JPH0731773A - Sewing machine - Google Patents

Abstract

PURPOSE:To execute a sewing operation in the state less in noise by installing a needle bar and a cloth holder in a base frame respectively so as to be freely vertically moved, and vertically moving the needle bar and the cloth holder by a needle bar driving mechanism and a cloth holder driving mechanism operated individually. CONSTITUTION:This sewing machine is provided with a needle bar driving mechanism 8 for connecting a driving motor to an end part of a main shaft 7, and executing a vertical motion of a needle bar by driving force of the main shaft 7, and a cloth holder driving mechanism 9 for executing a vertical motion of a cloth holder 40. When the main shaft 7 turns, the needle bar 30 repeats a vertical reciprocating motion between the top dead center and the bottom dead center by the needle bar driving mechanism 8, and by synchronizing with an operation of the needle bar 30, the cloth holder 40 execute repeatedly the vertical motion between the top dead center and the bottom dead by a cloth holder driving mechanism. In such a way, the needle bar 30 and the cloth holder 40 are driven by the separate driving mechanism 8, 9, respectively, therefore sewing can be executed in the state less in noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine of a type in which a cloth presser moves up and down in association with vertical movement of a needle.

[0002]

2. Description of the Related Art In a conventional sewing machine of this type, a needle bar and a cloth presser are provided with a pair of connecting portions, and the cloth bar is moved up and down through the connecting portions by the vertical movement of the needle bar.

[0003]

In such a sewing machine, there is a problem that noise is generated at the connecting portion in the case of sewing.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art. When the needle bar and the presser foot are moved up and down respectively to perform sewing, a quiet operation can be performed. The purpose is to provide a sewing machine that has

[0005]

In order to achieve the above object, a sewing machine according to the present invention has a base frame to which a needle bar having a needle at its lower end and a presser foot are mounted so as to be vertically movable. In the sewing machine, a needle bar drive mechanism for moving the needle bar up and down and a cloth presser drive mechanism for moving the cloth bar up and down are individually connected to each other.

[0006]

[Function] The needle bar drive mechanism moves the needle bar up and down. On the other hand, the presser foot drive mechanism moves the presser foot up and down. Sewing is performed on the cloth by vertically moving the needle bar and the cloth presser.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, which shows a part of a multi-head sewing machine as an example of a sewing machine, 1 is a frame for supporting a large number of sewing machine heads, which is also called a bridge. Reference numeral 2 shows one sewing machine head mounted on the frame 1. Reference numeral 3 is a needle plate attached to the table of the multi-head sewing machine below the sewing machine head 2, and a shuttle is arranged below the needle plate as is well known. 3a is a needle drop hole. 2, which shows the details of the sewing machine head, 4 is a well-known base frame fixed to the frame 1, 5 is a needle bar mechanism attached to the base frame 4, 6 is a balance mechanism, and 7 is each mechanism in the sewing machine head. A main shaft serving as a drive source for performing the operation is provided so as to sequentially pass through a large number of sewing machine heads, and a well-known drive motor is connected to an end portion (not shown). Reference numeral 8 is a needle bar drive mechanism for vertically moving the needle bar by the rotating force of the main shaft 7, 9 is a cloth presser drive mechanism for vertically moving the cloth presser, and 10 is a balance drive mechanism.

Next, the needle bar mechanism 5 will be described in detail mainly with reference to FIGS. Reference numeral 14 denotes a holding frame for vertically movably supporting a plurality of needle bars and a presser foot, and is composed of a lower frame 15 and an upper frame 21 which are widely separated from each other so as to stably support a long needle bar 30. is there. The lower frame 15 is rotatably attached to the base frame 4 using bearings 16. 17 and 17 ... are needle bar guide holes, 18 and 18 ... are presser foot guide holes, and these are for selectively positioning a plurality of needle bars and presser foot at the same operating position in the same posture. , The needle bar guide holes 17 are arranged at equal intervals on one circumference centered on the center of rotation of the lower frame 15, and the presser foot guide holes 18 are the center of rotation and the needle bar guide holes.
They are arranged side by side on an extension of a straight line connecting with 17 and on the circumference centered on the center of rotation. Reference numeral 19 is a positioning portion for positioning the rotation position of the holding frame 14, which is for selectively positioning the plurality of needle bars and the work clamp at the operating position, and is attached to the base frame 4. The recessed part which made it possible to make a fitting body (not shown) fit selectively is illustrated. Reference numeral 20 denotes a lever for performing the above selection operation, which is operated by a well-known selection mechanism (not shown). Upper frame of the holding frame 14
The needle bar guide holes 22 are formed at positions corresponding to the plurality of needle bar guide holes 17 respectively, and at positions 21 on the radial side of the guide holes 22 with respect to the center of rotation of the holding frame 14. A through hole 23 for stopping the anti-rotation member is bored, and is integrally connected to the lower frame 15 by connecting bodies 24, 24. Reference numeral 25 shown in FIG. 2 is a lubricating member for lubricating the outer peripheral surface of the needle bar. For example, a felt impregnated with oil is used, and it is attached to the upper frame 21 with a cover 26 for fastening.

Next, 30 is a needle bar mounted in the guide holes 17 and 22 so as to be movable up and down, and a needle 32 for sewing is detachably fixed to a lower end thereof by using a needle stopper 31. Reference numeral 33 denotes a driven element for receiving a driving force from the needle bar driving mechanism 8, which has a fitting portion 34 for fitting with the driving element of the driving mechanism 8 and is fixed to the upper end of the needle bar 30. The fitting portion 34 can receive both downward and upward driving forces from the driver.
The side surface is formed in a U shape as shown in the drawing. 35 is a needle bar
A member for preventing rotation of the driven member 33 and the driven member 33, and a rotation stop piece 36 having the lower end fixed to the stop hole 23 is inserted therethrough so that it can move up and down along the rotation stop piece 36. Has become. 37
Is a needle bar holding spring for holding the needle bar 30 at the top dead center position,
A compression coil spring is used and is interposed between the upper frame 21 and the member 35. 38 is a positioning member for positioning the top dead center position of the needle bar 30 and is fixed to the upper part of the rotation stop piece 36 so that the vertical position can be changed. 39 is a detent member 35 with respect to the positioning member 38
An O-ring is illustrated as a cushioning member for cushioning the contact of the above.

Next, reference numeral 40 indicates a presser foot. Reference numeral 41 denotes its elevating rod, which is vertically movably mounted in the guide hole 18 and has a pressing piece 42 at its lower end. 43 is a well-known pressing part. Reference numeral 44 is a driven element for receiving a driving force from the presser foot drive mechanism 9, and its upper surface serves as an interlocking portion with the above mechanism 9 so as to receive a downward drive force. As in the case of the needle bar 30, it may be formed in the shape of a U-shaped fitting portion so as to be able to receive both the downward and downward driving forces. The driven member 44 is mounted on the needle bar 30 so as to move up and down so as to move up and down along the needle bar 30 parallel to the lifting rod 41 in order to regulate the rotation of the presser foot. Reference numeral 45 is a presser foot holding spring for holding the cloth presser at the top dead center position, which is a compression coil spring and is interposed between the lower frame 15 and the driven element 44. Reference numeral 46 shown in FIG. 2 is a cushioning member for cushioning the rise of the presser foot 40 when it is stopped at the top dead center position by the upper frame 21, and is an example of a rubber O-ring.

Next, the needle bar drive mechanism 8 will be described in detail mainly with reference to FIGS. 2, 3, 6, and 8. Reference numeral 50 is a guide rod for guiding the vertical movement of the lifting body, and the lower portion and the upper portion thereof are supported by the base frame 4 and the support frame 4a attached to the base frame 4, respectively. The guide rod 50 has a function as an interlocking rod for rotating the balance mechanism 6 in conjunction with the needle bar mechanism 5, and is rotatable with respect to the base frame 4 and the support frame 4a. . Reference numeral 51 denotes an interlocking piece for rotating the guide rod 50 integrally with the holding frame 14. Reference numeral 52 is an elevating body for moving the needle bar 30 up and down, and 53 is an elevating mechanism for converting the rotational movement of the main shaft 7 into vertical movement, transmitting it to the elevating body 52, and vertically moving it. The elevating body 52 will be described. 54 is a lifting body, which is the above guide bar
It is attached to 50 so that it can move up and down. Reference numeral 55 is a needle bar driver, and for example, a shaft 55a is attached to the lifting / lowering main body 54 in order to change the position between the driving position for driving the needle bar 30 and the skip position for not driving the needle bar.
The horizontal swing is freely pivoted by. Reference numeral 56 denotes a spring for holding the driver element 55 in a driving position, and a tension spring is used, and it is provided between a spring hook portion 57 formed integrally with the driver element 55 and a spring hook piece 58 fixed to the main body 54. It is stretched. 59
Is a driven piece for skipping operation attached to the driver 55, and receives a force from a known skipping operating mechanism (not shown) to drive the needle bar driver.
This is for retracting 55 to the skipped position as shown by the chain double-dashed line in FIG. A driving piece of the operating mechanism is arranged with respect to the driven piece 59 as shown by reference numeral 60 in FIG. No. 4-292194). Next, as the lifting mechanism 53, a well-known lever crank mechanism is exemplified. The mechanism consists of an eccentric wheel 61 mounted on the main shaft 7.
A crank rod 62 which is moved up and down by the rotation of the eccentric wheel; It is composed of a link 65 connecting the free end of the lever and the elevating body 54. When the main shaft 7 rotates, the lever 63 swings up and down to move the elevating body 54 up and down along the guide rod 50. Is done.

Next, description will be given mainly on FIGS. 2, 4, 7, and 10 showing the above-mentioned presser foot drive mechanism 9 in detail. 68 is an elevating / lowering body for moving the presser foot 40 up and down, and 69 is an elevating / lowering mechanism for converting the rotational movement of the main shaft 7 into up / down movement and transmitting it to the elevating / lowering body 68 to vertically move it. Reference numeral 70 denotes an elevating body, which is attached to the guide rod 50 so as to be vertically movable. 71-75 is the lifting body
A cloth presser driver 76, which will be described later, can be moved up and down in order to horizontally swing between a drive position for driving the cloth presser 40 and an eye-catching position not for driving, and to absorb a cloth thickness change. 71, 72 are bearings, 73 is a pivot shaft, bearings 71, 72
It is mounted so that it can rotate and move up and down. The members 74 and 75 are members for allowing the presser foot drive element 76 to rotate smoothly with respect to the pivot axis 73, and are provided on the pivot axis 73 at intervals corresponding to the thickness of the drive element 76. The fixed tsuba is illustrated. A cloth pressing driver 76 for exerting a driving force on the cloth pressing member 40 is attached to the pivot shaft 73 between the collars 74 and 75.
With such a structure, the work clamp driver 76 can be swung in the horizontal direction with respect to the main body 70, and can be vertically moved between the bearings 71 and 72. Reference numeral 77 denotes a cloth thickness change absorbing spring for urging the presser foot drive element 76 downward to always hold it at the lower limit position.A compression spring harder than the cloth presser holding spring 45 is used. Bearing 71 and tsuba
It is installed between 74. With such a configuration, even if the presser foot drive element 76 is always urged downward by the spring 77, the drive element 76 can be swung slightly horizontally between the collars 74 and 75. Reference numeral 78 is a holding spring for holding the driver element 76 in the driving position, and is stretched between a spring hook portion 79 formed integrally with the driver element 76 and a spring hook piece 80 fixed to the main body 70. . 81 is a driven piece for skipping attached to the driver 76,
The presser foot driver 76 is connected to the needle bar driver by an interlocking mechanism described later.
It is for interlocking with 55 and retracting it to the skip position.

Next, the lifting mechanism 69 will be described. Reference numeral 84 is a cam for driving the presser foot, which is a grooved cam having a cam groove 85 on its side surface, which is attached to the main shaft 7. Reference numeral 86 is a drive lever, the base portion of which is pivotally attached to the base frame 4 by a pivot attachment 87, and a follower 88 attached to the middle portion is driven by a cam groove 85. A transmission rod 89 is provided in parallel with the guide rod 50. The lower end is fixed to the elevating body 70, and the upper end is vertically movably held by a guide tube 90 attached to the support frame 4a. Reference numeral 93 is a link for connecting the free end of the drive lever 86 and the transmission rod 89, one end of which is pivotally attached to the free end of the lever 86 and the other end of which is connected to a connecting member 92 fixed to the transmission rod 89. I'm wearing it. In such a lifting mechanism 69, the drive lever 86 is arranged in a substantially horizontal state as clearly shown in FIG. 2, and the transmission rod 89 is arranged vertically at a position close to the guide rod 50. The space below the lever 86 can be largely vacant, and by forming the base frame 4 in the shape shown in the drawing, a space for arranging a thread holding mechanism 118 described later is formed below the base frame 4. be able to.

Next, reference numeral 94 shown in FIGS. 2, 6 and 7 is an interlocking mechanism for interlocking the work clamp driver 76 with the needle bar driver 55 and retracting it to the skip position, and is integral with the needle bar driver 55. It comprises a shaft 95 rotatably connected, an arm 96 fixed to the shaft, and an interlocking rod 97 having an upper end fixed to the free end of the arm 96 and a lower part facing the driven piece 81.

Next, the balance device 6 of FIG. 2 has the needle in the operating position.
It is a well-known one that feeds and pulls up a thread with respect to 32. 100 is a support body attached to the guide rod 50, 101 is a support body 100
The support frame attached to the, 102 is a balance, and the threading hole 103 is provided at one end.
However, a driving body fitting portion 104 and a positioning piece fitting portion 105 are formed at the other end, and an intermediate portion is attached to a support frame 101 by a support shaft 106 so as to be freely rotatable in a vertical plane. The balance 102 is arranged on the support frame 101 in an arrangement similar to the arrangement of the needle bars 30 with respect to the holding frame 14 in the number corresponding to the needle bars 30, and only the balance 102 corresponding to the needle bar that has reached the operating position is provided. All of the balances 102 that can move up and down and are in other retracted positions have their fitting portions 105 fitted to the positioning pieces 107 attached to the base frame 4 so as to move to the raised position as shown in FIG. (See Japanese Patent Laid-Open No. 4-224790). Reference numeral 108 is a known thread guide attached to the support 100. Next, the balance driving mechanism 10 receives the turning force of the main shaft 7 to move the balance 102 in the operating position up and down.
For example, a cam (not shown) attached to the main shaft 7 and a drive lever 109 having an intermediate portion pivotally attached to the base frame 4 by a pivot attachment 110 are provided, and a follower (not shown) provided at one end of the drive lever 109. Is driven by the above-mentioned cam, and the driving body 111 provided at the other end is located at a position where it can be fitted with the fitting portion 104 of the balance 102 in the operating position. When the plurality of balances 102 are selectively brought to the operating position by the rotation of the support body 100 interlocking with the holding frame 14, the fitting portion 104 of the balance 102 fits with the driving body 111, and the main shaft 7 rotates. When the lever 109 swings in response to the movement, the balance 102, which has reached the operating position, moves up and down (see Japanese Patent Laid-Open No. 4-224790).

Next, the cover 11 protects the above-mentioned various mechanisms, prevents the sound generated from the various mechanisms from diverging to the outside during the operation of the sewing machine head, and also the oil is scattered from the mechanisms of the respective parts during the operation. In order to prevent the oil from jumping out to the outside, it is configured to cover the front side (right side in FIG. 2), the left and right side sides, and the upper side of each mechanism, For example, it is made of a synthetic resin material and is detachably fixed to the base frame 4. 114 is the cover 1
1 is a slot for lateral movement of the balance, 115 is a slit for vertical movement of the thread 102 in the operating position, and 116 is a slot for lateral movement of the thread guide 108. Next, reference numeral 118 shown in FIG. 2 is a thread holding mechanism for holding the thread hung from the needle 32 in the retracted position in a pulled-up state so as not to interfere with the sewing, and is known (see, for example, JP-A-60-173156). )belongs to.

Next, the operation of the sewing machine having the above structure will be described.
The holding frame 14 is pivotally operated to position one of the plurality of needle bars 30 and the balance 102 at a predetermined operating position as shown in FIG. As a result, the fitting portion 34 of the needle bar is fitted with the needle bar driver 55, and the upper surface of the driven element 44 of the cloth presser 40 faces the lower surface of the cloth pressing driver 76. Further, the fitting portion 105 of the balance 102 is disengaged from the positioning piece 107, and the fitting portion 104 fits with the driving body 111. When the main shaft 7 rotates in this state, the needle bar 30 moves to the top dead center position shown in FIG.
Repeat the vertical reciprocating motion with the bottom dead center position shown in.
That is, when the main shaft 7 rotates, the lifting mechanism 53 lowers the lifting body 52 from the state of FIG. 8 as shown in FIG.
Causes the needle bar 30 to descend. Next, when the elevating body 52 rises, the needle bar 30 is pulled up to the top dead center by the driver 55.

Further, when the main shaft 7 is rotated, the work clamp drive mechanism 9 synchronizes with the operation of the needle bar 30 so that the work clamp 40 is moved to the position shown in FIG.
The vertical movement between the top dead center position of 0 and the bottom dead center position of FIG. 11 is repeated. That is, when the main shaft 7 rotates, the drive lever
86 swings downward as shown in FIG. The movement is transmitted to the main body 70 of the lifting body 68 via the link 93 and the transmission rod 89, and the lifting body 68 is guided by the guide rod 50 and descends as shown in FIG. By this descent, the cloth presser 40 is pushed downward by the cloth presser driving element 76 and descends as shown in the figure. In the process of this descending, when the pressing portion 43 of the cloth presser 40 abuts against the upper surface of the cloth 120 and presses it against the needle plate 3, thereafter, the lifting body 70
Even if is further lowered, the movement is absorbed by the cloth thickness change absorbing spring 77 (the spring 77 is compressed), and the cloth presser driver 76 does not excessively press down the cloth presser 40. Therefore, the cloth 120 may be damaged by the excessive lowering of the cloth presser 40,
Alternatively, it is possible to prevent the presser piece 42 of the cloth presser from being damaged. The height position at which the cloth presser 40 presses the cloth 120 against the needle plate 3 and its descent stops depends on the thickness and hardness of the cloth 120. The lowering of 70 is absorbed by the spring 77. When the main shaft 7 is further rotated, the lifting body 68 is lifted by the opposite operation to the above, and the work clamp 40 is lifted to the top dead center position by following the lifting of the lifting body 68 by the urging force of the work clamp holding spring 45. To do.

By repeating the vertical movement of the needle bar 30 as described above and the vertical movement of the work clamp 40 synchronized therewith,
Well-known sewing is performed on the cloth 120 with the thread 121 shown in FIG. In this case, even if the curve of the vertical movement of the needle bar 30 and the curve of the vertical movement of the presser foot 40 with respect to the transition of time are different, the needle bar 30 is changed by the eccentric wheel 61 and the cloth presser 40 is changed by the cam 84. The vertical movement is controlled independently, and the spindle 7 and needle bar
Since the 30 and the main shaft 7 and the presser foot 40 are always interlocked with each other (since engagement / disengagement is not repeated during the sewing operation unlike a thing having a connecting portion between the needle bar and the presser foot).
Sewing is performed with less noise.

If you want to skip the eyes during sewing,
The driven piece 59 of the needle bar driver 55 is pushed in the direction of the arrow in FIG.
Is disengaged from the fitting portion 34 as indicated by the chain double-dashed line and is moved to the skipped position where it is in the retracted state. This movement is transmitted to the driven piece 81 of the work clamp driving element 76 via the interlocking mechanism 94, and the driving element 55 is moved.
In the same manner as in the above case, the driving element 76 is moved from the position facing the upper surface of the driven element 44 to the skipped position where it is in the retracted state. In this state, each lifting body for the needle bar 30 and the presser foot 40
The needle bar 30 and the presser foot 40 do not move up and down even when the 52 and 68 move up and down, and the cloth 120 is not sewn.

When the thread 121 to be sewn is changed (the color of the thread or the type of thread is changed), the elevating body 52 for driving the needle bar and the elevating body 68 for driving the presser foot are respectively moved to the upper limit positions. With the needle bar 30 and the work clamp 40 reaching the top dead center
The rotation of is stopped, and the thread that has been sewn until then is held by the thread holding mechanism 118. And holding frame 14
Needle bar 30 loaded with thread for rotating
And the presser foot 40 corresponding thereto are placed in the operating position.
After that, the rotation of the main shaft 7 is started and the sewing is restarted.
When sewing is performed while exchanging the needle bar 30 and the cloth presser 40 in this manner, in the sewing machine, the cloth presser drive mechanism 9 is provided with a structure for absorbing the cloth thickness change by the spring 77. The structure is only one, and the function of absorbing the cloth thickness change can be exhibited regardless of which cloth presser 40 is operated.

[0022]

As described above, according to the present invention, the needle bar
Since the 30 and the cloth presser 40 are respectively driven by the individual drive mechanisms 8 and 9, there is an effect that the sewing can be performed in a state where the noise is small.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view.

FIG. 2 is a vertical sectional view.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a perspective view of a needle bar mechanism.

FIG. 6 is a perspective view of a needle bar drive mechanism.

FIG. 7 is a perspective view of a presser foot drive mechanism.

FIG. 8 is a cross-sectional view showing a state of the needle bar drive mechanism when the needle bar is at the top dead center position.

FIG. 9 is a sectional view showing a state of the needle bar drive mechanism when the needle bar is at the bottom dead center position.

FIG. 10 is a cross-sectional view showing a state of the work clamp drive mechanism when the work clamp is at the top dead center position.

FIG. 11 is a cross-sectional view showing a state of the work clamp drive mechanism when the work clamp is at the bottom dead center position.

[Explanation of symbols]

 4 Base frame 8 Needle bar drive mechanism 9 Cloth clamp drive mechanism 30 Needle bar 40 Cloth clamp

Claims (1)

[Claims] 1. A sewing machine in which a needle bar having a needle at its lower end and a presser foot are mounted on a base frame so as to be vertically movable, and the needle bar has a needle for moving the needle bar up and down. A sewing machine characterized in that a rod drive mechanism is individually connected to the cloth presser and a cloth presser drive mechanism for vertically moving the bar presser.