Multi-story recreational vehicle

I made a down payment to have this 30-foot 3-bedroom fifth-wheel trailer built in California.
Unfortunately the manufacturer went out of business and this project was never completed.
But this probably saved me money because the industry went into a slump a few years later.
Then I decided that a 20-foot motorhome would be a lot more practical than a 30-foot trailer.

Recreational vehicle with expandable living area

This was my earlier attempt at putting as many amenities as possible in a 20-foot motorhome.
But I was unhappy with these designs and abandoned my patent application a few years later.
It would take me over a decade longer to find a good solution to this problem or puzzle.
Unlike a fifth-wheel trailer, a small motorhome is suitable for most parts of the world.



This design was an improvement of an earlier patented design by Donald Hohenstein shown below. Hohenstein used a rotating rake which was left near the center of the litter box after each operation. I thought it would be nice to have a rake that is moved to a storage area at one end of the litter box. My earliest designs used a screw-drive mechanism as shown in this 1987 disclosure to the USPTO. However, I happened to own an Ektelon racket stringing machine with a rack-and-pinion mechanism. Unlike the screw-drive mechanism, this mechanism could have tracks that curve upwards at the ends. This enabled the rake to be pushed into the litter at one end and lifted out of the litter at the other end. I also found a way to use the top part of the rake to open and close the cover of the waste container. So in 1987 I built the world's first rack-and-pinion litter box shown above with the use of a handsaw. It was way too small for a cat but I just used it to make a video presentation to show how it worked. I also suggested that the teeth of the racks faced downward so the cat litter would not jam the gears. Since clumping litter was unavailable, I had to make my own fine-grained litter for my presentation. I proposed manufacturing a new type of cat litter but nobody seemed to be interested in doing this. I also made fake cat poops for my presentation by painting crumbled balls of aluminum foil in black.

However, Hohenstein's patent prevented others from making this type of litter box fully automatic. I called to ask if he was interested in licensing but he wanted to start manufacturing his own design. However, he never did and let his patent expire in 1994 so others were able to use our ideas for free. But nobody else was able to patent this basic rack-and-pinion design because of my earlier disclosure. By this time clumping litter had become widely available and it made the operation work a lot better.