US1412878A - Fluid-pressure-actuated motor - Google Patents

Description

T. LAURENT. l FLUID PRESSURE ACTUATED MOTOR.

APPLICATION FILED SEPT. 22, 19|?.

Patented Apr. IIS, i922.

IMI

narran statits THOMAS LAURENT, OF NEVI' YORK, N. Y., `ASSG'N'OR TO NATIONAL PNEUIVIATIC COMPANY, OF NEXV YORK, N. Y., A COREORATON Ol? WEST VIRGINIA.

FLUD-PRESS'URE-ACT'UATED MOTOR.

Specification of Letters Patent.

Patented Api'. f8, i922.

Application filed September 22, 1917. Serial No. 192,650.

To all whom. t may con-cern:

Be it known that I, T'HoMAs LAURENT, a citizen of the United States', residing at New York,- county of New York, State of New York, have` made a certain new and useful Invention in Fluid-Pressure-Actuated Motors, of which the following is a specification.

This invention relates to iluid pressure actuated motors.

The object of the invention is to provide a fluid pressure actua-ted motor of standard construction with a type of cushioning connection associated therewith, and to provide means for insuring the cushioning action of said connections.

A further object of the invention is to insure a proper sequence of operation of the controlling means of the motor.

Further objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location, and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown by the accompanying drawing, and finally pointed out in the appended claims.

Referring to the drawing Fig. 1 is a view in elevation of a standard type of fluid pressure motor with diagrammatic piping system and valve control of the same.

Figs. 2 and 3 are views of the valve and valve seat for various positions of the valvev on its seat.

Fig. l is a sectional view taken on the line 4 4 of Fig. 3 and looking in the Adirection of the arrows.

Fig. 'is a bottom face view of the valve employed in accordance with my invention;

Fig. Gis a sectional view taken on the line 5 5, Fig. 5, and looking in the direction of the arrows.

The same part is designated by the same reference numeral wherever it occurs throughout the several views.

In pneumatic engines or motors there are in practice three different types. In all types it is necessary to have some automatic means of cushioning or retarding the motion of the engine towards the `end of its stroke. In the one type, which l will call the first type, the pressure that has operated the engine in one direction is not liberated at the end of the stroke, but is retained until the moment the engine is reversed when part of this pressure is exhausted, a sufficient portion being retained however to cushion the final motion of the engine.

ln the second type, the pressure is automatically exhausted at the end of the travel of the engine, and when the engine is reversed the action is obtained by compressing the free air in that end of the engine. 0f necessity the relative arrangement and size of the exhaust ports that are suitable for the first type would be unsuitable for the second type as the pressure of the air on which the cushioning feature depends is much lower in the second type than in the first type.

The thirdg type of engine employs exterior auxiliary means for cushioning` the engine at the limits of its movements. This invention has reference to the first type of engine above described, and to that form of the same in which the controlling valve is manually operated. When the valve is operated electrically 'or pneumatically it is moved instantly from one desired position to another, but when manually operated it is possible for it to be moved slowly andgradually and therefore conditions may rise due to the position of the valve intermediate its proper extreme positions that could not arise with a power operated valve.

ln ordinary practice the valve is moved from one extreme position to the other, and heretofore, therefore, no exact detail has been followed in regard to the sequence with which the various ports were opened or closed, it being deemed sufficient in one extreme to have one piston or cylinder end open to pressure and closed to exhaust and the other piston or cylinder endopen to exhaust, usually through a more or less restrictive opening, and closed to pressure.

ln practice, however, as for instance, when used to operate doors on street cars, it has been found that sometimes the conductor will creep his control handle little by little from one extreme position to the other withthe result that the retarding pressure in either end of the cylinder is allowed to escape before the door starts to move, and the size of the cushioning' ports being suited to an engine that cushions on considerable pressure, there would not remain enough ie, e.

" the passage 21 controlli-ng the exhaust and pressure in the exhaust end of the engine to properly cushion its motion, and the door would slam open or shut. lt is among the special purposes of my present invent-ion to so rela-te the position of the ports that in :moving the valve from one extreme to the other, the following sequence is followed 1. rllie end of the cylinder that has been open to exhaust has the exhaust cut off while the other end of the engine still remains open to pressure.

2. The end formerly open to exhaust then becomes opened to pressure. The other end still remaining open to pressure. T his leaves both ends closed to exhaust and both ends open to pressure. This is the central or neutral position of the valve.

rlhe end thus far continuously open to pressure is thenclosed to pressure.

1l. The end which was originally open to pressure and which became closed in its third position nowbeconies open to exhaust.

lt will be seen, therefore, that at no position of the valve can the pressure blow through to exhaust, kand that. at the moment one end of the engine is commencing to be open to exhaust, the other end has already become open to pressure, so that the engine instantly responds to the pressure acting against the lessened pressure at the exhausting end, and the proper action of the cushioning effect is obtained.

Referring to the drawing wherein l show one embodiment of my invention, 1 designates the fluid pressure actuated motorof the usual or standard construction. My invention is not concerned in the specific type of motor employed, but l show a standard type which consists of cylinders 2, 3, in which operate the pistons 4l, 5, which pistons Aare connected by raclr bar 6, which rack bar meshes with the gear segment 7 wh'icli is connected to the arm S, which in turn controls the door or 'the moving body. The respective ends of the cylinders 2, 3, are connected by pipes 9, 10, to the ports 11, 12, respectively of the valvel seat 13.

Ports 14: and 15 of the valve seat 13 lead into the cylinders .2, 3, through pipes 16 and 17 respectively, Vand terminate in ports 18 and 19, which are uncoveredby pistons 1l, 5, at the limit of their travel in cylinders Fluid Vpressure is supplied to the valve andvalve seatthrough port 19 and the port 20 of the valve seat leads to exhaust. The

valve seat thus far described isrof the usual and standard type, and the valve 30v which operates on the saine lis Vlikewise of the usual standard typeV provided with the usual passages 21 and 22 inits seating face,

Y the passage 22 controlli-ng the supply. rlhe passage '21 is Vprovided with auxiliary passagesv of `smaller relative vsize 24,125, which are provided at Stlieir .ends with Vrelatively small ports 26 and 27, which ports are adapted to communicate with ports 11 and 12 respectively whenV the valve 30 is turned in one direction or another to its extreme position to operate the mot-or in onel direc.- tion or the other.

The operation of the system is obvious. lVith the valve in the position shown vin Fig. o, which is its central or neutral position, 1t will be seen that both ends of the cylinder are closed to exhaust inasmuch as none of the ports 14, 15, 11, or 12, arein communi.- cation with the exhaust port 20, the fluid pressure is allowed to flow from port "'19, passage 22, through port pipes 9 andv 10 to` both ends of thecylinder. `When the Valve is shifted towards the position shown in Fig. 2 port 12 becomes closed to the supply aiid port 11 remains open thereto soY that with the pressure removed .from the piston 5 the engine starts itsv movement to 4move the pistons 4 and 5 towards the right.

lhen it has reached its extreme position, namely, that illustrated in Fig. 2, it will be seen that the port 15 has become opened to 'exhaust through 'passage 21., and that there is a free exhaust from the cylinder 3 through pipe 17 to exhaust until the piston 5 closes` the port 19. rFhe restricted port 27 however is now in communication with port 12 and pipe 10 to theend of the cylinder 3 so that the remaining movement of the motor is against the restricted ex'-V haust of the fluid pressure which remains in they cylinder thereby insu-ringrthe cushioning action.l l

To operate the engine in theother direction from this position of the. Vvalve itv will be seen that the valve will have to pass through neutral position and will have to insure a supplyofpressure to the exhaust through both ends of the cylinder before either end can be exhausted thereby rendering the manual operation of this type'of .proper vfluid pressure motor or engine a proof against intentional or accidental Y misuse to prevent the proper functioning of the cushioning means employed in connection therewith. v' y Having now set forth the object and na-V ture of my invention, what l elaiin as'iiew and useful, and of my owninvention, 'and desire to secure by Letters Patent, is,--v Y 1. The combination with a fluid pressure motor compri-sing cylinders, pistons operating in said cylinders, a pipe line leading to the end of each of sai-dcylin-ders, a valve controlling said pipe line, Aa source of fluid pressure supply, and' an exhaust port controlled by said valve, means forestablish'- ies lll)v izo ing communication lbetween reach,Y of said pipe lines with either said exhaustfport vor said sourcejof' fluidl pressurel supply, and

pressure fromfsaid source to one of said l,means vfor preventing the admission vof fluid cylinders until said cylinder has been closed to exhaust, and for admitting pressure to said cylinder before the supply of fluid pressure to the other cylinder has been cut ofi', and in the initial operation from extreme position whereby a cushioning action is secured.

2. The combination with a fluid pressure motor comprising cylinders, pistons operating in said cylinders, a pipe line leading to the end of each of said cylinders, a valve controlling said pipe line, a source of fluid pressure supply, and an exhaust port controlled by said valve, means for establishingcommunication between each of said pipe lines with either said exhaust port or said source of fluid pressure supply, means for normally admitting fluid pressure to both of said pipe lines and prior to closing one of said cylinders to exhaust in initiating the operation of the motor from its extreme position whereby a cushioningv action is secured.

3. The combination with a fluid pressure motor comprising cylinders, pistons operating in said cylinders, a pipe line leading to the end of each of said cylinders, a valve controlling said pipe line, a source of fiuid pressure supply, and an exhaust port controlled by said valve, means for establishing communication between each of said pipe lines with either said exhaust port or said source of Huid pressure supply, means for normally admitting fluid pressure to both of said pipe lines and for closing said cylinder to exhaust when said valve is in its central or neutral position, and means when said valve is moved towards operative position for shutting ofi" the supply of pressure from one of said cylinders before opening said cylinder to exhaust in initiating the operation of the motor from its extreme limit of action in either direction.

4. In a fiuid pressure actuated motor, comprising cylinders, pistons operating in said cylinders, and means for supplying fluid pressure to and the exhaust thereof from said cylinders, ports for controlling the said supply and exhaust of fluid pressure to and from said cylinders, a manually operated valve for controlling said ports, and means for supplying fluid pressure to one of said cylinders prior to the movement of the piston therein in exhausting direction to cushion the movements of said piston irrespective of the position of the valve when moved towards an operative position.

5. ln a fluid pressure actuated motor, comprising cylinders, pistons operating in said cylinders, means for supplying fiuid pressure to and the exhaust thereof from said cylinders, ports controlling the said supply and exhaust of fiuid pressure to and from said cylinders, a manually operated Valve for controlling said ports, and means for supplying fiuid pressure to one of said cylinders prior to the initial movement of the piston therein in exhausting direction to cushion the movements of said piston irrespective of the length of time consumed in moving the valve to complete operative position.

6. ln a iuid pressure actuated motor, comprising cylinders, pistons operating in said cylinders, and means for supplying fluid pressure to and the exhaust thereof from said cylinders, a valve for controlling said fluid pressure comprising means for supplying fluid pressure to one cylinder, and opening the second cylinder to exhaust when the valve is at one limit of its movement and means controlled by the movement of the valve towards its other limit of movement for successively closing said second cylinder to exhaust, then supplying Huid pressure to said second cylinder, then shutting ofi' the supply of fluid pressure to said first cylinder, and finally opening said first cylinder to exhaust whereby a cushioning action is secured.

7. In a fluid pressure actuated motor, comprising cylinders, pistons operating in said cylinders, and means for supplying fluid pressure to and the exhaust thereof from said cylinders, a valve for controlling said fluid pressure comprising means for supplying fluid pressure to one cylinder, and opening the second cylinder to exhaust when the valve is at one limit of its movement, and means controlled by the movement of the valve towards its other limit of movement and irrespective of the speed of movement thereof for successively closing said second cylinder to exhaust, then supplying fluid pressure to said second cylinder, then shutting off the supply of fluid pressure to said first cylinder, and finally opening said first cylinder to exhaust whereby a cushioning action is secured.

ln testimony whereof l have hereunto set my hand on this 20th day of September A. D., 1917.

THOMAS LAURENT.

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