US2484439A - Hydraulic pump - Google Patents

Description

Oct. 11, 1949. WILLIAMSQN 2,484,439

HYDRAULIC PUMP Filed July 16, 1943 4 Sheets-Sheet l INVENTOR- LARKIN R. WILLIAMSON.

Oct. 11, 1949. 1.. R. WILLIAMSON 2,484,439

Q HYDRAULIC PUMP Filed July 16, 1945 4 Sheets-Sheet 2 INVENTOR 1 8 4 l 2 2 p .2 :2: w 1 H mg w LARKIN RWILLIAMSON ya jm mafia;

L. R. WILLIAMSON Oct. 11, 1949.

HYDRAULIC PUMP 4 Sheets-Sheet 5 Filed July 16, 1943 'INVENTOR. LARKIN R. WILLIAMSON;

1949. L. R. WILLIAMSON 2,434,439

HYDRAULIC PUMP Filed July 16, 1943 4 Sheets-Sheet 4 INVENTOR. LARKIN RWILLIAMSON Patented Oct. 11, 1949 r HYDRAULIC PUMP Larkin B. Williamson, Brooklyn, N. Y., assignor to E. W. Bliss Company, Brooklyn, N. Y., a corporation of Delaware Application July 18, 1943, Serial No. 494,917

8 Claims. (Cl. 103-11) have disclosed an hydraulically-operated clutch for controlling the movement of the ram of a power shear, in which the clutch is actuated by the admission of oil under pressure to a pair opposed cylinders.

The present invention is directed more speciflcally to a novel pump for supplying oil for actuating a clutch of the aforesaid type, but which may be used for various other purposes in which oil under pressure is required for intermittently actuating various machine and press parts.

A primary object of the invention is to provide a pump of the character described which will 0D- erate quickly and emciently to actuate clutches such as those to which reference has been made.

Another object of the invention is to provide a pump of the characterdescribed, in which the fluid is delivered under predetermined pressures developed through cam-actuated means.

Another object o! the invention is to provide a pump of the character described, in which the fluid is delivered under fairly high pressures, but in which means have been incorporated to relieve the pressure in the event that it exceeds a predetermined maximum.

Another object of the invention is to provide a pump or the character described having pressure relieving means, and in which means are also provided for visually indicating the absence or presence of such excess pressures.

A further object of the invention is to provide a pump of the character described, in which the fluid is delivered by motor-actuated piston means, and in which the motor is eflectively braked at the ends of its movements.

A further object of the invention is to provide a pump of the character described having a brake of novel construction, and in connection with which means are provided for visually in i tin the extreme limits of movement of the motor.

A still further object of the invention is to provide, in connection with a pump of the character described, a motor for, actuating the pump, as well as means responsive to the operation or the pump for deenergizing the motor at the ends movements.

To the accomplishment of the rforegoing and related ends, said invention, then, consists of the means hereinafter duly described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain structure embodying the invention, such disclosed means constituting, however, but One 01 various structural forms in which the principle of the invention may be used.

In said annexed drawings Fig. 1 is a top plan view of a pump embodying the invention, but with the cover removed to more clearly reveal some or the internal construction;

Fig. 2 is a transverse cross-sectional view of the pump, taken on the line 22 of Fig. 1;"

Fig. 3 is a longitudinal cross-sectional view of the pump, taken on the line 33 of Fig. 1, and showing the torque motor drive for the pump;

of its Fig. 4 is an elevational view of the brake, with Fig. 8 is a fragmentary cross-sectional view,

taken on the line 8-8 of Fig. 3.

Referring more particularly to the drawings,

, the pum will be seen to comprise a housing I,

having secured thereto, as by screwbolts 1, a cover 3. The housing is provided with bracketlike extensions 4, whereby the housing may be secured to a suitable portion of a power press or other machine, in connection with which the pump is to be used.

Secured to the lower end of the housing I, as by screwbolts 5, is a cylinder block 6, having an oil outlet-opening I, and a cylindrical extension 8, which extends into a bore a in the housing, the

slot or recess II in its upper end, and is also provided at a point somewhat below this slot-with an oil inlet hole I. (Fig. 3). The housing i is also provided with a vertically extending groove il in the wall of the bore l, and the lower end of this groove communicates at all times with the hole It, the function of which, together with that of groove l1, will presently be described.

The housing i is provided at opposite sides thereof with bores II and II, in which are mounted 'ball bearings II and 2| respectively. A cam shaft 22 is Journalled in these bearings. and projects outwardly at both ends through the aforesaid bores.

Secured as by screwbolts II to the housing I adjacent the bore I. is a retainer N for the bearing 2i, an oil seal 2! being interposed between this retainer and the shaft 22.

The cam shaft 22 has keyed thereto intermediate its ends, a cam II, having hub portions 21 and 28, to which are secured, as by setscrews 29, earns and II, respectively, these latter cams having flat portions I2, whose function will be presently described.

Mounted for reciprocal movement in the cylinder iii of the cylinder block 8, is a piston II, provided with cord type piston rings 34, and having a recess 85 in its lower end, in which is mounted a compression coil spring I, the lower end of which abuts the cylinder block 0. The piston is also provided with an oil inlet hole 33a, which, in the position shown, is in registry with the hole I6 in the extension l. Mounted in the upper portion of the piston 33, and extending transversely thereof, is a roller pin 81 having a projecting pin II which is disposed in the recess IS in the extension I of the cylinder block so as to maintain the piston against rotation during reciprocation thereof. The pin 31 is secured against rotation as well as axial displacement by means of a set screw 39. The pin 31 has journalled thereon intermediate its ends a cam roller 40, which is constantly maintained in engagement with the cam 20, due to the action of the spring 30.

Projecting upwardly from the cover I is a block is, to the opposite sides of which are secured, as by screws 4|, micro-switches, one of which, 42, is hereinafter referred to as the forward micro-switch, and the other of which, 43, is hereinafter referred to as the reverse microswitch. These micro-switches are adapted to be energized and deenergized as a result of the movements of the cams 3| and II, and for this purpose, each cam engages a plunger 44 mounted for reciprocal movement in the cover I, and normally urged into engagement with the cams by means of springs 45.

Secured to the housing I, as by means of screw bolts 46, is a cylindrical brake housing 41, to the outer face of which is secured a cover 48, as by means of screws 4!. The housing has secured within the lower portion thereof, as by means of screws 50, a stop block Ii, whose function will be presently described.

A portion of the shaft 22 extends into the housing 41, and has keyed thereto a brake hub 52, which retains the bearing 2| in position, and is, in turn, retained against axial displacement by means of a washer 58 secured to the end of the shaft by means of screws ll.

The brake hub 52 has a radial flange I! which is provided at circumferentialiy-spaced points with threaded openings 88, and at points on the periphery thereof spaced 90 degrees apart with V-nctches l1 and II (Hg. 6). Studs II are threadedly secured to the openings ll of the, brake hub, and these have secured to the outer ends thereof nuts II, which are secured against rotation by means of cotter pins ll. Mounted on each of the studs II is a pair of washers l2 and 83, between which are interposed springs N. These springs serve to yieldingly urge a brake disc 8| toward the flange ll of the brake hub, a lining N of friction material being interposed between the brake disc and the flange II.

The brake disc II is provided at circumferentially-spaced points with arcuate slots 01, a stop piece '8 being secured to the disc II at a point intermediate two of such slots. The studs 89 extend through the slots Cl, and the stop piece II is disposed in the plane of the stop block. ll, being, in fact, adapted to engage the ends of the stop block, as will be presently described.

At a point substantially diametrically pp site the stop block II, the housing I! is provided with a boss ll, through which a bore ll extends, this bore being threaded in its upper portion for the'reception of a spring adjusting screw II. Disposed in the bore ll, between the lower end of the screw II and a washer 12, is a spring 13, which bears at its lower end against a ball II. This ball bears against the periphery of the flange of the brake hub, and engages an indicator rod 16 which extends through the bore II and through an axial opening in the screw ll, being visible above the screw.

Disposed within the cylindrical recesses II and II of the cylinder block I are accumulator pistons ll, each of which is provided at its lower end with a leather cup II, which is secured to the piston by means of a seat II, which, in turn, is secured to the pistonby ascrew ll.

4 Secured to the upper end of each piston II, as by means of a bolt Ii, is a cup-like spring retainer II, which provides a seat for the lower end of a compression spring 03, the upper end of which abuts a retainer ll, similar to retainer I2, and maintained against axial displacement byanadiustingscrewll. Thescrewllis threadedly secured in the housing cover 3, and is provided with a head It whereby it may be adjusted to increase or decrease the compression of the spring 83. The screw has an axial passageway 81 through which an indicator rod l8 extends, the lower ends of the rods OI being secured to the heads of the bolts ll by means of cotter pins as. An oil gauge II is also secured to the housing i, so that the oil level in the housing may be visually inspected at all times.

The pump further includes a gear II which is keyed to one end of the shaft 22, and is adapted to be driven by a pinion I! on the end of the shaft 03 of a torque motor 04. The gear ii is maintained against axial displacement by means of a washer OI, secured to the end of the shaft by means of screws It. The motor is mounted on a bracket :1, as by-means of bolts II, and nuts to, and the bracket is rigidly secured to the housing I by means of cap screws ill.

The pump, as thus described, and with the various parts thereof in the positions as shown in the drawings, is filled with oil to a level such as to be clearly visible through the gauge ll. it being noted that the piston u is in its uppermost position, so that the oil inlet hole "a B in registration with the hole ll and the oil in the pump therefore has access through the groove l and through these holes to the space below op nin and supplying oil to the opposed cylinders of a clutch such as described in myaforesaid atent. It will also be noted that the ball II is disposed in the V-notch 51 in theperiphery of the flange 55 of the brake hub, so that the indicator rod II is 'ina lowered position, which can be readily seen by the operator. At the same time, the indicator rods 88 are in their lowermost position, as can be readily seen by looking at the exposed upper ends of these rods. Moreover, thestop piece is is in engagement with the stop block II, as shown in Fig. 4, and the micro-switch ll has been deenergized due to the fact that the plunger ll of such switch has fallen upon the flat surface 3!- of the cam 3!, thereby stopping the motor N.

The motor 94 is then energized so as to cause the shaft 22 to rotate in a counterclockwise direction as viewed in Fig. 2, so that the cam causes the cam roller ll] and the piston 31 to. be depressed against the action of the spring 3'. The downward movement of the piston a seals access to the oil inlet hole 33;: from the hole ll, so that thereafter the oil below the piston is forced through the oil outlet opening I and through the conduit previously referred to and to the opposed s I therefore particularly point out and distinctly cylinders of the clutch as described in my aforesaid patent so as to energize the clutch.

To avoid excessive oil pressure in the line to the clutch; the oil pressure, after building up to a predetermined point, is relieved by upward movement of the pistons 11 against the springs 83, such movement being indicated by the posi stated by any of the following claims or the equi valent of such stated means be'employed.

'claim'as my invention: 0 q v 1. In combination, a hydraulic pump having-a shaft mounted therein, a reciprocating piston, a

cam on the shaft for driving-the piston, a motor 1, for rotating said shaft in bothdirections through a predetermined arc of less thanon'e revolution, means for braking the movement- 'of' saidjshaft at the ends'of its movements to thereby brake .said motor, switch means conditioning the motor for reversal thereof and cam means on the shaft for operating the switch means.

2. In combination, a hydraulic pump having a shaft mounted therein, a piston, a cam on the shaft for operating the piston, a motor for rotating said shaft in both directions through a predetermined arc of less than one revolution,

means for braking the movement of said shaft at the ends of its movements to thereby brake said motor, and means for visually indicating the extreme limits ofmovement of the shaft, a pair of switch mechanisms and cam means on the shaft for alternately operating the switches to deenergize themotor and to condition the motor for reversal.

\ 3. In combination, a hydraulic pump having a I I shaft therein, a piston, a cam on the shaft for operating the piston, a motor-for rotating said shaft in both directions through a predetermined arc of less than one revolution, means responsive to the movements of said shaft for deenergizing the motor at the extreme limits of movement of the shaft, said means comprising a pair of indethe relative movement of the brake hub and bralge disc acting through the brake lining interposed therebetween, the studs 59 riding in the slots l'l during such braking movement. At the end of this movement, the ball" drops into the notch 58, so that the rod 16 is again in a lowered position to indicate to the operator the end of the movement.

Due to the aforesaid movement of the cam shaft 22, the micro-switch 43 is, of course, again energized, so as to be in a position to be deenergized at the conclusion of the reverse movement of the cam shaft.

On the reverse movement of the cam shaft, oil will be drawn back into the bore Ill, and when the piston 33 has returned to its initial position, seepage of oil back through the hole 33a will relieve any excess pressure on the pistons 11 and allow these to return to their normal position.

It is thus seen that I have provided a pump which effectively accomplishes the objects and has inherent therein the advantages which have hereinbefore been stated and referred to.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the structure herein disclosed, provided the means pendently actuated micro-switches and a brake mechanism acting on the shaft and carried solely by the shaft.

5. In combination, a hydraulic pump having a housing structure, a shaft therein, a piston actuated by the shaft, a motor for rotating said shaft in both directions through a predetermined arc of less than one revolution, means responsive to the movements of said shaft for deenergizing the motor at the'extreme limits of movement of the shaft, said means comprising a pair of independently actuated micro-switches, cams-on said shaft for energizing anLdeenergizing said switches and a brake mechanism carried by the shaft and reacting against said housing structure during the terminal movements of the shaft.

6. In apparatus of the character described, the combination of a rotary electric torque motor, a non-rotating unicycle pump driven by the motor comprising a cylinder housing structure, a reversible shaft operable through less than one revolution in either direction and carried by the housing, a piston, a cam on the shaft for effecting a compression stroke of the piston during a part revolution of the shaft in one direction only, spring means for urging the piston against the cam during a reverse movement of the shaft and cam and a permanently closed brake mechanism mounted on the shaft and freely carried thereby during the major arcuate movements of the shaft mamas LARKIN R. WILLIAMSON.

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

UNT'J ZED STATES PATENTS Number Name Date Burke June 1, 1915 Number I Name nm Blrkizt Oct. 25, 1927 Heltzer Aug. 18, 1932 Been July 11, 1933 Brown Aug. 15, 1933 Bldney Mar. 13, 1934 Bernard -Oct. 8, 1935 Wnhlmerk Feb. 25, 1941 Camplon July 22, 1941 Gal-day Jan. 8, 1942 Nelson Mar. 24, 1942 Woelter Dec. 11, 1945

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