US2592043A - Air-operated pressure indicating controller - Google Patents

Description

April 8, 1952 E. E. LARSON ETAL 2,592,043

AIR-OPERATED PRESSURE INDICATING CONTROLLER Filed April 21, 1945 [/755195 .5 L M77511 ff/ Patented Apr. 8, 1952 AIR-OPERATED PRESSURE INDICATIN G CONTROLLER Earl E. Larson, Wadsworth, and Charles B. Luther, Akron, Ohio, assignors to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application April 21, 1945, Serial No. 589,578

3 Claims.

This invention relates to air-operated pressure controllers and is especially useful in controlling hydraulic apparatus.

Objects of the invention are to provide accurate control of high pressure, to provide control of pressure by use of a pressure gauge of the Bourdon type as a control actuating member, to provide throttling control of high pressures, and to provide safety of operation with accurate control of pressure.

These and other objects will appear from the following description and the accompanying drawing which is an elevation of the control mechanism.

Referring to the drawing, the numeral 10 designates a container which is to be maintained at substantially constant hydraulic pressure. For this purpose the container is supplied from any source of fluid pressure, such as a pump, by a pipe II. A diaphragm operated valve l2 in the supply line controls flow therethrough.

Connected to the container III by a pipe I3 is a pressure indicating gauge M of the Bourdon tube type in which a Bourdon tube l 5 is directly connected to the pipe l3 and has its closed free end l6 connected by a linkage I! with a swinging gear sector l8 which in turn meshes with a pinion IS on a rotatable stafi" 20. Mounted on the stall 20 is hub 2| to which is secured a cam plate 22. This plate rotates with the stair. 2lland is marked or engraved to indicate pressures. A stationary pointer 23 is provided to cooperate with the cam plate 22 in indicating pressures thereby providing for the cam plate to serve not only to give sensitive control of pressure but also direct, large scale visual indication of pressure.

The margin of the cam plate is formed with a cam surface having a concentric raised portion 24 extending from the region of zero pressure of the marked portion to a region where the indicated pressure is that desired to be maintained in the container ID, as at 25. At that position the cam drops away to a lower level 26 through an inclined portion 21 the shape of which determines the throttling range of the instrument, which shape can be made to give the desired breadth of throttling range, a more abrupt and shorter incline providing a narrower throttling range.

A cam roller 30 is freely mounted for rotation on an arm 3| pivotally mounted to a fixed member at 32, and rests upon the margin of the cam plate.

A vane 33 is fixed to arm 3!. An air jet 34 is located so as to discharge air under pressure against the vane 33 and the vane increases resistance of flow from the jet as it approaches the jet and decreases resistance as it moves further away.

For controlling the valve l2 by the flow of air from the jet 34 as permitted by the vane 33, a supply line 35 is provided with-a branch 36 connecting it to a needle valve 31. The supply line 38 from the needle valve 3'1 connects directly to a closed expansible elastic capsule 40 and also to jet 34. A branch 4| of air line 35 delivers air under pressure to a valve 42. This valve is a three-way valve controlled by a valve ball 43 which is controlled by a rod 44 attached to capsule 40. Rod 44 extends loosely through an exhaust tube 45 arranged opposite a delivery tube 45 which is connected to the diaphragm of valve l2. The arrangement is such that when pressure in capsule 40 is lowered, as by vane 33 moving away from jet 34, ball 43 is lowered closing exhaust pipe 45, and air from line 35 enters line 4| and line. 46 raising the air pressure at valve l2 and closing that valve, and when pressure in capsule 40 is raised, as by vane 33 approaching jet 34, ball 42 is raised, closing pipe 46, so that pressure in line 46 is lowered, and valve I2 is opened. By adjustment of needle valve 3'! air pressure conditions may be so adjusted that very slight changes in pressure at jet 34 eiTect operation of valve l2 and a constant throttling of valve l2 takes place.

The arrangement has the advantage that very little force is required to rotate the cam disc which is preferably made of light sheet material, such as aluminum, and the movements of the cam are therefore quite accurately efiected by the Bourdon tube. The vane 33 is also moved with slight force and its movements with respect to the jet 34 are very positive in controlling air pressure to the valve l2, so that accurate control of hydraulic pressure is made possible, while at the same time a direct, large scale visual indication of pressure is provided by the pressure indications on the cam disc, providing both pressure regulation and pressure indication by the single cam disc.

Variations may be made without departing from the scope of the invention as it is defined by the following claims.

We claim:

1. Apparatus for simultaneously indicating and regulating hydraulic pressure, said apparatus comprising a member movable in response to changes of hydraulic pressure, motion-trans mitting mechanism connected to said member and including an element rotatable in response to movement of said member, a disc mounted on said element for rotation therewith and having pressure-indicating markings to indicate pressure and comprising a cam surface thereon, a cam follower on said cam, an air supply, and means for controlling the flow of air including an air jet connected to said air supply and a vane on said cam follower opposed to said jet and movable in response to movement of said cam follower.

2. Apparatus for simultaneously indicating and regulating hydraulic pressure in a line having an air-operated controlling valve, said apparatus comprising a Bourdon tube connected to said line, motion-transmitting mechanism connected to said tube and including an element rotatable in response to deflection of said tube, a disc mounted on said element for rotation therewith having pressure-indicating markings to indicate pressure in said line, a cam surface thereon, a cam follower on said cam, an air supply to said air-operated valve, and means for controlling the flow of air to said valve including an air jet connected to said air supply and a vane on said cam followeropposed to said jet and movable in response to movement of said cam follower.

3. Apparatus suitable for sensitively regulating high levels of hydraulic pressure, an air pressure supply therefor, said apparatus comprising a Bourdon tube, a disc mounted for rotation in response to deflection of said tube, and thereby in response to change in the hydraulic pressure, said disc having a cam surface thereon extending through a limited are on the disc to provide by the extent of said are a limited throttling REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,301,405 Dexter Apr. 22, 1919 1,991,309 Annin Feb. 12, 1935 r 2,047,581 Grissett July 14, 1936 2,212,085 Tate Aug. 20, 1940 2,283,296 Temple May 19, 1942 2,366,246 Erbguth Jan. 5, 1945 2,427,235 Smoot Sept. 9, 1947

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