US2416171A - Pump - Google Patents

Description

Feb. 18, 1947. c, G 2,416,171

- Y PUMP I Filed Oct. 19, 1944 5 Sheets-Sheet 1 c. B.- GRAY Feb. 18, 1947.

PUMP

Filed 001:. 19, 1944 5 Sheets-Sheet 2 "ITaJe jCrx mss B. GRAY c. B. GRAY PUMP Filed Oct. 19, 1944 5 Sheets-Sheet 5 M61110! CHARLES B. GRAY Fe b. 18, 19.47. c. B. GRAY PUMP Filed Oct. 19, 1944 5 Sheets-Sheet 4 Inv'erzwr 1 Gun RLES B. GRAY C. B. GRAY Feb. 18, 1947.

PUMP

Filed Oct. 19, 1944 5 Sheets-Sheet 5 CHARLES B. GRAY Patented Feb. 18, 1947 UNITED STATES PATENT OFFICE" PUMP Charles B. Gray, Springfield, Pa. 7 Application October 19, 1944; Serial No. 552L400 4 Claims.

This invention relatesgenerally to fluid-presthe accompanying drawings and as finally pointed.

sure power mechanismsand more'particularly t vention is to provide: a. variable displacement.

pump of'simple construction. in which the. pressure fluid is displaced. by rectilinearly movable piston elements operating sequentially, the design,

construction and. operation of the pump. being;

generally such. as to provide. for a high.power-to-- weight ratio, high efficiency andan ability torespond readily to high. and rapid accelerations: as required ofv the developedfiuidpressure.

Still another. object of the present invention is to provide a multiple-pistontype of variable capacity pump whereinthe-necessity for extremely close clearances and tolerances betweenthe mov--- ing parts thereof. to prevent leakage of the high:

pressure fluid isobviated; which is suitable foruse with either 011- or water asthe fluid medium:- and which is capable of developing working pres-- sures unlimitedin amount.

A stillfurther object of the present inventionv is to provide a variable capacity reciprocating. pis=- ton type of pumphaving means for limiting the fluid pressure to a preselected value as well as means automatically. operative to maintain the developed pressure at its said preselected value.-

Generally, it is among the-objectsoi the-pres-- ent invention to provide a pump; the capacity or output of which may be readily varied at will without stopping the pump or varying: the speed of its prime mover; to provide apump which is exceedingly rugged in construction, which is capable of withstanding long periods of use at high speed and under high: developed fluid. pressures,

and which has a minimum. of moving parts, allct which are readily accessible for replacement adjustment and repair; and to provide a pump wherein frictional and other resistances, so characteristic of the radial type of variable capacity pump, are reduced. to a practically-neglible mini-- mum.

vention will appear more fully hereinafter, it being understood thatthe present invention-consists generally.- in. the combination, construction, location. andgeneral arrangement. of parts, all. as

will appear more fully hereinafter, as shown in;

Still. other objects and advantages of thein out in the appended claims.

Inthe said. accompanying drawings, which. are illustrative of. a preferred embodiment. of the. principles of the present invention:

Figure. 1. is a diagrammatic view illustrating, theapplicati'on-of thepump of the present invention for hydraulic operation of apress;

Figure 2 is a top plan view of the pump unit as. constructed in. accordance with and embodying theprinciples of] the present invention;

Figure 3.is a longitudinal sectional view of the, pump unit taken on the line 3-3 of Figure 2;

Figure 4 isa, sectional View taken. onthe line 44 of Figure 2;.

Figure 5 is. a transverse view, partially in section, taken on the line 5-5 of Figure 3;

Figure.6 is anendelevational ,view, practically broken away andsect'ioned,.of the pump unit;

Figure '7 is a. sectional view of a part of the pump takenon the lineL-Tof Figure 2;

v Figure 8 is a sectional view taken on. the line 8.-8.of Figure 2;. and.

Figures 9 to. 12, inclusive, are views'showing'the. relative positions of the pump actuating eccentrics uponthe main drivingshaft for the pump unit. 7

Figure l-illustratesmore or less schematically. an application of'the pump of the present invention in. a. system for. hydraulically operating. a. press, although it. will. be understood. that. this. pump is equally applicable for use in. the opera..- tion of. all kinds of hydraulic machinery, in connection with whichit is designed. toproduce a moving or holding force of unlimited magnitude. for usein pressing, forming, extruding,.drawlng or forging operations on metals and other com-e. positions, in shifting or moving. heavy loads as. in lift tables, elevators and. the like, and in other. fields wherein it is desired-to employ a fiuidunder. uniformly constant high. pressure. matic illustration of- Figure 1-, the pumpmechan. ism of the present invention, asenclosedwithin the-dotted line block, is represented by the reference" numeral I0, this pump being operative, to

Dump the fiuid into-a manifold I I at a rate. Sllf.--- ficient to maintain thereinapreselected operating, pressure for the fluid, the existing pressure in-the manifold bein visually determined-by: a suitable pressure guage l2. v

. The high pressurefluid" is delivered from the manifold H to the fiuidpressure-cylinder, 1.3- of themain ram I i-01 thepress by-way ofitheccnduit l5 andto the mud pressure cy1inders l\6-|;:6

of the pulbback rams l:1--l1 byway of the cone In the scheduits It. On the return or idle stroke of the main the main cylinder is discharged at low pressure intoa reservoir [9 by way of the low-pressure from its full line position as shown in Figure 1 for maintaining open only the fluid conduits l5 and 24 into a second position in which only the conduits l8 and 23 are open to passage of fluid therethrough. V The fluid is delivered from the eservoir l9 to a manifold from whence it is drawn intothe pump for forced discharge into the accumulator H or an equivalent pressure chamber. Suitable check valves 21-22 are interposed, re-

spectively, in theintake and discharge conduits to insure unidirectional flow of the fluid.

. As shown in Figure 1, the valve 25 is set for 3 high pressure fluid actuation of the main ram M of the pressand for discharge at low pressure of thefluid in the cylinders of the pull-back rams l'|--l1. By axially shifting the inner body 261 of the valve into its other operative position, the pull-back, rams are actuated by the high pressure fluid to return the main ram to its initial posi-, tion, while the fluid in the main ram cylinder is discharged therefrom at low pressure. Any suitable means may be employed for controlling the operation of the valve either manually or automatically, such means forming no part of the present invention which relates more particularly to the pump mechanism or unit per se.

"Referringrnow more particularly to Figures 2 to, 6 of, the drawings, it will be observed that the pump unit of the present invention essentially includes a plurality of fluid pressure cylinders 30, 3!; 32 and 33, suitably mounted upon a main supporting base 34 for the unit, each of said cylinders having operatively associated therewith a double-acting piston 35 designed for rectilinear,

reciprocating motion. Each cylininder is provided with a pair of fluid intake ports 363'| and a pair of fluid discharge ports38-39 (see Figure 3), the operation of each cylinder being such that upon downward thrust of its piston, the pressure,

fluidis drawn into the cylinder through the intake port 36 and forced therefrom out of the discharge port 38, while upon upward thrust of the piston, the fluid is drawn into the cylinder through the 'intake port 31 and forced therefrom, outof the discharge port 39. Thus. for each:

cycle of operation of each piston 35, fluid is alternately pumped by way of the conduits 46 and 4| and through the check valves 22 thereof into the, high pressure fluid'manifold II. The several piston 35 are respectively guided for rectilinear,

cylindrical seat 46 upon which is suitably journalled one end of a main power shaft 41 extending transversely-across the top of the said front structure 43. The upper edge 48 of the body member 44 intermediate the power shaft supporting pedestals 45--45 terminates at a point spaced well below the main shaft 41 to provide the necessary clearance for other parts of the apparatus to be presently described. Also extending transversely across and bridging. the space between the shaft-supporting pedestals 4545 is a top member 49, the opposite ends of which are respectively provided With downwardly presenting semi-cylindrical seats 50-50 which are complemental to the fixed seats 46-46 to provide therewith complete journal boxes for the opposite ends of the main power shaft 41. Preferably, these journal boxes may be internall fitted with Suitable ler bea s or the like (not shown) for theshaft. The complementally shape-d parts of the pedestals 45-45 and the bridging member 49 are secured together by bolts 5|.

As most clearly appears in Figures 5 and 6, the bridging member 49 is undercut or notched at uniformly spaced intervals, as at 52, to provide a series of spaced portions 53 to which are respectively secured, as by the bolts 54, intermediate supporting members 55 for the main shaft 41. These intermediate supporting members 55 are also complementally shaped to provide, conjointly with the portions of the bridging member to which they are secured, auxiliary journal boxes for the shaft, which auxiliary journal boxes may be fitted with roller bearings as in the case of the end journal boxes for the shaft,

The several unsupported portions of the shaft disposed within the spaces 52 formed in the eccentric enlargements 56, 51, 58 and 59, each ofthese eccentric portions of the shaft being in turn embraced by an eccentric strap suitably formed of two parts secured together, as by the bolts 6!. As appears most clearly in Figure 6 and in Figures 9 to 12, these eccentric portions 56, 51, 58 and 59 are angularly spaced apart to the extent necessary to equalize and balance the effort of the shaft and insure the production of uniform pulsations of the pressure fluid as discharged from the several pressure cylinders which are respectively operatively associated with the several angularly related eccentric portions of the main drive shaft. In the apparatus as shown, four such pressure cylinders are employed and by angularly spacing the ecentric portions of the power'shaft 60 degrees apart, each pressure cylinder is caused to deliver two fluid pressure im leakage of the fluid along the pulses for each revolution of the main drive shaft 41, the several impulses per shaft-revolution being delivered sequentially at uniformly timed,

intervals.

As most clearly appears in Figures 3 and 6, the

lower halves of the eccentric straps 69 are each provided with 2. depending stem 62, which in each instanceis secured, by means of a pin '63, to theupper clevised end 64 of a vertically reciprocable bar 65. The several bars 65 are respectively received within guide channels or grooves 66 formedin the front face of the transversely extending body member 44 and are confined against displacement therefrom by a plate 51 extending across the said front face of the member 44 and secured thereto by the bolts 68. The guide channels or-grooves 66 thus insure rec tilinear motion of the bars'65upon'reciprocation gunner.

nected, through the intervention oflinks 11., to

the upper ends of the several piston rds 42'of.

the fluid pressure cylinders 30', 3|, 32 and 33.,-

The opposite ends of the intervening links H5. arerespectively secured, in each instance, to the lever 10' and to the piston rod 42 by pivot pins 12zan'd. 73, the arrangement being such that the oscil'ilating motion of the lever 10 may be translated" into a straight line reciprocating motion: for its associated piston rod- 42.

Each of the levers l 0-is slotted to provide a longitudinally extending opening 14 within which is slidably fitted a fulcrum block 15, this block being slidable lengthwise of the slot 14 to vary the position of the fulcrum for the lever 10. Extending traversely across the several laterally spaced parallel levers "l0 and in vertically spaced relation with respect thereto is a relatively heavy beam 16 from the lower edge of which depends a plurality of pairs of spaced parallel lugs 11. Each-pair of these lugs embraces one of the levers 10, as most clearly appears in Figure 5, these lugs being of sufficient length tolikewise embracethe opposite sides of the slidable fulcrum block carried by the lever. A transversely extending rod 18 projects commonly through the several fulcrum blocks 15 and their embracing pairs of lugs 11 carried by the beam 16', thereby insuring against lateral displacement of each fulcrum block from its a sociated lever 10 while at thesame time permitting the several blocks to shift lengthwise of their guide slots 14.. in the several laterally spaced levers l0. Shifting ofthefulcrum'blocks l lengthwise of their respective guide slots 14 is effected in unison by bodily shifting the beam 15 in a direction normal to its transversely extending vertical plane, it being apparent that as said beam 16 is so sh fted. it correspondingly shifts the fulcrum rod 18 and so varies the fulcrum point of oscillation of the several levers It is, of course. desirable to prevent skewing of the beam 16 with respect to its normal line of shifting movement, and in order to prevent any such possibility of skewing, the opposite ends of. the beam are each for-med with a pair of spaced flange elements 19-10, each pairof which embraces a toothed pinion 8i). These pinions Bil-80.

are respectively journalled for rotation upon a' common shaft 8!. which extends lengthwise along the top of the beam l6 and rests in a groove formed in the top surface of. said beam The beam is suitably recessed or chambered, as at 83, immediately beneath. each of the pinions 80 to provide the, necessaryyclearance for free rotation thereof relatively to the beam. and about the: axis of the pinion shaft 8|...

The beam '56 istransversely bored,.as at 84-434,

nally extending racks 86 which are'lrespectlvely" in toothed. engagement. with the pinion-s 80-80; The forward ends of these longitudinallyextendsing parallel: guide bars 85 are suitably secured inany manner to a fixed part of the front struce ture of the: apparatus, while the rear ends. of these bars. are similarly secured in any suitable manner'to a; fixed. structure provided at the rear end of. the apparatus, such, as for example, the. vertically extending pedestals. 8l-81, the upper ends of these pedestals 81.8'l being suitably interconnected'; by transversely extending rear at points located respectively immediately be.-

neath the-pinions 80, these bores being so-located as. to be in communication with the arcuate reframe member 88 (see.- more particularly Fig-- ures 2. and 3).

From the foregoing, it will be apparent that the beam. l6, which commonly supports and carries the laterally spaced fulcrum blocks 16 forthe; several levers 1-0,.i's'in turn slidabl'y supported upon the laterally spaced, parallelguide bars 85. It will be apparent also that by reason: of the: interengagement of the pinions with their respective toothed rack portions 86. of the guide bars 85, thebeam 16, is free to be moved along said? guide bars by. the means and for the punpose presently to be: described The. pinions 00" respectively coacting with. the longitudinally extending toothed racks 8B serve as equalizers for insuring the beam 86 at all times maintains a. position normalto its direction of shift.

Suitably mounted upon the rear structure of; the apparatus. centrally between the laterally spaced standards 818| thereof is a fluid pressure cylinder 90 with which is operatively asso ciatedp a piston 9| having. a rod 92 projecting through the top cross member 88 of the said rear structure. The forward end of the piston rod: 92 is connected, as at 93, to. the rear side of thetransverse beam 16 preferablyat a point disposed centrally between its opposite ends. Secured to the frontal side of the said transverse beam 16, as by means of an eye bolt 94 or otherwise, is: a cable 95 which extends over and around apairof vertically spaced. sheaves 96-91 suitably mounted upon a fixed part. of the front structure 43" of: the apparatus, these. sheaves being preferably housed within a removable casing 98 (see Figure: 3). The opposite end of the said cable. 951 is secured, as at 99, to the forward end of acoiled tension. spring 100.. The rear end of this. spring. is in turn connected, as at l0l, to a rod [02,. the threaded portion I03 of which projects through a bracket m4 rigidly secured in any suitable manner to the rear fixed structure of the apparatus. A hand. wheel IE5 or other suchtension adjusting device threadedly engages. the threaded, portion 03. of the rod I02. and bears against the surface NE of the-bracket I04 under the influence of the biasing action exerted by the coiled spring 500. A conduit I01 extends; between the manifold H and the interior I08 of the. pressure; adjusting cylinder 90', while a press sure gau e ms isalso connected to the said interiorl-OB of'the cylinderfill. In describing the operation of the: pump: me-- chanism or the present invention as hereinbefore described", it will be assumed that the. several parts, of the apparatus are in their related position, as shown in Figure 3 of the drawings. In this condition of the apparatus, the beam '16 is practically at itsforward limit of movement, in consequence of which the several levers 10 are so related to their common, fulcrum axis. "as to. provide for a maximum magnitude of oscilla; tion of. the. rear end of each of these levers. The oscillation of these levers is, efiected, ofrcourse;

which depend from and are actuated by the sev 7 bars 65 which in turn are confined to a I'ECti.

linear motion. Thus, the levers l partake only of an oscillating motion about their common fulcrum 18 to effect reciprocation of the several pistons 35 of the fluid pressure cylinders 30, 3|, 32 and 33. In normal operation of the apparatus, the rotative speed of the main driving shaft 41 is maintained constant and each lever performs a complete oscillation about its fulcrum 18 for each revolution of the main shaft. The mag-j nitude of this oscillation is, however, dependent upon the relative position which is assumed by the fulcrum shaft 78, it being apparent that as said shaft'lB is shifted toward the rear extermity of the slot 14 in the lever 10, the magnitude of oscillation of the rear end of the shaft is cor.

. respondingly reduced. When the fulcrum 18 is shifted to the dotted line position shown in Figure 3, oscillation of the rear ends of the shafts 10 is reduced to zero and in such event reciprocation of the pistons 35 no longer takes place.

Assuming that it is desired to establish and maintain an operating fluid pressure of say four thousand pounds, all that is necessary is to start the pump working by imparting rotation to the main shaft 4'! thereof by means of its prime mover (not shown). With theparts of the apparatus as shown in Figure 3, the several levers 10 will oscillate to in turn effect reciprocation of the fluid pressure cylinder pistons 35 at their full or maximum strokes. As the fluid pressure developed by the several pressure cylinders builds up toward the'preselected value, the developed pressure will be'indicated in the pressure gauges I2 and I09. Simultaneously as the fluid pressure builds up toward its predetermined limit, as indicated by the gauges, the hand wheel H35 is manipulated to relieve the tension pull exerted by the spring {00 on the fulcrum-carrying beam 13 sufllciently to permit the latter to be drawn rearwardly under the influence of the fluid pressure which has been developed in the pressure chamber I08 of the compensating fluid pressure cylinder 90, the final adjustment of the hand wheel Hi5 being such that the effort of the fluid pressure pull on the beam 16 relatively to that of the spring we thereon causes the beam 16 to shift rearwardly to an extent suflicient to locate the fulcrum axis 18 of the several levers at the dotted line or neutral position shown in Figure 3 when the fluid pressure, as indicated by thegauges l2 and [BBQ reaches its predetermined limit.

Thus, by proper manipulation of the spring tension adjusting knob I05, the pull of the spring on one side of the beam 16 is overbalanced by the pull of the fluid pressure actuated piston 9| on the opposite side of the said beam 16 to maintain the latter in neutral position when the developed fluid pressure is of the desired magnitude. Should the fluid pressure as developed by the several pressure cylinders to drop below the desired predetermined limit, the pull of the piston 9| of the compensating cylinder 90 onthe. beam .16

immediately. drops, with the result that the said beam 16 is then drawn forwardly through the effort of the tension spring I00, thereby positionally readjusting the fulcrum axis 18 to provide for an increased magnitude of oscillation of,

the rear ends of the several levers l0 and corresponding increased length of stroke of the reciprocating pistons 35 in the main fluid pressure cylinders. As the pressure increases due to the increased displacement of 'the fluid from these pressure cylinders, the pull differential between the spring I00 and the compensating pressure cylinder is reestablished for the predetermined pressure desired to be maintained.

Should it be desired to obtain a higher fluid pressure than aforesaid, then the hand wheel H15 is manipulated to increase the tension pull of the spring lllll, thereby requiring a greater effort to be exerted by the fluid pressure piston 9l-to overcome the same and so permitting a correspondingly greater pressure to be developed by the pump. Conversely, should it be desired to reduce the fluid pressure limit, the tension pull of the spring I00 on the beam 16 is relieved to the desired extent by proper manipulation of the adjusting knob H15, in consequence of which the beam l6is drawn to its rearmost or neutral position by the piston 9| when the fluid pressure is at its predetermined maximum value. It will be understood, of course, that the apparatus of the present invention is susceptible of various changes and modifications which may be made from time to time without departing from the general principles or real spirit of the invention as hereinbefore'set forth. For example, instead of employing a tension spring such as 'is shown in the accompanying drawings, a movable counter-balancing weight maybe employed for exerting a pull on the fulcrum-carrying means in position to the fluid pressure effort exerted by the piston 9! of the compensating fluid pressure cylinder. Also, instead of employing double act-' ingpressure cylinders as hereinbefore described and shown in the accompanying drawings, such fluid pressure cylinders may be of the single acting type. Of course, the number of fluid pressure cylinders employed may be varied as desired, and in fact a pump maybe constructed in accordance with the principles of the present invention in which only a single fluidpressure cylinder of adequate capacity is employed. It is accordingly intended to claim the same broadly, as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. In a fluid pressure pump mechanism of the character described, in combination, a plurality of fluid pressure cylinders each having its own reciprocating piston, a fulcrumed lever for each cylinder having one end thereof operatively connectedto the cylinder piston for effecting rectilinear reciprocation thereof, the opposite end of the lever being pivotally connected to a rectilinearly reciprocable member spaced from but paralleling the axis of reciprocation of the piston, a positionally adjustable fulcrum for each'lever disposed intermediate the opposite ends there of, means operative at constantspeed for commonly effecting oscillation of the several levers about their respective fulcrums, means serving as a common support for the several fulcrums and shiftable lengthwise of'the levers to uniformly vary the positions of the several fulcrums and so change the magnitudes of oscillation of the several levers, said fulcrum-supporting means being normally biased to maintain the fulcrums in position for maximum oscillation of the several levers, and a fluid-pressure motor actuated by the fluid pressure developed by the pump mechanism and operative to overcome the aforesaid normal bias on said fulcrum-supporting means whereby to present the several fulcrums in position for reducing the magnitude of oscillation of the several levers as the developed fluid pressure increases to a predetermined value.

2. In a fluid pressure mechanism of the character defined in claim 1, means for insuring against skewing of the fulcrum-supporting means during positional adjustment thereof lengthwise of said oscillatable levers.

3. In a fluid pressure mechanism of the character defined in claim 1 wherein said fulcrumsupporting means is in the form of a beam extending transversely across the said several oscillating levers, the opposite ends of said beams being slidably supported upon a pair of guiderods extending in parallel relation to the planes of oscillation of the several levers.

4. In a fluid pressure mechanism of the character defined in claim 1 wherein said fulcrumsupporting means is in the form of a beam extending transversely across the said several oscillating levers, a pair of laterally spaced parallel guide rods respectively extending through the opposite ends of said beam for supporting and guiding the same in its movement lengthwise of the several levers, and coasting rack and pinion means arranged at said opposite ends of the beam for insuring that the longitudinal axis of the beam is at all times normal to the parallel planes of oscillation of the several levers.

CHARLES E. GRAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 635,258 Lange Oct, '17, 1899 870,630 Kinsman Nov. 12, 1907 2,191,552 Zimmermann Feb. 27, 1940 2,284,897 Harrington June 2, 1942 762,055 Hibbard June 7, 1904

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