US 4,314,388 AGranted

Roller drive for draw frame

AssigneeZinser Textilmaschinen GmbH

InventorsMax Hartmannsgruber, Horst Wolf

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Abstract

An assembly of fiber-drawing rollers, used for stretching rovings or fiber bundles in a spinning machine, is divided into a plurality of stages each including an elongate driven roller and a set of coacting counterrollers, the driven rollers being rotated at predetermined relative speeds with the aid of several motors including at least one pair of synchronous motors positively coupled with a drawing roller at opposite ends thereof. These synchronous motors are energized with three-phase current of a frequency determined by the setting of a digitally adjustable frequency selector controlling a solid-state frequency inverter. The selector comprises a frequency divider in the output of a preferably also adjustable source of timing signals which may be a pulse generator driven by a motor coupled with another drawing roller.

Claims9

Dependent claims

A fiber-drawing assembly comprising:

a plurality of cascaded drawing stages each including an elongate driven roller and a set of coacting counterrollers;
drive means for simultaneously rotating said driven rollers at different but mutually correlated speeds, said drive means including at least one pair of synchronous motors positively coupled with opposite ends of the driven roller of one of said drawing stages at axially spaced-apart locations;
and
a common supply of three-phase current connected to said pair of synchronous motors in a joint energizing circuit for operating same in step with each other, thereby preventing the development of torsional stresses between said locations, said supply including a power line, a solid-state frequency inverter with three phase leads inserted between said power line and said pair of synchronous motors, and a frequency divider of digitally variable step-down ratio inserted between a source of timing signals and said frequency inverter for varying the rhythm of energization of said phase leads.

1 more element

Dependencies are inferred from the claim text.