Title:
Reservoir for a liquid pump including means for initially forcing liquid into the pump
United States Patent 3871560
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 within the chamber has a lower outlet closure section which closes the outlet when the reservoir is removed for filling, and an upwardly-extending post forming an inlet closure section. When the reservoir is placed in position on the fixture, the closure member is raised to its upper position and the fixture moves a substantial distance into the chamber. The post and inlet are arranged to engage in sealed relationship during a range of intermediate positions of the closure member, thereby forcing a portion of the liquid in the chamber into the pump inlet. The post is designed to open the inlet to the chamber in upper and lower positions of the closure member.
US Patent References:
Apparatus for filling receptacles with liquid
Olson - November 1931 - 1831028
Liquid measuring and dispensing apparatus
Shimp - November 1948 - 2453080
ORAL HYGIENE APPARATUS OF THE WATER JET TYPE
Mattingly - September 1969 - 3467083
LIQUID DISCHARGE APPARATUS
Freedman - February 1970 - 3495587
RESERVOIR FOR A LIQUID PUMP, INCLUDING A FLOAT VALVE
Moret et al. - November 1973 - 3771557
Apparatus for filling receptacles with liquid
Olson - November 1931 - 1831028
Liquid measuring and dispensing apparatus
Shimp - November 1948 - 2453080
ORAL HYGIENE APPARATUS OF THE WATER JET TYPE
Mattingly - September 1969 - 3467083
LIQUID DISCHARGE APPARATUS
Freedman - February 1970 - 3495587
RESERVOIR FOR A LIQUID PUMP, INCLUDING A FLOAT VALVE
Moret et al. - November 1973 - 3771557
Application Number:
05/384513
Publication Date:
03/18/1975
Filing Date:
08/01/1973
View Patent Images:
Export Citation:
Assignee:
Les Produits, Associes SA. (Geneva, CH)
Primary Class:
Other Classes:
601/162, 222/372
International Classes:
A61C1/00; G01F11/30
Field of Search:
222/185,325,383,372,181,333 128/66,62A
Primary Examiner:
Schacher, Richard A.
Assistant Examiner:
Slattery, James M.
Attorney, Agent or Firm:
Pennie & Edmonds
Claims:
I claim
1. Apparatus for supplying liquid to a pump which comprises
2. Apparatus according to claim 1 in which the upper portion of said closure member, in the lower position thereof with respect to the chamber, is at least partially within said inlet to the chamber in non-sealing guided relationship therewith.
3. Apparatus for supplying liquid to a pump which comprises
4. Apparatus according to claim 3 in which said post has a cylindrical section and said inlet has a sealing ring engaging therewith through said range of intermediate positions of the closure member.
5. Apparatus according to claim 3 in which said inlet has a cylindrical surface and said post has a sealing ring engaging therewith through said range of intermediate positions of the closure member.
6. Apparatus according to claim 4 in which the upper portion of said post, in the lower position of said closure member with respect to the chamber, is at least partially within said inlet to the chamber in non-sealing guided relationship therewith.
1. Apparatus for supplying liquid to a pump which comprises
2. Apparatus according to claim 1 in which the upper portion of said closure member, in the lower position thereof with respect to the chamber, is at least partially within said inlet to the chamber in non-sealing guided relationship therewith.
3. Apparatus for supplying liquid to a pump which comprises
4. Apparatus according to claim 3 in which said post has a cylindrical section and said inlet has a sealing ring engaging therewith through said range of intermediate positions of the closure member.
5. Apparatus according to claim 3 in which said inlet has a cylindrical surface and said post has a sealing ring engaging therewith through said range of intermediate positions of the closure member.
6. Apparatus according to claim 4 in which the upper portion of said post, in the lower position of said closure member with respect to the chamber, is at least partially within said inlet to the chamber in non-sealing guided relationship therewith.
Description:
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 U.S. 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 applicance 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 basin.
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 to fill the pump chamber, which may be partially empty or may contain air pockets. The results 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.
In application Ser. No. 226,826 filed Feb. 16, 1972 by Moret and Jousson, now Pat. No. 3,771,557, these drawbacks are overcome 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. In that application the reservoir includes a chamber in the bottom thereof containing an outlet closure member and a float valve. As the reservoir is filled, the float valve rises to close off the inlet to the chamber. When the reservoir is placed on the pump inlet fixture, the latter opens the outlet closure member and enters the chamber. Since the float valve prevents liquid from flowing into the chamber from the portion of the reservoir thereabove, the liquid displaced by the pump inlet fixture is forced into the pump. Advantageously the volume of liquid forced into the pump is sufficient to fill the pump chamber and drive out air pockets sufficiently to cause the pump to operate effectively as soon as it is turned on. During operation, the float moves downward on each suction stroke and allows liquid to flow into the chamber from the portion of the reservoir thereabove.
While effective, the foregoing arrangement utilizes separate float and closure members, with means for preventing jamming of the members if the reservoir is tilted during the filling operation.
The present invention is directed toward a simpler structure which accomplishes similar results.
SUMMARY OF THE INVENTION
In accordance with the present invention, a closure member vertically movable in a chamber at the bottom of the reservoir has vertically spaced inlet and outlet closure sections. In the lower position of the closure member, the outlet closure section closes the chamber outlet and the inlet to the chamber is open so that the reservoir, including the chamber, can be filled. The inlet closure section and the inlet to the chamber are designed to close the inlet through a range of intermediate positions of the closure member, and open the inlet in upper and lower positions of the closure member.
The chamber outlet and the pump inlet fixture are designed so that, when the reservoir is placed in position, the fixture enters the chamber a substantial distance and displaces a substantial amount of liquid therein. Sealing means provides a seal between the chamber outlet and the pump inlet fixture. Means are also provided for moving the closure member upward as the reservoir is placed on the fixture thereby opening the chamber outlet. During the aforesaid intermediate range of positions, the inlet closure section closes the inlet to the chamber, thereby forcing the displaced liquid 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.
When the reservoir is fully in position, the closure member is in its upper position and the inlet to the chamber is open to the portion of the reservoir thereabove. Thus liquid is supplied to the pump without further movement of the closure member.
As described hereinafter, the inlet closure section is in the form of an upwardly extending post. Advantageously the post has a cylindrical section and the inlet has a sealing ring engaging therewith through the desired range of intermediate positions during which liquid is forced into the pump. The top of the post, in the lower position of the closure member, is at least partially within the inlet in non-sealing guided relationship therewith, thus maintaining the closure member in proper position while allowing liquid to flow thereby.
Alternatively, the inlet may have a cylindrical surface and the post provided with a sealing ring which engages the cylindrical surface during said range of intermediate positions.
A spring biases the closure member toward its lower position, so as to overcome the friction of the seal in the range of intermediate positions so that, upon removal of the reservoir, the closure member moves quickly from its upper to its lower position to close the chamber outlet.
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. 3a and FIG. 3b show cross-sections of FIG. 3 taken along the lines 3a--3a and 3b--3b thereof;
FIG. 4 shows the reservoir and fixture of FIG. 3 in an intermediate inserted position and FIG. 5 shows the fully inserted position;
FIG. 6 shows a modification of the invention; and
FIG. 7 shows a cross-section along the line 7--7 of FIG. 6.
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. 244,879 filed Apr. 17, 1972 by Moret and Jousson for "Hydraulically Operated Hand Appliance for personal Hygiene", now U.S. Pat. No. 3,771,186, as 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 of a 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 chamber 21 at the bottom thereof. A horizontal wall 22 divides the upper main portion of the reservoir from chamber 21, with an inlet 23 to the chamber. A sealing ring 24 is mounted in the inlet. The wall of chamber 21 is here shown as cylindrical, and a flanged cap 25 is attached to the wall, with a sealing ring 26 secured therebetween. Cap 25 has a central opening 27 forming the outlet of the chamber.
The closure member has a disk-shaped outlet closure section 28 with a downwardly extending lip 29 which engages sealing ring 26 in the lower position shown. A post generally designated 31 extends upwardly from disk section 28 and forms the inlet closure member. The post comprises a smaller diameter lower section 32, a larger diameter intermediate section 33, and an upper section 34 formed of crossed ribs (FIG. 3a) which allow the flow of liquid thereby but guide the closure member in sealing ring 24. A compression spring 35 biases the closure member to its lower position shown, so that outlet 27 is closed and inlet 23 is open. Thus the reservoir, including chamber 21, can be filled.
The pump inlet fixture comprises a cylindrical stub 36 dimensioned to fit into the outlet 27 of the reservoir chamber, ring 26 providing a seal between the chamber outlet and the stub as the reservoir is placed in position thereon. A pipe 37 is centrally located in the top of the stub, 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 37 may lead directly to the inlet chamber thereof. Additional structure may be provided for supporting the reservoir when in operating position, if desired.
Referring to FIG. 4, the reservoir 13 is shown in an intermediate position as it is placed in position on the pump inlet fixture. Outlet closure section 28 has been moved upward away from its seat on sealing ring 26 by the top of stub 36. Small ribs 38 on the bottom of disk 28, best seen in FIG. 3b, maintain sufficient separation to allow liquid to flow to pipe 37 as shown by the arrows. Disk 28 is provided with small projections 39 which maintain the disk approximately centered, while allowing the flow of liquid thereby, and also serve as abutments for one end of spring 35.
Throughout a range of intermediate positions of the closure member, the enlarged cylindrical surface 33 is in sealed relationship with the chamber inlet sealing ring 24. Thus the liquid displaced by stub 36 is forced into outlet pipe 37 and thence to the pump. The length of surface 33 may be selected with respect to the diameter of fixture 36 so that sufficient liquid is forced into outlet pipe 37 to fill the pump chamber and drive out air pockets therein sufficiently to enable the pump to operate effectively as soon as it is switched on.
FIG. 5 shows the fully inserted position. Here the closure member is in its upper position with enlarged cylinder 33 above sealing ring 24. Accordingly liquid from the upper portion of the reservoir can flow freely into chamber 21 and thence to outlet pipe 37. Spring 35 is now compressed, but it may be made sufficiently weak so as not to force the reservoir off the inlet fixture. The principal purpose of spring 35 is to move the closure member downwardly through the position shown in FIG. 4 when the reservoir is removed, and it need only be strong eough to overcome the friction between cylinder 33 and sealing ring 24.
Referring to FIG. 6, a modification is shown which is similar to the foregoing except for the inlet to the chamber 21 and the inlet closure section. Here the inlet has a cylindrical section 41 which is engaged by a sealing ring 42 on the upwardly extending post 43. The portion of the post below ring 42 is fluted as shown in FIG. 7. The top of the post is similar to that of FIGS. 3 and 3a. Thus in the position shown, with the closure member in its lower position, the chamber outlet is closed by disk 28 and the reservoir can be filled. Liquid flows into chamber 21 as indicated by the arrows. When the reservoir is placed on the pump inlet fixture in the manner shown in FIG. 4, sealing ring 42 engages cylindrical surface 41 in the range of intermediate positions. This seals the chamber inlet and liquid displaced by the fixture is forced into the pipe 37 of the fixture. The dimensions are selected so that when the closure member is in its upper position, similar to FIG. 5, sealing ring 42 is above cylindrical surface 41 and liquid flows past the fluted portion 43 into chamber 21 as required by the pump.
The embodiment of FIGS. 3-5 is presently preferred to that of FIG. 6. In FIG. 6 water below the top of cylindrical section 41 is unused. Adding a horizontal partition at the level of the top would prevent accumulation of unused water, but would lead to a more complicated structure. Also, ring seal 42 may need to be harder than seal 24, leading to greater friction.
The invention has been described in connection with specific embodiments thereof. Variations are possible within the spirit and scope of the invention. For example, instead of employing a pipe 37 opening at the top of stub 36, holes may be employed in the stub sidewall lying inside chmaber 21 when the reservoir is placed in position. Then the outlet closure section 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.
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 U.S. 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 applicance 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 basin.
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 to fill the pump chamber, which may be partially empty or may contain air pockets. The results 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.
In application Ser. No. 226,826 filed Feb. 16, 1972 by Moret and Jousson, now Pat. No. 3,771,557, these drawbacks are overcome 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. In that application the reservoir includes a chamber in the bottom thereof containing an outlet closure member and a float valve. As the reservoir is filled, the float valve rises to close off the inlet to the chamber. When the reservoir is placed on the pump inlet fixture, the latter opens the outlet closure member and enters the chamber. Since the float valve prevents liquid from flowing into the chamber from the portion of the reservoir thereabove, the liquid displaced by the pump inlet fixture is forced into the pump. Advantageously the volume of liquid forced into the pump is sufficient to fill the pump chamber and drive out air pockets sufficiently to cause the pump to operate effectively as soon as it is turned on. During operation, the float moves downward on each suction stroke and allows liquid to flow into the chamber from the portion of the reservoir thereabove.
While effective, the foregoing arrangement utilizes separate float and closure members, with means for preventing jamming of the members if the reservoir is tilted during the filling operation.
The present invention is directed toward a simpler structure which accomplishes similar results.
SUMMARY OF THE INVENTION
In accordance with the present invention, a closure member vertically movable in a chamber at the bottom of the reservoir has vertically spaced inlet and outlet closure sections. In the lower position of the closure member, the outlet closure section closes the chamber outlet and the inlet to the chamber is open so that the reservoir, including the chamber, can be filled. The inlet closure section and the inlet to the chamber are designed to close the inlet through a range of intermediate positions of the closure member, and open the inlet in upper and lower positions of the closure member.
The chamber outlet and the pump inlet fixture are designed so that, when the reservoir is placed in position, the fixture enters the chamber a substantial distance and displaces a substantial amount of liquid therein. Sealing means provides a seal between the chamber outlet and the pump inlet fixture. Means are also provided for moving the closure member upward as the reservoir is placed on the fixture thereby opening the chamber outlet. During the aforesaid intermediate range of positions, the inlet closure section closes the inlet to the chamber, thereby forcing the displaced liquid 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.
When the reservoir is fully in position, the closure member is in its upper position and the inlet to the chamber is open to the portion of the reservoir thereabove. Thus liquid is supplied to the pump without further movement of the closure member.
As described hereinafter, the inlet closure section is in the form of an upwardly extending post. Advantageously the post has a cylindrical section and the inlet has a sealing ring engaging therewith through the desired range of intermediate positions during which liquid is forced into the pump. The top of the post, in the lower position of the closure member, is at least partially within the inlet in non-sealing guided relationship therewith, thus maintaining the closure member in proper position while allowing liquid to flow thereby.
Alternatively, the inlet may have a cylindrical surface and the post provided with a sealing ring which engages the cylindrical surface during said range of intermediate positions.
A spring biases the closure member toward its lower position, so as to overcome the friction of the seal in the range of intermediate positions so that, upon removal of the reservoir, the closure member moves quickly from its upper to its lower position to close the chamber outlet.
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. 3a and FIG. 3b show cross-sections of FIG. 3 taken along the lines 3a--3a and 3b--3b thereof;
FIG. 4 shows the reservoir and fixture of FIG. 3 in an intermediate inserted position and FIG. 5 shows the fully inserted position;
FIG. 6 shows a modification of the invention; and
FIG. 7 shows a cross-section along the line 7--7 of FIG. 6.
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. 244,879 filed Apr. 17, 1972 by Moret and Jousson for "Hydraulically Operated Hand Appliance for personal Hygiene", now U.S. Pat. No. 3,771,186, as 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 of a 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 chamber 21 at the bottom thereof. A horizontal wall 22 divides the upper main portion of the reservoir from chamber 21, with an inlet 23 to the chamber. A sealing ring 24 is mounted in the inlet. The wall of chamber 21 is here shown as cylindrical, and a flanged cap 25 is attached to the wall, with a sealing ring 26 secured therebetween. Cap 25 has a central opening 27 forming the outlet of the chamber.
The closure member has a disk-shaped outlet closure section 28 with a downwardly extending lip 29 which engages sealing ring 26 in the lower position shown. A post generally designated 31 extends upwardly from disk section 28 and forms the inlet closure member. The post comprises a smaller diameter lower section 32, a larger diameter intermediate section 33, and an upper section 34 formed of crossed ribs (FIG. 3a) which allow the flow of liquid thereby but guide the closure member in sealing ring 24. A compression spring 35 biases the closure member to its lower position shown, so that outlet 27 is closed and inlet 23 is open. Thus the reservoir, including chamber 21, can be filled.
The pump inlet fixture comprises a cylindrical stub 36 dimensioned to fit into the outlet 27 of the reservoir chamber, ring 26 providing a seal between the chamber outlet and the stub as the reservoir is placed in position thereon. A pipe 37 is centrally located in the top of the stub, 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 37 may lead directly to the inlet chamber thereof. Additional structure may be provided for supporting the reservoir when in operating position, if desired.
Referring to FIG. 4, the reservoir 13 is shown in an intermediate position as it is placed in position on the pump inlet fixture. Outlet closure section 28 has been moved upward away from its seat on sealing ring 26 by the top of stub 36. Small ribs 38 on the bottom of disk 28, best seen in FIG. 3b, maintain sufficient separation to allow liquid to flow to pipe 37 as shown by the arrows. Disk 28 is provided with small projections 39 which maintain the disk approximately centered, while allowing the flow of liquid thereby, and also serve as abutments for one end of spring 35.
Throughout a range of intermediate positions of the closure member, the enlarged cylindrical surface 33 is in sealed relationship with the chamber inlet sealing ring 24. Thus the liquid displaced by stub 36 is forced into outlet pipe 37 and thence to the pump. The length of surface 33 may be selected with respect to the diameter of fixture 36 so that sufficient liquid is forced into outlet pipe 37 to fill the pump chamber and drive out air pockets therein sufficiently to enable the pump to operate effectively as soon as it is switched on.
FIG. 5 shows the fully inserted position. Here the closure member is in its upper position with enlarged cylinder 33 above sealing ring 24. Accordingly liquid from the upper portion of the reservoir can flow freely into chamber 21 and thence to outlet pipe 37. Spring 35 is now compressed, but it may be made sufficiently weak so as not to force the reservoir off the inlet fixture. The principal purpose of spring 35 is to move the closure member downwardly through the position shown in FIG. 4 when the reservoir is removed, and it need only be strong eough to overcome the friction between cylinder 33 and sealing ring 24.
Referring to FIG. 6, a modification is shown which is similar to the foregoing except for the inlet to the chamber 21 and the inlet closure section. Here the inlet has a cylindrical section 41 which is engaged by a sealing ring 42 on the upwardly extending post 43. The portion of the post below ring 42 is fluted as shown in FIG. 7. The top of the post is similar to that of FIGS. 3 and 3a. Thus in the position shown, with the closure member in its lower position, the chamber outlet is closed by disk 28 and the reservoir can be filled. Liquid flows into chamber 21 as indicated by the arrows. When the reservoir is placed on the pump inlet fixture in the manner shown in FIG. 4, sealing ring 42 engages cylindrical surface 41 in the range of intermediate positions. This seals the chamber inlet and liquid displaced by the fixture is forced into the pipe 37 of the fixture. The dimensions are selected so that when the closure member is in its upper position, similar to FIG. 5, sealing ring 42 is above cylindrical surface 41 and liquid flows past the fluted portion 43 into chamber 21 as required by the pump.
The embodiment of FIGS. 3-5 is presently preferred to that of FIG. 6. In FIG. 6 water below the top of cylindrical section 41 is unused. Adding a horizontal partition at the level of the top would prevent accumulation of unused water, but would lead to a more complicated structure. Also, ring seal 42 may need to be harder than seal 24, leading to greater friction.
The invention has been described in connection with specific embodiments thereof. Variations are possible within the spirit and scope of the invention. For example, instead of employing a pipe 37 opening at the top of stub 36, holes may be employed in the stub sidewall lying inside chmaber 21 when the reservoir is placed in position. Then the outlet closure section 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.