GB2149063A - Wave generator - Google Patents

Abstract

A pneumatically operated wave generator for generating waves for example in a swimming pool 10 comprises a source 15 of high pressure air and an air conduit 16, 17, 18, 18' connected between the source and a pressure compartment 11. Valve means 21, 25 in the conduit is alternately operated between a first condition in which it closes an aperture 22 in the conduit while permitting air flow therealong to the compartment and a second condition in which it shuts off air flow along the conduit and opens the aperture to permit exhaust of air therethrough from the compartment. <IMAGE>

Description

SPECIFICATION Wave generator This invention relates to pneumatically operated wave generators. Such wave generators may be used in swimming baths to create waves for the enjoyment of swimmers but can also be used for scientific and other purposes in which waves in a liquid are required.

The invention provides a pneumatically operated wave generator comprising a source of high pressure air, and an air conduit for connection between the source and a pressure compartment, the conduit having valve means mounted therein for cooperation with an aperture in the conduit, the valve means being operable between a first condition in which it closes the aperture while permitting high pressure air flow along the conduit to the compartment and a second condition in which it shuts off the flow of high pressure air along the conduit and opens the aperture to permit exhaust of air therethrough from the compartment.

The adjective "high" is used here in a relative sense so that although the high pressure air source might typically be an air blower, with the aperture communicating with the ambient atmosphere, an alternative arrangement could be to connect the aperture to a suction pump in which case the high pressure air source could be the ambient atmosphere.

Preferably, the valve means comprises a first valve arranged to close the aperture in the first condition and open it in the second condition, and a second valve arranged to close off the conduit in the second condition and open it in the first condition.

The first valve may typically be a first pivotally mounted vane arranged to close the aperture in a first angular position and open it in a second angular position. Conveniently, the pivotal axis of the first vane may be generally central thereof and located substantially midway across the conduit.

Similarly, the second valve may be a second pivotally mounted vane arranged to open the conduit in a first angular position and close it in a second angular position. Again, the pivotal axis of the second vane may be generally central thereof and located substantially midway across the aperture.

The valves are preferably interconnected such that operation of one of the valve causes operation of the other. Such interconnection may be by means of a link pivoted at its ends to the vanes.

For convenience, the valves may be operated by a single actuator. This actuator may preferably be arranged to act on the first valve.

The generator may further comprise a second pressure compartment and a second conduit connected to the second compartment and arranged to supply high pressure air thereto from the first conduit from a location upstream of the first-mentioned valve means, the second conduit having second valve means mounted therein for cooperation with an aperture in the second conduit and operable in the same manner as the first valve means.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a longitudinal cross-section through a swimming pool; Figure 2 is an exploded perspective view showing a wave generator embodying the invention; and Figures 3 and 4 are sectional side elevations showing valve means of the generator in first and second conditions respectively.

Fig. 1 shows a swimming pool 10 in which the invention may typically be utilised. The waves are generated from the right, as seen in Fig. 1, and the bottom of the pool is inclined gently upwardly at the left to provide a surface on which the waves may "break" without significant reflection.

An enclosed pressure chamber 11 is formed by means of a dividing wall 1 2 extending part way of the depth of the pool at that point parallel to a rer wall 1 9. The remaining space below the lower end of the wall 1 2 and the bottom of the pool is preferably protected, for example by a wire grid 1 3 or similar, in order to prevent swimmers swimming underneath the wall 12.

In order to produce waves in the pool 10, the pressure of air in the pressure compartment, or plenum chamber as it may be known, 11 is regularly varied. It will be appreciated that this causes the water level in the compartment 11 to rise and fall, causing water to flow in and out of the chamber through the wire grill 1 3, thereby producing waves in the pool.

Referring now to Fig. 2, high pressure air is supplied to the chamber 11 from an air blower 1 5 via an air conduit connected therebetween. The conduit comprises an elbow section 16, expansion section 1 7 and a parallel section 1 8 connected to the chamber 11 at an aperture 1 4 therein. expansion section 1 7 and a parallel section 1 8. The operation of the embodiment may be best understood by reference to Figs. 3 and 4 which show valve means generally indicated 20, which is mounted in the parallel section 18, in first and second positions respectively.

The valve means 20 comprises a first valve in the form of a pivotally mounted vane 21 which cooperates with a lateral aperture 22 in the parallel section 1 8. The vane 21 is pivotally mounted to the parallel section 1 8 and the pivotal axis, indicated at 23, is oriented transversely of the section 1 8 midway across the aperture 22 and central of the vane 21.

The vane 21 is shown in Fig. 3 in a first regular position in which it closes the aperture 22, while Fig. 4 shows the vane rotated to a second angular position in which it permits air to exhaust out through the aperture 22.

A second valve in the form of another pivotable vane 25 is provided within the parallel section 1 8 to control the supply of the high pressure air to the pressure compartment 11. The vane 25 is pivotally mounted at its ends to the parallel section 1 8 for movement about an axis indicated at 26 which is parallel to the axis 23, both being transverse of the section 1 8. The axis 26 is located midway across the section 1 8 and is central of the vane 25. The vane 25 is shown in a first angular position in Fig. 3 oriented generally parallel to the parallel section 1 8 thereby permitting flow of high pressure air along the conduit to the pressure compartment 11 (as shown by arrows).Fig. 4 shows the vane 25 rotated to a second angular position in which it shuts off supply of high pressure air along the parallel section 18, since the other ends of the vane 25 engage the upper and lower walls of the section 1 8.

The vanes 21 and 25 are interconnected by a link 28 pivoted at opposite ends to the vanes. Thus rotation of the vane 21 from its first position to its second position causes similar rotation of the vane 25. Reverse movement of the vane 21 causes similar reverse movement of the vane 25. The link 28 is not shown in Fig. 2 for the sake of clarity; there may be one, two or more such links.

Any suitable means may be used for operating the valves, for example hydraulic, pneumatic electrical or machanical. In the embodiment shown, a pneumatic ram 3O is used as an actuator to rotate the vane 21. The ram 30 comprises a pivotally mounted cylinder 32 (neither the pivotal mounting nor the pneumatic ducts being shown) having a piston slideable therein as is well known. The piston rod 31 carries at its outer end a head 33 which is pivotally connected to the vane 21. The pneumatic circuit is appropriately controlled to provide periodic movement of the valve means from one condition to the second condition and back at desired frequencies, for example half a cycle per second.It will be understood that this causes, alternately, admission of high pressure air to the compartment 11 and exhaust of air therefrom out through the aperture 22, thus generating the required waves.

Referring now back to Fig. 2, the expansion section 1 7 also feeds high pressure air to a second pressure compartment 11' via a second parallel section 18'. By providing two pressure compartments 11, 11' or indeed more than two, various wave pattens can be created in the swimming pool by independent variation of pressure in the compartments.

The parallel section 1 8', connected to compartment 11' at entry aperture 1 4', is exactly similar to the parallel section 1 8 and has mounted therein a valve means again exactly similar to the valve means 20. The valve means in the section 18' is shown in Fig. 2 in ghost lines in its first condition, while the valve means of section 1 8 is shown in the second condition. The pneumatic rams of the two sets of valves are controlled from a single control circuit so that the valves can be set in phase or at a set relationship out of phase, or indeed at random with respect to each other.

Claims (11)

1. A pneumatically operated wave generator comprising a source of high pressure air, and an air conduit for connection between the source and a pressure compartment, the conduit having valve means mounted therein for cooperation with an aperture in the conduit, the valve means being operable between a first condition in which it closes the aperture while permitting high pressure air flow along the conduit to the compartment and a second condition in which it shuts off the flow of high pressure air along the conduit and opens the aperture to permit exhaust of air therethrough from the compartment.

2. A generator as claimed in Claim 1 wherein the valve means comprises a first valve arranged to close the aperture in the first condition and open it in the second condition, and a second valve arranged to close off the conduit in the second condition and open it in the first condition.

3. A generator as claimed in Claim 2 wherein the first valve is a first pivotally mounted vane arranged to close the aperture in a first angular position and open it in a second angular position.

4. A generator as claimed in Claim 3 wherein the pivotal axis of the first vane is generally central thereof and located substantially midway across the conduit.

5. A generator as claimed in any one of Claims 2 to 4 wherein the second valve is a second pivotally vane arranged to open the conduit in a first angular position and close it in a second angular position.

6. A generator as claimed in Claim 5 wherein the pivotal axis of the second vane is generally central thereof and located substantially midway across the aperture.

7. A generator as claimed in any one of Claims 2 to 6 wherein the valves are interconnected such that operation of one of the valves causes operation of the other.

8. A generator as claimed in Claim 7 when dependent on Claims 3 and 5 wherein the valves are interconnected by means of a link pivoted at its ends to the vanes.

9. A generator as claimed in either Claim 7 or Claim 8 wherein the valves are operated by a single actuator.

1 0. A generator as claimed in Claim 9 wherein the actuator is arranged to act on the first valve.

11. A generator as claimed in any preceding claim further comprising a second pressure compartment and a second conduit connected to the second compartment to supply high pressure air thereto from the first conduit from a location upstream of the first-mentioned valve means, the second conduit having second valve means mounted therein for cooperation with an aperture in the second conduit and operable in the same manner as the first valve means.

1 2. A pneumatically operated wave generator substantially as hereinbefore described with reference to and as shown in the accompanying drawings.