Apparatus for working floor surfaces

FIELD OF THE INVENTION

The present invention refers to an apparatus for working floor surfaces, for example when laying a floor with a thermosetting plastic surface, comprising a handle which is designed as an extension arm which is connected to a tool carrier having at least one working tool, which are brought to sweep the floor surface by rotation of the tool carrier around an axis of rotation which is substantially vertical in use, and which handle enables movement of the apparatus along the floor surface and is connected to the tool carrier via a pivot shaft which is substantially horizontal in use.

BACKGROUND OF THE INVENTION

Devices according to the above are known and may for example be used for laying an epoxy floor, in order to even out and planish the surface of the sticky, not yet hardened plastic surface, usually after spreading out slip protection upon said surface. These known devices are driven by an electric motor which obtains electric current via a long electric cable from a common mains socket.

The apparatus is handled by an operator equipped with spike shoes which pushes and pulls the apparatus to and fro and sideways, in order to provide an even sweeping of the surface of the floor. At the same time, the operator must ensure that the electric cable does not get into contact with the sticky surface.

Common areas of use are usually large factory premises where the surface may exceed 1000 square meters. The coating of the surface usually must be made over the entire surface in one step, so that no seam will be created.

Because the prior art apparatus for this object is heavy to handle, it is the cause of stress upon the arms, shoulders and back of the operator.

THE TECHNICAL PROBLEM

One object of the present invention is therefore to provide an apparatus which causes less stress upon the operator and which may be designed as to be saving weight.

THE SOLUTION

For this object, the invention is characterized in that the pivot connection of the handle to the tool carrier is located at a distance from the axis of rotation of the tool carrier, and that a support means for the handle is located at the opposite side of the axis of rotation, relative to the pivot connection of the handle. By this design of the apparatus, the operator may make it move to the left or to the right, merely by lifting or lowering the handle.

In use, the handle preferably extends at an oblique angle to the horizontal plane from its pivot connection, upwards past the axis of rotation of the tool carrier and the support means, to an operator of the apparatus.

The axis of rotation of the tool carrier is preferably carried by a chassis member which also carries the pivot connection of the handle and the support means. This chassis part may also be provided with a drive motor for driving the rotation axis of the tool carrier.

The drive motor is preferably electrical and connected via a cable to a source of electricity which may be one or more electricity accumulators which are being carried by the operator.

DESCRIPTION OF THE DRAWINGS

The invention will be described hereinafter with reference to embodiments that are shown in the enclosed drawings, wherein

Fig. 1 is a plane view of the apparatus according to the invention, and

Fig. 2 is ^' a section along the line II-II in Fig. 1.

DESCRIPTION OF EMBODIMENTS

The apparatus shown in Fig. 1 and 2 comprises a handle 10 which is designed as a T-shaped extension arm having two hand grips 11. The opposite end of the handle 10 as seen from the hand grips is designed as a fork with two shanks 12, which are connected to a rectangular chassis member 13 via projecting horizontal arms 14 which are provided with pivot points 15.

The chassis member 13 is provided with a bearing unit 16 for a vertical rotation shaft 17 belonging to a tool carrier 18 which is designed as a wheel and is provided with a number of scraping iron blades 19. These blades 19 are brought to sweep the floor surface by the rotation of the tool carrier, which is provided by an electric motor 20 which is connected to the axis of rotation 17 by not shown gearing and transmission means.

The chassis member is also provided with a support means 21 for the handle 10 which is located at the opposite side of the axis 17 of rotation, relative to the pivot connection 15 of the handle. Because the pivot connection of the handle to the chassis member 13 is located at a certain distance from the axis 17 of rotation of the tool carrier, the weight of the handle together with the weight of the electric motor 20 in position of use upon a floor surface, will exert a pressure upon the opposite side of the axis 17, as seen from the handle 10. If on the other hand the handle 10 is allowed to rest upon the support means 21, the centre of gravity will be moved from said earlier mentioned position at the

pivot points 15, to the sport means at the opposite side of the axis of rotation 17.

This shifting of the centre of gravity, from one side to the other side of the axis 17 of rotation, makes it possible for the operator to steer the apparatus in a simple way laterally. In this respect, the apparatus moves to the right in Fig. 1, when the direction of rotation is clockwise in Fig. 1, if the handle is lifted from the support means 21, and to the left in Fig. 1 if the handle is allowed to rest upon the support means. If the direction of rotation is the opposite, the "steering characteristics" will also be the opposite.

According to prior art, by centring the weight and centre of gravity immediately above the axis of rotation of the tool carrier, stability was accomplished at the expense of manageability, so that the apparatus became heavy to control along a floor surface.

According to the invention, an apparatus is provided which is light and by being unstable, has become unexpectedly simple to steer along a floor surface, in such a manner that the apparatus does not risk "running away" to any unwanted direction.

At the same time, the apparatus according to the invention may be designed so light that the drive motor 20 may be of a type so electricity-saving, that the source of energy may be rechargeable batteries which can be carried by the operator, e.g. within a backpack. In this way, it is not necessary to pull an electric cable over an easily damaged, sticky floor surface.

The invention is not limited to the above described embodiment, instead more variants are conceivable within the scoop of the following claims. For example, the handle 10,

the chassis member 13 and the support means 21 may be designed differently, e.g. in such a way that the pivot points of the handle are located at the operator side of the axis 17 of rotation and the support member at the opposite side, wherein the handle is lifted against the support means when the apparatus ^* is to be moved to one side.