A power wheelchair with front anti-tip wheels for substantially eliminating partial
tips of the wheelchair is described. The anti-tip wheels are attached to the end
of an extension arm which is attached to the frame of the wheelchair. A spring
connects the anti-tip wheels with the frame at a second point. The spring tends
to hold the anti-tip wheels in a neutral position at a predetermined height above
the ground. A lowering mechanism is provided which positions the anti-tip wheels
in a position engaged with or just above the ground. A retaining system holds the
anti-tip wheels on or near the ground until the user or a release trigger device
releases the retaining system, at which time the anti-tip wheels return to the
neutral position. While the retaining system is disengaged, the wheels are free
to rise in response to an upward force in order to climb over an obstacle in the
wheelchair's path of travel.
