JPH0663258A - Needle feed/lowering feed switch gear for sewing machine with needle feeding function - Google Patents

Abstract

PURPOSE:To enable the simplification of switching operation between states of needle feed and lowering feed and moreover, the holding of a needlebar in the lowering feed state at a specified oscillation position. CONSTITUTION:A link member 39 one end of which is connected to a needlebar oscillation shaft 42 with the other end thereof connected to one end of a feed rock shaft 32 through a needle bar rock crank 36 is arranged while timing pulleys 28 and 29 are provided on an upper shaft 15 and a lower shaft 16 respectively and a timing belt 29 is looped on the timing pulleys 28 and 29. An eccentric wheel 34 is fastened on the lower shaft 16 and connected to the feed rack shaft 32 through a horizontal feed connecting rod 30 fitted externally into the eccentric wheel 34 rotatably and a horizontal feed link 31. Thus, it is so arranged that an angle of mounting the timing pulley 29 of the lower shaft 16 can be set freely to allow switching between states of needle feed and lowering feed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle feed / sewing machine having a needle feed function for feeding a work cloth by cooperation of a sewing needle and a feed dog.
The present invention relates to a lower feed switching device.

[0002]

2. Description of the Related Art Generally, for example, in order to reliably prevent a defective feeding of a work cloth when sewing a relatively thick work cloth such as jeans, the work needle is stabbed with a sewing needle and the sewing needle is used as a feed dog. There is known a sewing machine with a needle feed function which is configured to swing in synchronization with the above and to assist the cloth feed by the feed dog. Normally, the sewing machine with the needle feed function is switched to switch between a needle feed state in which the work cloth is fed by cooperation of the sewing needle and the feed dog, and a lower feed state in which the work cloth is fed only by the feed tooth. A device is provided, and this switching device is switched according to the thickness of the work cloth so that stitches can be reliably formed at a set feed pitch for both thick and thin work cloth. .

As the switching device, for example, the actual fairness 2
No. 23243, one end of a horizontal feed shaft is rotatably mounted on a bearing sleeve fixed to a machine frame, and is releasably connected to a portion near one end of the horizontal feed shaft by a first screw member. A first needle feed arm is provided, and a second needle feed arm detachably connected to the bearing sleeve by a second screw member is provided,
It is described that a pivot shaft pivotally supported in the vicinity of the tips of both needle feed arms and a needle bar swing shaft are connected by a link member. In the switching device, the first screw member is fastened and the second screw member is loosened to be in a needle feed state, and the first screw member is loosened and the second screw member is fastened to be in a lower feed state. Has been done.

[0004]

By the way, in the switching device described in the above-mentioned publication, in order to switch between the needle feeding state and the lower feeding state, the fastening work and the loosening work are performed for the two screw members each time. And lacks operability for switching. Also, when switching to the lower feed state,
Since the swing position of the sewing needle is determined according to the fastening position of the second needle feed arm with respect to the bearing sleeve, the fastening position setting operation of the second needle feed arm corresponding to the predetermined swing position of the sewing needle becomes complicated. Furthermore, when both screw members are simultaneously fastened due to a user's erroneous operation, the rotational force of the horizontal feed shaft is transmitted to the bearing sleeve fixed to the machine frame via both needle feed arms and the pivot shaft, and switching is performed. There is a problem such as damage to the device.

The present invention has been made to solve the above problems, and an object thereof is to simplify the switching operation between the needle feed state and the lower feed state, and to set a predetermined needle bar in the lower feed state. It is an object of the present invention to provide a needle feed / lower feed switching device for a sewing machine with a needle feed function that can be held in a swing position.

[0006]

In order to achieve the above object, a needle feed / lower feed switching device for a sewing machine with a needle feed function according to a first aspect of the present invention comprises an upper shaft rotatably supported in a sewing machine arm. , A needle bar base that is swingably supported in the cloth feed direction around a spindle parallel to the upper shaft, a needle bar that is vertically movable on the needle bar base and moves up and down in conjunction with the upper shaft, and a sewing machine A lower shaft that is rotatably supported in the bed, a rotation transmission connector that interlocks and connects a rotor that is supported at one end of the upper shaft and a rotor that is supported at one end of the lower shaft, and the lower shaft A connected horizontal feed shaft, a feed dog that interlocks with the lower shaft and the horizontal feed shaft, and makes four feed motions, and a needle bar swing shaft that is interlocked with the horizontal feed shaft and swings the needle bar base in the cloth feed direction. In a sewing machine with a needle feed function equipped with and, the interlocking mechanism that interlocks and connects the needle bar swing shaft to the horizontal feed shaft, A link member connected to the needle bar swinging shaft at the other end is connected to the horizontal feed shaft at the end,
A crank mechanism that interlocks one end of the link member with the horizontal feed shaft, an eccentric position provided on the crank mechanism, where one end of the link member is eccentric to the horizontal feed shaft, and one end of the link member is attached to the horizontal feed shaft. On the other hand, a switching mechanism that can switch to a concentric position that is not eccentric is provided.

It should be noted that one of the rotating body supported at one end of the upper shaft and the rotating body supported at one end of the lower shaft has a first position for needle feed with respect to the shaft supporting it. Alternatively, it may be configured to be selectively switchably fixed to the second position for releasing the needle feed, which is rotated about the axis from the first position by a predetermined angle.

[0008]

In the needle feed / lower feed switching device for a sewing machine with a needle feed function according to the first aspect of the present invention, one end of the link member connected to the horizontal feed shaft via the crank mechanism is provided with the switching mechanism. The needle feed state is established by moving the eccentric position to the horizontal feed shaft via the eccentric position, and the lower feed state is established by moving the eccentric position to the concentric position with respect to the horizontal feed shaft. That is, when one end of the link member is switched to an eccentric position eccentric to the horizontal feed shaft, the rotational force of the horizontal feed shaft is transmitted to the link member via the link mechanism, and the needle bar is supported together with the needle bar base. The work cloth is fed around the shaft in synchronism with the longitudinal movement of the feed dog, and the work cloth is fed by the cooperation of the sewing needle and the feed dog. On the other hand, when one end of the link member is switched to the concentric position that is not eccentric with respect to the horizontal feed shaft through the switching mechanism, the rotational force of the horizontal feed shaft is not transmitted to the link member through the link mechanism and the feed dog The work cloth is fed by only.

As described above, the needle feed state and the downward feed state can be set by simply switching the position of the one end of the link member between the eccentric position and the concentric position. The switching operation to the feeding state can be simplified, and the needle bar in the downward feeding state can be held at a predetermined eccentric position. Furthermore, since the position of the one end of the link member is selectively switched between the eccentric position and the concentric position, damage to the switching device can be reliably prevented.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an electronically controlled lockstitch needle feed sewing machine. As shown in FIG. 1, the electronically controlled lockstitch needle feed sewing machine M includes a sewing machine bed 10, a pedestal portion 11 extending upward from a right end portion of the sewing machine bed 10, and a sewing machine from an upper end portion of the pedestal portion 11. The sewing machine arm 12 extends to the left so as to face the bed 10. An upper shaft 15 extending in the left-right direction is rotatably supported on the machine frame 5 of the sewing machine arm 12, and a needle bar vertical movement mechanism 20 and a balance vertical movement mechanism are provided.

Since this balance up-and-down moving mechanism is similar to a normal sewing machine, its explanation is omitted, and the needle-bar up-and-down moving mechanism 20 will be briefly described. The needle bar 21 having a sewing needle (not shown) at its lower end is The needle bar base 22 is vertically movably supported by a vertically extending needle bar base 22.
It is supported by a support shaft 23 fixed to the machine frame 5 so that it can swing back and forth. On the other hand, a needle bar crank 24 is fixed to the left end of the upper shaft 15, and the connecting rod 2 is attached to the needle bar crank 24.
The upper end of 5 is rotatably pivotally attached, and the lower end of the connecting rod 25 is connected to the center of the needle bar 21 in the height direction via a needle bar holder 26. Therefore, since the needle bar crank 24 is rotated by the rotation of the upper shaft 15, the needle bar 21 is vertically reciprocated via the connecting rod 25 and the needle bar holder 26.

A lower shaft 16 extending in the left-right direction is rotatably supported by the machine frame 5 on the sewing machine bed 10.
A timing belt (corresponding to the rotating body of the present invention) 27 connected to the right end of the shaft and a timing pulley (corresponding to the rotating body of the present invention) 28 fixed to the right end of the upper shaft 15; 29 (corresponding to the connection body for rotation transmission of the present invention) is stretched. Therefore, the upper shaft 15 is rotationally driven by the rotational driving of the sewing machine motor (not shown),
At the same time, the lower shaft 16 is rotationally driven via the timing belt 29.

A disc-shaped eccentric ring 34 is fixed to the lower shaft 16, and a rear end portion of the horizontal feed connecting rod 30 is rotatably fitted to the eccentric ring 34 so that the front end of the horizontal feed connecting rod 30. The portion is fixed to the lower end of the horizontal feed link 31, and the upper end of the horizontal feed link 31 is rotatably connected to a horizontal feed arm 33 fixed to a horizontal feed shaft 32 extending in the left-right direction.
Therefore, as the lower shaft 16 is driven to rotate, the front end portion of the horizontal feed connecting rod 30 swings in the front-rear direction via the eccentric wheel 34, so that the horizontal feed shaft 32 moves through the horizontal feed link 31 and the horizontal feed arm 33. Rock. Here, at the left end of the lower shaft 16, a feed dog up-and-down moving mechanism for up and down movement of the feed dog (not shown) is connected, and at the left end of the horizontal feed shaft 32, a feed dog front and back for moving the feed dog back and forth. The moving mechanism is connected.

Next, the connecting mechanism 35 for swinging the needle bar 21 in the front-rear direction in synchronization with the forward-backward movement of the feed dog will be described. At the right end of the horizontal feed shaft 32, as shown in FIG.
As shown in FIG. 4, a needle bar swinging crank 36 having a substantially L shape in a front view is fixed, and a guide pin 37 with a screw is screwed on a horizontal wall portion 36 a of the needle bar swinging crank 36. . A front end portion of a link member 39 extending in the front-rear direction is rotatably supported by a screw 40 on a sliding member 38 fitted to the guide pin 37 so as to be vertically movable. here,
As shown in FIG. 2, the sliding member 38 is a position that is slid on the guide pin 37 and moved upward from the axis L of the horizontal feed shaft 32, and is an eccentric position where the needle bar 21 can be swung. And Fig. 4
As shown in FIG. 7, the position of sliding on the guide pin 37 and moving on the axis L of the substantially horizontal feed shaft 32, and the concentric position where the needle bar 21 is not swung can be slid. Has become. The sliding member 38 is held at an eccentric position or a concentric position by a positioning screw 41 screwed onto the sliding member 38. Further, when the sliding member 38 moves to the concentric position, the center position of the front end portion of the link member 39 moves to the axis L of the horizontal feed shaft 32. The needle bar swing crank 36 and the screw 40 correspond to the crank mechanism of the present invention, and the horizontal wall portion 36a, the guide pin 37, the sliding member 38, and the positioning screw 41 constitute the switching mechanism of the present invention. Equivalent to.

On the other hand, the upper end of a vertically extending needle bar swinging rod 43 is fixed to the right end of the needle bar swinging shaft 42 arranged in parallel with the upper shaft 15, and the needle bar swinging rod 43 is fixed. A lower end portion of the dynamic connecting rod 43 is rotatably connected to a rear end portion of the link member 39. Further, the base end portion of the needle bar swing arm 44 is fixed to the left end portion of the needle bar swing shaft 42, and the tip end portion of the needle bar swing arm 44 is formed at the lower end portion of the needle bar base 22. It is slidably engaged with the engagement groove 22a extending in the vertical direction. Therefore, when the slide member 38 is switched to the eccentric position shown in FIG. 2, the needle bar swing crank 36 is swung by the swing of the horizontal feed shaft 32.
Of the horizontal feed shaft 32, the sliding member 38 that has moved above the axis L of the horizontal feed shaft 32 swings, and the sliding member 38 moves through the link member 39, the needle bar swinging rod 43, and the needle bar swinging shaft 42. Lever needle arm 4
4 simultaneously swings and the needle bar 21 swings back and forth by the swing of the needle bar base 22.

However, when the sliding member 38 is switched to the concentric position shown in FIG. 4, since the center position of the front end portion of the link member 39 moves on the axis L of the horizontal feed shaft 32, The front end portion of the link member 39 is held at a predetermined position in spite of the swing of the horizontal feed shaft 32 and the swing of the needle bar swing crank 36, so that the needle bar base 22 is held at a predetermined eccentric position. As a result, the needle bar 21 is vertically driven at a predetermined eccentric position without swinging back and forth.

Next, the timing changing mechanism 45 for changing the vertical movement timing of the needle bar 21 and the vertical movement timing of the feed dog will be described with reference to FIGS. 1, 3 and 5. A cylindrical sleeve member 46 externally fitted to the lower shaft 16 is fixed to the timing pulley 27, and three threaded holes 46a, 46b, 46c are formed in the sleeve member 46 at different positions in the circumferential direction. Has been formed. Here, the screw hole 46a is formed at a position rotated by about 160 ° in the clockwise direction in FIG. 2 with respect to the screw hole 46c. Further, a recess is formed in the outer peripheral portion of the lower shaft 16 corresponding to the screw hole 46a, and the tip end of the positioning screw 47 screwed into the screw hole 46a engages with the recess, and the lower shaft 16 and the timing pulley. Positioning is performed so that the phase with 27 is in a predetermined phase relationship. A set screw 48 is screwed into the screw hole 46b. Here, the position of the timing pulley 27 where the screw hole 46a faces the concave portion of the lower shaft 16 is the first position for needle feeding.

Therefore, as shown in FIG. 3, the timing pulley 27 is at the first position for needle feed, and the positioning screw 47 is used.
Is screwed into the screw hole 46a and the tip of the positioning screw 47 engages with the concave portion of the lower shaft 16, the needle bar 21 moves downward when the feed dog moves upward, and when the feed dog moves downward. The needle bar 21 moves up, and when the feed dog further moves back and forth, the needle bar 21 also moves back and forth at the same time, and the lower shaft 16 and the timing pulley 27 are set in a needle feed phase relationship. On the other hand, as shown in FIG. 5, after the positioning screw 47 is removed from the screw hole 46a and the set screw 48 is loosened, the timing pulley 27 is rotated clockwise by about 160 ° in FIG. When the set screw 48 is tightened, the positioning screw 47 is screwed into the screw hole 46c, and the tip of the positioning screw 47 engages with the recess of the lower shaft 16, the needle bar 21 also moves upward when the feed dog moves upward. Further, when the feed dog moves downward, the needle bar 21 also moves downward, and when the feed tooth further moves forward and backward, the needle bar 21 moves up and down at a predetermined position, and the lower shaft 1
6 and the timing pulley 27 are set in a normal feed phase relationship by only the feed dog. Here, the position of the timing pulley 27 where the screw hole 46c faces the concave portion of the lower shaft 16 is the second position for releasing the needle feed.

Next, the operation of the connecting mechanism 35 and the timing changing mechanism 45 will be described. First, at the time of the needle feeding operation of swinging the needle bar 21 in synchronization with the cloth feeding operation of the feed dog, as shown in FIGS.
When the timing pulley 27 is set to the first position for needle feeding while the eccentric position is changed to the eccentric position shown in FIG. 5, the sliding member 38 oscillates, and the link member 39, the needle bar oscillating rod 43, and the needle bar as described above. The needle bar swing arm 44 simultaneously swings via the swing shaft 42, and the needle bar base 22 swings to move the needle bar 21 up and down and reciprocate back and forth. Since the lower shaft 16 and the timing pulley 27 are set in a needle feed phase relationship, the work cloth is fed by the cooperation of the feed dog and the sewing needle.

However, at the time of the lower feed operation using only the feed dog, as shown in FIGS. 1, 4, and 5, the sliding member 3
8 is switched to the concentric position shown in FIG. 4, and when the timing pulley 27 is at the needle feed releasing second position,
As described above, since the front end portion of the link member 39 is held at a predetermined position despite the needle bar swinging crank 36 swinging, the needle bar base 22 is held at a predetermined eccentric position,
As a result, the needle bar 21 is vertically driven at a predetermined eccentric position without swinging back and forth, and at the same time, the lower shaft 16 and the timing pulley 27 are set in a normal feed phase relationship by only the feed dog. The work cloth is fed only by the feed dog.

As described above, during the needle feeding operation,
While the sliding member 38 is switched to the eccentric position, the needle feeding state and the downward feeding state can be set by switching the sliding member 38 to the concentric position during the downward feeding operation. It is possible to simplify the switching operation between and and to hold the needle bar 21 in a predetermined swing position in the downward feed state. Further, since the front end portion of the link member 39 is selectively switched between the eccentric position and the concentric position,
It is possible to reliably prevent damage to the switching mechanism. In addition, the timing pulley 27 positions the positioning screw 47 at the first position for needle feed with respect to the lower shaft 16 and the second position for needle feed release rotated by a predetermined angle around the axis from the first position.
Since it is fixed so as to be selectively switchable via the, it is possible to easily switch the timing between the four feed motions of the feed dog and the vertical movement of the needle bar 21 in correspondence with the needle feed state and the lower feed state.

The timing changing mechanism 45 may be provided on the timing pulley 28 side. Further, the switching mechanism is merely an example, and the sliding member 38 can be configured to be switchable to the concentric position or the eccentric position with respect to the link member 39 without using the guide pin 37. It is also possible to configure the switching mechanism by using the member.

[0023]

As described in detail above, according to the needle feed / lower feed switching device of the sewing machine with the needle feed function according to the present invention, the interlocking mechanism is provided with the link member, the crank mechanism and the switching mechanism. , By switching the position of one end of the link member between the eccentric position and the concentric position, it is possible to set by switching between the needle feed state and the lower feed state. In addition, the needle bar in the downward feed state can be held at a predetermined swing position. Furthermore, since the position of the one end of the link member is selectively switched between the eccentric position and the concentric position, damage to the switching device can be reliably prevented. It should be noted that one of the rotating body supported by one end of the upper shaft and the rotating body supported by one end of the lower shaft has a first position for needle feeding with respect to the shaft supporting the rotating body and the first position. When it is selectively switchably fixed to the second position for releasing the needle feed which is rotated about the axis from the position by a predetermined angle (claim 2), it corresponds to the needle feed state and the lower feed state. The timing of the four-feed movement of the feed dog and the vertical movement of the needle bar can be easily switched.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an internal mechanism of an electronically controlled lockstitch needle feed sewing machine.

FIG. 2 is an enlarged partial front view of a main portion of a needle bar swing crank and a guide pin when a sliding member is switched to a swing position.

FIG. 3 is a vertical cross-sectional side view of essential parts when a lower shaft and a timing pulley are set in a needle feed phase relationship.

FIG. 4 is a view when a sliding member is switched to a swing stop position.
FIG.

FIG. 5 is a diagram corresponding to FIG. 3 when the lower shaft and the timing pulley are set in a normal feed phase relationship.

[Explanation of symbols]

 M Sewing machine with needle feed function 10 Sewing machine bed 12 Sewing machine arm 15 Upper shaft 16 Lower shaft 21 Needle bar 22 Needle bar base 27 Timing pulley 28 Timing pulley 29 Timing belt 32 Horizontal feed shaft 35 Interlocking mechanism 39 Link member 42 Needle bar swing axis

Claims (2)

[Claims] 1. An upper shaft rotatably supported in a sewing machine arm, a needle bar base supported swingably in a cloth feed direction around a support shaft parallel to the upper shaft, and the needle bar base. A needle bar that is vertically movable and moves up and down in conjunction with the upper shaft, a lower shaft that is rotatably supported in the sewing machine bed, a rotating body that is supported at one end of the upper shaft, and one end of the lower shaft. A rotary transmission coupling body that interlocks and couples a rotating body supported by a horizontal feed shaft that is interlockingly coupled to the lower shaft; and a feed dog that performs four feeding motions that is interlockingly coupled to the lower shaft and the horizontal feed shaft. In a sewing machine with a needle feed function, which is interlocked with the horizontal feed shaft and swings a needle bar base in the cloth feed direction, a needle bar swing shaft is interlocked with the horizontal feed shaft. The interlocking mechanism is connected at one end to the horizontal feed shaft and at the other end to the needle bar swing shaft. A link member, a crank mechanism in which one end of the link member is interlocked with a horizontal feed shaft, an eccentric position provided on the crank mechanism in which one end of the link member is eccentric with respect to the horizontal feed shaft, and A needle feed / lower feed switching device for a sewing machine with a needle feed function, which is provided with a switching mechanism capable of switching one end to a concentric position that is not eccentric to the horizontal feed shaft. 2. The rotating body supported at one end of the upper shaft and one of the rotating bodies supported at one end of the lower shaft have a first position for needle feeding with respect to a shaft supporting the rotating body. The needle feed function according to claim 1, wherein the needle feed function is fixed to a second position for releasing the needle feed, which is rotated about the axis from the first position by a predetermined angle, so as to be selectively switchable. Needle feed of sewing machine /
Lower feed switching device.