Hydraulic and earth engineering – Fluid control – treatment – or containment – Wave generation or enhancement
Reexamination Certificate
1999-09-21
2001-04-17
Lillis, Eileen D. (Department: 3673)
Hydraulic and earth engineering
Fluid control, treatment, or containment
Wave generation or enhancement
C004S491000, C472S128000
Reexamination Certificate
active
06217256
ABSTRACT:
FIELD OF THE INVENTION
The present invention refers to a device that creates waves in a liquid, especially when this liquid is contained in a pond or a pool. Such devices are used for example in fun fairs, but also in hydraulic or naval testing ponds.
The invention also refers to a wave creation method using the said device.
BACKGROUND AND PRIOR ART
It is know from U.S. Pat. No. 3,789,612 is a method that makes waves in a volume of water.
In one of the options of this method, a massive plunger, to which a vertical reciprocating motion is applied, is used for making waves. The plunger requires significant mechanical means to move it and to guide it.
In another option of that method, an open lower end tank is used. When the tank is lifted up above the surface of the water, the water volume that it contains discharges suddenly, resulting in the creation of a disturbance. This system allows the creation of one wave, but not of a system of sustained waves.
In international application WO 91/14062 a motion generation system in a liquid is known, especially at the surface of that liquid. That system uses a device containing two elements one of which moves relatively to the other. That relative displacement creates inertial forces, which make the whole device move in the liquid. That displacement creates excitations in the liquid, which are transformed in waves. In one of the embodiments of that system, one of the elements is a hollow sphere in which the second element moves. That kind of system effectively allows making waves at the surface of a liquid. But it has several disadvantages.
In the embodiment where the device is a sphere and also in other forms, the vertical stability of the system is not satisfactory. Specially, it can turn upside down when the mobile mass is in high position with respect to the shell.
The inertia forces being proportional to the moving mass, the mass of the device must be significant to create appreciable waves. The weight of the device makes its handling difficult. Moreover, the components designed to make the relative movement of the two elements have to be dimensioned accordingly, to be able to displace that significant mass, which has an incidence on the cost.
When a mobile element is moved by a harmonic movement of fixed amplitude, for example by a crank-connected rod system, the inertia force created is proportional to the weight and to the square of the frequency of the movement. It is thus not possible to adjust that excitation force independently from the frequency, or conversely, it is not possible to modify the frequency without modifying the excitation force. At the start, it is not possible to progressively increase the excitation force before reaching normal operating conditions.
The components designed to make the relative movement are part of the device. In that way, they are under the ambient conditions of the liquid, and are subject to damage by any small tightness default of the box. Moreover, they are hardly accessible for maintenance.
In one form of embodiment of that device, the power needed to put in motion the elements of the device is transferred to the device, for example by the means of an electrical cable. That cable is moved by the repetitive movements of the device. It is subject to wear or may be broken, and represent a risk. Moreover, the presence of that cable in the liquid makes a constraint.
In another form of embodiment of that device, the power needed to put the elements of the device in motion is stored inside the device, for example by means of electric energy in a battery, or pressure energy in a tank. In that case, the periodical need of recharge is a disadvantage for its operation.
Different wave machines based on various principles, for example by the EP 0 236 653, or EP 0 732 468, are also known but all request a major adaptation of the pool. These devices are not adapted to the generation of waves in existing pools.
SUMMARY OF THE INVENTION
The present invention has precisely the aim to provide a device that has not the aforesaid disadvantages. It has the aim to provide a wave generation device for pools, that is easy to install and operate, that consumes few energy, whose components in contact with the liquid are resistant to the environment wherein they are placed, that can be placed in an existing pool without any need to change the infrastructure, and that is easily removable to leave the pool in its original state.
The invention concerns a device that makes waves in a liquid contained in a pond or a pool, by a substantially vertical reciprocating motion of a body placed within the liquid or at the surface thereof. The body used for that is a shell capable of being filled with the said liquid. The shell is connected with a linking means to an element capable of periodically applying an upward-oriented force in a substantially vertical direction, then leaving the said shell to fall down again.
The principle of the invention is to transfer energy to the liquid, in phase with the kinetic energy of the wave.
The shell contains preferably a horizontal base and substantially vertical side walls. So, in the neighborhood of the shell, the vertical movement of the liquid is favored.
To allow the shell to be filled with water when it is placed within the water, a simple hole can be added to the bottom side of the shell. The shell may contain a flotation element.
In one embodiment, the shell of the device according to the invention contains a base equipped with a plurality of holes. These holes are advantageously able to favor the penetration of the liquid into the shell, but to disfavor its exit.
In another embodiment, the shell contains a topside shaped as a dish cover, containing at least one aperture for air flow. This aperture or these apertures are advantageously able to favor the exit of the air located in the upper part of the shell, but to disfavor its penetration.
The shell can also be made combining the characteristics of both the above mentioned embodiments.
The element capable of periodically applying an upward-oriented force preferably contains a winch able to roll and unroll the linking means. That winch preferably contains a regulation control box able to adjust the rolling and unrolling period of the said winch and its motor torque.
The invention also concerns a process in which a shell is suspended above a place of the pond, the said shell being partially immersed in the said pond, and where one periodically executes the action of lifting the said shell during a given period, then leaving it to fall down again.
In that process, the period of the movements imposed to the shell is determined preferably in a way to excite one of the natural oscillation frequencies of the liquid contained in the pond, and the motor torque applied to the winch during the shell lifting in a way to obtain the wanted amplitude of the waves. The motor torque applied to the winch during the falling down of the shell is preferably determined in a way to maintain the linking means permanently under stress.
REFERENCES:
patent: 3789612 (1974-02-01), Richard et al.
patent: 3973405 (1976-08-01), Duport
patent: 4276664 (1981-07-01), Baker
patent: 4507018 (1985-03-01), Andersen
patent: 4705428 (1987-11-01), Andersen
patent: 4810129 (1989-03-01), Guevel et al.
patent: 5320449 (1994-06-01), Demarteau
patent: 5621925 (1997-04-01), Bastenhof
patent: 0236653 (1987-09-01), None
patent: 0732468 (1996-09-01), None
patent: 409236 (1934-05-01), None
patent: 9114062 (1991-09-01), None
Ladas and Parry
Lillis Eileen D.
Mayo Tara L.
LandOfFree
Wave machine for liquids does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wave machine for liquids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wave machine for liquids will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485955