JPS6142595B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a sewing machine having a fixed blade and a movable blade for cutting edges of fabric, and a movable blade resting mechanism that allows the movable blade to be placed at a predetermined resting position when not in use. It is related to the device.

PRIOR ART As such a suspension device, there are conventional ones described in, for example, Japanese Utility Model Publication No. 42-21588 and Japanese Utility Model Application Publication No. 51-53165. The former rotates an eccentric wheel together with the main shaft of the sewing machine, and the eccentric action of the eccentric wheel causes a lever provided on the head of the sewing machine to reciprocate around a single axis, thereby causing a cutting operation of the movable blade via a link and a connecting rod. When the movable blade is to be stopped, the operating lever is used to pull up the pivot point between the link and the connecting rod onto an extension of the rotation axis of the lever, and the movable blade is pulled up, disabling the reciprocating movement of the lever and stopping the movable blade. This prevents the cutting operation from occurring.

In addition, in the latter, a pin connected to the movable blade is held between two forked rods, and the rod is rotated back and forth to cause the movable blade to perform cutting operations. By rotating the fitted bell crank, the pin is separated from the forked portion of the rod, nullifying the reciprocating rotation of the rod and pulling down the movable blade.

As described above, all of the above-mentioned conventional blades require a link or a crank to stop the movable blade, so it is necessary to secure the installation space and the space required for rotation thereof. Therefore, if an attempt is made to assemble such a stop device in a narrow space such as a cylindrical bed of a free arm sewing machine, there is a risk that the internal mechanism will become crowded and the assembling will become troublesome.

Purpose of the Invention The purpose of the present invention is to eliminate the need for the above-mentioned space, to be able to be easily assembled and placed in a narrow place such as the cylindrical bed of a free arm sewing machine, and to be able to easily set the movable blade between the use position and the rest position. It is an object of the present invention to provide a movable blade suspension device that can extremely easily switch to the movable blade and that can reliably hold the movable blade in the suspension device.

Embodiment Hereinafter, an embodiment embodying the present invention will be described based on the drawings. In the drawing, 1 is a sewing machine frame;
A known needle bar (not shown) that can move vertically and horizontally is attached to the head of the arm 2, and a needle 3 for forming a lockstitch and a lockstitch are attached to the lower end of the needle bar (not shown). A twin needle consisting of a sewing needle 3 and a needle 4 for forming an overcast stitch located in front of the right side of the sewing needle 3 is fixed.

5 is a cylindrical sewing machine bed disposed below the arm 2; 6 is a throat plate fixed to the front of the upper surface of the sewing machine bed 5; A needle hole 8 located on the front right side of the needle hole 7 and having an open rear side for the overlock stitch needle 4, and a tongue piece 9 for forming an overcast stitch adjacent to the right side of the needle hole 8. , an opening 11 for the feed dog 10 are formed. Reference numeral 12 denotes a sliding plate arranged so as to be slidable back and forth behind the throat plate 6, and as shown in FIGS. 2 and 3, it cooperates with the lockstitch needle 3 to form lockstitch stitches. Therefore, the upper part of the horizontal hook 13 provided in the sewing machine bed 5 is covered.

Reference numeral 14 denotes an open portion formed on the right side of the overlock stitching direction line passing above the overlock sewing needle hole 8;
It is constructed by cutting out the front portions of the front wall portion 5a and bottom wall portion 5b of the sewing machine bed 5 on the right side of the sewing machine bed.

A sliding plate 15 is slidably attached to the outer surface of the sewing machine bed 5 so as to open and close the opening 14, and its upper surface is located on the same plane as the upper surface of the throat plate 6. Reference numeral 16 denotes a protruding piece integrally formed at the rear left end of the sliding plate 15, and as shown in FIG. It is becoming more and more integrated. 17 is a notch formed at the lower left side of the sliding plate 15; 18 is a protrusion integrally formed at the lower right side so as to correspond left and right to the notch 17;
Reference numeral 9 denotes a forward bulge formed between the notch 17 and the protrusion 18. Note that a leaf spring or the like is provided between the sliding plate 15 and the sewing machine bed 5 for slidingly guiding the sliding plate 15 so that it does not come off and for holding the sliding plate 15 in the closed position and the open position. A holding member (not shown) is provided,
A receiving shelf 20 for supporting the edge of the sliding plate 15 is formed at the open side edge of the throat plate 6.

Reference numeral 21 denotes an opening/closing lid rotatably attached to the bed 5 by a shaft 22 at the lower end so as to cover the lower left side of the front opening 14a of the opening 14, and as shown in FIG. The cutout portion 17 of the sliding plate 15 can be placed in a position where it stands up along the open surface of the opening portion 14a and a position where it lies forward from the upright position, and is in a closed state when it is upright.
It is adapted to be engaged with the inner edge and held in that state.

23, as shown in FIGS. 2, 6, and 8, is inserted into a bulge 24 protruding from the inner surface of the front wall 5 of the sewing machine bed 5, and can be adjusted to move in the axial direction with a screw 25. The fixed shaft is fixed, and a plate-shaped portion 23a is integrally formed on the right end thereof.
Reference numeral 26 denotes a fixed blade fixed to the plate-shaped portion 23a by a screw 27, the upper end of which faces the notch 28 formed on the right edge of the open side of the throat plate 6, and the upper end of the blade 2
6a is located substantially on the same plane as the upper surface of the throat plate 6, and is located parallel to the hem stitching direction line.

Next, a mechanism for cutting the edge of the work cloth in cooperation with the fixed blade 26 will be explained.
5 and 7, 29 is a bearing fixed to the inner bottom of the sewing machine bed 5, 30 is a support shaft inserted into and supported by the bearing 29, and a hole 31 at the right end is provided with a bearing. A locking pin 32 that fits into the forked portion 33 of the base portion of 29 is inserted and fixed, preventing rotation of the support shaft 30 and allowing movement only in the axial direction. There is.
Reference numeral 34 designates a prismatic support portion integrally formed at the left end portion of the support shaft 30, in which two through holes 35 and 36 are formed. 37 is the left through hole 3 in the middle part
A guide shaft 39 is inserted into the right through hole 36 at its upper end, and has an eccentric portion 39a in its downward protrusion. A square piece 40 is rotatably fitted into 39a. The eccentric shaft 39 is rotatably adjusted so that the position of the square piece 40 is displaced by the action of the eccentric portion 39a, and is fixed by a set screw 41 at an arbitrary position. 42 is the support shaft 30
This is a spring that biases the to the left.

43, as shown in FIGS. 5, 7, and 8, is a support body disposed to surround the support portion 34 of the support shaft 30 from above and below, and the guide shaft is attached to both the upper and lower plate portions of the support body 43. A guide hole 44 for inserting the guide shaft 37 is formed, and the guide shaft 37 can be moved diagonally up and down along the guide shaft 37. Reference numeral 45 denotes a bifurcated portion formed at the right end of the bottom plate portion of the support body 43, into which the square piece 40 is slidably fitted. 46 is a guide groove formed on the front side of the support body 43. 47 is a movable blade fixed to the upper end of the right side of the support body 43 by two screws 48, and the support part 34 and the guide shaft 3 are moved by the biasing force of the spring 42.
7 and the support body 43, it is pressed against the fixed blade 26 with an appropriate force. The movable blade 47, with its upper end protruding from the upper surface of the throat plate 6, moves up and down within a certain range L shown in FIG. The blade portion 47a faces the blade portion 26a of the fixed blade 26 from above so as to be able to cut the edge of the work cloth. Also, this movable blade 47
As will be described later, when not in use, the needle plate 6 is lowered to at least a position where it does not protrude from the upper surface of the throat plate 6.

50, as shown in FIGS. 11, 12, and 15, is an internal frame fixed to the internal upper surface of the sewing machine bed 5, and the two needles 3, 4 are mounted on both the front and back sides of the internal frame.
A pair of support walls 5 inclined with respect to the direction of vertical movement
1 and 52 are integrally formed. 53, as shown in FIGS. 14 and 15, both the supporting walls 51,
An eccentric shaft serving as an eccentric member is rotatably supported between the support walls 51 and 52, and an eccentric shaft portion 53a is formed between the supporting walls 51 and 52. Reference numeral 54 designates an operating knob as an operating member fixed to the front end of the eccentric shaft 53 outside the internal frame 50, and as shown in FIG.
The eccentric shaft 53 can be rotated from the outside. Therefore, by rotating the operating knob 54, the eccentric shaft portion 53a can be rotationally displaced. In addition,
A spring washer 56 is interposed between the operating knob 54 and the internal frame 50 to prevent the operating knob 54 from moving inadvertently. Further, this operating knob 54 is connected to the sliding plate 15 as shown in FIG.
When the opening part 14 is closed, the sliding plate 15 is covered by the protrusion 18 on the right side, and when it is opened as shown in FIG. 1, the notch 17 on the left side of the sliding plate 15 is covered.
Furthermore, the bulge 19 prevents interference between the sliding plate 15 and the operating knob 54 when the sliding plate 15 slides.

As shown in FIGS. 11, 14, and 15, 57 is a swinging lever that is swingably supported by the eccentric shaft portion 53a of the eccentric shaft 53 at the intermediate portion;
At its left end, a square piece 59 is fitted with a shaft 58 so as to be slidably fitted into the guide groove 46 of the support body 43.
A fork-shaped driven part 5 is attached to the right end.
7a is formed. Therefore, by rotating the eccentric shaft 53 using the operating knob 54, the swinging fulcrum of the swinging lever 57 is vertically displaced.

Reference numeral 60 denotes an operating shaft rotatably supported between the supporting walls 51 and 52 on the right side of the eccentric shaft 53, and 61 indicates an operating member fixed to the operating shaft 60, as shown in FIG. An eccentric cam portion 62, a connecting arm 63, and a fan-shaped gear portion 64 are integrally formed in this order from the front side, and the bifurcated driven portion 57a of the swing lever 57 engages with the outer periphery of the eccentric cam portion 62. There is. Therefore, by the rotation of the eccentric cam portion 62 of the operating body 61, the swing lever 57 is swung around the eccentric shaft portion 53a of the eccentric shaft 53, and the swing lever 57 is
The left end square piece 59 and the guide groove 4 of the support body 43
The support body 43 is moved up and down through engagement with 6,
The movable blade 47 will move up and down. In this embodiment, the actuating member 61 is designed to be reciprocally rotated within a range of about 90 degrees, and when the actuating member 61 reaches one rotation limit as shown in FIG. 47 is located at the upper limit of movement, and as shown in FIG. 16, when the other rotation limit is reached, the movable blade 47 is located at the lower limit of movement. In this embodiment, as shown in FIGS. 14 and 16, when the eccentric shaft portion 53a is rotatably arranged in the upper position, the movable blade 47 moves up and down within the lifting range L, and the eccentric shaft 53a moves up and down within the lifting range L. When the movable blade 47 is rotated approximately 180 degrees from the positions shown in FIGS. 14 and 16 and the eccentric shaft portion 53a is placed in the lower position as shown in FIG. It is designed so that it can be lowered to a position that is flush with the upper surface or slightly submerged than the upper surface, and then rests there.

Next, a mechanism for forming an overlock stitch in cooperation with the overseam needle 4 will be explained. 65 shown in FIGS. A bearing 52 is rotatably supported, and 67 is a mounting shaft slidably supported by the bearing 65. A looper 68 for oversewing is fixedly attached to the tip end. Reference numeral 69 denotes a rocking body which is rotatably supported on the support wall 52 on the rear side by a shaft 70, and the right end of the mounting shaft 67 is pivotally connected to the arm portion 69a, and the actuating member body is connected to the rear side. A gear portion 71 that meshes with the gear portion 64 of 61 is integrally formed.

When the gear portion 64 of the operating body 61 reciprocates, the rocking body 69 reciprocates between the lower position shown in FIG. 14 and the upper position shown in FIG.
As a result, the looper 68 is alternately moved up and down the throat plate 6 in synchronization with the vertical movement of the overlocking needle 4, as shown in FIG. It is now possible to form a or,
This looper 68 has the movable blade 47 within a lifting range L.
When located at the lower limit, it is located below the throat plate 6,
It is arranged so that it is located above the throat plate 6 when it is located at the upper limit. Next, the motion transmission mechanism for reciprocating the operating body 61 in synchronization with the vertical movement of the needles 3 and 4 will be explained.
As shown in FIG. 15, the support wall 5 on the rear side
The hollow rotating shaft is rotatably supported by the boss portion 52a of the inner frame 50, and the rear end of the inner frame 50 protruding to the outside has a lower shaft as a drive source that interlocks with the main shaft (not shown) of the sewing machine. A worm wheel 75 as a rotating body that meshes with a worm 74 on 73 is attached so as to be relatively rotatable. 76 is the 12th
As shown in the figure and FIG.
The clutch pawl body is tiltably supported inside the rotating shaft 72, and rotates together with the rotating shaft 72. This clutch claw body 76
A groove 78 formed in the rotating shaft 72 is provided at the rear end.
A claw portion 76a is integrally formed, and is movable between a position where it engages an engagement groove 79 formed in the worm wheel 75 through the worm wheel 75 and a position where it is recessed into the rotating shaft 72. There is a groove portion 9 formed in the shaft portion of the rotating shaft 72 and the crank body 81 described later.
A protruding portion 76b that protrudes in the opposite direction to the claw portion 76a through 0 and 91 is integrally formed. 80
is a spring that urges the claw portion 76a toward the engaging groove 79. Therefore, when the claw portion 76a is fitted into the engagement groove 79 of the worm wheel 75, the rotation of the worm wheel 75 is transmitted to the rotating shaft 72, and when the claw portion 76a is disengaged from the engagement groove 79, the rotation of the worm wheel 75 is transmitted to the rotation shaft 72. The wheel 75 is rotated independently of the rotating shaft 72.

Reference numeral 81 denotes a crank body fixed to the front end of the rotating shaft 72. A link 82 is articulated between the tip of the crank arm 81a and the tip of the connecting arm 63 of the operating body 61. The actuating member 61 is rotated back and forth within a range of approximately 90 degrees each time the actuating member 61 rotates once.

Therefore, when the clutch claw body 76 is fitted into the engagement groove 79 of the worm wheel 75, the rotation of the lower shaft 73 is caused by the rotation of the worm wheel 75 and the rotating shaft 7.
2 to the crank body 81, the actuating member body 61 performs reciprocating rotation, and as described above, the movable blade 47 moves up and down via the eccentric cam portion 62 and the swing lever 57. The overlock sewing looper 68 performs the capture and transfer operations of the thread ring via the gear portion 64 of the operating portion 61, the swinging body 69, and the like.

Next, a clutch release mechanism for disengaging the clutch between the clutch pawl body 76 and the worm wheel 75 and a restraining mechanism for preventing the movement of the actuating member body 61 will be explained. As shown in Figures 13 and 14,
A support shaft 84 fixed to the rear support wall 52 is a clutch release plate as a clutch release member rotatably supported by the support shaft 83.
As the actuating member 61 rotates, the protruding portion 76b of the clutch claw body 76 is engaged with the movable blade 47 and the looper 68 in a state in which the movable blade 47 and the looper 68 are located at one of the rotation limits of the reciprocating rotation range. a hooking portion 84a that prevents rotation of the rotating shaft 72; and a protruding portion 76b that is attached to the hooking portion 84a;
It has an integral guide cam surface 84b that engages with and tilts the clutch claw body 76 so as to disengage from the engagement groove 79 of the worm wheel 75.
85 is the front surface of the clutch release plate 84,
A restraining plate as a restraining member rotatably supported by the support shaft 83, as shown in FIG. a restraining portion 85a that clamps the clutch pawl body 76 and prevents the clutch pawl body 76 from reversing;
As shown in FIG. 19, a guide cam surface 85b that engages with the protrusion 76b of the clutch pawl 76 and retracts the restraint plate 85 prior to this prevention is integrally formed. The clutch release plate 84 and the restraining plate 85 have extending portions 84c and 8 facing each other.
5c is formed, and a spring 86 is stretched between both extending portions 84c and 85c.

A connecting rod 87 holds an eccentric ring 88 fixed to the eccentric portion 53a of the eccentric shaft 53 at its left end, and is connected to the clutch release plate 84 at its right end by a pin 89. This pin 89 engages with a stopper portion 85d formed protrudingly from a part of the restraint plate 85, and pushes the restraint plate 85 against the spring 86.
It is designed to be held in a predetermined position by the biasing force of.

Then, as shown in FIGS. 14 and 16, the eccentric shaft 53 is moved to the swing lever 57 by the operation knob 54.
When the connecting rod 87 is moved to the right by the action of the eccentric link 88, the clutch release plate 84 and the restraint plate 85 move along the rotational trajectory of the clutch claw body 76. It is now being placed outside.

Further, as shown in FIG. 18, when the eccentric shaft 53 is rotated by the operation knob 54 so as to lower the swing fulcrum of the swing lever 57, the connection rod 87 is moved to the left by the rotation of the eccentric ring 88. , and the clutch release plate 84 is rotated clockwise via the pin 89, so that the engaging portion 84a thereof is located within the rotation locus of the clutch pawl body 76. Therefore, as the clutch claw body 76 rotates, the protrusion 7
6b is the guide cam surface 84b of the clutch release plate 84
As shown in FIG. 13, the claw portion 76a is disengaged from the engagement groove 79 of the worm wheel 75, and the connection between the worm wheel 75 and the rotating shaft 72 is disengaged, and the protrusion of the worm wheel 75 is released. When engaged with the portion 84a, the rotation of the clutch claw body 76 is prevented, and the actuating member body 61 is stopped at the rotational position shown in FIG. 18.

At the same time, due to the rotation of the clutch release plate 84, the restraining plate 85 is pulled by the spring 86 and rotates following the pin 89, and the restraining portion 85a of the restraining plate 85 is released from the clutch. It is located within the rotation locus of the claw body 76. And the 19th
As shown in the figure, the rotating clutch pawl 76 engages with the cam surface 85b of the restraint plate 85, and the restraint plate 85 moves away and rotates against the biasing force of the spring 86. Due to the biasing force, the restraint plate 85 returns to the position shown in FIG. prevent the reversal of

Next, the operation of the sewing machine configured as described above will be explained. Now, when performing overedge stitching,
As shown in FIG. 1, the sliding plate 15 is slid open and the opening/closing cover 21 is rotated open to open the opening portion 14 of the sewing machine bed 5. In this way, the notch 17 of the sliding plate 15 and the operating knob 54 correspond to each other, and the operating knob 54 is exposed. When the eccentric shaft 53 is rotated using the operating knob 54 in this state, the swing fulcrum of the swing lever 57 is pulled up as shown in FIG. Body 43 and movable blade 4
7 rises and its blade portion 47a protrudes to the upper surface side of the throat plate 6, and the rotation of the eccentric ring 88 moves the connecting rod 87 to the right, causing the clutch release plate 84 and the restraining plate 85 to engage the clutch pawl. It is arranged outside the rotation locus of the body 76.

When the sewing machine is started in this state, the lower shaft 73 shown in FIGS. 12 and 13 is rotated, and the worm 7
The worm wheel 75 is rotated via the worm wheel 4.
At this time, if the clutch claw body 76 is already engaged with the engagement groove 79 of the worm wheel 75 when the operation knob 54 is operated, the rotation shaft 72
rotates immediately and the clutch pawl 76 is not engaged with the engagement groove 79 of the worm wheel 75, when the engagement groove 79 and the groove 78 of the rotating shaft 72 are aligned, the leaf spring The clutch pawl body 76 fits into the engagement groove 79 due to the biasing force of 80, and the rotation shaft 7
2 is rotated clockwise in FIG.

Therefore, the actuating member 61 is reciprocated via the crank body 81 and the link 82, and the eccentric cam portion 6
2, the swing lever 57 swings back and forth, the support body 43 moves up and down, and the movable blade 47 moves up and down within the range L shown in FIG. Cut the edge of the cloth.

On the other hand, due to the reciprocating rotation of the operating body 61, the oscillating body 69 is reciprocally rotated based on the meshing action between the gear portion 64 thereof and the gear portion 71 of the oscillating body 69, and the mounting shaft 67
As shown in FIG. 8, the looper 68 moves up and down in front of and behind the overlocking needle 4 to capture and transfer the thread loop, and the looper 68 is cut by the fixed blade 26 and the movable blade 47. Overlock stitching is performed on the edges of the fabric.

Then, for the work cloth to be hemmed in this way, a lockstitch seam for sewing is created on the side of the hemlock seam by the cooperative action of the lockstitch needle 3 and the horizontal lid 13. is formed.

Next, if you want to stop overlocking and only perform lockstitch work, first stop the operation of the sewing machine, the lower shaft 73 will stop, and the operating mechanisms such as the rotating shaft 72 and the operating shaft 61 will stop. Then, the movable blade 47 and the looper 68 are stopped at an arbitrary position.

Thereafter, when the operating knob 54 is rotated in the opposite direction, the swinging fulcrum of the swinging lever 57 is lowered by the action of the eccentric shaft portion 53a of the eccentric shaft 53.
As the movable blade 47 is pulled down, the connecting rod 8
7 is moved to the left by the action of the eccentric ring 88, the clutch release plate 84 and the restraining plate 85 are rotated clockwise, and their engaging portions 84a and restraining portions 85a follow the rotation locus of the clutch pawl body 76. placed within.

In this state, when the handwheel is manually operated to rotate the lower shaft 73, the rotation shaft 73 is rotated based on the lower shaft 73.
As the clutch pawl body 76 rotates, the protrusion 76 of the clutch pawl body 76
b engages with the guide cam surface 85b of the restraint plate 85, and the restraint part 85a is retracted.
5 is rotated, it slides into engagement with the guide cam surface 84b of the clutch release plate 84, and is then latched onto the latching portion 84a. Therefore, the clutch pawl body 76
is rotated to the position shown in FIG.
a is disengaged from the engagement groove 79 of the worm wheel 75, and the driving connection between the worm wheel 75 and the rotating shaft 72 is disengaged, and the clutch pawl 76 is engaged with the latching portion 84a by the restraining portion 85a. It is restrained from rotating in any direction. Therefore, at this stage, the drive connection between the drive shaft of the sewing machine and the operating body 61 is cut off.

When the clutch pawl body 76 in the rotating shaft 72 is engaged with the clutch release plate 84 in this way, the actuating member body 6
1 is stopped at a predetermined rotation angle position shown in FIG. At this time, the swinging fulcrum of the swinging lever 57 is lowered, so the movable blade 47 is placed below the lower limit of its lifting range L, and the looper 68 is placed at the lower limit of its lifting stroke.
Therefore, the movable blade 47 is lowered to a position where it does not protrude from the upper surface of the throat plate 6, and the looper 68 is retracted downward into the throat plate 6.

In this state, the needles 3 and 4 are located below the throat plate 6, so the handwheel is manually rotated to position the needles 3 and 4 above the throat plate 6. A single needle corresponding to only the needle 3 is attached instead of the double needle consisting of both needles, and the opening/closing cover 21 is raised and slid to the closed position of the sliding plate 15 to close the open part of the sewing machine bed 5. do. As a result, the top surface of the throat plate 6 and the top surface of the sliding plate 15 are continuous, and normal lockstitch work can be performed by subsequent operation of the sewing machine. Also, at this time, as described above, the driving connection between the lower shaft 73 and the operating body 61 is disengaged, and the clutch pawl body 76 is restrained so that it cannot rotate. Even if the lower shaft 73 rotates, the rotation will not be transmitted to the operating body 61, and even if vibrations due to sewing machine operation act on the operating body 61, the operating body will not be transmitted to the operating body 61. The body 61 is not rotated, and an unexpected situation in which the movable blade 47 and the looper 68 move up and down and protrude toward the upper surface of the throat plate 6 can be prevented.

Furthermore, when the opening part 14 is in the closed state, the operating knob 54 is covered by the protruding part 18 on the right side of the sliding plate 15, so that the operating knob 54 is prevented from being rotated by mistake, and the movable blade It is possible to reliably prevent the movable blade 47 and the looper 68 from rising or from engaging the clutch and starting to move up and down the movable blade 47 and the looper 68.

In particular, in this embodiment, the movable blade 4
The movable blade 47 can be switched between the use position and the rest position by the action of the eccentric shaft 53a of the eccentric shaft 53, which constitutes the swing fulcrum of the swing lever 57 for cutting the blade 7. Since the switching arrangement of the movable blade 47 can be performed only by rotating the eccentric shaft 53 used as the swinging fulcrum of the swinging lever 57, there is no need for links, bell cranks, etc., unlike the conventional method described above. First, the structure is extremely simple, and the narrow space within the cylindrical sewing machine bed 5 will not be crowded.

When the movable blade 47 is placed at the rest position by the operating knob 54, the clutch release plate 84 connects the lower shaft 73 and the rotating shaft 72 via the connecting rod 87.
The clutch between the movable blade 47 and the movable blade 47 is disengaged, and the movable blade 47 is not moved up or down in the rest position, but is securely held in the rest position, and there is no risk of interfering with lockstitching that does not use the movable blade 47.

In the embodiment described above, when the movable blade 47 is at rest, the upper end of the movable blade 47 is configured to coincide with the upper surface of the throat plate 6, but it is configured to sink to the bottom of the throat plate 6. It is also possible. Furthermore, the clutch means and the clutch disengagement member are not limited to the configurations in the embodiments described above, but can be modified in various ways, and an eccentric wheel may be used in place of the eccentric shaft 53 in the embodiments described above.

Effects of the Invention As exemplified in the embodiments above, the present invention comprises an eccentric member as the swing fulcrum of the swing lever that gives the movable blade 47 vertical movement, and the eccentric member can be manually operated from outside the sewing machine bed. An operating member is provided which is rotated by the user to change the position of the pivot point of the swing lever, and further includes a clutch means disposed between the swing lever and the lower shaft of the sewing machine, and a clutch means for operating the operating member. A clutch release member for interrupting the clutch of the clutch means is provided in conjunction with the movable blade, so that when the movable blade is at rest, the movable blade is lowered to at least a position where it does not protrude from the throat plate. Unlike other models, it has a simple structure that does not require levers or links, and it is extremely easy to switch the movable blade between the operating position and the rest position, and it also has the advantage of being able to reliably hold the movable blade in the rest position. It has a great effect.

[Brief explanation of the drawing]

The drawings show a sewing machine embodying the present invention, and FIG. 1 is a partial perspective view showing the sewing machine bed when the opening part is opened, with the internal mechanism omitted;
Fig. 2 is a partially cutaway plan view of the sewing machine bed when the opening section is closed, Fig. 3 is a partial plan view of the sewing machine bed when the opening section is open, and Fig. 4 is a partial front view of the sewing machine bed when the opening section is closed. , FIG. 5 is a sectional view taken along the line 5--5 in FIG. 3 during oversewing, FIG. 6 is an exploded perspective view showing the fixed blade support mechanism, and FIG. 7 is an exploded perspective view showing the movable blade support mechanism. , FIG. 8 is a sectional view taken along the line 8--8 in FIG. 5, FIG. 9 is a sectional view taken along the line 9--9 in FIG. 10
11 is a sectional view taken along line 11-11 in FIG. 4, FIG. 12 is a sectional view taken along line 12-12 in FIG. 14, and FIG. 13 is a sectional view of the main part of FIG. Fig. 14 is a partially cutaway front view showing the operating mechanism of the looper and movable blade, Fig. 15 is a plan sectional view showing the operating mechanism of the looper and movable blade, and Fig. 16 is the operation of the operating mechanism of the movable blade. Fig. 17 is a partially cutaway front view showing the operating state of the looper; Fig. 18 is a partially cutaway front view showing the operating state of the looper operating mechanism;
19 is a partially cutaway front view of the operating mechanism when the looper and movable blade are at rest, and FIG. 19 is a partially cutaway front view of the operating mechanism before the clutch pawl and the clutch release plate are engaged. Sewing machine bed 5, throat plate 6, fixed blade 26, blade part 2
6a, support body 43, movable blade 47, blade portion 47a, eccentric shaft 53, operating knob 54, swing lever 57, rotating shaft 72, lower shaft 73, worm wheel 75, clutch claw body 76, clutch release plate 84.

Claims (1)

[Scope of Claims] 1. A fixed blade 2 that is fixed to the sewing machine bed 5 and whose blade portion 26a is located in substantially the same plane as the upper surface of the throat plate 6.
6, a support 43 mounted in the sewing machine bed 5 so as to be movable up and down, and a movable blade 47 fixed to the support 43, with a blade 47a facing the blade 26a of the fixed blade 26 from above. However, in a sewing machine in which the movable blade 47 cooperates with the fixed blade 26 to cut the fabric edge by the vertical movement of the support 43, in order to impart the vertical movement to the support 43,
a swinging lever 57 operatively connected at one end to its support 43 and at the other end to the lower shaft 73 of the sewing machine; While swingably supporting the lever 57,
The eccentric member 53 that constitutes the swing fulcrum of the swing lever 57 is rotated by manual operation from outside the sewing machine bed 5, and the swing lever 57 is rotated by manual operation from outside the sewing machine bed 5.
an operating member 54 for vertically moving the swinging fulcrum of the
and, disposed in the motion transmission mechanism 75, 81, 61, etc. between the swing lever 57 and the lower shaft 73 of the sewing machine, for controlling transmission/blocking of the swing motion to the swing lever 57. a clutch means 76, etc. of the movable blade 47; and a clutch release member 84 that acts on the clutch means 76 etc. in connection with manual operation of the operating member 54 and blocks the swinging movement of the swinging lever 57; When at rest, the movable blade 47
A movable blade resting device characterized in that the movable blade is lowered to a position where it does not protrude at least from the upper surface of the throat plate 6. 2. The sewing machine according to claim 1, wherein the eccentric member includes an eccentric shaft 53 that supports a swing lever 57 at an eccentric shaft portion 53a, and an operating member 54 is fixed to an end of the eccentric shaft 53. movable blade rest device. 3. The movable blade resting device for a sewing machine according to claim 2, wherein the clutch release member 84 is connected to the eccentric shaft 53 via a link 82.