JP3450883B2 - Sewing machine with multiple feed dogs - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of feed teeth which are adjacent to each other in a cloth feed direction, and to a set sewing condition such as a plurality of kinds of feed amount and a differential ratio. The present invention relates to a sewing machine with a plurality of feed dogs for differentially feeding a cloth. 2. Description of the Related Art Conventionally, as a sewing machine of this type, a sewing machine described in Japanese Patent Publication No. 63-57077 has been proposed. In this sewing machine, as shown in FIG. 10, a drive shaft 400 that rotates in accordance with the vertical movement of the sewing needle is provided.
Eccentric wheels 402 and 404 were fixed to the drive shaft 400. One ends of the connecting rods 406 and 408 are rotatably supported by eccentric wheels 402 and 404, respectively.
The other ends of the connecting rods 406 and 408 are respectively connected to the link mechanism 41.
0, 412 so as to be rotatable. The link mechanisms 410 and 412 are configured to swing the feed dog tables 418 and 420 to which the feed dogs 414 and 416 are fixed up and down and up and down. Therefore, when the drive shaft 400 rotates, the power is transmitted by the connecting rods 406 and 408 to the link mechanism 41.
0, 412 so that the link mechanisms 410, 412 actuate the feed dogs 414, 416. The link mechanisms 410 and 412 are
By changing the swing position, the feed dog 41
4, 416 was configured to change the feed amount.
In order to change the swing position of the link mechanisms 410 and 412, the adjusting arms 422 and 424
28 to the link mechanisms 410 and 412. The adjusting arms 422 and 424 are connected to the motors 430 and 43
It is configured to rotate around adjustment shafts 434 and 436 rotated by 2. Therefore, the motors 430, 43
2, the feed amount is adjusted according to the sewing conditions. These motors 430 and 432 are configured to rotate based on the feed amounts of the feed dogs 414 and 416 that are separately input. Then, a plurality of feed dogs 414,
The sewing machine mechanically connecting the 416 receives the feed movement itself from the drive shaft 400, so that the sewing machine shown in FIGS.
As shown in FIG. 7, even if the sewing conditions such as the feed amount and the differential ratio of the feed dogs 414 and 416 are changed, the two feed teeth 414 and
No. 16 was designed to always start sending fabric from the same position. That is, the distances f7 to f9 are equal and the distance k7
To k9, the feeding of the fabric was started. Further, the trajectories of the two feed dogs 414 and 416 are configured to be independently changed. However, as shown in FIGS. 7 to 9, when the cloth is fed once,
Two feed teeth 414, 416 adjacent in the cloth feed direction
Gaps p7, p8, and p9 become narrower depending on sewing conditions such as the feed amount of the feed dogs 414 and 416 and the differential ratio,
Or, it was widened or large unevenness was generated in the gap. In particular, when the gap is widened or when the cloth is sewn (see FIGS. 7 and 9), the sewn cloth falls into the gap between the two feed dogs 414 and 416. There is a problem that the fabric becomes unstable. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object the purpose of irrespective of sewing conditions such as the feed amount and differential ratio of a plurality of feed dogs adjacent in the cloth feed direction. Another object of the present invention is to provide a sewing machine with a plurality of feed dogs that can stably perform sewing. In order to achieve this object, a sewing machine with a plurality of feed dogs according to the present invention is provided for each of a plurality of feed dogs, and these feed dogs are separately arranged in a horizontal direction. a plurality of pulse motor for driving the, Ya feed amount set
Start position of feed dog based on sewing conditions such as differential ratio
Is calculated, and the calculated feed start position and the
When the two feed dogs adjacent to each other in the cloth feeding direction are closest to each other based on the sewing conditions,
Regardless of the sewing conditions such as the feed amount of each feed dog and the differential ratio,
Control means for controlling the pulse motor so as to be equal to each other. In the sewing machine with a plurality of feed dogs of the present invention having the above configuration, a plurality of pulse motors are provided corresponding to each of the plurality of feed dogs, and these feed teeth are separately provided in the horizontal direction. Drive. The control unit sets the feed dog start position
Is calculated, and the calculated feed start position and the
The gap when two adjacent feed dogs in the cloth feed direction are closest to each other based on the sewing conditions is determined by the sewing conditions such as the feed amount and the differential ratio of the two feed dogs adjacent in the cloth feed direction. Not equal
Kunar so on, automatically controls the pulse motor. An embodiment of the present invention will be described below with reference to the drawings. A drive shaft 3 extending in the horizontal direction perpendicular to the cloth feeding direction A is fixed to the axial direction and rotatably installed in the sewing machine frame 1. A feed height cam 5 is mounted on the drive shaft 3 with a screw 7 and a main feed base 39 described later is connected to a sewing needle B.
It is configured to regulate in the height direction almost in synchronism with the ascending / descending. The main frame 1 has a main feed pulse motor 9 and a differential feed pulse motor 11 having motor shafts 9a and 11a extending in the same direction as the drive shaft 3.
They are attached by screws 13 and 14, respectively. At the ends of the motor shafts 9a, 11a of the main feed pulse motor 9 and the differential feed pulse motor 11, a main feed pulley 15 and a differential feed pulley 17 are respectively provided with screws 19,
21 attached. The pulse motors 9 and 11 are configured to rotate by an angle corresponding to the feed amount each time one stitch is formed. further,
Shafts 23 and 25 extending in the same direction as the drive shaft 3 are fixed to the sewing machine frame 1 by screws 27 and 29. The rotation ranges of the pulse motors 9 and 11 can be freely set. A main feed swing arm 31 is rotatably mounted on the shaft 23 by a retaining ring 33 and a set collar 34 so as to be axially immovable. One end of the main feed swing arm 31 is provided with a fan-shaped gear 31a which engages with the main feed pulley 15 described above. A shaft 35 extending in the same direction as the drive shaft 3 is attached by a screw 37 to the upper end of the arm 31b at the other end with the shaft 23 interposed therebetween. A main feed base 39 is rotatably mounted on the shaft 35 and is immovable in the axial direction by a retaining ring 40. The main feed dog 39 has a main feed dog 41 with a screw 4
3 attached. Further, the main feed bar 39
The guide hole 39a extends in the direction of the main feed dog 41 and guides a differential feed table 55 described later, a screw hole 39b at a position where the feed height cam 5 is engaged, and a screw hole on the lower surface. 3
9c and a groove 39d to be engaged with a rotation stopper 58 described later are formed. A height adjusting screw 45 is screwed into the screw hole 39b.
Is configured to prevent loosening. Then, a leaf spring 49 is attached by a screw 50 screwed into the screw hole 39c, and the height adjusting screw 45 is pressed against the feed height cam 5. Height adjustment screw 4
By taking 5 in and out of the main feed stand 39,
The main feed dog 41 is configured to adjust its height. Further, a main feed play stopper 52 is provided on the sewing machine frame 1 by a screw 54 so as to prevent play of the main feed stand 39. Further, the differential feed swing arm 51 is connected to the shaft 25
, And is mounted so as to be immovable in the axial direction by a retaining ring 53. At one end of the differential feed swing arm 51, a fan-shaped gear 51a is provided which is engaged with the differential feed pulley 17 and has a fan shape. A groove 51b having a constant width is provided in the other arm across the shaft 25. The ratio of the pitch circle radius of the gear 51a to the length from the shaft 25 to the groove 51b is:
The ratio between the pitch circle radius of the gear 31a of the main feed swing arm 31 and the length from the shaft 23 to the shaft 35 is substantially the same. A differential feed base 55 is engaged with the guide hole 39a of the main feed base 39. A rotation stopper 58 is attached to the differential feed base 55 with a screw 60,
The differential feed base 55 is engaged with the groove 39d of the main feed base 39.
Is configured to prevent rotation. A differential feed dog 57 is attached to the differential feed base 55 with a screw 59 so that the height of the differential feed tooth 57 is constant with that of the main feed dog 41. Further, a shaft 61 is mounted by a screw 63 at a position where the shaft 61 engages with the groove 51 b of the differential feed swing arm 51. A roller 65 is rotatably mounted on the shaft 61 and is immovable in the axial direction by a retaining ring 67. Roller 65
Is engaged with the groove 51b. As described above, the mechanism for adjusting the feed amount is shared with the motor control mechanism. Further, a pulse motor 9,
The power transmission paths from 11 to the feed dogs 41 and 57 are independent of each other. An operation panel 71 is provided on the front of the sewing machine C.
A control device 73 is provided for controlling a signal instructed therefrom and transmitting the signal to each of the pulse motors 9 and 11. Further, the operation panel section 71 is provided with buttons 74 and 75 for setting the main feed amount and the differential ratio, and displays 77 and 79 for displaying the set amounts. This control device 73
Is configured to output a signal to each of the pulse motors 9 and 11 each time one stitch is formed. Shutters 81 and 83 are attached to the main feed pulley 15 and the differential feed pulley 17 by screws 85 and 87, and a detecting device 8 for detecting their positions.
9 and 91 are attached to the sewing machine frame 1 by screws (not shown). In order to prevent the main feed dog 41 and the differential feed dog 57 from colliding with the needle plate 93, stoppers 95 and 97 are provided on the sewing machine frame 1, and the gears 31a of the swing arms 31 and 51 are provided. 51a. The control device 73 includes pulse motors 9 and 1
1 is arbitrarily controlled. Further, the control device 73 determines, based on the set feed amount and the differential ratio,
The feed start positions of the feed dogs 41 and 57 are calculated, and the pulse motors 9 and 11 are controlled based on the calculation results. Therefore, the control device 73 sets the sub feed dog 5 based on the feed amount of the main feed dog 41 and the set differential ratio.
7 is controlled. Further, the control device 73 is configured to automatically calculate the feed amount of the sub-feed dog 57 based on the feed amount of the main feed dog 41 and the set differential ratio. In the storage device incorporated in the control device 73, the closest distances k3, p4,
A storage area for storing p5, the closest approach distances n3 to n5 with the needle plate 93, and a control calculation program is provided. Next, the operation of the sewing machine C having the above configuration will be described. The operator adjusts and sets the scale of the main feed display 77 of the operation panel 71 to a desired stitch length with the button 74. Next, the operator adjusts the ratio (differential ratio) of the differential feed amount to the main feed amount according to the sewing conditions, and sets the differential ratio display body 79.
Is adjusted and set with the button 75. The controller 73 calculates the optimum swing position, swing timing, swing angle, etc. per stitch of the pulse motors 9 and 11 required for main feed and differential feed from the set signals. Then, the signals are transmitted to the respective pulse motors 9 and 11. Each of the pulse motors 9 and 11 has a
The normal rotation and the reverse rotation are repeated in conjunction with the up and down of 9. Then, the main feed swing arm 31 swings by transmitting the rotation of the pulse motor 9 with the shaft 23 as a fulcrum. The main feed dog 41 is the main feed base 39
Rocks back and forth through Further, it is vertically swung by the feed height cam 5. Further, the differential feed dog 57 also swings back and forth and up and down in the same manner. Next, the locus of the feed dogs 41 and 57 will be described. First, the feed amount m3 of the main feed dog 41 (= m
The case where the ratio (differential ratio) of the feed amount d3 (= d7) of the differential feed dog 57 to 7) is smaller than 1 (d3 / m3 <1) will be described with reference to FIG. At the time of starting the feeding of the fabric, the main feed dog 41 and the differential feed dog 57 come closest to each other. At the beginning of feeding the fabric, the main feed dog 41 is located at a distance f3 (= n3 + m3) from the needle plate end 93a, and the differential feed dog 57 is located at a distance k3 from the main feed dog 41. When the pulse motors 9 and 11 rotate, the main feed dog 41 moves by the feed amount m3 and the differential feed dog 57 moves by the feed amount d3 in the cloth feed direction A. As a result, at the end of the feed of the fabric, the main feed dog 4
1 is located at a distance n3 from the needle plate end 93a, and the differential feed dog 57 is at a distance p3 (= k
3 + d3-m3) located at a distance. Next, the feed amount m4 of the main feed dog 41 (= m
The case where the ratio (differential ratio) of the feed amount d4 (= d8) of the differential feed dog 57 to 8) is larger than 1 (d4 / m4> 1) will be described with reference to FIG. At the end of the feed, the main feed dog 41 and the differential feed dog 57 come closest to each other. At the start of feeding, the main feed dog 41 is positioned at a distance f4 (= n4 + m4) from the needle plate end 93a, and the differential feed dog 57 is moved at a distance k4 from the main feed dog 41.
(= D4-m4-p4). When the pulse motors 9 and 11 rotate, the main feed dog 41 moves by the feed amount m4 and the differential feed dog 57 moves by the feed amount d4 in the cloth feed direction A. As a result, at the end of sending,
The main feed dog 41 is located at a distance n4 from the needle plate end 93a, and the differential feed dog 57 is positioned at a distance p4 from the main feed dog 41.
Located away. Next, the feed amount m5 of the main feed dog 41 (= m
The case where the ratio (differential ratio) of the feed amount d5 (= d9) of the differential feed dog 57 to 9) is larger than 1 (d5 / m5> 1) will be described with reference to FIG. At the end of the feed, the main feed dog 41 and the differential feed dog 57 come closest to each other.
The feed amounts d5 and m5 are smaller than the feed amounts d4 and m4. At the start of feeding, the main feed dog 41 is located at a distance f5 (= n5 + m5) from the needle plate end 93a, and the differential feed dog 57 is positioned at a distance k5 from the main feed dog 41.
(= D5-m5-p5). When the pulse motors 9 and 11 rotate, the main feed dog 41 moves by the feed amount m5, and the differential feed dog 57 moves by the feed amount d5 in the cloth feed direction A. As a result, at the end of sending,
The main feed dog 41 is located at a distance n5 from the needle plate end 93a, and the differential feed dog 57 is positioned at a distance p5 from the main feed dog 41.
Located away. Regardless of the sewing conditions such as the feed amount of the feed dogs 41 and 57 and the differential ratio, k3, p4, p5 and n3
To n5 are almost equal, and are small gaps that do not allow the fabric to fall. In this embodiment, when the interval between the needle plate end 93a and the main feed dog 41 is at the end of sewing, the distance n3
(Or n4, n5), so that the fabric is prevented from dropping between the needle plate 93 and the main feed dog 41 to cause the resistance of the fabric feed. Therefore,
Even when sewing with the fabric slackened, the fabric can be sent smoothly. In this embodiment, the feed amount can be adjusted by the rotation of the pulse motors 9 and 11, and the mechanism for adjusting the feed amount is shared with the motor control mechanism. The mechanical elements between and the feed dogs 41, 57 have been largely omitted. Accordingly, the configuration is simplified, and downsizing of the sewing machine C can be promoted. Further, in the sewing machine C of the present embodiment, the rotation range of the pulse motors 9 and 11 can be set freely, and the swing range of the feed dogs 41 and 57 can be set freely.
As shown in the figure, the swing range of the feed dog 41 is set to the needle plate end 93a.
In addition, if the swing range of the feed dog 57 is maximized starting from the vicinity of the needle plate end 93b, the differential ratio (d6 / m6) of 2 or more, which was impossible with the conventional sewing machine, is obtained.
Can occur. In addition, in the conventional sewing machine, since the feed dogs 414 and 416 are mechanically connected, the swing range of the conventional feed dogs 414 and 416 is limited. The present invention is not limited to the embodiment described in detail above, and various changes can be made without departing from the gist of the present invention. In this embodiment, the description has been given of a sewing machine having two feeders, that is, a main feed and a differential feed. However, the same applies to a case where a plurality of feeders are provided. The swing of the pulse motors 9 and 11 is controlled by the swing arm 3.
It is transmitted to each feed base 39, 55 via 1, 51,
Gears are provided on the feed stands 39 and 55, and pulse motors 9 and 11 are provided.
May be directly transmitted to the feed stands 39 and 55. As is apparent from the above description, according to the sewing machine with a plurality of feed dogs of the present invention, the gap when two adjacent feed dogs are closest in the cloth feed direction is reduced. ,
Since the pulse motor is automatically controlled by the control device so as to be equal regardless of the sewing conditions such as the feed amount and the differential ratio, the fabric can be fed stably and sewing can be performed satisfactorily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view showing a sewing machine according to an embodiment of the present invention. FIG. 2 is a sectional side view of the sewing machine. FIG. 3 is a view showing the movement of the feed dog when the differential ratio is smaller than 1 in the sewing machine. FIG. 4 is a diagram showing the movement of the feed dog when the differential ratio is greater than 1 in the sewing machine. FIG. 5 is a diagram illustrating a differential ratio of the sewing machine according to the first embodiment;
It is a figure showing movement of a feed dog when a feed amount of a feed dog is small. FIG. 6 is a view showing the movement of the feed dog when the differential ratio is larger than 2 in the sewing machine. FIG. 7 is a view showing the movement of the feed dog when the differential ratio is smaller than 1 in the conventional sewing machine. FIG. 8 is a diagram showing the movement of the feed dog when the differential ratio is greater than 1 in a conventional sewing machine. FIG. 9 is a view showing the movement of the feed dog when the differential ratio is larger than 1 and the feed amount of the feed dog is small in the conventional sewing machine. FIG. 10 is a perspective view showing a feed mechanism in a conventional sewing machine. [Description of Symbols] A Cloth feed direction 9 Main feed pulse motor 11 Differential feed pulse motor 41 Main feed dog 57 Differential feed dog

Continuation of front page (72) Inventor Akihiro Wakayama 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Inside Brother Industries, Ltd. (56) References JP-A-5-23463 (JP, A) JP-A-4-75687 (JP) JP-A-63-43688 (JP, A) JP-A-61-92695 (JP, A) JP-A-3-112588 (JP, A) JP-A-7-59968 (JP, A) 7-59970 (JP, A) JP-B 63-57077 (JP, B1) (58) Fields studied (Int. Cl. ⁷ , DB name) D05B 27/08

Claims (1)

(57) [Claims] [Claim 1] Differential feed of a cloth is performed by a plurality of feed dogs adjacent in the cloth feed direction based on sewing conditions such as a plurality of kinds of set feed amounts and a differential ratio. In a sewing machine with a plurality of feed dogs, a plurality of pulse motors provided for each of the plurality of feed dogs and separately driving these feed teeth in a horizontal direction, and sewing conditions such as a set feed amount and a differential ratio. Based on
Calculate the feed start position of the tooth and calculate the calculated feed start position.
The gap between two adjacent feed dogs in the cloth feeding direction based on the setting and the set sewing conditions is the gap between the two feed dogs adjacent in the cloth feeding direction and the differential ratio. And a control means for controlling the pulse motor so as to be equal irrespective of sewing conditions such as sewing conditions.