DE836877C - Sewing machine - Google Patents

Description

(WiGBl. P. 175)

ISSUED MAY 15, 1952

P -'3334 VIl 152 a D

sewing machine

The present invention relates to sewing machines and in particular on sewing machines, which are used for the production of angle or corner seams be used, d. H. for the production of stitch seams, which have a line of stitches continues around a sharp corner into another line of stitches.

When using sewing machines for the production of angle seams, such as. B. essentially right-angled sutures, it has been customary to bring the needle into the workpiece, after the machine has stopped so as to rotate the tailpiece around the needle after the hook or loop pick-up has caught the needle thread loop. This procedure was necessary because twisting the workpiece around the needle had the result that further the workpiece shear of the needle thread loop extending from the eye of the needle and is anchored to the workpiece, wraps around the needle; thereby it was the needle not possible to correctly present the needle thread loop for entry through the hook.

When using chain stitch sewing machines to produce angle seams, this resulted a further difficulty existing heretofore from the fact that when the piece of work is about the Needle was rotated, the needle thread loop previously grasped by the looper or spread out by the looper bent around a side edge of the needle slot or needle hole in the needle plate became; thereby the needle thread

loop excessively taut, resulting in a thread breakage or thread from the supply was removed and thereby produced a loose stitch or the workpiece bulged or was bulged.

The main purpose of the present invention is to provide a sewing machine with facilities create by which the above difficulties are avoided when the work piece in any position of the needle that penetrates the workpiece beyond the eye of the needle around the Naddl is rotated, thereby the manufacture and the quality of the product considerably to improve.

In the drawing, an embodiment of the invention is shown.

Fig. Ι is a front end view of a chain stitch sewing machine, on which the present invention is embodied; the fabric support plate is in vertical section and the machine arm is partial shown broken away;

Fig. 2 is a bottom view of part of the machine in the area of the needle, with the looper broken away to show the suture positioning portion;

Fig. 3 is, on an enlarged scale, an end view, partly in vertical section, of the stitch formation and workpiece advancing means with the needle being substantially is in its lowest position, while it is arranged in the front piece; the knife valve is reproduced in section along its row of teeth on the left, and the workpiece is in Line of seam formation cut;

Fi ₁ K- 4> ^{st € me} side view from the front, partly in vertical section, of the stitch forming devices in their position shown in FIG. 3; the cut runs essentially through the path of the needle transversely to the feed line;

FIG. 5 is a view similar to FIG. 3, but with the workpiece rotated 90 ^degrees to the left about the needle; FIG.

Fig. 6 is a view corresponding to Fig. 4, but with the workpiece rotated about the needle as in Fig. 5;

Fig. 7 is a view corresponding to FIG. 6, but in a position of the upstroke of Needle in which the work piece leg of the needle thread loop is bent outwards and the Gripper stepped into it;

Figure 8 is a top plan view of the device shown in Figure 7; the needle is in the cut and the finished stitches are partially shown in section, they are essentially vertical arranged to the seam formation line;

9 is a partial plan view, on an enlarged scale, of the throat plate, fabric slider, and FIG of the hook and gives, partly in section, the needle thread loop in the loop release position the grapple again;

Fig. 10 is a partial view on an enlarged scale from above of the part that brings the needle thread into position, the needle and the needle thread in a horizontal cut and the needle slot (needle hole) of the needle plate in dash-dotted lines Lines are shown;

Fig. 11 is a perspective view of the throat plate;

Fig. 12 is a perspective view of the needle thread positioning member;

Fig. 13 is a perspective view of the stuffing valve.

According to the drawings, the sewing machine partially shown has a frame which a fabric support plate 1 comprises, with a throat plate 2 is provided, which in connection with the surface of the machine plate a workpiece carrier forms. Above the fabric support plate 1 is an overhanging machine arm, the ends in a head 3 in its free end.

In the head 3 of the machine arm, one can be moved vertically up and down in the axial direction The needle bar 4 and a push bar 5 which can be moved vertically in the axial direction are supported. the The needle bar 4 carries in its lower end a needle 6 provided with an eye, while the push bar 5 carries a presser foot 7 at its lower end; this push rod5 is on a any customary or appropriate way pressed down by spring force.

The needle 6 starts the formation of single-thread chain stitches below the workpiece carrier a rotatable gripper 8 of conventional shape. As usual, the gripper 8 has a curved, the thread grasping point 9, which in a body part 10 spreading the loop passes, which ends in a transverse, the loop retaining groove 11. To the rear and beyond the groove 11 extends a twisting loop and spreading wing 12, around the captured and spread needle thread loop in a position to subsequent entry of the tip 9 of the gripper to hold. The gripper 8 has a shaft pin 13 entering an end bore of a rotatable looper shaft 14; on this wave is the Shank bolt 13 fastened by a screw 15. The gripper shaft continues to carry the usual spacer collar 16, which is on the shaft by a Screw 17 is fixed and arranged near the gripper. The looper shaft 14 is at the bottom the fabric support plate 1 is stored horizontally and is driven to complete each time Rotate the needle up and down.

The throat plate 2 has a needle slot (Stitch hole) 18 provided, which is extended in the line of seam formation and backwards around extends a considerable distance beyond the path of the up and down needle 6; the The needle moves up and down in the front end of the needle slot 18.

The throat plate 2 is furthermore provided with a plurality of material slide slots 19, 20, 21 and 22 (see Fig. 11) provided; the middle slider 'slits 20 and 21 are in alignment

and are in front of or behind the needle slot 18 in arranged on the line of stitch formation. The fabric slit 19 is on the right side of the Needle slot 18 arranged; this fabric slide slot starts near the front end of the needle Slot 18 and terminates at its rear end near the rear end of the fabric slit 2T. The material slide slot 22 is attached to the left side of the needle slot 18.

to arranges and preferably extends from near the front end of the stuffing slide slot 20 to near the rear end of the stuffing slide slot 21.

Through the throat plate pre-scribing slots described above A fabric valve 23 works through it (see Fig. 13), which in the acts acting on the work piece movements relative to the presser foot 7 is arranged. The knife gate valve 23 has a right-hand row of teeth 24 through the Slide slot 19 can work through, a middle front row of teeth 25, which through the slide slot 20 can work through, a middle row of teeth 26 which through work through the rear slide slot, and a left row of teeth 27 which through the slide slot 22 can work through it.

The upper surface of the throat plate 2 is between the needle guard 18 and the fabric slide slot

22 cut out or pressed in in order to create a recess 28 in the needle plate for the free movement of the thread, which preferably begins a little behind the front end of the needle slot or needle hole; this will adequately support the arm piece near the path of the needle. The edge which defines the front end of the recess 28 is preferably inclined forwards towards the slide slot 22 , and the lower wall of the recess 28 is bent slightly upwards at the rear end of the recess to gradually enter the upper surface of the throat plate 2 to pass over.

The left row of teeth 27 of the fabric slide

23 is also interrupted or cut away between the ends of the row in order to expose it Movement of the thread near the throat plate recess 28 to an indentation or recess 29 create, which forms a continuation of the throat plate recess 28.

The fabric squint> he 23 is held by a fabric pusher rod 30 carried, which is arranged below the fabric support plate. The rear The end of the material pusher rod 30 is pivotably connected to a material pusher rocker arm 31, which on a feeder rocker shaft 32 after ol> en, which is mounted and driven in any customary or appropriate manner can be. The front end of the shuttle bar 30 is slidable to include a pivot block 33 supported by a Crank arm 34 is carried, which extends backwards from a strabismus> raised swinging shaft or Knife gate valve rocker shaft 35 extends, which is also to any conventional or preferred Stored in a way that is related to the movements of the feeder swing shaft 32 can be set and driven to the knife 23 intermittent feed movements for the work to be granted.

In order to achieve the necessary cooperation between the needle 6 and the gripper 8 in the gripping of To ensure needle thread loops by the hook, a needle guide 36 is used which is curved upward from its shaft 37; this shaft 37 is connected by a screw 38 the underside of the fabric support plate 1 connected. The needle guide 36 has a needle deflecting surface 39, which slopes downwards and into a substantially vertical needle support surface 40 passes, which is located on the side of the long groove of the needle, d. H. the surface 40 is on the Side of the needle arranged opposite that side on which the looper 8 in the needle thread loops entry. Since the surface 40 is arranged in the immediate vicinity of the path of the needle moving up and down, the surface serves 40 of the needle guide as an abutment or support, which during the upward movement of the Needle the opening of the needle thread loops on the looper side, which causes the needle. '

It is well known in the art that the gripper 8 enters the needle thread loop a, b between the needle 6 and the needle thread loop leg b which is anchored in the workpiece. This leg b of the needle thread loop is therefore generally referred to as the work piece leg, while the other leg α of the needle thread loop on the opposite side of the needle is usually referred to as the tightening leg because it extends through the work piece to the needle thread take-up (not shown).

The throat plate 2 is provided on its underside and on the side of the hook tip of the needle path with a recess in order to provide a seat 41 for the shaft 42 (see FIGS. 2 and 12) of an axially adjustable, the needle guiding and the thread loop in Provide position bringing part 43; this part 43 is connected in the working position to the throat plate 2 by screws 44 which pass through a slot which is formed in the longitudinal direction in the shaft 42. The parallel side edges of the seat 41, which limit the axial adjustment of the shaft 42 are inclined rearwardly at an angle of about 50 ⁰ for the seaming line.

The part 43 extends in front of and across the throat plate slide slot 19 against the path of the needle moving up and down. The part 43 has, near its free end, the edge 46 which guides a needle and brings the thread loop into position, which edge is preferably beveled backwards at an angle of approximately 10 ° relative to the seam formation line. The edge 46 of the part 43 extends partially across the throat plate needle slot 18 and somewhat beyond the needle path in close proximity to this path iss on the side of the path of the workpiece leg

the needle thread loop, whereby in any desired position of the needle passing through the work piece beyond the eye of the needle, said edge 46 extends substantially tangentially to the needle 6 behind said work piece leg b of the needle thread loop. The edge 46 preferably terminates at its rearward end substantially in the plane which contains the seam formation line and the path of the needle reciprocation. By axially adjusting the part 43, its edge 46 can be shifted to and from the path of the needle moving up and down laterally in a direction inclined to the length of the needle slot 18 of the throat plate 2.
The rear end of the edge 46 which brings the thread loop into position or holds it merges into a thread loop shedding edge 47 which runs obliquely backwards away from the seam formation line at the edge 46 of this line; the

Thus, the ejection edge 47 is arranged on the workpiece leg side b of the seam formation line and is beveled in a direction opposite to the direction of inclination of the edge 46.

As shown in Fig. 10 of the drawing,

5 the inclined edge 46 of the part 43 works to push the work piece leg b of the needle thread loop a, b forward when the eye of the needle passes said edge 46 during the downward movement or the movement of the needle 6 penetrating the workpiece. Since the needle 6 is held by the needle guide 36 against deflection away from the edge 46 and because the edge 46 is substantially tangent to the needle path directly behind the Arbeitsstückschenkelf), the work piece leg is b by the complementary action of the needle 6 and the edge 46 from prevented from migrating rearwardly therebetween in any position of the needle penetrating the workpiece beyond the eye of the needle.

This condition is particularly advantageous when the work piece is rotated around the needle for the production of angular or corner seams, because the work piece leg b is thereby prevented from wrapping around the needle at any point below the part 43, whereby the work piece leg b is The needle thread loop is properly spread out and presented for the purpose of being grasped by the gripper. In other words: the present invention enables the workpiece to be rotated around the needle for edge or corner sewing in any position of the needle penetrating the workpiece, because the workpiece limb is inevitably pushed forward and into the correct position for gripping by the gripper is brought.

The stitch formation is shown in FIGS. 3 to 9 including the drawings. In "Fig. 3, the work piece W is shown as it is advanced in the seam formation line; the X needle 6 is shown essentially at the lower end of its stroke. The thread loop α ¹ , b ¹ previously grasped and spread out is behind the needle 6 through the The groove 11 of the looper 8 is held open and the point 9 of the looper is shown approaching the needle Since it is essential that the thread loop α ¹ , b ¹ should be located behind the needle at this point in time It is also important that the upper end of this thread loop o ¹ , b ¹ must have become free in order to move during the previous feed movement of the workpiece in the longitudinal direction of the needle plate needle slot 18. Since the needle 6 is located outside the workpiece during the advance of the workpiece , the device bringing the work piece into position allows the needle thread loop a ¹ , b ¹ to move freely during said advance of the work piece kes to advance in the rearward direction in the needle slot 18.

Fig. 4 of the drawings shows the same position of the parts as in Fig. 3, but seen from the front of the machine. It can be seen that the contact surface 40 of the needle guide 36 is arranged opposite the part 43 guiding the needle and placing the thread in position, whereby the needle is forced to move up and down in such close proximity to the part 43 that it has a backward movement of the work piece handle b out of the correct position for the purpose of gripping by the gripper 8 with go security.

In Figs. 5 and 6, the parts are shown in the same position as in Figs. 3 and 4, but the workpiece is about 90 ⁰ , such as. B. when sewing corners, has been rotated. From Fig. 6 it is seen that, while the Arbeitsstückschenkelt the needle thread loop is wrapped above-making in position member 43 partially around the needle ¹ to 6, as a result of rotating the work piece about the needle 6, the portion of the work piece leg b below the part 43 remains in the position which, as can be seen by a comparison with FIG. 4, is the same as that when the workpiece was rotated.

Now, when the needle starts to move upwards, as shown in Figs. 7 and 8 is shown, the Arl> eitsstückschenkel b spreads into the correct position for the purpose of detection by the hook point 9, although the work piece 90 ⁰ to the Needle 6 has been turned around. This condition is evidently obtained when the workpiece is rotated around the needle in any position of the needle penetrating the workpiece. By eliminating any need to properly adjust the needle prior to rotating the workpiece, performance is greatly increased.

In chain stitch sewing machines, e.g. B. stitching machines on which the present invention has been embodied, which are intended to make long stitches, the legs α ¹ , b ^{1 of} the thread soleplate, which are held spread by the gripper, are sharp by rotating the workpiece around the needle bent around a side edge of the needle slot. This results from the fact that the length of the stitches is greater than dfe

The width of the needle slot is i8. By bending the thread loop α ¹ , b ¹ around the edge of the needle slot 18 in this way, the thread loop is possibly excessively tensioned in order to result in skipped stitches or actually a thread breakage. This condition is exacerbated to some extent by the thread-holding effect of the locating part 43.

According to the present invention, the vonl>eschriel> eiien recesses 28 and 29 in the throat plate and in the stuffing slide near the needle slot 18 create enough space for the thread to practically neglect the tension applied to the thread when the workpiece is around the X a del is turned to the left. This is clearly shown in FIGS. 5 and 8 of the drawings, which show the upper ends of the loop legs a ¹ and Λ ¹ as they lie in the recesses 28 and 29. By this way the (learning thread impressed voltage is mitigated, the Arbeitsstückschcnke! Xadelfadenschleife of b less tendency backwards between the needle 6 and hike the portion 43, when the Arl> eitsstück rotated around the needle.

When the thread loop a ¹ , Z ' ^{1 has been} thrown off the gripper, its leg o ¹ lies below the throw-off edge 47, which is arranged at an obtuse angle to the edge 46 of the part 43 that arranges the thread. This position of the thread loop α ¹ , b ¹ is shown in Fig. 9 of the drawings. As a result of the mutual relationships of the edges 46 and 47, the thread loop α ¹ , fr ¹ can be drawn freely onto the work piece to form the stitch without the thread loop being held up by the converging corner of the edges mentioned .

Claims (9)

Patent claims: τ. Sewing machine for the production of angled stitch seams with a and removable needle, which works through a needle guard in the throat plate, and a looper cooperating with the needle to form stitches thereby characterized in that a thread-guiding member (43) with respect to the path of the needle on the work piece thigh side of the needle thread loop and cooperates with the needle to flip the workpiece leg the needle thread loop around the needle as a result of turning the tailpiece in one direction to prevent the needle. 2. Sewing machine according to claim 1, characterized in that the thread-guiding member (43) has a straight thread-guiding edge (46) which is located behind the path of the needle the work piece thigh side of the needle thread loop and in an angle backwards at an angle against the seam line, and that edge (46) in any that Work piece penetrating position of the needle beyond the eye of the needle essentially is arranged tangentially to the needle behind the workpiece leg. 3. Sewing machine according to claim 2, characterized in that the thread-guiding edge (46) ends at its rear end essentially in the El> ene which contains the path of the needle and the seam formation line. 4. Sewing machine according to claim 1, characterized in that the thread-leading edge (46) is arranged inclined at an angle of about 10 ° to the seam formation line. 5. Sewing machine according to claim 1, characterized in that the thread-leading edge (46) towards and away from Nadetoveg is adjustable. 6. Sewing machine according to claim 2, characterized in that the thread-guiding part (43) underneath the throat plate is adjustable. 7. Sewing machine according to claim 2, characterized in that the thread-leading edge (46) can be adjusted laterally in a direction which corresponds to the length of the needle slot in the Throat plate is inclined. 8. Sewing machine according to claim 2, characterized in that the thread-guiding (46) and an edge throwing off the thread loop (47) of the thread-guiding part (43) to the stitch formation line on the work piece leg side the needle thread loop are bevelled opposite and these edges (46, 47) in the Area of the needle plate behind and in the immediate vicinity of the path of the needle into one another ül> endure. 9. chain stitch sewing machine according to claim 1 and 2, characterized in that the top the throat plate is provided with a recess (28) that gives the thread clearance, which extends from the needle slot to the fabric slide slot, and that in the teeth of the The material slide has a recess (29) close to the recess which gives the thread clearance (28) of the throat plate is provided and forms a continuation of the recess (28), to create a clearance for the thread sole that extends from the workpiece to the gripper 110 ' extends when the workpiece is rotated about the needle. 1 sheet of drawings © 5020 5.52