JPS631875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cloth presser device that presses down the cloth being sewn in an automatic sewing machine that automatically sews according to stored sewing information.

[Prior art]

Automatic sewing machines that automatically sew by moving the workpiece in any direction while holding it between cloth holding plates in accordance with sewing information stored in a memory element are well-known, and can be used not only as industrial sewing machines but also as household sewing machines. It has been widely put into practical use.

This type of automatic sewing machine is equipped with a presser foot device that presses the cloth being sewn. During automatic sewing, in order to smoothly feed the cloth, the presser foot of this presser foot device is usually held at a level that does not interfere with cloth feeding. The height is set and sewing is performed. That is, when the object to be sewn is so-called plain stitching in which a plurality of cloths are sewn one on top of the other, the height of the presser foot is set in accordance with the number of cloths to be sewn.

However, this is fine if the material to be sewn is plain stitched from the beginning to the end of sewing, but it is not possible to combine so-called step stitching and flat stitching in which the number of sewn pieces or the thickness of the fabric changes during sewing in one sewing pattern. If the height of the presser foot is set for flat stitching, the presser foot will hit the step when it comes to the step sewing area, making it impossible to sew. When the height of the presser foot is set for step stitching, there is a drawback in that an appropriate presser foot action cannot be obtained in the plain seam section.

Therefore, conventionally, in order to make it possible to sew a workpiece having flat stitches and step stitches in one sewing pattern, the height of the presser foot was made vertically movable so as to vary between, for example, 2 mm and 5 mm. A presser foot device has been developed, and automatic sewing machines equipped with this device have become widely used.

However, in conventional automatic sewing machines equipped with this type of presser foot device that can move up and down, when the needle passes through or comes out between the presser foot and the fabric during plain sewing, the fabric flaps and skipped stitches occur. Smooth and proper automatic sewing may not be carried out due to poor thread tightening, and improvements have long been requested.

[Summary of the invention]

The present invention has been developed in view of the above-mentioned points, and is provided with a conversion mechanism between the rotation of the main shaft and the vertical movement of the presser foot, and a mechanism for adjusting the amount of vertical movement of the presser foot, and a part of the conversion mechanism is a swinging member and a connecting member that connects the swinging ends of the swinging member, and one end of the linking member can be selectively pivoted to either the swinging end or the swinging center of the swinging member. The present invention provides a cloth presser device for an automatic sewing machine, which is configured to be able to be worn, thereby enabling smooth and proper automatic sewing without skipped stitches, poor thread tightening, etc., on various objects to be sewn. Embodiments of the present invention will be described in detail below with reference to the drawings.

[Embodiments of the invention]

1 to 4 show an embodiment of the presser foot device according to the present invention, FIG. 1 is a perspective view showing the general configuration of an automatic sewing machine implementing the same, and FIG. 2 is an exploded perspective view of the main parts. Figures 3 and 4 each show a side view from A in Figure 1, Figure 3 is a side view when the vertical motion of the presser foot is switched to an adjustable state, and Figure 4 is the same. It is a side view when switching to a zero state. In these figures, a main shaft 3 is rotatably supported through a sewing machine arm 1 and is driven and connected to a drive device (not shown) by a belt stretched around a pulley 2. The crank 4 is fixed. On the other hand, a needle bar 5 that is orthogonal to the main shaft 3 is vertically supported on the head of the sewing machine arm 1 so as to be vertically movable, and a needle 6 is inserted and fixed into the lower end of the needle bar 5 from below. The stopper 7 fitted and fixed to the center of the needle bar 5 and the eccentric part of the crank 4 are connected by a rod 8, and the main shaft 3
When the needle bar 5 rotates, the eccentric action of the crank 4 causes the needle bar 5 to move up and down.

At a position close to the needle bar 5, a presser foot bar 9 parallel to the needle bar 5 is vertically supported on the sewing machine arm 1 via an adjusting screw 10 and a bush 11 so as to be movable up and down. A presser foot 12 is fixed by screws 13 to the section, which extends along the needle bar 5 and has a cylindrical distal end through which the needle 6 passes. The one indicated by numeral 14 has a screw 15 attached to the presser rod 9.
A compression coil spring 16 is interposed between this and the adjustment screw 10 to press and bias the presser foot bar 9 downward, and rotates the adjustment screw 10. Accordingly, the position of the presser foot 24 is adjusted. 1
7 is an upper thread guide fixed to the spring receiver 14 with a screw 18.

A mounting plate 19 is fixed to the upper side of the sewing machine arm 1 with screws 20, and a threaded piece provided on a projecting piece of this mounting plate 19 has an adjusting screw 2.
1 is screwed in. 22 is the upper end adjusting screw 21
It is a spring shaft that is brought into contact with the spring shaft, and its lower end is L.
It is in contact with an L fitting 23 formed in a letter shape,
A bell crank 24 as an L-shaped swinging member is rotatably supported on the L fitting 23 by a stepped screw 25 . The bell crank 24 has one free end pivotally connected to a link 39, which will be described later, and the other free end, which is supported by a stepped shaft 47 and a protruding shaft 48, which will be described later. L during normal times
The movement of the fulcrum position by the metal fitting 23 is restricted, and the bell crank 24 by the L metal fitting 23 is moved up and down by rotating the adjusting screw 21 and expanding and contracting the compression spring 26 on the spring shaft 22. The fulcrum position is configured to move. That is, on the main shaft 3, there is an eccentric cam 27 in which the axis of the inner circumferential shaft hole and the axis of the outer circumference are eccentric.
is fitted and fixed with a screw 28, and a rod 29 is fitted on the outer periphery of the eccentric cam 27, and a screw 30
A thrust collar 31 fixed to the main shaft 3 is interposed between the stepped portion of the main shaft 3 and is freely rotatably fitted. On the other hand, a swing shaft 32 is rotatably supported on the head of the sewing machine arm 1, and the free end of the rod 27 forms an arc of a swing arm 33 fixed to one end of the swing shaft 32. It is pivotally mounted in the elongated hole 34 by a stepped screw 35 and a nut 37 with a washer 36 so as to be movably adjustable. Further, another swinging arm 38 as a swinging member is fixed to the end of the swinging shaft 32,
Each end of a link 39 serving as a connecting member is pivotally connected to the free end of the swing arm 38 and the upper free end of the bell crank 24 by stepped screws 40 and 41, respectively. By doing this, the main shaft 3
When the bell crank 24 rotates, the eccentric action of the eccentric cam 27 causes the swing shaft 32 to reciprocate via the rod 29 and the swing arm 33, and the bell crank 24 swings via the swing arm 38 and the link 39. As shown in FIG.
The structure is such that the swinging of the bell crank 24 is stopped by replacing it with the screw hole 43 of the swing shaft 32. Furthermore, a protruding shaft 45 pivotally connected to the spring receiver 14 is engaged with a shaft hole 44 provided at the lateral free end of the bell crank 24. 9 and the presser foot 12 are configured to move up and down. By changing the pivoting position of the rod 29 relative to the elongated hole 34, the vertical motion of the presser foot 12 is adjusted, and by stopping the bell crank 24 as described above, the vertical motion of the presser foot 12 becomes zero. Reference numeral 46 denotes a protrusion for manually lifting the presser foot shaft 9. Furthermore, a roller 49 is provided at a location adjacent to the stepped portion 48 of the stepped shaft 47 screwed into the end surface of the protruding shaft 45 that engages with the shaft hole 44 of the bell crank 24.
is pivotally supported, and this roller 49 is attached to a bell crank guide 5 fixed to the sewing machine arm 1 with a screw 50.
The bell crank 24 is engaged with the long groove 52 of the bell crank 24.
It is configured to guide the vertical movement of the free end.

Further, above the sewing machine table 53, there are provided an upper fabric holding plate 54 and a lower fabric holding plate 55 for holding and feeding the fabric, and below the sewing machine table 53, there is provided a hook 56 which is conventionally known and which stores the bobbin thread. is rotatably supported and driven from the main shaft 3 side via transmission shafts 57 and 58.

The operation of the automatic sewing machine configured as described above will first be described with respect to a sewn product having a single sewing pattern that includes plain stitching and step stitching. In this case, one end of the link 39 is pivotally connected to a screw hole 42 at the free end of the swing arm 38 with a stepped screw 41. When the motor is started by passing the upper thread and bobbin thread and pressing the cloth with the presser foot 12, the main shaft 3 rotates and the needle 6 operates.
When the eccentric cam 29 rotates, the rod 29 reciprocates due to its eccentric action, and the swing shaft 32 reciprocates via the swing arm 33. This rotation is the swing arm 3
8 and the link 39 to the bell crank 24, and the bell crank 24 swings about the stepped screw 25 as a fulcrum. Since a protruding shaft 45 is engaged with a shaft hole 44 provided at the other free end of the bell crank 24, the swinging of the bell crank 24 is controlled by the spring bearing 14.
This is converted into the vertical movement of the fixed presser foot shaft 9, and the presser foot shaft 9 moves up and down while causing the rollers 49 of the stepped screw 47 to slide up and down along the long grooves 52. Accordingly, the presser foot 12 also moves up and down. In this case, the compression coil spring 26 presses the spring shaft 22 downward, and the L fitting 23 and the bell crank 24
and are fixed with stepped screws 25,
By rotating the adjusting screw 21, the fulcrum position of the bell crank 24 is adjusted. The timing of the vertical movement of the presser foot 12 relative to the vertical movement of the needle 6 is determined by the fixed phase of the eccentric cam 27 with respect to the main shaft 3. Also, the vertical movement of the presser foot 12 is the rod 29
It is adjusted by moving and fixing the swing arm 33 along the long hole 34 of the swing arm 33. In other words, the closer the pivot point of the rod 29 is to the swing shaft 32, the greater the swing angle of the swing arm 33.
The vertical movement of the presser foot 12 varies, for example, between 2 mm and 5 mm.

Next, in the case of a sewn product having a sewing pattern with only one-sided stitching, one end of the link 39 is pivoted with a stepped screw 41 into a screw hole 43 drilled in the axis of the swing shaft 32, as shown in FIG. When the main shaft 3 is rotated,
The swing shaft 32 reciprocates in the same manner as above, but
Since the link 39 is pivotally connected to the axis of the swing shaft 32, no swing motion is applied to the bell crank 24, and therefore the vertical momentum of the presser foot 12 becomes zero.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a presser foot device for an automatic sewing machine is provided with a mechanism for converting the rotation of the main shaft and the vertical movement of the presser foot, and a mechanism for adjusting the amount of vertical movement of the presser foot. It consists of a part of the mechanism and a connecting member that connects two swinging members and their swinging ends, and one end of the linking member is connected between the swinging ends of the swinging members and the swinging center. By being configured so that it can be selectively pivoted to either one, the appropriate presser foot height can be set for both objects that have plain stitches and step stitches in one sewing pattern, and objects that only have plain stitches. As a result, it is possible to always ensure excellent sewing performance without the presser foot hitting the stepped part, skipped stitches or poor thread tightening, and also to ensure excellent sewing performance depending on the material to be sewn. There is no need to use different models, improving the versatility of the sewing machine.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the presser foot device for an automatic sewing machine according to the present invention, FIG. 1 is a perspective view showing the general structure of an automatic sewing machine implementing this, and FIG. Exploded perspective view of the section, Figure 3,
Fig. 4 shows a side view from A in Fig. 1, Fig. 3 is a side view when the vertical motion of the presser foot is adjustable, and Fig. 4 shows a side view when the vertical motion of the presser foot is switched to zero. FIG. 3... Main shaft, 5... Needle shaft, 9... Presser foot shaft, 1
2...presser foot, 24...bell crank, 27...
Eccentric cam, 29...rod, 32...swing shaft, 3
3... Swinging arm, 34... Long hole, 38... Swinging arm, 39... Link.

Claims (1)

[Claims] 1. A conversion mechanism that converts the rotation of a main shaft that drives the vertical movement of the needle shaft into vertical movement of the presser foot, and an adjustment mechanism that adjusts the amount of vertical movement of the presser foot are provided, and a part of the conversion mechanism is and a connecting member pivotally attached to the swinging ends of the swinging members to connect them, and one end of the linking member is connected to the swinging end of the swinging member. A presser foot device for an automatic sewing machine, characterized in that the presser foot device is configured to be selectively pivotally attachable to either of the moving center portions.