On-off Arrangement For A Liquid Jet Hand Appliance

Abstract

In a liquid jet hand appliance for personal hygiene, receiving liquid pressure pulses from a pump unit through a flexible tube, a chamber in the appliance has an outlet at one end connected to the outlet passage of the appliance, an opening to the atmosphere at the other end, and an inlet intermediate the outlet and opening connected to receive the liquid pressure pulses. A bistable valve includes a sealing ring at the chamber outlet and a valve member on the end of a rod passing into the chamber through the opening, the valve member being of larger diameter than the rod. A manual control member moves the rod and valve member to a closed position engaging the valve member with the sealing ring, and to an open position in which the valve member is withdrawn into the chamber. A slidable sealing member is slidably mounted on the rod intermediate the valve member and opening in engagement with the encircling wall of the chamber, and has a projecting annular resilient lip engageable with the end wall of the chamber around the opening.

Description

BACKGROUND OF THE INVENTION

Liquid jet devices for personal hygiene are known, particularly for cleaning the teeth and massaging the gums, in which liquid pressure pulses are produced by a pump unit and delivered through a flexible tube to a hand appliance having a jet nozzle attachment.

In such apparatus it is desirable to be able to turn the jet on and off at the hand appliance, so as to allow the jet nozzle to be inserted into and removed from the mouth without splashing while leaving the pump unit on until the cleaning and massaging is finished.

Several problems arise in designing an on-off valve mechanism which is simple yet satisfactory in operation. It is preferred to have the valve bistable, so that it will remain in either its on or off condition without requiring continuous manual force. Also, it is desirable to avoid excessive loading of the pump when the hand appliance is turned off with the pump running. Further, since the starting torque of the pump motor is commonly less than its running torque, it is desirable to avoid excessive torque requirements when the pump unit is started with the hand appliance in its off condition.

The present invention is designed to provide the foregoing desired features in a simple structure which is easy and convenient to operate.

SUMMARY OF THE INVENTION

In accordance with the invention the hand appliance comprises an elongated casing having an inlet passage for receiving liquid pressure pulses (usually water or a mouthwash solution) from a pump unit through a flexible tube, and an outlet passage preferably extending to the front end of the appliance. A chamber has an outlet at one end connected with the outlet passage, an opening to the atmosphere at the other end, and an inlet intermediate the outlet and said opening and connected with the inlet passage. A bistable valve in the chamber includes a sealing ring at the chamber outlet, and a valve member affixed at one end of a longitudinally movable rod passing into the chamber through said opening. The valve member is of larger diameter than the rod, and engages the sealing ring in the closed position of the valve. In the open position, the valve member is withdrawn into the chamber. A manual control member is attached to the rod, and preferably stop means is provided for establishing the open and closed positions. Guide means are advantageously employed for the valve member near the sealing ring, and has one or more openings for the flow of liquid through the chamber outlet in the open position of the valve.

As explained hereinafter, the pressures on the ends of the valve member in either the open or closed positions produce forces which maintain the valve member in either position, once moved thereto by the manual control member.

A slidable sealing member is slidably mounted on the control rod between the valve member and the chamber opening to the atmosphere, and engages the encircling wall of the chamber. The slidable member has an annular resilient lip engageable with the end wall of the chamber around said opening. When the valve in the hand appliance is closed and the pump unit is running, on pressure strokes of the pump piston the resilient lip allows the slidable sealing member to move toward the chamber end wall, and on suction strokes the resiliency of the lip forces the member back to the unstrained condition of the lip, or even away from the end wall if the chamber pressure goes below atmospheric pressure. Thus there will be no excessive loading of the pump. If, on the other hand, the pump unit is turned on with the valve in the hand appliance closed, the resiliency of the lip allows the slidable member to move toward the chamber end, thus reducing the starting torque required to resume operation.

These operations will be described more fully hereinafter.

It is preferred to employ a generally cylindrical chamber extending longitudinally of the casing, with the chamber opening to the atmosphere and the manual control member toward the front end of the appliance.

Other features will be described in connection with the specific embodiment shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall view of a pump unit with the liquid jet hand appliance connected thereto.

FIG. 2 is a longitudinal cross-section of the hand appliance showing the valve mechanism in its closed position, and FIG. 2a is a detail illustrating operation of the sliding seal member when the valve is closed;

FIG 3 is a cross-section similar to FIG. 2 showing the valve mechanism in its open position; and

FIG. 4 is a cross-section taken along the line 4--4 of FIG. 3.

DESCRIPTION OF THE SPECIFIC EMBODIMENT

Referring to FIG. 1, a piston type pump generally indicated as 10 has an inlet 11 for receiving liquid from a reservoir, and an outlet connected to flexible tube 12. Piston 13 is reciprocated by an electric motor and drive mechanism, not shown. Knob 14 may be rotated to control the pressure of the pulses delivered to tube 12. The construction may be similar to that shown in U.S. Pat. No. 3,720,486 issued Mar. 13, 1973 to Jousson et al., and includes an inlet valve for admitting liquid to the working chamber of the pump on the suction stroke of the piston, and provision for bypassing a selectable portion of the liquid in the working chamber to the inlet chamber of the pump on the pressure stroke of the piston, the degree of bypassing being controlled by knob 14. No outlet regulating valve is employed.

Tube 12 is connected to the inlet of the hand appliance generally designated as 15. A manually operated control member 16 may be pushed forward to open a valve in the appliance and supply the liquid pressure pulses to the jet spray attachment 17, or pulled rearward to close the valve. With the valve closed and the pump operating, liquid will flow back and forth in tube 12 as the pump piston reciprocates.

Referring to FIGS. 2-4, the hand appliance 15 is in the form of an elongated casing 21 forming a handle, with the valve structure positioned in the forward portion of the casing. Tube 12 is attached to a fitting 22 having an inlet passage 23 connecting with the side of valve chamber 24 intermediate the ends of the chamber. An outlet at the rear end of the chamber connects with an outlet passage 25 which is connected to the jet spray attachment 17. Suitable means are provided for holding the attachment in place, while allowing manual rotation thereof, and here is shown as an annular projection 26 on a fitting fixed in the casing which is engaged by spring fingers 27 of the attachment. Further description of the specific attaching means is believed unnecessary since it forms no part of the present invention.

A sealing O-ring 28 of resilient material is mounted at the rear of the cylindrical longitudinally-extending valve chamber 24 and, in the closed condition of the valve shown in FIG. 2, is engaged by valve member 29 attached to the end of control rod 31 and having a larger diameter than the rod. Valve member 29 may be of metal or plastic, as desired. The front wall of chamber 24 has an opening 32 to the atmosphere, and rod 31 passes therethrough in spaced relationship. Control member 16 is attached to the front end of rod 31 and is longitudinally movable to control the position of the rod. An annular slot 33 in member 16 mates with an annular section 34 of the casing to serve as a quide for the control member and front end of the rod. Normal production tolerances allow the pressure at opening 32 to remain at atmospheric pressure.

A quide member 35 is fixedly mounted in chamber 24 and serves as a guide for the valve member 29 and rear end of rod 31, and also holds O-ring 28 in place. Openings 36 in the guide member 35 (see FIG. 4) allow the passage of liquid through O-ring 28 when the valve is open, as shown in FIG. 3. In the embodiment shown, openings 36 are between two forwardly extending fingers 35' of the guide member.

Abutment 37 on the casing serves to limit rearward movement of the control member 16 and hence of the rod 31 and valve member 29, so as to establish the closed position of the valve. Abutment 38 limits forward movement and establishes the open position of the valve in which valve member 29 is withdrawn into chamber 24.

A slidable sealing member 41 is slidably mounted on rod 31 between valve member 29 and opening 32, and engages the encircling portion of chamber 24. The member is made of resilient material such as neoprene, etc. The front end of member 41 has an annular lip 42, preferably projecting forwardly as shown, which is adapted to engage the end wall of chamber 24 around opening 32. Annular grooves 43 and 44 allow the outer ends of the member to flex, and recess 43 can partially overlap the fingers 35' of the guide member to stop rearward movement of the member 41. Advantageously the annular resilient lip 42 projects forwardly and inwardly from the portion of member 41 outside groove 44, as shown.

Describing the operation, in the closed position of the valve as shown in FIG. 2, valve member 29 engages O-ring 28 in sealing relationship and cuts off flow of the pressure pulses from inlet passage 23 to outlet passage 25. Any pressure in chamber 24 produces a force on the front portion of valve member 24 which extends outwardly from rod 31, thereby maintaining the valve closed when the control member 16 is released. The rear end of the valve member is exposed to atmospheric pressure through conduit 25.

To open the valve and turn the appliance on, control member 16 is pushed forward as in FIG. 3, and liquid pressure pulses pass from inlet passage 23 through O-ring 28 to the outlet passage 25. In this position, pressure in chamber 24 produces a greater force on the rear end of valve member 29 than on the front end, since the area at the rear includes the area of rod 31 whereas the area at the front does not. Thus the valve is maintained open when member 16 is released.

Accordingly the valve is stable in both its closed and open conditions.

Considering now the action of the slidable sealing member 41, when the appliance valve is closed as in FIG. 2, and the pump unit is running, the pressure in chamber 24 varies cyclically from a maximum to a minimum as the pump piston reciprocates, and the minimum may be below atmospheric pressure, that is, a small suction. At each maximum peak, member 41 is forced to the right and the lip 42 is pressed against the wall around opening 32, thereby bending the lip. As the pressure decreases, the resiliency of the lip forces member 41 to the left until the lip reaches its unstrained condition. If the chamber pressure goes below atmospheric, member 41 may move away from opening 32 as shown in FIG. 2a, depending on the relative values of the suction and friction forces. Thus there will be no excessive increase in the load on the pump motor when the hand appliance is turned off and the motor left running. Accordingly increases in pump noise and motor heating are avoided.

When the pump unit is turned off, it commonly stops in its pressure condition and member 41 will be forced to its forward position with its lip pressed against the end of chamber 24. Commonly there is some leakage through the inlet valve of the pump so that the pressure in chamber 24 will decrease and the member 41 will move back. Upon subsequent restarting of the pump unit, the lip 42 can again bend, thereby reducing the starting torque required to resume operation.

With the pump unit running and the valve open, as in FIG. 3, there is low resistance to flow through O-ring 28 and outlet passage 25. The pressure in chamber 24 varies cyclically, but commonly will not go below atmospheric pressure and there may be gaps between successive pressure pulses. The lip 42 of member 41 may bend somewhat on the pressure peaks but will not interfere with normal operation. Desirably the spring force of the lip should not be so high as to flatten the pressure peaks excessively.

It will be understood that changes in the construction details are possible and that certain features of the invention may be employed and others omitted as meets the judgment of the designer or the requirements of a particular application.

Claims

I claim:

1. A liquid jet hand appliance for personal hygiene, for receiving liquid pressure pulses from a pump unit through a flexible tube, said hand appliance comprising

a. an elongated casing having an inlet passage for receiving said liquid pressure pulses and an outlet passage,

b. a chamber having an outlet at one end connected with said outlet passage, an opening to the atmosphere at the other end thereof, and an inlet intermediate said outlet and opening and connected with said inlet passage,

c. a bistable valve in said chamber including a sealing ring at the chamber outlet and a valve member affixed at the end of a longitudinally movable rod passing into the chamber through said opening,

d. said valve member being of larger diameter than said rod and adapted for engaging said sealing ring in the closed position of the valve and disengaging from the sealing ring upon movement into said chamber to the open position of the valve,

e. a manual control member attached to said rod for moving said valve member to said closed and open positions thereof,

f. and a slidable sealing member slidably mounted on said rod between said valve member and said opening and engaging the encircling wall of said chamber,

g. said slidable sealing member having an annular resilient lip engageable with said other end of the chamber around said opening.

2. A hand appliance according to claim 1 including guide means for said valve member positioned near said sealing ring and having an opening for flow of liquid through the chamber outlet in the disengaged position of the valve member.

3. A hand appliance according to claim 1 in which said annular resilient lip projects outward from said slidable sealing member.

4. A hand appliance according to claim 1 including stop means for establishing said closed and open positions of the valve member.

5. A hand appliance according to claim 1 in which said chamber is a generally cylindrical chamber extending longitudinally of said casing with said outlet at the rear end thereof, said opening at the front end thereof, and said inlet at the side thereof, and in which said outlet passage extends to the front end of the appliance and said manual control member is near the front end of the appliance.

6. A hand appliance according to claim 5 in which said slidable sealing member has annular grooves in each end thereof and said resilient lip projects forwardly and inwardly from the portion of the member outside the forward annular groove therein.

7. A liquid jet hand appliance for personal hygiene, for receiving liquid pressure pulses from a pump unit through a flexible tube, said hand appliance comprising

a. an elongated casing having an inlet passage for receiving said liquid pressure pulses and an outlet passage extending to the front end of the appliance,

b. a generally cylindrical chamber extending longitudinally of said casing having an outlet at the rear end thereof connected with said outlet passage, an opening to the atmosphere at the front end thereof, and an inlet at the side thereof intermediate said outlet and opening and connected with said inlet passage,

c. a bistable valve mechanism including a sealing ring at the chamber outlet and a longitudinally movable control rod passing into the chamber through said opening and having a valve member at the rear end thereof of larger diameter than the rod,

d. a manual control member mounted near the front end of said appliance and attached to said rod,

e. means for establishing a rear position of said rod in which said valve member engages said sealing ring to prevent liquid flow thereby and a forward position disengaging the valve member from the sealing ring,

f. guide means for said valve member positioned near said sealing ring and having an opening for flow of liquid through the chamber outlet in the disengaged position of the valve member,

g. and a slidable sealing member slidably mounted on said rod between said valve member and said opening and engaging the cylindrical wall of said chamber,

h. said slidable sealing member having a forwardly projecting annular resilient lip engageable against the front wall of said chamber around said opening.

8. A hand appliance according to claim 7 in which said slidable sealing member has annular grooves in each end thereof and said resilient lip projects forwardly and inwardly from the portion of the member outside the forward annular groove therein.