JP3446266B2 - Sewing machine circular sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circular sewing machine for sewing a circular edge portion of a workpiece to be overcast. 2. Description of the Related Art In a general sewing machine, for example, an overlock sewing machine, a circular emblem may be formed by overcasting a circular emblem or the like.
An attachment is used as a circular sewing device that presses the center of a workpiece to be sewn so as to be rotated so as to rotate. If the attachment is a simple plate, it is difficult to remove the sewing object.
JP-A-126178 discloses a structure in which, when a sewing object is taken out by pressing with a spring force, a gap is formed between the object and the sewing object by utilizing the contraction of the spring. ing. FIG. 10 shows a conventional attachment disclosed in the above publication. FIG. 10 shows a substantially cylindrical main body 54 having an upper small hole 52 and a lower opening 53 concentrically, in which a pressing spring 55 and a cloth pressing needle (hereinafter referred to as a cloth pressing pin) 51 are provided.
The tip of the presser foot pin 51 is
It is designed to protrude from. A small diameter portion 56 extending from the upper end of the cloth holding pin 51 projects from the upper small hole 52,
A knob 57 is formed at the upper end of the small diameter portion 56. One or several grooves 58 are formed in the main body 54 so as to extend further in the radial direction than the upper small holes 52, and pins 59 which are selectively fitted in the grooves 58 project radially from the small diameter portion 56. I have. The above-mentioned attachment further includes a main body 54.
Form a cam on the upper surface, position the pin on this cam surface,
Rotate the knob 57 to move the pin on the cam surface.
And the cloth holding pin 51 can be raised above the cloth.
Has been disclosed. [0005] However, FIG.
In the conventional apparatus shown in FIG. 1, the sewing machine can be removed by rotating the knob 57 to remove the work.
Adjust the lifting amount of the pin by turning the knob.
There is a need. For this reason, the knob 57 is
Operation that must rotate a predetermined amount against force
There are difficulties. According to the present invention, the position of the cloth holding pin in the vertical direction is determined.
Adjustment can be easily performed, and the cloth presser pin can be moved up and down with respect to the workpiece only by pushing and pulling.
An object of the present invention is to provide a circular sewing machine of a sewing machine which does not give stress to a finger or the like. According to the present invention, there is provided an arm having a cloth holding pin supported at both ends thereof in a loosely inserted state, and the cloth fixed to the cloth holding pin between the both ends of the arm and being externally provided with the cloth holding pin. A fixing plate that enables the presser pin to rotate, a pressing spring that is interposed between the fixing plate and one end of the arm, and urges the cloth presser pin in the needle plate direction; An elevating means interposed between the other end of the arm and the vertical movement of the presser pin in conjunction with the rotation of the presser pin by an external operation on the fixing plate. The lifting means is provided on a fixed plate.
An adjusting screw that adjusts the height of the cloth holding pin by turning,
A cam provided on the arm for guiding the tip of the adjusting screw;
Rotation of the work clamp pin by external operation to the fixing plate
The tip of the adjusting screw is guided by the cam in conjunction with
Is moved up and down. This cam is formed on the upper surface of the other end of the arm, and the lower surface of the fixing plate can be brought into contact with the low position surface, the inclined surface, and the high position surface .
Can be The position of the fixing plate can be changed on the presser foot pin by the height adjusting screw . In the present invention in which the lifting means is a cam, when the cloth presser pin is lifted from a state where the cloth presser pin is pressing the workpiece, when the fixing plate is pressed, the fixing plate becomes a cloth. While rotating the presser pin, it moves from the low position surface to the high position surface via the slope. As a result, the presser foot pin is raised in the same manner as the fixing plate is raised by the cam, and is separated from the workpiece by the difference in height between the low position surface and the high position surface. Further, in the present invention, when an adjusting screw for changing the height position of the presser foot pin according to the thickness of the workpiece is provided, the fixing plate can be fixed to the presser foot pin even if the height position is adjusted. By changing the position above, the pressing force on the workpiece by the pressing spring can be fixed or adjusted. As described above, according to the present invention, an externally operable fixing plate is provided on the presser foot pin supported at both ends of the arm in a loosely inserted state, and the fixing plate is fixed to the presser foot. Since the elevating means for raising and lowering the presser foot pin by pushing and pulling around the pin is provided, the presser foot pin can be moved up and down by a simple operation that does not give stress to the arms, fingers and the like. Further, even if the height of the cloth holding pin is adjusted in accordance with the thickness of the workpiece, the pressing force applied to the workpiece by the pressing spring may be constant or adjusted in accordance with the material or thickness of the cloth. it can. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment shown in FIGS. 1 to 9 in which the present invention is applied to an overlock sewing machine will be described in detail below. 1 to 3 show the overlock sewing machine in a state where the attachment is mounted. In this overlock sewing machine, as shown in FIG. 2, the attachment 2 is mounted on a mounting plate 3 mounted behind the sewing machine head 1. Specifically, the mounting plate 3 extends in the direction perpendicular to the vertical movement direction of the needle bar 16 on the needle drop side.
Is a rigid body having Attachment 2 is extended portion 3
It can be installed at any position of a. Once installed,
By operating the flat screw 9, the size of the workpiece W can be dealt with by sliding on the extending portion 3 a, and the workpiece W can be removed. Note that a scale (not shown) that determines the position of the attachment 2 in accordance with the size of the workpiece W may be printed or engraved on the extending portion 3a. That is, the attachment 2 of the present embodiment
Is a lower slider 4 slidably secured to the extending portion 3a and an upper slider guided by the central elongated groove 3b of the extending portion 3a and fixed to the lower slider 4 with the extending portion 3a interposed therebetween. A slider 6 (see FIG. 9) made up of an upper slider 5 and an arm 8 having a base end supported by the upper slider 5 are provided. Upper slider 5
However, as will be described later, the arm can support the arm 8 so that the entire arm can be stopped at an arbitrary elevation angle centered on the support shaft at the base end. As shown in FIGS. 3 and 4, the lower slider 4 and the upper slider 5 are fixed to each other with a flat screw 9 having a threaded portion penetrating the central elongated groove 3b of the extending portion 3a. As can be seen from FIGS. 2 and 3, the upper slider 5
a, a flat piece 5b that slides on the upper side of the sewing machine head, and an upright piece 5b that rises above the sewing machine head side, and extends forward of the sewing machine head 1 to determine one end position of rotation of the arm 8. And a positioning stopper piece 5c. As shown in FIG. 5, a pair of spring members 10 are fixed to the distal end portion of the positioning stopper piece 5c so as to stand on both sides of the positioning stopper piece 5c. The arm 8 can be retracted upward to the other rotation end position where the rear side surface of the base end portion 8a hits the flat portion 5a of the slider 6. As shown in FIG. 4, the arm 8 has a base end 8a which is pivotally attached to the standing piece 5b by an elastic washer 22 in a frictional state, and protrudes forward of the sewing head 1 from the base end 8a. And a U-shaped tip 8c. As shown in FIG. 3, between the upper piece 8d of the distal end portion 8c and the two divided lower pieces 8e and 8f, the cloth holding pin 7 is mounted at both ends supported to freely move in the vertical direction. . More specifically, the upper part of the pressure pin 7 is loosely inserted into the upper piece 8d, and the lower part of the pressure pin 7 is loosely inserted into one lower piece 8e. A fixing plate 12 having a pressing spring 11 interposed between the cloth holding pin 7 and the upper piece 8d is fixed to a substantially middle portion of the cloth pressing pin 7 by a screw 28. The fixing plate 12 is provided with an adjusting screw 13 for adjusting the height of the presser foot pin 7 in accordance with the thickness of the cloth at a position slightly away from the presser foot pin 7 and a knob member 15 on its head. It is mounted in a state where the screw portion protrudes from the lower surface side of the fixing plate 12. The distal end of the screw portion of the adjusting screw 13 comes into contact with the lower piece 8f. Note that a nut 27 is fastened between the knob member 15 and the fixed plate 12. The upper surface of the lower piece 8f with which the tip of the screw portion of the adjusting screw 13 abuts is located on the lower position surface 14 around the presser pin 7.
a, a cam surface comprising a high position surface 14b and a slope 14c connecting these two surfaces. With the configuration of this cam surface,
Knob member 15 attached to the tip of adjustment screw 13
Is pressed in the direction in contact with the rotation direction of the presser foot pin 7, the presser foot pin 7 can be moved up and down by the difference between the low position surface 14a and the high position surface 14b. Here, the high position surface 14b
Is formed with a stopper 23 at which the fixing plate 12 contacts. The stopper for the low position surface 14b is a side end surface of the distal end portion 8c connecting the upper piece 8d and the lower pieces 8e and 8f. The high position surface 14b is formed with a groove for fitting the distal end of the adjusting screw 13, so that the low position surface 14a is formed.
Return can be prevented. On the other hand, in the vicinity of the pole side on the needle plate when the needle bar 16 is moved down, there is provided a cloth pressing roller 17 having a tapered surface in contact with the needle plate. The cloth presser roller 17 rotates around a shaft 18 (FIG. 3) obliquely intersecting the vertical movement direction of the needle bar 16 with the tapered side facing the workpiece. A shaft rod 20 is connected to the support member 19 of the cloth pressing roller 17 on the base end side. The rotation of the shaft rod 20 allows the cloth pressing roller 17 to swing up and down. Further, the cloth press roller 17 is pressed by the press bar 21 from the sewing machine head, and obtains a pressing force of the cloth press roller 17 against the workpiece. A feed dog (not shown) is provided on the needle plate so as to face the cloth pressing roller 17. The operation of performing circular stitching with the overlock sewing machine having the above configuration will be described. Assume that the arm 8 is set in a retracted state with the cloth holding pin 7 facing upward as shown in FIG. First, the flat screw 9 is loosened, and the slider 6 is positioned at the scale position on the extending portion 3a that matches the size of the workpiece W. Thus, the distance between the needle drop point and the presser foot pin 7 is set according to the size of the workpiece W. Subsequently, as shown in FIGS. 3 and 5, the arm 8 is
It is lowered to the landing state against the frictional force between the base end portion 8a and the standing piece 5b by the elastic washer 22. Arm 8 has an elevation angle of 0 °
Is brought into contact with the positioning stopper piece 5c.
At this time, the cloth presser pin 7 lands at the center of the cloth feed motion of the workpiece W sent by the feed dog. Next, when the presser foot pin 7 is at the raised position in the landing state, the work W is set between the presser foot pin 7 and the needle plate or the cloth plate 30. The workpiece W is marked in the center in advance. Accordingly, the center of the workpiece W can be adjusted to the cloth holding pin 7 at the ascending position. Next, the fixing plate 12 or the knob member 15 is pulled back.
As a result, the tip of the screw portion of the adjusting screw 13 is
b to the low position surface 14a, and the presser foot pin 7 presses the center of the workpiece W. Then, the needle bar 16 and the feed dog are operated to perform sewing. As a result, a circular stitch portion is formed at the edge of the workpiece W. In order to remove the workpiece W, the fixing plate 12 or the gripping member 15 is then pressed to rotate the fixing plate 12 about the cloth holding pin 7 (FIG. 7). The tip of the screw portion of the adjusting screw 13 moves from the low position surface 14a to the inclined surface 14c, further moves to the high position surface 14b, and the fixing plate 12
Is raised by the difference d (FIG. 8) between the low position surface 14a and the high position surface 14b, and the sewing object W can be removed. As described above, according to the present invention, only the pushing and pulling-back operations of the fixing plate 12 or the gripping member 15 can be performed.
Can be set and removed. Next, according to the circular sewing device of the present embodiment, the height can be adjusted by the adjusting screw 13. The adjustment by the screw can adjust the cloth holding pin up and down very delicately, as compared with forming a special step or a taper, and can cope with various cloth materials or cloth thicknesses of the sewing object. When the height is adjusted according to the thickness of the cloth, the pressing force of the pressing spring 11 on the workpiece W also changes. For example, when the knob 15 is turned clockwise, the pressing force is reduced. At this time, if the cloth quality of the work W is strong, it may be desired to increase the pressing force. In this embodiment, in such a case, by changing the position of the fixing plate 12 so that the distance between the fixing plate 12 and the upper piece 8d is shortened by the screw 28,
The pressing force can be increased according to a strong cloth or a thick cloth. In the opposite case, the fixing plate 12 and the upper piece 8
What is necessary is just to make the interval with d long. Further, as shown in FIG. 8, by setting a distance between the nut 27 and the knob member 15, the height adjustment range can be changed. On the other hand, when circular sewing is not performed, the entire arm may be pulled up so as to release the restraint of the spring member 10 by gripping the distal end portion 8c of the arm 8 or the cloth holding pin 17. When the spring member 10 is released from the restraint, the arm 8 is moved upward by the frictional force between the upright piece 5b of the slider 5 and the base end 8a of the arm, as shown in FIG. Fixed. The arm angle in the retracted state can be set to an arbitrary elevation angle position by the frictional force between the upright piece 5b and the base end 8a.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view showing a circular sewing device of a sewing machine according to an embodiment of the present invention. FIG. 2 is a plan view of FIG. 1; FIG. 3 is a side view of FIG. 1; FIG. 4 is a sectional view taken along line BB of FIG. 2; FIG. 5 is a sectional view taken along line CC of FIG. 3; FIG. 6 is a sectional view taken along line AA of FIG. 3; FIG. 7 is a sectional view taken along line DD of FIG. 8; FIG. 8 is an explanatory diagram of an operation of lifting a cloth holding pin for removing a cloth. FIG. 9 is a side view showing the circular sewing device in a retracted state. FIG. 10 is an explanatory view showing a conventional circular sewing device. [Description of Signs] 1 ... sewing head, 2 ... attachment, 3 ... mounting plate, 6 ... slider (4 ... lower slider, 5 ... upper slider), 7 ... cloth holding pin, 8 ... arm, 10 ... spring member,
12: fixing plate, 13: adjusting screw, 14a, 14b, 14
c: cam surface, 15: knob member

Claims (1)

(57) [Claims] (1) A cloth presser pin for pressing a work to be sewn on the side of the needle drop on the needle plate, and the cloth presser pin is moved by the feed dog to move the cloth to be sewn. In a circular sewing machine of a sewing machine, which rotates a workpiece as a center and performs circular sewing, an arm supporting the cloth presser pins in both ends in a loosely inserted state and a cloth presser pin between the both ends of the arm are fixed. A fixing plate enabling the cloth presser pin to be rotatably operated from outside;
A pressing spring interposed between the fixing plate and one end of the arm, for urging the cloth holding pin in the direction of the needle plate, and a height of the cloth holding pin provided on the fixing plate by rotation. Adjustment
Adjusting screw and the tip of the adjusting screw provided on the arm
And the tip of the adjusting screw is moved in conjunction with the rotation of the pressure pin by an external operation to the fixing plate.
Circular sewing device of a sewing machine, characterized by comprising a lift means for vertically moving the cloth presser pin is guided by the cam.