EP2508157A1

EP2508157A1 - Wheelchair

Info

Publication number: EP2508157A1
Application number: EP12162131A
Authority: EP
Inventors: Frank Van Houten
Original assignee: Handicare BV
Current assignee: Handicare BV
Priority date: 2011-04-07
Filing date: 2012-03-29
Publication date: 2012-10-10
Also published as: NL2006569C2

Abstract

A wheelchair comprising at least two driven wheels, a framework, a drive unit connected to the framework for driving the driven wheels, a seat assembly, to be referred to as "seat", and a backrest assembly, to be referred to as "backrest", which wheelchair further comprises a brake for braking the wheelchair on the wheels, characterised in that the wheelchair is provided with a switch for turning off the drive in dependence on activation of the brake by a wheelchair user.

Description

The invention relates to a wheelchair comprising at least two driven wheels, a framework, a drive unit connected to the framework for driving the driven wheels, a seat assembly, to be referred to as "seat", and a backrest assembly, to be referred to as "backrest", which wheelchair further comprises a brake for braking the wheelchair on the wheels. More in particular, an electric drive system is used, in which use is made of a battery connected to the framework, which battery powers an electric motor.
Such a wheelchair is generally known, for example from Dutch patent publication No. 1023378 . The known wheelchair is usually fitted with an electric drive system, in which two 12 V batteries power a 24 V electric motor, for example. Such a wheelchair, in practice also referred to as "scoot mobile", is frequently configured as a three-wheeled, four-wheeled or five-wheeled scooter intended for disabled persons or persons having mobility problems.
The object of the invention is to improve the known wheelchair, and in order to accomplish that object a wheelchair of the kind described in the introduction is according to the invention characterised in that the wheelchair is provided with a switch for turning off the drive in dependence on activation of the brake by a wheelchair user. In this way perilous situations in which the wheelchair is at the same time driven and braked can be prevented. After all, as soon as the brake is activated by a wheelchair user, the drive is automatically turned off by the system according to the invention.
In a preferred embodiment of a wheelchair according to the invention, the wheelchair comprises a sensor for delivering an electrical signal to the switch in dependence on detection by the sensor of activation of the brake by a wheelchair user. In other words, as soon as the sensor detects that the brake is being activated, the sensor will transmit an electrical signal to the switch to turn off the drive.
In another preferred embodiment of a wheelchair according to the invention, the wheelchair comprises a controller by means of which a wheelchair user can control the speed of the wheelchair, wherein an electrical signal delivered to the drive unit by the controller can be interrupted by the switch in dependence on activation of the brake by a wheelchair user. The controller is usually configured as a throttle handle, whilst the brake frequently comprises a brake handle. As soon as the brake handle is operated, the electrical signal sent to the drive unit by the throttle handle is interrupted, so that it is not possible to effectively operate the two handles at the same time. The switch is in particular movable between a closed position, in which the drive is activated, and an open position, in which the drive is deactivated.
In another preferred embodiment of a wheelchair according to the invention, the brake is a drum brake.
The invention will now be explained in more detail with reference to figures illustrated in a drawing of a preferred embodiment of the invention, in which:

Figure 1 is a schematic side view of an electric, rear-wheel driven wheelchair according to the invention;
Figure 2 relates to a brake used in the wheelchair shown in figure 1; and
Figures 3 and four show an electric diagram as used in the wheelchair of figure 1.

Figure 1 shows a wheelchair or "scoot mobile" 1 according to the invention, which is provided with two electrically driven rear wheels 2 interconnected by a rigid rear axle, two front wheels 3, a framework 4, as well as a seat assembly 5 and a backrest assembly 6. For the sake of simplicity the two assemblies are shown without the respective seat and back cushions so as not to complicate the figure unnecessarily. The scoot mobile 1 further comprises a steering wheel 7, on either side of which a brake handle 8 and a throttle handle 9 are mounted on a steering column 10. The brake handle 8 and the throttle handle 9 can thus be manually operated for braking or accelerating, respectively, the scoot mobile 1.
Figure 2 is a detail view of the brake handle 8 used in figure 1, which is configured as a squeeze handle. In the upper drawing the brake handle 8 is shown in a "drive situation", i.e. a situation in which the brake handle 8 is not being pulled and consequently the brake is not activated. In that situation the scoot mobile 1 is driving and the throttle handle 9 can be operated for further acceleration of the scoot mobile 1. In the lower drawing, the brake handle 8 is shown in a "brake and parking brake situation". In the latter situation the scoot mobile 1 is braked (the brake handle 8 is being pulled), or the scoot mobile 1 is parked in the pulled position of the brake handle 8 (the brake handle 8 is fixed in the pulled position by means of a catch 11). By pulling the brake handle 8, an electrical signal is delivered via an electric wire 12 to enable braking on the driven wheels 2. In the pulled position of the brake handle 8, an electrical signal is also delivered, via the electric wire 13, to prevent the scoot mobile 1 from being simultaneously accelerated by means of the throttle handle 9. This will be explained in more detail yet with reference to figures 3 and 4.
In figure 3 the wiring diagram used in figures 1 and 2 is shown in detail view, with figure 3 relating to a situation in which the brake is not activated (the brake handle 8 is not being pulled), and figure 4 relating to a situation in which, on the contrary, the brake is activated (the brake handle 8 is being pulled). In figure 3 the switches A, B of the brake are open, so that no electrical signal is being delivered via the wires 12, 13. The scoot mobile 1 is driving and can be accelerated by pulling the throttle handle 9 - likewise configured as a squeeze handle. As soon as the brake is activated by pulling the brake handle 8, the switches A,B close, as shown in figure 4. An electrical signal is sent to the system control electronics via the electric wire 13, as a result of which the drive signal to the motor control system is interrupted. In the absence of the drive signal, the motor control system will no longer drive the motor and the motor will brake as a result of an electromagnetic counterforce. The energy thus generated is stored in the battery. At the same time an electrical signal is transmitted for braking on the wheels 2 of the scoot mobile 1. The invention thus provides for

intuitive braking (pulling the brake handle rather than releasing the throttle handle as done on conventional scoot mobiles);
a so-called "single fault safe system", according to which braking will take place (either by no longer activating the motor or by braking on the wheels of the scoot mobile 1) in spite of the absence of one of the electric signals in the electric wires 12, 13;
more powerful braking, since braking takes place both on the motor and on the wheels;
preventing simultaneous effective operation of the brake handle 8 and the throttle handle 9; and
possible activation of optical signalling (brake lights/warning lights) when the brake is activated.

The invention is not limited to the embodiment described herein, but it also extends to other preferred variants that fall within the scope of the appended claims.

Claims

A wheelchair comprising at least two driven wheels, a framework, a drive unit connected to the framework for driving the driven wheels, a seat assembly, to be referred to as "seat", and a backrest assembly, to be referred to as "backrest", which wheelchair further comprises a brake for braking the wheelchair on the wheels, characterised in that the wheelchair is provided with a switch for turning off the drive in dependence on activation of the brake by a wheelchair user, wherein the wheelchair comprises a throttle handle by means of which a wheelchair user can control the speed of the wheelchair, and wherein an electrical signal delivered to the drive unit by the throttle handle can be interrupted by the switch in dependence on activation of the brake by a wheelchair user.
A wheelchair according to claim 1, wherein the wheelchair comprises a sensor for delivering an electrical signal to the switch in dependence on detection by the sensor of activation of the brake by a wheelchair user.
A wheelchair according to claim 1 or 2, wherein the switch is movable from a closed position, in which the drive is activated, to an open position, in which the drive is deactivated, and vice versa.
A wheelchair according to any one of the preceding claims 1, 2 or 3, wherein the brake is a drum brake.