An actuator (12) for a device for clutch actuation in a motor vehicle has cylinder housing (14) with a pneumatic pressure connection (Ep) and at least one hydraulic pressure connection (E.sub.H1, E.sub.H2), in which cylinder housing a piston (16) is operatively connected to a longitudinally moveably control element (G). The piston together with the cylinder housing defines a pneumatic chamber (K.sub.p) that can be pressurized via the pneumatic pressure connection. At least one hydraulic chamber (K.sub.H1, K.sub.H2) is connected to the hydraulic pressure connection. The chambers are separated from one another by a sealing arrangement (18, 20). In a very compact design of the actuator, a pneumatic operative surface (A.sub.H2) axially delimiting the hydraulic chamber are formed on the piston, so that by pressurizing the pneumatic chamber the control element can be longitudinally moved via the piston in an actuating direction (B) against an external return force acting in a return direction (R), and a piston movement can be controlled by a pressure build-up in the at least one hydraulic chamber.

A switchable one-way clutch is able to switch between operating as a one-way clutch and a clutch that locks in both directions. The clutch includes an inner race, and an outer race that includes an inner surface with a plurality of ramped profiles. A control plate is located radially outward from the inner race and moveable in an axial direction relative to the outer race. A plurality of rollers are contactable with the outer and inner races. A roller cage is configured to position and contain the plurality of rollers. A hydraulic piston is coupled to an actuator arm, such that movement of the piston along the axis moves the actuator arm along the axis. To switch and engage the clutch such that rotation is locked in both directions, the piston and actuator arm move axially to hold the control plate and attached roller cage against rotation.

The invention relates to an electrohydraulic actuator comprising a hydraulic piston, a spindle drive for moving the piston along an axis of rotation, wherein the spindle drive comprises a spindle and a nut, and a worm wheel, which is coaxially attached to the nut. Furthermore, an electric motor having a worm, which meshes with the worm wheel, is provided. The nut is radially and axially supported by means of a bearing. In addition, there is a single-armed rotation-prevention mechanism in order to prevent the spindle from rotating. An angle with respect to the axis of rotation is included between a point of action of the worm on the worm wheel and the effective direction of the rotation-prevention mechanism, wherein the angle is selected in such a way that, for a predetermined torque acting on the nut, a radial force acting on the piston is minimized.

A mechanical clutch such as a dog clutch includes a plurality of balls or rollers disposed in a carrier and positioned between opposed sets of straight cut teeth extending from opposed drive and driven elements. A ball or roller is positioned between each adjacent pair of teeth such that the torque load is transferred from the tooth on a first or drive element, through the ball or roller, to an adjacent projection or tooth on a second or driven element. The balls or rollers are maintained in position by the carrier having an inner ring and a concentric outer ring. Greatly reduced disengagement force, even under load, is exhibited by a clutch of this configuration.

A device (10) for uncoupling a vehicle's wheel shaft drive, which device is intended to be placed close to a drive shaft (11) in order to uncouple/couple a driven unit to which the drive shaft (11) is coupled. The device (10) comprises includes at least one bearing (12) fitted around the end (13) of the drive shaft (11). A carrier (14) coupled to the unit or to the drive shaft, has an inner cavity large enough to surround the drive shaft's end (13) and the bearing (12) and is fastened in the bearing (12) so as to be freely rotatable relative to the drive shaft (11). A coupling ring (15) is coupled rotationally to the drive shaft (11) and is movable axially relative to the drive shaft (11). A coupling fork (17) at least partly surrounds the coupling ring (15) and is movable axially relative to the drive shaft (11). An activating device which acts upon the coupling fork (17) to move the latter in axial directions along the drive shaft (11). Coupling the drive shaft (11) to the unit involves the coupling fork (17) and the coupling ring (15) being moved axially towards the carrier (14) by the activating device (20) so that the drive shaft (11) becomes rotationally coupled with the carrier (14) and the unit via the coupling ring (15).

A hydrostatically operated clutch system having a hydrostatic clutch actuator for hydrostatically operating a clutch, in particular a pulse separation clutch of a hybrid drive, such that the hydrostatic clutch actuator is combined with a valve arrangement which is to be opened actively and enables the clutch to be engaged rapidly.

A safety valve (100) for a pneumatic conduit (798) includes a valve body (120) having a pressure port (122) pneumatically connected to a pressure side (840) of the pneumatic conduit (798) and a release port (124) pneumatically connected to a release side (860) of the pneumatic conduit (798), a valve piston (140) axially movable along a valve axis (AV) relative to the valve body (120) between a release-side end position (SP1) and a pressure-side end position (SP2), and a valve piston spring (160) that pushes the valve piston (140) into the pressure-side end position (SP2). The safety valve (100) includes a pressure-side gasket (130), which is adapted to inhibit the air flow (AF) between the pressure port (122) and the release port (124) when the valve piston (140) is in the pressure-side end position (SP2).

A safety valve (100) for a pneumatic conduit (798) includes: a valve body (120) with a pressure port (122) pneumatically connected to a pressure side (840) of the pneumatic conduit (798) and a release port (124) pneumatically connected to a release side (860) of the pneumatic conduit (798), a valve piston (140) axially movable along a valve axis (AV) relative to the valve body (120) between a release-side end position (SP1) and a pressure-side end position (SP2), and a valve piston spring (160) to push the valve piston (140) into the pressure-side end position (SP2). A bypass conduit (150) extends through the valve body (120) or the valve piston (140) and, depending on the position of the valve body, permits a release airflow (AF) to flow through the bypass conduit between the pressure port (122) and the release port (124).

A horizontal directional drilling system. The system has a pilot drill and an exit side drill, with a drill string extending between them. A backreamer is positioned between the drills to enlarge a borehole. The pilot drill pulls and rotates the backreamer. The exit side drill adds segments to the product pipe and pushes the product pipe into the enlarged borehole. The exit side drill is equipped with a rotational disconnect. The disconnect is engaged to allow torque transfer between a motor and a spindle when adding segments to the product pipe. The disconnect is disengaged to prevent torque transfer between the motor and the spindle when pushing the product pipe into the enlarged borehole.

A master cylinder for a hydraulic brake or clutch system, in particular, a handlebar steered vehicle, in particular a bicycle, comprises a housing containing a cylinder chamber, in which are disposed a piston slidable therein and a pressure chamber. A compensation chamber is connected with the pressure chamber through at least one compensation bore. Also provided is a cover closing the housing and a counterpart for mounting the master cylinder on a handlebar tube. Further provided is at least one connecting device for connecting the counterpart with the housing of the master cylinder. Included with the connecting device is a first connecting portion for connecting the cover with the housing of the master cylinder and a second connecting portion for connecting the counterpart with the master cylinder and for mounting the master cylinder on a handlebar tube.