JPS6010753B2 - Sewing machine presser foot device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a presser foot device for a sewing machine, and more particularly to a presser foot device for a sewing machine that applies a presser foot pressure responsive to the speed of the main shaft of the sewing machine to the presser foot.

Prior art: In a sewing machine configured to transport a workpiece cloth onto a workpiece cloth support surface through cooperation between a feed dog and a presser foot, there is a mechanism for applying presser pressure to the presser foot. A cloth presser spring and an adjusting means for adjusting the cloth presser pressure of the cloth presser spring are provided, and a predetermined cloth presser pressure can be adjusted and set according to the material, thickness, etc. of the fabric to be processed prior to sewing. Sewing was performed in the setting state.

However, there is a remarkable trend toward higher speeds in recent overlock sewing machines, etc. - The rotational speed of the main shaft of the sewing machine is 10
00 enemies. p. m. There are also high-speed sewing machines on the market that can reach this level. In such high-speed sewing machines, various adverse effects occur when sewing is performed using the initially set constant presser foot pressure as described above. In other words, if the presser foot pressure is set to be strong to match the high speed operation of the sewing machine, when the sewing machine is operated at low speed at the start of sewing or in the middle of sewing, the presser foot pressure set to be strong will be applied to the workpiece fabric. On the other hand, if the presser foot pressure is set weakly to match the low-speed operation of the sewing machine, it may cause damage to the fabric being processed. Due to the high-speed operation of the feed dog, the presser foot was pushed up and lifted up, causing a phenomenon in which the cloth was not fed properly.One solution to this problem was proposed in Japanese Patent Publication No. 29-6373. A speed-responsive presser foot device for a sewing machine is also known, as shown in the publication No. 2,541,888 and its corresponding specification and drawings.

However, in this speed-responsive presser foot device,
A mechanical governor device is provided on the sewing machine spindle to apply a presser foot pressure responsive to the speed of the sewing machine spindle to the presser foot.

Even with this kind of mechanical governor installation, it is not possible to adapt to high-speed sewing machines such as those of recent sewing machines, where the rotational speed of the sewing machine main shaft reaches 1000 rpm, and it does not respond to the speed of the sewing machine main shaft. Not only is it not possible to obtain an accurate presser foot pressure, but there are also problems with the durability of the mechanical governor device and the generation of noise.On the other hand, Japanese Patent Publication No. 31-2728 and A fluid pressure actuation mechanism for sewing machines is also known, as shown in its counterpart US Pat. No. 2,750,908 and in the drawings.

However, in this fluid pressure operating mechanism, air from an air pump attached to the output shaft of a power transmission device having a clutch and a brake is guided to an air cylinder attached to the arm of the sewing machine, and air is passed through the air cylinder. Presser foot pressure is applied to the presser foot. It is well known that the compression ratio of air is much higher than that of liquids, and for this reason, it is difficult to , it is impossible to apply accurate presser foot pressure to the presser foot in response to the speed of the main shaft of the sewing machine.Furthermore, since the air pump is attached to the output shaft of the power transmission device, Since it is necessary to connect the attached air cylinder with a long, thick flexible hose, the number of parts increases, which not only increases costs but also spoils the appearance of the sewing machine. It can also be a cause.

Therefore, the inventor of this application said, ``In view of the current demand for faster sewing machines due to improved work efficiency, as a result of extensive research and experiments, we have developed a presser foot for sewing machines that can eliminate the defects of conventional sewing machines at once.'' The device was devised.

Purpose The main purpose of this invention is 1000 piles p. m. To provide a presser foot device for a sewing machine that can accurately apply presser foot pressure responsive to the speed of the main shaft of the sewing machine from the start of sewing to the high-speed operation, even when operating at high speeds reaching up to be.

EXAMPLE The following will also be described in detail based on an example in which the present invention is embodied in an overlock sewing machine.

As shown in FIG. (not shown) and a feed dog closure 3a are formed.Also, the sewing machine frame has an accommodation chamber for accommodating each movement mechanism therein, as clearly shown in Figures 4 to 4. A main feed dog 4 and a sub feed dog 5 are provided in the sewing machine frame below the throat plate 3. The sewing machine frame 1 has a needle bar 6 which is movable up and down in the head portion of the sewing machine frame 1 above the throat plate 3. A needle 7 is attached to the lower end of the needle 7 for forming an overlock stitch in the work cloth in cooperation with a looper mechanism (not shown) provided in the sewing machine frame 1 below the throat plate 3. As shown in FIG. 1, a rotating shaft 8 is rotatably supported at the rear of the sewing machine frame 1 around a horizontal axis, and a rotating arm 9 is fixed to one end of the rotating shaft 8.

A push-up lever 10 is fixed to the end of the spinning shaft 8, and the chain 1
1 to a push-up pedal (not shown). A support arm 13 is supported by a pin 12 on the rotary arm 9 so as to be rotatable in the lateral direction at a rear end bifurcated portion 13a. A presser foot 14 is mounted on the support surface 2 for transferring the work cloth. When the push-up pedal is depressed, the support arm 13 is rotated counterclockwise from the state shown in FIG. The legs 14 are raised from above the work cloth support surface 2,
Further, when the support arm 13 is rotated laterally about the pin 12, the presser foot 14 is retracted laterally from the position corresponding to the feed teeth 4, 5. 1st, 2nd
As shown in Figures 3 and 5, a diamond plate 6 is fixed to the left side of the head of the sewing machine frame 1 by a plurality of mounting screws 15, and a diamond plate 6 is fixed to the left side of the head portion of the sewing machine frame 1, and a recess that closes downward and rearward is provided at the lower front end of the diamond plate 6. A location 16a is formed.

A presser bar 17 is supported in a vertically movable manner approximately in the center of the pitching board 16, and a fork 17a is formed at its lower end to engage with the upper front end of the support arm 13. A concave engaging portion 17b is formed in the portion. An adjustment knob 18 for adjusting the pressure of the presser foot is rotatably screwed onto the upper part of the cover plate 16 so as to be fitted to the upper end of the presser rod 17. A cloth presser spring 19 is interposed between the adjustment knob 18 and the presser foot 17, and based on the spring force adjusted and set by the adjustment knob 18, the presser foot 17 and the support arm 1
Presser pressure is applied to the presser foot 14 via the presser foot 3. At the rear of the presser foot 17, a pressure release rod 20 is supported on the cover plate 16 so as to be movable up and down, and the lower end thereof is engaged with a concave engagement portion 17b of the presser foot IT in a recess 16a of the cover plate 16. An engaging convex portion 20a that can be engaged is formed. A compression spring 22 is interposed between the washer 21 at the upper end of the cover plate 16 and the pressure release rod 20.
is biased downward. A pressure release lever 24 is rotatably attached to the upper end of the pressure release rod 20 by a pin 23, and when the pressure release lever 24 is rotated counterclockwise from the state shown in FIG. Cam part 24
The pressure release rod 20 is moved upward by the action of a, and the presser rod 17
is raised, and the presser pressure of the cloth presser spring 19 against the cloth presser foot 14 is released. As shown in FIGS. 5, 7, and 8, a rotating shaft 26 is rotatably supported around a horizontal axis through a pair of bearing metals 25 at the rear upper part of the sewing machine frame 1. An operating lever 28 is fixed to the right end by a bolt 27, and a rotating lever 30 is fixed to the left end by a bolt 29 at approximately the middle thereof.

As shown in FIGS. 1 and 4, a pair of regulating screws 31 and 32 are rotatably screwed into the upper and rear parts of the sewing machine frame in correspondence with the upper and lower arms of the rotary lever 30.
It is fixed at an appropriate adjustment position by fixing screws 33 and 34, and the range of rotation of the rotary lever 30 is restricted. A stepped screw 35 is attached to the lower arm of the rotating lever 30.
A connecting rod 36 is rotatably attached to the connecting rod 36, and its tip extends forward. As shown in FIGS. 1, 3, and 5, a support member 38 is attached to the left side surface of the diamond plate 16 near the tip of the connecting rod 36 by screws 37. An interlocking lever 39 is rotatably supported on the support boss portion of the support body 38 on the inside of the lid plate 16 at its lower end shaft portion 39a, and a long hole is provided at the upper end of the interlocking lever 39 to be connected to the tip of the connecting rod 36. 39b is formed. Fujibe 39 of interlocking lever 39
A bar 41 is fixed to the outer end of the screw 4 by applying pressure, and as shown in FIGS. Engagement part 17
b. A transmission spring 42 is interposed between the rotation lever 30 and the movement lever 39 on the connecting rod 36, and the rotation lever 30 is moved counterclockwise by the rotation shaft 26 as shown in FIGS. When the transmission spring 42 is rotated to , the pressure applying lever 41 is rotated clockwise via the interlocking lever 39 after the transmission spring 42 is compressed by a predetermined amount. The pressure is applied to the presser foot j4 superimposed on the presser foot pressure by the presser foot imitation 19. In this embodiment, the rotating shaft 2 is rotated in response to the rotational speed of the main shaft of the sewing machine.
6 is determined, and the presser foot pressure of the presser foot 14 is changed.

In other words, ``On the right inner surface of the sewing machine frame 1 are the fifth to
As shown in FIG. 9, a mounting boss portion 43 is formed to protrude, and a sewing machine main shaft 46 is rotatable around a horizontal axis by a plurality of bearings 44 passing through the mounting boss portion 43 and inside the sewing machine frame. is supported by. A pulley 47 is attached to the right end of the sewing machine main shaft 45 through a bolt 461, and a belt hook is fitted between the pulley hook 7 and a motor with a clutch (not shown). When the clutch is connected by depressing the foot pedal connected to the motor with the clutch, "belt tortoise flea and pulley 4" are connected.
The sewing machine main shaft turtle 5 is rotated clockwise in FIG. 8 through the feed dog 4? 5 "Each movement mechanism of the sewing machine including the needle Ayatomi etc. is driven. The sewing machine main shaft "Turtle 1" is mounted in the post section 43 of the sewing machine frame 1.
A drive gear turtle 9 with helical teeth is fixed to its main shaft 4.
It is designed to rotate together with the weight. First and second pumps 50 and 51 made of trochoid pumps are provided on the lower and upper surfaces of the boss part 3 in the sewing machine frame, and their pump shafts 52 and 53 are the same at the rear of the main part of the sewing machine. It extends toward the inside of the boss portion 43 on the vertical line of gravity.

The sewing machine main shaft &
A single driven gear 54 with bevel teeth meshing with the drive gear turtle 9 on the top of the gear 5 is provided, and the pump shafts 529 and 31 are respectively fixed by the fixing screws 5 at both upper and lower ends thereof, and the connecting pins 561 Trowel pump marrow 52,631
This section is connected. Therefore, as the sewing machine main shaft heat 5 rotates, the pump shafts 52, 6 of the first and second pumps 51, 61 are
3 are rotated at the same time. As shown in FIGS. 7, 10, and 12, the pump body 57 of the first pump 50 is fixed to the lower surface of the boss portion 43 in the sewing machine frame 1 with two mounting screws 58, and has a pump chamber 59a inside. A cover 61 is fixed to the lower surface of the housing 59 with two mounting screws 60 and has arcuate recesses 61a and 61b on the inner surface on the suction side and the discharge side.
It is composed of.

A suction port 62 and a discharge port 63 are formed at the bottoms of the recesses 61a and 61b, and the pump chamber 59 of the housing 59
It is suitable for a and lotus. As shown in FIGS. 7 and 8, a suction tube 65 is attached to the lower end of the suction port 62 and extends into an oil tank 64 provided at the bottom of the sewing machine frame 1, and a mesh filter 66 is attached to the outer periphery of the suction tube 65. is provided. A supply pipe 68 is connected to the lower end of the discharge port 63 via a pipe joint 67, and oil is supplied to each movement mechanism of the sewing machine via this supply pipe 68. As shown in Figure 7, Figure 0, an inner rotor 70 is fixed to the lower end of the pump shaft 52 in the pump chamber 59a of the housing 59 by means of a fixing screw 691, and the inner rotor 70 is fixed to the lower end of the pump shaft 52 in the pump chamber 59a of the housing 59 so as to mesh with the inner rotor 7. 59a
Seven turtles of the outer row are rotatably housed inside.

Therefore, when the pump shaft 52 is rotated via the driving gear 49 and the driven gear as the sewing machine main shaft mother 5 rotates, the inner rotor 7Q and the outer rotor 71
is rotated in the direction of the rebound indicator in Figure 1B, and the oil in the oil tank is pumped into the pump chamber 59a through the suction cylinder 65 and the suction port 62.
The liquid is sucked into the sewing machine and supplied to each movement mechanism part of the sewing machine via the discharge port 63 and the supply pipe 68. No.? ,8,1
As shown in FIGS. 1 and 12, between the suction port 2 and the discharge port 63, the cover 61 has an oil passageway extending in the front-rear direction. 2 is formed and is opened downward at one end and closed at the rear at the other end.

A suction cylinder 73 extending into the oil tank 64 is attached to the entrance at one end of the oil passage 72, and a mesh filter 74 is provided on its outer periphery. A guide pipe 76 is connected via a pipe joint 75, and oil is guided to the second pump 51 via this guide pipe 76.As shown in FIGS. 51 pump main body 77 is the first pump 50
It is fixed to the upper surface of the post part 43 in the sewing machine frame 1 by two mounting screws 78, almost in the same way as the pump body 57 of
and a housing 79 in which a pump chamber 79a is provided.
and a cover 81 which is fixed to the upper surface of the housing 79 with two mounting screws 80 and has arcuate recesses 81a and 81b formed on the inner surface on the suction side and the discharge side.

A suction port 82 and a discharge port 83 are formed at the tops of the recesses 81a and 81b, and the pump chamber 79 of the housing 79
It is suitable for a and lotus. As shown in FIGS. 7 and 8, a guide pipe 76 extending from the oil passage 72 of the first pump 50 is connected to the upper end of the suction port 82 via a pipe joint 87. Also, in this second pump 51, similarly to the first pump 50, an inner rotor 90 is fixed to the upper end of the pump shaft 53 in the pump chamber 79a of the housing 79 with a fixing screw 89. An outer rotor 91 is rotatably housed in the pump chamber 76a so as to mesh with the outer rotor 91. As the sewing machine main shaft 45 rotates, the driving gear 4
9 and the secondary gear 54 when the pump shaft 53 is rotated. The rotor 90 and the outer rotor 91 are rotated in the same direction, and the oil in the oil tank 64 flows through the suction cylinder 73 on the lower surface of the first pump 50, the oil passage 72, the guide pipe 76, and the suction port 82 of the second pump 51. pump room 79
The oil is sucked into the sewing machine a and is discharged from the discharge port 83 at a pressure that corresponds to the rotational speed of the main shaft 45 of the sewing machine. As shown in FIGS. 5 to 8, a hydraulic sill 92 is integrally provided on the upper surface of the second pump 51 as a unit with the second pump 51, and is discharged from the discharge port 83 of the second pump 51. is actuated in response to the oil pressure applied to rotate the rotation shaft 26 via the actuation lever 28;
The presser foot pressure of the presser foot 14 is changed.

A cylinder chamber 93 of the hydraulic cylinder 92 is integrally formed on the upper surface of the cover 81 of the pump body 77, passes through the discharge port 83, and extends upwardly on the same axis as the discharge port 83. A piston 94 is inserted into the cylinder chamber 93 so as to be movable up and down, and its upper end engages with the operating lever 28, as shown in FIGS. 7 and 8. Therefore, when this piston 94 is moved upward in response to the oil pressure from the discharge port 83 and the rotational speed of the sewing machine main shaft 45 increases beyond a predetermined speed, the presser foot 14 is rotated according to the amount of increase. Presser foot pressure is increased. The operation of the sewing machine constructed as described above will now be described.

Now, when this sewing machine is stopped, the presser foot 14 is lowered onto the work cloth support surface 2 as shown in FIG. 1, and the first and second pumps 50 and 51 shown in FIGS. 7 and 8 are stopped. in a state.

In this state, the presser foot 14 is raised by pressing the push-up pedal (not shown) and the work cloth is set on the work cloth support surface 2, and then the presser foot 14 is lowered again. The presser pressure of the presser spring 19, which has been adjusted in advance at step 18, is applied to the presser foot 14, and the workpiece cloth is reliably moved between the presser foot 14 and the workpiece cloth support surface 2 without any movement. Retained. When the foot pedal connected to the clutch-equipped motor is depressed in this state where the work cloth is set, the main shaft 45 of the sewing machine is rotated, and the feed dogs 4 and 5 are actuated in accordance with the rotation, and the presser foot 14 is rotated.
A feeding action is applied to the work cloth in cooperation with the sewing machine, and the needle 7 and the looper mechanism (not shown) are operated to start the sewing operation.

As the sewing machine main shaft 45 rotates, the pump shafts 52, 53 of the first and second pumps 50, 51 are simultaneously rotated via the drive gear 49 and the driven gear 54, as is clear from FIGS. The first pump 50' starts supplying oil to each movement mechanism part of the sewing machine, and the piston 94 of the hydraulic cylinder 92 is raised by the pressure of the oil discharged from the second pump 51. However,
Immediately after the sewing machine starts sewing, the sewing machine main shaft 45
Since the rotational speed of the hydraulic cylinder 92 is small, the piston 94 of the hydraulic cylinder 92 is not raised significantly, and as the piston 94 rises, the transmission spring 42 is Only by being compressed, the presser foot pressure of the hydraulic cylinder 92 is reduced to the presser foot 14.
is not granted.

Therefore, as shown in FIG. 13, until the rotational speed of the sewing machine main shaft 45 reaches a predetermined speed, a constant pressure of the presser foot by the presser spring 19 is applied to the presser foot 14', similar to when the sewing machine is stopped. The work cloth is attached to the presser foot 14.
By the cooperation of the feed dogs 4 and 5, the material is transferred accurately without any movement. Further, the presser pressure of the presser spring 19 immediately after the start of sewing can be adjusted by rotating the adjustment knob 18 as shown by the two-dot chain line in FIG. The settings can be changed as appropriate depending on the thickness and material of the work cloth, such as increasing the presser foot pressure and decreasing the presser foot pressure for thin work cloths. As described above, when sewing is started and the rotational speed of the sewing machine main shaft 45 is increased beyond a predetermined speed, the pressure of the oil discharged from the second pump 51 increases according to the amount of increase, and the pressure of the oil discharged from the hydraulic cylinder 92 increases. The piston 94 is raised greatly,
A downward pressure is applied to the presser bar 17 via the operating lever 28, the rotating rock 26, the turning lever 30, the transmission spring 42, the interlocking lever 39, and the pressure applying lever turtle, and the presser foot 41 is moved downward. The presser foot pressure by the cloth presser spring 19 and the presser foot pressure by the hydraulic cylinder 92 are applied together.
Therefore, while the sewing machine is in operation, as the rotational speed of the main shaft 45 of the sewing machine increases, the pressure of the presser foot is increased, as shown in FIG.
Due to the high-speed operation of No. 8, there is no fear that the presser foot is pushed up and floats up, and good cloth feeding is always performed. Also, during sewing with this sewing machine, when the amount of depression of the foot pedal is adjusted and the rotational speed of the main shaft 4 of the sewing machine decreases, the pressure of the oil discharged from the second pump decreases and the oil pressure increases. The piston of the cylinder is lowered and the presser foot pressure applied to the presser foot electric turtle is reduced.Also, when the rotational speed of the sewing machine main shaft mechanism decreases beyond a predetermined speed, as described above. As in the case immediately after the start of sewing, a constant pressure of the presser foot is applied to the presser foot 14 due to the presser foot 9'.

On the other hand, when the rotational speed of the main shaft 45 of the sewing machine reaches a predetermined high speed in the middle of sewing, the upper arm portion of the sewing lever 3Q shown in FIGS. 1 and 4 engages with the upper regulating screw 311. Further rotation of the rotating lever is restricted.

Therefore, as shown in Fig. 3, even if the rotational speed of the sewing machine main shaft turtle 5 increases beyond a predetermined high speed, the pressure of the presser foot against the presser foot increases in accordance with the amount of increase. The upper limit pressure of the presser foot during high-speed operation can be determined by rotating the upper regulating screw 31 as shown by the dashed line in Fig. 13. By adjusting the amount of protrusion from the lever 30, you can reduce the pressure of the presser foot for thin work cloths, etc.
The settings can be changed as appropriate depending on the thickness, material, etc. of the work cloth. In addition, in this embodiment, the pump shaft 53
The oil sucked into the suction side of the pump chamber 79a from the suction port 82 of the second pump 51 as the second pump 51 rotates is not configured so as to be discharged to the outside from the discharge side. Since the oil in the pump is moved to the suction side through the gaps between the inner rotor 90 and the outer rotor 91 and between each rotor 90, 91 and the housing 79, it does not interfere with the operation of the pump. There is no. Therefore, “
In this second pump 51, the sewing machine main shaft 4
Oil pressure proportional to the rotational speed of the pump shaft 53 that is interlocked with the lying position acts on the piston 941 of the hydraulic cylinder 92. Another Embodiment Next, another embodiment that is completely different from the previous embodiment will be explained according to the first example. The configuration provided to the presser foot is different from that of the previous embodiment.

Therefore, regarding the parts that are the same as or similar to the above embodiments, we will refer to the code ``Denjiden'' corresponding to 4 turtles in the above embodiments and omit their detailed explanation.
Only the parts that are different from the previous embodiment will be explained.
Well, in this example, there is also a hole in the rear of the cover plate attached to the left side of the sewing machine frame quantity Iwatomi.
is formed, and an auxiliary lid turtle 4 is attached to the rear side of the lid plate 1 group 6 with two screw turtles 48 so as to fit the through hole and the lotus.

The cloth presser spring mother g9 is interposed between the washer neck 46, which is fitted to allow the presser foot to move up and down, and the lower end of the presser foot 7, and the cloth presser foot spring 9 causes the cloth presser foot to move up and down. It is designed to apply a predetermined presser foot pressure. Similar to the embodiment described above, a four-piece pressure-applying lever is directly fixed at the base end of the rotating hoe turtle 26, which is rotated via the second pump and hydraulic cylinder according to the rotational speed of the main shaft of the sewing machine. - Its forked tip enters into the lid plate 116 from inside the auxiliary lid turtle 44 through the through hole 142 of the lid plate head 6, and the presser foot 11
The presser foot 114 is engaged with the upper surface of the washer 145 on the sewing machine main shaft to apply pressure to the presser foot 114 in response to the rotational speed of the main shaft of the sewing machine, superimposing the presser foot pressure exerted by the presser spring 119 on the presser foot 114. . Further, the compression spring 122 that biases the pressure release rod 120 downward is connected to a washer 146 provided approximately at the center of the cover plate 116 so as not to interfere with the forked portion of the pressure applying lever 141. It is interposed between the lower end of Therefore, in this embodiment as well as in the case of the previous embodiment, when the sewing machine is stopped and immediately after sewing starts, the pressure of the presser foot is adjusted to the preset presser spring amount 19 from the adjustment knob 18'. 114 to prevent the work cloth from moving inadvertently, and when the rotational speed of the sewing machine main shaft is increased beyond a predetermined speed,
According to the increased amount, the presser foot pressure of the presser foot Kametomikame is increased via the second pump and the hydraulic cylinder, so that the sewing work can be performed with a good presser foot pressure at all times.

Note that this invention is not limited to the above-described embodiments. It is also possible to arbitrarily change the configuration of each part without departing from the spirit of the invention.

Effects As described in detail above, the present invention is applicable to a sewing machine having a presser foot to which presser foot pressure is applied by a presser foot pressure applying means. Even if an operating means including a hydraulic cylinder or the like is provided between the oil pump and the presser foot, the operating means superimposes the pressure of the presser foot on the presser foot due to the oil from the outlet of the oil pump. It is designed to add more energy to the body, and ``thereby exhibits various excellent effects such as the following.

'1} This invention is ``constructed as described above, and due to the fact that liquids such as oil have a much lower compression ratio than air, ``during high-speed operation of sewing machines reaching 1000 ratio p.m. Also, from the start of sewing to high-speed operation, it is possible to always accurately apply presser foot pressure in response to the speed of the sewing machine main spindle to the presser foot.

'21 In particular, in the case of high-speed sewing machines, an oil tank is always provided to supply oil to each movement mechanism. When using, there is no need to install a special oil tank, and the oil in the oil tank for refueling can be used for the oil pump, and the oil pump is placed in the housing chamber of the frame, In addition, since it is configured to be driven and connected to the main shaft of the sewing machine, it is possible to integrate the intermediate connection structure, and despite the lack of responsiveness as described above,
It can be manufactured at low cost.

'31 This invention states that ``Until the rotational speed of the main shaft of the sewing machine reaches a predetermined speed, the presser foot pressure applied by the presser foot pressure applying means is applied to the presser foot, and the rotational speed of the main shaft of the sewing machine does not reach the predetermined speed. When the thickness of the workpiece cloth increases, the pressure of the presser foot is increased in accordance with the amount of increase, so when the sewing machine is stopped or immediately after starting sewing, the thickness By applying a predetermined presser foot pressure according to the
That is, the presser foot pressure on the work cloth is changed in response to the cloth feed speed by the feed dog, so that the work cloth can be transferred favorably.

[Brief explanation of the drawing]

The Sagi-Kame figure is a sectional side view of the main parts of an overlock sewing machine embodying the present invention. FIG. 8 is a partially enlarged sectional view taken along line 2...2 of the lotus diagram. FIG. 3 is a partially enlarged sectional view taken along line 3-3 of the turtle diagram. The 1st umbrella diagram is a partial sectional view taken along line 4 of the 1st groove diagram. FIG. 5 is a plan cross-sectional view of essential parts showing the overlock sewing machine of FIG. 1 in a reduced scale. The second mackerel illustration is S skin 6 of the blind flea illustration.
It is a partial cross-sectional view of paper. Figure 5 is Figure 5's go?
FIG. The weight diagram is crab-8 in Figure 7.
FIG. Is Figure 9 the 9th one? FIG. 3 is a partially enlarged sectional view taken along line 9-9 in the figure. Figure Q of the turtle is the wing Q of Figure 7.
- It is a partially enlarged cross-sectional view along the Tomi Q line. The military map is a partial sectional view taken along the Army 1-Army 1 line in Figure 6. 12th
The figure is a bottom view of the first pump taken along line 12--Turtle 2 in FIG. 6. Figure 3 is a graph showing changes in presser foot pressure with respect to the rotational speed of the main shaft of the sewing machine. FIG. 14 is a sectional side view of a main part of an overlock sewing machine showing another embodiment of the present invention. Sewing machine frame...1,101,
Processing cloth support surface...2, 102, presser foot...
...14,114, Presser bar...179 117, Adjustment knob as manual adjustment means...18,118, Cloth presser spring as presser foot pressure applying means...19,11
9. Rotating shaft...26,126, Pressure applying lever...41,141, Sewing machine main shaft...4
5. Drive gear...49. Second pump...
51, Pump shaft...53, Driven gear...64, Oil tank...64, Suction port...82, Discharge port...83,
Hydraulic shilling...92 (this 92 etc. constitute the actuating means). Crab 1 figure fin 2 stupid fin 3 cloudy figure 4 figure crab 68 heron 6 figure 78 heron 88 crab 9 figure fin 10 figure fin 11 European sea 12 bad fin 18 figure meat 14 bad

Claims (1)

[Claims] 1. A storage chamber for accommodating each movement mechanism therein;
and a frame 1 on which a work cloth support surface 2, 102 is formed;
101, presser feet 14, 114 for pressing the work cloth on the work cloth support surfaces 2, 102, and presser foot pressure applying means 19 for applying presser pressure to the presser feet 14, 114. , 119 and the frame 1, 101
a sewing machine main shaft 45 rotatably supported by the sewing machine main shaft 45; an oil tank 64 disposed adjacent to the accommodation chamber; an oil pump 51 disposed within the accommodation chamber and drivingly connected to the sewing machine main shaft 45; The oil pump 51 is connected to the oil tank 64.
the oil pump 51 and the presser foot 14;
, 114 and for applying presser foot pressure to the presser foot 14, 114 with oil from the discharge port 83, A presser foot device for a sewing machine, characterized in that the presser foot pressure caused by the presser foot and the presser foot pressure generated by the operating means 92 and the like are applied to the presser feet 14, 114 in a superimposed manner. 2. The presser foot device for a sewing machine according to claim 1, wherein the presser foot pressure applying means comprises elastic presser foot pressure applying means 19, 119. 3. The presser foot device for a sewing machine according to claim 1, further comprising manual adjustment means 18, 118 for adjusting the pressing force of the presser foot pressure applying means 19, 119. 4. The presser foot device for a sewing machine according to claim 1, wherein the oil pump 51 is a trochoid pump. 5. The presser foot device for a sewing machine according to claim 1, wherein the operating means includes a hydraulic cylinder 92.