US28229A - Improvement in air-pumps for steam-engines - Google Patents

Description

UNITED STATES VPATENT OFFICE.

DANIEL A. IVOODBURY, OF ROCHESTER, NEIV YORK.

IMPROVEMENTIN AIR-PUMPS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 28,229, dated May S, 1860.

To a/ZZ wton it may concern:

Be it known that I, DANIEL A. WOODBUEY, of Rochester, in the county of Monroe and State of New York, have invented anew and useful Improvement in Air-Pumps for Condensing Steam-Engines; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a longitudinal section of an airpump with my improvement. Eig. 2 exhibits a modification of the piston.

Similar letters of reference indicate corresponding parts in the two iigures.

The object of my invention is to enable the air-pump of acondensing-engine to be worked at as high a rate of speed as it is desirable to work the engine without producing the concussions which attend the working of the airpumps in common use for such engines, and which are more or less violent, according to the speed of the engine; and to this end my invention consists in the employment in such an air-pump of a piston or plunger elongated at one or both ends, substantially as hereinafter described, whereby both water and air are caused to be discharged simultaneously from the commencement of the stroke and sufficient air is retained to serve as a cushion to the piston to the end of the stroke.

My invention also consists in a certain arrangement of the passages and valves whereby the simultaneous discharge of water and air is provided for.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A is the cylinder or barrel of the pump, having its head B and bottom C made of conical form.

D is the piston, made either solid or hollow, but without apassage through it, fitted to the cylinder A with packing c in the usual manner, and elongated at both ends, as shown at d CZ, in a conical form corresponding with the form of the top and bottom of the cylinder. This elongation of the piston should preferably be such that its lower end will never -leave the water in the cylinder.

E is a valve-chest secured to or cast on one side of the cylinder and extending nearly the whole length thereof, divided into three valvechambers F G II, each fitted with double valves of vulcanized india-rubber. Thevalveports b b of the lower chamber F communicate with the receiving-chamber I, to which the receiving-pipe- K from the condenser is,

has communication by its valve-portsf f with a passage g, which forms a communication between the middle chamber G and the upper part of the cylinder. The passages c and g communicate with the cylinder at the ends of its parallel bore, in which the piston works tightly.

In the operation of this pump the bottom of f the piston enters the water so gradually that it produces no concussion, even if it be not so much elongated that its lower extremity will never entirely leave the water, and the water rnd air are discharged simultaneously, and a portion of the air is retained in the cylinder throughout both the up and down strokes, except just at the close of the latter, when it is expelled by the piston passing the upper edge c of the opening c; but as the descent of the piston has then almost ceased andthe passage of the air ceases very gradually no concussion is produced by the continued descent, and hence the piston is practically perfectly cushioned with air, and yet all the airis expelled from the lower part of the pump-cylinder. A small quantity of air is, however, always retained in the upperpart of the cylinder, owing to the clearance necessarily allowed between the piston and the head B; but this is not essential, as the upper part of the pump is only auxiliary to the lower and might be dispensed with; but the pump works better with it.

By the simultaneous discharge of the water and air as affected by the elongation ot' the piston a great advantage is obtained over the discharge of the air first and the water afterward in the relief aiforded to the valves by the more gradual discharge of the water consequent upon its discharge through the whole stroke. In the downward stroke of the piston,with the arrangement of valves receiving-chamber I, valve-ports b b', cham- Y ber F, and passage c, and leave the upper part of the cylinder by the passage g, ports f f',

chamber H, and pipe J. Instead of elongating the piston in the conical form represented in Fig. l, it may be elongated in the cylindrical form shown at i in Fig. 2; but the conical form is preferable, as it effects a more gradual discharge of the air.

By this improvement I have succeeded in working a condensing-engine at one hundred and fifty strokes per minute without any perceptible concussion or other objectionable effects, the air-pump working at the same velocity, while with the ordinarily-constructed air-pumps a concussion is very perceptible in engines workingas slowly as twenty strokes per minute. This capability of working at a high Velocity makes the invention of immense advantage for propeller and mill engines.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. The elongation of the piston of the airpump at one or both ends, substantially as herein specified, tov produce the results herein set forth.

2. The arrangement of `the 4three valve-A chambers, the valves, valve-ports, and passages, substantially as and for the purpose herein set forth. l

D. A. WOODBURY. Witnesses:

Y Y. JAMES HOLZLAND, MARTIN BRIGGs.

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