DE1216083B - Double chain stitch sewing machine - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

D 05b

German class: 52 a - 3

Number: 1216 083

File number: M 49027 VII a / 52 a

Filing date: May 12, 1961

Opening day: May 5, 1966

The invention relates to a sewing machine for producing a two-thread chain stitch seam with a thread-guiding needle, a thread-guiding gripper that oscillates transversely to the direction of fabric feed and a spreader vibrating in the direction of the material feed.

In such known sewing machines, the gripper performs a reciprocating oscillating movement The spreader is used to remove and open the thread triangle. The hook must have the needle thread triangle hold open until the needle enters. To do this, the gripper performs a non-uniform movement from what requires complicated drive means.

The purpose of the invention is to enable the gripper to move smoothly. This was to solve the technical task, the direct involvement of the gripper in holding the thread triangle to be made superfluous by a special design of the thread spreader, which is known per se. To the solution This object is proposed according to the invention that the spreader is fork-shaped and its movement is coordinated with the movement of the hook and the needle that when the Needle in the thread triangle, the legs of the spreader on both sides of the needle and the thread triangle keep.

With this training, the spreader takes over the thread triangle and keeps it in the correct position Position for the needle thread take-up so that the hook is no longer in the area of the needle path during the entry of the needle into the thread triangle is required. This makes it possible to make the gripper uniform To perform movements that are faster than before, so that the sewing speed increases will. Despite uniform gripper movements, the needle stroke is shorter than before the end.

Thread stops are preferably arranged on the underside of the legs of the spreader.

An embodiment according to the invention is shown in the drawing, namely are

F i g. 1 is a plan view of the stitch-forming tools and their drive devices,

F i g. 2, 3 and 4 a view from below, transversely to the feed direction and in the feed direction of the stitch-forming tools and their drive devices,

F i g. 5 shows a section along line 13-13 in FIG. 4 and

F i g. 6 to 10 perspective views of the position of the stitch-forming tools in successive Stitch formation phases.

Double chain stitch sewing machine

Applicant:

Man-Sew Corporation, New York, N.Y.

(V. St. A.)

Representative:

Dr.-Ing. C. Reinländer, patent attorney,
Munich 8, Zeppelinstr. 73

Named as inventor:
Victor Joseph Sigoda,
Greta Neck, NY (V. St. A.)

^ao claimed priority:

V. St. v. America May 20, 1960 (30 682)

*

The drive shaft 9 is mounted in the lower housing 1 of the sewing machine. On the needle bar 19 is the Needle 14 attached. The shaft 9 carries a gear 24 which meshes with the pinion 11. The pinion 11 is

attached to the shaft 12. The shaft 12 is mounted in bearings carried by the sleeve 25, which is received in the bore 26 of the lower housing 1. At the end of the shaft 12 is an eccentric block 28 attached, the eccentric pin 29 a certain distance from the axis of rotation of the eccentric block 28 has the necessary eccentricity to swing the lever arm carrying the spreader 36 30 to achieve. The lever arm 30 is for this purpose with one end of a link 32 via a pin 34 rotatably connected, while in the other end of the handlebar 32 a bore for receiving of the eccentric pin 29 is provided. At the upper end of the lever arm 30 is a device for adjustable fastening of the spreader 36 is provided. Each time the shaft 9 rotates, one becomes one from one Forward oscillation and a backward oscillation existing cycle generated for the spreader 36, in time coordination with the up and down movement of the needle 14.

The spreader 36 has a shaft with which it is clamped in the lever arm 30, and one with this

609 567/187

Shank connected, fork-shaped part extending horizontally forwards in the direction of material advance. This fork has a left leg 36 α and a right leg 36 &. The right leg 36 b has a thread stop 36 c with a downwardly directed edge 36 d. The left leg 36 α has a thread stop 36 e with an edge 36 / also directed downwards.

A downwardly projecting housing 60 is provided on the underside of the machine bed. On the Shaft 9 is also fitted with a gear 62 that drives the gripper.

A casting 64 provided with a flange 65 is attached to the underside of the housing 60. That Cast 64 has two upwardly projecting lugs 66, between which a frame 68 about an axis is rotatably mounted. Two shafts 69 and 70 for the gears 71 and 72 are mounted in the frame 68. The frame 68 enables an ao when attaching the casting 64 to the housing 60 wall-free engagement of the gears 62, 71, 72 and also enables a compensation caused by deviations in the machining of the bottom of the housing 60 is required. The frame 68 is on top of it Axis adjustable by means of opposing adjusting screws73.

The casting 64 also has a downwardly extending housing 74, which is at the bottom by a gasketed plate 75 is sealed. The gear 72 protrudes into the housing 74 and is in Engagement with a further gear 76, which is mounted on the one in the side walls of the housing 74 Shaft 78 is attached. The shaft 78 carries at its outer end an eccentric block 79, the eccentric attached pin 80 fits into the bore of a bearing located in the enlarged end of a handlebar 81 is located. The casting 64 also has a cantilever arm 82 which terminates in a bearing lug 84, in which a shaft 85 is gelagerc parallel to the shaft 78. A rocker arm 86 is clamped on the shaft 85, which is connected via the link 81 to the eccentric block 79 for oscillating the shaft 85 is. A gripper carrier 88 is clamped onto the front end of the shaft 85, in which the gripper 89 is attached adjustable in height. The gripper 89 has a dome 91 on the underside. When turning of the shaft 9, the gripper 89 is therefore pivoted transversely to the direction of material advance, in time Coordination with the vertical up and down movement of the needle 14 and that parallel to the feed line swinging of the spreader 36.

The casting 64 has an additional arm 90 which has a bore and is split around a To form a clamp in which the pivot axis of the lever arm 30 is held. On a hub 41 is a thread tensioner clamped on.

The operation of the device is as follows:

In the starting position (Fig. 8, 9), in which the Needle 14 assumes the lowest position, the gripper 89 is already on its path of movement to the right (as seen by the operator) to pick up the needle thread loop. The spreader 36, the fork legs 36 α and 36 & on the operator are too directed and encompass the needle shaft, begins its backward movement (away from the operator).

When the main shaft rotates 25 °, the needle 14 is about 2.8 mm above its lowest position upscale. The needle thread is slack and the friction of the material forms around the eye of the needle a loop into which the gripper 89 enters.

When the main shaft is rotated from the 25 ° position to the 95 ° position, the needle 14 is raised into a position which is approximately 3.17 mm above the surface of the material to be sewn. Meanwhile, the looper 89 moves to the right (as seen by the operator), and the needle thread loop lying on the looper 89 rests on the tip 91 of the looper 89 Tip 91 the needle thread loop to the right. However, the inside of the leg 36 b of the spreader 36 has such a position that it prevents the needle thread loop from moving to the right. With further backward movement (away from the operator) of the spreader 36, only the rear run of the needle thread loop is held back when the dome 91 is pressed through the needle thread loop. This retention of the needle thread loop reduces the amount of needle thread required during stitch formation. Since less thread is consumed, less thread take-up is required and there is less frictional wear on the thread, which enables a higher working speed.

When the main shaft reaches the 140 ° position (FIG. 10), the needle 14 continues to move above the material and the knife moves upwards and clamps the material against it the underside of the presser foot, whereupon the sewing material is advanced, which is up to about the 225 ° position the main shaft takes place. The gripper 89 is located now in its extreme right position and the spreader 36 in its rear position, with the ends its two legs 36 α and 36 & immediately behind the hook 89 free of the needle thread loop stand. The needle thread is now tight around the middle part of the looper 89 on the left side of the dome 91 been drawn.

The needle 14 rises to its highest position between the 140 ° position and the 180 ° position of the main shaft. The thread take-up device pulls the needle thread tight and the feed movement becomes effective. The gripper 89 now moves to the left and the tip 91 pushes the needle thread loop with it to the left. The spreader 36 moves forward and the front end of the leg 36 b pushes past the looper thread, which leads from the eye of the looper 89, which is still far to the right of the axis of needle movement, to the needle hole through which the The bobbin thread was initially pulled either by hand under the presser foot at the beginning of sewing or through its anchoring in the sewing material, which has since been advanced by one stitch length.

When the main shaft reaches the 180 ° position, the needle 14 is in its highest position. The movement of the thread take-up device pulls the needle thread in such a way that it lies tightly around the looper 89. The fabric feed movement still stops. Since the looper 89 now moves to the left (as seen by the operator), the needle thread loop must now move up the toe slope of the dome 91. During the forward movement (towards the operator) of the spreader 36, the left side of the leg 36 α rests on the rear run of the needle

thread loop that had been moved to the left by the dome 91 as the looper 89 moved in that direction. The needle thread loop is therefore prevented from moving into the needle path. The leg 36 b moves further to the left of the looper thread.

When the main shaft is turned further into the 215 ° position or 220 ° position (Fig. 6), the needle lowers to about 9.52 mm to 12.7 mm above the throat plate and the movement of the thread take-up device pulls the thread tight . The looper 89 continues to move to the left in order to throw off the needle thread loop from the dome 91 as it expires. The spreader 36 continues to move forward. Now the right side of the leg 36 b holds the looper thread back when the looper 89 moves past the spreader 36 to the left. The left side of the leg 36 α keeps the discarded needle thread loop, which is now around the looper thread, from moving into the needle path.

On reaching the 250 ° or 260 ° position of the main shaft (FIG. 7), the needle 14 has lowered so that it is now only about 3.17 mm to 6.35 mm above the throat plate. The thread take-up device quickly pulls the needle thread up firmly. However, since some excess thread has been released by the shedding of the needle thread loop, this movement does not take up all of the excess thread. The material feed movement has now ended. The gripper 89 is still moving to the left and the spreader 36 is moving forward. During this forward movement, the thread stop 36 c detects the looper thread on the leg 36 b .

After a further rotation of the main shaft by 20 °, the needle 14 has lowered so far that it is on the surface of the material to be sewn. The thread take-up device pulls the needle thread loop tightly around the looper thread and the looper 89 moves to the left almost to the end of its stroke. The spreader 36 moves forward. During this movement, the thread stop 36 / of the leg 36 α detects the looper thread in order to form the base line of the thread triangle. With further forward movement of the spreader 36, this base line is guided past the axis of the needle up and down movement.

In the 295 "position of the main shaft, the Needle 14 moves through the sewing material and enters the thread triangle. The gripper 89 is located now in its extreme left position and the spreader 36 in its foremost position. The thread triangle is fully formed and its apex is directed obliquely upwards. When the movement of the If the thread take-up device pulls the needle thread loop tightly around the looper thread, this forms the anchorage for the left side of the triangle, the right side of which is anchored at the top of the workpiece. The tightened needle thread loop is to the left outside the needle path from the left side of the leg 36 α des Spreader 36 held.

When turning the main shaft into the 360 ° position

ίο the needle 14 reaches its lowest position within the thread triangle. The gripper 89 is already on the path of its movement to the right to receive the next needle thread loop. The spreader 36 moves backwards, with the base line of the thread triangle around its legs 36 α, 36 b . When the looper thread moves backwards, the looper thread presses the needle thread into the groove on the front side of the needle 14 and in this way forms a thread loop on the rear side of the

ao needle 14. The loop is flawlessly formed, so that a good grasp through which is fast approaching hook point takes place.

Claims (2)

Patent claims: 1. Sewing machine for the production of a two-thread chain stitch seam with a thread-guiding needle, a thread-guiding gripper swinging transversely to the direction of material feed and a spreader swinging in the direction of material feed, characterized in that the spreader (36) is fork-shaped and its movement with the movement of the gripper ( 89) and the needle (14) is coordinated so that when the needle (14) enters the thread triangle, the legs (36 cc, 36b) of the spreader are on both sides of the needle (14) and hold the thread triangle. 2. Sewing machine according to claim 1, characterized in that on the underside of the legs (36 a, 36 b) of the spreader thread stops (36 c, 36 e) are arranged. Considered publications:
German patent specifications No. 944 916, 662 259,
627 303, 497170, 496193, 487 913, 483 989,
416426; U.S. Patent No. 1618,213;
"The sewing machine specialist", W. Rent er s, 8th edition, 1957, Verlag Bielefelder Verlagsanstalt, Bielefeld, B. 1, pp. 168/169. For this purpose 2 sheets of drawings 609 567/187 4.66 © Bundesdruckerei Berlin