GB1604247A - Switch assembly responsive to fluid flow - Google Patents

Description

(54) SWITCH ASSEMBLY RESPONSIVE TO FLUID FLOW (71) I GEORGE MORGAN, a British Subject of Westridge, Rigga Lane, Duffield, Derbyshire do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a switch assembly particularly, but not exclusively, for use in a shower unit, and also to a shower unit incorporating such a switch assembly.

In existing shower systems there is often not a sufficient head of water between the water tank and the shower outlet in the bathroom to provide an adequate flow, or indeed to provide a flow capable of operating a pressure sensitive switch which could in turn electrically control a pump for pumping the water from the tank when the shower is switched on by the user. Other forms of switch can be provided for the pump but as these have to be located outside of the bathroom they are either inconvenient to operate or must be provided with some other facility enabling remote operation by the user.

According to the present invention there is provided a switch assembly comprising a body which has a bore extending longitudinally between an inlet and an outlet for flow of fluid therethrough, a control member retained within the body for movement longitudinally in the bore and having a first part, which can movably locate with minimum clearance in a first section of the bore, and a second part, which can engage across said first section on a seating defined in the bore, and a switch device with magnetic contacts mounted on the body externally of the bore and being connectible in an external electrical control circuit, the control member having magnetic properties such that movement of the control member due to a flow of fluid into the body can control operation of the switch device.

Preferably the control member is formed of a material capable of withstanding substantial variations in temperature of the fluid without being subject to any substantial physical change. The material may be of a polypropylene type.

Advantageously the first section of the control member is of cylindrical cross section and the second section of the control member is of hexagonal cross section.

According to the present invention there is also provided a shower unit adapted to be connected to a water source and-comprising a water outlet, a switch assembly according to any of the three preceding paragraphs for connection between the outlet and the water source, a water pump, and electrical control circuitry for the water p um including the switch device of the switch assembly.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Fig. 1 is a cross section through a flow switch assembly according to the invention; Fig. 2 is a view in the direction of arrow A of Fig. 1; and Fig. 3 is a circuit diagram of the pump control for a shower unit.

Referring to Figs. I and 2 of the drawings a flow switch assembly comprises a body 10 formed of a suitable metal and being in the form of a pipe union having a central cylindrical section 12 defining a through bore 14 and at the ends thereof enlarged internally threaded connecting parts 16 defining an inlet and outlet for connecting to complementary externally threaded ends of a water pipe.

In the bore 14 of the part 12 there is located a control member or float 18. The bore 14 is inwardly stepped at one end to define a reduced diameter first section having a shoulder portion 20 and the float 18 is formed with two parts of different diameters defining a corresponding shoulder 22 enabling the float to seat in the bore 14with the shoulder 22 mating with the shoulder 20. At the other end of the bore 14 there is provided a retaining clip 24 in the form of a spring circlip located in an annular groove 26. The float 18 is therefore held captive in the bore 14.

The float 18 has its first or smaller diameter section 28 of cylindrical cross section merging to a point at its free end, and its second or larger diameter section 30 of hexagonal cross section. The float 18 is dimensioned such that in the in-use position of the switch assembly, i.e. as viewed in Fig.

1, the float under gravity seats in the bore 14 with the section 28 a tight but movable fit, i.e.

with minimum clearance, in the reduced diameter section of the bore 14. With a flow of water into the body 10 through the lower end thereof, as viewed in Fig. t, the tight fitting of the float 18 renders it very sensitive to the water flow and the float will be lifted off its seating in response to a water flow provided by as little as a 4inch head of water. When the float is lifted off its seating the hexagonal section 30 enables the water to flow sufficiently through the larger diameter second section of the bore 14.

The float 18 is provided with an internal magnet 32 and a switch module 34 incorporating a reed relay is mounted externally of the body 10 on the central part 12 thereof with a securing clip (not shown) holding the module 34 in position. The movement of tht float 18 off its seating causes closing of the magnetic contacts 36 of the reed relay.

When the flow switch assembly is mounted in a shower system the lower end of the body 10 is connected through suitable pipework to the water source and the upper end is connected to a shower outlet (not shown). The reed relay contact 36 are included in an electrical control circuit (Fig.

3) for a water pump (not shown) such that closing of the contacts 36 of the reed relay operates a solid state switch in the form of a triac 38 which switches on the electrical motor of 4.he pumD. In use, movement of the float 18 is created by flow of water from the source when the shower outlet is opened by the user and the water pump is automatically switched on. When the shower outlet is closed and flow of water ceases, the float 18 moves back under gravity on to its seating which thereby causes opening of contacts 36 of the reed relay, removing the trigger signal to the triac 38 and thus switching off the pump motor, The float 18 is formed of a material which can withstand temperature variations ocioned by the use of hot water or cold water in the shower without experiencing any bubstantial physical changes and thus ensuring the maintenance of the tight fit of the float in the bore but capability of movement under minimum water pressure.

It is envisaged that the float 18 is formed of a polypropylene type material.

Various modifications may be made without departing from the invention. For example the float may be of other configuration than that described and other suitable types of retaining clips can be used in the bore. Also the switch module need not be mounted centrally as shown but could be off-set to either side of the body if desired.

WHAT I CLAIM IS: 1. A switch assembly comprising a body which has a bore extending longitudinally between an inlet and an outlet for flow of fluid therethrough, a control member retained within the body for movement longitudinally in the bore and having a first part, which can movably locate with minimum clearance in a first section of the bore, and a second part, which can engage across said first section on a seating defined in the bore, and a switch device with magnetic contacts mounted on the body externally of the bore and being connected in an external electrical control circuit, the control member having magnetic properties such that movement of the control member due to a flow of fluid into the body can control operation of the switch device.

2. A switch assembly according to Claim 1, wherein the control member is formed of a material capable of withstanding substantial variations in temperature of the fluid without being subject to any substantial physical change.

3. A switch assembly according to Claim 2, wherein the control member is formed of a polypropylene type material.

4. A switch assembly according to any of Claims 1 to 3, wherein the second part of the control member can movably locate in a second section of the bore with such clearance as to allow flow of fluid therepast.

5. A switch assembly according to any of the preceding claims, wherein the first part of the control member is of cylindrical cross section and the second part is of hexagonal cross section.

6. A switch assembly according to any of the preceding claims, wherein retaining means for the control member is provided at an end of the bore remote from the seating.

7. A shower unit adapted to be connected to a water source and comprising a water outlet, a switch assembly according to any of the preceding claims for connection between the outlet and the water source, a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. bore 14with the shoulder 22 mating with the shoulder 20. At the other end of the bore 14 there is provided a retaining clip 24 in the form of a spring circlip located in an annular groove 26. The float 18 is therefore held captive in the bore 14. The float 18 has its first or smaller diameter section 28 of cylindrical cross section merging to a point at its free end, and its second or larger diameter section 30 of hexagonal cross section. The float 18 is dimensioned such that in the in-use position of the switch assembly, i.e. as viewed in Fig.

1, the float under gravity seats in the bore 14 with the section 28 a tight but movable fit, i.e.

with minimum clearance, in the reduced diameter section of the bore 14. With a flow of water into the body 10 through the lower end thereof, as viewed in Fig. t, the tight fitting of the float 18 renders it very sensitive to the water flow and the float will be lifted off its seating in response to a water flow provided by as little as a 4inch head of water. When the float is lifted off its seating the hexagonal section 30 enables the water to flow sufficiently through the larger diameter second section of the bore 14.

The float 18 is provided with an internal magnet 32 and a switch module 34 incorporating a reed relay is mounted externally of the body 10 on the central part 12 thereof with a securing clip (not shown) holding the module 34 in position. The movement of tht float 18 off its seating causes closing of the magnetic contacts 36 of the reed relay.

When the flow switch assembly is mounted in a shower system the lower end of the body 10 is connected through suitable pipework to the water source and the upper end is connected to a shower outlet (not shown). The reed relay contact 36 are included in an electrical control circuit (Fig.

3) for a water pump (not shown) such that closing of the contacts 36 of the reed relay operates a solid state switch in the form of a triac 38 which switches on the electrical motor of 4.he pumD. In use, movement of the float 18 is created by flow of water from the source when the shower outlet is opened by the user and the water pump is automatically switched on. When the shower outlet is closed and flow of water ceases, the float 18 moves back under gravity on to its seating which thereby causes opening of contacts 36 of the reed relay, removing the trigger signal to the triac 38 and thus switching off the pump motor, The float 18 is formed of a material which can withstand temperature variations ocioned by the use of hot water or cold water in the shower without experiencing any bubstantial physical changes and thus ensuring the maintenance of the tight fit of the float in the bore but capability of movement under minimum water pressure.

It is envisaged that the float 18 is formed of a polypropylene type material.

Various modifications may be made without departing from the invention. For example the float may be of other configuration than that described and other suitable types of retaining clips can be used in the bore. Also the switch module need not be mounted centrally as shown but could be off-set to either side of the body if desired.

WHAT I CLAIM IS: 1. A switch assembly comprising a body which has a bore extending longitudinally between an inlet and an outlet for flow of fluid therethrough, a control member retained within the body for movement longitudinally in the bore and having a first part, which can movably locate with minimum clearance in a first section of the bore, and a second part, which can engage across said first section on a seating defined in the bore, and a switch device with magnetic contacts mounted on the body externally of the bore and being connected in an external electrical control circuit, the control member having magnetic properties such that movement of the control member due to a flow of fluid into the body can control operation of the switch device.

2. A switch assembly according to Claim 1, wherein the control member is formed of a material capable of withstanding substantial variations in temperature of the fluid without being subject to any substantial physical change.

3. A switch assembly according to Claim 2, wherein the control member is formed of a polypropylene type material.

4. A switch assembly according to any of Claims 1 to 3, wherein the second part of the control member can movably locate in a second section of the bore with such clearance as to allow flow of fluid therepast.

5. A switch assembly according to any of the preceding claims, wherein the first part of the control member is of cylindrical cross section and the second part is of hexagonal cross section.

6. A switch assembly according to any of the preceding claims, wherein retaining means for the control member is provided at an end of the bore remote from the seating.

7. A shower unit adapted to be connected to a water source and comprising a water outlet, a switch assembly according to any of the preceding claims for connection between the outlet and the water source, a

water pump, and electrical control circuitry for the water pump including the switch device of the switch assembly.

8. A switch assembly substantially as hereinbefore described with reference to the accompanying drawing.

9. A shower unit substantially as hereinbefore described with reference to the accompanying drawing.