Brushes of the kind discussed herein are disc-shaped and have a central hub from which brush-threads extend radially. The hub is adapted to be supported on the rotary axle of a cleansing machine and presents internal, single or double, stop lugs arranged for engagement with slots or cams in the surface of the axle to carry the brush as the axle rotates.

The brushes are usually supported on the axle with an intermediate spacer ring to offer a suitable density and rigidity of the operative brush cylinder. The axle driven for rotation rests against the ground by its own weight or by an added pressure, the optimal work result being obtained only at a certain, suitable thread density or rigidity in the brush cylinder. A problem arising from time to time usually manifests itself in that the brush cylinder jumps and leaves stripes in the brushed surface, if the flexibility of the brush cylinder were to be altered e. g. through the"wavering"and entangling of adjacent brushes.

Another problem arising is that the stop lugs sometimes break, whereby the damaged brush is not carried along in the rotation and its brush threads become entangled in those of the adjacent brush.

Another disadvantage with conventional brushes is that they may seldom be designed to cooperate with different types of axles, as these present significant differences in the design of the grooves or cams that are to ensure that the brushes are carried along.

It is an object of the invention to present a brush that through its design and structure sets aside the above problems and disadvantages.

This object is achieved with a brush according to the attached claims.

The invention will be described in more detail below with reference to the appended drawings in which: Fig. 1 is an exploded view showing a conventional, disc-shaped brush with spacer rings and a conventional type of axle for a cleansing machine, Fig. 2 is a perspective view of the hub of the brush according to the invention, Fig. 3 is a schematic end view of the brush according to the invention, with an axle shown in section, Fig. 4 is a schematic side view of a number of hubs according to the invention, coupled together into a rotationally rigid package of brushes, and Fig. 5 shows a number of sectional views of existing axles having different designs.

With reference to Fig. 1 there is shown an axle 1, comprising ends 2 between which a number of ridges or cams 3 extend. Prior art brushes 4 present a central hub 5 with internal stop lugs 6 to engage with the cams 3 when the brushes are supported on the axle. Insert rings 7 are arranged on the axle as spacer means between adjacent brushes 4, and retaining rings 8 hold the brushes axially on the axle. A groove 9 in the end enables the brushes to be thread onto the axle.

Figs. 2-4 show the hub 10 of the brush according to the invention. The hub 10 comprises a circular ring, the end surfaces of which present a number of evenly spaced, opposed projections 11 with intermediate indentations 12. The projections 11 and indentations 12 extend in parallel planes perpendicularly to the central axis of the hub, while inclined transition surfaces 13 join the projections 11 and indentations 12. From the periphery of the hub 10 brush- threads 14 (see Fig. 3) extend radially, the design of the hub causing the periphery of the disc-shaped brush to run in two essentially wave-or zigzag- shaped lines that alternately diverge and meet in a regular pattern.

One or more of the projections 11 in one of the end surfaces of the hub is/are formed with coupling means 15 that, when the brushes are mounted on the axle, cooperate with mating coupling means 16 in the opposed end surface of the hub. The coupling means 15 and 16 are preferably comprised of one or more lugs 15 and one or more receiving holes 16, respectively. In the mounted position, the coupling means 15 and 16 enable the brushes to be supported on the axle in the form of a rotationally rigid package, ensuring that all of the brushes are carried along in the rotation of the axle, even if a brush were to lose its engagement with the cams, ridges or grooves of the axle. The coupling means 15,16 thus prevent an undesired relative rotation between the brushes, and may, as in this embodiment, have a circular cross section but may also present an oval cross section with a larger dimension in the direction of the periphery than in the radial direction, to have a greater breaking strength in the direction of rotation.

For engagement with the axle, the hub 10 presents a carrier 17, in the embodiment shown having the shape of a radially inwardly projecting pin 17.

Preferably, the projections 11 and the indentations 12 are of the same arc length, so that the brushes may nest in each other during transport. For this reason, receiving holes 18 are arranged in the indentation 12, for fitting of the pins 15.

Fig. 3 shows the brush according to the invention supported on a axle 19, with the carrier 17 engaging the axle for rotation in the direction of arrow P. Through the relative coupling of the brushes into a rotationally rigid package of brushes there is only required a simple engagement with the axle, enabling the brush according to the invention to be given a universal design to cooperate with axles of different kinds. It will be understood that, as a consequence, the costs for stock-keeping and spare parts may be substantially decreased. It will also be understood that the design of the hub implies that the insert rings for the conventional brush are eliminated by this invention. It will further be understood that the risk for any of the carriers 17 to be damaged and the threads of adjacent brushes to stick into each other due to relative rotation between the brushes is substantially decreased, due to the total breaking strength of the carriers and coupling means 15. This also entails that the desired flexibility of the brush cylinder may be maintained also to a maximum level of wear, where all of the brushes are to be replaced anyway, enabling the operation and the desired result to be guaranteed with the brush and brush hub 10 of the invention.

In Fig. 5 there is shown, for comparison, a number of existing axles having different designs. From the figure of the drawing it is apparent that the conventional brush has to be formed with stop lugs adapted to the axle, to prevent relative rotation between brush and axle. With the present invention, the need for complex anchoring to the axle lapses, since the brushes are coupled together into a rotationally rigid package that prevents an undesired, relative rotation between the brushes.