Abstract: A high-speed reciprocating actuator, of the type used as a print hammer in high-speed printers or for operating valves or the like, is made more compact and efficient by the arrangement of a stator yoke. The stator yoke provides a series of aligned magnetic gaps that cooperate with armature bars contained in a reciprocating ram member. These gaps are made part of a plurality of independent flux conducting loops. One or more activating coils pass through each of the loops to induce magnetic flux when ram actuation is desired.

Abstract: For producing a transducer access opening in a stack of rotating flexible magnetic record disks, a co-rotating part axially deflects the peripheral edges of selected disks for partially axially separating same. The co-rotating part may take the form of a thin disk, several thin disks, or shaped as a roll. The axis of the roll is obliquely inclined against the disk pack rotational axis. The roll has a resilient surface such that, after the roll has been inserted into the disk pack, the flexible disks move up the outer surface of the roll to be deflected.

Abstract: The vibration forces between a frame and a continuously oscillating mass are absorbed by making the oscillating mass system and its drive means equal and by fitting each such system and means to the frame with identical resilient elements such that oscillation movements of system and means occur out of phase one with the other to absorb the exciting vibration forces.