Park release method and vehicle having park release means

Abstract

In one aspect of the invention there is provided a method of manually releasing power actuated vehicle park means in the absence of power, the method comprising the steps of: rotating a power actuated selector shaft from a park mode position in which one or more wheels are locked by the park means to a park release mode position in which the one or more wheels are released by the park means; and locking the selector shaft in the release mode position by means of locking means, whereby the successive steps of rotating the selector shaft to the release mode position and subsequently locking the selector shaft in the release mode position comprise manual translation or rotation of one or more members in first and second directions respectively, the first direction being different from the second direction.

1 . A transmission comprising:
 a power actuated park means operable to lock one or more wheels of a vehicle in a substantially stationary condition, the park means comprising a power actuated selector shaft for selecting an operational mode of the park means, the selector shaft being rotatable between a park mode position in which the one or more wheels are locked by the park means and a park release mode position in which the one or more wheels are released by the park means;   wherein the selector shaft may be locked in the release mode position by insertion of a locking pin member into an aperture; and   a handle coupled to the selector shaft, the handle being operable to rotate the shaft to the release mode position by rotation thereof,   the park means being operable whereby the selector shaft may be rotated to the park release mode position and locked by the locking pin member in the park release mode position.   
     
     
         2 . A transmission as claimed in  claim 1  wherein the transmission includes the locking pin member and wherein the locking pin member comprises retention means by means of which the locking pin member may be locked in the aperture thereby to prevent removal of the locking pin member unless the locking pin member is first unlocked. 
     
     
         3 . A transmission as claimed in  claim 2  wherein the retention means is provided in the form of a substantially T-shaped portion of the locking pin member, the locking pin member and aperture being arranged wherein the retention means may be introduced into the aperture and the locking pin member twisted to lock the locking pin member in the aperture. 
     
     
         4 . A transmission comprising:
 power actuated park means operable to lock one or more wheels of a vehicle in a substantially stationary condition, the park means comprising a power actuated selector shaft for selecting an operational mode of the park means, the selector shaft being rotatable between a park mode position in which the one or more wheels are locked by the park means and a park release mode position in which the one or more wheels are released by the park means;   locking means for locking the selector shaft in the park release mode position; and   a handle coupled to the selector shaft, the handle being operable to rotate the shaft to the release mode position by rotation thereof,   the park means being operable whereby the selector shaft may be rotated to the park release mode position and locked by the locking means in the park release mode position by translating at least a portion of the handle.   
     
     
         5 . A transmission as claimed in  claim 4  comprising a latch arrangement for locking the selector shaft in the release mode position. 
     
     
         6 . A transmission as claimed in  claim 4  wherein the handle comprises a bi-stable longitudinal member operable to assume first and second shape forms, the selector shaft being rotatable from the park mode position to the park release mode position by rotation of the handle from a corresponding park mode position to a corresponding park release mode position whilst the handle is in the first shape form, with the selector shaft in the park release mode position the handle being operable to assume the second shape form, with the selector shaft in the park release mode position and the handle in the second shape form, the handle being prevented from rotating back to the park mode position by interference with one or more components of the vehicle. 
     
     
         7 . A transmission as claimed in  claim 6  wherein with the handle in the park mode release position thereof and in the second shape form a portion of the handle penetrates a recess defined by one or more components of the vehicle thereby to prevent rotation of the handle back to the park mode position thereof. 
     
     
         8 . A transmission comprising:
 power actuated park means operable to lock one or more wheels of a vehicle in a substantially stationary condition, the park means comprising a power actuated selector shaft for selecting an operational mode of the park means, the selector shaft being rotatable between a park mode position in which the one or more wheels are locked by the park means and a park release mode position in which the one or more wheels are released by the park means; and   locking means for locking the selector shaft in the park release mode position, the locking means comprising a hook member; and   the park means being operable whereby the selector shaft may be rotated to the park release mode position and locked by the locking means in the park release mode position.   
     
     
         9 . A transmission as claimed in  claim 8  comprising a handle coupled to the selector shaft, the handle being operable to rotate the shaft to the release mode position by rotation thereof. 
     
     
         10 . A transmission as claimed in  claim 9  wherein the hook member is coupled to the handle, the hook member being operable to hook to an anchor point being a point substantially fixed with respect to an axis of rotation of the selector shaft thereby to lock the selector shaft in the park mode release position. 
     
     
         11 . A transmission as claimed in  claim 10  wherein the anchor point comprises an aperture arranged to receive a locking pin member to which the hook member may be hooked. 
     
     
         12 . A transmission as claimed in  claim 9  wherein the hook member is coupled to an anchor point that is substantially fixed with respect to the axis of rotation of the selector shaft, the hook member being operable to be hooked to the handle thereby to constrain movement of the handle and maintain the selector shaft in the release mode position. 
     
     
         13 . A transmission as claimed in  claim 12  whereby the park means is operable whereby the selector shaft may be rotated to the park release mode position and locked by the locking means in the park release mode position by manual translation or rotation of the handle in first and second directions respectively in the absence of power, the first direction being different from the second direction. 
     
     
         14 . A transmission as claimed in  claim 13  operable to release the park means and lock the selector shaft in the release mode position by translation or rotation of the one or more members in substantially orthogonal first and second directions. 
     
     
         15 . A transmission as claimed in  claim 14  comprising a Bowden cable arrangement operable to rotate the selector shaft from the park mode position to the park mode release position when a pull member of the arrangement is pulled.