Abstract: An ink ribbon cartridge is provided with means to control ribbon tension which takes the form of an O-ring driven by the supply spool which is trained around a drag post. When ribbon is to be drawn from the supply spool as by ribbon feed mechanism operative incident to a print action, the rotation of the supply spool is resisted by the drag or friction between the O-ring and the post. The drag force to be overcome to rotate the supply spool is low and does not vary significantly from full to empty supply spool. The resilience of the O-ring also stores energy which acts oppositely on the supply spool when the force to draw off ribbon is removed.

Abstract: Cartridges housing ribbon spools with a length of ribbon extending externally of the cartridge between exit and inlet openings in the cartridge are provided with an integral anti spool rotation device to prevent spool rotation as would allow inadvertent or accidental withdrawal of an undue length of ribbon externally of the cartridge. Incident to mounting the cartridge on a machine, the locking device is moved to a spool release position without detachment or separation from the cartridge for later movement to anti rotation position if removal of an unspent cartridge is required.

Abstract: A jam release control for a typewriter provided with a motor driven power train to rotate a power roll. The train includes a normally engaged clutch which can be momentarily disengaged by an operator when the power train is jammed thereby allowing the motor to come up to speed and develop torque as will overcome a jam incident to reengagement of the clutch.

Abstract: A linking arms mechanism for a prong type loose-leaf paper binder having spacer bars with recessed portions within which curved spaced prongs are fixed and integral raised shear stops are formed which cooperate with a hinge assembly.

Abstract: A roll fed copier is provided with mechanism responsive to depression of a copy button to start or turn on power to the machine and thereby initiate the feed of copy paper from a supply roll and to cock a sprng-powered knife which is tripped by linkage operated by an adjustable copy length control on the movable original carrying platen. Additional mechanism is also provided to break the power lines to the machines if the copy button is not actuated for a predetermined interval.

Abstract: A top loading ribbon cartridge having a threaded ribbon guide for directing ribbon in the cartridge out of and back into the cartridge which is mountable on one side of a machine printing point. The threaded ribbon guide is movable relative to the cartridge from a retracted position away from the printing point to an extended position to expose ribbon in front of the printing point incident to typing actions. The movement of the ribbon guide is in a lateral direction which permits the mounting of a similar cartridge on the opposite side of the printing point which may contain error correction ribbon or ribbon of a different color in readiness for operation under operator control.

Abstract: A non-homing positioning mechanism to effect type selective movements of a single element typehead by means of coordinate band systems wherein the coordinate band systems are cntrolled by a translator comprising a four armed cross-shaped member unidirectionally rotatable in 90.degree. steps. A set of radially spaced pins are arranged along opposing arms of the cross-shaped member, the sets being alternately selectively settable in response to successive character selections to cause selective band displacement incident to each 90.degree. rotation of said cross-member. One end of each band system is anchored and the other end is connected to position and hold the typehead to a selected character in accordance with the displacement thereof through selected pins on opposing arms of and incident to movement of the cross-shaped member.

Abstract: A looseleaf binder mechanism having a pin-and-slot mounted shiftable latching slide provided with novel positive detenting means comprising an elastomeric washer mounted on the pin and cooperable with a protuberance formed on the latching member intermediate the ends of the slot, to thereby hold the latching member detented in its respective shifted end positions.