Oscillation switch and a portable electrically driving machine with the oscillation switch
First Claim
1. An oscillation switch comprising an annular member electrically insulated at at least both end portions thereof, a pair of disc-shaped electrodes provided on said both end portions of said annular member and having opposed inner surfaces separated from each other at a distance and defining a space therebetween, each of said inner surfaces having a central portion, a projection formed on said central portion of said inner surface of at least one of said disc-shaped electrodes, said distance being a minimum substantially between said central portions of said inner surfaces of said electrodes, said inner surface of the other electrode being undepressed, and a plurality of balls made of an electrically conducting material and disposed in said space, each of said balls having a diameter larger than said minimum distance and smaller than a distance between opposed portions of said disc-shaped electrodes with which said projection is not provided.
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Accused Products
Abstract
An oscillation switch consists of a pair of ring-shaped electrodes each having an inner surface coaxially provided with a projection and spaced apart at a predetermined distance, and balls arranged in a space formed between the electrodes so that the balls engage the projections to electrically connect the electrodes together when oscillation or lateral sliding occur. A portable electrically driven machine provided with the oscillation switch has the oscillation switch provided on a frame and has a structure which stops a tool rotating motor and a feed motor by interrupting the electric power supply to a control unit of the electric tool. The use of the oscillation switch allows the tool rotating motor or the feed motor to stop as soon as lateral sliding or oscillation starts to occur or when the portable electrically driven machine starts to fall down even if the portable electrically driven tool takes any posture.
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Citations
7 Claims
- 1. An oscillation switch comprising an annular member electrically insulated at at least both end portions thereof, a pair of disc-shaped electrodes provided on said both end portions of said annular member and having opposed inner surfaces separated from each other at a distance and defining a space therebetween, each of said inner surfaces having a central portion, a projection formed on said central portion of said inner surface of at least one of said disc-shaped electrodes, said distance being a minimum substantially between said central portions of said inner surfaces of said electrodes, said inner surface of the other electrode being undepressed, and a plurality of balls made of an electrically conducting material and disposed in said space, each of said balls having a diameter larger than said minimum distance and smaller than a distance between opposed portions of said disc-shaped electrodes with which said projection is not provided.
Specification