JPS61154596A - Hook apparatus of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention deals with the movement of a hook device of a sewing machine, particularly a needle bar that reciprocates up and down during the sewing cycle of the sewing machine, and which rotates at a predetermined rotation ratio. This invention relates to an improvement in a rotation prevention mechanism for an inner hook rotatably disposed within the hook.

[Prior Art] Figures 18 to 20 show a hook device of a conventional sewing machine. In Figure 1, (1B) is a mounting base attached to the back of the sewing machine bed, and (18) is this mounting base (1B). The outer hook (20) is the tip of the outer hook (18), and (22) is the outer hook (18). ) is rotated at a predetermined timing.

(28) is an inner hook that is rotatably arranged in the outer hook (18) and is operated by the opener (22), (32) is an opener stand that swings around the pin (33) position, and (34)
) is a link whose one end is pivotally connected to the opener stand (32) via a stepped bottle (35) to interlock the outer hook (18) and the opener stand (32), and (38) is the upper flange of the inner hook (28). (58) is a throat plate having a groove in which the feed dog can operate; (58a) is a protrusion formed on both sides of this throat plate (58); 80) is a locking groove with a beautifully finished machined surface on a part of the protrusion (58a), and (58) is a locking groove provided at one location of the upper flange (42) of the inner hook (28). This is a protruding tongue that engages with the groove (80) to prevent the inner hook (28) from rotating.

The hook device of a conventional sewing machine is constructed as described above, in which the outer hook (18) rotates horizontally in synchronization with the up and down reciprocation of the needle bar, and the opener (22) rotates at a predetermined timing accordingly.
), the opener stand (32) swings. And outer kama (1
The rotation of the inner hook (28) accompanying the rotation of the inner hook (28) is prevented by the engagement between the projecting tongue (58) and the locking groove (60).

[Problems to be solved by the invention] In the conventional sewing machine hook device as described above, the outer hook (1
After attaching the mounting base (1B) that rotatably supports the sewing machine 8) to the back of the sewing machine bed, attach the protruding tongue part (28) of the inner hook (28).
It is necessary to blindly attach and assemble the throat plate (58) to the upper surface of the sewing machine so that the needle plate (58) can be fitted and engaged with the locking groove (80) of the throat plate (58), which is difficult.

In addition, it is almost impossible to check whether the two are aligned, which often causes problems with assembly accuracy, especially when assembling a sewing machine.
A problem arises when a user who is inexperienced with adjustment performs such work for the purpose of maintenance or inspection.

In addition, a protrusion (58a) that requires a special shape is required on the back surface of the throat plate (58).
) must be provided with a locking groove that requires precision machining.
There is a problem in that the manufacturing cost increases and the financial burden on the person purchasing the sewing machine increases.

The present invention has been made to solve these problems, and an object of the present invention is to provide a hook device for a sewing machine that is easy to manufacture, inexpensive, and easy to assemble.

Means for Solving Problem E] The hook device of the sewing machine according to the present invention omits the locking groove that was conventionally provided on the back surface of the throat plate and provides a locking groove at one location on the outer periphery of the upper end of the inner hook. In addition, the opener is provided with a stopper that can be engaged with the locking groove, and the inner hook is normally prevented from rotating by the engagement between the stopper and the locking groove, and the sewing thread is not inserted into the locking groove. When passing through, the inner hook is operated by the opener to temporarily release the engagement between the locking groove and the stopper.

[Function] In this invention, since the inner hook is prevented from rotating by engagement between the locking groove provided on the inner hook and the stopper attached to the opener, there is no need for a locking groove on the throat plate. This reduces costs, and since the hook and stopper can be assembled outside the sewing machine, assembly is easy and assembly accuracy can be improved.

[Embodiment] Figures 1 to 7 show an embodiment of the present invention, in which (1) is an arm, (2) is a bed, and (3) is a rotatable unit inside the arm (1). A pivotally supported main shaft (4) is a swingable needle bar support whose upper end is pivotally connected to the arm (1), (
5) is a needle bar supported by a needle bar support (0) so as to be able to reciprocate up and down, and (8) is attached via a pin (7) to a crank (8) attached to one end of the main shaft (3). The needle bar (5) is driven by the crank rod (8). (9) is a pulley for rotating the main shaft fixed to the other end of the main shaft (3), and (10) is a pulley for rotating the main shaft. (3) is a toothed belt pulley pivotally attached to the middle part of the bed (ii) is
A ball bearing (12) and a bearing (
The lower shaft is rotatably attached via (13), (14
) is a toothed belt pulley attached to the shaft end of the lower shaft (11), which is connected to the toothed belt pulley (10) by an endless toothed belt (15) and transmits the rotational force of the main shaft (3). The signal is transmitted to the lower shaft (11).

In addition, (16) is a mounting base that is attached to the mounting part on the back side of the bed (2) via a set screw (17) so that its position can be adjusted;
) is an outer hook that has a shaft part (21) for a support shaft, and like the known one, the tip of the needle plunges into the loop of sewing thread formed around the needle hole of the needle (18) and captures the sewing thread. Part (2
0) and an eccentric ring part (23) for driving an opener (22) to be described later, and is rotatably supported on a shaft part (21) by a bearing (24) provided on a mounting base (16). The blade tip (20) of the outer hook (18) is rotated parallel to the surface of the bed (2). (25) is a screw gear attached to the shaft (21) of the outer hook (18) with a set screw (26) so that both ends can contact the end of the bearing (24) for axial positioning. , are meshed with respective helical gears (27) attached to the lower shaft (11). As a result, when the main shaft (3) rotates, the outer hook (18) rotates in a predetermined direction at a rotation ratio of 1:2 with respect to the main shaft (3).

(28) is a normal inner hook that accommodates the bobbin (28) on which the bobbin thread is wound and allows the bobbin thread to be pulled out from a predetermined hole. (1
8) into the race groove (31) and rotate freely.
18), but when the outer hook (18) rotates, it rotates in the same direction as the outer hook (18) rotates due to the frictional resistance of the fitting.

(32) is an opener stand, and in this embodiment, as shown in FIGS. 4 and 5, the attachment stand (16) is
) is swingably supported. (30 is a link, -
One side is fitted into the eccentric ring part (23) of the outer hook (18), and the other side is connected to the opener base (3) by a stepped pin (35).
2). And with this, the main axis (3)
When the outer hook (18) rotates, the opener stand (
32) is configured to swing by an amount proportional to the eccentricity of the eccentric ring portion (23) at a predetermined rotation angle timing with reference to the tip of the outer hook (18) @(2o).

(3B) is a locking groove formed by cutting out one part of the upper surface flange (42) of the inner hook (28), and
As the outer hook (18) rotates, the sewing thread captured by the tip (20) of the inner hook (28) slides on the top flange (42) of the inner hook (28) and moves sequentially to the locking groove (3B). It is especially beautifully finished so that there is no problem with the passage of sewing thread during the period when the sewing machine passes through. (3?) is a stopper that is attached to the - side of the opener stand (32) via a set screw (38) so that its position can be adjusted, and it engages with the locking groove (3B) with the required clearance. However, as the outer hook (18) rotates, the inner hook (28) is prevented from rotating in the same direction as the outer hook (18). 18), the contact surface (43) of the locking groove (3B) and the stopper (37) are always engaged as shown in FIG. (39) is a projecting part formed in one place of the upper flange part (42) of the inner hook (28) in a shape that does not cause any trouble for the sewing thread to pass through. An opener (22) is attached to the end via a set screw (41) so that its position can be adjusted, and is engaged when necessary, as shown in FIG.

In the sewing machine hook device configured as above, 1
When driving force from a drive source (not shown) is transmitted to the main shaft (3) via the pulley (8), the main shaft (3) rotates and the needle bar (5) and the needle (18) at its lower end move up and down. While reciprocating, the lower shaft (11) is rotationally driven in the same direction as the main shaft (3), and each individual gear (27) rotates.

When the large threaded gear (27) rotates, the shaft (21) is driven via the threaded gear (25) that meshes with it, and the outer hook (18) integrated with this drives the shaft (21) at a 1/2 angle with respect to the main shaft (3). : It is rotated parallel to the bed (2) surface at a rotation ratio of 2. As a result, the tip (20) rotates together with the outer hook (18) parallel to the surface of the bed (2), and the tip plunges into the loop of sewing thread that is formed on one side around the needle hole of the needle (18). Capture the sewing thread.

On the other hand, when the shaft part (21) and the outer hook (18) rotate, the eccentric ring part (23) at the upper end of the shaft part (21) is eccentrically rotated, and this driving force is as shown in FIG. Link(
30 to the opener stand (32), and the opener stand (32) uses the pin (33) position as a fulcrum and the tip portion (2o) by an amount proportional to the eccentricity of the eccentric ring portion (23). It is driven to swing at the timing of a predetermined reference rotation angle. The inner hook (28) rotatably disposed inside the outer hook (18) is connected to the opener (22) and the stopper (
37) by engaging with the inner hook (28), the outer hook (18)
;7) Free rotation accompanying rotation is prevented, and
Sewing thread connects to opener (22) and stopper (37)
When passing through the section, the engagement is temporarily released by swinging of the opener stand (32).

In other words, as shown in Figure 6, the sewing thread is attached to the inner hook (28).
When the inner kettle (2
8) is pressed by the opener (22). Then, the inner hook (28) is pushed back in the direction opposite to the direction of rotation of the outer hook (18), and the contact surface of the locking groove (36) with which the S/P (37) is engaged. A gap is generated between the stopper (43) and the stopper (37), and the engagement between the two is temporarily released. Thereby, the sewing thread can pass through the engagement groove (3B) portion without any hindrance to the sashimi. On the other hand, as shown in FIG. 7, when the sewing thread passes through the overhang (38) of the inner hook (28) as the outer hook (18) rotates,
Contact surface (43) between stopper (37) and locking groove (36)
When they come into contact with each other, the inner hook (28) is pushed back in the direction opposite to the rotational direction of the outer hook (18), and a gap is generated between the opener (22) and the overhang (38). Therefore, the sewing thread can pass through the overhang (39) portion without any hindrance.

8 to 10 show other embodiments of the opener drive mechanism, in which the same reference numerals as in FIGS. 1 to 7 indicate the same or corresponding parts, (44) is the outer hook (18 ) shaft part (
An eccentric ring is attached to the lower end of the outer hook (18) via a set screw (45), and by loosening the set screw (45) and rotating it around the shaft (21), the tip part ( 20)
The eccentric direction can be adjusted with respect to the position. (46
) is an opener stand (32) that pivotally supports the opener stand (32) with respect to the mounting stand (16), and a shaft portion of the body (
47) is an arm whose end is attached to the lower end of this shaft (4B) via a set screw (48); (48) is this arm (4B);
7) with a step screw connecting the other end to the free end of the link (34) fitted to the eccentric ring (4B).
) is transmitted to the opener stand (32) via the link (34), arm (47), and shaft (46), and 32)
It is designed to oscillate.

According to FIGS. 8 to 10, by adjusting the position of the eccentric wheel (44), the timing of operation of the opener (22) can be freely selected according to the nature of the sewing thread and the nature of the sewing material, resulting in more beautiful seams. It will be done.

FIGS. 10 to 13 show still other embodiments of the opener drive mechanism, in which the same reference numerals as in FIGS. 1 to 10 indicate the same or corresponding parts. 18
), the eccentric bushing is inserted in such a way that the locking position can be rotated and adjusted.
(50) is a set screw for fixing the eccentric bushing (51) to the mounting base (18) after adjusting its position.
) is pivotally supported by an integral shaft portion (4B).

According to FIGS. 11 to 13, the eccentric bushing (51)
The locking groove (3B) of the inner hook (28) is
The engagement position of the stopper (37) and the inner hook (28)
Since the locking position of the opener (22) with respect to the overhang (38) can be freely selected, beautiful seams with good thread alignment can be obtained for many types of sewing threads and materials.

FIGS. 14 and 15 show other embodiments of the stopper. In the figures, the same reference numerals as in FIGS. 1 to 13 indicate the same or corresponding parts. In the case of this embodiment, The stopper (3) is engaged with the locking groove (3B) of the inner hook (28).
7) has a shape that generates an elastic function. In the case shown in FIG. 6, when the sewing thread passes through the locking groove (3B), the stopper (37) moves upward of the outer hook (18) due to the influence of the shape of the peripheral wall of the outer hook (18). Particularly when using a hard and thick sewing thread, an excessive load is applied to the stopper (37) or the opener stand (32) in an attempt to lift the stopper (37) upward. However, in the case of FIGS. 14 and 15, even if an excessive load is applied to the stopper (37), the stopper (37) bends due to its elasticity, so that the locking groove (36) and the stopper (37) ) may be disengaged from the
Alternatively, there is no risk of damage to the stopper (37) or the like.

FIGS. 16 and 17 show other embodiments of the inner hook rotation prevention mechanism, in which the same reference numerals as in FIGS. 1 to 15 indicate the same or corresponding parts (52).

(53) is a stopper groove provided at three locations on the outer periphery of the top flange (42) of the inner hammer (28), and (54) is a rotatably supported opener base (32) on the mounting base (16). The opener stand (32) is attached to the eccentric shaft (23) provided on the shaft (21) of the outer hook (18) or the shaft (21).
) The outer hook (18
) at a predetermined timing.

(55) and (5B) are stop plates that are attached to both ends of the open base (32) through set screws (57) so that the position can be adjusted to some extent, and each of the stopper grooves (52), (
Each stopper groove (52) has a bent shape that corresponds to the swinging force direction of the opener stand (32), and is designed to prevent the inner hook (28) from rotating by alternately engaging with the stopper groove (53). , (53) can be smoothly engaged and released.

That is, as shown in FIG. 16, the tip (20) of the outer hook (18) enters into the loop of sewing thread created around the needle hole of the needle (19), and the thread is transferred to the tip (20) of the outer hook (18). ), the sewing thread sequentially slides on the top flange (42) of the inner hook (28) as the outer hook (1B) rotates and enters the stopper groove (
53), the stop plate (56) is pulled out from the stopper groove (53) by the open base (32) that swings in conjunction with the outer hook (18), and the stop plate (55) The inner hook (28) is prevented from rotating by engaging with the stopper groove (52). Therefore, the sewing thread passes through the stopper groove (53) without any hindrance, and the upper flange (42) of the inner hook (28) can be moved as the outer hook (18) rotates.

On the other hand, (18) is further rotated by an external force, and the sewing thread passes through the stopper groove (52) as shown in FIG.
In the fourth stage, the stop plate (56) engages with the stopper groove (53) to prevent the inner hook (28) from rotating, and the stopper plate (55) is pulled out from the stopper groove (53). .

Thereby, the sewing thread can smoothly pass through the stopper groove (52).

[Effects of the Invention] As explained above, the present invention eliminates the locking groove conventionally provided on the back surface of the throat plate, provides a locking groove at one location on the outer periphery of the upper end of the inner hook, and also provides the above-mentioned locking groove on the opener. A stop and a pawl that can be engaged with the locking groove are provided, and the inner hook is normally prevented from rotating by engagement between the stopper and the locking groove, and when the second thread passes through the locking groove. Since the above-mentioned opener operates the inner hook to temporarily release the engagement between the locking groove and the stopper, the locking groove on the throat plate is not required, reducing costs, and the locking groove and stopper are removed. Since the stopper can be assembled outside the sewing machine, assembly is easy and assembly accuracy can be improved. Further, since a space can be provided at the engagement portion between the throat plate and the hook, there is an effect that the design of the automatic thread cutting device etc. can be carried out freely.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram showing one embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view along the line ■-■ in Fig. 1, Fig. 3 is a plan view of Fig. 2, and Fig. 4 is a 5 is a sectional view taken along the line v-v in FIG. 4, FIGS. 6 and 7 are explanatory diagrams showing the operation of the hook device, and FIG. 4 is a view corresponding to another embodiment, FIG. 9 is a view corresponding to FIG. 2, FIG. 10 is a view taken along the line X-X of FIG. 9, and FIG. FIG. 12 is a cross-sectional view taken along the ■-cut edge line in FIG. 11, FIG. 13 is a cross-sectional view taken along the single layer line in FIG. A sectional view of main parts showing other embodiments,
18 and 17 are views corresponding to FIGS. 6 and 7 showing other embodiments of the inner hook rotation prevention mechanism, and FIG. 18 is a view corresponding to FIG. 3 showing a conventional sewing machine hook device, and FIG. 18 is a sectional view taken along the line XIX-XIX in FIG. 18, and FIG. 20 is a perspective view showing a conventional throat plate. - In the figure, (2) is the bed, (3) is the main shaft, (5) is the needle bar, (11
) is the lower shaft, (16) is the mounting base, and (1B) is the outer hook. (19) is the needle, (2G) is the tip, (21)
is the shaft, (22) is the opener, (23) is the eccentric shaft, (28) is the inner hook, (29) is the bobbin,
(32) is the opener stand, (34) is the link, (3
6) is a locking groove, (37) is a stopper, (38) is an overhang, (42) is a top flange, and (43) is a contact surface. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 2 55, 56: ah-me East Figure 3 Figure 5 Figure 6 Figure 7 Figure 9 Figure 11 Figure 12 Figure 14 Figure 15 Figure 16

Claims (1)

[Claims] An outer hook is supported on the sewing machine so that it can rotate horizontally in synchronization with the needle bar that reciprocates up and down, and the outer hook is rotatably arranged within the outer hook and has a locking groove at one location on the outer periphery of the upper end. It is equipped with an inner hook, an opener that swings at a predetermined timing in accordance with the rotation of the outer hook to operate the inner hook, and a stopper that is attached to the opener and can be engaged with the locking groove. The engagement of the stopper with the locking groove prevents the inner hook from rotating, and when the sewing thread passes through the locking groove, the inner hook is actuated by the opener to connect the locking groove and the stopper. A hook device for a sewing machine, characterized in that the engagement of the hook is temporarily released.