Robert Boschgmbh

Credo Technology Corporation

S-b Power Tool Corporation

Robert Bosch Tool Corporation

Illya Kovarik

Joseph S. Scaduto

Harald Krondorfer

David S Pozgay

Stephen C Oberheim

John DeCicco

Wolfgang Hirschburger

Peter W Neumann

Markus Allemann

Joseph S Scaduto

George R Gawell

Martin Bartholet

John Decicco

A control mechanism for a rotary hand tool of the type having a generally cylindrical housing in which a drive motor is located, the housing having a nose portion from which a motor output shaft extends and a grip portion, the mechanism including an electrical control circuit that controls the application of power to and the operation of the motor, and a light touch switch having at least a first position or state and a second position or state coupled to the electrical control circuit for selectively enabling or disabling the control circuit to turn the motor on and off. The switch is disposed on the nose portion of the rotary hand tool such that an operator can actuate the switch substantially without altering the operator's grip on the tool.

Nose tip control for cordless high speed rotary tool

A method of operating a hand power tool in one embodiment includes generating a variable speed control signal with a solid state switch that corresponds to a selected speed for a motor, generating a pulse width modulated (PWM) signal corresponding to the variable speed control signal, generating H-bridge driving signals for an H-bridge circuit in correspondence with the PWM signal, and selectively coupling a motor to a power source using the H-bridge circuit in accordance with the H-bridge driving signals.

Method of operating drill with solid state speed control

Embodiments of a power miter saw comprises a saw base having a fence for positioning a work piece, a table rotatably connected to the saw base, a miter arm assembly for angularly positioning the table, a saw blade and motor assembly pivotally connected to the table having a normally elevated rest position and being configured to lower a saw blade toward the table, a handle connected to the saw blade and motor assembly for lowering the saw blade into cutting position, an activation switch adjacent the handle and positioned to be engaged by an operator, a proximity sensor disposed on the saw blade and motor assembly for detecting the presence of objects within a zone of detection associated with the table, and electrical circuitry connected to the proximity sensor configured to generate an electrical detection signal in response to the proximity sensor detecting the presence of an object.

Proximity sensor for stationary power tools

A power tool includes an optical speed control switch for controlling the variable speed of an electrical motor in the tool. The tool includes a moveable member having a reflective surface and the moveable member traversing a distance between a stop position and a full speed position, a biasing member operatively coupled to the moveable member to bias the moveable member toward the stop position, an optical signal generator for generating an optical signal, the optical signal generator being oriented so that the optical signal is directed toward the reflective surface of the moveable member, and a speed control signal generator for generating a speed control signal that corresponds to a reflection of the generated optical signal reflected by the reflective surface of the moveable member.

Articulating drill with optical speed control and method of operation

A power tool includes solid-state motor control. The tool includes a solid state variable speed control signal generator for generating a variable speed control signal, a microcontroller for generating a pulse width modulated (PWM) signal corresponding to the variable speed control signal, a driver circuit for generating H-bridge driving signals corresponding to the PWM signal, and an H-bridge circuit for selectively coupling a motor to a power source in accordance with the H-bridge driving signals.

Drill with solid state speed control

A battery-powered tool indicates to an operator that a torque limit has been reached. The tool comprises a driver circuit for generating motor interface driving signals, a motor interface circuit coupled to a motor to selectively couple power to the motor in accordance with the motor driving signals, a torque limit signal generator for generating a torque limit signal, a motor torque signal generator for generating a torque signal corresponding to a torque generated by the motor, and a microcontroller for comparing the motor torque signal to the torque limit signal and for generating a torque limit indicating signal in response to the torque signal being equal to or greater than the torque limit signal so the driver circuit operates the motor to vibrate to alert an operator that the torque limit has been reached.

Method and apparatus for providing torque limit feedback in a power drill

The present invention provides a power tool with a hand proximity detector to detect the hand of an operator and a trigger circuit operable with the detector to control the operation of a light in the housing or to provide a safety lockout function. One embodiment includes an operating mode indicating light that is responsive to the detector.

Power hand tool having a proximity detector

The present invention provides a power tool with a hand proximity detector to detect the hand of an operator and a trigger circuit operable with the detector to control the operation of a light in the housing or to provide a safety lockout function.

A voltage indicator circuit for indicating a charge state of a power supply, such as a battery pack, is disclosed. The voltage indicator circuit includes a voltage divider circuit that connects to a plurality of series connected light sources, such as light emitting diodes. Upon activation of the voltage divider circuit, one or more of the light sources may illuminate to provide a visual indication of the current charge state of the power supply. More particularly, the number of light sources illuminated varies according to the charge state of the battery pack.

Battery charge indicating circuit

A DC&mdash;DC voltage converter that is capable of increasing as well as decreasing the voltage of a battery pack for application to a power tool or other load. The converter thereby enables different voltage batteries to be used with power tools that have motors that operate at different voltages. The voltage conversion is accomplished by using a relatively high speed switching circuit wherein the duty cycle of the switching circuitry varies the output voltage. An alternative embodiment utilizes feedback control circuitry to automatically adjust the duty cycle so that the speed of the motor, which is a function of the voltage applied to it, would be held generally constant.

Growing community of inventors

Chicago, IL, United States of America

Illya Kovarik