DE227678C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The present invention relates to a twin sewing machine for simultaneous hemming two parallel fabric edges mainly for the production of handkerchiefs; but she can can also be used in machines for other manufacturing purposes.

It is already a device for hollow hemming or for the usual hemming of the Edges of lengths of fabric for the purpose of manufacture

ίο been given by handkerchiefs. at This device consists of two machines for hemming the edges of the fabric at the same time arranged. In this case, automatically acting devices are made, by virtue of which in the event of a thread breakage or in the event of a missing thread at all, the two machines be shut down. The arrangements in question are of a purely mechanical nature there, and the driving force of the machine is used to uncouple the driving connections made usable.

Arrangement is made in accordance with the present invention in such machines has been, in which the main functions are performed electrically, thereby a substantial simplification the construction of the machine is achieved. The drawing illustrates an embodiment the invention.

Fig. Ι is a front view of the device taken in partial section.

Fig. 2 illustrates a component part of the device.

3 illustrates one of the machine arms in an enlarged front view.

Fig. 4 is a side view of Fig. 3,

Fig. 5 is a circuit diagram of the electrical connections and

6 shows an individual representation of one of the knives to be used.

In the drawing, the two frame arms of a twin sewing machine are designated with AA ¹ , which are mounted on the table α. The drive is derived from a shaft b by means of a belt or cord, which can be moved on short shafts ee ¹ . Set seated stepped washers dd ^x to rotate. On the shafts ee ^{1 there} are also disks ff ¹ , which are connected to the drive shafts gg ^{1 of} the two machines by a cord or belt. On the lower side of the table α two three-armed levers hh ^{1 are} provided, which carry pins ii ¹ , by means of which the disks dd ¹ are coupled to the disks ff ¹ for the purpose of driving the machines. When the levers move in the opposite direction, braking surfaces jj ¹ lie against the circumference of the disks ff ¹ and stop them at the same time that the pins ii ^{x come} out of engagement with the disks dd ¹ . The movements of the levers hh ¹ are regulated by electromagnets BB ¹ . The electromagnets are in the circuit of the control devices arranged on the machine arms, in such a way that by virtue of the latter, the magnets can be opened when one breaks or becomes slack

Thread of any machine to release the discs dd ^{1 are} caused. From FIGS. 3 and 4 it can be seen that the thread of the thread spool runs over the usual tensioning device and then comes under the hook 0 of the weight p. From here the thread is guided through the second tensioning device q to the arm / of the thread pick-up and then to the needle s in the usual way. The weight p carries at its upper end an inclined surface t which is usually in engagement with the lower end of a lever u rotatably mounted at υ. When the thread take-up arm r is in the upper stroke position, the lever releases the weight p for a moment, which is then held in normal operation by the tension of the thread m . However, if the thread has broken, the weight will drop when the lever u is released . This movement of the weight or another part is made usable in some way for regulating the action of the electromagnets BB ^1. In the construction shown, the weight p moves in a metal sleeve b ^l to which the wire Q ^{1 is} connected. The weight carries an inclined end a ³ which, for the purpose of closing the circuit QQ ¹ , can come into contact with a plate b ^s which is seated on a carrier made of insulating material. Both machine arms A and A ^x are equipped with this arrangement. With reference to Fig. 5, which shows the circuit diagram, it should be noted that a small generator X can be used as a power source, which is expediently driven by the shaft b or some other continuously rotating shaft. From the circuit diagram it can be seen that the two magnets B and S ^{1 are} connected to the generator X and the poles b ³ δ ⁴ , so that when a weight falls, the circuit is closed across both magnets, the latter, i.e. both , are energized and lift levers hh ¹ , which disengages the clutch. The circuit is usually open so that the magnets do not have any influence on the lever hh ¹ in terms of lifting. The levers hh ¹ are usually held in their lower or braking position by springs c ³ c ⁴ seated on the pins d ³ d ^l . As shown in FIG. 2, the pins are arranged at the ends of levers e ³ (or e ⁴ ) which are connected to handlebars f ³ (or f ⁴ ).

The latter are rotatably seated on the hand levers g ³ (or g ⁴ ), which can rotate in bearings or carriers arranged on the front of the machine. If the hand lever g ^{3 is} in the position according to FIG. 2, the spring c ⁸ exerts a pressure against the lever h which is large enough to keep the clutch in effect; However, if a thread breaks or if it is missing for any reason, the magnet B pulls the lever upwards against the tension of its spring and releases the clutch. When the lever g ^{3 is} in the position indicated by dotted lines, a small pin rests against the underside of the lever and moves it upwards into the position shown in FIG. In this position it has no effect whether the magnet is excited or not, since the clutch is kept disengaged under all circumstances.

The purpose of the facility is to be able to use any machine from To put the hand out of action and to be able to hold it in such a position to inspect, To make repairs and the like. In the setup described, there are two machines precisely controlled in an automatic manner, so that if a thread is missing on one of the machines, both machines immediately and safely shut down.

In order to bring about a stop of the machines in the absence or breakage of the bobbin thread (shuttle thread), the presser foot i ^{5 is} divided - as shown in FIG. 4 - and a knife j ^b sharpened at the upper edge has been arranged between the two parts. If a shuttle thread breaks or the bobbin has run out, the upper thread is no longer locked on the lower side of the fabric, so that after a few stitches of the machine - passed through the needle - it assumes the oblique position dotted in FIG. As the needle goes up and down, the thread is brought over the edge of the knife j ⁵ and cut with the next downward movement of the needle, whereupon the weight p falls and the two machines are stopped. When using twin sewing machines of the present type, one machine can run backwards so that the thread, instead of - as in FIG. 3 - to lie backwards, is directed towards the front of the presser foot. In this case, the thread can be cut off essentially in the manner described by a short knife I ^s (FIG. 6) which is provided on the back of the presser foot. In certain cases, e.g. B. If the control mechanism is designed so that a slight movement of the weight o. The like. Is possible, the knife for cutting the thread can also be omitted. To make this possible, the contacts b ^{3 of} the weights pp ¹ are set so that a slight movement is sufficient to release the clutch. With such an arrangement, when the thread runs out, there is sufficient slack in the thread part m between

see the clamping devices η and q generated to allow a slight downward movement of the weight, thus closing the circuit QQ ¹ and opening the clutch.

The individual arrangements of the present invention can - instead of as shown - be replaced by equivalent ones. Also the electrical system can be in the most diverse

ίο way varies and instead of weight z. B. a lever or the like can be used. The invention generally includes electrical Means one that is used in the absence of thread from a single machine in twin sewing machines also shut down the machine on which the Thread is fine. It is immaterial whether the machines are usually mechanical ■ Means are kept in operation and stopped by influencing magnets or whether this happens the other way around. The electrical system has a red light or switch on any other signal in a shunt, which indicates power failure, so that the machine can be shut down manually if necessary. It can be a electrical system can be used in which all machines in the event of a power failure be shut down. This then requires the arrangement of either relays or circuit breakers on control weights or lifting legs that break or go limp of the thread or when a machine is left behind come into effect.

Claims (2)

Patent Claims: 1. Twin sewing machine for the simultaneous hemming of two parallel fabric edges, at what after breaking or running out of thread of one machine the other or both Machines at the same time, usually by one under the influence of the thread tension standing device is effected, characterized in that the machines with their drive mechanisms connecting organs (couplings, etc.) triggered by an electrical circuit which is closed or interrupted in the absence of the thread. 2. twin sewing machine according to claim 1, characterized in that when tearing or running out of the bobbin thread (shuttle thread) the electrical release in the This causes the upper thread to be cut by a knife assembly, or the resulting slack of the upper thread is used to bring a contact device into effect. 1 sheet of drawings.