JPS6063087A - Double ring stitch looper mechanism of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a double chainstitch looper mechanism for a sewing machine that forms double chainstitch stitches through the cooperation of a plurality of needles and a double chainstitch looper.

In the conventional double chainstitch looper mechanism of this type of sewing machine, the double chainstitch looper is generally connected to the double chainstitch looper through the first link type motion transmission mechanism according to the rotation of the drive shaft, which is rotated in synchronization with the up and down reciprocation of the needle. A first reciprocating motion in the cloth feeding direction is imparted to the looper, and a second reciprocating motion in a direction perpendicular to the cloth feeding direction is imparted to the same looper via a second link type motion transmission mechanism. As shown by solid lines A and B in Figure 1, the tip 1a of the double chainstitch looper 1 has a plurality of (for example, three) needles 2a, 2b, 2 arranged along a direction perpendicular to the cloth feeding direction W.
The planar shape passing through the cloth feeding side and the cloth feeding side of c is operated in a nearly elliptical trajectory, and the looper 1 moves the needles 2a and 2.
When passing through the cloth feeding side of cloth feeders b and 2c, the needle thread loops supported by the rising needles 2a, 2b and 2c are caught by the looper 1, and the looper 1
Needles 2a and 2b descend when passing through the cloth feeding side of needle 2c.
, 2c captures the looper thread supported by the looper 1, forming a double chain stitch.

However, in the double chainstitch looper mechanism of this conventional sewing machine, in particular, the first link type motion transmission mechanism is connected to a rotary drive body such as a crankshaft, which is provided eccentrically from the rotation center of the drive shaft, and Consisting of one or more links that directly connect the rotation driving body and the looper,
When the rotation angle of the drive shaft is at two points (for example, 190° and 270°) separated by half a rotation (180'), the looper 1 moves to the needle 2a.

21) Since the maximum displacement is made to the cloth feeding side and cloth feeding side at a position away from 20, when adjusting the gap between the tip 1a of the looper 1 and the needles 2a, 2b, 2G. , when the rightmost needle 2a is used as a reference, the gap gradually increases between the middle and leftmost needles 2b and 2G as shown in Fig. 1, causing skipped stitches, and if adjusted only by the timing of the trajectory of the looper 1. , the needle 2a on which the looper 1 descends.

If the looper yarn is too thick, the looper yarn is not captured by the needles, causing skipped stitches, and it is extremely difficult to adjust the meeting point between the tip 1a of the looper 1 and the plurality of needles 2a, 2b, and 2C.

Purpose of the Invention The present invention solves the above-mentioned deficiencies in the conventional structure, and makes it possible to arbitrarily set the maximum displacement point of the double chainstitch looper toward the cloth feeding side and the cloth feeding side in relation to the positions and operation timings of a plurality of needles. You can easily adjust the meeting point between the looper and needles, including adjusting the gap between the looper tip and multiple needles, and create beautiful double chainstitch stitches with no skipped stitches. The purpose of the present invention is to provide a new double chainstitch looper mechanism for a sewing machine that can form a double chainstitch looper mechanism.

Structure of the Invention In order to achieve the above object, the present invention rotates in synchronization with the vertical reciprocation of a plurality of needles arranged along a direction perpendicular to the cloth feeding direction. According to the rotation of the drive shaft, the first reciprocating motion in the cloth feeding direction is transmitted to the double chainstitch looper through the first link-type motion transmission mechanism, and the second reciprocating motion is transmitted through the second link-type motion transmission mechanism. A second reciprocating motion is applied to the looper in a direction perpendicular to the cloth feeding direction, and a double chain stitch is formed by the cooperation of the plurality of needles and the looper. In the chainstitch looper mechanism, the first link type motion transmission mechanism is swingably supported by a rotary drive body provided on the drive shaft eccentrically with respect to the rotation center of the drive shaft, and by the vent. and a two-pronged portion that embraces the rotary driving body at one end, and a swinging body linked to the double chainstitch looper at the other end via a link, and the double chainstitch The point of maximum displacement toward the cloth feeding side when the looper moves forward is set to approximately the center of the amount of the plurality of needles, and the maximum displacement point toward the cloth feeding side when the looper moves backward is set to the point where the plurality of needles are approximately at the center of the amount of needles. The relationship between the distance between the rotation center of the drive shaft and the oscillation center of the oscillating body and the eccentricity of the rotation driving body is determined so that the looper thread supported by the heavy chainstitch looper is captured. This is the setting.

EXAMPLE Hereinafter, an example of the present invention will be explained according to the drawings.
Also in the sewing machine of this embodiment, three needles 2a, 2
1), 2c is the sewing machine frame bed (not shown)
They are arranged above the bed along a direction perpendicular to the cloth feeding direction W, and are reciprocated in the vertical direction as the sewing machine main shaft 3, which is a drive shaft provided in the bed, rotates. A double chainstitch looper 1 provided in the bed so as to form a double chainstitch stitch in cooperation with the needles 2a, 2b, and 2c is fixed to a looper holder IA and its upper end, and has a tip 1a. It is composed of a looper unit 1B. The sewing machine main shaft 3 and the looper holder I
A, a first link-type motion transmission mechanism 4 for imparting a first reciprocating motion in the cloth feeding direction to the double chainstitch looper 1 according to the rotation of the main shaft 3; A second link-type motion transmission mechanism 5 for imparting a second reciprocating motion to the looper 1 in a direction perpendicular to the cloth feeding direction.
and is provided.

Therefore, to explain the first link type motion transmission mechanism 4 in detail, a rotation shaft 6 is supported within the bend so as to extend parallel to the main shaft 3 of the sewing machine, and a bearing body 7 is attached to a part of the rotation shaft 6. Fixed. A support shaft 8 is rotatably supported on the bearing body 7, and the double chainstitch thread 1 is attached to the end thereof.
A root halter IA is fixed at the lower end. Therefore, the double chainstitch looper 1 can reciprocate in the cloth feeding direction W around the axis of the rotating shaft 6, and reciprocate in the direction perpendicular to the cloth feeding direction W around the axis of the support shaft 8. It is movably supported in the bed of the sewing machine frame.

On the other hand, a pair of crank discs 9 are fixed to the main shaft 3 of the sewing machine, and between the two crank discs 9, a crank shaft as a rotary drive body is arranged so as to be eccentric to the main shaft 3 by a predetermined eccentric amount D1. 10 have been erected. A rocking body 12 is rockably supported on the bed via a support shaft 11 so that its rocking center is located at a predetermined distance D2 from the rotation center of the main shaft 3. One end of this rocking body 12 has a three-pronged portion 12a that embraces the crankshaft 10 via a sliding piece 13.
is provided. Further, the other end of the swinging body 12 is connected to a link 14.
via a stepped screw 15,16 to a lever 17 on said pivot shaft 6.

Next, to explain the second link type motion transmission mechanism 5 in detail, a pair of crank discs 18 are fixed to the sewing machine main shaft 3, and a pair of crank discs 18 are located between the two crank discs 18 eccentrically by a predetermined amount with respect to the main shaft 3. The crankshaft 19 is installed as shown in FIG. A rotating shaft 20 is supported within the bend so as to extend in a direction perpendicular to the main shaft 3, and is linked to the crankshaft 19 via a crank rod 21 and a ball bearing 22. A lever 23 is fixed to the end of the rotating shaft 20, and its tip is connected to one looper holder of the double chainstitch looper 1 by a connecting iron 24 via ball bearings 25 and 26.

Therefore, when the sewing machine main shaft 3 is rotated, the crankshaft 10 on the first link type motion transmission mechanism 4 side is rotated on the circumference with the eccentricity D1 as the radius, as is clear from FIGS. 2 to 4. The oscillating body 12 is oscillated by the link 1.
4 and the lever 1γ, the rotation shaft 6 is reciprocated,
The double chainstitch looper 1 supported on the rotating shaft 6 undergoes a first reciprocating motion in the cloth feeding direction W. Further, as the sewing machine main shaft 3 rotates, the crankshaft 19 on the second link type motion transmission mechanism 5 side is rotated on the circumference having its eccentricity as a radius, as is clear from FIG. The rotation shaft 20 is reciprocated via the clutch/chronograph 21,
A second reciprocating motion in a direction perpendicular to the cloth feeding direction W is applied to the double chainstitch looper 1 via the lever 23 and the connecting iron 24. As a result, the double chainstitch looper 1 is operated so that its tip 1a traces a nearly elliptical locus in plan view as shown by chain lines C and solid lines B in FIG. Three needles 2a, 213.
In cooperation with 20, a double chain stitch is formed.

By the way, in this embodiment, as is clear from FIGS. 1 and 4, the maximum displacement point P1 toward the cloth feeding side when the double chainstitch looper 1 moves forward is determined by the three needles 2a, .
21] and 2c, and the maximum displacement point P2 toward the cloth feeding side when the looper 1 moves backward.
Of the three books mentioned above? 12a, 21J, and 20 capture the looper thread supported by the double chainstitch looper 1. The relative relationship between the distance D2 from the center of swing and the eccentricity D1 of the crankshaft 10 is adjusted and set.

That is, in this embodiment, as is clear from FIGS. 3 and 4, the crankshaft 10 is held by the forked part 12a of the swinging body 12 via the sliding piece 13, and the rotation of the crankshaft 10 When the rocking body 12 is rocked accordingly, a line connecting the rocking center of the rocking body 12 and the center of the crankshaft 10 (the rocking body 12
Relative movement of the crankshaft 10 with respect to the oscillating body 12 is allowed on the center line of the oscillator 12. Therefore, unlike a configuration in which the crankshaft 10 and the double chainstitch looper 1 are connected without play movement by a plurality of links,
When the rocking body 12 swings as the crankshaft 10 rotates, as shown in FIG. When the double chain stitch looper 1 is located at the two contact points 'I'1 and 'I'2 with a predetermined angle a smaller than a half rotation of 180°, the double chainstitch looper 1 moves to the cloth feeding side and the cloth feeding side. to the maximum displacement point P1. P2
It will reach .

Therefore, as described above, by arbitrarily adjusting the relationship between the distance D2 between the rotation center of the sewing machine main shaft 3 and the swing center of the swinging body 12, and the eccentricity D1 of the crankshaft 10 with respect to the sewing machine main shaft 3, , the maximum displacement point P1 of the double chainstitch looper 1 toward the cloth feeding side and the cloth feeding side. The setting of P2 can be easily changed. Then, this maximum displacement point P1.
By setting P2 in relation to the positions and operation timings of the three needles 2a, 2b, :2c as described above, as is clear from FIG. The tip ja of the heavy chainstitch looper 1 is now moved in a direction perpendicular to the cloth feeding direction W. Therefore, when the double chainstitch looper 1 moves forward, its tip 1a passes through the cloth feeding side of each hook 2a + 2bv2C with a predetermined approximately equal gap, and the looper 1 The needle thread loops supported by the hooks 2a, 21J, and 2c are captured accurately, and when the looper 1 moves back, the needles 2a, 2b, and 'la are relatively close to the looper 1. The needles 2a, 2b, 2<
s, the looper thread supported by roots "-1" is accurately extracted, and a beautiful double chain stitch without skipped stitches is formed.

Incidentally, in this embodiment, the contacts 'I'' 1,
The angle α formed by '1' and 2 is 150'', and the contact point 'l 1
, T2 is the rotation angle of the sewing machine main shaft 3 of 230° and 80°.
The relative relationship between the distance D2 and the eccentricity D1 is set so that the distance D2 is at the time 00.

Note that this invention is not limited to the above-mentioned embodiments, and for example, an eccentric cam may be provided in place of the crankshaft 10 as a rotational drive body in the first sliding/sliding type motion transmission mechanism 4. It is also possible to change the configuration of each part arbitrarily within a range that does not deviate from the above.

Effects of the Invention As detailed above, according to the present invention, the maximum displacement points of the double chainstitch louver toward the cloth feed side and the cloth feed side are arbitrarily set in relation to the positions and actuation timings of a plurality of needles. It is possible to easily adjust the meeting point between the louver and the needles, including the adjustment between the tip of the louver and multiple needles, and form a beautiful double chain stitch without skipped stitches. can do.

[Brief explanation of drawings]

Fig. 1 is a plan view of the road body without showing the operating locus of the tip of the double chainstitch louver, Fig. 2 is a perspective view showing the entire double chainstitch looper mechanism of a sewing machine embodying the present invention, and Fig. 3V 'i In particular, the side view showing the first link type motion transmission mechanism, FIG.
FIG. Double chainstitch louver 1, needle 2 ++, 21), 2
C, sewing machine main shaft 3 as a drive shaft, first link type motion transmission mechanism 4, second link type motion transmission mechanism 5, crankshaft 10 as a rotary drive body, rocking body 12, bifurcated part 12a
1 Link 14゜Patent applicant: Brother Industries, Ltd. Agent: Hironobu Onda, patent attorney

Claims (1)

[Claims] 1. A plurality of needles (2a. 21), 2C) that can reciprocate up and down and are arranged along a direction perpendicular to the cloth feeding direction (W'); , 2b, 2c) to form a double chainstitch seam, so that the first reciprocating movement in the cloth feeding direction (W) and the second reciprocating movement in the direction orthogonal thereto can be performed. a double chainstitch root (1) supported on the bed of the sewing machine frame; a double chainstitch root (1) rotatably supported on the bend;
a drive shaft (3) that rotates in synchronization with the reciprocating motion of the parts 2a, 21), 20), and a drive shaft (3) provided between the drive shaft (3) and the double chainstitch loop/<-(1), A first link-type motion transmission mechanism (4) for imparting the first reciprocating motion to the double chainstitch looper (1) according to the rotation of the drive shaft (3); and a double chainstitch connected to the drive shaft (3). The drive shaft (3) is provided between the looper (1) and the drive shaft (3).
a second link-type motion giving machine 1' for imparting the second reciprocating motion to the double chainstitch looper (1) according to the rotation of the chain stitch looper (1);
In the double chainstitch looper mechanism of the sewing machine, the first link type motion transmission mechanism (4) is connected to the drive shaft (3).
) on the drive shaft (3) eccentrically with respect to the center of rotation of the drive shaft (3); an oscillating body (12) whose other end is linked to the double chainstitch looper (1) via a link (14); When the chainstitch looper (1) moves forward, the maximum displacement point (Pl) toward the cloth feeding side is set by the plurality of needles (2a).
. 0 distance () between the rotation center of the drive shaft (3) and the swing center of the swing body (12) so that D2) and the eccentricity (Dl) of the rotary drive body (1D). 2. 3. A double chainstitch looper mechanism for a sewing machine according to claim 1, comprising a crankshaft (1o) formed in the form of a crankshaft (1o).3. A double chainstitch looper mechanism for a sewing machine according to claim 1, comprising: