EP0051046A1

EP0051046A1 - Floor polishing machine having an epicycloidal drive for the motion of the brushes

Info

Publication number: EP0051046A1
Application number: EP81830186A
Authority: EP
Inventors: Mario Tecchiati; Gentile Marafante
Original assignee: Vorwerk Folletto SRL
Current assignee: Vorwerk Folletto SRL
Priority date: 1980-10-27
Filing date: 1981-10-07
Publication date: 1982-05-05
Also published as: IT8025601A0; IT1134060B

Abstract

A floor scrubbing and polishing machine provides for an epicyclic train for imparting to the brushes a sun-and-planet motion with respect to a central axis of symmetry, said epicyclic train including two driving members in form of coaxial gearwheels (2,3).

The machine further provides for brushes or brush sectors (20) that do not rotate about an axis, mounted between pairs of rotating brushes (6). One or more smaller rotating brushes (10) projecting outward and directly coupled to one of the driving members can be provided for cleaning the floor corners.

Description

The invention relates to a floor polishing machine in general and more particularly to a scrubbing-polishing machine having an improved driving system.
Conventional floor-polishers include an electric motor driving through belts or by friction engagement a plurality of rotating bodies in form of disks that carry the brushes. Such rotating bodies are usually placed around the central axis of the machine and are coupled to the motor by belts or by friction engagement of the lateral surface of the rotating bodies.
These polishing machines have a number of inconveniences, mainly due to the slipping of the driving.shaft over either the peripheral rubber driving members or belts, and to the power loss caused by worn out friction members or belts. Furthermore the rotation of close brushes only rotating about their axis, produces a polishing with close parallel strips corresponding-to the movement of translation of the machine when in use. The aesthetical result of the polishing is therefore partially spoiled by the excessive evidence of polishing streaks that are rather narrow.
Finally in the conventional polishing machines it is practically impossible to change the arrangement of the rotating brushes and/or their sizes, e.g. to get a good polishing also in the floor corners.
It is the object of the present invention to realize a floor polishing machine of a new and improved type that eliminates the above inconveniences. The invention will now be illustrated hereinafter referring to some preferred embodiments shown in the attached drawings in which:

FIGURE 1 is a schematic plan view of the arrangement of the brushes and of the drive members of the polisher according to the invention;
FIGURE 2 is a schematic cross-section of the machine along lines II-II of Fig. 1;
FIGURE 3 is a schematic plan view of an embodiment of the polisher according to the invention; and
FIGURES 4, 5 and 6 illustrate the features of a polish obtained by a conventional machine and by a machine according to the invention, respectively.

The polishing machine of the invention having the drive system schematically illustrated in Figs. 1 and 2 includes a main gear wheel or pinion 1, connected to the electric motor through means not shown in the figures, engaging a first drive member or gear wheel 2 having a diameter that is much 'larger than the diameter of pinion 1. Above gear wheel 2 and coaxially to it there is provided a second drive member or gear wheel 3 having a diameter approximatively equal to the radius of gear wheel 2 and fixed to the frame of the machine. During the rotation, gear wheel 3 is stationary with respect to the machine i.e. it docs not rotate and engages other gear wheels 4 rotatably mounted on gear wheel 2 thanks to shafts 5 passing therethrough and suitably supported as to rotate with respect to gear wheel 2. At their other ends shafts 5 carry brushes 6 of the polishing machine, either directly by-means of hubs or by means of suitable support bodies in form of disks of a type usually employed in the art. More particularly there can be used brushes not requiring a support body as the onesdisclosed in the Italian Patent Application No.25600 A/80 filed on October 27, 1980 in the name of the applicant. Such brushes are particularly suitable to realize a polisher with reduced height when employed together with the epicycloidal drive of the present invention.
A further brush 10 for polishing the floor corners can be provided at the periphery of wheel 2 and will be illustrated in more detail later.
From the above description the working of the machine can be easily understood. Main shaft or pinion 1 is forced to rotate by the electric motor and keeps rotating the first drive member or gear wheel 2 carrying the brushes. Thanks to the above mentioned arrangement brushes 6 are driven along a revolution path around central axis 9 of the machine. Moreover the coupling between stationary gear wheel 3 and gears4 causes brushes 6 to further rotate about their axes 8 when rolling over stationary gear 3. Therefore the motion of each brush is of a sun-and-planet type, i.e. similar to the combined rotation of a planet on its axis and revolution about a central axis.
There are several advantages provided by such a system. The drive or transmission system is simpler, less cumbersome and requires less servicing when compared with the belt or friction transmission systems of today. Moreover a maximum of polishing efficiency can be obtained by a low power motor and the speed ratios are chosen in order to give the best polishing effect. More particularly the angular velocity of gear wheel 2 is about 180 rpm whereas the satellite gears 4 rotate about their axes at about 400 rpm. The velocity of a brush element at a given instant will be the vectorial sum of the component due to the revolution about axis 9 and of the component due to the angular velocity of the brush element about axis 8. Of course the transational movement imparted by the user moving the polisher over the floor is to be added to the above motion.
Transmission or drive means have been shown as gear wheels but it will be evident to the skilled of the art that different transmission means, such as friction wheels, can be used.
According to the embodiment of Fig.. 3, additional brushes or brush sectors 20, not rotating and having a shape generally triangular or trapezoidal, are positioned near the periphery of gear wheel 2 to enhance the polishing action of the rotating brushes. Since these non rotating brushes 20 are fixed to gear wheel 2, they only accomplish a revolution motion about central axis 9 of the machine. The effect of such brushes, in addition to increase the number of passagesover a given surface so that the machine appears as having a single large brush (61 in Fig. 6), is to render the polished surface uniform. Referring to Figs. 4 to 6 the polishing result of a conventional polisher having three or four rotating brushes is compared to the one of a polishing machine according to the present invention. Fig. 4 illustrated the polish obtained by moving the conventional polisher along a given direction. The polished areas produced by each rotating brush give rise to corresponding polished streakings or strips 40, 41, 42 extending along the direction of advancing. Since the sizes of the brushes are small and no interaction take place between them, the polished strips are visible as streakings when looking the floor against the light.
The polish obtained with the machine according to the invention, schematically shown in Figs. 5' and 6, the latter on a reduced scale, is such as to produce a single uniformely polished area having a width equal to the width of gear wheel 2, i.e. to the entire machine (62 in Fig. 6). Advancing the machine produces a polished band 50, practically omogeneous and quite large so that the floor appears as polished in a more uniform way. Of course such a kind of polishing is obtained by the combined action of the rotation and revolution motions of brushes 6 and 20.
According to another ambodiment of the invention one or more additional outer brushes can be mounted, one being shown with reference 10 in Figs. 1 to 3. Such brush is mounted on shaft 11 outside gear wheel 2 and is driven by a gear wheel 12 directly engaging the outer periphery of gear wheel 2. The usefulness of such additional brush is rather evident for polishing floor corners. By choosing proper sizes for brush 10 and its gear wheel 12 with respect to brushes 6 and gear wheels 4, a small peripheral outer brush rotating at high speed and adapted to polish perfectly also the floor corners where the machine could never reach, can be obtained. For further details reference is made to Italian Patent Application No.25602 A/80 filed on October 27, 1980 in the name of the applicant. A plurality of rotating outer brushes can be arranged around the machine, but a single brush for polishing the corners is preferable and usually sufficient to the purpose. This-outer brush too can be equipped with a drive means without gear wheals but, for example, can provide for a friction means.
The epicycloidal drive system of the present invention is quite adapted for building a polisher having a very low main body and to which a drive bar is applied that is foldable over the body in rest position as disclosed in the Italian Patent Application No.25603 A/80 filed on October 27, 1980 in the name of the applicant.
Whereas the invention has been described with reference to particular embodiments, it is not to be limited to these but it extends to the obvious_' changes and/or modifications anyhow employing an epicycloidal transmission system for the brushes, in case associated with peripheral brush sectors and/or with outer rotating brushes for polishing the floor corners.

Claims

1. A floor polishing machine characterized in that the transmission system for driving the brushes comprises:

- a pinion (1) rotated by the motor of the machine;

- a first drive member (2) in driving engagement with said pinion (1) and rotatably supporting,in equally spaced apart holes along an intermediate circumference of said drive member (2) a plurality of rotating shafts (5);

- a second drive member (3) coaxial to said first drive member and fixed to the frame of the machine;

- a plurality of circular brushes (6), each mounted at one end of said rotating shafts (5), the other ends of each shaft being equipped with drive means (4) adapted to engage said second stationary drive member .(3) imparting them a motion of rotation about their axes (8) as said drive means (4) rolls over said drive member in order to realize for each circular brush (6) a motion of rotation about its axis (8) and a motion of revolution around a common axis (9).

2. A floor polisher as claimed in claim 1 characterized in that said first and second drive member are gear wheels (2, 3) and that said drive means at one end of the shafts (5) are gear wheels (4) engaging the gear wheel (3) stationary with respect to the frame of the polisher.

3. A floor polisher as claimed in claim 1 or 2 characte rized in that it comprises additional brushes or brush sectors (20) that do not rotate about their axes and are fixed to said first drive member, each brush sector being placed between a pair of adjacent rotating circular brushes.

4. A floor polisher as claimed in claim 3 characterized in that the axis of rotation of said pinion or main gear (1) is outside the circular surface defined by said first drive member (2) and that the circular brushes (6) and the brush sectors (20) are within said surface.

5. A floor polisher as claimed in claim 4 characterized in that is provides for at least an additional brush, external to said circular surface, for polishing the floor corners, that is equipped with a drive member or gear engaging said first drive member.