The present invention relates to a moving aid for the (fore)arm of a person. Moving aids as such are known in the art, for example from
In many cases this is done by supporting the (fore)arm in a certain position, or by providing a movable support for the (fore)arm with respect to a (roller)chair or bed. The support is then arranged for moving along with the arm, and may or may not be powered in order to ease the movement for a user.
In general, these aids provide an improvement in the well-being of the person, but still there are some disadvantages associated with them. In particular, the arrangements on (wheel-) chairs are voluminous, which causes - in the case of a wheelchair - for instance trouble when trying to pass through doors and other small openings. Furthermore, the operation of the existing aids is in many cases still intensive and exhausting for their users.
For that reason, and in general for providing a useful alternative to the existing moving aids, it is a goal of the present invention to provide a moving aid that at least partly lacks the above disadvantages, and that provides benefits over the prior art.
The present invention thereto proposes a moving aid for the (fore)arm of a person, comprising an armrest for receiving the (fore)arm of a person, a carrier for the arm rest, a support, for movably supporting the carrier with respect to the (wheel)chair, work place, bed or other fixed world, wherein the support comprises a first parallelogram, having a first essentially horizontal extending upper side, connected to the (wheel)chair, work place, bed or other fixed world, and a first lower side, situated below the upper side, coinciding with a second lower side, forming part of a second parallelogram, which second parallelogram comprises a second upper side, situated above the first upper side of the first parallelogram and which holds the carrier; and wherein at least one of the legs of the second parallelogram that connect the second lower side and the second upper side extends beyond the second lower side; and wherein the lower end of the at least one leg that extends beyond the second lower side is beared in a conductor-track, which conductor-track is formed such that a second upper side of the second parallelogram is urged in a desired track, such as an essentially horizontal track.
The moving aid according to the present invention provides the advantage that an arm rest is provided that is able to follow for instance horizontal movement of the (fore)arm of a person, while being compact and robust. Alternative solutions according to the prior art with sliding constructions have appeared not to be able to resist the weight of an arm and a load for the arm for a long time without wear, and yet other solutions according to the prior art are not able to follow a straight horizontal or other desired movement of the arm, or are not compact.
The use of a double parallelogram enables the carrier for the arm rest and thus the arm rest to follow a straight horizontal path. The path is further controlled by the conductor-track through which the lower end of the at least one leg that extends beyond the second lower side is beared. This conductor track may thereto for instance have a V-shape, as will be explained later on with respect to the figures.
In order to increase the safety of the use of the moving aid, the conductor-track may be arranged under a cover. This also avoids dirt from entering the track and this causing malfunctioning. The cover may further have an aesthetic or ergonomic effect.
In an embodiment, the carrier comprises at least two mutually hinged parts, which are at least together rotatable about a vertical axis with respect to the support, and wherein the second hinged part is rotatable about a horizontal axis with respect to the first hinged part.
The at least two mutually hinged parts thus form two "arms" of which the carrier is formed, and together with the axes of rotation mentioned above enable to perfectly follow a user's arm movement.
In a further embodiment, the rotation about the vertical axis comprises a lock. Such lock prevents undesired and/or uncontrolled rotation and movements of a user's arm, and enables to fix the arm support in a desired position, which may be a preferred setting of a user. The lock may comprise a number of pins, arranged in a circle, and a different number of holes for receiving the pins, arranged in a circle with the same diameter, for enabling a number of locking positions that is equal to the product of the number of pins times the number of holes. Thereto, the greatest common divider of both numbers should be chosen equal to 1. This number of locking positions may be obtained if the number of pins and the number of holes are not a multitude of each other. The pins may be biased to move into a hole when the pin and the hole are outlined, for instance by a spring, and an unlocking mechanism may be present to remove the pin from a hole.
In yet another embodiment, the rotation of the second hinged part with respect to the first hinged part is restricted by a stop that defines the lowest position of the arm rest. The stop may be movable by means of an actuator, which can be arranged for moving the stop with an armrest resting on it. The actuator and the stop have a double function this way. On one hand, they serve to set the lowest rest position for the arm of the user, on the other hand, they provide lifting power for a user's arm and a load carried by that arm. The stop according to the invention may also be used without the features of the independent claim.
Preferably, the arm rest is balanced about its axis of rotation. That is, a counter-force is provided for the weight of the arm, or the arm and a load, so that a user minimally needs to exert a force for moving. Such balance may be obtained by a using a zero free length spring for the balanced support of the arm rest, which zero free length spring may have an adjustable bias. In a specific embodiment, the zero free length spring comprises a compression-spring.
The invention will now be elucidated into more detail with reference to the following figures. Herein:
In the embodiment shown, the rotation about the vertical axis J comprises a lock 11, comprising a number of pins 12, arranged in a circle, and a different number of holes 13 for receiving the pins, arranged in a circle with the same diameter, for enabling a number of locking positions that is equal to the product of the number of pins 12 times the number of holes 13. In order to obtain that effect, these numbers should not be a multitude of each other wherein the greatest common divider is one.
The figure further shows in detail 16 how the rotation of the second hinged part 10 with respect to the first hinged part 9 is restricted by a stop 17 that defines the lowest position of the arm rest. The stop 17 cooperates with a protrusion 18 provided on lever 19 which determines the relative movement of hinged parts 9 and 10. The stop 17 is movable by means of an actuator 20 which drives a spindle 21. In a practical embodiment, the actuator 20 is arranged for moving the stop 17 with an arm resting on arm rest 2.
The arm rest is balanced about its axis of rotation L, that is, a vertical movement can be performed without the need of exerting a force. Thereto, the lever 19 may be provided with a zero free length spring construction for the balanced support of the arm rest. As detail 14 shows, the zero free length spring may - in order to create a very compact configuration - comprise a compression-spring 22. Detail 15 finally shows a lock for the rotations about two horizontal axes. The embodiments shown are for illustrative purposes only and do not limit the scope of the patent, which is defined in the following claims.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.