Usually, handsaws only cut in one direction and buck or bow saws can cut when pushing as well as pulling, but then half of their teeth are always moving backwards, hindering downward movement. A way to improve on these is a saw blade with teeth that are always pointing in the thrusting direction, backwards as well as forwards.
This saw has movable, hardened steel teeth that can rock back and forth in sockets in the blade. When the saw is pushed forward, the teeth’s cutting edges are forced into position by the material being sawed. Pulling the saw then rotates the teeth into the most efficient cutting surface for that direction.-- FarmerJohn, Jun 22 2004 (?) schematic http://www.geocitie...nnie/sawteeth.html? [FarmerJohn, Oct 05 2004, last modified Oct 17 2004] # saw teeth that rockyes.-- dpsyplc, Jun 22 2004 sorry I don't get it. saws where the teeth cut in both directions exist in the traditional designed saw format. that bit is easy. the problem is that it is extremely hard work to cut on the pull aswell as the push, unless it is the old two person saw thingy. so I think this would be really impractical to use, but nice pic.-- etherman, Jun 22 2004 //it is extremely hard work to cut on the pull aswell as the push// I take it you've never sawed branches with a one man bow saw.-- FarmerJohn, Jun 22 2004 One man bow saws are fine provided the blade is really taught and the cut is reaonably straight, otherwise they are a pain to use.-- engineer1, Jun 22 2004 I like the idea but the wood curls will hamper the swinging teeth, I think it needs a curved slot cut into the stationary teeth for a clean out. Or you could shape the teeth like a locomotive cow scoop so the wood is evacuated to each side.-- 2 fries shy of a happy meal, Jun 22 2004 Yes, a shard expulsion system is necessary.
The complexity (and therefore expense) means that only the Rockefellers' personal carpenter will be able to afford one of these, but he'll really like it. Really, really like it.
Bread!-- shapu, Jun 22 2004 random, halfbakery