WHEELCHAIR COMPRISING A LOCKING SYSTEM

Abstract

 A wheelchair (10) is described comprising: a central crosspiece (12), at the ends of which two wheels (14, 16) are connected, and a column (22) having a first end connected to a seat (21) and the opposite end connected to an anti-tip wheel assembly (31), the column (22) being connected in a sliding manner to the central crosspiece (12) and fixed by means of a locking system (50) comprising a locking element (51) associated with the central crosspiece (12); the wheelchair (10) further comprises first locking means (61) configured to fix the locking element (51) to the central crosspiece (12) and second locking means (62) configured to fix the locking element (51) to the column (22), so as to lock the column (22) between the central crosspiece (12) and the locking element (51) in the position desired by a user.

Description

[0001] The present invention relates to a wheelchair comprising a locking system, in particular for locking a crossbar connected to the wheels and a column connected to an anti-tipping wheel assembly.

[0002] More specifically, the invention refers to a wheelchair for sports activities, for practicing sports using a manual self-propelled wheelchair, such as tennis and basketball.

[0003] Italian patent 1418939 in the name of the Applicant describes a wheelchair comprising a central crosspiece, two wheels connected to the two ends of the central crosspiece and a column having a first end connected to a seat and the opposite end connected to an anti-tip wheels group; the column is connected in a sliding way to the central crosspiece to adjust the distance of the anti-tip wheels unit from the support surface of the wheels.

[0004] The column is adapted to be locked to the central crosspiece with locking means, for example quick release means inserted in slots and holes made in the column and in the central crosspiece.

[0005] The Applicant has observed that the known locking system described in Italian patent 1418939 has the problem of not allowing an optimal locking of the central crosspiece and of the column.

[0006] During the use of the wheelchair, the known locking system presents problems of loosening of the tightening, which causes the movement of the anti-tip wheels unit until the wheels of the unit come into contact with the ground and the incorrect positioning (centering) of the wheelchair axis of the column with respect to the central crosspiece, and therefore with respect to the axis of the wheels.

[0007] Another problem of this known locking system is represented by the difficulty of adjusting the height of the wheel group, using the quick release means inserted in the slots and holes made in the column, while using the wheelchair in the field.

[0008] Document EP-A1-2 826 453 describes a wheelchair according to the preamble of Claim 1.

[0009] Object of the present invention is solving the aforementioned prior art problems by providing a wheelchair comprising a locking system that allows to perform an optimal tightening of the column and central crosspiece, to keep the anti-tip wheels unit in the desired position, while maintaining the correct centering of the axis of the column with respect to the central crosspiece and therefore with respect to the axis of the wheels.

[0010] Another object of the invention is allowing an easy adjustment of the height of the wheel assembly during the use of the wheelchair.

[0011] The above and other objects and advantages of the invention, as will emerge from the following description, are achieved with a wheelchair comprising a locking system such as that described in the independent claim. Preferred embodiments and non-trivial variants of the present invention form the subject matter of the dependent claims.

[0012] It is understood that the attached claims form an integral part of the present description.

[0013] It will be immediately obvious that innumerable variations and modifications (for example related to shape, dimensions, arrangements and parts with equivalent functionality) can be made to what has been described without departing from the scope of the invention as appears from the attached claims.

[0014] The present invention will be better described by a preferred embodiment thereof, provided by way of non-limiting example, with reference to the attached drawings, in which:

- Figure 1 shows a front view of a wheelchair according to the present invention;

- Figure 2 shows a top view of a wheelchair locking system according to the present invention in the working position;

- Figure 3 shows a top view of a wheelchair locking system according to the present invention;

- Figure 4 shows a sectional perspective view of a locking system of a wheelchair according to the present invention in the working position;

- Figure 5 shows a top view of a detail of the wheelchair according to the present invention; and

-- Figure 6 shows a front view of a detail of the wheelchair according to the present invention.

[0015] With reference to the Figures, the wheelchair 10 according to the invention comprises: a central crosspiece 12, at the ends of which two wheels 14, 16 are connected, and a column 22 having a first end connected to a seat 21 and the opposite end connected to an anti-tipping wheel assembly 31; the column 22 is connected in a sliding manner to the central crosspiece 12 and is fixed by means of the locking system 50 of the invention to adjust the distance of the anti-tipping wheel assembly 31 from the support surface of the wheels, while allowing optimum locking of the column 22 with the central crossbar 12.

[0016] The locking system 50 of a wheelchair according to the invention comprises a locking element 51 associated with the central crosspiece 12, first locking means 61 configured to fix the locking element 51 to the central crosspiece 12 and second locking means 62 configured for fixinmg the locking element 51 to the column 22, so as to lock the column 22 between the central crosspiece 12 and the locking element 51 in the position desired by the user.

[0017] Preferably, the central crosspiece 12 comprises a first seat 63 inside which the column 22 is inserted and an opening 64, preferably substantially perpendicular to the first seat 63, into which the locking element 51 is inserted, which in turn comprises a second seat 65 in which the column 22 is inserted.

[0018] The locking element 51 is mounted inside the opening 64 so that the second seat 65 is in correspondence with the first seat 63, and the column 22 is inserted in the first seat 63 and in the second seat 65 superimposed which have for example the same shape.

[0019] Preferably, the first locking means 61 comprise a pin 71 configured for example to be inserted into a hole 72 made in a wall of the opening 64; preferably the pin 71 is threaded and the locking element 51 is locked against the central crosspiece 12 by means of a nut 66 screwed onto the threaded pin 71.

[0020] Preferably, the second locking means 62 comprise quick release means 73 which can be inserted into slots 75 and/or holes made in the column 22; preferably, the slots 75 and/or the holes are arranged in two parallel rows, more preferably the slots 75 and/or the holes of one row are not aligned with the slots 75 and/or the holes of the other row to allow a precise adjustment of the height of the wheel unit.

[0021] Preferably, the quick release means 73 comprise a pin 78 which can be inserted in the slots 75 and/or holes made in the column 22, for example a threaded pin 78 configured to be screwed into the locking element 51.

[0022] Preferably, the locking element 51 comprises at least one external wall 76 configured to be mounted in contact with the central crosspiece 12 and an internal wall 77 in contact with the post 22 when it is locked between the central crosspiece 12 and the locking element 51 by the first locking means 61 and by the second locking means 62.

[0023] Preferably, the first locking means 61 and the second locking means 62 are arranged in correspondence with opposite walls of the central crosspiece 12.

[0024] In a preferred embodiment of the wheelchair 10 according to the invention, the central crosspiece 12 is connected to the wheels 14, 16 by means of hubs which can rotate around a pin perpendicular to the axis of the wheel, and the column 22 comprises a first part connected to the central crosspiece 12 and a second sliding part inside the first part.

[0025] Preferably, the post 22 has a quadrangular section, and the slots 75 and/or the holes are arranged in two rows formed on two different walls of the post 22.

[0026] In the operation of the wheelchair 10 according to the invention, the block element 51 is inserted in the opening 64, so that the first seat 63 and the second seat 65 are superimposed to insert the column 22 inside them; subsequently, the first locking means 61 and the second locking means 62 are locked to fix the locking element 51 to the central crosspiece 12 and to the column 22, in particular by locking said at least one external wall 76 against the central crosspiece 12 and said wall 77 against the stem 22, so as to lock the stem 22 between the central crosspiece 12 and the locking element 51 in the position desired by the user.

[0027] To adjust the distance of the anti-tipping wheel assembly 31 from the support surface of the wheels 14, 16, the first locking means 61 are released, for example by unscrewing the nut 66, together with the second locking means 62, for example by extracting the pin 78 from the slot 75 of one of the two rows, making the column 22 advance by a step corresponding to the distance between two successive slots 75 of a row, allowing to obtain a precise height adjustment; finally, the column 22 is locked in the position desired by the user by closing the first locking means 61 and the second locking means 62.

[0028] Advantageously, the locking system of the wheelchair of the invention allows obtaining an optimal tightening of the column and central crosspiece, to keep the anti-tipping wheel unit in the desired position, maintaining the correct centering of the column axis with respect to the central crosspiece and therefore with respect to the wheel axle.

[0029] Another advantage of the invention is that of allowing an easy adjustment of the height of the wheel group while using the wheelchair.

Claims

1. Wheelchair (10) comprising: a central crosspiece (12), at the ends of which two wheels (14, 16) are connected, and a column (22) having a first end connected to a seat (21) and an opposite end connected to an anti-tipping wheel assembly (31), said column (22) being connected in a sliding manner to the central crosspiece (12) and fixed by means of a locking system (50) comprising a locking element (51) associated with the central crosspiece (12),
characterized in that it further comprises first locking means (61) configured to fix the locking element (51) to the central crosspiece (12) and second locking means (62) configured to fix the locking element (51) to the column (22), so as to lock the column (22) between the central crosspiece (12) and the locking element (51) in a position desired by a user.

2. Wheelchair (10) according to claim 1, characterized in that the central crosspiece (12) comprises a first seat (63) into which the column (22) is inserted and an opening (64) into which the locking element (51) is inserted, which comprises a second seat (65) into which the column (22) is inserted.

3. Wheelchair (10) according to claim 2, characterized in that the locking element (51) is mounted inside the opening (64) so that the second seat (65) is in correspondence with the first seat (63) and the stem (22) is inserted in the first (63) and in the second seat (65).

4. Wheelchair (10) according to any one of the preceding claims, characterized in that the locking element (51) comprises at least one external wall (76) configured to be mounted in contact with the central crosspiece (12) and an internal wall (77) in contact with the column (22) when it is locked between the central crosspiece (12) and the locking element (51) by the first locking means (61) and by the second locking means (62).

5. Wheelchair (10) according to any one of the preceding claims, characterized in that the first locking means (61) and the second locking means (62) are arranged in correspondence with opposite walls of the central crosspiece (12).

6. Wheelchair (10) according to any one of the preceding claims, characterized in that the first locking means (61) comprise a pin (71) configured to be inserted into a hole (72) obtained in a wall of the opening (64).

7. Wheelchair (10) according to claim 6, characterized in that the pin (71) is threaded and the locking element (51) is locked against the central crosspiece (12) by means of a nut (66) screwed onto the threaded pin (71).

8. Wheelchair (10) according to any one of the preceding claims, characterized in that the second locking means (62) comprise quick release means (73) which is designed to be inserted into slots (75) and/or holes made in the column (22).

9. Wheelchair (10) according to claim 8, characterized in that the quick release means (73) comprise a pin (78) which is designed to be inserted into the slots (75) and/or holes.

10. Wheelchair (10) according to claim 8 or 9, characterized in that the slots (75) and/or the holes are arranged in two rows.

Drawing