According to an aspect of the invention, there is provided an electrostatic chuck including: a ceramic dielectric substrate having a first major surface, a second major surface, and a through-hole; a metallic base plate which has a gas introduction path that communicates with the through-hole; and a bonding layer which is provided between the ceramic dielectric substrate and the base plate and includes a resin material, the bonding layer having a space which is provided between an opening of the through-hole in the second major surface and the gas introduction path and is larger than the opening in a horizontal direction, and a first area in which an end face of the bonding layer on a side of the space intersects with the second major surface being recessed from the opening further than another second area of the end face which is different from the first area.

A power tool for driving an accessary removably held between first and second clamp parts includes a first shaft having the first clamp part, a second shaft for moving the second clamp part, a holding member movable relative to the second shaft, a moving member for moving the holding member, and a biasing member for biasing the moving member. The second shaft is disposed inside the first shaft. The holding member enables the second clamp part and the first clamp part to hold the tool accessary therebetween in a first position, and disables the second clamp part and the first clamp part from holding the tool accessary in a second position. The moving member moves the holding member from the first position to the second position, and the biasing member biases the moving member when the holding member is located in the second position.

An accessory for use with an oscillating power tool includes an attachment plate and a raised annular rim extending from the attachment plate. The raised annular rim has a central recess and a keyed sidewall with a star shape configured to be engaged by a first mating geometry of an oscillating power tool. The raised annular rim may further include a receiving portion formed thereon configured to be engaged by a second mating geometry of an oscillating power tool.

It is an object of the invention to increase the degree of freedom in designing a power tool. A representative power tool 100 has a spindle 124 that transmits a driving force of a motor 115 to a tool accessory 145, a tool accessory holding member 127 that is configured to be movable in a direction of a spindle rotation axis direction 124a between a holding position for holding the tool accessory 145 and a releasing position for releasing the tool accessory 145, a lock mechanism 130 that locks the tool accessory holding member 127 in the holding position, and a body housing 101. The lock mechanism 130 is disposed between a second end 1241 of the spindle 124 and a wall of the body housing 101 in the spindle rotation axis direction 124a.

The present invention is directed to a bi-stable coupling for controlling the depth of a tool insertion, such as drilling, and similar processes. The bi-stable coupling can be used to penetrate (e.g., drill or push) through a material layer of unknown thickness without plunging the tool into the adjacent layer. In accordance with the invention, in a first state, force is applied to the tool to initiate penetration and a reactive force maintains the device in the first state during penetration and when tool penetrates the material, the reactive force is diminished enabling the device to transition to a second state in which the tool becomes retracted. In medical applications, the invention allows for drilling through bone of unknown thickness without plunging into the adjacent soft tissue.

A power tool having a housing, a motor, a tool holder driven about an output axis by the motor, and an output element for performing an operation on a workpiece. The tool holder has a locating feature including a tapered portion becoming narrower in a direction away from the surface of the tool holder. The output element has an aperture for receiving the locating feature and a face facing the surface of the tool holder when the locating feature is received. The power tool also includes a flange for transferring a clamping force for urging the output element towards the tool holder and a tab projecting from the flange for finger tightening the flange. A biasing member provides the clamping force toollessly. A gap is defined between the surface of the tool holder and the face when the tapered portion of the locating feature is fully received in the aperture.

A power tool includes a spindle and a clamp shaft, and drives a tool accessory clamped by an outer flange and a clamp head. A ball or a grooved clamping element is configured to hold the clamp shaft against the spindle in a fixed manner. A holding element holds and moves the ball or grooved clamping element. A coil spring biases the holding element. The ball or grooved clamping element is movable between a first position where it holds the clamp shaft and a second position where it does not hold the clamp shaft. The holding element is capable of moving the ball or the grooved clamping element from the first position to the second position. The coil spring biases the holding element and prevents movement of the holding element when the ball or the grooved clamping element is located in the second position.

A clamp arrangement for securing an accessory to an oscillating power tool can include a clamp assembly including a first clamp member that moves relative to the accessory between a closed position wherein the clamp assembly retains the accessory and an open position wherein the first clamp is offset from the accessory permitting removal of the first accessory from the clamp assembly. The clamp assembly can further comprise a second clamp member having a first portion that opposes the first clamp member and cooperates with the first clamp member to clamp the accessory between the first and second clamp members. An attachment plate can carry the clamp assembly. The attachment plate can have a first mating detail formed thereon that is configured to selectively and removably mate with a complementary second mating detail on the power tool in an assembled position.

A power tool includes a clamp shaft for clamping a tool accessory to the power tool and a clamp shaft holding mechanism for selectively locking the clamp shaft to hold the clamp shaft in a position that secures the tool accessory on the power tool. The power tool also includes a lever for shifting the clamp shaft holding mechanism between clamped and unclamped states. The lever is configured such that when an operator grasps the lever and moves it toward a position for releasing the tool accessory, the lever and the operator's hand move away from the tool accessory.

A method of using an oscillating accessory with an oscillating power tool may include providing an attachment member. The attachment member may include an attachment plate, a raised rim portion extending from the attachment plate, the raised rim having a central recess, a keyed sidewall with an at least partially star shape configured to be engaged by a first mating geometry of an oscillating power tool, and a top wall that includes a receiving portion having a plurality of recesses configured to be engaged by a second mating geometry of an oscillating power tool. The central recess may not be in communication with any of the plurality of recesses. The attachment member may be used to facilitate tool-free attachment of a working portion to the oscillating power tool via a clamp assembly having a first clamp member moveable relative to a second clamp member without use of a secondary tool.