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US 2008/0196565 A1Published application
Injury mitigation system for power tools
AssigneeRobert Bosch GmbH
InventorErin F. Eppard
Life of this patent
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Abstract
A power tool comprises a detection system for detecting a situation where an operator using a power tool of the type which has an exposed rotating component contacts the rotating component, and a protection system for minimizing the possibility of an operator being injured by contacting the rotating component.
Claims16
A detection system for a power tool having a rotating component and a trigger that is depressed by a user to operate the power tool, comprising:
- an optoisolator circuit configured for isolating a high voltage input from a power supply at a first part of the power tool, and for applying a lower voltage to a trigger plate of the power tool to provide a differential in voltages on the power tool;
- a sensor configured for sensing a change in voltage on said trigger plate of the power tool when the user contacts the rotating component;
- wherein when said sensor senses said voltage change for a predetermined duration, said sensor emits an actuating signal to actuate a solenoid or a relay.
A braking mechanism for a power tool having a rotating component comprising:
- a brake actuation mechanism including a solenoid or a relay mounted on a frame having at least one linkage and a releasable structure attached to said at least one linkage;
- a brake caliper mechanism including a first portion for slidingly receiving a first caliper member, and a second portion having a second caliper member, wherein said first caliper member is received in said first portion, and said first caliper member and said second caliper member are configured to oppose each other on each side of the rotating component;
- wherein when said solenoid or relay is actuated, said solenoid or relay removes said releasable structure from engagement with said first caliper member to permit said first caliper member to extend towards said second caliper member under spring force from a coil spring.
A stopping mechanism for a power tool having a rotating component comprising:
- a gear fixed to rotate with the rotating component having a first surface and at least one detent, wherein a first end of said detent has a receiving structure;
- at least one latch having a moveable member slidably mounted in a fixed but pivotable tube, said moveable member having a hook structure configured to engage said receiving structure of said detent;
- wherein an actuator pivots said latch to position said hook structure into range of said detent, wherein said hook structure engages with said receiving structure and stops the rotation of the rotating component.
A power tool comprising:
- a rotatable member operable upon a user depressing a trigger;
- a detection system comprising:
- an optoisolator circuit configured for isolating a high voltage input and for applying a lower voltage to the trigger;
- a sensor configured for sensing the decrease of said lower voltage on a trigger plate of said trigger when the user contacts said rotating component, said sensor emitting an actuating signal to actuate a solenoid;
- and
- a protection system comprising:
- a braking mechanism having a first caliper member slidingly received in a tube that, upon actuation by said solenoid, extends to engage said rotating component generally perpendicularly.
4 more elements
Dependencies are inferred from the claim text.