JP4105913B2 - Sewing machine feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sewing machine feeding device, and more particularly to a zigzag sewing machine feeding device that performs zigzag sewing while alternately swinging a needle bar in a direction orthogonal to a cloth feeding direction, that is, a so-called needle swinging direction.
[0002]
[Prior art]
As is generally known, a feed mechanism of a conventional staggered sewing machine feeds a cloth by feeding and retracting an elliptical feed dog from a needle plate.
[0003]
However, since the staggered sewing machine performs sewing while alternately swinging the needles in the needle swinging direction as shown in FIG. 8, after the sewing, the cloth shrinks in the direction orthogonal to the cloth feed direction. In order to prevent this shrinkage of the cloth, it is necessary for the operator to perform sewing while stretching the cloth horizontally by hand. This work required advanced sewing techniques.
[0004]
In addition, as shown in FIG. 9, when a staggered sewing machine is used to sew between the left and right body parts, a gap may be formed between the stitched left and right body parts, and a misalignment may occur. . In order to prevent this, it is necessary for the operator to perform sewing while bringing the cloth to the center by hand. This work also required advanced sewing techniques.
[0005]
Japanese Patent Laid-Open No. 12-271364 and Japanese Patent Laid-Open No. 12-218077 have proposed a sewing machine feed device for preventing a sewing failure without requiring the above-described advanced sewing technique. These devices are provided with a feed dog divided into left and right and an opening / closing drive mechanism that opens and closes the feed dog in a direction orthogonal to the feed direction of the cloth in conjunction with the sewing machine main shaft.
[0006]
[Problems to be solved by the invention]
However, the sewing machine feeding device provided with the opening / closing drive mechanism has a complicated mechanism, which leads to an increase in cost and has not been introduced.
[0007]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an inexpensive sewing machine feeding device that prevents the occurrence of stitch shrinkage and stitch deviation peculiar to a staggered sewing machine.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1
A vertical feed shaft and a horizontal feed shaft that are rotatably supported by the machine frame and swing in conjunction with the main shaft;
A feed base connected to the vertical feed shaft and the horizontal feed shaft, and provided with an elliptical motion in which a vertical motion and a horizontal motion are combined;
In a sewing machine feeder having left and right feed dogs divided along the cloth feed direction,
A stepped screw that is mounted on the feed base and supports one end side of the left and right feed dogs individually and rotatably;
A guide shaft provided separately on the other end side of the left and right feed dogs;
A cam member fixed to the machine frame, engaged with the guide shaft, and having a groove portion symmetrical to the needle along the cloth feeding direction,
The cam member is composed of a left cam member and a right cam member, the left cam member and the right cam member can be interchanged and mounted,
With the forward movement of the left and right feed dogs in the cloth feed direction, the left and right feed dogs are guided symmetrically with respect to the needle and in a direction crossing the cloth feed direction.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
The staggered sewing machine feed device 1 has a vertical feed shaft 2 disposed along one horizontal direction below a sewing machine bed (not shown). A horizontal feed shaft 3 is disposed in parallel with the vertical feed shaft 2. The vertical feed shaft 2 and the horizontal feed shaft 3 are supported by a metal bearing fixed to a sewing machine frame (not shown) so as to be individually rotatable. The vertical feed shaft 2 and the horizontal feed shaft 3 are connected to the main shaft by a link (not shown). For this reason, when the main shaft rotates, the vertical feed shaft 2 and the horizontal feed shaft 3 swing.
[0017]
A vertical feed cam 4 is fixed to the end side of the vertical feed shaft 2. The vertical feed cam 4 is connected to one end side of the vertical feed link 5. The other end side of the vertical feed link 5 is connected to the lower end portion of the feed base arm portion 7 via the connecting shaft 6. The feed base arm portion 7 is formed so as to extend downward from the bottom surface of the feed base 8. Further, the lower end side of the horizontal feed arm 9 is fixed to the shaft end of the horizontal feed shaft 3. The upper end side of the horizontal feed arm 9 is connected to the feed base 8 via a connecting shaft 10.
[0018]
A feed dog base 11 is fixed to the upper right side of the feed base 8. One end side of the feed dog base 11 supports a left and right feed dog 12 composed of a right feed dog 12a and a left feed dog 12b. Screw holes 11 a and 11 a are formed on the right support surface of the feed dog base 11 that supports the left and right feed dogs 12, corresponding to the left and right feed dogs 12. In addition, through holes 12aa and 12ba are provided in corresponding portions of the right feed dog 12a and the left feed dog 12b, respectively.
[0019]
The right feed dog 12a and the left feed dog 12b supported by the feed dog base 11 are inserted with stepped screws 13 and 13 from above through the through holes 12aa and 12ba. The stepped screw 13 has a shaft portion at the center and a screw at the lower end. By mounting the stepped screws 13, 13, one end side of the left and right feed dogs 12 is rotatably supported by the feed dog base 11. The other end side of the left and right feed dogs 12 is supported by the feed base 8. In addition, a right cam member 14 and a left cam member 15 having grooves are arranged at the lower part on the other end side of the left and right feed dogs 12.
[0020]
The right cam member (guide member) 14 and the left cam member (guide member) 15 are each fixed in block form to the sewing machine frame. The right cam member 14 and the left cam member 15 have cam grooves 14a and 15a formed individually on the upper surfaces thereof. The cam grooves 14a and 15a are formed symmetrically with respect to the needle (point Q in the drawing) located at the center of the left and right needle drop points along the cloth feeding direction P. The cam grooves 14a and 15a are linear groove portions that are inclined so as to approach each other along the cloth feeding direction P, which is separated from the worker.
[0021]
Guiding shafts (guide members) 12ab and 12bb are provided downward on the bottom surfaces of the right feed dog 12a and the left feed dog 12b, and the guide shafts 12ab and 12bb play in the cam grooves 14a and 15a, respectively. To fit. Note that the upper surfaces of the left and right cam members (guide members) 14 and 15 and the bottom surface of the left and right feed dogs 12 are arranged so as not to come into contact with each other even when a feed motion is applied.
[0022]
The operation of the first embodiment will be described.
[0023]
When the main shaft rotates, the vertical feed shaft 2 and the horizontal feed shaft 3 swing. Due to the swinging of the vertical feed shaft 2 and the horizontal feed shaft 3, elliptical motion is imparted to the left and right feed dogs 12 via the feed base 8. FIG. 2 shows a state of starting feeding, that is, a state in which the left and right feed dogs 12 start to rise and move in the cloth feeding direction P. At this time, the guide shafts 12ab and 12bb of the left and right feed dogs 12 are fitted with play on the operator side of the cam grooves 14a and 15a, respectively. The left and right feed dogs 12 in the starting state are in an open state. Thereafter, as the left and right feed dogs 12 feed the cloth, the left and right feed dogs 12 move forward and are guided by the cam grooves 14a and 15a to close. FIG. 3 shows the closed state after the forward movement of the left and right feed dogs 12 is completed. Thus, with the forward movement of the left and right feed dogs 12 (based on the horizontal movement applied to the left and right feed dogs 12 via the feed base 8), the left and right feed dogs 12 are closed from the open state. Change to state.
[0024]
For this reason, the left and right feed dogs 12 are fed while bringing the cloth toward the center. If this movement of the feed dog is used when the left and right body parts are stitched together, a stitch misalignment that creates a gap between the stitched left and right body parts is prevented, and high-quality sewing is guaranteed.
[0025]
Next, another usage pattern of the first embodiment will be described with reference to FIGS.
FIG. 4 is a view in which the right cam member 14 and the left cam member 15 of the first embodiment are replaced. As a result of the replacement, the cam grooves 15a and 14a are formed symmetrically with respect to the needle (point Q in the drawing) located in the center of the left and right needle drop points along the cloth feeding direction P. The cam grooves 14a and 15a are linear groove portions that are inclined along the cloth feeding direction P so as to be separated from each other. In this case, as the left and right feed dogs 12 move forward, the left and right feed dogs 12 shown in FIG. 5 are closed (based on the horizontal movement applied to the left and right feed dogs 12 via the feed base 8). It changes to the open state of FIG. For this reason, the left and right feed dogs 12 feed the cloth while stretching it left and right. This feed movement prevents the occurrence of shrinkage stitches when sewing with a staggered sewing machine.
[0026]
Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, cam members 18 and 19 are attached to the bottom surface of the needle plate 17. Cam members 18 and 19 have cam grooves 18a and 19a formed on the bottom surface side. The cam grooves 18a and 19a are linear groove portions that are separated from the operator as viewed from the upper surface of the needle plate and are inclined so as to be separated along the cloth feeding direction.
[0027]
The left and right feed dogs 20a, 20b are rotatably supported at one end side 20aa, 20ba close to the operator by stepped pins 21, 21, and directed upward at the other end side. Is equipped. The guide shafts 22 and 23 are fitted in the cam grooves 18a and 19a with play.
[0028]
Also in the second embodiment, the left and right feed dogs 20 feed the cloth while stretching it to the left and right as in the first embodiment. This feed movement prevents the occurrence of shrinkage stitches when sewing with a staggered sewing machine. Further, in the second embodiment, since the groove cams 18 and 19 are formed on the needle plate 17, even when this feeding device is applied to a conventional zigzag sewing machine, the machining of the sewing machine body is not necessary. What is necessary is just to replace | exchange for the needle plate and feed dog to which this invention was applied, and retrofit becomes easy.
[0029]
The present invention can be variously modified without being limited to the above embodiment.
For example, in the above-described embodiment, the guide member is composed of the cam members 14 and 15 and the guide shafts 12ab and 12bb that engage with the cam members 14 and 15. It is also easily conceivable to give an opening / closing motion to the left and right feed dogs.
[0030]
In the above embodiment, the left and right feed dogs 12 are provided with the guide shafts 12ab and 12bb, and the cam members 14 and 15 fixed to the machine frame are provided with cam grooves. It is also conceivable to provide a guide shaft on the cam member. Moreover, although the cam member is comprised from the left cam member 14 and the right cam member 15, it replaces with this and forming a some cam groove in one block can also be considered easily. Moreover, in the said embodiment, although the linear cam groove was formed, changing to circular arc shape can also be considered easily.
[0031]
Furthermore, it is easily conceivable to change the left and right feed dogs to bevel teeth and amplify cloth stretching and close-up.
[0032]
As described above, according to the first aspect of the present invention, the left and right feed dogs are guided by the guide member in a direction symmetrical to the needle and intersecting the cloth feed direction. For this reason, when the feed dog is guided so as to extend the cloth to the left and right, the shrinkage of the cloth is prevented. Further, when the feed dog is guided so as to bring the cloth closer, the stitches are prevented from slipping. As the guide member, a combination of a groove cam and a shaft engaged with the groove cam, a cam engaged with the side surface of the feed dog, and the like can be considered, and an inexpensive sewing machine feed device can be provided.
According to the first aspect of the present invention, the open / close state of the left and right feed dogs can be changed by changing the left and right cam members.
[Brief description of the drawings]
FIG. 1 is a front view and a side view of a sewing machine feeding apparatus according to a first embodiment.
FIG. 2 is a state diagram at the start of feeding by the feed dog of the first embodiment.
FIG. 3 is a state diagram in which the feed dog feed of the first embodiment is finished.
FIG. 4 is a diagram showing another use state of the first embodiment.
FIG. 5 is a state diagram showing that the feed dog in another use state starts feeding.
FIG. 6 is a state diagram in which the feed dog in another use state has been fed.
FIGS. 7A and 7B are a front view and a side view of a sewing machine feeding apparatus according to a second embodiment. FIGS.
FIG. 8 is an explanatory diagram when sewing is performed with a conventional staggered sewing machine.
FIG. 9 is an explanatory diagram when sewing is performed with a conventional staggered sewing machine.
[Explanation of symbols]
2 ... vertical feed shaft 3 ... horizontal feed shaft 8 ... feed base 12 ... left / right feed dog 20 ... left / right feed dog 12ab ... guide shaft (guide member)
12bb ・ ・ Induction shaft (guide member)
14. ・ Cam member (guide member)
15 .. Cam member (guide member)
22. ・ Guiding shaft (guide member)
23. ・ Guiding shaft (guide member)
18. ・ Cam member 19 ・ ・ Cam member

Claims (1)

A vertical feed shaft and a horizontal feed shaft that are rotatably supported by the machine frame and swing in conjunction with the main shaft;
A feed base connected to the vertical feed shaft and the horizontal feed shaft, and provided with an elliptical motion in which a vertical motion and a horizontal motion are combined;
In a sewing machine feeder having left and right feed dogs divided along the cloth feed direction,
A stepped screw that is mounted on the feed base and supports one end side of the left and right feed dogs individually and rotatably;
A guide shaft provided separately on the other end side of the left and right feed dogs;
A cam member that is fixed to the machine frame, engages with the guide shaft, and has a groove that is symmetrical with respect to the needle along the cloth feeding direction.
The cam member is composed of a left cam member and a right cam member, the left cam member and the right cam member can be interchanged and mounted,
A sewing machine feed device characterized by causing the left and right feed dogs to be guided symmetrically with respect to the needle and in a direction crossing the cloth feed direction as the left and right feed dogs move forward in the cloth feed direction.

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