This is very interesting!And here is an interesting tid bit for the McFans out there, McCulloch actually had a patent for certain features on their earliest CP Cushioned Power models. (The Cushioned Power label on the 570 reminded me of this)
View attachment 986379
View attachment 986378
Mark
I thought Danarm held the first patents on vibration mounting, they certainly made claims, and proudly displayed their patent numbers on their products right back to the early '70s.
Danarm used coil springs, 1-71- SS model probably the most prominent model, but the 55 was offered with the system as a pro model too. Everything but the handles was sprung, Mac of course kept some more unsprung mass in their models.
Of course there are Country patents and World patents are much more expensive, so may be this is the case.
Who was first??
Roland.