OPERATING UNIT FOR AN ELECTRIC PARKING BRAKE
An operating unit for a parking brake of motor vehicles including an operatively connected unit having of a drive spindle and nut, which forms an axially longitudinally adjustable element of a linear drive. The drive spindle has a drive side for connection to an electric drive and a substantially cylindrical spindle portion having an external thread. The nut has a sleeve-shaped central body having an internal thread and a head portion designed to act as a pressure piston on a brake element of the parking brake. The internal and external threads intermesh in the operative connection and define a common axial axis of rotation. The thread is a symmetrical thread, and the flank angles, relative to a radial reference plane perpendicular to the axis of rotation, have angle values which are substantially equal in magnitude.
1 . An operating unit for a parking brake of motor vehicles, the operating unit comprising: an operatively connected unit including a drive spindle and a nut which acts as an axially length-adjustable element of a linear drive;
the drive spindle has a drive side for connection to an electric drive and a substantially cylindrical spindle portion with an external thread;
the nut has a sleeve-shaped central body with an internal thread and a head portion formed in order to act as a pressure piston on a brake element of the parking brake;
the internal and external threads intermesh as an operative connection and have a common axial axis of rotation;
the threads are symmetrical threads and flank angles of the threads relative to a radial reference plane perpendicular to the axis of rotation, have angle values which are substantially equal in magnitude.
2 . The operating unit as claimed in claim 1 , wherein the drive spindle is formed as a cold formed metal molded part.
3 . The operating unit as claimed in claim 1 , wherein the nut is formed as a cold formed metal molded part.
4 . The operating unit as claimed in claim 1 , wherein the flank angles are selected to be from 12° to 18°.
5 . A linear drive for a parking brake of motor vehicles comprising the operating unit as claimed in claim 1 .