CA2150902A1

CA2150902A1 - Adjustable backrest

Info

Publication number: CA2150902A1
Application number: CA002150902A
Authority: CA
Inventors: David Quennell; Tim Poupore; Craig Pirie
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-06-02
Filing date: 1995-06-02
Publication date: 1996-12-03

Abstract

An adjustable backrest has a semi-rigid upright spine and a plurality of support arms and a plurality of attachment arms extending laterally from either side thereof, said arms being removably attachable to said spine at adjustable locations thereon. The support arms are adjustably curved laterally and forwardly and the attachment arms are adapted to fasten to the frame of a wheelchair and the like.

Description

2 INPROVED ADJUSTARLE R~ T

3 This invention relates to an improved design for a 4 backrest. More particularly, it relates to a design for a backrest which may be employed in conjunction with a 6 wheelchair or the like and is suited for people who require 7 postural support.

8 As society pays more attention to the mobility of 9 people who are physically disabled, there is an increasing supply of vehicles, such as wheelchairs and motorized chairs, 11 etc.

12 However, many of these are of the traditional style 13 which provide only a fabric panel for the seat and backrest, 14 or more modern versions which provide a fairly rigid and padded seat and backrest designed for comfort and posture.

16 Although these meet the needs of those people who 17 have difficulty walking, most of these conventional devices do 18 not provide adequate back support for those people who could 1 sit upright in a chair or wheelchair but require specialized 2 support because of muscular-skeletal problems such as 3 curvature of the spine or degenerative conditions.

4 Numerous devices have been developed in response to the well known problem commonly known as "low back pain 6 syndrome" but most of these are directed to providing support 7 for the usual curvature of the lumbar portion of the spine.

8 These devices are found in office chairs, automobile seats, 9 and portable backrests.

It is the purpose of this invention to provide a 11 back support for people with more serious disability, capable 12 of being adjusted in various ways to provide a variety of 13 configurations adaptable to the needs of the individual user.

14 It is also the purpose of this invention to provide a back support which is capable of being used in conjunction 16 with a vehicle such as a wheelchair.

17 These objects and other advantages may be achieved 18 by means of a back support of the present invention which ~150902 1 comprises a substantially upright longitudinally extending 2 spine and a plurality of support arms extending laterally on 3 either side and a plurality of attaching arms extending 4 laterally on either side, said arms being removably attachable to the spine at adjustable locations thereon. Ideally, the 6 attaching means comprises a plurality of grooves 7 longitudinally extending and laterally spaced on the spine and 8 at least one lug adapted to fit into said grooves located on 9 each of the arms. Threaded means are provided so that the attaching means may be tightened to snugly position the arms 11 in position.

12 The support arms are a semi-rigid flexible panel 13 with means to adjust the panels in a laterally and forwardly 14 curved direction. This is achieved by a pivot cap which is lS concave and fastened to the back side of the panel and has 16 threaded means to vary the space between the panel and the 17 concave pivot cap.

18 The attaching arms are also adjustably located to 1 extend laterally and have means whereby they can be affixed to 2 the structure of wheelchairs and the like.

3 The invention may be better understood by a 4 description of one embodiment thereof with reference to the accompanying drawings in which:

6 Figure 1 is an elevation view of a backrest in 7 accordance with the present invention;

8 Figure 2 is a horizontal cross-sectional view of one 9 side of the backrest in Figure 1 along the line 2-2;

11 Figure 3 is a horizontal cross-sectional view of 12 one-half of the backrest in Figure 1 along 13 the line 3-3.

14 Figure 4 is an enlarged version of the view in Figure 2.

16 The embodiment of the invention illustrated in 17 Figures 1, 2, 3 and 4 comprises a substantially rigid upright 18 spine 2 having side arms 20 and attaching arms 40 extending 1laterally on either side, as seen generally in Figure 1.

2The spine 2 is an elongated piece of uniform cross-3section preferably of a strong material such as a rigid 4plastic or aluminum to provide a strong base for the 5additional attachments to be described later.

6In detail, shown best in Figure 2, the spine 2 has 7a front face 8 which is substantially planar but has a series 8of parallel vertically extending and laterally spaced dove-9tail shaped grooves 10 along the front face.

10The back of the spine has a curved section 12 which 11forms a reinforcing structure for the front planar portion 8 12by being joined thereto at the sides 14 and 16 respectively, 13as well as the struts 18 in the middle.

14This curved formation not only adds strength and 15rigidity but conforms the curved shape of most wheelchairs 16which have a backrest of a curved configuration.

17On either side of the spine are located a plurality 18of side arms 20 which not only provide additional width to the 1 backrest but by being curved forwardly provide some lateral 2 support as well.

3 Also spaced along each side of the spine and 4 attached thereto are a plurality of attaching arms 40 by which the backrest may be securely attached to the upright posts or 6 other structure usually found on conventional wheelchairs.

7 As seen best in Figure 2 the side arms 20 comprise 8 a strut 22 which has one or more dove-tail shaped lugs 24 g adapted to fit the grooves 10 of the spine as illustrated. In addition, it has one or more nuts 26 which also fit within the 11 grooves 10 so that the side arm may be clamped tightly in a 12 fixed position on the grooves by a bolt which threadably 13 engages the nut 26.

14 On the outboard end of each side arm is a pivot cap 28 fastened to the side arm 22 by an adjustable bolt 30 with 16 an adjusting knob 31 and pivotal head 33. Mounted on the bolt 17 30 between the pivot cap 28 and the side arm 22 is a bias 18 spring 32. The pivot cap 28 and the end of the side arm 22 1are fastened by a rivet or similar fastener at point 34.

2It will be apparent that adjustment of the bolt 30 3against the bias of the spring 32 will cause the end of the 4side arms to curb more or less in a forward direction as 5desired by the operator.

6In addition, the front of the side arm and pivot 7cap have a semi-rigid but flexible panel 36 which in turn is 8covered by a soft polymeric foam or other cushioning material 9 38.

10Also shown in Figure 1 and detailed in Figure 4 11there is a plurality of attachment arms 40 which are attached 12to the spine by means of the dove-tailed lugs 42 similar to 13those on the side arms, which engage the grooves 10 of the 14spine. The similar nut 44 and cooperating bolt also engages 15the dove-tailed grooves and allows the attachment arm to be 16adjustably fixed in a chosen position.

17In the illustrated embodiment, as detailed in Figure 183, the adjusting arm extends laterally from the spine 2 215090~

1 thence outwardly and rearwardly at 46 and thence outwardly and 2 forwardly at 48 and has at its outer end a curved hook 50 3 which is designed to engage a post such as schematically 4 illustrated at 54 or other structural piece of a conventional wheelchair. Preferably, some sort of clamping means such as 6 the screw 52 is provided by which the device can be safely and 7 rigidly attached to the wheelchair. Element 54 is illustrated 8 as a tubular structural piece in a conventional wheelchair but g it should be recognized that use to which this invention may be put may require modifications to the attaching means which 11 do not necessarily limit the scope of this invention or depart 12 from the inventive concept herein.

13 From the details of the illustrated embodiment 14 described above, it will be apparent that a backrest of this nature may be used on a conventional wheelchair by fastening 16 the hooks 50 to a strut such as 54 or handle support. This 17 attachment may be adjusted for various dimensions by locating 18 the lugs of the attachment arms 40 in the appropriate groove 1 10 to achieve the desired lateral dimension, and by adjusting 2 the arm up and down the length of the grooves to achieve the 3 desired vertical location.

4 Similarly, the side arms may be adapted for the particular needs of the person who is using the backrest by 6 adjusting them vertically up and down the length of the slots 7 and by selecting the appropriate groove to move the side arms 8 laterally in or out as required.

9 Furthermore, the side arms may be adjusted as to curvature by adjusting the knob 31 on bolt 30 against the bias 11 of the spring 32 so that the ends of the side arms will be 12 more flat or more curved as desired.

13 Not only can this backrest be adjusted for vertical 14 and lateral dimensions, but each side arm may be located differently and varied as to its curvature so that people 16 with spinal curvature or irregular posture may be fitted in 17 the most helpful and comfortable way.

18 The invention has additional advantages by virtue of 1 its design as illustrated because the spine 2 is separate from 2 the side arms 4 or the attaching arm 6. The spine may 3 therefore be made of a constant cross-sectional shape and 4 therefore is adapted to economical and easy manufacture by extrusion. Furthermore, the part may be extruded in a rigid 6 plastic or aluminum or any other equally suitable material and 7 the extruded product need only be cut at whatever desirable 8 length is required.

9 Similarly, the side arm pieces 22 and the attachment arms 40 with their dove-tailed lugs which conform with the 11 groove 10 in the spine also, if desired, be made by extrusion 12 and merely cut into the appropriate width.

13 Because of this adaptability the backrest may be 14 used with more or fewer side arms or attachment arm pieces, and broken or worn out pieces may be removed for repair or 16 replacement.

17 It should be realized as well that the centre 18 portion of the spine may be fitted with a soft cushioning 1 - material such as polymer foam to provide comfort and support 2 in the area between the side arms. This cushion, although not 3 illustrated, may also be designed with a backing having lugs 4 adapted to fit into the grooves 10 of the spine.

It will, of course, be realized that numerous 6 modifications and variations from the illustrated embodiment 7 may be employed without departing from the inventive concept 8 herein.

Claims

1. An adjustable backrest comprising:
- an upright longitudinally extending spine;
- a plurality of support arms attachable to said spine and extending laterally on either side thereof;
- a plurality of attaching arms attachable to said spine and extending laterally on either side thereof.

2. A backrest as claimed in claim 1 in which said arms are removably attachable to said spine at adjustable locations thereon.

3. An adjustable backrest as claimed in claim 2 in which said adjustable attaching means comprises a plurality of grooves longitudinally extending and laterally spaced on said spine and at least one lug adapted to fit said grooves located on each of said arms.

4. An adjustable backrest as claimed in claim 3 in which said adjustable attaching means includes threaded means adapted to tighten said lugs snugly in position in said grooves.

5. A backrest as claimed in claims 1, 2, 3 and 4 in which said support arms comprise a semi-rigid flexible panel and means mounted thereon to adjustably alter the curvature of said arm in a laterally and forwardly direction.

6. A backrest as claimed in claims 1, 2, 3 and 4 in which said support arms comprise a semi-rigid flexible panel and means mounted thereon to adjustably alter the curvature of said arm in a laterally and forwardly direction, said curvature adjusting means comprising a pivot cap having a concave configuration adjacent to the back of said flexible panel at the ends thereof and spaced from the flexible panel in the centre thereof and threaded means extending between said flexible panel and the centre of said pivot cap to vary the measure of said space.

7. A backrest as claimed in claims 1, 2, 3 and 4 in which said attaching arms have means thereon for attachment to wheelchairs and the like.

8. A backrest as claimed in claims 1, 2 and 3 in which said attachment arms are located in vertically spaced relationship between pairs of adjacent support arms.