[0001] The present invention relates to a thermal disk device for single-brush machines
used for polishing and hot-washing surfaces, in particular floors.
[0002] It is well-known in the art to use single-brush polishing machines to perform the
operations of polishing and washing floors or other surfaces with the aid of chemical
substances in the form of a paste or liquids which are spread over said surfaces before
and while the work is being performed. It is also known that said operations are performed
most successfully if heat is supplied to the polishing surface, basically in the case
of all types of floor (including those made of linoleum and with the exception of
those made of thermoplastic materials), even though the best results are obtained
on marbles and granites.
[0003] At present, there exist single-brush polishing machines which use heat supplying
devices in which the disk is heated from the outside by means of hot air blowers which
direct the heat axially towards the centre so that it then spreads radially over the
whole disk. In other embodiments the friction generated by the contact between the
rotating polishing disk and a disk, which is fixed or rotating with different speed
and associated face-to-face with the former, is used as the heat source. Both the
said heat supplying devices have obvious problems, i.e. in terms of excessive overall
dimensions and low efficiency in the first case, rapid wear of the disks in the second
case, and high energy consumption in both cases.
[0004] US-A-5,587,021 also discloses a single-brush polishing machine, the rotating disk
of which is supplied with an auxiliary treatment means (such as water or another suitable
solution) passing through the disk itself, via special openings formed therein, said
treatment means being heated by means of electric resistances which are embedded in
the rotating disk. The extreme constructional complexity and the problems of maintenance
associated with this solution, as well as the high costs involved, are obvious.
[0005] The object of the present invention is that of providing instead, at a reasonable
cost, a thermal disk device which is of great constructional simplicity and reliable
to use. In this device the disk is heated in a diffused and efficient manner with
a relatively low energy consumption and has relatively small dimensions.
[0006] According to a first essential aspect of the present invention, a thermal-disk device
for single-brush polishing machines is therefore provided, characterized in that it
is composed of a rotating polishing disk and a fixed disk which is face-to-face associated
with the rotating polishing disk and made of material with good heat-conducting properties,
a suitably energized electric resistance being incorporated in the rotating polishing
disk and silicone grease being applied onto the contact surface between the fixed
disk and the rotating polishing disk in order to ensure lubrication and promote the
transfer of heat from the first to the second disk, while keeping the distance between
them as small as possible.
[0007] According to a further aspect of the present invention, a layer of heat insulating
material, for example sponge rubber, is interposed between said fixed disk and a cold
housing which surrounds the whole device at the top.
[0008] The invention will now be described in greater detail, with reference to the accompanying
drawing of a currently preferred embodiment thereof, said figure being an axial cross-sectional
view of a single-brush polishing machine equipped with the thermal disk according
to the invention.
[0009] In the polishing machine shown in the Figure, a rotating polishing disk 1 is connected
to the shaft 2 of a drive motor, not shown, by means of screws 3 and is mounted by
means of bearings 4 which allow rotation thereof with respect a fixed disk 5 with
which it is associated, with the respective circular surfaces facing each other and
being arranged very close together. Said fixed disk 5 is composed of material with
good heat-conducting properties and has incorporated an electric resistance 6 which
is controlled by a temperature regulator 7 and is supplied with mains power via a
cable 8. This resistance is obviously fixed and supplying thereof with the electric
current which also supplies the motor of the polishing machine does not involve any
constructional complications or maintenance. A layer of insulating material 10, for
example sponge rubber, which thermally insulates the thermal disk device from the
housing and the motor, is arranged between the fixed disk 5 and a cold housing 9.
Spacers 11 ensure that the layer of insulating material 10 has a constant thickness
and join the fixed disk 5 to the cold housing 9. A bracket 12 connects the thermal
disk device to the assembly of the single-brush polishing machine which comprises,
in a known manner, also an operating lever 13 and a wheel 14 for effecting displacements
in the non-operating condition of the machine.
[0010] At the time of assembly, a thick layer of silicone grease is applied onto the contact
surfaces between the fixed disk 5 and the rotating polishing disk 1. This grease has
a dual function. On the one hand, it ensures efficient lubrication, indispensable
for achieving free rotation of the disk 1 with respect to the disk 5, despite the
fact that they are very close to each other. On the other hand, it promotes the transfer
of heat supplied by the resistance of the disk 5 to the disk 1 which thus works at
a high temperature, as desired.
[0011] A safety thermostat which starts to function in the event of a malfunction of the
temperature regulator may also be envisaged.
1. Thermal disk device for single-brush polishing machines, characterized in that it
is composed of a rotating polishing disk and a fixed disk which is associated face-to-face
with the rotating polishing disk and made of material with good heat-conducting properties,
an electric resistance being incorporated in the rotating polishing disk, and silicone
grease being applied onto the contact surface between the fixed disk and the rotating
polishing disk in order to ensure lubrication and promote the transfer of heat from
the first to the second disk, while keeping the distance between them as small as
possible.
2. Thermal disk device for single-brush polishing machines as claimed in Claim 1, wherein
a layer of heat-insulating material, for example sponge rubber, is interposed between
said fixed disk and a cold housing which surrounds the whole device at the top.
3. Thermal disk device as claimed in Claims 1 and 2, wherein said resistance is energized
via a temperature regulator.
4. Thermal disk device as claimed in Claims 1 to 3, also comprising a safety thermostat.
