JPS6326145Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a buttonhole sewing device for a sewing machine in which buttonhole sewing is performed in a zigzag stitch of a constant width by moving a cloth placed on an operation panel together with the operation panel.

This type of buttonhole sewing device generally has a cam plate with a plurality of buttonhole-shaped annular gears of different shapes and sizes slidably attached to the operation panel, and a pinion that is driven to rotate intermittently in conjunction with the sewing machine is connected to the gears. A pin protruding from the bed is loosely fitted into a guide groove drilled in the operation plate so that the operation plate operated by the pinion makes a predetermined movement. be supported. Conventionally, there are two types of guide grooves drilled into the operation panel: one is horizontally parallel to the long groove for needle entry (Fig. 1A), and the other is vertically (Fig. 1B). Therefore, in order to obtain the desired symmetrical buttonhole, it is necessary to take into account the deformation and form the ring gear into the shape shown in the figure. It is not easy to form an annular gear into a shape that corrects deformation so that a buttonhole of a desired shape and size can be obtained.

These problems can be solved by locating the pivot point on the center line of the buttonhole and distributing the operation panel evenly to the left and right from the center. The latter conforms to this, and allows you to obtain a buttonhole with the same shape and size as the ring gear, but on the other hand, the length is longer by L than the former, and the bed width is not as wide as that of a free arm type sewing machine. If the guide groove is short, the guide groove portion protrudes beyond the bed, and the pin that fits into the guide groove must be provided at a distance to the rear of the bed, which also becomes a nuisance.

This idea provides guide grooves on both sides of the long groove for needle drop, and a pin protruding from the bed is fitted into each guide groove to allow the operation plate to slide and pivot (tilt) along the center line of the long groove for needle drop. ) To provide a buttonhole sewing device which is configured to be movable so that the pivot center of the operation plate can be positioned on the center line of the buttonhole without providing a guide groove on the extension of the long groove for needle entry. It is something to do.

This will be explained with reference to the drawings. Reference numeral 1 denotes an operation plate, and a plate cam (not shown) is attached to the cam mounting part 2, and is moved to the left or right by rotation of the knob 3.
Of the buttonhole-shaped annular gears provided on the back surface of the plate cam with different shapes and sizes, the desired annular gear meshes with a pinion (not shown) that is driven to rotate intermittently in conjunction with the sewing machine, and is operated by the pinion. It is similar to what is known in that it is adapted to be moved over the bed together with a cloth applied to the board.

The operation panel 1 has guide grooves 6 on both sides of the long groove 5 for needle entry.
are formed in a left-right symmetrical shape, and each guide groove 6
Pins 8 protruding from the needle plate 7, which are spaced at the same distance between the outer edges 61 of the guide grooves, are fitted in contact with the outer edges 61 of the guide grooves. Thus, the operation plate 1 moves in the vertical direction (indicated by the arrow) guided by the pin 8 that joins the outer edge of the guide groove, and the pin 8 and the inner edge of the guide groove 6
2, it is possible to pivot (tilt) the operation plate with the pivot point on the center line of the long groove for needle entry. As shown in FIG. 2, when the operation plate 1 pivots at an angle α, a gap is formed between the pin 8 and the outer edge 61 of the guide groove, but the angle of the operation plate tilted during buttonhole sewing is too large. It is not a problem, and the movement of the operation panel will not become unstable. It is possible to form the pin so that it always remains connected to the outer edge of the guide groove when the operation plate is tilted during buttonhole sewing.

In FIG. 3, the pin 8 is formed into an arcuate shape, and as shown in the figure, the pin always remains in contact with the outer edge 61 even when the operating plate is tilted at an angle α.

Although the above example shows that the pin 8 is joined to the outer edge of the guide groove, it may be formed so as to be joined to the inner edge of the guide groove. In order for the pin to slide smoothly along the inner edge of the guide groove, an appropriate amount of clearance is required between the two, which allows for the tilting of the operating plate required when sewing buttonholes. It is from.

In the above embodiment, the pin 8 is provided on the throat plate, but depending on the sewing machine, it may be provided on the cover plate or protruding from the bed.

As mentioned above, the buttonhole sewing device of this invention has a guide groove that guides the movement of the operation panel and is arranged side by side with the long groove for needle entry, so the length does not become long, and therefore it can be used as a free arm type sewing machine. Not only can it be used on sewing machines with short bed widths, such as the one shown in the figure, but the pivot center is located on the center line of the long groove for needle entry, and the operation plate is formed in a plate cam so that it can be swung evenly from side to side. The same buttonhole as the buttonhole-shaped annular gear is formed, and when forming the annular gear, there is no need to take into account or correct the resulting deformation of the buttonhole, and it is extremely easy to manufacture. .

[Brief explanation of the drawing]

1A and 1B are bottom views of a conventional buttonhole sewing device, FIG. 2 is a plan view of a buttonhole sewing device according to the present invention, and FIG. 3 is an explanatory view of the operation. 1... Operation board, 5... Long groove for needle entry, 6... Guide groove, 8... Pin.

Claims (1)

[Claims for Utility Model Registration] (1) The operation plate 1 includes a mounting portion 2 for mounting a cam member formed with a buttonhole-shaped ring gear that meshes with a pinion that is driven to rotate intermittently in conjunction with the sewing machine. A long groove 5 for needle entry and guide grooves 6 formed symmetrically on both sides of the long groove are provided, and a pair of pins 8 protruding from the needle plate or bed of the cover plate 7 are fitted into each of the guide grooves. A buttonhole sewing device for a sewing machine in which one side edge of the buttonhole is guided and the operation plate 1 is moved along the longitudinal direction of the guide groove by the pinion and is tilted about the center line of the long groove for needle entry as a pivot point. (2) The buttonhole sewing device according to claim 1, wherein the pin has an arcuate shape, and the circular arc portion thereof is joined to the outer edge of the guide groove.