TWI548792B - Sewing machine tangent mechanism - Google Patents

Description

Cutting mechanism of sewing machine

The invention relates to an automatic thread cutting device, in particular to a direct drive automatic thread cutting mechanism for a sawtooth sewing machine.

Generally, when the sewing machine is nearing the end of the sewing machine, the sewing thread will be cut through the thread cutting mechanism to wait for the next sewing work, such as the Republic of China Patent No. M383002, which is a tangent structure of the three sewing machines. Mainly corresponding to the sewing machine having a tangential structure, the tangential structure comprises a driving group controlled by the signal to drive the operation of the tangential structure, the driving group is driven by a power source to make the ejector rod to a position after the protruding stroke The front and rear movements are used to cause the ejector rod to drive the connecting rod group to interlock with the hooking group to move the hook of the working piece to be cut back by the cutter, and no need to manually cut the thread to achieve automatic thread trimming. purpose. Or, for example, the Republic of China Patent No. I320437, which is a sewing machine needle cutting device for connecting to a sewing machine body, the cutting device comprising a cam mechanism, a holding mechanism, a supporting mechanism, a scissors driving group and a needle scissors, wherein the cam The mechanism comprises a cam, a scissors and a positioning cam arm, the holding mechanism comprises a fixed arm and a moving component capable of sliding relative to the fixed arm, the supporting mechanism comprises a seat plate driven by the positioning cam arm and connected to the moving component and a connecting plate The support arm set, the scissor drive set includes a drive arm coupled to the scissor cam arm and a lever pivotally coupled to the support arm set, the stitch scissor including a fixed blade coupled to the support arm set and a movable blade coupled to the fixed blade edge.

However, as described in the above-mentioned sewing machine patented tangential mechanism, the structure of the driving cutter is linked by a connecting rod group composed of more than two connecting rods, which not only increases the complexity of the structure, but also increases the various factors in the transmission process. The error caused by the difference in size or looseness between the links, and thus the tangential work cannot be performed accurately. Further, the conventional tangent The mechanism is driven by a positioning motor that controls the rotation of the cam, and the speed of the rotation of the cam is controlled by the positioning motor to control the speed of the tangential cutting of the scissors driving group. The scissors driving group is not directly controlled by the positioning motor, and the scissors driving group and positioning are performed. This cam is still present between the motors and is an indirect drive, so as described above, there is a problem that the tangential operation cannot be accurately controlled.

The main object of the present invention is to solve the problem that the tangential device of a general sewing machine uses a plurality of connecting rods and cams to drive the tangential cutter group, which makes it impossible to accurately control the tangential cutter group.

In order to achieve the above object, the present invention provides a thread cutting mechanism for a sewing machine, which is mounted on a sewing machine having a sewing platform, the thread cutting mechanism of the sewing machine comprising a driving assembly, and a tangential assembly for driving the tangential line by the driving assembly . The driving assembly comprises a stepping motor, a swinging rod pivoted to the stepping motor, and a push rod connecting the stepping motor and the swinging rod driven by the stepping motor for a horizontal reciprocating stroke, the swinging rod a pivoting portion that is in pivotal relationship with the stepping motor housing, and a swinging portion that is coupled to the push rod and is rotated by the push rod and pivoted by the pivoting portion. The stepping motor includes a The push rod is a parallel rotating disc, and a linking portion disposed on the rotating disc and pivoted to the push rod and driving the push rod to perform the horizontal reciprocating stroke when the rotating disc rotates. The tangential component is disposed on the sewing platform, and the tangential component comprises a hooking knife connected to the swinging portion and connected to the swinging portion by a linear trajectory to hook back a sewing thread and have a hook line path, and a A tangential cutter that cuts the sewing thread when the hook hook is hooked back to the sewing thread on the hook path.

In one embodiment, the tangential assembly includes a load-bearing portion disposed on the sewing platform, and a sliding slot that is opened on the load-bearing portion along the hook line for the hook knife to be displaced back and forth with the tangential cutter.

In an embodiment, the tangential assembly includes two protrusions protruding from the two ends of the sliding slot to limit the displacement of the tangential cutter.

In one embodiment, the tangential assembly includes a cover that covers the load bearing portion to limit vertical displacement of the tangential cutter, and a sluice port is disposed at the sluice port to abut the hook knives and the tangential line The knife fits against the top.

In one embodiment, the tangential cutter includes a blade portion disposed at one end edge, and an opening formed along the hook line path, the hook wire cutter includes a through hole and abutting against the opening when displaced The hole wall cooperates with the piercing portion of the tangential cutter displacement, and a hook line portion hooked back to the sewing thread is provided on the same side of the blade edge portion.

In an embodiment, the tangential cutter includes an abutting portion disposed on the other end edge, the hooking knife includes a pushing portion disposed on the same side of the abutting portion, and the tangential assembly includes a tangential cutter disposed on the tangential cutter a movable limiting portion on one side, the movable limiting portion includes an elastic member for providing an elastic force, and a rotational force is driven by the elastic force to abut against the abutting portion when the hooking knife is displaced toward the sewing thread Restricting the tangential cutter displacement and the rotating arm that is topped by the push top when the hook knives are hooked back to the sewing thread.

In one embodiment, the swinging lever includes a returning portion that is coupled to the swinging portion and is rotated by the swinging portion and pivoted by the pivoting portion. The driving component includes a detecting portion of the stepping motor. The returning portion generates a sensing element that stops the signal.

The utility model has the beneficial effects that the stepping motor directly drives the push rod to perform the horizontal reciprocating stroke to drive the swinging rod, and the hooking knife and the tangential cutter are tangentially linked, and the stepping motor and the tangential component are only transmitted through A push rod is interlocked with a swing rod, and the linkage mode of the invention is simple and straightforward compared with the conventional thread cutter device with more than two links, because the transmission is reduced by a small number of connecting rods. The energy is required, and the error of the transmission between the connecting rods is greatly reduced, and the tangent of the tangential component can be controlled more accurately. In addition, the tangential speed of the tangential component can be directly controlled by direct drive by controlling the rotational speed and angle of the rotary disk of the stepping motor, and the indirect drive structure for controlling the tangential line is controlled by the conventional tangential mechanism controlling the rotation speed of the cam. , more precise control of the tangent.

10‧‧‧Zigzag sewing machine

11‧‧‧Sewing platform

2‧‧‧Drive components

21‧‧‧Stepper motor

211‧‧‧ rotating disk

212‧‧‧ linkage department

22‧‧‧Swing rod

221‧‧‧ pivotal department

222‧‧‧ swinging department

223‧‧‧Return to zero

23‧‧‧Put

24‧‧‧Inductive components

3‧‧‧tangential components

31‧‧‧Hook knife

311‧‧‧ Department of Wear

312‧‧‧Pushing Department

313‧‧‧Hook line

32‧‧‧Thread cutter

321‧‧‧Knife

322‧‧‧Abutment

323‧‧‧Opening

33‧‧‧Loading Department

34‧‧‧Chute

35a, 35b‧‧‧Prominent Department

36‧‧‧Event Limitation Department

361‧‧‧Flexible components

362‧‧‧Rotating arm

37‧‧‧ Cover

38‧‧‧ arrive at the top

4‧‧‧Sewing thread

R‧‧‧ hook line path

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view showing the structure of a sewing machine in accordance with a preferred embodiment of the present invention.

Figure 2 is a schematic view of the appearance of a preferred embodiment of the present invention.

3 is a schematic exploded view of a preferred embodiment of the present invention.

Figure 4 is a top plan view of a preferred embodiment of the present invention.

5-1 to 5-5 are schematic views of the tangential actuation of a preferred embodiment of the present invention.

The detailed description and technical contents of the present invention will now be described with reference to the drawings. Please refer to FIG. 1 , FIG. 2 , FIG. 3 and FIG. 4 , which are schematic exploded view, appearance and structure of the sewing machine according to a preferred embodiment of the present invention. The exploded view and the upper view are as shown in the figure: The present invention is a thread cutting mechanism of a sewing machine, which is mounted on a zigzag sewing machine 10, which is mainly used for sewn stitching, shoulder straps and general "Z". The glyph sewing has a sewing platform 11, the thread cutting mechanism of the sewing machine comprising a drive assembly 2, and a tangential assembly 3 driven by the drive assembly 2 to tangentially. The driving assembly 2 includes a stepping motor 21, a swinging lever 22 pivotally connected to the stepping motor 21, and a stepping motor 21 and the swinging lever 22 are driven by the stepping motor 21 to perform a horizontal reciprocating stroke. a push rod 23, the swing rod 22 includes a pivoting portion 221 in a pivotal relationship with the outer casing of the stepping motor 21, and is coupled to the push rod 23 and coupled by the push rod 23, wherein the pivot portion 221 is The swinging portion 222 that pivots the fulcrum. The tangential assembly 3 is disposed on the sewing platform 11 . The tangential assembly 3 includes a trajectory that is connected to the oscillating portion 222 and is linearly traversed by the oscillating portion 222 to hook back a sewing thread 4 (shown in Figure 5-1). And a slash cutter 32 having a hook line path R and a tangential cutter 32 disposed on the hook line path R to cut the sewing thread 4 when the hook thread cutter 31 is hooked back to the sewing thread 4.

Specifically, the stepping motor 21 includes a rotating disc 211, and a rotating disc 211 is pivotally connected to the push rod 23 and drives the push rod 23 to perform the horizontal reciprocating stroke when the rotating disc 211 rotates. The linking unit 212. The tangential assembly 3 includes a bearing portion 33 disposed on the sewing platform 11, a sliding slot 34 extending along the hooking path R on the carrying portion 33, and the tangential cutter 32 and the hooking cutter 31. The hook groove 34 slides back and forth along the hook line path R, and the convex portions 35a and 35b which are protruded from the sliding groove 34 to restrict the displacement of the tangential cutter 32. The tangential cutter 32 is disposed above the hook knives 31. The tangential cutter 32 includes a blade portion 321 disposed at one end edge, an abutting portion 322 disposed at the other end edge, and a path along the hook line R. An opening 323 between the blade portion 321 and the abutting portion 322, the hooking blade 31 includes a through portion 311 through which the opening 323 is inserted, and a pushing portion 312 disposed on the same side of the abutting portion 322 And a hooking portion 313 hooked back to the sewing thread 4 is provided on the same side as the blade portion 321 . In addition, the tangential assembly 3 further includes a movable limiting portion 36 disposed on one side of the tangential cutter 32. The movable limiting portion 36 includes a resilient member 361 for providing an elastic force, and a rotation driven by the elastic force. Rotating arm 362 of the stroke.

As shown in FIG. 5-1 to FIG. 5-4, in the initial state, the tangential cutter 32 and the hook knives 31 are accommodated in the sliding groove 34, and the rotating arm 362 abuts against The tangential cutter 32 and the hook knives 31 are rotated clockwise 211 when the stepping motor 21 is energized, and the urging portion 212 is rotated to pull the push rod 23, and the push rod 23 further pulls the swing The rod 22 is displaced by the swinging rod 22 along the sliding slot 34, and then the through portion 311 of the hooking cutter 31 abuts against the opening 323 of the tangential cutter 32, thereby further The tangential cutter 32 is interlocked along the sliding groove 34 until it stops against the convex portion 35a. When the tangential cutter 32 stops displacement against the convex portion 35a, the hook knives 31 are simultaneously stopped and displaced to the position at which the hook portion 31 hooks the sewing thread 4. Then, the stepping motor 21 drives the rotating disc 211 to rotate counterclockwise, and the push rod 23 is interlocked outwardly, thereby driving the swinging portion 222 of the swinging lever 22 to perform the rotating stroke, and the hooking knife 31 is interlocked by the swinging lever 22 Displaces backward and hooks back the sewing thread 4, at which time the sewing thread 4 is clamped to the hook knife 31 Between the tangential cutter 32 and the rotary disc 211 of the stepping motor 21, the second step is rotated counterclockwise, and the hook knives 31 are further pulled backward. At this time, the blade portion 321 of the tangential cutter 32 cuts off the knives 32. Sewing thread 4, complete the two-stage tangent. When the hooking knife 313 continues to be displaced backward, the pushing portion 312 pushes the rotating arm 362, and the through portion 311 abuts against the hole of the opening 323 of the tangential cutter 32 to drive the tangential cutter 32 to be displaced rearward. Finally, the abutting portion 322 of the tangential cutter 32 abuts against the other of the protruding portions 35b to stop the displacement, and completes the operation of the entire tangential line.

In addition, the swinging lever 22 of the present invention includes a returning portion 223 that is coupled to the swinging portion 222 and is rotated by the swinging portion 222 and pivoted by the pivoting portion 221. The driving assembly 2 includes a step disposed at the step. The motor 21 detects the return to the 223 and generates a stop signal sensing element 24. In the initial state, the returning portion 223 is located in front of the sensing element 24, and the sensing element 24 detects the zeroing portion 223 and defines an origin position when the stepping motor 21 drives the swinging portion When the 222 is rotated, the returning portion 223 is simultaneously rotated by the swinging portion 222 and rotated by the pivoting portion 221 to leave the origin position, and then the stepping motor 21 reversely rotates the rotating disc 211 to cause the tangent assembly 3 When the homing portion 223 is reversely rotated to the origin position, the sensing component 24 detects the homing portion 223 to generate the stop signal, and the stop signal is transmitted to the stepping motor 21 to cause the step. The intake motor 21 is stopped, and the drive assembly 2 and the tangent assembly 3 are returned to the origin to achieve the effect of returning to zero.

In addition, as shown in FIG. 1 and FIG. 3, the tangential assembly 3 includes a cover plate 37 that covers the load-bearing portion 33 to limit the vertical displacement of the tangential cutter 32, and a port disposed on the slot 34 to abut the hook. The wire cutter 31 is configured such that the hooking blade 31 and the nipper 32 are attached to the top portion 38, and the bottom plate 38 is vertically coupled to the abutting portion 38 to make a gap between the hooking blade 31 and the tangential cutter 32. When the hooking blade 31 is hooked back to the sewing thread 4, the sewing thread 4 can be quickly and forcefully cut.

In summary, the present invention directly drives the push rod 23 through the stepping motor 21 to perform the horizontal reciprocating stroke to drive the swing rod 22, and the hook line cutter 31 is tangential to the tangential cutter 32, and is passed through the stepping motor 21. Controlling the rotational speed of the rotating disk 211 to control the cutting The tangential speed of the wire assembly 3, the stepping motor 21 and the tangential assembly 3 are only connected to a swinging rod 22 through a push rod 23, and the complex transmission of more than two connecting rods is compared with the tangential device of the general sewing machine. Mechanism, the linkage mode of the invention is very simple and direct, because the transmission energy required for the transmission is reduced by a small number of connecting rods, and the error of the transmission between the connecting rods is greatly reduced, and the tangent of the tangent assembly can be controlled more accurately.

2‧‧‧Drive components

21‧‧‧Stepper motor

22‧‧‧Swing rod

223‧‧‧Return to zero

23‧‧‧Put

24‧‧‧Inductive components

3‧‧‧tangential components

31‧‧‧Hook knife

32‧‧‧Thread cutter

33‧‧‧Loading Department

Claims (7)

A thread cutting mechanism of a sewing machine is mounted on a sewing machine, the sewing machine has a sewing platform, and the thread cutting mechanism of the sewing machine comprises: a driving assembly comprising a stepping motor and a swinging rod pivoted to the stepping motor And a push rod connecting the stepping motor and the swinging rod to be driven by the stepping motor for a horizontal reciprocating stroke, the swinging rod includes a pivoting portion that is in pivotal relationship with the stepping motor housing, and a The push rod is connected to and coupled by the push rod, and the pivoting portion is rotated by the pivoting portion. The stepping motor comprises a rotating disc parallel to the push rod, and a rotating disc is disposed on the rotating disc and the push rod a linking portion that pivotally drives the push rod to perform the horizontal reciprocating stroke when the rotating disc rotates; and a line assembly disposed on the sewing platform, including a line connected with the swing portion and a straight line running back and forth by the swing portion The trajectory is a hook knife that hooks back a sewing thread and has a hook line path, and a tangential cutter that is disposed on the hook line path to cut the sewing thread when the hook thread cutter is hooked back to the sewing thread. The thread cutting mechanism of the sewing machine according to Item 1, wherein the thread cutting assembly comprises a bearing portion disposed on the sewing platform, and a hook line path is opened on the bearing portion for the hook knife and The tangential cutter moves the chute back and forth. The tangential mechanism of the sewing machine of claim 2, wherein the tangential assembly comprises two protrusions protruding from the two ends of the chute to limit the displacement of the tangential cutter. The tangential mechanism of the sewing machine of claim 2, wherein the tangential assembly comprises a cover plate that covers the load bearing portion to limit vertical displacement of the tangential cutter, and a sash line disposed on the chute port to abut the hook line The knife causes the hook knife to abut the top of the thread cutter. The thread cutting mechanism of the sewing machine of claim 1, wherein the thread cutting knife comprises a blade portion disposed at one end edge, and an opening formed along the hook line path, the hook wire cutter comprising a threaded opening The hole is coupled to the opening portion of the opening of the tangential cutter against the wall of the opening, and a hook line portion hooked to the sewing thread is disposed on the same side of the blade portion. The tangential mechanism of the sewing machine of claim 5, wherein the tangential cutter comprises an abutting portion disposed at the other end edge, the hooking knife comprising a pushing portion disposed on the same side of the abutting portion, The tangential assembly includes a movable limiting portion disposed on one side of the tangential cutter, the movable limiting portion includes an elastic member that provides an elastic force, and is driven by the elastic force to perform a rotational stroke to the sewing thread to the sewing thread When the displacement is against the abutting portion, the rotating arm that limits the displacement of the tangential cutter and is opened by the pushing top when the hooking knife is hooked back to the sewing thread. The tangential mechanism of the sewing machine of claim 1, wherein the oscillating lever comprises a returning portion connected to the oscillating portion and rotated by the oscillating portion and pivoted with the pivoting portion as a fulcrum, the driving component comprising a The sensing element is disposed on the stepping motor to detect the returning portion to generate a stop signal.