US2208273A

US2208273A - Pump

Info

Publication number: US2208273A
Application number: US96234A
Authority: US
Inventors: Karasick Samuel
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-08-15
Filing date: 1936-08-15
Publication date: 1940-07-16
Anticipated expiration: 1957-07-16

Description

July 16, 1940.

s. KARASICVK Filed Aug. 15, 1936 8 Sheets-Sheet 1 #2 729? 'ZZZIUQ 1N VE NTOR (2f/K. BY A ymw 4 1:5 ATTORNEY.

S. KARASICK July 16, 1940.

PUM P Filed Aug. 15, 1936 8 Sheets -Sheet 2 INVENTOR. 5amuel I K A). WW

%;5 ATTORNEY.

S, KARASICK PUMP Jdy 16, 194o.- I 2,208,273

Filed Aug. 15, '1936 INVENTOR.

' ".1 flagezz md %z's ATTORNEY.-

Y. j' July 16, 1940 S -K R MK 2,208,273

PUMP

Filed Aug. 15, 1936 8 Sheets-Sheet 4 3 Q O/////, 4 x 271 .90 7/; m 2

. INVENTOR. fia'maelfi raswk' /4ls ATTORNEY.

- 1; 16, 1940. s. KARASICK 2,208,273

. PUMP Filed Aug. 15, 19156 8 Sheets-Sheet 5 8 Shegts-Sheet 6 M 16, 1 940. s. KARA SICK PUMP Filed Aug. 15, 1956 INVENTOR.

4155 ATTORNEY.

smuezzizrma 'AMW July 16, 1940. 5 R s c 2,208,273 gum? Filed Aug; 15, 19256 8 Sheets-Sheet 7 INV ENTOR 5m ZZ a ras a:

BY AW Lis ATTORNEY.

k July 16, 1940. s, KARASICK 2,208,273

PUMP

Filed Au 15. .1936 s Sheets-Shet s INVENTOR; 5mm Zia r05 r ATTORNEY.

Patented July 16, 1940 PUMP Samuel Karasick, Mount Vernon, N. Y.

Application August 15,

1936, Serial No. 96,234

29 Claims. (01. 230-147) The present invention relates to rotary pumps, such asicomprcssors and so called high vacuum pumps.

Prior pumps of this type have not possessed the degree of efficiency desired where large numbers of vessels 01' envelopes were to be evacuated rapidly, such as in the manufacture of incandescent electric lamps or so-called vacuum tubes. Pumps of this type have also been open'to the objection that they became flooded with oil in the event that the attendant failed to shut off the oil supply when the pump was stopped. Such flooding of the pump system with oil has necessitated the disassembling of the pump so that the various. parts thereof could be freed from surplus oil, with the resultant delay in production and the high cost of the cleaning operation.

The main feature of the present invention relates to the provision of an eificient rotary pump which has long life, which is of relatively simple design, and which can be manufactured at relatively low cost.

Another feature of the invention relates to a pump in which the stream of gas through the pump passages, does not have to make any sharp turns and in which there are substantially no pockets or voids tending to set up friction and back pressure.

A further feature of the invention relates to a rotary pump system in which the parts thereof and the oil supply thereto are so arranged that the system will not become flooded with oil even though the attendant fails to shut oh the oil supply when the pump is stopped.

An additional feature of the invention relates to a rotary pump unit in which means associated with the rotary piston thereof forces the air or gas drawn from the vessel to be evacuated, into the piston chamber wherein the piston in the course of its rotation, compresses this air or gas and forces it out of the pump.

Still another feature of the invention relates to the provision of a multi-unit pump with its units arranged to operate in tandem at high efficiency;

Other features and advantages of the invention will appear from the detailed description and claims when taken with the drawings in which: Fig. 1 is a front elevational view of a multi-unit pump constructed in accordance with the present invention: Fig. 2 is a top plan view of the pump shown in Fig. 1; Fig. 3 is an enlarged longitudinal sectional view of the pump taken on line 3- --3 in Fig. 2; Fig. 4 is an enlarged sectional view of the preliminary pump taken on line i -4 in Fig. 1;

Figs. 5 and 6 are enlarged transverse sectional views of the pump taken respectively on the lines 5-5 and 6--6 in Fig. 1; Fig. 'lis a cross sectional view of the pump taken on line 'l-l in Fig. 2 particularly illustrating the relation of to the rocking member; Fig. 8 illustrates a sectional view through the pump on thalipe 8-8 of Fig. 1 and also illustrates a conventional oil supply tank; Fig. 9 is a side elevation of the pistons and the rocker members connected thereto show- 10 ing the relation of these parts; Fig. 10 is a sectional view taken on the line Ill-4U of Fig. 1, with the casing omitted, particularly disclosing the arrangement for lubricating the bearings as well as the piston and rotary element driver of 1 the pumps; Fig. 11 is a detailed sectional view taken on the line lI-Jl of Fig. 10 illustrating the lubricating groove between the piston and the driver; Fig. 12 is a fragmentary sectional view taken on the line i2-|2 of Fig. 1 disclosing the 20 contour of the inner wall of the sub-chamber and the adjacent surface of the rocker member whereby a minimum amount of gas or air remains in the subwhamber at the end of each cycle; and.

Fig. 13 is a horizontal section through the sub- 25 chamber taken on the line |3--l3 of Fig. 12.

For a clearer understanding of the invention.

reference is made especially to Figs. 1, 2 and 3, wherein there is illustrated a compound pump PF, including a preliminary pump unit P of large 30 capacity and a final pump unit F oi smaller ca pacity, connected in tandem. Thus the capacity of the pump units increases from the final unit to the preliminary unit. It will be appreciated,

however, that the invention is not limited to the 35 arrangement herein disclosed but also includes a pump comprising three or more units connected in tandem where higher capacity per unit of time is required, or the pump may comprise but a single unit where a lower capacity per unit of time 40 will satisfy the requirements.

The preliminary pump P includes a casing l0 open at its ends and having its internal surfaces properly shaped and carefully machined to provide a piston chamber and a sub-chamber to be 45 described. The final pump a casing H of similar construction, also open at its ends. The remote endsof the casings ID and. H are respectively closed by an end plate 12 and by an end plate posed end to end in displacedangular relation of approximately twenty-six degrees, are closed. by a common connector plate M having openings or passageways cast therein and extending along the principal axis of the plate.

F likewise comprises the inlet 5 l3. These casings, which are d'is- These passage ways permit cooling air to flow therethrough by convection to prevent; overheating of the plate. It will be appreciated that if such cooling of the plate were not provided, it would become overheated to the point where the oil films on its opposite surfaces would be dissipated, with a consequent decrease in the emciency of the pump units. The connector plate is provided therein with a conduit I9 communicating with the interior of the casings I0 and H and also communicating with the inlet pipe 24, to which a vessel may be attached for effecting the preliminary or rough evacuation thereof. The end plate I3 of the final pump has an inlet therein communicating with the pipe 26, to which a vessel that has been roughly evacuated, can be connected to effect the final evacuation thereof. The

outlet of the pump is in the sub-chamber of the preliminary pump unit P, which outlet communicates through the pipe 21 with an oil tank 3I of conventional design, where the oil vapors condense and the air or gas expelled from the pump escapes through the exhaust 19 to the atmosphere. It will be understood that in practice lamp bulbs or vacuum tubes are exhausted while moving on a conveyor, the exhaust being effected through a valve connected to a rough or preliminary manifold andv a final manifold. The rough manifold is connected to the inlet of the preliminary pump and the final manifold is connected to the inlet of the final pump. The operation of evacuation is usually progressive and the bulbs are given what-is termed a rough or preliminary evacuation to remove the greater portion of the gas therein and are then subjected to what is termed the final evacuation to exhaust the bulbs completely.

The internal construction of the final pump unit F and the operating parts therein are disclosed especially in Figs. 3, 4, 5, 6 and '7. Since the construction of the preliminary pump unit P and that of the final pump unit F are substantially the same, it will be sufficient to describe the construction of the final pump only. Identical parts ofthe preliminary pump will be identified by the same reference characters as applied to identical parts of the final pump, except that the corresponding characters designating parts of the preliminary pump will be primed.

The interior of the casing I I is provided, with a compression or piston chamber 5| of cylindrical form, having its ends closed by the end plates I3 and I4, the walls of the chamber being accurately finished. The casing II also has an extension 52, the accurately machined internal surfaces of which provide a sub-chamber 43 defined by the arcuate wall 44 and the flattened wall 45, as well as by the end plates I3 and It.

A cylindrical piston 58 of smaller diameter than the diameter of the piston chamber but of such length that it is adapted to move in oilsealed engagement with the plates I3 and It of the chamber, operates in the casing. Thepiston, which is hollow, rotates on the rotary driver element 60 eccentrically attached to the shaft 2|. This shaft, as best illustrated in Fig. 3, extends through both casings and is journaled in the bearing 22 in the end plate I2 as well as in the bearing I8 in the connector plate It and the bearing 23 in the end plate I3. Thus this shaft is common to both pump units and may be driven from any source of power such as an electric mo- .tor, not shown. The pistons 58, and 58' are displaced 180 degrees about the shaft 2I (Fig. 6) to mechanically balance the moving parts of the pump units. By this construction the final pump unit is discharging gas while the preliminary pump unitis removing the discharged gas. It will be appreciated that the dimensions of each piston and its rotary course within its piston chamber are such that successive portions of the cylindrical surface of the piston progressively engage the entire cylindrical inner surface of the piston chamber, so that gas is drawn into the piston chamber at the rear of the piston and gas in advance of the piston is forced out of the piston chamber, as the piston advances.

The sub-chamber 43, which opens into the piston chamber 4| in the absence of the operating parts of the pump, is separated from the piston chamber by a rocker member 41, having an edge 48 pivotally mounted in a slot 49 in the wall portion of the casing. The rocker member is of such length that it is freely movable with its ends in oil-sealed relation with the end plate I3 and the connector plate I4. This rocker member is formed with an overhanging sweep 50 defining a pocket or passage 5i which communicates with the inlet 25 in the end plate I3.

The upper surface of the pocket 5| is inclined downwardly and its left end, as illustrated in Fig. 3, is closed by the portion 55 illustrated in dotted lines, so that gas entering the pocket 5| can only pass into the compression chamber and will not escape directly to the outlet portion of the subchamber. The outer surface 52 of the sweep 5D is machined to arcuate form so that it is adapted to slidably engage the arcuate surface 44 of the casing, in oil-sealed relation therewith, as shown especially in Fig. 6. The wall of the casing may be provided with an insert 53 of hardened metal to constitute a surface of the subchamber which can be accurately machined to provide a gas-tight fit with the surface 52 of the sweep.

The rocker member is pivotally connected to the piston 58 along one edge of the passage 5|, by means of a pin'tle 56 so that as the piston follows its planetary course within the piston chamber, the rocker member will rock the sweep 50 up and down in the sub-chamber. It will be noted that the under surface of the rocker member 41 is machined to provide a curved surface BI having the same-curvature as the periphery of the pistact will exist between the surface SI of the rocker member and a substantial portion of the surface-of the piston. Thus all gas which has been compressed in advance of the piston will be expelled through the openings 68, and. through the valve mechanism in the rocker member (Fig. 6).

The valve mechanism, which may be of any conventional form, is herein illustrated (Fig. 5) as including packing. 69 superimposed over the openings 68 and a valve plate 1| held in its closed position against the packing by adjustable springs 72. These springs are positioned Within threaded caps 73 which enclose the valve guides 62 of the valve plate and which extend through a cover plate M. Suitable lock nuts are provided to hold the caps 13 in their adjusted position. Although a plurality of holes 68 for the escape of gas through the rocker member is herein illustrated, a single long slot can be substituted therefor.

It will be understood that oil must not only be applied to the bearings for proper lubrication but must also be uniformly supplied to the surpipe branches 32 a 92 at the other end (Figs. 5, 6 and 7) so that when faces of the moving parts to provide an oil seal so the gas will not be by-passed or leak around certain parts of the pump. As shown in Fig. 8. oil for lubrication and sealing is supplied from the oil tank 3! through the pipe 29 which has branches 32 and 33 (see also Fig. 2) to supply oil respectively to the bearings l8 and 22. Each of the and 33 comprises a direct feed pipe 34 and the by-pass feed pipe 35, which is provided with a control hand valve 36 whereby the flow of oil therethrough may be regulated.

The oil for effecting the oil seal between the moving parts of the pump issucked into the interior thereof by the action of the pistons. As shown in Fig. 8, the oil inlet pipe 32 supplies oil through the pipe 35 and the passages 35' in the bearing l8, which passages communicate with the interiors of both piston chambers at points illustrated by the dotted circle 35' (Figs. and 6). These outlets of the passages 35' are off-center with respect to the axis of the rotary course of the pistons 58 and 5B. The oil inlet pipe 33 (Fig. supplies oil through the pipe 35 and a passage 35' in the bearing 22 to the left end. of the piston chamber of the preliminary pump unit. The outlet of this last mentioned passage 35 is likewise located in off-center relation with respect to the axis of rotation of the piston 58'. A suitable stuffing box 86 in a housing leakage around the shaft at bearing 22. end-bearing 88 in the casing-bearing 23 for the shaft 2i receives its lubrication from oil that finds its way around the end of piston 58.

At the junction of each of the end surfaces of the piston 58 with its driver 60, there is provided an annular groove 8!, and in the end surfaces of the driver there are provided radial grooves 82, leading from the annular grooves to the surface of the shaft 2|. By this construction the rotation of the piston causes the mentioned grooves to wipe across the oil orifices and to pick up a small amount of oil each time that the orifices are passed. The pump unit while in operation is developing a high vacuum so that when the oil orifice 35' registers with a groove, the difference of pressure between the oil in the tank 3i and the'pressure in flowing to the pump in an amount regulated by the valves 36.

By this oiling arrangement if the valves in the oil supply line from the oil tank to the pump units P and F are inadvertently left open when the operation of the pump FF is stopped, the pump units will not be flooded with oil. The possibility of flooding is obviated due to the fact that the air pressure in the exhaust side of the sub-chamber of the final pump unit is different from the atmospheric pressure in the exhaust side of the sub-chamber of the preliminary pump unit and when the operation of the pump is stopped, the air pressures in the pump units thus become balanced to "break" the vacuum therein. With the vacuum broken, that is, with atmospheric pressure prevailing in the pump units, oil will not flow to flood the exhaust system.

It will be noted that the path of flow of gas through the pump units, as represented by the arrows in Fig. 3, is such as to offer a minimum of resistance to the passage of gas, since the guiding surfaces for the gases are free from sharp turns or corners. Attention should be directed to the fact that the wall of the sub-chamber of the final pump unit is curved as indicated at 90, and that the face of the rocker member 41 is tapered from the edge 9| at one end to the edge the pump results in oil this rocker member is in its highest position illust'rated in Fig. '1, thereis very little gas or oil left in the sub-chamber 43 due to the mentioned curved surface of the casing tapered surface of the rocker member. The flat face of the rocker member 41 of the preliminary pump unit is not tapered in this manner but the adjacent wall of its sub-chamber 43, is funnelshaped or tapered toward (Fig. 4).

In the operation of the pump, the rotation of the shaft 2| causes the pistons 58 and 58' t0 planetate n their individual piston chambers in 180 degree displaced relation with respect to each other. The planetation of these pistons in turn causes the rocker members 41 and 41' pivotally connected thereto, to rock toward and away from their respective piston chambers in similar displaced relation, so that one member is rockin downward while the other member is rocking upward, The action of the rocker members will be understood by tracing their paths of movement. In the course of one half of the cycle of planetation of each piston, ton 58, its rocker member 41 rocks downward toward the piston chamber 4| from its high point shown in Fig. '7 to its low point, which is identical with the position of the rocker member 41' of the preliminary pump unit, indicated in dotted lines so in-this figure. During the remaining half of the cycle, the rocker member 41 rocks upward from this mentioned low point back to the mentioned high point.

Since the upper surface such as 54 of the pocket such as 5| in each rocker member is inclined downward from its related inlet orifice, when its rocker member rocks downward the gas in the pocket is crowded into a rapidly decreasing space,

with the result that the movement of gas toward 0,

the piston chamber, is accelerated. This action is especially effective as a high vacuum is approached, since the gas then becomes rarifled and its flow becomes sluggish.

In order to understandhow evacuation is ef- 5 fected by the pump, let it be assumed that the cycle of the pump begins when the movable parts thereof are in approximately the position shown in Fig. '7. Gas from the pipe 26 enters the pocket 5! in the rocker member and as scends a short distance during the rotation of its piston, its pocket communicates with the piston chamber and accelerates the movement of the gas into the space 61 (Fig. 5) in this chamber, at the rear of the piston. This continues until the rock- 55 er member and piston reach a position corresponding to that occupied by rocker member 41' and piston 58 as indicated in dotted lines'in Fig. 7. While this is taking place, the gas in advance of the piston 58, where it has been trapped 60 during the preceding cycle of the pump, is being compressed. As the piston continues to rotate from the mentioned position, the rocker member starts to rise, and the gas in advance of the piston is fu ther compressed, causing it to ex- 5 haust through openings 68, past valve ll, into the sub-chamber. The fiat tapered face of the rising rocker member forces this exhaust gas into the conduit IS. The compression and exhaust of the gas in advance of the piston the cycle is completed, when the piston 52 and its rocker member move to the position shown in Fig. '7.

At the beginning of the mentioned cycle, the

piston 58 and the rocker 41' of the preliminary 15 and due to the 5 the exhaust pipe 21 10 for example, the pls- 26 this member de- 50 continues until pump unit are in the position illustrated in dotted lines in Fig. 7. From this position, the piston 58' rotates to compress the gas ahead of it whichhas been introduced into the piston chamber 4! during the preceding cycle. pressed is exhausted through valve H into the sub-chamber 43'. At this time the rocker member 41"is rising to its high point and therefore its flat face forces this exhaust gas into pipe 21 from which it flows to the oil tank and thence to the atmosphere. When the rocker member 41 reaches its high point itstarts to descend, which movement takes place while the final pump unit is exhausting gas into conduit I9. in the rocker mcmberfl' thus forces this exhaust into the space in the piston chamber 4| at the rear piston 58'. As the piston 58' rotates in the course of the succeeding cycle, it expels this. last mentioned gas into exhaust pipe 21 as above described.

The operating cycle just described is effected so rapidly,that there is practically an uninterrupted flow oi' gas'through the pump units.

It should be particularly pointed out that there is communication between the inlet oi" the pump unit and aportion of its piston chamber as well as communication between the outlet of this unit and another portion of its the major portion of each It should be noted that piston chamber during a portion of the time that the contacting portion of each piston is traveling from a point at one side of the sub-chamber to a point at the other side thereof.. By this arrangement. a long period of injection of gas into the piston chamber and a long period for exhaustinggas therefrom is aiTorded in each'cycle of operation.

The present disclosure is given as an example of one form of the invention but it will be understood that there may be various changes and modifications thereof. except as defined in the following claims, without departing from the spirit of the invention.

What I claim is:

1. A pump of the class described comprising a piston, a piston chamber, and a sub-chamber,

The pocket 5| cycle. gas is supplied to each an inlet and an outlet in said sub-chamber, an'

eccentric driver element for operating said piston to effect a movement of gas through said inlet, a member in and rockably mounted with respect to said sub-chamber, a sweep on said member defining a passage'flaring axially of said piston chamber, means pivoting the free end of said member to said piston-for moving said sweep along the path of travel of said gas to accelerate the movement thereof toward said piston chamber, and means carried by said member for releasing therethrough gas compressed by said piston for discharge through said outlet.

2. A pump of the class described comprising a piston-chamber and a sub-chamber, a piston in said piston chamber, an inlet and an outlet in said sub-chamber, an eccentric driver element for-operating said piston to effect a movement of gas through said inlet, a member in and rockably mounted with respect to said sub-chamber,

a sweep on said member defining a passage flaring axially of said piston chamber, means pivoting the free end of said member to said piston for moving said sweep along the path of travel of said gas to accelerate the movement thereof toward said piston-chamber, anda valve in said member operable to release therethrough gas This gas as it is com piston chamber, during said piston for escape through said compression-chamber and a sub-chamber, a piston in said compression-chamber, a rocker member separating said chambers, an inlet to said sub-chamber on one side of said member, a passage in said sub-chamber for the travel of gas from said inlet to said compression-chamber, an outlet for said sub-chamber on the other side of said member, a pivot for said rocker-member on the wall oi said sub-chamber, a blade having an inclined surface on the free end of said member and defining a passage flaring axially'of said piston chamber, means cooperating with said piston for oscillating said rocker-member to move said inclined surface in the path of gas to said compression chamber to accelerate the movement of said gas, and means for releasing therethrough gas compressed by said piston for escape through said outlet.

4. A multiple pump comprising a plurality of casings, each casing having a compression chamber and a sub-chamber, means for securing said casings in endwise relation, a communicating conduit between said sub-chambers, an inlet in 'one casing, an outlet in the other casing, pistons in said compression chambers, a movable member in the sub-chamber of one casing cooperating with the piston thereof and having a passage flaring longitudinally of said casing and in a direction away from the other casing to deliver gas to the compression chamber of its casing,

for admitting comsaid conduit for delivery to the the other casing, a second movthe sub-chamber of the other casing cooperating with the piston thereof and having a passage flaring in the same direction as that in the first-mentioned movable'member to deliver gas from said conduit to the compression chamber of said other casing, and means on said second member for the release of gas from said last mentioned casing.

5. A rotary pump comprising a casing having cylindrical compression chamber and a subchamber, a piston movable in said compression chamber, a rocker arm separating said chambers and provided with an outlet passage therethrough, said sub-'chamber having an inlet and an outlet, an eccentric driver element for operating said piston, means for causing an oscillation of said rocker arm during operation of said piston, a passage flaring longitudinally of said casing on one side of said rocker arm for effecting communication with said compression chamber on one side of said piston, and spring 'controlled valve means carried by said arm for controlling communication through said outlet passage between said outlet and the compression chamber on the other side of said piston.

6. A rotary pump comprising a casing having ing a cylindrical compression chamber and a sub-chamber, a piston :in said compression chamber, a rocker arm dividing said chambers, said sub-chamber having an inlet and an outlet, means for causing an oscillation of said rocker arm during operation of-said piston, a passage flaring longitudinally of said casing on one side ofgsaid rocker arm for effecting communication with said compression chamber on one side of said. piston, said arm having a passage therethrough afiordingcommunication with the compression chamber on the other side of said piston. and a spring controlled valve in said passage.

7. A rotary pump comprising a casing having a cylindrical compression chamber and a subchamber, a piston in said compression chamber, a rocker arm separating said chambers, said subchamber having an inlet and an outlet, means for causing an oscillation of said rocker arm during operation of said piston, said rocker arm having a passage flaring longitudinally of said casing for effecting communication with said compression chamber on one side of said piston, said arm having another passage therethrough affording communication with the compression chamber on the other side of said piston and, a valve controlling said passage.

8. A rotary pump comprising a casing having ing a compression chamber and a sub-chamber, a piston in said compression chamber, said subchamber having an inlet and an outlet, a rocker arm pivoted at one side of said sub-chamber, means connecting said arm with said piston to cause,'an'oscillation of said arm upon operation of said piston, said arm having an outlet passage and means defining a passage tapering longitudinally of said casing to accelerate the movement of gases from said inlet to one side of said piston, and spring-controlled means in the outlet passage in said arm for passing gases from the other side of said piston to said outlet.

9. A pump of the class described comprising a casing having a compression chamber and a subchamber, an eccentrically mounted piston in said compression chamber, a rocker arm having one end pivoted inthe wall of said casing and movable in said sub-chamber, a pocket tapering longitudinally of said casing at the other end of said arm, an inlet to said sub-chamber, means for positioning said pocket in communication with said inlet and in position to deliver gas into said' compression chamber, and an outlet from said compression chamber controlled by a valve in said arm.

10. A pump of the class described comprising a casing having a compression chamber and a sub-chamber, an eccentrically mounted piston in said compression chamber, a rocker arm with an outlet opening and having one end pivoted in the wall of said casing and movable in said sub-chamber, a blade on the other end of said arm serving in conjunction with the wall of said sub-chamber to form a pocket flaring longitudinally of said casing, an inlet to said sub-chamber, means for moving said blade to position said pocket in communication with said inlet to receive gas and for moving said blade to accelerate the movement of said gas into said compression chamber, an outlet for said subchamber, and means carried in the opening of said arm for releasing compressed gas to said outlet.

11. A pump of theclass described comprising a casing having a piston chamber and a sub-chamber a piston in said piston chamber, a rockermember in said sub-chamber, means for pivotally mounting one end of said rocker-member in the wall of said sub-chamber, a blade at the other end of the rocker member. said blade operating in conjunction with the walls of said sub-chamber to form a passage flaring longitudinally of said casing, an inlet in said sub-chamber at one end of said passage. said piston being operable to move said rocker member to accelerate the movement of gas from said inlet toward said piston chamber and effect communication between said passage and said piston chamber.

12. A pump of the class described comprising a ber in the wall of piston chamber, an outlet in compression chamber and a sub-chamber, a piston in said compression chamber, a rocker-member separating said chambers, an inlet to said sub-chamber on one side of said member, a passage in said sub-chamber for the travel of gas from said inlet to said compression chamber, an outlet for said sub-chamber on the other side of said member. a pivot for said rocker-member on the outlet side of said sub-chamber, a blade having an inclined surface, flaring longitudinally of said casing, on the free end of said member, means cooperating with said piston for oscillating said rocker-member to move said inclined surface in the path of gas flowing to said compression chamber to accelerate the movement of said gas, and a valve carried by said rocker-member for releasing gas compressed by said piston for escape through said outlet.

13. A pump of the class described comprising a casing having a piston chamber and a subchamber, a piston in said piston chamber, a

rocker-member in said sub-chamber, means for pivotally mounting one end of said rocker-memsaid sub-chamber, a blade at the other end of the rocker-member, said blade operating in conjunction with the walls of said sub-chamber to form a longitudinally flaring passage, an inlet in said sub-chamber at one end of said passage, means operable in cooperation with said piston to move said rocker-member to carry gas from said inlet toward said piston chamber, means operable upon a movement of said piston to effect communication between said passage and said piston chamber, an outlet in said sub-chamber, and valve means in said rocker-member for. affording communication between said outlet and said piston chamber when said piston has moved to compress gas in said piston chamber.

14. A pump of the class described comprising a casing having a piston chamber and a sub-chamber, apiston in said piston chamber, a rockermember in said sub-chamber, means for pivotally mounting one end of said rocker-member in the wall of said sub-chamber, a blade at the other end of the rocker-member, said blade operating in conjunction with the walls of said sub-chamber to form a passage flaring longitudinally of said casing, an inlet in said sub-chamber at one end of said passage, means operable in cooperation with said piston to move said rocker-member to carry gas from said inlet toward said piston chamber, said piston being operable to effect communication between said passage and said said sub-chamber, and avalve in said rocker-member operable under the force of gas compressed by said piston to release said gas for escape through said outlet.

15. A pump of the class described comprising a casing, a rocker-member, a piston chamber in said casing, an inlet passage and an outlet passage for said casing, a piston, a rocker-chamber in said casing, an inlet and an outlet for said rocker-chamber, means for pivoting one end of said rocker-member in a wall of said rockerchamber with itsfree end connected to the piston so that it extends across the outlet passage and is swingable to open and close the inlet pasvalve member being formed passage, and a sub-chamber, an inlet and an outlet in said sub-chamber, a piston,

ber comprising a valve member with one end pivoted to a wall of said sub-chamber, extending movement of gas and means in said toward said piston chamber, valve member between its pivoted and piston-connected ends for releasing gascompressed by said piston for escape through said outlet passage. I v

17. A vacuum pump comprising a generally cylindrical casing with a valve chamber extending therefrom, a hollow cylindrical piston movable in said casing, end plates closing said casing,

an eccentric rotary driver element carrying said valve member to oscillate about its connectionwith said casing, said valve member having a passage, defined by a blade extending from the free end thereof, and flaring axially of said casing, an inlet port in the end plate closing the end of said casing adjacent the large end of said passage, said piston during movement causing said valve to open and close off said inlet port to the casing on one side of said piston, said pivotal with an outlet passage, and a spring controlled closure element mounted in said passage for governing the exhaust movement of gas therethrough from the casing on the other side of said piston.

18. A pump comprising a casing with a compression chamber and a valve chamber extending therefrom, a piston movable in said compression chamber, means closing the ends of said casing, a driver element carrying said piston, a shaft on which said driver element is mounted, a valve member pivotally connected to said casing and serving to separate said compression and valve chambers, the free end of said valve member being pivoted to said piston whereby the latter is caused to planetate about the axis of said shaft, and the valve member oscillates about its connection with said casing, said valve member having a passage flaring axially of said casing, an inlet port in the means closing the end of the said casing adjacent the flared end of said passage. said piston during movement causing said valve to open and close off said port. said valve being formed with an outlet passage, and means in said passage for governing the exhaust movement ofgas therethrough.

19. A preliminary and final pump assembly comprising two casings, each with a compression chamber and a valve chamber extending therefrom, a piston movable in each compression chamber, means closing the extreme ends of said casings and connecting the adjacent ends, a driver element carrying each piston, a shaft on which said driver elements are mounted out-ofphase with respect to one another, so that gas from the final pump is discharged to the preliminary pump at about the beginning of the latter's piston stroke, a valve member pivotally connected to each casing and serving to separate the compression and valve chambers thereof, the free end of each valve member being'pivoted to latter is caused to planesaid shaft, and the valve oscillates about the connection with its casing, the valve members having passages flaring in the same direction longitudinally of their casings, with that in the preliminary pump flaring toward the final pump, inlet and connecting ports positioned, respectively, in the means closing the extreme end of the final pump casing adjacent the flared end of its the effective capacity 21. A pump of the of said subchamber. class described comprising piston chamberand a subdirect the fiow of fluid thereto.

outlet to the other end of said member to reduce the effective capacity of said subchamber, and means adjacent the outlet port end of said subchamber to further reduce the capacity of said subchamber.

23. A pump of the class described comprising a casing including a piston chamber and a subchamber communicating therewith, said subchamber having an inlet port through one end wall thereof and an outlet port through a side wall thereof, a piston mounted to pl'anetate in said piston chamber, a rocker member in said subchamber and pivoted at one side to said side wall of said subchamber, another side of said rocker member being pivotally connected to said piston whereby said member normally prevents communication between said piston chamber and said outlet port, and valve controlled means in said member effecting communication between said piston chamber and said outlet port, the surface of said side wall having a funnel-shaped contour converging toward said outlet port to 24. A multiple pump of the class described comprising a plurality of casings, each casing having a cylindrical compression chamber and a subchamber, an end plate for securing said casings together in endwise relation with said cylindrical compression chambers disposed in substantially axial alinement and with the subchambers displaced approximately 26 with rethe subchamber of one casing,

spect to each other about the common axis oi. said compression chambers, said end plate closing the adjacent ends of said compression chambers and subchambers and having a conduit therein communicating with said subchambers, an inlet in an outlet in the subchamber of the other casing, pistons mounted to planetate about the common axis of said compression chambers, one piston being mounted to planetate in eachcompression chamber. said pistons being displaced approximately 180 with respect to each other, a movable rocker member ineach subchamber, the movable rocker member in the subchamber having said inlet being .pivotally connected at one side to a wall of its subchamber and at another side to its related piston to prevent direct communication between said inlet and said conduit, the movable rocker member in the .subchamber having said outlet being pivotally connected at one side to a wall of its subchamber and at another side to its related piston to prevent direct communication between said conduit and said outlet, and valve controlled means in said rocker members efiecting communication between the compression chambers and their related subchambers.

25. A multiple pump comprising a plurality of casings. each casing having a cylindrical compression chamber and a subchamber. communi eating with the cylindrical compression chamber, an end plate for securingsaid casings together in endwise relation and for closing the adjacent ends of said chambers. a conduit in said plate communicating with said subchambers. said plate also having a passage therein communicating with said conduit and with the exterior of said pump, an inlet in one casing, an outlet in the other casing. pistons mounted for planetary movement in said compression chambers, a movable member in the subchamber of one casing cooperating with the piston thereof to deliver gas to the compression chamber thereoflsald member having therein a passage providing communication between said inlet and its related compression chamber, said member having means for releasing gas from its compression chamber to said conduit, a second movable member in the subchamber ot the other casing cooperating with the piston thereof'to deliver gas from said conduit to the compression chamber of said other casing, said second member having a valve controlled opening therein communicating with said outlet for the release of gas from said last-mentioned casing. I 26. A multiple pump for progressively exhausting hollow vessels comprising apreliminary vacuum pump unit and a final vacuum pump unit, each of said units having an inlet and an outlet, said pump units being supported in adjacent relation with the outlet of said final pump unit in approximate alinement with the inlet of saidpreliminary pump unit, fluid conducting means connecting said pump units, said means having a substantially straight conduit therein connecting the outlet of said final pump unit to the inlet of said preliminary pump unit, said means also having a passage therein communicating with said conduit, said passage being independent of the inlet of said final-pump unit and being adapted to be connected to a hollow vessel initially at atmospheric pressure whereby said preliminary pump unit will partially exhaust the same, said inlet oi! said final pump unit being likewise adapted to be connected to a hollow vessel for further exhaustion which vessel has been partially exhausted by said preliminary pump unit while connected to said passage.

2'7. A multiple pump for progressively exhausting hollow vessels comprising a preliminary pump unit and a final pump unit, each of said units having a piston chamber and a subchamber communicating therewith, a piston in each of said piston chambers, mounted for planetary movement therein, a common shaft for driving said pistons, each of said subchambers having an inendwise relation .and closing the adjacent ends of said piston chambers and'subchambers, said end plate having a conduit therein connecting the outlet of said final pump unit to the inlet of said preliminary pump unit and also having a passage therein communicating with said conduit and with the exterior of said pump, said passage being independent of the inlet of said final pump unit and being adapted to be connected to a hollow vessel initially at atmospheric pressure whereby said preliminary pump unit will partially exhaust the same, said inlet of said final pump unit being likewise adapted to be connected to a hollow vessel for further exhaustion which vessel has been partially exhausted by said preliminary pump while connected to said passage.

28. A multiple pump including a preliminary pump unit and a final pump unit, each unit comprising a casing having a cylindrical compression chamber and a subchamber communicating therewith, a planetary piston in each conipression chamber progressively contacting the inner cylindrical wall thereof to provide inlet and outlet compartments at opposite sides of the line of contact during each cycle of the piston, a rocker member in each subchamber longitudinally dividing each subchamber into an inlet part and an outlet part, each rocker member cooperating with its related piston to prevent d1 axis of said compression'chambers, said end plate closing the adjacent ends of said compression chambers and subchambers and having a conduit therethrough opening into the inlet part of the subchamber of said preliminary pump unit and the outlet part of the subchamber of said final pump unit to provide respectively an inlet port and an outlet port for said subchambers, said inlet port and outlet port being in approximate alinement whereby said conduit is relatively short, an inlet pipe for the inlet part of the subchamber of said final pump unit, and an outlet pipe for the outlet part of the subchamber of said preliminary pump unit. I

29. A multiple pump including a preliminary pump unit and a final pump unit, each unit comprising a casing having a cylindrical compression chamber and a subchamber communicating therewith, a planetary piston in each compression chamber progressively contacting. the inner cylindrical wall thereof to provide inlet and outlet compartments at oppositeof contact during each cycle sides of the line of the piston, a

rocker member in each subchamber longitudinally dividing each subchamber into an inlet part and an outlet part, each rocker member cooperating with its related piston to prevent direct clommunication between the inlet and outlet therethrough opening into the inlet part of the subchamber of said preliminary pump unit and into the outlet part of the subchamber of said finalpump unit to provide respectively an inlet port. and an outlet port for said subchambers, said inlet port and outlet port being in approximate alinement whereby said conduit is'relatively short, an inlet pipe for the inlet part of the subchamber of said final pump unit, an outlet pipe for the outlet part of the subchamber of said preliminary pump unit, and a passage in said end plate communicating with said conduit and with the exterior of said multiple pump, said passage being independent of said inlet pipe.

SAMUEL KARASICK.