EP2003957A2

EP2003957A2 - Rotary platform support and alignment mechanism

Info

Publication number: EP2003957A2
Application number: EP07747707A
Authority: EP
Inventors: John Chapman
Original assignee: DeLaval Holding AB
Current assignee: DeLaval Holding AB
Priority date: 2006-04-12
Filing date: 2007-04-12
Publication date: 2008-12-24
Also published as: WO2007117162A2; NZ546565A; WO2007117162A3

Abstract

A support system for a rotary platform (1) provided with an annular support track (19) attached to a lower surface and/or peripheral edge of the platform, said support system including a plurality of support stations (7) spatially disposed below the platform to engage with the support track (20), said support stations (7) including: individual primary support stations provided with at least one support roller (11) rotatable about a substantially horizontal axis to engage in use with a lower surface of the support track to enable horizontal rotation of the platform (1) and bear the platform's weight; individual lateral support stations (13) provided with at least one location roller (12) rotatable about a substantially vertical axis to engage in use with at least one substantially vertical portion of the support track, such that the lateral support station (13) rollers collectively provide a centering force to maintain the position of the platform (1) periphery within defined limits during platform rotation.

Description

ROTARY PLATFORM SUPPORT AND ALIGNMENT MECHANISM

STATEMENT OF CORRESPONDING APPLICATIONS

This application is based on the complete specification filed in relation to New Zealand Patent Application Number 546565, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to a support and alignment means for rotatable platforms, and in particular rotary milking platforms.

BACKGROUND ART

Rotary milking platforms (also known as rotary milking parlours or turntables) utilise a circular disc or annular platform, typically with an annulus width of 1¹/4 - 3 metres and provided with 40 - 60 milking stalls, although platforms with over 100 milking stalls have been produced. After being drafted into an individual stall on the rotating platform, each cow is fitted with milking cups and remains on the platform being milked for one (possibly two) rotations before exiting the milking stall. The entry and exit positions of the platform are located adjacently through a portion known as the 'bridge' provided with appropriate drafting facilities and associated ingress and egress stock fencing.

The ability to substantially automate the regular milking process for dairy cattle enables rotary milking platforms to significantly increase the efficiency of dairy farms and has consequently become popular throughout dairying industries worldwide.

Nevertheless, there is still a requirement to reduce fixed and ongoing costs associated with the milking process. This pressure has seen larger platform sizes and an increasing daily throughput of stock using the platform. This creates an attendant increase in platform manufacturing and maintenance costs necessary to produce the larger platforms and/or ensure they are sufficiently robust to withstand the increased usage rates.

Presently, milking platforms are supported by a series of horizontal axis rollers placed on pedestals located in an annular support ring underneath the platform. The support rollers typically act on the lower surface of an 'I-beam' support track (or 'track web') attached to the platform underside. Each pedestal is also provided with a side location roller with a vertical rotation axis orthogonal to the support roller. The side roller acts on the outer surface of the vertical centre-section of the I-beam support track to ensure the rotation of the platform remains centred.

However, such pedestal configurations with a combination of support and side roller possess several disadvantages, namely;

- each pedestal is required to be manufactured with an overly-robust construction for that required to simply support the vertical loads of the platform, in order to accommodate any horizontal forces on the side rollers.

- a surfeit of side rollers over the minimum necessary to constrain the platform rotation from eccentric rotation. Theoretically three side rollers are capable of providing the necessary constraints with an additional side roller used for safety. Existing combination pedestals typically result in 10-20 side rollers being employed for this role, thereby adding an unnecessary financial and logistical overhead to the platform assembly.

- a limited ability to accommodate fluctuations in the rotational path of the turntable. Intermittently, the platform rotation may be displaced by an object (e.g. a cows leg) falling between the platform and the bridge or the failure of one of the milking cups, support or side rollers, or the like. The plurality of side rollers being employed in typical systems together with the alignment tolerances introduced during manufacturing and installation of the platform may thus result in one or more side rollers being positioned either out of contact with the annular support beam (and thus susceptible to seizing through lack of use) or be subjected to elevated side forces and consequently vulnerable to early failure. This lateral overloading can cause damage to track webs.

It is thus desirable to produce a rotary platform support system which reduces the total number of side rollers required, whilst accurately locating and maintaining the axis of rotation within defined limits and provides a less costly system without any impairment of the platform function.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process. It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided a support system for a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said support system including:

a plurality of support stations spatially disposed below the platform to engage with the support track, said support stations including:

- individual primary support stations provided with at least one support roller rotatable about a substantially horizontal axis to engage in use with a lower surface of the support track to enable horizontal rotation of the platform and bear the platform's weight;

- individual lateral support stations provided with at least one location roller rotatable about a substantially vertical axis to engage in use with at least one substantially vertical portion of the support track

such that the lateral support station rollers collectively provide a centering force to maintain the position of the platform periphery within defined limits during platform rotation.

Segregation of the vertical and lateral platform loads (both static and dynamic) between the primary support stations and lateral support stations respectively enable both types of station to be optimised for their individual roles without the compromises of the prior art configurations. Thus, the primary support stations may be produced to withstand the vertical force of the platform weight plus a full complement of cattle and associated milking equipment, stalls, and so forth without additional strengthening to accommodate lateral loads. Conversely, the lateral support stations may be optimised for their role both by a construction configured to control the lateral movement of the platform and also by reducing the total number of stations used to the minimum necessary to effect such control.

In a preferred embodiment, said support system employs at least 3, preferably 3 - 5 lateral support stations to control the lateral movement of the platform. The minimum number of stations necessary to locate and control rotation of a circular platform is three (preferably substantially equidistantly spaced) stations. To provide a measure of security, one or two additional stations may be employed to prevent catastrophic damage to the platform and/or support system in the event of a failure of one of the lateral support stations.

Thus, separating the vertical and lateral support functions into distinct stations enables a significant reduction in the total number of lateral support stations, in addition to cost savings resultant from the role-specific construction of the two support station types.

Additional benefits are provided from a further aspect of the present invention in the form of an improved lateral support station. Currently, the position of the vertical location roller in lateral support stations is fixed via a rigid attachment of the roller axle to the rigid lateral support station structure, itself rigidly fixed to the ground. Thus each of the location rollers bearing on the outward surface of the annular support track are essentially only capable of applying an inward restorative force to the support track if the roller remains in contact with the track. Consequently, one or more location rollers may not even contact the platform depending on the dimensional manufacturing and installation tolerances. The platform itself may not be a true circle and may have a degree of radial variation. The positioning of the support stations during the platform installation process is also subject to inevitable inaccuracies with stations being placed out of accurate alignment with the annular support track. Clearly, both sources of error may have a compounding effect to produce an eccentric rotation.

Thus, according to a further aspect, the present invention provides a support system for a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said support system including:

a plurality of at least partially resilient lateral support stations spatially disposed below the platform to engage radially with the support track, said support stations including:

- at least one location roller rotatable about a substantially vertical axis to resiliency engage in use with at least one substantially vertical portion of the support track such that the lateral support station rollers collectively provide a centering force to maintain the position of the platform periphery within defined limits during platform rotation.

According to a further aspect, the present invention further provides a support system for a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said support system including:

a plurality of at least partially resilient lateral support stations spatially disposed below the platform to engage radially with the support track, said support stations including: - at least two substantially opposed location rollers rotatable about substantially vertical axes to resiliently engage in use with opposing substantially vertical portions of the support track to maintain the position of the support track platform periphery within defined limits during platform rotation. --.

According to one embodiment, said location rollers are formed from a resilient material.

As used herein, a resilient material includes any appropriate material or structure capable of absorbing a force or shock and retain its shape and/or position without permanent deformation or rupture.

According to a further embodiment, said location rollers are resiliently attached to the lateral support station.

The resilient attachment may be configured in a variety of arrangements. The roller axles may be resiliently attached to a rigid ground engaging portion of the support station. Alternatively, the rollers may be rigidly attached to a mounting coupling, which is in turn resiliently attached to a rigid ground engaging portion of the support station. The resilience may be provided by springs, buffers, elastomeric materials, rubbers and the like.

In a yet further embodiment, the resilience of said resilient lateral support stations is at least partially provided by the configuration and/or material of the support station. Thus, it is possible for a degree of lateral flexibility to be incorporated into the design of the whole support station, whilst maintaining the necessary rigidity vertically and tangentially to the rotation of the platform.

Thus, it can be thus seen that the resilient engagement of the location rollers with the support track may be provided by inherent properties of the rollers themselves, or the type of mounting of the rollers, or even a combination of same.

Resiliency biasing the rollers into contact with the support track enables even a single roller to remain in contact with the support track through a greater range of lateral movement than the non-resilient prior art configurations. When used with two (or more) rollers biased into resilient contact with opposing sides of the support track, even higher levels of corrective force are available to resist fluctuation in the platform's lateral position and to restore the orbit of the track about the correct axis.

Using two fixed location rollers formed with elastomeric contact surfaces enables a relatively simple and economical construction to be implemented. Possible limitations include the increased wear on the rollers due to their elastomeric construction and limitations on the maximum lateral defection that may be accommodated by compressing the rollers without damage to the roller or possible seizing.

Conversely, rollers rigidly attached to a mounting coupling which is resiliently attached to a rigid ground engaging portion of the support station provides capacity for a greater degree of lateral movement and greater flexibility in the type of bias applied by the resilient mounting, albeit at the expense of greater constructional complexity. It will be readily appreciated that a wide variety of mounting couplings are possible which may provide the same functionality, and, as such, fall within the scope of the invention.

Preferably, the rollers are substantially cylindrical, though frusto-conical rollers, ball rollers, or the like may also be employed.

Conventional milking platforms are rotated by a drive unit which acts on the annular support ring via a pair of contra-rotating driven wheels engaging opposing vertical sides of the support track. According to the present invention, such drive units may also be employed as lateral support stations, either

- rigidly mounted to a ground-engaging portion of the support station with resilient drive wheel contact surfaces and/or

- attached to a mounting coupling, which is in turn resiliently attached to a rigid ground engaging portion of the support station.

The use of a drive unit as a lateral support station enables the total number of support stations to be further reduced with a further saving in system costs.

Typically the support stations are formed from galvanised box-section steelwork in the form of substantially upright pedestals with lower ground securing means (e.g. bolts) with brackets at an upper distal portion to mount the rollers. Clearly, numerous alternative structures may be employed, the construction of which is not germane to the inventive aspects of the invention and are thus not discussed further.

As discussed above, cattle ingress to, and egress from the platform occurs in a region known as the bridge, in which a portion of the ground surface adjacent the platform is raised to align with the level of the platform upper surface to facilitate cattle movement. The separation between the platform and the bridge is the most critical region of the platform periphery, wherein it is important to maintain a minimal gap (to prevent a hoof of the like becoming entrapped), whilst still allowing for any lateral platform alignment fluctuations during rotation. To minimise the effects of such fluctuations in support systems utilising three or more lateral support stations and ensure the greatest accuracy, lateral support stations are located proximate to either side of the bridge portion.

It will also be appreciated by one skilled in the art that the present invention may reside in several forms in addition to a support system for a rotary platform, namely a complete rotary platform equipped with a support system substantially as described herein and also a method of operating such a platform to maintain rotational alignment within desired limits.

Thus, according to further aspects, the present invention provides a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system including:

According to a further aspect, the present invention provides a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system including:

a plurality of at least partially resilient lateral support stations spatially disposed below the platform to engage radially with the support track, said support stations including: - at least one location roller rotatable about a substantially vertical axis to resiliently engage in use with at least one substantially vertical portion of the support track such that the lateral support station rollers collectively provide a centering force to maintain the position of the platform periphery within defined limits during platform rotation.

According to a further aspect, the present invention further provides a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system including:

- a plurality of at least partially resilient lateral support stations spatially disposed below the platform to engage radially with the support track, said support stations including:

at least two substantially opposed location rollers rotatable about substantially vertical axes to resiliently engage in use with opposing substantially vertical portions of the support track to maintain the position of the support track platform periphery within defined limits during platform rotation.

According to a yet further aspect, the present invention provides a method of platform alignment for a milking platform substantially as hereinbefore described, said method including the steps:

- periodically rotating said platform to allow sequential ingress and egress of individual stock animals into individual milking stalls;

- restraining rotation to an axis centred within defined limits between said lateral support stations by application of a resilient radial biasing force.

The present invention thus provides in its different aspects a means of reducing the manufacturing and installation costs of new rotary milking platforms and the like and also providing the capacity for retro-fitting to existing installations during routine preventative or corrective maintenance of existing support stations.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1. shows a plan view of a rotary milking platform and associated stock animals;

Figure 2. shows a perspective view of a prior art platform support station incorporating a primary horizontally-mounted roller and a vertically- mounted lateral side location roller;

Figure 3. shows an isometric view of a preferred embodiment of the present invention in the form of a lateral support station with twin opposed resilient vertically-mounted location rollers;

Figure 4. shows a front side elevation of the preferred embodiment depicted in figure 3;

Figure 5. an isometric view of a further preferred embodiment of the present invention in the form of a lateral support station with a resilient mounting coupling for twin opposed vertically-mounted location rollers engaged with a platform support track;

Figure 6. shows an exploded view of the lateral support station of figure 6; and

Figure 7. shows an isometric view of a rotatable platform drive unit adapted as a lateral support station in accordance with a yet further embodiment of the present invention. BEST MODES FOR CARRYING OUT THE INVENTION

Rotary milking platforms are well know and as shown in figure 1, typically comprise a circular steel or concrete disc-shaped platform (1) onto which cattle (2) enter and exit via adjacent passageways (3, 4). The cattle (2) are coupled to milking cups at a station (5) shortly after entering the platform (1) and milked for the duration of a full platform revolution until the milking cups are removed at a further station (6) immediately prior to the platform exit (4).

The platform (1) is rotatably supported on its underside by a support system composed of plurality of support stations (7) generally composed of a ground engaging pedestal structure (8) provided at its distal upper end with bracketing (9) and (10) to mount a horizontally-mounted primary support roller (11) and a vertically-mounted lateral location roller (12) respectively.

In use, the upper surface of the support roller (11) receives the lower surface of an annular I-beam support track (not shown in figure 2) to bear a portion of the platform (1) weight. Typically 10-20 such support stations (7) are employed beneath a typical platform (1 ) sharing the platform weight between the 10-20 corresponding support rollers (11 ).

In use, the side location roller (12) engages with an outer vertical portion of the support track (not shown) to maintain the platform within a defined rotational path. However, the use of 10-20 side location roller is excessive for typical installations, resulting in unnecessary support system costs. Moreover, the combination of both the support roller (11 ) and the side location roller (12) on the same support station forced the construction of a pedestal structure sufficiently robust to withstand any anticipated side loads exerted by the platform (1 ) due to eccentric fluctuations in the platform (1 ) rotation.

Thus, by separating the functional and physical roles of the support rollers (11 ) and side location rollers (12), significant improvements may be achieved in both manufacturing and installation costs but also in operational performance efficiency.

Figures 3 and 4 show a first preferred embodiment of an individual lateral support station (13) formed with ground engaging base portion (14) and securing means (bolts 15), an upstanding elongate centre section (16), with confronting C-shaped mounting brackets (17) at an upper distal end. The brackets (17) mount a pair or vertically-mounted opposed resilient rollers (18). Figure 4 shows the rollers (18) engaged on opposing sides (19) of the platform (1) support track (19). The resilient material forming at least the outer contact surface of the rollers (18) enables both rollers to be positioned to apply a continual biasing force to maintain the support track (20) in a desired equilibrium position between the rollers (18). Any displacement of the support track (20) from this equilibrium position results in an increased reactive biasing force from the compressed roller to restore the support track (20) to the correct position.

It will be appreciated that only three of the dedicated lateral support stations (13) are necessary to locate and regulate the rotation of the platform (1). To ensure necessary safeguards for stock and operator alike, together with mitigating the financial hardships imposed in platform malfunction from a station (13) failure, the platform support system of the present invention typically incorporates a further one or two lateral support stations (13).

It will be appreciated that a complimentary embodiment may be configured utilising the characteristics of a resilient roller (18) in a combination support station as shown in figure 2. Whilst such configurations possess certain performance shortcomings, it nevertheless provide an improvement over the prior art.

Figures 5 and 6 show illustrations of a further embodiment of the present invention in which the support track (20) is again engaged on both opposing vertical sides (19) by a pair of confronting rollers (21) which may optionally (but not necessarily ) be formed from a resilient material. The lateral support station (13) also includes a ground engaging base portion (14) and an upstanding elongate centre section (16) as per the preceding embodiment. However, rather than attaching the side location rollers (21.) directly and rigidly to the centre section (16), the rollers (21 ) and associated mounting brackets (22) are attached to a mounting coupling (23) resiliently attached to the base/centre section (14, 16) and which biases the mounting coupling (23) to a predetermined position correlating to the desired lateral location of the platform (1 ).

Figure 6 shows the individual componentry of the lateral support station (13) shown in figure 5 in an exploded view. The mounting coupling (23) is formed in part from a substantially cuboid upper housing (24) to which the rollers (21 ) and mounting brackets (22) are rigidly fixed. The upper housing (24) envelops and is slideably mounted on the remaindered of the mounting coupling (23) in the form of a substantially cuboid lower housing (25) which is rigidly attached to the centre section (16). In use, lateral movement of the support track (19) causes the upper housing (24) to move relative to the lower housing (25) sleeved inside the upper housing (24). This relative movement causes corresponding compression of spring damper units (26) attached to an anchor block (27) attached to the upper housing (24) and located inside the lower housing (25). The compression of the spring dampers (26) causes a reactionary force in the opposing direction to the lateral displacement of the support track (19) to realigned the support track (19) position within the desired limits.

Figure 7 shows a drive unit 28 used to supply motive rotational power to the platform. The unit (28) is secured to the ground by a support framework (29) and typically comprises an electrical three phase drive, acting on the support track (19)

(not shown in figure 7) via a pair of contra-rotating wheels (29). In an analogous manner to the above-described embodiments, the drive unit (28) may be functionally employed as a lateral support station. This may be implemented either by rigidly-mounting the drive unit (28) to the ground and using resilient drive wheels (29) or alternatively, the drive wheels (29) may be resiliently attached to a mounting coupling (not show) which is in turn rigidly attached to the ground by appropriate means. Thus, the drive unit (28) may be used to further reduce the number of lateral support stations required to effectively control the lateral position of the turn platform (1), thereby reducing overall costs.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

Claims:

1. A support system for a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said support system including:

- a plurality of support stations spatially disposed below the platform to engage with the support track, said support stations including:

- individual lateral support stations provided with at least one location roller rotatable about a substantially vertical axis to engage in use with at least one substantially vertical portion of the support track,

- such that the lateral support station rollers collectively provide a centering force to maintain the position of the platform periphery within defined limits during platform rotation.

2. A support system for a rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said support system including:

- at least one location roller rotatable about a substantially vertical axis to resiliently engage in use with at least one substantially vertical portion of the support track such that the lateral support station rollers collectively provide a centering force to maintain the position of the platform periphery within defined limits during platform rotation.

3. A support system as claimed in claim 2, wherein said support stations include:

- at least two substantially opposed location rollers rotatable about substantially vertical axes to resiliently engage in use with opposing substantially vertical portions of the support track to maintain the position of the support track platform periphery within defined limits during platform rotation.

4. A support system as claimed in claim 2 or claim 3, wherein said location rollers are formed from a resilient material.

5. A support system as claimed in any one of claims 2 - 4, wherein said location rollers are resiliently attached to the lateral support station.

6. A support system as claimed in any one of claims 4 - 5, wherein roller axles supporting said location rollers are resiliently attached to a rigid ground engaging portion of the support station.

7. A support system as claimed in any one of claims 4 - 5, wherein roller axles supporting said location rollers are rigidly attached to a mounting coupling, which is in turn resiliently attached to a rigid ground engaging portion of the support station.

8. A support system as claimed in any one of claims 4 - 7, wherein the resilience of said resilient lateral support stations is at least partially provided by the configuration and/or material of the support station.

9. A support system as claimed in any one of claims 1 - 9, wherein at least one said support station is a drive unit configured to acts on the annular support track via a pair of contra-rotating driven wheels engaging opposing vertical sides of the support track.

10. A support system as claimed in claims 9, wherein said drive unit employed as lateral support stations, is either

11. A support system as claimed in any one of claims 1 - 10, including at least 3 lateral support stations to control the lateral movement of the platform.

12. A rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system as claimed in any one of claims 1-11.

13. A rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system including:

14. A rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system including:

15. A rotary platform provided with an annular support track attached to a lower surface and/or peripheral edge of the platform, said platform including a support system including:

16. A rotary platform as claimed in any one of claims 13-15, including at least 3 lateral support stations to control the lateral movement of the platform.

17. A method of platform alignment for a milking platform substantially as hereinbefore described, said method including the steps:

18. A support system substantially as hereinbefore described, with respect to, and as shown in the accompanying drawings.

19. A rotary platform substantially as hereinbefore described, with respect to, and as shown in the accompanying drawings.