R Healthcare Technical Information Manual - Dash Page 23 March 2007 Revision B
A typical misuse of parking brakes is that they are applied when the wheel is still turning, acting as
retardation brakes. This imposes heavy wear on the tyre surface and brake mechanism. Brakes
acting on pneumatic tyres depend upon tyre pressure to be effective. Many reported instances of
brake malfunction are actually a result of insufficient tyre pressure; these must be inflated to
manufactures recommendations – details on wall of tyre. Puncture free tyres are more consistent
in this respect.
When wheelchairs are used in transportation, the reliable operation of parking brakes during
transfer to and from the vehicle is very important. Particular attention should be made to brakes on
wheelchairs which are used in this type of environment.
Service staff should note the condition of brakes at each service, adjusting the brake function, and
resetting where appropriate. Replacement of brakes is necessary when wear is excessive and
function is affected. Frequent misuse or excessive wear and damage should be noted. The brake or
tyre specification should be reviewed in the light of such service experience.
9.0
CASTORS :
The Dash castor consists of an aluminium fork with a fixed pivoting spindle which locates in a
housing bolted to each side of the front of the tubular chair frame.
The castor housing body is a two piece construction. An aluminium base plate locates on the frame
tube, and upon this is mounted an injection moulded castor head bearing housing. This housing
can be angle adjusted to suit the required inclination of the wheelchair frame. The castor fixing nut
is accessed by removal of the dust cap in the top of this housing.
The castor mounting is fixed to the bottom
element of the rigid front frame. When wheels
positions or specifications are changed or
reconfigured, it is necessary to check for correct
alignment of the castor. Dash has the facility for
optimising the castor angle in line with this
requirement.
See section 3.12.3. for details.
Service staff should be aware of the need for
assessment by a rehabilitation engineer or
healthcare professional prior to making such
changes to a chair