Browse Prior Art Database

Variable Speed Drive

IP.com Disclosure Number: IPCOM000081595D
Original Publication Date: 1974-Jul-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 72K

Publishing Venue

IBM

Related People

Herron, TF: AUTHOR

Abstract

Rotational speed of a cylinder or the like supported by a carriage is adjustable within limits relative to the constant translational speed of a rack and associated structure relative to the carriage.

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Variable Speed Drive

Rotational speed of a cylinder or the like supported by a carriage is adjustable within limits relative to the constant translational speed of a rack and associated structure relative to the carriage.

A toothed timing belt 1 driven by pulley 2 drives pulley 3 for rotating plate cylinder 4. Pulley 2 is keyed to a splined shaft 5 on which is mounted a pinion 6 adapted to mesh with teeth 7, in the form of rails on a stationary ladder-like rack
8. Endmost rail 7a is vertical, whereas each successive rail 7b...7n is canted or inclined a preselected fixed amount relative to the preceding rail to provide rack 8 with teeth that have a nominal pitch, lesser pitch or greater pitch, according to whether pinion 6 meshes with the rails along center line CL or below or above it, respectively, as viewed in the drawing.

Pinion 6 is vertically adjustable by a suitably calibrated micrometer screw 9 that raises and lowers a bifurcated member 10 that straddles the pinion 6. A pinion 11 driven by motor 12 has teeth which mesh with the rails 7 at a fixed vertical location (e.g., along CL); i.e., the position of pinion 11 is not vertically adjustable.

In operation, carriage 13 which supports the timing belt drive 1, 2, 3, cylinder 4, pinions 6, 11 and motor 12 is moved manually toward rack 8 in a guide track, not shown, until the teeth of pinion 11 engage rail 7a. Motor 12 is then turned on, rotating pinion 11 to move rack 8 and hence a frame 14 and a negative film...