JP2562097B2 - Sewing machine for tatami sewing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine for tatami stitching, and in particular, a sewn edge cloth is sewn to a side end portion of a simple tatami mat formed by sticking a tatami mat to a core plate made of synthetic resin foam or insulation board. The present invention relates to a sewing machine suitable for carrying out.

[0002]

2. Description of the Related Art In recent years, tatami mats have been used for temporary use at hotels, meeting rooms, auditoriums, etc., or laid to create a partial tatami space in a flooring-finished ocean. As a comparatively thin tatami mat, a tatami mat is attached to a core plate such as a synthetic resin foam or an insulation board.

Even in this type of simple tatami mat, an edge cloth (tatami edge) for covering the side edge of the tatami mat and the core plate is provided at a side end portion orthogonal to the tatami mat surface material. Is generally sewn to the upper surface of the tatami mat, and folded back at this portion and the other end is turned to the lower surface side of the core plate for adhesion, or is sewn again for fixation, and two steps of sewing and adhesion or Two sewing processes were required, and the manufacturing process was troublesome.

Therefore, the applicant has found that the thickness is 25 at most.
As a simple tatami mat of this kind having a size of mm, a thermoplastic resin foam mainly composed of an olefin resin is used as a core plate, and a tatami-mat table is substantially entirely adhered and attached to the surface thereof. The hem cloth that covers the side edges is turned from the tatami upper surface to the lower surface of the core plate, and both ends of the tatami upper surface side and the lower surface side are sewn to the core plate at the same time by sewing, simplifying the sewing work. It has been proposed to make it (Japanese Patent Application No. 4-11
6455).

In this case, since the sewing thread (seam) appears as it is for the sewing of the hem cloth, the sewing pitch as in the case of the hem cloth sewing in a general tatami mat, for example, a flat cloth for tatami sewing is used. Stab machine (eg Japanese Patent Publication No. 1-39796)
In the case of sewing with a relatively large sewing pitch due to, the seams are coarse and the appearance is unstructured. Therefore, the sewing pitch of the sewing of the edge cloth is at most 5
It is desirable to make the pitch as small as about mm.

By the way, generally, a sewing machine is provided with a crank mechanism for converting the rotation of a main shaft into the vertical movement of a sewing machine needle.
Each time the crank part makes one rotation, the sewing needle moves up and down once to perform the sewing operation once. Therefore, if the sewing pitch by sewing is reduced as described above, the number of stitches per unit length increases, and it takes time to sew the edge cloth.

Therefore, in order to increase the sewing efficiency of the hem cloth, the number of rotations of the main shaft may be increased to speed up the sewing operation of the sewing machine. However, the top dead center side and the bottom dead center in the vertical movement of the sewing machine needle may be increased. If there is not much difference in momentum and speed on the side, the sewing object is a simple tatami with a thickness of around 25 mm, and in terms of sewing machine operation, from the top surface of the sewing object to the sewing needle at the top dead center. Since it is not possible to set a large interval, the time during which the sewing machine needle is pulled out above the sewing object becomes short, and it is not possible to expect high speed due to the intermittent feed of the sewing object.

That is, the sewing object is set to be fed while the sewing machine needle is pulled out above the sewing object, especially while the sewing needle is held at a constant interval (usually 10 to 15 mm). However, as the vertical movement speed of the sewing machine needle becomes faster as described above, the time for holding the interval becomes shorter and the feeding becomes difficult.

It is to be noted that increasing the vertical movement stroke of the sewing machine needle and increasing the distance from the upper surface of the sewing object to the sewing machine needle at the top dead center increase the size of the sewing machine and increase the amount of useless movement. However, there is a problem in that excessive force is applied, which is not preferable.

Therefore, as a sewing machine used for sewing this kind of edge cloth, the vertical momentum on the top dead center side of the sewing machine needle is small and slow, and the vertical momentum on the bottom dead center side is large and fast. Is desirable.

The present invention has been made in view of the above, and when sewing the edge cloth to the tatami at a relatively small sewing pitch, the sewing machine can be sewn at high speed and efficiently. A sewing machine for tatami sewing is provided. Furthermore, the present invention provides a tatami sewing machine provided with an intermittent feeding means capable of reliably advancing a sewing object such as a tatami mat or a cloth having a relatively large plate shape without distortion or displacement.

[0012]

A sewing machine for tatami stitching according to the present invention is movably supported by a head portion of an arm having a main shaft which is rotated by a driving means, and a needle bar having a sewing needle attached to a lower end thereof. A motion converting and transmitting means for converting the rotation of the main shaft into a reciprocating motion and transmitting the reciprocating motion to the needle bar to move the needle bar up and down, and intermittently responding to the up and down motion of the needle bar such as tatami mat and hem cloth. A sewing machine provided with an intermittent feeding means for feeding the sewing object forward, and in order to solve the above-mentioned problems, in particular, the motion conversion transmitting means is provided on the top dead center side substantially half portion in the rotation of the main shaft. The vertical momentum of the needle bar in the angular range is
It is characterized in that it is set to be less than a fraction of the vertical momentum in the angular range of approximately half of the bottom dead center side.

For example, when the motion converting / transmitting means is a crank mechanism, is the axial distance of the crank rod connecting the crank bar provided at the end of the main shaft and the needle bar substantially the same as the eccentricity of the crank bar? Alternatively, by slightly increasing it, the vertical movement of the needle bar in the angular range of approximately the half part on the top dead center side in the rotation of the crank part can be adjusted to a few minutes of the vertical momentum of the needle bar in the angular range of the approximately half part at the bottom dead center side. Set to 1 or less.

A second aspect of the present invention is a sewing machine for tatami stitching similar to that described above, wherein, as an intermittent feeding means, a pair of upper and lower tatami mats and hem cloth are formed in a slightly backward direction of the sewing position by a sewing machine needle. Feeding means such as rollers capable of elastically sandwiching and rotating the sewing object from above and below are provided, and the upper and lower feeding means are connected to the main shaft through a transmission means including intermittent rotation means, It is characterized in that the sewing machine is provided so as to intermittently rotate in synchronization with each other in correspondence with the vertical movement, and is provided so as to intermittently advance the sewing object.

[0015]

When the hem cloth is sewn to the tatami by the sewing machine having the above structure, the hem cloth is rotated from the tatami front surface side to the back surface side at the side end portion orthogonal to the tatami mat surface material to cover the tatami mat and the side end portion of the core plate. And supply it. By rotationally driving the main shaft in this way, this rotation is transmitted to the needle bar via the motion converting and transmitting means such as a crank mechanism, and the needle bar, that is, the sewing machine needle attached to the lower end of the needle bar moves up and down. At the same time, the tatami mat and the cloth to be sewn are intermittently advanced by the intermittent feeding means in response to the vertical movement of the needle bar, and the cloth is sewn to the side end of the tatami at a constant sewing pitch. Sewn on.

In the motion conversion transmitting means, the vertical movement amount of the needle bar, that is, the sewing machine needle in the angular range of the approximately half portion on the top dead center side in the rotation of the main shaft, is the angular range of the approximately half portion at the bottom dead center side. It is set to be less than a fraction of the vertical momentum.

That is, although the movement time is the same in the angular range of the half-dead center side and the upper dead center side in the main shaft rotation, the lower part of the vertical motion of the sewing machine needle attached to the needle bar is the same. The momentum in the angular range of the approximately half of the dead center is large and fast, and the momentum in the angular range of the approximately half of the top dead center is very small and slow.

Therefore, although the sewing object is thick like a tatami mat, the sewing operation by sewing the sewing machine needle into the sewing object is fast, and the rotation of the main shaft is increased to perform the sewing operation. When the speed is increased, the interval and time required for feeding the sewing object can be sufficiently secured in the vicinity of the top dead center even if the vertical movement stroke is not so large.

Further, as intermittent feeding means, feeding means such as a pair of upper and lower rollers are arranged slightly behind the sewing position of the sewing machine in the feeding direction, and the sewing object is sandwiched by the upper and lower rotary feeding members. In this state, both the upper and lower feed means are synchronously driven to rotate so as to feed the sewing object forward in response to the vertical movement of the needle bar, thus forming a relatively large plate shape. Sewable objects such as tatami mats and bedding can be reliably fed forward without distortion or misalignment.

[0020]

An embodiment of the present invention will be described below with reference to the drawings.

1 to 5, (1) is a main body frame of a sewing machine, which includes a supporting leg portion (3) erected on a bed (2) and an arm (horizontal extending laterally from the supporting leg portion (3)). 4) and.

Inside the arm (4), a main shaft (5) of the sewing machine is supported by bearings and is supported horizontally, and the arm (4) extends outward from the end of the arm (4) on the supporting leg (3) side. The projecting shaft end portion (5a) is connected to a driving unit (not shown) such as a motor via a transmission unit (6) such as a belt or a chain so as to be rotationally driven. A handle (7) for manual operation is attached to the shaft end (5a).

As shown in FIGS. 3 and 4, the head portion (4a) of the arm (4) is equipped with a needle bar (10) extending in the vertical direction so as to vertically move through the upper and lower walls of the head portion. A sewing machine needle (11) is detachably attached to the lower end of the needle bar (10). The upper part of the needle bar (10) is loosely fitted in a guide tube (12) for vertical movement attached to the upper wall of the head part. (13) is a stopper that regulates the downward movement of the needle bar beyond a certain level.

The needle bar (10) is connected to the main shaft (5) through a crank mechanism (15) which is a motion converting and transmitting means, and is adapted to perform a vertical movement by the rotation of the main shaft (5). There is.

That is, the head portion (4) of the spindle (5) is
a) A disk-shaped crank portion (16) is provided at the end portion that protrudes into the inside.
Is provided so as to rotate together with the main shaft (5), and a crank pin (17) is attached to the crank portion (15) at a position eccentric from the main shaft (5). The crank rod (18), which is a connecting member, is rotatable at one end thereof to the crank pin (17) and at the other end thereof to a connecting pin (19) fixedly installed at an arbitrary position of the needle bar (10). When the main shaft (5) rotates, the crank action of the main shaft (5) causes the crank rod (18) to move the needle bar (1).
0) moves up and down.

The crank portion (16) may have an arm shape extending in one direction in addition to the disk shape shown in the drawing.

Particularly, in the crank mechanism (15) which is the motion conversion transmission means, the crank rod (1
The distance (L) between the shafts 8) is the amount of eccentricity of the crank part (16), that is, from the shaft center of the main shaft (5) to the crank pin (1
The amount of eccentricity (K) up to the shaft center of 7) is set to be substantially the same as or slightly larger than the eccentric amount (K). The vertical momentum of the needle bar (10) in the angle range of (degrees) is less than a fraction of the vertical momentum of the needle bar (10) in the angle range of the bottom dead center side (180 degrees), preferably 1 /
It is set to be 5 or less.

That is, as shown in FIGS. 5A to 5D, the crank portion (16) is rotated by the rotation of the main shaft (5).
When the crank rotates at a constant speed, the crank pin (17) and the crank rod (18) in the eccentric position are caused by the crank action.
The needle bar (10) moves up and down via.

At this time, when the axial distance (L) of the crank rod is set to be about the eccentric amount (K) of the crank portion (16) or slightly larger, the bottom dead center side is substantially set. The movement time is the same in the angle range of the half part and the angle range of the substantially half part on the top dead center side, but the lower part in the vertical movement of the needle bar (10), that is, the sewing machine needle (11) attached to the needle bar (10). The momentum in the angular range of the approximately half of the dead center is large and fast, and the momentum in the angular range of the approximately half of the top dead center is very small and slow.

For example, when the total thickness of the tatami (T) and the edge cloth (F) to be sewn is about 20 mm, when the sewing machine needle (11) is at the top dead center, the space between 15m
Since it is necessary to secure an interval of about m, normally, the eccentric amount (K) of the crank portion (16) is set to 20 mm,
The vertical stroke of the sewing machine needle (11) is set to 40 mm, and in this case, the vertical movement amount of the sewing machine needle (11) in the angular range of the top dead center side is approximately half the bottom dead center side. Make sure that the vertical movement of the needle is about 5 mm,
The axial distance (L) of the crank rod (18) is 21 m.
Set to about a little less than m.

By doing so, even when the rotation of the main shaft (5) is increased to speed up the sewing machine operation, the momentum of the sewing machine needle (11) is small in the angular range of the substantially half portion on the top dead center side, and Because of the delay, the sewing target (T) can be fed without any trouble.

As the motion conversion transmission means for converting the rotation of the main shaft (5) into the vertical movement of the needle bar (10), other conversion transmission means such as a cam mechanism can be used.
Also in this case, it is possible to set the vertical momentum of the needle bar (10) in the same manner as described above. In practice, it is preferable to use the illustrated crank mechanism.

Reference numeral (20) is a presser bar that penetrates through the upper and lower walls of the head portion (4a) and is vertically movable in parallel with the needle bar (10). A forked pressing piece (21) for pressing F) is connected. A cylinder device (22) such as an air cylinder is connected to the upper end of the presser bar (20), and when the sewing machine is in operation, the cylinder device (22) operates to lower the brim (F) to the tatami (T). It is provided so as to press. As a means for moving the presser bar (20) up and down to perform a pressing action, it is possible to use other spring means or the like.

Reference numeral (23) is a balance for feeding and tightening the upper thread, and the crank portion (16) is similar to the conventional one.
When the needle bar (10) is rotated, the needle bar (10) swings vertically. Reference numeral (24) is a cover plate of the head portion (4a), which is detachably provided.

In FIG. 2, reference numeral (25) is a transmission shaft arranged in the supporting leg portion (3) of the main body frame (1) and extending in the vertical direction, and the upper end portion thereof is formed by bevel gears (26) (27). The lower end is connected to the main shaft (5) and has a bevel gear (28).
(29) is connected to the shuttle drive shaft (30) arranged on the lower side of the bed (2), and is provided so as to transmit the rotation of the main shaft (5) to the shuttle drive shaft (30).

At the end of the shuttle drive shaft (30), a shuttle (31) for holding a bobbin case for the lower thread and having thread catching means is attached as shown in FIG. The lower thread is held, adjusted, and supplied by performing a rotary motion corresponding to the vertical movement, and the upper thread guided by the sewing machine needle (11) is captured and crossed with the lower thread.
Since its structure is similar to that of the conventional sewing machine, its detailed description is omitted. In addition to the lock stitch using the upper thread and the lower thread, in the case of chain stitch using only the upper thread, thread hooking means for locking the upper thread is provided instead of the hook.

Further, the intermittent feeding means for intermittently advancing the sewing object such as tatami mat and edge cloth corresponding to the vertical movement of the needle bar (10) has the following construction.

As shown in FIGS. 6 and 7, the sewing machine needle (1
1) A pair of upper and lower pairs are provided as rotary feed means for elastically sandwiching and rotating the tatami (T) and the edge cloth (F), which are the objects to be sewn, in the slightly forward direction of the sewing position. Two sets of large and small eggplant rolls (40a) (40b), (50
a) (50b) are arranged at a slight distance in the front-rear direction.

The above two sets of upper and lower rollers (40a) (4)
0b), (50a), (50b), the lower roller (40b) (50b) is such that a part of the outer peripheral surface of the lower roller (40b) (50b) is slightly exposed to the feed movement surface of the sewing object. 2)
It is attached to and supported by the rotating shafts (41) and (51) which are rotatably supported on the lower side. The upper roller (40
a) (50a), the shaft portions (42) (52) are rotatably supported by the support arms (43) (53) on the left and right sides, and the support arms (43) (53) are respectively The frame (33) extending rearward from the arm (4) of the main body frame (1) is pin-connected to a support plate (34), and is supported by the pin connection parts (44) and (54) so as to be vertically movable. ing.

Cylinder devices (45) (55) such as air cylinders are connected to the support arms (43) (53). The cylinder devices (45) (55)
The upper rollers (40a) (50a) move up and down together with the support arms (43) (53). By lowering the upper rollers (40a) (50a), the sewing object is moved to the lower rollers (40b) (50).
It can be clamped between b). This clamping pressure can be arbitrarily set by adjusting the pressure of the cylinder devices (45) (55).

Further, the two sets of rollers (40a) (4)
0b), (50a) and (50b) are provided so as to be rotationally driven intermittently in synchronization with the vertical movement of the needle bar (10) to perform intermittent feeding.

In the case of this embodiment, as shown in FIGS. 7 to 11, the shaft portions (42) and (52) of the upper rollers (40a) and (50a) are respectively provided with two universal joint portions (46). ) (56) drive transmission shaft (47) (57)
The drive transmission shaft (47) on the side of the larger roller (40a) is connected to the main shaft (5) via the transmission means including the intermittent rotation means (60).

As the intermittent rotation means (60), as shown in FIG. 11, for example, a main shaft (5) is provided in a box (61).
A pin wheel (63) connected to the shaft end (5a) of the shaft by a belt (62), chain, or other means, and a grooved wheel (66) having a notch groove (65) at equal intervals in the circumferential direction and having a gear shape. And are provided. The pin wheel (63) and the grooved wheel (66) face each other at an eccentric position, and the pin (64) of the pinned wheel (63) comes into the notch groove (65) of the grooved wheel (66) due to the rotation thereof. It is provided so that the grooved wheel (66) is fitted and rotated by a required angle, and the rotation of the grooved wheel (66) is stopped when the pin (64) separates from the notch groove (65). The rotation of the pin wheel (63) is intermittently transmitted to the groove wheel (66).

Further, in the case of this figure, 1 of the pin wheel (63) is used.
Two pins (64) provided at 80 degrees opposite position,
Set to alternately insert into the notch groove (65) of the groove wheel (66) and repeat the rotation transmission and non-transmission state with respect to the groove wheel (66) every 90 degrees in one rotation of the pin wheel (63). (Fig. 12). Therefore, the spindle (5) is 1
The pin wheel (63) is set to rotate 180 degrees during the rotation so as to transmit the rotation once to the groove wheel (66).

The box (6) of the grooved wheel (66) is
A pinion (67) is provided on the shaft end protruding from 1), and the pinion (67) is connected to the drive transmission shaft (4).
7) meshes with the upper gear (48a),
The drive transmission shaft (47) is rotated according to the intermittent rotation of (6), and the roller (40a) connected thereto is provided so as to be rotated intermittently.

Further, the drive transmission shaft (47) is provided with another gear (49a), and this gear (49a) is provided with an upper small roller (50) through an intermediate gear (36).
It is meshed with a gear (58) on the drive transmission shaft (57) of (a) and is provided so as to rotate in the same direction at the same time as the rotation of the roller (40a).

Further, the gears (48a) (49a) provided on the drive transmission shaft (47) are respectively provided on the lower roller (4).
0b) has a rotation shaft (41) having gears (48b) (49).
b) meshes with the lower roller (40
b) is provided so as to rotate in synchronization with the upper roller (40a).

The drive transmission shaft (5) of the roller (50a)
7) is provided with a gear (59a) different from the gear (58), and the gear (59a) is provided on the lower side of the bed (2) on the rotary shaft (51). And the rollers (50a) that are paired up and down.
(50b) is provided so as to rotate synchronously (FIG. 7).

The above-mentioned two sets of large and small rollers (40a)
(40b), (50a) and (50b) have their diameters and the above-mentioned transmission gears (4) so that their peripheral speeds match.
8a) (49a) (48b) (49b) (58) (59
a) The number of teeth of (59b) and the like are determined. Before and after 2
It is also possible to keep the roller diameters of the group the same.

(37) is the drive transmission shaft (47) (5)
7) is a support member that rotatably supports. (38) is a guide plate for positioning the side end portion of the tatami (T) which is the sewing object. The support portion of the bobbin for the upper thread is provided on the upper portion of the body frame (1) or the like.

When the edge cloth (F) is sewn to the side end of the tatami (T) with the sewing machine having the above-mentioned construction, the edge of the edge side of the edge cloth (F) is folded inward and the core paper is inserted if necessary. With the
The tatami mat is supplied by coating it from the top side to the back side so as to rotate it. At this time, it is preferable to temporarily fix the sewing start end of the hem cloth (F) and other necessary parts to the tatami (T) by an adhesive means or the like.

In order to feed and feed a relatively large and thick plate-shaped tatami (T) to the sewing position without bending or distortion, for example, as shown in FIG. A table (70) for sliding tatami mats having a guide (71) with which the ends abut is provided.

A pressing means (72) such as a cylinder is provided on the side of the table (70) facing the guide (71), and the side end of the tatami (T) is in contact with the guide (71). It can be supplied.

Then, the tatami (T) having the side edges covered with the edge cloth (F) is placed on the table (70), and the sewing start end is set at the sewing position by the sewing needle (11). The main shaft (5) of the sewing machine is driven to rotate, and the crank mechanism (1
While the needle bar (10) is moved up and down via 5), the tatami is forward-fed and the edge cloth (F) is sewn to the tatami (T). The upper and lower rollers constituting the intermittent feeding means described above. (40a)
Since (40b), (50a) and (50b) are provided slightly behind the sewing position, the tatami (T) is sewn by the pushing means (73) such as a cylinder until the tatami reaches that position. Corresponding to, it pushes intermittently and feeds.

The tip of the tatami (T) is the roller (50a).
When the portion (50b) is reached, the upper roller (50a)
The roller (40a) (40a) (40a).
When the position of b) is reached, the upper roller (40a) is lowered and sandwiched between the lower roller (40b) and the two rollers (40a) (40b) (50a) (50).
The intermittent rotation of b) corresponds to the vertical movement of the needle bar (10), and the sewing machine needle (11) is fed by a predetermined size while the sewing machine needle (11) is being pulled out above the sewing object.

In this way, the rotation of the main shaft causes the needle bar (10), that is, the sewing needle (11) provided at the lower end of the needle bar to move up and down, and at the same time,
As mentioned above, the tatami (T) and the edge cloth (F) which are the sewing objects.
However, as described above, the rollers (40a) (40b) (50
a) (50b), and the needle bar (1
0) Upward and downward movement is ensured intermittently without distortion, and the edge cloth (F) has a constant stitching pitch on the side end of the tatami (T), and the end and the back of the tatami surface side. The side end is sewn at the same time (FIG. 14).

Particularly, as described above, the sewing machine needle (11)
Even when the rotation of the main shaft is increased to speed up the sewing operation of the sewing machine by reducing the momentum on the top dead center side in the vertical motion of the sewing machine, the sewing target is required to be fed near the top dead center. Since the interval and time can be secured, the sewing pitch can be reduced and the number of rotations can be increased to increase the speed without increasing the vertical movement stroke of the sewing machine needle.

In the above-described embodiment, as the rotary feeding means for intermittent feeding, a pair of upper and lower pairs of rollers, large and small, are arranged at the front and the back. By providing it, it is also possible to provide a set of upper and lower rollers and carry out intermittent feeding similarly to the above. Further, instead of the two pairs of front and rear rollers, an endlessly rotating belt may be arranged vertically so that the sewing object can be clamped. In either case, the feed pitch is set so as to perform intermittent feed according to the sewing pitch of the sewing needle.

[0059]

As described above, according to the sewing machine of the present invention, the vertical momentum of the needle bar in the angular range of the approximately half-dead-center side in the rotation of the main shaft is determined by the angular range of the approximately half-dead-center-side. By setting it to be less than a fraction of the vertical momentum in, the sewing of the edge cloth on a relatively large plate-shaped tatami having a total thickness of 25 mm can be performed by increasing the rotation of the main shaft. Even if the sewing operation is speeded up and the vertical movement stroke of the sewing needle is not so large, the interval and time required for feeding the tatami can be sufficiently secured, and the sewing operation can be performed without any inconvenience.

Therefore, the sewing pitch can be made small, the speed and efficiency of the sewing can be increased, and the sewing machine does not become large.

Further, as in claim 2 of the present invention, as the intermittent feeding means, the sewing object is sandwiched by the rotary feeding members such as a pair of upper and lower rollers, and both the upper and lower rotary feeding members are synchronized. When driven to rotate, a sewing object such as a relatively large plate-shaped tatami or edge cloth can be reliably fed forward without distortion or displacement.

Therefore, according to the present invention, the edge cloth in the simple tatami mat can be sewn at a small stitching pitch and at the same time the end portion on the tatami surface side and the end portion on the back surface side, and the sewing efficiency is remarkably improved. You can

[Brief description of drawings]

FIG. 1 is a front view showing the entire sewing machine arm.

FIG. 2 is a vertical sectional view of a main part of the present invention.

FIG. 3 is an enlarged sectional view of a head portion of an arm.

FIG. 4 is a front view with the lid plate above being omitted.

FIG. 5 is an explanatory diagram of a motion state of a needle bar by a crank mechanism.

FIG. 6 is a side view of a portion of intermittent feeding means.

FIG. 7 is an enlarged perspective view showing the interlocking structure of the power transmission portions of the rollers that constitute the intermittent feeding means, with the bed omitted.

FIG. 8 is a plan view showing an associative structure of a transmission portion of an upper roller.

FIG. 9 is a plan view showing an associative structure of a transmission portion of a lower roller.

FIG. 10 is a front view showing an associative structure of upper and lower rollers on the rear side.

FIG. 11 is an enlarged cross-sectional view of a portion of intermittent rotation transmission means.

FIG. 12 is an explanatory diagram of a linked state between the pin wheel and the grooved wheel of the above.

FIG. 13 is a schematic plan view showing a tatami mat supply state to the sewing machine.

FIG. 14 is a partially enlarged perspective view showing a hem sewing state.

[Explanation of symbols]

 (1) Body frame (2) Bed (3) Support leg (4) Arm (4a) Head (5) Spindle (10) Needle bar (11) Sewing needle (15) Crank mechanism (16) Crank (17) Crank pin (18) Crank rod (19) Connecting pin (20) Presser bar (30) Hook drive shaft (31) Hook (40a) (40b) Roller (50a) (50b) Roller (41) (51) Rotating shaft ( 43) (53) Support arm (44) (54) Pin connection part (45) (55) Cylinder device (47) (57) Drive transmission shaft (60) Intermittent rotation means (63) Pin wheel (66) Groove wheel ( 70) Table (71) Guide (72) Pressing means (73) Pushing means

Claims (2)

(57) [Claims] 1. A needle bar, which is vertically movably supported by a head portion of an arm having a main shaft which is rotated by an appropriate drive means, and a rotation of the main shaft is converted into a reciprocating motion by converting a rotation of the main shaft into a reciprocating motion. A motion conversion transmitting means for transmitting to the needle bar to move the needle bar up and down, and an intermittent feeding means for intermittently advancing the tatami and the tatami edge of the sewing object in correspondence with the vertical movement of the needle bar. In the sewing machine, the vertical movement amount of the needle bar in the angular range of the approximately half-dead-center side in the rotation of the main shaft is the vertical movement amount in the angular range of the approximately half-dead-center side. A sewing machine for tatami stitching, characterized in that the sewing machine is set to be a fraction or less of the above. 2. A needle bar movably supported up and down by a head portion of an arm having a main shaft which is rotated by a suitable drive means, and a rotation of the main shaft is converted into a reciprocating motion by converting the rotation of the main shaft into a reciprocating motion. A motion conversion transmitting means for transmitting to the needle bar to move the needle bar up and down, and an intermittent feeding means for intermittently advancing the tatami and the tatami edge of the sewing object in correspondence with the vertical movement of the needle bar. As the intermittent feed means, a feed means such as a roller that forms a pair in the upper and lower direction and that can rotate by pinching the sewing object from above and below is provided in the feeding direction slightly backward of the sewing position by the sewing machine needle. The upper and lower feed means are connected to the main shaft via a transmission means including an intermittent rotation means so as to rotate intermittently in response to the vertical movement of the needle bar, and the sewing object is intermittently moved forward. Tatami edge sewing characterized by being provided for feeding Shin.