JP2006212289A - Device for reducing operating force for manual lever of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce operating force for a manual operating lever to improve its operability in a manual operating lever operating force reducing device for a sewing machine. <P>SOLUTION: The operating force-reducing device 60 for a manual operating lever in the sewing machine having the manual operating lever which is manually operated, has a detecting means 43 for detecting that the manual operating lever is manually operated, and an assisting means 74 for assisting to reduce the manual operating force for the manual operating lever when manual operation is detected by the detecting means 43. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a manual operation lever operating force reduction device in a sewing machine, and more particularly to a device configured to reduce manual operation force when a manual operation lever is manually operated.

  Conventionally, manual operation levers provided in a sewing machine include, for example, a reverse stitching lever, a presser lifting lever, and the like. It is used to switch the cloth feed direction by the cloth feed mechanism from forward feed to reverse feed by manually operating this reverse stitching lever at the start of sewing or at the end of sewing.

Patent Document 1 discloses a sewing machine provided with a reverse stitching lever on the front surface of a pedestal, and the cloth feed mechanism of the sewing machine has a front end of a feed amount setting member provided to be rotatable about a pivot shaft. A pair of upper and lower feed amount adjustment surfaces are formed on the forked portion of the portion, and a substantially hemispherical engagement piece is formed at the rear end of the feed adjustment knob, and the engagement piece is provided to engage with the feed amount adjustment surface. ing. When the engagement piece engages with the lower feed amount adjustment surface, the feed dog moves forward, while when the engagement piece engages with the upper feed amount adjustment surface, reverse feed movement occurs. The inclination angle of the feed amount setting member is changed and the cloth feed amount by the feed dog is changed by the forward or backward movement of the engagement piece accompanying the turning operation of the feed adjustment knob.
Japanese Patent No. 2876888

By the way, in order to prevent the yarn from fraying at the end of sewing, there is a case in which condensation sewing is performed in which the cloth feed direction is reversely fed by reducing the normal feed pitch. In the sewing machine disclosed in Patent Document 1, the feed adjustment knob engaging piece is engaged with one of the upper and lower feed amount adjustment surfaces of the feed amount setting member by the rotation of the feed amount setting member about the pivot shaft. For this reason, it is impossible to adjust the inclination angle to be different between the case where the engagement piece engages with the upper feed amount adjustment surface and the case where the engagement piece engages with the lower feed amount adjustment surface. As a result, the cloth feed amount cannot be changed between the normal feed and the reverse feed.
Therefore, when performing condensation sewing, adjust the manual operation force of the reverse stitching lever so that the engagement piece is positioned at a predetermined intermediate position where it does not engage the upper feed amount adjustment surface, and the feed set with the feed adjustment knob. The inclination angle is changed to be smaller than the inclination angle of the quantity setting member, the feed pitch is reduced, and the cloth feed direction is reversely fed.

  A tension spring is provided at the rear end of the feed amount setting member to bias it to the forward feed side. When the hand is released from the reverse stitching lever and the cloth feed direction is switched from reverse feed to normal feed, the feed amount is set. In order to suppress the vibration generated when the member and the engagement piece come into contact with each other, it is necessary to provide a tension spring having a large spring force. Then, when manually operating the reverse stitching lever, a large operating force is required, so that the operability is deteriorated.

  An object of the present invention is to reduce the manual operation force of the manual operation lever and improve its operability.

  The manual operation lever operating force reduction device for a sewing machine according to claim 1 is a manual operation lever operation force reduction device for a sewing machine having a manually operated manual operation lever, and detects that the manual operation lever has been manually operated. And detecting means for assisting, and assist means for assisting to reduce the manual operation force of the manual operation lever when a manual operation is detected by the detection means.

  When the manual operation lever is manually operated and the manual operation of the manual operation lever is detected by the detecting means, the assist means is assisted to reduce the manual operation force of the manual operation lever. The manual operation force required for operation is reduced, and the operability is improved.

  The manual operation lever operating force reduction device for a sewing machine according to claim 2 is the electric actuator according to claim 1, wherein the assist means generates an assist force that resists an elastic biasing force acting on the manual operation lever; And a control unit that drives and controls the actuator when a manual operation is detected by the detection unit.

  A manual operation lever operating force reduction device for a sewing machine according to claim 3 is a manual operation lever operation force reduction device for a sewing machine having a manually operated manual operation lever so as to reduce the manual operation force of the manual operation lever. Assisting means for assisting, an assist mode in which the assisting means operates, and a mode setting means that can alternatively set a normal mode in which the assisting means does not operate.

  When the mode setting means is set to assist mode and the manual operation lever is operated manually, the assist means is assisted to reduce the manual operation force of the manual operation lever. The required manual operation force is reduced and the operability is improved.

  According to a fourth aspect of the present invention, there is provided a device for reducing manual operation lever operating force of the sewing machine according to the third aspect of the invention, wherein the assist means generates an assist force that resists an elastic biasing force acting on the manual operation lever; And control means for driving and controlling the actuator when the assist mode is set by the mode setting means.

  According to a fifth aspect of the present invention, there is provided the manual operating lever operating force reducing device for a sewing machine according to any one of the first to fourth aspects, wherein the manual operating lever is a reverse stitching lever for switching the cloth feeding direction by the cloth feeding mechanism to reverse feeding. It is characterized by being.

  A manual operation lever operating force reduction device for a sewing machine according to claim 6 is connected to the cloth feed mechanism in conjunction with a manual operation lever for switching the cloth feed direction to reverse feed, and interlocked with the cloth feed mechanism to reverse feed in the cloth feed direction. An operation force reducing device for a manual operation lever in a sewing machine having an electric actuator for switching to a reverse feed and a reverse feed switch set for reverse feed, wherein the manual operation lever is manually operated using the driving force of the electric actuator. A mode setting switch for setting an assist mode for reducing the operation force, a detecting means for detecting that the manual operation lever is manually operated, and a manual operation by the detecting means in the assist mode set by the mode setting switch. When the manual operation of the operation lever is detected, the actuator is driven and controlled to drive the actuator. Characterized in that a control means to reduce the manual operating force of the manual operation lever with.

  When the mode setting means is set to the assist mode, when the manual operation lever is manually operated and the manual operation of the manual operation lever is detected by the detection means, the actuator is driven by the control means. Since the manual operation force of the manual operation lever is reduced, the manual operation force required for manually operating the manual operation lever is reduced, and the operability is improved.

  According to the first aspect of the present invention, the detection means for detecting that the manual operation lever is manually operated, and assisting to reduce the manual operation force of the manual operation lever when the manual operation is detected by the detection means. Since the assist means is provided, when the manual operation lever is manually operated and the manual operation of the manual operation lever is detected by the detection means, the assist means is activated to assist the manual operation force of the manual operation lever. Thereby, the manual operation force required when manually operating the manual operation lever is reduced, and the operability is improved. In addition, since the assist means is automatically activated when a manual operation is detected by the detection means, setting for operating the assist means is unnecessary, and it is easy for the user to use.

  According to the second aspect of the present invention, the assisting means controls the drive of the actuator when the assisting means detects an assisting force against the elastic biasing force acting on the manual operation lever, and when the detecting means detects the manual operation. Therefore, it is advantageous in terms of cost to use an inexpensive electric actuator to generate the assist force.

  According to the invention of claim 3, the assist means for assisting to reduce the manual operation force of the manual operation lever, the assist mode in which the assist means operates, and the normal mode in which the assist means does not operate are alternatively set. Since the mode setting means is set to the assist mode and the manual operation lever is manually operated, the assist means is activated to assist the manual operation force of the manual operation lever. Thereby, the manual operation force required when manually operating the manual operation lever is reduced, and the operability is improved. Further, since the mode setting means can be set alternatively between the assist mode and the normal mode, it is possible to select whether or not to assist according to the user's preference, and the convenience is enhanced.

  According to the invention of claim 4, the assist means generates an assist force that resists the elastic biasing force acting on the manual operation lever, and the actuator is set when the assist mode is set by the mode setting means. Since it has the control means for driving control, the same effect as in the second aspect can be obtained.

  According to the invention of claim 5, since the manual operation lever is a reverse stitching lever for switching the cloth feeding direction by the cloth feeding mechanism to reverse feeding, for example, when manually operating the reverse stitching lever such as when performing condensation sewing, The manual operation force required for manually operating the reverse stitching lever is reduced, and the operability is improved.

  According to the invention of claim 6, the mode setting switch for setting the assist mode, the detection means for detecting that the manual operation lever is manually operated, and the detection means in the assist mode set by the mode setting switch. When the manual operation of the manual operation lever is detected, the actuator is controlled to reduce the manual operation force of the manual operation lever by using the driving force of the actuator, so that, for example, condensation sewing is performed. When manually operating the manual operation lever for switching the cloth feed direction to reverse feed, etc., when the mode setting means is set to the assist mode, the control means is detected when the manual operation of the manual operation lever is detected by the detection means. The electric actuator is driven by the means, and the manual operation force of the manual operation lever is assisted. . Thereby, the manual operation force required when manually operating the manual operation lever is reduced, and the operability is improved.

  Furthermore, since the mode setting means can be set alternatively between the assist mode and the normal mode, it is possible to select whether or not to assist according to the user's preference, and the convenience is enhanced. Moreover, since this electric actuator can be applied in conjunction with the cloth feed mechanism and is provided for switching the cloth feed direction to reverse feed, it is not necessary to newly provide an electric actuator, and the manufacturing cost of the apparatus is reduced. Further reduction can be achieved.

  A manual operation lever operating force reduction device for a sewing machine according to the present invention is a manual operation lever operation force reduction device for a sewing machine having a manually operated manual operation lever, and detects that the manual operation lever has been manually operated. And an assist means for assisting to reduce the manual operation force of the manual operation lever when a manual operation is detected by the detection means.

  Another device for reducing the manual operation lever operating force of the sewing machine is a device for reducing the operating force of the manual operation lever in a sewing machine having a manually operated manual operation lever so as to reduce the manual operation force of the manual operation lever. An assist means for assisting, an assist mode in which the assist means operates, and a mode setting means capable of alternatively setting a normal mode in which the assist means does not operate are provided.

  In addition, the manual operation lever operating force reduction device of another sewing machine is linked to the cloth feed mechanism and linked to the cloth feed mechanism, and the manual operation lever is linked to the cloth feed mechanism and linked to the cloth feed mechanism to reverse the cloth feed direction. An operation force reducing device for a manual operation lever in a sewing machine having an electric actuator for switching to a reverse feed switch and a reverse feed switch set for reverse feed, wherein the manual operation of the manual operation lever is performed using the driving force of the electric actuator A mode setting switch for setting an assist mode for reducing the force, a detecting means for detecting that the manual operation lever is manually operated, and a manual operation lever manually operated by the detecting means in the assist mode set by the mode setting switch. When an operation is detected, the actuator is driven and controlled using the actuator's driving force. It is characterized in that a control means to reduce the manual operation force.

Embodiments of the present invention will be described below with reference to the drawings.
In this embodiment, the present invention is applied to an industrial lockstitch machine.
As shown in FIG. 1, the lockstitch sewing machine M has a sewing machine bed portion 1, a pedestal portion 2 erected from the right end of the bed portion 1, and the pedestal portion 2 to face the bed portion 1. And an arm portion 3 extending leftward. The bed 1 is provided with a cloth feed mechanism 10 (see FIG. 2) for driving the feed dog 11 (see FIG. 2) in the front-rear direction (cloth feed direction) and driving the feed dog in the up-down direction. . The arm 3 includes a needle bar drive mechanism (not shown) that moves the needle bar 4 that can be attached to the lower end of the sewing needle 5 up and down, and a balance that moves the balance up and down by adjusting the needle bar 4 up and down. A drive mechanism (not shown) and the like are provided. The cloth feed mechanism 10, the needle bar drive mechanism, and the balance drive mechanism of the feed dog 11 are driven by a sewing machine motor 72 (see FIG. 4).

  A reverse feed switch 6 for setting the cloth feed direction to reverse feed is provided on the head of the arm portion 3. The front surface of the pedestal 2 is provided with a reverse stitching lever 40 (manual operation lever) for switching the cloth feed direction to reverse feed, and it is detected that the reverse stitching lever 40 is manually operated above the reverse stitching lever 40. An assist switch 43 (detection means) is connected.

  Next, the cloth feed mechanism 10 that drives the feed dog 11 in the front-rear direction and the up-down direction will be described with reference to FIGS. As shown in FIG. 2, an eccentric cam 13 is fixed to the sewing machine main shaft 12 disposed in the arm portion 3, and an upper end portion of a crank rod 14 extending in the vertical direction is rotatably attached to the eccentric cam 13. It is fitted. On the other hand, a horizontal feed shaft 15 is rotatably supported by the machine frame F in the bed portion 1, and a swing arm 16 is fixed to the horizontal feed shaft 15, and a support shaft 17 fixed to the swing arm 16 and A pair of first links 18 are connected to the support shaft 41 fixed to the lower end of the crank rod 14. A front end portion of the pair of second links 19 is rotatably supported by the support shaft 41, and a rear end portion of the second link 19 is connected to the switcher 20 by a support shaft 42. A manual operation pulley 21 is provided at one end of the sewing machine main shaft 12.

  A feed amount setting member 22 provided on the lower side of the main shaft 12 is rotatably supported by being inserted through a pivot shaft 23 parallel to the main shaft 12. The front end portion of the feed amount setting member 22 is omitted in side view. A square-shaped bifurcated portion is formed, and a pair of upper and lower feed amount adjustment surfaces 24 are formed on the bifurcated portion. A tension spring 25 extending in the vertical direction is stretched between the rear end portion of the feed amount setting member 22 and the machine frame F, and the feed amount setting member 22 is always elastically biased clockwise in FIG. . A rear end portion of the feed amount setting member 22 is connected to an upper end portion of a connecting rod 26 extending in the vertical direction, and a lower end portion of the connecting rod 26 is fixed to a left end portion of the switcher 20.

  A feed adjustment knob 29 for arbitrarily adjusting the feed amount is screwed onto the machine frame F of the arm portion 3 via a screw part 29a, and is formed in a substantially hemispherical shape formed at the rear end portion of the feed adjustment knob 29. The engagement piece 29b is engaged with the lower feed amount adjustment surface 24 of the feed amount setting member 22, and the feed amount is set by the forward or backward movement of the engagement piece 29b accompanying the turning operation of the feed adjustment knob 29. The inclination angle of the member 22, that is, the cloth feed amount in the forward cloth feed operation by the feed dog 11 is changed. The feed dog 11 is fixed to a feed base 32 rotatably supported near the left end of the horizontal feed shaft 15.

  As shown in FIG. 2, a left end portion of a vertical feed shaft 33 that is arranged in parallel with the horizontal feed shaft 15 and swings through an eccentric cam (not shown) and a connecting rod (not shown) as the main shaft 12 rotates. The bifurcated arm 34 is fixed, the front end of the feed base 32 is engaged with the bifurcated arm 34, and the feed dog 11 reciprocates in the vertical direction by swinging the vertical feed shaft 33.

  Accordingly, the rotation of the main shaft 12 causes the crank rod 14 to reciprocate in the vertical direction via the eccentric cam 13, so that the first link 18 swings around the support shaft 17 and the second link 19 and the switch. The vessel 20 swings around the support shaft 42 as a rotation center. At this time, when the support shaft 42 is not located on the line connecting the support shaft 17 and the support shaft 41, the pivot center position of both the links 18 and 19 is not in a straight line, so that the swing arm 16 swings. Movement occurs, and the feed dog 11 moves in the front-rear direction via the horizontal feed shaft 15 and the feed base 32. In addition, the feed dog 11 is moved in the front-rear direction and reciprocated in the vertical direction by the swinging of the vertical feed shaft 33. As a result, the work cloth can be fed in the forward feed direction.

Below the main shaft 12, a feed adjustment shaft 35 parallel to the main shaft 12 is rotatably supported by the machine frame F, and a front end portion of the connection lever 36 is fixed to one end portion of the feed adjustment shaft 35, and the connection rod 26 is provided with a substantially triangular engaging protrusion 37 in a side view protruding rearward, and a lower end portion of the engaging protrusion 37 is engaged with a pivot pin 38 pivotally supported by the connecting lever 36. is doing. The reverse stitching lever 40 is fixed to the right end portion of the feed adjusting shaft 35 at the base end portion.
On the right side of the connecting rod 26, a reverse feed solenoid 50 (electric actuator) is attached to the machine frame F, and the front end portion of the plunger 51 of the reverse feed solenoid 50 is connected to a connecting arm 52 fixed to the feed adjusting shaft 35. It is connected so that it can rotate.

  Next, the reverse stitching lever 40 will be described. As shown in FIG. 3, the reverse stitching lever 40 has a substantially rectangular operation body 40a and a support arm 40b in plan view. When the reverse stitching lever 40 is not manually operated, as shown by a solid line in FIG. 3, the rear end portion of the feed amount setting member 22 is positioned downward by the spring force of the tension spring 25, and the engagement piece 29b is moved downward. The feed adjusting shaft 35 is engaged with the amount adjusting surface 24, is a predetermined forward feed turning position, and the cloth feed direction is forward feed.

  When the reverse stitching lever 40 is pushed downward, the engaging projection 37 of the connecting rod 26 is pushed upward by the pivot pin 38 of the connecting lever 36, and the connecting rod 26 moves upward. At this time, if the reverse stitching lever 40 is manually operated with an elastic biasing force acting on the reverse stitching lever 40, that is, a manual operation force corresponding to the spring force of the tension spring 25, the feed amount setting is performed as shown by a two-dot chain line in FIG. The rear end portion of the member 22 is positioned upward, the engagement piece 29b is engaged with the upper feed amount adjustment surface 24, and the feed adjustment shaft 35 is rotated to the reverse feed rotation position. As a result, the inclination angles of the second link 19 and the switcher 20 are changed. That is, since the switch 20 is tilted to an angle that reverses the feed amount, the support shaft 42 moves to the upper side of the straight line connecting the support shaft 17 and the support shaft 41, and swings for reverse feed to the swing arm 16. Movement occurs, and the feed dog 11 moves backward.

  Next, the assist switch 43 will be described. As shown in FIG. 3, the assist switch 43 includes an operation plate 44 made of a leaf spring and a limit switch 45. The operation plate 44 has an upper plate portion 46 whose front end portion is bent, and a pair of side plate portions 47 provided downward at the rear end portion. The limit switch 45 is embedded in the operation body 40a, and the operation part 48 of the limit switch 45 protrudes from the upper surface of the operation body 40a. The assist switch 43 is attached to the reverse stitching lever 40 with screws 49 in connection holes (not shown) formed in the side plate portion 47 of the operation plate 44 and screw holes (not shown) formed in the side surface portion of the support arm 40b. This is done by screwing together.

  When the reverse stitching lever 40 is not manually operated, the operation plate 44 is biased upward, so that the lower surface of the upper plate portion 46 of the operation plate 44 is separated from the operating portion 48 of the limit switch 45 and the assist switch 43 is turned off. State. On the other hand, when the reverse stitching lever 40 is manually operated, the lower surface of the upper plate portion 46 of the operation plate 44 comes into contact with the operating portion 48 of the limit switch 45 and the assist switch 43 is turned on. At this time, the assist switch 43 detects that the reverse stitching lever 40 has been manually operated.

  Next, a control system of the lockstitch sewing machine M provided with the manual operation lever operating force reduction device 60 will be described. As shown in FIG. 4, the manual operation lever operating force reduction device 60 includes an assist switch 43, a reverse feed solenoid 50, and a control device 61. The control device 61 is driven by an input interface 62, a non-volatile flash memory 66 that can be electrically rewritten with the CPU 63, the ROM 64, and the RAM 65, an output interface 67, and a bus 68 such as a data bus that interconnects them. Circuits 69 and 70 are included.

  Connected to the input interface 62 are a start / stop switch 71, a rotational position detection sensor 73 for detecting the rotational position of the sewing machine motor 72 (rotational position of the sewing machine main shaft) and rotational speed, the reverse feed switch 6, the assist switch 43, and the like. Has been. A drive circuit 69 for the sewing machine motor 72 and a drive circuit 70 for driving the reverse feed solenoid 50 are connected to the output interface 67. The drive circuit 70 is provided with a drive voltage switching circuit (not shown) for switching the drive voltage for driving the reverse feed solenoid 50, and selectively supplies two drive voltages, a high voltage and a low voltage. Is configured to do. When the assist switch 43 is off, the drive voltage is switched to a high voltage, and when the assist switch 43 is on, the drive voltage is switched to a low voltage. It is assumed that the high drive voltage is set to 27V and the low drive voltage is set to 15V.

  The ROM 64 has a drive control program for driving and controlling a motor for driving various drive mechanisms, a control program for driving and controlling the reverse feed solenoid 50 when a manual operation of the reverse stitching lever 40 is detected by the assist switch 43, and display. A control program for data creation control is stored in advance.

  The RAM 65 is provided with a sewing data memory for storing sewing data to be used for sewing, various memories for storing calculation results calculated by the CPU 63, pointers, counters, and the like as necessary. The control device 61 corresponds to the control means, and the reverse feed solenoid 50 and the control device 61 correspond to the assist mechanism 74 (assist means).

  Next, driving of the reverse feed solenoid 50 will be described. The reverse feed solenoid 50 is driven when a command for reversing the cloth feed direction input from the reverse feed switch 6 is input and when the assist switch 43 is turned on. When the reverse feed solenoid 50 is not driven, the plunger 51 is retracted into the reverse feed solenoid 50 by the spring force of the tension spring 25.

  When a command from the reverse feed switch 6 is input and the cloth feed direction is switched to reverse feed by the reverse feed solenoid 50, the reverse feed solenoid 50 is driven with a drive voltage of 27V. Then, as shown in FIG. 5 and FIG. 6, the plunger 51 protrudes forward by a stroke that allows the plunger 51 to operate by the force (force at the time of reverse rotation) generated by the reverse feed solenoid 50 when driven by the drive voltage 27V. . As a result, the feed adjusting shaft 35 is turned to the reverse feed turning position via the connecting arm 52, and at the same time, the connecting rod 26 is moved upward by the upward swing of the connecting lever 36. At this time, since the force at the time of reverse rotation is larger than the spring force of the tension spring 25, the connecting rod 26 is moved upward until the engagement piece 29b is engaged with the upper feed amount adjustment surface 24 of the feed amount setting member 22. Move.

  On the other hand, when the assist switch 43 is turned on and it is detected that the reverse stitching lever 40 is manually operated, the reverse feed solenoid 50 is driven with a drive voltage of 15V. Then, as shown in FIGS. 5 and 6, the plunger 51 tends to come out slightly forward by the force (assist force) generated by the reverse feed solenoid 50 when driven by the drive voltage 15V. As a result, the feed adjusting shaft 35 is rotated via the connecting arm 52, and at the same time, the connecting rod 36 is moved slightly upward by the upward swing of the connecting lever 36. At this time, since the assist force is about half of the spring force of the tension spring 25, the cloth feed direction is not switched to the reverse feed at this time.

  Next, based on the flowchart of FIG. 7, when a manual operation of the reverse stitching lever 40 is detected by the assist switch 43, an assist force is generated by the driving force of the reverse feed solenoid 50, and the manual operation force of the reverse stitching lever 40 is detected. The control of the manual operation lever operating force reducing device 60 for reducing the above will be described. In the figure, Si (i = 1, 2, 3...) Indicates each step.

  This control program is started when the assist switch 43 is turned on. At the end of sewing, the assist switch 43 is turned on by manually operating the reverse stitching lever 40 to perform condensation sewing (S1; Yes), and the reverse stitching lever 40 is turned on. When it is detected that it is manually operated, the drive voltage of the reverse feed solenoid 50 is switched to 15 V (S2). The reverse feed solenoid 50 is driven with a drive voltage of 15 V (S3), and an assist force is generated against the spring force of the tension spring 25 acting on the reverse stitching lever 40. As shown in FIG. 6, since about half of the spring force of the tension spring 25 is assisted by the assist force, when performing condensation sewing, a manual operation corresponding to the force obtained by subtracting the assist force from the spring force of the tension spring 25 is performed. The reverse stitching lever 40 can be manually operated by force. On the other hand, when the assist switch 43 is OFF (S1; No), the process returns.

  Next, it is detected by the assist switch 43 whether or not the reverse stitching lever 40 has been manually operated. When the assist switch 43 is on (S4; No), it is detected that the reverse stitching lever 40 has been manually operated and the reverse operation continues. The feed solenoid 50 is driven (S3). When the condensation sewing is completed and the hand is released from the reverse stitching lever 40, the assist switch 43 is turned off (S4; Yes), and it is detected that the reverse stitching lever 40 is not manually operated, and the drive of the reverse feed solenoid 50 is stopped. (S5), the drive voltage of the reverse feed solenoid 50 is switched to 27V (S6), and the process returns.

  Next, operations and effects of the above-described sewing machine manual operation lever operating force reduction device 60 will be described. When manually operating the reverse stitching lever 40 for switching the cloth feed direction to reverse feed, such as when performing condensation sewing at the end of the sewing operation, when the manual operation of the reverse stitching lever 40 is detected by the assist switch 43, the control device The reverse feed solenoid 50 is driven by 61 and the manual operation force of the reverse stitching lever 40 is assisted. Thereby, the manual operation force required when manually operating the reverse stitching lever 40 is reduced, and the operability is improved.

  Furthermore, when manual operation is detected by the assist switch 43, the reverse feed solenoid 50 is automatically operated by the control device 61 to generate assist force, so that setting for generating assist force is unnecessary, It is easy for the person to use without taking time and effort. In addition, it is advantageous in terms of cost if an inexpensive solenoid is used to generate the assist force, and in particular, a reverse feed solenoid 50 that is linked to the cloth feed mechanism 10 and that switches the cloth feed direction to reverse feed is applied. In this case, it is not necessary to newly provide a solenoid, and the manufacturing cost of the manual operation lever operation force reducing device 60 can be further reduced.

Next, a modified example in which the above embodiment is partially modified will be described.
1) As shown in FIG. 8, the manual operation lever operating force reduction device 60 </ b> A has a mode setting switch 75 that can alternatively set an assist mode for operating the assist mechanism 74 and a normal mode for not operating the assist mechanism 74. (Mode setting means) may be provided. In this case, in the flow of the control of the assist mechanism 74 in FIG. 7, it is detected whether or not the mode setting switch 75 is in the assist mode before the processing of S1, and the assist mode 74 In the case, the process of S1 is performed, and in the normal mode, the process is returned. Thereby, it is possible to select whether or not to assist according to the preference of the user, and convenience is enhanced.

  2) Although the manual operation lever has been described as the reverse stitching lever 40 in the embodiment, other manual operation levers provided on the sewing machine, such as a presser lifting lever for raising and lowering the presser foot, may be used. 3) In the embodiment, the reverse feed solenoid 50 that is interlocked and linked to the cloth feed mechanism 10 and switches the cloth feed direction to the reverse feed is applied to the solenoid that generates the assist force. It may be provided separately.

4) A command for setting the assist mode may be entered in the sewing data, and the assist mode may be automatically set at the start and end of sewing.
5) The high-voltage and low-voltage drive voltages in the reverse feed solenoid 50 and the assist force generated there can be changed.
6) In addition, those skilled in the art can implement the present invention in a form in which various modifications are added, and the present invention includes such various modified forms.

It is a front view of the lockstitch sewing machine provided with the manual operation lever operation force reduction device of the present invention. It is a schematic perspective view which shows the cloth feed mechanism of a lock stitch sewing machine. It is a principal part vertical side view which shows the feed amount setting member in a cloth feed mechanism, a reverse stitching lever, and an assist switch. It is a block diagram which shows the control system of the lock stitch sewing machine provided with the manual operation lever operation force reduction apparatus. It is a diagram which shows the relationship between a drive voltage and the force which generate | occur | produces with a reverse feed solenoid. It is a diagram which shows the relationship between the spring force of a tension spring, and assist force. It is a flowchart of control in a manual operation lever operation force reduction device. FIG. 5 is a diagram corresponding to FIG. 4 of a modified example.

Explanation of symbols

M Sewing machine 6 Reverse feed switch 10 Cloth feed mechanism 40 Reverse stitching lever (manual operation lever)
43 Assist switch (detection means)
50 Reverse feed solenoid (electric actuator)
60, 60A Manual lever operating force reduction device 61 Control device 74 Assist mechanism 75 Mode setting switch

Claims (6)

A device for reducing the operating force of a manual operating lever in a sewing machine having a manually operated manual operating lever,
Detecting means for detecting that the manual operation lever is manually operated;
Assist means for assisting to reduce manual operation force of the manual operation lever when manual operation is detected by the detection means;
A device for reducing the manual operation lever operating force of the sewing machine, characterized by comprising:   The assist means includes an electric actuator that generates an assist force that resists an elastic biasing force that acts on a manual operation lever, and a control means that drives and controls the actuator when a manual operation is detected by the detection means. The apparatus for reducing the manual operation lever operating force of the sewing machine according to claim 1. A device for reducing the operating force of a manual operating lever in a sewing machine having a manually operated manual operating lever,
Assist means for assisting to reduce manual operation force of the manual operation lever;
A mode setting means capable of alternatively setting an assist mode in which the assist means operates and a normal mode in which the assist means does not operate;
A device for reducing the manual operation lever operating force of the sewing machine, characterized by comprising:   An electric actuator that generates an assist force that resists an elastic biasing force acting on a manual operation lever; and a control unit that drives and controls the actuator when the assist mode is set by the mode setting unit. The apparatus for reducing the manual operation lever operating force of the sewing machine according to claim 3, comprising:   The manual operation lever operating force reduction device for a sewing machine according to any one of claims 1 to 4, wherein the manual operation lever is a reverse stitching lever for switching the cloth feeding direction by the cloth feeding mechanism to reverse feeding. A manual operation lever that is linked to the cloth feed mechanism to switch the cloth feed direction to reverse feed, an electric actuator that is linked to the cloth feed mechanism to switch the cloth feed direction to reverse feed, and set to the reverse feed An operation force reducing device for a manual operation lever in a sewing machine having a reverse feed switch,
A mode setting switch for setting an assist mode for reducing the manual operation force of the manual operation lever using the driving force of the electric actuator;
Detecting means for detecting that the manual operation lever is manually operated;
When the manual operation of the manual operation lever is detected by the detection means in the assist mode set by the mode setting switch, the manual operation force of the manual operation lever is controlled by driving the actuator and using the driving force of the actuator. Control means to reduce
A device for reducing the manual operation lever operating force of the sewing machine, characterized by comprising: