GB2465351A

GB2465351A - Seating apparatus

Info

Publication number: GB2465351A
Application number: GB0820735A
Authority: GB
Inventors: Simon Parish; Andrew Farrow
Original assignee: Smirthwaite Ltd
Current assignee: Smirthwaite Ltd
Priority date: 2008-11-13
Filing date: 2008-11-13
Publication date: 2010-05-19
Also published as: GB2465351A8; GB0820735D0

Abstract

A chair 10 with an adjustable tray 24, the chair having an engagement feature and the tray having at least one engagement device for engagement with the engagement features 48 50. A locking mechanism locks the tray in a position relative to the chair. The locking mechanism is released by a release mechanism, which is located such that when the tray is engaged with the chair, the release mechanism 62 is inaccessible to a person sitting in the chair, preferably on the underside of the tray at an edge opposite to a person sitting in the chair. The locking mechanism may be a series of apertures, teeth, notches or indents which engage with a locking element, for example a spring loaded cam shaped pawl (Fig 9) or pivotal tongue (Fig 8). There may be two locking mechanisms and the release mechanism 62 may release both locking mechanisms simultaneously. The engagement feature may be located on the arm rest 18 20. The chair can be used as a special needs chair.

Description

Seating apparatus The present invention relates to seating apparatus, in particular the invention relates to chairs with removable trays.

The seating apparatus is particular suitable for special needs seating.

People with special needs, such as physically and mentally disabled adults and children have special seating requirements, calling for specialised chairs. Such chairs are designed to offer postural support and are adapted for the needs of a particular user. A user of a special needs chair will often spend a significant amount of time in their chair, which may become a safe space' for the user.

It is desirable to provide a tray with special needs chairs, so that the user can sit in the chair to eat or to carry out activities. Conventional methods of attaching trays to chairs cause several disadvantages. Attaching the tray onto both sides of the chair is cumbersome and time consuming, particularly during busy periods such as meal times. Whilst a helper is fitting or removing the tray, he or she will be within reach of the user, whilst losing eye contact. This arrangement leaves the helper vulnerable to abuse such as hair pulling etc from some mentally disabled users, who can be both strong and violent. Additionally, in conventional methods for attaching trays to chairs, the means of securing the tray to the chair is within reach of the user. The user is therefore able to remove the tray, which may upset a meal or objects placed on it.

Furthermore, the loosened tray can be used as a projectile.

Figures 1 to 3 illustrate a known special needs chair and tray.

The special needs chair 10 has a wheeled base frame 12 which supports the chair and enables it to be manoeuvred. The chair is provided with a seat 14, back support 16 and two arm rests 18,20. A handle 22 is provided on the rear of the back support for pushing the chair.

A tray 24 has a flat surface 26 and is generally U' shaped, with two extending arms 28,30.

As shown in Figure 1, the arm rests 18,20 of the chair are provided with a series of apertures 32. The extending arms of the tray are each provided with a retractable pin 34.

As illustrated in Figure 2, the tray is attached to the chair by resting the tray 24 on the arms 18,20 of the chair 10. The tray 24 is placed in a desired position, ensuring that the end of the extending arms 28,30 is pushed underneath a flange 36 on each side of the back rest which holds the end of the extending arms 28,30 against the arms 18,20 of the chair 10.

Once the tray is in the desired position, the retractable pins 34 are inserted into the appropriate aperture 32. The combination of the flanges 36 and the pins 34 hold the tray in position.

To hold the tray securely in position and to prevent tampering, straps are provided as a final step in securing the tray. Side straps 38 are attached between the chair 10 and tray 24. These side straps 38 cover the pins to prevent tampering. Front straps and rear straps 42 are also connected to hold the tray securely in position.

A first aspect of the present invention provides a seating apparatus with adjustable tray, comprising: a chair, comprising a chair seat, chair back, and at least one engagement feature; a tray comprising a tray surface, at least one engagement device, for engagement with the engagement features of the chair; a locking mechanism to enable the tray to be locked in a position relative to the chair; and a release mechanism to release the locking mechanism, wherein the release mechanism is inaccessible to a person sitting in the chair.

The person sitting in the chair therefore cannot remove the tray, ensuring the safety of helpers and people in the vicinity.

The at least one engagement device may be in sliding engagement with the at least one engagement features of the chair. The at least one engagement device may comprise two engagement devices.

In one embodiment, the at least one engagement device comprises an engagement channel. The engagement channel may comprise an elongate groove. The at least one engagement device may comprise two parallel engagement channels. Each engagement channel may be provided with parallel elongate grooves. The grooves of the parallel engagement channels may face one another.

The at least one engagement device may limit motion of the tray relative to the chair in one or more dimensions. Ideally, the motion of the tray is limited relative to the chair in two dimensions. The at least one engagement device may limit lateral motion (i.e. side to side motion) of the tray relative to the chair. The at least one engagement device may limit vertical motion (i.e. up and down) of the tray relative to the chair. The at least one engagement device may allow linear motion forwards and backwards relative to the chair, for example sliding motion.

In a preferred embodiment, the linear motion is limited by the locking mechanism.

The locking mechanism may comprise a locking element on one of the chair and tray for engagement with a series of locking features on the other of the chair and tray. In one embodiment, the series of locking features comprises a series of apertures.

Alternatively, the series of locking features may comprise a series of teeth, notches, indents, holes etc. The locking element may comprise a pivotable element.

In one embodiment, the locking mechanism comprises a linear ratchet mechanism. The locking mechanism may comprise a pawl which is deflected by the one or more engagement features on the chair on relative motion of the chair and tray in a first direction and is in locking engagement on relative motion in a second direction. The pawl may comprise a sprung pawl. In one embodiment, the pawl is cam shaped.

Other locking mechanisms would be suitable, for example a friction lock, pin and aperture etc. The locking mechanism may be actuated by an electrically operated mechanism, for example a solenoid or other known alternatives.

The release mechanism may be located on a lower surface of the tray. The release mechanism may be located on the tray, positioned at a side of the tray remote from the chair, when the tray is engaged with the chair.

In one embodiment, the release mechanism may comprise a handle located on the tray. The release mechanism may alternatively comprise a remote control, lever, push button or other known devices.

In one embodiment, the at least one engagement devices comprises two engagement devices arid wherein each engagement device is provided with a locking mechanism. The release mechanism may release both locking mechanisms simultaneously.

The chair may further comprise arm rests. The at least one engagement features may be located on the arm rests or part of the chair which supports the arm rests.

The at least one engagement feature may comprise at least one rail. The at least one engagement device may comprise at least one channel. In one embodiment, the at least one engagement feature comprises two rails and the at least one engagement device comprises two channels.

In another embodiment, the at least one engagement feature comprises at least one first tube and the at least one engagement device comprises at least one second tube. The at least one first tube and at least one second tube may be arranged for sliding engagement.

The seating apparatus may comprise a special needs seating apparatus.

A second aspect of the present invention provides an adjustable tray for a chair, the adjustable tray comprising: a tray surface at least one engagement device, for engagement with at least one engagement feature of the chair; a locking mechanism to enable the tray to be locked in a position relative to the chair; a release mechanism to release the locking mechanism, wherein the location of the release mechanism is such that when the tray is engaged with the chair, the release mechanism is inaccessible to a person sitting in the chair.

A third aspect of the present invention provides a special needs seating apparatus, comprising a chair and an adjustable tray.

A fourth aspect of the present invention provides a method of attaching and releasing an adjustable tray relative to a chair, comprising the steps of: engaging at least one engagement device of the adjustable tray with at least one engagement feature of the chair, adjusting the position of the tray relative to the chair; actuating a release mechanism to thereby release a locking mechanism to enable motion of the tray in a direction away from the chair.

Preferred features of the second, third and fourth aspects of the invention may be as described above in connection with the first aspect.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", mean "including but not limited to", and do not exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Other features of the present invention will become apparent from the following example. Generally speaking the invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings). Thus features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Moreover unless stated otherwise, any feature disclosed herein may be replaced by an alternative feature serving the same or a similar purpose.

The present invention will now be described by way of example only and with reference to the accompanying illustrative drawings, in which: Figure 1 is a perspective view of a prior art chair and tray, with the tray removed; Figure 2 is a perspective view of the prior art chair and tray of Figure 1, with the tray attached; Figure 3 is a perspective view of the prior art chair and tray of Figures 1 and 2 with the tray attached and secured by straps; Figure 4 is a perspective view of the chair and tray of the present invention with the tray removed; Figure 5 is a perspective view of the chair and tray of Figure 5 with the tray attached; Figure 6 is a perspective view of the chair and tray of Figures 5, viewed from below; Figure 7 is a perspective view of the tray of Figures 4 to 6, viewed from below; Figure 8 is an enlarged area of Figure 7, showing the locking mechanism; Figure 9 is a cross sectional view showing the locking mechanism of a second embodiment of the invention; and Figure 10 is a cross section through AA on Figure 9.

Figure 4 to 6 illustrate the special needs chair of the present invention. Features of the special needs chair which are identical or similar to those illustrated in Figures 1 to 3 will use the same reference numbers.

Figure 4 illustrates the tray 24 for use in the present invention. As in the embodiment illustrated in Figures 1 to 3, it has a flat surface 26, formed in a substantially U' shape with two extending arms 28,30. Figure 4 also illustrates the chair 10 which, as in the prior art chairs shown in Figures 1 to 3, has a wheeled base frame 12, seat 14, back support 16 and arm rests 18,20.

Each of the arm rests 18,20 comprise a padded arm support 44 mounted on an elongate plate 46. The elongate plate 46 has a greater width than the padded arm support 44, causing the edge of the elongate plate to protrude outwards. This protruding edge forms a rail which engages with the tray 24. The elongate plate is made from a polyamide, such as Nylon. However, it could be made from other materials, such as plastics, metal or wood materials.

Figure 7 illustrates the lower surface of the tray 24. On the underneath of the tray 24, each extending arm 28,30 is provided with an engagement channel 48,50. The engagement channels 48,50 are mounted parallel with the extending arms 28,30 and each other. Each engagement channel 48,50 has an elongate groove 52,54 on its inner surface. The engagement channels are typically made from extruded aluminium, which provided both strength and light weight.

The tray is mounted onto the chair by sliding the engagement channels 48,50 onto the rails provided on the arm rests 18,20 of the chair. This engagement of the channels and rails limit vertical and lateral motion of the tray, whilst enabling sliding backwards and forwards motion of the tray relative to the chair.

Figures 5 and 6 illustrate the tray attached to the chair.

The tray is provided with a locking mechanism to lock the tray in a desired position.

As illustrated in Figure 6, the bottom surface of the elongate plate 46 of the chair arms 18,20 are provided with a series of incrementally spaced apertures 56. The locking mechanism of the tray can engage with any of these apertures to lock the tray in a variety of positions.

Figure 7 shows the underneath of the tray, illustrating the locking mechanism, which is shown in more detail in Figure 8.

The locking mechanism comprises a pivotable tongue 58 which is shaped such that when the tray is slid toward the chair (i.e. in the direction of arrow A), the pivotable tongue 58 is deflected by the apertures 56. When the tray is slid away from the chair (i.e. in a direction opposite to arrow A), the pivotable tongue will engage with its adjacent aperture.

The locking mechanism is thus effectively a ratchet and pawl device.

The locking mechanism enables a helper to engage easily the tray with the chair and push it into position. However, if the chair user pushes against the tray, the locking mechanism will prevent the user from removing it.

A release mechanism is provided for releasing the locking mechanism and thus enabling the tray to be removed. Figure 8 shows a lever 60 which when actuated disengages the pivotable tongue 58 from the aperture in which it is engaged. A release handle 62 (shown in Figures 6 and 7) is provided to actuate the lever 60. A wire 64 connects the release handle 62 to the lever and on operation of the release handle, the wire pulls the lever 60 against spring 66, causing the pivoting tongue to disengage.

The pivoting tongue 58, lever 60 and spring 66 of the locking mechanism are located within a housing 52,48 (shown in Figure 7) to protect them against tampering.

Although the locking mechanism is only shown on one side of the tray, locking mechanisms are provided on both sides; these locking mechanisms may have a symmetrical arrangement. Both locking mechanism are actuated by the same release handle 62.

The release handle 62 is provided on the lower surface of the tray, at the side remote from the user. Due to this positioning, the handle cannot be accessed by the user in the chair.

Therefore, the user cannot remove the tray without assistance.

The arrangement of a single release mechanism for the tray enables the helper to activate the release mechanism single handed.

The position of the release handle on the tray has the advantage that the user can attach and release the tray whilst maintaining eye contact and conversation with the user. The position of the release handle further ensures that the helper can attach and release the tray whilst remaining out of reach with the user, thus eliminating the risk of attack.

The release mechanism is not necessarily mounted on the tray, for example it might alternatively comprise a remote control.

Alternative method locking mechanisms are envisaged, for example a solenoid may be used to actuate a pin between engaged and released position.

Other release mechanisms are also possible, for example the locking mechanism may be released by remote control. The remote control may advantageously be mounted on the tray, out of reach of the chair user.

An alternative embodiment of the invention is illustrated in Figures 9 and 10. In this embodiment, the rails and channels of the chair and tray are replaced by telescopic tubes. Figure 9 is a longitudinal cross section through the chair and tray tubes and Figure 10 is a cross section of the tray tube along lines A-A. Chair tube 70 is attached to a chair arm and is a hollow tube, with a series of apertures 81,82,83 at spaced intervals. Tray tube 72 is a hollow tube with an outer diameter dimensioned to allow it to fit within the inner diameter of the chair tube 70.

Sliding motion of tray tube 72 within chair tube 70 enables adjustment of the tray position.

A locking mechanism is located inside the tray tube 72, comprising a pivotable tongue 74 which protrudes from an opening in the tray tube 72. The tongue 74 is rotatable about a pivot 76 and is shaped so that the extent of its protrusion through the opening 80 varies as it rotates. A spring 78 biases the tongue 74 into its position of maximum protrusion, the extent of rotation being limited by a stop 88 which abuts the edge of the aperture 80.

As the tray tube 72 is pushed into the chair tube 70 in the direction of arrow B, the gently sloping face 84 of the tongue 74 is deflected by the edge of the aperture 82 against the bias of the spring 76. In this manner, the tray can be pushed onto the chair without the locking mechanism preventing the movement.

If the tray tube 72 is pulled in a direction opposite to arrow B, i.e. to remove the tray, the edge of the aperture 82 abuts face 86 of the tongue 74. The shape of curved face 86 encourages the tongue 74 to move clockwise, forcing the stop 88 against the edge of the opening 80, thereby preventing movement of the tray tube and locking it in position.

The tray tube can be released by pulling on the release cable which causes the tongue 74 to rotate anticlockwise against the bias of the spring 76, disengaging the tongue 74 with the aperture 82.

Although the above embodiments describe the tray being mounted onto the chair arms, the tray may be mounted onto another part of the chair.

The embodiments shown in Figures 1 to 10 describe the locking mechanism provided on the tray. However, the locking mechanism may alternatively be provided on the chair, with corresponding features, such as aperture on the tray.

Claims

Claims 1. A seating apparatus with adjustable tray, comprising: a chair, comprising a chair seat, chair back, and at least one engagement feature; a tray comprising a tray surface, at least one engagement device, for engagement with the at least one engagement feature of the chair; a locking mechanism to enable the tray to be locked in a position relative to the chair; and a release mechanism to release the locking mechanism, wherein the release mechanism is inaccessible to a person sitting in the chair.
2. A seating apparatus according to any one of the preceding claims, wherein the at least one engagement device is in sliding engagement with the at least one engagement feature.
3. A seating apparatus according to any one of the preceding claims, wherein the at least one engagement device comprises two engagement devices.
4. A seating apparatus according to any one of the preceding claims wherein said at least one engagement device comprises at least one engagement channel.
5. A seating apparatus according to claim 4 wherein said engagement channel comprises an elongate groove or tube.
6. A seating apparatus according to any one of the preceding claims wherein the at least one engagement device comprises two parallel engagement channels.
7. A seating apparatus according to claim 6 wherein each engagement channel comprises an elongate groove or tube.
8. A seating apparatus according to claim 7 wherein the parallel engagement channels comprise grooves which face one another.
9. A seating apparatus according to any one of the preceding claims wherein the at least one engagement device limits motion of the tray relative to the chair in one or more dimensions.
10. A seating apparatus according to any one of the preceding claims wherein the at least one engagement device limits one or both of lateral and vertical motion of the tray relative to the chair.
11. A seating apparatus according to any one of the preceding claims wherein the at least one engagement device allows linear motion forwards and backwards relative to the chair.
12. A seating apparatus according to any one of the preceding claims wherein the locking mechanism comprises a locking element on one of the chair and tray for engagement with a series of locking features on the other of the chair and tray.
13. A seating apparatus according to claim 12 wherein the series of locking features comprises a series of apertures, teeth, notches or indents.
14. A seating apparatus according to any one of the preceding claims wherein the locking element comprises a pivotable locking element.
15. A seating apparatus according to any one of the preceding claims, wherein the locking mechanism comprises a linear ratchet mechanism.
16. A seating apparatus according to any of claim 12 to 14, wherein the locking element comprises a pawl which is deflected by the one or more engagement features on relative motion of the tray and chair in a first direction and is in locking engagement on relative motion in a second direction.
17. A seating apparatus according to claim 16 wherein the pawl comprises a sprung pawl.
18. A seating apparatus according to any of claims 16 or 17 wherein the pawl is cam shaped.
19. A seating apparatus according to any one of the preceding claims wherein the release mechanism is located on a lower surface of the tray.
20. A seating apparatus according to any one of the preceding claims wherein the release mechanism is located on the tray, positioned at a side of the tray remote from the chair, when the tray is engaged with the chair.
21. A seating apparatus according to any one of the preceding claims wherein said at least one engagement device comprises two engagement devices and wherein each engagement device has an associated locking mechanism.
22. A seating apparatus according to claim 21 wherein the release mechanism releases both locking mechanisms simultaneously.
23. A seating apparatus according to any one of the preceding claims wherein the chair further comprises arm rests.
24. A seating apparatus according to claim 23 wherein the at least one engagement features are located on an arm rest or part of the chair which supports an arm rest.
25. A seating apparatus according to any one of the preceding claims wherein the at least one engagement feature comprises at least one rail and the at least one engagement device comprises at least one channel.
26. A seating apparatus according to any one of claims 1 to 24 wherein the at least one engagement feature comprises at least one first tube and the at least one engagement device comprises at least one second tube, wherein the at least one first tube and the at least one second tube are arranged for sliding engagement.
27. A seating apparatus according to any one of the preceding claims wherein the seating apparatus comprises a special needs seating apparatus.
28. An adjustable tray for a chair, the adjustable tray comprising: a tray surface at least one engagement device, for engagement with at least one engagement feature of the chair; a locking mechanism to enable the tray to be locked in a position relative to the chair; a release mechanism to release the locking mechanism, wherein the release mechanism is located such that when the tray is engaged with the chair, the release mechanism is inaccessible to a person sitting in the chair.
29. An adjustable tray according to claim 28, wherein the at least one engagement device is arranged for sliding engagement with the at least one engagement feature.
30. An adjustable tray according to any one of claims 28 or 29 wherein the locking mechanism comprises a locking element for engagement with a series of locking features on the chair.
31. An adjustable tray according any of claims 28 to 30 wherein the locking mechanism comprises a pivotable locking element.
32. An adjustable tray according to any one of claims 28 to 31, wherein the locking mechanism comprises a linear ratchet mechanism.
33. An adjustable tray according to any of claims 30 to 32, wherein the locking element comprises a pawl which is deflected by the one or more engagement features on relative motion of the tray and chair in a first direction and is in locking engagement on relative motion in a second direction.
34. An adjustable tray according to claim 33 wherein the pawl comprises a sprung pawl.
35. An adjustable tray according to any of claims 33 or 34 wherein the pawl is cam shaped.
36. An adjustable tray according to any one of claims 28 to 35 wherein the release mechanism is located on a lower surface of the tray.
37. An adjustable tray according to any one of claims 28 to 36 wherein the release mechanism is located on the tray, positioned at a side of the tray remote from the chair, when the tray is engaged with the chair.
38. A special needs seating apparatus, comprising a chair and an adjustable tray according to any one of claims 29 to 37.
39. A method of attaching and releasing an adjustable tray relative to a chair, comprising the steps of: engaging at least one engagement device of the adjustable tray with at least one engagement feature of the chair, adjusting the position of the tray relative to the chair; actuating a release mechanism to thereby release a locking mechanism to enable motion of the tray in a direction away from the chair.