阅读说明：本技术 织带机的底线摆杆连动机构 (Bottom thread swing rod linkage mechanism of ribbon loom ) 是由 郑正雄 曾文彬 郑晶华 于 2020-04-30 设计创作，主要内容包括：本发明是关于织带机的底线摆杆连动机构,其包含一枢转轴及一枢转组件；枢转轴能转动地设于支撑结构上,且用于固设底线摆杆；枢转组件包含一摇臂、一抵靠轮及一凸轮；摇臂枢设于支撑结构上,且连接于枢转轴,并能拉动转动枢转轴；抵靠轮能转动地设于摇臂上；凸轮固设驱动轴并随着驱动轴旋转；凸轮的外环面抵靠于抵靠轮的外环面,且两外环面在抵靠处相平行。通过凸轮随着驱动轴转动,而适时通过抵靠轮与摇臂拉动旋转枢转轴。由于抵靠轮与凸轮之间滚动接触,并且运作中凸轮的外环面与抵靠轮的外环面在抵靠处维持相互平行,故能大幅降低摩擦损耗。(The invention relates to a bottom thread swing rod linkage mechanism of a ribbon loom, which comprises a pivot shaft and a pivot component; the pivotal shaft is rotatably arranged on the supporting structure and is used for fixedly arranging the bottom line swing rod; the pivoting component comprises a rocker arm, an abutting wheel and a cam; the rocker arm is pivoted on the supporting structure, is connected to the pivot shaft and can pull the pivot shaft to rotate; the leaning wheel can be rotatably arranged on the rocker arm; the cam is fixedly arranged on the driving shaft and rotates along with the driving shaft; the outer ring surface of the cam is abutted against the outer ring surface of the abutting wheel, and the two outer ring surfaces are parallel at the abutting position. The cam rotates along with the driving shaft, and the rotary pivot shaft is timely pulled by abutting against the wheel and the rocker arm. The abutting wheel is in rolling contact with the cam, and the outer ring surface of the cam and the outer ring surface of the abutting wheel are kept parallel to each other at the abutting position in operation, so that the friction loss can be greatly reduced.)

1. A bottom thread swing rod linkage mechanism of a ribbon loom is characterized in that the bottom thread swing rod linkage mechanism of the ribbon loom is used for being arranged on a supporting structure of the ribbon loom and fixedly arranging a bottom thread swing rod; the ribbon loom includes a driving shaft; this bobbin thread pendulum rod interlock mechanism of inkle loom contains:

a base body, which is used for being arranged on the supporting structure;

the pivot shaft can penetrate through the seat body in a rotating manner and comprises a first end and a second end which are opposite; the first end is used for fixedly arranging the bottom line swing rod;

a pivot assembly, comprising:

a traction part which is fixedly arranged at the second end of the pivotal shaft;

the connecting rod is connected with the traction piece, and the connecting position of the connecting rod and the traction piece is not positioned on the axial extension line of the pivot shaft;

one end of the rocker arm is pivoted on the supporting structure, and the other end of the rocker arm is connected with the connecting rod;

the leaning wheel can be rotatably arranged on the rocker arm;

a cam, which is used for fixedly sleeving the driving shaft and rotating along with the driving shaft; the outer ring surface of the cam is abutted against the outer ring surface of the abutting wheel, and the outer ring surface of the cam is parallel to the outer ring surface of the abutting wheel at the abutting position;

and the elastic element is connected with the pivoting component and can enable the abutting wheel to abut against the cam.

2. The bobbin thread oscillating bar linkage mechanism of the ribbon loom as claimed in claim 1, wherein the elastic member is a torsion spring; the elastic element is connected to the pivot shaft and provides a torque for the pivot shaft, so that the elastic element is connected with the pivot assembly through the pivot shaft to enable the abutting wheel to abut against the cam.

3. The bobbin thread pendulum bar linkage mechanism of the webbing loom of claim 2, wherein the bobbin thread pendulum bar linkage mechanism of the webbing loom further comprises:

a first direction of rotation;

a second rotation direction opposite to the first rotation direction;

the adjusting piece is sleeved on the pivot shaft and can rotate relative to the pivot shaft; one end of the elastic element is fixedly arranged on the adjusting piece, and the other end of the elastic element is fixedly arranged on the pivot shaft; when the adjusting member rotates along the first rotating direction relative to the pivot shaft, the torque is increased; when the adjusting piece rotates along the second rotating direction relative to the pivot shaft, the torque is reduced; the adjusting member includes:

the clamping parts are annularly arranged and are positioned in the radial direction of the pivot shaft;

a clamping component which is fixedly arranged on the seat body; the clamping component is abutted against one of the clamping parts of the adjusting piece and stops the adjusting piece in the second rotating direction.

4. The bobbin thread oscillating bar linkage mechanism according to claim 3, wherein each of the engaging portions of the adjusting member is formed on an outer circumferential surface of the adjusting member.

5. The bobbin thread oscillating bar linkage mechanism of the ribbon loom as claimed in claim 3, wherein the locking member comprises:

a clamping seat which is fixedly arranged on the seat body and comprises a propping wall;

a clamping piece which is pivoted on the clamping seat; when the adjusting piece rotates along the first rotating direction relative to the pivot shaft, the plurality of clamping parts of the adjusting piece enable the clamping piece to pivot relative to the clamping seat in sequence; when the adjusting member rotates along the second rotation direction relative to the pivot shaft, one of the clamping parts of the adjusting member abuts against the clamping member and the clamping member abuts against the abutting wall of the clamping seat, so that the adjusting member is stopped in the second rotation direction.

6. The bobbin thread pendulum bar linkage mechanism of the ribbon loom of claim 5,

the clamping seat of the clamping component further comprises:

a first surface facing the adjusting member;

a second surface facing away from the adjusting member;

a through hole penetrating through the first surface and the second surface; the abutting wall of the clamping seat is formed on the inner wall surface of the through hole;

two pivoting grooves which are communicated with the through hole and are positioned at two opposite sides of the through hole; each pivot groove is provided with an opening on the second surface;

the clamping member of the clamping assembly further comprises:

the abutting part can abut against the abutting wall of the clamping seat and can abut against one clamping part of the adjusting piece;

two pivoting parts formed at two ends of the abutting part and respectively rotatably arranged in the two pivoting grooves of the clamping seat; each pivot part can enter or leave the corresponding pivot groove from the opening formed on the second surface by the corresponding pivot groove; the clamping component further comprises:

and the clamping cover can be separately arranged on the second surface of the clamping seat and seals the opening formed on the second surface by each pivoting groove.

7. The bobbin thread pendulum bar linkage mechanism of the ribbon loom of claim 3, wherein the adjusting member further comprises:

the slots are annularly arranged and are positioned in the radial direction of the pivot shaft; each slot is provided with an opening on the outer ring surface of the adjusting piece.

8. The bobbin thread pendulum bar linkage mechanism of claim 7, wherein each slot extends in a radial direction of the pivot axis.

Technical Field

The invention relates to a bottom line swing rod linkage machine of a ribbon loom

Background

In some prior art needle looms, in order to allow the weft hooks, the knitting needles and the bottom thread oscillating bars to have enough operating space to cooperate with each other, the oscillating direction of the bottom thread oscillating bars is designed to be inclined to the moving direction of the weft hooks (which are approximately transverse) and the knitting needles (which are approximately longitudinal), so as to avoid mutual collision and interference.

Referring to fig. 6 and 7, to achieve the above purpose, the prior art ribbon loom includes a first shaft 91, a weft hook 92, a second shaft 93, a pushing member 94, a fixing seat 95, a pivot shaft 96, a pushing member, and a bottom swing link 98. The first shaft 91 is connected to a driving device (not shown), and the weft hook 92 is fixed on the first shaft 91, so that the driving device can drive the weft hook 92 to move back and forth through the first shaft 91. The second shaft 93 is connected to the first shaft 91 by a belt, and is rotated by the first shaft 91. The pushing and abutting piece 94 is fixedly arranged on the outer annular surface of the second shaft 93 and moves along with the rotation of the second shaft 93; the pushing member 94 has a pushing curved surface 941. The holder 95 is fixedly arranged on the support structure of the ribbon loom. The pivot shaft 96 is rotatably provided on the holder 95. The abutting assembly includes an abutting seat 971, an abutting block 972 and a spring 973. The abutting seat 971 is fixedly disposed on the outer annular surface of the pivot shaft 96 and is movable relative to the fixed seat 95. The abutting block 972 is disposed on the abutting seat 971 and abuts against the abutting curved surface 941 of the abutting member 94. The spring 973 is disposed between the fixing seat 95 and the abutting seat 971, so that the abutting block 972 can maintain abutting against the abutting curved surface 941 during operation by abutting against the abutting seat 971. The bobbin thread swing link 98 is fixed on one end of the pivot shaft 96 protruding from the fixed seat 95 and can move along with the rotation of the pivot shaft 96.

With the above structure, when the second shaft 93 rotates along with the first shaft 91, the pushing member 94 moves along with the first shaft and gradually pushes against the block 972 with the pushing curved surface 941. Since the abutting block 972 is disposed on the abutting seat 971 and the abutting seat 971 is fixedly disposed on the outer annular surface of the pivot shaft 96, when the abutting curved surface 941 abuts against the abutting block 972, a moment is equally generated on the pivot shaft 96; at this point, the spring 973 is pushed and compressed, and finally the moment rotates the pivot shaft 96 relative to the fixed seat 95; on the contrary, when the abutting member 94 moves reversely along with the second shaft 93, the abutting block 972 is urged by the spring 973 to gradually return along with the abutting curved surface 941, so that the bobbin thread oscillating bar 98 swings back and forth along a desired path. Furthermore, since the first shaft 91 and the second shaft 93 are engaged with the belt, they rotate back and forth synchronously, so that the bottom line swing link 98 can swing back and forth to weave the webbing in coordination with the operation of the weft hook 92.

However, the above structure has the following disadvantages:

firstly, since the second shaft 93 rotates back and forth synchronously with the first shaft 91, the pushing member 94 fixed on the second shaft 93 also moves back and forth synchronously with the first shaft 91; in addition, the abutting block 972 is continuously abutted against the abutting curved surface 941 by the urging of the spring 973, so that the abutting curved surface 941 and the abutting block 972 continuously rub back and forth during the process of the back and forth movement of the urging member 94, thereby causing severe abrasion.

Second, since the abutting block 972 actually moves arcuately with the pivot shaft 96 as the axis, the abutting block 972 and the pushing curved surface 941 do not maintain complete positive abutting during the operation process, but the abutting block 972 gradually inclines to the pushing curved surface 941 during the pushing process of the pushing curved surface 941, which results in more serious friction loss.

Third, since the bottom line swing link 98 must swing the webbing in coordination with the movement of the weft hook 92, and the swing timing and distance of the bottom line swing link 98 are completely determined by the timing and degree of the pushing member 94 pushing against the block 972, the pushing curved surface 941 of the pushing member 94 must be designed in coordination with the movement of the weft hook 92, and thus the pushing curved surface 941 is inevitably an irregular curved surface. In addition, the offset curved surface 941 must have sufficient accuracy, so that the design calculation simulation and the manufacturing tolerance control must be very strict. Therefore, higher design and manufacturing costs are inevitably incurred.

Fourth, some manufacturers have made abutment block 972 of plastic in order to reduce the frictional noise described above. However, the friction loss of the abutting block 972 itself is more severe, which leads to a more rapid misalignment of the swing timing and amplitude of the bobbin thread swing link 98.

Fifth, the mechanism of the prior art is bulky and has many parts, so the mechanism is complex and is not easy to disassemble, assemble and maintain.

Disclosure of Invention

In view of the above-mentioned drawbacks and disadvantages of the prior art, the present invention provides a bobbin thread swing link mechanism for a webbing loom, which can greatly reduce friction loss, and thus is more durable and cost-effective. In addition, the design is simple, the volume is small, the disassembly, the assembly and the maintenance are easy, and the cost of design, manufacture and maintenance can be further reduced.

In order to achieve the above object, the present invention provides a bobbin thread oscillating bar linkage mechanism of a ribbon loom, which is used for being arranged on a supporting structure of the ribbon loom and for fixedly arranging a bobbin thread oscillating bar; the ribbon loom includes a driving shaft; the bottom line pendulum rod interlock mechanism of inkle loom contains:

a base body, which is used for being arranged on the supporting structure;

the pivot shaft can penetrate through the seat body in a rotating manner and comprises a first end and a second end which are opposite; the first end is used for fixedly arranging the bottom line swing rod;

a pivot assembly, comprising:

a traction part which is fixedly arranged at the second end of the pivotal shaft;

the connecting rod is connected to the traction piece, and the connecting position of the connecting rod and the traction piece is not positioned on the axial extension line of the pivot shaft;

one end of the rocker arm is pivoted on the supporting structure, and the other end of the rocker arm is connected with the connecting rod;

the leaning wheel can be rotatably arranged on the rocker arm;

a cam, which is used for fixedly sleeving the driving shaft and rotating along with the driving shaft; the outer ring surface of the cam is abutted against the outer ring surface of the abutting wheel, and the outer ring surface of the cam is parallel to the outer ring surface of the abutting wheel at the abutting position;

and the elastic element is connected with the pivoting component and can enable the abutting wheel to abut against the cam.

The hinge shaft has the advantages that the traction piece is fixedly arranged at the second end of the hinge shaft, and the connecting position of the connecting rod and the traction piece is not positioned on the axial extension line of the hinge shaft, so that the hinge shaft can be driven when the traction piece is pulled by the connecting rod. And, through the rocking arm, support wheel and cam cooperation, the cam just can be along with the drive shaft rotates and in good time through supporting wheel and rocking arm pulling connecting rod, borrow this to drive rotatory pivot axle. The abutting wheel and the cam are in rolling contact, so that friction loss between the abutting wheel and the cam is extremely low; in addition, in operation, the outer ring surface of the cam and the outer ring surface of the abutting wheel are kept parallel to each other at the abutting position, so that compared with the sliding contact which is gradually inclined in the prior art, the friction loss can be further greatly reduced, and the cam is more durable and saves the cost. In addition, the invention has simple design, small volume and easy disassembly, assembly and maintenance, and can further reduce the cost of design, manufacture and maintenance.

Further, the bobbin thread swing link linkage mechanism of the ribbon loom is characterized in that the elastic element is a torsion spring; the elastic element is connected to the pivot shaft and provides a torque for the pivot shaft, so that the elastic element is connected with the pivot assembly through the pivot shaft to enable the abutting wheel to abut against the cam.

Further, the bobbin thread pendulum rod interlock mechanism of inkle loom, wherein, this bobbin thread pendulum rod interlock mechanism of inkle loom further includes:

a first direction of rotation;

a second rotation direction opposite to the first rotation direction;

the adjusting piece is sleeved on the pivot shaft and can rotate relative to the pivot shaft; one end of the elastic element is fixedly arranged on the adjusting piece, and the other end of the elastic element is fixedly arranged on the pivot shaft; when the adjusting member rotates along the first rotating direction relative to the pivot shaft, the torque is increased; when the adjusting piece rotates along the second rotating direction relative to the pivot shaft, the torque is reduced; the adjusting member includes:

the clamping parts are annularly arranged and are positioned in the radial direction of the pivot shaft;

a clamping component which is fixedly arranged on the seat body; the clamping component is abutted against one of the clamping parts of the adjusting piece and stops the adjusting piece in the second rotating direction.

Further, in the bobbin thread oscillating bar linkage mechanism of the webbing loom, each of the engaging portions of the adjusting member is formed on an outer circumferential surface of the adjusting member.

Further, the bobbin thread pendulum rod interlock mechanism of inkle loom, wherein, should block solid subassembly and include:

a clamping seat which is fixedly arranged on the seat body and comprises a propping wall;

a clamping piece which is pivoted on the clamping seat; when the adjusting piece rotates along the first rotating direction relative to the pivot shaft, the plurality of clamping parts of the adjusting piece enable the clamping piece to pivot relative to the clamping seat in sequence; when the adjusting member rotates along the second rotation direction relative to the pivot shaft, one of the clamping parts of the adjusting member abuts against the clamping member and the clamping member abuts against the abutting wall of the clamping seat, so that the adjusting member is stopped in the second rotation direction.

Further, the bottom thread swing rod linkage mechanism of the ribbon loom is characterized in that,

the clamping seat of the clamping component further comprises:

a first surface facing the adjusting member;

a second surface facing away from the adjusting member;

a through hole penetrating through the first surface and the second surface; the abutting wall of the clamping seat is formed on the inner wall surface of the through hole;

two pivoting grooves which are communicated with the through hole and are positioned at two opposite sides of the through hole; each pivot groove is provided with an opening on the second surface;

the clamping member of the clamping assembly further comprises:

the abutting part can abut against the abutting wall of the clamping seat and can abut against one clamping part of the adjusting piece;

two pivoting parts formed at two ends of the abutting part and respectively rotatably arranged in the two pivoting grooves of the clamping seat; each pivot part can enter or leave the corresponding pivot groove from the opening formed on the second surface by the corresponding pivot groove;

the clamping component further comprises:

and the clamping cover can be separately arranged on the second surface of the clamping seat and seals the opening formed on the second surface by each pivoting groove.

Further, the bobbin thread pendulum rod interlock mechanism of inkle loom, wherein, this adjusting part further includes:

the slots are annularly arranged and are positioned in the radial direction of the pivot shaft; each slot is provided with an opening on the outer ring surface of the adjusting piece.

Further, in the bobbin thread swing link mechanism of the webbing loom, each slot extends along the radial direction of the pivot shaft.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

fig. 1 is a perspective view of the present invention.

Fig. 2 is a side view of the rocker arm, abutment wheel and cam of the present invention.

Fig. 3 is an exploded view of the components of the present invention.

Fig. 4 is an exploded view of another element of the present invention.

FIG. 5 is a cross-sectional view of the adjusting member and the clamping member of the present invention.

Fig. 6 is a perspective view of a bobbin thread swing link mechanism according to the prior art.

Fig. 7 is a bottom enlarged view of the prior art.

Detailed Description

The technical means adopted by the invention to achieve the predetermined object of the invention are further described below with reference to the drawings and the preferred embodiments of the invention.

Referring to fig. 1 and 3, the bobbin thread swing link mechanism of the webbing loom of the present invention is disposed on a supporting structure (not shown) of the webbing loom and is used to fix a bobbin thread swing link a. The webbing loom includes a drive shaft B. Wherein, the supporting structure can be a machine table or a framework of the ribbon loom. The bottom line swing link linkage mechanism of the ribbon loom comprises a seat body 10, a pivot shaft 20, a pivot component 30 and an elastic element 40.

Referring to fig. 3 and 4, the base 10 is disposed on the supporting structure, and in the embodiment, the base 10 includes a base portion 11 and two supporting portions 12. The two carrying portions 12 are formed on two opposite sides of the base portion 11 and extend toward the same side of the base portion 11; in other words, the base 10 has a concave structure in the present embodiment.

The pivot shaft 20 can rotatably penetrate through the base 10, specifically, can rotatably penetrate through the two bearing portions 12, and the pivot shaft 20 includes a first end 21 and a second end 22 opposite to each other. The first end 21 is used for fixing the bottom line swing rod A.

Please further refer to fig. 2, fig. 3 and fig. 4. The pivot assembly 30 includes a pulling member 31, a connecting rod 32, a rocker arm 33, an abutment wheel 34 and a cam 35. The pulling member 31 is fixed to the second end 22 of the pivot shaft 20. The connecting rod 32 is connected to the pulling member 31, and the connection point of the connecting rod 32 and the pulling member 31 is not located on the axial extension line of the pivot shaft 20, i.e. the connection point of the connecting rod 32 and the pulling member 31 is spaced from the axial extension line of the pivot shaft 20, so that when the connecting rod 32 pulls the pulling member 31, the pivot shaft 20 can be driven to rotate. One end of the rocker arm 33 is pivotally mounted to the support structure, and the other end of the rocker arm 33 is connected to the connecting rod 32. The abutment wheel 34 is rotatably provided on the rocker arm 33. The cam 35 is fixedly sleeved on the driving shaft B and rotates along with the driving shaft B; also, the outer annular surface of the cam 35 abuts against the outer annular surface of the abutment pulley 34, and the outer annular surface of the cam 35 and the outer annular surface of the abutment pulley 34 are parallel to each other at the abutment. In other words, the cams 35 are in contact with and roll-connected to the abutment wheels 34 with their respective outer annular surfaces, while the outer annular surfaces of the cams 35 and the outer annular surfaces of the abutment wheels 34 are maintained parallel to each other at the abutment during the relative rolling of the two.

The elastic element 40 is connected to the pivoting assembly 30 and tends to bring the abutment wheel 34 into abutment against the cam 35. Specifically, in the embodiment, the elastic element 40 is a torsion spring, and the elastic element 40 is connected to the pivot shaft 20 and provides a torque to the pivot shaft 20, which maintains the abutting wheel 34 abutting against the cam 35 through the pivot shaft 20, the pulling member 31, the connecting rod 32 and the rocker arm 33. However, in other embodiments, the elastic element 40 is not limited to a torsion spring and is connected to the pivot shaft 20, and may be a compression spring, for example, and one end of the compression spring abuts against the supporting structure and the other end abuts against the rocker arm 33, so that the abutting wheel 34 can also be maintained abutting against the cam 35.

In addition, referring to fig. 3, fig. 4 and fig. 5, the bobbin thread swing link linkage mechanism of the webbing loom in the present embodiment further includes a first rotating direction D1, a second rotating direction D2, an adjusting member 50 and a locking member 60.

The first rotational direction D1 is opposite to the second rotational direction D2.

The adjusting member 50 is sleeved on the pivot shaft 20 and can rotate relative to the pivot shaft 20. One end of the elastic element 40 is fixed to the adjusting member 50, and the other end of the elastic element 40 is fixed to the pivot shaft 20. When the adjustment member 50 is rotated in the first rotational direction D1 relative to the pivot shaft 20, the torque of the elastic element 40 increases; when the adjustment member 50 is rotated in the second rotational direction D2 relative to the pivot axle 20, the torque of the resilient member 40 is reduced. The adjusting member 50 includes a plurality of engaging portions 51 and a plurality of slots 52. The plurality of fastening portions 51 are annularly arranged and located in a radial direction of the pivot shaft 20, and specifically, each fastening portion 51 is formed on an outer annular surface of the adjusting member 50 in the present embodiment, but may be formed on a side surface of the adjusting member 50 in other embodiments. The slots 52 are annularly arranged and located in the radial direction of the pivot shaft 20, and each slot 52 forms an opening on the outer circumferential surface of the adjusting member 50. The insertion groove 52 penetrates the trim portion 51 in the present embodiment, and an opening is formed in the trim portion 51. In the present embodiment the slots 52 extend in the radial direction of the pivot axis 20.

The fixing component 60 is fixed on the seat body 10, and abuts against one of the fixing portions 51 of the adjusting component 50, and stops the adjusting component 50 in the second rotation direction D2. The fastening assembly 60 includes a fastening base 61, a fastening member 62 and a fastening cover 63.

The fastening seat 61 is fixed on the seat body 10 and includes a supporting wall 611, a first surface 612, a second surface 613, a through hole 614 and two pivoting grooves 615. An abutment wall 611 is formed on an inner wall surface of the penetration hole 614. The first face 612 faces the conditioning piece 50. Second face 613 faces away from conditioning element 50. The through hole 614 penetrates the first and second faces 612 and 613. The two pivoting slots 615 are connected to the through hole 614 and located at two opposite sides of the through hole 614, and each pivoting slot 615 forms an opening on the second surface 613.

The fastening member 62 is pivotally disposed on the fastening base 61. When the adjusting member 50 rotates along the first rotating direction D1 relative to the pivot shaft 20, the plurality of engaging portions 51 of the adjusting member 50 sequentially move the engaging member 62 to pivot the engaging member 62 relative to the engaging base 61; when the adjuster 50 rotates along the second rotation direction D2 relative to the pivot 20, the retainer 62 abuts against one of the retainer 51 of the adjuster 50 and the abutting wall 611 of the retainer 61, and stops the adjuster 50 in the second rotation direction D2. The fastening member 62 includes an abutting portion 621 and two pivoting portions 622, the abutting portion 621 can abut against the abutting wall 611 of the fastening seat 61, and can abut against one of the fastening portions 51 of the adjusting member 50. The two pivoting portions 622 are formed at two ends of the abutting portion 621 and are respectively rotatably disposed in the two pivoting grooves 615 of the fastening seat 61. Each pivot portion 622 can enter or leave the corresponding pivot slot 615 through the opening formed on the second surface 613 by the corresponding pivot slot 615.

The fastening cover 63 is detachably disposed on the second surface 613 of the fastening base 61, and closes the opening formed on the second surface 613 of each pivoting groove 615.

In use, an operator can insert any rod into one of the slots 52 and rotate the adjusting member 50 in the first rotating direction D1, so that the torque provided by the elastic element 40 is increased, and the abutting wheel 34 abuts against the cam 35 more tightly, thereby the swing of the bobbin thread swing rod a is more accurate.

In addition, during the adjustment process, when the operator rotates the adjustment member 50 in the first rotation direction D1, since the engaging member 62 is not limited, the plurality of engaging portions 51 of the adjustment member 50 can sequentially move the engaging member 62 to pivot the engaging member 62 relative to the engaging base 61; in other words, since the locking member 62 is not restricted to rotate relative to the locking seat 61 in the direction along the first rotation direction D1, the locking member 62 is pulled without stopping the adjusting member 50 from rotating toward the first rotation direction D1.

Conversely, when the torque provided by the resilient element 40 is sufficient, the operator stops applying the force in the first rotational direction D1, and the torque of the resilient element 40 tends to rotate the adjusting member 50 in the second rotational direction D2; however, when the adjusting element 50 rotates along the second rotating direction D2, the engaging element 62 abuts against one of the engaging portion 51 of the adjusting element 50 and the abutting wall 611 of the engaging seat 61, and stops the adjusting element 50 in the second rotating direction D2. In other words, in the direction along the second rotation direction D2, the retainer 62 is limited by the abutting wall 611 and cannot rotate relative to the retainer seat 61, so the abutting portion 621 of the adjuster 50 cannot pull the retainer 62, but is abutted and retained by the retainer 62, and the adjuster 50 cannot continue to rotate along the second rotation direction D2. Thus, the adjusted torque can be maintained.

The pulling member 31 is fixed to the second end 22 of the pivot shaft 20, and the connecting point of the connecting rod 32 and the pulling member 31 is not located on the axial extension line of the pivot shaft 20, so that the connecting rod 32 pulls the pulling member 31 to drive the pivot shaft 20 to rotate. And, through the cooperation of the rocker arm 33, the abutting wheel 34 and the cam 35, the cam 35 can pull the connecting rod 32 through the abutting wheel 34 and the rocker arm 33 at the proper time along with the rotation of the driving shaft B, thereby driving the rotating pivot shaft 20. Wherein, because the abutting wheel 34 and the cam 35 are in rolling contact, the friction loss between the two is extremely small; in addition, in operation, the outer annular surface of the cam 35 and the outer annular surface of the abutment wheel 34 are kept parallel to each other at the abutment, so that the friction loss can be further greatly reduced compared to the sliding contact of the prior art, which is gradually inclined, thereby being more durable and cost-saving. In addition, the invention has simple design, small volume and easy disassembly, assembly and maintenance, and can further reduce the cost of design, manufacture and maintenance.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.