Wheelchair Dog Apparatus

Details of Wheelchair Dog Apparatus

First: The dog and handler require special training. Don't build this apparatus unless you have have an experienced carting dog and handler. If you just hook Fido up, you are likely to end up with the wheel chair occupant and/or Fido getting hurt.

The basic construction is a transverse tube (A.) that attaches to the wheelchair and two fore-aft tubes (B.) that attach to the dog's harness C.

All the parts except the cloth came from the local hardware store.

The exact dimensions of everything will vary depending on the wheel chair and dog.

All three tubes are constructed from 1/2" EMT (electro metallic tubing, commonly but incorrectly called thin wall conduit). The transverse tube is covered with heat-shrink tubing, the fore-aft tubes are covered with 1/2" foam hot water pipe insulation which is in turn covered with a home-made cloth tube. I'd probably cover the center portion of the

The transverse tube attaches to the wheelchair with u-bolts. Note: I was attaching to an old-fashioned heavy steel wheelchair. If I was attaching to one of the neat new lightweight chairs, I wouldn't do it this way. Marine supply stores have all manner of clamps for 7/8" and 1" boat rails. Check out the West Marine catalog.

Each end of the tubes has a 3/8" rod tie pressed in and brazed to keep it in place. (A rod tie is kind of like a big long nut.) The rod ties are used to attach a spherical bearing (often called a Heim joint or Rose joint -- Heim is a common American brand, Rose is a common British brand). The spherical bearing allows the fore-aft tubes complete freedom to pivot up and down, and about 20 degrees of freedom left and right. Note: spherical bearings come in many quality grades. Race cars and airplanes use the very best (most expensive). Since this rig wasn't going to do the Indy at 200 mph, I used the cheapest ones I could find -- about $10 each.

There's a washer on each side of the spherical bearing to keep it from moving TOO far left and right (they don't like that).

There's a lock nut on the threaded part of the spherical bearing to tighten against the rod tie.

The dog end of the fore-aft tubes has an eye bolt screwed into the rod tie. The eye bolt also has a lock nut. The eye bolts attach to the dog harness with small aluminum carabiners.

The harness is a chest band type because A. that's what I had, and B. I couldn't figure out how to make the Siwash type work.

Once you get it all together, start with an experienced carting dog and handler. Start with some ballast in the wheelchair -- when empty it will swing all over the place. Get a good deal of practice before putting a human in.

Pushing a wheelchair through a crowded street fair is a pain because the occupant's feet stick out in front of their "personal space" and are forever running into people. With a Newfie pulling, the crowd parts like the Red Sea. Beau quickly learned that a cold Newf nose on a bare leg would get people to move in a hurry.

http://www.almaden.ibm.com/cs/people/triblet/wheelchair.html
Last updated: 09:15 AM, Thursday, May 13, 2004