----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
At 02:35 PM 4/28/2004, Ed Burkhead wrote: >Ron quoted: > > "any of a set of wheels or rotating balls mounted in a swivel frame" > > >Ron, I still don't get it. > >Ralph was telling me that the word castor only applies if it turns 360 >degrees. I believe the confusion is that the term 'castor' has come to mean a hardware store item which to its name from the engineering term. At Home Depot, a castor is, indeed, a wheel which goes under a heavy thing and which (generally) swivels 360 degrees. When they were first made, they probably were called 'castored wheel assemblies' but that quickly got shortened to 'castors.' What make the name proper is that they inevitably have their axles offset some distance from the axes of their vertical pivots. Thus, when you push on something to which they're attached, the wheel 'castors' into a position where it's rolling nicely, rather than skidding and scrubbing as it would if the axis weren't offset and you just pushed off in some random direction. So 'castors' are so-called because they 'castor' which is to say they have 'castor' to cause them to align themselves in the direction of travel. Greg ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers/
<<attachment: winmail.dat>>
