The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 29, 1987
Filed:
Nov. 24, 1986
Fujio Horie, Nagoya, JP;
Brother Kogyo Kabushiki Kaisha, Nagoya, JP;
Abstract
A feed device drives a feed dog directly by a stepping motor having a predetermined number P of excitation modes, and devised so that the output shaft thereof is turned by a unit amount S when the excitation mode is changed over. A stopper is disposed so as to define the range of the horizontal feed motion of the feed dog. An excitation control means excites the stepping motor in a specific excitation mode at the start or at the end of horizontal feed operation. The specific excitation mode is one of the excitation modes in which the stepping motor is excited while the output shaft thereof is turned by an amount P.multidot.S/2 from a position where the output shaft of the stepping motor is restrained from rotation by the stopper. When the step-out of the stepping motor occurs due to an excessive load acting through the feed dog on the stepping motor during stitching operation, the output shaft of the stepping motor is held at a predetermined angular position by the stopper, and then the stepping motor is excited in the specific excitation mode to restore the stepping motor to synchronism from step-out. Thus, the deformation of the pattern is limited to the least extent.