M&M Tool and Machinery is offering SawStop, wood saws with a safety device that detects if a human finger touches a blade, activating a brake to stop it in milliseconds, and preventing catastrophic wood sawblade injury. SawStop's industrial cabinet saw and its SawStop contractor saw are designed with a an electronic safety system that detects electronic fluctuations at the blade. It responds when something, particularly flesh, makes the slightest contact with the blade by activating an aluminum brake, which is thrust into the blade, stopping it within milliseconds. Technically, SawStop's safety system induces an electrical signal onto the saw blade. This signal is constantly monitored for fluctuations by a digital signal processor. Because the human body is inherently conductive, its proximity and contact with the saw blade produces a fluctuation in the electrical signal which, in turn, understands that the blade has made contact with something other than the cutting material. Within a fraction of a second of this detection, a heavy-duty spring pushes an aluminum block (a brake pawl) into the teeth of the blade forcing it, as well as power to the saw's motor, to an immediate halt. According to SawStop, this action occurs in just 3 – 5 milliseconds, or 1/200th of one second. Source: toolsandmachinery.com
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