Technical field
[0001] The present invention relates, in general, to a wheelchair for sports, adapted to
be used for sports requiring the use of a manually self-propelled wheelchair, such
as tennis and basketball.
[0002] In particular, the present invention relates to a manually self-propelled wheelchair
for sports provided with anti-tip wheels.
Prior art
[0003] Self-propelled wheelchairs for sports which are designed to achieve high stiffness
of the structure and of the anti-tip wheels while limiting the weight of the wheelchair
are known in the field.
[0004] The wheels of known wheelchairs for sports are mounted with a camber angle fixed
with respect to a plane perpendicular to the support plane, in order to provide better
maneuverability.
[0005] The Applicant has observed that the wheelchairs known in the field have a plurality
of problems.
[0006] A first problem concerns the difficulty of adaptation and adjustment of the components
of the wheelchair to the needs and to the physical characteristics of the user, and
in particular they do not allow an easy adaptation to different users that share the
use of the same wheelchair for practicing sports nor adaptation to the user's changing
needs, which vary with his/her physical preparation and with the improvement of his/her
sport skills.
[0007] A second problem is that the possible adjustments on known wheelchairs require complex
interventions and cannot be made quickly on the playing field, but have to be made
in a workshop.
[0008] A further problem of known wheelchairs consists in the fact that in order to maintain
good traction of the wheels on the ground, the anti-tip wheels must be kept away from
the ground, thus causing a pronounced pitching of the wheelchair while pushing.
[0009] Therefore, the known self-propelled wheelchairs for use in sports have a plurality
of problems.
Summary of the Invention
[0010] It is an object of the present invention to provide a self-propelled wheelchairs
for sports that solves the problem of eliminating or greatly reducing the pitching
of the wheelchair while pushing, without decreasing the traction of the wheels.
[0011] Another object is to have a wheelchair that allows easy adjustment of its components,
to be performed in a short time and without the need for specific tools, unlike the
solutions adopted in the prior art.
[0012] According to the present invention, the above and other objects are achieved by means
of a self-propelled wheelchair for sports defined in the characterizing part of the
appended claim 1.
[0013] It is to be intended that the appended claims form an integral part of the technical
teaching provided herein in the description in respect of the present invention.
Brief Description of the Figures
[0014] Further features and advantages of the present invention will become apparent from
the following detailed description, given only by way of non-limiting example, with
reference to the accompanying drawings, in which:
- figure 1 is a schematic front view of a wheelchair for sports according to the present
invention;
- figure 2 is a schematic side view of a wheelchair for sports according to the present
invention;
- figure 3 is an enlarged view of a detail of a wheelchair for sports according to the
present invention; and
- figure 4 is a perspective view of a wheelchair for sports according to the present
invention.
Description of Preferred Embodiments
[0015] With reference to the figures, a wheelchair for sports 10 according to the present
invention comprises a central cross-beam 12, a first wheel 14 having a first hub 13
connected to a first end of the central cross-beam 12 and a second wheel 16 having
a second hub 15 connected to a second end of the central cross-beam 12.
[0016] The wheelchair 10 of the invention further comprises a seat post 22 having a first
end connected to a seat 21 and the opposite end connected, for example by welding,
to an anti-tip wheels assembly 31.
[0017] The seat post 22 is slidably connected to the central cross-beam 12; preferably the
seat post 22 is connected to the central cross-beam 12 by means of sliding guides,
for adjusting the distance of the anti-tip wheels assembly 31 from the ground.
[0018] For example, in the embodiment of the invention shown in the figures, in the central
cross-beam 12 there is provided a seat, within which the seat post 22 slides; preferably
the seat post 22 is adapted to be locked to the central cross-beam 12 by known locking
means 32, for example by quick release means, that are for example inserted in slots
and holes formed in the seat post 22 and in the central cross-beam 12.
[0019] The anti-tip wheels assembly 31 comprises a first arm 35, a second arm 36 and at
least two anti-tip wheels 33, each wheel being connected to the first arm 35 and to
the second arm 36 through resilient means 37.
[0020] The arms 35 and 36 are made in a known manner of metal, for example aluminum, steel,
titanium alloy, or even carbon fiber, so as to have a rigid structure.
[0021] Advantageously, the resilient means 37, consisting, for example, of leaf springs,
are adapted to keep the anti-tip wheels 33 in contact with the ground during the moving
of the wheelchair, compensating the variations in distance between the anti-tip wheels
assemblies 31 and the ground that occur when pushing the wheelchair.
[0022] In a second embodiment of the wheelchair 10 of the invention the anti-tip wheels
assembly 31 comprises three arms, each arm being connected to an anti-tip wheel 33
through the resilient means 37; in a further embodiment of the wheelchair 10 of the
invention the anti-tip wheels assembly 31 comprises four arms, each arm being connected
to an anti-tip wheel 33 through the resilient means 37.
[0023] Preferably, the seat 21 is slidably mounted on the seat post 22; according to an
embodiment of the invention the seat 21 is connected to an inner post 23 which in
turn is slidably mounted with respect to the seat post 22, for example, is slidably
mounted inside the seat post 22.
[0024] Preferably, the seat 21 is rotatably connected with respect to the inner post 23
by means of a first pivot 25, and is adapted to rotate about the axis of the first
pivot 25 for varying its inclination; the axis of the first pivot 25 has a direction
substantially perpendicular to the inner post 23 and substantially parallel to the
central cross-beam 12. Preferably, the seat 21 is adapted to be locked to the inner
post 23 with the desired inclination, for example up to thirty degrees, by known locking
means 32, for example by quick release means, inserted for example in slots and holes
formed in the seat 21, or in a plate connected to it, and in the inner post 23.
[0025] The seat of the wheelchair of the invention comprises a seat base 28 and a backrest
29 that can rotate with respect to the seat base; in a preferred manner the seat base
can be inclined up to thirty degrees, and the inclination of the backrest 29 can vary
by an angle between 70 and 90 degrees with respect to the seat base 28.
[0026] Optionally, the seat base of the seat 21 is slidably adjustable with respect to the
post, in particular on a plane perpendicular or transverse to the post; for example,
the seat 28 is adapted to slide with respect to a plate fixed to the seat post 22
or fixed to the inner post 23, and fixed by the locking means 32 or other known means
inserted in holes formed in the seat and in the seat post 22 or in the inner post
23.
[0027] Preferably, the seat post 22 and the inner post 23 are constituted by a tube or a
metal section, for example an extruded piece of aluminum, steel, or titanium alloy,
or it can also be made of carbon fiber or other materials suitable to reduce its weight.
[0028] The wheels 14, 16 of the wheelchair for sports 10 of the invention are manually self-propelled
wheels of the known type, and preferably have the camber angle, that is the inclination
angle, and the distance between their hubs 13, 15, adjustable.
[0029] To allow adjustment of the camber angle the first hub 13 and the second hub 15 are
rotatably connected to the central cross-beam 12, and are adapted to rotate about
a pin perpendicular to the axis of the wheel, so as to allow a variation of the inclination
angle of the wheel hub 13, 15 with respect to the central cross-beam 12.
[0030] For example, the first hub 13 and the second hub 15 are fork hubs, and the variation
of the inclination angle of the hub is obtained by means of a plurality of reference
holes which are formed in the hubs and in the central cross-beam and in which there
are inserted known locking means 32, for example quick release means adapted to allow
the adjustment of the inclination angle to a plurality of predefined values, by locking
the rotation of the hub with respect to the cross-beam.
[0031] Preferably, the camber angle can be varied between 10 and 30 degrees; more preferably
from 14 to 24 degrees.
[0032] In an embodiment of the invention the central cross-beam 12 has two movable ends;
in particular a first movable cross-beam 18 and a second movable cross-beam 19 are
slidably connected, for example on known guides, each at one end of the central cross-beam
12, and are adapted to adjust the distance between the first wheel 14 and the second
wheel 16, allowing its adjustment.
[0033] Also in this embodiment the adjustment of the position of the movable cross-beams
18, 19 with respect to the central cross-beam 12 is obtained by means of a plurality
of reference holes or slots which are formed in the movable cross-beams 18, 19 and
in the central cross-beam and in which there are inserted the known locking means
32, for example quick release means adapted to lock the sliding of the movable cross-beams
with respect to the central cross-beam 12. Preferably, the wheelchair 10 of the invention
comprises a platform 26 for supporting the user's feet, with height and angle adjustable
in a known manner, for example through the quick release means 32.
[0034] The operation of the wheelchair for sports 10 of the invention is the following.
[0035] A first adjustment of the wheelchair of the invention is the adjustment of the distance
of the anti-tip wheels assembly 31 from the ground, which is realized by sliding the
seat post 22 with respect to the central cross-beam 12 and locking it at the desired
height, by means of the known locking means 32, for example the quick release means.
[0036] Advantageously, the wheelchair of the invention allows to adjust the distance of
the anti-tip wheels assembly 31 from the ground so that the anti-tip wheels 33 are
always in contact with the ground when the user is pushing the wheels 14, 16.
[0037] Moreover, the anti-tip wheels 33 remain in contact with the ground thanks to the
presence of the resilient means 37, in particular when these are constituted by leaf
springs, even in the presence of pitching of the wheelchair 10 and of the anti-tip
wheels assembly 31, which is absorbed by the resilient means 37.
[0038] This brings about the advantage of improving the efficiency in the transmission of
the pushing force to the wheels 14, 16; this behavior is improved by the presence
of three arms and three wheels in the anti-tip wheels assembly 31 and is maintained
effective also in the presence of four wheels and four arms.
[0039] A second possible adjustment in an embodiment of the wheelchair 10 of the invention
is that of the camber angle of the wheels 14, 16; in particular, the wheelchair of
the invention allows to adjust the angle of the hubs 13, 15 so as to have one wheel
with a camber angle different from that of the other wheel.
[0040] In general, the width obtainable for the camber angle of the wheels obtainable is
greater in the embodiment of the invention in which there are the first movable cross-beam
18 and the second movable cross-beam 19.
[0041] In fact, in the wheelchair according to this embodiment, it is possible to space
the wheel hubs by sliding the mobile cross beams 18, 19 with respect to the central
cross-beam 12, thus allowing the increase of the inclination angle of the hubs 13,
15 and therefore the camber angle of the wheels, keeping the top of the wheels, on
which the user acts while pushing, at the optimal distance from the seat.
[0042] Other possible adjustments in embodiments of the wheelchair according to the invention
are those of the seat 21, in particular of the seat base 28, by sliding the seat post
22 or the inner post 23 with respect to the central cross-beam 12, and of the inclination
of the seat base 28 and of the backrest 29.
[0043] Advantageously, the presence of a plurality of adjustable elements in the wheelchair
10 of the invention, such as the seat 21, the seat base, the inclination of the hubs
13, 15 of the wheels and their distance, allows to adapt the wheelchair 10 to the
needs of the individual user, while also allowing to share the use of a wheelchair
for sports practice by different users or to adapt it to changes in the playing style
and ability of a user.
[0044] Moreover, the presence of the quick release means allows to adjust the wheelchair
of the invention quickly "on the field" at user-level, without the need to use any
equipment or tools.
[0045] In all the embodiments described the wheelchair for sports 10 of the invention advantageously
allows to eliminate or strongly reduce the pitching of the wheelchair while pushing,
without decreasing the traction of the wheels.
[0046] The wheelchair of the invention also has the advantage of allowing easy adjustment
of its components, to be performed in a short time and without the need for special
tools.
[0047] Of course, obvious changes and/or variations are possible with respect to the above
description, in dimensions, shapes, materials, components, connections, as well as
in the details of the illustrated construction and the method of operating without
departing from the scope of the invention as defined in the appended claims.
1. Wheelchair for sports (10) comprising:
- a central cross-beam (12);
- a first wheel (14) having a first hub (13) connected to a first end of the central
cross-beam (12);
- a second wheel (16) having a second hub (15) connected to a second end of the central
cross-beam (12);
- a seat post (22) slidably connected to the central cross-beam (12);
- a seat (21) slidably mounted on the seat post (22), characterized in that it further comprises an anti-tip wheels assembly (31) connected to that end of the
seat post (22) which is opposite to the seat (21), said anti-tip wheels assembly (31)
comprising a first arm (35), a second arm (36), and at least two anti-tip wheels (33),
each wheel being connected to said first arm (35) and to said second arm (36) through
resilient means (37).
2. Wheelchair for sports (10) according to claim 1, characterized in that the anti-tip wheels assembly (31) comprises at least three arms and at least three
anti-tip wheels (33), each wheel being connected to an arm through said resilient
means (37).
3. Wheelchair for sports (10) according to any of the preceding claims, characterized in that said first hub (13) and said second hub (15) are rotatably connected to the central
cross-beam (12) for varying the inclination angle of the wheels (13, 15).
4. Wheelchair for sports (10) according to claim 3, characterized in that said first hub (13) and said second hub (15) are fork hubs.
5. Wheelchair for sports (10) according to any of the preceding claims, characterized in that it comprises a first movable cross-beam (18) and a second movable cross-beam (19)
slidably connected to an end of the central cross-beam (12) for adjusting the distance
between the wheels (13, 15).
6. Wheelchair for sports (10) according to any of the preceding claims, characterized in that it further comprises an inner post (23) connected to the seat (21), said inner post
(23) being slidably mounted with respect to the seat post (22).
7. Wheelchair for sports (10) according to claim 6, characterized in that the seat (21) is rotatably connected with respect to the inner post (23).
8. Wheelchair for sports (10) according to any of the preceding claims, characterized in that said seat (21), said seat post (22), said inner post (23), said first hub (13) and
said second hub (15) are adapted to be locked by quick release means.
9. Anti-tip wheels assembly (31) for a wheelchair for sports (10), said anti-tip wheels
assembly (31) being connectable to a seat post (22) of the wheelchair (10) and comprising
at least three arms and at least three anti-tip wheels (33), each wheel being connected
to an arm through said resilient means (37).
10. Anti-tip wheels assembly (31) for a wheelchair for sports (10) according to claim
9, characterized in that said resilient means (37) are leaf springs.