US3771557A

US3771557A - Reservoir for a liquid pump, including a float valve

Info

Publication number: US3771557A
Authority: US
Inventors: M Moret; P Jousson
Original assignee: WOOG INST RECH
Current assignee: INSTITUT DE RECHERCHE WOOG CH; WOOG INST RECH
Priority date: 1971-03-19
Filing date: 1972-02-16
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13
Also published as: DE2211274C3; FR2129728A5; CH537523A; DE2211274A1; JPS5532374B1; DE2211274B2

Abstract

Apparatus for supplying liquid to a pump includes a pump inlet fixture and a removable reservoir. The reservoir has a chamber at the bottom thereof with an inlet from the portion of the reservoir thereabove, and an outlet. A closure member closes the outlet when the reservoir is removed from the fixture for filling, and a float in the chamber closes the inlet in the raised position thereof. The chamber outlet and the pump inlet fixture are designed so that the fixture opens the closure member and moves a substantial distance into the chamber as the reservoir is placed in position on the fixture. With liquid in the reservoir, the chamber inlet is closed by the float when the reservoir is placed in position, and a portion of the liquid in the chamber is forced into the pump inlet.

Description

Moret et al.

1 Nov. 13, 1973 RESERVOIR FOR A LIQUID PUMP,

INCLUDING A FLOAT VALVE Inventors: Michel A. Moret; Pierre J. Jousson,

both of Geneva, Switzerland Institut de Recherche Woog, Geneva, Switzerland 22 Filed: Feb. 16, 1972 21 Appl. No.: 226,826

[73] Assignee:

[30] Foreign Application Priority Data Mar. 19, 1971 Switzerland 4106/71 [52] US. Cl. 137/565, 128/62 A, 128/66 [51] Int. Cl...... A61k 7/00, A61k 9/00, A46b 13/06 [58] Field of Search 15/22; 128/62 A,

[56]. References Cited UNITED STATES PATENTS 3,393,673 7/1968 Mattingly 128/66 3,484,885 12/1969 Deines et al. 15/22 R 2/1970 Freedman 128/66 2/1971 Trenary et a1. 15/22 R Primary Examiner- -Henry T. Klinksiek Attorney-Dean S. Edmonds et al.

[5 7] ABSTRACT Apparatus for supplying liquid to a pump includes a pump inlet fixture and a removable reservoir. The reservoir has a chamber at the bottom thereof with an inlet from the portion of the reservoir thereabove, and an outlet. A closure member closes the outlet when the reservoir. is removed from the fixture for filling, and a float in'the chamber closes the inlet in the raised position thereof. The chamber outlet and the pump inlet fixture are designed so that the fixture opens the closure member and moves a substantial distance into the chamber as the reservoir is placed in position on the fixture. With liquid in the reservoir, the chamber inlet is closed by the float when the reservoir is placed in position, and a portion of the liquid in the chamber is forced into the pump inlet.

10 Claims, 8 Drawing Figures Patented Nov. 13, 1973 3,771,557

5 Sheets-Sheet 3 RESERVOIR FOR A LIQUID PUMP, INCLUDING A FLOAT VALVE BACKGROUND OF THE INVENTION This invention relates to apparatus for supplying liquid to a pump including a pump inlet fitting and a removable reservoir, and is particularly applicable to pump units for supplying liquid under pressure to a body-care appliance such as a water jet or an hydraulically operated toothbrush.

In known apparatus a removable reservoir is provided with a gravity valve in the bottom thereof which is closed when the reservoir is removed for filling. The pump unit includes an inlet fixture on which the reservoir is placed in sealed relationship, with the gravity valve in alignment with the inlet fixture. The fixture is designed to open the valve when the reservoir is in position, thereby allowing liquid (usually water) to flow through the fixture to the pump.

Such an arrangement is shown, for example, in US. Pat. No. 3,536,065 issued Oct. 27, 1970 to Moret. As also described in that patent, the pump supplies liquid pressure pulses through a flexible conduit to a unitary hand appliance containing an hydraulic piston-type motor for driving a toothbrush attachment, or other attachment, and a conduit for supplying the pressure pulses to a water jet attachment. A manual valve is provided which is actuable to yield either type of operation. As also described, a return conduit from the hand appliance to the pump unit is advantageously employed, and the valve has a position for connecting the supply conduit to the return conduit so that the appliance may be switched off with the pump still running.

In order for the pump to supply a pressure output immediately after the pump motor is switched on, the pump chamber must contain sufficient liquid without large air pockets. Otherwise no liquid, or insufficient liquid, is pumped, and the pump system must first be bled of air in some suitable way. If, therefore, there are air pockets in the pump chamber before the pump is started, they must be forced out by the liquid flowing into the chamber after the reservoir has been fitted. However, the hydraulic system downstream of the pump, especially the connecting hose between the pump and the manual appliance, which may also include the return as well as the supply tube, is generally more or less full of liquid. The pump, hose and manual appliance form a system of intercommunicating tubes, with the manual appliance often at a higher level than the pump. It may, for example, be hung on a wall bracket while the pump is fitted beneath the wash ba- In order to allow liquid to enter a pump chamber which contains air pockets, after the reservoir has been fitted on the pump it is usually necessary to overcome the force produced by the weight of the liquid in the hydraulic system above the level of the pump, which counteracts the entry of liquid. Only then will it be possible positively to force into the pump outlet pipe those air pockets which cannot escape into the reservoir through its inlet valve, and to remove them from the hydraulic system thereafter.

It has been found that, in the known pump units of this kind, the pressure provided simply by the height of the column of water in the reservoir is often insufficient, because of the factors mentioned above, adequately toflll the pump chamber, which may be partially empty or may contain air pockets. The result of this is that, after the pump motor has been switched on, no liquid at all, or at least an insufficient quantity thereof, is forced along by the pump. This undesirable effect occurs particularly frequently, of course, if the reservoir is only partially filled with liquid.

The present invention overcomes these drawbacks by providing means for forcing a certain quantity of liquid into the pump chamber as the reservoir is placed in position on the pump inlet fixture, utilizing the weight of the reservoir and the liquid therein, supplemented by manual pressure if required.

SUMMARY OF THE INVENTION The present invention employs a pump inlet fixture for supplying liquid to the pump, and a removable reservoir for supplying liquid to the pump inlet fixture when placed in position thereon.

In accordance with the invention, the reservoir'has a chamber at the bottom thereof with an inlet from the portion of the reservoir thereabove, and an outlet. A float in the chamber is adapted to close the chamber inlet in the raised position thereof, and a closure member is provided to close the chamber outlet when the reservoir is removed for filling. As the reservoir is filled, water enters the chamber and causes the float to rise to close the chamber inlet.

The pump inlet fixture is designed so that when the reservoir is placed in position thereon, it enters the chamber a substantial distance, and sealing means provides a seal between the chamber outlet and the pump inlet fixture during entry of the fixture into the chamber. Means are also provided for moving the closure member away from its closed position as the reservoir is placed on the fixture. During this operation, with water in the reservoir, the float seals the inlet to the chamber. Consequently, as the pump inlet fixture enters the chamber, a portion of the liquid in the chamber is forced into the fixture and thence to the pump chamber.

Advantageously the size of the inlet fixture and the distance it enters the reservoir chamber are selected so that the volume of liquid forced into the pump chamber is sufficient to fill the pump chamber and drive out air pockets therein sufficiently to cause the pump to operate effectively as soon as it is switched on.

As the pump operates, it withdraws liquid from the chamber at the bottom of the reservoir. Consequently the float in the reservoir chamber moves downwards, thereby opening the chamber inlet and allowing liquid to flow into the chamber from the portion of the reservoir thereabove. Thus liquid flows through the chamber to the pump as required for proper pump operation.

Further features of the invention will be described in connection with specific embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a pump unit connected to a toothbrush hand appliance;

FIG. 2 illustrates a water jet attachment for the hand appliance of FIG. 1

FIG. 3 is a partial cross-section of a reservoir in accordance with the invention, shown in removed relationship with respect to a pump inlet fixture;

FIG. 4 illustrates the reservoir and fixture of FIG. 3

I in assembled relationship, with water in the reservoir;

FIG. 5 is a view similar to FIG. 4, with the reservoir empty;

FIG. 6 is a cross-section of a modified arrangement of the reservoir chamber and inlet pump fixture in assembled relationship;

FIG. 7 is a cross-section of a further modification of the reservoir chamber and inlet pump fixture in assembled relationship; and

FIG. 8 is a bottom view of the closure member of FIG. 7.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS Referring to'FIG. 1, a pump unit generally designated as 10 is connected to a toothbrush hand appliance 11 by a flexible dual tube 12. The pump unit includes a water reservoir 13 supplying water to a pump 14 through conduit 15, the pump being driven by an electric motor (not shown). Liquid pressure pulses are supplied through tube 12 to hand appliance 11, and the other tube 12" allows water to be returned from the hand appliance to the reservoir 13 of the pump unit.

The hand appliance 11 may be designed in accordance with the aforesaid U.S. Pat. No. 3,536,065 or application Ser. No. 117,466 filed Feb. 22, 1971 by Moret and Jousson for Hydraulically Operated Hand Appliance for Personal Hygiene," now abandoned, as a unitary device capable of both toothbrush and water jet operation by simply interchanging the appliance heads. FIG. 1 shows a toothbrush head 16 in place, and FIG. 2 shows a water jet attachment 17 which may be substituted for the toothbrush head 16.

The hand appliance 11 contains a reciprocating hydraulic piston motor (not shown) driven in one direction by pressure pulses from tube 12 and returned in the opposite direction by a compression spring. For water jet operation, the pressure pulses are supplied through an internal conduit in appliance 11 to head 17. Valve means in 11 provides for applying the pressure pulses to either the hydraulic motor or internal conduit, under control ofa slidable member 18. Member 18 also has a rear position in which the supply tube 12' is connected to the return tube 12" so as to return the water to the pump unit without operating the hydraulic motor or water jet.

Referring to FIG. 3, the lower portion of reservoir 13 is shown, with a valve chamber 21 at the bottom thereof. As here shown, the wall 22 of the chamber'has a cylindrical inner surface and is mounted in the bottom of reservoir 13 in sealed relationship therewith by a flange 23 and a cap 24. Cap 24 has an opening 25 therein forming an inlet to chamber 21 from the portion of the reservoir thereabove. At the bottom of the chamber is an outlet 26 and an outlet valve closure member 27. In the removed position of the reservoir shown in FIG. 3, the disc-shaped closure member 27 seats onan annular flange 28 at the bottom of the chamber and closes the chamber outlet 26. A float 31 is placed in the container above the closure member, and is freely movable up and down therein depending on the liquid level. The float has a specific gravity less than the liquid to be introduced in the reservoir, and

may be a sealed hollow body of plastic or other mate-.

rial.

In its raised position, float 31 bears against the annular flange 29 of cap 24 and closes inlet 25, thereby forming an inlet valve for the chamber 21. A series of narrow ribs 32 or similar projections are provided on the under side of the float so that, when it contacts the upper surface of closure member 27 in the absence of water in the chamber, the float will not tend to stick or adhere to the closure member, thereby facilitating upward and downward movement of the float as required. At the lower end of outlet 26 an O-ring is provided for establishing a seal to the pump inlet fixture as the reservoir is inserted thereon.

The float 31 and closure member 27 have a diameter smaller than the inside diameter of chamber 21 so as to allow liquid to pass thereby in the open positions thereof.

The pump inlet fixture has a centrally positioned cylindrical stub 34 adapted to fit into the outlet 26 of the reservoir chamber, the O-ring 33 providing a seal between the chamber outlet and the stub 34 as the reservoir is placed in position thereon. A pipe 35 is centrally located in the top of stub 34 and is connected to the pump by a flexible tube 15 (FIG. 1) in the embodiment shown. If the pump inlet fixture is directly on top of the pump housing, pipe 35 may lead directly to the inlet chamber thereof. Narrow crossed ribs 36 are formed on the top of stub 34, and act as spacers to maintain a separation between the top of the stub and the closure member 27 when the reservoir is in its operating position. The pump inlet fixture 34 is mounted in asuitable fitting 37 which may be attached to the pump unit, and has an upper annular region 38 which engages the bottom of reservoir 13 and limits the downward movement of the reservoir onto the fixture 34.

As shown in FIG. 3, with the reservoir 13 filled with liquid, closure member 27 will prevent flow of liquid out of the reservoir and, as the chamber 21 becomes filled with liquid, float 31 rises to close the chamber inlet 25.

Referring to FIG. 4, the reservoir 13 is shown in position on the pump inlet fixture. When the reservoir is placed in position, it moves downward due to the weight of the reservoir and the water therein, assisted if necessary by manually pressing the reservoir downward. As the stub 34 enters the outlet of the chamber 21, O-ring 33 establishes a seal therebetween. At the same time the top of stub 34 engages the closure member 27 and raises it from its seat on the annular flange 28. Ribs 36 maintain a slight separation between the closure member and the top of the stub. Accordingly water can flow from the chamber 21 through the space between the closure member and the stub and through pipe 35 to the pump inlet chamber, as indicated by the arrows.

During this movement the float 31 closes the inlet 25, so that no water can flow back to the portion of the reservoir thereabove. Accordingly a portion of the water in the chamber 21 is forced into the outlet tube 35 and thence to the pump, thereby insuring a positive charge of liquid to the pump and forcing out any air in the pump inlet passage. The size of stub 34 and the distance it projects into chamber 21 is advantageously selected so that the amount of liquid forced through tube 35 as the reservoir is placed in position is sufficient to approximately fill the inlet chamber of the pump so that, upon turning on thepump, a pressure stream of water will immediately be produced. In pumps commonly used for body-care appliances such as shown in FIG. 1, the volume need not be very great, amounting, for example, to only a few cubic centimeters. The volume of any connecting line, such as 15 in FIG. 1, will of course be taken into account in determining the overall volume required.

As the pump operates, water will be withdrawn from chamber 21, thereby allowing float 31 to move downward to uncover inlet 25 and replenish the water in the chamber from the-portion of the reservoir thereabove. With a piston pump as illustrated, for example, in the aforesaid US. Pat. No. 3,536,065, there is an inlet chamber connecting with the working chamber through a spring-biased valve which opens on each suction stroke of the piston. Thus on each suction stroke, float 31 in the reservoir chamber will move downward as water is withdrawn therefrom and allow water to flowin from above.

When all the water in the reservoir has been used up, the parts will assume the positions shown in FIG. 5, wherein the float 31 has moved down and rests upon closure member 27. The reservoir may then be removed for refilling and the ribs 32 will prevent the float from sticking to the closure member, thereby allowing the closure member to seat on flange 28 and close the outlet 26 and the float to rise as the reservoir is filled, as illustrated in FIG. 3.

Referring to FIG. 6, an alternative arrangement of the float and closure member is shown. Here the float 41 is formed with a central recess 42 in the underside thereof, and closure member 43 has a central upward projection 44 which cooperates with the recess 42 to maintain approximate alignment of the float and closure member in chamber 21. Here the float and closure member are provided with outwardly extending

fins

45 and 46, respectively, so as to maintain the members centered in the chamber while allowing the water to flow thereby during operation.

The underside of the closure member 43 is provided with ribs 47 which space the closure member from the top of stub 34 in operation. The tip of member 44 is designed to maintain the bottom of the float out of contact with the closure member when the reservoir is empty, so that ribs 32 (FIG. 3) are unnecessary.

The upper portion of float 41 is frusto-conical and extends through the inlet opening 25. Advantageously the vertical dimensions of the float 41 and closure member 43 are selected so that, when the closure member rests of flange 28 as the reservoir is removed for filling, the top of the float extends somewhat above opening 25. This prevents possible jamming of the members by excessive tilting while the reservoir is being handled.

Other structural changes are shown in FIG. 6 but are believed unnecessary to describe in detail.

Referring to FIG. 7 the embodiment is similar to FIG. 6 but differs in detail. Here a frusto-conical member 51 with apertures 52 is placed over the inlet 25 to the chamber 21. Apertures 52 may be spaced around the periphery of a member 51 or may be arcuate with supporting sections therebetween (not shown). An elastic sealing ring 53 is positioned around the inlet 25 so that, when float 41 rises thereagainst a good liquid-tight seal will be provided. The closure member 43 is provided with a thin periphery 54 to facilitate obtaining a tight seal when it rests on annular ledge 28 as indicated in FIG. 3. The sealing ring 33' is shaped to engage the periphery of stub 34 as or just before the top of the stub raises the closure member off ledge 28 as the reservoir is inserted in position.

Here the central upward projection 44 of the closure member and the central recess 42 in the float are of cylindrical configuration with side clearance therebetween, and the projection 44' has a flat top which maintains a slight separation between the float and the closure member when the reservoir is empty, thereby preventing sticking therebetween when the reservoir is once more filled. Means are provided for limiting the downward movement of the reservoir in a manner similar to that shown in previous figures, but are omitted here for simplicity.

FIG. 8 is a bottom view of the closure member 43' showing small rib-like spacers 56 which maintain a separation between the closure member and the top of stub 34 of the inlet fixture when the reservoir is in its operating position.

In the arrangement of FIG. 7 the overall height of the closure member and float is less than the height of the chamber 21. However, their construction, together with member 51, guards against jamming while the reservoir is being handled off the pump inlet fixture.

Although several embodiments of the invention have been specifically described, other variations arepossible within the spirit and scope of the invention. For example, instead of employing a pipe 35 opening at the top of stub 34, holes may be employed in the stub sidewall lying inside the chamber 21 when the reservoir is placed in position. Then the closure member could simply lie on the blind top of the stub. Also, instead of raising the closure member by the stub top, a pin arranged centrally in the stub could be employed. Also, if desired, the radial fins on the float and/or closure mem-' ber, such as 45 and 46 in FIG. 6, could be guided in axially extending grooves in the chamber wall, so as to prevent rotation thereof.

We claim:

1. Apparatus for supplying liquid to a pump whic comprises a. a pump inlet fixture for supplying liquid to said b. a removable reservoir for supplying liquid to said pump inlet fixture when placed in position thereon,

c. said reservoir including a chamber at the bottom thereof having an inlet from the portion of the reservoir thereabove and an outlet,

d. a float in said chamber constructed and adapted to close said inlet to the chamber in the raised position of the float,

e. a closure member in said chamber constructed and adapted to close said outlet of the chamber when the reservoir is removed from said fixture for fillf. said outlet and said pump inlet fixture being designed and adapted for substantial movement of the fixture into said chamber as the reservoir is placed in position on the fixture,

g. sealing means for maintaining a water-tight relationship between said outlet and pump inlet fixture as the reservoir is placed in position on the fixture,

and means for moving said closure member away from the closed position thereof at said outlet of the chamber as the reservoir is placed in position on said fixture,

. whereby a portion of the liquid in said chamber is forced into said pump inlet fixture as the reservoir is placed in position t thereon.

2. Apparatus for supplying liquid to a pump which comprises a. an upwardly extending pump inlet fixture for supplying liquid to said pump,

b. a removable reservoir for supplying liquid to said pump inlet fixture when placed in position thereon,

c. said reservoir including a chamber at the bottom thereof having an inlet from the portion of the reservoir thereabove and an outlet beneath the inlet,

d. a closure member in said chamber designed and adapted to close said outlet when the reservoir is removed from said fixture for filling,

e. and a float in said chamber above said closure member constructed and adapted to close said inlet to the chamber in the raised position of the float,

f. said outlet being constructed and adapted to fit over said pump inlet fixture for a substantial movement of the fixture into said chamber as the reservoir is placed in position on the fixture,

h. said pump inlet fixture being constructed and adapted to raise said closure member from its closed position at said outlet of the chamber as the reservoir is placed in position on the fixture and allow liquid flow from said chamber into the pump inlet fixture,

i. whereby a portion of the liquid in said chamber is forced into said pump inlet fixture as the reservoir is placed in position thereon.

3. Apparatus according to claim 2 including limiting means for establishing a lowermost position of said reservoir on said pump inlet fixture, sealing means on the inner wall of said chamber at or beneath the outlet of the chamber closed by said closure member for engaging the outer wall of said fixture in sealed relationship therewith during the downward movement of said reservoir to said lowermost position, said fixture having an opening into said chamber above said sealing means as the reservoir is placed in position thereon.

4. Apparatus according to claim 3 in which the inlet to said chamber includes an annular flange against which said float seats in the raised position thereof, the outlet of said chamber includes an annular flange against which said closure member seats in the lower position thereof, said float and closure member are freely movable up and down in said chamber in the re moved empty condition of the reservoir, and the float and closure member have peripheral regions spaced from the chamber wall to allow liquid flow thereby in the unseated positions thereof.

5. Apparatus according to claim 3 in which said opening in the pump inlet fixture is in the top face thereof, and rib means for maintaining a separation between said closure member and said top face of the pump inlet fixture when the fixture raises the closure member from its closed position.

6. Apparatus according to claim 3 in which said closure member has a central upward projection and said float has a cooperating central recess on the underside thereof for approximately aligning the float and closure member and maintaining a separation between the major portions of the adjacent surfaces thereof in the empty condition of said chamber, peripheral regions of said float and closure member being spaced from the chamber wall to allow liquid flow thereby in the unclosed positions thereof.

7. Apparatus according to claim 2 including means for establishing a clearance between the major portions of the adjacent surfaces of said float and closure memher.

8. Apparatus according to claim 2 in which said float has peripherally spaced outwardly extending segments for approximately centering the float in said chamber.

9. Apparatus according to claim 2 in which the size of said pump inlet fixture and the movement thereof into said chamber are predetermined to force a volume of liquid from the chamber into the inlet fixture which approximately fills the inlet chamber of the pump.

10. Apparatus according to claim 4 in which said opening in the pump inlet fixture is in the top face thereof, means for maintaining a separation between said closure member and said top face of the pump inlet fixture when the fixture raises the closure member from its closed position, said closure member having central upward projection and said float having a cooperating recess on the underside thereof for approximately aligning the float and closure member and maintaining a separation between the major portions of the adjacent surfaces thereof in the empty condition of said chamber, said float having a central upwardly projecting section extending above said annular flange at the inlet of the chamber in the raised position of the float.

' Cls-R'll VIC/\Tlfi O 1" (10 R R ICC'IION Patent No. 3,771,55 Dated November 7 Invc'ntoflsj MICHEL A. MORET and PIERRE J. JOUSSON I; is eertifi ed thar error appears in the above-identified parent and that sald Letters Patent are hereby corrected as shown below:

Column ,3, line 26," after ner; ebandoz ze oi' reed aecontinuation of which issued as Patent No. 3,=77J .,l86 on November 13, 1973 Column 5, line Y for "of" read on Column 6, line 59, before ."and" insert h.

Column 8, line 38 before "central." a

. Signed and. sealed this 11th day of Jena 197k". I

(SEAL) Attest:

EDWARD M.FLETCH ER,JR-. c. MAR SHALL DANN Attesting Officer} Commissioner of P atenta

Claims

1. Apparatus for supplying liquid to a pump which comprises a. a pump inlet fixture for supplying liquid to said pump, b. a removable reservoir for supplying liquid to said pump inlet fixture when placed in position thereon, c. said reservoir including a chamber at the bottom thereof having an inlet from the portion of the reservoir thereabove and an outlet, d. a float in said chamber constructed and adapted to close said inlet to the chamber in the raised position of the float, e. a closure member in said chamber constructed and adapted to close said outlet of the chamber when the reservoir is removed from said fixture for filling, f. said outlet and said pump inlet fixture being designed and adapted for substantial movement of the fixture into said chamber as the reservoir is placed in position on the fixture, g. sealing means for maintaining a water-tight relationship between said outlet and pump inlet fixture as the reservoir is placed in position on the fixture, and means for moving said closure member away from the closed position thereof at said outlet of the chamber as the reservoir is placed in position on said fixture, i. whereby a portion of the liquid in said chamber is forced into said pump inlet fixture as the reservoir is placed in position t thereon.

2. Apparatus for supplying liquid to a pump which comprises a. an upwardly extending pump inlet fixture for supplying liquid to said pump, b. a removable reservoir for supplying liquid to said pump inlet fixture when placed in position thereon, c. said reservoir including a chamber at the bottom thereof having an inlet from the portion of the reservoir thereabove and an outlet beneath the inlet, d. a closure member in said chamber designed and adapted to close said outlet when the reservoir is removed from said fixture for filling, e. and a float in said chamber above said closure member constructed and adapted to close said inlet to the chamber in the raised position of the float, f. said outlet being constructed and adapted to fit over said pump inlet fixture for a substantial movement of the fixture into said chamber as the reservoir is placed in position on the fixture, g. sealing means for maintaining a water-tight relationship between said outlet and pump inlet fixture as the reservoir is placed in position on the fixture, h. said pump inlet fixture being constructed and adapted to raise said closure member from its closed position at said outlet of the chamber as the reservoir is placed in position on the fixture and allow liquid flow from said chamber into the pump inlet fixture, i. whereby a portion of the liquid in said chamber is forced into said pump inlet fixture as the reservoir is placed in position thereon.

4. Apparatus according to claim 3 in which the inlet to said chamber includes an annular flange against which said float seats in the raised position thereof, the outlet of said chamber includes an annular flange against which said closure member seats in the lower position thereof, said float and closure member are freely movable up and down in said chamber in the removed empty condition of the reservoir, and the float and closure member have peripheral regions spaced from the chamber wall to allow liquid flow thereby in the unseated positions thereof.

7. Apparatus according to claim 2 including means for establishing a clearance between the major portions of the adjacent surfaces of said float and closure member.