GB2352225A

GB2352225A - Automatic control for a turntable

Info

Publication number: GB2352225A
Application number: GB9916314A
Authority: GB
Inventors: Alan Barsby; Albert John Wheeler
Original assignee: WESSEX MEDICAL EQUIPMENT COMPA
Current assignee: WESSEX MEDICAL EQUIPMENT COMPA
Priority date: 1999-07-12
Filing date: 1999-07-12
Publication date: 2001-01-24
Also published as: GB9916314D0

Abstract

A control system for a turntable 9 associated with a conveyance such as a patient handling hoist 2 in which the control signal for the turntable is generated by the operation of the traverse controls 11 of the hoist. The turntable is adapted to interconnect a plurality of guides 4-7, the conveyance being configured to move along a said guide; the motion of the conveyance along a said guide being responsive to a motion control of the conveyance control unit 11, the turntable being configured such that when the conveyance is on the turntable, rotation of the turntable between two of the plurality of guides is responsive to user operation of the motion control. Preferably, the turntable has means for detecting the presence of the hoist on the turntable, and means for rotating the turntable if the motion of the hoist is interrupted for a predetermined period of time by the user.

Description

2352225 M&C Folio: 230P80942 Document #.- 399164 Automatic Control for a

Turntable This application is generally concerned with turntable apparatus and methods of operating turntables. More particularly it relates to methods and apparatus for automatic control of turntables.

It is known to use a ceiling-mounted hoist to lift disabled people. It is also known to suspend the hoist from a slotted track to enable the patient, once lifted, to be moved from place to place.

The hoist is normally provided with a remote control fitted with switches to enable the patient to be lifted or lowered and further switches to traverse the hoist automatically along the track in either direction.

Whenever the patient needs access to areas that cannot be served by a single track, it is known to provide a plurality of intersecting tracks, together with a tumtable enabling the hoist to enter from one track and to subsequently leave it by one of several other tracks.

With existing turntable systems, after the hoist has entered a rotor incorporated into the turntable from a first track, the operator may either cause the hoist to continue in the same direction and exit via an opposite track or, alternatively, may operate a turntable control to cause the rotor to turn, typically through 900, to allow the hoist to exit in either direction at right angles to its direction of entry.

A disadvantage of known systems is that a separate control is necessary to enable the operator to rotate the turntable when required.

This second control is generally a pendant switch and the control itself may represent a nuisance when the turntable is installed - as is often the case at a junction between corridors or gangways.

It is normal for patients using a hoist of this type to be aided by an attendant, who will use one hand to steady the patient and to stop him from swinging excessively. When entering the turntable of known systems, it is 2 generally necessary for the attendant to release the hoist control in order to operate that for the turntable. This may be awkward to achieve whilst maintaining a steadying hand on the patient.

A further disadvantage of known systems relates to the not insignificant cost of the provision and installation of control switches for the turntable.

It is an object of the present invention to provide an improved control system for a turntable which avoids the need for a dedicated control, and so alleviates the above-listed disadvantages.

The invention is as set out in the attached claims. According to one embodiment of the present invention, when a hoist enters the rotor of a turntable, the control circuit is arranged to stop the hoist briefly on the rotor, in the position shown in Figure 1.

The control circuit is designed so that, in the event that the operator maintains pressure on the traverse button, throughout a brief delay, the hoist is caused to resume travel in its original direction, that is leaving the turntable along the track opposite the entry track.

However, if, when the hoist has entered the rotor and stopped, as described above, the operator releases the traverse button, the control circuit is designed to automatically cause the rotor to turn so that the hoist becomes aligned with an alternative track or pair of tracks.

The operator may then choose to press either the forward or reverse traverse switch of the hoist control, so driving the hoist in the required direction.

In an alternative, and preferred, embodiment the turntable is caused to respond to the presence or absence of a hoist traverse signal at the end of the said pre-determined delay, that is if a traverse signal is present at the end of the delay, the hoist will traverse without turntable rotation: if such a signal is not present, the turntable rotor will turn to its alternative position as described above.

It will be clear that, using this embodiment, it is possible for the operator to select one of four, rather than three exit routes: the operator has an option of changing his mind and reversing the hoist back along its entry route.

3 Such a turntable therefore, needs no dedicated control (12) associated with the turntable, the movement of the latter being controlled purely from the operation of the hoist's traverse control.

These and other aspects of the invention will now be further described, by way of example only, with reference to:

Figure 1 which illustrates a ceiling-mounted mobile hoist and a turntable of the type described; and Figure 2, which illustrates a turntable control system.

In Figure 1, a hoist (1) may have a spreader bar (2) equipped with hooks to which patient supporting slings may be attached. The spreader bar may be supported by a flexible tape (3) to allow the patient to be raised and lowered. The hoist may run along ceiling tracks (4), (5), (6) and (7), each of which terminates close to the rotor (8) of the turntable assembly (9). Within the rotor is included a short track (10) which is capable of bridging between tracks (4) and (5) or between tracks (6) and (7) according to the angular position for the time being of the rotor.

The hoist (1) is equipped with a remote control (11) (which may be a pendant control or a radio/infra-red transmitter). The control (12), normally supplied to operate the turntable, becomes redundant.

In operation, the hoist may arrive at the turntable, for example, along track (4), with, say, the "forward" traverse button of the hoist control (11) being operated. To exit via track (5), the operator would simply maintain pressure on the "forward" control, whilst the hoist briefly stops and then resumes its journey To exit on track (6) the operator would wait until the hoist stops, and release the "forward" control until the rotor turns through 901. Assuming that the rotor has turned clockwise seen from below, re-applying pressure to the "forward" button would re-start the hoist along track (6). Alternatively, if it were required to exit along track (7), the "reverse" button of control (11) would be operated.

Using the preferred embodiment of the invention described above, exit by the entry track (4) would be achieved by the operator releasing one traverse 4 control and then operating that to the other direction, and completing this activity within the said predetermined period.

Figure 2 shows the operation of the turntable control system in schematic form, and illustrates how a hoist approaching a track intersection equipped with a turntable may be controlled to go straight ahead, to turn left or right, or to reverse.

Claims

CLAIMS:

1. A control system for a turntable associated with a patient handling hoist in which the control signal for the turntable is generated by the operation of the traverse controls of the hoist.

2. A control system for a turntable as described in Claim 1, in which the hoist, when arriving at the turntable, is caused to pause for a predetermined period.

3. A control system for a turntable as described in Claim 2, in which maintenance of the hoist traverse control signal throughout the said predetermined period inhibits rotation of the turntable, and in which interruption of the said signal during the said pre-determined period causes the turntable rotor to turn from a first to a second operating position.

4. A control system for a turntable as described in Claim 2, in which the presence of a traverse signal at the end of the said pre-determined period inhibits rotation of the turntable, and in which absence of a traverse signal at the end of said period causes the turntable rotor to turn from a first to a second operating position.

5. A control system for a turntable for a conveyance, the turntable being adapted to interconnect a plurality of guides, the conveyance being configured to move along a said guide; the motion of the conveyance along a said guide being responsive to a motion control of a conveyance control unit; the turntable being configured such that when the conveyance is on the turntable, rotation of the turntable between two of the plurality of guides is responsive to user operation of the motion control.

6 6. A control system for a turntable as claimed in claim 5 wherein the turntable is configured to rotate in response to the absence of a motion control signal from the conveyance control unit.

7. A control system for a turntable as claimed in claim 5 wherein the turntable is configured to rotate in response to a user manipulation changing the state of the motion control, whilst the hoist in on the turntable.

8. A control system for a turntable as claimed in any one of claims 5 to 7 wherein said absence of a user control signal is evaluated after a predetermined time interval having a start time determined by the time at which the conveyance arrives at or on the turntable.

9. A control system for a turntable as claimed in any one of claims 5 to 8 configured to rotate between first and second positions in which the turntable selectively connects respective first and second pairs of guides.

10. A control system for a turntable as claimed in any one of claims 5 to 9 configured for use with a ceiling-mounted, person-carrying conveyance.

11. A turntable equipped with a control system as described in any previous claim.

12. A turntable and hoist combination operating as described in any previous claim.

13. A method of controlling a turntable for a conveyance, the method comprising: operating a control unit to move the conveyance onto the turntable from a first position; detecting an operational state of a conveyance-moving control of the control unit; 7 selecting a second position in response to the result of said detecting step; and moving the conveyance off the turntable to the second position.

14. A method as claimed in claim 13 wherein the turntable has conveyanceguiding track and wherein said first and second positions are determined by end points of guide track interconnected by the turntable.

15. A method as claimed in claim 13 or 14 wherein said step of detecting is carried out a predetermined time interval after the conveyance arrives at or on the turntable.

16. A method as claimed in claim 15 wherein said first and second positions are substantially opposite one another when operation of the conveyancemoving control is detected after the predetermined interval.

17. A turntable for a ceiling-mounted hoist configured to rotate, when the hoist is on the turntable, in response to manual operation of a traverse control for the hoist.

18. A control system for a turntable for connecting a plurality of guide tracks along which a hoist is movable, the hoist having a control for controlling movement of the hoist along the guide tracks, the turntable having means for detecting presence of the hoist on the turntable; and means for rotating the turntable in response to either the presence or the absence of a signal from the hoist control a predetermined delay after detection of the hoist on the turntable.

19. A turntable for connecting a plurality of guide tracks along which a hoist moves, the hoist having a control for controlling movement of the hoist along the guide tracks and the turntable having means for detecting the presence of the hoist on the turntable, and means for rotating the turntable if the motion of the hoist is interrupted for a predetermined period of time by the user.

I 8

20. A turntable for a patient handling hoist without a dedicated control.

21. A turntable control system configured to operate substantially as hereinbefore described with reference to Figure 2.