GB2272023A

GB2272023A - Pump for ablutionary installations.

Info

Publication number: GB2272023A
Application number: GB9222870A
Authority: GB
Inventors: Stephen Russell Geor Thorndale; Terence Leslie Winnington
Original assignee: Kohler Mira Ltd
Current assignee: Kohler Mira Ltd
Priority date: 1992-10-31
Filing date: 1992-10-31
Publication date: 1994-05-04
Anticipated expiration: 2012-10-31
Also published as: GB2272023B; GB9222870D0; IE74131B1; IE930810A1

Abstract

A centrifugal pump 8 has parallel inlet and outlet connections 18 and 22 respectively on one side of an impeller 17, and a spiral flow diffuser 19 of increasing cross-section in the direction of flow from the periphery of the impeller 17 to an outlet chamber 21 concentric with the inlet 18. The impeller 17 is mounted on a drive shaft 16 of a motor 9 controlled by a flow responsive switch 24 positioned in the outlet 22. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO ABLUTIONARY INSTALLATIONS This invention concerns improvements in or relating to ablutionary installations and in particular, though not exclusively, ablutionary shower installations of the kind in which there is a shower head to which water is supplied by a connection to a source of preconditioned water at a desired or predetermined or selected temperature.

The water source may be a mixing valve connected to the hot and cold supplies or a water heater connected to the cold supply. In many installations, it is necessary to boost the water pressure to obtain a satisfactory spray by pumps fitted in the water circuit.

Centrifugal pumps commonly have an outlet tangential to the pump motor housing and this can give rise to problems in making the necessary connections where the available space is limited.

The present invention has been made from a consideration of this problem and has for its object the provision of a centrifugal pump which can be fitted in a simple manner.

Other features, benefits and advantages of the invention will be understood from the description of the exemplary embodiments herein.

According to one aspect of the present invention there is provided a centrifugal pump comprising a water inlet, a water outlet parallel to the water inlet, an impeller and, peripherally of the impeller, a flow diffuser provided by a spiral duct connected to the water outlet, the cross-section of the duct increasing in the direction of water flow.

By the use of a spiral duct of increasing cross-section for the flow diffuser, the velocity energy in the water leaving the impeller is changed in part into pressure energy reducing the water velocity and enabling the water outlet to be parallel to the water inlet. In this way, the water connections to the pump are simplified for fitment of the pump, especially where the available space is limited.

Preferably, the water inlet and water outlet are provided on the same side of the impeller. As a result, the pump is compact with only limited access required for making the water connections.

Advantageously, the water inlet is coaxial with the impeller and the flow diffuser is connected to the water outlet via an outlet chamber concentric with the water inlet. By such arrangement, the water outlet can be provided at any desired location with respect to the water inlet.

The pump may be controlled by switch means responsive to water flow so that the pump operates only where is sufficient water flow.

Preferably, the switch means is located at the water outlet and is magnetically actuated by displacement of a piston between first and second positions in response to water flow to control operation of the pump.

Preferably, the piston is resiliently biassed to the first position in which the pump is switched off, and is movable in response to water flow against the biassing to the second position for switching the pump on. In this way, the piston is automatically returned to the first position to switch the pump off when there is insufficient water flow. By such resilient biassing of the piston, the pump can be installed with the water outlet directed downwards without affecting operation of the switch means.

Advantageously, the piston is a close fit in the outlet in the first position and a clearance fit in the outlet in the second position with respective guide vanes at each end for locating and aligning the piston in the outlet.

According to another aspect of the invention there is provided flow responsive switch means comprising a piston for mounting in a fluid passageway and movable between first and second positions in response to water flow for actuating a switch, the piston substantially closing the passageway in the first position and being a clearance fit in the passageway in the second position, and means biassing the piston towards the first position.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings wherein: FIGURE 1 is a perspective view of an ablutionary shower installation embodying the invention; FIGURE 2 is a side view of the booster pump unit shown in Figure 1; FIGURE 3 is a front view of the booster pump unit shown in Figure 2 with the cover removed; FIGURE 4 is a front view similar to Figure 3 with the pump shown in section; FIGURE 5 is a front view similar to Figure 4 with the pump shown in part section; and FIGURES 6a.b.c are cross-sections through the flow switch showing different stages of operation.

The ablutionary shower installation shown in the accompanying drawings comprises a booster pump unit 1 connected by respective flexible pipes 2 and 3 to a source of preconditioned water (not shown) and a shower spray head 4.

The source of preconditioned water may be a mixing valve for hot and cold water to provide water having a temperature selected by the user, and the booster pump unit 1 is operable to increase the pressure of the preconditioned water supplied to the spray head 4.

The spray head 4 comprises a handset carried by an adjustable support bracket 5 mounted on a slide rail 6 of the booster pump unit 1.

The support bracket 5 can be slid up and down the rail 6 and clamped at any adjusted position to vary the vertical height of the spray head 4 above the base of the installation, for example a shower tray or bath.

The support bracket 5 is also adjustable to vary the attitude of the spray head 4 in any adjusted position.

The spray head 4 is detachable from the support bracket 5 and is prevented from positioning below the spillover level of the base of the installation by passing the flexible pipe 3 through a retainer ring 7 mounted at the lower end of the slide rail 6.

The booster pump unit 1 comprises a centrifugal pump 8 and a motor 9 supported on the back wall 10 of a rectangular mounting box 11 provided with through holes for screws 12 to fix the mounting box 11 to a wall structure.

The slide rail 6 extends vertically upwards from the mounting box 11 and is secured at the lower end by the upper fixing screw 12. The upper end of the rail 6 is secured by a mounting bracket 13 fixed to the wall structure by screws (not shown).

The mounting box 11 is closed by a mating rectangular cover 14 to form an enclosure 15 for the pump 8 and motor 9. The cover 14 is releasably secured to the mounting box 11 for installation and maintenance of the booster pump unit 1.

The motor 9 is mounted above the pump 8 and has a drive shaft 16 on which an impeller 17 of the pump 8 is mounted.

The pump 8 has a water inlet 18 coaxial with the drive shaft 16 on the opposite side of the impeller 17 to which the source of preconditioned water is connected via the pipe 2.

Peripherally of the impeller 17, the pump 8 has a flow diffuser 19 forming a spiral flow passage 20 of progressively increasing cross-section in the direction of water flow that terminates in an outlet chamber 21 concentric with the water inlet 18.

A water outlet 22 extends parallel to the water inlet 18 from the chamber 21 and is connected to the spray head 4 by the pipe 3.

The motor 9 is connected to a power source (not shown) such as the mains electricity supply via a switch relay 23 controlled by switch means 24 responsive to water flow at the outlet 22.

The switch means 24 comprises a reed switch 25 that is actuated by a magnet 26 carried by a piston 27 mounted in the outlet 22.

The piston 27 is a close fit in a first bore portion. 28 of the outlet 22 and a clearance fit in a second bore portion 29 of the outlet 22.

The piston 27 has guide vanes 30 at one end sized to fit the first bore portion 28 and guide vanes 31 at the other end sized to fit the second bore portion 29.

The reed switch 25 is positioned externally of the second bore portion 29 and the piston 27 is axially biassed by a spring 32 to the position shown in Figure 6a in which it is received in and substantially blocks the first bore portion 28 when there is no water flow.

In this position, the reed switch 25 is open and the relay 23 is switched to interrupt the power supply to the motor 9 so that the pump 8 does not operate.

The piston 27 is displaced against the spring bias as water flow occurs and, as it reaches the intermediate position shown in Figure 6b, the reed switch 25 is closed by the magnet 26 and the relay 23 is switched to connect the power supply to the motor 9 thereby bringing the pump 8 into operation to boost the water pressure.

As the water pressure increases, the piston 27 is moved to the position shown in Figure 6c in which it no longer blocks the first bore portion 28 allowing water to flow around the outside of the piston 27 through the outlet 22 to the spray head 4.

On cessation of the water flow, the piston 27 is automatically returned to the position shown in Figure 6a by the spring 32. As a result, the reed switch 25 is opened and the relay 23 is switched to interrupt the power supply to the motor 9 so that the pump 8 stops.

As will be understood, the parallel arrangement of the water inlet 18 and water outlet 22 on the same side of the impeller 17 is compact and simplifies connection to the water source and spray head 4.

The water source may be a mixing valve as described or an instantaneous water heater or any other suitable controllable water supply.

Preferably, the water source is adapted to maintain the selected water temperature substantially constant, for example a thermostatically controlled mixing valve.

The spray head may be adjustable to vary the sprat type and/or pattern and may be incorporated in a handset as shown or wall mounted.

It will be understood that the invented centrifugal pump has general application and use where it is desired to booster water pressure for any reason and is not limited to the shower booster pump unit above-described.

Such applications and uses will be apparent to those skilled in the art and are deemed to be within the scope of the invention.

It will also be appreciated that the invented centrifugal pump abovedescribed may be modified without departing from the concept of parallel inlet and outlet with spiral diffuser. For example, the flow switch may be of any suitable type and may be arranged to sense water flow at the inlet. For some applications, the flow switch may be replaced by a manually operable switch to activate the pump motor. Other variations and modifications will be apparent to those familiar with the diverse applications and uses of centrifugal pumps and are deemed to be within the scope of this invention.

Finally, the special form of flow switch described herein may be employed in a wide range of applications where switching of a power supply in response to water flow is required. For example to control the power supply to an instantaneous water heater.

Claims

Claims:

1. A centrifugal pump comprising a water inlet, a water outlet parallel to the water inlet, an impeller and, peripherally of the impeller, a flow diffuser provided by a spiral duct connected to the water outlet, the cross-section of the duct increasing in the direction of water flow.

2. A centrifugal pump according to Claim 1 wherein the water inlet and water outlet are provided on the same side of the impeller.

3. A centrifugal pump according to Claim 1 or Claim 2 wherein the water inlet is coaxial with the impeller and the flow diffuser is connected to the water outlet via an outlet chamber concentric with the water inlet.

4. A centrifugal pump according to any one of the preceding Claims wherein the pump is controlled by switch means responsive to water flow so that the pump operates only where is sufficient water flow.

5. A centrifugal pump according to Claim 4 wherein the switch means is located at the water outlet and is magnetically actuated by displacement of a piston between first and second positions in response to water flow to control operation of the pump.

6. A centrifugal pump according to Claim 5 wherein the piston is resiliently biassed to the first position in which the pump is switched off, and is movable in response to water flow against the biassing to the second position for switching the pump on.

7. A centrifugal pump according to Claim 5 or Claim 6 wherein the piston is a close fit in the outlet in the first position and a clearance fit in the outlet in the second position with respective guide vanes at each end for locating and aligning the piston in the outlet.

8. A centrifugal pump according to any one of Claims 4 to 7 wherein the impeller is mounted on a drive shaft of a motor, and the switch means controls operation of the motor in response to water flow.

9. A centrifugal pump according to Claim 8 wherein the water inlet and motor are arranged on opposite sides of the impeller.

10. A centrifugal pump according to Claim 9 wherein the water inlet is coaxial with the drive shaft.

11. A centrifugal pump according to any one of the preceding Claims supported on a wall of a mounting box providing an enclosure for the pump.

12. A centrifugal pump according to Claim 11 wherein the mounting box has a slide rail provided with an adjustable support bracket for a shower spray head.

13. A centrifugal pump according to Claim 12 wherein the slide rail is provided with an apertured ring member for passage of a flexible pipe connecting the water outlet to the spray head.

14. A centrifugal pump according to any one of Claims 11 to 13 wherein the mounting box is provided with a removable cover for access to the pump.

15. A centrifugal pump having substantially parallel water inlet and water outlet connections on one side of an impeller and, peripherally of the impeller, a spiral duct of increasing cross-section in the direction of flow from the impeller to the water outlet.

16. A centrifugal pump substantially as hereinbefore described with reference to the accompanying drawings.

17. An ablutionary shower installation comprising a source of preconditioned water connected to the water inlet of the centrifugal pump according to any one of the preceding Claims, and a spray head connected to the water outlet.

18. A booster pump unit for an ablutionary appliance, the unit comprising a centrifugal pump and an electric motor responsive to water flow to control operation of the pump, the pump having an impeller and, peripherally of the impeller, a spiral duct of increasing cross-section in the direction of water flow from the impeller to a water outlet, the water outlet being provided on the same side of the impeller as a water inlet, and the water inlet and water outlet being arranged in parallel for connection respectively to a water supply and to an ablutionary appliance.

19. A booster pump unit according to Claim 18 wherein the pump and motor are housed in a mounting box provided with a slide rail carrying an adjustable bracket for a shower spray head.

20. A booster pump unit according to Claim 18 or Claim 19 including a flow switch positioned at the outlet for controlling operation of the motor in response to water flow.

21. A booster pump unit according to any one of Claims 18 to 20 wherein the water inlet is coaxial with the impeller and the water outlet extends from an outlet chamber surrounding the water inlet.

22. A booster pump unit according to any one of Claims 18 to 21 wherein the motor is arranged on that side of the impeller remote from the water inlet and water outlet.

23. A booster pump unit according to Claim 18 substantially as hereinbefore described with reference to the accompanying drawings.