Sewing machine

Abstract

To provide a sewing machine that suppresses adhesion of lubricant to unnecessary parts.SOLUTION: A sewing machine includes a sewing machine motor, a needle plate, a lower shaft disposed below the needle plate, which is rotated by power generated by the sewing machine motor, a conversion member fixed to the lower shaft, which converts the rotary motion of the lower shaft to a swing motion, a holding member which holds at least a part of the conversion member, a lubrication port through which lubricant is supplied between the conversion member and the holding member, and a first cover disposed on at least a part of the surroundings of the conversion member. In the axial direction of the lower shaft, the size of the first cover is smaller than that of the lower shaft.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a sewing machine. [Background technology]

[0002] BACKGROUND ART In the technical field related to sewing machines, a sewing machine having an oil pan, such as that disclosed in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-121895 Summary of the Invention [Problem to be solved by the invention]

[0004] There are only a limited number of parts of a sewing machine that require lubrication. If the oil pan becomes larger, there is a possibility that lubrication oil will adhere to parts that do not require lubrication.

[0005] The technology disclosed in this specification aims to prevent lubricating oil from adhering to unnecessary parts of a sewing machine. [Means for solving the problem]

[0006] This specification discloses a sewing machine. The sewing machine includes a sewing machine motor, a needle plate, a lower shaft disposed below the needle plate and rotated by power generated by the sewing machine motor, a conversion member fixed to the lower shaft and converting the rotational motion of the lower shaft into swinging motion, a holding member that holds at least a portion of the conversion member, an oil supply port that supplies lubricating oil between the conversion member and the holding member, and a first cover disposed around at least a portion of the conversion member. In the axial direction of the lower shaft, the dimension of the first cover is smaller than the dimension of the lower shaft. [Effects of the Invention]

[0007] According to the technology disclosed in this specification, the adhesion of lubricating oil to unnecessary parts of a sewing machine is suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a sewing machine according to a first embodiment, seen from the upper left rear. [Figure 2] FIG. 2 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper left rear. [Figure 3] FIG. 3 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper left rear. [Figure 4] FIG. 4 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper right front. [Figure 5] FIG. 5 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper left rear. [Figure 6] FIG. 6 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper right front. [Figure 7] FIG. 7 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper left rear. [Figure 8] FIG. 8 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper right front. [Figure 9] FIG. 9 is a view of a part of the sewing machine according to the first embodiment as seen from the right. [Figure 10] FIG. 10 is a view of a part of the sewing machine according to the first embodiment as seen from the right. [Figure 11] FIG. 11 is a view of a part of the sewing machine according to the first embodiment as seen from behind. [Figure 12] FIG. 12 is a cross-sectional view showing a part of the sewing machine according to the first embodiment. [Figure 13] FIG. 13 is a perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper left front. [Figure 14] FIG. 14 is a perspective cross-sectional view showing a part of the sewing machine according to the first embodiment, seen from the upper left front. [Figure 15]FIG. 15 is a cross-sectional view showing a part of the sewing machine according to the first embodiment. [Figure 16] FIG. 16 is an exploded perspective view showing a part of the sewing machine according to the first embodiment, seen from the upper left front. [Figure 17] FIG. 17 is a cross-sectional view showing a first cover according to the second embodiment. [Figure 18] FIG. 18 is a perspective view showing a part of the sewing machine according to the third embodiment, seen from the upper left rear. [Figure 19] FIG. 19 is a perspective view showing a part of a sewing machine according to a third embodiment, seen from the upper right front. [Figure 20] FIG. 20 is a perspective view showing a part of the sewing machine according to the third embodiment, seen from the upper left front. [Figure 21] FIG. 21 is an exploded perspective view showing a part of a sewing machine according to a third embodiment, seen from the upper left front. [Figure 22] FIG. 22 is a cross-sectional perspective view showing a part of the sewing machine according to the third embodiment, seen from the upper left rear. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the embodiments, an XYZ Cartesian coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ Cartesian coordinate system. The direction parallel to the X axis of a predetermined plane is defined as the X axis direction. The direction parallel to the Y axis of a predetermined plane, which is perpendicular to the X axis, is defined as the Y axis direction. The direction parallel to the Z axis, which is perpendicular to the predetermined plane, is defined as the Z axis direction. Furthermore, the direction of rotation or tilt around the X axis is defined as the θX direction. The direction of rotation or tilt around the Y axis is defined as the θY direction. The direction of rotation or tilt around the Z axis is defined as the θZ direction.

[0010] In this embodiment, the predetermined plane is parallel to the horizontal plane. The X-axis direction is the front-to-back direction. The Y-axis direction is the left-to-right direction. The Z-axis direction is the up-to-down direction. The +X direction is the forward direction, and the -X direction is the backward direction. The +Y direction is the left direction, and the -Y direction is the right direction. The +Z direction is the upward direction, and the -Z direction is the downward direction. The XY plane may be inclined with respect to the horizontal plane.

[0011] [First embodiment] A first embodiment will be described.

[0012] <Sewing machine> Fig. 1 is a perspective view from the upper left rear of a sewing machine 1 according to an embodiment. Fig. 2 is a perspective view from the upper left rear of a sewing machine 1 according to an embodiment. The sewing machine 1 is an industrial sewing machine. The sewing machine 1 is a double chainstitch sewing machine that performs double chainstitching.

[0013] As shown in Figures 1 and 2, the sewing machine 1 includes a sewing machine bed 2, a sewing machine head 3, a needle bar 5, a thread take-up lever 6, a needle plate 7, a presser foot 8, an upper thread tension regulator 9A, a lower thread tension regulator 9B, a feed foot 10, a feed dog 11, and a sewing machine motor 12.

[0014] The sewing machine head 3 is disposed above the sewing machine bed 2. The needle bar 5, thread take-up lever 6, presser foot 8, upper thread tensioner 9A, lower thread tensioner 9B, feed foot 10, and sewing machine motor 12 are each supported by the sewing machine head 3.

[0015] The needle bar 5 holds the sewing needle 4. The needle bar 5 holds the sewing needle 4 so that it is parallel to the Z-axis. The needle bar 5 holds multiple sewing needles 4. In this embodiment, the needle bar 5 holds two sewing needles 4. The needle bar 5 moves back and forth in the up and down direction while holding the sewing needle 4. The sewing needle 4 has a threading hole through which the upper thread passes. The sewing needle 4 holds the upper thread on the inner surface of the threading hole. As the needle bar 5 moves back and forth in the up and down direction, the sewing needle 4 moves back and forth in the up and down direction while holding the upper thread.

[0016] The thread take-up lever 6 supplies the upper thread to the sewing machine needle 4. In this embodiment, the thread take-up lever 6 is disposed inside the cover 6C. The thread take-up lever 6 moves back and forth up and down while holding the upper thread. The thread take-up lever 6 has a holding hole through which the upper thread passes. The thread take-up lever 6 holds the upper thread on the inner surface of the holding hole. By moving back and forth up and down, the thread take-up lever 6 unwinds and pulls up the upper thread used to sew the sewing object.

[0017] The needle plate 7 is positioned below the needle bar 5. The needle plate 7 supports the sewing object from below. The needle plate 7 supports the sewing object below the needle bar 5. The sewing needle 4 held by the needle bar 5 and the needle plate 7 face each other. The needle plate 7 has a needle hole through which the sewing needle 4 can pass. After penetrating the sewing object supported by the needle plate 7, the sewing needle 4 passes through the needle hole.

[0018] The presser foot 8 presses down from above the sewing object supported by the needle plate 7. The presser foot 8 is disposed around at least a portion of the sewing needle 4.

[0019] The needle thread tensioner 9A applies tension to the needle thread supplied to the sewing machine needle 4. The needle thread is supplied to the needle thread tensioner 9A from an needle thread supply source.

[0020] The lower thread tensioner 9B applies tension to the lower thread supplied to the looper 20, which will be described later. The lower thread is supplied to the lower thread tensioner 9B from a lower thread supply source.

[0021] The walking foot 10 operates to feed the sewing object supported by the needle plate 7 forward. The walking foot 10 is positioned above the needle plate 7. The walking foot 10 comes into contact with the upper surface of the sewing object. The walking foot 10 moves along a predetermined feed trajectory to feed the sewing object forward.

[0022] The feed dog 11 operates to feed the sewing object supported by the needle plate 7 forward. At least a portion of the feed dog 11 is positioned below the needle plate 7. The feed dog 11 appears and disappears through an opening provided in the needle plate 7. The feed dog 11 comes into contact with the underside of the sewing object. The feed dog 11 moves along a predetermined feed trajectory to feed the sewing object forward.

[0023] The sewing machine motor 12 generates power for operating each of the needle bar 5, the feed foot 10, the feed dog 11, and the looper 20. The sewing machine motor 12 includes a pulse motor.

[0024] <Internal structure of the sewing machine bed> The following describes the internal structure of the sewing machine bed 2. The components of the internal structure of the sewing machine bed 2 are arranged below the needle plate 7.

[0025] FIG. 3 is a perspective view from the upper left rear showing a portion of the sewing machine 1 according to the embodiment. FIG. 4 is a perspective view from the upper right front showing a portion of the sewing machine 1 according to the embodiment. FIG. 5 is a perspective view from the upper left rear showing a portion of the sewing machine 1 according to the embodiment. FIG. 6 is a perspective view from the upper right front showing a portion of the sewing machine 1 according to the embodiment. FIG. 5 corresponds to a view in which some components have been removed from FIG. 3. FIG. 6 corresponds to a view in which some components have been removed from FIG. 4.

[0026] As shown in Figures 3, 4, 5, and 6, the sewing machine 1 includes a feed dog 11, a base member 13, a drive shaft 14, a belt 15, a driven shaft 16, a feed dog drive mechanism 18, a looper 20, a conversion member 80, a looper drive mechanism 21, a pump 30, a first cover 40, a fixed plate 70, a second cover 50, and a relay section 60.

[0027] The base member 13 is fixed to at least a part of the sewing machine bed 2 inside the sewing machine bed 2. The position of the base member 13 is substantially fixed.

[0028] The drive shaft 14 is disposed below the needle plate 7. The drive shaft 14 is rotatably supported on the base member 13 via a bearing. The drive shaft 14 extends in the left-right direction. The right end of the drive shaft 14 is connected to the sewing machine motor 12 via a power transmission mechanism (not shown). The drive shaft 14 rotates by the power generated by the sewing machine motor 12. The drive shaft 14 rotates in the θY direction around the central axis CX of the drive shaft 14. The central axis CX of the drive shaft 14 is parallel to the Y axis.

[0029] The driven shaft 16 is disposed below the needle plate 7. The driven shaft 16 is rotatably supported on the base member 13 via a bearing. The driven shaft 16 extends in the left-right direction. The driven shaft 16 is disposed forward of the drive shaft 14. The driven shaft 16 is disposed parallel to the drive shaft 14. The driven shaft 16 rotates by power generated by the sewing machine motor 12. In this embodiment, a gear provided at the left end of the drive shaft 14 and a gear provided at the left end of the driven shaft 16 are connected via a belt 15. When the drive shaft 14 rotates by the power generated by the sewing machine motor 12, the rotational force of the drive shaft 14 is transmitted to the driven shaft 16 via the belt 15. The driven shaft 16 rotates in the θY direction around the central axis DX of the driven shaft 16 in synchronization with the drive shaft 14. The central axis DX of the driven shaft 16 is parallel to the Y axis.

[0030] The feed dog drive mechanism 18 operates to move the feed dog 11 along a predetermined feed path. The feed dog drive mechanism 18 has a horizontal feed shaft 17, a vertical feed shaft 19, a support arm 18A that supports the feed dog 11, a first link mechanism 18B that connects the horizontal feed shaft 17 and the support arm 18A, and a second link mechanism 18C that connects the horizontal feed shaft 17 and the support arm 18A.

[0031] The horizontal feed shaft 17 is rotatably supported on the sewing machine bed 2 via a bearing. The horizontal feed shaft 17 extends in the left-right direction. The horizontal feed shaft 17 is disposed forward of the driven shaft 16. The horizontal feed shaft 17 is disposed in parallel to the driven shaft 16. The right end of the horizontal feed shaft 17 is connected to the sewing machine motor 12 via a power transmission mechanism (not shown). The horizontal feed shaft 17 rotates by the power generated by the sewing machine motor 12. The horizontal feed shaft 17 rotates in the θY direction around the central axis of the horizontal feed shaft 17. The central axis of the horizontal feed shaft 17 is parallel to the Y axis.

[0032] The vertical feed shaft 19 is rotatably supported on the sewing machine bed 2 via a bearing. The vertical feed shaft 19 extends in the left-right direction. The vertical feed shaft 19 is arranged rearward of the drive shaft 14. The vertical feed shaft 19 is arranged parallel to the horizontal feed shaft 17. The right end of the vertical feed shaft 19 is connected to the sewing machine motor 12 via a power transmission mechanism (not shown). The vertical feed shaft 19 rotates by the power generated by the sewing machine motor 12. The vertical feed shaft 19 rotates in the θY direction around the central axis of the vertical feed shaft 19. The central axis of the vertical feed shaft 19 is parallel to the Y axis.

[0033] The first link mechanism 18B is connected to the left end of the horizontal feed shaft 17. The first link mechanism 18B is actuated by the rotation of the horizontal feed shaft 17. The actuation of the first link mechanism 18B causes the support arm 18A to reciprocate in the front-to-rear direction.

[0034] The second link mechanism 18C is connected to the left end of the vertical feed shaft 19. The second link mechanism 18C is actuated by the rotation of the vertical feed shaft 19. The actuation of the second link mechanism 18C causes the support arm 18A to reciprocate up and down.

[0035] The first link mechanism 18B and the second link mechanism 18C operate in synchronization. The support arm 18A moves back and forth in the front-to-back and up-to-down directions by the operation of the first link mechanism 18B and the second link mechanism 18C. As the support arm 18A moves, the feed dog 11 supported by the support arm 18A moves along a predetermined feed trajectory.

[0036] FIG. 7 is a perspective view from the upper left rear showing a portion of the sewing machine 1 according to the embodiment. FIG. 8 is a perspective view from the upper right front showing a portion of the sewing machine 1 according to the embodiment. FIG. 9 is a view of a portion of the sewing machine 1 according to the embodiment as seen from the right. FIG. 7 corresponds to a view of FIG. 5 with some components removed. FIG. 8 corresponds to a view of FIG. 6 with some components removed. FIG. 9 corresponds to a view of FIGS. 7 and 8 as seen from the right.

[0037] The looper 20 supplies the bobbin thread to the sewing object. The looper 20 is supported by a looper drive mechanism 21. The looper 20 rotates in the θX direction to scoop up the upper thread from the sewing object and the sewing machine needle 4 that has passed through the needle hole of the needle plate 7, and entangle it with the bobbin thread. Multiple loopers 20 are provided. The number of loopers 20 provided is the same as the number of sewing machine needles 4. In this embodiment, two loopers 20 are provided.

[0038] The conversion member 80 is fixed to the driven shaft 16. The conversion member 80 rotates together with the driven shaft 16. The conversion member 80 converts the rotational motion of the driven shaft 16 into a swinging motion. The conversion member 80 connects the driven shaft 16 and the looper drive mechanism 21.

[0039] The looper drive mechanism 21 operates to rotate the looper 20 in the θX direction based on the power generated by the sewing machine motor 12. The looper drive mechanism 21 is connected to a conversion member 80. The power generated by the sewing machine motor 12 is transmitted to the looper drive mechanism 21 via the drive shaft 14, the belt 15, the driven shaft 16, and the conversion member 80. The looper drive mechanism 21 operates due to the rotation of the conversion member 80.

[0040] The looper drive mechanism 21 has a connecting rod 90 connected to the conversion member 80, a connecting member 22 connected to the connecting rod 90, and a looper shaft 23 connected to the connecting member 22. The connecting rod 90 holds at least a portion of the conversion member 80. The looper shaft 23 is connected to the connecting rod 90 via the connecting member 22. The looper shaft 23 is rotatably supported by bearings 24 and 25. The looper 20 is fixed to the looper shaft 23.

[0041] The pump 30 discharges lubricating oil. The pump 30 is arranged outside the first cover 40. The pump 30 is arranged outside the second cover 50. The pump 30 is supported by the base member 13. The pump 30 has a joint 31 that discharges the lubricating oil. The joint 31 is connected to the relay part 60 via a first tube 101. The lubricating oil discharged from the joint 31 is supplied to the relay part 60 via the first tube 101.

[0042] The relay part 60 relays the lubricating oil supplied from the pump 30. The relay part 60 is provided in a part of the base member 13. The relay part 60 has a joint 61 to which the lubricating oil from the pump 30 is supplied. The joint 61 is connected to the joint 31 of the pump 30 via a first tube 101. The lubricating oil discharged from the joint 31 and supplied to the joint 61 via the first tube 101 is supplied to the conversion member 80 via the relay part 60 and the driven shaft 16.

[0043] As will be described later, the sewing machine 1 is provided with an oil filler port 85C that supplies lubricating oil between the conversion member 80 and the connecting rod 90. The oil filler port 85C is provided on the conversion member 80. The pump 30 discharges the lubricating oil supplied to the oil filler port 85C. The lubricating oil supplied from the pump 30 to the conversion member 80 via the relay unit 60 and the driven shaft 16 is supplied between the conversion member 80 and the connecting rod 90 from the oil filler port 85C provided on the conversion member 80.

[0044] The first cover 40 is disposed around at least a portion of the periphery of the conversion member 80. The first cover 40 covers at least a portion of the conversion member 80 from below. The first cover 40 suppresses scattering of lubricating oil supplied from the oil filler port 85C between the conversion member 80 and the connecting rod 90. The first cover 40 is fixed to the base member 13 via a fixing plate 70.

[0045] The second cover 50 is disposed around at least a portion of the periphery of the conversion member 80. The second cover 50 covers at least a portion of the conversion member 80 from above. The second cover 50 suppresses scattering of lubricating oil supplied from the oil filler port 85C between the conversion member 80 and the connecting rod 90. The second cover 50 is connected to the connecting rod 90.

[0046] 10 is a view of a part of the sewing machine 1 according to the embodiment as seen from the right side. FIG. 10 corresponds to a diagram in which some of the components in FIG. 9 are extracted.

[0047] As shown in Figures 9 and 10, the pump 30 is disposed rearward of the drive shaft 14. The pump 30 includes a pump body 36, a joint 31 protruding rearward from the rear surface of the pump body 36, a movable member 32 disposed in the front portion of the pump body 36, a plate 33 fixed to the movable member 32, and a coil spring 34 connected to the plate 33. The pump body 36 is fixed to the base member 13. The movable member 32 is supported by the pump body 36 so as to be movable in the front-rear direction. A portion of the coil spring 34 is connected to the front surface of the pump body 36. Another portion of the coil spring 34 is connected to the plate 33. The coil spring 34 generates an elastic force that moves the plate 33 away from the pump body 36. That is, the coil spring 34 generates an elastic force that moves the movable member 32 forward.

[0048] The drive shaft 14 rotates in the θY direction around a central axis CX of the drive shaft 14, which extends in the left-right direction. An eccentric sleeve 35 is fixed to the drive shaft 14. In a plane perpendicular to the central axis CX, the outer shape of the eccentric sleeve 35 is circular. The center of the eccentric sleeve 35 and the central axis CX of the drive shaft 14 are misaligned.

[0049] The pump 30 is disposed rearward of the eccentric sleeve 35. The movable member 32 contacts the outer surface of the eccentric sleeve 35. When the eccentric sleeve 35 rotates together with the drive shaft 14, the outer surface of the eccentric sleeve 35 approaches and moves away from the front surface of the pump body 36. As the outer surface of the eccentric sleeve 35 approaches the front surface of the pump body 36, the movable member 32, which is in contact with the outer surface of the eccentric sleeve 35, moves rearward. In other words, the movable member 32 is pushed rearward by the eccentric sleeve 35. As the movable member 32 moves rearward, lubricating oil is discharged from the joint 31.

[0050] The coil spring 34 generates an elastic force that moves the movable member 32 forward. When the outer surface of the eccentric sleeve 35 moves away from the front surface of the pump body 36, the plate 33 and the movable member 32 move forward due to the elastic force of the coil spring 34. In other words, the plate 33 to which the movable member 32 is fixed is pushed forward by the coil spring 34.

[0051] The movable member 32 reciprocates in the front-rear direction due to the rotation of the eccentric sleeve 35 and the elastic force of the coil spring 34. As the movable member 32 reciprocates, lubricating oil is intermittently discharged from the joint 31.

[0052] FIG. 11 is a view of a portion of the sewing machine 1 according to the embodiment as seen from the rear. FIG. 12 is a cross-sectional view of a portion of the sewing machine 1 according to the embodiment. FIG. 13 is a perspective view of a portion of the sewing machine 1 according to the embodiment, seen from the upper left front. FIG. 14 is a perspective cross-sectional view of a portion of the sewing machine 1 according to the embodiment, seen from the upper left front. FIG. 15 is a cross-sectional view of a portion of the sewing machine 1 according to the embodiment. FIG. 16 is an exploded perspective view of a portion of the sewing machine 1 according to the embodiment, seen from the upper left front. FIG. 12 corresponds to the cross-sectional view taken along line AA in FIG. 11. FIG. 14 corresponds to the perspective cross-sectional view of FIG. 13, FIG. 15 corresponds to the side cross-sectional view of FIG. 13, and FIG. 16 corresponds to an exploded perspective view of FIG. 13 with some parts removed.

[0053] As shown in FIGS. 11, 12, 13, 14, 15, and 16, the sewing machine 1 includes a driven shaft 16, a conversion member 80, a looper drive mechanism 21, a looper 20, and a relay unit 60.

[0054] The driven shaft 16 has a right driven shaft 161 connected to the right end of the conversion member 80 and a left driven shaft 162 connected to the left end of the conversion member 80 .

[0055] The conversion member 80 has a right sleeve portion 81 into which the left end of the right driven shaft 161 is inserted, a left sleeve portion 82 into which the right end of the left driven shaft 162 is inserted, a spherical bearing 85 arranged between the right sleeve portion 81 and the left sleeve portion 82, a right flange portion 83 arranged between the right sleeve portion 81 and the spherical bearing 85, and a left flange portion 84 arranged between the left sleeve portion 82 and the spherical bearing 85. The right flange portion 83 is provided at the left end of the right sleeve portion 81. The left flange portion 84 is provided at the right end of the left sleeve portion 82. The spherical bearing 85 is arranged between the right flange portion 83 and the left flange portion 84. The right sleeve portion 81 is connected to the spherical bearing 85 via the right flange portion 83. The left sleeve portion 82 is connected to the spherical bearing 85 via the left flange portion 84.

[0056] The right driven shaft 161 is inserted into the right sleeve portion 81 and fixed to the right sleeve portion 81 with a screw. The left driven shaft 162 is inserted into the left sleeve portion 82 and fixed to the left sleeve portion 82 with a screw. When the driven shaft 16 rotates, the conversion member 80 rotates together with the driven shaft 16.

[0057] The spherical bearing 85 is an oil-lubricated spherical plain bearing. The driven shaft 16 rotates in the θY direction around the central axis DX of the driven shaft 16, which extends in the left-right direction. The center of the spherical bearing 85 is located at a position offset from the central axis DX of the driven shaft 16. As the driven shaft 16 rotates around the central axis DX, the spherical bearing 85 oscillates in the up-down direction and the front-back direction. The spherical bearing 85 converts the rotational motion of the driven shaft 16 around the central axis DX into oscillating motion in the up-down direction and the front-back direction.

[0058] The looper drive mechanism 21 operates to rotate the looper 20 in the θX direction. The looper drive mechanism 21 has a connecting rod 90 connected to the conversion member 80, a connecting member 22 connected to the connecting rod 90, a looper shaft 23 connected to the connecting member 22, and bearings 24 and 25 that rotatably support the looper shaft 23.

[0059] The connecting rod 90 has a lower holding portion 91 that holds the spherical bearing 85, an upper holding portion 92 that holds the spherical portion 22A of the connecting member 22, and a rod portion 93 that connects the lower holding portion 91 and the upper holding portion 92. The lower holding portion 91 is separable. After the spherical bearing 85 is placed inside the divided lower holding portion 91, the divided lower holding portion 91 is integrated with a screw 94. Similarly, the upper holding portion 92 is separable. After the spherical portion 22A is placed inside the divided upper holding portion 92, the divided upper holding portion 92 is integrated with a screw 95.

[0060] The spherical bearing 85 has a spherical bearing surface 85S. The lower holding portion 91 has a slide surface 91S that faces the bearing surface 85S.

[0061] The connecting member 22 has a spherical portion 22A that is held by the upper holding portion 92, and a holding portion 22B that holds the looper shaft 23. The holding portion 22B is located to the right of the spherical portion 22A. The spherical portion 22A has a spherical sliding surface 22S. The holding portion 22B has a holding surface 92S that faces the sliding surface 22S. The connecting member 22 has a holding surface 22T that faces the outer surface of the looper shaft 23. The upper holding portion 92 and the looper shaft 23 are fixed together.

[0062] The looper shaft 23 is rotatably supported on the base member 13 via bearings 24 and 25. The looper shaft 23 extends in the front-to-rear direction. The front end of the looper shaft 23 is fixed to the upper holding portion 92 of the connecting member 22. The looper shaft 23 rotates in the θX direction around the central axis EX of the looper shaft 23. The central axis EX of the looper shaft 23 is parallel to the X-axis.

[0063] As the driven shaft 16 rotates, the spherical bearing 85 swings up and down and in the front-to-rear direction. As the spherical bearing 85 swings, the connecting rod 90 swings up and down. When the connecting rod 90 swings up and down, the spherical portion 22A swings up and down. When the spherical portion 22A swings up and down, the holding portion 22B and the looper shaft 23 held by the holding portion 22B rotate. The looper shaft 23 rotates back and forth by a predetermined angle in the θX direction around the central axis EX of the looper shaft 23. As the looper shaft 23 rotates back and forth, the looper 20 fixed to the looper shaft 23 rotates in the θX direction.

[0064] 14 and 15 , the sewing machine 1 has an oil supply port 85C that supplies lubricating oil between the conversion member 80 and the connecting rod 90. The oil supply port 85C supplies lubricating oil between the bearing surface 85S of the spherical bearing 85 and the slide surface 91S of the lower holding portion 91. The oil supply port 85C is provided on the spherical bearing 85.

[0065] Lubricating oil is supplied from the relay part 60 to the oil filler port 85C via the right driven shaft 161. As shown in FIG. 12, the relay part 60 has a retaining hole 63 in which a bearing 62 is disposed. The right driven shaft 161 is rotatably supported by the bearing 62. The relay part 60 has a passage 60A that leads to the joint 61. The bearing 62 has a passage 62A that leads to the passage 60A. As shown in FIGS. 12 and 15, the right driven shaft 161 has a hole 161A that can be connected to the passage 62A, and a hollow hole 161B that extends axially inside the right driven shaft 161. The hole 161A is connected to the right end of the hollow hole 161B. The left end of the hollow hole 161B is open.

[0066] The lubricating oil discharged from the joint 31 of the pump 30 is supplied to the joint 61 of the relay section 60 via the first tube 101. The lubricating oil that flows into the joint 61 passes through passages 60A and 62A and then flows into the hole 161A. As the right driven shaft 161 rotates, the lubricating oil that passes through passages 60A and 62A intermittently flows into the hole 161A. The lubricating oil that flows into the hole 161A flows into the hollow hole 161B. The lubricating oil that is supplied from the pump 30 and flows into the hollow hole 161B flows to the left through the hollow hole 161B.

[0067] 15, the left end of the right driven shaft 161 is disposed in the internal space 81A of the right sleeve portion 81. The spherical bearing 85 has a passage 85A through which lubricating oil flows from the hollow hole 161B. The passage 85A is provided inside the spherical bearing 85. The passage 85A is connected to the internal space 81A.

[0068] The oil filler port 85C is provided on the bearing surface 85S of the spherical bearing 85. The internal space 81A is connected to the oil filler port 85C via the passage 85A. The lubricating oil supplied from the hollow hole 161B to the internal space 81A is supplied to the oil filler port 85C via the passage 85A. The oil filler port 85C supplies the lubricating oil from the passage 85A to between the bearing surface 85S of the spherical bearing 85 and the sliding surface 91S of the lower holding part 91. The supply of the lubricating oil from the oil filler port 85C to between the bearing surface 85S of the spherical bearing 85 and the sliding surface 91S of the lower holding part 91 allows the lower holding part 91 to rotate smoothly relative to the spherical bearing 85.

[0069] The first cover 40 is arranged to cover, from below, the conversion member 80 that connects the driven shaft 16 and the connecting rod 90 of the looper drive mechanism 21. The first cover 40 is arranged to cover, from below, at least the spherical bearing 85. The first cover 40 prevents the lubricating oil supplied from the oil fill port 85C to between the bearing surface 85S and the slide surface 91S from splashing around the conversion member 80.

[0070] In the left-right direction, which is the axial direction of the driven shaft 16, the dimension of the first cover 40 is smaller than the dimension of the driven shaft 16. In the embodiment, the dimension of the driven shaft 16 is the distance between the right end of the right driven shaft 161 and the left end of the left driven shaft 162.

[0071] The first cover 40 has a front plate portion 40A, a rear plate portion 40B, a left plate portion 40C, a right plate portion 40D, and a bottom plate portion 40E. The rear plate portion 40B is positioned rearward of the front plate portion 40A. The left plate portion 40C is connected to the left end of the front plate portion 40A and the left end of the rear plate portion 40B. The right plate portion 40D is connected to the right end of the front plate portion 40A and the right end of the rear plate portion 40B. The bottom plate portion 40E is connected to the lower end of the front plate portion 40A, the lower end of the rear plate portion 40B, the lower end of the left plate portion 40C, and the lower end of the right plate portion 40D.

[0072] The front plate portion 40A is disposed forward of the driven shaft 16. The rear plate portion 40B is disposed rearward of the driven shaft 16. The upper end portion of the rear plate portion 40B is disposed higher than the upper end portion of the front plate portion 40A. At least a portion of the left driven shaft 162 is disposed leftward of the left plate portion 40C. At least a portion of the right driven shaft 161 is disposed rightward of the right plate portion 40D.

[0073] A recess 43 is provided in each of the left plate portion 40C and the right plate portion 40D. The recess 43 in the left plate portion 40C is recessed downward from the upper end portion of the left plate portion 40C. The recess 43 in the right plate portion 40D is recessed downward from the upper end portion of the right plate portion 40D. At least a portion of the driven shaft 16 and the conversion member 80 is disposed inside the recess 43.

[0074] The left plate portion 40C is positioned to the right of the left end portion of the left driven shaft 162. The left plate portion 40C is positioned to the right of the left end portion of the conversion member 80. The left plate portion 40C is positioned to the left of the left flange portion 84. At least a portion of the left sleeve portion 82 is positioned in the recess 43 of the left plate portion 40C.

[0075] The right plate portion 40D is positioned to the left of the right end portion of the right driven shaft 161. The right plate portion 40D is positioned to the left of the right end portion of the conversion member 80. The right plate portion 40D is positioned to the right of the right flange portion 83. At least a portion of the right sleeve portion 81 is positioned in the recess 43 of the right plate portion 40D.

[0076] The left plate portion 40C is disposed to the left of the left flange portion 84. At least a portion of the left plate portion 40C faces the left flange portion 84. At least a portion of the right surface of the left plate portion 40C faces the left surface of the left flange portion 84.

[0077] The right plate portion 40D is disposed to the right of the right flange portion 83. At least a portion of the right plate portion 40D faces the right flange portion 83. At least a portion of the left surface of the right plate portion 40D faces the right surface of the right flange portion 83.

[0078] As shown in Fig. 9, the rear plate portion 40B is disposed forward of the looper 20 and the drive shaft 14. The upper end of the rear plate portion 40B is disposed below the looper shaft 23. As shown in Fig. 4, the front plate portion 40A is disposed rearward of the front end of the base member 13. Note that the front plate portion 40A may be disposed at the same position as the front end of the base member 13 in the front-to-rear direction.

[0079] The first cover 40 is fixed to the base member 13 via a fixing plate 70. The fixing plate 70 is fixed to the lower surface of the bottom plate portion 40E of the first cover 40 by screws 42.

[0080] The second cover 50 is arranged to cover from above the conversion member 80 that connects the driven shaft 16 and the connecting rod 90 of the looper drive mechanism 21. The second cover 50 is arranged to cover at least the spherical bearing 85 from above. The second cover 50 prevents the lubricating oil supplied from the oil fill port 85C to between the bearing surface 85S and the slide surface 91S from splashing around the conversion member 80.

[0081] The dimension of the first cover 40 in the left-right direction is larger than the dimension of the second cover 50. The left end of the first cover 40 is located to the left of the left end of the second cover 50. The right end of the first cover 40 is located to the right of the right end of the second cover 50. The front end of the second cover 50 is located slightly rearward of the front end of the first cover 40. The rear end of the second cover 50 is located slightly rearward of the rear end of the first cover 40.

[0082] A rear end portion 51 of the second cover 50 is fixed to the base member 13. A plurality of screw openings 51A are provided in the rear end portion 51. Screws are inserted into the screw openings 51A and then inserted into screw holes provided in the base member 13.

[0083] The tip portion 52 (front end portion) of the second cover 50 is inclined downward toward the front. The tip portion 52 is provided so as to enclose the conversion member 80.

[0084] A hole 53 is provided in the middle portion of the second cover 50. A part of the upper holding portion 92 of the connecting rod 90 is disposed in the hole 53. The upper holding portion 92 is fixed to the second cover 50 while disposed in the hole 53. The middle portion of the second cover 50 is fixed to the connecting rod 90.

[0085] The second cover 50 is flexible. The second cover 50 is made of rubber. When the connecting rod 90 moves in the vertical direction, the middle portion of the second cover 50 also moves in the vertical direction. Because the rear end portion 51 is fixed to the base member 13, when the connecting rod 90 moves in the vertical direction, the second cover 50 flexes and deforms so that the middle portion and the tip portion 52 of the second cover 50 are displaced in the vertical direction.

[0086] The first cover 40 is spaced apart from the driven shaft 16 and the conversion member 80. Because the first cover 40 is spaced apart from the driven shaft 16 and the conversion member 80, each of the driven shaft 16 and the conversion member 80 can rotate smoothly.

[0087] The second cover 50 is spaced apart from the driven shaft 16 and the conversion member 80. Because the second cover 50 is spaced apart from the driven shaft 16 and the conversion member 80, each of the driven shaft 16 and the conversion member 80 can rotate smoothly.

[0088] The lubricating oil supplied from the oil filler port 85C to between the bearing surface 85S and the slide surface 91S falls to the inside of the first cover 40 by the action of gravity and is contained in the first cover 40. In addition, the lubricating oil that splashes out from between the bearing surface 85S and the slide surface 91S is also contained in the first cover 40.

[0089] A joint 41 is provided on the bottom plate portion 40E of the first cover 40. The lubricating oil discharged from the first cover 40 flows through the joint 41. The joint 41 is connected to the joint 37 of the pump 30 via a second tube 102. The lubricating oil contained in the first cover 40 is sent to the pump 30 via the second tube 102.

[0090] In the embodiment, the lubricating oil circulates in a circulation path including the pump 30, the relay unit 60, the driven shaft 16, the conversion member 80, the first cover 40, and an oil tank (not shown).

[0091] <Operation> When the sewing machine motor 12 is driven, the needle bar 5 moves back and forth in the vertical direction, the feed foot 10 moves along the feed track, the feed dog 11 moves along the feed track, and the looper 20 rotates in the θX direction. The needle bar 5 and the sewing needle 4 held by the needle bar 5 move back and forth in the vertical direction based on the power generated by the sewing machine motor 12. The looper 20 rotates in the θX direction in synchronization with the up and down reciprocating movement of the needle bar 5 so that the bobbin thread is supplied to the sewing object. The feed foot 10 swings back and forth and up and down in synchronization with the up and down reciprocating movement of the needle bar 5 so as to feed the sewing object forward. The feed dog 11 swings back and forth and up and down in synchronization with the up and down reciprocating movement of the needle bar 5 so as to feed the sewing object forward. The sewing machine 1 sews the sewing object through cooperation of the sewing needle 4 held by the needle bar 5 and the looper 20.

[0092] When drive shaft 14 rotates due to the power generated by sewing machine motor 12, eccentric sleeve 35 rotates. Movable member 32 of pump 30 reciprocates back and forth due to the rotation of eccentric sleeve 35 and the elastic force of coil spring 34. As movable member 32 reciprocates, lubricating oil is intermittently discharged from coupling 31.

[0093] The lubricating oil discharged from the joint 31 of the pump 30 is supplied to the joint 61 of the relay part 60 via the first tube 101. The lubricating oil that flows into the joint 61 passes through the passage 60A of the relay part 60 and the passage 62A of the bearing 62, and then flows into the hole 161A of the right driven shaft 161. The lubricating oil that flows into the hole 161A flows into the hollow hole 161B of the right driven shaft 161. The lubricating oil that flows into the hollow hole 161B flows to the left through the hollow hole 161B.

[0094] The lubricating oil supplied from the hollow hole 161B to the internal space 81A of the right sleeve portion 81 is supplied to the oil filler port 85C via the passage 85A of the spherical bearing 85. The oil filler port 85C supplies the lubricating oil between the bearing surface 85S and the slide surface 91S. The supply of the lubricating oil from the oil filler port 85C between the bearing surface 85S and the slide surface 91S allows the lower holding portion 91 to rotate smoothly relative to the spherical bearing 85.

[0095] The lubricating oil supplied from the oil supply port 85C to between the bearing surface 85S and the slide surface 91S is contained in the first cover 40. The joint 41 of the first cover 40 and the joint 37 of the pump 30 are connected by a second tube 102. The lubricating oil contained in the first cover 40 flows out from the joint 41. The lubricating oil flowing out from the joint 41 is sent to the pump 30 via the second tube 102.

[0096] <Effects> As described above, the sewing machine 1 according to the embodiment includes the sewing machine motor 12, the needle plate 7, the driven shaft 16, which is a lower shaft disposed below the needle plate 7 and rotates by power generated by the sewing machine motor 12 and the rotational force of the drive shaft 14, the conversion member 80 fixed to the driven shaft 16 and converts the rotational motion of the driven shaft 16 into swinging motion, the connecting rod 90, which is a holding member that holds at least a portion of the conversion member 80, the oil supply port 85C that supplies lubricating oil between the conversion member 80 and the connecting rod 90, and the first cover 40 disposed around at least a portion of the conversion member 80. In the left-right direction, which is the axial direction of the driven shaft 16, the dimension of the first cover 40 is smaller than the dimension of the driven shaft 16.

[0097] According to the embodiment, the outer dimensions of the first cover 40 that contains the lubricating oil are smaller than the dimensions of the driven shaft 16, thereby preventing the lubricating oil from adhering to areas of the sewing machine 1 where it is not needed. If the dimensions of the first cover 40 were larger than the dimensions of the driven shaft 16, the lubricating oil contained in the first cover 40 could potentially adhere to areas where it is not needed. Examples of areas where lubricating oil is not needed include the right end and middle of the right driven shaft 161 and the left end and middle of the left driven shaft 162. If the lubricating oil adheres to areas where it is not needed, it could increase the effort required to clean those areas or result in the lubricating oil being unintentionally applied to the sewing object. Furthermore, if the first cover 40 is large and the opening at the top end of the first cover 40 is large, foreign matter such as metal powder, lint, and dust could potentially get into the lubricating oil contained in the first cover 40 through the opening. According to the embodiment, the first cover 40 is small, preventing the above-mentioned problems from occurring. The conversion member 80 and the connecting rod 90 move relative to each other, and therefore require lubrication. The first cover 40 is disposed around at least a portion of the conversion member 80, which is a portion requiring lubrication, and therefore prevents the lubrication oil supplied between the conversion member 80 and the connecting rod 90 from the oil filler port 85C from splashing around the conversion member 80.

[0098] The sewing machine 1 includes a base member 13 that rotatably supports the driven shaft 16. The first cover 40 is fixed to the base member 13. As a result, the position of the first cover 40 is fixed to at least a portion of the periphery of the conversion member 80.

[0099] First cover 40 covers at least a portion of converting member 80 from below. As a result, lubricating oil supplied from oil filler port 85C to between bearing surface 85S and slide surface 91S falls to the inside of first cover 40 by the action of gravity and is contained in first cover 40.

[0100] The conversion member 80 has a spherical bearing 85. The connecting rod 90 has a sliding surface 91S that faces the bearing surface 85S of the spherical bearing 85. The center of the spherical bearing 85 is positioned offset from the central axis DX of the driven shaft 16. An oil filler port 85C supplies lubricating oil between the bearing surface 85S and the sliding surface 91S. The first cover 40 covers the spherical bearing 85 from below. Because the center of the spherical bearing 85 is positioned offset from the central axis DX of the driven shaft 16, the conversion member 80 can convert the rotational motion of the driven shaft 16 into vertical swinging motion of the connecting rod 90. The bearing surface 85S of the spherical bearing 85 and the sliding surface 91S of the connecting rod 90 slide against each other, and therefore require lubrication. The first cover 40 covers the spherical bearing 85, which is a part that requires lubrication oil, from below, thereby preventing the lubrication oil supplied between the spherical bearing 85 and the connecting rod 90 from splashing around the spherical bearing 85.

[0101] The oil supply port 85C is provided in the spherical bearing 85. This allows lubricating oil to be supplied between the bearing surface 85S and the slide surface 91S.

[0102] The sewing machine 1 includes a looper 20 that supplies a bobbin thread to a sewing object, and a looper drive mechanism 21 that operates to rotate the looper 20. The looper drive mechanism 21 includes a connecting rod 90. The connecting rod 90 of the looper drive mechanism 21 slides smoothly relative to the spherical bearing 85, allowing the looper drive mechanism 21 to operate smoothly.

[0103] The looper drive mechanism 21 has a looper shaft 23 to which the looper 20 is fixed and which is connected to a connecting rod 90 via a connecting member 22. The connecting rod 90 has a lower holding portion 91 having a slide surface 91S and an upper holding portion 92 which holds the spherical portion 22A of the connecting member 22. This allows the looper 20 fixed to the looper shaft 23 to rotate.

[0104] The first cover 40 has a recess 43 in which at least a portion of the driven shaft 16 is disposed. The driven shaft 16 extends in the left-right direction. The first cover 40 has a front plate 40A disposed forward of the driven shaft 16, a rear plate 40B disposed rearward of the driven shaft 16, a left plate 40C connected to the left end of the front plate 40A and the left end of the rear plate 40B, a right plate 40D connected to the right end of the front plate 40A and the right end of the rear plate 40B, and a bottom plate 40E connected to the lower end of the front plate 40A, the lower end of the rear plate 40B, the lower end of the left plate 40C, and the lower end of the right plate 40D. The recess 43 is provided in each of the left plate 40C and the right plate 40D. Because at least a portion of the driven shaft 16 fits inside the recess 43, the oil supply mechanism of the sewing machine 1 is prevented from becoming large. Furthermore, since the first cover 40 is close to the spherical bearing 85, scattering of the lubricating oil is suppressed.

[0105] The driven shaft 16 includes a left driven shaft 162, which is a lower left shaft and at least a portion of which is located to the left of the left plate portion 40C, and a right driven shaft 161, which is a lower right shaft and at least a portion of which is located to the right of the right plate portion 40D. The conversion member 80 includes a left sleeve portion 82 into which the left driven shaft 162 is inserted and a right sleeve portion 81 into which the right driven shaft 161 is inserted. The spherical bearing 85 is disposed between the left sleeve portion 82 and the right sleeve portion 81. At least a portion of the left sleeve portion 82 is disposed in the recessed portion 43 of the left plate portion 40C. At least a portion of the right sleeve portion 81 is disposed in the recessed portion 43 of the right plate portion 40D. Because the left sleeve portion 82 and the right sleeve portion 81 each fit inside the recessed portion 43, an increase in size of the oil supply mechanism of the sewing machine 1 is suppressed. Furthermore, because the first cover 40 is close to the spherical bearing 85, splashing of lubricating oil is suppressed.

[0106] The conversion member 80 has a left flange portion 84 disposed between the left sleeve portion 82 and the spherical bearing 85, and a right flange portion 83 disposed between the right sleeve portion 81 and the spherical bearing 85. At least a portion of the left plate portion 40C faces the left flange portion 84. At least a portion of the right plate portion 40D faces the right flange portion 83. Because at least a portion of the left plate portion 40C faces the left flange portion 84 and at least a portion of the right plate portion 40D faces the right flange portion 83, the oil supply mechanism of the sewing machine 1 is prevented from becoming large. In addition, because the gap between the conversion member 80 and the first cover 40 is reduced, splashing of lubricating oil is suppressed.

[0107] The sewing machine 1 includes a pump 30 that is disposed outside the first cover 40 and that discharges lubricating oil to be supplied to the oil filler port 85C. Because the pump 30 is disposed outside the first cover 40, an increase in the size of the first cover 40 is suppressed.

[0108] The driven shaft 16 has a hollow hole 161B through which the lubricating oil supplied from the pump 30 flows. The conversion member 80 has a passage 85A through which the lubricating oil flows from the hollow hole 161B. An oil supply port 85C is provided in the conversion member 80. The oil supply port 85C supplies the lubricating oil from the passage 85A between the conversion member 80 and the connecting rod 90. This allows the lubricating oil to be supplied between the spherical bearing 85 and the lower holding portion 91.

[0109] The lubricating oil contained in the first cover 40 is sent to the pump 30. This causes the lubricating oil to circulate.

[0110] The sewing machine 1 is provided with a second cover 50 that is connected to the connecting rod 90 and covers the spherical bearing 85 from above. Since the second cover 50 is arranged to cover the spherical bearing 85 from above, the lubricating oil supplied from the oil supply port 85C between the spherical bearing 85 and the lower holding portion 91 is prevented from scattering around the spherical bearing 85.

[0111] In the left-right direction, the dimension of the first cover 40 is larger than the dimension of the second cover 50. This prevents the oil supply mechanism of the sewing machine 1 from becoming larger.

[0112] The left end of the first cover 40 is located to the left of the left end of the second cover 50. The right end of the first cover 40 is located to the right of the right end of the second cover 50. This prevents the oil supply mechanism of the sewing machine 1 from becoming too large.

[0113] A tip end 52 of the second cover 50 is inclined downward toward the front. Since the second cover 50 is disposed so as to encase the spherical bearing 85, the lubricating oil supplied from the oil filler port 85C between the spherical bearing 85 and the lower holding portion 91 is prevented from scattering around the spherical bearing 85.

[0114] The second cover 50 is made of rubber, which allows the second cover 50 to bend and deform.

[0115] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0116] FIG. 17 is a cross-sectional view showing a first cover 40 according to an embodiment. As shown in FIG. 17, a filter 45 may be disposed inside the first cover 40. The lubricating oil that passes through the filter 45 is discharged from a joint 41 provided on the bottom plate portion 40E. Although the opening provided at the upper end of the first cover 40 is small, foreign matter such as metal powder, lint, and dust may be mixed into the lubricating oil contained in the first cover 40. The filter 45 collects the foreign matter from the lubricating oil. Because the filter 45 collects the foreign matter, clean lubricating oil is sent from the joint 41 to the pump 30. As shown in FIG. 17, the filter 45 may be disposed at a position away from the bottom plate portion 40E of the first cover 40. If the filter 45 is in contact with the bottom surface of the first cover 40, at least some of the foreign matter collected by the filter 45 is likely to move to the joint 41. By arranging the filter 45 at a position away from the bottom surface of the first cover 40, foreign matter collected in the filter 45 is prevented from moving to the joint 41.

[0117] [Third embodiment] A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of these components will be simplified or omitted.

[0118] Fig. 18 is a perspective view from the upper left rear showing a portion of the sewing machine 1 according to the embodiment. Fig. 19 is a perspective view from the upper right front showing a portion of the sewing machine 1 according to the embodiment. Fig. 20 is a perspective view from the upper left front showing a portion of the sewing machine 1 according to the embodiment. Fig. 21 is an exploded perspective view from the upper left front showing a portion of the sewing machine 1 according to the embodiment. Fig. 22 is a cross-sectional perspective view from the upper left rear showing a portion of the sewing machine 1 according to the embodiment.

[0119] The sewing machine 1 includes a drive shaft 14, a driven shaft 16, a looper 20, a conversion member 80, a looper drive mechanism 21, a first cover 340, and a second cover 350.

[0120] The looper 20 supplies a lower thread to a sewing object. The looper 20 is supported by a looper drive mechanism 21. Two loopers 20 are provided.

[0121] The conversion member 80 is fixed to the driven shaft 16. The conversion member 80 rotates together with the driven shaft 16. The conversion member 80 converts the rotational motion of the driven shaft 16 into a swinging motion. The conversion member 80 connects the driven shaft 16 and the looper drive mechanism 21.

[0122] The looper drive mechanism 21 operates to rotate the looper 20 in the θX direction based on the power generated by the sewing machine motor 12. The looper drive mechanism 21 is connected to the conversion member 80. The looper drive mechanism 21 operates due to the rotation of the conversion member 80.

[0123] The looper drive mechanism 21 has a connecting rod 90 connected to the conversion member 80, a connecting member 22 connected to the connecting rod 90, and a looper shaft 23 connected to the connecting member 22. The connecting rod 90 holds at least a portion of the conversion member 80. The looper shaft 23 is connected to the connecting rod 90 via the connecting member 22. The looper shaft 23 is rotatably supported by bearings 24 and 25. The looper 20 is fixed to the looper shaft 23.

[0124] The first cover 340 is disposed around at least a portion of the conversion member 80. The first cover 340 covers at least a portion of the conversion member 80 from below. The first cover 340 covers the left portion of the drive shaft 14 and the left portion of the driven shaft 16 from below. The first cover 340 covers the connecting mechanism 300 that connects the drive shaft 14 and the looper shaft 23 from below. The first cover 340 prevents the lubricating oil supplied between the conversion member 80 and the connecting rod 90 from splashing.

[0125] The second cover 350 is disposed around at least a portion of the periphery of the conversion member 80. The second cover 350 covers at least a portion of the conversion member 80 from above. The second cover 350 suppresses scattering of lubricating oil supplied between the conversion member 80 and the connecting rod 90. The second cover 350 is connected to the connecting rod 90.

[0126] The first cover 340 is arranged to cover, from below, the conversion member 80 that connects the driven shaft 16 and the connecting rod 90 of the looper drive mechanism 21. As described in the first embodiment above, the conversion member 80 has a spherical bearing 85. The first cover 340 is arranged to cover at least the spherical bearing 85 from below.

[0127] In the left-right direction, which is the axial direction of the driven shaft 16, the dimension of the first cover 340 is smaller than the dimension of the driven shaft 16. In the embodiment, the dimension of the driven shaft 16 is the distance between the right end of the right driven shaft 161 and the left end of the left driven shaft 162.

[0128] The first cover 340 has a front plate portion 340A, a rear plate portion 340B, a left plate portion 340C, a right plate portion 340D, and a bottom plate portion 340E.

[0129] The front plate portion 340A is positioned forward of the driven shaft 16. The rear plate portion 40B is positioned rearward of the drive shaft 14. The left plate portion 40C is positioned to the left of the conversion member 80 and the connecting mechanism 300. The left plate portion 40C is positioned to the right of the left end of the drive shaft 14 and the left end of the driven shaft 16. A pulley portion 14A, around which a belt 15 is wound, is provided at the left end of the drive shaft 14. A pulley portion 16A, around which a belt 15 is wound, is provided at the left end of the driven shaft 16. The left plate portion 40C is positioned to the right of the pulley portion 14A and the pulley portion 16A. The right plate portion 340D is positioned to the right of the conversion member 80 and the connecting mechanism 300.

[0130] The second cover 350 is arranged to cover from above the conversion member 80 that connects the driven shaft 16 and the connecting rod 90 of the looper drive mechanism 21. The second cover 350 is arranged to cover at least the spherical bearing 85 from above.

[0131] The dimension of the first cover 340 in the left-right direction is larger than the dimension of the second cover 350. The left end of the first cover 340 is located to the left of the left end of the second cover 350. The right end of the first cover 340 is located to the right of the right end of the second cover 350. The front end of the second cover 350 is located rearward of the front end of the first cover 340. The rear end of the second cover 350 is located forward of the rear end of the first cover 340.

[0132] The rear end of the second cover 350 is inclined downward toward the rear. The rear end of the second cover 350 is provided so as to enclose the conversion member 80. The front end of the second cover 350 is inclined downward toward the front. The front end of the second cover 350 is provided so as to enclose the conversion member 80. The middle part of the second cover 350 and the connecting rod 90 are fixed with screws 351.

[0133] The second cover 350 is flexible. The second cover 350 is made of rubber. When the connecting rod 90 moves up and down, the middle portion of the second cover 350 also moves up and down. Because the middle portion of the second cover 350 is fixed to the connecting rod 90 by the screws 351, when the connecting rod 90 moves up and down, the second cover 350 flexes and deforms so that the front and rear ends of the second cover 350 are displaced up and down.

[0134] The first cover 340 is spaced apart from the drive shaft 14, the driven shaft 16, the conversion member 80, and the coupling mechanism 300. Because the first cover 340 is spaced apart from the drive shaft 14, the driven shaft 16, the conversion member 80, and the coupling mechanism 300, the drive shaft 14, the driven shaft 16, the conversion member 80, and the coupling mechanism 300 can rotate smoothly.

[0135] The second cover 350 is spaced apart from the drive shaft 14, the driven shaft 16, the conversion member 80, and the coupling mechanism 300. Because the second cover 350 is spaced apart from the drive shaft 14, the driven shaft 16, the conversion member 80, and the coupling mechanism 300, the drive shaft 14, the driven shaft 16, the conversion member 80, and the coupling mechanism 300 can rotate smoothly.

[0136] The lubricating oil supplied between the conversion member 80 and the connecting rod 90 falls to the inside of the first cover 340 due to the action of gravity and is contained in the first cover 340. In addition, the lubricating oil that splashes out from between the conversion member 80 and the connecting rod 90 is also contained in the first cover 340.

[0137] A circulation fitting 360 is provided on the bottom plate portion 340E of the first cover 340. The lubricating oil discharged from the first cover 340 flows through the circulation fitting 360. The circulation fitting 360 includes a filter. The circulation fitting 360 is connected to the joint 37 of the pump 30 via the second tube 102 described in the first embodiment above. The lubricating oil discharged from the first cover 340 via the circulation fitting 360 is sent to the pump 30 via the second tube 102.

[0138] [Other embodiments] In the above-described embodiment, the conversion member 80 includes the right sleeve portion 81, the left sleeve portion 82, the right flange portion 83, the left flange portion 84, and the spherical bearing 85. In the conversion member 80, for example, the left sleeve portion 82 may be omitted. In the conversion member 80, for example, the left sleeve portion 82 and the left flange portion 84 may be omitted. When the left sleeve portion 82 is omitted in the conversion member 80, the recess 43 may be provided in the right plate portion 40D and not in the left plate portion 40C. [Explanation of symbols]

[0139] 1...sewing machine, 2...sewing machine bed, 3...sewing machine head, 4...sewing machine needle, 5...needle bar, 6...take-up lever, 6C...cover, 7...throat plate, 8...presser foot, 9A...upper thread tension controller, 9B...lower thread tension controller, 10...feed foot, 11...feed dog, 12...sewing machine motor, 13...base member, 14...drive shaft, 14A...pulley section, 15...belt, 16...driven shaft (lower shaft), 16A...pulley section, 17...horizontal feed shaft, 18...feed dog drive mechanism, 18A...support arm, 18B...first link mechanism, 18C...second link mechanism, 19...upper and lower Feed shaft, 20...looper, 21...looper drive mechanism, 22...connecting member, 22A...spherical portion, 22B...holding portion, 22S...slide surface, 22T...holding surface, 23...looper shaft, 24...bearing, 25...bearing, 30...pump, 31...joint, 32...movable member, 33...plate, 34...coil spring, 35...eccentric sleeve, 36...pump body, 37...joint, 40...first cover, 40A...front plate portion, 40B...rear plate portion, 40C...left plate portion, 40D...right plate portion, 40E...bottom plate portion, 41...joint, 42...screw, 43...recess, 45...Filter, 50...Second cover, 51...Rear end, 51A...Screw opening, 52...Tip portion, 53...Hole, 60...Relay portion, 60A...Passage, 61...Joint, 62...Bearing, 62A...Passage, 63...Retaining hole, 70...Fixing plate, 80...Conversion member, 81...Right sleeve portion, 81A...Internal space, 82...Left sleeve portion, 83...Right flange portion, 84...Left flange portion, 85...Spherical bearing, 85A...Passage, 85C...Oil filler port, 85S...Bearing surface, 90...Connecting rod (retaining member), 91...Lower retaining portion, 91S...Slide surface, 92 ...Upper holding portion, 92S...holding surface, 93...rod portion, 94...screw, 95...screw, 101...first tube, 102...second tube, 161...right driven shaft (lower right shaft), 161A...hole, 161B...hollow hole, 162...left driven shaft (lower left shaft), 300...connecting mechanism, 340...first cover, 340A...front plate portion, 340B...rear plate portion, 340C...left plate portion, 340D...right plate portion, 340E...bottom plate portion, 350...second cover, 351...screw, 360...reflux part, CX...central axis, DX...central axis, EX...central axis.

Claims

1. A sewing machine motor; The needle plate and a lower shaft that is disposed below the needle plate and that rotates by power generated by the sewing machine motor; a conversion member fixed to the lower shaft and configured to convert a rotational motion of the lower shaft into a swinging motion; a holding member that holds at least a portion of the conversion member; an oil supply port for supplying lubricating oil between the conversion member and the holding member; a first cover disposed around at least a portion of the conversion member; a dimension of the first cover in the axial direction of the lower shaft is smaller than a dimension of the lower shaft; sewing machine.

2. a base member that rotatably supports the lower shaft; The first cover is fixed to the base member.

2. The sewing machine according to claim 1.

3. The first cover covers at least a portion of the conversion member from below.

2. The sewing machine according to claim 1.

4. The conversion member has a spherical bearing, the holding member has a slide surface facing the bearing surface of the spherical bearing, the center of the spherical bearing is disposed at a position offset from the central axis of the lower shaft, the oil supply port supplies lubricating oil between the bearing surface and the slide surface, the first cover covers the spherical bearing from below; 4. The sewing machine according to claim 3.

5. The oil filler port is provided on the spherical bearing.

5. The sewing machine according to claim 4.

6. a looper for supplying a bobbin thread to a sewing object; a looper drive mechanism that operates to rotate the looper, The looper drive mechanism includes the holding member.

5. The sewing machine according to claim 4.

7. The looper drive mechanism includes: Connecting rod and a looper shaft to which the looper is fixed and which is connected to the connecting rod via a connecting member, The connecting rod is a lower holding portion having the slide surface; and an upper holding portion that holds the spherical portion of the connecting member.

7. The sewing machine according to claim 6.

8. The first cover has a recess in which at least a portion of the lower shaft is disposed.

8. The sewing machine according to claim 7.

9. the conversion member has a sleeve portion to which the spherical bearing is connected and into which the lower shaft is inserted, At least a portion of the sleeve portion is disposed in the recess.

9. The sewing machine according to claim 8.

10. The lower shaft extends in the left-right direction, The first cover is a front plate portion disposed forward of the lower shaft; a rear plate portion disposed rearward of the lower shaft; a left plate portion connected to a left end portion of the front plate portion and a left end portion of the rear plate portion; a right plate portion connected to a right end portion of the front plate portion and a right end portion of the rear plate portion; a bottom plate portion connected to a lower end of the front plate portion, a lower end of the rear plate portion, a lower end of the left plate portion, and a lower end of the right plate portion; The recessed portion is provided in each of the left plate portion and the right plate portion.

9. The sewing machine according to claim 8.

11. The lower shaft a left lower shaft at least a portion of which is disposed to the left of the left plate portion; a right lower shaft, at least a portion of which is disposed to the right of the right plate portion, The conversion member is a left sleeve portion into which the left lower shaft is inserted; a right sleeve portion into which the right lower shaft is inserted, the spherical bearing is disposed between the left sleeve portion and the right sleeve portion, At least a portion of the left sleeve portion is disposed in the recess of the left plate portion, At least a portion of the right sleeve portion is disposed in the recess of the right plate portion. The sewing machine according to claim 10.

12. The conversion member is a left flange portion disposed between the left sleeve portion and the spherical bearing; a right flange portion disposed between the right sleeve portion and the spherical bearing, At least a portion of the left plate portion faces the left flange portion, At least a portion of the right plate portion faces the right flange portion. The sewing machine according to claim 11.

13. a pump disposed outside the first cover and configured to discharge the lubricating oil to be supplied to the oil filler port; 2. The sewing machine according to claim 1.

14. the lower shaft has a hollow hole through which the lubricating oil supplied from the pump flows, The conversion member has a passage through which lubricating oil flows from the hollow hole, The oil supply port is provided in the conversion member and supplies the lubricating oil from the passage between the conversion member and the holding member.

14. The sewing machine according to claim 13.

15. The lubricating oil contained in the first cover is sent to the pump.

15. The sewing machine of claim 14.

16. a joint provided on a bottom plate portion of the first cover and through which lubricating oil discharged from the first cover flows; a filter disposed inside the first cover, The filter is disposed at a position spaced apart from the bottom plate portion.

16. The sewing machine according to claim 15.

17. a second cover connected to the connecting rod and covering the spherical bearing from above; The sewing machine according to claim 10.

18. The dimension of the first cover is larger than the dimension of the second cover in the left-right direction.

18. The sewing machine of claim 17.

19. The left end of the first cover is disposed to the left of the left end of the second cover, and the right end of the first cover is disposed to the right of the right end of the second cover.

19. The sewing machine of claim 18.

20. The tip of the second cover is inclined downward toward the front.

19. The sewing machine of claim 18.

21. The second cover is fixed to the connecting rod.

18. The sewing machine of claim 17.

22. The second cover is made of rubber.

22. The sewing machine of claim 21.

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