A selection system, comprising: a sheath defining an internal housing extending in a longitudinal direction; a link rod disposed in said internal housing, and extending in the longitudinal direction; and a selection slide mounted to slide in the internal housing, about the link rod; the link rod being held stationary relative to the sheath against movement in translation in the longitudinal direction by stop means; the system being characterized in that the stop means comprise: a base that is a body of revolution and includes a conical portion; and a shell comprising two shell portions each including a conical portion configured to come to bear in plane manner against the conical portion of the base.

A drilling aid system which comprises a body with a first cavity, a shaft mounted to be able to rotate within the first cavity, a slider which has a proximal end mounted to be able to move in translation within the first cavity, where the slider has a second cavity which extends the first cavity, a collar that is able to move in translation on the shaft, a first compression spring having a first stiffness and pressing against the collar and against the proximal end of the slider, and a second compression spring having a second stiffness greater than the first stiffness, and pressing against the collar and against the proximal end of the body. A system of this kind makes it possible to make the user perceive that the end of the drilling operation is nigh and that therefore the force applied to the drill should be reduced.

A spindle device includes: a spindle shaft; a first housing configured to house the spindle shaft to which a gas is supplied, the first housing having a bearing that rotatably supports the spindle shaft; a motor located at an end of the spindle shaft and configured to rotate the spindle shaft; a second housing configured to house the motor, the second housing being joined to the first housing; and a duct having one end located at the bottom of a space inside the second housing and another end projecting from the second housing.

A drilling aid system which comprises a body with a first cavity, a shaft mounted to be able to rotate within the first cavity, a slider which has a proximal end mounted to be able to move in translation within the first cavity, where the slider has a second cavity which extends the first cavity, a collar that is able to move in translation on the shaft, a first compression spring having a first stiffness and pressing against the collar and against the proximal end of the slider, and a second compression spring having a second stiffness greater than the first stiffness, and pressing against the collar and against the proximal end of the body. A system of this kind makes it possible to make the user perceive that the end of the drilling operation is nigh and that therefore the force applied to the drill should be reduced.

A release unit for a machine tool spindle, in particular motor spindle, for releasing a tool clamp, wherein the release unit comprises at least one adjustment element which can be linearly adjusted along an adjustment path for actuating the tool clamp, which release unit reduces the structural and/or economic complexity. This is achieved according to the invention in that the release unit is constructed as an electric motor which comprises an electromagnetic drive system having a hollow-cylindrical rotor shaft which rotates about a rotation axis, in that the linearly adjustable adjustment element is constructed as a spindle element of a conversion unit for converting the rotation of the electric motor into a linear adjustment and in that the rotor shaft is constructed as a spindle nut of the conversion unit which rotates about the rotation axis.

A selection system, comprising: a sheath defining an internal housing extending in a longitudinal direction; a link rod disposed in said internal housing, and extending in the longitudinal direction; and a selection slide mounted to slide in the internal housing, about the link rod; the link rod being held stationary relative to the sheath against movement in translation in the longitudinal direction by stop means; the system being characterized in that the stop means comprise: a base that is a body of revolution and includes a conical portion; and a shell comprising two shell portions each including a conical portion configured to come to bear in plane manner against the conical portion of the base.