EP 0009570 B1 19830309 - THREAD SUPPLY CHECKING DEVICE FOR THE BOTTOM THREAD OF A SEWING MACHINE
Title (en)
THREAD SUPPLY CHECKING DEVICE FOR THE BOTTOM THREAD OF A SEWING MACHINE
Publication
Application
Priority
DE 7827499 U 19780915
Abstract (en)
[origin: US4237807A] A thread monitoring device for monitoring the thread supply in a sewing machine, having a rotary hook, comprises, a hook body with a thread bobbin having thread thereon which is connected to a rotatable shaft for rotation thereby. The hook includes a stationary bobbin case which is enclosed by a hook body which has a hub portion connected to the shaft. A light source is disposed on one side of the hook and a light receiver is disposed on the opposite side. Light is transmitted by the light source through a path intercepting the thread on the bobbin so that, when the thread on the bobbin is paid out during the stitching operation, beyond a predetermined amount, the light will be transmitted to a reflective wall portion of the hook body and deflected by the wall portion to the light receiver. The light receiver is connected in a control circuit to operate a control for operating the sewing machine or for actuating an indicator to show that the thread has been used up to the predetermined amount.
IPC 1-7
IPC 8 full level
D05B 59/02 (2006.01)
CPC (source: EP US)
D05B 59/02 (2013.01 - EP US)
Designated contracting state (EPC)
CH FR GB IT SE
DOCDB simple family (publication)
EP 0009570 A1 19800416; EP 0009570 B1 19830309; DE 7827499 U1 19781221; JP S5543897 U 19800322; US 4237807 A 19801209
DOCDB simple family (application)
EP 79102827 A 19790806; DE 7827499 U 19780915; JP 12145079 U 19790904; US 7638079 A 19790917