US263514A - Vacuum exhaust-pipe - Google Patents

Description

I (No Model.)

D. HARRIGAN.

VACUUM EXHAUST PIPE.

No. 263,514. Patented Aug. 29, 188-2.

. Invert/ i'an M I kgfim Nrrac STATES PATENT OFFICE.

DENNIS HARRIGAN, OF SOMERVILLE, MASSACHUSETTS.

VACUUM EXHAUST-Pl PE.

SPECIFICATION forming part of Letters Patent No. 263,514, dated August 29, 1882.

Application filed July 13, 1882.

the same, reference being had to the annexed drawings, making a part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 ot' the drawings is a perspective view of the complete device with the tips attached. Fig. 2 is a top View with the tips removed. Fig. 3 is a top view of the tips. Fig.

4 is a section through Fig. 2 from A to B. Fig. 5 is a section through Fig. 3fro1nO to D. Fig. 6 isa bottom view of the complete exhaust, and Fig. 7 is a bottom view of the tips.

The invention is intended not only to diminish what is called the back-pressure upon the piston, which naturally results from the contraction of the nozzle of the exhaust-pipe, but to utilize such back-pressure by creating a vacuum in front of the other advancing piston. The arrangement of parts is such that this action alternates from one piston to the other, according to which of the two exhaustpipes is in use for the escape of exhaust-steam.

The device hereinafter described is analogous to one for which Letters Patent No. 240,249, dated April 19, 1881 have been granted to me, but improved and rendered more effective by a rearrangementand modification ofits parts. a

The exhaust-pipes-one for each cylinder-- are arranged near each other, as in the ordinary method, and united together in such way, by casting all but thetips in onepiece, so as to prevent any connection between the steam-spaces e andf upon their opposite sides.

a b are the openings in the tips for the passage of the exhaust-steam after leaving the main exhaust.

c d are the openings of the main exhaustpipes and represent the main pipes.

g h are annular chambers surrounding the main exhaust-pipes, each having a suitable opening into one of the steainspaces e f.

G is a plate forming part of the casting, ex-

(No model.)

tending around the outsides of the exhaustpipes, and sufficiently largeto admit the inclosing of a space upon its surface outside the annular chambers to makethesteam spacesef.

Upon thejinside of the exhaust-pipe 0, near the point where the exhaust-steam enters, a port, k, of suitable dimensions, is cut through its cylindrical wall for the passage of steam into the steam-space e, and a similar port, n, in the wall of the exhaust-pipe (1, allows the passage of exhaust-steam into the steam-space f. At the opposite end of this steam-space f an opening connects with the annular chamber g, and a similar opening from the steam-space e connects with the annular chamber h.

The tips are made in a separate casting, to be attached to the main exhaust by screws at suitable points, so as to be removable at pleasure, and the openings a bin the tips aresomewhat reduced in size from those in the main exhaust. The tips may bediscarded altogether by providing suitable coverings t'orthestealnspaces ef, so as to prevent the escape of steam except through theannularchambers; but the detachable tips arein many respects preferable.

When in use the exhaust operates as follows: if the steam is passing from the cylinder upon that side through the exhaust-pipe c, the contracting sides of that exhaust-pipe retard its escape, and a portion passes through the port k and steam-space 0 into the annular chamber h, and thence outward through the tip I). This escaping steam, rushing through the tip bwhen the opposite side is exhausting, serves to create a vacuum in the main pipe (I, and thus assist in removing the obstruction of atmospheric pressure or dead steam from the path of the advancing piston. Similar action takes place when the other cylinder is exhausting, but upon the opposite exhaust-pipe, and thus the action alternates from one pipe to the other in perfect regularity, according to the strokes of the pistons on either side.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. Avacuum-exhaustconsistingof twopipes provided with steam-spaces, and annularchambers and suitable ports, and connecting-passages between said spaces and chambers for creatingavacuum in the pipe not then exhaust- In testimony that I claim the above I have hereunto subscribed my name in the presence 10 of two witnesses.

ing, constructed and arranged substantially as I shown and described. I 2. In combination withthe plateG,thepipes c (1, surrounded by the annular chambers g h, and the steam-spaces cf, provided with suitable ports and connectirig-passages, with the tips (6 1), arranged and constructed substantially as shown, and for the purpose set forth.

DENNIS HARRIGAN.

\Vitnesses:

3ERKLEY POWELL, EDGAR H. WooDMAN.

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