US428120A - Steam air-pump - Google Patents

Description

No Model.)

A. P. MASSBY.

STEAM AIR PUMP. No. 428,120. Patented May 20, 1890.

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UNITED STATES PATENT OFFICE.

ALBERT MASSEY, OF VATERTOIVN, NEV YORK.

ySTEAM AIR-PUM P.

SPECIFICATION forming part of Letters Patent No. 428,120, dated May 20, 1890.

Application filed February 14, 1890. Serial No. 340,406. (No model.)

To a/ZZ whom, t may concern.-

Be it known that I, ALBERT P. MASSEY, a citizen of the United States, residing in the city of Watertown, in the county of Jefferson and State of New York, haveinvented certain new and useful Improvements in Steam Air- Pumps, of which the following, taken in connection with'the accompanying drawings, is a specification.

The object of my invention is to produce a duplex steam air-pump that will work with greater economy of steam than those at present in use. I compress the contents of two air-cylinders of unequal size into the smaller cylinder by means of one steam-piston, and then compress the contents of the smaller cylinder still further by means of another steampiston. l

Figure 1 is a sectional View of the complete apparatus. Fig. 2 is a view of the upper head of the steam-cylinders. Fig. 8 is a view of the upper head of the air-cylinders.

The steam-valves are actuated by what is known as the duplex system.

In the drawings, 1 and 2 are steam-cylinders.

3 and 4 are air-cylinders.

5 and 6 are valves for controlling the action of the steam-pistons.

7 and 8 are valve-stems.

9 and 10 are valves admitting air alternately to the larger air-cylinder.

11 and 12 are valves between the two aircylinders.

13 and 14 are valves between the smaller air-cylinder and the reservoir connectedvto pump at 15.

Steam is -admitted to the steam-chests 16 and 17 through port 18, and is exhausted through port 19.

The valve-stems 7 and S are actuated by the plates 20, which are secured to the pistons and come incontact with the tappets on the valve-stem in a manner described in Patent No, 115,668, issued to George `Westing house, .lune 6, 1871.

The cycle of operations is as follows: In the position shown the air-piston in cylinder4 has completed its downward stroke and compressed its contents through valve 12 into cylinder The plate 2O on steam-piston 21 has moved valve 6 to its lowest position. This admits steam through port 23 to upper side of piston 22, and will cause the piston to descend and expel the partially-compressed air in cylinder 3 through valve 14 and passage 15 into the reservoir. Meanwhile the cylinder 4 has become filled above the piston with air at atmospheric pressure through valve 9, and the cylinder 3 will be filled with air at atmospheric pressure through valves 9 and 11, both of which open inward and are seated by gravity. Vhen piston 22 reaches the end of its downward stroke, the plate 2O strikes the tappet on valve-stem 7 and moves valve 5 to its lowest position, thus uncovering port 24 and admitting steam through port 24 25 26 to the lower side of piston 21, thus causing piston 21 to rise and compress the air which is in cylinder 4 through valve 11 into upper part of cylinder 3. J ust as piston 21 completes its stroke its plate 2O strikes the tappet on valve-stein 8 and moves -valve 6 to its highest position, uncovering port 27` and admitting steam through 27 2S 29 to the lower side of piston 22, causing the piston to rise and expel the partially-compressed air in cylinder 3 through valve 13 into passage 15,and thence into the reservoir. Vhile the pistons were compressing the air above them into the reservoir, the air-cylinder below the pistons would fill with air at atmospheric pressure through valves 10 and 12,-ready for another cycle of operation.

' In a single-cylinder air-pump the resistance in the air-cylinder varies each stroke from naught to the extreme pressure in the reservoir-say one hundred. pounds. The steampiston must therefore have sufiicient area to produce this final pressure and expel the air into the reservoir. In other words, the steampiston must be as large as the air-piston in ordinary locomotive practice, where the usual pressure in the boiler is from one hundred and twenty pounds upward.

In my invention the extreme resistance to the leading piston 21 is to compress the contents of the two air-cylinders into one. The arca of the leading air-cylinder 4 can therefore be as much greater than the steamcylinder as the steam-pressure exceeds the final pressure in the air-cylinder with due allowance for friction, &c. In practice the area of cylinder 4 may be twice that of cyl- IOO inder 2. The other cylinders 1 and 3 are the same size as 2. It follows, therefore1 that the linal resistance in cylinder 1 would be the pressure resul ting from compressing three volumes of air into one volume or thirty pounds above atmospheric pressure. A steamcylinder of one-third the area would therefore be ample with steam at one hundred and twenty pounds; but the ratio of two to one serves for illustration. Ihenthe Cylinder 3 is filled with air at thirty pounds pressure, the resistance each stroke will vary from thirty pounds to one hundred pounds, and a steam-piston of the same area will be required to expel the air into vthe reservoir. Thus it may he seen that two cylinders full or Volumes of steam at boiler-pressure will deliver three volumes of air into the reservoir, whereas in a single-cylinder air-pump two Volumes of steam at boiler-pressure would deliverbut two volumes of air into the reservoir.

As I claim novel features in both the cngine and the pump, I have made a separate application for those pertaining' to the pump, which was filed September 21, 1889, Serial No. 324,619.

, lVhat I claim as new, and desire to secure by Letters Patent, is-

In a duplex steam air-pump, the cylinders 1 and i and pistons 22 and 21, each connected to a piston in an air-cylimler, in combination with Valve-stems 7 and S, tappets 20, and valves and G, with ports communicating with each end of the opposite cylinder, substantially as set forth.

In testimony whereof I have signed my name lo this specification, in the presence of two subscribing witnesses,on this 10th day of February, A. I). 1890.

ALBERT I. MASSEY.

Witnesses:

HENRY W. BOYER, MICHAEL J. MoRKIN.

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