Abstract: A saw blade provided with two walls set apart from each other and with blade teeth arranged on each wall in a pattern along the distal end of each wall and on the inner surface of each wall. During a single cutting motion, the distal teeth provide the initial cut and the inner teeth remove additional material along the pathway. This increases the amount of material removed in one cut, leaving a small amount of material (bone) at the bottom of the slot for the surgeon to remove in the final step. Thus, the blade configuration and the tooth pattern of the saw blade improves the cutting efficiency.

Abstract: An electric saw device includes a first saw blade and a second saw blade. The first and the second saw blades are respectively driven by a small transmission shaft and a large transmission shaft to rotate in opposite directions. A round rib is disposed on an inner end surface of the first saw blade, and at least three recessed holes are arranged in a top end surface of the round rib at equal angle intervals. A steel ball is accommodated in each of the recessed holes, and protrudes out of the recessed hole. Protruding ends of the steel balls urge against an inner surface of the second saw blade, so as to limit a distance between the first saw blade and the second saw blade, and form a rolling friction when the first and the second saw blade rotate in the opposite directions.

Abstract: A double chain saw arrangement which has diametrically oppositely extending chain saws powered by a single motor driving two sprockets on said hub, each engaged with an associated chain saw chains on each chain saw bar mounted to the hub. A series of hooked capture pieces project from one side of the chain saw bars in a plane parallel to the chain saw bars, which pieces act to cause brush and limbs to be captured and forced into contact with the saw chains to be cut thereby.

Abstract: A synchronized reciprocating sawing device having at least one drive plate, saw retaining plates, and a plurality of blades which exhibit little or no vibration during the application of high torque and high revolutions. This device is comprised of one or more drive plates mounted between two mounting blocks which contain grooves that form a channel within which saw retaining plates are constrained to move as a reciprocating force is transmitted from at least one drive plate to saw retaining plates. The force is transmitted in a plane defined by the plane of each drive plate and the saw retaining plates to which each of said driving plates is operatively attached.