Sewing – Elements – Starting or stopping
Patent
1986-07-17
1988-08-16
Nerbun, Peter
Sewing
Elements
Starting or stopping
112278, D05B 6936
Patent
active
047635886
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for the monitoring of one or more threads in a sewing machine with a number of sewing heads for at least one upper thread and one lower thread and with at least one signal emitter for generating an electric signal in correspondence to the movement of the lower thread during a certain period of time.
Apparatus for the monitoring and sensing of the upper and lower threads in sewing machines with one, and in many cases several, sewing heads are exposed to relatively great mechanical stresses and have failed, as a result of shortcomings in strength and unreliability, to reach any desired degree of use. However, it is an extremely urgent demand in this art to be able to monitor the threads in order to attain as faultless seams and sewing as possible. The quicker the machines work, the greater is the need of being able to monitor the threads. Moreover, it is, in many cases desirable to be able to stop the machine automatically in the event of thread breakage. Hence, there is a great need within this art for a reliable and mechanically durable signal emitter.
The task of satisfying the above-outlined needs forms the basis of the present invention.
SUMMARY OF THE INVENTION
This task is solved according to the present invention in that the apparatus disclosed by way of introduction is characterized in that the signal emitter includes a spring arm which is fixedly anchored at one end and, at the opposite end, supports a magnet, that this opposite end is located in the path of movement of the lower thread, in order to be influenced by the lower thread in at least a certain movement thereof, that an element sensitive to the position of the magnet is disposed so as, in correspondence to the change of position of the magnet as a result of the movement of the lower thread, to generate the electric signal, and that the element is coupled to a signal evaluation circuit for indicating the loss of the signal during at least a certain period of time and possibly stopping of the sewing machine.
By means of an apparatus according to the present invention, there will be realized an extremely reliable and trustworthy monitoring of a desired movement of the lower thread in one or more sewing heads of a sewing machine. The apparatus according to the present invention has proved to satisfy stringent mechanical strength requirements and to display a great degree of reliability.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in greater detail below with reference to the accompanying Drawings.
FIG. 1 is a schematic view of a signal emitter according to one embodiment of an apparatus according to the present invention.
FIG. 2 is a diagram of the signal emitter of FIG. 1.
FIG. 3 shows the diagram of FIG. 2 in greater detail.
FIG. 4 is a diagram of a part of a signal evaluation circuit according to the present invention.
FIG. 5 is a block diagram of a circuit for the evaluation of thread monitoring signals from both the upper thread signal emitter and the lower thread signal emitter.
FIG. 6 is a coupling diagram for the circuit illustrated in FIG. 5.
FIG. 7 is a block diagram of a circuit for the evaluation of thread monitoring signals from a number of lower thread signal emitters.
FIGS. 8a, 8b are a coupling diagram for the circuit illustrated in FIG. 7, a number of identical parts having been omitted.
FIG. 9 is a block diagram for a central unit for a sewing machine
FIGS. 10A, 10B, 10C and 10D are a coupling diagram for the central unit shown in FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The signal emitter shown in FIG. 1, according to one embodiment of the present invention, is built-up on a plate 1 which may suitably be cast in an appropriate plastic material. On the plate 1, there is fixedly disposed a spring thread arm 2 which is wound at least one turn about a pin 3 so that the arm 2 proper is pivotal about the pin 3. One end of the spring thread arm 2 is anchored in a hole 4 in the plate 1. The free end of t
REFERENCES:
patent: 3783811 (1974-01-01), Schmedding et al.
patent: 4180007 (1979-12-01), Peterson et al.
patent: 4372235 (1983-02-01), Principe
LandOfFree
Apparatus for thread monitoring in a sewing machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for thread monitoring in a sewing machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for thread monitoring in a sewing machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-593891