DE510151C - Chain stitch sewing machine with threadless and thread-guiding hooks moving back and forth - Google Patents

Description

Chainstitch sewing machine with threadless and thread-guiding reciprocating Grippers The invention relates to a chain stitch sewing machine with back and forth moving threadless and thread-guiding hooks, both with the needle underneath of the fabric work together in such a way that the threadless looper is in the needle thread loop enters and holds the latter back until the needle has come out of the fabric. The thread-guiding looper then guides the entry of the descending needle a loop of the looper thread through the needle thread loop. According to the Invention, the device is made so that the threadless gripper, the one has a maximum thickness that is less than the width of the needle thread loop, and the thread-guiding looper its reciprocating movement in a plane on the same Side of the needle track parallel to the vertical plane in the direction of the seam carry out. This ensures that an expansion or lateral displacement the needle thread loop when the threadless looper enters the latter will.

In the drawings, one embodiment of the invention is for example shown, namely Fig. r is a side view, partly in section, of a Sewing machine according to the invention.

Figure 2 is a bottom plan view and Figure 3 illustrates in a view of the rotating needle thread take-up.

Fig.q. is a section along the line 4-q. fig. r.

Figure 5 is an end view of the cylindrical machine base and illustrates the stitch forming apparatus. The needles are just beginning to move upwards.

Fig. 5a is a side view of the needles and threadless looper, in a direction opposite to the feed direction - and during the in Fig.5 shown time of the working cycle. - Fig. 6 is one of the figs. 5 similar view, but at a somewhat later point in time in the stitch formation cycle. The needles go up above the work piece, and the threadless grippers hold back the needle thread loops without stretching the latter.

Fig. 6.a is a side view of the parts shown in Fig. 6 seen in the feed direction.

Figure 7 illustrates the stitching tools when the needles are are at the top of their movement. The thread-guiding grippers are in the retained ones Needle thread loops have occurred and the threadless loops are about to decline.

Fig. 8 illustrates the needles moving downward while the threadless The looper and the thread-guiding looper both go back.

Fig. 9 illustrates the entry of the needles: into the bobbin thread loops thread-guiding hooks go back, while the threadless hooks their movement reverse or are at the time of their rest position.

Fig. Io is a perspective view of the carrier, one of the thread-guiding hook is removed.

Fig. I i illustrates in perspective view that of the wearer removed thread-guiding hook. Figure 12 is a top plan view of the throat plate.

Fig. 13 is a section along line 13-t3 of Fig. 12.

Fig. 14 is a section along line 14-14 of Fig. 12.

Fig. 15 is a cross section through the drive shaft for the threadless Looper and the hub of the carrier for the thread-guiding looper.

Fig. 16 is a top plan view of the needle thread tensioning device. Figure 17 is a vertical cross-section through the tensioning device.

Fig. I $ and 1g illustrate this in diagrammatic representations control element used for voltage release and the control element driven by the latter Part.

Figure 20 is a rear view of the machine base and illustrated the bobbin thread tensioning devices and the bobbin thread guide device.

Figure 21 is a perspective view of that removed from the machine Undercut guide device, and Fig. 22 is a section along line 22-22 of Fig.2o.

In the illustrated embodiment, the machine has a frame on, which consists of the foot i, which with a horizontally extending cylindrical Base plate 2 is provided. The stand 3 of the overhanging one extends from the foot i Machine arm 4, which runs out in the head 5. The machine drive shaft is in the machine arm 4 6 stored, which carries the rotating needle thread take-up 7 and the usual crank and handlebar connection 8 with the needle bar 9, which carries three needles io, which in turn are arranged in a plane transverse to the feed direction.

In the base plate 2 are the coaxially extending and swinging out Shafts i i, 12 mounted, of which the shaft i i is solid and the shaft 12 is hollow is. The shaft i i carries the threadless grippers 13. The upper end of each gripper 13 is bent to form an awl-like, loop-engaging part 14, which see moved in the direction of its length and grasped a needle thread loop, without expanding it.

The split collar 15 is clamped onto the hollow shaft 12 which the pin 16 sits parallel to the shaft i i. The collar 15 and the pin 16 form a carrier for the thread-guiding gripper 17. The leaves of this gripper lie in parallel planes which essentially coincide with the planes in which the loop-engaging parts 14 are located. The thread-guiding looper 17 work just below the throat plate 18. The oscillating shafts 11, 12 are of moves the eccentrics 1g, 2o sitting on the machine drive shaft, the, the handlebars 21, 22 drive the lower ends of which on the shafts i i and 12 seated cranks 23, 24 attack. The time of the eccentric 1g is set so that that the threadless grippers 13, 14 capture the loops of thread that are raised by the ascending ones Needles are formed (Figs. 5 and 5a), and the eccentric 20 is independent of the eccentric 1g set in time so that the thread-guiding gripper 17 to the go back at the right time and open the lower thread loop, so that in the latter the tips of the descending needles can enter (Figures 8 and 9).

The feed device has the knife 25, which is on the Material slide carrier 26 is seated, which is swingable at 27 with a crank arm 28 of the oscillating shaft 29 is connected. A link 31 is connected to the material slide carrier at 3o, ornamental at 32 on a crank arm 33 seated on the oscillating shaft 34. the Oscillating shafts: 29, 34 lie inside the cylindrical base plate 2 and extend in their longitudinal direction. Crank arms sit at the rear ends of the shafts 35, 36, which are connected by links 37, 38 with the feed eccentrics 39, 40 on the machine drive shaft 6 are connected. The eccentric 4o can be adjusted in a known manner by the stitch length to change.

The throat plate 18 has the fabric slide slots 41 and the stitch holes 42, (Fig. I i and 12) - In each tap hole there is preferably one on the bottom Wall 4.3 is provided, which has a beveled front edge 44, which of the Eye of the thread-guiding looper to the last stitch going under thread after the deflects one side, causing the bobbin thread to flex away from the looper blade is supported, uni the bobbin thread loop for the entry of the descending Open needle.

The tips of the threadless and thread-leading Grapple 14 and 17 move in tracks on the same side of the associated needle tracks and parallel to the direction of advance. As a result, the threadless grippers need to have no lateral thickenings in order to expand the needle thread loops or to move the latter sideways to the other side of the associated needle tracks, how this would be necessary if the threadless and thread-guiding grippers were on opposite sides of the associated needle tracks would work. The threadless ones and thread-guiding hooks only perform reciprocating movements, d. H. they lead only the loop-grasping and loop-throwing movements, but no lateral movements or evasive movements. As a result, the drive device can be extremely be of simple construction. The free end of the shaft i i and the pin 16 form a Pair of separately lying pivot pins, each of which has its associated part of the Carrying stitch-forming tools, which in turn have a flat shape and thin hubs are provided so that they can be attached close together.

The needle threads are preferably taken from a rotating thread take-up controlled, the parallel disks lying at a certain distance from each other 7, between which the stationary plate 45 is located, which has the thread slot 46 having. A thread guide 47 made of bent wire provides the needle threads in the required manner on both sides of the thread take-up disks 7, so that the latter can act on the needle threads.

The thread clasp has a seat 48 and a head 49. The seat surface 48 is resiliently mounted in a recess 50 on the side of the machine arm 4, and the coil springs 5i act on its rear side. The outward movement of this seat surface 48 under the influence of the springs 51 is limited by the retaining screws 52. The head 49 is mounted on the reciprocating rod 53 which is mounted transversely to the arm: 56 is driven.

The needle threads go from the supply source to the thread clamp through a multiple thread tensioning device which has a plurality of thread tensioning members 57 which are mounted on the plate 58, which in turn are held at a certain distance from the plate 59 by means of the four corner posts 6o and on the latter is attached. The plate 59 is carried by a bearing block 61 which is screwed onto the upper side of the arm 4. On the corner post 6o, the movable plate 62 is slidably mounted between the plates 58, 59 and has a disc 63 on its inner surface, which in turn is provided on its exposed surface (Fig. Icg) with control cams 64 opposite in diameter. An oscillating shaft 65 is mounted in the bearing block 61, at one end of which sits the head 66, which is provided with an annular flange and has recesses 67 for receiving the control cams 64 seated on the disk 63; these control cams 64 are held in engagement with the head 66 by an arc spring 68 (FIG. 16) which is fixed between its ends to the plate 58 and which presses on the movable plate 62. When the shaft 65 is swung out, the inclined surfaces of the indentations 67 push the movable plate 62 away from the plate 59 and cause the plate 62 to engage the individual tension release pins 69 which cause the tension disks of the individual pairs to separate at the same time .

The shaft 65 is actuated by the usual crank arm 70 and the link 71, which is connected to the usual lifting lever 72 for the presser foot 73.

The cylindrical base plate a has a longitudinal groove 75 (Fig. 2z), in which a multiple thread guide tube 76 for the bobbin threads is removably attached; this tube is in the groove 75 by transverse Holding wires 77 held on the cylindrical base plate by means of the screws 78 are attached.

The stitch formation cycle takes place in the following way. The needles io (Figs. 5 and 5a) go up and throw out their needle loops, which are grasped and held back by the threadless grippers 14, but not expanded. The needles then go up further, and the thread-guiding grippers 17 then swing close to the threadless grippers (Fig. 6, 6a) in planes -or which essentially coincide with the planes of the threadless grippers. The thread-guiding grippers 17 enter the thread loops and swing forwards until the end of their movement (Fig. 7), while the threadless grippers go back and release their thread loops onto the thread-guiding grippers. The thread-guiding hooks 1 7 then go back (Fig. 8) and throw out their needle thread loops, into which the falling needles can now enter (Fig. 9). The falling needles, together with the thread take-up 7, tighten the previously formed needle thread loops as soon as the latter escape from the thread-guiding grippers.

Claims (1)

PATENT CLAIM: Chainstitch sewing machine with threadless moving back and forth and thread-guiding loops, both with the needle below the fabric in the Work together so that the threadless looper enters the needle thread loop and holds the latter back until the needle has come out of the fabric, -vorauf the thread-guiding looper makes a loop of the looper thread through the needle thread loop through for the entry of the descending needle, characterized in that that the threadless gripper, which has a maximum thickness that is less than the width of the needle thread loop, and the thread-guiding looper its reciprocation in a plane on the same side of the needle path parallel to that in the sewing direction execute lying vertical plane.