Lincoln Tanker your welcome... There are actually many more but even using http://www.google.com/patents where I found these it takes a lot of time as names are often misspelt etc, and not necesarily in the name of the manufacturer as with Turnbull...... I was actually looking for Hornsbys patents using various versions of "Endless Track" and ended getting Sidetracked it was just to interesting......
Hi Chris thanks Ive posted these on a seperate hornsby patent thread I did find four patents originally related to tracks but at the moment I can only locate three, must have failed to save one....