US1011918A - Fluid-pressure governor. - Google Patents

Description

H. W. CHENEY.

FLUID PRESSURE GOVERNOR.

APPLICATION FILED MAR. 27, 1909.

1,011,918, y Patented De0.19,1911.

2SHEETS-SHEET 1.

H. W. CHENEY.

FLUID PRESSURE GOVERNOR.

AIPLIGATION FILED 1113.27, 1909.

1,011,918, Patented Dec. 19,1911.

2 SHEETSSHEET 2.

UMTED sTATEs PATENT oEEIcE.

HERBERT W. CHENEY, F MILWAUKEE, WISCONSIN, ASSIGNOR T0 ALLIS-GHALMEBS COMPANY, A CORPORATION 0F NEW JERSEY.

FLUID-PRESSURE GOVERNOR.

Specification of Letters Patent.

Application led March 27, 1909. Serial No. 486,239.

To all whom'it may concern:

Be it known that I, HERBERT W. CHENEY, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Fluid- Pressure Governors, of which the following is a full, clear, and exact specification.

This invention relates to governors for fluid compressors, and particularly to that type of governor which includes an electric switch together with suitable means for operating the switch so as to close or open the circuit of an electric motor which drives the compressor, when the fluid pressure varies beyond certain predetermined limits.

The object of the invention is a provision of a governor which is effective and reliable in operation, but which consists of few parts and is very simple in construction and durable.

The invention may be briefly summarized as consisting in certain novel details of construction and colnbinations and arrangements of parts which will be described in the specification and setforth in the accompanying claims. Y f

Reference is had to the accompanying sheets of drawings in which- Figure 1 is a sectional view taken through a governor constructed in accordance with my invention, parts being broken away for the sake of clearness, and the switch being here shown open; Fig. 2 is a similar view of part of the governor, the switch being here shown closed; Fig. 3 is a transverse sectional view taken substantially along the line 3%?) of Fig. 1, looking in the direction indicated by the arrow; Fig. 4 is a fragmentarytransverse sectional view 'subst-antally along the line 4-4 of Fig. 3 looking in the direction indicated by the arrow.

{eferring to the figures of the drawing, 10 represents a casting which includes a cylinder or casing 11 and a flat base 11 at one end of thecylinder for supporting part of the governor mechanism. At the opposite end of the cylinder is a tightly clamped flexible diaphragm 12 which is preferably made of strong rubber and is adapted to be shifted back and forth by variations vin fluid pressure so as to operate the governor, the diaphragm being clamped between the open end of the cylinder and a cap 13 which is secured to the cylinder.

Between one side of the diaphragm and cap is a cavity or chamber 14 which will -be connected to the fluid reservoir or to the pres sure system by a pipe (not shown) adapted to'be secured into a socket 15. On the opposite side of the diaphragm and engaging the latter yso as to be shifted inward or outward by variations in the flexure thereof is a head or enlarged portion 1G of a plunger having a shank 17 which extends through the cylinder and has its free end extending through an opening# in the .base 11a. The movement of the plunger and of the diaphragm 12 is resisted by a rather heavy coil spring 18 which surrounds the shank 17 of the plunger and bears against the enlarged portion 1G thereof and a disk 19 which may be adjusted by set screws 2() extending through the base 11a of the casting and engaging the disk 19. By adjusting these screws in the well known manner, the high and low limits of fluid pressure may be varied. The outer end of the plunger 17 is provided with a reduced portion 2l and with a pair of shoulders or flanges 22 and 9.3 between which the end of a lever, to be referred to presently, is held, and the lat-ter of which serves by engagement with a block 23 secured to the top of the base, to limit the inward movement of the plunger.

The major portion of the mechanism of the lgovernor is held or clamped between parallel adjacent sides 24 and 25 of a frame which is preferably punched from sheet metal and is secured to the base 118L by means of screws 26.

At 27 is shown a switch lever which is pivotally supported by means of a pin 28 extending transversely between the sides of the frame, this lever extending on both sides of its pivotal support and including an arm 29 which is pivotedj and yieldingly supported on the main portion of the lever and which carries at its free end a. movablev switch contact 30. This arm 29 extends through a slot in an arcing chute 31, which of conductors 34 and 35 (to the motor, not shown) and to the blow-out magnet 3G having pole shoes 37 and 38 located on opposite sides of the arcing chute and on opposite sides of the contacts 30 and 33 so that the flux may extinguish the arc.

Before describing in detail the mechanism by which the switch lever is "operated, it may be stated that by the mechanism which l have provided, the switch lever is held stationary, so that it cannot be prematurely closed or opened, by means of the spring-pressed holding member or detent, and is released by a lost motion device operated by the plunger or the diaphragm and designed to shift the holding member1 so as to permit the lever to be moved in one direction or the other by one of two springs provided for this purpose, one spring being compressed when the pressure rises and serving to open the switch when the pressure reaches the predetermined high limit, and the other being compressed when the pressure falls and serving to close the switch when the pressure reaches the predetermined low limit.

Referring now again to the figures of the drawings, it will be seen that the rear end 37 of the switch lever, or the end on the side of the supporting pin 28 opposite to the Contact 30 is enlarged and is provided with a socket or cavity containing a coil spring 38 and a detent or latch, in this case in the form of a ball 39 which is pressed upward by said spring. This spring-pressed ball is adapted to coperate with a block 40 to hold the switch in either its closed or open position, this block having two sockets 41 and 42 which are so located and are of such a size that when the switch is closed the ball will be forced by the spring into the upper socket 41, the ball extending a sutlicient distance into the socket to hold the switch in its closed position, and when the switch is open the ball is forced by the spring a suitable distance into the socket 42 to hold the switch lever in its open position. A pin 27L extending transversely between the sides of the frame is adapted to be engaged by the lever to limit the opening movement of the switch and to prevent the ball passing beyond the socket 42 when the switch is opened. This ball is adapted to be shifted from the sockets by means of a lost motion device in the form of an arm or strip 43 which is adapted to slide longitudinally through a slot 44 provided centrally in the block 40 and intersecting the sockets 41 and 42. This arm is pivotally connected at its lower end to one end of a lever 45 which is mounted upon a pin 46 extending between the sides of the frame adjacent the outer end of the shank 17 of the plunger, the pin 4G being connected to the lever intermediate the ends of the latter. The opposite end of the lever 45 is bifurcated and straddles the reduced portion 21 of the shank 17 of the plunger, the free ends of the slotted portion of the lever being somewhat rounded and being located between the shoulders 22 and 23 so that when the plunger is shifted either outward or inward with respect to the cylinder 11, the lever 45 and the arm 43 will be shifted.

The portion of the arm 43 extending through the block 40 is provided with a notch or recessed portion, the ends of which are inclined so as to form two spaced cam faces 47 and 48, the upper cam face 47 being designed to engage the ball 39 and to move the same from the socket 41 when the arm 43 is moved downward, and the cam face 48 being designed to engage the ball and move the same from the socket 42 when the arm 43 is moved upward. These two cam faces will be spaced apart a suitable distance which will govern to a considerable extent the range of fluid pressure in the compressor cylinder or reservoir. Other means for varying the range of pressure will be explained later.

In order that the switch may be opened with a quick movement when the ball is moved from the upper socket 41, and quickly closed when the ball is lifted from the socket 42, I have provided the following mechanism Pivotally connected to the lever 45 between the pin 46 and the connection of the'lever with the arm 43 is a rod 49 which is designed to be moved longitudinally by the lever 45 and which passes loosely through an opening in the switch lever 27 between the pin 28 and the enlarged socketed end 37 and loosely through a pin 5() extending between the sides of the frame near the outer or upper part thereof. Carried by the rod 49 near the two ends thereof are two abutments in the form of collars 51 and 52, the position of the upper collar 51 being adjustable by means of nuts 51a engaging a threaded portion of the rod, and loosely mounted upon the rod 49 and bearing against opposite sides of the lever are two sleeves 53 and 54 respectively. Surrounding the rod 49 between the collar 51 and the sleeve 53 is a coil spring 55 which, as will be explained, is compressed when the pressure rises, and is designed to open the switch when the pressure reaches a predetermined value, and between the collar 52 and the sleeve 54 is a coil spring 56 which is compressed when the fluid pressure falls and again closes the switch when the fluid pressure is reduced to a predetermined value.

The mechanism of the governor mounted upon the portion 11 of the cylinder casting is inclosed in a casing which is preferably made of non-magnetic material and consists of two parts 57 and 58 which may be secured to the casting in any desired manner and held together by a suitable latch, a portion of which is shown at 59.

The governor, which may be located in any desired position relative to the compressor will be adjusted by means of screws 20 so as to operate at a desired maximum or minimum pressure which may vary between any desired limits, say for example, between 90 pounds and 100 pounds. The range of pressure or the vdifference between the maximum and minimum pressures may be varied by adjusting the nuts 51* on the upper end of rod 49 and hence the degree of compression of coil spring 55. It may also be varied by changing the distancebetween the cam faces 47 and 48 on arm 43.

Assuming that the switch is open and the motor which drives the compressor is stationary, the plunger will move gradually inward relative tothe cylinder as the fluid pressure is decreased and as the diaphragm becomes less flexed. As the plunger moves inward, the arm 43 and rod 49 are gradually moved outward compressing coil spring 56. When the fluid pressure falls to a predetermined value, the cam face 48 engages the ball 39 and moves the same from the socket 42 so as to release the lever 27 and permit the spring 56 to close t-he switch.

WVhen the switch is closed, the motor will be started and the fluid pressure will be again built up. 'As the fluid pressure increases the diaphragm 12 will be moved outwardly against the tension of the coil spring 18 moving the plunger upward and causing the rod 49 and the arm 43 to move inward. While this is taking place, coil spring 55 is being compressed and cam face 47 a proaches the ball 39 which now engages t e socket 41. When the pressure rises to a predetermined value, the cam face 47 moves the ball from the socket 41 so as to again release the lever and permit the coil spring 55 to open the switch.

The mechanism which I have described above has proven by practice to be extremely eflicient and reliable, and in fact answers all the requirements of operation and durability, and at the same time is compact and inexpensive to manufacture.

I do not desire vto be confined to the exact details shown and described, but aim in my claims to cover all modifications which do not involve a departure from the spirit and' said switch lever against movement during certain ranges of fluid pressure, and means including a cam member operated by said plunger after a predetermined movement thereof for releasin the lever so that it can be shifted by one o said springs.

2. In a governor for a fluid compressor, a

plunger shifted inward or outward by variations in fluid pressure, a switch including a switch leverresponsive to the action of said plunger, a pair of springs, one serving to openthe switch and the other to close the switch, and one being compressed when the plunger is moved in one direction and the other compressed when the plunger is moved in the opposite direction, means for holding said switch lever against movement during a certain range of fluid pressure, and means including a cam member operated by 'said plunger after a predetermined movement thereof for releasing the lever so that it can be shifted by one of said springs.

3. In a governor for a fluid compressor, a plunger shifted inward or outward by variations in fluid pressure, a switch lever responsive to the action of said plunger, a pair of springs acting on said lever and one serving to shift the lever in one direction and the other to shift the lever in the opposite direction, means for holding said lever stationary during a certainl range of movement of said plunger, means for compressing one of said springs during said movement, and a lost motion device having a cam portion operated by said plunger and serving to release the lever after a predetermined movement of the plunger.

4. In a fluid pressure governor, a plunger adapted to be shifted by variations in fluid pressure, a switch including a pivoted switch lever, means for holding said lever against movement during a certain range offluid pressure, said means comprising a stationary member and a detent carried by the lever, said member having sockets in which said detent is adapted to be. inserted, and' means operated by said plunger for shifting said detent from said sockets when the high and low limits of pressureV have been reached so as to release the lever.

5. In a governor for fluid compressors, a movablewall adapted to be shifted inward or outward by variations in fluid pressure, a pivoted switch lever, means for holding said lever against movement through a certain range of fluid pressure, said means comprising a spring-pressed device carried by the lever, and a stationary member having sockets in which said device is adapted to be inserted, and means for shifting said device from the sockets so as to release the lever comprising a movable member adapted to be shifted by said movable wall into engagement with said spring-pressed device.

6. In -a governor for air compressors, a

plunger adapted to be actuated by variations in fluid pressure, a switch comprising a pivoted lever, a spring for shifting the lever, a spring-pressed holding device, and a member having a pair of sockets in either one of which the device is adapted to be inserted so as to hold the switch in its open or closed position during a definite range of fluid pressure, and means operated by said plunger for placing said spring under stress, and after a certain movement thereof for shifting said holding device from a socket so as to release the lever and permit the spring to shift the same.

7. In combination, in a governor for fluid compressors, a movable member shifted back and forth by variations in fluid pressure, a switch comprising a pivoted lever, means for holding said switch lever against movement with the switch either closed or open during certain ranges of fluid pressure comprising a spring-pressed device carried by the lever, a stationary member having a pair of sockets in which said spring-pressed device is adapted to, be "inserted, a spring for shifting said lever, and means operated by said pressure actuated member for storing energy in said spring and for causing the release of said lever.

8. In combination, in a. fluid pressure governor, a plunger adapted to be actuated by variations in fluid pressure, a switch comprising a pivoted switch lever, means for holding said lever against movement during a certain range of fluid pressure comprising a spring-pressed device carried by said lever, a stationary member having a pair of spaced sockets in which said device is adapted to be inserted, and means operated by said plunger, when the latter is moved a certain amount in one direction, to shift said spring-pressed device from one of the sockets and to permit the switch to be opened, and when the plunger is moved a certain amount in the opposite direction, to shift said spring-pressed device from the other socket to permit the switch to be closed.

9. In a governor for fluid compressors, a member adapted to be actuated by variations in fluid pressure, a switch comprising a pivoted switch lever, a pair of springs acting on opposite sides of said lever and when compressed serving respectively to shift the lever to open and close the switch, a movable holding latch carried by said lever, a member having a pair of Sockets in which the latch is to be inserted so as to hold the switch against movement during a certain range of fluid pressure variation, the switch being held closed when the latch is in one socketand held open when the latch is in an other socket, andan arm shifted by said pressure actuated member for moving said latch from the sockets to permit the switch lever to be shifted.

10. In a governor for fluid compressors, a plunger adapted to be shifted in opposite directions by variations in fluid pressure, a switch comprising a pivoted switch lever, means for holding said lever against movement during a. certain range of fluid pressure variation, said means comprising a spring-pressed member carried by the lever and a block having a pair of sockets, one of which the spring-pressed member engages so as to hold the switch closed, and the other of which the spring-pressed member engages so as to hold the switch open, a spring acting on lsaid lever so as to shift the same, and means for storing up energy in said spring and for shifting said spring-pressed member from said notches comprising a lever connected to the plunger, and an arm having a pair of spaced cam faces adapted to engage said spring-pressed member.

1l. In a governor for fluid compressors, a plunger adapted to be shifted by variations in fluid pressure, a switch comprising a pivoted switch lever, a pair of coil springs acting upon opposite sides of said lever and serving respectively to open and close the switch, means for holding the switch lever against movement during a definite range of fluid pressure variations, said means comprising a spring-pressed latch carried by the lever, and a block having a pair of spaced sockets in one of which the latch is adapted to be inserted so as to hold the switch closed, and in the other of which it is adapted to be inserted so as to hold the switch open, and means for storing energy in either one of said springs and for causing said latch to be withdrawn from either one of the sockets depending on the direction in which the plunger is shifted, said means comprising a lever pivotally connected to said plunger, a rod connected to the lever and passing through said coil springs, and an arm connected to the lever and passing through said block, said arm having cam faces adapted to engage the latch.

Milwaukee, 1Vis., MarchQ-l, 1909.

In testimony whereof I aliX my signature, in the presence of two witnesses.

HERBERT 1V. CHENEY. lVitnesses C. CASE, CHAS. L. BYRON.

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