GB2579062A

GB2579062A - Apparatus for converting motion

Info

Publication number: GB2579062A
Application number: GB1818731.0A
Authority: GB
Inventors: Martyn David
Original assignee: Ten Fold Engineering Ltd
Current assignee: Ten Fold Engineering Ltd
Priority date: 2018-11-16
Filing date: 2018-11-16
Publication date: 2020-06-10
Anticipated expiration: 2038-11-16
Also published as: GB201818731D0; GB2579062B

Abstract

The assembly 2 comprising a first arm 8 rotatable on a first fixed pivot 4; a second arm 10 rotatable on a second fixed pivot 6; a third arm 12 pivotably connected to the second arm. A first connecting arm 16 extends between the first arm and the third arm and a second connecting arm 22 extends between the first arm and the second arm. Furthermore, a drive assembly 40 comprising a drive arm assembly 42 connected to a component 30 being moved by the assembly, the drive arm assembly comprising at least one drive arm 44 , the drive arm pivotably connected to an arm of the assembly with a drive cable 54 connected to the drive arm assembly.

Description

APPARATUS FOR CONVERTING MOTION

The present invention relates to an apparatus for converting motion. In a further aspect, the present invention provides an assembly comprising the apparatus, including but not limited to an expandable building assembly.

Mechanisms for converting motion, in particular producing a straight line motion from a rotational motion are known in the art. Such straight line mechanisms may be characterised by comprising a first member rotatable about an axis passing through the member and a second member linked to or associated with the first member, the arrangement being such that rotational movement of the first member about the axis results in a straight line movement of the second member.

Examples of early mechanisms for producing a straight line motion include the straight line mechanism design by James Watt, comprising a series of three levers in end-to-end configuration, with movement of the two end levers about pivots at their free ends causing the middle lever to follow a close approximation to a straight line over a portion of its movement. A related linkage comprising three levers, with the middle lever constrained to follow a straight line was proposed by Tchebicheff. The Peaucellier-Lipkin inversor consists of an arrangement of seven levers and provides a conversion of circular motion into linear motion and vice versa. A related four-lever mechanism was proposed by Hart. A linear converter, known as the half beam mechanism, in which a first linear motion is converted to a second linear motion perpendicular to the first, was designed by Scott Russell.

An analysis of a variety of multi-lever, straight line linkages is provided 30 by Dijksman, E.A. 'Advances in Robot Kinematics and Computationed Geometry', pages 411 to 420, [1994] Kluwer Academic Publishers.

US 4,248,103 discloses a straight line mechanism, in particular a mechanism of the so-called conchoid' type. There is disclosed a linkage mechanism for an industrial manipulator comprising at least two of the said straight line mechanisms.

US 4,400,985 concerns a straight line link mechanism, comprising a plurality of pivotally connected links. The links are connected between a support and a controlled member. As one of the links is moved in a 360° arc, the controlled member alternately moves in a first direction along a linear path and thereafter in the opposite direction along a curved path. The weight of the controlled member may be balanced by the use of a counter weight, to provide a lifting mechanism. A cam may be employed to control the motion of the controlled member.

More recently, US 4,747,353 discloses a straight line motion mechanism formed from a pair linkage mechanisms arranged in a parallelogram in combination with a motion control means. The motion control means interconnects the two linkage mechanisms and provide a uniform angular displacement of each linkage mechanism.

US 5,102,290 concerns a transfer device for transferring a workpiece from a first location to a second location. The workpiece is moved in a trochoidal arc by means of a pickup arm mounted to roll along a flat surface.

A straight line mechanism is disclosed in US 5,237,887. The mechanism comprises a static base and a platform supported by first and second arm assemblies. Each of the first and second arm assemblies comprises portions pivotally connected to the static base. The arrangement of the pivoted arm portions of each arm assembly is such that the platform is constrained to move in a straight line, as the portions of the arms move about their respective pivot connections.

Still more recently, WO 97/33725 discloses a device for the relative movement of two elements. The device comprises at least two first links connected to a first element by a hinged connection so as to form a four-hinge system and pivot in a plane parallel to the plane of the first element. At least two second links are connected to the second element so as to form a four-hinge system and to pivot in a plane parallel to the plane of the second element. The two four-hinge systems provided by the first and second links are coupled in series to allow relative motion of the first and second elements.

WO 99/14018 discloses a device for the relative movement of two elements. The device comprises at least two link devices coupled between the elements, each comprising two mutually articulated link units. A first link unit is connected to first, moveable element. The second of the link units is connected to the second, static element. Power applied to the link units causes the first element to move relative to the second.

A mechanical linkage is described and shown in US 2,506,151. The linkage comprises a plurality of interconnected levers. The linkage provides for movement of one member with respect to a fixed member. The linkage is specifically described and shown for use in providing movement for components of a chair, in particular to allow for movement of the seat of the chair in a rearwardly-downwardly and forwardly-upwardly direction. The linkage is indicated in US 2,506,151 to provide for movement of the moveable member in a straight path with respect to the fixed member.

US 2,529,451 discloses a linkage for a chair for a theatre. The linkage connects the seat portion of the seat to the back portion, allowing relative movement between the seat and the back.

Perhaps most recently, WO 2013/182834 discloses an assembly for converting motion. The assembly comprises: a first arm rotatable at a first position thereon about a first fixed pivot; a second arm rotatable at a first position thereon about a second fixed pivot, the second fixed pivot spaced apart from the first fixed pivot; a third arm pivotably connected at a first position thereon to the second arm at a second position on the second arm, the second position spaced apart from the first position on the second arm; a first connecting arm extending between the first arm and the third arm, the first connecting arm pivotably connected to a second position on the first arm spaced apart from the first position and pivotably connected to the third arm at a second position thereon spaced apart from the first position thereon; and a second connecting arm extending between the first arm and the second arm, the second connecting arm pivotably connected to a third position on the first arm disposed between the first and second positions thereon and pivotably connected to a third position on the second arm.

Developments of the assembly of WO 2013/182834 are disclosed in subsequently published documents, including WO 2014/029954, WO 2014/184513, W02015/033111, WO 2015/033116, W02016/030659, and WO 2016/030660.

In particular, WO 2016/030659 discloses an assembly of the general configuration of WO 2013/182834 with a locking assembly comprising a first locking member connected to one of the first second or third arms of one of the first or second connecting arms of the assembly and a second locking member.

There is a continuing need to provide improved assemblies for converting motion, in particular assemblies for providing movement and support to components to be moved. It would be particularly advantageous if the assembly could be in a compact form when in a retracted position It would also be advantageous if the assembly and its accompanying components could be supported and moved easily between the retracted position and an extended position.

There has now been found a development to the assembly described and shown in WO 2013/182834 which provides significant additional advantages in the operation of the assembly, in particular when used for moving and supporting components. More particularly, there has now been found a development to the assembly described in WO 2013/1828134 which has improved ease of operation, especially in moving the assembly and the attached components between the retracted and extended positions.

According to a first aspect of the present invention, there is provided an assembly for converting motion, the assembly comprising: a first arm rotatable at a first position on the first arm about a first fixed pivot; a second arm rotatable at a first position on the second arm about a second fixed pivot, the second fixed pivot spaced apart from the first fixed pivot; a third arm pivotably connected at a first position on the third arm to the 25 second arm at a second position on the second arm, the second position on the second arm spaced apart from the first position on the second arm; a first connecting arm extending between the first arm and the third arm, the first connecting arm pivotably connected to a second position on the first arm spaced apart from the first position on the first arm and pivotably connected to the third arm at a second position on the third arm spaced apart from the first position on the third arm; a second connecting arm extending between the first arm and the second arm, the second connecting arm piyotably connected to a third position on the first arm spaced apart from the first position on the first arm and pivotably connected to a third position on the second arm spaced apart from the first position on the second arm; a drive assembly comprising: a drive arm assembly connected to a component being moved by the assembly, the drive arm assembly comprising at least one drive arm, the drive arm piyotably connected at a first position on the drive arm to an arm of the assembly; and a drive cable connected to the drive arm assembly.

In operation of the assembly, rotation of the first arm about the first fixed pivot results in rotation of the second arm about the second fixed pivot and movement of the third arm. In particular, the third arm is caused to move such that a point on the third arm (herein referred to as 'the said point') spaced from the first position on the third arm and located such that the second position on the third arm lies between the said point and the first position moves in a straight line. Thus, rotational motion of the first arm and the second arm about their respective fixed pivots results in a straight line motion of the said point on the third arm. In this respect, it is to be noted that the said point on the third arm referred to traces a line that is substantially straight, that is represents a very close approximation to a straight line. In particular, the path followed by the said point may be characterised as being a very flat sine wave, that is a sine wave of high wavelength and very low amplitude.

In a particularly preferred embodiment, movement of the assembly between a retracted position and an extended position results in movement of the said point on the third arm along a substantially straight line extending perpendicular to the line joining the first and second fixed pivots. This is a particularly advantageous arrangement, for example when employing the assembly in a building to provide movement of one portion of the building with respect to another, such as moving a portion of the building laterally from a fixed building structure.

The assembly of the present invention may be arranged such that the arms of the assembly are accommodated in a very compact configuration in the retracted position, such as with the arms lying closely together or adjacent one another, for example one within the other. In one preferred embodiment, the arms are sized and arranged so that they all lie between the first and second fixed pivots in the retracted position. This compactness is a significant advantage of the assembly of this invention.

Further, in some embodiments of the assembly the said point on the third arm is arranged to be the forwardmost point of the assembly in the direction extending away from and to one side of the first and second fixed pivots during movement of the assembly. This arrangement provides significant advantages over known assemblies, where the point of the assembly moving in a straight line is contained within or otherwise surrounded by other components of the assembly.

It is a particularly preferred embodiment of the assembly of the present invention that all the components of the assembly are to one side only of the line joining the first and second fixed pivots when the assembly is moving between the retracted position and the extended position.

The point on the third arm referred to above is spaced from the first position on the third arm, with the second position on the third arm lying between the said point and the first position. The location of the said point will depend upon the length of the arms of the device and the positions of their interconnections. In one preferred embodiment, the said point is arranged to be at a distal location on the third arm, that is distal from the first and second positions on the third arm, preferably with the said point being located at the distal end of the third arm or in an end portion at the distal end of the arm.

The extent of the straight line motion of the said point on the third arm varies according the precise positioning of the connections between the arms. For example, in one embodiment, it has been found that this close approximation to a straight line motion by the said point on the third arm occurs over a distance that is up to 85% of the distance between the first and second fixed pivots. Further embodiments provide motion of the said point on the third arm that follows a close approximation to a straight line for a distance up to or exceeding 100% of the distance between the first and second fixed pivots. References herein to a motion of the said point on the third arm in a 'straight line' are references to this movement.

As noted, the said point on the third arm moves in a pattern that is a close approximation to a straight line. The deviation of the movement of the said point from a straight line may be exemplified by the following: In an embodiment of the assembly in which the distance between the first fixed pivot and the second fixed pivot is 3250 mm, the said point on the third arm describes an approximate straight line of 2750 mm in length. In particular, the said point moves between a first or retracted position and a second or extended position. In this respect, references to motion of the said point are with respect to the line joining the first and second fixed pivots, with the retracted position being at or close to the line joining the first and second fixed pivots and the retracted position being distant therefrom. As noted, the said point on the third arm moves between the retracted position and the extended position, with the line joining the retracted and extended positions being a straight line perpendicular to the line extending between the first and second pivots. However, in moving between the retracted and extended positions, the said point follows a sine wave having a maximum deviation from the straight line of 8 mm. This deviation represents a deviation of just 0.25% of the distance travelled by the said point between the retracted and extended positions and is generally insignificant in the context of most if not all practical applications of the assembly.

In another embodiment of the assembly in which the distance between the first fixed pivot and the second fixed pivot is 3250 mm, the said point on the third arm describes an approximate straight line of 3254 mm in length. In this embodiment, the deviation of the said point moves in a sine wave having a maximum deviation from a straight line of just 31.4 mm, that is just 0.96% of the distance travelled by the said point.

The arrangement of the assembly of the present invention may be varied depending upon the requirements. For example, the assembly may be arranged to provide a longer straight line movement of the said point on the third arm with a slightly greater deviation from a straight line. Alternatively, the assembly may be arranged to provide a shorter straight line movement of the said point, with the path traced by the said point being a closer approximation to a straight line with less deviation.

As noted above, in many embodiments of the assembly, the straight line path followed by the said point on the third arm extends perpendicular to the line joining the first and second pivot points. This is an advantage over assemblies of the prior art and allows the assembly of the present invention to be more versatile and have a wider range of applications. In particular, it allows the assembly to be placed or mounted on a plane, that is with the first and second fixed pivots lying in the plane, and to have all motion of the components confined to one side of the plane. Thus, for example, the assembly may be used on a surface of a construction, such as a building or the like, and all components move from the retracted to the extended positions on one side of the plane, without encroaching on or requiring space on the other side of the plane.

The assembly has been defined hereinbefore by reference to a plurality of arms. It is to be understood that the term 'arm' is used as a general reference to any component that may be connected as hereinbefore described and/or moved about a pivot connection. Accordingly, the term 'arm' is to be understood as being a reference to any such component, regardless of shape or configuration References herein to distal' and 'proximal' with respect to the position of components of the assembly are to be understood as being relative to the first and second fixed pivots in the extended position of the assembly, that is 'proximal' being at or towards the first and second fixed pivots and 'distal' being away from the first and second fixed pivots.

The assembly of the present invention is connected to a pair of fixed pivots comprising a first fixed pivot and a second fixed pivot. In this respect, the term fixed' as used in relation to the fixed pivots is a reference to the first and second pivots being fixed in relation to one another, such that the distance between the first and second fixed pivots is constant. The first and second fixed pivots are typically provided on a member or structure. The member or structure may be non-moveable, such as a building, or may be moveable. The components of the assembly are to be considered to be moveable with respect to the first and second fixed pivots and references to the movement of the components of the assembly are to be understood in this respect.

The fixed pivots are spaced apart and are fixed in relation to one another. In one embodiment, the line joining the first and second fixed pivots is arranged vertically, with the first fixed pivot above the second fixed pivot. However, the assembly may have other orientations. In particular, the line joining the first and second fixed pivots may be arranged vertically with the second fixed pivot above the first fixed pivot. Other orientations are also possible, such as with the first and second fixed pivots arranged other than vertically.

The assembly of the present invention comprises a first arm. The first arm may have any shape and configuration. A preferred form for the first arm is an elongate member, for example a bar or a rod.

The first arm is rotatable at a first position on the first arm about the first fixed pivot. Preferably, the first arm is pivotably mounted at a first position on the arm to the first fixed pivot. The pivot connection at the first position of the first arm may be of any suitable form that allows rotation of the first arm about the first fixed pivot. For example, the pivot connection may comprise a pivot member, such as a pin, spindle or axle, passing through the arm and/or the first fixed pivot.

The first position on the first arm may be in any suitable location on the first arm. In one preferred embodiment, the first position is at or adjacent one end of the first arm.

The first arm may have any suitable length. However, generally, the ratio of the length of the first arm, that is the distance between the first and second positions on the first arm, to the distance between the first and second fixed pivots may range from 0.5 to 2.0, more preferably from 0.6 to 1.75, still more preferably from 0.75 to 1.5. The first arm is preferably no longer than, more preferably the same or shorter in length than the distance between the first and second fixed pivots. The ratio of the length of the first arm to the distance between the first and second fixed pivots is therefore more preferably from 0.75 to 0.99, still more preferably from 0.8 to 0.99, in particular from 0.9 to 0.99. A ratio of about 0.92 to about 0.98 is particularly suitable for many applications. In this way, the first arm can lie between the first and second fixed pivots in the retracted position.

The assembly further comprises a second arm. The second arm may have any shape and configuration. A preferred form for the second arm is an elongate member, for example a bar or a rod.

The second arm is rotatable at a first position on the second arm about the second fixed pivot. Preferably, the second arm is pivotably mounted at a first position on the second arm to the second fixed pivot. The pivot connection at the first position of the second arm may be of any suitable form that allows rotation of the second arm about the second fixed pivot. For example, the pivot connection may comprise a pivot member, such as a pin, spindle or axle, passing through the arm and/or the second fixed pivot.

The first position on the second arm may be in any suitable location on the second arm. In one preferred embodiment, the first position is at or adjacent one end of the second arm The second arm may have any suitable length. The ratio of the length of the second arm, that is the distance between the first and second positions on the second arm, to the distance between the first and second fixed pivots may range from 0.5 to 2.0, more preferably from 0.6 to 1.75, still more preferably from 0.75 to 1.5. The second arm is preferably the same or shorter in length than the distance between the first and second fixed pivots. The ratio of the length of the second arm to the distance between the first and second fixed pivots is therefore more preferably from 0.75 to 0.99, still more preferably from 0.8 to 0.99, in particular from 0.9 to 0.99. A ratio of about 0.92 to about 0.98 is particularly suitable for many applications. In this way, the second arm can lie between the first and second fixed pivots in the retracted position.

The length of the second arm is preferably selected to be as long as possible, within the constraints of the other components of the assembly and the desired motion. In this way, the arc through which the second position on the second arm moves about the second fixed pivot has as large a radius as possible. This facilitates the positioning of the second connecting arm.

The second arm may be longer or shorter than the first arm. In one preferred embodiment, the first and second arms are of the same length.

The assembly further comprises a third arm. The third arm may have any shape and configuration. A preferred form for the third arm is an elongate member, for example a bar or a rod.

The third arm is pivotably mounted at a first position on the third arm to the second arm at a second position on the second arm. The pivot connection between the second and third arms may be of any suitable form that allows rotation of the third arm about the second position on the second arm. For example, the pivot connection may comprise a pivot member, such as a pin, spindle or axle, passing through one or both of the second and third arms about which one or both of the arms are free to move.

The third arm is pivotably connected to the second arm at a first position on the third arm and a second position on the second arm. The first position may be in any suitable location on the third arm. In one preferred embodiment, the first position is at or adjacent one end of the third arm.

The second position on the second arm is spaced apart from the first position on the second arm. In one preferred embodiment, the second position on the second arm is at or adjacent the second end of the second arm.

In operation of the assembly, as noted above, the third arm has a position, point A, thereon that follows the path of a straight line when the assembly is moved between the retracted and extended positions. This point on the third arm is spaced apart from the first position on the third arm, that is the position on the third arm at which the second and third arms are pivotably connected together.

The third arm may have any suitable length. The ratio of the length of the third arm, that is the distance between the first position and the said point on the third arm, to the distance between the first and second fixed pivots may range from 0.5 to 2.0, more preferably from 0.6 to 1.75, still more preferably from 0.75 to 1.5. The third arm is preferably the same or shorter in length than the distance between the first and second fixed pivots. The ratio of the length of the third arm to the distance between the first and second fixed pivots is therefore more preferably from 0.75 to 0.99, still more preferably from 0.8 to 0.99, in particular from 0.9 to 0.99. A ratio of about 0.92 to about 0.98 is particularly suitable for many applications. In this way, the third arm can lie between the first and second fixed pivots in the retracted position.

Taking the length of the third arm to be the distance between the first position on the third arm and the said point on the third arm, the length of the third arm will be determined by the arrangement of the first and second arms, together with the connecting arms. In some embodiments, the length of the third arm is less than that of the first and second arms, in particular from 0.9 to 0.99 of the length of the first and/or second arms. For example, with the first and second arms being of equal length and less than the distance between the first and second fixed pivots, the third arm has a length of about 0.975 of the length of the first and/or second arms In one preferred embodiment, the length of the third arm is the same as that of the first arm and/or the second arm. In one particularly preferred arrangement, the first, second and third arms are the same length. In this way, the assembly can be formed from a minimum number of different components.

The assembly further comprises a first connecting arm. The first connecting arm extends between the first arm and the third arm. The first connecting arm may have any shape and configuration. A preferred form for the first connecting arm is an elongate member, for example a bar or a rod.

The first connecting arm is pivotably mounted to each of the first and third arms. The pivot connections between the first connecting arm and each of the first and third arms may be of any suitable form to allow the first connecting arm to pivot about each of the first and third arms. For example, the pivot connection may comprise a pivot member, such as a pin, spindle or axle, passing through one or both of the first connecting arm and the second arm or the third arm about which one or both of the arms are free to move.

The pivot connections may be at any suitable location on the first connecting arm. In one embodiment, the pivot connection between the first connecting arm and the first arm is at or adjacent one end of the first connecting arm and/or the pivot connection between the first connecting arm and the third arm is at or adjacent the second end of the first connecting arm. Alternatively, the first connecting arm may extend beyond the first arm in the direction towards the line joining the first and second fixed pivots.

Alternatively, or in addition, the first connecting arm may extend beyond the third arm in the direction away from the line joining the first and second fixed pivots.

The first connecting arm is connected to the first arm at a second position on the first arm. The second position on the first arm is spaced apart from the first position on the first arm. In one preferred embodiment, the second position on the first arm is at or adjacent the second end of the first arm.

The first connecting arm is further connected to the third arm at a second position on the third arm, which second position is spaced apart from the first position on the third arm.

The first connecting arm may have any suitable length. Its length may be the distance between the positions on the first and third arms between which the first connecting arm extends. Alternatively, the first connecting arm may extend beyond one or both of the first and third arms in either one or both of the distal and proximal directions.

The second position on the third arm, at which the first connecting arm is connected, is disposed between the first position on the third arm and the said point on the third arm. The second position on the third arm may be selected according to a number of factors. First, the first connecting arm acts to provide support for the third arm, in particular to assist in supporting any load applied to the third arm. The requirement for the third arm to be supported in this manner by the first connecting arm is a factor in determining the location of the second position on the third arm. Second, the overall strength and stability of the assembly is related to the length of the first connecting arm, with the strength and stability reducing as the length of the first connecting arm increases.

In one preferred embodiment, the first connecting arm extends perpendicular to the line joining the first and second fixed pivots in the extended position.

The assembly further comprises a second connecting arm. The second connecting arm extends between the first arm and the second arm. The second connecting arm may have any shape and configuration. A preferred form for the second connecting arm is an elongate member, for example a bar or a rod.

The second connecting arm is pivotably mounted to each of the first and second arms. The pivot connections between the second connecting arm and each of the first and second arms may be of any suitable form to allow the second connecting arm to pivot about each of the first and second arms. For example, the pivot connection may comprise a pivot member, such as a pin, spindle or axle, passing through one or both of the second connecting arm and the first arm or the second arm about which one or both of the arms are free to move.

The pivot connections may be at any suitable location on the second connecting arm. In one embodiment, the pivot connection between the second connecting arm and the first arm is at or adjacent one end of the second connecting arm and/or the pivot connection between the second connecting arm and the second arm is at or adjacent the second end of the second connecting arm. Alternatively, the second connecting arm may extend beyond the first arm in the direction towards the line joining the first and second fixed pivots. Alternatively, or in addition, the second connecting arm may extend beyond the second arm in the direction away from the line joining the first and second fixed pivots.

The second connecting arm is connected to the first arm at a third position on the first arm. In one embodiment, the third position on the first arm is spaced apart from and between both the first and second positions on the first arm. In an alternative embodiment, the third position on the first arm coincides with the second position on the first arm, such that the second connecting arm is pivotally connected to the first arm and also pivotally connected to the first connecting arm.

The third position on the first arm, at which the second connecting arm is connected, may be selected according to a number of factors. First, the second connecting arm acts to provide support for the first arm, in particular to assist in supporting any load applied to the first arm. The requirement for the first arm to be supported in this manner by the first connecting arm is a factor in determining the location of the third position on the first arm. Second, as with the first connecting arm, the overall strength and stability of the assembly is related to the length of the second connecting arm, with the strength and stability reducing as the length of the second connecting arm increases.

The second connecting arm is further pivotally connected to the second arm at a third position on the second arm. In one embodiment of the assembly, the third position is spaced apart from and between the first and second positions on the second arm. In an alternative embodiment, the third position on the second arm coincides with the second position on the second arm, such that the second connecting arm is connected to both the second and third arms.

The second connecting arm may have any suitable length. Its length may be the distance between the positions on the first and second arms between which the second connecting arm extends. Alternatively, the second connecting arm may extend beyond one or both of the first and third arms in either one or both of the distal and proximal directions.

In one preferred embodiment, the second connecting arm extends perpendicular to the line joining the first and second fixed pivots in the extended position.

In many preferred embodiments, the length of the first connecting arm is equal to the length of the second connecting arm. In particular, in many preferred embodiments, the length of the first connecting arm between its connections with the first arm and the third arm is equal to the length of the second connecting arm between its connections with the first arm and the second arm.

In one preferred embodiment, the first connecting arm extends parallel to the second connecting arm when the assembly is in the extended position, more preferably with both arms extending perpendicular to the line joining the first and second fixed pivots.

The arms of the assembly of the present invention may consist essentially of the first, second and third arms and first and second connecting arms described hereinbefore, together with the locking assembly as described hereinafter. Alternatively, the assembly may comprise one or more further arms connected to the aforementioned first, second, third and connecting arms. Further arms may be added, for example, to provide additional support to one or more components being moved by the assembly and connected thereto.

In one preferred embodiment, the assembly comprises a fourth arm pivotably connected at a first position on the fourth arm to the first arm at a fourth position on the first arm.

The fourth arm may have any shape and configuration. A preferred form for the fourth arm is an elongate member, for example a bar or a rod. The fourth arm is pivotably mounted at a first position on the fourth arm to the first arm at a fourth position on the first arm. The pivot connection between the first and fourth arms may be of any suitable form to allow the rotational movement of the fourth arm relative to the first arm. For example, the pivot connection may comprise a pivot member, such as a pin, spindle or axle, passing through one or both of the arms about which the arms are free to move.

The fourth arm is pivotably connected to the first arm at a first position on the fourth arm and a fourth position on the first arm. The first position may be in any suitable location on the fourth arm. In one preferred embodiment, the first position is at or adjacent one end of the fourth arm, in particular the end of the fourth arm that is proximal to the first and second fixed pivots in the extended position.

The fourth position on the first arm is spaced apart from the first position on the first arm. In one preferred embodiment, the fourth position on the first arm is at or adjacent the second end of the first arm, that is the end distal of the first fixed pivot. In a particularly preferred embodiment, the fourth position on the first arm coincides with the second position on the first arm, that is the fourth arm is connected to the first arm at the same position as the first connecting arm.

The fourth arm may be a driven arm, that is moved under the action of movement of the first and second arms. In this case, rotation of the first arm about the first fixed pivot causes the fourth arm to move. Alternatively, the fourth arm may be a driving arm, that is have a force applied thereto resulting in movement of the fourth arm, which in turn drives the other components of the assembly to result in movement of the first arm about the first fixed pivot and the second arm about the second fixed pivot.

The fourth arm may be connected to an object to be moved relative to the first and second fixed pivots. The connection between the fourth arm and the object is preferably in the region of, more preferably at, the end of the fourth arm that is distal of the first and second fixed pivots. It has been found that when the fourth arm is connected to the object to be moved there is a position, point B, on the fourth arm that moves in a substantially straight line, corresponding to the movement of the said point on the third arm described in detail above. The connection between the fourth arm and the object is preferably in the region of, more preferably at, this position on the fourth arm.

Taking the length of the fourth arm to be the distance between the first position on the fourth arm and the said point on the fourth arm, the length of the fourth arm will be determined by the arrangement of the first and second arms, together with the connecting arms. The length of the fourth arm is preferably less than the distance between the first and second fixed pivots. In this way, the fourth arm may be accommodated between the first and second fixed pivots, when the assembly is in the retracted position. In some embodiments, the length of the fourth arm is less than that of the first and second arms, in particular from 0.9 to 0.99 of the length of the first and/or second arms. For example, with the first and second arms being of equal length and less than the distance between the first and second fixed pivots, the fourth arm has a length of about 0.975 of the length of the first and second arms.

In alternative embodiments, the length of the fourth arm is the same as that of the first arm and/or the second arm. Preferably, the length of the fourth arm is the same as the length of the third arm. In one particularly preferred arrangement, the first, second, third and fourth arms are the same length.

In one embodiment, both the third arm and the fourth arm are connected to the same object to be moved, most preferably with both arms connected to the object at the said point on each of the third and fourth arm.

In alternative embodiment, each of the third and fourth arms is connected to a respective component or object to be moved. In this way, two components or objects may be moved independently of each other by the same assembly.

As noted above, the assembly comprises a first connecting arm and a second connecting arm. In one preferred embodiment, the assembly comprises a third connecting arm. The third connecting arm is preferably 15 arranged in the manner disclosed in WO 2016/030660.

In one embodiment, the third connecting arm extends between the first arm and the third arm. The second connecting arm may have any shape and configuration. A preferred form for the second connecting arm is an elongate member, for example a bar or a rod. The second connecting arm is pivotably mounted to each of the first and third arms. The pivot connections between the second connecting arm and each of the first and third arms may be of any suitable form, preferably a pin, spindle or axle passing through one or both of the arms about which one or both of the arms are free to move.

The pivot connections may be at any suitable location on the third connecting arm. In one preferred embodiment, the pivot connection between the third connecting arm and the first arm is at or adjacent one end of the third connecting arm and/or the pivot connection between the third connecting arm and the third arm is at or adjacent the second end of the third connecting arm.

The third connecting arm is connected to the first arm at a fourth position on the first arm, which fourth position is spaced apart from and between both the second and third positions on the first arm.

The fourth position on the first arm, at which the third connecting arm is connected, may be selected according to a number of factors. First, the third connecting arm acts to provide support for the first arm, in particular to assist in supporting any load applied to the first arm. The requirement for the first arm to be supported in this manner by the third connecting arm is a factor in determining the location of the fourth position on the first arm. Second, as with the first and second connecting arms, the overall strength and stability of the assembly is related to the length of the third connecting arm, with the strength and stability reducing as the length of the third connecting arm increases.

The fourth position on the first arm may be at any suitable position. In particular, the ratio of the distance between the fourth position and the second position on the first arm and the distance between the fourth position and the third position on the first arm may be from 0.5 to 2.0, more preferably from 0.75 to 1.5, still more preferably from 0.9 to 1.1. A preferred ratio is 1.0, that is the fourth position is equidistant from the second and third positions on the first arm.

The third connecting arm is further connected to the third arm at a third position on the third arm. The third position on the third arm is spaced apart from and between the first and second positions on the third arm. In this way, the third connecting arm is disposed between the first and second connecting arms.

The third position on the third arm may be at any suitable position. In particular, the ratio of the distance between the third position and the first position on the third arm and the distance between the third position and the second position on the third arm may be from 0.5 to 2.0, more preferably from 0.75 to 1.5, still more preferably from 0.9 to 1.1. A preferred ratio is 1.0, that is the third position is equidistant from the first and second positions on the first arm.

In a particularly preferred embodiment, the third connecting arm is spaced equidistantly from the first and second connecting arms.

Preferably, the third connecting arm extends perpendicular to the line joining the first and second fixed pivots when the assembly is in the extended position.

The third connecting arm may have any suitable length. Its length may be the distance between the positions on the first and third arms between which the second connecting arm extends.

Preferably, the length of the third connecting arm, that is the distance between the connection between the third connecting arm and each of the first and third arms, is equal to the length of the first connecting arm and/or the second connecting arm, preferably both the first and second connecting arms.

In one preferred embodiment, the third connecting arm extends parallel to the first connecting arm and/or the second connecting arm when the assembly is in the extended position, more preferably parallel with both the first and second connecting arms.

As noted above, the assembly may comprise additional arms. Such 30 additional arms may be rigidly connected to one of the aforementioned arms of the assembly or may be pivotably connected to an aforementioned arm.

The additional arms may be provided to provide support for one or more components or structures to be moved by the assembly. Alternatively or in addition, the additional arms may be provided to extend the distance a component or object may be moved and supported relative to the first and second fixed pivots.

The assembly of the present invention further comprises a drive assembly. The drive assembly comprises a drive arm assembly comprising one or more drive arms. The drive assembly further comprises a drive cable.

The components of the drive assembly are discussed in more detail below.

In operation, the drive assembly acts to move the assembly and components connected to and being moved in turn by the assembly.

It is an advantage of the assembly of the present invention that it may be moved between the retracted position and the extended position with a minimum of drive effort and a minimum of force being applied. In some preferred embodiments, the components of the drive assembly may be of a weight that further assists moving the assembly and the attached components between the retracted position and the extended position, at least in one direction.

The drive assembly may be arranged to move the assembly between the retracted position and the extended position, in one or both directions.

In one embodiment, the drive assembly is arranged to move the assembly in the direction from the retracted position towards the extended position, with the assembly being returned in the opposite direction towards 30 the retracted position by the weight of one or more components of the assembly and/or the weight of one or more components being moved by the assembly.

In an alternative embodiment, the drive assembly is arranged to move the assembly in the direction from the extended position towards the retracted position, with the assembly being moved in the opposite direction towards the extended position by the weight of one or more components of the assembly and/or the weight of one or more components being moved by the assembly.

The drive assembly comprises a drive arm assembly having at least one drive arm. The drive arm is pivotably connected at a first position on the drive arm to an arm of the assembly, in particular one of the arms hereinbefore described, in particular one of the first arm, the second arm, the third arm, the first connecting arm, or the second connecting arm, or the fourth arm or the third connecting arm, if present.

In one embodiment, the drive arm is connected at its first position to the second arm of the assembly. The connection between the drive arm and the second arm may be at any suitable location on the second arm and is preferably between the centre of the second arm and the second position on the second arm. In this respect, the centre of the second arm is the position equidistant between the first position on the second arm and the second position on the second arm. In one embodiment, the drive arm is connected to the second arm at a position equidistant from the centre and the second position on the second arm. In an alternative embodiment, the drive arm is pivotably connected to the second arm at the second position on the second arm.

In an alternative embodiment, the drive arm is connected at its first position to the third arm of the assembly. The connection between the drive arm and the third arm may be at any suitable location on the third arm and is preferably between the centre of the third arm and the first position on the third arm. In this respect, the centre of the third arm is the position equidistant between the first position on the third arm and the said point on the third arm. In one embodiment, the drive arm is connected to the third arm at a position substantially equidistant from the centre and the first position on the third arm.

In an alternative embodiment, the drive arm is pivotably connected to the third arm at the first position on the third arm.

In some embodiments, the drive arm assembly has a single drive arm.

If a single drive arm is employed, the drive arm is connected at a second position on the drive arm to a component being moved by the assembly. The connection between the drive arm and the component being moved is preferably a pivot connection.

More preferably, the drive arm assembly comprises a plurality of drive arms. In one preferred embodiment, the drive arm assembly comprises a first drive arm and a second drive arm. Preferably, the first drive arm is pivotably connected at a first position on the first drive arm to an arm of the assembly, as described above. The first drive arm is further pivotably connected at a second position on the first drive arm to the second drive arm at a first position on the second drive arm. Preferably, the second drive arm is connected at a second position on the second drive arm to a component being moved by the assembly. The connection is preferably a pivot connection.

In embodiments in which the drive arm assembly comprises a plurality of drive arms, the drive arms may be of the same or different lengths. In many preferred embodiments, the drive arms are equal in length.

The drive assembly further comprises a drive cable connected to the 30 drive arm assembly. The cable may be connected to any suitable position on the drive arm assembly. In many preferred embodiments, the cable is connected to the drive arm. In embodiments in which the drive arm assembly comprises a single drive arm, the cable is attached to a position on the drive arm spaced apart from the first position on the drive arm. In embodiments in which the drive arm assembly comprises a plurality of drive arms, the cable may be connected to the drive arm that is pivotably connected to an arm of the assembly. For example, in embodiments in which the drive arm assembly comprises a first drive arm and a second drive arm, the cable is preferably connected to the first drive arm at a position on the first drive arm spaced apart from the first position on the first drive arm. The cable may be connected to the first drive arm at a position between the first and second positions on the first drive arm. In some preferred embodiments, the cable is connected to the first drive arm at the second position on the first drive arm, such that the cable is connected to both the first and the second drive arms.

The cable may be of any suitable material and dimensions. The material and dimensions of the cable will be determined by the load to be applied to the cable The cable is preferably substantially inelastic.

In operation, the cable is pulled, which in turn moves the drive arm to which the cable is attached, thereby moving the arms of the assembly and the components being moved by the assembly.

The drive assembly preferably further comprises one or more guide members around which the cable passes. The use of a guide member allows the direction in which the cable is pulled to be varied to better suit the assembly and the components being moved. Any suitable form for the guide member may be employed. The guide member may be formed to rotate about a pivot. In many preferred embodiments, the guide member is a pulley.

In many embodiments, a single guide member is employed. In a number of embodiments, a plurality of guide members is employed.

The guide member may be located in any suitable position relative to 5 the assembly, the drive assembly and the components being moved by the assembly.

In one embodiment, the drive assembly comprises a guide member that is fixed in relation to the first and second fixed pivots. For example, the guide member may be arranged at one of the first and second fixed pivots. In the case of a rotatable guide member, such as a pulley, the axis of rotation of the guide member is coincident with one of the first and second fixed pivots. In many preferred embodiments, the guide member, such as a pulley, is mounted to the first fixed pivot, more preferably to have an axis of rotation that is coincident with the first fixed pivot.

In an alternative embodiment, the drive assembly comprises a guide member located at a position that is spaced from both the first and second fixed pivots. The guide member may be arranged on the line joining the first and second fixed pivots. Alternatively, the position of the guide member may be to one side of the line on which the first and second fixed pivots both lie. In one embodiment, in which the arms of the assembly all move to one side of the line joining the first and second fixed pivots, the guide member is positioned on the opposite side of the line joining the first and second fixed pivots.

In an alternative embodiment, the drive assembly comprises a guide member that is moveable relative to the first and second fixed pivots. By having the guide member moveable relative to the first and second fixed pivots, the length of the cable required to move the assembly between the retracted position and the extended position can be reduced. In addition, by having the guide member moveable, the direction of the pull of the cable on the drive arm assembly can be varied. This allows the load applied to the cable to be reduced during the movement of the assembly.

In many preferred embodiments. the drive assembly comprises a guide member connected to an arm of the assembly. For example, the guide member may be connected to the first arm, the second arm, the third arm or the fourth arm, if present. In other embodiments, the guide member is connected to the first connecting arm or the second connecting arm.

The guide member may be mounted on an arm of the assembly. Alternatively, the guide member may be connected to an arm of the assembly by a guide member connecting arm, preferably pivotably mounted to the arm of the assembly, whereby movement of the arm causes the guide member connecting arm to move, in turn moving the guide member. The guide member may be connected to the first arm, second arm, third arm, first connecting arm or second connecting arm, or the fourth arm or third connecting arm if either is present.

In one preferred embodiment, the guide member is connected to the second connecting arm, more preferably to a portion of the second connecting arm extending beyond the first arm in the direction from the second arm to the first arm. In this arrangement, it is especially preferred that the guide member is mounted on the second arm at a position between the first and second fixed pivots. In this way, the guide member will travel along a path between the first and second fixed pivots as the assembly moves between the extended and retracted positions.

In another preferred embodiment, the assembly comprises a fourth arm 30 and the drive assembly comprises a guide member mounted on the fourth arm, preferably at or in the region of the point B on the fourth arm.

Alternatively, the position of the guide member may be to one side of the line on which the first and second fixed pivots both lie. In one embodiment, in which the arms of the assembly all move to one side of the line joining the first and second fixed pivots, the guide member is positioned on the opposite side of the line joining the first and second fixed pivots.

The guide member may be connected to one of the first or second fixed pivots by a guide member connecting arm, with the arm being pivotably mounted to the first or second fixed pivot. In many preferred embodiments, the guide member is pivotably connected to the first fixed pivot by a guide member connecting arm, such that the guide member can move in an arc around the first fixed pivot. In these embodiments, the guide member may also be connected by way of a guide member connecting arm to an arm of the assembly. In one embodiment, the guide member is connected to the second connecting arm by a connecting arm.

In one preferred embodiment, the guide member is connected to the first fixed pivot by a first guide member connecting arm and is connected to the second connecting arm by a second guide member connecting arm. The first guide member connecting arm is pivotably connected to the guide member and the first fixed pivot. Similarly, the second guide member connecting arm is pivotably attached to the second connecting arm and to the guide member.

As noted above, the drive assembly may comprise a plurality of guide members, around which the cable is routed. The number and position of the guide members is selected to allow the cable to apply a pulling action on the drive assembly in the most appropriate direction to move the assembly. One or more of the guide members may be fixed relative to the first and second fixed pivots. Alternatively, one or more of the guide members may be moveable relative to the first and second fixed pivots.

In one embodiment, the drive assembly comprises a first guide member and a second guide member. The first guide member may be fixed or moveable relative to the first and second fixed pivots and may be located at a position described above. The second guide member may be fixed or moveable relative to the first and second fixed pivots and may be located at a position described above, different to the position of the first guide member.

For example, the first guide member may be a fixed guide member, for example mounted at or connected to the first fixed pivot as described above, and the second guide member may be a moveable guide member mounted to an arm of the assembly. In one embodiment, the assembly comprises a fourth arm and the second guide member is mounted to the fourth arm, preferably at or adjacent to the said point on the fourth arm.

The cable may be attached to a drive system arranged to pull the cable, such as a winch powered by a motor or hand-operated. Alternatively, in many embodiments, a weight may be attached to the second end of the cable. The weight is preferably sufficient to counterbalance the weight of the drive arm assembly and the components being moved. In this way, the assembly and the components being moved can be operated with a very minor amount of force, for example by hand.

One or more arms of the assembly may extend beyond a pivotal connection and intersect with another arm of the assembly. A locking assembly may be provided at the position where the two arms intersect, to provide a means of locking the assembly in the extended position. For example, the second connecting arm may extend beyond the first arm in the direction of the line joining the first and second fixed pivots and intersect with the line joining the first and second fixed pivots, when the assembly is in the extended position. A locking assembly mounted on the component or structure providing the first and second fixed pivots at this point of intersection allows the second connecting arm to lock with the component or structure.

Similarly, the first connecting arm may extend beyond the third arm in the direction away from the line joining the first and second fixed pivots and engage with a component or structure connected to the third arm and, if present the fourth arm. Again, a locking assembly may be provided at this point of intersection to allow the assembly to be locked in the extended position. Suitable locking assemblies are as discussed above. The locking assemblies are preferably releasable, allowing the assembly to be moved from the extended position to the retracted position, as required.

It is an advantage of the assembly of present invention that it is highly scaleable and may be constructed and applied at a wide range of scales to convert motion, as described hereinbefore.

The assembly of the present invention finds wide applications and uses, in particular by allowing relative movement between a first component and a second component.

Accordingly, in a further aspect, the present invention provides an assembly comprising a first component and a second component, the first component being arranged for movement with respect to the second component, wherein an assembly as hereinbefore described is provided between the first component and second component, operation of the assembly providing movement of the first component with respect to the second component.

One of the first and second components is preferably connected to the third arm of the assembly and, optionally to the fourth arm in embodiments having a fourth arm. The other of the first and second components provides the first and second fixed pivot points to which the first and second arms are pivotally connected. In this way, movement of the first component with respect to the second component is effected by use of the drive assembly.

In many applications, a plurality of assemblies of the present invention is employed. In particular, a plurality of assemblies may be employed in a spaced apart relationship on opposing sides of an object to be moved. For example, a first and second assembly may be provided on opposing sides of an object to be moved with the third arms of two assemblies connected to opposing sides of the object.

Applications of the assembly of the present invention to convert rotational motion to linear motion include the support and movement of building structures relative to one another.

Accordingly, the present invention further provides a building comprising: a first building portion and a second building portion, the first building portion being moveable relative to the second building portion between a retracted position and an extended position; wherein relative movement between the first and the second building portions and support of one of the first and second building portions with respect to the other of the first and second building portions are provided by an assembly as hereinbefore described.

The first building portion may be any structure or part of a building, in particular a fixed structure, such as a house, apartment or office building, or a mobile building structure, such as a mobile house, caravan or the like. The second building structure may be any structure or component of the installation that is required to be moved relative to the first building portion between the retracted and extended positions. Examples of such structures include balconies, walls, floor extensions, roof extensions, canopies and the like.

The principles and operation of the assembly of the present invention will be further explained by reference to the accompanying figures, in which: Figure 1 is a diagrammatical representation of an assembly according to a first embodiment of the present invention in an extended position; Figure 2a is a diagrammatical representation of the assembly of Figure 1 in a first partially retracted position; Figure 2b is a diagrammatical representation of the assembly of Figure 1 in a second partially retracted position; Figure 2c is a diagrammatical representation of the assembly of Figure 1 in a third partially retracted position; Figure 2d is a diagrammatical representation of the assembly of Figure 1 in a retracted position; Figure 3 is a diagrammatical representation of an assembly according to a second embodiment of the present invention in an extended position; Figure 4 is a diagrammatical representation of an assembly according to a third embodiment of the present invention in an extended position; Figure 5 is a diagrammatical representation of an assembly according to a fourth embodiment of the present invention in an extended position; Figure 6a is a diagrammatical representation of the assembly of Figure 5 in a first partially retracted position; Figure 6b is a diagrammatical representation of the assembly of Figure 5 in a second partially retracted position, Figure 6c is a diagrammatical representation of the assembly of Figure in a third partially retracted position; Figure 6d is a diagrammatical representation of the assembly of Figure 5 in a retracted position; Figure 7 is a diagrammatical representation of an assembly according to a fifth embodiment of the present invention in an extended position; Figure 8 is a diagrammatical representation of an assembly according to a sixth embodiment of the present invention in an extended position; Figure 9a is a diagrammatical representation of the assembly of Figure 8 in a first partially retracted position, Figure 9b is a diagrammatical representation of the assembly of Figure 8 in a second partially retracted position; Figure 9c is a diagrammatical representation of the assembly of Figure 8 in a third partially retracted position; Figure 9d is a diagrammatical representation of the assembly of Figure 8 in a retracted position; Figure 10 is a diagrammatical representation of an assembly according to a seventh embodiment of the present invention in an extended position; Figure 11 is a diagrammatical representation of an assembly according to an eighth embodiment of the present invention in an extended position; Figure 12a is a diagrammatical representation of the assembly of Figure 11 in a first partially retracted position; Figure 12b is a diagrammatical representation of the assembly of Figure 11 in a second partially retracted position; Figure 12c is a diagrammatical representation of the assembly of Figure 11 in a third partially retracted position; and Figure 12d is a diagrammatical representation of the assembly of Figure 11 in a retracted position.

Turning to Figure 1, there is shown a diagrammatical representation of an assembly of one embodiment of the present invention, generally indicated as 2. The assembly 2 is shown mounted to a fixed structure at a first fixed pivot 4 and a second fixed pivot 6. The fixed pivots 4, 6 are spaced apart and are fixed in relation to one another. In the embodiment shown, the line joining the first and second fixed pivots 4, 6 is arranged vertically, with the first fixed pivot 4 above the second fixed pivot 6. However, the assembly 2 may have other orientations. In particular, the line joining the first and second fixed pivots 4, 6 may be arranged vertically with the second fixed pivot 6 above the first fixed pivot 4. Other orientations are also possible, such as with the first and second fixed pivots 4, 6 arranged other than vertically.

The fixed pivots 4, 6 are provided in a component or structure, which can be considered to be fixed and with movement of the components of the assembly 2 being relative to this component or structure. For the purposes of illustration only, the fixed pivots 4, 6 are shown in Figure 1 provided on a fixed component 3.

A first arm 8 is pivotally connected at a first position at one end of the first arm to the first fixed pivot 4. A second arm 10 is pivotally connected at a first position on the second arm at one end to the second fixed pivot 6. A third arm 12 is connected at a first position at one end of the third arm by a pivot connection 14 at a second position at the second end of the second arm 10. The third arm 12 has a point A thereon that moves in a substantially straight line perpendicular to the line joining the first and second fixed pivots 4, 6, as the assembly 2 moves between the extended position and its retracted position.

A first connecting arm 16 is connected at one end by a pivot connection 18 at a second position at the second end of the first arm 8. The second end of the first connecting arm 16 is connected by a pivot connection 20 to the third arm 12 spaced from the pivot connection 14.

A second connecting arm 22 is connected at one end by a pivot connection 24 to the first arm at a third position on the first arm 8 spaced apart from both the first and second positions on the first arm. The second end of the second connecting arm 22 is mounted to the pivot connection 14, such that the second connecting arm 22 is pivotally connected at the connection 14 to both the second arm 10 and the third arm 12.

The pivot connections may be formed by any suitable means, for example by pins extending through holes in one or both of the arms being pivotally joined.

A component assembly to be supported and moved by the assembly 2 is generally indicated as 30 in Figure 1 and comprises a first component member 32 pivotally connected to the second fixed pivot 6 and a second component member 34 pivotally connected to the third arm 12 at the point A on the third arm. The first and second component members 32, 34 are pivotally connected to each other by a pivot connection 36.

The assembly 2 of Figure 1 further comprises a drive assembly, generally indicated as 40. The drive assembly 40 comprises a drive arm assembly 42 comprising a first drive arm 44 and a second drive arm 46. The first drive arm 44 is pivotably connected at a first position at one end to the third arm 12 by a pivot connection 48. The second end of the first drive arm 44 is connected to one end of the second drive arm 46 by a pivot connection 50. The second end of the second drive arm 46 is pivotably connected to both the first and second component members 32, 34 by way of the pivot connection 36.

The drive assembly 40 further comprises a guide member in the form of a pulley 52. The pulley 52 is fixed in relation to the first and second fixed pivots and is mounted to rotate about the first fixed pivot 4. A cable 54 is connected at one end to the pivot connection 50 between the first and second drive arms 44, 46. In this way the cable 54 is attached to both the first and second drive arms 44, 46. The cable 54 extends around the pulley 52 as shown in Figure 1.

In operation, the cable is pulled at its second end in the direction of the arrow 56 in Figure 1. This action causes the assembly 2 to move from the extended position shown in Figure 1 to the retracted position.

Turning now to Figures 2a to 2d, there is shown a sequence of representations of the assembly of Figure 1 in positions between a partially extended position, shown in Figure 2a, and a retracted position shown in Figure 2d. The components of the assembly of Figures 2a to 2d have been identified using the same reference numerals as used in relation to Figure 1 and discussed above.

The assembly 2 is shown in Figure 2a in a first partially retracted position, with the assembly 2 having moved out of the extended position of Figure 1 towards a retracted position. As can be seen in Figures 2a to 2d, the movement of the components of the assembly is all to one side of the line joining the first and second fixed pivots 4, 6. In the movement from the position of Figure 1 to the position of Figure 2a, the point A at the end of the third arm 12 is following a substantially straight line.

Figure 2b shows the assembly 2 in a second partially retracted position. Again, the point A on the third arm 12 is tracing a substantially straight line from its position in the extended position of Figure 1.

Similarly, Figure 2c shows the assembly 2 in a third partially retracted position, with the third arm 12 moved further towards the fixed pivots 4, 6 and the point A on the third arm 12 still following a straight line path.

Referring to Figure 2d, the assembly 2 is shown in a retracted position. The arms of the assembly are formed to lie within one another when in the retracted position of Figure 2d, in particular with the arms having appropriate flat, 'L-shaped and 'U-shaped forms at portions along their lengths. In this way, the assembly 2 occupies the minimum amount of space when in the retracted position As an alternative to pulling the cable, if a weight is applied to the second end of the cable 54 to counterbalance the weight of the component assembly 30, the assembly 2 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 3, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 102. The assembly 102 has the same general configuration as the assembly 2 of Figure 1. Components of the assembly of Figure 3 that are common to the assembly of Figure 1 are indicated using the same references and are as discussed above. The differences between the assembly of Figure 3 and the assembly of Figure 1 are as follows: As with the assembly of Figure 1, the assembly 102 of Figure 3 comprises a drive assembly having a guide member in the form of a pulley 104. In this embodiment, the pulley 104 is moveable with respect to the first and second fixed pivots 4, 6. The pulley 104 is mounted to the first arm 8, in particular to the pivot connection 24 between the first arm 8 and the second connecting arm 22. The pulley 104 is arranged to rotate about an axis that coincides with the axis of the pivot connection 24.

A cable 106 is connected at one end to the pivot connection 50 between the first and second drive arms 44, 46 and extends around the pulley 104.

In operation, a load is applied to pull the cable in the direction of the arrow 108 of Figure 3, which moves the assembly 102 out of the extended position shown in Figure 3 towards a retracted position. The pattern of movement of the assembly is analogous to that shown in Figures 2a to 2d.

The arrangement of the assembly 102 of Figure 3 provides the advantage that the length of the cable 106 is relatively short and the distance the cable needs to be pulled is low.

Again, as an alternative to pulling the cable, if a weight is applied to the second end of the cable 106 to counterbalance the weight of the component assembly 30, the assembly 102 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 4, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 202. The assembly 202 has the same general configuration as the assembly 2 of Figure 1. Components of the assembly of Figure 4 that are common to the assembly of Figure 1 are indicated using the same references and are as discussed above. The differences between the assembly of Figure 4 and the assembly of Figure 1 are as follows: As with the assembly of Figure 1, the assembly 202 of Figure 4 comprises a drive assembly having a first guide member in the form of a pulley 52 mounted at the first fixed pivot 4, as described above. However, in this embodiment, the drive assembly comprises a second guide member in the form of a pulley 204. The pulley 204 is moveable with respect to the first and second fixed pivots 4, 6. The pulley 204 is mounted to the second arm 10, in particular to the pivot connection 14 between the second arm 10 and the third arm 12. The pulley 204 is arranged to rotate about an axis that coincides with the axis of the pivot connection 14.

A cable 206 is connected at one end to the pivot connection 50 between the first and second drive arms 44, 46 and extends first around the pulley 204 and then around the pulley 52.

In operation, a load is applied to pull the cable in the direction of the arrow 208 of Figure 4, which moves the assembly 202 out of the extended position shown in Figure 4 towards a retracted position. The pattern of movement of the assembly is analogous to that shown in Figures 2a to 2d.

Again, as an alternative to pulling the cable, if a weight is applied to the second end of the cable 206 to counterbalance the weight of the component assembly 30, the assembly 202 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 5, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 302. The assembly 302 is shown mounted to a fixed structure at a first fixed pivot 304 and a second fixed pivot 306. The fixed pivots 304, 306 are spaced apart and are fixed in relation to one another. In the embodiment shown, the line joining the first and second fixed pivots 304, 306 is arranged vertically, with the first fixed pivot 304 above the second fixed pivot 306. However, the assembly 302 may have other orientations. In particular, the line joining the first and second fixed pivots 304, 306 may be arranged vertically with the second fixed pivot 306 above the first fixed pivot 304. Other orientations are also possible, such as with the first and second fixed pivots 304, 306 arranged other than vertically.

The fixed pivots 304, 306 are provided in a component or structure, which can be considered to be fixed and with movement of the components of the assembly 302 being relative to this component or structure. For the purposes of illustration only, the fixed pivots 304, 306 are shown in Figure 5 provided on a fixed component 303.

A first arm 308 is pivotally connected at a first position at one end of the first arm to the first fixed pivot 304. A second arm 310 is pivotally connected at a first position on the second arm at one end to the second fixed pivot 306.

A third arm 312 is connected at a first position at one end of the third arm by a pivot connection 314 at a second position at the second end of the second arm 310. The third arm 312 has a point A thereon that moves in a substantially straight line perpendicular to the line joining the first and second fixed pivots 304, 306, as the assembly 302 moves between the extended position and its retracted position.

A first connecting arm 316 is connected at one end by a pivot connection 318 at a second position at the second end of the first arm 308.

The second end of the first connecting arm 316 is connected by a pivot connection 320 to the third arm 312 spaced from the pivot connection 314. The first connecting arm 316 extends beyond the pivot connection 320 and the third arm 312 away from the first and second fixed pivots 304, 306, as can be seen in Figure 5.

A second connecting arm 322 is connected at one end by a pivot connection 324 to the first arm 308 at a third position on the first arm 308 spaced apart from both the first and second positions on the first arm 308. The second end of the second connecting arm 322 is mounted to the pivot connection 314, such that the second connecting arm 322 is pivotally connected at the connection 314 to both the second arm 310 and the third arm 312. The second connecting arm 322 extends beyond the pivot connection 324 and the first arm 308 in the direction towards the first and second fixed pivots 304, 306 and the member 303.

The assembly 302 of Figure 5 further comprises a fourth arm 326. The fourth arm 326 is pivotably connected at one end to the pivot connection 318 between the first arm 308 and the first connecting arm 316. The fourth arm 326 has a point B thereon that moves in a substantially straight line perpendicular to the line joining the first and second fixed pivots 304, 306, as the assembly 302 moves between the extended position and its retracted position, in an analogous manner to the movement of the point A on the third arm 312, described above.

The third arm 312 and the fourth arm 326 of the assembly 302 may be connected to a component or structure to be moved relative to the first and second fixed pivots. In particular, a component or structure can be pivotably connected to the points A and B on the third arm 312 and the fourth arm 326. In this way, the component or structure can be moved in a substantially straight line extending perpendicular to the line joining the first and second fixed pivots 304, 306. For the purposes of illustration only, the points A and B in the assembly 302 are shown in Figure 5 to be pivotably connected to a moveable component 330.

The moveable component 330 may be an arm extending between the third and fourth arms 312, 326, for example connected to the points A and B on the third and fourth arms 312, 326.

The moveable component 330 may provide the first and second fixed pivots for another assembly, for example an assembly of the kind described above and shown in the accompanying figures, which assembly would function in an analogous manner to that described herein.

In the assembly of the embodiment of Figure 5, in the extended position shown, the first connecting arm 316 extends from the first arm 8 to the pivot connection 320 with the third arm 312 and further beyond the third arm 312 to the moveable component 330. A locking assembly (not shown for clarity) may be provided to lock the distal end of the first connecting arm 316 with the moveable component 330 in the extended position.

Similarly, as noted above, the second connecting arm 322 extends from the second arm 310 to the pivot connection 324 with the first arm 308 and further beyond the first arm 308 to the component 303 providing the first and second fixed pivots 304, 306. A locking assembly (not shown for clarity) may be provided to lock the proximal end of the second connecting arm 322 with the component 303 in the extended position.

A component assembly to be supported and moved by the assembly 302 is generally indicated as 340 in Figure 5 and comprises a first component member 342 pivotally connected to the second fixed pivot 306 and a second component member 344 pivotally connected to the third arm 312 at the point A on the third arm. The first and second component members 342, 344 are pivotally connected to each other by a pivot connection 346.

The assembly 302 of Figure 5 further comprises a drive assembly, generally indicated as 350. The drive assembly 350 comprises a drive arm assembly 352 comprising a first drive arm 354 and a second drive arm 356.

The first drive arm 354 is pivotably connected at a first position at one end to the second arm 310 by a pivot connection 358. The second end of the first drive arm 354 is connected to one end of the second drive arm 356 by a pivot connection 360. The second end of the second drive arm 356 is pivotably connected to both the first and second component members 342, 344 by way of the pivot connection 346.

The drive assembly 350 further comprises a first guide member in the form of a first pulley 362. The first pulley 362 is fixed in relation to the first and second fixed pivots and is mounted to rotate about the first fixed pivot 304. The drive assembly further comprises a second guide member in the form of a second pulley 364. The second pulley 364 is mounted to rotate about the pivot connection 314 between the second arm 310 and the third arm 312.

A cable 366 is connected at one end to the pivot connection 360 between the first and second drive arms 354, 356. In this way the cable 366 is attached to both the first and second drive arms 354, 356. The cable 366 extends around the second pulley 364 and the first pulley 362 as shown in Figure 5.

In operation, the cable 366 is pulled at its second end in the direction of 20 the arrow 368 in Figure 5. This action causes the assembly 302 to move from the extended position shown in Figure 5 towards the retracted position.

Again, as an alternative to pulling the cable, if a weight is applied to the second end of the cable 366 to counterbalance the weight of the component assembly 340, the assembly 302 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning now to Figures 6a to 6d, there is shown a sequence of representations of the assembly of Figure 5 in positions between a partially extended position, shown in Figure 6a, and a retracted position shown in Figure 6d. The components of the assembly of Figures 6a to 6d have been identified using the same reference numerals as used in relation to Figure 5 and discussed above.

The assembly 302 is shown in Figure 6a in a first partially retracted position, with the assembly 302 having moved out of the extended position of Figure 5 towards a retracted position. As can be seen in Figures 6a to 6d, the movement of the components of the assembly is all to one side of the line joining the first and second fixed pivots 304, 306. In the movement from the position of Figure 5 to the position of Figure 6a, the point A at the end of the third arm 312 and the point B on the fourth arm 326 are each following a substantially straight line.

Figure 6b shows the assembly 302 in a second partially retracted position. Again, the points A and B on the third arm 312 and the fourth arm 326 are each tracing a substantially straight line from the position in the extended position of Figure 5.

Similarly, Figure 6c shows the assembly 302 in a third partially retracted position, with the third arm 312 and the fourth arm 326 moved further towards the fixed pivots 304, 306 and the points A and B each still following a straight line path.

Referring to Figure 6d, the assembly 302 is shown in a retracted position. The arms of the assembly are formed to lie within one another when in the retracted position of Figure 6d, in particular with the arms having appropriate flat, L'-shaped and 'U-shaped forms at portions along their lengths. In this way, the assembly 302 occupies the minimum amount of space when in the retracted position.

As an alternative to pulling the cable, if a weight is applied to the second end of the cable 366 to counterbalance the weight of the component assembly 340, the assembly 302 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 7, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 402. The assembly 402 has the same general configuration as the assembly 302 of Figure 5. Components of the assembly of Figure 7 that are common to the assembly of Figure 5 are indicated using the same references and are as discussed above. The differences between the assembly of Figure 7 and the assembly of Figure 5 are as follows: The assembly 402 of Figure 7 comprises a drive assembly 404. The drive assembly comprises a drive arm assembly 352 having first and second drive arms 354, 356 as in the assembly shown in Figure 5. In the embodiment of Figure 7, the drive assembly comprises a first guide member in the form of a first pulley 406. The first pulley 406 is moveable in relation to the first and second fixed pivots 304, 306 and is mounted to rotate about the pivot connection 314 between the second arm 310 and the third arm 312. The drive assembly further comprises a second guide member in the form of a second pulley 408. The second pulley 408 is mounted to the second connecting arm 322 at the proximal end portion of the connecting arm 322.

A cable 410 is connected at one end to the pivot connection 360 between the first and second drive arms 354, 356. In this way the cable 410 is attached to both the first and second drive arms 354, 356. The cable 410 extends around the first pulley 406 and the second pulley 408 as shown in Figure 7.

In operation, the cable 410 is pulled at its second end in the direction of the arrow 412 in Figure 7. This action causes the assembly 402 to move from the extended position shown in Figure 7 towards the retracted position. As the assembly 402 moves towards the retracted position, the second pulley 408 moves in the direction away from the first fixed pivot 304 towards the second fixed pivot 306, that is downwards as viewed in Figure 7. This motion of the second pulley 408 reduces the length of the cable 410 required to move the assembly towards the retracted position.

The movement of the assembly towards the retracted position is analogous to that shown in Figures 6a to 6d.

Again, as an alternative to pulling the cable, if a weight is applied to the second end of the cable 410 to counterbalance the weight of the component assembly 340, the assembly 402 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 8, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 502. The assembly 502 has the same general configuration as the assembly 302 of Figure 5. Components of the assembly of Figure 8 that are common to the assembly of Figure 5 are indicated using the same references and are as discussed above. The differences between the assembly of Figure 8 and the assembly of Figure 5 are as follows: The assembly 502 of Figure 8 comprises a drive assembly 504 30 comprising a drive arm assembly 506. The drive arm assembly 506 comprises a first drive arm 508 and a second drive arm 510. The first drive arm 508 is pivotably connected at a first position at one end to the second arm 310 and the third arm 312 at the pivot connection 314. The second end of the first drive arm 508 is connected to one end of the second drive arm 510 by a pivot connection 512. The second end of the second drive arm 510 is pivotably connected to both the first and second component members 342, 344 by way of the pivot connection 346.

The drive assembly 504 further comprises a guide member in the form of a pulley 520. The pulley 520 is rotatably mounted by way of guide member connecting arms 522a, 522b. The first guide member connecting arm 522a is pivotally mounted to the first fixed pivot 304. The second guide member connecting arm 522b is pivotably mounted to the distal end of the second connecting arm 322. As a result, the pulley 520 moves relative to the first and second fixed pivots 304, 306 as the second connecting arm 322 moves.

The drive assembly 504 further comprises a cable 524. The cable 524 is connected at one end to the pivot connection 512 between the first and second drive arms 508, 510. In this way the cable 524 is attached to both the first and second drive arms 508, 510. The cable 524 extends around the pulley 520 as shown in Figure 8.

In operation, the cable 524 is pulled at its second end in the direction of the arrow 526 in Figure 8. This action causes the assembly 502 to move from the extended position shown in Figure 8 towards the retracted position.

Turning now to Figures 9a to 9d, there is shown a sequence of representations of the assembly of Figure 8 in positions between a partially extended position, shown in Figure 9a, and a retracted position shown in Figure 9d. The components of the assembly of Figures 9a to 9d have been identified using the same reference numerals as used in relation to Figure 8 and discussed above.

The assembly 502 is shown in Figure 9a in a first partially retracted position, with the assembly 502 having moved out of the extended position of Figure 8 towards a retracted position. As can be seen in Figures 9a to 9d, the movement of the components of the assembly is all to one side of the line joining the first and second fixed pivots 304, 306. In the movement from the position of Figure 8 to the position of Figure 9a, the point A at the end of the third arm 312 and the point B on the fourth arm 326 are each following a substantially straight line. As can also be seen, the pulley 520 is moving in an arc generally towards the second fixed pivot 306 under the action of the second connecting arm 322 moving.

Figure 9b shows the assembly 502 in a second partially retracted position. Again, the points A and B each tracing a substantially straight line from its position in the extended position of Figure 8.

Similarly, Figure 9c shows the assembly 502 in a third partially retracted position, with the third arm 312 and the fourth arm 326 moved further towards the fixed pivots 304, 306 and the points A and B each still following a straight line path.

Referring to Figure 9d, the assembly 502 is shown in a retracted position. The arms of the assembly are formed to lie within one another when in the retracted position of Figure 9d, in particular with the arms having appropriate flat, L'-shaped and 'U-shaped forms at portions along their lengths. In this way, the assembly 502 occupies the minimum amount of space when in the retracted position. As can be seen, the pulley 520 has moved towards the second fixed pivot 306 and inwards towards the line joining the first and second fixed pivots 304, 306.

Again, as an alternative to pulling the cable, if a weight is applied to the second end of the cable 524 to counterbalance the weight of the component assembly 340, the assembly 502 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 10, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 602. The assembly 602 has the same general configuration as the assembly 302 of Figure 5. Components of the assembly of Figure 10 that are common to the assembly of Figure 5 are indicated using the same references and are as discussed above. The differences between the assembly of Figure 10 and the assembly of Figure 5 are as follows: The assembly 602 of Figure 10 comprises a drive assembly 604 comprising a drive arm assembly 606. The drive arm assembly 606 comprises a first drive arm 608 and a second drive arm 610. The first drive arm 608 is pivotably connected at a first position at one end to the second arm 310 and the third arm 312 at the pivot connection 314. The second end of the first drive arm 608 is connected to one end of the second drive arm 610 by a pivot connection 612. The second end of the second drive arm 610 is pivotably connected to both the first and second component members 342, 344 by way of the pivot connection 346.

The drive assembly 604 further comprises a guide member in the form of a pulley 620. The pulley 620 is rotatably mounted in a fixed position relative to the first and second fixed pivots 304, 306 by way of guide member connecting arms 622a, 622b both extending from the fixed component 303 in the region of the first fixed pivot 304.

The drive assembly 604 further comprises a cable 624. The cable 624 is connected at one end to the pivot connection 612 between the first and second drive arms 608, 610. In this way the cable 624 is attached to both the first and second drive arms 608, 610. The cable 624 extends around the pulley 620 as shown in Figure 10.

In operation, the cable 624 is pulled at its second end in the direction of the arrow 626 in Figure 10. This action causes the assembly 602 to move from the extended position shown in Figure 10 towards the retracted position.

The movement of the assembly towards the retracted position is analogous to that shown in Figures 9a to 9d.

Again, as an alternative to pulling the cable, if a weight is applied to the second end of the cable 624 to counterbalance the weight of the component assembly 340, the assembly 602 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand.

Turning to Figure 11, there is shown a diagrammatical representation of an assembly of a further embodiment of the present invention, generally indicated as 702. The assembly 702 has the same general configuration as the assembly 302 of Figure 5. Components of the assembly of Figure 11 that are common to the assembly of Figure 5 are indicated using the same references and are as discussed above. The differences between the assembly of Figure 11 and the assembly of Figure 5 are as follows: The assembly 702 of Figure 11 comprises a drive assembly 704 comprising a drive arm assembly 706. The drive arm assembly 706 comprises a first drive arm 708 and a second drive arm 710. The first drive arm 708 is pivotably connected at a first position at one end to the second arm 310 and the third arm 312 at the pivot connection 314. The second end of the first drive arm 708 is connected to one end of the second drive arm 710 by a pivot connection 712. The second end of the second drive arm 710 is pivotably connected to both the first and second component members 342, 344 by way of the pivot connection 346.

The drive assembly 704 further comprises a first guide member in the form of a first pulley 720. The first pulley 720 is rotatably mounted to the first fixed pivot 304. The first pulley 720 is fixed in relation to the position of the first and second fixed pivots 304, 306.

The drive assembly 704 comprises a second guide member in the form of a second pulley 722. The second pulley 722 is rotatably mounted to the fourth arm 326 at the point B on the arm. The second pulley 722 is moveable relative to the positions of the first and second fixed pivots 304, 306.

The drive assembly 704 further comprises a cable 724. The cable 724 is connected at one end to the pivot connection 712 between the first and second drive arms 708, 710. In this way the cable 724 is attached to both the first and second drive arms 708, 710. The cable 724 extends around the second pulley 722 and the first pulley 720 as shown in Figure 11.

In operation, the cable 724 is pulled at its second end in the direction of the arrow 726 in Figure 11. This action causes the assembly 702 to move from the extended position shown in Figure 11 towards the retracted position.

Turning now to Figures 12a to 12d, there is shown a sequence of representations of the assembly of Figure 11 in positions between a partially extended position, shown in Figure 11a, and a retracted position shown in Figure 11 d. The components of the assembly of Figures lla to 11d have been identified using the same reference numerals as used in relation to Figure 11 and discussed above The assembly 702 is shown in Figure lia in a first partially retracted position, with the assembly 702 having moved out of the extended position of Figure 11 towards a retracted position. As can be seen in Figures lla to 11d, the movement of the components of the assembly is all to one side of the line joining the first and second fixed pivots 304, 306. In the movement from the position of Figure 11 to the position of Figure 12a, the point A at the end of the third arm 312 and the point B on the fourth arm 326 are each following a substantially straight line.

Figure llb shows the assembly 702 in a second partially retracted position. Again, the points A and B each tracing a substantially straight line from its position in the extended position of Figure 11.

Similarly, Figure 11c shows the assembly 702 in a third partially retracted position, with the third arm 312 and the fourth arm 326 moved further towards the fixed pivots 304, 306 and the points A and B each still following a straight line path.

Referring to Figure 11 d, the assembly 502 is shown in a retracted position. The arms of the assembly are formed to lie within one another when in the retracted position of Figure 11d, in particular with the arms having appropriate flat, L'-shaped and 'U-shaped forms at portions along their lengths. In this way, the assembly 702 occupies the minimum amount of space when in the retracted position.

Again, as an alternative to pulling the cable, if a weight is applied to the 30 second end of the cable 724 to counterbalance the weight of the component assembly 340, the assembly 702 may be moved between the retracted position and the extended position with minimal force. Such a force can be applied to any of the arms of the assembly, for example by hand The number and position of the drive arms in the drive assemblies of the embodiments shown in the figures are just examples. While a drive arm assembly having first and second drive arms is particularly advantageous, this is just one embodiment. Drive arm assemblies having just one drive arm or three or more drive arms may also be employed.

Similarly, the number and position of the guide members of the drive assemblies of the embodiments shown in the figures are just examples. The number and position of the guide members may be varied. For example, the arrangement of the guide members shown in the accompanying figures may be interchanged or combined.

Claims

CLAIMSAn assembly for converting motion, the assembly comprising: a first arm rotatable at a first position on the first arm about a first fixed pivot; a second arm rotatable at a first position on the second arm about a second fixed pivot, the second fixed pivot spaced apart from the first fixed pivot; a third arm pivotably connected at a first position on the third arm to the 10 second arm at a second position on the second arm, the second position on the second arm spaced apart from the first position on the second arm; a first connecting arm extending between the first arm and the third arm, the first connecting arm pivotably connected to a second position on the first arm spaced apart from the first position on the first arm and pivotably connected to the third arm at a second position on the third arm spaced apart from the first position on the third arm; a second connecting arm extending between the first arm and the second arm, the second connecting arm pivotably connected to a third position on the first arm spaced apart from the first position on the first arm and pivotably connected to a third position on the second arm spaced apart from the first position on the second arm; a drive assembly comprising: a drive arm assembly connected to a component being moved by the assembly, the drive arm assembly comprising at least one drive arm, the drive arm pivotably connected at a first position on the drive arm to an arm of the assembly; and a drive cable connected to the drive arm assembly.
2. The assembly according to claim 1, wherein the first position on the first arm is at or adjacent an end of the first arm and/or the second position on the first arm is at or adjacent an end of the first arm.
3. The assembly according to either of claims 1 or 2, wherein the first position on the second arm is at or adjacent an end of the second arm and/or the second position on the second arm is at or adjacent an end of the second arm and/or wherein the first position on the third arm is at or adjacent an end of the third arm.
4. The assembly according to any preceding claim, wherein the length of the first arm is no greater than the distance between the first and second fixed pivots and/or the length of the second arm is no greater than the distance between the first and second fixed pivots.
5. The assembly according to any preceding claim, wherein the length of the first and second arms is substantially the same.
6. The assembly according to any preceding claim, wherein the lengths of the first, second and third arms are substantially the same.
7. The assembly according to any preceding claim, further comprising a fourth arm, the fourth arm pivotably connected at a first position on the fourth arm to the first arm at a third position on the first arm.
8. The assembly according to claim 7, wherein the third position on the first arm coincides with the second position, such that the fourth arm is also pivotably connected to the first connecting arm.
9. The assembly according to any preceding claim, wherein the drive assembly is arranged to move the assembly in the direction from the retracted 59 position towards the extended position, with the assembly being returned in the opposite direction towards the retracted position by the weight of one or more components of the assembly and/or the weight of one or more components being moved by the assembly; or wherein the drive assembly is arranged to move the assembly in the direction from the extended position towards the retracted position, with the assembly being moved in the opposite direction towards the extended position by the weight of one or more components of the assembly and/or the weight of one or more components being moved by the assembly.
10. The assembly according to any preceding claim, wherein the drive arm assembly comprises a first drive arm, the first drive arm pivotably connected at a first position on the first drive arm to the second arm or the third arm of the assembly.
11. The assembly according to any preceding claim, wherein the drive arm assembly comprises a first drive arm and a second drive arm.
12. The assembly according to claim 11, wherein the first drive arm is pivotably connected at a first position on the drive arm to an arm of the assembly, the second drive arm is pivotably connected at a first position on the second drive arm to the component being moved, and the first drive arm is pivotably connected at a second position on the first drive arm to the second drive arm at a second position on the second drive arm.
13. The assembly according to either of claims 11 or 12, wherein the first and second drive arms are equal in length.
14. The assembly according to any preceding claim, wherein the drive 30 assembly further comprises a guide member.
15. The assembly according to claim 14, wherein the guide member is rotatable.
16. The assembly according to either of claims 14 or 15, wherein the position of the guide member is fixed in relation to the first and second fixed pivots.
17. The assembly according to claim 16, wherein the guide member is rotatable and has its axis of rotation coincident with one of the first fixed pivot or the second fixed pivot.
18. The assembly according to either of claims 14 or 15, wherein the position of the guide member is moveable in relation to the first and second fixed pivots.
19. The assembly according to claim 18, wherein the guide member is connected to an arm of the assembly.
20. The assembly according to either of claims 18 or 19, wherein the guide member is connected to either the first fixed pivot or the second fixed pivot by a guide member connecting arm, such that the guide member is moveable in an arc about the fixed pivot.
21. The assembly according to claim 20, wherein the guide member is 25 connected to an arm of the assembly by a further guide member connecting arm.
22. The assembly according to claim 19, wherein the guide member is mounted on an arm of the assembly.
23. The assembly according to any of claims 14 to 22, wherein the drive assembly comprises a plurality of guide members.
24. The assembly according to claim 23, wherein the position of one or more of the guide members relative to the first and second fixed pivots is fixed.
25. The assembly according to either of claims 23 or 24, wherein the position of the one or more of the guide members relative to the first and second fixed pivots is moveable.
26. The assembly according to any preceding claim, wherein a weight is provided on an end of the cable, the weight at least partially counterbalancing the weight of the component being moved.
27. An assembly comprising a first component and a second component, the first component being arranged for movement with respect to the second component, wherein an assembly for converting motion according to any preceding claim is provided between the first component and the second component, operation of the assembly providing movement of the first component with respect to the second component.
28. The assembly according to claim 27 wherein the first component is moveable in a liner motion with respect to the second component between a retracted position and an extended position.
29. The assembly according to either of claims 27 or 28, wherein the first component and the second component are components of a building.