Abstract: A stack of envelopes has its lowermost envelope advanced from the stack by two sets of longitudinally spaced kick rollers, which are driven through a gear train by a unidirectional motor. A separator, which includes a feed roll and a restraint roll driven by the unidirectional motor, allows only one envelope to pass therethrough. The gear train includes two sets of interrupted teeth on a gear for stopping advancement of each of the two sets of kick rollers so that another envelope is not advanced from the stack during a cycle of operation. The gear has a third set of interrupted teeth for stopping the feed and restraint rolls after the envelope has passed the separator. The envelope is advanced to a printer by drive rolls, which cooperate with spring biased back-up rolls to form a nip, driven by the unidirectional motor. When the envelope enters the drive rolls, a latch holds the gear having the interrupted teeth from rotating.

Abstract: In a liquid toner chamber (2) of a copier or printer a top plate (5) is moved upward and allowed to fall. The capacitance between the plates is used to define their separation and the time for the plates to move between predetermined locations is used to define the concentration of the liquid toner. This is accurate and inexpensive, while other measurement systems are not suitable to measure the high concentrations with which this invention functions.

Abstract: A ribbon cartridge is provided to be used in a high speed impact printer having means for driving only one reel in the ribbon cartridge, the take-up reel. The ribbon cartridge comprises a cartridge housing having an open end, and supply and take-up reels rotatably mounted in said housing. The supply reel supports an inventory of unused ribbon web which runs from the supply reel to the take-up reel. The rib is mounted in the cartridge housing facing the open end in a position closer to the supply reel than to the take-up reel.The printer into which the ribbon cartridge is to be inserted contains driving means for driving only the take-up reel. The printer receiving means into which the cartridge is to be inserted includes a stop element disposed so as to block the rib to stop the engagement of the cartridge and the receiving means when the cartridge is being inserted in a direction towards the undesirable engagement of the drive means with the supply reel rather than with the take-up reel.

Abstract: In an impact printer including a print wheel having a plurality of selectable character type bearing elements for respectively printing a plurality of characters, said print wheel being rotatable for selectively positioning selected type elements in successive print positions, impact means impellable against the selected elements to drive said elements against the printing medium and means for impelling the impact means against said selected type element, the present invention provides the improvement comprising means for sensing the flight time of the impelled impact means until impact by sensing variations in velocity of said impact means and means responsive to said sensed flight time for controlling the impelling means to vary the flight time.

Abstract: A bounce dampening system reduces switch actuator bounce when the actuators are restored to their home position. Included are selection interposers, one of which is selectively driven to thereby effect motion of selection bails and corresponding switch actuators. A reverse interposer is simultaneously driven. A spring restores the reverse interposer after the actuation cycle thereby carrying the bails and switch actuators to their home position. The return spring and the mass of the reverse interposer prevents actuator bounce and insures a timely return of the actuators.