CA1199603A

CA1199603A - Rotatable platforms

Info

Publication number: CA1199603A
Application number: CA000423547A
Authority: CA
Inventors: John A. Graham
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-12
Filing date: 1983-03-14
Publication date: 1986-01-21
Also published as: AU1240683A; AU569028B2

Abstract

ABSTRACT (fig. 2) The present invention provides a rotatable platform which comprises a rotatable member (2) supported over a base (1) by a fluid (3) such as air or water. The rotatable member (2) has a loading deck (5). In one application when the platform is used for supporting animals (not shown) during milking the loading deck is provided with a plurality of bales defining stations for milking animals.

Description

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 - . ~ 2 ~ ~r~

. b~ ' 3~)3 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 3~

OE;03 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~

- 3a -9~03 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.

39~;~3 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 ` i, .`!
`' " ' , ;03 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.

. .

t3g~3 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.

)3 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.

.

~ ~ ~39~;03 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.
_g _ .

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A rotatable platform comprising a base and a rotatable member having a loading deck arranged to be supported from said base by a liquid, said rotatable member being rotatable with respect to the base whilst being supported above the base by said liquid, and driving means for rotating the rotatable member, there being a liquid sink between the sides of the rotatable member and the sides of the base, the arrangement being such that the plan area of the rotatable member on a plane of liquid surface is greater that the area of the free surface of the liquid within the liquid sink and the construction being characterised in that the rotatable member is freely floating relative to the base and is restrained against tilting by said liquid.

2. A rotatable platform as claimed in claim 1 wherein the loading of the rotatable member results in a downward displacement thereof which causes a rise in the level of the free surface of the liquid sink which is greater than the downward displacement of the rotatable member.

3. A rotatable platform as claimed in claim 1 wherein the base comprises a substantially circular trough and the rotatable member is a pontoon, said pontoon having side walls extending upwardly from its bottom and a loading deck which is spaced from the sides of the pontoon such that there exists a pit area between the side walls and the raised loading deck where an attendant can be positioned whilst the platform is rotated.

4. A rotatable platform as claimed in claim 1 wherein the base comprises a substantially circular trough and the rotatable member is a pontoon, said pontoon having side walls extending upwardly from its bottom and a loading deck supported from the bottom so that there exists a pit area at the centre of the pontoon where an attendant can be positioned whilst the platform is rotated.

5. A rotatable platform comprising a base and a rotatable member having a loading deck arranged to be supported from said base by a liquid, said rotatable member being rotatable with respect to the base whilst being supported above the base by said liquid, there being a liquid sink between the sides of the rotatable member and the sides of the base, the arrangement being such that the plan area of the rotatable member on a plane on the liquid surface is greater than the area of the free surface of liquid within the liquid sink and the construction being characterised in that the rotatable member is freely floating relative to the base and is restrained against tilting by said liquid and wherein the loading of the rotatable member results in a downward displacement of the rotatable member.

6. A rotatable platform as claimed in claim 5 wherein the base comprises a substantially circular trough and the rotatable member is a pontoon having at least its base shaped to be complementary to the shape of the trough, said pontoon having side walls extending upwardly from the base and a loading deck which is spaced from the sides of the pontoon so that there exists a pit area between the side walls and the raised loading deck where an attendant can be positioned whilst the platform is rotated.

7. A rotatable platform as claimed in claim 5 wherein the base comprises a substantially circular trough and the rotatable member is a pontoon, said pontoon having side walls extending upwardly from its bottom and a loading deck supported from the bottom so that there exists a pit area at the center of the pontoon where an attendant can be positioned whilst the platform is rotated.

8. A rotatable platform comprising a base and a rotatable member having a loading deck arranged to be supported from the base by a liquid, said rotatable member being rotatable with respect to the base whilst being supported above the base by a liquid, there being a liquid sink between the sides of the rotatable member and the sides of the base, the arrangement being such that the plan area of the rotatable member on a plane on the liquid surface is greater than the area of the free surface of the liquid within the liquid sink characterised in that the rotatable member includes an air trap to assist rotation.

9. A rotatable platform as claimed in claim 8 wherein the base comprises a continuous trough and the rotatable member has a loading deck and a floatation section depending downwardly from the loading deck, said floatation section being disposed within the trough and including a segmented air trap.

10. A rotatable platform as claimed in claim 8 having a segmented air trap whichis arranged to receive air under pressure from pumping means which can be associated with a milking plant.

11. A rotatable member as claimed in claim 8 wherein the floatation section is defined by a pair of spaced side walls depending downwardly from said loading deck, a bottom member, said bottom member defining an air trap with the liquid in the trough and said base including a plurality of air feed outlets arranged to disperse pressurised air into the said air traps via the liquid above the base.

12. A rotatable platform comprising a base and a rotatable member having a loading deck arranged to be supported from the base by a fluid said rotatable member being rotatable with respect to the base whilst being supported above the base by said fluid wherein the platform is supported by fluid pressure developed by mechanical means and the base is a raised disk-like member and the loading deck is arranged to be supported over the base, there being provided sealing means at the periphery of said disk-like member such that fluid chambers are defined between the upper surface of the disk-like member and the lower surface of said loading deck and sealing means and pumping means is arranged to supply fluid under pressure to said fluid chambers.

13. A rotatable member as claimed in claim 12 wherein the loading deck is provided with a plurality of joinable segments.

14. A rotatable platform as claimed in claim 12 wherein the sealing means comprises at least one sealing strip, the arrangement being such that the pressure exerted internally of said sealing stip increases localised fluid pressure in said fluid chambers.

15. A method of forming a rotatable platform wherein the platform comprises a base and a rotatable member arranged to be supported from said base by a liquid, said rotatable member being rotatable with respect to the base whilst being supported above the base by said liquid, there being a liquid sink between the sides of the rotatable member and the sides of the base, said method comprising the steps of forming the base in a mouldable material, applying a material to the base for the purpose of ensuring that further mouldable material applied thereto does not adhere to the base and applying a mouldable material over the base and shaping said material to form a pontoon within the area defined by said base and on curing of the mouldable material, floating said pontoon from said base.