US2391996A - Control mechanism - Google Patents

Description

Jan. 1, 1946.

J. A. MULLER 2,391,996

CONTROL MECHANISM Filed June 15, 1942 INVENTOR douAN A. MULLER.

' X ATTORNEY Johten A. Muller,

ATENl ram T Dayton, Gh'io, assignor to The oriuc E draulic Development ilorporation, Kna, Wii= 1 -i' Del a corporation of Delaware Application June 15, 1942, Serial No. time? 8 tillaims.

pumps in closed hydraulic systems, but is by no means limited thereto.

It is an object of the invention to provide simplified control means adapted to be used in connection with hydraulic systems for controlling fluid operable machinery.

It is another objecirto provide a control mechanism for a reciprocable member adapted tocontrol hydraulic machinery, which control mecha-- nism is operable automatically by said machinery in a hydromechanical way.

It is a further object of the invention to provide a control mechanism for a reciprocable member, with which the reciprocable control is shiftable selectively in one or the opposite direction by fluid columns which are adapted to be actuated in a purely mechanical way.

It is a, still further object of the invention to provide a control mechanism, as set forth in the preceding paragraph, which is provided with means operable selectively for varying the stroke of the reciprocable member.

Still another object of the invention consists in the provision of a control mechanism for a reciprocable member controlling the supply of operating fluid to hydraulic machinery, in which means is associated with said machinery for automatically eflecting hydraulic control of said reciprocable member.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, which diagrammatically.

illustrates the present invention by. way of example.

General arrangement fluid, so that when said cylinder-piston-assembly is-actuated in one direction, a fluid column moves the reciproca'ble member in a first direction. whereas actuation of said cylinder-piston-assembly in the opposite direction, will cause another fluid column to impart upon said reciprocable member, movement in a second direction.

The cylinder-piston-assembly is operable in a purely mechanical way selectively either manually or automatically by a machine, and may b controlled by the reciprocable member.

According to further features of the invention, the stroke of the reciprocable member may be varied and, if desired, the reciprocable member may be held in an intermediate or neutral position for any desired length of time.

Structural arrangement Referring now to the drawing in detail, the systern shown therein substantially comprises a re:- versible variable delivery pump l, which may be of any standard design, and includes a reciprocable flow-control member (not shown), the position oi. which controls the delivery of the pump.

The flow-control member is operable in one direction b a plunger 2, whereas movement or the flow-control member in the opposite direction is adapted to be eflected by the fluid operable plunger 3.

The fluid operable plungers 2 and 3 are respectively reciprocable in cylinders 4 and 5. The

cylinders 3 and 8 have hydraulicallyconnected' thereto a conduit 8 with two check valve I and 8. The conduit 6 also comprises an accumulator 9.

The check valve lie so arranged that it allows in the cylinder l I is a piston I! having connected thereto a piston rod i3.

Similarly branching oil? from the conduit 6,

'between the cylinder 6 and the check valve 8, is a conduit it leading to a cylinder It, in which is reciprocably mounted a piston IS with a piston rod H. The cylinder-piston-assemblies ll, l2 and I5, I t are identical and of thesame'capacity. The fluid in the conduits I0, I 4 and 6, as well asin the cylinders! and 5, is preferably held at a slight pressure according to the pressure of the fluid in the accumulator 9. In this way, a predetermined pressure condition will, at all times, be assured in the cylinders '4 and 5. The cylinders Ii and i5 are mounted on a support I8, which has connected thereto an extension l9. Pivotally connected to the extension 9 is a main control lever 29, having two cam portions 2| and 22 for respectively engaging and actuating the piston rods i3 and II. The control lever 29 has also connected thereto a handle 23, allowing manual shifting operation of the control lever 29. The control lever 29 furthermore carries a reciprocable pin or latch 24, adapted to engage a correspondingly shaped recess 25 in the extension l9, when the lever 29 occupies a substantially horizontal position, so that the pistons l2 and I8 are on the same level. The pin or latch 24 is adapted to be shifted into one or the other direction by means of the handle 25 connected to the pin 24, and adapted to slightly rotate, the pin 24, and to engage selectively either the slot 2'! or the slot 28 for locking the pin 24 in its respective end position.

The shifting movement of the control lever 29 about the pivot 29 may be varied by means of abutment screws 39, 3|, which are held in their adjusted position by means of locking nuts 32, 33. The control lever 29 is furthermore provided with a cut out portion 34, both ends of which are curved in correspondence with the curvature of a roller 35, carried by a reversing lever, generally designated 35. The lever 38, which is shiftable about a pivot 31, has connected thereto a handle 38 for actuating the lever 38.

The lever 38 comprises a cylindrical portion 39 which is slotted at its upper end for guiding a 1 a corresponding direction, for instance. in connection with thadrawing in clockwise direction.

The lower end of the reversing lever 38 has an extension 43, which is adapted to be engaged and actuated in one or the other direction by the dogs 44 and 45 respectively, which dogs are adiustably mounted on and carried by a table 48. The table 48 is connected, in any convenient manner, for instance by means of a screw 41 and a collar 48, with one end of a piston rod 49, the other end of which is connected to a piston 59. The piston 59 is reciprocably mounted in a cylinder 5| through which extends a piston rod 52, which is preferably of the same diameter as the piston rod 49, and is also connected to the piston 59.

The left handend of the cylinder 5| is connected to. a conduit 53 comprising a check valve 54 and leading to a fluid reservoir or tank 55. The tank 55 furthermore communicates with a conduit 58 comprising a check valve 51, and leading to a conduit 58. One end of the conduit 58 communicates with the right hand end of the cylinder 5|, whereas the other end of the conduit 58 leads to one side of the pump I, the other side of which communicates through conduit 59 with the conduit 53.

Operation umed that, at the horizontal position of the lever 29, the plungers 2 and 3 occupy an intermediate position, at which they are equally spaced from the adjacent outer ends of the respective cylinders 4 and 5.

If it is now desired to carry out a working cycle, the operator first unlocks the latch 24 by moving the handle 28 out of the slot 21 and into the slot 28. Thereupon, the operator, by actuating the handle 23, shifts the control lever 29 in anti-clockwise direction. As a result thereof, the spring 4| expands and causes the roller 38 to support the anti-clockwise shifting movement of the control lever 29. The operator may immediately thereafter release the handle 23, while the roller 35 will complete the shifting operation of the handle 29 until the latter is stopped by engagement of its right hand end with the abutment screw 3|.

Due to the above described operation of the lever 29 in anti-clockwise direction, the cam portion 22 has moved the piston rod l1 and thereby also the piston I8 upwardly. The fluid expelled from the cylinder i5 during this upward movement of the piston l8, passes through conduits i4 and 8 into the cylinder 4 where it acts upon the piston 2 and causes the latter to move toward the left, and also moving the flow-control member toward the left for shifting the pump into full stroke position in one direction. Due to the'leftward movement of the piston 2, and the flow-control member pertaining to the pump. the piston 3 likewise moves toward the left, and the fluid expelled from the cylinder 5 passes through conduits 8 and 9 into the cylinder IL This results in a downward movement of the piston |2 by the same distance as the distance at which the piston i6 has moved upwardly.

It will be appreciated that the check valves 1 and 8 prevent. fluid from flowing from the cylinders l5 and 5 respectively through these check valves to the accumulator 9. If, due to leakage, fluid should escape from any of the cylinders or conduits connected thereto, the escaped fluid will be made up by the pressure fluid from the accumulator 9 through check valves 1 and 8.

All parts are now occupying the position shown in the drawing, and pressure fluid from the pump now flows through conduit 53 into the left hand end of thecylinder 5|, thereby moving the piston 59 toward the right. Fluid expelled during this movement of the piston 59 from the right hand end of the cylinder 5| flows through conduit 58 to the now suction side of the pump I.

Since it was assumed that the diameters of the piston rods 49 and 52 are substantially equal, the quantity of fluid admitted to the right hand side of the piston 59 at any time during the right hand movement thereof, will equal the quantity of fluid expelled by the piston 59 from the right hand end 'of the cylinder 5|. If, however, a greater quantity of fluid had to be supplied by the pump to the left side of the piston 59 than is expelled from the right hand end of the cylinder 5|, additional fluid would be conveyed from the tank 55 through the check valve 8| and conduit 58 to the now suction side of the pump When the piston 59 approaches the end of its rightward stroke, the dog 45 engages the extension 43 so as to shift the reversing lever 38 about the pivot 31 in anti-clockwise direction. This causes the roller 35 to move toward the left hand v end of the cut out portion 34, thereby shifting accuses the control lever 28 in clockwise direction. As a result thereof, the cam portion 2| moves the piston rod is and, thereby, the piston II-upwardly. This upward movement causes fluid to be expelled from the cylinder ll into the cylinder 5, where, acting upon the plunger 3, it moves.

Rightward movement of the plunger 8 causes the plunger 2 likewise to move toward the right, with the result that fluid is expelled fromcylinjder 4 in the same quantity as was expelled into the cylinder 5. The fluid expelled from the cilinder ll passes through conduits 8 and I l into the cylinder I5, where it acts upon the piston l6 and moves the latter downwardly until the piston rod ll is stopped by engagement with the cam portion 22'.

The shifting movement of the control lever 20 in clockwise direction is halted by engagement of the left hand portion of the lever 20 with the abutment screw 30.

Pressure fluid from the pump 8 now flows through conduit 58 toward the right hand end of the cylinder bl where it acts uponthe piston t and moves the latter toward the left. Fluid expelled from the left hand end of the cylinder 58, during this left hand movement of the cylinder 50, flows through conduits 53 and 58 toward th suction side of the pump I. v

If the diameter of the piston rod 52 equals the diameter of the piston rod 68, the quantity of fluid conveyed through conduit 58 to the cylinder i equals the quantity of fluid expelled from the left hand end of the cylinder 5i. If more fluid is to be conveyed toward the right hand end of the cylinder bl than is expelled from the left hand end of the cylinder 5i, additional fluid passes from the tank 55 through check valve 54 and conduit 53 to the conduit 59.

When the piston 56 approaches the end of 'its.

leftward movement, the dog 55 engages the extension 33 so as to shift the reverse lever 38 in clockwise direction, in a manner similar to that described above in connection with the shifting movement of the lever 38 in anti-clockwise direction. The pump 9 will then again be reversed and a new rightward stroke of the piston 50 will bestarted.

If the operator wishes to stop the pistonfifl,

at any desired point, he has merely manually that the piston l2 moves upwardly to a certain extent, while the piston ll moves downwardly to the same extent. In other words, both pistons will halt when their upper surfac is at the same level.

The upward movement of the piston 12 will cause fluid to flow from the cylinder it into the cylinder 5 and shift the plunger 3 and. thereby. the flow-control member pertaining to the pump 5 into its neutral or intermediateposition. at which the pump delivers practically no fluid, nor takes any fluid out of the cylinder 5|. ,Consequently, the piston fit is hydraulically blocked and, therefore, comes to a stop.

ii the shitting movement oi the lever 2@ into its horlzohtal podtion were effected while the right hand. end of the lever 20 is in its lower position, fluid expelled, due to the upward movement of the piston It, would shift the plunger 2 and thereby the flow-control member of the pump I, from its right hand position toward a neutral position, so that the pump I would likewise be in neutral or no delivery position. The piston 50 would, therefore, also be halted.

" It will be obvious that the shifting movement of the pump l to neutral position for halting the piston 80, may be eflected at any point of travel of the piston 50 in either direction.

If it is desired to vary the stroke of the plunger-s 2 and 8, and thereby vary the delivery of the pump I, it is merely necessary to efiect a corresponding adjustment of the abutment screws 30 and 3 I. It will be obvious that. if desired, the adjustment of the screws 30 and 3| may be so eflected that the movement of the plungers '2 and 3 r to one side may be larger than the movement thereof to the other side, thereby causing the piston 50 to move in one direction faster than in the opposite direction.

- It will be understood that I desire to compre hend within my invention such modifications as come within the scope of the claims.

Having thus fully described my invention, what I claim as new and desire to secureby Letters I Patent, is:

I. In combination, a reciprocable member, fluid operable means associated with said member for selectively shifting the same in one or the opposite direction, cylinder-piston means for exerting I hydraulic pressure on said fluid operable means for reciprocating the same, supporting means, an actuating element pivotally connected to said supporting means and movable selectively in clockwise or anti-clockwise direction for actuating said cylinder-piston means, adjustable abutment means for limiting the angular movement 01' said actuating element, and a yieldable member continuously urged into engagement with said actuating element and operable selectively'to bring about shifting movement of said element in clocksaid actuating element and operable selectively to bring about shifting movement of said element in clockwise or anti-clockwise direction.

3. In combination, a first reciprocable member, fluid operable means associated with said member for selectively shifting the same in one or the opposite direction, cylinder-piston means for exerting hydraulic pressure on said fluid operable means for reciprocating the same, support-, ing means, an actuating element pivotally connected to said supporting means and movable selectively in clockwise or anti-clockwise direction for actuating said cylinder-piston means, a yieldable member continuously urged into engagement with said actuating element and operable selectively to bring about shifting movement of said element in clockwise or anti-clockwise direction, and a second reciprocable member operable automatically in response to a predetermined travel thereof to eilect actuating movement or said yieldable member.

4. In combination, a first reciprocable member, fluid operable means associated with said member for actuating the same, said fluid operable means having a first and a second eflective area, a first cylinder, first conduit means inferconnecting said first cylinder and said first area,

a first plunger reciprocabie in said first cylinder, a second cylinder, second conduit means separated from said first conduit means and hydraulically interconnecting said second cylinder and said secactuating member in opposite directions, and a second reciprocable member operable in response .to a predetermined travel thereof alternately to shift said lever means in said first or said second direction.

5. In combination, a reciprocabie member,

fluid operable means associated with said member and provided with two oppositely effective areas, two fiuid operable plungers, separate conduit means respectively interconnecting said plungers with said areas, means for filling said conduit means and maintaining the same filled with fluid, pivoted actuating means movable for selectively actuating one or the other plunger, said actuating means being provided with a cam area, lever means movable in oppositedirections for actuating said actuating means and spring pressed means carried by said lever means for yieldably engaging said cam area for substantially instantaneously actuating said actuating means in response to a predetermined movement of said lever means.

6. In combination, a reciprocabie member,

and moving said yieldable means, said lever means and said yieldable means carried thereby cooperating to cause said control means to be substantially instantaneously actuated in either direction.

7. In combination, a fiuid urnp having a, reciprocabie fiow control member associated therewith, a' reciprocable ram connected with said pump to be driven in both directions thereby, fluid operable means associated with said flow control member for selectively shifting the same in one or in opposite directions, cylinder-piston means for exerting hydraulic pressure on said fluid operable means for reciprocating said member thereby to vary said pump delivery and the reciprocation of said ram, a pivoted actuating element movable selectively in a clockwise or anti-clockwise direction for actuating said cylinder-piston means, adjustable abutment means i for limiting the angular movement of said gctuating element thereby to limit the movement of said flow control member and thereby the delivery of said'pump and the speed of saidram, a yieldable member continuously urged into engagementwith said actuating element and operable selectively to bring about shifting movement of said element in both directions, and means associated with said reciprocabie ram for shifting said actuating element at predetermined points in the travel of said ram in both directions.

8. In combination, a fiuid pump having a reciprocabie fiow control member associated therewith, a reciprocabie ram connected with said Dump to be driven in both directions thereby, fluid operable means associated with said fiow control member for selectively shifting the same in one or in opposite directions, cylinder-piston .means for exerting hydraulic pressure on said fluid operable means for reciprocating said member thereby to vary said pump delivery and the reciprocation of said ram, a pivoted actuating element movable selectively in a clockwise or anti-clockwise direction for actuating said cylinder-piston means, adjustable abutment means for limiting the angular movement of said actuating element thereby to limit the movement of said fiow control member and thereby the delivery of said pump and the speed of said ram, a yieldable member continuously urged into engagement with said actuating element and operable selectively to bring about shifting movement of said element in both directions, and adjustable means associated with said ram for shifting said actuating element at predetermined points in the travel of said ram in both directions.

JOHAN A, MULLER.

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