Note: Descriptions are shown in the official language in which they were submitted.
3~ 603
This invention relates to rotatable platforms.
Rotatable platforms are used for supporting animals
during milking, the pla-tforms being known as rotary
milking platforms.
The present invention is of relevence and has applic-
ation to rotary milking platforms, however, as will
be appreciated from the ensuing description which
s given by way of example in relation to the above
application~ a rotatable platform in accordance wi-th
the present invention has a broad and useful applic-
ation to the conveying loads o~ any type for any
purpose, other examples of possible uses being
vehicle turn-arounds or domestic, industrial or
commercial rotary conveyors.
~ilking sheds for herd milking generally have milking
stations or positions arranged in a herring-bone
layout where animals are positioned in rows, the
positioning of t.he cows being determined by bales
defining the rows, or alternatively rotary milking
platEorms are used where ~ni mAl s to be milked are
placed on a rotatable platform in other arrangements
such that the various matters requiring attention
during milking of the ~nim~l can be conveniently
attended to. The rotary platforms may be circular
and mount the cow bales or alternatively cow bales
are fixed to a rotating annular platfor~.
For rotary platforms the rotating platform or part
ther~f is rotated about a central pivot and the
platform is supported by support means and rotated
by mechanical drivers. Support means for such
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rotary platforms are complicated and expensive and because
of their size and/or the loads which the platforms need
to support plus they need constant maintenance, they have
not been universally adopted.
It is an object of the present invention to
provide a rotatable platform incorporating improved fluid
support means which will yo at least some way to eliminate
the disadvantages inherent in conventionally supported
rotary platforms.
Further objects of the present invention will
b~come apparent from the ensuing description which is
given by way of example.
Accordin~ to a first aspect oE the present
invention there is provided a rotatable platform comprising
a base and a rotating member having a loading deck arranged
to be supported from the base by a fluid. The rotatincs
member is rotatable with respect to the base while being
supported above the base by the fluids. The driving
means is provided for rotating the rotating member. A
fluid sink is provided between the sides oE the rotatable
member and the sides of the base. The arrangement is such
that the plan area of the rotatable member on a plane oE
liquid surface is greater than the area of the free sur~ace
of the fluid within the Eluid sink and the construction
is characterised in that the rotatable member floats freely
and is not restrained relative to the base against tilting
by any means other than the fluid.
There is also provided a method oE Eormin~ a
rotatable platform wherein the platEorm comprises a base
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and a Eotatirlg member arranged to be suppor-ted from the base
by a fluid. Thc rotatable member is rotatable with respect
to -the base while being supported above the base b~ the
fluid, there being a fluid sink between the sides of the
rotatable member and the sides of the base. The method
comprises the steps o forming the base in a moul~able
material, applying a material to the base for the purpose
; of ensuriny- that further mouldable material appliea thereto
does not adhere to the base and applying a mouldable ma-terial
over the base and shaping -the material to form a pontoon
within the area defined by the base and on curing the
mouldable material, floating the pontoon from the ~aseO
Aspects of the present inventior~ will now be
described by way of example only with reference to -the
accompanying drawings in which:
Figure 1: is a plan view of a rotatable platform in
accordance with one possible embodimen~ of
the present invention, and
Figure ~: is a diayL~ ic cross-section taken ~ II:II
of figure 1, and
Figure 3: is a plan view of a rotatable ~latform in
accordance with a further possible embodiment
of the present invention, and
Figure 4: is a diay~ ~Lic cross-section at IV:I~ of
figure 3, and
Figures 5 illustrate a rotatable platform in accordance
& 6
with a further possible embodiment of the
present invention, and
Figure 7: is a diayL~Lic cross-sectional drawin~
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showing one method by which a rotatable platform
in accordance ~.rJith figures 3, 4, 5 and 6 can be
formed, and
Figure 8: is a plan view of a rotatable platform in accord-
ance with another possible embodiment of the
present inven-tion, and
Figure 9: is a diagramatic cross~section of the rotatable
platform of figure 8, and
Figure 10: is a typical cross-section at the periphery
of the rotatable platform of figures 8 and 9,
and,
Figure 11: is a diagram~atic explanatory drawiIlg relating
(adjacent
fig. 7) to floatation principles for rotatable platform
constructions in accordance with embodiments
of the present invention.
With respect to the drawings, a rotatable platform
in accordance with the present invention comprises a base
generally indicated by arrow 2 arranged to be supported
from the base 1 by a fluid, said rotating member 2 being
rotatable with respect to the base 1 while being supported
by the base by the fluid 3.
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With respect to the embodiment of the present
invention illustrated by figures 1 and 2 of the
drawings, the base 1 comprises a continuous trough
4 and the rota~,ing member 2 has a loading deck 5
and a floatation section generally indicated by
arrow 6 depending downwardly from said loading
deck 5. The ~loatation section is disposed within
the trough 4. In the embodiment illustrated the
floatation section 6 is defi.ned by a pair of spaced
side walls 8 depending downwardly from the loading
deck 5 and a bottom member 9 which defines an air
trap 10 in the -trough with the liquid 3, the base
also includ.ing a plurality of air feed outlets 11
arranged to disperse air into the air trap 10 via
the liquid above the base (see bubbles indicated
on figure 2). Where the air trap 10 is provided
this can be segmented by a plurality of divider
walls 9A dividing the air trap into say, six
segmented compartments lOA. Each segmented compart-
men~ is provided with its own outlet 11 which receives
air under pressure from pumping means (not shown).
In a milking installation the trouyh 4 conveniently
provides a water resevoir for pumps which may be
associated with the milking plant and further
u provides a silencer exhaust for a vacuum plant of
the milking plant,
Sinple mechanical valves (not shown) for exclmple,
large ballcock control valves can control air being
exhausted from the segmented air traps lOA and when
one side of the rotating member ~ moves down under
load the valves closest to the point of loadiny close
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allowing incoming air to build up pressure and
displace more water. Conversely, when one side
moves up air is released deducing displacement.
The base 1 can be formed in a mouldable material
such as concrete formed on site, and the rotating
member 2 can be fabxicated wholly of partially
~rom plastics or any other suitable material or
combination of materials.
Where the rotatable platform is used for supporting
milking ~nim~l S bales 14 and a ramp 16. to the
rotatable member 2 are provided.
With respect to the embodiments of the present
invention illustrated by figures :~ and 4 and 5 and
6 of the drawings, in each case the base 1 comprises
a substantially circular trough 11 and the rotating
member 2 is a pontoon having a base 12 shaped -to be
complimentary with the surface shape of trough 11.
In the case of the embodi~ment of the present
invention illustrated by figures 3 and 4 of the
drawings, the loading deck 13 is a substantially
annular deck which overlies the outer surfaces of
the pontoon and where the rotatable platform is
used for supporting a plurality of milking animals
(not shown) the loading deck 13 mounts bales 14.
The loading deck 13 is supported from its base 12
by supports lS which can be in the form of spaced
piles (not shown) or a nib wall (as shown). Where
the supports 15 are in the form of a nib wall a
water run-off pipe 16 can be provided for access
to the l,owçx,cen't~al,,~r.t,s,of the rotating member
2 where there i.s a sump 12A.
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In the case of the embodiment illustrated by
figures 5 and 6 o:~ the drawings the base 12 o~ the
pontoon supports a loading deck 17 which covers
most of the base 12 of the pontoon. The pon-toon
can be constructed about a suhstant.ially annular
floatation material piece 1~ which is covered by
a mouldable material to form sides 19 and a top 20,
and the outer parts 21 o~ the base 12. Between the
sides 19 of the loading deck 17 and the sides 22 of
the base 12 a pit area 23 is formed which can have
a drain 2~ for water run-off to the centre of the
pon-toon from where accumulated water can be pumped
or otherwise cleared and ~here the rotatable
platform is used for supporting milking animals the
deck 17 can mount bales 25.
With respect to figure 7 of the drawings, the base
1 for the rotatable platforms and the rotating
member 2 may be formed in mouldable material such
as concrete b~ a method of construction which comprises
the steps of mounting a central pivot support means
26 in a pit 27 formed in a ground surface 2~ and
using a rotatable screed 2~ having a shapecl s~rface
Eorming member 30 which is supported centrally with
respect to the pivot support means 26. A mouldable
material such as concrete ls placed over the pit 27
and the mouldable material is shaped with the screed
29 to form a base 1. Once the base 1 has been ~ormed
as is set a material such as plastics sheet (not
shown) can be applied over the base for the purpose
of en~uring that further mouldab~e material applied
thereto will not adhere to the base, and a rotating
member 2 (see figures 2,3,4, and 5) formed directl~
on site on the haseO ~hen the construction o~ the
rotating member is complete and materials set the
rotating member and the base can be separated and
the trough ~illed with water or another liquid.
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With respect to ~igure 11 of the drawings the
rotatable platforms illustrated by way of
example with reference to fi~ures 1,2,3,4,5, and
6 are all designed in accor~ance with similar
floatation principles. In each case there is a
fluid sink 31 between the .~~sides 32 of the rotating
member 2 and the sides 33 ~f the base 1. The
rotatable platforms designed are such that a plan
area A of the rotating member 2 on a plane B on
the liquid surface is greater than the area C of the
free surface of the liquid within the fluid sink 31.
An alternative design criteria may be that the plan
area A of the ro-tating member 2 on the plane B on
the liquid surface is less or equal to the area C
of the free surface of the liquid within the fluid
sink, although a ro-tatable platform constructed in
accordance with this latter principle is likely
to be ~omewhat unstable inder load.
An important design feature of the present invention'
is that one unit of vertical displac~ment of -therotating
member produces a number of units of rise in the
free liquid surface in the fluid sink 31. Hence
the vertical settlement of the rotating member when
loaded is minimised because the effective liquid displaced
has been magnified by the above area ratios causing the
liquid surface to rise around the rotatable member by a
number of tim~s grea~ter than its downward displacement.
With respect to the embodiment of the present invention
illustrated by figures 3,9, and 10 of the drawings the
rotating member 2 of the rotatable platform 2 which is
substantially circular is formed in joinable segments 35.
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The ~luid which can be stored in a reservoir 37 formed
inside the base 36 and is transferred by a pump 38 into
fluid chambers 39 formed between the under surface ~0
of the rotating member 2, the top surface 41 o~ the
base 36 and sealing means indicated by arrow ~2 at
the periphery of the base 36.
The pump has an extending conduit 43 which extends
into the reservoir 37 and fluid pumped therefrom is
expressed by the pump into the fluid chambers 39 (see
path arrows of figure 9). The rotating member 2
is thus supported by the 1uid.
The sealing means 42 comprises a pair of I shaped
sealing strips 44 which are fixed to surface 40 of the
rotating member and pressure inside the fluid chambers
39 causes lower flanges 45 thereof to seal against
the surface 41. Fluid which may have escaped from
beneath the inside sealing strip 44 can re-enter
the reservoir 37 via drain holes 46 and fluid which
escapes the further outer sealing strip beyond the drain
holes 46 is collected in a sump 47 and re-turned to the
reservoir 37 via apertures 48. A sealing bearing or rotary
gland ~9 surrounds the conduit ~3 to prevent leakage.
It is to be appreciated that a platform supported
by a fluid~-d~r pressure could be supported by a
gas such as air, similar construction details (excepting
for the reservoir) being used.
In all cases the ro-tating members 2 can be driven(rota-ted)
by driving means (not shown) such as a hydrau]ic or air
motor through driving means such as rack and pinion gears
or the motors may drive a wheel which contacts with the
sides of the rotatabl~ members.
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