US2989002A

US2989002A - Liquid pump dispenser

Info

Publication number: US2989002A
Authority: US
Inventors: William J Dobkin
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-10-03
Filing date: 1955-10-03
Publication date: 1961-06-20
Anticipated expiration: 1978-06-20

Description

June 20, 1961 w. J. DoBKlN LIQUID PUMP DISPENSER 2 Sheets-Sheet 1 Filed OCT.. 5, 1955 ATTORNEY June 20, 1961 w. J. DOBKIN 2,989,002

LIQUID PUMP DISPENSER Filed OCT.. 5, 1955 2 Sheets-Shea?I 2 INVENTOR /f//mf f .0MM/v ATTO R N EY United Statesv 2,989,002 LIQUID PUMP DISPENSER William J. Dobkin, Jackson Heights, N.Y. (7 324- Flagler Blvd., P.O. BOX 817, Kendall, Fla.) Filed Oct. 3, 1955, Ser. No. 538,121 8 Claims. (Cl. 103"38) The present invention relates to a hand pump of the type, which is employed to dispense a predetermined amount of liquid from a supply source, such as a drum. Such a pump, may for example, be employed to dispense syrups or flavoring concentrates in soda fountains, to dispense detergents for dishwashing, oor washing or other cleaning operations, to dispense shampoos, oils or other beauty or toilet preparations in beauty or barber shops, to iill small containers with lubricants, medicine, or other liquids from drums or other supply source, etc.

`One object of the present invention is to provide a new and improved hand pump of the general type described, having a comparatively short operating handle com-pactly arranged with respect to the pump unit and connected to the piston of the pump with a linkage system, designed to operate the piston through a comparatively long stroke with a maximum of mechanical advantage, to permit the handle to be operated with ease.

Another object of the present invention is to provide a new and improved hand pump of the general type described, which is operable to dispense a measured amount of liquid in response to a single manipulation of the handle and which can be easily and readily adjusted to vary selectively this amount.

A vfurther object of the present invention is to provide a pump of the general type described, designed to prevent contact of the liquid being pumped with those movable parts of the pump, which might contaminate said liquid, thereby meeting the sanitary requirements of such industries as the food or medical industry.

Another object of -the present invention -is to provide a pump of the general -type described, constructed to permit visible observation of the entire body of liquid in the pump chamber before it is discharged, so that the observer may inspect the conditions of the liquid and may gauge by eye, the amount of liquid discharged at every handle manipulation.

p Another object of the present invention is to provide a new and improved pump of the general type described, which can be easily supported on a wall or other supporting structure, which is compact, easy to assemble or disassemble and economical to manufacture, and in which the design and construction of the different features which impart the desirable utility to the pump, also lend decorative and ornamental appeal to the pump unit.

Various `other objects, features and advantages of the invention are apparent from the lfollowing particular description and from the accompanying drawings, in which:

FIG. l is a vertical section through Ilthe pump embodying the present invention and shown at the end of the suction stroke or at the beginning of the pumping stroke with the handle in raised position;

FIG. 2 is a top plan view partly in section of the pump but shown with the handle in intermediate horizontal position in the process of completing the pumping stroke;

FIG. 3 is a top plan view of the bracket by which the pump is supported on a wall and the pump cylinder is supported in position, said bracket being shown on a smaller scale than that of FIGS. 1 and 2;

FIG. 4 is a side elevation of the bracket of FIG. 3 and of part of the handle linkage, by which the pump piston may be moved up and down; l

2,989,002 Patented June 20, 1961- rice FIG. 5 is the side view partly in section of the pump piston assembly; and

FIG. 6 is a perspective of the pump cylinder in the procws of being lowered into a cylinder holder forming part of the bracket of FIG. 3.

Referring to the drawings, the pump embodying the present invention comprises in general a vessel 10 in the form of a cylinder defining a pump chamber and having an inlet 11 and an outlet 12, a bracket 13 for supporting said cylinder on a wall, a piston carrier 14 shown in the form of a hood, disposed over said cylinder and adapted to be ltelescoped over said cylinder during the pumping stroke, a pumping piston 15 carried by the hood 14 and reciprocable in said cylinder, a handle 16 and linkage 18 between said handle and said hood to reciprocate said hood and in turn the piston in the cylinder.

The bracket assembly 13 comprises a supporting frame in the form of a back wall plate 20 of generally rec tangular form adapted to be secured to a wall 21 at the operating station by screws 19. This wall plate 20 which is preferably of metal, has side edges 22 turned inwardly to form rails or tracks for the hood 14, as will be more fullyl described. Also forming part of the bracket assembly 13 is a cylinder holder 23, preferably of metal, having a ilat ring 25 through which the pump cylinder 10 extends and on which it is directly supported, and a forwardly tapering iiange 26 extending around said ring and depending therefrom to impart structural strengthto said ring, the rear deeper section 27 of said ilange being at and being disposed in face contact withthe wall plate 20, this rear flange section 27 being rigidly secured to said wall plate preferably by spot welding or brazing.

To lock removably the pump cylinder 10 to the cylinder holder 23 against axial withdrawal, the ring 25 has a generally circular opening with a serrated catch formation around its peripheral edge defining alternate peripheral notches 30 and tongues 31 of substantially equal lengths.

The pump cylinder 10 is molded from transparent plastic to permit clear visual observation of the contents of said cylinder and comprises an upper head 32, a cylindrical wall 33 depending therefrom and a bottom wall 34 with the inlet 11 and outlet 12. The upper cylinder head 32 has a catch formation to engage the ring 25 on the cylinder holder 23, and to that end, this cylinder head comprises a continuous rim flange 35, which is circular except for the rear side, as will be more fully described, and which seats on the bracket ring 25, and a series of arcuate lugs 36 circumferentially spaced by spaces 37 dening notches, said lugs and notches being of substantially equal lengths and being dimensioned to mate with the tongues 31 and notches 30 of the ring 25, to permit the lugs 36 on the cylinder 10 to pass freely down through the notches 30 respectively of the ring and the notches 37 on the cylinder to move freely downwardly over the tongues 31 respectively of the ring, in the process of assembling. These lugs 36 are spaced from the ange 35 by grooves 38, dimensioned to permit the tongues 31 in the bracket ring 25 to slide freely edgewise therein, after the cylinder 10 has been lowered through the ring until the rim flange 35 on said cylinder seats on said ring and while the cylinder so seated is being turned. Since there are four notches 30 and -four tongues 31 on the bracket ring 25, quadrantly arranged, and there are corresponding lugs 36 and notches 37 on the cylinder 10, the turning of the cylinder 45 in the ring, after being lowered therein and seated thereon, as described, will lock the cylinder to Ithe ring against axial withdrawal.,

Arotation in the axially locked position indicated, the ring e 25 has a hole 39 on its rear side and the cylinder head 32 notch 41 conforming in radius to the radius of the hole 39 and registering with said hole when the cylinder 10 is turned into proper position to lock it against axial withdrawal. The upper end of the back wall plate 20 has a forwardly turned lip 42 with a hole 43 in registry with the hole 39 in the ring 25, anda rod 44 passes through said hole 43, through the notch 41 in the cylinder head 32 and through the hole 39 in the ring 25, to lock the pump cylinder against turning. The rod 44 is in the form of a screw for the purpose to be described, -and has a head 45 heated on the back wall lip 42 and a groove 46 under the head in which a snap ring `47 fits, preventing the rod from being withdrawn lengthwise out of locking position, while permitting it to be rotated, for the purpose to be described.

The bottom wall 34 of the cylinder 10 is provided with two openings 52 and 53 to define the inlet 11 and outlet 12. The inlet opening 52 is at the rear of the bottom cylinder wall 33 and is provided with -a threaded neck 54 for the purpose of attaching a supply tube 55 thereto. To effect this attachment, there is provided a fitting 56 in the form of a nipple having yan end flange 57 on which is seated a soft gasket l58, and a gland or stuffing nut 60 threaded onto the neck 54 of the cylinder 10 for holding the fitting 56 in position and for compressing the gasket 58 to seal the connection between the neck 54 and the nipple 56. The supply tube 55 preferably made of rubber or of a suitable elastomeric plastic is forced on to the nipple 56 and extends down into the supply reservoir (not shown), as for example, a drum containing the liquid to be dispensed.

A check valve at the mouth of the intake 11 comprises a ball 62 resting on a seat 63 on the upper end of the nipple 56 and an inverted U-shaped wire 64 having its ends welded to the flange 57 of said nipple and straddling said ball, localizes the ball within the neck 54 at the bottom of the pump cylinder 10, while permitting the ball to be lifted away from its seat during the suction stroke of the pump.

The outlet opening 53 in the bottom wall 34 of the cylinder 10 near the front has a cylindrical collar or nipple 65 sloping downwardly and forwardly therefrom and rigidly secured thereto, as for example, by molding it in position and embracing said nipple is the upper end of a tube 66 made of resilient plastic material and serving as a spout for the pump. The upper end of the spout tube 66 where it embraces the nipple 65 is round, while the lower end 67 is inherently flat to seal said tube, and a clamp 68 secures this upper end of the spout tube to the nipple 65. A metal leaf spring 69 made in the form of an inverted T, has its upper end anchored in position to the nipple 65 by the clamp 68 and at its lower crosshead end 70 yieldably presses yagainst the lower flat end 67 of the spout tube 66 and thereby aids in sealably closing this end of the spout tube. A tubular metal guard 71 having the spout tube 66 and the spring 69 is secured at its upper end to the nipple 65 by the clamp 68. This guard 71 may be made from flat metal stock, bent iat its upper end into round shape to embrace the `upper end of the spout tube 66 and rectangularly shaped at its lower end to present a flat wall 72 against which the lower end 67 of said spout tube is pressed into closed position by the spring 69. The clamp 68 may simply consist of wing extensions on the upper end of the guard 71.

The hood 14 is designed to carry the pump piston 15 as described and to slide down and then up to move said piston in the pump cylinder 10 correspondingly. For guiding the hood 14 in this down and up movement, the hood has a peripheral U-shaped wall 80 with its outer ends 81 turned outward and wound around the inwardly turned rail edges 22 to serve as runners by which said hood may guidably slide along said rail edges. This peripheral hood wall 80 has a front circular section 82 concentric with the cylinder wall 33 and flat parallel side y through thei hole 101.

sections 83, and is suiciently larger than the cylinder holder 23 to permit said hood wall 80 to pass with clearance -freely over said holder andthe cylinder 10 supported thereon, during the down and up slide movement of the hood 14. Y

The U-shaped peripheral wall of the hood 14 is cut square at the top and at the bottom is cut on a bias to conform with the lower edge of the bracket flange 26, and its outer runner ends 81 extend the full height of the hood 14, thereby affording a relatively long slide bearing for the hood. Closing the top of the hood 14 is a cover plate 85 having a peripheral ange 86 overlapping the upper margin of the peripheral hood wall 80 and rigidly secured thereto, as for example, by spot welding. Across the rear wider section of this cover plate 85 is a stiffening bead 87, the more specific purpose of which, will be described more fully.

For securing the pump piston 15 to the hood 14, there is attached to the cover plate 85 of said hood a U-shaped metal bracket 88 having upper side flanges 90 secured to the underside of said cover plate, as for example, by spot welding, and having a base cross-piece 91 carrying the pump piston.

The piston assembly 15 carried by the bracket 88 comprises two superposed, axially aligned

circular metal discs

92 and 93 of equal outside diameters. The lower disc 92 is dished to define a cylindrical crown 94 extending to the underside of the upper disc 93 and secured thereto, as for example, by spot welding to form a permanent assembly therewith, and a brim 95 axially spaced from the upper disc 93 to form a recess to receive an O ring or gasket 96 of suitable resilient material, such as neoprene (chloroprene). This O ring 96 extends beyond the aligned peripheries of the two

discs

92 and 93 and is dimensioned to engage the inner periphery of the cylinder wall 33 with a slide sealing iit.

For attaching the pump piston 15 to the bracket 88, the disc 93 has yan extruded or spun center section 100 with a center hole 101 to receive a stud 102. This stud 102 has a base l103 seated on the crown 94 of the disc 92 and abutting the lower face of the disc 93 around the margin of its hole 101, this stud base being too large to pass This stud `102 also has a shank 104 passing freely through the hole 101 in the upper disc 93 with peripheral clearance to permit the stud to float from side to side freely in relation to the

piston discs

92 and 93 and passing through a hole 105 in the bottom cross-piece 91 of the bracket 88 with peripheral clearance to permit the stud to float from side to side freely in relation to said bracket, for the purpose to be described. Below the head of the stud 102 is a groove 106 to receive a snap ring 107 by which the stud is attached to the piston 15 and to the bracket 88.

With the construction described, the pump piston 15 is carried by the hood 14 through the bracket 88 and suficient freedom is afforded to the stud 102 to float sideways both within the assembly of the two

piston discs

92 and 93 and additionally within the bracket 88, so that the piston assembly comprising said discs and the gasket ring 96 m-ay be free to float sideways in relation to the bracket and Iadjust itself automatically to the conning action of the wall of the cylinder '10, as said piston assembly is moved down and up in said cylinder.

The means for moving the hood 14 and in turn the piston 15 up and down comprises the handle 16. This handle `16 is U-shaped in the form of a yoke and is preferably made of metal, and attached to the center of the bend of said handle by means of a screw 110 is a ball 111, which is preferably of plastic material and which serves as a knob to be held in the hand in the manipulation of the handle.

The handle 16 straddles the hood 14 and is pivotally connected to the sides of the wall plate 20. To provide such a pivotal connection, the sides of the wall plate 20 are provided with ears 112 respectively having respective holes 113 for receiving shoulder rivets 114 passing through the ends of the side arms of the handle 16 and serving as pivot pins for said handle.

For transmitting theangular movement of the handle 16 to the hood 14, there is provided a pair of similar parallel links 116 on opposite sides of the handle, each of said links having free pivotal connections at its

ends

117 and 118 to said hood and to said handle respectively. The pivotal connection between each link 116 at its lower end 117 and the corresponding side of the hood 14 comprises a pivot stud 120 passing through said link and through a raised section 121 of said hood defining a recess to receive the head of said stud. This pivot stud 120 has a groove to receive a snap ring 122 by which the stud is retained in link mounting position.

The pivotal connection between each link 116 at its upper-end 118 and the corresponding side arm of the handle 16 comprises a pivot pin 123 in the form of a rivet passing through said link and said handle. This upper end 118 of the link 116 is offset from the body of the link to form a projection 125 at this end, which rests against the corresponding folded rail side 22 of the wall plate 20, in uppermost position of the handle shown in FIG. 1, thus limiting the angular movement of the handle in its upward stroke.

On the downward stroke, the handle 16 is limited either by the engagement of the top of the hood 14 with the top ofthe cylinder or by an adjustable stop device, according to the desired length of piston stroke. This stop device comprises a U-shaped stop member 126 preferably of metal having its lower leg 127 longer than its upper leg 128 toseat on the top of the pump cylinder 10 in lowermost position of said stop member and having its back cross-piece 129 slidably engaging the front face of the wall plate 20, to hold said stop member against rotation, while permitting it to move up and down. The rod 44 serving to lock the pump cylinder 10 against rotative movement is a screw threaded through the two legsv 127 and 128 of the stop member 126. Thus, when the screw 44 is turned through its slotted head 45, although the screw will be retained against axial rnovement bythe snap ring 47, it will move the stop member 126 up and down.

The bead 87 on the top plate 85 of the hood 14 pres'ents an edge 131, and the upper leg 128 of the stop member 126 is suciently short, so that said bead edge clears said leg during the downward stroke of the hood 14, but the lower leg 127' of the stop member is sulfic'iently long, so that when said stop member is in elevated position, said lower leg is in the path of downward movementof said bead edge and thereby serves as a stop for said hood'in limiting its downward stroke. If the stop member126 is located at its bottom position, as shown in FIG'. 1, the hood 14' will be free to move downward a full stroke, being limited by the engagement of the top' plate 85 ywith the top of the cylinder flange 35. If it is desired to discharge a less amount of liquid per stroke than the full capacity of the pump cylinder 10, the screw 44 is turned to bring the stop member 126 up to the desired position, according to the desired amount of liquid to `be discharged per pumping stroke.

'Ihe effective capacitive height of the pump cylinder 10'is greater than the length of the full stroke of the hood 14 and in turn of the piston 15'. Therefore, the suction created by the piston 15 in its upward movement, does not completely fill the cylinder 10 with liquid, but leaves an air space between the top of the liquid in thecylinder and the bottom of the piston, even when the stop member 126 controlling the length of the piston stroke is in its lowermost position shown in FIG. 1. As a result, an air cushion is interposed between the liquid and the piston 15 during the downward pumping stroke of the piston, this air barrier being maintained until the piston reaches the bottom of this stroke. At the bottom of the downward stroke of the piston 15, although all 6 of the liquid in the cylinder 10 has been discharged through the outlet 12, the piston is still spaced above the bottom of said cylinder, so that the liquid is drawn through the intake 11 and into the cylinder 10 during theupward suction stroke of the piston against the air barrier on the underside of the piston. The piston 15 is, therefore, never in contact with the liquid that may be in the cylinder, and therefore, there is no danger of the liquid coagulating on the piston, or escaping above the piston and over the sides of the cylinder 10, or of being contaminated by the piston. This feature of maintaining the piston 15 out of contact with the liquid being pumped is useful in any case, since liquids adhering to the piston for prolonged periods of time become thick and cause the piston to stick and the effect of this feature in preventing contamination of the liquid is particularly useful in cases where the liquid to be dispensed is a food or a medicine which must be handled under the strictest of sanitary requirements.

The pump of the present invention may be employed for dispensing a shot of liquid of measured predetermined amount by a single handle operation. The pump is particularly useful, for example, in cases where a single shot of detergent is to be dumped into a batch of water for washing dishes or clothes, or in a soda fountain, where a single measured shot of syrup is to be discharged into a glass or dish for a single set-up, or in a barber shop or beauty parlor, where a single batch of shampoo is employed for a single hair washing, or in cases where it is desired to ll small containers with individual portions of liquid foods, such as sauces and cream, or individual portions of lubricants, `liquid medicine, etc.

` Although the operation of the pump is believed apparent from the foregoing description, it is herein summarized briefly.A

' At the endof an upward suction stroke of the piston 15, the handle 16 will be in the upper upright position shown in FIG. 1, with the ends 118 of the links 116 abutting the rail sides 22 of the wall plate 20. In this limiting position,l which is the position assumed, when the pump is inactive,l the handle 16 with its knob 111, will be in rearward position near the supporting wall 21 and out of the way, so that no part of this handle projects forwardly ofthe hood 14 or of the cylinder 10. Although the handle 16 under these conditions is in unojbstrusive position, it 'is nevertheless in convenient position to be grasped for the next pumping operation. Also, although'nosprings are employed to hold the handle 16 in the upright position shown in FIG. l, the linkage mechanism supporting the handle and the friction at the pivot mounting 114 for the handle are such, as to maintain the handle in lthis position, until manipulated for pumping action.

While the handle 116 is in upright position indicated in FIG. l, the cylinder 10 has a charge of the liquid therein from the previous suction stroke of the piston 15 at a level spaced below Vthe piston, the hood 14 is in elevated position, the cylinder .10 is exposed and the spout tube 66 is closed. Since the cylindrical wall 33 of the cylinder 10 is transparent, the charge of liquid in said cylinder is visible to the observer, so that he can gauge by eye the amount of this charge and can note the condition of the liquid.

Upon downward swinging operation of the handle 16 about its fixed pivot-supports 114, the links 116 transmit this downward movement to the hood 14. Since the hood 14 is guided and restricted by the rail sides 22 of the wall plate 20 to straight up and down movement, the lower ends 117 of the links 116 move along straight lines A (FIG. 1) while the upper ends 118 of the links swing with the handle 16 in an arc B.

' During the downward swinging movement of the handle 16, as described, the hood 14 is moved downward thereby, and since the piston 15 is carried by said hood through thebracket 88,7the pistonmoves downward in the cylinder 10, forcing the liquid out through the outlet 12 by the pressure of said piston on the air cushion between said piston and the top surface of the liquid. During this downward pumping action, the ball 62 of the intake valve is forced down on its seat 63, while the liquid is forced through the resilient spout tube 66, opening up the at discharge end 67 of said tube against the action of the spring 69. As the piston 15 moves downward in the cylinder 10, it is free to center itself automatically in the cylinder due to the oat mounting of said piston on the bracket 88.

As the handle 16 is moved downward, the hood 14 telescopes over the cylinder and this handle continues its downward movement, until the top of the hood reaches the top of the cylinder or the bead edge 131 on the top plate S5 of the hood reaches the leg 127 of the stop member 126, if the stop member be adjusted to so limit the downward movement of the handle. In either case, at the end of the downward stroke of the handle 16, although all of the liquid has been discharged from the cylinder 10, the piston is still spaced above the bottom of said cylinder to maintain the air cushion underneath the piston. When the handle 16 is moved upward about its pivot mounting, the suction in the cylinder 15 created by this action, closes the discharge end of the spout tube 66, aided by the spring 69 and lifts the ball 62 of the intake valve ofi its seat 63, thereby causing the liquid to be sucked in from the supply reservoir (not shown) through the intake 11 and into the cylinder. The liquid drawn into the cylinder by this suction action is still prevented from reaching the level of the piston by the intervening air cushion. The upward movement of the handle 16 is continued, until said handle reaches the limiting position indicated in FIG. l, in prepa-ration for the next pumping stroke.

If it is desired to alter the stroke of the piston, so that the amount of each charge dispensed for every operation of the handle 16 is correspondingly varied, the screw 44 is turned through its slotted head 45 to move the stop member 126 up or down, until the desired limiting position is reached. The extent of adjustment of this stop member 126 in terms of the amount of liquid dispensed at each handle operation, may be gauged by eye, by observing the contents of the cylinder 10 through its transparent wall 33 at the end of the suction stroke, or a scale may be provided in connection with the stop member 126 calibrated to translate the position of said stop member into the amount of liquid dispensed at each handle operation.

While the invention has been described with particular reference to a specific embodiment, it is to be understood that it is not to be limited thereto, but is to be construed broadly and restricted solely by the scope of the appended claims.

What is claimed is:

l. A liquid pump comprising a frame structure adapted to be supported on a wall and having side rails extending upright in wall supported position of said frame structure, a pump vessel on said frame structure adapted to extend in upright position in wall supported position of said frame structure, and having an inlet and an outlet, a hood for said vessel having side runners slidably engaging said rails, said hood being adapted to move along said rails in telescopic relationship to said vessel, handle means supported on said frame structure for so moving said hood, and a piston carried by said hood and extending into said pump vessel for movement therein.

2. A liquid pump as described in claim l, wherein said hood has a wall on the end thereof remote from said pump vessel, said pump comprising a bracket connected to the inner side of said hood wall and depending therefrom in wall supported position of said frame structure, said piston being mounted on said bracket.

3. A liquid pump as described in claim 1, wherein said handle means comprises a U-shaped handle straddling said hood and having its ends pivotally secured to the sides of said frame structure, and a pair of similar parallel links, each having one end pivotally secured to a corresponding arm of said handle and the other end pivotally secured to the corresponding side of said hood.

4. A liquid pump comprising a bracket adapted to be supported on a wall and having a guide, said bracket including a ring, a pump vessel located in said ring and supported therefrom, catch means between the head of said vessel and said ring, permitting said vessel to be dropped in said ring and turned to lock said vessel to said ring against axial withdrawal from said ring, a locking screw extending through a hole in said bracket and through an opening in the head of said pump vessel when turned into axially locked position, to lock said vessel against turning in said axially locked position, said screw being held against axial movement but being permitted to turn, a piston carrier supported for movement along said guide, a piston on said carrier and in said vessel, a handle supported on said bracket for movement, connecting means between said handle and said piston carrier to move said piston in said vessel upon movement of said handle, and a stop device for limiting the stroke of said piston in said vessel, threaded on said screw and disposed in the path of guided movement of said piston carrier, said screw extending in the general direction of guided movement of said piston carrier to vary selectively the stroke of said piston upon the turning of said screw.

5. In a liquid pump, the combination comprising a pump vessel having an inlet and an outlet near one end and open to the atmosphere at its other end, a hood fitted in one extreme position over the open end of the pump vessel in telescopic relationship thereto, means supporting said hood for slide movement along said vessel in telescopic relationship thereto, -a piston carried by said hood and extending into said pump vessel for reciprocating movement therein with said hood, said piston in said extreme position of the hood being at the end of its intake stroke, a handle, means supporting said handle for movement, and connecting means between said handle and said hood for slidably moving said hood from said extreme position telescopically over and along said vessel and for simultaneously moving said piston through its discharging stroke upon actuation of said handle.

6. A liquid pump comprising a pump cylinder having a transparent peripheral wall permitting visual observation of the liquid contents of said cylinder, a piston in said cylinder movable therein through intake and discharge strokes, a hood with an opaque peripheral wall disposed over said cylinder and carrying said piston, means mounting said hood for movement along said cylinder from one extreme position in which said cylinder is almost completely exposed and said piston is at the end of its intake stroke and is encircled by said hood to another extreme position at the end of the discharge stroke, in which said hood covers a substantial length of said cylinder and encircles said piston, a handle, and connecting means between said handle and said hood for moving said hood between said extreme positions upon actuation of said handle.

7. In a liquid pump, the combination comprising a pump vessel having an inlet and an outlet, a hood, a piston carried by said hood and extending in said pump vessel for reciprocating movement therewith, handle means for moving said hood over and along said vessel in telescopic relationship therewith, a stop device in the interior of said hood and in the path of movement of a part rigid with said hood for limiting the stroke of said piston in said vessel, and means for adjusting the position of said stop device to vary selectively the stroke of said piston.

8. A liquid pump comprising a bracket adapted to be supported on a wall and having a guide, a pump vessel mounted on said bracket, a hood provided with a cover plate at one end and supported for movement along said bracket, a piston carried by said hood and in said vessel, a handle supported on said bracket for movement, connecting means between said handle and said hood for moving said hood over and along said Ivessel in telescopic relationship therewith, a stop device in the interior of said hood and in the path of said cover plate for limiting the stroke of said piston in said vessel, and a screw supported on said bracket against endwise movement and having a head accessible for operation in the vicinity of said cover plate, said screw having a threaded engagement with said stop device for adjusting the position of said stop device upon rotation of said screw to vary selectively the stroke of said piston.

White et al. Oct. 2, 1877 Schmidt Apr. 5, 1892 10 Wallace Feb. 27, 1894 Ralph Oct. 10, 1933 Wayer et al. Feb. 27, 1934 Wilkes Sept. 11, 1934 Stoddard Dec. 9, 1941 Estenes Oct. 20, 1942 Heftler Mar. 2, 1943 Geissler Jan. 25, 1944 Packwood Feb. 8, 1949 Geroy Ian. 17, 1950 Cripe June 19, 1951 Meczelski Aug. 7, 1951 Churchill et al July 29, 1952 Stcczynski et al. Nov. 3, 1953 Yuza Nov. 8, 1955 Keller Nov. 29, 1955 Brown Jan. 10, 1956 Simpson Ian. 31, 1956 Dueringer et a1. Feb. 28, 1956