WO2009038483A1

WO2009038483A1 - Joystick for a mobility device

Info

Publication number: WO2009038483A1
Application number: PCT/NZ2008/000244
Authority: WO
Inventors: Roland T. Forrer; Gary Andrew James Dellow
Original assignee: Dynamic Controls
Priority date: 2007-09-19
Filing date: 2008-09-18
Publication date: 2009-03-26

Abstract

A joystick for attachment to a joystick shaft of a mobility device, the joystick including first and second separate elements, wherein the first element includes a connection means for connecting the joystick to the joystick shaft, and a first attachment means, and the second element includes a second attachment means for semi-permanent attachment to the first attachment means of the first element.

Description

JOYSTICK FOR A MOBILITY DEVICE

FIELD OF THE INVENTION

The present invention relates to joystick for a mobility device. In particular, it relates to a joystick for a mobility device that has two elements, one being semipermanently attached to the other.

BACKGROUND

Motorised mobility devices, such as motorised wheelchairs and scooters or the like, utilise a joystick in order to allow the user to control the speed and/or direction in which the mobility device is to move. The joystick assembly is connected to a shaft which forms part of a detection system. The detection system determines the radial direction in which the joystick is being operated, as well as, optionally, the amount of movement in any particular direction.

A problem encountered with joysticks used on such mobility devices is the damage that can be caused when the mobility device is moved in such a way that the joystick comes into contact with other objects or surfaces. There is a potential problem in that the joystick can be damaged or snapped off from the joystick shaft, resulting in use of the mobility device becoming awkward or indeed impossible without replacing the entire joystick assembly with a new joystick assembly.

Further, sensitivity of the joystick is important to the user in order for the user to efficiently control the movement of the device at the correct rate of movement and in the correct direction.

In situations where the joystick comes into contact with other objects or surfaces and is not snapped off completely from the joystick shaft, problems can occur where the tension placed on the joystick renders the control of the mobility device less precise. That is, the joystick may become damaged internally at the point where it comes into contact with the joystick shaft such that the joystick gives erroneous or inaccurate speed and direction signal outputs.

An object of the present invention is to overcome, or at least alleviate, the afore- mentioned problems, with a view to at least providing the public with a useful choice.

STATEMENT OF INVENTION

According to one aspect of the invention, there is provided a joystick for attachment to a joystick shaft of a mobility device, the joystick including first and second separate elements, wherein the first element includes a connection means for connecting the joystick to the joystick shaft, and a first attachment means, and the second element includes a second attachment means for semi- permanent attachment to the first attachment means of the first element.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1A shows an exploded view of components of a joystick assembly according to an embodiment of the present invention;

Figure 1B shows a perspective view of the components shown in Figure 1A; Figure 1C shows a cross sectional side view of the components shown in Figure

1A connected together;

Figure 2A shows a side view of an assembly carrier according to an embodiment of the present invention;

Figure 2B shows a perspective view of the assembly carrier shown in Figure 2A; Figure 3A shows a side view of a detachable assembly according to an embodiment of the present invention;

Figure 3B shows a perspective view of the detachable assembly shown in Figure

3A; Figure 4A shows a cross sectional side view of a joystick assembly with a gaiter attached according to an embodiment of the present invention; Figure 4B shows a side view of the joystick assembly shown in Figure 4A; Figure 5 depicts a scenario wherein the joystick assembly has an abnormal force applied to it;

Figure 6 shows a cross sectional side view of components of a joystick assembly according to an embodiment of the present invention;

Figure 7 shows a side view of components of a joystick assembly according to an embodiment of the present invention;

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

Figure 1A shows a number of components of a joystick assembly according to this embodiment. It will be understood that there are other components that make up the complete joystick assembly, and that these are not shown for clarity reasons.

The joystick assembly attaches to a shaft 101. The assembly includes a first element 103 in the form of an assembly carrier, a second element 105 in the form of a detachable assembly and a third element 107 in the form of a knob.

The shaft 101 is a solid cylindrical steel shaft that is attached to the control mechanism of the mobility device, which in this embodiment is a motorised wheelchair. When the shaft is moved, detection systems (not shown) detect the movement, or degree of movement, in order to control motors that drive the wheelchair.

At one distal end of the shaft 101 there is a fixing hole 109 that is formed through the shaft in a direction perpendicular to the length of the shaft. At a second distal end of the shaft 101 there are attachment elements 111 which allow the shaft to be in mechanical connection with the detection systems. The attachment elements 111 in this embodiment include two further fixing holes formed through the shaft body in the same direction as fixing hole 109. The fixing holes are used in conjunction with steel fixing pins that are placed through the holes to fix the shaft 101 in position.

In a lower portion of the assembly carrier 103 is formed a recess 112 of sufficient dimensions to accept the shaft 101 therein. A fixing hole 113 is formed through the assembly carrier 103 in a position such that it is aligned with the fixing hole 109 of the shaft 101 when the shaft 101 is located within the recess 112 of the assembly carrier 103. When the shaft 101 and assembly carrier 103 are connected together, a fixing pin can be inserted through the fixing holes 109 &

113 to lock the shaft 101 and assembly carrier 103 together.

At one end of an upper portion of the assembly carrier 103 is formed a first attachment means in the form of a recess 115 around the circumference of the carrier. The recess 115 includes an upper lip and a lower lip. The upper lip has a substantially perpendicular edge formed thereon, whereas the lower lip has a slightly rounded perpendicular edge. A second end of the upper portion of the assembly carrier 103 is dimensioned to fit within a recess within the detachable assembly 105. As the assembly carrier 103 and the detachable assembly 105 are brought together, they are arranged to become semi-permanently attached via a second attachment means 117 on the detachable assembly attaching to the recessi 15, as will be explained below.

The detachable assembly 105 includes an extending portion 119 of smaller diameter to the main body that is dimensioned to provide a friction fit within a recess 121 formed within the knob 107. In this embodiment, the knob 107 is arranged to be interchangeable so that a user can easily replace a worn knob or attach any desired knob to the joystick assembly.

Figure 1 B shows a perspective view of the components shown in Figure 1A. The attachment means 117 are formed at three points around the inner circumference of the internal recess of the detachable assembly 105. In this embodiment, the attachment means 117 are protrusions that are arranged to slide over the upper lip of the recess 115 when the detachable assembly 105 and assembly carrier 103 are pushed together. When pushed together, the protrusions 117 sit within the recess 115 thus semi-permanently attaching the detachable assembly 105 to the assembly carrier 103. An upper lip of the protrusions 117 creates a stop against the upper lip of the recess 115 such that a pulling force on the detachable assembly 105 in a direction substantially parallel to the shaft 101 does not release the detachable assembly 105 from the assembly carrier 103. The protrusions 117 are biased towards the recess 115. The amount of force required to detach the detachable assembly 105 from the assembly carrier 103 is dependent on the relative stiffness of the protrusions 117 and recess 115. Further, the amount of force required to detach the detachable assembly 105 from the assembly carrier 103 is dependent on the dimensions of the protrusions and recess as well as the angles of the lips.

When an excessive force is applied to the detachable assembly 105 relative to the assembly carrier 103 in any other direction, this causes the combination of recess 115 and protrusions 117 to act in a hinge like manner and become detached from each other in a non-destructive manner. That is, negligible damage is caused to the assembly carrier 103 and detachable assembly 105.

Figure 1C shows a cross sectional side view of the components shown in Figure

1A connected together. This view shows the protrusions 117 acting as a locking finger against the upper lip of the recess 115. Also shown are anti-rotation recesses 123 formed within an upper surface of the assembly carrier 103 on the surface that comes into contact with an inner surface of the detachable assembly 105. On the inner surface of detachable assembly 105 are located anti-rotation protrusions that are arranged to align with the anti-rotation recesses 123 such that the assembly carrier 103 and detachable assembly 105 are inhibited from rotating relative to each other. It will be understood that, as an alternative, the anti-rotation recesses are formed on the detachable assembly and the anti- rotation protrusions are formed on the assembly carrier. Further, it will be understood that, as an alternative, the assembly carrier and detachable assembly may be formed without any anti-rotation features thus allowing the detachable assembly and assembly carrier to rotate relative to each other. Figure 2A shows a side view of the assembly carrier 103. The upper lip 201 and lower lip 203 of the recess 115 are shown in more detail. The upper lip 201 has a substantially perpendicular cross section which enables the protrusions 117 to lock under the lip when attached. The lower lip 203 has a smooth contoured surface formed thereon upon which the detachable assembly can move when an abnormal force is applied in order to create a hinge like movement without damaging either the assembly carrier 103 or detachable assembly 105.

Figure 2B shows a perspective view of the assembly carrier 103. In this view, the shaft recess 112 can be more easily seen. This recess 112 is dimension to allow the shaft 101 to sit within the recess 112 with limited movement, so that maximum control is provided without any hysteresis.

Figure 3A shows a side view of the detachable assembly 105. The main body 301 is formed with the extending portion 119 for attachment to the knob 107.

Figure 3B shows a perspective view of the detachable assembly 105. The protrusions 117 are shown in more detail.

The above described components are fitted together and used in conjunction with other elements of a joystick assembly. Figure 4A shows a cross sectional side view of a joystick assembly with a gaiter 401 attached according to this embodiment. The gaiter 401 is a rubber protective element to stop moisture, dirt or dust from affecting the mechanical functionality of the joystick. In this embodiment, the gaiter 401 is a tubular concertinaed piece of material. A gaiter protector 403 is placed over the assembly carrier 103 in order to lock an upper portion of the gaiter 401 in position. The gaiter protector 403 includes a central recess 405 through which the assembly carrier 103 can pass. Directed towards the centre of the recess 405 are attachment protrusions 407 that slide over the upper portion of the assembly carrier 103 until they locate within the assembly carrier recess 115. When the detachable assembly 105 is fitted to the assembly carrier 103, the detachable assembly protrusions 117 apply a downwards force on the gaiter protector 403 in order to pinch the gaiter 401 against the lower lip of the assembly carrier 103 to lock it into place and provide a seal. At the lower portion of the assembly, a gaiter retaining clip 409 is fitted to lock the lower portion of the gaiter in place. This clip is formed as a ring. Further, a sealing flange 411 is provided that seals the lower portion of the assembly against moisture, dirt or dust.

Figure 4B shows a side view of an assembled joystick assembly as described above.

Figure 5 depicts a scenario wherein the joystick assembly 501 has an abnormal force applied to it. The wheelchair 503 is travelling in a direction indicated by the arrow 505. An immovable object 507, such as a table top, comes into contact with the joystick assembly 501. An abnormal force is then applied to the joystick assembly 501 in the direction of the arrow 509. Under prior known joysticks, the joystick would be damaged such the wheelchair would could not be operated in a safe manner. For example, the wheelchair may not be accurately controlled as the components of the joystick require additional movement in order to make the wheelchair move. This may be because internal elements of the joystick have changed in dimensions due to the abnormal force, or because they have broken off.

When the joystick according to embodiments of the invention comes into contact with such an abnormal force, it will become detached from the main assembly in such a manner that no discernible damage is caused. That is, the detachable assembly becomes detached from the assembly carrier such that it can be immediately refitted to the joystick assembly to enable the wheelchair to be operated in a safe manner.

An abnormal force is considered to be, for the purposes of this application, an excessive force that is applied to the joystick in a certain direction. It does not include a force that is applied when using the joystick in a normal manner. That is, an abnormal force is an excessive force that is applied to the joystick in a direction other than a direction that is substantially parallel to the length of the joystick shaft. The abnormal force may be, for example, a bending force that is applied to the joystick as the joystick comes into contact with an object that resists movement.

Further embodiments

It will be understood that the embodiments of the present invention described herein are by way of example only, and that various changes and modifications may be made without departing from the scope of invention.

An alternative embodiment is shown in Figure 6. This figure shows a cross sectional side view of components of a joystick assembly. The assembly has the same components as described above in relation to Figure 1A. That is, a shaft 601 , assembly carrier 603, detachable assembly 605 and knob 607. Further, the shaft 601 and assembly carrier 603 attach to each other in the same way using fixing holes (609, 613) and a shaft recess 612. Also, the knob 607 and detachable assembly are arranged to attach to each other in the same way via an extension portion 619 and knob recess 621 to create a friction fit. However, in this embodiment, the detachable assembly 605 attaches to the assembly carrier 603 in a different manner. Protrusions or fingers 617 are formed so they extend from the assembly carrier 603 towards the detachable assembly 605. The fingers 617 are located around the circumference of the assembly carrier 603. The detachable assembly 605 has a circumferential recess 615 located on a lower cylindrical extending portion 623. The recess 615 acts in the same way as the recess 115 of the first embodiment. The fingers 617 act in the same way as the protrusions 117 of the first embodiment.

It will be understood that other arrangements for attaching the first and second elements are envisaged. For example, rather than the first element having an aperture or protrusion formed around the circumference of the element, the aperture or protrusion may be formed around one portion of the circumference.

In this manner, the first and second elements are not arranged to rotate with respect to each other. With this arrangement, anti-rotation dimples are not required to stop relative rotation of the first and second elements as the attachment means carries out both the detachable function and anti-rotation function.

Figure 7 shows a further alternative embodiment. A side view of components of a joystick assembly is shown wherein both the assembly carrier 701 and detachable assembly 703 include interlocking fingers (705, 707). That is, the assembly carrier 701 has formed on an outer perimeter of its body an upstanding finger portion that includes an attachment surface 709. The detachable assembly 703 includes a down-standing finger portion that includes an attachment surface 711. When the assembly carrier 701 and detachable assembly 703 are attached together, the down-standing finger 707 of the detachable assembly slides over the up-standing finger 705 of the assembly carrier 701 such that the attachment surfaces (709, 711 ) come into contact with each other to semi-permanently attach the attachable assembly and detachable assembly.

Claims

CLAIMS:

1. A joystick for attachment to a joystick shaft of a mobility device, the joystick including first and second separate elements, wherein the first element includes a connection means for connecting the joystick to the joystick shaft, and a first attachment means, and the second element includes a second attachment means for semi-permanent attachment to the first attachment means of the first element.

2. The joystick of claim 1 , wherein the second element is arranged to rotate relative to the first element.

3. The joystick of claim 1 , wherein the second attachment means is arranged to detach from the first attachment means in a non-destructive manner when an abnormal force is applied to the second element relative to the first element.

4. The joystick of claim 3, wherein the abnormal force is a bending force.

5. The joystick of claim 1 , wherein one of the first and second attachment means includes a recess located on an outer portion of the relevant attachment means, and the other includes a protrusion arranged to locate at least partially within the recess.

6. The joystick of claim 5, wherein the protrusion is arranged to bias towards the recess such that the amount of abnormal force required to be applied in order to detach the second attachment means from the first attachment means is dependent on the relative stiffness of the first and second attachment means.

7. The joystick of claim 1 , wherein the first and second attachment means are arranged to act as a hinge when an abnormal force is applied.

8. The joystick of claim 1 , wherein the first and second elements include anti-rotation means arranged to inhibit the second element from rotating with respect to the first element.

9. The joystick of claim 8, wherein the anti-rotation means includes at least one recess on one of the first or second attachment means, and at least one protrusion on the other first or second attachment means, wherein the protrusion is arranged to locate within the recess when the first and second attachment means are attached.

10. The joystick of claim 1 further including a third element for moving the joystick shaft during normal use, the third element arranged to be interchangeable and connectable to the second element by a friction fit.

11. The joystick of claim 1 , further including a protection element arranged to locate over the joystick shaft and further arranged to be attached at a first end to the first element by external pressure applied by the second element.

12. The joystick of claim 11 , further including a retaining clip arranged to attach the protection element at a second end.

13. The joystick of claim 12, further including a cover arranged to locate over the first element and provide protection for the protection element when the joystick is in use.

14. A joystick for a mobility device substantially as herein described with reference to the accompanying drawings.