There is provided a drilling device for drilling a sheet having conical portions, including a tool-holder plate provided with a plurality of rotary drilling spindles with drill bits oriented according to drilling directions parallel to a mean drilling direction, said drilling spindles being distributed in columns configured to be arranged according to an axial direction and in rows configured to be arranged according to a transverse direction at right angles to the axial direction, the device including at least two rows of spindles and at least two columns of spindles, wherein a center-to-center distance between two spindles of a row is different from a center-to-center distance between two spindles of another row.

A deburring tool includes a shank attached at a first end to a chuck and a working portion at a second end of the shank. The working portion includes a first end portion closest to and joining the second end of the shank at a first end of the first end portion, a second end portion furthest from the shank, and an intermediate portion disposed between the first end portion and the second end portion, a first end of the intermediate portion joining a second end of the first end portion and a second end of the intermediate portion joining a first end of the second end portion. The intermediate portion tapers continuously from a largest diameter at the first end of the intermediate portion to a smallest diameter at the second end of the intermediate portion, and deburring cutter members provided on the second end portion adjacent the second end of the intermediate portion.

The invention relates to a drilling device for drilling a sheet having conical portions, comprising a tool-holder plate provided with a plurality of rotary drilling spindles with drill bits oriented according to drilling directions parallel to a mean drilling direction, said drilling spindles being distributed, on the one hand, in columns intended to be arranged according to an axial direction and, on the other hand, in rows intended to be arranged according to a transverse direction at right angles to the axial direction, the device comprising at least two rows of spindles and at least two columns of spindles. The center-to-center distance between two spindles of a row is different from the center-to-center distance between two spindles of another row.

A screwing tool includes a tool head and a tool shaft having an external thread. A first support section is disposed between the tool head and the external thread, and a second support section is disposed between the external thread and a free end of the tool shaft. The second support section has radially outwardly projecting supporting elements that are disposed at a distance from each other in the circumferential direction.

The invention relates to an expanding clamping sleeve for an expanding chuck having a first and a second bearing section, a clamping section that can grasp a tool, and a thrust section that is arranged between the clamping section and the first bearing section. The invention further relates to a toolholder having such an expanding clamping sleeve, wherein a contact surface is provided for a tool-side stop. The invention finally relates to a method for clamping a tool using an expanding chuck, in which, in a first step, a shaft of the tool is inserted into the expanding chuck, then the expanding chuck is subjected to pressure so that a clamping section of the expanding chuck clamps the tool shaft in the radial direction, and a thrust section of the expanding chuck displaces the tool shaft in the axial direction so that a tool-side stop is forced against a contact surface of a toolholder with an axial minimum clamping force.

This invention relates to a maintaining device for mechanical pieces, comprising a slider-holder formed by a body and a head with a central bore in which a part of the piece to be maintained is placed, the piece to be maintained exceeding the head, the head comprising a conical area, the maintaining device having at least two sliders and an actuation element for the sliders, wherein the head comprises at least two lateral bores, one leading into the conical area and the other to the central bore, the sliders are placed in the lateral bores, the sliders being adjustable in the lateral bores, the sliders exceeding the conical area of the head, the actuation element of the sliders being arranged to move the sliders in the corresponding lateral bores along an axis perpendicular to a longitudinal axis of the central bore.

A tool receptacle for a screw-in tool having a main body, which has a receiving region including at least one conical contact surface for supporting a corresponding conical support surface of the screw-in tool. For thread-protection and for tightening with high concentricity and low production outlay, an insert is disposed in the main body, the insert is movable transversely with respect to the longitudinal axis of the main body and is rotationally-fixed with respect to the main body and has a mating thread for a thread on the screw-in tool.

Drill bit (20) including a drilling shaft and a cutting portion having a first drilling segment (23-1) and a second drilling segment (23-2). The first drilling segment (23-1) has a first inner lateral surface (28-1) with a first inner distance (B.sub.1(), h)), and the second drilling segment (23-2) has a second inner lateral surface (28-2) with a second inner distance (B.sub.2(, h)) from the longitudinal axis (24) of the drilling shaft. The first inner lateral surface (28-1) is formed as a portion of a first inner cone (34-1) which tapers in the direction of a first upper side (32-1) opposite to the underside (31-1) of the first drilling segment (23-1).

Drill bit (20) including a drilling shaft and a cutting portion having a first drilling segment (23-1) and a second drilling segment (23-2). The first drilling segment (23-1) has a first inner lateral surface (28-1) with a first inner distance (B.sub.1(, h)), and the second drilling segment (23-2) has a second inner lateral surface (28-2) with a second inner distance (B.sub.2(, h)) from the longitudinal axis (24) of the drilling shaft. The first inner distance (B.sub.1(, h)) varies between a first maximum value (B.sub.max,1) and a first minimum value (B.sub.min,1) over the circumference of the first drilling segment (23-1) and has precisely one first absolute minimum value (B.sub.min,1). The second inner distance (B.sub.2(, h)) is greater than or equal to the first absolute minimum value (B.sub.min,1) over the circumference of the second drilling segment (23-2).

Drill bit including a drilling shaft and a cutting portion having a first drilling segment, a second drilling segment and a third drilling segment. The first drilling segment has a first inner lateral surface with a first inner distance, the second drilling segment has a second inner lateral surface with a second inner distance, and the third drilling segment has a third inner lateral surface with a third inner distance from the longitudinal axis of the drilling shaft. The first inner distance varies between a first maximum value and a first minimum value over the circumference of the first drilling segment and has precisely one first absolute minimum value. The second inner distance is greater than or equal to the first absolute minimum value over the circumference of the second drilling segment, and the third inner distance is greater than or equal to the first absolute minimum value over the circumference of the third drilling segment.