GB2465172A

GB2465172A - Chair moving mechanism comprising wheels

Info

Publication number: GB2465172A
Application number: GB0820354A
Authority: GB
Inventors: Christopher Alcock
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-06
Filing date: 2008-11-06
Publication date: 2010-05-12
Anticipated expiration: 2028-11-06
Also published as: GB2465172B; GB2465042A; GB0912516D0; GB0820354D0

Abstract

A chair moving mechanism comprises at least two levers 6a-6d, each of which is rotatably connected to a different chair leg 2 about a pivot point 8 and has a wheel 14. The levers are interconnected, and rotation of the levers causes the wheels to move from a first position (Fig. 1A) to a second position (Fig. 2A). The mechanism may comprise four levers interconnected such that rotation of any one of the levers causes all four levers to rotate simultaneously, causing the wheels to extend below the end of the leg to lift the legs off the ground. The levers connected to rear legs may be interconnected by a pedal bar 16, and may be connected to respective front legs by connector bars 18, 20. The levers may be biased into a position wherein the wheels are retracted.

Description

MECHANISM FOR MOVING CHAIRS

The present invention relates to a wheeled mechanism which may be selectively deployed so as to assist in moving a chair. The present invention also relates to a chair comprising a wheeled moving mechanism.

A number of different types of devices for assisting in moving chairs are known. In particular, chair moving devices are known which deploy wheels in order to lift two chair legs off the ground. However, such devices have been found to be of little use when it is desired to move the chair in more than one direction. There remains a need for a chair moving mechanism which is simple, reliable and convenient to use.

The present invention provides a chair comprising a chair moving mechanism. The chair moving mechanism has four levers, each of which is rotatably connected to a different chair leg about a pivot point and comprises a wheel. The four levers are interconnected such that, in use, rotation of any one of the levers about its pivot point causes all four of the levers to rotate about their respective pivot points and such that the wheels move from positions wherein said chair legs contact the ground to positions wherein said four chair legs are lifted off the ground by the wheels.

The present invention provides a simple, reliable and effective way of lifting chair legs off the ground and deploying wheels in their place. This is of particular benefit in moving the chair, for example, whilst a person still occupies the chair. Once the chair has been moved to its desired position the chair moving mechanism can be returned to its original position such that the wheels are retracted and the chair legs contact the ground once again.

According to the preferred embodiments, each lever is rotatably connected to a chair leg at a first end and is coupled to at least one other lever at its second end. Movement of the second end of each lever about its pivot point and preferably towards the ground deploys the wheels beneath the chair legs.

The mechanism is preferably provided with pivot members for allowing the levers to rotate about their respective pivot points. The pivot members are configured to engage the levers with the chair legs in a manner whereby the levers can rotate relative to the chair legs about the pivot points. Preferably, the pivot members comprise a hole through the lever and preferably a screw, bolt or nail for connecting the lever to the chair leg through the hole. However, the pivot members may comprise any other means of providing the rotatable connection between the levers and the chair legs. Preferably, the locations of the pivot points are substantially adjacent to the free ends of the chair legs and are preferably in a fixed position relative to the chair legs.

The distance between the pivot point on each lever and the free end of the chair leg to which the lever is connected is preferably smaller than the distance between the pivot point and the axis of the wheel on the lever. As such, when each lever is rotated at least a pdrtion of the wheel moves into a position below the end of the chair leg so as to lift the leg off the ground.

Each lever preferably comprises a wheel arranged between its two ends. In the preferred embodiments, the distance between the pivot point on each lever and the axis of the wheel is smaller than the distance between the axis of the wheel and the second end of the lever. Preferably, the wheel is substantially adjacent to the pivot point. As such, the force required to be applied at the second end of each lever in order to deploy the wheels below the chair legs is relatively small.

In the preferred embodiments the levers are elongated members having a longitudinal axis and length between their first and second ends, and a lateral width in the plane of rotation of the levers. The levers are preferably elongated plates or rods.

Preferably, at least a portion of the wheel on each lever extends beyond the lateral edge of the lever so that as the lever is rotated the wheel contacts the ground before the lever. In the preferred embodiments, the axis of the wheel is located closer to one lateral edge of the lever than the other.

In the particularly preferred embodiments, each lever has a substantially uniform lateral width except for a projection extending in the lateral direction, wherein the axis of the wheel is connected to the projection. This arrangement results in the axis of the wheel being significantly laterally offset from the longitudinal axis of the lever. As such, when the lever is rotated to deploy the wheel the main body of the lever is maintained raised off the ground.

Preferably, the levers are rotatably connected to the inner sides of the chair legs and are interconnected in a direction between the chair legs.

In the preferred embodiments, the levers that are rotatably connected to the two back chair legs are connected to each other by a pedal bar.

The mechanism is preferably configured such that a downward force, or a substantially downward force, on the pedal bar causes rotation of the levers so that the wheels lift the chair legs off the ground. Preferably, the pedal bar is connected to the second ends of the levers. Preferably, the pedal bar is an elongated rod or plate that is attached at its ends to the levers on the back legs of the chair. The engagements between the ends of the pedal bar and the levers preferably enable the pedal bar to rotate about its longitudinal axis relative to the back two levers. As such, when a foot is used to depress the pedal bar so as to rotate the levers, the pedal bar does not rotate relative to the user's foot.

According to the preferred embodiments, the lever that is rotatably connected to the back right-hand chair leg is coupled to the lever that is rotatably connected to the front right-hand chair leg by a connector bar. The lever that is rotatably connected to the back left-hand chair leg is also preferably coupled to the lever that is rotatably connected to the front left-hand chair leg by a further connector bar. The connector bars are arranged and configured such that rotation of the levers that are rotatably connected to the back chair legs about their pivot points (e.g. by depressing the pedal bar) causes simultaneous rotation of the levers that are rotatably connected to the front chair legs about their pivot points, so as to deploy all of the wheels under the four chair legs.

In less preferred embodiments the two levers attached to the front two chair legs may also be coupled to each other by a third connector bar.

Preferably, the connector bars interconnect the second ends of the levers. The connector bars are preferably elongated rods or plates.

Preferably, the connector bars have rotatable engagements with the levers so as to allow the levers to rotate relative the ends of the connector bars about the rotatable engagements.

In the preferred embodiments each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which it is connected and a second position in which the wheel does extend below the end of the chair leg so as to lift the chair leg off the ground. As such, when each lever is in the first position the chair legs remain in contact with the ground and therefore the chair remains difficult to move. Preferably, the wheels do not even contact the ground when the levers are in this position. In the preferred embodiments, at least a portion of each wheel extends out behind the back of each chair leg when the levers are in the first position. When each lever is moved into the second position the chair legs are lifted off the ground by the wheels and so the chair is relatively easy to move on the wheels, even when occupied by a person.

In the preferred embodiments, the mechanism is configured such that the longitudinal axis of each lever is arranged substantially parallel with the chair leg to which it is connected when the lever is in said first position.

When it is desired to deploy the wheels, each lever is rotated into said second position and such that the longitudinal axis of the lever is at an angle with the chair leg.

In these embodiments, when each lever is in the first position and the wheels are not deployed, the levers are essentially hidden adjacent to the chair legs and the pedal bar and connector bars are raised upwards away from the ground. This prevents the levers and bars of the mechanism from being kicked or interfering with other activities, such as vacuum cleaning beneath the chair. Furthermore, when the levers are upright the weight of the mechanism falls through the pivot points and so little or no restraining means are required in order to prevent the levers from rotating and deploying the wheels by mistake. Additionally, as the pedal bar preferably extends between the back chair legs the mechanism is configured so that the levers and pedal bar provide extra structural support between the back legs of the chair.

In the preferred embodiments, one or more restraining members may be provided to prevent rotation of the levers about their pivot points.

Restraining members may be provided to permanently prevent rotation of the levers in an undesirable direction. For example, in the preferred embodiments where the pedal bar rotates the levers backwards and downwards from said first position in order to deploy the wheels, the restraining members can prevent the levers from rotating forward from the first position and in front of their respective chair legs. The one or more restraining members may simply be a restraining plate attached to the front side of at least one of the chair legs and which blocks the rotation of at least one of the levers past the restraining plate.

One or more restraining members may additionally, or alternatively, be provided in order to selectively prevent rotation of the levers in order to deploy the wheels. In these embodiments the restraining members must be deactivated in order to deploy the wheels.

In the preferred embodiments, the chair moving mechanism comprises means for inhibiting inadvertent deployment of the wheels.

Preferably, the chair moving mechanism comprises a biasing mechanismfor biasing the levers to a position where the wheels are not deployed. More preferably, the levers are biased to the first position wherein the longitudinal axes of the levers are aligned with the chair legs. In the particularly preferred embodiments the biasing mechanism comprises at least one resilient or retractive material for biasing the levers, i.e. a material that tends to retract towards its original length when stretched. The material is arranged and configured such that when the pedal bar is depressed the levers are able to rotate so that the wheels lift the chair legs off the ground, but also such that when the force is removed from the pedal bar the levers return upwards so that the wheels are retracted.

Preferably, the biasing mechanism comprises at least one resilient or retractive cord for biasing the levers. The at least one cord is connected at one end to the chair and at the other end to at least one of the levers and/or connector bars and/or pedal bar. In the preferred embodiments, one end of the at least one cord is attached to one of the above-mentioned restraining members that prevent the levers from rotating in the undesired direction.

Preferably, the one or more cords are elastic cords. However, it will be appreciated that the biasing means may comprise any other means of biasing the levers. For example, at least one spring may be employed in place of the above-described at least one resilient or retractive cord.

In other embodiments, a compressive material may be used as the biasing means, i.e. a material that tends to expand towards its original length when compressed by rotation of the levers and which biases the levers back towards the first position. For example, at least one spring or resilient member may be arranged and configured to be compressed by rotation of the levers and such that it expands to bias the levers to the first position.

From another aspect the present invention provides a chair comprising a chair moving mechanism. The mechanism comprises four levers, each lever comprising a wheel and being rotatably connected to a different chair leg about a pivot point. The four levers are interconnected such that, in use, rotation of any one of the levers about its pivot point causes all four levers to rotate about their respective pivot points. Each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which the lever is connected and a second position in which the wheel extends below the end of the chair leg. The mechanism is arranged and configured such that each lever is substantially parallel with the chair leg to which it is connected when in said first position and is at an angle with said chair leg when in said second position.

From another aspect the present invention provides a chair moving mechanism for attachment to a chair. The mechanism comprises four spaced apart levers, each of which has a wheel and a pivot member for rotatably connecting each lever to a different chair leg. The four levers are interconnected such that, in use, rotation of any one of the levers about its pivot member causes all four levers to simultaneously rotate about their respective pivot members and such that the wheels move from positions wherein the chair legs contact the ground to positions wherein the four chair legs are lifted off the ground by the wheels.

It will be appreciated that the chair moving mechanism of the present invention may include any individual feature, or combination of features, that have been described above in relation to the chair comprising the chair moving mechanism.

From another aspect the present invention provides a chair comprising a chair moving mechanism having two levers. Each lever comprises a wheel and is rotatably connected to a different chair leg about a pivot point, the levers being interconnected and spaced apart from each other by a pedal bar. Each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which it is connected and a second position in which the wheel extends below the end of the chair leg so as to lift the chair leg off the ground. The mechanism is also arranged and configured such that each lever is substantially parallel with the chair leg to which it is connected in said first position and is at an angle with said chair leg in said second position. The levers are preferably attached to the back two legs of the chair.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figures lA-IC show a preferred embodiment of the present invention when the wheels are not deployed and from perspective, side and rear views respectively; and Figures 2A-2C show the embodiment of Figures lA-IC when the wheels are deployed and from perspective, side and rear views respectively.

Figures lA-I C show an embodiment of the present invention when the chair moving mechanism is not deployed and the chair legs 2 are in contact with the floor 4. The chair moving mechanism comprises four elongated levers 6a-6d, each of which is rotatably connected to the inner side of a different chair leg 2. A first end of each lever 6a-6d is rotatably connected to its respective chair leg 2 by a pivot member 8 arranged in the region of the free end of the chair leg 2. Each lever 6a-6d extends towards a second end 10 that is not attached to the chair leg 2 and which is able to rotate about the pivot point provided by the pivot member 8. Each lever 6a- 6d comprises a projection 12 which extends transversely outwards relative to the longitudinal axis of the lever 6a-6d and in the plane of rotation of the lever 6a-6d. A wheel 14 is arranged on each lever 6a-6d between the pivot member 8 and the second end 10 of the lever 6a-6d. The axis of the wheel 14 is mounted on the projection 12 of the lever 6a-6d. The axis of the wheel 14 is substantially adjacent to the pivot member 8 and is significantly closer to the pivot point 8 than the second end 10 of the lever 6a-6d.

The second end 10 of each lever 6a-6d is coupled to the second end 10 of at least one other lever 6a-6d so that rotation of any one lever 6a-6d causes rotation of all of the levers 6a-6d. More specifically, the second ends of the levers 6c,6d that are rotatably attached to the back chair legs 2 are interconnected by a pedal bar 16. The second end 10 of the lever 6c that is rotatably attached to the back right chair leg 2 is also connected to the second end 10 of the lever 6a that is rotatably attached to the front right chair leg 2 by a connector bar 18. The second end 10 of the lever 6d that is rotatably attached to the back left chair leg 2 is also connected to the second end of the lever 6b that is rotatably attached to the front left chair leg 2 by a connector bar 20. The connections between the ends of the connector bars 18,20 and the second ends 10 of the levers 6a-6d enable the connector bars 18,20 to rotate relative to the levers 6a-6d.

As can be seen in Figures lA-iC, when the wheel mechanism is not deployed the levers 6a-6d are arranged such that their longitudinal axes extend vertically upwards and substantially in line with the chair legs 2. In this arrangement, the wheels 14 extend out behind the backs of the chair legs 2. A biasing mechanism is provided in order to bias the levers 6a-6d into this position, atthough this will be described in more detait below with reference to Figures 2A-2C.

Figures 1 B and I C show side and rear views respectively of the embodiment shown in Figure 1A, wherein the wheel mechanism is not deployed.

When it is desired to move the chair, particularly whilst the chair is still occupied by a person, the chair moving mechanism is deployed. In order to do this the pedal bar 16 is depressed so as to rotate the levers 6a-6d backwards and downwards about the pivot points 8. As the distance between the pivot point 8 and the axis of the wheel 14 on each lever 6a-6d is greater than the distance from the pivot point 8 to the free end of the chair leg 2, rotation of the levers 6a-6d causes the wheels 14 to extend below the ends of the chair legs 2. This action forces the chair legs 2 upwards so that the chair rests only on the wheels 14, as shown in Figures 2A-2C. The chair can thus be moved easily, even when occupied by a person.

Figures 2A-2C also illustrate the restraining members and biasing mechanism of the preferred embodiment. Restraining members in the form of restraining plates 22 are connected to the front sides of the front two chair legs 2. The restraining plates 22 project a distance between the front chair legs 2 so as to prevent the second ends 10 of the front two levers 6a,6b from rotating forwards and past the restraining plates 22. As all of the four levers 6a-6d are interconnected, the restraining plates 22 prevent all of the four levers 6a-6d from falling forwards, i.e. in the wrong direction to deploy the wheels 14.

Elastic cords 24 are also provided as a biasing means for preventing the inadvertent deployment of the wheels 14. One end of each elastic cord 24 is attached to the restraining plates 22. The other end of each elastic -10 -cord 24 is attached to an end of the pedal bar 16. The length and tension in the elastic cords 24 are selected such that the levers 6a-6d are biased into the position shown in Figures lA-iC, wherein the longitudinal axes of the levers 6a-6d are aligned with the chair legs 2. However, the length and tension of the elastic cords 24 are also selected such that the cords 24 may stretch without breaking when the pedal bar 16 is depressed in order to deploy the wheels 14.

Other embodiments are also contemplated wherein rollers could be provided as the wheels 14 in the present invention.

Claims

Claims: 1. A chair comprising a chair moving mechanism having four levers, each lever being rotatably connected to a different chair leg about a pivot point and comprising a wheel, wherein the four levers are interconnected such that, in use, rotation of any one of the levers about its pivot point causes all four levers to rotate about their respective pivot points such that the wheels move from positions wherein said chair legs contact the ground to positions wherein said four chair legs are lifted off the ground by the wheels.
2. A chair as claimed in claim 1, wherein each lever is rotatably connected to a chair leg at one end of the lever and is coupled to at least one other lever at its other end.
3. A chair as claimed in claim 1 or 2, wherein for each lever, the distance between its pivot point and the free end of the chair leg to which the lever is connected is smaller than the distance between the pivot point and the axis of the wheel.
4. A chair as claimed in any preceding claim, wherein the levers that are rotatably connected to the back chair legs are connected to each other by a pedal bar.
5. A chair as claimed in any preceding claim, wherein the lever that is rotatably connected to the back right-hand chair leg is connected to the lever that is rotatably connected to the front right-hand chair leg by a connector bar, and wherein the lever that is rotatably connected to the back left-hand chair leg is connected to the lever that is rotatably connected to the front left-hand chair leg by a connector bar.

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6. A chair as claimed in claim 5, wherein the connector bars are arranged and configured such that rotation of the levers that are rotatably connected to the back chair legs about their pivot points causes simultaneous rotation of the levers that are rotatably connected to the front chair legs about their pivot points so as to deploy all of the wheels under the four chair legs.
7. A chair as claimed in claim 4, 5 or 6, wherein the connector bars and/or pedal bar have rotatable connections with the levers.
8. A chair as claimed in any preceding claim, wherein each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which the lever is connected and a second position in which the wheel does extend below the end of the chair leg so as to lift the chair leg off the ground.
9. A chair as claimed in claim 8, wherein the lever is arranged substantially parallel with the chair leg to which it is connected in said first position and is at an angle with said chair leg in said second position.
10. A chair as claimed in claim 8 or 9, further comprising a biasing mechanism for biasing said lever into said first position.
11. A chair as claimed in any preceding claim, wherein the levers are rotatably connected to the inner sides of the chair legs and such that they are interconnected in a direction between the chair legs.
12. A chair comprising a chair moving mechanism having four levers, each lever comprising a wheel and being rotatably connected to a different chair leg about a pivot point, wherein the four levers are interconnected such that, in use, rotation of any one of the levers about its pivot point causes all four levers to rotate about their respective pivot points, wherein each lever is -13 -rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which the lever is connected and a second position in which the wheel extends below the end of the chair leg, and wherein the mechanism is arranged and configured such that each lever is substantially parallel with the chair leg to which it is connected when in said first position and is at an angle with said chair leg when in said second position.
13. A chair moving mechanism for attachment to a chair, said mechanism comprising four spaced apart levers, each of which has a wheel and a pivot member for rotatably connecting each lever to a different chair leg, wherein the four levers are interconnected such that, in use, rotation of any one of the levers about its pivot member causes all four levers to simultaneously rotate about their respective pivot members such that the wheels move from positions wherein the chair legs contact the ground to positions wherein the four chair legs are lifted off the ground by the wheels.
14. A chair comprising a chair moving mechanism having two levers, each lever comprising a wheel and being rotatably connected to a different chair leg about a pivot point, said levers being interconnected and spaced apart from each other by a pedal bar; wherein, in use, each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which it is connected and a second position in which the wheel extends below the end of the chair leg so as to lift the chair leg off the ground, and wherein the mechanism is arranged and configured such that each lever is substantially parallel with the chair leg to which it is connected in said first position and is at an angle with said chair leg in said second position.Amendments to the claims have been filed as follows Claims: 1. A chair comprising a chair moving mechanism having four levers, each lever being rotatably connected to a different chair leg about a pivot point and comprising a wheel, wherein the four levers are interconnected such that, in use, rotation of any one of the levers about its pivot point causes all four levers to rotate about their respective pivot points such that the wheels move from positions wherein said chair legs contact the ground to positions wherein said four chair legs are lifted off the ground by the wheels.2. A chair as claimed in claim 1, wherein each lever is rotatably connected to a chair leg at one end of the lever and is coupled to at least one other lever at its other end.3. A chair as claimed in claim 1 or 2, wherein for each lever, the distance between its pivot point and the free end of the chair leg to which the lever is connected is smaller than the distance between the pivot point and the axis of the wheel.4. A chair as claimed in any preceding claim, wherein the levers that are rotatably connected to the back chair legs are connected to each other by a pedal bar.5. A chair as claimed in any preceding claim, wherein the lever that is rotatably connected to the back right-hand chair leg is connected to the lever that is rotatably connected to the front right-hand chair leg by a connector bar, and wherein the lever that is rotatably connected to the back left-hand chair leg is connected to the lever that is rotatably connected to the front left-hand chair leg by a connector bar.6. A chair as claimed in claim 5, wherein the connector bars are arranged and configured such that rotation of the levers that are rotatably connected to the back chair legs about their pivot points causes simultaneous rotation of the levers that are rotatably connected to the front chair legs about their pivot points so as to deploy all of the wheels under the four chair legs.7. A chair as claimed in claim 4, 5 or 6, wherein the connector bars and/or pedal bar have rotatable connections with the levers.8. A chair as claimed in any preceding claim, wherein each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which the lever is connected and a second position in which the wheel does extend below the end of the chair leg so as to lift the chair leg off the ground.9. A chair as claimed in claim 8, wherein the lever is arranged substantially parallel with the chair leg to which it is connected in said first position and is at an angle with said chair leg in said second position.10. A chair as claimed in claim 8 or 9, further comprising a biasing mechanism for biasing said lever into said first position.11. A chair as claimed in any preceding claim, wherein the levers are rotatably connected to the inner sides of the chair legs and such that they are interconnected in a direction between the chair legs.12. A chair comprising a chair moving mechanism having four levers, each lever comprising a wheel and being rotatably connected to a different chair leg about a pivot point, wherein the four levers are interconnected such that, in use, rotation of any one of the levers about its pivot point causes all four levers to rotate about their respective pivot points, wherein each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which the lever is connected and a second position in which the wheel extends below the end of the chair leg, and wherein the mechanism is arranged and configured such that each lever is substantially parallel with the chair leg to which it is connected when in said first position and is at an angle with said chair leg when in said second position.13. A chair moving mechanism for attachment to a chair, said mechanism comprising four spaced apart levers, each of which has a wheel and a pivot member for rotatably connecting each lever to a different chair leg, wherein the four levers are interconnected such that, in use, rotation of any one of the levers about its pivot member causes all four levers to simultaneously rotate about their respective pivot members such that the wheels move from positions wherein the chair legs contact the ground to positions wherein the four chair legs are lifted off the ground by the wheels.14. A chair comprising a chair moving mechanism having two levers, each lever comprising a wheel and being rotatably connected to a different chair leg about a pivot point, said levers being interconnected and spaced apart from each other by a pedal bar; wherein, in use, each lever is rotatable about its respective pivot point between a first position in which its wheel does not extend below the end of the chair leg to which it is connected and a second position in which the wheel extends below the end of the chair leg so as to lift the chair leg off the ground, and wherein the mechanism is arranged and configured such that each lever is substantially parallel with the chair leg to which it is connected in said first position and is at an angle with said chair leg in said second position.I15. A chair as claimed in claim 14, wherein the chair moving mechanism is provided with pivot members configured to engage the levers with the chair legs in a manner whereby the levers can rotate relative to the chair legs about the pivot points, and wherein the pivot members comprise a hole through the lever and a screw, bolt or nail for connecting the lever to the chair leg through the hole.16. A chair as claimed in claim 14 or 15, wherein the levers are elongated members having a lateral width in the plane of rotation of the levers, wherein each lever has a substantially uniform lateral width except for a projection extending in the lateral direction, wherein the axis of the wheel is connected to the projection.17. A chair as claimed in claim 14, 15 or 16, wherein the engagements between the ends of the pedal bar and the levers enable the pedal bar to rotate about its longitudinal axis relative to the levers.*:* 18. A chair as claimed in any one of claims 14-17, wherein the levers are I l attached to the back two legs of the chair. * S S * SS 4** S.S * 5,S * 45S