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:
Nov. 03, 1992
Filed:
Jul. 30, 1991
Kurt Arnold, Kaiserslautern, DE;
Peter Liell, Stelzenberg, DE;
G. M. Pfaff Atkiengesellschaft, Kaiserslautern, DE;
Abstract
A sewing machine is provided with a device for stopping the drive in the case of a thread disturbance. The device has a light source, a first light guide device for transmitting the light beams to the monitoring point, a second light guide device, via which a signal can be sent to a receiver in the absence of thread at the monitoring point, and a control unit for signal evaluation and to report a thread disturbance, even in the case of maximum deflection of the thread at right angles to the pull-off direction, only when a thread disturbance does really exist. To achieve this, the first light guide device is designed, on its side facing the thread, in a plane perpendicular to the thread pull-off direction, with a radiation outlet which extends preferably in the horizontal direction. The first light guide device causes light beams to be sent over the maximum range of movement of the thread at equal radiation intensity over an entire radiation cross section. A radiation inlet of the second light guide device, whose radiation inlet is intended to receive the light beams passing through the maximum range of movement of the thread at right angles to the pull-off direction after the thread has been removed. The control unit of the device causes a signal to be issued in the case of a change in the intensity of the radiation signal entering the receiver due to the absence of thread in the zone of the monitoring point.