US222950A - Improvement in pneumatic motors - Google Patents

Description

GEORGE H. REYNOLDS,

UNITED STATES PATENT OFFICE.

OF NEVVYORK, N. Y., AND HERMAN HAUPT, OF

PHILADELPHIA, PA.

IMPROVEMENT IN PNEUMATIC MOTORS.

Specification forming part of Letters Patent No. 922,950, dated December 23,1879; application filed March 26, 1879.

To all whom at may concern- Be it known that we, GEORGE H. REY- NOLDS, of the city and State of New York, and HERMAN HAUPT, of the city andcounty of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Pneumatic Motors, of which the following is a full, clear, and exact description, reference being had to the accom panyingdrawings, forming part of the same. 1

This invention relates to the use of compressed air as a motive agent, and although applicable to motors for various purposes is more especially designed to be used for driving locomotive enginesor carriages on tramways and other roads.

In the use of compressed air as a motive power for locomotive purposes it is desirable, on account of the limit of reservoir-capacity, to use the air at the highest practicable initial pressure.

The use of the air at such high pressure has been attended with great difiiculties, one of which is the liability to congelation of moistwe on the surfaces of the engine, resulting from the low temperature consequent upon the high rate of expansion.

Another difliculty results from the excessive pressure upon the valves, which renders them liable to cut; and a further one is that, owing to the necessity of cutting 0E very early in the stroke of the piston, the full initial pressure is exerted on the engine-crank only while it is in its least efl'ective position-via, when it is at or very near its dead-center.

The first-mentioned difliculty hasbeen partially overcome by heating the air before introducing it to the enginecylinder; but when this has been. done an engine of the sim le type has always been used.

The object of our invention is to further overcome the several difficulties above mentioned; and to this end we employ an engine of the compound type, andthough we may or may not heat the air before its introduction to the engine we always heat it after its exhaust from the high-pressure cylinder and before its induction to the low pressure cylinder; and to this end our invention consists in the combination, with a compound engine for the use of compressed air for motive power, of a heater placed between itshigh and low pressure cylinders and containing heated water or other liquid, through or in contact with which the air passes between its eduction from the one cylinder and its induction into the other.

In the application of the invention to 1000- motives or locomotive-cars this heater may occupy any convenient position on or under the locomotive or car, and may be filled with hot water, or such other hot liquid as it may be desirable to use, from a "stationary boiler or heater suitably placedat the terminus or other 0011- venient place near the track".

In other applications of our invention the said heater may be supplied with heated water or other liquid in .any convenient manner.

Referring to the accompanying drawings, Figure 1 represents a sectional plan of a compressed-air locomotive-engine in part having the invention applied, and Fig. 2 ,a transverse section thereof through the working cylinders of the engine.

A represents the framing of the locomotive,

which may be. of any suitable construction, and

B B its running and drivingwheels. G is the smaller cylinder, and D the larger cylinder, of a compound engine used to propel the locomotive or carriage, and the pistons a b of which are respectively connected by suitable rods with cranks c d on the driving-shaft E.

G G are compressed-air reservoirs,of which there-may be any suitable number carried by the locomotive, and which may be-charged or recharged with compressed air under a high pressure at the termini or any intermediate places on the road. The air from these reservoirs is first conducted by pipesle to a heater, H, which may be termed a ihighpressure heater, and from thence, by a pipe, f, to the highpressure or smaller cylinder 0 of the compound engine, subject,- of course, to the control of a suitable valve applied to said cylinder. After the air has performed its duty in the hi gh-pressure cylinder 0 it is exhausted therefrom and passed, by a pipe, 9, to a heater, H, which may be termed the low-pressure heater, and from whence it is passed. bv a pipe, h, to the valve-box of" the larger or low pressure cylinder I), there to do its duty by expansion, and ultimately'escape to the atmosphere by a pipe, 1'.

The low-pressure heater-H, which is the prrncipaltfcature of the combination which constitutes our invention, may be of any suitablehonstruction capable of .sustalning the pressure due to the heat of the water or other liquid with which it is to be charged for the j cylinder D, and should have suitable provision afforded by its form or construction for the air introduced into it from the one cylinder to pass through or in extensive surface-contact with the, hot water or other liquid contained therein before its advent to the low-pressure cylinder, The higlrpressure heater may he of similar construction.

The air in passing through or in contact with the hot liquid in the heater H, may have its expansive force very con siderablyincreased by the heat which it takes up from the liquid, while there is a very gradual reduction of the temperature. This is'owing to the difference between the specific-heat'of the air and of the liquid. When the liquid usediu the heater H is water a very considerable increment of. ex pansive force is obtained from the vapor which is' taken up by and mixedwvit'h the air.

By means of the compound engine air at a very 'igh pressure in the. reservoir ma be used without employing a reducer, and Without much or any cutting of the valves, and without cutting ofi dis-advantageously early in the stroke, by reason of the piston of the highpressure cylinder being exposed on its exhaust side to the working pressure of theair in the larger or low-pressure cylinder.

4 The number of heaters interposed between the cylinders may be varied, and, if' desired, the air from the reservoirs may be passed direct from the latter to the first, or high-pressure; cylinder-without circulating it through a heater; but'it'is preferred to use heaters for warming, expanding, and keeping up the pressore of the air in the transmission of it to the high' pressure cylinder as well-as to'the' lowpressure cylinder," thus obtaining the advantage to be derived from heating of the air in both cylinders.

We are aware that heaters have been employed in compound steam-enginesi'or heating the steam between the high and low pressure cylinders; butwemake no claim for steamengines. 7

We are also aware that compressed air has been heated beforeits introduction to an englue, and we therefore do not claim anything relating to such heating of the air but What we claim as our invention is-,

The combination, with a compound engine for the use of compressed air as a motive power, of a heater, arranged-between the high and low pressure cylinders of such engine, and

"containing heated water or other liquid,

through or in direct contact with whichlth'e air passeson its way from the high-pressure to the low-pressure cylinder, substantially as and for the purpose herein described.

eno. H. REYNOLDS; H. HAUPT.

Witnesses:

HENRY T. BRo'WNE,

FRED. HAYNES.

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