US1591393A - Centrifugal unloader - Google Patents

Description

July 6, 1926. 1,591,393

R. c; MCALLISTER CENTRIFUKGAL UNLOADER Fi led 0st. 5 1-925 2 Sheets-Shet l INVENTOR gimondamilllis'fin KZJ/Q M d 4 /a A ,ML

' ms ATTORNEY July s, 1926. 1,591,393

R. C. M ALLISTER CENTRIFUGAL UNLOADER' Filed Oct. 5 1925 2 Sheets-Sheet 2 INVENTOR @MondaMJZHIidZ'I-p Patented July 6, 1925.

UNITED STATES PATENT OFFICE.

,RAYMOND c. MGALLISTER, or PAINTED Post, NEW Yo mnssIoNoR 'ro INGERSOLL- RAND comrenror JERSEY CITY, NEW JERSEY, A CORPORATION or NEw'JnEs Y.

cENTRIEUoAL UNLOAD R.

Application filed October 3, 1925. Serial No. 60,142. M

P; Pins V extend into the guides T' and are This invention relates toair compressor unloaders, and more particularly to that type which is adapted to unload'the compressor to enable the driving element to ac celerate before loading the compressor.

Electric motors or internal combust on engines, as is well known, have low startlng torque. In cases in which they are used for driving air compressors it is desirable that the load be removed in order either to permit the engineto accelerate, in the case of an internal combustion engine, or, in the case of an electric motor, to prevent heavy drafts of current at starting.

'One object of this invention is to unload the compressor while the motor is accelerating by means which at high speeds of the motor disengage, so that there are no wearing parts engaged whilethe compressor 2 operating at normal speed.

Other objects and advantages of the mvention will be in part obvious and in part pointed out hereinafter.

In the drawin forming part of this specification in whic similar reference characters refer to similar parts, I

Figure l is a longitudinal vertical section through a compressor provided with an unloader constructed in accordance with the practice of the invention,

Figure 2 is a view of the compressor, the unloader being shown in section along the line 22 looking in the direction of the arrows, and

Figure 3 is a cross section of the unloader along the line 3'-3 looking in the direction of the arrows.

Referring to the drawing, the compressor includes a casing A having cylinders B 4 formed integrally therewith, and a crank shaft C provided with main bearings D, and

cranks E for o erating'the pistons F in the cylinders B. X cylinder liead G houses the intake valve assemblies for the cylinders B,

each valve assembly including a valve seat.

H, an inlet valve J and a valve back stop Ksuitably held together by a bolt L. The

valve seats H are held in position in apertures O by means of cages P which are screwed into a threaded aperture Q in the head G. For unloading the compressor the valves J are adapted to be pressed from their seats H by spiders R provided with plungers S arranged to slide in guides '1 mounted in suitable apertures U of the cages adapted to press against theupperfaces of the plungers S to epress thespiders :R for pressing the valves J from their seats: The interior of the cages P is adapted to com municate with the inlet manifold through a plurality of apertures'X in the WHlHSEOf the cage P. i as] In accordance with the practiceof'j'this invention the unloading mechanism. is' operated through a medium. of a shaft Y driven by the compressor through a gear Z mounted at the end of. the crankshaft C and 'a pinion b keyed to the shaft Y. The shaft-Y is journalled in a boss (1 preferably formed integrally with a cover e attached in any suitable manner to the'endf of the crank case A. A disc f is loosely mounted on the exterior of the boss or jour'nal'cl concentrically with the shaft Y and is attached by means of a suitable pin 9 remote from the center of rotation of the disc 1 to a system of links and levers comprising a link k, a lever 7' connected to a lay shaft in having arms 0 adapted to pressvagainst pins V for opening the compressor valves K. Upon rotation of the disc f in a counterclockwise direction, the link it is pulled downwardly, thereby opening the compres sor valves. Upon rotation of the disc 7 in a clockwise direction. thepin 9 assumes a position at the opposite side of the shaft Y whereupon the link his similarly held down.

It will be seen therefore that the compressor valves are opened upon rotation of the disc f in either direction.

The disc f is adapted to be actuated or rotated by one or more weights ;0 which are spring pressed, as for instance by means of a coil spring 9, to able slot '1' may be ormed in the periphery of the weights p to admit the coil sprlng 9 so that the spring lies embedded in the weights p. In order to rotate the weights p, a cover 8 keyed to the end of the shaft Y is provided with inwardly projecting pi'ns t engagin slots u in the faces of the links p. The slots 11 extend radially and permit the weights p to. move radially outward and away from the disc f. Longitudinal movement of the weights p is prevented in either direction by the cover 8 and by a flange 'v of the disc f. If desired, a layer of suitable friction material w may be attached to the periphery of the disc f to form a good gripgrip the disc 1. A suitand therefore pulling on the link 72. to open the compressor valve. As the compressor operating motor speeds up, the shaft Y rotates more rapidlyand by centrifugal force theweights p overcome the tension in the spring g, causing the weights to fly out- .Wardly disengaging the disc f, whereupon the link h, being released. permits the spider R to disengage thevalve K permitting them to function normally. Whlle operating at high speed the disc f is free and there are no engaging surfaces to wear out. The outward movement of the weights p is limited by the circular flange a; surrounding the weights and formed integrally with the cover 8. I

The compressor operating motor (not shown) may be connected to the crank shaft C 'at the fly wheel y located on the crank shaftic exterior to the casing A.

When operating normally the spiders R,

are held out of contact with the valves J by coil springs 2 within the spiders R and ressing against the valve seats H. .The unoading mechanism above describedoperates against the tension of these springs to hold the valves J off their seats H.

I claim:

1. In combination with a compressor and by cenlevers associated with said disc for opening 1 said compressor valves. 2. In combination with a compressor and its valves, a shaft adapted to be rotated by the compressor, a disc journaled concentrically with the shaft, a plurality of weights rotated by said shaft surrounding said disc, said weights being spring pressed to engage said disc frictionally at slow speeds of the shaft and disengaged by centrifugal' force from said disc at high speeds of the shaft, and a system of links and levers associated with said disc for opening said compressor valves.

3. In combination with a compressor and its valves, a shaft adapted to be rotated by a compressor, a disc journaled concentrical- 1y with the shaft, a cover rigidly attached to the shaft, weights within said cover at- I tached thereto and spring pressed to engage said disc at slow speeds of the shaft and adapted to be disengaged by centrifugal force from said disc at high speeds, a link attached to said disc, a lay shaft adjacent the valves to be operated by said link, and

means associated with said lay shaft to open said compressor valves.

In testimony whereof I have signed this specification.

RAYMOND C. MOALLISTER.

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