection on the cylinder housing 310 is a casing 335 equipped with a bore 336 communicating with an annular chamber 337. The positionable element 322 is equipped with an integral annular ange as at 338 which is positioned within the chamber 337. The casing 335 is equipped with suitable seals as at 339 arranged to conform to the shape of the element 322 so as to seal Ithe refrigerant gas coming from the suction line 315:1 from the chamber 337 which is filled with hydraulic uid.

The chamber 337 is defined in part by the wall 340 equipped with ow ports 341 `and 342. Overlying this portion of the wall 340 is a supplemental casing 343 which is equipped with an oil inlet as at 344 and an aperture 34S through which a control knob 346 projects. Positioned about the control handle 346 is a exible seal 347 secured to a Valve .actuator 348. The actuator 348 is equipped with curved ends which extend under a valve plate 349 as at 350 and 351.

Movement of the lever handle 346 upwardly in FIG. 5 results in raising the lower end of the valve plate 349 so that fluid is able to flow out of the upper end of chamber 337 into the supplemental casing chamber 352 and then 'through the port 342 into the Ilower portion of the chamber 337. This permits the element 322 to be moved upwardly under the joint inuence of gas pressure against the bottom as well as the frictional engagement thereof by the pistons. When the desired position of the element 322 has been achieved, the lever handle 346 is returned to neutral position, after which the lower end of the valve element 349 covers the port 342 and serves yas a check valve.

Movement of the lever handle 346 downwardly results in the uncovering of the port 341, i.e., preventing the valve element 349 from serving as a check valve so that uid issuing from the chamber 337 through the port 342 into the supplemental casing chamber 352 is able to reenter the chamber 337 through the port 341. This results in a downward movement of the element 322 under the influence of suction and the frictional engagement of the pistons with the element 322. A light spring pressure may be applied by the spring 353 to provide the initial downward movement of the element 322 prior to the same becoming frictionally engaged wi-th the pistons (not shown).

While, in the foregoing specification, a detailed description of the invention has been given for clearness of understanding, those skilled in the Aart will perceive many variations in the details herein given without departing from the spirit and scope of the invention.

I claim:

1. In a refrigeration apparatus, a pair of cylinders in side-by-side relation, each having side and top walls dening a compression chamber, a piston mounted in each of said cylinders for reciprocal movement defining intake and compression strokes, said Cylinders being equipped with an opening in each of their side walls, means containing refrigerant iuid communicating with said openings, an element positioned between said cylinders and IrlOLlIl-ifd in Said openings for movement therein independent of the movement of said pistons, port means in said cyli-nders for introducing and removing refrigerant lluid, and means for positioning said element in said openings for changing the effective area of said openings and :to provide uid flow therethrough during selected initial portions of each of the pistons compression strokes up to and including substantially all of the pistons compression strokes.

2. In a device of the character described, a pair of adjacent cylinders each containing a piston for reciprocation therein, a crankshaft for driving said pistons in outof-phase relationship, an opening in the common wall between said pair of cylinders, a movable element mounted within said opening and having its opposite sides shaped to lit closely to said pistons when adjacent thereto, means for positioning said element within said opening to vary the effective size of said opening, and means in said element for owing fluid therethrough into said cylinders.

3. In a gas compressor, a frame providing a cylinder cavity and an outlet port for compressed refrigerant gas, an element movably mounted in said frame and having at least a segmental cylindrical wall to provide at least a portion of the wall defining said cylinder cavity, a piston mounted in said cylinder cavity for reciprocal movement detining intake and compression strokes, means for moving said piston and means for moving said element independent of said piston to change the effective area of said cavity, said element containing a flow passage for refrigerant gas communicating with said cylinder cavity.

4. The structure of claim 3 in which said means for moving said element includes a casing about said element and providing a hydraulic fluid chamber, a ange on said element projecting into said chamber to divide the same into two portions, a llow passage communicating said portions, and selectively operable check valve means in said ow passage.

References Cited by the Examiner UNlTED STATES PATENTS 877,492 1/ 1908 Doelling 230-25 1,481,358 1/1924 Dwyer 103-37 1,632,841 6/1927 Le Valley 230-22 1,878,326 9/1932 Ricardo 230-22 2,004,474 6/1935 Schaer 230-21 2,011,864 8/1935 Lundh 103-37 2,041,422 5/1936 LOrange 103--37 2,041,468 5/1936 Grubbs 103-37 2,501,054 3/1950 Huber 10S-173 2,524,235 10/1950 Schenk 103--37 2,555,004 5/1951 Rinehart 23 0-30 2,555,005 5/ 1951 Warneke 23 0-30 2,854,187 9/1958 Crooks 230-21 2,833,462 5/ 1958 Scheerer 230-21 FOREIGN PATENTS 893,213 1/1944 France. 1,044,494 6/1953 France.

622,780 12/ 1935 Germany.

742,768 12/1943 Germany.

403,180 12/1933 Great Britain.

Examiners.

G. M. THOMAS, W. I. KRAUSS, Assistant Examiners.

Claims (1)

1. 2. IN A DEVICE OF THE CHARACTER DESCRIBED, A PAIR OF ADJACENT CYLINDERS EACH CONTAINING A PISTON FOR RECIPROCATION THEREIN, A CRANKSHAFT FOR DRIVING SAID PISTONS IN OUTOF-PHASE RELATIONSHIP, AN OPENING IN THE COMMON WALL BETWEEN SAID PAIR OF CYLINDERS, A MOVABLE ELEMENT MOUNTED WITHIN SAID OPENING AND HAVING ITS OPPOSITE SIDES SHAPTED TO FIT CLOSELY TO SAID PISTONS WHEN ADJACENT THERETO, MEANS FOR POSITIONING SAID ELEMENT WITHIN SAID OPENING TO VARY THE EFFECTIVE SIZE OF SAID OPENING, AND MEANS IN SAID ELEMENT FOR FLOWING FLUID THERETHROUGH INTO SAID CYLINDERS.

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