US1843939A - Pumping device - Google Patents

Description

Feb. 9, 1932. L. H. WHEELER 1,843,939

PUMPING DEVICE Feb. 9, 1932. H. WHEELER 1,843,939

PUMPING DEVICE Filed Nov. 30, 1928 2 Sheets-Sheet 2 MMR PatentedFeb. 9, 1932 UNITED STATES PATENT OFFICE- LEONARD H. WHEELER, OF CHICAGO, ILLINOIS, ASSIGNOR TO STEWART-WARNER COB- PORATION,OF CHICAGO, ILLINOIS, A CORPORATION OF VIRGINIA PUIPING DEVICE Application led November 30, 1928. Serial No. 322,815.

The purpose of this invention is to provide an improved construction of a pumping device for developing vacuum or the status of sub-atmospheric pressure, in a chamber to which the structure embodying the invention may'be connected, the structure shown being particularly designed for connection with the vacuum chamber of a vacuum fuel feeding device commonly called vacuum tank, for

producing the necessary vacuum therein for lifting fuel for -an engine from a low level source; and for this use the invention as herein shown is arranged to be operated by a shaft of the engine reached by intrusion into the crank case. In certain details the present device is designed particularly for avoidance of return to the crank case of the gases Withdrawn from the vacuum chamber in developing the necessary vacuum therein. y

The invention consists in the elements and features of construction shown and described, as indicated in the claims.

In the drawings z- Figure 1 is a vertical section of a pumping construction embodying this invention, the same being shown diagrammatically in relation to the crank case and to the vacuum tank with which it may be connected for developing vacuum.

Figure 2 is a section at the line 2-2 on Figure 1.

Figure 3 isa section at the line 3-3 on Figure 1. A

Figure 4 is a detail section showing a slight modification. y

Figure 5 is a section at the line 5-5 on Figure 4.

Figure 6 is a view similar to Figure l showing a modified form of the device.

Figure 7 is an upperend plan view of thisform. v

Figure 8 is an elevation lookmginthe di- Figure 9.

Referring to the drawings, the pumping dev1ce comprises a casing A, having a pumping cylinder, l20, with inlet port, 22, and inlet plug, 28, having a terminal pin, 29,'for limit-y lng the opening movement of the check valve, the initial portion of the inlet passage, 23, from the intake pipe connection, 23, intersecting the bore, 24, at the lower end, and the final portion, 22, of the inlet passage which is bored in from the cylinder end parallel with the portion, 24, is connected'with the latter above the check valve seat by boring in from the outside to form the port of connection as seen at 22, the outer end of the bore being closed by plug, 22h.

The casing A, comprises in addition to the piston cylinder 20, a passage 80 in a horizontal limb, A2, said limb being provided for mounting the casing on the engine crank case and said passage, 30, leading to the outer end of the limb for registering with an uaperture in the crank case at which the casing is to be mounted.

The piston indicated at C, comprises an upper disc, c2, and lower disk, c1, and a cu leather, C1, clamped between the disks Wit its cup flange folded downwardly, that is, away from the inlet port of the cylinder.

The lower disk c1', is dimensionedto allow the cup leather flange to be flexed downwardly inwardly, that is, slightly away from the cylinder wall so that the piston operates substantially as a check valve obtaining pistonwise fit of the cup leather only in the down stroke, which is the suction stroke, the cup leather yielding in the reverse stroke permitting the pumped fluid to pass by the piston into the portion of the cylinder cavity and passage, 30, below the piston.

The piston is connected for actuation'by its stem, C2, to which at thelower end there is pivotally connected an operating' lever, D,

which extends through the passage, 30, being fulcrumed at toward the end of the limb, A2, and projecting out from the open end of said limb for protruding into the crank case when the casing is mounted on the lat- ,ter as above indicated, for which mounting it is provided with a flange, a?, arranged to be secured by bolts in an obvious manner. It is contemplated that the lever, D, will be actuated by an eccentric cam G, on the shaft S, accessible to the lever at its intrusion into thc crank' case, the positive actuation thus derived being in with direction for giving the piston its suction stroke. The reverse stroke of the piston is produced by a spring, E, lodged at one end in the lower end of the casing where a seat is provided as seen at .35, the upper end of the spring is provided with a cap disk, 36, having a central depression for seating a downwardly projecting lug, d, on the inner end of the lever, D, by which the reaction of the spring is transmitted through said lever to the piston stem and piston for giving the latter its return stroke, in which, f

as above explained, the pumped fluid escapes past the check valve formed by the piston cup lever above described.

In view of the contemplated"=use of this pumping device for producing vacuum in the vacuum chamber ofa vacuum tank, and in.

view of the fact that the gases withdrawn from such vacuum chamber for producing the vacuumv are liable to consist of air more or less heavily charged with gasoline vapor, it is desirable to provide in the pumping device means for preventing this vapor to any substantial extent being fed into the engine crank case, as in the absence of provision Y to the contrary would result from the con- .struction by which the casing is mounted on the crank case at an aperture through which the operating lever extends for protruding into the crank case tov reach the operating cam. Means for preventing this delivery into the crank case of the gases pumped from the vacuum cham? ber, a vent port, 51, is formed at the lower end ofthe crank case and most conveniently at the foot of the seat, 35, in which the spring, E,.is seated; and the passage, 30, is blocked for substantially defeatin fluidcommunication between the cavity o the casing and the engine crank case by the construction of the lever and the portion of the casing at which the lever is fulcrumed, aswill now be described.

The casing limb, A2, .at the locality of the fulcrum of the lever is formed with opposite inwardly protruding' bosses, 52, 52, protrudingvtoward each other and spaced apart a distance for admitting between them the lever D, which is dimensioned for fitting thus v tween them snugly, but not to the impairment'of its necessary pivotal action.

designed and shown the lever is substantially square in cross section at this point but has projecting upwardly and downward ly from it bosses, 56, 56, which at their extremities are spherically arcuate about the intersection of the pivot axis with the axis of the passage, 30, which is cylindrical in form, these bosses being formed with lateral projections, 57 57 at opposite sides projecting respectivel above and below the inwardly protruding osses, 52, of the casing member, A2. For the purpose of 'conveniently forming the casing, A, by casting, and for that purpose designing it to make the necessary cores withdrawable, the bosses, 52, 52, are formed as seen in the drawings cylindrically curved at their outer ends and extending with the full diameter of the cylindrically curved ends, the entire length of the limb, A2, of the casing, so that at their inner ends they terminate at the cavity which constitutes the piston cylinder; and this cavity, as will be seen from Figure 1, is arranged for withdrawal of the core by which it is formed, transversely with respect to the bosses, 52, 52; and it will be seen that this construction permits the making of the casing by casting. The form thus imposed upon the bosses, 52, as distinguished from the form of simple cylindrical bosses, which would serve the purpose of positioning and aiording pivotal support forv the lever, prevents completely blockading the passage through the limb, A2, at the plane of the lever pivot as might otherwise be done by theextensions, 57, of the bosses, 56, extending above and below the bosses, 52, as mentioned, to the extent that these overhanging projections are necessarily spaced from the bosses, 52, which they overhang a distance sufficient to accommodate the angular movement of the lever by which it actuates the piston, the space thus allowed between the projections, 57, and the bosses',

.52, being seen at 58 in Figure 1.

I do not limit myself to this particular expedient for blockading the passage, and another obvious method for accomplishing this result is illustrated in Fi res 4 and 5, consisting of a sleeve, 100, dlmensioned for fitting tightly in the assage, 30, and having pivot bearings, 101, or a pivot boss, 102, with 'which the lever is provided projecting at opnotwithstanding the slightly incomplete blockade which it supports', merely by reason of the economy of construction when the casing, A, is designed for casting.

A simpler, and, on that account, a somewhat preferred form of this invention, is shown in Figures 6, 7 and 8. In this form the casing member, A.x corresponding to the member, A, of the earlier figures consists of a sheet metal stam ing having a check valve fitting, 21x,'screwe into its upper, otherwise closed, end. This fitting is formed to allord seat, as seen at 22x, for an inwardly and down- .10 wardly opening-upwardly and outwardly 20 tered in its chamber by approximately diametric fit therein.

' In this modification, also, for simplicity of construction, the lever, D, is fulcrumed in the terminal portion of the casing member, 30. without provision for closing or approximately closing the entrance to said casing member which, on the contrary, is left open for free fluid communication with the crank case when the device is mounted on the engine as described. For thus fulcruming the lever in the end of the casing member has interiorly projecting bosses, 52, as in the form shown in the earlier -gures, and the lever is provided with bosses, d, of substantially the same diameter as the bosses, 52, and dimensioned for fitting snugly between the latter when the lever is connected to the casing by the pivot pin, 50.

I claim y1. A pumping device for service in connection with an engine having a pump cylinder and a piston member consistin of two rigid disks and a cup leather clamped etween them, both disks being substantially less in diam- 45 eter than the cylinder cavity, the disk at the inner side of the cup leather being substantially less in diameter than the other disk and substantially less than the inner diameter of the cup leather, whereby the cup leather is 50 adapted to act as a check valve for passing 4 the fluid pumped from the side opposite the cup cavity to the other side, the pump cylinder having inflow connection at the side of the piston opposite ythe cup cavity of the 55 cup leather, and a check valve controlling said inflow connection opening for inflow and seating against reverse flow', and engine-operated means for reciprocating the piston connected therewith for saidoperation at the side opposite the outflow connection.

2. A pumping device adapted to be mounted on an engine for producing vacuum to serve the operation of the engine, said device comprising in combination with a pump cylinder, a piston member having its peripheral portion resiliently iiexible radially normally seating throughout its circumference on the cylinder wall and trending in one direction longitudinally of the cylinder throughout its whole circumference, whereby it itsladapted at a marginal circumferential part to yield inwardly and in said longitudinal direction when the piston is moved in the opposite direction; the pump cylinder having inilow connection at the side of the piston opposite said direction of trend; a check valve controlling said inflow connection opening for inow and seating against reverse flow, and engine-operated means for reciprocating the LEONARD H. WHEELER.

piston.

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