US2379291A - Fluid pressure motor - Google Patents

Description

June26, 1945. Y, w, H. GLAss l 2,379,291

-FLUID PRESSURE MOTOR Filed March 51, 1943 'I INVENTO WlliamHLass BY im ATTORN EY Patented June 26, 1945 FLUID PRESSURE MOTOR William H. Glass, Pittsburgh, Pa., assigner to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania l Application March `31, 1943, Seal No. 481,195

3 claims. (o1. 121-48) This invention relates to fluid pressure motors and more particularly to the type employing movable actuating abutments in the form of ilexible diaphragme.

Flexible disk like diaphragms made from rubber composition and having molded therein 'suitable reinforcing fabric having been developed tok withstand high uid pressures such as encountered in certain fluid pressure controlled devices. In fluid pressure motors diaphragms of this type have been advantageously employed where it is desired to obtain movement of a control element upon small variations in control pressure. Unlike ringed pistons however, the movement or deflection of such diaphragms must be limited in order to avoid the overstressing of the diaphragms and possible consequent premature failure thereof. Where it is desired to move a control element a greater distance than is practicable to attain by the deflection of an operating diaphragm without danger of damage to the diaphragm, it has been necessary to resortto a ringed piston and due to the friction between the ring and the bore in which it operates, variations in the increments of pressure for operation must necessarilyv be increased.

The principal object of the invention is the provision of an improved iluid pressure motor of the diaphragm type which operates on small variations in pressure and which is so constructed as to provide for the long travel of the element to be actuated without overstressing the diaphragm structure.

Other objects and advantages will appear from the following more detailed description of the invention.

In the accompanying drawing, the single figure is a sectional view showing a uid pressure motor embodying the invention.

As shown in the drawing the fluid pressure motor may comprise a horizontally disposed casing portion I having a pair of spaced downwardly projecting body portions 2 and 3 which are open at opposite ends, and may further comprise a pair of cap members 4 and 5for closing the open ends of the body portions 2 and 3, respectively.

Clamped between the body portion 2 and the cap member 4 is a flexible diaphragm 6 and clamped between the body portion 3 and the cap member 5 is a similar fiexible diaphragm 1, which diaphragms in the present embodiment of the invention have been shown as being of substantially the same area.

At one side of diaphragm 6 there is a chamber Ill and at one side of diaphragm 1 there is a chamber II which chambers are connected together by means of a passage I2 which in turn is connected'to a pipe I4,

At the opposite side of diaphragm 6 there is a chamber I5 and at the opposite side of diaphragm 1 there is a chamber I6 which chambers are in constant open communication with the atmosphere by way of passages I1 and I8, respectively.

-The diaphragm 6 is clamped between a diaphragm follower contained in chamber I5 and a diaphragm follower 2| contained in chamber I0 at the opposite side of the diaphragm, by means of nut 22 having screw-threadedconnection with a stud portion 23 carried at one end of a stem or rod `24, which stud portion passes through a suitable central opening in the followers 20 and 2|. The stem or rod 24 passes through chamber I 5 and extends through a suitable opening in the end wall of the chamber to the exterior thereof. Contained in chamber I5 and surrounding the stem or rod 24-is a spring 25 which, at all times, tends to urge the 'diaphragm assemblage including diaphragm 6, follows 20 and 2l and stem or rod 24 in a direction toward the left hand as viewed in the drawing.

The diaphragm 1 is clamped between av diaphragm follower 21 contained in chamber. lIl' and a diaphragmfollower 28 containedin chamber II at the opposite side of the diaphragm, by means of a nut 29 having screw-threaded connection with a stud portion 30 carried at one end of a stem or rod 3l, which stud portion passes through a suitable central opening in the followers 21 an'd 28. The stem or rod 3l passes horizontally through chamber I6 and extends through a suitable opening in the end wall of the chamber to the exterior thereof. Contained in the space between the body portions 2 and 3. The

lever 31 is provided with a slotted opening 38 which extends longitudinally of the lever and is disposed nearer to the end of the lever connected to the jaw 35 than to the opposite end of the lever. Contained in the slotted opening 38 of the lever 31 is a pin 40 which is carried by a jaw 4I provided at the outer end of the stem or rod 3l.

In use, with chambers I and II at atmospheric pressure the springs 25 and 32 act to maintain the diaphragm assemblies in the body portions 2 and 3, respectively, and thereby the lever 31, in the position in which they are shown in the draw- If fluid under pressure is supplied to pipe I4 it flowstherefrom to chambers I0 and Il by Way of passage I2. Fluid under pressure thus supplied to chamber I0 acts on diaphragm 6 in opposition to that of spring 25 and fluid under pressure supplied to chamber I I acts on diaphragm 1 in opposition to that of spring 32. When the pres-'- sure of fluid in these chambers and acting on diaphragm 6 and 1 has been increased to a degree suilicient to overcome the opposing force of springs 25 and 32 the diaphragm 6 will be caused to deflect in a direction toward the right hand while the diaphragm 1 will be caused to deflect in a direction toward the left hand.

The diaphragm 6 as it deflects in a direction toward the right hand, causes the rod 24 to move in the same direction, and the diaphragm 1 as it deects in a direction toward the left hand, causesthe rod 3| to move in the same direction. As therods 24 and 3l are thus moved in opposite directions, the force transmitted through the rods acts on opposite sides of the lever 31 causing said lever to pivot about the pins 38 and 40 to actuate the lever 31 in a clockwise direction.

It should here be noted that both diaphragms -operate to move the rods 24 and 3| in opposite directions, and since the rods are operatively connected to the lever at different positions along its length each diaphragm as it is deflected functions to increase the distance of travel of the lever 31. From this it will be seen that the distance of travel of the lever Will be-considerably greater than the distance each diaphragm deects. By reason of this arrangement pistons or impracticable diaphragms need not be resorted to in order to move the lever a relatively long distance.

When fluid under pressure is released from chambers I0 and II by way of passage I2 and pipe I4 the springs 25 and 32 act to cause the diaphragms 6 and 1 to deflect in opposite directions to thereby move the rods 24 and 3| and the connected lever 31 to the position in which they are shown in the drawing.

under pressure simultaneously thereto, means forv conducting pressure fluid simultaneously to the diaphragms, a floating lever, meansI for operatively connecting one of said diaphragms to said lever at one place between the ends of the lever, and other means for operatively connecting the other of said diaphragms to said lever at a different place between the ends of said lever both of said means being operative upon a deflection of said diaphragms for actuating said lever.

2. A fluid pressure motor comprising a casing having a pair of spaced body portions, a pair-'of flexible diaphragms, one of said diaphragms being disposed in one of said body portions and being arranged for deflection in one direction the other of said diaphragms being disposed in the other of said body portions and being arranged for deflection in the opposite direction upon the sup-y ply ofvuid under pressure simultaneously thereto, means for conducting pressure fluid simultaneously to the diaphragms, a floating lever having one of its end portions extending into the space between said body portions, and means operatively connecting said'diaphragms to said end portion of the lever at different places in the direction of the length of the lever, said means being operative upon deflection `of said di aphragms for actuating said lever. Y

3. A fluid pressure motor comprising a casing, a pair of flexible diaphragms disposed in said casing and provided for deflection in a direction toward each other upon the supply of fluid under pressure simultaneously thereto, means for conducting pressure fluid simultaneously to the diaphragms, a floating lever having one end "portion disposed between said diaphragms, and means operatively connecting said diaphragms to said lever` for effecting actuation 0f said lever upon deflection of said diaphragms. I

WILLIAM H. Grass.l

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