Abstract: A knob assembly includes a lower housing, a pushing member, an upper housing, and a screw member. The lower housing includes a tank and hook structures. A through via is formed at the center of the lower housing. The upper housing is rotatably stacked on the lower housing. A lower surface of the upper housing includes an annular hook groove. The pushing member is disposed between the upper and the lower housing, and includes a body and pushing structures. A screw hole is formed at the center of the body. When the screw member is screwed into the screw hole through the through via, the pushing member moves toward and locks the lower housing, and the pushing structures push the hook structures to cause the hook structures to expand outward and be hooked to the annular hook groove, so that the upper housing is limited by the lower housing.

Abstract: The present invention provides a sheet conveying apparatus for conveying a sheet comprising a convey member for applying a conveying force to a sheet, a drive source for driving the convey member, and a drive transmitting means for transmitting a drive force from a first drive transmitting member attached to the drive source to a second drive transmitting member attached to the convey member through one or more speed reduction members stepwisely. Among the first drive transmitting member, second drive transmitting member and speed reduction members, manufacturing accuracy of the speed reduction member disposed at a front stage of the second drive transmitting member is greater than manufacturing accuracies of the other members.

Abstract: A printer for printing characters and images on recording paper comprising: a paper cassette for storing the recording paper; a platen roller around which the recorrding paper is wound at the time of the transfer of images for printing; a clamping mechanism for clamping the recording paper between the clamping mechanism and the platen roller; a motor for driving the platen roller through a gear unit; a thermal printing head for transfferring images onto the recording paper; a paper feeding rollers for feeding the recording paper from the paper cassette to the clamper; a paper discharging rollers for discharging the recording paper upon the completion of the transfer of images thereto; and an ink cassette storing an ink sheet inside thereof; in which the clamping mechanism comprises a clamper which is mounted on the platen roller in such a manner as to permit the free movement of the clamper, holds the recording paper by pushing the recording paper onto the platen roller in a first position and also releases t

Abstract: In a printer, a sheet feeder includes a motor which is used for a plurality of mechanisms in common so as to make the printer lighter in weight and more compact in size. The sheet feeder can vary the feeding amount of the sheet in response to the printing operation. The sheet feeder also permits the manual operation of a sheet feed roller shaft by disconnecting power from a motor via a power switching mechanism. The power switching mechanism includes a clutch mechanism which has a gear for transmitting the power of the motor, and a clutch wheel. The clutch mechanism is used when feeding the sheet by the operation of the motor. The sheet feeding amount is varied by the operation of a partial gear which comes into contact selectively with a first or second feed cam. These feed cams have projections having different heights.

Abstract: A sheet conveying device provided with a detent mechanism and capable of effecting automatic feeding of the shet by the use of a drive source and also capable of effecting feeding of the sheet by manual operation, the sheet conveying device including a rotational member for conveying a sheet, a drive source for driving the rotational member, a drive transmitting device for transmitting the drive force of the drive source to the rotational member to rotate the rotational member by the drive force of the drive source, a manual operating member for manually driving the rotational member, a detent device producing a rotation restraining force, a restraining force transmitting device for transmitting the restraining force from the detent device, and apparatus for connecting and disconnecting the restraining force transmitting device and the drive transmitting device.

Abstract: A thermal transfer recording apparatus wherein it comprises a power transmitting device for transmitting power from a driving motor of the apparatus to a platen roller of the apparatus, which device can change rotational speed of the platen roller to rotate the platen roller at high speed, thereby shortening a non-printing time such as required for introduction and ejection of a recording paper to reduce the total recording time of the thermal transfer recording apparatus. Further, the power transmitting device has a neutral position where the platen roller can be freely rotated, thereby easily restoring the recording apparatus to its normal conditions even when the recording paper and/or an inked ribbon is jammed.

Abstract: A line spacing mechanism for printing machines comprises an electric motor which is operable to rotate selectively in either direction. A worm on the shaft of the motor meshes with a helicoidally toothed wheel to cause a platen roller to rotate in the clockwise direction or the anticlockwise direction. The motor is support pivotally by trunions and urged by a spring to eliminate radial play between the worm and toothed wheel. Another spring, lever and ball apply thrust to the motor shaft to take up axial play in its bearing, i.e. between the worm and the motor.

Abstract: A platen variable apparatus is disclosed for rotatably adjusting a platen in step increments and in fine amounts in a typewriter. The apparatus includes an individual hub member rotatably mounted on a platen extension and having teeth thereon intermeshed with teeth of a flexspline fixed on the platen extension. A coarse adjusting member is fixedly coupled on the platen extension for positively rotating the platen in step increments controlled by a detent. A rotatable fine adjusting wheel has an internal wave generator surface that cooperates with the flexspline for moving the flexspline relative to the hub member which adjusts the platen in fine amounts.

Abstract: A paper feed assembly for a printer which permits manual paper advance includes a pair of rotatable rollers for advancing a print paper therebetween, a paper feed gear mounted on one roller and a drive gear alternately operatively engaged with the paper feed gear. The drive gear includes a paper feed portion for incrementally rotating the paper feed gear for advance of the print paper and a drive portion for effecting proper alignment of the paper feed gear and drive gear prior to paper advancement.

Abstract: A control for platen rotation in printers, and particularly in telex machines where the platen rotation drive, either a stepping motor or a DC motor, is provided with an incremental control actuated by keyboard keys to advance or counter advance the platen by a small increment of the full line space whereby alignment of the imprinting line with form spaces is facilitated.