US 4,141,305 AGranted

Electronic pattern control for a sewing machine

AssigneeJanome Sewing Machine Co., Ltd.

InventorsHideaki Takenoya, Hachiro Makabe

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Abstract

A logic circuit generates in succession the stitch-control data for the successive stitches of a selected stitch pattern. The logic circuit does not store simultaneously all the stitch-control data for all the stitches of all the selectable stitch patterns, in the way done by conventional addressable random-access stitch-pattern memories. Instead, the logic circuit assumes successive states, in response to successive machine-synchronized pulses. In each state it generates, in the sense of bringing into existence for the first time, stitch-control data for the next stitch to be produced, this stitch-control data being derived from data related to a preceding stitch, e.g., the stitch-control data for the preceding stitch. The number of logic elements needed is low compared to that needed for a random-access stitch-pattern memory of the type storing all the stitch-control data for all the stitches of all the selectable patterns.

Claims10

Dependent claims

In a sewing machine, in combination,

stitch-forming means operative for changing the relative positions of the needle and the material being sewn in the course of sewing a stitch pattern;
drive means operative for controlling the stitch-forming means in dependence upon received stitch-control data;
pulse-generating means generating synchronizing pulses in synchronism with the operation of a cyclically operative component of the sewing machine;
logic circuit means operative in response to successive synchronizing pulses for generating and applying to the drive means stitch-control data for successive stitches of the stitch-pattern to be sewn but without storing simultaneously all the stitch-control data for all the stitches of the stitch pattern to be sewn,
the logic circuit means assuming successive states in response to successive synchronizing pulses,
the logic circuit means when in its successive states producing successive state data, each state data comprising stitch-control data for a stitch of the stitch pattern,
the logic circuit, in performing transitions to successive states, generating and thereby bringing into existence the state data for successive states by deriving it from the state data of preceding states.

4 more elements

Dependencies are inferred from the claim text.