Seat tilt apparatus for a wheelchair

Abstract

One aspect of the invention is a seat tilt apparatus for a wheelchair, which wheelchair comprises a chassis and a seat. The seat tilt apparatus comprises a base member, a seat supporting member, a pivotal arm and a linear drive member The base member is fixable to the chassis and provided with a guide slot. The seat supporting member is arranged to supportably receive the seat, movable in relation to the base member and guided by the guide slot. The pivotal arm is pivotally connected to the base member at a first point and to the seat supporting member. The linear drive member is pivotally connected to the base member and to the seat supporting member, for moving the seat supporting member in relation to the base member. The guide slot provided in the base member comprises a first portion which is proximal to the first point and which has a first general direction of extension. A second portion of the guide slot, which is distal to the first point, has a second general direction of extension, which second general direction of extension is different from the first general direction of extension.

1 . Seat tilt apparatus for a wheelchair, which wheelchair comprises a chassis and a seat, which seat tilt apparatus comprises; 
 a base member, which is fixable to the chassis and which is provided with a guide slot;    a seat supporting member which is arranged to supportably receive the seat, movable in relation to the base member and guided by the guide slot;    a pivotal arm which is pivotally connected to the base member at a first point and to the seat supporting member; and    a linear drive member which is pivotally connected to the base member and to the seat supporting member, for moving the seat supporting member in relation to the base member; wherein    the guide slot comprises a first portion being proximal to the first point and having a first general direction of extension and a second portion being distal to the first point and having a second general direction of extension, which second general direction of extension is different from said first general direction of extension.    
   
   
       2 . Seat tilt apparatus according to  claim 1 , wherein the first portion of the guide slot is essentially horizontal when mounted on the chassis and the second portion is angled downwards in relation to said first portion.  
   
   
       3 . Seat tilt apparatus according to  claim 1 , wherein the first and second portions of the guide slot are connected by a curved portion.  
   
   
       4 . Seat tilt apparatus according to  claim 1 , wherein the base member comprises two side members fixedly connected to each other in parallel, side by side and at a distance from each other, each side member being provided with a guide slot; the seat supporting member comprises two support arms connected to each other by a first axle, which first axle is guided by both guide slots; and each support arm is connected to one of said side members by means of a respective said pivotal arm.  
   
   
       5 . Seat tilt arrangement according to  claim 4 , wherein the linear drive member is arranged at a first side of a first of said two side members, which first side is opposite to a second of said two side members; and the linear drive member is pivotally connected to the first axle.  
   
   
       6 . Seat tilt arrangement according to  claim 5 , wherein the two pivotal arms are fixedly connected to a second axle, at slightly different rotational angles, which second axle is pivotally connected to the two side members.  
   
   
       7 . Wheelchair comprising a chassis, a seat and a seat tilt apparatus, wherein the seat is tiltable in relation to the chassis by means of the seat tilt apparatus, which seat tilt apparatus comprises; 
 a base member, which is fixable to the chassis and which is provided with a guide slot;    a seat supporting member which is arranged to supportably receive the seat, movable in relation to the base member and guided by the guide slot;    a pivotal arm which is pivotally connected to the base member and to the seat supporting member; and    a linear drive member which is pivotally connected to the base member at a first point and to the seat supporting member, for moving the seat supporting member in relation to the base member; wherein    the guide slot comprises a first portion being proximal to the first point and having a first general direction of extension and a second portion being distal to the first point and having a second general direction of extension, which second general direction of extension is different from said first general direction of extension of said first portion.    
   
   
       8 . A wheelchair according to  claim 7 , wherein the chassis comprises a seat lift device having a first part stationary relative to the chassis and a second part vertically movable in relation to the chassis, for vertical movement of the seat in relation to the chassis; and the seat tilt apparatus is fixed to the second part of the seat lift device.