US1742953A - Automatic single-needle embroidering machine - Google Patents

Description

Jan. 7, 1930. F. J. Vcam-{LER-r r-:r A1. 1,742,953

AUTOMATIC SINGLE NEEDLE EIBROIDERING IAGHINE Filed Nov. 9. 1926 #H ma v Paz n;

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Patented Jan. 7, 1930i UNITED STATES PATENT OFFICE y AUTOMATIC SINGLE-NEEDLE EMBROIDERING MACHINE Application filed November 9, 1926, Serial No. l47,306, and in Germany March 1, 1926.

This invention relates to improvements in the construction of automatic single-needle embroidering machines controlled by a jacquard card.

The object of the invention is to provide means for automatically stopping the automatic single-needle embroidering machines as soon as the thread gets slack, when the thread breaks or when the embroidery pattern is finished, the same device serving to prevent the restarting of the machine as long as the thread is broken or if nothreads are in the embroidering tools.

One person attends usually to several automatic single-needle embroidering machines and has to remedy the disturbances which occur during the embroidering process and which consist mainly of breaking of the threads, said attendant having also to stop the machine when the embroidery pattern is finished. It depends therefore entirely on the skill of the attendant Whether more or less great faults occur in the embroidery When the thread breaks. These faults have tobe repaired by hand. The number of machines attended to by one person is limited by the fact that the greater the number of machines to which one person attends is, the greater will becclne the number of faults in the embroidery, the economy of single-needle embroidering machines being further impaired by this difficulty.

The inconveniences which have just been mentioned are obviated by the invention or reduced to a minimum, by providing means for automatically stopping the automatic single-needle embroidering machine at slackening or breaking of a thread, or when the embroidery pattern is finished, and to prevent re-starting of the machine as long as the thread has not been threaded into the needle. The repairing work is, therefore, done away with almost entirely, and one person is able to attend to a greater number of machines than hitherto, without unfavorable influence upon the quality of the work.

The invention is illustrated in the accompanying drawing.

Referring to the drawing the thread bobbin 67 is rotatably mounted on a pin 68 fixed in the machine frame which is not shown in the drawing. The thread 69 unwound from the bobbin 68 passes through between a pair of brake-pulleys 70 Which are fixed on the machine frame. The thread 69 is then guided around guide bolts 71 and 72, a bolt 7 3 on one end of a thread stretching lever 74, a bolt 75 at one end of the thread guiding lever 76, and then through the eye of the embroidering needle 77 to be stitched through the fabric 45. The guide bolts 71 and 72 are fixed on the machine frame, the thread stretching lever 74, and the thread guiding lever 76 being pivotably mounted on the machine frame at the points 78, 79 respectively. The needle 77 is mounted in the machine frame so that it can be shifted in longitudinal direction. The thread stretching lever 7 4 has two arms, a spring 80 attached at one end to the machine trame being attached at the other end to the free arm of said thread stretching lever 74. This spring 80 serves to pull the free end of the thread stretching lever against a contact 81 when the thread is not in the needle, this contact `81 being fixed in and insulated from the machine frame. At the end 82 of the two-armed thread guiding lever 7 6 a roller 83 is rotatably mounted which engages with a groove 84 of an eccentric 85 keyed on .the main needle shaft 86. On the main shaft 86 a control cam 87 is also keyed which cooperates With a contact spring 88 iixed on and insulated from'the machine frame.

The switch of the driving motor 89, which is shown diagrammatically, consists essentially of a switch lever 90, a locking pawl 91, a spring 92 connecting said two last men- 'tioned elements, and al contact spring 93. The

base plate 94 of the switch-is made from insulating material. The three-armed switch lever is pivotally mounted on a pivot axle l 95 of a bearing 96. On the bearing 96 a locking pawl 91, composed of three arms, is pivota-bly mounted at 98. The spring 92 the one end of which is attached at 99 to the lever 100 of the switch lever is attached at the other lever 90tending at the same time to make the switch lever pivot into the cutting-out position this being prevented, when said switch lever is in the switching in position, by a locking nose 104 of the locking pawl 91. The arm 105 of the switch lever, 90 produces the circuit closing if it'co'mes into contact with the contact spring 93. This arm has further a knob 106 of insulating material by means of Which the switch can be operated by hand. The contact spring is fixed on the base plate 94 at the point 107. The locking arm 102 of the locking pawl 91 has a second locking nose 108 which limits the movement of the switch lever 90 in the cutting-out position so that complete slackening of spring 92 is thus prevented. The arm 109 ofthe locking pawl 91 serves for releasing by hand and it has, with this object in view, a knob 110 of insulating material. On the arm 111 of the locking pawl 91 a lifting wire 112 is hingedly fixed at the point 113. This lifting Wire 112 is shiftablymounted in a bearing 114 and insulated from the machine frame. The lifting wire 112 is shifted from the jacquard card 57 which lmoves in the direction of the arrow fv. On

the base plate 94 of the switch an electromagnet 115 is mounted the armature of which is formed by the locking arm 102 of the locking pawl 91, 116 and 117 are the two conductors of the net. .118 is the conductor for the switch lever 90, 1.19 is the conductor leading from the contact spring 93 to the driving motor 89 and 120 is the return conductor to the conductor 116 of the net. The conductor 118, the arm l05'of the switch lever, the contact spring 93,-the conductor 119, the electromotor 89 and the conductor 1'20 form therefore the circuit for the drivingmotor 89. g Through the two conductors 121 and 122 the. primary winding 123 of a transformer 124 is further connected to the net conductors 116, 117. The secondary winding 125 of the transformer 124 forms, together with a conductor 121, the electromagnet 115, a conductor 127, the contact 81,

the thread stretching lever 74, the mass of t-he machine frame which is not shown and which is designed to be'represented by the conductor 128 shown in dash lines, the cam 87, the contact spring 88 and the conductor 129 the so-called releasing circuit.

The operation of-this mechanism is as follows After the. thread 69 which is wound oil'l the bobbin 67 has been passed over its guide bolts the switch lever 90 is depressed by hand so that the locking nose 104 of pawl 91 rips under the locking arm 103 of the switch ever and is held in this position by the pull exerted by spring 92. By the depresslon of the switch lever 90 which comes into contact with4 the contact spring 93the circuit 117,118, 105, 93, 119, 89, 120 and 116 of the electromotor is closed, so that the electromotor and through it the main shaft 86 are rotated, In

the movements which now begin, owing to the oscillation of the thread guiding lever 76 which is driven by the eccentric 84, 85 and by the descending and ascending needle 77, the driving mechanism for which is not shown as it is not necessary for explaining the'present invention, the thread stretching lever 74 is alternately pulled away from the contact 81 at the moment when the tension of the thread is produced and then when the thread is subsequently pulled. At the same instant the cam 87 acts upon the contact spring 88. If, during the embroidering process, the tension of the thread 69 slackens for any reason or if the thread breaks, a displacement of the movement of the thread stretching lever 74 will take place in the first case, or said thread stretching lever 74 will in the second case remain pressed against the contact 81. The main shaft 86 continuing to rotate the cam 87 will act again upon the contact spring 88 so that this time as the thread stretching lever 74 is pressed against the corresponding contact 81, the releasing circuit 125, 126, 127, 81, 74, 128, 86, 87, 88 and 129 is closed. The releasing electromagnet l`115 is thus excited and attracts its armature, consisting of the locking arm 102 of the three-armed locking pawl 91. The locking arm 103 of the switch lever 90 is thus released and pulled, by the action of spring 92, into its position ofrest so that it rests upon the nose 108 of the locking -pawl 91, the arm 105 of the switch lever 90 interrupting the contact with the contact spring 93 whereby the circuit for the electromotor 89 is interrupted and this electromotor and the ing previously threa ed the thread into the needle, one presses upon the knob 106 of the.

switch lever 90, the motor 89 will be started, and the main shaft 86 rotated, but the motor will be switched out againl during the first rotation of shaft 86 by the action of the cam 87 upon the contact spring 88,- as the thread stretching lever 74 is still in touch with the contact 81. When, however, prior to starting the electric motor, the thread 69 is threaded into the needle, the thread stretching lever-74 will bemoved away from the contact 81 at the moment when the cam 87 acts upon the contact spring 88 after the electromotor 89 has been switched in by the depression of the switch lever 90, this oscillation of the thread stretching lever 74 being l caused by the pull exerted by the thread' guiding lever 76, whereby closmg of the releasingl circuit is prevented. The machine will therefore remain running. To stop the machine for any reason whatsoever it is merely necessary t de ress the `knob 110 of the arm 109 of th'e loc ing pawl 91, whereby the same effect is produced as described with reference to they electromagnetic releasing. If the embroidery pattern is finished, the jacquard dard 57 Q f the automatic embroider,

not shown on the drawing, pushes against the lifting wire 112 as said card has at this point no perforation, and moves periodically at every stitch in the direction of the arrow o towards the lifting wire 112, wherefrom results that the locking pawl 91 is raised and the switch lever 90 pulled back by the action of spring 92 into its cutting-out position. That this does not occur during the embroidering process is due to the fact that the jacquard card 57 for the lifting wire 112 has for each stitch one hole. a

The above described mechanism stops the machine also at breaking of the shuttlethread, not shown on the drawing, as in K this case the tension of the thread 69 slackens also. No special thread-detector is required.

We claim A l. In an electrically driven automatic oneneedle embroidering machine an electromotor, a switch inserted in the circuit of such motor, a shaft driven by the said motor, a cam on the shaft, a thread tensioning arm over which the embroidering thread passes, a locking -member which normally locks the switch of the motor circuit to keep the said switch in the closed position, and a release circuit provided with an electromagnet and controlled by the said cam, said electromagnet when energized operating to actuate the said locking member so as to cause the switch in the motor circuit to open the motor circuit said electromagnet being. inoperative 'until the thread tensioning arm rises upon the slackening of the thread.

2. In an electrically driven' automatic oneneedle embroidering machine an electro-motor, a switch inserted in the circuit of such motor, a. shaft driven by the said motor, a cam on the shaft, a contact spring with which the cam makes contact on rotation of the shaft, a tensioning arm over which the embroidering thread passes, a contact member for such arm, the said t read tensioning arm and contact forming a closed switch when slackening of the thread allows contact between the said arm and Contact member, a locking member normally maintaining the the embroidering thread passes, a contact member for such arm, the said thread tensioning arm and contact member forming a closed` switch when slackening of the thread allows contact of the said arm and contact member, a locking member normally maintaining the switch of the motor circuit closed, an electroof the armature thereof the switch in the motor circuit and thus open the latter when the thread slackens and allows the thread tensioning arm and its contact member ineluded in the release circuit to make contact. In testimony whereof we have affixed our signatures.

FRANZ JOSEF GAHLERT. MAX BRETSCHNEIDER.

switch of the motor circuit closed, the cam,

contact spring, tensioning arm, contact member, and locking member being included in a release circuit which is closed by the cam on its rotation to operate the locking member to release the switch and thus openthe motor circuit. only when the thread has slackened and allowedcontact between the thread tensioning arm and its contact member included in the release circuit.

3. In an electrically driven automatic oneneedle embroidering machine an electro-motor, a switch inserted in the circuit of such motor, a shaft driven by the said motor, a

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