DE49886C - Lockstitch sewing machine - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The illustrated in Figs. 1 to 12 of the drawing and lockstitch sewing machine explained in the present specification operates with a uniformly rotating claws provided with a notch on the raised edge and is equipped with a thread tightening device that works every time the gripper is used, the action before the uniformly rotating gripper enters the new loop comes. In this way a loop will always be understood and completed before a new loop is picked up by the regularly rotating gripper will.

The already moved with an irregular angular velocity gripper and a thread take-up working sewing machines show as a result of the slowed down and again accelerated movement of the hook slightly disturbances in the stitch formation, an irregular gait and great wear and tear of the parts, and moreover they lack due to the non-existent notch in the raised gripper edge the possibility of vertical feeding of the i-thread to the fabric, which is essential for the evenness of the stitches is necessary.

The present machine is intended to be equally safe and of the thread tension little dependent loop formation as achieved with shuttle sewing machines, as well as one even and firm stitch formation can be achieved; the evils of the previous shuttle and gripper machines avoided and the advantages of both systems be combined in the new gripper machine.

Fig. Ι the accompanying drawing shows in a .Längenschnitt respectively. a view of the gleichmäfsig w to the shaft revolving gripper e, and the thread take-up device ff ^1/2/3/4, which is η of the curve washer set in swinging motion; so that at each revolution of the shaft an up and down going motion w of the thread take-up lever / results. 5 to 9 show the various positions of the looper and the effectiveness of the thread take-up lever f. Ρ is the bobbin for the bobbin thread.

In the position of FIGS. 5, 6 and 7, the loop is formed in the manner customary in the known gripper machines; only in FIG. 8 does the distinguishing effect become noticeable. In this figure the upper thread loop i is not held on the hook (by a brush) as before, but lies freely on the hook, and the thread portion i ^J leading to the fabric rests vertically in the notch e ^{4 of} the raised one. Gripper edge. Now, if f the thread take-up lever located in the lowest position of Fig. 8 now makes its upward movement, as he has done this in Fig. 9, the loop is i subtracted from regelmäfsig revolving gripper and it is the stitch by means of the vertical fed yarn i ^l correctly formed before the looper point e ¹ again steps behind the thread lying on the needle, i.e. between the thread and the needle. The protective sector ν serves as loop protection and prevents the loop from slipping.

Fig. 10 shows in a top view the recess e ⁴ on the raised gripper edge, on the one hand by the same, on the other hand by the

Claims (2)

Projection v ^{l is} flanked. This projection is especially used to take the thread loop with you. This explains the characteristic in the formation of the lock stitch; for explanation the movement mechanisms serve the following: The upper thread coming from the bobbin ρ goes through the thread guide ρ and then through the eyelet of the thread take-up lever / and from there to the eye of the needle. The thread take-up lever ff ¹ has the axis of rotation d; to f ¹ engages the tie rod / ^2, which is the other part / ³ / secured to the two-armed lever ^4; / ⁹ is the fulcrum of this lever. On the arm / ⁴ sits a roller g, which is guided in the cam plate η . Adjusting the leg f ^{1 of} the "angle lever ff ¹ " adjusts the thread tension. The cam disk η is coupled by a stud screw I to the eccentric ring m , which sits firmly on the shaft w. The latter is set in rotation ^{by pulley m 1.} The needle is moved from this axis w by means of the eccentric m, which sets the eccentric rod e ² in motion. The rod e ² is connected by the intermediate piece e ³ to the two-armed lever e ⁵ e ⁴ , which raises and lowers the needle bar ^{e e.} Except for the peculiar drive mechanisms for thread take-up levers and The needle bar is still one of the previously used arrangements different. The same is done in the following way: q is the material slide which is carried by the piece s ^s moved in the slide guide hj, FIG. 4. The piece s ³ hangs in the slide guide h by means of pin s ^{4 and can therefore also oscillate about this axis s 4 in} addition to a back and forth movement in the slide. The cast piece s ³ is now supported by the eccentric e ⁷ , which sits on the main axis n> and causes the material slide to be lifted. A spring e ⁸ always pulls the carriage s ³ back into its guide (Fig. 4, arrow direction P) and its forward movement and thus also that of the material slide is caused by the lever o ² o ³ located along the axis n> , the pivot point of which is at o ⁴ lies. The arm o ³ has a vertical ^{pin o 9} , which is encompassed by a slotted piece o ⁵ , which by the action of the spring e ⁸ always rests on the one-sided obliquely cut disk s ⁶ , which sits on the main shaft w. The slotted piece o ⁵ can be adjusted in the vertical direction by means of angled lever KK ¹ , which indicates its position outwards by pointer K ^2. Depending on the position of the piece o ⁵ , the action of the disc s ⁶ , which is cut off obliquely on one side, is larger or smaller and thus an adjustment of the material slide is created. In order to be able to produce a chain stitch seam on the present gripper sewing machine, the gripper ee ^{1 can be} removed from the axis w ; the removal is done by pressing the button K ⁷ , Fig. 2, whereby a resilient lever K ⁸ seated on axis w is moved and its pin K ^{9 is free} from the axis of the gripper. The gripper G ^α shown in FIGS. 11 and 12 for the chain stitch seam can now be inserted into the shaft w , and after the latter has been loosened from the constantly rotating eccentric ring m by loosening the screw / in the cam disk η, thus turning off the thread take-up lever f you can make a chain stitch seam on the machine. Pa τ ε ν τ- An s ρ rü c η ε: ι. A lockstitch sewing machine with a uniformly rotating, with notch e * gripper provided on the raised gripper edge in conjunction with a separately driven by the needle bar thread tightening device works which the latter before entering the looper point in the new loop the cut off, through the called notch held open and the fabric vertically fed loop draws. 2. A sewing machine of the type described under 1., in which the thread tightening device is formed from the angle lever // ¹ provided with an extendable arm, the pull rod / ² and the two-armed lever / ³ / * moved by the cam disk η. For this purpose ι sheet of drawings.