US2483343A - Fluid actuated control mechanism - Google Patents

Description

P 1949- R. K. JEFFREY 2,483,343

FLUID ACTUATED CONTROL MECHANISM Original Filed Aug. 10, 1943 3 Sheets-Sheet 1 33 '37 l4l p42 \m No 4-7 '43 |44 n .1

lxwewv'oe 20am K. JEFFRFY, DECEASED,

BY Fwzmcr. H.C. JEFFREY, Exncuflmx,

ATT'Y.

Sept. 27, 1949. R. K. JEFFREY FLUID- ACTUA'I'ED CONTROL MECHANISM Original Filed Aug. 10, 1943 3 Sheets-Sheet 2 lllVE/VTOE FFREY, DECEASED,

QOBERT K J 5Y FLORENQEHLJEFFQEY, EXEQUTmX,

ATT'Y.

Sept. 27, 1949. R. K. JEFFFQEY 2,483,343

FLUID ACTUATED CONThOL MECHANISM Original Filed Aug. 10, 1943 3 Sheets-Sheet 3 Patented Sept. 27, 1949 FLUID ACTUATED CONTROL MECHANISM Robert K. Jeffrey, deceased, late of Bexley, Ohio, by Florence H. C. Jeffrey, executrix, Bexley, Ohio, assignor, by mesne assignments, to The Jefl'rey Manufacturing Company, a corporation of Ohio Original application August 10, 1943, Serial No.

498,087, now Patent No. 2,452,760, dated November 2, 1948.

Divided and this application July 7, 1944, Serial No. 543,191

6 Claims. 1

This invention relates to rotary fluid pressure pumps of the tiltable swash plate type, and one of the objects of the invention is the provision of fluid pressure motor mechanism for varying the inclination of a tiltable swash plate of arotaryfluid pressure pump.

Another object of the invention is the provision of fluid pressure motor mechanism adapted to tilt the swash plate of a rotary fluid pressure pump, combined with manually operated valve mechanism to predetermine the tilted position of such swash plate.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the claims hereto appended.

This application is a division of the co-pending application of the aforesaid Robert K Jeffrey, Serial No. 498,037, filed August 10, 1943, now Patent No. 2,452,760, dated November 2, l948,.for an improvement in Mining machines.

In the accompanying drawings,

Fig. 1 is a sectional elevation of a variable volume hydraulic pump with a manually set hydraulically actuated volume control device and balance cylinder connected thereto;

Fig. 2 is an elevation of the left-hand end of the unit illustrated in section in Fig. 1;

Fig. 3 is a sectional plan view taken of that portion of Fig. 1 back of the central horizontal shaft;

Fig. 4 is a sectional elevation of the upper right-hand portion of Fig. 2;

Fig. 5 is an elevational view of the right-hand upper portion of Fig. 2;

Fig. 6 is a sectional elevation taken in a plane at right angles to the upper central portion of Fig. 4;

Fig. 7 is a sectional elevation taken on the line I'I of Fig. 1, looking in the direction of the arrows;

Fig. 8 is a sectional elevation taken on the line 8--8 of Fig. 1, looking in the direction of the arrows;

Fig. 9 is a sectional bottom plan view taken on the line 9-9 of Fig. 7, looking upwardly in the direction of the arrows;

Fig. 10 is an enlarged sectional elevation of the manually set hydraulically actuated volume control device and balance cylinder shown in Fig. l;

and

Fig. 11 is a development of a portion of the interior of a valve sleeve and co-operating valve I post.

2 angle of tilt of a swash plate 69 (Fig. 1). A hydraulic motor I26 comprising a cylinder I21 and a plunger I28 is mounted in position to act on a roller I29 as shown in Fig. 1. The hydraulic motor I26 acts as a balancing motor and is always connected to the high pressure side of the circuit.

To a port I30 at the left-hand end of the cylinder I2! is connected a pipe I3I. A pipe I32 branches to the left from pipe I3I as shown in' Fig, 10. The pipe I32 is connected to a port I32 of a manually set hydraulically actuated volume control device I 33 which is shown in sectional elevation in Fig. 10.

The volume control device I33 comprises a casing I34 which is rigidly secured to a base plate I35 to which is also rigidly secured the casing I36 of the pump 64 (Fig. 1). To the outer end of the casing I34 of the volume control device I 33 is secured a bearing block I31 in which is journaled a core valve or post I38. To the outer end of the valve or post I38 is secured a handle I39. By means of the handle I39 the valve I 38 may be rotated to various positions to secure adjustment of the tilt of the swash plate 69.

The casing I34 in reality constitutes a hydraulic cylinder because within the same is a piston I40 of a piston motor. Extending to the right from the central portion of the piston I40, as viewed in Fig. 1, is a cylinder I4I closed at its right-hand end by a bearing block I42. Extending to the right from the central portion of the casing. I34 is a cylinder I43 adapted to act as a tubular guide for a plunger I44 the outer end of which is in engagement with a roller I29 mounted on the swash plate 69diametrically opposite the roller I29.

The valve or post I38 is provided with two parallel longitudinal bores I45 and I 46, each closed at its ends but each in communication with a pair of spaced lateral ports or passageways I45 and I55, each pair of which is connected by a groove or channel as seen in Fig. I0. A port I32 communicates with an annular groove I41 in the end or hearing block I31. A port I48 at one end of the bore I45 is always in communication with this annular groove I41, as shown in Fig. 10.

High pressure oil flows through the pipe I3I to the port I30 at the left-hand end of the-hydraulic motor I26, as viewed in Fig. 1. The pressure in the cylinder I21 on the plunger I28 tends to tilt the swash plate 69 away from central position, thus increasing the volume of flow from the pump 64. The flow will be at a minimum when the parts occupy the positions shown in Figs. 1 and 10,

because the piston I40 is then in its extreme righthand position where it is locked by the oil'confined in chambers II and I64 01 the volume control device I33. The piston I40 is confined to a rectilinear movement by a spline or key I52 between the cylinder I and the cylinder or tubular guide I43.

Within the cylinder III is a spiral groove I53 which extends substantially the full length thereof making one complete convolution and connects chambers I5I and I54. The separate ports I45 and I55 for the bores I45 and I46, respectively, normally straddle this groove I53 and may selectively be brought into communication with the spiral groove I53 by opposite relative rectilinear or axial movements between cylinder Ill and core valve or post I38. When the core valve I38 is turned by means of the handle I30 until the port I55 communicates with the spiral groove I53, the chambers I5I and I54 will be in communication with the port I55 through the: spiral groove I53 and will be vented through the bore I46, an annular groove I56, and a pipe I50 to a gear case or oil sump, not shown. The hydraulic motor I26 then acts to move its plunger I28 outwardly and at the same time due to the venting of the oil through the spiral groove I53 the plunger I44 will be retracted. The tilt of the swash plate 65 will thus be increased to efiect an increase in the output volume of liquid pumped by the pump 64.

When motor I26 acting through swash plate 69 moves cylinder I to such extent that the spiral groove I53 is no longer in communication with the port I55 the pump 64 attains the output volume predetermined by the setting of the core valve I38. That is to say, as the piston I40 moves into the chamber I5I, the port I55 moves away from the spiral groove I53 and the flow of liquid through the latter is discontinued. The liquid in the chambers I 54 and I5I again becomes trapped because the vent connections of the chambers I5I and I54 through spiral groove I53 and port I55 to the sump are sealed. The swash plate 69 is held at its adjusted angle because plunger I44 can recede no further and motor I26 is always acting to rotate the swash plate 69 to apply pressure upon it. Thus the pump is confined to the output volume predetermined by the setting of the core valve I38.

Now in order to decrease the output volume of the pump 64, that is, to expand the volume control device I33 and to retract the piston I28 of motor I26, the core valve I36 is rotated until the high pressure oil port I45 is in communication with the spiral groove I53. Then oil under high ressure flows through the spiral groove I53 into the chambers I5I and I54 and acts upon the piston I 40 and bearing block I42 to move the plunger I44 outwardly or to the right as seen in Fig. 1. At the same time high pressure oil acts on the plunger I28 of the motor I26 to move it to the right, but because the combined areas of the piston I40 and bearing block I42 is greater than the cross-sectional area of the plunger I28. Consequently the plunger I44 will be extended and the plunger I28 will be retracted, thereby effecting tilting of the swash plate 69 toward central position to decrease the output volume of the pump 64.

As the piston I40 moves the plunger I44 outwardly from the cylinder I43, the port I45 will be moved away from the spiral groove I 53 and the flow of oil into the chambers I 5| and I54 cut oii, whereupon the oil in the chambers I5I and as seen in Fig. 1, against movement to the left in the casing I34. locked in adjusted position in. accordance with the manual setting of the core valve I38.

Under normal or balanced conditions, as illustrated in Fig. 11, the ports I55 and I straddle spiral groove I53 with ports I55 and I45 so located that as post I38 is rotated from its "Full-on" position toward the Full-oil! position to decrease the normal pump output, the pressure port I45 moves toward the spiral groove I53 and the exhaust port I55 moves away from said spiral groove.

It will be seen that when the pressure port I45 opens into the spiral groove I53 as a result of such movement, high pressure oil will flow into the chambers I5I and I54 to cause the piston I40 to move upwardly until the sleeve I4I closes the port I45. Thus the piston I40 will move upwardly as the post I38 is rotated from its "Full-on position toward its "Full-oil position.

As fully shown and described in my paren Patent No. 2,452,760 above identified, the apparatus described in this application is employed in a hydraulic system which includes a valving system that is responsive to overload conditions of an electric driving motor and overload and underload conditions of the pressure of the hydraulie liquid in the high pressure portion of the hydraulic system.

When the apparatus herein shown and described is employed in the hydraulic system above referred to and an overload or high pressure condition occurs in the hydraulic system a pressure responsive valve connects the ports I30 and I32 of the hydraulic motor I26 and volume control device I33, respectively, and the pipe I to the output side of the pump 64. When the above mentioned pressure responsive valve connect the ports I30, I 32' and pipe I50 to the output side of the pump 64 the pressure of the liquid in pipe I50 increases. sure oil enters chambers I5I and I54 through check valve I10 and passageway I II, the piston I40 will be moved upwardly even though the port I45 be closed. When this occurs the exhaust port I will be placed in communication with the spiral groove I53 but because the passa e I46 is also subjected to the pressure of the oil entering the chambers I5I and I54 from pipe I50 it is effectively sealed from the sump. When the overload condition in the hydraulic system has been relieved, and consequently the high pressure in pipe I50 removed, the oil in chambers I5I and I54 will flow or be exhausted through the spiral groove I53 and port I55 to the pipe I50 and to the sump, as previously described, to permit the piston I40 to move downwardly until the spiral groove I53 is again straddled by the ports I55 and I45.

A single exception to the above description relating to the communication between the exhaust port I55 and the spiral groove I53 is when the post is set to the Full-oil position. In this setting of the post the exhaust port I55, as viewed in Fig. 11, is positioned so far to the left that it does not meet the spiral groove. This because it is desired to lock the piston in the Full-off position by closing the exhaust port I55. The maximum angle through which post I38 can be rotated from the Full-on" to the Full-ofl' positions is preferably not over 180 degrees. The spiral groove I53 extends preferably through an angle of 360 degrees but not more. As viewed in Fig. 11, the pressure port I45 will be just below and near the top of the groove 53 when the post I54 will be locked to block or hold the piston I40, I38 is in the Full- 11 position.

The swash plate will thus be' It will be seen that when high pres-' As previously described under certain conditions high pressureoil is delivered to the exhaust pipe I58 of volume control device I33, whereupon oil will flow from the annular groove I58 past the 7 check valve I18 and through the passageway I1I into the chamber I5I From the chamber I5I the oil will flow through the spiral groove I53 into the chamber I54. Consequently, hydraulic pressure will-be exerted on both the bottom of the closure block I 42 and the bottom of the piston I40; This will cause tilting of the swash plate 89 toward its central Full-oil position, thereby decreasing the output volume of the pump 84. Under these conditions, port I55 will communicate with groove I53 regardless of the manual setting of post I38 except in case it also is in the Full-o position. Consequently when normal conditions are restored in the pump circuit and the pressure in pipe I50 is reduced or released, the pump will automatically return to its normal predetermined position as determined by the position of adjustable post I38.

It will be evident that during normal control the core valve I38 is rotated in one direction or .the other, to adjust swash plate 69 to a desired position for a predetermined output volume of the pump 64 and the swash plate will be automatically hydraulically locked and held in adjusted position unless automatic reduction of its output volume is eflected by an overload resulting in a build up of pressure inpipe I58. After the overload condition is relieved the pump 64 will again discharge liquid at the output volume for which it was adjusted or any desired readjustment of the output volume of the pump may be efiected by manually rotating the core valve I38.

Mechanism for indicating the delivery volume of the pump 54 is illustrated in Figs. 4, 5 and 6. The swash plate 69 carries an arcuate rack 261 with which meshes a pinion 288. The pinion 268 is secured to the inner end of a shaft 269 which is journaled in a bearing block 210. This bearin block may be detachably secured to the casing I36 by means of a cap screw, as shown in Fig. 4.

Secured to the outer end of the shaft 259 is a pointer 21I movable over a scale on a plate 212 as shown in Fig. 5. When the swash plate 69 is centered as shown in Fig. 1, the pointer 21 I should be at the designation indicating zero volume of pump delivery. When the swash plate is tilted to its maximum extent the pointer 21I will be moved clockwise, as viewed in Fig. 5, until it reaches the last designation on the scale.

The swash plate 69 may be provided with diametrically opposite extension pivot plates 213 each adapted to be journaled on a trunnion one of which is shown'at 214 in the sectional plan view in ,Fig. 3. These trunnions are carried by supports one of which i shown at 215 in Fig. 3 fitting into a side opening in the casing I36 and secured to the latter by means of cap screws 216. It will thus be seen that the swash plate 89 is tiltable on a horizontal transverse axis which lies in a horizontal plane intermediate the pivotal axes of the rollers I29, I29.

Journaled in the ends of the casing I35 i a shaft 68 to which is 'keyed a cylinder block 211 having a, plurality of cylinders 218 in which are adapted to reciprocate pistons 219 each of which is urged by means of springs (Fig. 1) to have its outer end impinge against a ring 288 mounted on the swash plate 89.

In end plate-28I are two separate ports 282, 283 which are respectively in communication with ports 284 and 285, as shown in Figs. 2 and '1. Of

6 the ports 288, 285 one is the inlet and the other the outlet for the pump 64.- The left-hand ends of the cylinders 218 are provided with arcuate ports 286 as shown in Figs. 1 and 8. The cylinder block 211 is driven by means of an electric driving motor, coupled to the splined end 31 of the shaft 68.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and it is therefore wished not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what is desired to be secured by Letters Patent of the United States is:

l. Fluid actuated mechanism including in combination a cylinder, a piston in said cylinder cooperating therewith to form a closed expandable working chamber, said piston having an axially extending bore including a spiral groove connected with said chamber, a rotatable cylindrical member having spaced inlet and exhaust ports cooperating with said bore to form a valve, said ports normally straddling said spiral groove to trap hydraulic fluid in said working chamber for locking said piston against movement in one direction, a conduit connecting one of said ports with said chamber, and valve means in said conduit automatically operative in response to a predetermined pressure therein to control independently of said rotary valve means the increase in quantity of fluid in said closed expandable working chamber.

2. Fluid actuated mechanism including in combination a cylinder member, a piston member in said cylinder member cooperating therewith to form a closed expandable working chamber, said piston member having an axially extending bore, a cylindrical member rotatable and reciprocable in said bore, one of said members having a spiral groove opening into said chamber and the other of said members having spaced inlet and exhaust ports constructed and arranged to straddle normally said spiral groove to trap hydraulic fluid in said working chamber for locking said piston against movement in one direction, a conduit connecting one of said ports with said working chamber, and valve means in said conduit automatically operative in response to a predetermined pressure therein to control independently of said ports and groove the increase in quantity of hydraulic fluid present in said closed expandable working chamber.

3. Fluid actuated mechanism including in combination means forming an expandable fluid chamber including a cylinder member and a piston member movable relative to one another, means associated with said first named means forming an adjustable valve for setting the normal relative positions of said members, said valve including a spiral groove connected with said fluid chamber and movable with one of said members and spaced inlet and exhaust ports movable with the other of said members, said spiral groove and ports being shiftable relative to one another to admit to or exhaust hydraulic fluid from said expandable chamber to cause said members to reciprocate relative to one another in response to adjustment of said valve, said ports normally straddling said spiral groove, said inlet and exhaust ports being constructed and arranged in such manner that one of said ports is at all times in communication with said spiral groove when said members are adjusted to operative positions relative to one another and are displaced from their normal relative position with respect to each other whereby said members will seek the normal position for which said valve is set, a conduit connectin one of said ports with said expandable chamber, and valve means in said conduit automatically operative in response to a predetermined pressure therein to control independently of said valve the increase in quantity of fluid in said expandable chamber.

4. Fluid actuated mechanism including in com bination means forming an expandable fluid chamber including a cylinder member and a piston member movable relative to one another, means associated with said first named means forming an adjustable valve for setting the normal relative positions of said members, said valve including a spiral groove connected with said fluid chamber and movable with one of said members and spaced inlet and exhaust ports movable with the other of said members, said spiral groove and ports being shiftable relative to one another to admit to or exhaust hydraulic fluid from said expandable chamber to cause said members to reciprocate relative to one another in response to adjustment of said valve, said ports normally straddling said spiral groove, said inlet and exhaust ports being constructed and arranged in such manner that one of said ports is at all times in communication with said spiral groove when said members are adjusted to operative positions relative to one another and are displaced from their normal relative position with respect to each other whereby said members will seek the normal position for which said valve is set, a conduit connecting said exhaust port with said expandable chamber, and valve means in said conduit automatically operative in response to a predetermined pressure therein to control independently of said valve the increase in quantity of fluid in said expandable chamber.

5. Fluid actuated mechanism including in com bination a cylinder, a piston in said cylinder cooperating therewith to form a closed expandable workin chamber, said piston having an axial central bore including a spiral groove, a rotatable cylindrical member having spaced fluid inlet and exhaust ports and hydraulic pressure and exhaust conduits therein leading thereto extending into and cooperating with said bore to form a valve and a second working chamber, said spiral groove connecting said chambers and being normally straddled by said inlet and exhaust ports to trap hydraulic fluid in said working chambers for locking said piston against movement in one direction, the movable working area of said second mentioned chamber and the working area of said piston being substantially equal to the total area defined by the diameter of said piston, conduit means connecting said exhaust conduit and said chambers, and valve means in said conduit means operative automatically upon a predetermined pressure in said exhaust conduit for admitting hydraulic fluid to said chambers independently of said valve.

6. Fluid actuated mechanism including in combination a cylinder, a piston in said cylinder cooperating therewith to form a closed expandable working chamber, said piston having an axial central bore including a spiral groove, a cylindrical member having spaced fluid inlet and exhaust ports adapted to be connected to a source of hydraulic fluid under pressure and to a fluid receiver respectively cooperating with said bore to form a valve and a, second working chamber, said spiral groove connecting said chambers and being normally straddled by said inlet and exhaust ports to trap hydraulic fluid in said working chambers, the movable working area of said second mentioned chamber and the working area of said piston being substantially equal to the total area defined by the diameter of said piston, conduit means connecting one of said ports and said chambers, and valve means in said conduit means operative automatically upon a predetermined pressure in said one conduit for admitting hydraulic fluid to said chambers independently of said valve.

FLORENCE H. C. JEFFREY, Erecutfix of the Estate of Robert K. Jefirey,

Deceased.

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

Germany 1936

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