NZ718139A - Powered mobility device with tilt mechanism having multiple pivots - Google Patents

Abstract

Disclosed is an easily operable powered wheelchair that is able to be controlled by the weight displacement of a user, especially a user with significant loss of movement of their limbs. The powered wheelchair 100 has a tilt mechanism having multiple pivots that allow the user to operate and control the backwards and forwards movement and steering of the wheelchair 100 in response to the displacement of the user’s weight within the wheelchair 100. The wheelchair 100 has two spaced apart drive wheels 101, each mounted to a separate shaft 104 that is independent of the other drive wheel. A drive controller drivingly coupled to the shafts 104 and the drive controller is housed within a base 102 that is pivotally situated on the shafts 104. A seat 103 mounted on a tilt mechanism enables the seat to tilt in a forward, backward, left and right direction as a result of the user displacing their body weight in either of those directions. The tilt mechanism includes three pivots, a primary pivot P1, secondary pivot P2 and tertiary pivot P3. The primary pivot P1 pivotally connects the base 102 to the shafts 104. The secondary pivot P2 is situated above and adjacent the base 102 so that the respective ends of the rod 105 are pivotally connected to the base 102. The tilt mechanism and the drive controller are connected to a weight displacement sensor to control the movement and direction of travel of the wheelchair 100. Both the primary and secondary pivots P1 & P2 allow the seat 103 to pivotally move in a forward and backward direction (103F, 103B) relative to the wheels 101 and such movement is sensed by the weight displacement sensor that in turn causes the drive controller to impart drive to one or both of the drive wheels to move the wheelchair 100 in the sensed direction e.g. forward or backward. The secondary pivot P2 enhances the offset of weight transfer by a user so as to cause increased control of the back or forward tilt (103F, 103B) of the seat 103 relative to the shaft 104 which is not possible with just a primary pivot P1. The tertiary pivot P3 is situated above the secondary pivot P2 and is situated below and adjacent the seat 103 so as to pivotally connect the respective ends of the rod 105 to the seat. Tertiary pivot P3 allows the tilt mechanism to tilt the seat 104 in left and right directions (103R, 103L) and the weight displacement sensor upon sensing left or right movement causes the drive controller to impart drive to one or both of the drive wheels to turn the wheelchair 100 left or right.