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US 10,293,472 B2Granted
Speed limiting governor of a rotating shaft in air
AssigneesRobert Bosch Tool Corporation, Robert Bosch GmbH
InventorsBradley D. Padget, Daniel Blythe
Life of this patent
Estimating the term…
Abstract
A power tool includes a housing, an output shaft, and a tool holder connected to the output shaft. A rotor assembly is attached to the output shaft that is configured to be acted on by a fluid flow through the housing to cause rotation of the output shaft. A centrifugally movable fluid flow governor is coupled to the output shaft that is configured to move outwardly from the output shaft to alter a force acting on the rotor assembly when the output shaft reaches a predetermined speed.
Claims17
A power tool comprising:
- a housing defining a fluid flow passage and including a fluid flow inlet and a fluid flow outlet, at least one of the fluid flow inlet and the fluid flow outlet being configured to be connected to a fluid flow source, the fluid flow source being configured to cause a fluid flow through the fluid flow passage from the fluid flow inlet to the fluid flow outlet;
- an output shaft rotatably supported in the housing for rotation about a drive axis;
- a tool holder connected to the output shaft and rotatable therewith about the drive axis, the tool holder being located externally with respect to the housing;
- a rotor assembly attached to the output shaft and located in the fluid flow passage between the fluid flow inlet and the fluid flow outlet, the rotor assembly being configured to be acted on by the fluid flow through the fluid flow passage such that the rotor assembly and the output shaft are rotated about the drive axis by the fluid flow;
- and
- a centrifugally movable fluid flow governor coupled to the output shaft between the rotor assembly and the fluid flow outlet and configured to be rotated by the output shaft about the drive axis, the centrifugally movable fluid flow governor being located in the fluid flow passage between the fluid flow inlet and the fluid flow outlet and including at least one movable structure configured to move outwardly with respect to the output shaft in dependence on a magnitude of a centrifugal force acting on the at least one movable structure, the centrifugal force depending in part on a rotation speed of the output shaft,
- wherein the at least one movable structure is configured to alter a force acting on the rotor assembly in response to the output shaft reaching a predetermined speed, and
- wherein the fluid flow outlet is configured to be connected to a vacuum source, the vacuum source being the fluid flow source.
5 more elements
A power tool comprising:
- a housing defining a fluid flow passage and including a fluid flow inlet and a fluid flow outlet, at least one of the fluid flow inlet and the fluid flow outlet being configured to be connected to a fluid flow source, the fluid flow source being configured to cause a fluid flow through the fluid flow passage from the fluid flow inlet to the fluid flow outlet;
- an output shaft rotatably supported in the housing for rotation about a drive axis;
- a tool holder connected to the output shaft and rotatable therewith about the drive axis, the tool holder being located externally with respect to the housing;
- a rotor assembly attached to the output shaft and located in the fluid flow passage between the fluid flow inlet and the fluid flow outlet, the rotor assembly being configured to be acted on by the fluid flow through the fluid flow passage such that the rotor assembly and the output shaft are rotated about the drive axis by the fluid flow;
- and
- a centrifugally movable fluid flow governor coupled to the output shaft between the rotor assembly and the fluid flow outlet and configured to be rotated by the output shaft about the drive axis, the centrifugally movable fluid flow governor being located in the fluid flow passage between the fluid flow inlet and the fluid flow outlet and including at least one movable structure configured to move outwardly with respect to the output shaft in dependence on a magnitude of a centrifugal force acting on the at least one movable structure, the centrifugal force depending in part on a rotation speed of the output shaft,
- wherein the at least one movable structure is configured to restrict the fluid flow acting on the rotor assembly in response to the output shaft reaching a predetermined speed,
- wherein the housing includes a nose portion at a first end of the housing and a rear portion at a second end of the housing, the output shaft extending through the nose portion,
- wherein the fluid flow outlet is defined in the rear portion of the housing and the fluid flow inlet is defined in the nose portion of the cylindrical housing, and
- wherein the rear portion of the housing is configured to be connected to a vacuum cleaner as the fluid flow source.
7 more elements
Dependencies are inferred from the claim text.