GB1591246A

GB1591246A - Machine for cleaning underwater surfaces

Info

Publication number: GB1591246A
Application number: GB46510/77A
Authority: GB
Original assignee: CHRISTENSEN ENGINEERING AS
Current assignee: CHRISTENSEN ENGINEERING AS
Priority date: 1976-11-09
Filing date: 1977-11-08
Publication date: 1981-06-17
Also published as: SE7712590L; DK491477A; DE2748890A1; NO763802L; ES464131A1; JPS53101858A; FR2369952A1; IT1087477B; GR63724B; NO137849C; NO137849B

Description

(54) A MACHINE FOR CLEANING UNDERWATER SURFACES (71) We, CHRISTENSEN ENGINEERING A/S, a Norwegian Body Corporation, residing at . Langgate 50, N-3100 Tonsberg, Norway, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a cleaning machine for cleaning underwater surfaces such as a ship's bottom.

A large number of mechanical cleaning devices have been proposed which have brushes and are used on underwater surfaces e.g. to clean the bottom of a ship. Such devices are of particular use for large vessels such as super tankers where the possibility for docking in order to clean the underwater hull is low. Such devices are usually fully or partly motorized thereby enabling their operation to be remotely controlled or controlled by a diver or frogman. However, these prior art devices are complicated and expensive, both to make as well as in maintenance and operation.

It is an object of the present invention to provide an improved cleaning device for cleaning underwater surfaces consisting of few and mechanically simple parts, which is thus inexpensive both to make and use.

The invention consists in a cleaning device machine for cleaning underwater surfaces, said machine having at least one pair of oppositely rotatable coacting cleaning heads, each head having its own driving means and being arranged in such a manner that the axes of rotation for each of said pairs mutually form a fixed acute outwardly diverging angle relative to the normal to a work surface so that each cleaning head will bear more strongly against said work surface over the outer portion of its sweep path than over the inner portion of its sweep path.

With such an arrangement, the cleaning heads of the device will have the inherent property of providing a self-advancing movement during their rotation simultaneously with the rotatable cleaning heads being held towards the side of the ship or the like for efficient cleaning thereof.

The invention will now be further described, by way of example, with reference to the accompanying drawings which schematically illustrate a preferred embodiment according to the invention, and in which: Fig. 1 is a schematic plan view of a pair of brushes of a cleaning device, and Fig. 2 shows the same pair of brushes in side elevation.

As shown in Fig. 2, a pair of cleaning heads formed by two brush discs 1, 2 are arranged with their axes of rotation R in dined upwardly and outwardly relative to a plane work surface A. Thus there is a small angle cc between the axes R and the normals P to the work surface A. With both brush discs arranged in this way, the outer circumferential portions 1', 2' of the circular sweep path of the brushes, will bear more strongly against the work surface A than the inner circumferential portions 1", 2". Since the two brush discs 1, 2 are arranged to rotate in opposite directions by means of the motors 3 and 4, as indicated by the arrows in Fig. 1, this will cause the cleaning device inherently to advance itself in the direction F.Simultaneously the brush discs 1, 2 will, due to their respective rotation in the ambient water, provide a suction effect against the work surface A. The cleaning machine will thus by means of its own motors 3, 4 be held firmly against the work surface A to be treated simultaneously with the inherent movement in the direction of the arrow F.

In order to obtain overlapping treatment by the two brush discs these are preferably arranged staggered as indicated by the dashed circle 2' in Fig. 1. When advanced in the direction F the work surface will then be brushed completely without having portions between the brushes not treated.

As a power source for operation of the brush discs 1 and 2, pressurized air or electricity may be used. For tankers where danger of explosion always is present pressurized air is preferred. The driving motors 3, 4 for the brushes 1, 2 may be arranged in direct connection with the brushes as indicated in Fig. 2 and the complete assembly of brushes and motors may be mounted in a simple framework (not shown) which is easy to handle.

Instead of using brushes having bristles, other cleaning heads whose active working surface is provided with studs, knobs, or other scrubbing means known per se, may be used.

In order to control the direction of advancement of the machine suitable control means may be provided for the drive motors for the brushes in order that the rotational velocity thereof may be varied. By letting one brush in the pair of brushes rotate at a different rate from the other it is possible to cause the machine to change its direction of advancement.

WHAT WE CLAIM IS: 1. A cleaning machine for cleaning underwater surfaces, said machine having at least one pair of oppositely rotatable coacting cleaning heads, each head having its own driving means and being arranged in such a manner that the axes of rotation for each of said pairs mutually form a fixed acute outwardly diverging angle relative to the normal to a work surface so that each cleaning head will bear more strongly against said work surface over the outer portion of its sweep path than over the inner portion of its sweep path.

2. A machine according to claim 1 wherein the two cleaning heads of the or each pair are staggered in such a manner relative to the direction of advance that their sweep paths overlap.

3. A machine according to claim 1 or 2 wherein the driving means are arranged in direct connection with the cleaning heads.

4. A machine according to claim 1, 2 or 3, wherein the speed of rotation of the driving means for the or each pair of cleaning heads is adjustable.

5. A machine according to any preceding claim, wherein each cleaning head is a cleaning brush.

6. A cleaning machine for cleaning underwater surfaces substantially as hereinbefore described with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Instead of using brushes having bristles, other cleaning heads whose active working surface is provided with studs, knobs, or other scrubbing means known per se, may be used. In order to control the direction of advancement of the machine suitable control means may be provided for the drive motors for the brushes in order that the rotational velocity thereof may be varied. By letting one brush in the pair of brushes rotate at a different rate from the other it is possible to cause the machine to change its direction of advancement. WHAT WE CLAIM IS:

1. A cleaning machine for cleaning underwater surfaces, said machine having at least one pair of oppositely rotatable coacting cleaning heads, each head having its own driving means and being arranged in such a manner that the axes of rotation for each of said pairs mutually form a fixed acute outwardly diverging angle relative to the normal to a work surface so that each cleaning head will bear more strongly against said work surface over the outer portion of its sweep path than over the inner portion of its sweep path.