JPS62605Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a feed switching mechanism for sewing buttonholes in a sewing machine.

(Prior Art) In conventional sewing machines, the feed for buttonhole sewing is set by changing the inclination angle of the feed adjuster.

In this case, the feed amount for forward sewing and backward sewing of right and left line tack sewing is determined by the buttonhole sewing selection dial, which feeds the follower between the forward cam and backward cam, which are arranged opposite to the adjustment dial. The inclination of the feed adjuster is changed by moving the feed adjuster.In bartack sewing, the feed adjuster is positioned at the midpoint between forward and backward movement to obtain a feed of "0". However, it is mechanically difficult to adjust the feed amount for buttonhole sewing and other sewing patterns so that the mutual feed "0" matches each other. In addition, in order to sew buttonholes, it is necessary to switch the selection dial for buttonhole sewing in the order of right line tack, bar tack, left line tack, and bar tack, but switching of the selection dial is done using the feed adjuster, which is biased by a strong spring. Since this is done by directly operating the switch as described above, there is a drawback that the switching operation becomes laborious.

(Purpose) The purpose of this invention is to set the inclination of the feed adjuster directly once using the feed dial, and to sew each part of the buttonhole sewing by switching the selection button. By moving the horizontal feed cam relative to the lower shaft, the feed cam is inactive and the feed is reliably set to "0" from the right line tack of forward sewing to the downward bar tack and the left side of backward sewing of the same pitch as the right line tack. To provide a buttonhole sewing feed switching mechanism for a sewing machine configured to easily switch between line tack and upper bar tack, and to perform the switching operation with a smaller operating force than conventional ones.

(Structure) The structure of the present invention will be explained below using examples. In FIG. 1, a sewing machine 1 is equipped with a plurality of sewing pattern selection buttons 2 including buttonhole sewing at the lower front of the sewing machine 1, and a sewing pattern selection mechanism 3 that selects a sewing pattern by locking these buttons 2 when operated, and a sewing pattern selection mechanism 3 that selects a sewing pattern. A feed dial 4 as a control member and an amplitude dial 5 as an amplitude control member are provided.

To explain these in detail, the buttons 2 for selecting various sewing patterns and the buttons 2', 2'', 2 for selecting buttons related to buttonhole sewing are respectively attached to the holder 6.
and fixed to the holders 6', 6'', and 6.
Hereinafter, these buttons and holders will be referred to as 2 and 6 unless a particular distinction is required. Each holder 6 is pivotally attached to a shaft 8 fixed to a machine frame 7, and arranged at intervals as shown in FIG. 2 by a plurality of collars 9 and a plurality of rings 10. The horizontal position in the figure is regulated by the ring 12 and the like. Although other "shafts" will be mentioned in the explanation below, it is assumed that each shaft is fixed to the machine frame 7 unless otherwise specified.
The feed dial 4 is configured to control the tilt of the feed adjuster via a transmission mechanism by a feed control cam (not shown) formed on the dial.

Next, referring mainly to FIGS. 4 to 6, each holder 6 is rotated clockwise in FIG. energized.

That is, one end of each torsion coil spring 13 is locked to each holder 6, and the other end is locked to the shaft 14, and the lower surface of the notch 6b formed in each holder 6 is normally connected to the shaft 14. A plurality of regulating pieces 15 are attached and regulate the position of each holder 6 in the thickness direction.
It is in contact with the lower surface of the cushion member 15 provided with a. The holder receiver 16 is biased clockwise in FIG. 4 around a shaft 17, and when the holder 6 is rotated counterclockwise in the same figure by pressing the button 2, the lower surface of the locking portion 6c is pressed against the protrusion 16a. Rotate the holder receiver 16 counterclockwise through the fifth
As shown in the figure, the holder receiver 16 returns clockwise at the position where the corner 6d is locked with the locking protrusion 16b, and as shown in FIG. button 2 is in the selected state.

The feed switching arm 18 is pivotally connected to the shaft 17, and the feed switching arm includes a member 1 having horn portions 19a and 19b.
9 is fixed, button 2'' for bar tack for buttonhole sewing and button 2 for left line tack.
are located below the respective holders 6'' and 6, and the feed switching arm is connected to the pin 21a of the base plate 21 via the pin 18a and the rod 20 as shown in FIG.
The other end of the feed lever is pivotally connected to the pin portion 22a of the feed lever 22 which is pivotally connected to the base plate 2.
It is connected via a pin 23a to a feed switching plate 23 which is guided by a pin 21b fixed to the horizontal feed cam 24 and moved linearly.
is moved along the lower shaft 25 as described later, and the horizontal feed cam is switched to the forward position, neutral position, and reverse position.

The horizontal feed cam 24 is slidably and rotatably fitted into the lower shaft 25, and has engaging portions 24a and 24 at both ends, respectively, as shown in FIG.
They are formed with a certain phase difference a', approximately 180° in this embodiment. An engaging body 26 for forward movement and an engaging body 27 for backward movement, in which protrusions 26a and 27a are respectively formed so as to sandwich the horizontal feed cam 24 from both sides, are fixed to the lower shaft 25 with screws 39 and 40, and between both protrusions 26a and 27a. is horizontal feed cam 2
4 with a sufficient gap between them.
The engaging portions 24a and 24a' are formed of shallow steps 24b and 24b', respectively, and deeper grooves 24c and 24c' connected to these, respectively, and when engaged with the protrusion 26a or 27a, It is configured to engage the groove 24c or 24c' from the side of the shallow step 24b or 24b', respectively. The horizontal feed cam 24 is biased to the left in FIG.
, and is in a forward feeding state.

A feed bar equipped with feed teeth (not shown) is engaged with the horizontal feed cam 24, and the feed bar is caused to move horizontally and is also made to move vertically by a vertical feed mechanism (not shown), and both feed movements are combined. ,
Performs a so-called four-feed motion.

A follower 30 is pivotally attached to each holder 6,
When the button (2) is selected, one end is driven by a pattern cam 33 that is integrally fixed to the gear 31 and pivoted to a shaft 32, and the other end is brought into contact with a shaft 35 fixed to a claw plate 34. It is configured as follows. The output end 34a of the pawl plate 34 is connected to a link mechanism that swings the needle bar in the amplitude direction, and the pawl plate 34 is biased clockwise in FIG. 4 about the shaft 8 by the link mechanism. Rotation clockwise by a pin member 38 fixed to an amplitude limiting arm 37 controlled by a cam (not shown) of the amplitude dial 5 which is pivotally connected to the shaft 8 and brought into contact by the biasing force of a spring 36 are becoming restricted.

(Function) Next, the function of the present invention configured as described above will be explained. To sew buttonholes, use the feed dial 4 to control the inclination of the feed adjuster to set the feed amount to a value suitable for sewing buttonholes, and with the amplitude dial 5 set to the maximum amplitude position, turn the right line tack. button 2' for bar touch, button 2'' for bar touch, button 2 for left line touch
and bar tack button 2'' in this order, and operate the cams for each part of the buttonhole sewing of the pattern cam 33 to select the right line tack L ₁ , the lower bar tack B ₁ , and the left line tack L ₂ as shown in FIG.
and sew the upper bartack _B2 .

In the buttonhole sewing process described above, right line tack L ₁ is selected by selecting button 2' for right line tack.
After sewing, when button 2'' for bartack sewing is selected, the holder 6'' pushes the corner 19a, so the feed switching arm 18 rotates clockwise around the shaft 17, and the rod 20 and the feed lever 22 and the feed switching plate 23, the horizontal feed cam 24 is moved to the left in FIG. 7 along the lower shaft 25, and as shown in FIG.
and the engaging body 27 are in a disengaged state,
No horizontal feed motion is transmitted to the feed table, and the downward bartack _B1 with a feed amount of "0" is reliably sewn.

Next, when the left line tack sewing button 2 is selected, the holder 6 pushes the corner 19b, and the feed switching arm 18 rotates by a larger angle clockwise about the shaft 17 than in the case of bar tack sewing. , the horizontal feed cam 24 engages with the engaging body 27, and the feed base is fed backward at a pitch equal to the forward feed amount for the right line tack stitch, and for the left line tack stitch.
L ₂ is sewn.

Next, when button 2'' for bartack sewing is selected, upper bartack _B2 is sewn in the same manner as lower bartack _B1 , and buttonhole sewing is completed.

In the above-mentioned buttonhole sewing, the selection operation for buttonhole sewing-related button 2' is easy, and for button 2'' and button 2, the horizontal feed cam 24 is simply moved against the spring 28, so the conventional This can be done with lighter operating force than when directly controlling the feed adjuster.

(Effects) As described above, with the present invention, it is only necessary to set the inclination of the feed adjuster directly once using the feed dial.
To sew each part of buttonhole sewing, by switching the selection button and moving the horizontal feed cam relative to the lower shaft, the feed can be reliably changed from the right line tack of forward sewing with the feed cam inactive. The effect is that it is possible to easily switch to the left line tack and upper bar tack of backward stitching of the same pitch as the lower bar tack and right line tack of 0''. Moreover, these switching operations can be performed with less operating force than conventional ones, so
The present invention has the advantage that it is possible to eliminate the unnecessary labor required in conventional buttonhole sewing, and contribute to providing a sewing machine with good operability.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention, and FIG. 1 is a perspective view of the sewing machine, FIG. 2 is a plan view of the main part of the sewing pattern selection mechanism, FIG. 3 is a view taken from arrow A in FIG. 2, and FIG. 6th
The figure is a vertical cross section of the main part taken along the line C-C in Figure 2.
The figure shows the button in a non-selected state, FIG. 5 shows the button in the middle of the button selection operation, and FIG. 6 shows the button after the button selection operation. Figures 7 and 8 are views showing the main parts of the horizontal feed cam switching mechanism in the direction of arrow D in Figure 6. Figure 7 shows the forward feeding state, and Figure 8 shows the horizontal feed cam in the inactive state. Show each. FIG. 9 is a developed view of the horizontal feed cam and the engaging body, and FIG. 10 is a plan view showing the buttonhole seam. In the figure, 1 is a sewing machine, 2 is a button for selecting sewing patterns,
2' is a button for right line tack, 2'' is a button for bar tack, 2 is a button for left line tack, 19 is a member, 19a, 19b are two parts, 23
24 is a horizontal feed cam, 25 is a lower shaft, and 26 and 27 are engaging bodies.

Claims (1)

[Scope of utility model registration request] A horizontal feed cam rotatably and slidably disposed on the lower shaft of the sewing machine is selectively engaged with either a forward engaging member or a backward engaging member to convert the horizontal feed between forward and backward movement. A sewing pattern selection method in which a sewing pattern is selected by locking a plurality of sewing pattern selection buttons, including a right line tack button, a bar tack button, and a left line tack button during buttonhole sewing, on a sewing machine that sews buttonholes. The mechanism is provided with a member that is mechanically connected to the feed switching plate for moving the horizontal feed cam and has a pair of horn parts that are rotated when the bar touch button and the left line touch button are selected. However, when the bar tack button and the left line tack button are selected, the horizontal feed cam changes from the forward position for right line tack of buttonhole sewing to the neutral position where horizontal feed is not performed and backward feed at the same pitch as the forward feed. A feed switching mechanism for buttonhole sewing of a sewing machine, characterized in that the feed switching mechanism is configured to be able to switch between positions.