JPH0673577B2 - Cloth pressing device for rake stitch sewing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressing device for intermittently pressing a cloth against a cloth presser in synchronization with the operation of a rake needle in a lock stitch or chain stitch rake stitch sewing machine.

[0002]

2. Description of the Related Art As a cloth pressing device for a sewn sewing machine, a rotating shaft reciprocally rotated at a predetermined angle in a circumferential direction is supported by a bearing member mounted on a frame so as to be movable up and down. Then, a plunger (cloth lifting) that rotates in the circumferential direction together with the rotating shaft and presses the cloth against the cloth presser is attached to one end of the rotating shaft, and the bearing member and the adjusting screw provided on the frame In the meantime, it is known that an urging spring is provided to urge the bearing member to move upward so that the plunger approaches the presser foot (Japanese Patent Publication No. 60-3).
2464 publication).

In this pressing device, for example, a portion where a large number of cloths are piled up and the thickness thereof is large, such as a sewn portion at the folded-back portion of the pants hem, moves between the cloth presser and the plunger. Then, the bearing member bends the biasing spring and moves downward, so that the plunger is lowered by the increase in the cloth thickness. Adjust the elastic force of the biasing spring with the adjusting screw.

[0004]

In the above-described conventional cloth pressing device, since a short biasing spring is used, when the thickness of the cloth changes, the elasticity of the biasing spring greatly changes, and it is suitable for scooping. It has an adverse effect. In addition, the number of layers of cloth at the sewn portion in the folded-back portion of the trouser hem is usually four, and when the portion is further folded and sewn so that the thread is finally hidden, the sewn portion has three layers. Since they overlap each other, the number of stacked layers is six.

In theory, it is possible to solve the above-mentioned problems by using a biasing spring having a long length, but if the biasing spring is long, the adjustment range of the elasticity becomes too large and within one rotation. It is necessary to turn the adjusting screw many times, and the adjustment becomes extremely troublesome. After all, in the structure of the conventional pressing device, it is not possible to obtain a cloth pressing device in which the fluctuation range of the plunger urging force is small and the urging force can be easily adjusted only by changing the length of the urging spring.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cloth pressing device for a sewn sewing machine which can reduce the fluctuation range of the plunger biasing force and can easily and accurately adjust the biasing force. .

In order to achieve the above object, the present invention provides
A rotating shaft that reciprocally rotates in a circumferential direction at a predetermined angle is rotatably supported by a bearing member that is movably attached to the frame, and the axial direction of the rotating shaft is substantially orthogonal to the moving direction of the bearing member. In a cloth pressing device in a rake sewing machine having a plunger attached to one end to rotate in the circumferential direction together with a rotating shaft to press the cloth against a presser foot, the bearing member is rotated about a fulcrum member as a fulcrum. A spring mechanism mainly composed of an urging spring that connects one end of a rotating lever and rotates the rotating lever around a fulcrum member as a fulcrum so that the plunger approaches the cloth retainer by movement of the bearing member. And the fulcrum member is provided so as to be movable relative to the spring mechanism in the axial direction of the turning lever.

[0008]

If the fulcrum member is moved relative to the spring mechanism and the ratio of the distance between the fulcrum member and the spring mechanism to the distance between the fulcrum member and the plunger is increased, the plunger biasing force of the spring mechanism increases. Further, when the above ratio is reduced, the plunger biasing force is reduced.

When a long-length biasing spring is used for the spring mechanism, the fluctuation range of the plunger biasing force with respect to the change of the cloth thickness becomes small, but even in this case, the plunger biasing force can be adjusted easily and accurately. it can.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The attached drawings show an embodiment of the present invention.
Reference numeral 1 in the figure is a frame. The frame 1 is provided with a pair of upper and lower fixed shafts 2 and 3 horizontally and in parallel with each other at a predetermined interval. Bearing members 4 and 5 are individually supported by the fixed shafts 2 and 3, respectively. Each bearing member 4, 5 is vertically rotatable about each fixed shaft 2, 3.

Rotating shafts 6 and 7 are individually supported by the free ends of the bearing members 4 and 5, respectively. The rotary shafts 6 and 7 are provided in parallel with the fixed shafts 2 and 3. At the left ends of the rotary shafts 6 and 7 in FIG. 1, fan-shaped plungers 8 and 9 are provided.
Are fixed individually. The plungers 8 and 9 together with the rotating shafts 6 and 7 rotate alternately in the circumferential direction to press the cloth against a cloth retainer (not shown).

The pair of upper and lower drive shafts 1 is attached to the bearings 10 and 11 provided on the right side of the frame 1 in FIG.
Numerals 2 and 13 are axially supported with the same spacing as the vertical spacing of the fixed shafts 2 and 3 described above and with the axial direction aligned parallel to the axial direction of the fixed shafts 2 and 3. The drive shafts 12 and 13 are rotating shafts 6,
7 are provided almost on their extension lines.

Drive arms 16 and 17 each having sliders 14 and 15 rotatably at the ends thereof are individually fixed to the ends of the drive shafts 12 and 13 on the side of the rotary shafts 6 and 7, respectively. . At the ends of the rotary shafts 6, 7 on the drive shaft 12, 13 side,
The driven arms 18 and 19 having the slide grooves 18a and 19a are individually fixed, and the sliders 14 and 15 of the drive arms 16 and 17 are slidably fitted in the slide grooves 18a and 19a, respectively.

Therefore, when the drive shafts 12 and 13 are rotated in the circumferential direction, the rotation is performed via the drive arms 16 and 17, the sliders 14 and 15, and the driven arms 18 and 19, respectively. 7, the rotary shafts 6 and 7 rotate in the circumferential direction. When the rotary shafts 6 and 7 move with respect to the drive shafts 12 and 13, the sliders 14 and 15 slide in the slide grooves 18a and 19a to rotate the driven arms 18 and 1, respectively.
9 is transmitted.

Gears 20, 21 are individually fixed to the drive shafts 12, 13 and mesh with each other. The gear 21 of the lower drive shaft 13 is made larger than the gear 20 of the upper drive shaft 12, and the upper plunger 8 having a smaller turning radius is used.
The rotation width of the peripheral portion of the lower plunger 9 having a large rotation radius is substantially the same as the rotation width of the peripheral portion. A gear 22 having the same diameter as the gear 20 is loosely attached to the upper drive shaft 12,
This is also meshed with the gear 21. The gear 22 is stopped by a set screw (not shown) to prevent backlash of the gear 21.

A swing lever 23 is fixed to the lower drive shaft 13. One end of a swing arm 24 is connected to the tip of the swing lever 23 by a pin 25. Swing arm 2
A round hole 24a is formed at the other end of the hole 4. An eccentric ring 27 of a rotary shaft 26 that is rotated by a driving device (not shown) is fitted in the round hole 24a.

At the free ends of the bearing members 4 and 5, one end of the rotating levers 30 and 31 is provided with universal joints 32 and 33 such as ball joints.
Are individually connected via. Each rotation lever 30, 3
1 is individually supported at its intermediate portion by fulcrum members 34 and 35. The fulcrum members 34 and 35 are provided with the rotation stopping portion 3
4a, 35a and screw parts 34b, 35b are integrally provided, and the rotation stopping parts 34 are provided in the long holes 1a, 1b formed in the frame 1.
a and 35a are fitted to project the respective screw portions 34b and 35b to the front surface of the frame 1 (on the right side in FIG. 6), and the knobs 36 and 37 are individually screwed to the screw portions 34b and 35b, respectively. It is installed. Each stop 34
a and 35a are formed in an elongated shape, and each fulcrum member 34, 35a
Is prevented from freely rotating and is freely movable along the long holes 1a and 1b.

The upper ends of links 38 and 39 are individually connected to the other ends of the rotary levers 30 and 31 by universal joints 40 and 41 such as ball joints. The lower ends of the links 38, 39 are bell joints 44, 45 with universal joints 42, 43 such as ball joints.
Are individually connected to one end of. Each bell crank 44,
45 is rotatably attached to another frame 28 by pivots 46 and 47, and biasing springs 48 and 49 are attached to the other ends.
Are individually connected at one end thereof. Each biasing spring 48, 49
The other ends of the screw rods 50 and 51 are individually connected to each other, and each screw rod 50, 51 is provided with an adjusting nut 52,
It is individually screwed into 53.

Biasing springs 48 and 49 and bell crank 44,
45, the links 38, 39, etc. are respectively the spring mechanism 5
4, 55 are composed. The spring mechanisms 54 and 55 rotate the rotating levers 30 and 31 about the fulcrum members 34 and 35 to urge the plungers 8 and 9 to rise.

Pressers 56 are disposed on the left and right sides of the plungers 8 and 9 in FIG. The presser foot 56 is attached to the upper end of a presser lever 58, which is attached to the frame 1 so as to be vertically rotatable about a mounting shaft 57 (FIG. 3), by a pin 59 so as to be vertically rotatable. Presser lever 5
8 is biased upward by a coil spring 61 so as to come into contact with a screw shaft 60 screwed to the frame 1 and stop. Above the presser foot 56, a feed dog (not shown) that cyclically moves in a vertical plane to feed the cloth is provided. The presser foot provided above the feed dog and the plungers 8 and 9 is well known.

Next, the operation of the cloth pressing device in the rake stitch sewing machine according to the present invention constructed as described above will be described. When the eccentric wheel 27 is rotated by the rotary shaft 26, the swing arm 24 swings left and right in FIG.
Is reciprocally rotated in the circumferential direction at a predetermined angle.

The above-mentioned rotation of the drive shaft 13 is transmitted to the rotary shaft 7 via the drive arm 17 and the like on the one hand, and to the other rotary shaft via the gears 21 and 20 and the drive arm 16 and the like on the other hand. 6. The plungers 8 and 9 attached to the rotary shafts 6 and 7 are rotated in the opposite directions by the above rotation of the rotary shafts 6 and 7 to alternately push up the cloth as is well known.

When the cloth to be sewn on is thick, the plungers 8 and 9 are automatically lowered against the resilience of the biasing springs 48 and 49, and the surface of the sewn portion is cracked or the needle is sewn. Prevent problems such as breaking. When it is desired to increase the plunger biasing force of each biasing spring 48, 49, the knobs 36, 37 are loosened, and the fulcrum member 34.35 is moved to the left in FIG. 1 to tighten the knobs 36, 37. By this operation, with respect to the distance between the fulcrum members 34 and 35 and the plungers 8 and 9,
Since the ratio of the distance between the fulcrum members 34, 35 and the universal joints 40, 41 is increased, the plunger urging force of each urging spring 48, 49 is increased. It goes without saying that if the fulcrum members 34 and 35 are moved to the right in FIG. 1, the elastic forces of the biasing springs 48 and 49 are weakened.

In addition to the above, the elasticity of the biasing springs 48 and 49 can be adjusted by operating the adjusting nuts 52 and 53 to change the tension of the biasing springs 48 and 49. Normally, this is done when the sewing machine is assembled. Only.

Examples other than the above will be listed below. (1) In the illustrated embodiment, the fulcrum members 34 and 35 are configured to be moved along the rotary levers 30 and 31.
The spring mechanism 54.55 can be moved to achieve the same purpose and effect as above.

(2) The fulcrum members 34 and 35 are provided at the ends of the rotating levers 30.31, and the rotating levers 30.31 are provided with spring mechanisms 54 and 55 between the fulcrum members 34 and 35 and the plungers 8 and 9. The urging force of can be applied. Also in this case, the fulcrum members 34 and 35 and the spring mechanism 54,
Any of 55 may be movable.

(3) The bearing members 4 and 5 in the figure are configured to rotate up and down about the fixed shafts 2 and 3, but either one of the bearing member and the rotating shafts 4 and 5, or The present invention can also be applied to a sewing machine in which both of them move up and down along the guide member (for example, the sewing machine of Japanese Patent Publication No. 60-32464).

[0028]

As described above, the cloth pressing device in the rake stitch sewing machine according to the present invention is such that the bearing member mounted movably on the frame is reciprocally rotated at a predetermined angle in the circumferential direction. A shaft is supported with its axial direction substantially orthogonal to the moving direction of the bearing member, and a plunger that rotates in the circumferential direction together with the rotating shaft to press the cloth against the presser foot is attached to one end of the rotating shaft. In a cloth pressing device for a sewn sewing machine, one end of a rotary lever that rotates about a fulcrum member as a fulcrum is connected to the bearing member, and the plunger is woven by the movement of the bearing member to the rotary lever. A spring mechanism mainly composed of an urging spring for rotating the rotating lever about the fulcrum member as a fulcrum so as to approach the presser is connected, and the fulcrum member is arranged in the axial direction of the rotating lever with respect to the spring mechanism. Relative Since there is a movably provided configuration, it is possible to reduce the fluctuation range of the plunger biasing force by the spring mechanism, also it is possible to adjust the biasing force thereof easily and accurately.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a cloth pressing device in a rake sewing machine according to the present invention.

FIG. 2 is a front view showing a relationship between a bearing member and a spring mechanism and the like.

FIG. 3 is a front view showing a relationship between a bearing member and a plunger or the like.

FIG. 4 is an external view showing a relationship between a rotating lever, a bearing member, a spring mechanism, and the like.

FIG. 5 is a front view showing a relationship between a driven arm and a slider.

FIG. 6 is a cross-sectional view showing how the fulcrum member is attached to the frame.

[Explanation of symbols]

 1 frame 4,5 bearing member 6,7 rotating shaft 8,9 plunger 34,35 fulcrum member 38,39 link 44,45 bell rank 48,49 urging spring 54,55 spring mechanism

Claims (1)

[Claims] 1. A bearing member movably attached to a frame, and a rotary shaft reciprocally rotating in a circumferential direction at a predetermined angle is axially supported with its axial direction substantially orthogonal to the moving direction of the bearing member. A cloth pressing device in a rake stitch sewing machine, in which a plunger that rotates in the circumferential direction together with the rotating shaft to press the cloth against the cloth presser is attached to one end of the rotating shaft, wherein a fulcrum member is provided on the bearing member. One end of a rotating lever that rotates as a fulcrum is connected, and the urging spring that rotates the rotating lever with the fulcrum member as a fulcrum is connected to the rotating lever so that the plunger approaches the cloth retainer when the bearing member moves. And a fulcrum member is provided so as to be movable relative to the spring mechanism in the axial direction of the turning lever. Pressing device .