US722416A - Vacuum-pump. - Google Patents

Description

PATBNTED MAR. l0, 1903.

J. STUMPF. VACUUM PUMP.

APPLIOATION FILED ooms. 1901.

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PATBNTUD MAR. 1o, 1903.

J. sTUMPP. VACUUM PUMP.

APPLIOATION FILED OUT. 8, 1901.

2 SHEETS-SHEET 2 I0 MODEL.

UNITED STATES PATENT EEICE.

JOHN STUMPF, OF BERLIN, GERMANY.

SPECIFICATION forming part of Letters Patent No. 722,416, dated March 10, 1903.

y Application filed October 8, 1901.

To a/ZZ whom. it ntcty concern:

Be it known that I, JOHN STUHPF, a subject of the King of Prussia, German Emperor, re-

siding at Berlin, Kingdom of Irussia, German Empire, have invented a new and useful Improvement in Vacuum-Pumps, of which the following is a specification. 1

My invention relates to an improvement in vacuum-pumps for use in'withdrawingair or gas, as from a chamber wherein it is desired to create or maintain a partial vacuum.

My object is to provide a-vsteam-actuated double-acting vacuum-pump of simple and improved construction and having relatively great working capacity.

In the drawings, Figure l is -a longitudinal section of a double-acting vacuum-pump of my improved construction; Fig. 2, a broken and enlarged section through one ofthe steam slide-valves, showing the valve in exhaust position; Fig. 3, a similar view of the same valve in the position of opening the steam-inlet port, and Fig. 4a broken and enlarged section showing one of the air or gasv outlet valves of the pump-cylinder.

A is a shell or casing, which maybe con-` structed in sections, as shown,for convenience in placing the parts inposition. 'Ihe shell A incloses a pump-cylinder B and steam-cyl-A inders C D. Surrounding the cylinder B is a cored chamberfE, having an inlet E,'and communicating with the interior'of the ,cyl-A inder B through an annular series of openings a., located exactly midway between the cylinder-heads b c. Working in the cylinder B is a hollow piston F, and formed integral therewith are hollow pistons F F2, working in the cylinders C D. OnY the outer ends of the cylinders O D are valve-chests C D', respectively, each provided centrally with a cylindrical valve-chamber d, communicating through an annular series of ports e with an annular steam-inlet chamber e', receiving steam through the pipe e2, and provided also with an annular series of exhaust-ports f, communicating with an annular exhaustchamber f', having an exhaust-pipe f2.' In the chambers d are cylindrical slide-valves G. Each valve G is formed with a central enlarged part g, working in the chamber d, and reduced end portions g g2, working in guide-openings at opposite ends of the chamserii No. 78,006. (No man.)

ber d. The valve G is hollow and is provided through its enlarged part g with a steam inlet and exhaust opening g3. The valves G are on the ends of the valve-stems G', having heads h attheir free ends and shoulders 7i adjacent to the slide-valves. In the parts F F2 of the piston device are guidetubes t', provided in their ends with guideopenings z'" for the stems G. In the guidest around the openings t are annular shoulders 712 to engage the heads 7L, as hereinafter described. The hollow slide-valves contain annular chambers 7c in open communication with the cylinders C D and with the steamports g3. H H are outwardly-opening eX- haust-valves in the cylinder-heads b c. The valves Hare held to their seats by springs Z.

The piston F is of a length slightly less than one-half the length of the chamber ot' the cylinder B, whereby when moved to either cylinder-head b c it will just uncover the ports a. The pistons F F2 are preferably of about the same length as the chambers of the cylinders C D, though they may be somewhat shorter.

In practice the inlet-opening E communicates with the chamber from which air or gas Ais to be withdrawn, and the valves H open to the surrounding atmosphere. Any air or gas in the chamber'or the like to be exhausted will expand through the inlet E to the annularchamber E. In the movement or' the piston F to the position shown it has created a Vvacuum in that part of the cylinder B to the left of the ports a, so that when the piston has reached the position shown any air in the chamber E will expand into the cylinder. In the nal movement of the piston F to the cylinder-head c air in that half of the cylinder has been discharged through .the respective valve H, and the engagement IOO this movement of the piston a vacuum is created between it and the cylinder-head c, whereby when the ports ct are uncovered the air or gas to be withdrawn will expand into the cylinder. In the final movement of the piston in either direction it engages the head h of the stem of one valve to open the steaminlet and engages the stop h.' of the stem of the other valve to close the steam-inlet port and open the steam-exhaust port. Thus the actions are repeated. In spite of the difference in area between the working faces of the piston F and the pistons F' F2 as the resistance t0 movement is never greater than atmospheric pressure' the steam-pressure need not be high. To give the pump the greatest capacity, there should be no clearance between the piston F and adjacent cylinder-head when the piston reaches the end of its stroke. The pump may be operated at any desired speed andl may be caused to withdraw air or gas very rapidly.

While I prefer to constructmy improvements throughout substantially as shown and described, they may be variously modifiedL in the matter of details of construction without departing from my invention as defined by the claims.

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

1. In a vacuum-pump, the combination of a pump-cylinder provided in its ends with valved outlet-ports and midway between its ends with an inlet-port, a pump-piston movable in the cylinder to the ends thereof without clearance and adapted at the end of its stroke in either direction to uncover the inlet-port, a steam-cylinder at each end of and concentric with the pump-cylinder, steampistons connected with the pump-piston and movable in the steam-cylinders, and steamvalves at the steam-cylinders movable to admit and exhaust the steam alternately at the steam-cylinders, said valves being controlled by the movement of the pistons.

2. In a vacuum-pump, the combination of a pump-cylinder provided in its ends with valved outlet-ports and midway between its ends with an annular series of openings forming the inlet-port, an inlet-chamber communicating with the series of openings, a pumppiston movable in the cylinder to the ends thereof without clearance and adapted at the end of its stroke in either direction to uncover the series of openings, a steam-cylinder at each end of and concentric with the pumpcylinder, steam-pistons connected with the pump-piston and movable in the steam-cylinders, a valve-chest at the end of each steamcylinder, a slide-valve in each chest in axial alinement with the pistons, said valves being moved by movement of the pistons.

JOHN STUMPF.

In preseneeof- HENRY HAsPER, 'WOLDEMAR HAUPT.

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