GB1280911A - Apparatus for recording graphic representation - Google Patents

Abstract

1280911 Recording-apparatus R STAUBLI 1 July 1970 [4 July 1969] 31955/70 Heading G1J Recording-apparatus as described in the parent Specification having a reduction gear chain between the drive motor and its coupling to the writing instrument has friction means for maintaining the reduction gear under load (to prevent tooth back lash when the writing instrument is returned to its starting position) provided at least in part in the power transmission path between the drive to the reduction gear chain and the drive to the coupling. The friction may be adapted to the reduction of the gear by providing an adjustable brake to act on the output shaft 1, Fig. 3, of the reduction gear or by distributing the friction among the individual gear stages, so that the output shaft has to be braked only by a small amount either directly or at the meshing points of the gear-wheels, Fig.10. Adjustable braking on a shaft may be axial as in Fig.3 and Figs.2, 8, 9 (not shown) or radial as in Figs.4, 5, 6, 7 (not shown). Friction can be produced at the meshing points of gear wheels, G, A by providing an identical gear-wheel behind G indicated by teeth 35, 36, rotatable relative thereto by the back lash and so arranged that in its resting position it covers the tooth gaps at least by the extent of the back lash and is rotatable in a direction for reducing the tooth gap.