JPH0223243Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention is a needle-feed sewing machine in which the needle inserted into the fabric is moved together with the feed dog to feed the fabric, and this invention converts the needle into the fabric to be fed only by the feed dog. Regarding the mechanism for

[Conventional technology] When sewing thick fabrics, feeding the fabric using only the feed teeth of a normal sewing machine can cause the fabric to slip or
Problems such as only the lower fabric being fed occurred. Therefore, in the case of thick fabrics, the sewing needle inserted into the fabric is moved horizontally together with the feed dog to feed the fabric.
A so-called needle feed sewing machine is used.

This needle-feed sewing machine is basically a sewing machine that feeds cloth using only a normal feed dog, but is provided with a swing mechanism that swings the needle in the horizontal direction. Therefore, this sewing machine is usually not only used for thick fabrics, but also for thin fabrics, it is also possible to convert the sewing machine to a fabric feed operation using only the feed dog (hereinafter referred to as "lower feed"). .

This conversion stops the operation of the needle swing mechanism and also changes the phase between the vertical movement of the needle and the four movements of the feed dog.
This is done by shifting 180 degrees. In other words, when feeding the fabric by needle feed, the sewing needle needs to descend when the feed dog rises, and when feeding downward, the sewing needle needs to rise when the feed dog rises, so the phase need to be shifted 180 degrees.

[Problems to be solved by the invention] By the way, when shifting the phase between the sewing needle and the feed dog as described above, the upper shaft that moves the needle up and down, the lower shaft that drives the feed dog and the needle swing mechanism, Remove the timing belt wrapped around the shaft from the upper shaft,
This was done by rotating the upper shaft 180 degrees.

However, when rotating the upper shaft 180 degrees,
Since the operator had to do this visually, it was extremely difficult to set the rotation angle accurately, and a great deal of work time was required.

This invention was created by focusing on the above-mentioned problem, and is a needle feed/lower feed sewing machine that can accurately and quickly change the phase between the feed dog and the sewing needle during needle feed/lower feed conversion. The purpose is to provide a feed conversion mechanism.

[Means for Solving the Problems] This invention provides rotating bodies around the upper and lower shafts for winding the rotation transmission band, and at least one of the rotating bodies is fixed to the shaft on which the rotating bodies are mounted. , is composed of a positioning member having engaging parts of the same shape at two points symmetrical about the center of the axis, and a cylindrical member that can engage and disengage from both the engaging parts, and a needle feeding shaft and a lower shaft. This device is equipped with a breaker that cuts off the interlock with the needle and moves the needle up and down along a fixed axis.

[Function] In this invention, when converting the phase between the vertical movement of the sewing needle and the four movements of the feed dog, the engagement state between the two engaging parts of the rotating member and the positioning member is released, and the rotating member is By rotating it approximately 1/2 turn and engaging the two engaging portions, the phase can be changed accurately.

[Example of the invention] Hereinafter, an example of this invention will be shown in Figures 1 to 3.
This will be explained based on the diagram.

1 and 2 are diagrams showing the configuration of a needle feed sewing machine applied to this embodiment.

In FIG. 1, 1 is an upper shaft, and an upper sprocket 2 as a rotating body is fixed to one end of the upper shaft. Reference numeral 3 denotes a lower shaft for moving a feed dog (not shown) in the vertical direction, and a rotating body 4, which will be described later, is fixed to one end of the lower shaft. 5 is the upper sprocket 2 and the rotating body 4
6 is a disc-shaped eccentric cam fixed to the lower shaft 3, and 7 is connected at one end so as to be slidable along the outer periphery of the eccentric cam 6. The other end of the horizontal feed arm is rotatably connected to the connecting arm 9.

Further, this connecting arm 9 is fixed to a horizontal feed shaft 10 that moves the feed dog in the horizontal direction, and a weight 9 is attached to the other end.
a is fixed. Further, one end of the horizontal feed shaft 10 is inserted through a cylindrical metal 10a fixed to a machine frame M of the sewing machine. 11 is this horizontal axis 10
12 is a needle feeding arm fastened to the outer periphery of the metal 10a with a screw 12a, and is disposed at a predetermined distance from the needle feeding arm 11; A support shaft 13 is fixed to the lower end of the double needle feeding arm 11. The needle feeding arm 12 is fixed to the rear metal 10a by tightening a screw 12a, and can be rotated on the outer peripheral surface of the rear metal 12a by loosening the screw 12a. The needle feeding arms 11, 12 and the rear metal 10a constitute a blocking mechanism P. Note that this shutoff mechanism P does not include the needle feed arm 12 and the rear metal 10a, and is configured by simply removing the needle feed rod 14 from the needle feed arm and fixing the needle feed rod 14 to the sewing machine frame M. Also good.

14 is a needle feed rod whose one end is inserted through the support shaft 13; 17 is a needle feed shaft that drives a needle feed mechanism to be described later; a needle feed shaft arm 15 is fastened to one end of the needle feed rod 14; Further, a shaft 1 is provided at the lower end of this needle feeding arm 15.
At 6, the other end of the needle feeding rod 14 is rotatably connected.

FIG. 2 is a diagram showing the configuration of a needle feeding mechanism connected to the mechanism shown in FIG. 1.

In the figure, reference numeral 18 denotes a needle bar swinging arm whose one end is fixed to the other end of the needle feed shaft 17, and a square piece 19 is movably provided at the other end. Reference numeral 20 denotes a needle bar rocking base rotatably supported around a shaft 21, into which a needle bar 22 supporting a sewing needle is inserted so as to be vertically movable. Further, an engagement recess 20a is formed at the lower end of the needle bar rocking table 20.
The square piece 19 is slidably engaged with. 2
3 is a counterweight fixed to the other end of the upper shaft 1; 24 is an arm supporting the needle bar 22; one end of the arm is connected to the end of the counterweight 23 via a needle bar crank (not shown); Rotatably connected.

FIG. 3 is an exploded perspective view showing the structure of a rotating body 4 provided on the lower shaft 3, and this rotating body 4 consists of a sprocket bush, a sprocket, and a thrust collar.

That is, 41 is a cylindrical sprocket bush (positioning member) into which the lower shaft 3 is inserted;
A circular collar portion 41a is formed at one end thereof. Further, on the outer peripheral surface of the collar portion 41a, two engaging protrusions (engaging portions) 41a1 and 41a1, 41a1 and 41a1 of the same shape are provided.
1a2 is formed, and each protrusion 41a1, 41
a2 is 80 degrees off-centered from the center of the lower shaft 3 into which it is inserted, so that it is symmetrical with respect to a point. The lower shaft 3 fitted into this sprocket bush 41 has a cylindrical portion 41.
It is fixed with a set screw 42a1 screwed into the screw hole a1 of b. 42 is a cylindrical sprocket (rotating member) that meshes with the timing belt 5, and has an annular wall 42b formed inside, into which the cylindrical portion 41b of the sprocket bush 41 is inserted. . 42a1 and 42a2 are 2 formed on one side end surface of the sprocket 42.
The two engagement protrusions 41a1, 4
1a2. Reference numeral 43 denotes a thrust collar into which the cylindrical portion 41b of the sprocket bush 41 inserted through the sprocket 42 is fitted, and the cylindrical portion 41b is fixed by screwing the setscrew b2 into the screw hole a2. ing.

Based on the above configuration, the operation will be explained next.

First, the operation of each mechanism during needle feeding operation will be explained. In this state, the screw 11a is tightened and the horizontal feed shaft 10 and the needle feed shaft 17 are integrated, and the screw 12a is loosened and the needle feed arm 11 moves on the outer peripheral surface of the rear metal 10a. It is designed to rotate.

When the upper shaft 1 is rotated by a motor (not shown), this rotation is transmitted to the arm 24 via the counterweight 23, where it is converted into vertical movement of the needle bar 22.

Further, the rotation of the upper shaft 1 is transmitted from the upper sprocket 2 to the rotating body 4 via the timing belt 5.
The lower shaft 3 rotates in the same phase as the upper shaft 1. Lower shaft 3
The rotation of is converted into a rocking motion by the eccentric cam 6 and the horizontal feed arm 3, and this rocking motion is transmitted to the horizontal feed shaft 10 via the connecting arm 9. The swinging of the horizontal feed shaft 9 and the rotation of the lower shaft 3 are transmitted to a feed dog drive mechanism (not shown), and four movements of the feed dog are performed. Further, as the horizontal feed shaft 9 swings, the needle feed arms 11 and 12 swing, causing the needle feed rod 14 to swing. This swinging motion of the needle feed rod 14 is transmitted to the needle feed shaft 17 via the needle feed shaft arm 15.

When the needle feed shaft 17 swings, the needle bar swing arm 18 swings about the shaft 17. This swinging motion is transmitted to the needle bar swinging stand 20 via the square piece 19, and the swinging stand 20 swings about the shaft 21 in the cloth feeding direction and in the opposite direction.

As a result, the needle bar 22 moves along the cloth feeding direction in addition to the above-described vertical movement. In other words, the sewing needle also makes four movements, forming stitches while feeding the fabric together with the feed dog.

By the way, when attempting to convert the sewing machine from the needle feeding operation to cloth feeding operation, the following operations are performed. That is, first loosen the setscrew b2 of the thrust collar 43, and then remove the sprocket 4 from the engagement protrusions 41a1, 41a2 of the sprocket bush 41.
2 engagement grooves 42a1 and 42a2 are removed.

After that, turn the sprocket 42 about 1/2 turn,
Engagement grooves 42a1, 42a2 and engagement protrusion 41a1,
41a2 in a combination opposite to the initial combination. In other words, when the needle is fed, the engagement groove 42
If a1 is engaged with the engagement protrusion 41a2 and the engagement groove 42a2 is engaged with the engagement protrusion 41a2, then at the time of this conversion, the engagement groove 42a1 is engaged with the engagement protrusion 42a2, and the engagement groove 42a2 is engaged with the engagement protrusion 41a2. 42a1
be engaged with each other. This ensures that the sprocket 42 rotates 180 degrees. This rotation is transmitted to the upper shaft 1 by the timing belt 5, and the upper shaft 1 also rotates 180 degrees. As the upper shaft 1 rotates, the needle bar 22 moves up or down and stops at a position 180 degrees out of phase from its initial position. for example,
If the needle bar 22 was initially at the top dead center, then the upper shaft 1
As a result of the 180 degree rotation of the needle bar 22, the needle bar 22 stops at the bottom dead center.

On the other hand, the lower shaft 3 is not rotated at all during the above operation.
Since the feed dog is maintained at its original phase, the sewing needle can be reliably shifted in phase by 180 degrees with respect to the feed dog.

Then, by fixing the thrust collar 43 to the thrust bush 41 again, the phase change operation between the feed dog and the sewing needle in needle feed/down feed conversion is completed.

After that, the screw 11a of the needle feed arm 11 is loosened to release the engagement between the needle feed arm 11 and the horizontal feed shaft 10, and the screw 12a of the needle feed arm 12 is further tightened.
The needle feeding arm 12 is fixed at a predetermined position on the rear metal 10a (a position where the needle moves vertically up and down). As a result, the swinging movement of the horizontal feed shaft 10 is not transmitted to the needle feed rod 14, and the above-mentioned swinging movement of the needle can be stopped, and the needle can move up and down along the vertical fixed axis. Become. With the above steps, the conversion work from needle feed to bottom feed is completed.

In addition, when converting from downward feed to needle feed, screws 11a and 12a of needle feed arms 11 and 12
Tighten the engaging protrusion 41a of the thrust bush 41.
1, 41a2 and sprocket 42a1, 42a2
What is necessary is to change the combination of engagement.

In the above embodiment, the rotating body 4 provided on the lower shaft 3 was constructed from the above three members, but it is also possible to provide a simple sprocket on the lower shaft 3 and provide a rotating body composed of the above three members on the upper shaft 1. It is possible. However, in this case, since various drive mechanisms are connected to the lower shaft, considerable force must be applied to rotate it.

[Effects of the invention] As explained above, according to this invention, the phase change between the feed dog and the sewing needle in the needle feed/lower feed conversion is performed by the engagement of the members, resulting in accurate accuracy. As well as making conversion possible,
This has the effect of simplifying the work and significantly reducing work time.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of this invention, Fig. 2 is a perspective view showing a needle swinging mechanism, and Fig. 3 is a perspective view showing an embodiment of the invention.
FIG. 2 is an exploded perspective view of a main part of what is shown in the figure. 1... Upper shaft, 2... Upper sprocket (rotating body),
3... Lower shaft, 4... Rotating body, 41... Sprocket bush (positioning member), 41a1, 41a
2... Engaging protrusion (engaging portion), 42... Sprocket (rotating member), 42a1, 42a2... Engaging groove,
5...Timing belt (rotation transmission connection band),
P...Shutoff mechanism.

Claims (1)

[Scope of Claim for Utility Model Registration] A lower shaft rotatably supported on the machine frame and with a rotating body supported at one end, a feed dog that moves in four directions in conjunction with the lower shaft, and a rotating shaft that rotates in conjunction with the lower shaft. a rotating needle feed shaft, an upper shaft rotatably supported on the machine frame and supporting a rotating body at one end, and a rotation transmission coupling body wrapped around both the rotating bodies supported on the upper shaft and the lower shaft. , a needle that moves up and down in conjunction with the rotation of the upper shaft and swings along the cloth feeding direction in conjunction with the needle feed shaft, and at least one of the two rotating bodies has a circumferential surface. an engaging groove is formed in the rotating body, and the rotating body has at least an engaging portion that engages with the engaging groove of the rotating body, which is attached to a shaft on which the rotating body is supported and is movable from a fixed position. A needle feed/lower feed conversion mechanism in a needle feed sewing machine, characterized in that the needle feed/lower feed conversion mechanism is engaged and supported by a positioning member.