Agreed, the glider can do whatever you want it to. So the question is how glider designers chose. Is there some engineering/structural reason or is the motion of the glider designed to somehow please the occupant more than a rocking chair. Given no compelling engineering reason for the motion...
OK thanks. I think you've answered my question: there's no engineering reason for gliders using either parallelogram or more complex 4-bar linkages. So a reasonable conclusion is that the design of the 4-bar linkage is to make the glider rock in a way most pleasing to the occupant.
Sam.
Thanks for confirming that a parallelogram can't rock. Thanks for confirming that real-world gliders aren't parallelograms. Would anyone like to speculate as to the engineering considerations on the choice of parallelogram or not? Is it purely what customers want or are there technical...
Thanks for confirming that the glider isn't actually a parallelogram. So can we conclude that glider designers want that and want some angular rotation of the occupant? Thus the various references that state gliders simply move back and forth are incorrect?
e.g. See...
Thanks for the responses. I agree the motion itself of the glider is different than that of a rocking chair and more horizontal. Is yours closer to a "parallelogram" 4-bar linkage or a "double-rocker"? Do you agree a parallelogram 4-bar linkage would keep the person horizontal at all times...
There's a slow motion discussion on Wikipedia about how a glider works versus a rocking chair. See: http://en.wikipedia.org/wiki/Talk:Glider_(furniture)
Are gliders deliberately designed to move like a rocking chair or is the design intent to make the motion different?
Thanks.
Sam.
