Monday, January 28, 2008

simplest machine





Pictured above, in the large photo, is the now old back gate pulley-closer. Had I known how long I was making that thing to last I might have employed better esthetics. But there it is, and in service for more years than I can count. Or remember.
When the gate is opened the sash weight is raised by the rope, and when the gate is closed, the mere but concenrated weight of the pulley draws it snugly closed. The hook and eye, now rusty, secures it from high winds. Otherwise, it doesn't need to be hooked. The sash weight does the job.
When Leland was little, he would forget and let the gate slam behind him sometimes. Users usually know ahead that you can't let the thing go by itself or it WILL slam. Lee's slamming gate is a thread in the texture of our recollections at this address.
Wikipedia says the following:

A pulley (also called a sheave or block) is a wheel with a groove between two flanges around its circumference. The groove normally locates a rope, cable or belt. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

I'm looking through the seething and churning basement stuff for another wood pulley, for a neighbor who wants to duplicate the effect on his back gate. So far I haven't found it but I know it's there someplace.



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