WO2000051871A1

WO2000051871A1 - Braking device

Info

Publication number: WO2000051871A1
Application number: PCT/NL2000/000128
Authority: WO
Inventors: Willem Michael Post
Original assignee: Montis Bv
Priority date: 1999-03-02
Filing date: 2000-03-01
Publication date: 2000-09-08
Also published as: AU2948300A; NL1011426C2

Abstract

A braking device for braking a wheel of a vehicle, comprising an operating element and a brake element, which brake element can be pushed against the wheel surface by moving the operating element, wherein the operating element and the brake element are movably attached to a frame, and wherein the operating element can push the brake element against the wheel surface by means of a tilting element which is capable of tilting movement with respect to the frame.

Description

BRAKING DEVICE

The invention relates to a braking device for braking a wheel of a vehicle, in particular a wheelchair, comprising an operating element and a brake element, which brake element can be pushed against the wheel surface by moving the operating element, wherein the operating element and the brake element are movably attached to a frame.

Wheelchair users benefit from a simple and also ergonomically sound operation of their vehicle. They need to perform many different operations when propelling and stopping the wheelchair, needing both hands to accelerate, propel, steer, brake and lock the wheelchair. Increasingly people are coming to realise that the parts of the wheelchair must be constructed to enable a precise, simple operation, so that the freedom of movement of a person who is bound to his wheelchair will be impeded as little as possible.

An important role in the aforesaid operations is played by the braking device as referred to in the introduction, by means of which the wheelchair is locked in its stationary position. Such a braking device is generally known. The prior art braking device comprises a pivotable operating handle, which functions as a lever, by means of which a brake block is pushed against a wheel surface of the wheelchair and which can subsequently be locked in position.

One drawback of the prior art braking device is the fact that the user, in order to lock the wheelchair, must push the handle with relatively great force in a direction which is disadvantageous for him, or that the user or another person or an object accidentally catches behind it, so that the risk of accidents is not excluded. Moreover, the lever construction hardly contributes to an aesthetic appearance.

The object of the invention is to provide a braking device which is simple and safe to operate, which provides an advantageous transmission of forces from the operating element to the brake element, and which in addition enables an optically attractive design.

In order to accomplish that objective the braking device according to the invention is characterized in that the operating element can push the brake element against the wheel surface by means of a tilting element which is capable of tilting movement with respect to the frame. The tilting element takes care of the transmission of forces from the operating element to the brake element, wherein the tilting movement causes the force that is exerted on the brake element to increase while the speed of movement of the operating element remains constant during the movement from the non-braked condition to the braked condition and the speed of movement of the brake element decreases. In practice it has become apparent that this leads to a very advantageous transmission of forces. Moreover, the aforesaid lever construction with its inherent drawbacks can be left out when this braking device is used.

In one embodiment the operating element and/or the brake element form part of the tilting element. The operating element may be a knob, for example, which is fixedly connected to one end of the tilting element, and the brake element may form part of the surface of the other end of the tilting element. The advantage of this arrangement is that it makes it possible to use a compact, simple construction.

In another embodiment, the operating element and/or the brake element form a separate part, which is pivotable with respect to the tilting element. The advantage of this arrangement is that the point of engagement of the operating element and/or the braking surface of the brake element can be spaced from the tilting element by some distance, thus enabling a more ergonomic construction and position. Preferably the operating element is mounted under the seat of the wheelchair, seen in the vertical plane, so that the user can push it down with an outstretched arm, using his body weight. This has the additional advantage that sitting down and getting up from one side is facilitated, since no obstacles are in the way. Likewise preferably, the brake element is mounted at the level of the wheel axle, seen in the vertical plane, so that the distance between the brake element and the wheel surface can be very small in non-braked condition, preferably less than 8 mm, since vertical adjustment of the wheel will only result in a minor variation in the horizontal position of the braking surface of the wheel at this location. Also the distance between the point at which the user engages the wheel upon propelling the wheelchair and the brake element is sufficiently large. These two aspects reduce the risk of the user's fingers getting wedged.

Preferably, the operating element and/or the tilting element and/or the brake element comprise guide means, which are in engagement with guide means in the frame. Said frame can form a housing which surrounds the operating element and/or the tilting element and/or the brake element at least partially. The guide means ensure that the forces which are exerted on the operating element are transferred to the brake element in an advantageous manner through guided movement of the tilting element. The housing hides the tilting element from view and prevents outside influences from interfering with its operation. Preferably, the guide means are positioned near the pivoting point between the operating element and the tilting element and/or near the pivoting point between the tilting element and the brake element . Said guide means may for example be projecting pivot pins used for pivotally interconnecting said elements, which pivot pins are capable of sliding movement in slots formed in the frame .

Preferably, the operating element and the brake element are mainly movable in linear direction, for example due to the form of said slots. The direction of movement of the operating element and the direction of movement of the brake element preferably include an acute angle with each other, wherein the direction of the line through the pivoting points of the tilting element and the direction of movement of the operating element include a right angle with each other near their end position, in which the brake element is pushed against the wheel. This point near the end position is a so-called "dead" point, at which no force is required for pushing the operating element further, and beyond which the brake block urges the tilting element into a locked position. Upon releasing the braking device it suffices to pull the operating element beyond the dead point.

Alternatively, said directions can include a right angle instead of an acute angle with each other, wherein the guide on the operating side extends beyond the intersection with the guide on the brake side in order to reach said locked position.

Preferably, a spring exerts a force on the brake element in a direction opposite to the direction in which the brake element can be pushed against the wheel. Said spring force ensures that the brake element will remain spaced from the wheel in the unlocked condition of the wheel .

The invention furthermore relates to a wheelchair fitted with a braking device according to the invention.

The invention will now be explained in more detail with reference to the drawing, which shows an embodiment of the invention, wherein:

Figure 1 is an exploded, perspective view of a braking device;

Figure 2 is a partial cross-sectional view of the braking device of Figure 1.

This embodiment merely serves to illustrate the invention and should not be considered to constitute a limitation thereof.

Referring both to Figure 1 and to Figure 2, brake element 1 consists of a brake block 2 and a brake rod 3. Brake rod 3 is pivotally connected, by means of pivot pin 4, to a tilting element, which consists of strips 5, 6. Strips 5, 6 are in turn pivotally connected, by means of pivot pin 7, to operating element 8, which consists of operating rod 9 and operating knob 10. Pivot pins 4, 7 are guided in slots 12 13 of housing 14 via guide sleeves 11. Housing 14 is fixed in mounting rail 17 by means of mounting elements 15 and mounting plate 16, which mounting rail is secured to the wheelchair.

Sliding movement of the braking device in rail 17 makes it possible to position the braking device accurately with respect to the wheel before securing it in position.

Brake rod 3 and operating rod 9 are guided in housing 14 via guide rings 18, 19. Brake element 1 is pushed away from the wheel by means of a coil spring 20, which pushes against stop ring 21.

The brake block is pushed against the wheel by moving the operating knob 10 downwards from the unlocked starting position. As a result of the tilting movement of tilting element 5, 6, the force that is exerted on the wheel is greatest near the end position. Since slots 12, 13 include an acute angle with each other, the braking device is automatically pushed and held in the locked position, wherein the tilting element 5, 6 is in line with the brake rod 3, by the force of the wheel and the coil spring 20 beyond the dead point, that is, the point at which the tilting element 5, 6 lies at a right angle to slot 13.

When the user wishes to release the braking device, he needs to pull back the operating knob beyond the dead point, after which the coil spring 20 will push the braking device to the released starting position.

Claims

1. A braking device for braking a wheel of a vehicle, comprising an operating element and a brake element, which brake element can be pushed against the wheel surface by moving the operating element, wherein the operating element and the brake element are movably attached to a frame, characterized in that the operating element can push the brake element against .the wheel surface by means of a tilting element which is capable of tilting movement with respect to the frame .

2. A braking device according to claim 1, wherein the operating element forms part of the tilting element .

3. A braking device according to claim 1, wherein the operating element is pivotable with respect to the tilting element.

4. A braking device according to claim 1, 2 or 3, wherein the brake element forms part of the tilting element .

5. A braking device according to claim 1, 2 or 3, wherein the brake element is pivotable with respect to the tilting element.

6. A braking device according to any one of the preceding claims 1 - 5, wherein the operating element and/or the tilting element and/or the brake element comprise guide means, which are in engagement with guide means in the frame .

A braking device according to any one of the preceding claims 1 - 6, wherein the frame forms a housing which surrounds the operating element and/or the tilting element and/or the brake element at least partially.

8. A braking device according to claim 6 or 7, wherein the guide means are positioned near the pivoting point between the operating element and the tilting element and/or near the pivoting point between the tilting element and the brake element.

9. A braking device according to any one of the preceding claims 1 - 8, wherein the operating element and the brake element are mainly movable in linear direction.

10. A braking device according to any one of the preceding claims 1 - 9, wherein direction of movement of the operating element and the direction of movement of the brake element include an acute angle with each other.

11. A braking device according to any one of the preceding claims 1 - 10, wherein the direction of the line through the pivoting points of the tilting element and the direction of movement of the operating element include a right angle with each other near their end position, in which the brake element is pushed against the wheel .

12. A braking device according to any one of the preceding claims 1 - 11, wherein a spring exerts a force on the brake element in a direction opposite to the direction in which the brake element can be pushed against the wheel .

13. A wheelchair fitted with a braking device according to any one of the preceding claims .