GB1570484A

GB1570484A - Shower apparatus

Info

Publication number: GB1570484A
Application number: GB31330/75A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-10-25
Filing date: 1976-10-25
Publication date: 1980-07-02

Description

(54) SHOWER APPARATUS (71) I, DANIEL CLELLAND ANDER SON, a British Subject of 13 Forgewood Drive, Halton, Lancaster, LA2 6NY, 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 shower apparatus.

One conventional form of shower apparatus comprises a mixing device with a cold water inlet, a hot water inlet and an outlet for a mixture of hot and cold water, and a shower head connected to that outlet.

In use the shower apparatus is connected to suitable supplies of hot and cold water, and valve means is provided to enable the relative quantities of hot and cold water to be adjusted so that the temperature of the water issuing from the shower head can be varied as desired.

A difficulty with that conventional form of shower apparatus is that the supplies of both the cold water and the hot water need to be at pressures such that the water can flow to the shower head and be discharged from it. In many domestic installations there is in the bathroom or near the bathroom a hot water tank with a cold water tank above it, the tanks being connected so that the pressure of the hot water supply is determined by the water level in the cold water tank. This pressure is normally adequate for the supply of hot water to taps on a basin and a bath in the bathroom, but is insufficient for the supply of hot water to a shower head which may be disposed only very slightly lower than the water level in the cold water tank.If a shower is to be installed in a bathroom provided with that type of installation other steps must be taken to provide a supply of hot water at an adequate pressure. To overcome this difficulty it has been the practice either to alter the installation so that at least the cold water tank is at a higher level than before, or to provide an electrically-powered, continuous-flow water heater supplied with cold water direct from the mains supply. Both solutions to the problem are relatively expensive.

An object of the present invention is to provide another method of overcoming or at least reducing that difficulty.

According to the present invention there is provided shower apparatus comprising in combination a mixing device with a cold water inlet, a hot water inlet and an outlet for a mixture of hot and cold water, and a shower head connected or suitable for connection to that outlet, the mixing device having a mixing chamber and a nozzle connected to the cold water inlet and directed into the mixing chamber, the hot water inlet leading to a space adjacent to the nozzle, the arrangement being such that in use cold water passing from the nozzle into the mixing chamber entrains hot water from said space, even though the hot water supply may be at a pressure lower than atmospheric pressure, the cold water and hot water become at least partially mixed in the mixing chamber and pass thence to the outlet and to the shower head.

In use the cold water inlet can normally be connected to the mains water supply, which is generally at a pressure more than adequate for the purpose. To limit the rate of flow and to provide a uniform maximum rate of flow an automatic flow regulator may be connected in the supply to the cold water inlet. The cold water supply may also be controlled by a manually operable valve which in normal use will be fully open. The hot water supply may be controlled by a manually operable valve such that the rate of flow of hot water can be varied as desired so as to vary the temperature of the water issuing from the shower head.

Preferably the bore of the nozzle and the mixing chamber are both of cylindrical shape and are co-axial. With such an arrangement it is found that the ratio of hot water to cold water supplied to the mixing chamber is largely determined by the ratio of the cross-sectional area of the nozzle to the cross-sectional area of the mixing chamber, provided of course that no extra restriction is applied to the hot water supply.

Preferably the ratio is between 0.06 1 and 0.28:1, and in the more preferred construc tions the ratio is between 0.1:1 1 and 0.2 Whether or not such constructions and ratio are adopted the nozzle preferably has a circular outlet of which the diameter is between 1.2 mm and 2.5 mm. In the more pre- ferred constructions the diameter of the o'it- let of the nozzle is between 1.5 mm and 2.0 mm.

The invention will now be more particularly described with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of one type of shower apparatus embodying the present invention; Figure 2 is a schematic side view of another type of shower apparatus embodying the present invention, and Figure 3 is a view to a large scale of a mixing device suitable for incorporation in both types of apparatus shown in Figures 1 and 2, much of the device being shown in section.

Referring firstly to Figure 1 there is here illustrated shower apparatus embodying the invention and which has been added to a previously existing domestic hot water installation. That existing installation comprises a cold water supply pipe 10 leading from the mains water supply to a cold water "header" tank 11. The water supply to the tank 11 is controlled by a float-operated valve 12 of conventional form so that the water in the tank is maintained at the level illustrated. A pipe 13 leads from the lower part of the tank 11 to the lower part of a hot water tank 14 which is provided with means such as an electric immersion heater for heating the water in the tank.

An outlet pipe 15 leads from the top of the hot water tank 14 and is connected by way of a non-return valve 16 to an overflow 17 discharging into the tank 11. Hot water is normally drawn from a pipe 18 connected to the outlet pipe 15 below the non-return valve 16.

To convert that installation into shower apparatus various additions have been made. A branch pipe 19 leads from the cold water supply pipe 10, by way of an automatic flow regulator 20 and a manually operable valve 21, to the cold water inlet of a mixing device 22. Also, the pipe 18 leads by way of a manually operable valve 23 to the hot water inlet of the mixing device 22. The mixing device has a mixing chamber and a nozzle connected to the cold water inlet and directed into the mixing chamber. The hot water inlet leads to a space adjacent to the nozzle, the arrangement being such that in use, when the valve 21 and 23 are open cold water passing from the nozzle into the mixing chamber entrains hot water from said space and carries it into the mixing chamber where it is at least partially mixed with the cold water.Water flows from the mixing chamber through an outlet 24 and passes by way of a pipe 25 to a shower head 26 of conventional form. The pipe 25, or part of it, may be flexible, and the shower head may be mounted on a handle, so that the user can direct the shower spray as desired. It will be observed, however, that both the mixing device 22 and the shower head 26 are disposed considerably above the level of the water in the tank 11. Thus, without special steps being taken no hot water would reach the mixing device and shower head. However the mixing device is such that the cold water issuing from the nozzle entrains the hot water even though the hot water supply, at the level of the mixing device, is at a pressure somewhat lower than atmospheric pressure.The arrangement illustrated in Figure 1 thus enables a shower to be installed, for example, on a floor above that where the existing hot water installation is disposed.

If the pressure of the water from the mains supply is insufficient to operate the mixing device a power-driven pump could be inserted in the branch pipe 19 but such a pump would not normally be necessary.

The apparatus shown in Figure 2 includes parts similar to parts in the apparatus shown in Figure 1. Similar parts in the two Figures are glven the same reference numerals.

The apparatus shown in Figure 2 is suitable for use where there is no existing source of hot water suitable for supplying the shower. The apparatus includes a hot water tank 27 of which the capacity may be considerably smaller than that of the tank 14. The upper part of the tank is open to the atmosphere. Water in the tank 27 is heated by an electric immersion heater 28. The tank is connected directly to the pipe 18.

Cold water can enter the tank 27 under the control of a float-operated valve 29, a pipe 30 from the valve 29 directing the incoming water towards the bottom of the tank. The valve 29 is connected to a pipe 31 connected to the cold water pipe 19 between the flow regulator 20 and the valve 21. A restrictor 32 in the pipe 31 allows water to enter the tank 27 only relatively slowly.

The apparatus operates as follows: water enters the tank 27 until it reaches the level indicated, the valve 29 then closing. The immersion heater 28, which is provided with a thermostat, heats the water to a predetermined temperature. The user can open the valve 21 and 23 and take a shower as with the apparatus shown in Figure 1, but the hot water supply substantially ceases when the level of water in the tank falls to that of the connection to the pipe 18. Sufficient water remains in the tank, though, to cover the immersion heater 28. The restrictor 32 is such that the tank is refilled slowly after the user closes the valves 21 and 23, so that the apparatus only enables showers of limited duration to be taken at intervals.

In one practical embodiment the tank 27 is mounted on the wall in or adjacent to the shower cubicle.

The mixing device shown in Figure 3 comprises a body 33 with a cold water inlet 34, a hot water inlet 35 and an outlet 36 for a mixture of hot and cold water. A bore is formed in the body 33, the inner end of which bore constitutes a mixing chamber 37 of cylindrical shape which leads to the outlet 36. Successive parts of the bore, from the mixing chamber 37 outwards, comprise a frusto-conical valve seat 38, a hot water inlet chamber 39 of cylindrical shape and with a lateral port communicating with the hot water inlet 35, and a cold water inlet chamber 40 of larger diameter than the chamber 39 and formed with a peripheral gallery 41 communicating with the cold water inlet 34. An end plate 42 covers the outer end of the bore and is secured to the body 33 by screws 43. An O-ring provides a seal between the end plate 42 and the body 33.

The cold water inlet chamber 40 contains a generally cylindrical liner formed with ports 45 aligned with the gallery 41. The liner is located against axial movement by the end plate 42 and by a shoulder formed between the cold and hot water inlet chamber. At the inner end the line 44 has an inwardly directed flange formed with a frusto-conical valve seat 46.

A sleeve 47 fixed to the end plate 42 projects axially into the cold water inlet chamber 40. A cylindrical portion of a rotor 48 is disposed in the sleeve, while an O-ring 49 in a groove in that portion of the rotor seals against the sleeve. An externally screw-threaded driving spindle 50 integral with the rotor 48 projects through a hole in the end plate 42 which is formed with a complementary screw thread. The spindle has a squared end for receiving a control knob (not shown). The rotor 48 also includes an outwardly directed portion 51 formed with a frusto-conical face complementary with the valve seat 46. A compression spring 52 around the sleeve 47 bears against the end plate 42 and the portion 51 of the rotor. Beyond the portion 51 the rotor 48 has a tubular portion 53 formed with lateral ports and with an open end.

The tubular portion 53 of the rotor 48 projects into the outer end part 54 of a nozzle component and is a sliding fit in that end part. A pin 55 extends diametrically across the tubular portion 53 and enters longitudinally extending slots in the end part 54 of the nozzle component. An outwardly directed flange 56 on the nozzle component is a sliding fit in the hot water inlet chamber 39. A compression spring 57 acts between the flange on the liner 44 and the flange 56 on the nozzle component. The inner part 58 of the nozzle component constitutes the nozzle proper and is formed with a cylindrical bore co-axial with the mixing chamber 37. The outer surface of the nozzle 58 is of frusto-conical shaPe and is complementary to the valve seat 38.

The mixing device operates in the following mannner. Cold water under pressure enters through the cold water inlet 34 and passes to the cold water inlet chamber 40 by way of the gallery 41 and the ports 45.

When the rotor 48 is in the position illustrated the water flows around the tubular portion 53 and through the ports in it. The water thence flows into the bore of the nozzle component and is discharged through the nozzle 58 into the mixing chamber 37.

With the nozzle component in the position illustrated there is an annular space between the nozzle 58 and the valve seat 38. The pressure in that space is reduced due to the flow of cold water, and hot water is drawn into the mixing chamber from that space.

The hot water reaches the space from the hot water inlet 35 by way of the hot water inlet chamber 39. The mixture of hot and cold water is discharged from the mixing device through the outlet 36.

If the rotor 48 is rotated the nozzle component also rotates, and both move in an axial direction. The arrangement is such that the movement of the nozzle 58 towards and away from the valve seat 38 varies the rate of flow of hot water and thus varies the temperature of the outflowing mixture. The rotor can be turned in one direction to a position in which the nozzle 58 engages the valve seat 38 thus cutting off the flow of hot water. When the nozzle is in that position the cold water can still flow, though at a somewhat reduced rate. On further rotation of the rotor in that direction the rotor moves axially inwards relative to the nozzle component against the action of the spring 57, the pin 55 sliding along the slots in the port 54. Finally the portion 51 engages the valve seat 46 thereby cutting off the flow of cold water.The two valves thus included in the mixing device correspond to the valves 21 and 23 shown in Figures 1 and 2. Rotation of the rotor 48 in the other direction causes the cold water to start flowing before the hot water flow can start, the rate of flow of cold water increasing as the nozzle 58 is withdrawn from its valve seat 38. In a modified construction (not illustrated) the cold water is able to flow at substantially its maximum rate for all open positions of the hot water valve; that arrangement however may decrease that rate of change of temperaturc of the water from the shower head with angular rotation of the rotor, and thus be less satisfactory than the arrangement previously described.

It is found that the cone angle of the outside surface of the nozzle 58, and the corresponding angle of the valve seat 38 have relatively little effect on the operation of the mixing device. As mentioned above the ratio of the cross-sectional area of the bore of the nozzle to the cross-sectional area of the mixing chamber is of particular significance. Preferred ranges are stated above. In one particular form of mixing device the diameter of the mixing chamber is 4.5 mm and the diameter of the bore of the nozzle is 1.7 mm, giving a ratio of 0.143: 1.

WHAT I CLAIM IS:- 1. Shower apparatus comprising in combination a mixing device with a cold water inlet, a hot water inlet and an outlet for a mixture of hot and cold water, and a shower head connected or suitable for connection to that outlet, the mixing device having a mixing chamber and a nozzle connected to the cold water inlet and directed into the mixing chamber, the hot water inlet leading to a space adjacent to the nozzle, the arrangement being such that in use cold water passing from the nozzle into the mixing chamber entrains hot water from said space, even though the hot water supply may be at a pressure lower than atmospheric pressure, the cold water and hot water become at least partially mixed in the mixing chamber and pass thence to the outlet and to the shower head.

2. Shower apparatus according to claim 1 in which the bore of the nozzle and the mixing chamber are both of cylindrical shape and are co-axial, the ratio of the cross-sectional area of the bore of the nozzle to the cross-sectional area of the mixing chamber being between 0.06 1 and 0.28 1.

3. Shower apparatus according to claim 2 in which the ratio is between 0.1:1 and 0.2: 1.

4. Shower apparatus according to any of the preceding claims in which the nozzle has a circular outlet of which the diameter is between 1.2 mm and 2.5 mm.

5. Shower apparatus according to claim 4 in which the diameter of the outlet of the nozzle is between 1.5 mm and 2.0 mm.

6. Shower apparatus according to any ot the preceding claims in which the nozzle is movable towards and away from the mixing chamber whereby the size of said space can be varied and in use the quantitiy of hot water entrained with the cold water per unit time is likewise varied.

7. Shower apparatus according to claim 6 in which the nozzle is movable towards the mixing chamber to a closed position in which said space is closed and in use no hot water is entrained with the cold water.

8. Shower apparatus according to either of claims 6 and 7 in which valve means is provided between the cold water inlet and the nozzle, the valve means being coupled to the nozzle in such a manner that when the space is of reduced size the valve is partially closed so that in use the rate of flow of cold water is reduced, and when the nozzle is moved to increase the size of the space the valve is opened further so that in use the rate of flow of cold water is increased.

9. Shower apparatus according to claim 8 as dependent on claim 7 in which the valve is movable to a closed position, the arrangement being such that when the nozzle is in its closed position the valve is partially open, but that the valve can then be closed.

10. Shower apparatus according to any of the preceding claims and in which the mixing device is substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.

11. Shower apparatus according to any of the preceding claims in combination with an automatic flow regulator connected, or suitable for connection, to the cold water inlet so that in use the rate of flow of cold water to the mixing device does not exceed a predetermined value which is determined by the regulator.

12. Shower apparatus according to any of the preceding claims in which the hot water inlet is connected to a source of hot water at a pressure insufficient to reach said space when cold water is not issuing from the nozzle.

13. Shower apparatus according to any of the preceding claims and substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

14. Shower apparatus according to any of the preceding claims and substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. water flow can start, the rate of flow of cold water increasing as the nozzle 58 is withdrawn from its valve seat 38. In a modified construction (not illustrated) the cold water is able to flow at substantially its maximum rate for all open positions of the hot water valve; that arrangement however may decrease that rate of change of temperaturc of the water from the shower head with angular rotation of the rotor, and thus be less satisfactory than the arrangement previously described. It is found that the cone angle of the outside surface of the nozzle 58, and the corresponding angle of the valve seat 38 have relatively little effect on the operation of the mixing device. As mentioned above the ratio of the cross-sectional area of the bore of the nozzle to the cross-sectional area of the mixing chamber is of particular significance. Preferred ranges are stated above. In one particular form of mixing device the diameter of the mixing chamber is 4.5 mm and the diameter of the bore of the nozzle is 1.7 mm, giving a ratio of 0.143: 1. WHAT I CLAIM IS:-

1. Shower apparatus comprising in combination a mixing device with a cold water inlet, a hot water inlet and an outlet for a mixture of hot and cold water, and a shower head connected or suitable for connection to that outlet, the mixing device having a mixing chamber and a nozzle connected to the cold water inlet and directed into the mixing chamber, the hot water inlet leading to a space adjacent to the nozzle, the arrangement being such that in use cold water passing from the nozzle into the mixing chamber entrains hot water from said space, even though the hot water supply may be at a pressure lower than atmospheric pressure, the cold water and hot water become at least partially mixed in the mixing chamber and pass thence to the outlet and to the shower head.