US1978387A - Regulator for fluid compressors - Google Patents

Description

Oct. 23, 1934. w. RAYMOND REGULATOR FOR FLUID COMPRESSORS v Filed May 16, 1952 Patented Oct. 23, 1934 UNITED STATES PATENT 1. OFFICE REGULATOR FOR FLUID COMPRESS'ORS Ward Raymond Eas'ton, Pa., assigiior to Pennsyl vania Pump 8; Compressor Company, Ea's'ton,

Pa a corporation of Pennsylvania,

Application May 16, 1932, Serial K0. 611,538 6 claims, ,(Cl. 230 44).

to novel means for regulating the unloading and loading of the compressor in a number of ,dis-' 6 tinct steps so that the volume of fluid compressed maybe varied with the demand upon the Compressor and the discharge pressure kept at sub stantially constant pressure under all loads of the compressor.

In variable volume compressors suchas disclosed in this application, a series of pressure operated unloading devices are employed, each effecting a partial unloading of the compressor, so that the compressor Capacity may be varied in accordance with the operation of the unloading devices, these unloading devices being individually operated by a regulator acted upon by the varying pressures within the receiver of the compressor to move the devices to positions Ior loading and unloading the compressor.

'An object of the present invention is to provide a regulator or governor mechanism to control the operation of said unloading devices, this mechanism beingcomparatively simple in construction,

positive in'operation, and suchthatsthe receiver pressure may be kept within close variations of pressure during wide fluctuations in demands upon the compressor.

More specifically, the present invention com-' priseslaplurality of individually operating distributing valves for controlling the distribution of fluid under pressure to the individually oper ated unloading devices each unloading device serving to partially unload-the compressor, these cessively actuate the individual distributor valves; 40 in their proper order. i

And finally it is an object to employ'mercury switches oscillated to opened and closed positions by movement of a regulator actuated by variations in receiver pressure, these switches when closed serving individually to energize electro magnets and when open energizing other electromagnets respectively controlling fluid valves for the admission-and withdrawal of fluid underpres sure to and from the different unloader devices.

invention, includes the features of construction and operation set forth in the followin specifi cationiand illustrated in the accompanying drawing. :1; a

With the above and other objects in view my In the accompanyingdrawingannexed hereto;

and forming a part of this specification I have shown my invention embodied in a single cylinder air compressor; but it will be understood that the inventioncan be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose,

vIn the drawing;

Figure 1 is a front elevation or the control m chanism showin t e connections to a comp essor cylinder,

Fig, 2 is a side elevation of a portion of the controller mechanism,

i 3 is n nla g d'view of one of the elec- 7o troma netlcally operated valves for controlling the supply of fluid to the unloader devices, and

F -A is an enlarged view of one of the mercury switches. H

In the above mentioned drawing I have shown 15 but one embodiment of the invention which is now deemed preferable, but it is to be understood that c an s and m difi a ns may be m d within-the scope of the appended claims without-departin .fromthe spirit of th invent on- Briefiy and in its broadest aspect my invention may includ the io lowing princ pal par s: F r a compressor cylinder havin a'plurality of unloading means operated by variations in discharge pr s eac a t n to partially un ad thecYI- s5 denseco d, d v dua va es co troll ng ad missio and exhaust or f u d to a d iro said unloading means; t i d, s tromagn 09 r v v onne d to sai va ves for actu in sa d valves; fourth, switches individually controlling the energizing of said magnets; and mm, pressure responsive means operating at slightly vary.- ing pressures to actuate said switches, v I

Referring more particularly to the figures of the drawing, an aircompressor cylinder is shown at 10' in which the pistonll reciprocates in the usual manner for compressing the fluid. In the cylinder 10fthe unloading and loading is accomplished by four individual unloading means 12 operating respectively upon four valves 13 (one 'onlyfbeing shown) controlling admission of fluid being compressedto receivers or clearance pock ets'li, It is to be understood, however, that the present unloading or controlling means illus- I trated and described in this specificationmay be employed with any form of compressors employingother methods, offunloading. v

. The control or governing apparatus for the unloading means 12 embodies a pressure actuated lever 15. "lhislever .15 is pivotally supported at an intermediate point, one end of the lever engaging a member 16 attached to the center of a pressure diaphragm 17. The opposite end of the lever 15 is suitably weighted by weights 18 suspended as will presently be described. Actuated by oscillation of the lever 15 is a vertically movable rod 19 on which are mounted spaced collars 20. Preferably the lever 15 has attached to it a depending arm 21 the lower end of which is attached to a bar 22 into which the lower end of rod 19 is fastened.

By reference to Fig. 1 it will be seen that the lever 15 moves from slightly'below horizontal position to slightly above horizontal. Thelink 23 connected to the weights 18 moves from one oblique position to another below the horizontal. These oblique positions are of greater angle than the positions of the lever 15. It follows, therefore, that as the lever rises by increased pressures above the diaphragm 17 the Weights 18 move slightly outwardly along thelever 15. The pressure required to raise the lever to successively higher positions increases slightly by reason of the slightly increased arm at which the weights 18 act upon the lever 15. To the enclosed space above the diaphragm 1'7 fluid under pressure may be admitted directly from the compressor receiver (not shown). For this purpose a connection 24 is provided. The oscillated position of the lever 15 therefore varies with variations of the discharge pressure of the compressor.

Adjacent the collars on the vertically disposed rod 19 are electric switches 25, those shown being of the mercoid type. These switches 25 I include a tiltable tube 26- containing a small amount of mercury which in one oscillated position of the tube 26 covers the terminals of cables 27 entering the tube. In the other oscillated position these terminals are above the level of the 'mercury. By oscillating this tube 26 therefore switches 25 are successively operated by continuous upward movement of the vertical rod 19 as the collars 20 are at successively greater distances from the different arms 28. As the rod 19 starts its movement upward the lowermost switch 25 first is actuated and then the second and so on for as many switches as may be provided. To retain the tube 26 of a switch 25 resiliently in either of its oscillated positions a spring 29 may be mounted on the member 30 carrying the arm 28. The resilience of spring 29 retains the member 30 in oneof its positions but permits movement of the tube 26 by slight pressure against the arm 28. The tube 26 may be pivoted at 31 to the frame of the switch and connected to the member 30 by a short connecting arm 32. As

' these mercoid switches arewellrknown and form have fluid under pressure admitted, to them through individual valves- 35. Each of these valves 35 is electromagnetic'ally operated by the coil 36 associated therewith and which may be energizedby their respective switches 25 being tilted to one oscillated position. With a valve 35 open fluid is admitted to the outer end of a device 12 which forces a piston in a direction to force a valve 13 to an open position. This latter Valve 13 of which there may be one for each switch 25 and electromagnetic valve 35 admits a portion of the fluid being compressed to a clearance pocket 14'thus fractionally unloading the cylinder as is well-known.

The structure of valve 35 is indicated in Fig. 3. A solenoid 37 within the coil 36 has a needle or conical valve 38 at its lower end. With the coil 36 energized=the armature is forced upwardly to move valve 38 from its seat 39. Fluid may therefore be admitted from connection 40 supplied with receiver pressure to the connection 41 leading to one of the unloader devices 12.

;With coil 36 deenergized the armature 37 rests with its entire weight upon the seat 39 so that valve 38is effectively closed. Fluid therefore is prevented from entering connection 41 and the unloader device 12 is not operated.

To release the pressure from the connections 41 to render the unloader devices 12 inoperative a second series of valves 42 is provided. These valves 42 are in every way similar to valves 35 but are connected as shown in Fig. 2 in a manner opposite to valves 35. Fluid enters valves 42 from connection 41 through a branch 43 therein and may be admitted to atmosphere from the connection 44.

Each unloader device 12 has its individual connection 41, valves 35 and 42 and switch 25. The first upward movement of lever 15 operates on device 12 through one ofthe switches 25 and valves 35 and 42. Continued upward movement of lever 15 operates another unloader device 12 through the second switch 25 and so on. With a slight drop in receiver pressure and consequent lowering movement of the lever 15 a collar 20.moves away from an arm 28 permitting a switch. 25 to return to open position thus de-en ergizing the coil 36 of valve 35. This allows valve 35 to close. Simultaneously the valve 42 is opened so that pressure mayexhaust from the connection 41.

. The coils for the valves 35 and 42 are wired in a circuit so that when one coil is energized the other is-de-energized. With the switch in the position shown in Fig. 4 the coil 36 for valve 35 is de-energized, while the coil for valve 42 is en-' ergized thus opening valve 42. In this position of the valves 35 and 42 no pressure can build up in the connection 41 so that the unloader device 12 for that set of valves is in position for normal energized at a time, and a bar having an undulating surface and moved upon variances in pressure of fluid compressed for operating said switches.

2. In a variable volume compressor, the combination with a cylinder, of a plurality of pressure-operated unloading devices, each acting to partly unload the cylinder, a distributing valve for supplyingpressure fluid to each of said unloading devices, exhaust valves for said devices independent electric operating means associated with each of said valves, whereby but one valve for an unloader device is open at a time and a bar having an undulating surface and moved upon variances in pressure of fluid pumped for operating said electrical operating means.

3. In a variable volume compressor, the combination with a cylinder of a plurality of pressure operated unloading devices each acting to partly unload the cylinder, a distributor valve for supplying pressure fluid to each of said unloading devices, exhaust valves for said devices independent electric operating means associated with each of said valves, whereby but one valve for an unloader device is open at a time, and a rod having a series of projections thereon movable upon variances in pressure of fluid pumped for controlling energizing of said electrical means.

4. In a variable volume compressor, the combination with a cylinder, of a plurality of pressure operated unloading devices each acting to partly unload the cylinder, a distributing valve for supplying pressure air to each of said unloading devices, independent electric operating means associated with each of said valves, whereby but one valve for an unloader device is open at a time, a rod having a series of projections thereon movable upon variances in pressure of fluid pumped for successively controlling energizing of said electrical means, and a compensator structure associated with said last named means for automatically adjusting it to increase or decrease the pressures required for operating said means. I

5. The combination with a variable volume air or gas compressor, of pressure operated unloading devices for loading and unloading the compressor, admission and exhaust valves of the needle type for controlling admission and exhausting of pressure fluid to and from said unloading devices, a solenoid connected to each of said distributor valves for operating them, switches for controlling energizing of said solenoids, and a bar having spaced enlargements thereon moved axially upon variations in discharge pressure of the compressor, said switches being disposed adjacent said projections for successive operation thereby.

6. The combination with a variable volume air or gas compressor, of pressure operated unloading devices for loading and unloading the compressor, distributor valves for controlling admission of pressure fluid to said unloading devices, a solenoid connected to each of said distributor valves for operating them a solenoid controlled exhaust valve for each of said unloading devices, switches for controlling energizing of said solenoids, and a vertically disposed bar moved axially upon variations in discharge pressure of the compressor, said bar having spaced projections thereon and said switches having operating arms extending into the path of and actuated by said projections whereby said switches may be successively operated by movement of said rod in one direction.

WARD RAYMOND.

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