Portable chain saw
AssigneeNippon Kuatsu System Co., Ltd.
InventorsTashiro Arai, Masaaki Sato, Eiji Kobayashi
Life of this patent
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Abstract
The present invention relates to improvements in a portable chain saw wherein power of a power device like a motor separated from the body of the chain saw is transmittted to a driving means of the chain saw by way of a flexible shaft, thus the body of the chain saw being small-sized and lighter at weight. Further, in the portable chain saw body an overload protection means is provided preceding to means transmitting power to a driving roller for driving a chain cutter so that no more power than a predetermined load is transmitted to a driving means of the chain saw and only power of the predetermined load is done thereto.
Claims9
A portable chain saw comprising a chain saw body, a power driven flexible shaft extending to said chain saw body, a chain saw cutter mounted on said chain saw body, and an overload protection means on said chain saw body interposed between said flexible shaft and said chain saw cutter such that the chain saw cutter is driven by said flexible shaft through said overload protection means, said overload protection means comprising a rotatable spherical member and a friction wheel operable to engage said rotatable spherical member, mounting means providing relative movement between said spherical member and said friction wheel, and biasing means urging said spherical member and friction wheel toward one another such that during normal load conditions power is transmitted through the frictional engagement between the spherical member and the friction wheel and upon encountering overload conditions, slippage occurs between the spherical member and the friction wheel to interrupt the power transmission.
Dependencies are inferred from the claim text.