TECHNICAL FIELD
[0001] The present invention relates generally to support devices for control assemblies.
BACKGROUND
[0002] A control assembly in connection with a seat is most often mounted somewhere along
the side of the seat, enabling the person to use the control assembly with one of
the hands while seated in the seat. Having the control assembly being supported by
a movable support device enables the control assembly to be adjusted such that the
control assembly is placed in a desired position by the particular user of the seat.
When using the control assembly the desired position is typically in front of the
person on the right or left hand side, whereas when not using the control assembly,
the desired position is typically in a retracted position further back or even behind
the user. In
US5326063 a movable support device for controlling the position of a control assembly is disclosed.
The movable support device of
US5326063 allows the control assembly to be locked in a retracted and an extended position.
[0003] An electrically powered wheelchair is usually controlled by a control assembly, such
as a joystick, a touch panel or a finger control assembly. In normal use, the electrically
powered wheelchair is used as means of transportation as well as means for sitting
when working, eating and interacting with other persons. When the electrically powered
wheelchair is used as a means for transportation, control precision and comfort is
of essence, why it is important that the control assembly can be positioned where
the user desires. When, on the other hand, the electrically powered wheelchair is
used as sitting means, especially at a table, it is highly desirable that the control
assembly can be stowed away, not to interfere with the mobility or activities of the
user.
[0004] A user of an electrically powered wheelchair, usually have some sort of disability
limiting the person's ability to move or limiting the muscular strength of that person.
This makes it difficult for the person to move objects or to affect mechanical constructions
with muscular strength. For non-disabled users it may be difficult to move a heavy
control assembly with the precision required to position the control assembly in a
desired position if the movable supporting device, to which the control assembly is
mounted, should fixate the control assembly adequately in normal use.
SUMMARY
[0005] A movable supporting device for changing the position of a control assembly is provided.
The movable supporting device comprises an operable joint and an electrically releasable
lock. The operable joint is adapted to be locked by the electrically releasable lock
such that the control assembly can be locked in a position along the motion track
of the movable supporting member.
[0006] According to one embodiment, the electrically releasable lock comprises an electromagnet
which interacts with friction creating elements for locking the movable supporting
device, such as an electromagnetic break.
[0007] According to another embodiment, the operable joint of the movable supporting device
is actively operable, e.g. by means of an electric motor. In other embodiments the
movable supporting device further comprises a second operable joint, which may be
interlinked with said first operable joint. The two operable joints could be interlinked
using a timing belt.
[0008] The movable supporting device could be adapted to create a pantographic movement
of the control assembly, for always maintaining the orientation of the control assembly.
The control assembly could be a mechanical, hydraulic, pneumatic or electric and could
be in the form of for example a joystick, a leaver, a wheel, a knob or a touch panel.
[0009] The movable supporting device could further comprise a switch for controlling the
electrically releasable lock, which could be an electrical switch possible to operate
without the use of large muscular force, which for example could be placed in connection
with the control assembly for easy access by a user.
[0010] According to one embodiment, the movable supporting device is movable along a motion
track, and the electrically releasable lock is adapted to lock the movable supporting
device anywhere along the motion track.
[0011] It is furthermore conceivable that the movable supporting device, according to any
one of the embodiments herein, further comprises a fixating element, which for example
could be adapted to fixate the movable supporting device to an armrest.
BREIF DESCRIPTION OF THE DRAWINGS
[0012] The invention is now described, by way of example, with reference to the accompanying
drawings, in which:
Fig. 1 shows a movable supporting device mounted to the armrest of a wheelchair.
Fig. 2 shows the movable supporting device of fig. 1 in further detail in a see-through
view.
Fig. 3 shows the movable supporting device and a control assembly, according to another
embodiment.
Fig. 4 illustrates the motion track of a movable supporting device and control assembly.
DETAILED DESCRIPTION
[0013] In the following a detailed description of embodiments will be given. In the drawing
figures, like reference numerals designate identical or corresponding elements throughout
the several figures. It will be appreciated that these figures are for illustration
only and are not in any way restricting the scope of the invention. Thus, any references
to direction, such as "up" or "down", are only referring to the directions shown in
the figures.
[0014] An operable joint is to be understood as a joint connecting two or more parts in
a way such that the two or more parts can be moved in relation to each other.
[0015] A control assembly is to be understood as an assembly with the purpose of affecting
the state or movement of a device, such as an electrical wheelchair or a construction
crane. Examples of control assemblies are mechanical, pneumatic, hydraulic and electrical
control assemblies which could be in the form of a joystick, a leaver, a wheel, a
knob or a touch panel.
[0016] Fig. 1 shows the movable supporting device 1 according to an embodiment in which
the movable supporting device 1 is fixated to the armrest 8 of a wheelchair. The movable
supporting device 1 is here adapted for changing the position of a control assembly
2, here being a joystick 2. The movable supporting device 1 comprises a first and
a second operable joint 5,6. The first operable joint 5 is in connection with the
armrest 8 of the wheelchair, whereas the second operable joint 6 is in connection
with a supporting plate 4 supporting the control assembly 2 fixated thereon. The two
operable joints 5,6 may be interlinked through a timing belt (shown in greater detail
in fig. 2) which enables the movable supporting device 1 to perform a pantographic
movement of the control assembly 2 which renders the orientation of the control assembly
2 unchanged when the movable supporting device 1 moves. The movable supporting device
1 further comprises an electrically releasable lock 7 in connection with the first
operable joint 5 for locking the movement of the movable supporting device 1. According
to the embodiment shown in fig 1, the electrically releasable lock 7 comprises an
electromagnet which is operated by a switch 3 placed in connection with the control
assembly 2, for activating the electromagnet and thereby releasing the electrically
releasable lock 7. When the electrically releasable lock 7 is released, the movable
supporting device 1 is easily movable, almost without friction, and thereby is the
position of the control assembly 2 easy to alter, for example from a position suitable
for operating the wheel chair, to a retracted position suitable for using the wheelchair
as sitting means while eating. The electrically releasable lock according to the embodiment
of fig. 1 comprises multiple friction creating discs, which are pushed against each
other by means of a spring member. An electromagnet is placed in connection with the
friction creating discs and releases the force created by the spring when activated,
thereby allowing the friction creating discs to move easily in relation to each other.
According to other embodiments multiple such friction creating discs may be used for
increasing the friction and hence the holding power of the electrically releasable
lock 7 locking the movable supporting device 1. This particular embodiment of an electrically
releasable lock 7 may of course, in any of the embodiments herein, be substituted
to any other electrically releasable lock. Such electrically releasable locks are
generally well known in the art. The movable supporting device is thereby movable,
with use of very small force, when the releasable lock is released, and locked in
a very firm hold, when the releasable lock is locked.
[0017] Fig. 2 shows the movable supporting device 1 according to fig. 1 in further detail,
where the first operable joint 5 comprises a centrally placed rotation axis 9a on
to which an inner gear wheel 12a in connection with the timing belt 11 is fixated.
The electrically releasable lock 7 is also fixated to the centrally placed rotation
axis 9a and adapted to lock the centrally placed rotation axis 9a when in its locked
state. By the connection with the timing belt 11, which interconnects the first centrally
placed rotation axis 9a with the centrally placed rotation axis 9b of the second operable
joint 6, the electrically releasable lock 7 also locks the second centrally placed
rotation axis 9b. The gear wheels 12a,b and the timing belt 11 is housed in a housing
10 preferably made of a durable material such as aluminum or polyamide.
[0018] According to other embodiments (not shown), the movable supporting device 1 comprises
two electrically releasable locks placed on the first centrally placed rotation axis
9a and the second centrally placed rotation axis 9b, respectively.
[0019] Fig. 3 shows the movable supporting device 1 in a side view when the movable supporting
device 1 is fixated to the armrest 8. The movable supporting device 1 comprises a
first and second operable joint 5,6, each comprising a centrally placed rotation axis
9a,b, interconnected with a timing belt 11 such that the control assembly 2 creates
a pantographic movement when the operable joints 5,6 are moved. The electrically releasable
lock 7 is here placed on the rear operable joint 5, however it is equally conceivable
that the electrically releasable lock 7 is placed on the frontal operable joint 6,
or that the movable supporting device 1 comprises two electrically releasable locks,
one located on the frontal operable joint 6 and one on the rear operable joint 5.
[0020] The movable supporting device 1 according to the embodiment of fig. 3 is actively
operable using an electric motor 13, which could enable a person to move the support
even if the person is unable to push the movable supporting device 1 with muscular
force. The electric motor 13 could for example be placed in the armrest 8 of a wheelchair
and could be operated using a switch on the control assembly 2 or a switch placed
in connection with the headrest or in a tongue control unit.
[0021] Fig. 4 shows the motion track of the movable supporting device 1 of fig. 1 from above,
displaying the pantographic movement made by the control assembly 2 by the connection
with the two interlinked operable joints 5 and 6. The electrically releasable lock
7 is adapted to lock the movable supporting device 1 anywhere along its motion track
and the pantographic movement guaranties that the control assembly 2 remains in the
same orientation wherever it is locked. In embodiments where the control assembly
2 is a joystick controlling the movements of a wheelchair the direction that the joystick
needs to be pushed in order for the wheelchair to travel foreword and backwards respectively,
will be the same, no matter where the movable supporting device 1 to which the joystick
2 is mounted, is locked. It is also conceivable that the moveable supporting device
1 shown in fig. 4 is actively operable to crate said pantographic movement, e.g.by
means of an electrical motor as shown with reference to fig. 3.
[0022] Please note that any embodiment or part of embodiment or feature described herein
may be combined in any way if such combination is not clearly contradictive.
1. A movable supporting device for changing the position of a control assembly, wherein
said movable supporting device (1) comprises an operable joint (5;6) , characterized in that said movable supporting device (1) further comprises an electrically releasable lock
(7), and wherein said operable joint (5;6) is adapted to be locked by said electrically
releasable lock (7).
2. The movable supporting device according to claim 1, wherein said electrically releasable
lock (7) comprises an electromagnet.
3. The movable supporting device according to any one of claims 1 and 2, wherein said
operable joint (5;6) is actively operable.
4. The movable supporting device according to claim 3, wherein said actively operable
joint is actively operable using an electric motor (13).
5. The movable supporting device according to any one of the preceding claims, wherein
said movable supporting device (1) further comprises a second operable joint (5;6).
6. The movable supporting device according to claim 5, wherein said two operable joints
(5,6) are interlinked.
7. The movable supporting device according to claim 6, wherein said two operable joints
(5,6) are interlinked using a timing belt (11).
8. The movable supporting device according to any one of claims 6 and 7, wherein said
movable supporting device (1) is adapted to create a pantographic movement of said
control assembly (2).
9. The movable supporting device according to any one of the preceding claims, wherein
said control assembly (2) is a joystick.
10. The movable supporting device according to any one of the preceding claims, wherein
said movable supporting device (1) further comprises a switch for controlling said
electrically releasable lock (7).
11. The movable supporting device according to any one of the preceding claims, wherein
said movable supporting device (1) is movable along a motion track and wherein said
electrically releasable lock (7) is adapted to lock said movable supporting device
(1) anywhere along said motion track.
12. The movable supporting device according to any one of the preceding claims, wherein
said movable supporting device (1) further comprises a fixating element adapted to
fixate said movable supporting device (1) to an armrest (8).