Abstract: Disclosed herein are safety and other controls for chain saws, feedback for use with chain saws, cutting variations in chain saws, and accessories for use with chain saws. In one example, a system comprises a chain saw, a sensor for detecting a condition, and a control system programmed to take an action upon detection of a programmed condition. The chain saw may comprise links with engaging hooks and recesses for articulation without decoupling. The saw bar may comprise a rail, and the links may have grooves such that the links straddle the rail. In one example, a sensor may comprise an image sensor, and a condition detected by the sensor may comprise a position of the chain saw. The control system may be programmed to take action such as to stop or direct movement of the chain saw and/or to produce a perceptible signal.

Abstract: Tools and other devices incorporating cutting chains are disclosed. In some examples, a knife comprises a chain of cutting links positioned along a chain path around a saw bar having a rail, wherein each of the cutting links comprises a groove such that the cutting links straddle the rail of the saw bar. In some examples, a knife comprises a chain of cutting links and a plurality of motors for driving the chain of cutting links. In some examples, a knife comprises a chain of cutting links driven along a blunt edge of the knife. In other examples, the tool is an axe, hatchet, or other device.

Abstract: Cutting guide systems for adjusting and stabilizing cutting devices are disclosed. Example cutting guide systems may be used in orthopedic surgery. In some examples, a cutting guide system comprises a support mount, a joint, and a cutting instrument support, wherein the joint permits the cutting instrument support to be adjusted with respect to the support mount. The joint may permit the cutting instrument support to be rotated about at least two axes. The joint may be lockable to hold the position of the cutting instrument support. A cutting instrument may be pivotable and/or movable in a longitudinal direction with respect to the cutting instrument support. In some examples, a cutting guide system comprises a track, wherein a cutting instrument support is connected to the track in a manner that permits the cutting instrument support to move along a path. Methods of using cutting guide systems are also disclosed.

Abstract: Improved chain saws, components for chain saws, methods of making chain saws and components, and methods of using chain saws and components are disclosed. In some embodiments, a chain saw comprises a saw bar and a plurality of links, wherein a first link has a hook that engages a recess of a second link, thereby coupling the first link and the second link and allowing them to articulate without decoupling. The saw bar may have a rail, and the links may have grooves such that the links straddle and ride over the rail. The rail may have a projection and the grooves of the links may have notches accommodating the projection such that the projection prevents dislocation of the links. The links may have conical or pyramidal cutting teeth. The chain may be bidirectional. Robotic and automated operation of saws and other instruments are also disclosed.