US1896790A - Automatic regulator for compressors - Google Patents

Description

Feb. 7, 1933. L. L; COLLINS 1,396,790

AUTOMATIC REGULATOR FOR COMPRESSORS Filed June 4, 1931 2 Sheets-Sheet l Q R: v Q g,

a D \N N o 1 o G N w b N 0 J R g INVENTOR.

A TTQRNEY.

Feb. 7, 1933. L COLLINS 1,896,790

' AUTOMATIC REGULATOR- FOR COMPRESSORS I Filed June 4, 1951 2 Sheets-Sheet 2 INVENTOR. Zesfer L. (of/ins ATTORNEY.

Patented Feb. 7, 1933 UNITED STATES FF CE] LESTER L. COLLINS, or FRANKLIN, r nmvsvilvnn n, Assr'eivon To onidneolrnnuammo TOOL COMPANY, or new YORK, 1v, Y., A CORPORATION 015 NEW JERSEY} AUTOMATIC REGULATOR Eon conrnnssons Application filed J'une 4, 1931. Serial No. 642,086.

This invention relates to fluid compressors or pumps, more particularly air. and gas compressors, the output of which is usually varied automatically in response to the demands upon thereceiver into which the compressed fluid is discharged. In the interests of economy and efliciency such machines are arranged to load and unload in a plurality of steps or stages. In certain aspects the invention may be considered an improvement upon or further development of the control apparatus disclosed and claimed in U. S. Patent No. 1,685,781issued0ctober 2, 1928 to Leon F. Hoffman.

Among the objects of the present invention are to devise a regulator which operates positively under slight changes in pressure, to produce a simplified design of regulator having a reduced number ofworking parts, and in general to simplify andto improve prior apparatus of this character. p

In the present invention the compensating mechanism by which exact regulation in stages is secured involves an oscillating cam which is connected directly to the power piston of conventional fluid pressure control apparatus such as a Mason regulator. The movement of the cam can then be made to correspond directly with the movement of the distributing piston which is also directly connected to the power piston. If proportional rather than substantially the same movementis required, this is easily accomplished by running the connection from the power pistonto the lever arm of the oscillating cam rather than to the cam itself. In any case the cam can be arranged directly above the power cylinder thereby producing a very compact and exceptionally simple construction. 7

In order to illustrate the invention, one concrete embodiment thereof is shown in the accompanying drawings, in which: 7 v

Fig. 1 is a plan view of the control unit;

Fig. 2 is a side elevational view of the parts shown in Fig. 1 on an enlarged scale and with certain portions shown in vertical section and Fig. 3 is a fragmentary horizontal sectional view substantially on the line 33 of Fig. 2.

The embodiment of the ,control unit or fluid pressure governor chosen for the pursuitably connected'to a source of fluid pressure, such asthe receiver of the machine to .be controlled. Secured to support 4 is a cas- 1ng5, the support .a-ndthe casing together providing .a chamber 6 which .is disposed a diaphragm 7, the lower face oit'iwhichis pose of f illustration comprises a support 4;

subjected-tofluid pressure through opening 8. Movement of diaphragm 7 underithe pressure of the motive fluid acts through a sad dle member 9 resting. upon or securedto'the diaphragm upon a lever arm, 10 pivoted at 11 and provided at its outer end with weights 12. Movement of lever 10 is transmitted armor link 14 from which'isisuspended a fluid control or pilot valve15 of the wellsages 16 and 17 leading to oppositeendsxof a chamber provided by a cylinder 18in which ireciprocates a piston The fluid controlled icy valve 15 may be water under pressure. P ston 19 is connected 'on' the eXterior-ofcylanced or -;do uble-headed piston 22 movable in ton 23 to the left (Fig. 3) serves to. connect to recelver'pressure in. succession pipes 25,

26, 27 and 28 which lead to the unloading devices (not shown) in the compressor, pump or other machines to beregulated. Thearrangem'ent shown is 'for the so-calledvfiveQ stage regulation whereby with the partsin the position illustrated in Fig. 3, the compressoris operating on fullload. Movement of piston 22'to the left will producequarter unloading with the opening of pipe 25 to receiver pressure, half unloading whenpipe 26 is. opened, 1 three-quarter unloading'jwith the opening of pipe 27 and total'unl'oading with.

the opening of pipe 28. A vent opening at through a yoke or other connection13 to an I .7 known Mason regulator type controlling pasinder 18 by a head and rod 21 t0 a bal-" pipe 29 serves to relieve the pressure in pipes 1 28, 27, 26 and 25 in succession when piston 22 moves to the right.

In order to insure that the movement of pistons 19 and 23 shall be controlled in well defined steps to produce the progressive stages of unloadingand loading of the mpressor, compensating means are provided quickly'to restore pilot valve 15 to neutral position after each movement. To this end a rod30 extends from head 20 and connects" directly to a cam arranged for rocking move ment through an arm. 32 which is pivoted at 33 atthe base of cylinder 18. The control surface of cam 31 is-slightl-yarcuate and" has a series of irregular depressions, four in number, corresponding to the extent of" move'ment' ofdistributing piston 22 necessary to contact pipes 25-28 inclusive in succession to receiver'pressure. Arm 32 extends 'radiallyjof the control surface as clearly in- V to overcome weights 12, lever moves upwardly carrying with it the yoke 13 and link l4'thus 'liftingpilot valve 15 which thereupon admits water to passage 16 and opens "a vent for passage 17 In consequence, plston 19 movestothe left and head-20 transmits this movement both to distributor piston 22' and rocking cam 31'; When piston 22 'moves'far enough to admit pressure fluid into pipe 25 roller 34 drops into the first depressionin cam 31. Due to-the swingingmovement of the cam this has the effect of lowering slightly the leftend of link 14 so that the pilot valve 15 is moved to neutral position and the control mechanism comes to rest after *suflicientmovement to eflect first stage unloading of the compressor. Upon further increase in pressure in the receiver, the next position of distributing piston 22 is assumed with pipe 26 uncovered to effect secend stage unloading of the compressor. Upon further increases "in pressure the remaining pipes 27 and 28 are uncovered in succession in an obvious manner. Upon a drop lnpressure the unloading steps are retraced in order to efle'ctprogressive loading of the compressor. The operating condition of the compressor. or other machine which is controlled may be indicated by the position of a pointer '19 attached to head 20 and moving across a L scale s secured to cylinder 18;

The operating range of the governor may I be adjusted by applying progressively greaterresistance to the rising movement of lever arm '10 as, for example, by a coil spring 38 attached at one end to a collar 39, slidable on lever arm 10 and at the other end-to a rangement, and that the connection of the cam directly to the cross headbetween the power and the distributing piston by a single link permits positive and accurate regulation of the movement of the distributing piston.

While the invention has been herein shown 1. In automatic regulating apparatus for a variable volume compressor, apilot valve "controlled by receiver pressure, a reciprocable piston controlled bysaid pilot valve, means for returning the pilot valve to neutralposition after each movement comprising a cam havlng a generally arcuate control surface,

an arm extending from said cam and radially of said control surface and arranged for swinglngor rockmg movement about a'pivotal point remote from said cam, anda connection between said cam and said piston whereby axial movement of the latter causes rocking movement "of the former. 2. A fluid pressure governor for a variable volume compressor comprising a control valve, means for effecting movement of said valve in response to variations in receiver pressure, a power piston controled' by said valve, a control piston adjacent to and in parallelismwith said power piston, a head connectingsaid pistons to effect movement of one with the other, compensating means for restoring said valve to; neutral position so as to effect successive-stages of movement of said pistons comprising a cam mounted above said-power piston for rocking move ment, and a connecting rod'pivoted respectively'to said cam and saidhead. 7'

3. A fluid pressure governor for a variable volume compressor comprising a weighted arm movablein response toreceiver-pressure, a pilot valve, a link from which said valveis suspended, a connection for said-arm to oneend of-said link whereby said valve' is movable in response to movement of said arm, a power piston controlled by said valve, and compensating means for restoring said valve to neutral position after movement comprising a cam member having an arcuate cam face, means including a connection to said piston for rocking said cam about a pivot point remote from its cam face, and a lever pivotally supported at its center and pivotally connected at one end to the end of said link remote from said weighted arm connection, said lever having a roller on its free end in engagement with the cam face of said cam member.

4. A fluid pressure governor for a variable volume compressor comprising a pilot valve, means for efi'ecting movement of said valve in response to receiver pressure, a power cylinder adjacent said valve having a piston controlled by said valve, and compensating means for restoring said valve to neutral position after each movement mounted upon and above said cylinder including a rockably mounted cam connected by a link to said piston.

5. A volume compressor comprising a pilot valve, means for eflecting movement of said valve in response to receiver pressure, a power cylinder adjacent said valve having a piston controlled by said valve, and compensating means for restoring said valve to neutral position after each movement mounted upon and above said cylinder including a link supporting said valve, a rockably mounted cam connected to said piston, and a single lever interposed between said cam and said link.

Signed by me at Franklin, in the county of Venango and State of Pennsylvania, this 1st day of June, 1931.

LESTER L. COLLINS.

fluid pressure governor for a variable v

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