A power shift transmission for a vehicle driveable by motor power and/or pedal power may include a transmission device which transmits a torque introducible on a drive in a transmission ratio settable via a plurality of gears to an output. The power shift transmission may also include two shifting devices via which the transmission device is shiftable for setting the transmission ratio of the transmission device.

A power shift transmission for a vehicle driveable by motor power and/or pedal power may include a transmission device which transmits a torque introducible on a drive in a transmission ratio settable via a plurality of gears to an output. The power shift transmission may also include two shifting devices via which the transmission device is shiftable for setting the transmission ratio of the transmission device.

A pedally propelled vehicle multi speed gear system includes a gear mechanism including a main shaft; a hollow first shaft and a hollow second shaft, both axially stationary and rotatably arranged about the main shaft; an epicyclical first gear section arranged about the main shaft between the first and second shafts, and including two radially stacked carrier elements; and a first shift mechanism arranged between the first shaft and the first gear section, and configured to rotationally engage the first shaft with either of the two radially stacked carriers. The first shift mechanism includes two first clutches radially stacked about the main shaft.

A pedally propelled vehicle multi speed gear system includes a gear mechanism including a main shaft; a hollow first shaft and a hollow second shaft, both axially stationary and rotatably arranged about the main shaft; an epicyclical first gear section arranged about the main shaft between the first and second shafts, and including two radially stacked carrier elements; and a first shift mechanism arranged between the first shaft and the first gear section, and configured to rotationally engage the first shaft with either of the two radially stacked carriers. The first shift mechanism includes two first clutches radially stacked about the main shaft.

A bicycle gear hub includes an axle, planetary gear modules, one-way clutches and a shift mechanism. The planetary gear modules are connected in series at the axle. The shift mechanism includes a shift actuator and control pawls movably disposed at different positions of the axle. The shift actuator includes recess portions to control opening and closing of a control protrusion of one control pawl, and further to control a sun gear of the corresponding planetary gear module to the axle. When a high gear is shifted to a low gear, a rotational direction of the shift actuator is identical to a rotational direction for closing the control pawl.

A bicycle gear hub includes an axle, planetary gear modules, one-way clutches and a shift mechanism. The planetary gear modules are connected in series at the axle. The shift mechanism includes a shift actuator and control pawls movably disposed at different positions of the axle. The shift actuator includes recess portions to control opening and closing of a control protrusion of one control pawl, and further to control a sun gear of the corresponding planetary gear module to the axle. When a high gear is shifted to a low gear, a rotational direction of the shift actuator is identical to a rotational direction for closing the control pawl.

The invention relates to a multi-speed transmission on a central axis (6a), comprising a drive-side hollow shaft (4a) and an output-side hub sleeve (I) and two, at least two-stage, planetary gearboxes (EG, NSG), arranged coaxially therebetween or therein, each gearbox having sun gears, planetary gears which are connected to one another via associated frames, and ring gears, and each can be shifted into a direct drive and into a plurality of stepped conversion modes, wherein the first planetary gearbox (EG) is driven on its frame (8) and can be selectively shifted, by means of three clutches (20, 30, 40), into the direct drive or by axially fixing individual sun gears (9c,9d) into said transmission modes, and the second planetary gearbox (NSG) can be shifted by further clutches (50, 60, 70, 80, 90) by means of an axial fixing of the sun gear (204) when the input drive and output drive are shifted between its ring gear (200) or frame (202) into a conversion mode at a low speed and into a conversion mode at high speed and directly into a gear. By means of an axially displaceable control slide, spring-loaded, radially extending coupling rings (e.g 91a, 91b) of a respective gear stage can be released, such that the control slide is guided in helical circular grooves (24 . . . 94) of a coaxial switching drum (6b) and in radial slots that are oriented parallel to the gear axis of a hollow axle (6a) enclosing them, respectively actuating the associated coupling rings.

The invention relates to a multi-speed transmission on a central axis (6a), comprising a drive-side hollow shaft (4a) and an output-side hub sleeve (I) and two, at least two-stage, planetary gearboxes (EG, NSG), arranged coaxially therebetween or therein, each gearbox having sun gears, planetary gears which are connected to one another via associated frames, and ring gears, and each can be shifted into a direct drive and into a plurality of stepped conversion modes, wherein the first planetary gearbox (EG) is driven on its frame (8) and can be selectively shifted, by means of three clutches (20, 30, 40), into the direct drive or by axially fixing individual sun gears (9c,9d) into said transmission modes, and the second planetary gearbox (NSG) can be shifted by further clutches (50, 60, 70, 80, 90) by means of an axial fixing of the sun gear (204) when the input drive and output drive are shifted between its ring gear (200) or frame (202) into a conversion mode at a low speed and into a conversion mode at high speed and directly into a gear. By means of an axially displaceable control slide, spring-loaded, radially extending coupling rings (e.g 91a, 91b) of a respective gear stage can be released, such that the control slide is guided in helical circular grooves (24 . . . 94) of a coaxial switching drum (6b) and in radial slots that are oriented parallel to the gear axis of a hollow axle (6a) enclosing them, respectively actuating the associated coupling rings.

A roughing grinding tool has a supporting body and at least one abrasive circle. The supporting body includes an abrasive grain for roughing grinding. The supporting body serves to support the at least one abrasive circle and itself for roughing grinding. The roughing grinding tool is easy to produce and robust and has a high removal capacity in conjunction with a long service life.

A roughing grinding tool has a supporting body and at least one abrasive circle. The supporting body includes an abrasive grain for roughing grinding. The supporting body serves to support the at least one abrasive circle and itself for roughing grinding. The roughing grinding tool is easy to produce and robust and has a high removal capacity in conjunction with a long service life.