Rotary disc planetary type surfacing machine

The invention relates to an arrangement for a mobile surfacing machine, preferably for the surfacing of stone floors. A frame supports a drive motor with a motor shaft. A planet disc is rotatably mounted in the fame, with three surfacing discs arranged on shafts rotatably mounted on the planet disc. The surfacing discs are in operative connection with a belt pulley arranged on the drive shaft of the motor via a drive belt running around first belt pulleys arranged on the aforementioned shafts. The shafts of the surfacing discs are so arranged, for the purpose of controlling the rotation of the planet disc, as to be in operative connection with the frame. The operative connection comprises, for example, a belt pulley attached to the frame, second belt pulleys arranged on the shafts of the surfacing discs, and a second belt running around these and the belt pulley attached to the frame.

BACKGROUND OF THE INVENTION 
The present invention relates to a mobile surfacing machine, preferably for 
the surfacing of stone floors, consisting of a frame which supports a 
drive motor with a motor shaft and a planet disc rotatably mounted in the 
frame, with three surfacing discs arranged on shafts rotatably mounted on 
the planet disc, which surfacing discs are operatively connected with a 
belt pulley arranged on the drive shaft of the motor via a drive belt 
running around first belt pulleys arranged on the aforementioned shafts. 
In a previously disclosed surfacing machine of this kind, the planet disc 
has a speed which depends very largely on the degree of engagement of the 
surfacing discs with the floor to be surfaced. This poses considerable 
risks of uncontrolled movement in the surfacing machine, with an 
associated reduction in processing capacity and increased wear on the 
surfacing discs. These risks can certainly be minimized, although not 
entirely eliminated by an experienced surfacing machine operator. 
SUMMARY OF THE INVENTION 
The object of the present invention is to make available a surfacing 
machine of the kind referred to by way of introduction, which does not 
suffer from the aforementioned disadvantages, which can be handled by an 
operator with only brief experience of surfacing, and which has a greater 
processing capacity in comparison with previously disclosed surfacing 
machines. 
This is achieved in accordance with the invention in that the shafts of the 
surfacing discs are so arranged, for the purpose of controlling the 
rotation of the planet disc, as to be in operative connection with the 
frame.

DESCCRIPTION OF THE EMBODIMENTS 
In accordance with a preferred embodiment, the aforementioned operative 
connection comprises a belt pulley attached to the frame, second belt 
pulleys arranged on the shafts of the surfacing discs, and a second belt 
running around these and the belt pulley attached to the frame. The 
combination of belt pulleys and belts imparts a certain extensibility to 
the operative connection, which is positive in this context. 
According to one particular characteristic of the invention, the operative 
connection comprises, as an alternative to the combination of belt pulleys 
and belts, an internal cylindrical contact surface attached to the frame 
for wheels arranged on the shafts of the surfacing discs. 
The invention is explained in greater detail below with reference to the 
accompanying drawing, in which FIG. 1 illustrates in schematic form a 
section through an illustrative embodiment of a surfacing machine in 
accordance with the invention. FIGS. 2a and 2b show respectively plan 
views of what is in itself a conventional drive for the surfacing discs of 
the surfacing machine in accordance with FIG. 1 and an embodiment of an 
operative connection in accordance with the invention between the frame of 
the surfacing machine and the shafts of the surfacing discs. FIG. 3 shows 
in a section, similar to that in FIG. 1, an alternative embodiment of the 
aforementioned operative connection. 
The reference numeral I is used in the drawings to designate a frame for a 
mobile surfacing machine, the frame is provided with attachment ears Ia 
for control devices not shown in the drawing, by means of which a machine 
operator can move the machine over a floor that is to be surfaced. The 
frame 1 supports a drive motor 2 and a planet disc 3 rotatably mounted in 
the frame 1. The planet disc 3 has the form of a flat cylindrical 
container with an upper end 3a and a lower end 3b connected together by 
means of a cylindrical wall. The rotatable mounting of the planet disc 3 
in the frame 1 is achieved by means of a rotary bearing 4 arranged in the 
upper end 3a and in the frame 1. The motor 2 has a shaft 2a provided with 
a belt pulley 2al, which shaft is connected at its outer end to the lower 
end 3b of the planet disc 3 by means of a rotary bearing 5. This mounting 
between the frame 1, the motor 2 and the planet disc 3 gives a highly 
robust construction while concurrently affording good protection between 
the ends 3a, 3c and between the frame 1 and the upper end 3a to the 
components described below. 
Rotatably mounted in the planet disc 3 by means of bearing 6, 7 are three 
shafts 8, each of which is equipped with a surfacing disc 8a at one end, 
and with a belt pulley 8b between the bearings. A drive belt 9, by means 
of which the motor 2 causes the surfacing discs 8a to rotate, runs around 
the belt pulley 2al and the three belt pulleys 8b, as can be readily 
appreciated from FIG. 2a. The belt 9 also runs over a tensioner pulley 10 
arranged between the ends 3a, 3b and rotatably mounted therein. The 
tensioner pulley is arranged so as to contribute to the belt 9 wrapping 
around the largest possible part of the circumference of the belt pulley 
2al, in order to achieve good power transmission between the belt 9 and 
the belt pulley 2al. 
In accordance with the invention, an operative connection is present 
between the respective shaft 8 and the frame 1 for controlling the 
rotation of the planet disc. In the embodiment illustrated in FIGS. 1 and 
2b, this operative connection comprises a belt pulley 1b attached to the 
frame 1, belt pulleys 8c attached to the other free ends 8 of the shafts 
8, and a belt 11 running over the aforementioned belt pulleys 8c, 1b. The 
gear ratio between the operative connections of the surfacing discs 8a and 
the frame 1 should be of the order of 1:15-1:30. 
It is obvious that the operative connection between the frame 1 and the 
surfacing discs 8a can be executed in many ways within the scope of the 
idea of invention. Such an alternative design of operative connection is 
illustrated in FIG. 3, where components which correspond to FIG. 1 have 
been allocated unchanged reference designations. This comprises wheels 8c 
arranged on the free ends of the shafts 8, which wheels are in engagement 
with an internal contact surface 1c attached to the frame.