US3361078A

US3361078A - Liquid dispenser

Info

Publication number: US3361078A
Application number: US523823A
Authority: US
Inventors: Walter W Cooprider
Original assignee: Diamond International Corp
Current assignee: Silgan Dispensing Systems Corp
Priority date: 1965-12-15
Filing date: 1965-12-15
Publication date: 1968-01-02
Anticipated expiration: 1985-01-02

Description

Jan. z, 1968 W, w. COOPRmER 3,361,078

LIQUID DISPENSER Y Filed Dec. l5, 1965 l ,o noi ATTORNEYS United States Patent O 3,361,078 LIQUID DISPENSER Waiter W. Coopriderg Diamond Bar, Calif., assignor, by

mesne assignments, to Diamond International Corporation, New York, N.Y., a corporation of Delaware Filed Dec. 15, 1965, Ser. No. 523,823 13 Claims. (Cl. 10S-188) ABSTRACT F THE DISCLOSURE A reciprocating liquid pump having an inlet valve for axial seating and unseating movement with respect to an inlet port through one axial end of the pump cylinder and in which the plunger has an axial discharge passage extending through it together with an outlet valve port within said passage. The inlet valve includes a valve stem slidably received within the plunger discharge passage and supporting an outlet valve for seating engagement with the outlet valve port. Also, the inlet valve stem carries a sealing valve in fixedly spaced relation to the inlet valve for seating engagement with the outlet valve port at one extremity of the movement of the plunger, the arrangement being such that, at the opposite extremities of the plunger stroke, the plunger passage is closed either by the outlet valve or by the sealing valve.

This invention relates to improvements in iuid dispensing pumps of the types generally exemplified in the co-pending application of Douglas F. Corsette, Ser. No. 318,683, and of common ownership herewith, now Patent No. 3,228,347, issued Ian. 1l, 1966.

In said prior application, as well as in the present invention, the pump valves and plunger are relatively interconnected to coordinate their actuation and to transmit suitable components of the reciprocating plunger movement to the respective valves in a manner to actuate them independently of gravity. In said prior application, an outlet valve carried by the plunger was yieldably connected to the inlet valve throughout the operative portion of the pump stroke to actuate both valves in coordinated relation to the plunger stroke. In those embodiments of the copending application which employed valves actuated by movement parallel to the plunger reciprocation, only the lower or inlet valve was positively seated in the fullydepressed position of the plunger to afford a shipping seal. However, the plunger discharge passage was left open by virtue of the then unseated outlet valve and could not prevent leakage of any iluid which might have entered the pump chamber. Only in a special embodiment of the invention disclosed in said prior application, and employing a special resiliently deformable outlet valve, was the plunger discharge passage positively closed in the fullydepressed position of the plunger.

The present invention, however, provides for the obtaining of this same additional advantage even in pumps wherein the valves are actuated by movement generally in the same direction as the plunger and without the need for such special deformable type of outlet valve.

Thus, important and primary objects of the invention are to provide such a pump employing inlet and outlet valves actuated by -movement of the plunger and in which one or the other of the said valves is positively seated by forces transmitted from the plunger in either its fullyraised or its fully-depressed positions; and to provide such a pump which includes an auxiliary seal or sealing valve for cooperation with the plunger discharge passage when the plunger is fully depressed to prevent the escape through that passage of liquid or fluid from within .the` pump chamber.

p 3,361,078 Patented Jan. 2, 1968 ICC It is a further important object to provide in such a dispensing pump a novel disposition and interconnection of the inlet and outlet valves with respect to each other and to the plunger for transmitting from the plunger, throughout the operative portions of its stroke, yielding forces for biasing the respective valves toward their seated or unseated positions respectively in accordance with the direction of plunger reciprocation.

A still further object is to provide a pump structure incorporating the foregoing novel features and advantages, which is nevertheless adapted for production with the use of minimium number of parts, which parts are individually adapted for economical mass production and assembly.

Further, it is an object to provide such a pump structure in which the several pump parts or components are particularly adapted for assembly in a minimum number of operations, wherein various of the separately-formed components cooperate to guide each other into assembled relation.

In accordance with the present invention, the inlet and sealing valves are disposed at opposite ends of a common valve stem, for cooperation with the inlet port and the plunger discharge passage respectively, to simultaneously close said port and said passage in the fully-depressed position of the plunger.

A further-- specific feature of the invention consists in the particular association of the inlet valve and plunger spring, in a manner such that the plunger is adapted to guide the spring onto its seat Within the pump chamber, -as the pump components are assembled, and thereafter to facilitate its removal from the chamber; and the spring in turn functions to limit the unseating movements of the inlet valve.

Further incidental features and objects will become apparent from a consideration of the preferred embodiment of the invention, as hereinafter described, and as illustrated in the accompanying drawings, in which:

FIGURE l is an axial cross section through a liquiddispensing pump in accordance with the invention with the plunger in its fully-projected position at the end of the suction stroke and showing a portion of the container on which the pump is adapted for mounting;

FIGURE 2 is a view similar to FIGURE l but showing the pump plunger in its fully inwardly-projected position to establish the several shipping seals; and

FIGURE 3 is a section on the line 3-3 of FIGURE l, showing the structure of the inlet valve as employed in the preferred embodiment of the invention. i

In the following detailed description of the preferred embodiment, the various elements or components of the invention and their relationships will -be described in specific terminology in order to facilitate an understanding of the best mode contemplated by me of practicing the invention. However, it is to be understood that the invention encompasses various changes, modifications, and omissions, such as will be obvious topersons of ordinary skill in the art; and the specific disclosure and specific terminology herein are not intended to limit the scope of invention in any manner not specifically required by the appended claims.

The liquid-dispensing pump illustrated in the accompanying drawings is adapted for application to a conventional container, which is exemplified at C in FIGURE l, to be supported within the dispensing opening thereof for actuation of its reciprocating plunger by finger pressure in a well-known manner. The pump is adapted and primarily intended for fabrication from conventional plastic materials, and the components in the present preferred embodiment are especially constructed to facilitate their assembly in the completed structure.

The pump structure comprises a pump cylinder, generally designated 10, which is open at its upper or outer end, while its inner end 12 is closed, but is formed to dene an inlet port 14 communicating with the liquid contents of the container through a conventional dip tube 16 supported by and herein shown as constituting an integral portion of the cylinder 10.

For supporting the cylinder within the dispensing opening defined by the container C, as herein exemplified by its externally-threaded neck N, upper or outer end of the cylinder 10 is provided with a preferably integral collar 18 which may, if desired, constitute an integral portion of the cylinder. The lower portion of this collar, in the form of sleeve 20, is adapted for reception through a circular opening in a conventional container closure cap D, here illustrated as provided with an internally-threaded skirt by means of which it is adapted for application to the externally-threaded neck of the container C. A radial ange 22 projecting outwardly from the collar 18, abuts against the lower face of the top wall of the cap Dv and also is adapted for reception between such lower face of the cap and the upper end of the container neck. Preferably the plastic material, from which the cylinder and gasket 22 are formed, is of a suiiiciently-exible nature to readily adapt the flange 22 for its function as a gasket.

The container cap D and cylinder are secured against axial displacement by means of the gasket or ange 22 in conjunction with an outwardly-directed and downwardly reversely-swaged beading 24 of the collar 18 which is formed by a suitable swaging operation after the cap is applied to the collar.

Disposed for reciprocation in the cylinder 10 is the pump plunger which is designated 26 in its entirety. At its inner end, the plunger 26 is formed With a suitable piston, which may be of the double-skirted type, including the generally depending main skirt 28 and, if desired, the auxiliary or sealing skirt 30. The hollow stem 32 of the plunger extends outwardly for reciprocation through the open outer end of the cylinder 10; and the plunger, including -both its piston portion and its hollow stem, is provided with an axial discharge passage 34 extending completely therethrough and operative to establish communication between the pump chamber 36 and a discharge head 38 carried at the upper or outer end of the plunger stem. The plunger 26 is normally urged resiliently outwardly toward its outermost or fully outwardlyprojected position by means of a coil spring 40 within the plunger chamber and under compression between the plunger and the closed end 12 of the cylinder.

For limiting the outward projection movement of the plunger on its suction stroke, the cylinder 10 is formed internally with a radially inwardly-projecting stop rib or bead 42 which, in the preferred embodiment, is formed after assembly of the plunger within the cylinder by a reversely inwardly-bending and swaging operation similar to that employed in connection with the beading 24 and substantially as disclosed in the said U.S. Patent No. 3,228,347 of Douglas F. Corsette. The plunger in turn is formed with an upwardly or outwardly `presented annular shoulder or abutment 44 adapted for abutting engagement with the plunger stop or beading 42. Preferably, the relatively abutting stop ribs or

beadings

42 and 44 have their abutting surfaces formed for sealing engagement with each other under the pressure of the spring 40 to thus prevent leakage or seepage of any liquid which might nd its way into the cylinder through the conventional vent opening 46 above the lower or sealing edge of the piston skirt 28 when the plunger is in its raised position. Preferably, the auxiliary or sealing skirt 30 of the plunger also is interposed between the vent 46 and the open outer end of the plunger to provide a second seal or barrier with the cylinder against such upward leakage or seepage of liquid when the plunger is in its fully outwardly-projected position. Since the sealing skirt 30 thus duplicates the sealing function of the annular shoulder 44, it will be apparent that the skirt 30 may be omitted or, if desired, the sealing function of the shoulder 44 and/ or the stop shoulder 42 may be omitted.

The plunger head or discharge head 38 herein illustrated is mainly of conventional structure and exemplifies any of various types of discharge heads. In the present embodiment, such discharge head is provided with a spray orifice 48 which communicates with the plunger discharge passage 34 in known manner through a system of grooves or channels partially shown at 50, extending between the interfaces of the socket 52 within the discharge head 38 which receives the outer end of the plunger stem. As is shown in FIGURE l, the plunger head is formed with an axially-extending probe 54 which is afxed to the upper or outer end wall of its socket 52 and extends axially into the passage 34, but in radially inwardly-spaced relation from the inner walls thereof to permit free flow of liquid. The depending free inner end of the probe 54 is adapted for engagement with the discharge Valve 56 to limit the unseating thereof and to coo-perate through it with the inlet valve as hereinafter more fully described.

For securing the plunger in its fully inwardly-projected position to establish various shipping seals, the plunger discharge head 38 is provided at its lower or inner end with an externally-threaded plug 58 which is adapted for reception in the outwardly-opening internally-threaded socket `60 of the collar 18. The particular structure here employed is known and disclosed in various prior patents of Calrnar, Inc. and, therefore, will not be described in detail other than to explain that the socket and plug 60 and 5S respectively may, if desired, be provided with a cooperating sealing flange 62 on the plug 58 for sealing engagement with the upwardly-presented sealing surface 64 of the collar and with a depending sealing skirt 66 on the collar adapted for sealing reception in a groove 68 opening axially into the threaded socket 60 of the collar.

The inlet port 14 of the pump cylinder is controlled by means of the inlet valve 70 which is disposed in the pump chamber 36 for reciprocation axially into and from seating engagement with the valve seat 72 at the inner end of the inlet port 14.

The discharge valve 56 is disposed in the discharge passage 34 for axial seating and unseating movement with respect to a valve seat 74 which controls a discharge port 76.

In the illustrated embodiment of the invention, the discharge passage 34 is shown as cylindrical, and the outlet or discharge port 74 is of circular configuration concentric to the passage but of substantially smaller diameter than the passage 34, and is formed at the inwardly-directed free end portion of a generally cylindrical sleeve 78. At its upper or outer end, the sleeve 78 is aiiixed to and preferably integral with the plunger stern, but the depending portion of the sleeve 78 is spaced radially inwardly from the inner wall of the discharge passage 34 to dene an ax1ally inwardly-opening annular sealing groove 8i) between the free end portion of the sleeve and the discharge passage wall.

The inlet valve 70 comprises a rigid valve stem 82, having an outwardly or upwardly-opening blind bore 84 therein and opening axially through its outer end for telescoping reception of and frictional engagement with the enlarged lower end 86 of the substantially-rigid outlet valve stern 88. Although the valve stems 82 and 88 are described as rigid, it is to be understood that they are sufficiently rigid to transmit a seating thrust from one valve to the other, but nevertheless have sucient lexibility and elasticity to permit ready assembly of the valves by forcing the enlarged head 86 of the outlet valve stem 88 into the bore 84 through a radially inwardly-projecting annular snap ring 90 near the upper end of the bore 84. After such insertion, the relatively smaller diameter snap ring 90 overlies the upwardly-presented stop shoulder 92 of the head 86 so as to establish a positive tension transmitting coupling between the two valve stems in their fully-extended telescoping relationship. At the upper or outer end of the inlet valve stem 82 is carried a sealing valve 94 for cooperation with the outlet port 76 to positively seal same against the escape of liquid from the pump chamber 36 when the plunger is secured in its fully inwardly-projected position as in FIGURE 3. For this purpose, the sealing valve 94 is in the form of a sleevelike extension of the valve stem 82, having outwardly-diverging conical lip 96 at its free end edge for wedging reception in the sealing groove 80 in the plunger `discharge passage.

It will thus be apparent that the interengaged surfaces of the groove 80 which coact with the valve 96 define a valve seat which is directed generally in an opposite axial direction from the valve seat 74 for the outlet or discharge valve 56, although both control the saine discharge or outlet port in the instant em-bodiment. The lower end portion of the sleeve 78 is preferably adapted for positivelyacting thrusting engagement with the stop beading 94] to limit the relative contracting movement of the telescoping valve stems 88 and 82 to insure that, in the fullydepressed position of the plunger, an axial seating thrust will be transmitted from the pump plunger through the sleeve 78 and valve stem 82 to the inlet valve 70 to firmly seat the latter so as to lbar the admission of the liquid into the pump chamber 36.

While the specific structure of the inlet valve and its cooperating seat may assume various forms without departing from the scope of the invention, the invention nevertheless contemplates a particularly advantageous structure of these parts to facilitate the assembly of the various components and also to utilize the valve spring 40 as means forlimiting the unseating movement of the inlet valve 70.

With this in mind, the inlet port 14 and valve seat 72 in the closed lower end of the cylinder are encircled by the annular groove 97, which is concentrically encircled by the annular spring seat 98, the axially-presented outwardly-directed seated surface of which is adapted for seating reception of the innermost or terminal coil of the spring `40 to support the latter above the bottom of the groove 97. It will be seen that the spring seat 98 is disposed in outwardly-spaced relation from the radially inner Wall of the groove 97 and that the inlet valve 70 is provided with a circular series of axially-directed fingers 100, each terminating at its free end in a radially outwardlydirected key portion 102. The said free ends of the fingers 100 extend into the groove 97 between the inner wall thereof and the outer wall which may be regarded as dened by the spring seat 98. The spring seat 98 is provided with a plurality of axial keyways 101 for reception of the respective keys 102 for axial sliding movement in the keyways between the blind axial end of the groove 97 and the terminal coil of the spring 40.

If desired, the end wall 12 of the cylinder may further be provided within the pump chamber 36 with an axially outwardly-tapering annular rib surrounding spring seat 98 so that its radially inner tapering surface functions as a vguide for directing the spring onto its seat as the parts are assembled and, of course, for directing the keys 102 into` the groove 97. The outer surface of the tapered rib 194 cooperates with the depending peripheral edge of the piston skirt 28 :by defining an annular sealing groove 10S for wedging and sealing reception yof the skirt in the fully inwardly-projected position of the plunger.

To facilitate the assembly of the several component parts of the pump structure, itis desirable to form the valve stem 82 with a depending extension 106 adapted to be guided into the inlet port and its communicating inlet passage by the tapered valve seat 72. This pilot 106 has ample clearance with the port and inlet passage to avoid obstructing the flow of liquid therethrough, but at the same time affords a sufliciently close t therewith to main` tain the valve stem 82 in substantial axial alignment with the cylinder 10. l

It will be understood that, in assembling the pump structure, the plunger spring 40 will normally be assembled axially onto the valve stern 32 with its lower end resting on the keys 182, following which the valve stem 82 with its associated inlet valve and the spring 40 are inserted into the cylinder through its open end to be guided into proper operative position by reception of the pilot 102 in the inlet port seat 72 and port 14, following which slight rotation of the valve stem may cause its keys 72 to register with the cooperating keyways 101. The plunger 26 together with the plunger discharge head 38 and the outlet valve 56 preferably will be assembled separately from the cylinder and inlet valve by inserting the outlet valve 56 and its valve stem 88 inwardly through the open outer end of the plunger passage 34, whereupon its depending enlarged head 86 at the inner or lower end of the valve stem 88, preferably being of suiciently small diameter to pass freely through the valve port 76, will permit the valve in its entirety to drop therethrough until its movement is arrested by seating engagement of the relatively-larger outlet valve 56 or seat 74. The discharge head 38 then is applied over the open end of the plunger stem or tube and secured thereon in fluid-tight manner in any conventional way, as for instance by the snap rings and grooves indicated at 41 in FIGURE l.

In subsequently applying the pre-assembled plunger, plunger head, and outlet valve to the pre-assembled cylinder I0, spring 40, and inlet valve structure, the piston end of the plunger is inserted into the open outer end of the cylinder 10. The head 86 at the inner end of the valve stem 88 is directed into the bore 84 of valve stem 82 by engagement with the tapered surface 96. The

, head 86 is then centered with respect to the snap ring by means of a conical pilot portion 87 and is forced through such snap ring by axial abutment of the relatively-adjoining ends of the Valve stem .S8 and the probe 54 carried by the plunger discharge head 38. After the parts are thus assembled, they are secured in their assembled relation by maintaining the plunger in a partially-depressed or inwardly-projected position within the cylinder, while the stop shoulder 42 is formed by known methods to limit the subsequent outward projection of the plunger.

After being thus assembled, the plunger and cylinder may be interlocked even prior to assembly to a container, to lirmly maintain the plunger in its fully inwardly-projected or depressed position, by applying axial inward pressure to the plunger head 38 preferably by means of its nger piece or push button portion 39 to move the threaded plug 58 thereof into the threaded socket 60 and thereafter relatively rotating the respective parts until they assume the positions shown in FIGURE 3. Such rotation may be imparted by suitable tools of a conventional nature and in a conventional manner; and, to facilitate this operation, the collar 18 at the outer end of the cylinder is formed to define an axially inwardly-presented series of teeth or castellations 19 for cooperation with mating teeth or castellations on a sleevelike tool or wrench.

In the operation of the invention, same will normally be received by the ultimate user applied to a liquid container and secured with the plunger in its fully-depressed position to thus establish the various shipping seals which prevent leakage of the liquid contents in transit and storage and/or during rough handling.

In order to place the pump into use, it is necessary only to rotate the plunger head 38 so as to release the threaded interconnection thereof with the collar 18, following which the spring 40 automatically projects the plunger outwardly on a suction stroke, following which reciprocation of the plunger by intermittent finger pressure on its finger piece 39 will produce the pumping action in well-known manner. On each upward or outward stroke of the plunger, the inlet valve 70 will be freed of seating pressure by the plunger, and the outward suction stroke of the plunger will cause the yieldable frictional connection between the telescoping valve stems 32 and 88 to seat the outlet valve S6 and to unseat the inlet valve 70. While such tensional interconnection between the valves will, in many instances, merely supplement the actions of gravity and of differential tiuid pressures, it will be apparent that the pump of the instant invention is not reliant upon these latter actions and, in particular, is adapted to function even though the structure is wholly or partially inverted.

The seated and unseated relationship of the outlet and inlet valves will thus draw fluid into the pump chamber 36 through the open inlet port 14 throughout the outward or suction stroke of the plunger. Near the conclusion of the suction stroke, the axial abutment between the valve stem portions 86 and 9i) will establish a positive coupling between the valves through which the full force of the plunger spring will be applied to seat the outlet valve 56 to thus provide a seal in the plunger discharge passage 34. At the same time, the auxiliary piston skirt 39 as well as the sealing interengagement between the stops or annular stop shoulders 42 and 44 will prevent any seepage or leakage of liquid from the container through the vent opening 46 and outwardly between the plunger and cylinder. Thus, there will be provided a suitable seal or seals for preventing inadvertent discharge or leaking of liquid through the pump in the fully-projected position of the plunger. This may be eiiective not only to prevent loss of the container contents in the event of tipping or inversion of the container; but, if desired, may be utilized as a shipping seal in lieu of the shipping seals provided when the plunger is secured in its fully-depressed position.

On initiation of each inward or compression stroke of the plunger, the probe 54 in the plunger discharge head will abut axially against the valve stem 88 to transmit a frictional seating force through the telescopicallyarranged valve stems 88 and 82 to the inlet valve 70 to thus seat the same even independently of the increased fluid pressure within the pump chamber 36. It will be appreciated, of course, that the frictional interconnection between the valve stems 82 and 88 will previously have opened the outlet valve 56 so that, throughout the balance of the compression stroke, iiuid within the pump chamber 36 will be forced outward through the discharge passage 34 and outlet port 76 into the discharge head where it ows outwardly through the passage Si) and spray orifice 48.

In the particular structure herein illustrated, it will be appreciated that the downward or compression stroke of the plunger is limited by abutment between the threaded collar 18 and plug 58 before it reaches the position shown in FIGURE 2 and before the shipping seals are interengaged or activated. Upon release of the finger pressure from the linger piece 39, the plunger is again caused to move outwardly through pressure of its spring to draw a further charge of liquid into the pump chamber 36. Thus, the plunger may be reciprocated as long as pumping action is desired.

When it is desired to return the plunger to its fullydepressed and sealed position, it is again pushed inwardly to bring the threads of the threaded plug into engagement with the threads of the internally-threaded collar, following which relative rotation between the collar and the plunger in the appropriate direction will result in moving the plunger to its fully-depressed position and maintaining it in such position until released for further use.

It will be apparent that, as the plunger is urged to its fully-depressed position, the inlet valve 70 will be positively seated due to the axial compressive thrust transrnitted from the plunger through the sleeve 78 and its valve stern 32. As an incident to transmitting such pressure, the sealing valve 94 at the outer end of the valve stern 32 is positively seated over the Outlet or discharge port 90, its resiliently flexible sealing skirt being wedging- 1y received in fluid-tight sealing relation in the groove S0.

Thus, where the pump of the invention has its plunger secured in fully-depressed position before application to a container, the inlet valve will be seated to prevent admission of tiuid from the container into the pump chamber. After the pump has been placed in use, there will, of course, be some residual liquid within the pump chamber when the plunger is fully depressed to its sealed position; but the closed or seated relation of the sealing valve 94 with respect to the discharge or outlet port at such time will positively resist any leakage or seepage of fluid outwardly beyond such port through the discharge passage. Although the air vent 46 at this time may be positioned to `admit liquid from the container into the cylinder 10 at a location above the piston structure, the escape of any such liquid through the outwardly-opening end of the cylinder is prevented in a manner well known by means of the

seals

62 and 66.

Having thus described my invention, I claim:

1. A liquid-dispensing pump, comprising a pump cylinder open at one axial end and formed with an inlet port adjacent its other axial end, a plunger disposed for axial reciprocation in said cylinder to dene therewith a variable volume pump chamber communicating with said inlet port, spring means compressed between said plunger and cylinder for resiliently urging the plunger axially outwardly through said open end of the cylinder on its suction stroke, said plunger projecting axially through said open end of the cylinder for movement into said cylinder on its compression stroke, said plunger being formed with a discharge passage extending axially therethrough from said pump chamber, means in said discharge passage defining an outlet port, a discharge head on said plunger communicating with said discharge passage, a pump outlet valve disposed in said discharge passage on the axially remote side of said `outlet port from the pump chamber for axial seating and unseating movement relative to said port, a pump inlet valve disposed in said chamber for axial movement outwardly and inwardly of said chamber respectively into and from seating relation with respect to said inlet port, means on said inlet valve and said cylinder for positively limiting the unseating movement of the inlet valve, lost-motion means for establishing a positive tension transmitting connection between said inlet and outlet valves near the end of the suction stroke of the plunger for positively seating said outlet valve by seating force derived from said spring means, thrust transmitting means operative near the end of the plunger compression stroke for establishing a positive interconnection between said plunger and the inlet valve for positively seating the latter, interlocking means on said plunger and said cylinder for selectively securing the plunger in its fully inwardly projected position, and means establishing a yieldable frictional coupling between said inlet and outlet valves throughout the major portion of the plunger stroke in each direction.

2. A fluid-dispensing pump as deiined in claim 1, in which said lost-motion means comprises telescopicallyinterconnected valve stems extending from the respective inlet and outlet valves axially through said pump chamber.

3. A fluid-dispensing pump as defined in claim 2, in which said valve stems are frictionally yieldably interconnected throughout the range of the relative lost motion to coordinate the opening and closing of said inlet and outlet valves with the movement of said plunger.

4. A liquid-dispensing pump as defined in claim 1, in which said inlet valve includes a rigid valve stem extending axially through said pump chamber for reception in said plunger discharge passage, an axially inwardly-directed sealing valve seat in said passage, a sealing Valve carried by said inlet valve stem for axial abutment with said sealing valve seat at the inner extremity of the plunger stroke for sealing said discharge passage and for transmitting an axial seating thrust from said plunger to the inlet valve.

5. A liquid-dispensing pump as defined in claim 4, in which said outlet valve includes a valve stem extending axially through said outlet port and frictionally telescopically connected with said inlet valve stem for a predetermined degree of relative axial yielding movement to coordinate the actuation of said Valves with the movements of said plunger, said stems establishing a positive connection between said valves in the fully-raised position of said plunger to positively seat said outlet valve.

i6. A liquid-dispensing pump as defined in claim 4, in which said means defining the outlet port in said discharge passage comprises a partition formed with axially in- Wardlyand outwardly-presented valve seats respectively around said outlet port, for alternate cooperation with said outlet valve and said sealing valve respectively.

7. A liquid-dispensing pump as defined in claim 4, in which said discharge passage includes a cylindrical portion, and a partition in the form of a generally-cylindrical sleeve is coaxially secured within said cylindrical passage portion, said sleeve having an axially inwardly-directed free end portion spaced radially inwardly from the wall of said cylindrical passage portion to define an axially inwardly-opening annular sealing groove between said free-end portion and the said discharge passage wall, said sealing valve being disposed for axial abutment with said free end portion, whereby to transmit a seating thrust from said plunger to the inlet valve, and also including an outwardly axially-directed annular skirt for sealing reception in said groove.

8. A liquid-dispensing pump as defined in claim 1, in which said inlet valve includes a rigid valve stem extending into said pump chamber coaxially to the plunger discharge passage, and a sealing valve carried by said valve stem for closing said discharge passage as an incident to the establishing of said positive interconnection between the plunger and the inlet valve.

9. A liquid-dispensing pump as dened in claim 1, in which said spring means comprises a coil spring, said inlet port being encircled by an inwardly-opening annular groove in the closed end of the cylinder, and an annular spring seat having an axially inwardly-presented surface in abutting engagement with the terminal coil of said spring at the inner end thereof, said seat concentrically encircling said inlet port and dening the outer Wall of said groove, said spring seat being formed with a plurality of axially-directed keyways opening radially into said groove, said inlet valve including a plurality of fingers extending axially into said groove, and radially outwardlydirected keys carried by said fingers within the respective keyways, for axial sliding movement between the bottom of said groove and said terminal coil of the valve spring.

10. A liquid-dispensing pump as defined in claim 9, further including a tapering annular rib concentrically encircling said terminal coil of the spring, said rib having its radially inner wall converging outwardly from said pump chamber to guide said spring onto said spring seat during assembly of the pump.

11. In a reciprocating liquid pump, including a pump cylinder having an inlet port through one axial end thereof, a plunger reciprocating axially in said cylinder, and an' inlet valve disposed within said cylinder for axial seating and unseating movement with respect to said inlet port, said plunger being provided with an axial discharge passage therethrough, means defining an axially directed outlet port within said passage, said inlet valve including a substantially rigid valve stem axially slidably received in said passage, and a sealing valve fixedly carried by said inlet valve stem between said inlet and outlet ports for seating engagement with said outlet port at one extremity of the movement of said plunger, the improvement wherein said plunger includes an outlet valve disposed in said passage on the remote side of said outlet port from the inlet port for axial movement into and from seating relation relative to the outlet port, said outlet valve having its stem slidably disposed through said outlet port, said outlet valve stem having a lost-motion tension transmitting connection with said inlet valve stem for establishing a positive connection between said inlet and outlet valves at the other extremity of the plunger movement, whereby to positively seat said outlet valve by tension transmitted from the inlet valve after the inlet valve has reached the limit of its unseating movement.

12. A reciprocating liquid pump including a pump cylinder having an inlet port through one axial end thereof, a plunger disposed for axial reciprocation in said cylinder, an inlet valve disposed for axial seating and unseating movement relative t0 said inlet port and on the inner side of said inlet port with respect to said cylinder, and means for positively limiting the unseating movement of said inlet valve, the improvement wherein said plunger is provided with an axial discharge passage therethrough and means defining an outlet port in said discharge passage, an outlet Valve disposed in said passage on the remote side of said outlet port from the inlet port for axial movement into and from seating relation with respect to the outlet port, lost-motion means including frictionally and telescopically interconnected valve stems extending from the respective inlet and outlet valves, said lost-motion means extending axially through the outlet port and interconnecting said inlet and outlet valves responsive to movement of the plunger in an axial direction away from said inlet port, whereby to yieldably seat and unseat the outlet valve incident to movement in opposite axial direction respectively of the plunger and to positively seat the outlet valve by tension transmitted from the inlet valve after the latter has reached the limit of its unseating movement, and a sealing valve affixed to said inlet valve in axially spaced relation therefrom on the side of said outlet port adjacent the inlet port for sealing said outlet port and for transmitting a positive seating thrust from said plunger to the inlet valve at the limit of movement of the plunger toward the inlet port.

13. In a reciprocating liquid pump, including a pump cylinder having an inlet port through one axial end thereof, a plunger disposed for yaxial reciprocation in said cylinder, and an inlet valve disposed for axial movement in' the cylinder into and from seating relation with said port, the improvement wherein said one end of the cylinder is formed to define an annular spring seat of substantial axial extent around said port, a coil spring compressed axially between said spring seat and said plunger, said seat being formed with an axial keyway along its inner periphery, said inlet valve including a key extending radi-ally outwardly into said keyway for movement in axial alignment with the coils of said coil spring and into abutment with said spring at the outer limit of the unseating movement of said valve.

References Cited UNITED STATES PATENTS 2,956,509 10/1960 Cooprider et al 103-178 3,228,347 1/1966 Corsette 103-178 3,257,961 6/1966 Schlenker 103-178 DONLEY I. STOCKING, Primary Examiner. HENRY F. RADUAZO, Examiner.