US 4,363,270 AGranted

Harmonic phasing device for printing press

AssigneeDidde Graphic Systems Corporation

InventorsFrank Ury, Howard L. Propheter, Carlton A. Bird

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Abstract

A dual harmonic gear phasing device forming a part of a web-forming printing tower or other web-handling station is disclosed which allows static or dynamic, 360.degree. infinite phase alterations of web-contacting rollers for coarse and fine tuning of the registration of a multiple-station printing press. The phasing device comprises an enclosed, oil filled structure having a pair of tandem coupled harmonic drive gears respectively connected through gearing or the like to the press drive and to a desired roller for phase changing purposes. Each phasing device also includes a selectively operable stepper motor coupled to one of the harmonic gears for effecting phase alterations. The harmonic gears serve as a 1:1 gear ratio transmission during normal running operations. The phasing device can be used on hard impression or perfecting printing towers, and on other types of web-handling equipment where proper registration is important, such as numbering and punching units.

Claims8

Dependent claims

A web-handling station, comprising:

a pair of elongated, axially rotatable rollers;
first motive means for rotation of said rollers;
transmission and phasing apparatus for coupling said first motive means and said rollers, and for selectively changing the phase of at least one of said rollers, including
a 1:1 gear ratio phasing device having first and second, rotatable, coaxial, juxtaposed harmonic drive gears each including an elliptical wave generator, a flexible, toothed, rotatable spline disposed about said wave generator, and a first-rigid, rotatable toothed spline about said flexible spline and for engagement therewith;
a second, rigid rotatable spline briding said first and second harmonic gears and disposed for simultaneous meshing engagement with the flexible spline of each harmonic gear;
selectively operable second motive means;
and
means coupling said second motive means and the wave generator of one of said harmonic gears for rotation of the coupled wave generator to effect said phase change upon operation of said second motive means, including means for selectively and intermittently operating said second motive means only in response to the need to effect said phase change, and for maintaining said coupled wave generator stationary during normal rotation of said rollers;
drive input structure operatively coupling said first motive means and the first spline of one of said harmonic gears;
and
drive output structure operatively coupling said one roller and the first spline of the other of said harmonic gears, including first and second gears respectively secured to said rollers, said first and second gears being in meshed, driving engagement and having a gearing ratio for driving said rollers at the same surface speed.

8 more elements

Dependencies are inferred from the claim text.