JP3983367B2 - Sewing machine presser foot - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cloth presser device for a sewing machine.
[0002]
[Prior art]
Conventionally, a sewing machine having a mechanism for moving the presser foot up and down within a predetermined range with a small stroke during sewing and retracting the presser foot further above the vertical movement range as required for thread trimming, frame movement, etc. A cloth presser is known.
[0003]
For example, in the apparatus described in FIG. 21 of Japanese Patent Laid-Open No. 7-231991, a presser foot is attached to the tip of a drive arm that is swung by the rotation of an eccentric cam via a plurality of links, and is synchronized with the rotation of the main shaft. The work clamp is moved up and down. When retracting the presser foot, the retracting lever is rotated to rotate the drive arm in the direction away from the eccentric cam. Although not shown in the figure, it is described in text that a spring is provided to keep the cam follower portion of the drive arm in contact with the eccentric cam (column 9, column 1 See line 2).
[0004]
Further, in the apparatus described in Japanese Patent Laid-Open No. 6-238078, a cam follower is fitted to a drive cam provided with a cam groove on the outer periphery for causing the cloth presser to move up and down, and is synchronized with the main shaft during sewing. Then, the presser foot is moved up and down with a predetermined stroke by rotating the drive cam. Then, as a mechanism for retracting the presser foot upward, a retraction groove is provided in a part of the wall of the cam groove opposite to the cam surface, and the link is provided by letting the cam follower escape to the retraction groove as necessary. The presser foot is raised to the retracted position via In this device, a biasing force is applied to keep the cam follower in contact with the cam surface by the second compression coil spring.
[0005]
[Problems to be solved by the invention]
In these prior arts, when retracting the presser foot upward, it is necessary to move the cam follower against the urging force of the spring abutting the cam follower. These springs have a relatively large urging force in order to cause the cam follower to correctly perform an operation following the cam surface. For this reason, the conventional apparatus has a problem that a large load is applied to the presser foot retracting mechanism. In particular, since the number of heads is increasing in the embroidery sewing machine, the total load on each sewing machine becomes a heavy load. The load applied to these presser foot retracting mechanisms becomes a considerably large value as a whole during the rotation of the main shaft of the multi-head sewing machine and becomes a burden on the main shaft.
[0006]
Further, in the one described in Japanese Patent Application Laid-Open No. 6-238078, when the work clamp once retracted to the raised position is returned to the operating position, the main shaft is driven until the cam follower is returned from the retracting groove into the cam groove. Can not do it. Since the structure described in Japanese Patent Application Laid-Open No. 7-231991 also has a structure in which the cloth presser is retracted obliquely rearward and upward, after returning the presser foot to the operating position so that the through hole of the presser foot is located directly below the sewing needle. Otherwise, the spindle cannot be driven.
[0007]
For this reason, these conventional devices also have a problem that it takes time to resume the sewing operation from the state in which the presser foot is retracted. Therefore, an object of the present invention is to solve such problems, to reduce the load when the presser foot is retracted, and to shorten the time until the sewing operation is resumed.
[0008]
[Means for Solving the Problems]
The presser foot device for the sewing machine of the present invention comprises:
The presser foot is moved up and down within a predetermined range in conjunction with the needle bar movement toward the needle drop position and, if necessary, retracted to a retreat position further above the range to be moved up and down. A sewing machine presser device,
The cam for driving the presser foot fixed to the main shaft, the first swinging member swinging within a predetermined range by the cam, and the first swinging member are connected to the two link members, A link mechanism that is connected to the presser foot by a link and includes a second swinging member that moves the presser foot up and down by swinging itself when the first swinging member swings. A guide arm that is pivotally attached to the support member so that the distal end portion is connected to an intermediate joint of the two link members, and the base portion can move the joint forward and backward along a predetermined arcuate path. By changing the position of the support member that rotatably supports the base portion of the guide arm, the second swinging member is operated to move the cloth presser up and down within a predetermined range, or the presser foot To raise to the retracted position Guide arm moving means, and a guide arm supporting member in the guide arm moving means and a link member connected to the joint, the base part is fixed to the one member, and the tip part is in contact with the other member. A positioning piece is provided so as to be in a releasable contact, and the contact position of the tip of the positioning piece is an axis on the second swing member side of the link member between the second swing member and the joint. The center is in contact with the axis on the base side of the guide arm, and the relative position between the link member and the support member is determined.
According to the sewing machine presser device, at the time of executing the sewing, the first swinging member swings along a predetermined locus in response to the rotation of the main shaft. Then, the 2nd rocking | swiveling member connected via the link with respect to this 1st rocking | swiveling member rock | fluctuates, and the work clamp is moved up and down. At this time, one joint in the link mechanism moves in a certain direction, and the range of vertical movement of the presser foot is defined by the movement range of this joint. On the other hand, when raising the presser foot to the retracted position, the moving range of the joint is changed to change the operating range of the second swing member. As a result, the presser foot is raised to the retracted position.
[0010]
According to this sewing machine presser device, when the presser foot is raised to the retracted position, the engagement with the joint movement direction control means that restricts the movement of the link mechanism is not cut off. Therefore, it is not necessary to apply an extra force such as a strong urging force as in the prior art in order to ensure the engagement with the joint movement direction control means at the time of sewing execution, and the load at the time of executing the retreat operation is reduced. be able to.
[0011]
Further, since the presser foot is only raised to the retracted position and the engagement with the joint movement direction control means is maintained even when the presser foot is in the retracted position, the work clamp is returned from the retracted position to the sewing execution position. Even if the main shaft is rotated during the operation, the presser foot only moves up and down via the link mechanism. Therefore, when the sewing is resumed from the retracted state, the rotation of the main spindle can be resumed before the presser foot returns to the sewing position, and the time required for the resumption can be shortened.
[0012]
Further, in the cloth presser device for a sewing machine according to the present invention, the second swing member further includes a first arm extending to the first swing member side and a second arm extending to the cloth presser side. A cam follower that includes two or more links between one arm and the first swing member and that is engaged with the arcuate cam groove is the first arm of the link connected to the first arm. The guide cam moving means is provided at an opposite joint, and when the position of the guide cam is changed so that the second swinging member is swung up, the arc-shaped cam groove is formed on the first arm. It is good to be comprised so that it may correspond to the locus | trajectory of the circular arc centering on the joint of a free end side.
[0013]
According to this configuration, even if the main shaft is continuously rotated while the presser foot is raised to the retracted position and the first swinging member is swung, the link connected to the first arm is free of the first arm. It only swings along an arc locus centering on the end, and no motion is transmitted to the second swing member. Therefore, the presser foot can be maintained at the retracted position. Normally, the needle bar will not move up and down if a jump device provided in this type of sewing machine is operated. Therefore, the main shaft may be kept rotating during the retreat operation.
[0014]
More specifically, the present invention moves the presser foot up and down within a predetermined range in conjunction with the operation of the needle bar, and if necessary, a retracted position further above the up and down range. The presser foot of the presser foot of the presser foot is provided with a presser foot driving cam fixed to the main shaft and supported by the base frame so as to be swingable. A first swinging member engaged with the groove via a first cam follower, and provided between the first swinging member and the cloth presser, is supported swingably with respect to the base frame. And a second oscillating member comprising a first arm extending toward the first oscillating member, a second arm extending toward the cloth pressing side, the first arm of the second oscillating member, A link between at least two or more oscillating members provided to connect the one oscillating member; A second cam follower provided at a joint opposite to the first arm of the link connected to the first arm of the second swing member among the two or more swing member links; A guide cam having an arcuate cam groove with which the second cam follower is engaged; and a guide cam swingably attached to the base frame; A guide cam swinging means for changing a position of the arcuate cam groove; and a presser foot connecting link for connecting the second arm of the second swinging member and the presser foot; When the guide cam is swung so that the second rocking member is swung up so that the presser foot is raised to the retracted position, the arc-shaped cam groove is connected to the joint on the free end side of the first arm. It is configured to match the trajectory of the center arc. It can be a sewing machine presser foot device for.
[0015]
In this cloth presser device, the above-described action can be exhibited by swinging the guide cam and changing the inclination with respect to the base frame. In order to change the position of the guide cam, it may be possible to make the guide cam slide with respect to the base frame, but in order to slide an accurate trajectory, something like a rail is required. Can be complicated. On the other hand, when the position is changed by swinging, it is only necessary to support the guide cam with a single shaft with respect to the base frame, and a simple structure is sufficient. Therefore, it is possible to achieve the characteristic operation of the present invention as described above with a simple structure. Also in this case, there is an advantage that it is not necessary to stop the main shaft during retraction.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
FIG. 1 is a perspective view showing a configuration of a sewing machine presser device 10 according to the present embodiment. FIG. 2 is an enlarged cross-sectional view showing a part thereof.
[0017]
This presser foot device 10 is mounted with a presser foot guide bar 13 fixed to a base frame 1 (see FIG. 4) via a guide bar support member 11 slidably with respect to the presser foot guide bar 13. The formed cylinder 15, the cloth presser 19 supported while being urged downward by the spring 17 with respect to the cylinder 15, and the cylinder 15 is moved up and down along the cloth presser guide bar 13. Link mechanism 20, a height control mechanism 40 for changing the height of the presser foot 19 moved by the link mechanism 20, and a fixing member 51 (see FIG. 1) fixed to the main shaft 50. Accordingly, a presser foot drive cam 52 for operating the link mechanism 20 is provided.
[0018]
The link mechanism 20 includes a first link 21, a second link 22, a third link 23, a fourth link 24, a fifth link 25, and a sixth link 26 from above. The first link 21 has one end 21 a fixed to the rotation shaft 31, and a cam follower 21 c attached to the shaft 21 d of the other end (free end) 21 b is fitted in the cam groove 53 of the presser foot drive cam 52. The upper end 22a of the second link 22 is at the free end 21a of the first link 21, the rear end 23a of the third link 23 is at the axis g2 of the lower end 22b of the second link 22, and the front of the third link 23. The upper end 24a of the fourth link 24 is rotatably connected to the shaft g1 of the end 23b. A cam follower 23c that is fitted to a guide cam 42 of a height control mechanism 40, which will be described later, is provided on the shaft g2 positioned at the joint of the rear end 23a of the third link 23. When the joint g2 is not restricted in the advancing / retreating direction, it may be difficult to transmit force by moving in a free direction.
[0019]
On the other hand, the lower end 24 b of the fourth link 24 and the rear end 25 a of the fifth link 25 are fixed at a predetermined angle via the rotation shaft 32. The pivot shaft 32 and the pivot shaft 31 described above are both supported by the base frame 1 so as to freely rotate at a fixed position (see FIG. 2). The upper end 26a of the sixth link 26 is rotatably connected to the shaft 25c of the front end 25b of the fifth link 25, and the lower end 26b of the sixth link 26 is connected to the upper end 15a of the cylindrical body 15 via the shaft 26c. It is pivotally connected.
[0020]
As a result of the configuration as described above, each of the arm-shaped links 21 to 26 that are the respective elements of the link mechanism 20 performs an operation as indicated by an arrow in the vicinity of the main shaft 50 when the main shaft 50 rotates. The presser 19 is moved up and down within a predetermined range.
[0021]
Next, the presser foot height control means 40 exemplified as the joint movement direction control means will be described.
The mechanism 40 as the height control means is a guide in which a control plate 41 whose upper end is rotatably supported with respect to the axis g3 in the base frame 1 and a cam follower 23c attached to the axis g2 are fitted. The cam 42 and a guide cam moving means 41 a for tilting the guide cam 42 fixed to the control plate 41 by controlling the tilt of the control plate 41 are provided. In the present embodiment, a motor with a non-excitation operation type electromagnetic brake is used as the motor 43 for the guide cam moving means 41a. The motor 43 is mounted on a plate 43a connected to the base frame 1, and as shown in FIG. 3, the control plate 41 is swung to a desired angle via the pinion gear 44 and the arc-shaped rack 45, and tilted. Can be maintained. Further, instead of the motor 43, an arbitrary rotational drive device such as a rotary solenoid 43b shown in FIG. 13 may be used. An arcuate cam groove 46 is formed in the guide cam 42.
[0022]
Next, the operation of the presser foot device 10 of the present embodiment will be described. 4 and 5 show the movements of the link mechanism 20 and the presser foot 19 during the sewing operation, and reference numeral 61 in the drawings is a needle bar. The needle bar 61 is mounted on the base frame 1 so as to be movable up and down, and has a sewing needle 62 for sewing at the lower end. A driven element 63 that engages with a driving element 71 a of the needle bar driving elevating body 71 is attached to the upper end of the needle bar 61.
[0023]
As is well known, the needle bar drive elevating body 71 is connected to a crank rod 73 (both shown in FIG. 1) that is moved up and down by an eccentric wheel 72 attached to the main shaft 50 via a lever crank mechanism (not shown). And move up and down in synchronization with the rotation of the main shaft 50. On the other hand, the driving element 71a is connected to an elevating body 71 that is mounted on the driving element guide rod 64 so as to be movable up and down. The connection configuration is such that a rotating shaft 71c protruding from the driver 71a is rotatably provided to the arm 71b protruding from the elevating body 71. The free end of the driver 71a is connected to the fitting portion 63a of the driven member 63 so as to be freely fitted and detached in the lateral direction. As is well known, the driver 71a is rotationally controlled by a rotary solenoid (not shown).
[0024]
Accordingly, when the needle bar driving lift 71 moves up and down in synchronization with the rotation of the main shaft 50, the needle bar 61 also moves up and down, and the position where the sewing needle 62 penetrates the needle plate 65 and the position where it comes out of the needle plate 65. Sewing is executed by moving up and down. At this time, the presser foot driving cam 52 also rotates as the main shaft 50 rotates, and the links 21 to 26 and the presser foot 19 operate as indicated by arrows in FIG. 4 shows a state in which the needle bar 61 and the presser foot 19 are raised most during sewing, and FIG. 5 shows a state in which the needle bar 61 and the work clamp 19 are lowered most.
[0025]
In addition, the code | symbol 66 in a figure is cloth. Further, as shown in the figure, the driver guide bar 64 and the presser foot guide bar 13 are mounted in parallel, and the shaft center of the sewing needle 62, the center of the through hole 19a of the presser foot 19, and the through hole of the needle plate 65 ( The center of the needle entry position) 65a coincides. Therefore, during operation, the needle bar and the presser foot do not collide because the vertical direction of the needle bar and the center movement direction of the through hole 19a of the presser foot 19 coincide.
[0026]
Next, a change in the height of the presser foot 19 that is a feature of the present embodiment will be described with reference to FIGS. 6 (A) to 6 (F). 6 (A) and 6 (D) correspond to those described with reference to FIGS. 4 and 5 and show the tilted state of the control plate 41 when an ordinary thin cloth 66 is embroidered. 6 (B) and 6 (E) show the tilted state of the control plate 41 when embroidering a thicker cloth 67 (for example, a urethane sheet). In these states, when the joint g2 reciprocates in the direction of the arrow, the joint g1 reciprocates in the left-right direction as shown (reciprocates in the positions of the solid line and the two-dot chain line, respectively). Further, FIGS. 6C and 6F show a case where the presser foot 19 is released to the retreat position where the sewing machine is set at a high place when the sewing machine is stopped alone or the embroidery frame 68 is moved. The state of the control board is shown. In the state where the presser foot 19 is released to this retracted position, the arcuate cam groove 46 has a radius between the joints g1 and g2 of the link and a center on the left joint g1 in the drawing. It is configured to stop at a position whose center coincides with the arc locus. Therefore, in this state, even if the main shaft 50 rotates, the joint g2 simply reciprocates in the direction of the arrow between the positions of the solid line and the two-dot chain line, and the movement is not transmitted downward from the fourth link 24. The presser 19 continues to be held at the retracted position. Note that the inclination of the control plate 41 is changed by driving the motor 43 in a predetermined direction by an amount electrically set in advance.
[0027]
As described above, in the present embodiment, when embroidery is performed on the thick cloth 67, the motor 43 is driven so that the rear edge 41b of the control plate 41 is moved with respect to the vertical axis as shown in FIG. 6B. It moves continuously to a position where the angle Y (<X) is smaller than usual, and is set at an arbitrary place. Thereby, the position and angle of the cam groove 46 of the guide cam 42 change, and the presser foot 19 moves up and down at a position higher than the state of FIG. When the embroidery frame 68 is moved, the motor 43 is driven and set so that the rear edge 41b of the control plate 41 is vertical as shown in FIG. 6C. As a result, the presser foot 19 is raised to the retracted position.
[0028]
After retracting the presser foot 19 and moving the embroidery frame 68 thereunder, the motor 43 is driven by a predetermined amount in the direction opposite to the previous direction, and the state shown in FIG. The tilt state of the control plate 41 is changed back to the state of 6 (B). As a result, embroidery can be resumed.
[0029]
By the way, in the present embodiment, the cam follower 23c provided at the rear end 23a of the third link 23 is kept engaged with the cam groove 46 of the guide cam 42 even in the retracted position. Further, since the presser foot 19 only moves in the vertical direction between the sewing position and the retracted position, the presser foot 19 is also in the retracted position or when returning from the retracted position to the sewing position. The center of the through hole 19 a coincides with the axis of the sewing needle 62. As a result, in the present embodiment, the spindle 50 can be started to rotate before the presser foot 19 is completely returned from the retracted position to the sewing position, and the waiting time from the retracted state to the restart of the embroidery can be reduced. Can do. Even if it is only a short time reduction when paying attention to only one evacuation operation, such an evacuation operation in an embroidery factory will perform a huge number of strokes in a day's work, so the accumulated time is large. As a result, the operating rate of the sewing machine can be greatly improved. As described above, since the rotational motion of the main shaft 50 is not transmitted downward from the fourth link 24 during the retraction operation, the main shaft 50 may continue to rotate as long as the needle bar 61 is in a jump state. Absent.
[0030]
In the present embodiment, the cam follower 23c is always engaged with the arcuate cam groove 46 of the guide cam 42. For example, Japanese Patent Laid-Open Nos. 7-231991 and 6-238078 are used. Unlike the configuration that provides a strong biasing force for maintaining the engaged state with respect to the cam as proposed in the above, particularly when the speed is increased, the engaged state with respect to the cam is strongly maintained. Unlike the configuration in which a strong urging force must be applied, it is not necessary to provide a strong urging force for maintaining a strong engagement state with the cam. Therefore, the load when retracting the presser foot 19 is exclusively the load for moving the link mechanism 20, and the load on the spindle in the retracted state can be reduced as well as the load applied to the spindle during high-speed operation. Is done. Eliminating the load caused by the urging force of these springs itself means that even if the load is not so much reduced when only one sewing machine is viewed, this is a multi-head sewing system that is often used in embroidery factories. Since a little load is accumulated on the main shaft, the load reduction of the sewing machine addressed to one head is cumulatively reduced.
[0031]
In the present embodiment, as the first swing member, the first link 21 that can be rotated by the rotation shaft 31 is shown, and as the second swing member, the rotation by the rotation shaft 32 is possible. The fourth link 24 and the fifth link 25 are exemplified. In the example, the fourth link 24 corresponds to the first arm, and the fifth link 25 corresponds to the second arm.
[0032]
Next, FIGS. 7 to 11 showing different examples of the control means having the same function as the joint movement direction control means 40 in the presser device for the sewing machine shown in FIGS. 1 to 6 will be described. In the description, in FIG. 7 to FIG. 13 functionally the same or equivalent parts as those in the previous FIG. 1 to FIG. To do.
The guide arm 81 in the joint movement direction control means 80 is pivotally attached to the axis g4 provided on the control plate 41 of the guide arm movement means 80a so that the base part 81a is pivotable, and the tip part 81b is connected to the axis g2. The shaft g2 is pivotally connected so as to guide the forward and backward movement of the shaft g2 with a radius having the shaft g4 of the base portion 81a of the guide arm 81 as a fulcrum (see also FIG. 11). The relative position of the shaft g4 and the shaft g2 facing each other is determined by rotating a motor 43 with a control plate 41 ( also simply referred to as a “support member” in this specification) that supports the shaft g4 in the guide arm moving means 80a. By rotating the shaft g3 as a center, it can be swung in the direction of the arrow as shown in FIG.
[0033]
With this configuration, compared with the cam system of FIG. 1, the cam follower 23c and the cam groove 46 can be eliminated, which has an effect of improving accuracy. Further, in comparison with the configuration of the guide cam 42 provided with the groove 46 and the cam method of forming the cam follower 23c, the method provided with the guide arm 81 is sufficient for the shaft g4 and the guide arm 81, so that the member cost is small and the processing cost is reduced. There is also a feature that makes it cheaper.
[0034]
The operation of the joint movement direction control means 80 constituted by the guide arm moving means 80a and the guide arm 81 shown in FIG. 7 is shown in FIG. The movement in FIG. 11 is substantially the same as the movement shown in FIG. 6. FIGS. 11A and 11D correspond to the configuration shown in FIGS. 9 and 10 and show the tilted state of the control plate 41 when an ordinary thin cloth 66 is embroidered. FIGS. 11B and 11E show the inclination state of the control plate 41 when embroidering is performed on a thicker cloth 67 (for example, a cloth laid with a urethane sheet). In these states, when the joint g2 reciprocates in the direction of the arrow, the joint g1 reciprocates in the left-right direction as shown (reciprocates in the positions of the solid line and the two-dot chain line, respectively). Further, FIGS. 11C and 11F show the state of the control plate 41 when the presser foot 19 is largely released to the upper retracted position when the embroidery frame 68 is moved. . In the state where the presser foot 19 is released to the retracted position, the shaft g4 and the shaft g1 overlap. The axis g2 has a radius between the joints g1 and g2 of the link, and is configured to move up and down along a trajectory that coincides with the circular arc trajectory centered on the left joint g1 in the figure. Accordingly, in this state, even if the main shaft 50 rotates, the joint g2 only reciprocates in the direction of the arrow between the positions of the solid line and the two-dot chain line, and the joint g1 does not move. The movement is not transmitted, and the presser foot 19 continues to be held at the retracted position. Note that the inclination of the control plate 41 is changed by driving the motor 43 in a predetermined direction by a predetermined amount.
[0035]
Next, in the positioning piece 85 shown in FIGS. 9 and 12, the base portion 86 is detachably fixed to the third link 23 with screws 88, and the free end 87 is supported by the guide arm 81 (or the base portion thereof). The control plate 41) is slidably contacted. In the state of FIG. 11A and FIG. 11B, the contact timing is not contacted even if the shaft g2 is moved up and down because the axes of the shaft g1 and the shaft g4 are separated from each other. However, when the shaft is rotated to the state of FIG. 11C, the shaft center g1a and the shaft center g4a of the shaft coincide with each other as shown in FIG.
Accordingly, when the position at which the control plate 41 is stopped is set and stored at the position shown in FIG. 11C with respect to the control means of the motor 43 at the time of factory shipment or after disassembly and repair, the control plate 41 is changed from the position shown in FIG. Rotate in the direction of 11C. Then, the free end 87 hits the guide arm 81 and the control plate 41 stops moving. That is, the stop position is a position where the axis g1 to be obtained and the axis center of the axis g4 coincide.
The adjustment ring 44b fixed to the pinion 44 of FIG. 8 is configured such that the rotation angle with the motor shaft 43d can be reset by loosening the fixing screw 44c. Therefore, when the control plate 41 is manually set at the position shown in FIG. 11C, it is convenient to execute it with the fixing screw 44c loosened.
[0036]
Thus, in this embodiment, when embroidery is performed on the thick cloth 67, the motor 43 is driven so that the trailing edge 41b of the control plate 41 is smaller than the normal angle Y with respect to the vertical axis. It moves continuously to a position where (<X), and is set at an arbitrary place. Thereby, the position of the axis g4 of the guide arm 81 is changed, the movement direction of the joint g2 is changed, and the presser foot 19 moves up and down at a position higher than the state of FIG. Further, when the embroidery frame 68 is moved, the motor 43 is driven and set so that the rear edge 41b of the control plate 41 is vertical. As a result, the presser foot 19 is raised to the retracted position as shown in FIG.
After retracting the presser foot 19 and moving the embroidery frame 68 below it, the motor 43 is driven by a predetermined amount in the direction opposite to the previous direction, and the state shown in FIG. The tilt state of the control plate 41 is changed back to the state of 11 (B). As a result, the movement direction of the joint g2 is changed to restrict the reciprocal movement locus so that the embroidery can be resumed.
[0037]
The embodiment described above is an example when the present invention is implemented, and may be implemented in various modes. For example, the motor 43 may be other than a motor with a non-excitation operation type electromagnetic brake as long as the motor shaft does not rotate when the motor is stopped.
[0038]
FIG. 13 shows an example in which a known solenoid motor is used in place of the motor 43. The solenoid motor 43b is mounted on the fixed plate 43a, and the arm 43c is fixed to the rotating shaft 43d thereof. The bifurcated connecting piece 43e at the free end of the arm 43c is engaged with the extension of the shaft g4, and the connecting piece 43e is rotated in the direction of the arrow to move the control plate 41 in the direction of the arrow 41g, as shown in FIGS. 11A to 11C. The range is reciprocally rotated.
The positioning piece 85a of FIG. 13 shows an example in which the mounting position is different from that shown in FIG. The base portion 86a is fixed to a part of the control plate 41, and the free end 87a is in contact with the upper position 24a of the fourth link 24 when the shaft g4 and the shaft g1 are in the coaxial center position. . The contact timing is the same as that of the free end 87 in the positioning piece 85 of FIG. 12, and the use and function are also the same.
[0039]
By providing the positioning piece 85 or 85a, the operation for obtaining the coincidence point between the two shaft centers g1a and g4a at the time of factory shipment or after the entire overhaul and repair is based on the operation relying on the original human intuition. Instead of the operation that relies on the positioning piece 85, the adjustment operation for obtaining the coincidence point shown in FIG. 11C becomes quick and accurate. In particular, the above work is generally difficult because it involves a complicated mechanism around the control plate 41 and is surrounded by these mechanisms, and it is very difficult to rely on human intuition. The proposal of the positioning piece 85 is useful for solving such problems and exhibits the above-described effects.
[0040]
【The invention's effect】
As described above, in the present invention, the second swinging member is controlled not by disengaging the mechanism for moving the presser foot up and down but by controlling the movement direction of one joint in the link. Is adopted so that the presser foot is moved up and down within a predetermined range, or the presser foot is moved up to the retracted position, so that the presser foot is returned from the retracted position to the sewing position. The rotation of the main shaft may be resumed, and the time until resuming sewing after retraction can be greatly shortened.
[0041]
In addition, since the presser foot is retracted without releasing the engagement of the mechanism in the middle, an urging force is applied to maintain the engagement of the cam mechanism during sewing as in the conventional product. There is no need to keep it, and the load for evacuation is reduced, and the effect of smooth movement is exhibited. This effect can reduce the load when the presser foot is retracted as compared with the conventional product, and can reduce the load on the spindle.
[0042]
Therefore, according to the present invention, the operating rate of the sewing machine can be improved, and particularly when applied to a multi-head sewing machine, a reduction in load and a significant increase in operating rate can be expected.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a main part of a presser device for a sewing machine according to an embodiment.
FIG. 2 is an enlarged sectional view of a part of the presser device for the sewing machine according to the embodiment.
FIG. 3 is a perspective view showing a configuration of a height control mechanism in the embodiment.
FIG. 4 is a cross-sectional view showing a sewing operation in the embodiment.
FIG. 5 is a cross-sectional view showing a sewing operation in the embodiment.
FIG. 6 is a schematic explanatory view showing an operation state of the height control mechanism in the sewing operation and the retracting operation in the embodiment.
FIG. 7 is a perspective view showing a main part of a presser device for a sewing machine according to an embodiment different from FIG. 1;
FIG. 8 is an enlarged cross-sectional view of a part of a presser device for a sewing machine according to an embodiment different from FIG. 2;
FIG. 9 is a cross-sectional view showing the sewing operation of the joint movement direction control means in an embodiment different from FIG. 4;
FIG. 10 is a partial cross-sectional view showing the sewing operation of the joint movement direction control means in an embodiment different from FIG. 5;
FIG. 11 is a schematic explanatory view showing an operation state of the height control mechanism in the sewing operation and the retracting operation in an embodiment different from FIG. 6;
12 is a cross-sectional view taken along the line AA in FIG. 9 for illustrating the arrangement of positioning pieces.
FIG. 13 is a perspective view showing a different example of guide arm moving means.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base frame 10 Material presser of sewing machine 13 Material presser guide bar 19 Material presser 19a Through-hole 20 Link mechanism 21-26 1st-6th link 21c, 23c Cam follower 31, 32 Rotating shaft 40 Height control mechanism 41 Control board 42 guide cam 43 motor 46 arc-shaped cam groove 50 main shaft 52 cloth presser drive cam 53 cam groove 61 needle bar 62 sewing needle 64 drive element guide bar 65 needle plate 65a through-hole 66 cloth 67 thick cloth 68 embroidery frame 80 joint movement direction control means 80a Guide arm moving means 81 Guide arm g4 axis

Claims (1)

The presser foot is moved up and down within a predetermined range in conjunction with the needle bar movement toward the needle drop position and, if necessary, retracted to a retreat position that is further above the range to be moved up and down. A sewing machine presser device,
A cam for driving the presser foot fixed to the main shaft;
The first swing member that is swung within a predetermined range by the cam, the first swing member and the link member are connected by two link members, and the cloth presser is also connected by a link. A link mechanism including a second swing member that moves the cloth presser up and down by swinging itself in response to the swing motion of
Further, the distal end portion is connected to an intermediate joint in the two link members, and the base portion is a guide arm pivotally attached to the support member so as to move the joint forward and backward along a predetermined arcuate locus,
By changing the position of the support member that rotatably supports the base portion of the guide arm, the second swinging member can be operated so as to move the cloth presser up and down within a predetermined range. Guide arm moving means for raising to a retracted position, and a base part for the support member of the guide arm in the guide arm moving means and the link member connected to the joint as the one member. fixation, and let includes a positioning piece which is freely separable the tip portion to the other member into contact, the contact position of the forward portion of the positioning piece is between the second oscillating member and the articulation The axial center of the link member on the second swinging member side is in contact with the axial center of the guide arm on the base portion side so as to determine the relative position of the link member and the support member. Sewing cloth presser device.

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