Abstract: A heel holder including a base plate on which is arranged a bearing block which can be pivoted laterally. A swivel head is supported in the bearing block on a transverse axle. Between the base plate and the bearing block there is provided a return spring. A locking mechanism is provided in addition, which locking mechanism holds the bearing block in its centered position. In order to hold the bearing block in the heel holder with pressure, the invention provides that the base plate carries a rectangular projection on its upper side, with which projection is associated a recess in the base of the bearing block, and that above the projection there is arranged the locking mechanism which acts through a frictional connection.

Abstract: The fluidic oscillator consists of a resonant fluid circuit having a fluid inertance and a dynamic fluid compliance. The inertance is a conduit interconnecting two locations of a chamber on each side of a working fluid jet issuing into one end of the chamber, the inertance conduit serving to transfer working fluid between the two locations. Through one or more output orifices located approximately at the opposite end of the chamber, the fluid exits from a chamber exit region which is shaped to facilitate formation of a vortex (the dynamic compliance) from the entering fluid. The flow pattern in the chamber and particularly the vortex in the chamber exit region provide flow aspiration on one side and surplus of flow on the opposite side of the chamber, which effects accelerate and respectively decelerate the fluid in the inertance conduit such as to cause reversal of the vortex after a time delay given by the inertance.