1. Field of the Invention
The present invention relates to a portable track device for a wheelchair which enables the occupant of the wheelchair to travel safely across difficult terrain, such as sand at a beach.
2. The Prior Art
Difficult terrain such a sandy beach limits the mobility of a person in a wheelchair who may wish to travel across the sand. Attempts have been made in the past to solve similar problems, and prior proposals are as follows.
The Green U.S. Pat. No. 4,376,596 discloses a portable roadway for use during periods of adverse weather conditions during which soil conditions are such that it is impossible to build a permanent road. This device will give motor vehicles traction in an area in which there would otherwise be none. It consists of a plurality of sections removably interconnected to each other by way of a latch and hook. Each section is constructed with a hardwood frame which supports a plywood surface.
The Arciszewski U.S. Pat. No. 4,681,482 discloses a rollable temporary roadway and apparatus for rolling up an installed temporary roadway. A temporary secure roadway enables vehicles to travel thereon when the soil conditions would not otherwise permit, which consists of supporting elements that are connected by hinge means. Two cables are situated on each side of the support elements and are integrated into the hinges to provide greater strength while supporting a load. There is also a reeling device which is used to roll up the roadway when its use is complete, and consists of an axle pipe with a rotary bearing on either end.
The Hughes U.S. Pat. No. 3,820,912 discloses a mobile collapsible ramp which consists of two sets of blocks, each of which are coupled to each other in a chain and are removably fixed to the ground. The first set of blocks are laid parallel to the second set, and each block has an upper surface for accommodating a vehicle wheel. This relates particularly to a mobile collapsible personal boat ramp.
The Boswell U.S. Pat. No. 4,176,982 discloses a bicycle path transport system.
The Pine U.S. Pat. No. 4,254,907 discloses a portable traction track for a vehicle driving wheel.