JP2762696B2 - sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a sewing machine in which a stitch is formed by cooperation of a sewing needle and a looper.

(Prior art) As an example of this kind of sewing machine, there is a hole sewing machine
The general structure is described below.

A needle bar driving cam and a looper driving cam are provided on the main shaft of the sewing machine so as to rotate integrally, and a cam follower is provided for each cam. A needle bar drive lever is connected to a cam follower linked to the needle bar drive cam, and the needle bar drive lever swings according to the rotation of the main shaft of the sewing machine, thereby driving the needle bar up and down. On the other hand, the cam follower linked to the looper drive cam is connected with the cam response lever and the looper link in order, and the displacement of the cam follower is transmitted to the looper drive mechanism for moving the looper via these, and synchronized with the rotation of the sewing machine spindle. Then the looper is driven. Thus, the sewing needle attached to the needle bar and the looper operate in synchronization with each other, and the stitches are sequentially formed by the cooperation of the two.

By the way, in order to form an appropriate stitch, it is necessary to make the tip of the looper enter the loop when the sewing needle is pierced into the cloth and the loop of the needle thread is formed. And the phase of the looper movement must be properly adjusted.

Therefore, conventionally, the phase of the needle bar movement is fixed,
A configuration has been considered in which the phase of the looper encounters with the sewing needle is adjusted by adjusting the phase of the looper movement. The configuration was as shown in FIGS. 8 and 9.
That is, the disc-shaped phase adjuster 1 is rotatably housed in a circular opening 3 formed in the sewing machine frame 2, and a set screw 4 screwed to the sewing machine frame 2 is formed on the peripheral surface of the phase adjuster 1. The phase adjuster 1 is fixed by entering the recessed groove 1a. A fulcrum shaft 5 protrudes from an eccentric position of the phase adjuster 1, and a cam responsive lever 6 is provided on the fulcrum shaft 5.
Are rotatably connected to each other, and a cam follower 8 is provided at an intermediate portion of the cam responsive lever 6 so as to engage with the looper drive cam 7. A tip of the cam responsive lever 6 is connected to a looper link 9 connected to the looper drive mechanism. Are linked.

To adjust the encounter phase of the looper in this configuration, the set screw 4 provided on the sewing machine frame 2 is loosened, and then a projection of a special tool (not shown) is fitted into a pair of adjustment holes 10 provided on the phase adjustment body 1. Then, the phase adjuster 1 is rotated in the opening 3. Then, the fulcrum shaft 5 of the phase adjuster 1
Move, the position of the cam follower 8 engaged with the looper drive cam 7 changes accordingly, and the phase of the looper movement changes.

(Problems to be Solved by the Invention) However, the above configuration is a structure in which the phase adjuster 1 is fixed from the peripheral surface side with the setscrew 4, so that the concave groove 1a is provided.
However, there was a disadvantage that the shape was easily collapsed and fine adjustment was difficult. Further, although the set screw 4 can be turned by a general flathead screwdriver, there is a problem that a special tool is required to rotate the phase adjuster 1 and adjustment is troublesome.

The present invention has been made in view of the above circumstances. Therefore, an object of the present invention is to provide a sewing machine which can freely adjust a phase where a looper meets a sewing needle, and does not require a special tool for the adjustment work.

[Structure of the Invention] (Means for Solving the Problems) A sewing machine according to the present invention is provided with a needle bar driving cam and a looper driving cam which are driven by a main shaft of the sewing machine and are provided so as to rotate integrally with each other. The needle bar drive lever that drives the needle bar by swinging according to the displacement of the cam follower linked to the cam, and the sewing machine frame can be rotated to adjust the phase where the looper encounters the sewing needle attached to the needle bar. A cam responsive provided with a provided phase adjuster and a cam follower rotatably supported by a fulcrum shaft provided at an eccentric position of the phase adjuster and interlocked with a looper drive cam at a position different from the fulcrum shaft A lever connected to the cam responsive lever and transmitting a motion to a looper driving mechanism for moving the looper. It is rotatably housed in a circular opening formed in the sewing machine and is attached to a fixing plate attached to the outer surface side of the sewing machine frame with a set screw from the outside of the sewing machine frame, so that the set screw is inserted through the fixed plate. The screw insertion hole is formed in an arc shape concentric with the phase adjusting body, and further, an engaging portion for rotating the phase adjusting body by a set screw tightening tool is formed on the phase adjusting body, and a fixing plate is formed. A feature is that a tool insertion hole for passing a tool for tightening a set screw is formed corresponding to the engaging portion.

(Operation) Since the phase adjusting member is fixed to the fixing plate attached to the outer surface side of the sewing machine frame with a set screw, FIGS.
As shown in the figure, compared to a configuration in which the phase adjustment body 1 is fixed from the peripheral surface side with the set screw 4, play is less likely to occur, and fine adjustment is possible. Further, the screw insertion hole formed to allow the set screw to pass through the fixing plate has an arc shape concentric with the phase adjusting body, and the phase adjusting body is rotated by a set screw tightening tool. Is formed, the set screw is loosened with a set screw tightening tool, and then the tool is engaged with the engaging portion of the phase adjuster to rotate the phase adjuster. Then, the set screw may be tightened again by the tool, and the phase adjustment of the looper can be easily completed with a kind of tool.

(Embodiment) An embodiment in which the present invention is applied to an eyelet buttonhole sewing machine will be described below with reference to FIGS. 1 to 7.

First, the overall configuration of the sewing machine will be briefly described with reference to FIG. The sewing machine frame 11 is configured such that a bed part 12 having a substantially rectangular box shape is integrally provided with an arm part 13 extending forward from an upper part in the back, and is mounted on a sewing machine table. A drive motor (not shown) serving as a drive source of the sewing machine, an operation panel for setting a sewing speed, a stitch pitch, and the like, a foot-operated start / stop switch, and the like are provided below the sewing machine table 14. A control device for controlling the operation of each mechanism is provided.

Needle bar with a sewing needle 15 attached to the tip of the arm 13
The bed portion 12 is provided with a looper base 17 which is located immediately below the needle bar 16 and has two loopers (not shown). These loopers are needle bar
The stitch is formed on the work cloth in cooperation with the sewing needle 15 by operating in synchronization with the vertical movement of the 16. In addition, the lower knife 18 is fixed to the bed portion 12 at the depth side of the looper base 17,
A hammer 19 that comes into contact with and separates from above the lower knife 18 from above is rotatably provided.

A feed stand 20 on which a work cloth is set is provided on the upper surface of the bed portion 12, and a pair of cloth holders for holding the work cloth set here on both sides of the cut formed by the lower knife 18. (Not shown) is provided on the feed base 20. The feed base 20 has a thin rectangular box shape as a whole, and is moved in an X direction (left and right direction) and a Y direction (front and rear direction) by a feed mechanism (not shown). Thereby, the work cloth pressed and fixed by the cloth presser is moved to a required position directly below the sewing needle 15, and the edge of the eyelet-shaped notch formed in the work cloth is sequentially subjected to overlock stitching. it can. The needle bar 16 and the looper base
17 is integrally rotated by a drive mechanism and an interlocking mechanism (not shown). When sewing the round hole portion of the eyelet hole, not only the feed bar 20 but also the needle bar 16 and the looper base 17 are sewn.
Are rotated slightly and constantly so that the sewing thread draws a radial pattern.

As shown in FIGS. 1 to 3, a sewing machine main shaft 29 which is rotationally driven by the drive motor is provided inside the arm portion 13, and a circular cam body 30 is attached thereto. The cam body 30 has a needle bar driving cam 31 on one end surface (see FIG. 2) and a looper driving cam 32 on the other end surface (see FIG. 1). It is driven by 29 and rotates integrally. A needle bar drive lever 33 extending in the front-rear direction is provided inside the arm 13.
33a, and the needle bar drive cam 3
A cam follower 34 engaging with 1 is provided. A slide link 35 is provided at the front end of the needle bar drive cam 31.
Are fitted, and this is engaged with a fulcrum pin 36 fixed to the needle bar 16. As a result, when the main shaft 29 of the sewing machine rotates, the needle bar drive cam 31 rotates, and the cam follower 34 interlocked therewith.
The needle bar drive lever 33 swings in the direction of arrow A in FIG. 1 in accordance with the displacement of the needle bar 16 and the needle bar 16 is driven up and down. When the needle bar 16 is driven up and down by the rotation of the sewing machine main shaft 29, the needle bar 16 is swung right and left by a needle swing mechanism (not shown) in synchronization with this.

On the other hand, as shown in FIGS. 4 and 5, a circular opening 37 is formed in the side wall of the arm 13 of the sewing machine frame 11, and a disk-shaped phase adjuster 38 is rotatable therein. It is stored in. Further, a fixing plate 39 having a disk shape as a whole is fixed to the outer surface side of the sewing machine frame 11 at a position closing the opening 37 by two screws 39a. The fixing plate 39 has a pair of screw insertion holes 40 formed in concentric arcs with the phase adjustment body 38 at symmetrical positions, and a tool insertion hole 41 at the center. Further, the phase adjuster 38
Are formed with two screw holes 43 in which the set screw 42 is screwed near the outer periphery, and a straight groove 44 corresponding to an engaging portion is formed through the center. Accordingly, the phase adjuster 38 is fixed to the fixing plate 39 and the sewing machine frame 11 by inserting the set screw 42 into the screw insertion hole 40 of the fixed plate 39, screwing it into the screw hole 43, and tightening the screw. By loosening the screw 42, rotation in the opening 37 is permitted. The set screw
For example, a slotted screw which is tightened by a flathead screwdriver is used for the
Can be inserted with a flathead screwdriver.

Next, a fulcrum shaft 45 is protrudingly provided at an eccentric position on a surface inside the sewing machine frame 11 of the phase adjusting body 38. One end of a cam response lever 46 is rotatably connected to the fulcrum shaft 45, and a cam follower 47 that engages with the looper drive cam 32 is protruded from an intermediate portion of the cam response lever 46. I have. Further, an upper end of a looper link 48 extending in the up-down direction is rotatably connected to a tip end of the cam responsive lever 46, and a lower end of the looper link 48 forms a looper driving mechanism 49 as a part of a looper driving mechanism 49. It is connected to the lever 50. Accordingly, when the looper driving cam 32 is rotated by the sewing machine main shaft 29, the cam responsive lever 46 is turned around the fulcrum shaft 45 of the phase adjustment body 38 in accordance with the displacement of the cam follower 47 in conjunction therewith, as shown in FIG. Swing in the B direction. Then, the looper link 48 reciprocates in the vertical direction (the direction of arrow C in FIG. 1) based on the swing of the cam response lever 46, and this movement is centered on the shaft 50a of the looper drive lever 50 in FIG. Looper base by swinging along the middle arrow D direction
The looper operates by being transmitted to the looper drive mechanism 49 provided in the unit 17.

Now, in the present embodiment, the adjustment of the encounter phase of the looper with the sewing needle 15 is performed as follows.

First, using a flathead screwdriver, loosen the two setscrews 42 fastened to the phase adjuster 38. Thereafter, the tip of the flathead screwdriver is fitted into the linear groove 44 of the phase adjuster 38 through the tool insertion hole 41 of the fixing plate 39, and the screwdriver is slightly turned. Then, the phase adjuster 38 is rotatably housed in the opening 37 of the sewing machine frame 11 and the fixed plate 39
Since each of the screw insertion holes 40 has an arc shape,
38 rotates in the opening 37 in accordance with the turning of the driver. When the phase adjuster 38 rotates in this way, the fulcrum shaft 45 provided at the eccentric position moves in an arc, and the cam follower integrated via the cam response lever 46 The position of 47 changes in the left-right direction in FIG. 1 in accordance with the amount of movement of the fulcrum shaft 45. At this time, since the position of the cam follower 26 engaged with the needle bar driving cam 31 integral with the looper driving cam 32 does not change, the phase of the needle bar motion does not change, and only the phase of the looper motion changes. become. Thus, the encounter phase of the looper with the sewing needle 15 can be adjusted. FIG. 7 shows how the phase of each of these movements changes in the present embodiment. In the figure, the sine wave curve drawn in the upper half is a needle bar curve indicating the position of the needle bar 16, and shows that the sine wave goes up and down twice with one rotation of the sewing machine main shaft 29.
In the lower half of the figure, the position of the looper is shown. By rotating the phase adjuster 38, the looper movement between the phase indicated by the dashed line and the phase indicated by the dashed line is shown. It has been shown that the phase can be changed. After rotating the phase adjuster 38 by the required amount as described above,
When the set screw 42 is tightened again with a flathead screwdriver, the phase adjuster 38 is fixed at that position.

According to the above embodiment, the following effects can be obtained. As shown in FIG. 8, in the conventional configuration in which the phase adjusting member 1 is fixed from the peripheral surface side with the set screw 4, the shape of the concave groove 1a and the tip of the set screw 4 is broken, and the rattle is likely to occur. there were. However, according to the above embodiment, the phase adjuster 38
Has a structure in which the fixing screw 39 screwed into the screw hole 43 is tightened and fixed to the fixing plate 39, so that rattling hardly occurs and fine adjustment is possible. If the tip of a flathead screwdriver used to tighten the setscrew 42 is inserted into the linear groove 44 of the phase adjuster 38, the driver adjusts the phase adjuster.
Since the 38 can be freely rotated, a special tool is not required, and the adjustment work can be performed with only one driver.

In the above embodiment, a case where a slotted screw that is tightened with a flathead screwdriver is used as the set screw is shown. However, the present invention is not limited to this. When used, the engaging portion provided on the phase adjustment body may be a cross-shaped hole that matches the driver. In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications within the scope without departing from the gist.

[Effects of the Invention] As described above, according to the present invention, there is an excellent effect that the encounter phase of the looper with the sewing needle can be finely adjusted, and a special tool is not required for the adjustment work.

[Brief description of the drawings]

1 to 7 show an embodiment of the present invention, FIG. 1 is a side view showing a main part of an internal structure, FIG. 2 is a side view of the same from the opposite direction, and FIG. 4 is an enlarged side view, FIG. 5 is a cross-sectional view taken along line VV in FIG. 4, FIG. 6 is an overall side view, and FIG. 7 is movement of a needle bar and a looper. FIG. FIG. 8 is a schematic side view of a main portion showing a conventional structure, and FIG. 9 is a sectional view taken along line IX-IX in FIG. In the drawing, 11 is a sewing machine frame, 15 is a sewing needle, 16 is a needle bar,
17 is a looper base, 20 is a feed stand, 29 is a sewing machine spindle, 31 is a needle bar drive cam, 32 is a looper drive cam, 33 is a needle bar drive lever, 34 is a cam follower, 37 is an opening, and 38 is a phase adjuster. , 39 is a fixing plate, 40 is a screw insertion hole, 41 is a tool insertion hole, 42
Is a set screw, 43 is a screw hole, 44 is a linear groove (engaging portion), 46 is a cam responsive lever, 47 is a cam follower, 48 is a looper link, and 49 is a looper drive mechanism.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuaki Koie 9-35, Horitadori, Mizuho-ku, Nagoya-shi, Aichi, Japan Brother Industries, Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) D05B 1/00-83/00

Claims (1)

(57) [Claims] 1. A needle bar drive cam and a looper drive cam which are driven by a main shaft of a sewing machine so as to rotate integrally with each other, and oscillate according to a displacement of a cam follower interlocked with the needle bar drive cam. A needle bar driving lever for driving a needle bar by means of a needle; a phase adjuster rotatably provided on a sewing machine frame for adjusting a phase where a looper encounters a sewing needle attached to the needle bar; and an eccentricity of the phase adjuster. A cam follower pivotally supported by a fulcrum shaft provided at a position and provided with a cam follower linked to the looper driving cam at a position different from the fulcrum shaft; and the looper connected to the cam responsive lever. A looper link for transmitting a motion to a looper drive mechanism for moving the phase adjuster, wherein the phase adjuster is provided in a circular opening formed in the sewing machine frame. A screw insertion hole which is rotatably housed and is attached to a fixing plate attached to the outer surface side of the sewing machine frame from outside of the sewing machine frame by a set screw, and the screw insertion hole formed to allow the set screw to pass through the fixed plate, The phase adjuster is formed in an arc shape concentric with the phase adjuster, and the phase adjuster is formed with an engaging portion for rotating the phase adjuster by the set screw tightening tool, and the engaging portion is engaged with the fixing plate. A sewing machine characterized in that a tool insertion hole for passing the set screw tightening tool is formed corresponding to the part.