Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
A MOTORISED CAM ARRANGEMENT
Document Type and Number:
WIPO Patent Application WO/2012/146898
Kind Code:
A1
Abstract:
A manoeuvrable body arranged for rotation about a fixed pivotal axis wherein rotation of the body about the pivot is achieved by means of an actuator cam arrangement positioned on an underside of the body, the arrangement comprising; enclosed in a single casing (2), a leadscrew (11) arranged to be rotated about its axis by an actuator; a rack nut (1) threadingly engaged with the leadscrew (11) and arranged such that rotation of the leadscrew (11) drives the rack nut (1) longitudinally with respect to the leadscrew (11); a toothed section (12) radially distanced from the leadscrew and integral with or coupled to the rack nut (1) for longitudinal movement with the rack nut (1); the toothed section (12) arranged to mesh with a first rotatably mounted gear (9) such that the longitudinal movement of the toothed section (12) causes rotation of the first gear (9), a second gear (4) coupled to the first gear (9) and rotationally statically fixed about a shaft (3) whereby when the leadscrew (11) is rotated, the rack nut (1) travels linearly along the leadscrew (11) which in turn drives the first gear (9) to rotate and travel around the second gear (4) thereby to rotate the casing (2) in its entirety about the shaft (3).

Inventors:
CORCORAN STEVEN (GB)
Application Number:
PCT/GB2012/000389
Publication Date:
November 01, 2012
Filing Date:
April 26, 2012
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
CORCOST LTD (GB)
CORCORAN STEVEN (GB)
International Classes:
F16H19/00
Domestic Patent References:
WO2005018522A12005-03-03
WO2010092346A12010-08-19
WO2011121262A12011-10-06
WO2005018522A12005-03-03
WO2011121262A12011-10-06
WO2010092346A12010-08-19
WO2011121262A12011-10-06
Foreign References:
EP2105637A12009-09-30
US4586392A1986-05-06
US4993006A1991-02-12
EP1902896A22008-03-26
Attorney, Agent or Firm:
BODEN, Keith McMurray (The GablesMassetts Road,Horley, Surrey RH6 7DQ, GB)
Download PDF:
Claims:
An actuator cam arrangement for adjusting an angular position of a body relative to a reference plane, the arrangement comprising, and optionally enclosed in a single casing: a leadscrew arranged to be rotated about its axis by an actuator; a rack nut threadabiy engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section, optionally radially distanced from the leadscrew, integral with or coupled to the rack nut for longitudinal movement with the rack nut; a first rotatably mounted gear coupled, directly or indirectly, to the toothed section, such that longitudinal movement of the toothed section causes rotation of the first gear; a second gear coupled, directly or indirectly, to the first gear and rotationally statically fixed, optionally to a shaft, whereby, when the leadscrew is rotated, the rack nut travels linearly along the leadscrew, which in turn drives the first gear to rotate, optionally travelling around the second gear, thereby to rotate a supported body, optionally rotating a casing, optionally in its entirety, and optionally about the shaft.

The arrangement as claimed in claim 1 , wherein the second gear is coupled directly to the first gear.

The arrangement as claimed in claim 1 , wherein the second gear is coupled indirectly to the first gear by one or more intermediate gears.

The arrangement as claimed in claim 3, wherein the second gear is surrounded by and coupled with an array of two or more satellite gears, which in turn are coupled with the radially inner surface of an annular gear and the first gear is coupled directly with the radially outer surface of the annular gear.

The arrangement as claimed in any of claims 1 to 4, wherein the first gear has a greater diameter than the second gear.

The arrangement as claimed in any of claims 1 to 5, wherein the toothed section is coupled directly to the first gear, optionally being arranged to mesh directly with the first gear.

7. The arrangement of any of claims 1 to 6, wherein the toothed section is radially distanced from the leadscrew.

8. The arrangement as claimed in any of claims 1 to 7, wherein the arrangement is disposed beneath a body to be raised, and the body is arranged to pivot about a fixed pivotal axis.

9. The arrangement as claimed in claim 8, wherein the fixed pivotal axis is radially distanced from, but in parallel alignment with, the rotational axis of the shaft.

10. The arrangement as claimed in claim 9, wherein the fixed pivotal axis and rotational axis of the shaft are radially connected by a mechanical arm.

11. The arrangement as claimed in claim 8, wherein the fixed pivotal axis and rotational axis of the shaft coincide.

12. The arrangement as claimed in any of claims 8 to 1 1 , wherein the body is selected from platforms and lifting devices, such as chairs, beds and hoists.

13. The arrangement as claimed in any of claims 1 to 12, further comprising: an arrester for arresting rotation of the body about the pivot.

14. The arrangement as claimed in claim 13, wherein the arrester incorporates a locking system which comprises a leadscrew which is arranged to be rotated about its axis by an actuator, a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew, a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut, a first casing portion enclosing and configured to travel with the leadscrew, and a second casing portion axially aligned with the first casing portion, the first and second casing portions being slidably engageable with each other along a common axis and facing ends of the first and second casing portions including an arrangement of one or more locking sub-systems comprising a protrusion on one of the first and second casing facing ends and a corresponding aperture or recess on the other of the first and second casing ends, the locking arrangement being radially distanced from the common axis, whereby, when a protrusion of a locking sub-system, engages with a corresponding aperture or recess, rotation of the leadscrew is arrested.

15. The arrangement as claimed in claim 14, wherein, in the locking arrangement, the first casing portion has a larger diameter than the second casing portion and incorporates a recessed plate into which one or more recesses or apertures of a sub-locking mechanism are embodied, and an end of the second casing portion includes one or more protrusions, the end and protrusions of the second casing portion being configured for plugging into the one more recesses or apertures of the first casing portion and engaging the recesses or apertures provided in the recessed plate.

16. The arrangement as claimed in claim 14 or 15, comprising a rotationally symmetrical array of two or more locking sub-systems.

17. The arrangement as claimed in any of claims 13 to 16, wherein the arrester includes a thread or track which encircles a circumferential surface and engages with the thread or track of an independently driven locking pin which is arranged to travel along the track when the drive for the locking pin and the rotating body operate in synchronicity.

18. The arrangement as claimed in claim 17, wherein the track or thread is in the form of a spiral or helical path encircling a casing of the arrester.

19. The arrangement as claimed in claim 17 or 18, wherein the locking pin comprises a leadscrew which is rotatably mounted in a casing and radially distanced from, but in parallel with, the arrester, a motor for driving rotation of the leadscrew, and a nut having a radial protrusion extending through a longitudinal slot in the casing, the arrangement being such that rotation of the leadscrew drives the nut longitudinally along the leadscrew and the radial protrusion along the slot of the casing, the radial protrusion being positioned to engage in the thread or track of the arrester and thereby serving as the functional part of the locking pin.

20. The arrangement as claimed in any of claims 1 to 19, wherein the casing includes a low friction protrusion on the outer surface thereof.

21. The arrangement as claimed in claim 20, wherein the protrusion comprises one of a single roller or multiple rollers.

22. The arrangement as claimed in claim 20, wherein the protrusion comprises one of a single bearing or multiple bearings.

23. The arrangement as claimed in claim 20, wherein the protrusion comprises a static protrusion formed a low friction material or a material having a low friction surface.

24. The arrangement as claimed in any of claims 20 to 23, wherein the protrusion comprises an integral corner of the casing.

25. The arrangement as claimed in any of claims 20 to 24, wherein the body includes a guide on an underside thereof and the protrusion is arranged to engage in the guide.

26. The arrangement as claimed in any of claims 1 to 25, wherein the actuator used to drive the actuator cam comprises a reduced space gearbox comprising: an actuator; a leadscrew arranged to be rotated about its axis by the actuator; a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut, the toothed section being arranged to couple with the gear, such that longitudinal movement of the toothed section causes rotation of the gear, with the output shaft being rotatably mounted and drivable to rotate on rotation of the gear and the output shaft being coupled to the leadscrew of the actuator cam.

27. The arrangement as claimed in claim 26, comprising a locking mechanism, the locking mechanism comprising an anchor shaft which is anchored to the body in axial alignment with a pivot thereof, a threaded portion or member encircling the anchor shaft, a thread follower which is arranged to engage the thread and connected to a nut, the nut being carried on a leadscrew and arranged to travel linearly along the leadscrew on rotation of the leadscrew, with rotation of the leadscrew being driven by an actuator, optionally a motor, fixedly positioned at a radial distance from the leadscrew, optionally in a bracket mounted about the shaft of the actuator cam, whereby, on synchronous movement of the cam about the shaft with the body about anchor shaft, the thread follower travels smoothly in the thread, but, on asynchronous rotation of the body and actuator cam, the thread and thread follower lock and thereby arrest further rotation of the body.

28. The arrangement as claimed in claim 26, comprising a locking mechanism, the locking mechanism comprising an anchor shaft which is anchored to the body in axial alignment with a pivot thereof, an actuator, optionally a motor, which drives rotation of a leadscrew contained in a common casing with the actuator, the actuator being optionally mounted to a bracket extending radially from the anchor shaft, a nut threaded on the leadscrew from which nut radially extends an arm which passes through a linear channel in a casing and supports a locking shaft, slidably engageabie in a bore in the anchor shaft, with the end of the locking shaft incorporating one or more protrusions or recesses radially spaced from the axis of the shaft which are engageabie in complimentary recesses or protrusions arranged on a member which is recessed into the bore of the anchor shaft, whereby, on engagement of the protrusions and recesses, rotation of the anchor shaft and hence the body is arrested.

29. An actuator cam arrangement in the form of a reduced-space gearbox, optionally enclosed in a casing, the arrangement comprising: an actuator; a leadscrew arranged to be rotated about its axis by the actuator; a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section, optionally radially distanced from the leadscrew, integral with or coupled to the rack nut for longitudinal movement with the rack nut, the toothed section being arranged to couple with a gear, such that longitudinal movement of the toothed section causes rotation of the gear, with the gear being arranged to couple with a rotationally static gear and thereby effect travel, optionally of the casing, around the rotationally static gear.

30. The actuator cam arrangement as claimed in any of claims 1 to 29, wherein the lead screw of the rack nut includes a second set of teeth which are arranged to engage with an additional gear.

31. A manoeuvrable body arranged for rotation about a fixed pivot axis, wherein rotation of the body about the pivot axis is achieved by means of an actuator cam arrangement positioned to the body, optionally on an underside of the body, the arrangement, optionally enclosed in a single casing, comprising: a leadscrew which is arranged to be rotated about its axis by an actuator; a rack nut which is threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section, optionally radially distanced from the leadscrew, integral with or coupled to the rack nut for longitudinal movement with the rack nut, a first rotatably mounted gear which is coupled, directly or indirectly, with the toothed section, such that longitudinal movement of the toothed section causes rotation of the first gear, a second gear coupled, directly or indirectly, to the first gear and rotationally statically fixed, optionally about a shaft, whereby, when the leadscrew is rotated, the rack nut travels linearly along the leadscrew, which in turn drives the first gear to rotate and travel around the second gear, thereby to rotate, optionally the casing, and optionally in its entirety, optionally about the shaft.

Description:
A MOTORISED CAM ARRANGEMENT

The present invention relates to a motorised cam arrangement suitable for use in (but not strictly limited to) the manoeuvring of platforms and lifting devices such as; chairs, beds and hoists. More particularly, the invention further improves upon and extends applications of the Applicant's novel cam based lifting devices as described in the Applicant's International Patent Publications nos WO2005/018522 A1 entitled Raiser Seat published 3 rd March 2005 and WO201 1/121262 A1 entitled Multi-Axis Manoeuvrable Platform published 6 th October 2011. In addition the present invention provides for a new application of the Applicant's novel gearbox technology described in the Applicant's International Patent Publication WO2010/092346 A1 published 19 th August 2010, though it will be understood that alternative gearbox arrangements may be used in the present invention.

WO2005/018522 A1 describes a raiser seat for assisting a person from a sitting to a standing position comprising: a seat frame ; a seat adapted for movement relative to the seat frame between a lowered position and a raised position; and a movement mechanism for moving the seat between the lowered and the raised positions; wherein the movement mechanism comprises at least one cam and wherein the seat is supported by the at least one cam such that rotation of the at least one cam results in movement of the seat relative to the seat frame. In preferred embodiments described therein the cam comprises at least one of the following features: an integral gear; an integral shaft; an integral bearing; an integral bearing surface; an integral roller; a one roller assembly; at least one connection member; a roller carriage ; an integrated roller carriage in whole or in part; an integral roller track; an integral seal; integral sealing surfaces or sealing area; an at least one integral location and retention component; a blade; a shaft recess; a bearing recess; a protrusion recess; an externally threaded member; an internally threaded member; one hole; one roller type or plain bearing/bush; one press fit member; one threaded member; one taper edge profile; one alternative edge profile; one increased thickness section that can run the full length of the cam; and multiple blade. In the event that the cam comprises more than one blade, the integral location and retention component can be an area at either side of a main cam and/or the integral gear can have a different diameter, size, form or shape from that of other sections of the cam shaft. The seat conveniently can comprise a guide track adapted to receive the connecting member. In one embodiment the guide track comprises a linear track located at the side of the seat in a position where the seat is supported by the at least one cam. In another embodiment, the seat can further comprise at least one thickened material section, roller, a bearing, a friction-reducing coating, or a friction reducing material, positioned along the part of the seat which is in contact with the at least one cam. If at least one roller or bearing is used, the track can be mounted on the at least one roller or bearing.

A motor is provided for rotating the cam and can be located anywhere within the raiser seat, and may be contained in a separate detachable casing. For example, it can be side-by-side, above or below the cam, or contained within the seat unit. The motor may drive the cam directly or indirectly. With an indirect drive various drive transfer components can be used, including drive couplings and meshed gears. If the motor drives the cam indirectly, the power transfer components can be chosen to allow the drive to be transferred from wherever the motor is located.

WO2011/121262 A1 describes a manoeuvrable platform comprising a planar base manoeuvrable by at least one cam operated lifting sub system positioned in relation to a back surface of the base, the or each lifting sub system comprising a cam blade arranged in a plane substantially parallel to that of the planar base section and operably connected to a cam drive in a casing, a first linear actuator operably connected to the cam drive casing and configured to provide linear displacement along a first axis, a second linear actuator operably connected to the cam drive casing and configured to provide linear displacement along a second axis and a pivoting means arranged for rotating the planar base.

Desirably there are multiple cam operated lifting subsystems arranged around the rotary actuator. In a preferred embodiment there are four subsystems arranged around the pivoting means which comprises a rotary actuator. In an option, the subsystems are arranged substantially symmetrically about the pivoting means but non symmetrical arrangements may be used to best suit a specific end use of the platform.

A rotary actuator pivoting means may comprise any mechanism capable of imparting rotation to the platform. WO2010/092346 A1 describes a reduced space gear box comprising a leadscrew rotatably mounted in a casing onto the thread of which is engaged a nut from which extends (at a radial distance from the nut axis) a toothed rack which in turn engages the teeth of a gear which drives an output shaft. Due to the confines of the casing around the assembled leadscrew, nut, toothed rack and gear, rotation of the leadscrew results in a linear travel of the toothed rack against the gear which rotational movement is used to drive the output shaft. The gear can be arranged either to drive the shaft directly or through a series of intermediate gears. Optionally the toothed rack is carried via a low friction interface, on a shaft which is also mounted in the casing. Figure 1 hereto illustrates one embodiment of such a gearbox.

In accordance with the present invention there is provided an actuator cam arrangement for adjusting the angular position of a body relative to a reference plane the arrangement comprising; enclosed in a single casing, a leadscrew arranged to be rotated about its axis by an actuator; a rack nut threadingly engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut; the toothed section arranged to mesh with a first rotatably mounted gear such that the longitudinal movement of the toothed section causes rotation of the first gear, a second gear coupled to the first gear and rotationally statically fixed about a shaft whereby when the leadscrew is rotated, the rack nut travels linearly along the leadscrew which in turn drives the first gear to rotate and travel around the second gear thereby to rotate the casing in its entirety about the shaft.

In one embodiment the second gear is coupled directly to the first gear. In an alternative embodiment, the second gear is surrounded by and meshes with an array of two or more satellite gears which in turn mesh with teeth on the radially inner surface of an annular gear and the first gear meshes directly with teeth on the radially outer surface of the annular gear.

The actuator cam is conveniently seated beneath a body to be raised, for example but without limitation, the body is selected from platforms and lifting devices such as; chairs, beds and hoists. The body is typically anchored about a fixed pivot point which may optionally coincide with the shaft of the actuator cam. In an alternative, the body is anchored about a fixed pivotal axis which is radially distanced from but parallel to the axis of the shaft. In the latter arrangement, the shaft is desirably connected to the fixed pivotal axis by a connecting arm.

The cam profile provided by the actuator cam can conveniently be defined by provision of a low friction protrusion from the outer surface of the casing. In preferred options, the protrusion comprises one of a single or multiple rollers, one of a single or multiple bearings or a combination thereof. In simpler options, the protrusion might comprise a static protrusion from a low friction material or material otherwise treated to provide a low friction surface.

It will be appreciated in one very simple arrangement; the protrusion may take the form of an integral corner of the casing.

In use, a guide is provided on an underside surface of the body to be lifted and the protrusion is arranged to engage in the guide.

In another aspect the invention comprises a manoeuvrable body arranged for rotation about a fixed pivot wherein rotation of the body about the pivot is achieved by means of an actuator cam arrangement positioned on an underside of the body, the arrangement comprising; enclosed in a single casing, a leadscrew arranged to be rotated about its axis by an actuator; a rack nut threadingly engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut; the toothed section arranged to mesh with a first rotatably mounted gear such that the longitudinal movement of the toothed section causes rotation of the first gear, a second gear coupled to the first gear and rotationally statically fixed about a shaft whereby when the leadscrew is rotated, the rack nut travels linearly along the leadscrew which in turn drives the first gear to rotate and travel around the second gear thereby to rotate the casing in its entirety about the shaft.

The actuator cam of the manoeuvrable body may have any of the optional features already described in relation to the actuator cam of the invention in any combination. The fixed pivotal axis may optionally coincide with the shaft of the actuator cam. Alternatively the pivot is radially distanced from but in parallel alignment with the shaft. In the latter arrangement, the shaft and pivot may be radially connected, for example, but without limitation by a mechanical arm extending from the axis of one to the axis of the other.

The manoeuvrable body may further include an arrester for arresting rotation of the body about the pivot point. The arrester may be manually controlled and/or influenced by external stimuli such as (but without limitation) excessive speed of rotation or rotation beyond a predetermined angle.

In one option, the arrester may incorporate a locking system which comprises a leadscrew arranged to be rotated about its axis by an actuator; a rack nut threadingly engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut, a first casing portion enclosing and configured to travel with the leadscrew and a second casing portion axially aligned with the first, the first and second casing portions being slidably engageable with each other along their common axis, the facing ends of the first and second casing portions including an arrangement of one or more locking sub-systems consisting of a protrusion on a first one of the first and second casing facing ends and a corresponding aperture or recess on the second of the first and second casing ends, the locking arrangements being radially distanced from the common axis, whereby when a protrusion of a locking subsystem engages with a corresponding aperture or recess, rotation of the leadscrew is arrested.

In an illustrated embodiment, the first casing portion has a larger diameter than the second casing and incorporates a recessed plate into which one or more recesses or apertures of a sub locking mechanism are embodied and the second casing has an end provided with one or more protrusions, the end and protrusions being configured for plugging into the recess of the first casing and engaging the recesses or apertures provided in the recessed plate. Desirably there is provided a rotationally symmetrical array of two or more locking sub-systems. In use the arrester is aligned with the pivot and the pivot can be locked either through manual rotation of the leadscrew or by means of an electronic actuator. The electronic actuator may incorporate a sensor to detect, for example, excessive load, speed or rotation of the seat about the pivot and on detection, rotate the leadscrew to bring about locking of the pivot.

In a further preferred option, the arrester is provided with a thread or track which encircles the outer circumferential surface. The track is conveniently spiralled or helical, in addition there is provided a leadscrew rotatably mounted in a casing and radially distanced from but in parallel with the arrester, a motor for driving rotation of the leadscrew and a nut having a radial protrusion extending through a longitudinal slot in the casing, the arrangement being such that rotation of the leadscrew drives the nut longitudinally along the leadscrew and the radial protrusion along the slot of the casing, the radial protrusion positioned to engage in the thread or track of the arrester.

With the above described arrangement, any inconsistency in the rotation characteristics between the body about the pivot and the actuator cam about its shaft can be detected. In the event of inconsistency, the track and radial protrusion do not engage synchronously and the rotation of one or both of the body and actuator cam is arrested.

One preferred form of actuator for use in driving the actuator cam is in the form of a reduced space gearbox comprising; an actuator; a leadscrew arranged to be rotated about its axis by the actuator; a rack nut threadingly engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut; the toothed section arranged to mesh with the gear such that the longitudinal movement of the toothed section causes rotation of the gear, the output shaft being rotatably mounted and drivable to rotate on rotation of the gear, the output shaft being coupled to the leadscrew of the actuator cam.

In one preferred aspect the present invention provides an actuator cam arrangement for adjusting an angular position of a body relative to a reference plane, the arrangement comprising, and optionally enclosed in a single casing: a leadscrew arranged to be rotated about its axis by an actuator; a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section integral with or coupled to the rack nut for longitudinal movement with the rack nut; a first rotatably mounted gear coupled, directly or indirectly, to the toothed section, such that longitudinal movement of the toothed section causes rotation of the first gear; a second gear coupled, directly or indirectly, to the first gear and rotationally statically fixed, optionally to a shaft, whereby, when the leadscrew is rotated, the rack nut travels linearly along the leadscrew, which in turn drives the first gear to rotate, optionally travelling around the second gear, thereby to rotate a supported body, optionally rotating a casing, optionally in its entirety, and optionally about the shaft.

In one embodiment the second gear is coupled directly to the first gear.

In another embodiment the second gear is coupled indirectly to the first gear by one or more intermediate gears.

In one embodiment the second gear is surrounded by and coupled with an array of two or more satellite gears, which in turn are coupled with the radially inner surface of an annular gear and the first gear is coupled directly with the radially outer surface of the annular gear.

In one embodiment the first gear has a greater diameter than the second gear.

In one embodiment the toothed section is coupled directly to the first gear, optionally being arranged to mesh directly with the first gear.

In one preferred embodiment the toothed section is radially distanced from the leadscrew.

In one embodiment the arrangement is disposed beneath a body to be raised, and the body is arranged to pivot about a fixed pivotal axis.

In one embodiment the fixed pivotal axis is radially distanced from, but in parallel alignment with, the rotational axis of the shaft. In one embodiment the fixed pivotal axis and rotational axis of the shaft are radially connected by a mechanical arm.

In another embodiment the fixed pivotal axis and rotational axis of the shaft coincide.

In one embodiment the body is selected from platforms and lifting devices, such as chairs, beds and hoists.

In one embodiment the arrangement further comprises: an arrester for arresting rotation of the body about the pivot.

In one embodiment the arrester incorporates a locking system which comprises a leadscrew which is arranged to be rotated about its axis by an actuator, a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew, a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut, a first casing portion enclosing and configured to travel with the leadscrew, and a second casing portion axially aligned with the first casing portion, the first and second casing portions being slidably engageable with each other along a common axis and facing ends of the first and second casing portions including an arrangement of one or more locking sub-systems comprising a protrusion on one of the first and second casing facing ends and a corresponding aperture or recess on the other of the first and second casing ends, the locking arrangement being radially distanced from the common axis, whereby, when a protrusion of a locking sub-system, engages with a corresponding aperture or recess, rotation of the leadscrew is arrested.

In one embodiment, in the locking arrangement, the first casing portion has a larger diameter than the second casing portion and incorporates a recessed plate into which one or more recesses or apertures of a sub-locking mechanism are embodied, and an end of the second casing portion includes one or more protrusions, the end and protrusions of the second casing portion being configured for plugging into the one more recesses or apertures of the first casing portion and engaging the recesses or apertures provided in the recessed plate. In one embodiment the arrangement comprises a rotationally symmetrical array of two or more locking sub-systems.

In one embodiment the arrester includes a thread or track which encircles a circumferential surface and engages with the thread or track of an independently driven locking pin which is arranged to travel along the track when the drive for the locking pin and the rotating body operate in synchronicity.

In one embodiment the track or thread is in the form of a spiral or helical path encircling a casing of the arrester.

In one embodiment the locking pin comprises a leadscrew which is rotatably mounted in a casing and radially distanced from, but in parallel with, the arrester, a motor for driving rotation of the leadscrew, and a nut having a radial protrusion extending through a longitudinal slot in the casing, the arrangement being such that rotation of the leadscrew drives the nut longitudinally along the leadscrew and the radial protrusion along the slot of the casing, the radial protrusion being positioned to engage in the thread or track of the arrester and thereby serving as the functional part of the locking pin.

In one embodiment the casing includes a low friction protrusion on the outer surface thereof.

In one embodiment the protrusion comprises one of a single roller or multiple rollers.

In another embodiment the protrusion comprises one of a single bearing or multiple bearings.

In a further embodiment the protrusion comprises a static protrusion formed a low friction material or a material having a low friction surface.

In one embodiment the protrusion comprises an integral corner of the casing. In one embodiment the body includes a guide on an underside thereof and the protrusion is arranged to engage in the guide.

In one embodiment the actuator used to drive the actuator cam comprises a reduced space gearbox comprising: an actuator; a leadscrew arranged to be rotated about its axis by the actuator; a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section radially distanced from the leadscrew and integral with or coupled to the rack nut for longitudinal movement with the rack nut, the toothed section being arranged to couple with the gear, such that longitudinal movement of the toothed section causes rotation of the gear, with the output shaft being rotatably mounted and drivable to rotate on rotation of the gear and the output shaft being coupled to the leadscrew of the actuator cam.

In one embodiment the arrangement comprises a locking mechanism, the locking mechanism comprising an anchor shaft which is anchored to the body in axial alignment with a pivot thereof, a threaded portion or member encircling the anchor shaft, a thread follower which is arranged to engage the thread and connected to a nut, the nut being carried on a leadscrew and arranged to travel linearly along the leadscrew on rotation of the leadscrew, with rotation of the leadscrew being driven by an actuator, optionally a motor, fixedly positioned at a radial distance from the leadscrew, optionally in a bracket mounted about the shaft of the actuator cam, whereby, on synchronous movement of the cam about the shaft with the body about anchor shaft, the thread follower travels smoothly in the thread, but, on asynchronous rotation of the body and actuator cam, the thread and thread follower lock and thereby arrest further rotation of the body.

In another embodiment the arrangement comprises a locking mechanism, the locking mechanism comprising an anchor shaft which is anchored to the body in axial alignment with a pivot thereof, an actuator, optionally a motor, which drives rotation of a leadscrew contained in a common casing with the actuator, the actuator being optionally mounted to a bracket extending radially from the anchor shaft, a nut threaded on the leadscrew from which nut radially extends an arm which passes through a linear channel in a casing and supports a locking shaft, slidably engageable in a bore in the anchor shaft, with the end of the locking shaft incorporating one or more protrusions or recesses radially spaced from the axis of the shaft which are engageable in complimentary recesses or protrusions arranged on a member which is recessed into the bore of the anchor shaft, whereby, on engagement of the protrusions and recesses, rotation of the anchor shaft and hence the body is arrested.

In another preferred aspect the present invention provides an actuator cam arrangement in the form of a reduced-space gearbox, optionally enclosed in a casing, the arrangement comprising: an actuator; a leadscrew arranged to be rotated about its axis by the actuator; a rack nut threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section, optionally radially distanced from the leadscrew, integral with or coupled to the rack nut for longitudinal movement with the rack nut, the toothed section being arranged to couple with a gear, such that longitudinal movement of the toothed section causes rotation of the gear, with the gear being arranged to couple with a rotationally static gear and thereby effect travel, optionally of the casing, around the rotationally static gear.

In one embodiment the lead screw of the rack nut includes a second set of teeth which are arranged to engage with an additional gear.

In a further preferred aspect the present invention provides a manoeuvrable body arranged for rotation about a fixed pivot axis, wherein rotation of the body about the pivot axis is achieved by means of an actuator cam arrangement positioned to the body, optionally on an underside of the body, the arrangement, optionally enclosed in a single casing, comprising: a leadscrew which is arranged to be rotated about its axis by an actuator; a rack nut which is threadably engaged with the leadscrew and arranged such that rotation of the leadscrew drives the rack nut longitudinally with respect to the leadscrew; a toothed section, optionally radially distanced from the leadscrew, integral with or coupled to the rack nut for longitudinal movement with the rack nut, a first rotatably mounted gear which is coupled, directly or indirectly, with the toothed section, such that longitudinal movement of the toothed section causes rotation of the first gear, a second gear coupled, directly or indirectly, to the first gear and rotationally statically fixed, optionally about a shaft, whereby, when the leadscrew is rotated, the rack nut travels linearly along the leadscrew, which in turn drives the first gear to rotate and travel around the second gear, thereby to rotate, optionally the casing, and optionally in its entirety, optionally about the shaft.

Preferred embodiments of the present invention will now be further described hereinbelow by way of example only with reference to the accompanying drawings, in which:

Figure 1 shows a first embodiment of an actuator cam in accordance with the invention;

Figure 2 shows a first embodiment of remote engager suitable for use in association with the actuator cam of Figure 1 ;

Figure 3 shows a plan view of an actuator cam embodied in raiser seat;

Figure 4 shows an alternative plan view exhibiting different components of the raiser seat of Figure 3;

Figure 5 shows a second embodiment of an actuator cam in accordance with the invention;

Figure 6 shows a side view of a raiser seat raising using an embodiment of the actuator cam of the invention;

Figure 7 shows views of a gearbox actuator cam;

Figure 8 shows a plan view of an application using an actuator cam;

Figures 9A to 9E show the side views of some of the movements of a seat resultant from the rotation of an actuator cam;

Figure 10 shows a side view of an arrester system for usage with an actuator cam;

Figure 1 1 shows a side view of a locking system for usage with an actuator cam and integrated with an arrester system from Figure 10; Figure 12 shows a plan view of the usage of a locking and arrester system from Figure 10 and 1 1 and with an actuator cam; and

Figure 13 shows an alternative embodiment of the usage of an actuator cam.

Figure 1 shows three orthogonal, cutaway views of a first embodiment of an actuator cam 6 in accordance with the invention and which is referenced generally in Figure 3 by reference numeral 30. As can be seen in Figure 1 , a leadscrew nut 1 meshes with a leadscrew 11 rotatably mounted by means of bearings 10 in a casing 2 which constrains movement of the leadscrew forcing the nut 1 to travel longitudinally along the leadscrew when the leadscrew is rotated. The nut or "rack nut" 1 as referred to herein incorporates an elongate, toothed arm section 12 which is radially distanced from but extends in parallel with the leadscrew. In the casing 2 is at least one guide channel 16 for the rack nut arm 12. The system can sit directly on a shaft 3 as shown in Figure 1 or can be sat on another shaft that is connected to a shaft in the position of shaft 3 as will be seen and further described in relation to Figures 3, 6, 8, 12 and 13.

The shaft 3 incorporates a gear 4 which can be fixed and fully or partially encased in the casing 2. The casing 2 has bearings 5 located either side of the gear 4. The gear 4 meshes either directly or indirectly with a second gear 9 which is arranged by means of bearings 8 to rotate about the axis of a second shaft 17 which is radially distanced from but in parallel alignment with the shaft 3. The leadscrew 1 1 rotates on bearings 10 and 13 and is connected to an actuator 15 which drives the gearbox 14 causing rotation of the leadscrew 1 1 .

A dotted outline referenced 18, 19, 20, 21 shows an optional extension 18 of the casing which may be integrally formed into the casing or be permanently or reversibly attached. The extension 18 has at least one roller or bearing or other such means 19 mounted on a shaft 20 which may be integrally formed into the casing or be permanently or reversibly attached thereto. Ends of the shaft 20 extend from the extension 18 of the casing 2 and are configured to engage a guide track 60 (refer Figure 6) on an underside of the body to be repositioned by the actuator cam 6. The extension 18. Reference numeral 21 identifies an optional roller or bearing or other such means which can incorporate any or all of the features described in relation the roller or bearing or other such means 19. If present, roller or bearing or other such means 21 may be configured to travel either in the same guide track as its neighbouring part 19, or a separate track (not shown).

On rotation of the leadscrew 11 , the drive rack nut 1 advances along the leadscrew 11 whereupon the teeth of the arm 12, which mesh gear 9, causes the gear 9 (which meshes with the gear 4) to travel around the shaft gear 4. Thus, the casing serves as a cam profile for a cam lifting mechanism and a stressed member with various structural means. The casing 2 is suitably shaped, of sufficient strength and dimensioned so as to keep the gears 9 and 4 in a meshed arrangement, the casing 2, when the leadscrew 1 is driven to rotate about the axis of shaft 3 on bearings 5.

The bearings 5 in the casing 2 are permanently or removably attached to the shaft 3 and assist on reducing friction between the casing and the shaft as the casing 2 rotates around the axis of the shaft 3. In an alternative embodiment (not shown), the casing 2 is configured with flexibility or linear movement capability and the gear 4 is oriented to have a different axis of rotation to the shaft 3, the actuator cam in this embodiment is able to rotate around the offset axis of the gear 4. In a further development of this embodiment, the gear 9 and bearings 5 can also be offset against shafts 17 and 3. Therefore, profiles of the actuator cam movement can be selected or adjusted by adjustment of a combination of parameters which include (without limitation) respective orientations of the axes of the shaft 3 and/or gear 9 and/or bearings 5 and/or gear 4.

The arrangement described can be incorporated as a cam in, for example a raiser seat as described in WO2005/018522 A1 or a manoeuvrable platform as described in WO201 1/121262 A1. A combination of the meshed arrangement between gears 4 and 9, and the confines of the casing enables that, when the leadscrew is driven to rotate, the entire casing incorporating gear 9, leadscrew 1 , rack nut 1 , 12, gearbox 14 and actuator 15 to travel around the circumference of gear 4 and rotate about the axis of shaft 3. As shown and described in Figure 1 , the casing may be provided with a low friction means for contacting a surface of a body to be lifted such as the bearings 19 and 21. For example but without limitation, the low friction means may incorporate rollers 19 and or extension shaft 20 which can travel in a guide track 60 (as shown in Figure 6) provided on the surface to be lifted. As the casing travels around the shaft 3 it serves as a cam which lifts the surface. As previously detailed, the surface might belong to any of a variety of bodies to be lifted, for example, but without limitation, platforms and lifting devices such as; chairs, beds and hoists. From Figure 1 , it is clear that the toothed drive rack nut 1 , 12 can be in a meshed relationship with the gear 4 as described above via its direct relationship with just one gear 9. It is to be understood, however, that rack nut 1 , 12 could be arranged to drive gear 9 via a train of one or more intermediate additional gears.

In a further alternative embodiment (not shown) the toothed drive rack 12 features a second toothed surface, most conveniently arranged at 180 degrees to the first toothed surface, i.e., the rack 12 has teeth top and bottom. In this arrangement, a further gear can be arranged on a fixed axis to mesh with and be driven by the second toothed surface. This arrangement assists in keeping the toothed drive rack 12 in an optimum meshed relationship with the gear 9 (or first in a train of gears via which the toothed rack 12 drives gear 9).

Figure 2 shows an optional internal locking means 22 for the cam device 6 of Figure 1. The locking means 22 can be purely mechanical or electronically operated. In a manual embodiment, a handle or other manual drive means may be coupled to the locking means 22. Figure 2 shows an electronically operated means for actuating the locking means 22.

The electronic means 22 consists of an actuator 23 which is encased in a casing 24 which includes one or more protrusions longitudinally, slidably engageable into corresponding recesses in the adjacent end of casing 25 . The actuator 23 rotates and drives a leadscrew 26 rotatably mounted in casing 25 by means of bearings 27. The leadscrew has a drive nut 28. A joining means 29 is permanently or removably attached or integrated to the nut 28 so that they encircle the leadscrew and protrudes through a longitudinal slot provided in the wall of casing 25. The actuator 23 serves to rotate the leadscrew 26 and bearing 27, in doing so the drive nut which is configured to carry the casing 25 with it, advances towards or retracts away from the actuator 23, in doing so a portion of the casing 25 moves over the outer of the casing 24, the protrusions of casing 24 engaging in the recesses of casing 25; thereby preventing any rotational movement that is not required.

Figure 3 and 4 show two views of an embodiment of the invention which can be but is not limited to being incorporated into a commode seat. It should, however be appreciated that the commode seat could be replaced with any of a number of alternative manoeuvrable bodies. The Figures show a section of just half of a seat from the underside. As can be seen, an actuator cam 30 (non-limiting examples of whose construction is described in detail in relation to Figure 1 above and Figure 5 below) is arranged adjacent an underside surface of the seat 31. The seat aperture 32, is an optional feature for the seat base and is in no way intended to considered as essential to the application of the present invention in a seat. A locking means 33 (for example having the construction as described in relation to Figure 2) is also shown, this connects to a bar that runs through the centre of an arrester 34 and the locking plate 35, the locking plate 35 being integrated with the seat 31 and the locking means, bar, arrester and locking plate all aligned with a main shaft 36 about which the seat can pivot. The main shaft 36 runs through the plate 35. The Figure shows an arm 37 connecting an output shaft of the actuator cam 30 to the main shaft 36 thereby to allow the actuator cam 30 a different pivot point to the seat 31.

In an alternative arrangement, however, the actuator cam 30 could be located on the main shaft 36 sharing a pivot point with the seat 31. Figure 3 also shows a motor 38 in a casing that is held fully or partially via the integration between the casing arm 39 and the holding block means 40 which is in turn integrated with the arm 37.

Figure 4 shows another part of the seat of Figure 3, a locking means of the configuration as described in Figure 2 is referenced 33 and corresponds to locking means 33 passing through arrester 34 in Figure 3. The arrester 34 in this embodiment is provided with at least an external track (not shown) which, for example, is in the form of a spiral or helical thread around its outer circumferential edge. The main shaft 36 (in line with the locking means 33 and arrester 34) incorporates bearings 41 to facilitate rotation of the seat 31 around the shaft 36. The motor 38 is coupled to worm drive 43 with an outer gear face, which meshes with a leadscrew 42 which has an integrated gear. The configuration is such that when the actuator 38 rotates the leadscrew 42 rotates and moves the drive nut with locking pin 44 backwards and forwards.

The locking pin 44 has a protrusion which engages in the described track around the circumferential edge of the arrester 34. The arrester 34 is connected to the plate 35, thus as the seat rotates around the main shaft 36 the arrester 34 rotates in unison. The actuator 38 rotates the leadscrew 42 as described and thus the drive nut with the locking means 44 (which as stated engages with the described track around the circumferential edge of the arrester 34) travels along the length of the arrester 34 linearly at the same time and to coincide with the rotation of arrester 34, the actuator 35 also coincides with the actuator 15 (see Figure 1 ) in the actuator cam 30 (see Figure 3) and thus all the system coincide with each other. Thus, as the actuator cam 30 rotates, it lifts the seat along a profile defined by the cam casing and rotates the seat about the axis of main shaft 36. This in turn rotates the plate 35 and the arrester 34. The arrester 34, by means of its circumferentially arranged thread engaging with locking pin 44 of the drive nut on leadscrew 42 moves linearly respective to the rotation of the leadscrew 42 and thus the rotation of the actuator 38. Consequently, if there is any difference between the input of the actuator 38 and the internal actuator 15 of the actuator cam 30 and subsequent mechanism and seat rotation, this will result in a changed rotation rate to the input of actuator cam 30 and thus the circumferentially arranged track of arrester 34 will not move synchronously with the drive nut protrusion 44. As a result, the system will lock, i.e. the arrester will arrest the seat, stop it from moving and hold the structure in place. This arrangement provides a useful safety means.

As already explained, locking means 33 connect to a shaft that runs through the arrester 34 and the main shaft 36. When the locking means 33 is activated the shaft located through the main shaft 36 will advance and extend from the main shaft 36 to locate in a corresponding aperture or recess in the frame and lock the seat 31 into the frame.

Figure 5 shows two views of an alternative embodiment of the actuator cam of the invention. In this embodiment, the actuator cam 100 has a series of meshed gears, the inner gears 45 mesh with a gear 46 fixed or integrated around the circumference of a shaft 47 and are arranged to travel around the fixed or integrated gear 46. The gears 45 are further arranged to mesh with teeth arranged radially inwardly of a surrounding annular gear 50. The radially outer edge of the annular gear 50 is in turn arranged to mesh with a toothed arm 51 of a drive rack nut 52 threaded on a leadscrew 53. It will be appreciated that linear movement of leadscrew 53 results in rotation of annular gear 50. The leadscrew 53 is mounted in a casing 54 by means of at least one bearing 55. Actuator 56 is operable to drive rotation of the leadscrew 53 and hence linear movement of toothed arm 51 and rotation of annular gear 50. The rotation of annular gear 50 in turn drives rotation of inner gears 45. Inner gears 45 are integrated with the casing 54 via integration means 57, this means that the casing 54 and subsequently the actuator 56, bearings 55, leadscrew 53 and drive rack nut 52 with arm 51 rotate about the axis of shaft 47. As described already in relation to casing 2 from Figure 1 , the casing 54 may incorporate on an outer wall thereof, low friction and or guide means such as rollers, bearings or sliders and the relationship between said, low friction and or guide means and the axis of rotation of the actuator cam 100 provide a cam profile which, relative to the pivot point of the seat, dictates seat movement such that the rotation of the actuator cam 100 results in the rotation of the seat and the seat can move relative to the cam profile. The casing may also optionally incorporate an extension similar to extension 18, 19, 20, 21 described in relation to Figure 1.

Figure 6 illustrates an actuator cam 58 in accordance with the invention which in this specific embodiment (which is by no means the only one possible) features rollers and/or bearings 59 which give the profile of the cam. It will be understood that repositioning of these rollers or bearings 59 can change the profile of the actuator cam. The actuator cam engages with the seat track or guide track 60 and is as described in other international patent publications of the Applicant already discussed herein. The shafts 61 and that at the centre of plate 62 correspond to the shafts which are connected by the arm 37 in Figure 3. The actuator cam is arranged for rotation around about the axis of shaft 61. The plate 62 corresponds to plate 35 as referenced above. The actuator cam and main shafts are connected via arm 63. In this case where the cam is rotating around a different axis to the main shaft around which the plate 62 sits. The connecting arm 63 and the cam shaft and main shaft remain in a rotationally static position while the cam rotates and brings about rotation of the seat.

Figure 7 shows two views of an embodiment of a gearbox 64 which can optionally and effectively be used to drive or itself as an actuator cam of the present invention. The gearbox may have all the functions and features of all the actuator cams as discussed above, more formally the actuator cam 6 from Figure 1 , the actuator cam 30 from Figure 3 and the actuator cam 100 from Figure 5 and be used in all the same applications as the actuator cams as previously discussed. Further embodiments of this concept are described in the Applicant's prior published international patent application no. WO2010/092346 A1 already discussed above.

Figure 7 shows a gearbox 64 that can used as an actuator cam in accordance with the invention. The gearbox is advantageous in that it is particularly compact for the drive it is able to provide. As can be seen the Figure shows two orthogonal views of the gearbox, a plan view and a side view. The unit is driven by an actuator 65 (typically an electric motor) which drives a leadscrew 66, the actuator is held in a rotationally static position by the casing 67 whilst the leadscrew 66 is rotatably mounted in the casing, but is held in such a way as to allow rotation but inhibit all other movement; this is achieved via by bearings 68 and 69 that allow the leadscrew 66 to rotate with very little friction. The bearings 68 and 69 can be, but are not restricted to roller type, ball type and plain type bearings or any combination thereof.

As the leadscrew rotates the toothed drive rack nut 70 which is meshed with the leadscrew, travels longitudinally along the leadscrew. The toothed drive rack nut 70 can be positioned within the casing and a low friction interface incorporated between the casing 67 and the toothed drive rack nut 70. Contact between the inner casing wall and an outer surface of the toothed drive rack nut 70 prevents the toothed drive rack nut rotating as the leadscrew 66 rotates and ensures smooth operation and movement along the axis of the leadscrew 66. The toothed section of the toothed drive rack nut 71 can optionally further be mounted around a bar 72. Conveniently the bar is treated to provide a low friction interface with an inner bore of the toothed drive rack nut 71 as it travels. With the toothed section is a bearing which typically but is not limited to a plain bearing 73. This allows the toothed drive rack section to slide backwards and forward depending on the rotation of the electric motor and thus leadscrew and bar allows a constant meshing of the toothed drive rack nut 71 with gear 74 which sits on the same shaft as the gear 75. The gear 75 is rotationally fixed with respect to shaft 81. The bar 72 can be held in the casing at both ends.

The toothed drive rack nut toothed section 71 meshes with the gear 74 with the gear 75 on the same shaft, the linear movement of 70 and thus 71 results in the rotation of the gear 74 and therefore the gear 75. Gear 75 meshes with gear 76 and thus the rotation of gear 75 yields rotation of gear 76 which is in turn meshed with the gear 77. Gear 77 is on the same shaft as the output shaft 78 and thus the rotation of the actuator 65 and therefore the leadscrew 66 results in the rotation of the casing about the output shaft 78.

One of the main features of this gearbox and all gearboxes of this type is that the leadscrew would require tremendous force to back drive or forward drive the gearbox if no drive is given by the actuator 65. The main reason for this is because high levels of force are required to back drive or forward drive a leadscrew if no rotational assistance is given.

The output shaft 78 passes through an end cap 79 which has at least one seal groove 80, whereby the seal groove, typically but not limited uses quad seals and or termed double lip seals. The seals seal against the end cap and the shaft 78 and thus stop any inward ingress of fluid and or particulates and any outward ingress of fluid and or particulates.

The gears are held on shafts with bearings, the gears 74 and 75 are on the same shaft 81 which is captivated in the casing 67 such that it can move in a rotary fashion and this is furthered in terms of a mounting of the low friction means between the shaft and the casing; in this case 82 is a bearing, the bearing is located at both ends of the shaft although only one bearing has been shown at one end of the shaft. The same is true for the gear 76 which is attached to the shaft 83 that is held with one bearing at one end and another bearing at the other end; only one bearing is shown at just one end of the shaft for instance 84. The same is true for the gear 77 which is as described is fixed to the shaft that is held by bearings at each end; in the Figure only one bearing 85 is shown at just one end of the shaft 78. In all these cases the bearing can either be roller, ball bearing and or plain bearing type. This gearbox can include an optional arrester system.

The output shaft may coupled with the leadscrew of the actuator cam of the invention and gearbox is thereby able to drive the actuator cam.

Figure 8 shows a no- limiting embodiment of the invention wherein the actuator cam forms part of an adjustable seat assembly 86. In this case the actuator cams 88 can have any configuration as already described in relation to Figures 1 , 3, 5, 6 or 7. In the case of the actuator cam from Figure 7 the output shaft 78 will connect directly to the shaft 89 of Figure 8. The at least one actuator cam 88 is attached to a shaft 89, typically the actuator cams casing surrounds the shaft 89 as described in Figure 1. The shaft 89 corresponds to the shaft 3 of Figure 1. The shaft 89 is connected to an arm 90 which is in turn connected to a shaft 91. The arm 90 corresponds to the arm 37 in Figure 3 and the shaft 91 corresponds to the shaft 36 from Figure 3. In the illustrated embodiment, the seat assembly features two actuator cams 88 and the seat 87 includes an optional aperture 92 to enable use of the seat as a commode. The aperture has no bearing on the operation of the inventive actuator cam mechanism. The seat 87 corresponds to the seat 31 from Figure 4. In this embodiment, as the actuator cam 88 starts to rotate, it travels around the axis of the shaft 89 and causes the seat 87 to rotate about the axis of the shaft 91. The actuator cam 88 can engage with the underside of the seat via a guide track 60 such as is shown and described in relation to Figure 6, for example by means of an extended portion corresponding to 18, 19, 20, 21 of Figure 1 and in particular the protruding shaft ends of shaft 21 as described in relation to Figure 1. The actuator cam 88 can conveniently incorporate at least one bearing (not shown) such as that referenced 19 and already described in relation to Figure 1 which engages the underside of the seat 87 to provide a low friction engagement.

Figure 9A to 9E shows illustrative movements of a seat in accordance with the invention. It will be appreciated that with different cam profiles, other paths of movement can be achieved. As the actuator cam moves, it is clear the seat rotates to different angles around an axis. The achievable angles include positive angles (Figures 9A to 9C), a neutral angle (Figure 9D) and a negative angle (Figure 9E). Where two independently operable cams are present in different locations on the seat (for example as shown in Figure 8) the seat can also be adjusted in a twisting movement. This is achieved by a first actuator cam stopping or being controlled to move in the opposite direction to, or at a slower rotation rate than a second actuator cam. This twisting movement permits that one edge and portion of the seat will be in advance of one other edge and portion of the seat and is particular advantageous in a lifting cycle for assisting stroke victims to sit and stand.

Figure 10, 11 and 12 show alternative embodiments of both an arrester and locking system suitable for use, either in combination or individually, in a manoeuvrable body in accordance with the invention. In the illustration now described, they are used in combination. The system 800 can be used with actuator cam 6 from Figure 1 or any other embodiment of the actuator cam falling within the scope of the invention. The arrester features a bracket 801 which is connected to shaft 802 which corresponds to the actuator cam shaft 3 from Figure 1. The bracket supports a motor 803 which is connected to a gear 804 such that when the motor rotates the gear 804 rotates. The gear 804 is meshed with a gear 806 which is in turn meshed with a gear 807. An outer bracket 805 supports the gears to make sure that they maintain their meshed arrangement. The arrangement further comprises one or more bearings (not shown) to assist in positioning and low friction rotation.

The gear 807 is connected to a leadscrew 808 which is meshed with a nut 809. The leadscrew is supported at one end by the bracket 801 and at the other by the bracket 810 where bracket 810 stems from the shaft 802. The surface section 811 is conveniently (but not essentially) arranged about an anchor shaft 812 which is fixed to or integral with the manoeuvrable body. The interface between the shaft 812 and the surface section 811 incorporates a bearing 813. The surface section 8 1 features an extension bracket 814 which connects to a threaded member 815 which in turn meshes with a nut 816.

The nature of the mesh between the nut member 815 and the nut 816 can vary depending on requirements. The thread can be a large helix protruding from the member 815 or protruding from the nut 816 with a corresponding recessed pattern intruding into the opposite meshed part, or channel projecting through the opposite meshed part. For example, in the case of a channel provided on member 815, the nut 816 can feature at least one notch or other radially inward protrusion that enters the channel and hence meshes the two components.

Referring to Figure 11 ,this illustrates a locking system for locking the body to a fixed surface, for example, where the body is a seat, a seat frame. The anchor shaft 812 is hollow and smaller diameter shaft 817 is slideably engageable therein. Low friction slideable engagement between the shafts 817 and 812 can be achieved by means of suitably selected seals, low friction materials such as thin circumferential bearings and/or lubrication (none of which are shown). The shaft 817 is connected to the movement arm 818 which in turn is fixed or integrated to the nut 819. The nut 819 meshes with the leadscrew 820 which is connected to the motor 821. The motor 821 and leadscrew 820 are conveniently (but not essentially) housed in a casing 823 and connected to bracket 822 which extends from the shaft 812.

Motor 821 rotates the leadscrew 820 which moves the nut 819 linearly along the leadscrew axis. The arm 818, attached to the nut, also moves linearly and guides the 00389

- 23 - shaft 817 into the anchor shaft 812, passing entirely through the hollow anchor shaft into the body. The lock can be disengaged by reversing the direction of rotation of the leadscrew and hence direction of travel of the nut 819 and arm 818 withdrawing shaft 817 from the body.

Figure 12 shows at least one actuator cam under a surface 826 (for example of a seat) where the surface can feature an aperture 827 (for example to enable use as a commode). The actuator cam can have any already described or contemplated configuration in accordance with the invention. As can be seen in the Figure, the anchor shaft 812 is connected with the shaft 802 (which shaft corresponds to the shaft 3 in Figure 1 ). Also shown in the Figure are the arm 818, the leadscrew casing 823 and the bracket 814. Typically the anchor shaft 812 fixedly held.

In the arrangements shown in Figure 10, actuator cam 824 (Figure 12) rotates about the shaft 802, a controller triggering the activation of the motor 803 which in turn rotates the gear 804 which in turn rotates gear and in turn gear 807. The rotation of the gear 807 rotates the leadscrew 808 causing nut 809 to travel linearly along the axis of the leadscrew. Simultaneously, as the actuator cam rotates the surface 826 (Figure 12) carrying with it surface section 81 1 and extension bracket 810. By virtue of its further connection to threaded member 815, the threaded member also rotates about shaft 802. As the threaded member 815 rotates, so the nut 809 which meshes with it is moved linearly. Resultant from the motor 803 being activated by the movement of the actuator cam and controller.

The motor 803, gears 804, 806 and 807 as well as leadscrew 808 are all matched to the helix or channel in the threaded member and consequently the operating speed and direction of rotation of the actuator cam 824 and the consequent rotation of the surface of the manoeuvrable body whereby the surface 81 1 rotates about the axis of the shaft 812. Due to these relationships, only if the linear movement of the nut 816 is synchronous with the rotational movement of the threaded member 815 will the rotation of the body and/or cam progress. The rotation of the surface 81 1 (and hence the body) is linked to the arrester device and the actuator cam. If the actuator cam d fails, then the surface 8 1 and body will stop moving (or in a worst case scenario begin to rotate towards the ground), however, due to the harmonised relationships as described, this counter rotation would force the nut 816 and threaded member 8 5 respective to there meshed interaction to become out of synchronisation with each other and as such the nut 816 and threaded member would lock. As the threaded member 815 is connected to the extension bracket 814 and the bracket 814 is connected to the surface 81 1 and the body,, the surface and hence the body would also lock in position and no longer rotate in any direction and as such the arrester is able to arrest the entire system.

Figure 13 shows a further embodiment 400 of a manoeuvrable body incorporating an actuator cam in accordance with the invention. In this Figure, the actuator cam 412 can take the form of any actuator cam as already described or contemplated in accordance with the invention.

In this case the actuator cam has at least one gear 41 1 which corresponds to gear 9 of Figure 1. The gear 411 is kept in a meshed relationship with the gear 409 by the lever bar 408. The gear 409 corresponds to the gear 4 from Figure 1. The lever bar 408 allows the gear 41 1 to rotate about the gear 411 axis and is rotatably mounted to the shaft of the gear 409. In this case the actuator cam is shown with an additional gear 407 mounted above the toothed drive rack nut 413 (corresponding to toothed rack 12 in Figure 1 ) which incorporates a second set of teeth which mesh with gear 407. The actuator cam 412 features an extension 404 corresponding to extension 18, 19, 20, 21 from Figure 1. As per Figure 1 , the extension in this case also comes with at least one roller and or bearing 402 with shaft 403 whereby the shaft can feature protruding ends which are arranged to engage the seat guide track 405 (which corresponds to seat guide track 60 of Figure 6). The extension 404 includes a roller and/or bearing 401 (corresponding to roller and/or bearing 21 from Figure 1 ). The actuator cam 412 is itself encased in its entirety within a seat 410.

The actuator cam 412 operates as has been described previously, for example in relation to Figure 1 above. Gear 407 is in a meshed relationship with the toothed drive rack 413 and as such assists to kept the optimum meshed relationship between the toothed drive rack nut 413 and the at least one gear 41 1 . Therefore as the actuator cam operates, the actuator cam begins to rotate and as such the seat will rotate about the axis of the gear shaft 409. However, unlike previous embodiments, where the arm (such as arm 90 from Figure 8 or the arm 63 from Figure 6) remains stationary, in this case the arm will rotate. The arm 408 is rotationally connected to both the gear 409 and to the gear 41 1 and thus as the at least one gear 41 1 starts to rotate, the rotary arm 408 will allow the gear to move around the circumference of the gear 409 and this result in the cam actuator 412 and the seat being rotated about their respective axis.

The guide rail 405 defines an open or closed channel 406 in which the protruding ends of shaft 403 engage thereby engaging the seat with the actuator cam 412.