Note: Descriptions are shown in the official language in which they were submitted.
CA 02088512 2000-04-03
H MOBILE FLOUR GRINDING VEHICLE
The present invention relates to vehicles for grinding
floors to a predetermined contour, for example, in order
to produce a substantially perfect flat surface on a
concrete floor.
S
The achievement of a perfectly Flat surface on a concrete
floor is particularly important in large industrial
1U buildings such as warehouses, where flatness is required
to enable forklift trucks to pass safely and efficiently
over the floor, remaining perfectly level even when
heavily loaded. It is also often necessary to provide
an accurately flat floor on which to attach heavy machine
i5 tools. In addition, where goods are to be stacked,
the floor must be substantially perfectly level to avoid
any danger of a stack toppling.
~t the present time, the required flatness has been
LU produced by manual techniques which, while proaucing
the results desired, nevertheless are laborious, labour
intensive and time consuming and, therefore, costly.
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It is an object of the invention to overcome the disadvantages
of the prior art and to provide a mechanised means for
grinding floors to a predetermined contour.
According to the invention there is provided a mobile floor-
grinding vehicle comprising a vehicle body movable in a
predetermined direction of travel over a floor; two powered
grinding tools mounted to said body via means to vary the spacing
of said grinding tools in a direction perpendicular to the
direction of travel; control means responsive to a signal
representative of a predetermined floor contour; and height
adjustment means responsive to said control means to vary the
lU vertical position of said grinding tools with respect to said
vehicle body as it traverses said floor; such that a pair of
parellel tracks may be formed in said floor in the general
direction of vehicle travel by said grinding tools according to
said predetermined contour.
i5 Preferably two support arms each carrying a grinding
tool are mounted at either side of the vehicle body
so as to swing outwardly with respect thereto in order
to provide an adjustable transverse spacing between
the grinding tools.
2U
Hlternatively, the or each grinding tool may be mounted
on a transverse beam, preferably provided with lengthtnise
adjustability, again so that the transverse position
of the grinding tools can be accurately set.
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The vehicle is preferably self-propelled, for example
by means of electric, hydraulic or diesel traction motors.
Electrical power may be obtained from batteries carriea
by the vehicle.
The control means may be responsive to a signal representing
a single predetermined.datum level. A typical example
is a horizontal laser beam from a fixed external source,
detected by a sensor on the vehicle which transmits
lU appropriate signals to the control means to regulate
the height of the grinding tools in relation to the
datum level.
Alternatively, and preferably in addition, the vehicle
includes a computer which is pre-programmable to control
the control means in accordance with a predetermined
pattern, e.g.,in accordance with data representing the
initial contours of the floor and its desired final
contours. In the latter case, the vehicle is self-propelled,
and the computer is linked to the propulsion means of
the vehicle so as to control the vertical position of
the grinding heads in such a way as to compensate for
variations in the initial contours and thereby grind
the floor to the~required degree of ~~atness.
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Hn embodiment of the invention will now be described,
by way of example only and with reference to the accompanying
drawings, in which:
Fig 1 is a diagran illustrating, in notional elevation,
principal component parts of the vehicle in a first
embodiment;
Fig 2 is a general outside view of the same vehicle;
lU
Fig 3 shows its propulsion and steering means;
Fig 4 shows, greatly simplified, main structural elements
of the same vehicle;
Fig 5 shows how grinding heads are mounted on the vehicle
of Figs i to 4;
Fig 6 is a simplified cross sectional elevation through
2U a grinding head;
Fig 7 is an outside elevation of a small part of the
grinding head as seen from the left-hand side of Fig
6;
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Figs 8 and 5 are diagrammatic views, in plan and elevation
respectively, showing parts of a mobile floor grinding
vehicle in a second embodiment;
Fig lU is a plan view in diagrammatic form of a mobile
floor grinding vehicle according to a still further
embodiment of the invention;
Fig li shows, in diagrammatic form, an elevation view
lU of the vehicle of Fig 10; and
Fig 12 is a section through the grinding head of the
embodiment shown in Figs lU and 11.
Referring to Fig i, a mobile floor grinding vehicle
comprises a body indicated in phantom lines at l, carried
by wheels 2 on which it is movable over a floor 3.
2U At least one rigid, transverse support beam 4 is supported
rigidly by the body 1 and is movable vertically in the
latter as indicated by the arrow 5. This movement is
effected by any suitable means, for example a hydraulic
piston and cylinder actuator 6.
The beam 4 defines a vertical plane 7, and is mounted
for limited rotation on the body 1 about a horizontal
WO 92/02334 PCT/GB91/01317
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-b-
transverse axis 8 in the plane 7. This rotation is
effected by any suitable means, for example by gravity
or by a rotary actuator, which is indicated at y and
which is controlled by a level sensor 10 in such a way
as to maintain the plane 7 of the beam 4 vertical at
all times. The reason for this will be apparent later.
A grinding head 11 is secured rigidly to the beam 4
so that its attitude and vertical position faithfully
lU follow those of the beam 4. The head 11 includes a
casing 12 to which a drive motor 13 is securely fastened.
A rotary floor grinding wheel 14, of any suitable type,
within the casing 12, is driven through a shaft 15 by
the motor 13, its axis of rotation 16 being contained
in or parallel to the plane 7.
The vehicle includes control means for the vertical
movement of the beam 4 in response to predetermined
input signals to control the vertical position of the
grinding wheel 14 as the vehicle is propelled over the
floor 3, by any suitable propulsion means 17 driving
a pair of the wheels 2.
The control means comprise a hydraulic control unit ,
1Fs which controls the actuator 6. The vehicle has two
different systems for supplying the above-mentioned
WO 92/02334 P~f/GB91/01317
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input signals to the control unit 18. The first ofd
these comprises a laser beam sensor iy which detects
a horizontal beam 2U transmitted from a laser fixed
in a suitable position up to, for example, about 3UU
metres from the vehicle.
The beam 2U defines a predetermined datum level, and
given that the floor 3 is intially undulating, then
as the vehicle travels over the floor the horizontal
lU level of the beam 20 with respect of the sensor i9 will
vary. This variation produces, in any known manner,
a varying input signal to the unit 18 which operates
the actuator 6 in such a way that the head 11, and therefore
the grinding wheel 14, remains at a constant vertical
distance from the laser beam 2D.
The other system for energising the unit 18 essentially
comprises a computer 2I, which is linked with the propulsion
means 17 so as to provide input signals to the unit
2U 18 that vary in accordance with the initial contours
of the floor, preprogrammed into the computer. This
preprogramming can be carried out in any known manner,
for example by the use of the plotting device known
as a PROFILERGRAPH. The signals supplied by the computer
21 represent an analogue of the contours plotted by
this device, the computer aetecting the progress of
the vehicle as it retraces the path previously followed
by the plotting device.
CA 02088512 2000-04-03
The embodiment shown in Figs 2 to 7 has two grinding
heads il, one on either side of the vehicle and carried
by a telescopic, rigid, transverse beams 22 which incorporates
the two corresponding beams 4, adjustable for transverse
spacing so as to position the grinding wheels l4~at
any desired track width. Associated with each head
1i is a separate sensor 19 and associated means for
controlling the vertical position of the grinding wheels
14,e.g.control unit 18 (in this case a hydraulic piston),
and actuator 6.
The body 1 includes a chassis 23 supported on the wheels
2, the front pair of which are idle and steerable by
a conventional steering linkage 24, while the rear wheels
2 are driven by independent electric motors 17. The
chassis 23 carries a cockpit 25 for the operator, with
electric batteries, for supplying power to the motors
17 and the control equipment, being mounted behind the
cockpit. the level sensor 10 is mounted on top of the
telescopic beam 22. The latter is supported rigidly,
by means not shown, on a rigid longitudinal main support
beam 26 of the chassis. It should be noted that the
track width between the two rear wheels is, in this example,
narrow enough to keep them out of the path of the grinding
wheels 14.
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The hydraulic motor 13 of each grinding head 11 may be
in line with the grinding wheel axis 9, or offset from
it so as to drive the grinding wheel through a belt
drive 27, Fig 5. Each grinding head casing 12 contains
a vacuum dust removal head 2d, mounted behind the grinding
caheel 14, the direction of travel being indicated at
29 in Fig b. H rubber dust skirt 3U extends around
the bottom.casing 12 in contact with the floor, being
carried on studs 31 fixed to the casing 12, and freely
lU movable up and down by means of slots 32 by which it
is supported on the studs 3i.
The embodiment just described is arranged to grind a
pair of parallel tracks, accurately levelled, in a floor.
There may, however, be any number of grinding heads,
and they may be so arranged that they together grind
the floor over the whole width of the vehicle, so that
an entire floor surface can eventually be levelled.
It will be understood that the grinding heads can take
U any suitable form. As shown, each grinding wheel 14
has diamond grinding rings 33, the casing 12 being effectively
sealed and having, besides the features mentioned above,
an inlet 34 for water under pressure. In Fig 6, the
piston of the associated actuator 6 is indicated at
=~ 35, being securely bolted to the ton of the casing 12.
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it will be understood that as the vehicle pitches longitudinally
or tilts sideways as its wheels 2 pass over the undulating
floor surface, the sensor lU maintains the grinding
wheel axes 16 vertical at all times.
Referring now to Figs 8 and 9, the vehicle, of which
some parts are shown here, differs from that described
above mainly in that, instead of being carried by the
transverse telescopic beam, each grinding head 11 is
carried on the free end of a corresponding rigid support
arm 36, which is supported on the vehicle chassis 23,
by means of a pivot having a pivotal axis 37. The pivotal
axes 37 of the arms 36 lie on a common transverse axis
38 with respect to the longitudinal axis 39 of the chassis
23.
Pivoting of each arm 36 is controlled by a cylinder-
type actuator 4U mounted transversely on the chassis
23.
Fig 8 shows one support arm a6 and head 11 on each side
of the chassis 23, illustrated both in their parked
position with the beam parallel with the chassis, and
in a swungout position. The head 11 is operative in
all beam positions.
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Tt~e chassis 23 may be arranged with further grinding
heads 11, each with its own support arm 36 and actuator
4U, mounted in front of and/or behind those shown.
Any support arm 36 can be arranged to swing inwards
as well as (or instead of) outwards. Each support arm
36 can be arranged to carry more than one head il.
The equipment carried by each support arm 36, to raise
and lower the grinding heads li is generally the same
m construction and operation as that carried by a support
lU beam 4 in Figs 1 to 7,e.g.cylinder actuator b operating
to reciprocate the head li in response to signals received
from the control unit 18.
The embodiment of Figs 8 and ~, by contrast with the
previous embodiment, has front traction wheels 41 as
the driving wheels, with the rear caheels 2 being steerable
by a conventional steering mechanism, not shown. A
liquid petroleum gas (LPG) combustion engine, not shown,
supplies hydraulic power to hydraulic traction motors
42 driving the wheels 4i, and also to the control equipment
of the grinding heads 11. It will, however, be understood
that, in any embodiment, either the front or the rear
wheels may be steerable; and that in any embodiment
traction may be electric or hydraulic.
H further embodiment of the invention is shown in Figs
lU to i2. In this emboaiment, those component parts
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zo~b5lz -12_
which are ttie same 'as in previous embodiments will have
the same reference numbers.
This further embodiment comprises a chassis 4a formed,
of two rigidly spaced beams 44 provided with front driving
wheels 45 and steerable trailing wheels 46. The front
wheels 45 are mounted on a drive axle 47 rotatably mounted
between the rigid beams 44 of the chassis 43. The drive
wheels 45 are more closely spaced with respect to the
lU central axis H of the chassis 43 than the rear wheels
46 and less than the track width to be ground by the
grinding wheels 14 of the grinding heads 11.
The rear wheels 46 are provided to steer the vehicle
and to this end are rotatably mounted on stub axles
48 projecting from the chassis beams 44.
A connecting rod.49 is pivotally mounted between two
pivoting arms 50, 51, both of which are pivotally mounted
to a pivot 52 on the stub axles 48. The arm 51 extends
to the other side of its associated stub axle 4B and
is connected to the piston rod 53 of a piston 54 pivotally
mounted at 55 to a rigid strut 5ti fixed between the
two beams 44. As will be appreciated hydraulic actuation
of the piston 54 through the steering mechanism of the
vehicle, not shown in detail, causes the wheels 4ti to
pivot on the stub axles 48 thus enabling the vehicle
to be steered over the ground.
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Power to drive the vehicle is supplied to the front
wheels 47 by means of a hydraulic motor 56 acting on
drive gear 57 coupled to the wheels 45 through a drive
coupling 58.
In this embodiment the support arms 36, see Fig lU,
are pivotally mounted on rigid support pieces 59 which
project from the chassis beams 44. In this way the
support arms 36 are able to be brought into abutment
I0 with the beams 44 in their parked position as shown
in dotted outline in Fig lU.
The support arms 36 are pivotally movable between the
said parked position and a maximum swung-out position
as shown in full outline in Fig lU. As in the Figs
8 and 9 embodiment, the pivotal axes of the arms 36
on the support pieces 59 lie on a common transverse
axis 38 with respect to the longitudinal axis A of the
chassis 43.
E~ctuation of the support arms 36 is effected by means
of a hydraulic piston bU mounted on the chassis 43 such
that the rod b2 thereof operates along the longitudinal
central axes of the chassis 43. The piston b0 acts
on two control arms tii of equal length pivotally mounted
at one end of each thereof to the end of the rod b2
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2088512 -14-
of the piston b0 and at the other ends respectively
to the rigid support arms 36 at equal distances from
the respective pivot points on the support pieces 59.
By means of this symmetrical arrangement, the arms 3b
may be moved outwardly upon actuation of the piston
60 by equal amounts at the same rate of travel such
that the grinding heads ll may be positioned to effect
a grinding operation at equal distances from the longitudinal
lU central axis A of the chassis 43.
As with the Figs 8 and 9 embodiment, the grinding heads
11, see Fig 12, are formed of a box structure having
an inner box part 63 carrying the grinding wheel 14
and connected to the rod 64 of a piston 65 the cylinder
of which is attached to an outer box part b6 of the
box structure, and within which the inner box part 63
is able to reciprocate upon actuation of the piston
65.
2U
The top_of the piston rod 64 carries the laser responsive
receiver 19, adjustably mounted thereon, signals from
which caused by variations of movement with respect
to laser beam 20 are used to actuate the piston b5 through
a control unit of the type. l8 described with reference
to Figs 1 to 7.
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Each grinding wheel 14, see Fig 12, is mounted to a
drive plate 67 connected to a drive shaft 68. The drive
shaft 68 revolves in a bearing 7U attached to a bottom
wall 69.of the inner box part b3 arid is driven by means
of a drive motor 71.
With reference now to Fig 11, the vehicle is provided
with a forward cockpit area 72 having a drivers seat
73 suitable positioned therein. A steering wheel 74
lU is provided in the cockpit 72 hydraulically coupled
to the piston 54 operating the rear wheels 46 by suitable
means, not shown, for steering the vehicle.
The vehicle is provided with a power pack in the form
15 of a diesel engine 75 coupled to a hydraulic pump 76
wMch powers the hydraulics of the system through a
controllable valuing arrangement, not shown, such as
the hydraulic motor 56, and pistons 54, 6U and ti5, and
thus travel of the vehicle, steering, position of support
20 arms 36, and height adjustment of the grinding heads
ll respectively. ell these operations may be effected
from the cockpit 72 using control equipment of conventional
design and familiar to one skilled in the art. The speed
of the vehicle is controlled by accelerator pedal 77,
25 coupled to the engine 75.
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To the rear of the vehicle is mounted a diesel fuel
tank 78 and a hyraulic oil storage tank 75.
To maintain the grinding area clear of ground dust and
other debris, clean water is fed from an external source
(not shown) to a water reservoir 8U above the grinding
wheels 14, see Fig 12. The clean water is delivered
to the grinding area as required via water outlets 81.
Dirty water and debris may be withdrawn from the grinding
lU area to a dirty water collection tank (not shown) by
means of a line connector 82. The dirty water collection
tank is caused to function using a vacuum unit 83 mounted
adjacent to the engine 75 and operated thereby. The
action of removing dirty water from the grinding area
is assisted by means of a rubber squeegee device 84
arranged around the grinding head, shown more particularly
in Fig 12.
25
