Piezoelectric clamping device
AssigneeRobert Bosch GmbH
InventorsHarald Krondorfer, Roland Hund, Alexandre Maciel
Life of this patent
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Abstract
A clamping apparatus has been developed for coupling a tool member to the output shaft of a power tool without the use of auxiliary hands tools or a shaft-lock lever. The clamping apparatus includes a clamp member and a piezoelectric element. The clamp member is coupled to an output shaft of a motor. The piezoelectric element opposes the first clamp member and is configured to change from a first state to a second state in response to being coupled to a source of electrical energy.
Claims15
A clamping apparatus for coupling a tool member to an output shaft of a power tool, the clamping apparatus comprising:
- a clamp member coupled to an output shaft;
- a piezoelectric element opposing the clamp member, the piezoelectric element configured to change from a first state to a second state in response to being coupled to a source of electrical energy;
- and
- a controller electrically coupled to the piezoelectric element, the controller including an actuator movable between a first position and a second position, wherein
- in response to the actuator moving from the first position to the second position the controller (i) couples the piezoelectric element to the source of electrical energy and (ii) energizes a source of rotation to rotate the output shaft after a first predetermined time period, and
- in response to the actuator moving from the second position to the first position the controller (i) deenergizes the source of rotation and (ii) decouples the piezoelectric element from the source of electrical energy after a second predetermined time period.
A clamping apparatus for coupling a tool member to a power tool, comprising:
- a piezoelectric member supported on an output shaft of a power tool, the piezoelectric member configured to change from a first state to a second state in response to being coupled to a source of electrical energy and to generate a clamping force in response to being in the second state;
- a first clamp member supported on the output shaft;
- a second clamp member supported on the output shaft, the second clamp member configured to impart the clamping force upon a tool member supported on the output shaft between the first clamp member and the second clamp member;
- and
- a controller electrically coupled to the piezoelectric member, the controller including an actuator movable between a first, a second, and a third position, wherein
- in response to the actuator moving from the first position to the second position the controller couples the piezoelectric member to the source of electrical energy,
- in response to the actuator moving from the second position to the third position the controller energizes a source of rotation to rotate the output shaft,
- in response to the actuator moving from the third position to the second position the controller deenergizes the source of rotation, and
- in response to the actuator moving from the second position to the first position the controller decouples the piezoelectric member from the source of electrical energy after a predetermined period of time.
A method of coupling and decoupling a tool member to an output shaft of a power tool, the method comprising:
- positioning a tool member on an output shaft of a power tool between a clamp member and a piezoelectric element;
- and
- coupling a source of electrical energy to the piezoelectric element to cause the piezoelectric element to impart a clamping force upon the tool member,
- wherein the coupling a source of electrical energy to the piezoelectric element, includes moving an actuator to a first position, the actuator being electrically coupled to a controller, and
- wherein in response to the actuator moving to the first position the controller (i) couples the source of electrical energy to the piezoelectric element and (ii) energizes a source of rotation to rotate the output shaft.
Dependencies are inferred from the claim text.