US1588256A - Compressor unloader - Google Patents

Description

June 8 1926. 1,588,256

C. W. METZGAR COMPRESSOR UNLOADER Filed Nov. 5, 1925 INVENTOR kESZ GHI L MGZ an H 5 ATTOR EY Patented June 8, 1926.

UNITED STATES PATENT OFFICE. 1

OEES'I'EB w. METZOAB, OF EASTON, PENNSYLVANIA, ASSIGNOB TO INGEBSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A. CORPORATION OF NEW JERSEY.

COMPRESSOR UNLOADEB.

' Application filed November 5 loading through the agency of a plurality of clearance chambers controlled by a single clearance valve in a simple, cheap and eflicient manner.

Another object of the inventlon is to provide fluid pressure controlled means for limiting the movement of the clearance valve for eflecting step by step regulation. Both the clearance valve and the stop are preferably automatically responsive to receive pressure.

Further objects of the invention will hereinafter appear and the invent on 1s shown in one of its preferred forms in the accompanying drawing which 1s a dlagrammatic sectional elevation partly in long1tudinal section and partly broken away showing the invention Referring to the drawing, the cyllnder A shown as double acting is provided with the 'piston B driven from any suitable englne or motor. The cylinder is provided with sultable intake and discharge valves C and which may be of the plate type and the air or fluid to be compressed entering at the 1nlet E is discharged at the outlet F connected as by means of the usual discharge connection or pipe G to the receiver H.

The cylinder is provided with a plurahty of sets of clearance chambers J, K and L, O, in this instance two sets of two clearance chambers each being provided, and a single clearance valve P or Q is provided for controlling each set of clearance chambers. There may be as many clearance chambers in each setas desired, but only two being illustrated in the drawing.

vThe chambers J and K controlled by the valve P are adapted to be placed in successive communication with one end of the cylinder through the ports R and S and the port T while the clearance chambers L and O vare adapted to be placed in communication successively with the other end of the cylinder throu h the ports U and V and the port W. ese sets ofports being respectivelyz controlled by the clearance valves P and Each clearance valve is provided with a a, 1925. Serial 110. 86,494.

plunger X in the cylinder a and a compression spring 6 underneath the plunger tends to open the valve. Receiver pressure supplied through the pipes c or d holds the clearance valves closed, the; supply and release of receiver pressure being controlled bythe regulator Y. A second cylinder e for each clearance valve-contains a plunger 7 having a stop pin 9 projecting into the cylinder a for limiting the movement of the clearance valve according of the plunger 7. A spring h beneath the plunger 7 tends to move the stop pin 9 outwardly and receiver pressure is admitted to the plungers f for forcing the stop inwardly. The pipes j and I: connect the stop cylinders a with the regulator Y as the receiver pressure increases through predetermined degrees. The apparatus and the regulator are so constructed that the clearance valve P is first permitted by the stop 9 to move a suflicient distance to open the port R of the clearance chamber J as indicated in the drawings for the first step of unloading, and upon a further increase of receiver pressure for the next step of unloading the other valve Q is permitted by its stop 9 to move a suflicient distance to place the clearance chamber L in communication with the cylinder through the port U. At the next step of unloadin pressure against the plunger 7, controlhng the stop for the clearance valve P, is released permitting the spring to retract the stop so that the clearance valve P-opens the port S and places the clearance chamber K in communication with the cylinder, and for the last step of unloading, a similar operation is carried out for the clearance valve Q which opens the port V and places the clearance chamber 0 in communication with the cylinder so that the cylinder is completely unloaded.

Any. suitable regulator Y may be provided; in this instance the regulator casing Z having a valve chamber 0 for the auxiliary or pilot valve 2 having the heads q and r. Receiver pressure is supplied from the receiver H through the pipe 8 to the port If in the regulator casing so that the space between the valve heads g and 1' is constantly open to receiver pressure. One end u of'the valve chamber 0 is open to atmosphere, and

ports and passages lead from the valve to the position chamber o to the valve chambers 12 of the main operating valves w having the heads a: and y. There are four of these main operating valves wall constructed in the same manner and operating in the same manner, but only two of these valves and a portion of the third valve are shown. The two lower valves '20 shown in the drawing, controlthe pipes o and d leading respectively to the cylinders for the plungers X of the clearance valves P and Q while the two upper main operating valves w of the regulator control the pipes j and is leading respectlvely to the cylinders of the plungers f of the stops for the clearance valves tively.

The valve chambers '0 between the valve heads m and y are constantly subject to receiver pressure through the-ports 3 connected by passages 4 to the main receiver pipe 8 and the valves w are provided with shoes 5 controlling ports 6 and 7 for supplying pressure to or releasing pressure from the P and Q respecclearance valve pipes 0, d, j and in respectively. The main valves 'w are actuated by the alternate supply and release of receiver pressure operating on the heads at and y.

The regulator Y is rovided with a diaphragm 8 for a .diap ragm chamber 9 'to which chamber is connected the pipe 10 leading to the receiver. A pin 12 in the guide 13 which bears on the diaphragm,

, supports the weighted lever 14 pivoted at the pomt 15 to a bracket 16 on the regulator casing. The pilot valve ;0 is hung by the valve stem 17 from the lever 14 and the valve p is normally at its lowermost position in the valve chest 0 so that receiver pressure passes to the'four passages 18, 19, 20 and 21 leading respectively to the left hand ends of the operating valves 10 so that these valves would normally be in their right hand positions as the figure is viewed.

Four similar passagesfof which only two, 22 and 23, are shown connect the right hand ends of the main operating valves m with points in the pilot valve chest 0 and these passages are normally open 'to atmosphere through the open 'upper end 24 of the valve chest 0.

In the operation of the device, let it be assumed that the receiver pressure has. in

' creased sufiiciently to actuate the weighted actuated to the le lever 14 sufliciently to lift the pilot valve 1 to the position shown in the drawin in which case one o eratin valve '10 wi be and t e pipe 0 from the casing of the clearance valve P ,will be placed in communication with atmosphere through the ports 6 and 7 and the atmosphenc port 25 in the regulator casing so that the first step of unloading will be effected. As the pilot valve 17' is raised through successive steps uncovering the passages 19, 20 and 21 respectively in the regulater and placing them in communication .-withatmosphere, the four main valves to will be actuated one after the other to effect the succeeding steps of unloading. When the pipe (1 is placed in communication with atmosphere, pressure behind the plunger X of the, clearance valve Q' is released and the valve opens until its plunger strikes the stop 9. When'the pipe 7' leading to the plunger casing of the, stop 9 of the clearance valve P is open to atmosphere by the regulator, the stop is retracted by its spring and the clearance valve P moves to open the clearance chamber K to the cylinder for the third step of unloading. The final step is effected when-the pipe 7*: controlling the stop for the clearance valve Q, is" open to atmosphere. The machine is automatically loaded step by step as the valves operate in reverse order.

3. In a compressor unloader, the combination of a cylinder and piston, inlet and dischar e valves for the cylinder, a plurality of clearance chambers,-and" a single pressure. fluid automatically actuated clearance valve, for successively controlling said plurality of clearance chambers for step by step unloading. I

4. In a compressor unloader, the combination of a cylinder and piston, inlet and discharge valves for the cylinder, a plurality of sets of clearance chambers, a single clearance valve for controlling each set of clearance: chambers, and automatic pressure responsive means for actuating said clearance valves for step by step unloading.

5. In a compressor unloader, the combination ot a cylinder and piston, inlet anddischarge valves for the cylinder, a plurality of clearance chambers, a single clearance valvev controlling said plurality of chambers, and a pressure fluid actuated stop for limiting the movement of said clearance valve.

6. In a compressor unloader, the combination of a cylinder and piston, inlet and dischar e valves for the cylinder, a plurality of c earance chambers, a single pressure fluid automatically actuated clearance valve for successively controlling said plurality of clearance chambers for step by step unloadmg, and a pressure fluid actuated stop for limiting the movement of said clearance ling said plurality of chambers, both the valve to control the said steps of unloading. valve and the stop being automatically re- 7 In a compressorunloader, the combinasponsive to receiver pressure. 10

tion of a cylinder and piston, inlet and dis- In testimony whereof I have signed this 5 char e valves for the cylinder, a plurality specification.

of ciarance chambers, a. single clearance valve and stop for said valve ion control CHESTER W. METZGAR.

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