US1621913A - Clearance unloader - Google Patents

Description

Patented Mar. 22, 1927.

N17! 151 ST All AS P 'rsair 0mm FREDERICK VAN 'DUZER LONGIACRE, OIE YONKERS, NEVT "YORK, ASSIGN'OR 'IO INGEB- 'SOLL-RANZD COMPANY, OF JERSEY CITY. NEW JERSEY, A 'CORPORATION 055 NEW JERSEY.

"CLEARANCE UNBOAJDER.

Application filed October 19, 1925. 'Eerial No. 3,308.

The invention relates to compressors, but more particularly to clearance MH lOQGlGPS, and the primary object of the invention is to obtain clearance control for a compressor by means and devices which avoid aising available valve space.

To accomplish this object 10116 or (more clearance chambers are located intermediate the cylinder and the discharge connection, and certain of the main discharge valves between the clearance chambers and the cylinder are adapted-to perform the additional function of clearance control valves. Auxiliary discharge valves may be provided between the clearance chamber and the discharge connection, so that when the :main discharge valves are rendered inoperative for freely opening the clearance chamber to unload the cylinder, the auxiliary valves function as discharge valves Further objects of the invention will hereinafter appear and the invention is illustrated in the accompanying drawing, which is adiagrammatic longitudinalsectional elevation of so much oi a compressor as will serve to make the invention clear.

Referring to the drawing, the compressor cylinder A is provided with the :recip- :rocating piston 13 and the usual water jacket C. .In this instance the compressor is shown as double acting, having the inlet D and the discharge connection Eada pted to be connected to a suitable receiver, :not shown. Any suitable or usual inlet valves F, shown in this instance of the plate type, are provided for eachend of the cylinder, and there may be as many of these valves as necessary or desirable.

Clearance chambers G and H are located in the cylinder casing intermediate the cylind'er A and the discharge connection E, and suitable discharge valves J and K, shown in this instance of the plate type, are located in the valve openings L and 0 between the clearance chambers G and H and each end of the cylinder A. Auxiliary discharge valves P and Q, are provided in the valve openings R and S between the clearance chambers Gr and H and the discharge connection E. Additional discharge valves, if desired, may be provided for each end of the cylinder controlling communication between the cylinder and the discharge connection E, but, for simplicity of illustration, these additional discharge valves are not shown.

Suitable means :are provided ztor sends r ing the main discharge valves J and K inoperative ior unloading the compressor in one or more steps by reducing the cylinder capacity, and in this instance the valve J is provided with pressure flu-id means for liftthe entire valve structure from'its seat Tin the cylinder while the valve K is shown with a hand-operated means for liiiting the valve from its iseat U in-the icyllinder, and either one oi these devices may :be used, 'as desired. i

A yoke V is connected to the valve J and a piston WV in the cylinder X is connected by the rod Y to the yoke V, :so that outa ward movement at the piston WV in the cylinder .X lifts the entire valve structure J from its seat and renders the valveinoperative, so that the volume of the clearance chamber G is added to thatof one end of the cylinder A tor reducing the capacity of the cylinder.

The auxiliary discharge valve -P operating in -conjunction with the main discharge alve J may also be provided with similar controlling means, comprising the :piston Z in the cylinder :6 connected bythe rod '1) to the yoke :0, which in turn is connected to the valve structure P. Suitable pressure fluid connections tor the cylinderslX and a n are provided in the form of pipes (Z and c, which may be controlled manually or automatically, :as desired, .and the connections are such that when pressure fluid-is supplied to the pipes (Z the piston NV od the valve J will be actuated inwardly to maintain the valve on its seat so that it functions as a main discharge valve, while the piston Z of the auxiliary valve P is actuated outwardly to remove the valve P from its seat, and permit free passage of fluid under pressure from the clearance chamber G to the discharge connection E. By opening the pipe connection (Z to atmosphere and applying pressure fluid to the pipe connection e,

the relative movement of the pistons W- and Z is reversed and the main discharge valve J is lifted from its seat and rendered inoperative while the auxiliary valve P is returned to its seat and becomes operative to function as a discharge valve. In such case the compressor cylinder is unloaded to the extent of the volume of the clearance chamber G. A plurality of such clearance chambers G may be provided for the same end of the cylinder, as desired, and controlled in the same manner by the main discharge valves.

Hand-operated means are shown in connection with the main discharge valve K for lifting the valve from its seat, in this instance the yoke 7' being connected by a screw threaded stem 9 to the hand or wheel h. The stem 9 co-operates with an internally screw threaded portion 7' of the cap or cover la, so that rotation of the stem 9 raises and lowers the valve structure K. The auxiliary valve Q, is preferably secured in fixed position in the valve opening S in any suitable manner and does not require mechanism for raising and lowering same, because if desired the auxiliary valves P and Q may remain operative at all times.

I claim:

1. In a compressor, the combination of a cylinder and piston, an inlet valve, a dis charge connection, a clearance chamber, a main discharge valve for discharging the compressed fluid through said clearance chamber to the discharge connection, means for rendering said main discharge valve inoperative, whereby free communication is afforded between the cylinder and clearance chamber for unloading the compressor by reducing the cylinder capacity, and an auxiliary discharge valve between the clearance chamber and the said discharge connection.

2. In a compressor, the combination of a cylinder and piston, an inlet valve, a discharge connection, a clearance chamber in termediate the cylinder and said discharge connection, a main discharge valve between the cylinder and said clearance chamber, an auxiliary discharge valve between the clearance chamber andthe discharge connection, and means for rendering the main discharge valve inoperative for unloading the compressor by reducing the cylinder capacity.

3. In a compressor, the combination of a cylinder and piston, an inlet valve,-a discharge connection, a clearance chamber intermediate the cylinder and said discharge connection, a main discharge valve between the cylinder and said clearance chamber, an auxiliary discharge valve between the clearance chamber and the discharge connection, and pressure fluid means for automatically rendering the main discharge valve inoperative while permitting the auxiliary discharge valve to function normally, thereby unloading the compressor by reducing the cylinder capacity.

4. In a compressor, the combination of a cylinder and piston, an inlet valve, a discharge connection, a clearance chamber intermediate the cylinder and said discharge connection, a main discharge valve between the cylinder and said clearance chamber, an auxiliary discharge valve between the clearance chamber and the discharge connection, and means for maintaining either one of said valves operative while the other is held inoperative for loading and unloading the compressor.

5. In a compressor, the combination of a cylinder and piston, an inlet valve, a dis charge connection, a clearance chamber, main and auxiliary discharge valve structures includin plate valves for discharging the compressed fluid through said clearance chamber to the discharge connection, means for bodily lifting the said main discharge valve structure from its seat in the cylinder to render the main discharge valve inoperative while maintaining the auxiliary discharge valve structure upon its seat, whereby free communication is afi'orded between the-cylinder and clearance chamber for unloading the compressor by reducing the cylinder capacity, and means for also lifting the auxiliary discharge valve structure from its seat in the clearance chamber to completely unload the cylinder.

In testimony whereof I have signed this specification.

FREDERICK van DUZER LONGACRE.

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