Patent ID: 8698430
Filing Date: 2014-04-15
Classification: B25F,H01H,H02K

Abstract:
1. A variable speed switch which is mounted to an electric power tool and capable of outputting an electric signal for increasing or decreasing the amount of electric power supplied to a motor of the electric power tool in proportion to a displacement amount of a switch operating portion, the variable speed switch comprising: a switch main body portion accommodated inside a housing of the electric power tool and mounted to the housing such that the switch main body portion is not relatively moved with respect to the housing; and a load sensor provided in the switch main body portion and capable of outputting an electric signal in proportion to the amount of distortion caused by a pressing force; a wake-up switch that is switched on only while pressed down and provided separately from the variable speed switch and configured to apply voltage to a control circuit of the motor in order to work the control circuit, wherein the switch operating portion is mounted on a surface of the housing so as to be capable of relative displacement with respect to the housing and transmits the pressing force applied to the switch operating portion to the load sensor, with the maximum amount of the relative displacement of the switch operating portion being set to equal to or less than 5 mm, the control circuit is configured such that after the wake-up switch is switched on, voltage continues to be applied to the control circuit while the variable speed switch is being operated, and when the operation of the variable speed switch stops, voltage is not applied to the control circuit; and the wake-up switch is configured not to be interlocked with the variable speed switch.