NZ734901A - A Seat - Google Patents

Abstract

The invention relates to a seat. It is known to provide seating such as wheelchairs for disabled users with specific postural care requirements where the incline of a seat is adjustable. The seat has a backrest, a base (3) for receiving the posterior of a human user, and an incline adjuster (4). The incline adjuster has a shaft (9), a lever (10), a follower (13), and a curved rack (15a) with a plurality of teeth (15). The shaft is moveable to swing the lever to cause the toothed follower (13) into or out of locking engagement with the rack (15a), the arrangement being such that when the follower is in the unlocked disposition the rack can move to adjust the incline of the backrest and base. The adjuster provides an alternative to the use of cables which may be exposed and can become damaged and need maintenance or replacement.

Description

TITLE A seat.

FIELD OF INVENTION This invention relates to a seat, for example for users with postural care requirements.

BACKGROUND It is known to provide seating for disabled users with specific postural care requirements where the incline of a seat is adjustable. The incline of some existing seats can be adjusted by way of a cable arrangement. It is a problem in that cables may be exposed and can become stretched or otherwise damaged and need maintenance or replacement.

It is an object of a preferred embodiment of the present invention to go at least some way towards addressing this problem. While this object applies to the preferred embodiment, it should be understood that the object of the invention per se is not so limited and is simply to provide a useful choice. Any objects and advantages of the preferred embodiment should not be seen as limitations on claims that do not mention them.

The term "comprising" and derivatives thereof, eg "comprises", if and when used herein in relation to a combination of features should not be taken as excluding the possibility that the combination may have further unspecified features. For example, a statement that an arrangement "comprises" certain parts does not mean that it cannot also, optionally, have additional parts.

SUMMARY OF INVENTION According to one aspect of the invention there is provided a seat having:  a backrest;  a base for receiving the posterior of a human user; and  an incline adjuster having: o a shaft; o a lever; o a follower; and o a rack the shaft being moveable to swing the lever to cause the follower into or out of locking engagement with the rack, the arrangement being such that when the follower is in the unlocked disposition the rack can move to adjust the incline of the backrest and base.

Optionally the incline adjuster is at one side of the seat and there is a second substantially similar incline adjuster at the opposite side of the seat, the adjusters being linked so that moving force transfers from one to the other so that they move in unison.

Optionally the seat has a chassis base and a tilt rail, the base and rail being combined by a link such that the rail can be moved forwards and backwards with respect to the base by way of rollers.

Optionally the lever pivots on the link.

Optionally there is a second lever which also pivots on the link and serves to assist movement of the follower with respect to the rack.

Optionally the tilt rail has at least one track which receives the rollers.

Optionally the tilt rail is curved.

Optionally the rack is curved.

Optionally the follower has teeth which are adapted to engage complimentary teeth of the rack in locking relationship.

Optionally the follower extends into an aperture in the tilt rail when the follower is in locking engagement with the rack.

Optionally the follower does not extend into the aperture in the tilt rail when the follower is out of locking engagement with the rack so that the rollers are able to move along the track.

Optionally a spring is able to be compressed to hold the follower out of locking engagement with the rack.

Optionally pressure on the spring is able to be released to move the follower into locking engagement with the rack.

Optionally the shaft, follower and rack are substantially enclosed.

Optionally movement of the shaft is activated by a foot pedal.

According to a further aspect of the invention there is provided seat having:  a backrest;  a base for receiving the posterior of a human user;  an incline adjuster; and  a support the adjuster being adapted to adjust the incline of the backrest and base with respect to the support wherein the adjuster is substantially enclosed within at least one housing.

BRIEF DESCRIPTION OF THE DRAWINGS Some preferred forms of the invention will now be described by way of example and with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a seat; Figure 2 is a side view of an angle adjuster; Figure 3 is a partially cut away side view of the angle adjuster; and Figure 4 is a perspective view of a tilt rail.

DETAILED DESCRIPTION Referring to figure 1, in a preferred form of the invention a seat 1 comprises a backrest 2, a base 3 for a user to sit on, and an incline adjuster 4. In the preferred embodiment the seat 1 is a commode but it should be appreciated that the invention may take different forms, for example a wheelchair or other form of disability seating.

Referring to figures 2 and 3, the incline adjuster 4 comprises a support or chassis base 5, a tilt rail 6, a castor mount 7, and a foot-operated tilt pedal 8. The pedal 8 is connected to a tilt rod 9 which abuts a lever or tilt lock cam 10. A tilt connector rod (not shown in figure 3) is positioned in a space 11 between the cam 10 and a second lever or tilt lock cam 12.

Each cam 10, 12 is in contact with a tilt lock follower 13. The tilt rail 6 is curved and tubular and comprises a curved rack 15a enclosed within the rail 6. The follower 13 has a plurality of teeth 14 which mesh with corresponding teeth 15 of the rack 15a.

The mount 7 is positioned on the chassis base 5 and comprises four pairs of castors or rollers 16 situated at the top of the mount 7.

When the teeth 14 of the follower 13 are engaged with the teeth 15 of the rack 15a, the adjuster 4 is in a locked disposition. The rail 6 cannot move and the backrest 2 and base 3, which are connected to the rail 6, are in a fixed position.

To adjust the angle of the backrest 2 and base 3, the user steps on the pedal 8 which causes the rod 9 to move from right to left. The rod 9 pushes against a lower part of the cam 10 which causes the cam 10 to move clockwise about a pivot point 17. The upper part of the cam 10 engages the follower 13 as it turns.

The movement of the rod 9 also moves the connector rod (not shown) into the second cam 12 which causes that cam 12 to also move clockwise about a second pivot point 18 into a further part of the follower 13. The connector rod compresses a pedal spring 19 which remains under pressure while the pedal 8 is depressed.

As the cams 10, 12 turn clockwise they move the follower 13 down so that the teeth 14 disengage from the rack teeth 15. The rail 6 is now free to run along the rollers 16 from left to right, or right to left.

When unlocked, the user can move the rail 6 manually to adjust the degree of incline of the backrest 2 and base 3. When the desired angle is reached the user steps off the pedal 8 releasing the pressure on the spring 19. This moves the connector rod and the rod 9 from left to right and turns the cams 10,12 counter-clockwise so that the teeth 14 reengage with the teeth 15, locking the rail 6 with respect to the mount 7.

A cross member or bar 20, as can be seen in figure 1, passes through the second pivot point 18 to connect with a second incline adjuster. The second adjuster comprises a second similar or identical castor mount and locking mechanism (not shown in figure 1) and a second tilt rail 21 on the other side of the seat 1. When the adjuster 4 is operated, the second adjuster moves in unison with it.

Figure 4 shows a cross section of the rail 6 without the rack 15a. The underside of the rail 6 has an opening 22 to accommodate the mount 7 when the seat 1 is assembled. Each pair of rollers 16 runs along grooves 23 on opposite sides of the opening 22. A slot 24 is sized to receive the rack 15a and teeth 15 which are able to engage and disengage with the follower teeth 14.

The rod 9 and spring 19 are housed within a chassis base panel 5a and the mount 7 is housed within a mount panel 7a (shown in figure 2). The rack 15a is housed within the rail 6. The follower 13, while attached to the mount 7, extends partly within the rail 6 when the follower teeth 14 engage the rack teeth 15. The rollers 16 are housed within the rail 6 along the grooves. The mechanism of the adjuster 4 is therefore substantially enclosed when the seat 1 is assembled. This assists in protecting the adjuster parts from any dirt, moisture, spillage of bodily fluids and/or other contaminants that can damage exposed parts. It also assists in mitigating the risk of a user’s fingers being accidentally caught in moving parts when the incline of the seat 1 is being adjusted.

While some preferred forms of the invention have been described by way of example it should be appreciated that modifications and improvements can occur without departing from the scope of the appended claims.

Claims (17)

1. A seat having:  a backrest; 5  a base for receiving the posterior of a human user; and  an incline adjuster having: o a shaft; o a lever; o a follower; and 10 o a rack the shaft being moveable to swing the lever to cause the follower into or out of locking engagement with the rack, the arrangement being such that when the follower is in the unlocked disposition the rack can move to adjust the incline of the backrest and base.

2. A seat according to claim 1, wherein the incline adjuster is at one side of the seat and there is a second substantially similar incline adjuster at the opposite side of the seat, the adjusters being linked so that moving force transfers from one to the other so that they move in unison.

3. A seat according to claim 1 or 2, having a chassis base and a tilt rail, the base and rail being combined by a link such that the rail can be moved forwards and backwards with respect to the base by way of rollers. 25

4. A seat according to claim 1, 2 or 3, wherein the lever pivots on the link.

5. A seat according to claim 4, wherein there is a second lever which also pivots on the link and serves to assist movement of the follower with respect to the rack.

6. A seat according to claim 3, wherein the tilt rail has at least one track which receives the rollers.

7. A seat according to claim 3 or 4, wherein the tilt rail is curved.

8. A seat according to any one of the preceding claims, wherein the rack is curved.

9. A seat according to any one of the preceding claims, wherein the follower has teeth which are adapted to engage complimentary teeth of the rack in locking 5 relationship.

10. A seat according to any one of claims 3-9, wherein the follower extends into an aperture in the tilt rail when the follower is in locking engagement with the rack.

11. A seat according to claim 10, wherein the follower does not extend into the aperture in the tilt rail when the follower is out of locking engagement with the rack so that the rollers are able to move along the track. 15

12. A seat according to any one of the preceding claims, wherein a spring is able to be compressed to hold the follower out of locking engagement with the rack.

13. A seat according to claim 12, wherein pressure on the spring is able to be 20 released to move the follower into locking engagement with the rack.

14. A seat according to claim 1, wherein the shaft, follower and rack are substantially enclosed. 25

15. A seat according to any one of the preceding claims, wherein movement of the shaft is activated by a foot pedal.

16. A seat having:  a backrest; 30  a base for receiving the posterior of a human user;  an incline adjuster; and  a support the adjuster being adapted to adjust the incline of the backrest and base with respect to the support wherein the adjuster is substantially enclosed within at 35 least one housing.

17. A seat substantially as herein described with reference to the accompanying drawings.