Sewing machine frame

Abstract

To provide a sewing machine frame which has achieved rigidity and lightness more than before.SOLUTION: A sewing machine frame 5 includes: a post frame 4; and an arm frame 8 which is the arm frame 8 extending in an extension direction J orthogonal to the longer direction D from one end in the longer direction D of the post frame 4, and which includes a first extension plate 81 extending in the extension direction J, a second extension plate 82 separated from the first extension plate 81 in the longer direction D, opposing to the first extension plate 81, and extending in the extension direction J, and an extension intermediate plate 83 which is the extension intermediate plate 83 expanding in the longer direction D, for connecting the first extension plate 81 and the second extension plate 82 in the longer direction D, and extending in the extension direction J, and which includes a curved surface.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a sewing machine frame.

Background Art

[0002] In a conventional sewing machine frame, the horizontal cross-section of the leg posts constituting the sewing machine frame is S-shaped along the longitudinal direction of the arm and the bed. The sewing machine frame is provided with X-shaped ribs for reinforcing the rigidity of the leg posts inside one of the frames located on the tip side of the arm. The leg posts and the ribs are made of a resin lighter than cast iron and aluminum die-cast, and weight reduction is achieved compared to conventional sewing machines.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional sewing machine frame, the influence of the load acting on the arm due to the drive of the needle bar arranged at a position away from the leg posts cannot be ignored. In order to ensure the rigidity of the sewing machine frame, if the thickness of the sewing machine frame is increased or the ribs are increased, the light weight of the sewing machine frame is impaired, so it is difficult to achieve both the rigidity and the light weight of the sewing machine frame.

[0005] An object of the present invention is to provide a sewing machine frame that achieves both higher rigidity and lighter weight than conventional ones.

Means for Solving the Problems

[0006] The sewing machine frame according to one aspect of the present invention includes a leg column frame and an extension frame that extends from one end in the longitudinal direction of the leg column frame in an extension direction orthogonal to the longitudinal direction. The extension frame includes a first extension plate that extends in the extension direction, a second extension plate that is spaced apart from the first extension plate in the longitudinal direction, faces the first extension plate, and extends in the extension direction, and an extension middle plate that extends in the extension direction by spreading in the longitudinal direction and connecting the first extension plate and the second extension plate in the longitudinal direction, and the extension middle plate has a curved surface. The extension middle plate of the sewing machine frame contributes to increasing the rigidity of the extension frame without increasing the weight compared to the case where the extension middle plate is formed only of a plane in the sewing machine frame where a load is likely to be applied due to the driving of the sewing machine. That is, the extension middle plate of the sewing machine frame contributes to achieving both rigidity and light weight more than before.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Best Mode for Carrying Out the Invention

[0008] A sewing machine 1 including a sewing machine frame 5 according to an embodiment of the present disclosure will be described with reference to the drawings. The vertical direction, lower left direction, upper right direction, upper left direction, and lower right direction in FIG. 1 are respectively the vertical direction, left direction, right direction, rear direction, and front direction of the sewing machine 1. The vertical direction, lower left direction, upper right direction, upper left direction, and lower right direction in FIG. 2 are respectively the vertical direction, left direction, right direction, rear direction, and front direction of the sewing machine frame 5. The longitudinal direction D of the leg column 12 and the leg column frame 4 is the vertical direction of the sewing machine 1 and the sewing machine frame 5. The left side is defined as the extending direction J. The front-rear direction orthogonal to each of the longitudinal direction D and the extending direction J is defined as the orthogonal direction W. The direction from the needle bar 26 toward the presser bar 28 is the rear direction, which is defined as the forward feed direction F and the second direction K2. The direction opposite to the forward feed direction F is the front direction, which is defined as the reverse feed direction B and the first direction K1.

[0009] As shown in FIGS. 1 and 2, the sewing machine 1 includes a sewing machine frame 5, a bed 7, leg columns 12, and an arm 13. The sewing machine frame 5 is formed of a metal having relatively high rigidity such as an aluminum alloy and supports the components of the sewing machine 1. The sewing machine frame 5 has a U-shaped configuration with the left side open when viewed from the front. The sewing machine frame 5 includes a leg column frame 4, a bed frame 6, and an arm frame 8. The arm frame 8 extends from one end of the leg column frame 4 in the longitudinal direction D in an extending direction J orthogonal to the longitudinal direction D. The bed frame 6 extends from the other end of the leg column frame 4 in the longitudinal direction D in an extending direction J orthogonal to the longitudinal direction D. The detailed configuration of the sewing machine frame 5 will be described later.

[0010] The leg post 12 extends in the vertical direction. Inside the leg post 12, a leg post frame 4, a sewing machine motor (not shown), a transmission member (not shown), and a power source (not shown) are provided. The leg post frame 4 supports the sewing machine motor and the transmission member. The sewing machine motor rotates a main shaft (described later) with electric power supplied from the power source. The transmission member transmits the power of the sewing machine motor to a lower shaft (described later). On the front side of the leg post 12, a vertically long liquid crystal display (LCD) 17 and a touch screen 16 are provided. The LCD 17 displays messages and the like necessary for sewing work. The touch screen 16 is provided on the front surface of the LCD 17. When the user operates the touch screen 16 with an indicator such as a finger or a dedicated pen to select an item displayed on the LCD 17, the selection position is detected. The user can input various instructions to the sewing machine 1 via the touch screen 16.

[0011] The bed 7 extends from the lower end of the leg post 12 in an extending direction J orthogonal to the vertical direction. The upper surface 15 of the bed 7 extends horizontally and is provided with a needle plate 3. The needle plate 3 is formed with a needle hole through which the sewing needle 29 is inserted. Below the needle plate 3 on the bed 7, a bed frame 6, a lower shaft (not shown), a feed mechanism, a bobbin mechanism, and the like are provided. The bed frame 6 supports the lower shaft, the feed mechanism, and the bobbin mechanism. The lower shaft extends in the left - right direction. The feed mechanism includes feed teeth and drives the feed teeth in response to the rotation of the lower shaft, moving the workpiece to be sewn in the forward feed direction F or the reverse feed direction B by a predetermined amount of movement. The forward feed direction F corresponds to the direction in which the sewing machine 1 is arranged with respect to the user. The bobbin mechanism includes a bobbin and drives the bobbin in response to the rotation of the lower shaft to twist the upper thread around the lower thread.

[0012] The arm 13 extends in the extending direction J parallel to the bed 7 from the upper end of the leg post 12 above the bed 7. Inside the arm 13, an arm frame 8 and a main shaft etc. are provided. The arm 13 has a head 14 at its left end. The head 14 includes a needle bar mechanism 21, a balance mechanism 23, an image sensor 22, and a projector module 20. The arm frame 8 supports the needle bar mechanism 21, the balance mechanism 23, the image sensor 22, and the projector module 20. The head 14 is further provided with a detachable cover 25. The needle bar mechanism 21, the balance mechanism 23, the projector module 20, and the image sensor 22 are supported by a metal frame fixed to the front side of the sewing machine frame 5 and covered by the cover 25 in a state of being attached to the head 14.

[0013] The needle bar mechanism 21 has a needle bar 26 extending in the vertical direction and reciprocates the needle bar 26 in the vertical direction. The lower end portion of the needle bar 26 projects downward from the lower end of the head 14. A sewing needle 29 is detachably attached to the lower end of the needle bar 26. The sewing needle 29 attached to the needle bar 26 reciprocates in the vertical direction. The presser bar 28 extends in the vertical direction behind the needle bar 26 and reciprocates in the vertical direction in synchronization with the drive of the needle bar 26. A presser foot 70 is detachably attached to the lower end of the presser bar 28. The upper thread inserted through the sewing needle 29 is intertwined with the lower thread by a bobbin to form a stitch on the workpiece to be sewn. The balance mechanism 23 has a balance 24 in which a hole through which the upper thread passes is formed. The balance 24 is provided in the reverse feed direction B, that is, in front of the needle bar 26. The balance mechanism 23 reciprocates the balance 24 in the vertical direction. Thereby, the balance 24 pulls up the upper thread and adjusts the position of the knot with the lower thread.

[0014] The image sensor 22 images the imaging area R2 on the bed 7. An example of the imaging target of the image sensor 22 is a projection image projected onto the object to be sewn. The imaging area R2 includes at least a part of the projection area R1 of the projector 2 described later. The projector module 20 is arranged at a distance from the needle bar 26 in the extending direction J. The projector module 20 includes the projector 2. The projector 2 is installed at the tip of the arm 13 in the extending direction J and is configured to project a projection image onto the projection area R1 on the bed 7.

[0015] A plurality of switches including a start / stop switch 27 are provided on the front surface of the arm 13. The start / stop switch 27 is a switch for instructing the start and stop of the sewing operation. An openable sewing machine cover (not shown) is provided on the upper part of the arm 13. In FIG. 1, the illustration of the sewing machine cover of the arm 13 is omitted. A thread storage portion 18 is provided on the upper surface 19 that is exposed when the sewing machine cover of the arm 13 is opened. The thread storage portion 18 is a downwardly concave portion capable of accommodating a bobbin around which the upper thread is wound.

[0016] The operation of the sewing machine 1 having the above configuration during sewing will be briefly described. When the sewing machine 1 detects the pressing of the start / stop switch 27, it drives the hook mechanism, the feed mechanism, the needle bar mechanism 21, and the balance mechanism 23 in synchronization. As a result, stitches are formed on the object to be sewn placed on the upper surface 15 of the bed 7 by the sewing needle 29 attached to the needle bar 26.

[0017] With reference to FIGS. 2 to 12, the sewing machine frame 5 will be described in detail. The longitudinal direction D of the leg column frame 4 is defined as the vertical direction. The extending direction J orthogonal to the longitudinal direction D is defined as the left direction. The orthogonal direction W orthogonal to each of the longitudinal direction D and the extending direction J is defined as the front-rear direction. The orthogonal direction W is a two-way direction and includes a first direction K1 and a second direction K2 opposite to the first direction K1. In this example, the orthogonal direction W is the front-rear direction, the first direction K1 is the front, and the second direction K2 is the rear. The thickness of the rib formed on the sewing machine frame 5 is defined as the length in the width direction orthogonal to each of the protruding direction of the rib and the longitudinal direction of the rib.

[0018] As shown in FIGS. 2 to 7, the leg post frame 4 includes a first leg post plate 41, a connecting curved plate 44, a second leg post plate 42, a leg post upper plate 121, a leg post lower plate 110, leg post plates 30 and 43, first leg post ribs 45, 46, 31, 32, 39, and second leg post ribs 47 to 57, 33 to 38. The first leg post plate 41 and the second leg post plate 42 extend in the longitudinal direction D. The first leg post plate 41 constitutes the left side surface of the leg post frame 4. The connecting curved plate 44 is an arc-shaped surface in a front view provided below the connecting portion 40 between the arm frame 8 and the leg post frame 4. The second leg post plate 42 constitutes the right side surface of the leg post frame 4. As shown in FIG. 6, the leg post frame 4 is trapezoidal in a right side view. The length L6 in the orthogonal direction W at the lower end of the leg post frame 4 is longer than the length L5 in the orthogonal direction W at the upper end of the leg post frame 4. Recesses 421, holes 422, and 423 are formed in the second leg post plate 42. The recess 421 is recessed leftward at the upper part of the second leg post plate 42. Cross-shaped ribs 425 and 426 are formed vertically side by side in the recess 421. The hole 422 is rectangular in a right side view and is formed below the recess 421. The hole 423 is rectangular in a right side view and is formed below the hole 422. The size of the hole 423 is larger than the size of the hole 422. When the sewing machine frame 5 is assembled to the sewing machine 1, the sewing machine motor of the sewing machine 1 is disposed in the hole 422. A power supply is disposed in the hole 423.

[0019] The leg post upper plate 121 extends in the horizontal direction orthogonal to the vertical direction at the upper end of the leg post frame 4. The leg post upper plate 121 is integrally formed with a first extension plate 81 of the arm frame 8 described later. The leg post lower plate 110 extends in the horizontal direction orthogonal to the vertical direction at the lower end of the leg post frame 4. The leg post lower plate 110 is integrally formed with a second bed plate 62 of the bed frame 6 described later. As shown in FIG. 8, a rectangular leg post hole 111 that penetrates in the vertical direction and has a bent side in a bottom view is formed in the leg post lower plate 110. Among the sides 112 to 115 forming the four sides of the leg post hole 111, the front side 113 and the rear side 115 are bent in an arc shape recessed rearward in a bottom view. The left side 112 and the right side 114 are linearly extended in the front-rear direction.

[0020] As shown in FIGS. 2 and 3, the leg post plate 43 extends in the extending direction J, connects the first leg post plate 41 and the second leg post plate 42 in the left-right direction, and extends in the longitudinal direction D. The leg post plate 43 has a curved surface extending upward from the bent side 113 of the leg post hole 111. As shown in FIGS. 9 and 10, the leg post plate 43 has a curved surface whose cross-sectional shape in the direction perpendicular to the longitudinal direction D forms a curve. The leg post plate 43 is connected to the first leg post plate 41 at portions spaced apart from each of the two ends of the first leg post plate 41 in the orthogonal direction W. The leg post plate 43 is connected to the second leg post plate 42 at the rear end of the second leg post plate 42 in the orthogonal direction W. The leg post plate 43 bends in accordance with the shapes of the sewing machine motor and the power supply when the sewing machine frame 5 is assembled to the sewing machine 1. Specifically, as shown in FIG. 4, the leg post plate 43 refracts in the second direction K2 above the hole 422 in the longitudinal direction D and then extends upward. The position of the portion 431 above the hole 422 of the leg post plate 43 in the orthogonal direction W is located rearward of the portion 432 below the hole 422. The portion 431 is connected to the extending intermediate plate 83.

[0021] As shown in FIGS. 4 and 5, the leg post plate 30 extends in the extending direction J, connects the first leg post plate 41 and the second leg post plate 42 in the left-right direction, and extends in the longitudinal direction D. The leg post plate 30 has a curved surface extending upward from the bent side 115 of the leg post hole 111. As shown in FIGS. 9 and 10, the leg post plate 30 has a curved surface whose cross-sectional shape in the orthogonal direction W perpendicular to the longitudinal direction D forms a curve. The leg post plate 30 is connected to the first leg post plate 41 at portions rearward of the leg post plate 43 and spaced apart from each of the two ends of the first leg post plate 41 in the orthogonal direction W. The leg post plate 30 is not connected to the second leg post plate 42. The leg post plate 30 bends in accordance with the shapes of the sewing machine motor and the power supply when the sewing machine frame 5 is assembled to the sewing machine 1. Specifically, as shown in FIG. 7, the leg post plate 30 refracts in the first direction K1 above the hole 423 in the longitudinal direction D and then extends upward. The position of the portion 301 above the hole 423 of the leg post plate 30 in the orthogonal direction W is located forward of the portion 302 below the hole 423. The distance in the orthogonal direction W between the leg post plate 43 and the leg post plate 30 increases in the order of the concave portion 421, the hole 422, and the hole 423.

[0022] As shown in FIGS. 2, 3, and 7, the first leg rib 45, 46, and the second leg rib 47 to 57 project forward from the front surface of the leg plate 43. The first leg rib 45, 46 is formed on the tangent line of the connecting curved plate 44 in the front view. The connecting curved plate 44 has a connecting portion 451 with the first leg rib 45, a connecting portion 461 with the first leg rib 46, a connecting portion 481 with the second leg rib 48, and a connecting portion 491 with the second leg rib 49. The first leg rib 45 extends obliquely downward to the right from the connecting portion 451 of the connecting curved plate 44. The first leg rib 46 extends obliquely downward to the right from the connecting portion 461 located below the first leg rib 45. The forward clockwise extension angle of the first leg rib 45 with respect to the horizontal direction is smaller than the forward clockwise extension angle of the first leg rib 46 with respect to the horizontal direction.

[0023] The second leg rib 47 extends in the vertical direction at the upper part of the leg frame 4. The upper end of the second leg rib 47 is connected to the upper leg plate 121. The lower end of the second leg rib 47 is connected to the first leg rib 45. The second leg rib 48 extends to the right from the connecting portion 481 located at the left end of the connecting curved plate 44. The right end of the second leg rib 48 is connected to the second leg rib 47. The second leg rib 49 extends obliquely upward to the right from the connecting portion 491 between the connecting portion 481 and the connecting portion 451 in the connecting curved plate 44. The right end of the second leg rib 49 is connected to the right end of the second leg rib 48 and the second leg rib 47. The second leg rib 50 extends obliquely downward to the right from the connecting portion 501 where the second leg rib 47 is connected to the second leg rib 48 and 49. The second leg rib 50 intersects with the second leg rib 58 described later. The second leg rib 50 has an intersection portion 502 that intersects with the second leg rib 58. The right end of the second leg rib 50 is connected to the second leg plate 42. The second leg rib 50 has a connecting portion 511 with the second leg rib 51 between the intersection portion 502 and the connecting portion 501 which is the left end of the second leg rib 50. The second leg rib 51 extends obliquely upward to the right from the connecting portion 511. The right end of the second leg rib 51 is connected to the second leg plate 42.

[0024] The second leg post rib 52 extends in the left - right direction below the left end of the first leg post rib 46. The left end of the second leg post rib 52 is connected to the first leg post plate 41. The right end of the second leg post rib 52 is connected to the second leg post plate 42. The second leg post rib 52 has an intersection portion 521 that intersects with the first leg post rib 45 and an intersection portion 522 that intersects with the first leg post rib 46. The second leg post rib 53 extends in the left - right direction below the second leg post rib 52. The left end of the second leg post rib 53 is connected to the first leg post plate 41. The right end of the second leg post rib 53 is connected to the second leg post plate 42. The second leg post rib 53 intersects with the first leg post rib 46. The second leg post rib 54 is connected to the lower end of the first leg post rib 45. The position of the second leg post rib 53 in the longitudinal direction D is substantially the same as the position of the first bed plate 61 of the bed frame 6 described later in the longitudinal direction D. The second leg post rib 54 extends in a V - shape in the front view below the second leg post rib 53. The second leg post rib 54 is connected to the lower ends of the first leg post ribs 45 and 46. The left end and the right end of the second leg post rib 54 are connected to the second leg post rib 53.

[0025] The second leg post ribs 55 and 56 each extend from the lower end of the first leg post plate 41 to the lower right. The lower ends of the second leg post ribs 55 and 56 are each connected to the leg post lower plate 110. The lower end of the second leg post rib 55 is located in the extending direction J with respect to the lower end of the second leg post rib 56. The second leg post rib 57 extends in the left - right direction below the second leg post rib 53. The left end of the second leg post rib 57 is connected to the second leg post rib 56. The right end of the second leg post rib 57 is connected to the second leg post plate 42. The first leg post rib 46 has a connecting portion 581 that connects to the second leg post rib 58 between the connecting portion 461 and the intersection portion 521. The second leg post rib 58 extends upward and to the right from the connecting portion 581. The second leg post rib 58 intersects with each of the second leg post rib 50 and the first leg post rib 45. The right end of the second leg post rib 58 is connected to the second leg post plate 42.

[0026] The lengths of the first leg rib 45, 46 in the longitudinal direction D are longer than the lengths of the second leg rib 47 to 58 in the longitudinal direction D. In the cross-sectional shape in the direction perpendicular to the orthogonal direction W, the thicknesses of the first leg rib 45, 46 are larger than the thicknesses of the second leg rib 47 to 58. The thicknesses of the first leg rib 45, 46 may be the same as each other or different from each other. The thicknesses of the second leg rib 47 to 58 may be the same as each other or different from each other. The thicknesses of the first leg rib 45, 46 are preferably 1.2 times to 3.0 times the thicknesses of the second leg rib 47 to 57. The thickness P1 of the first leg rib 45, 46 is, for example, 5 mm, and the thickness P2 of the second leg rib 47 to 57 is, for example, 3 mm. The protruding amounts of the first leg rib 45, 46 in the orthogonal direction W are larger than the protruding amounts of the arm rib 86 to 89, 94, 95 described later.

[0027] As shown in FIGS. 4 and 5, the first leg rib 31, 32, 39 and the second leg rib 33 to 38 protrude rearward from the back surface of the leg column plate 30. The connecting curved plate 44 has a connecting portion 341 with the second leg rib 34, a connecting portion 351 with the second leg rib 35, a connecting portion 311 with the first leg rib 31, and a connecting portion 321 with the first leg rib 32. The first leg rib 31, 32 are formed on the tangent line of the connecting curved plate 44 in the front view. The first leg rib 31 extends obliquely downward to the right from the connecting portion 311 of the connecting curved plate 44. The first leg rib 32 extends obliquely downward to the right from the connecting portion 321 of the connecting curved plate 44 below the first leg rib 31. The first leg rib 39 extends in the longitudinal direction D at the right end portion of the back surface of the leg column frame 4. The upper end of the first leg rib 39 is connected to the leg column upper plate 121, and the lower end of the first leg rib 39 is connected to the leg column lower plate 110. The first leg rib 39 is connected to each of the right end of the first leg rib 31 and the right end of the first leg rib 32.

[0028] The second leg post rib 33 extends in an arc shape with its upper right part protruding at the upper part of the leg post frame 4. The upper end of the second leg post rib 33 is connected to the leg post upper plate 121. The lower end of the second leg post rib 33 is connected to the first leg post rib 39. The second leg post rib 34 extends rightward and upward from the connecting part 341 of the connecting curved plate 44. The upper end of the second leg post rib 34 is connected to the upper end of the second leg post rib 33. The connecting part 351 is provided between the connecting part 341 and the connecting part 311. The second leg post rib 35 extends rightward and upward from the connecting part 351. The right end of the second leg post rib 35 is connected to the second leg post rib 33. The second leg post rib 36 extends rightward and downward below the second leg post rib 35. The right end of the second leg post rib 36 is connected to the first leg post rib 39. The left end of the second leg post rib 36 is connected to the first leg post rib 32. The second leg post rib 36 intersects the first leg post rib 31. The second leg post rib 37 extends in the left - right direction below the second leg post rib 36. The second leg post rib 37 intersects the first leg post rib 39. The left end of the second leg post rib 37 is connected to the first leg post plate 41. The second leg post rib 37 is connected to the lower end of the first leg post rib 31. The second leg post rib 37 intersects the first leg post rib 32. The second leg post rib 38 extends rightward and downward from the lower end of the first leg post plate 41. The lower end of the second leg post rib 38 is connected to the lower end of the first leg post rib 39 and the leg post lower plate 110.

[0029] The lengths in the longitudinal direction D of the first leg post ribs 31, 32, and 39 are longer than the lengths in the longitudinal direction D of the second leg post ribs 33 to 38. In the cross - sectional shape in the direction perpendicular to the orthogonal direction W, the thicknesses of the first leg post ribs 31, 32, and 39 are larger than the thicknesses of the second leg post ribs 33 to 38. The thicknesses of the first leg post ribs 31, 32, and 39 may be the same as each other or different from each other. It is preferable that the thicknesses of the first leg post ribs 31, 32, and 39 are 1.2 times to 3.0 times the thicknesses of the second leg post ribs 33 to 38. The thickness Q1 of the first leg post ribs 31, 32, and 39 is, for example, 5 mm, and the thickness Q2 of the second leg post ribs 33 to 38 is, for example, 3 mm. Holes 101 to 108 penetrating in the orthogonal direction W are formed in the leg post plates 30 and 43.

[0030] As shown in FIGS. 2 to 5, the bed frame 6 extends from the lower end of the leg post frame 4 in the extending direction J and faces the arm frame 8. The bed frame 6 includes a first bed plate 61, a second bed plate 62, a bed middle plate 63, bed ribs 66, 67, and kettle support plates 64, 65. The first bed plate 61 extends in the orthogonal direction W and extends in the extending direction J. The length of the first bed plate 61 in the orthogonal direction W is shorter toward the front end side in the extending direction J than the rear end side in the extending direction J. The second bed plate 62 is spaced apart from the first bed plate 61 in the longitudinal direction D, faces the first bed plate 61, extends in the orthogonal direction W, and extends in the extending direction J. The length of the second bed plate 62 in the orthogonal direction W is shorter than the length of the first bed plate 61 in the orthogonal direction W. The bed middle plate 63 extends in the longitudinal direction D, connects the first bed plate 61 and the second bed plate 62 in the longitudinal direction D, and extends in the extending direction J. The bed middle plate 63 is connected to the leg post plate 43. As shown in FIG. 9, the bed middle plate 63 has a curved surface whose cross-sectional shape in the direction perpendicular to the longitudinal direction D is a curve. The bed middle plate 63 of this example extends in the extending direction J while bending one or more times in the orthogonal direction W. The length R4 of the extending range of the bed middle plate 63 in the orthogonal direction W is smaller than half of the length of the extending range of the first bed plate 61 in the orthogonal direction W, and is also smaller than half of the length of the extending range of the second bed plate 62 in the orthogonal direction W. The length R4 of the extending range of the bed middle plate 63 in the orthogonal direction W of this example is larger than 1.2 times the thickness L8 of the bed middle plate 63, and more specifically, larger than 1.7 times the thickness L8 of the bed middle plate 63.

[0031] As shown in FIGS. 2 and 3, the bed rib 67 protrudes forward from the front surface of the bed middle plate 63. The bed rib 67 bends in an L shape when viewed from the front. The lower end of the bed rib 67 is connected to the second bed plate 62. A hole 69 is formed in the bed middle plate 63 along the bed rib 67. As shown in FIGS. 4 and 5, the bed rib 66 protrudes rearward from the rear surface of the bed middle plate 63. The bed rib 66 extends in a Y shape when viewed from the rear. The upper end of the bed rib 66 is connected to the first bed plate 61. The lower end of the bed rib 66 is connected to the second bed plate 62. The left end of the bed rib 66 is connected to the kettle support plate 65. A hole 68 is formed in the bed middle plate 63 along the bed rib 66.

[0032] The kettle support plates 64 and 65 are provided at the tip of the extending direction J of the bed frame 6. The kettle support plates 64 and 65 support the kettle mechanism of the sewing machine 1. The kettle support plate 64 is connected to the tip of the extending direction J of the second bed plate 62, extends horizontally, and extends in the extending direction J. The vertical position of the kettle support plate 64 is located above the vertical position of the second bed plate 62. The kettle support plate 65 extends upward from the rear end of the kettle support plate 64. The kettle support plate 65 is connected to the tip of the extending direction J of the bed middle plate 63. The kettle support plate 65 has a plane whose cross-sectional shape in the direction perpendicular to the longitudinal direction D forms a straight line.

[0033] The arm frame 8 includes a first extension plate 81, a second extension plate 82, an extension middle plate 83, arm ribs 86 to 89, 94 to 100, a head frame 84, and a projector support plate 85. The first extension plate 81 extends horizontally and extends in the extending direction J. The first extension plate 81 is connected to the tip of the extending direction J of the leg post upper plate 121. The second extension plate 82 is spaced apart from the first extension plate 81 in the longitudinal direction D, faces the first extension plate 81, extends horizontally, and extends in the extending direction J. The second extension plate 82 is connected to the tip of the extending direction J of the connecting curved plate 44. The extension middle plate 83 extends in the longitudinal direction D, connects the first extension plate 81 and the second extension plate 82 in the longitudinal direction D, and extends in the extending direction J. The extension middle plate 83 is connected to the leg post plate 43.

[0034] As shown in FIGS. 11 and 12, the first extension contour, which is the contour of the end 811 of the first extension plate 81 in the first direction K1, is a curve in plan view. The contour of the end 812 of the first extension plate 81 in the second direction K2 is a straight line in plan view. The second extension contour, which is the contour of the end 821 of the second extension plate 82 in the first direction K1, is a curve in plan view. The contour of the end 822 of the second extension plate 82 in the second direction K2 is a straight line in plan view. The end 821 of the second extension plate 82 is located in the first direction K1 relative to the end 811 of the first extension plate 81. The length in the orthogonal direction W of the first extension plate 81 is the longest length L1 at the portion 813 and the shortest length L2 at the portion 814. In the first extension plate 81, the portion 814 where the length in the orthogonal direction W is the shortest is located in the extension direction J relative to the portion 813 where the length in the orthogonal direction W is the longest. The length in the orthogonal direction W of the second extension plate 82 is the longest length L3 at the portion 823 and the shortest length L4 at the portion 824. In the second extension plate 82, the portion 823 where the length in the orthogonal direction W is the shortest is located in the extension direction J relative to the portion 824 where the length in the orthogonal direction W is the longest. The lengths in the orthogonal direction W of the first extension plate 81 and the second extension plate 82 are each shorter than the extension direction J.

[0035] The extension middle plate 83 has a curved surface. As shown in FIG. 11, the extension middle plate 83 has a curved surface whose cross-sectional shape in the direction perpendicular to the longitudinal direction D, that is, in the horizontal direction, is a curve. The extension middle plate 83 is connected to the first extension plate 81 at portions spaced apart from each of the two ends of the first extension plate 81 in the orthogonal direction W, and the extension middle plate 83 is connected to the first extension plate 81 at portions spaced apart from each of the two ends of the second extension plate 82 in the orthogonal direction W.

[0036] The length R3 of the extending range of the extending intermediate plate 83 in the orthogonal direction W is smaller than 1 / 2 of the length of the extending range of the first extending plate 81 in the orthogonal direction W and also smaller than 1 / 2 of the length of the extending range of the second extending plate 82 in the orthogonal direction W. Since the end 812 of the first extending plate 81 is linear, the length of the extending range of the first extending plate 81 in the orthogonal direction W is the length L1 of the portion 813. Since the end 822 of the second extending plate 82 is linear, the length of the extending range of the second extending plate 82 in the orthogonal direction W is the length L3 of the portion 823. The length R3 of the extending range of the extending intermediate plate 83 in the orthogonal direction W in this example is larger than 1.2 times the thickness L7 of the extending intermediate plate 83, and more specifically, larger than 1.7 times the thickness L7 of the extending intermediate plate 83. The tip of the extending intermediate plate 83 in the extending direction J is arranged near the center of the second extending plate 82 in the orthogonal direction W in the orthogonal direction W. The rear end of the extending intermediate plate 83 in the extending direction J is arranged behind the center of the second extending plate 82 in the orthogonal direction W in the orthogonal direction W. The horizontal cross-section of the extending intermediate plate 83 has a plurality of convex portions that protrude in the orthogonal direction W in a plan view. Among the front and rear surfaces of the extending intermediate plate 83, the area of the portion in contact with the virtual lines U1, U2 extending in the extending direction J for defining the extending range of the extending intermediate plate 83 in the orthogonal direction W is smaller than the area of the portion separated from the virtual lines U1, U2. On the front and rear surfaces of the extending intermediate plate 83, the area of the flat portion is smaller than the area of the curved surface portion. The extending intermediate plate 83 in this example extends in the extending direction J while bending a plurality of times in the orthogonal direction W, but is not limited to this configuration, and may form a curved surface by bending at least once.

[0037] As shown in FIGS. 2 and 3, the arm ribs 86 to 89, 94, 95 project forward along the orthogonal direction W from the front surface of the extending intermediate plate 83. The arm rib 86 is a rib bent in an L shape when viewed from the front. The upper end of the arm rib 86 is connected to the first extending plate 81, and the lower end of the arm rib 86 is connected to the second extending plate 82. The arm ribs 87 and 88 are ribs in an X shape when viewed from the front. The upper ends of the arm ribs 87 and 88 are each connected to the first extending plate 81, and the lower ends of the arm ribs 87 and 88 are each connected to the second extending plate 82. In the extending direction J, the arm rib 87 is disposed between the arm rib 86 and the arm rib 88. The arm rib 89 extends obliquely upward from the tip of the connecting curved plate 44 in the extending direction J. The upper end of the arm rib 89 is connected to the first extending plate 81, and the lower end of the arm rib 89 is connected to the second extending plate 82. The arm rib 89 is formed on the tangent line of the connecting curved plate 44 that is the same as the tangent line on which the first leg post rib 45 is formed. The arm rib 94 extends upward from the lower end of the arm rib 89. The upper end of the arm rib 94 is connected to the first extending plate 81. The arm rib 95 extends obliquely upward from the left side of the connecting portion 481. The upper end of the arm rib 95 is connected to the first extending plate 81. The thicknesses F1 of the arm ribs 86 to 89, 94, 95 may be the same as each other or different from each other. The thickness P1 of the first leg post ribs 45 and 46 is larger than the thickness F1 of the arm ribs 86 to 89, 94, 95. The thickness P2 of the second leg post ribs 47 to 58 is smaller than the thickness P1 of the first leg post ribs 45 and 46. The thickness F1 of the arm ribs 86 to 89, 94, 95 in this example is the same as the thickness P2 of the second leg post ribs 47 to 58, for example, 3 mm. The thickness F1 of the arm ribs 86 to 89, 94, 95 may be different from the thickness P2 of the second leg post ribs 47 to 58.

[0038] As shown in FIGS. 4 and 5, the arm ribs 96 to 100 project rearward along the orthogonal direction W from the back surface of the extending intermediate plate 83. Each of the arm ribs 96 to 99 is an X-shaped rib when viewed from the back. The arm rib 100 extends in the longitudinal direction D. The arm ribs 96 to 100 are arranged in this order from the tip to the rear end in the extending direction J. The upper end of each of the arm ribs 96 to 100 is connected to the first extending plate 81, and the lower end of each of the arm ribs 96 to 100 is connected to the second extending plate 82. The thicknesses of the arm ribs 96 to 100 may be the same as each other or different from each other. The thicknesses of the arm ribs 96 to 100 are smaller than the thicknesses of the first leg ribs 31, 32, 39. The protruding amount of the arm rib 96 in the orthogonal direction W is larger than the protruding amounts of the arm ribs 97 to 100 in the orthogonal direction W. The thickness Q1 of the first leg ribs 31, 32, 39 is larger than the thickness F2 of the arm ribs 96 to 100. The thickness Q2 of the second leg ribs 33 to 38 is smaller than the thickness Q1 of the first leg ribs 31, 32, 39. The thickness F2 of the arm ribs 96 to 100 in this example is the same as the thickness Q2 of the second leg ribs 33 to 38, for example, 3 mm. The thickness F2 of the arm ribs 96 to 100 may be different from the thickness Q2 of the second leg ribs 33 to 38. The rearward protruding amounts of the arm ribs 97 to 100 are smaller than the forward protruding amounts of the arm ribs 86 to 89, 94, 95.

[0039] A plurality of holes 90 to 93 penetrating in the orthogonal direction W are formed in the extending intermediate plate 83. The hole 90 is a triangular hole when viewed from the front, formed along the arm rib 96. The hole 91 is a rectangular hole when viewed from the front, formed along the arm ribs 88 and 97. The hole 92 is a rectangular hole when viewed from the front, formed along the arm ribs 88 and 98. The hole 93 is a rectangular hole when viewed from the front, formed along the arm ribs 89 and 99.

[0040] The head frame 84 is provided at the tip of the extending direction J of the arm frame 8. The head frame 84 is U-shaped with an open front in plan view. When the sewing machine frame 5 is assembled to the sewing machine 1, the head frame 84 supports the needle bar mechanism 21 and the balance mechanism 23. The projector support plate 85 is connected to the tip of the head frame 84 in the extending direction J. When the sewing machine frame 5 is assembled to the sewing machine 1, the projector support plate 85 supports the projector module 20 in the extending direction J beyond the needle bar mechanism 21.

[0041] Taking the sewing machine frame 5 having the above configuration as an example, the sewing machine frame 5 has the same dimensions in the longitudinal direction D and the extending direction J as those of a conventional sewing machine frame (for example, the sewing machine frame of the sewing machine described in JP-A-2020-5694). A sewing machine frame having the same configuration was used as a comparative example, and the rigidity and lightness of the sewing machine frame 5 of this example were evaluated. The materials of the conventional sewing machine frame and the sewing machine frame 5 were set under the same conditions. Although not shown, in the conventional sewing machine frame, the bed middle plate and the extending middle plate extend linearly in the extending direction J. The number of ribs of the conventional sewing machine frame is larger than the number of ribs of the sewing machine frame 5. The evaluation of the rigidity of the example was carried out by fixing the portions N1 to N7 at the bottom of the bed frame 6 and the leg column frame 4 in FIG. 8, and measuring the displacement amount of the sewing machine frame 5 with a simulator when a load of 10 N was applied downward and forward at each of the tip M1 of the arm frame 8 and the tip M2 of the bed frame 6 in FIG. 4. The evaluation of the rigidity of the comparative example was carried out in the same manner as in the example. The sewing machine frame 5 of the example was able to increase the rigidity by 1.4 times under the condition of being 68% lighter than the sewing machine frame of the comparative example.

[0042] In the above-described embodiment, the sewing machine frame 5, the leg post frame 4, the bed frame 6, and the arm frame 8 are each an example of the sewing machine frame, the leg post frame, the bed frame, and the extension frame of the present invention. The leg post plates 30 and 43 are an example of the leg post plate of the present invention. The first leg post ribs 31, 32, 39, 45, and 46 are each an example of the first leg post rib of the present invention. The second leg post ribs 33 to 58 are each an example of the second leg post rib of the present invention. The connecting curved plate 44, the first bed plate 61, the second bed plate 62, the bed middle plate 63, the first extension plate 81, the second extension plate 82, and the extension middle plate 83 are each an example of the connecting curved plate, the first bed plate, the second bed plate, the bed middle plate, the first extension plate, the second extension plate, and the extension middle plate of the present invention. The arm ribs 86 to 89 and 94 to 100 are each an example of the arm rib of the present invention. The holes 90 to 93 are an example of the plurality of holes of the present invention. The leg post bottom plate 110 and the leg post hole 111 are each an example of the leg post bottom plate and the leg post hole of the present invention. The end 811 is an example of the end of the first extension plate of the present invention. The end 821 is an example of the end of the second extension plate of the present invention. The longitudinal direction D, the extension direction J, the orthogonal direction W, the first direction K1, and the second direction K2 are each an example of the longitudinal direction, the extension direction, the orthogonal direction, the first direction, and the second direction of the present invention.

[0043] The sewing machine frame 5 of the above-described embodiment includes a leg post frame 4 and an arm frame 8 that extends from one end of the leg post frame 4 in the longitudinal direction D in the extension direction J that is orthogonal to the longitudinal direction D. The arm frame 8 includes a first extension plate 81 that extends in the extension direction J, a second extension plate 82 that is spaced apart from the first extension plate 81 in the longitudinal direction D and faces the first extension plate 81 and extends in the extension direction J, and an extension middle plate 83 that extends in the extension direction J by spreading in the longitudinal direction D and connecting the first extension plate 81 and the second extension plate 82, and the extension middle plate 83 has a curved surface. The extension middle plate 83 of the sewing machine frame 5 contributes to increasing the rigidity of the arm frame 8 without increasing the weight compared to the case where the extension middle plate 83 is formed only of a plane in the sewing machine frame 5 where a load is likely to be applied due to the drive of the sewing machine 1. That is, the extension middle plate 83 of the sewing machine frame 5 contributes to achieving both rigidity and light weight more than before.

[0044] The extending intermediate plate 83 has a curved surface with a cross-sectional shape in a direction perpendicular to the longitudinal direction D. The extending intermediate plate 83 can enhance the rigidity against the load applied in the longitudinal direction D compared to the case where the cross-sectional shape in the direction perpendicular to the longitudinal direction D is a plane, and can firmly connect the first extending plate 81 and the second extending plate 82.

[0045] When the longitudinal direction D of the leg column frame 4 is defined as the vertical direction, the arm frame 8 is an arm frame 8 extending in the extending direction J from the upper end of the leg column frame 4, and further includes a bed frame 6 extending in the extending direction J from the lower end of the leg column frame 4 and facing the arm frame 8. The extending intermediate plate 83 of the sewing machine frame 5 contributes to increasing the rigidity of the arm frame 8 where the load is likely to be applied due to the driving of the sewing machine 1 compared to the case where the extending intermediate plate 83 is formed only of a plane.

[0046] When the longitudinal direction D of the leg column frame 4 is defined as the vertical direction and the direction orthogonal to each of the longitudinal direction D and the extending direction J is defined as the orthogonal direction W, the orthogonal direction W includes a first direction K1 and a second direction K2 opposite to the first direction K1. The first extending contour, which is the contour of the end 811 of the first extending plate 81 in the first direction K1, is a curve in plan view, and the second extending contour, which is the contour of the end 821 of the second extending plate 82 in the first direction K1, is a curve in plan view. The first extending plate 81 and the second extending plate 82 of the sewing machine frame 5 contribute to increasing the rigidity of the arm frame 8 compared to the case where the first extending contour and the second extending contour are straight lines.

[0047] In the first extending plate 81, the portion 814 where the length in the orthogonal direction W is the shortest is located in the extending direction J relative to the portion 813 where the lengths L5 and L6 in the orthogonal direction W are the longest. In the second extending plate 82, the portion 824 where the length in the orthogonal direction W is the shortest is located in the extending direction J relative to the portion 823 where the length in the orthogonal direction W is the longest. The first extending plate 81 and the second extending plate 82 of the sewing machine frame 5 contribute to lightening the tip portion of the arm frame 8 in the extending direction J.

[0048] When the longitudinal direction D of the leg column frame 4 is defined as the vertical direction, the arm frame 8 is an arm frame 8 that extends from the upper end of the leg column frame 4 in the extending direction J. The sewing machine frame 5 includes a bed frame 6 that extends from the lower end of the leg column frame 4 and faces the arm frame 8 in the extending direction J. The bed frame 6 includes a first bed plate 61, a second bed plate 62, and a bed middle plate 63. The first bed plate 61 extends in the extending direction J. The second bed plate 62 is spaced apart from the first bed plate 61 in the longitudinal direction D, faces the first bed plate 61, and extends in the extending direction J. The bed middle plate 63 extends in the longitudinal direction D, connects the first bed plate 61 and the second bed plate 62 in the longitudinal direction D, and extends in the extending direction J. The bed middle plate 63 has a curved surface whose cross-sectional shape in a direction perpendicular to the longitudinal direction D forms a curve. The bed frame and the arm frame 8 of the sewing machine frame 5 contribute to increasing the rigidity of the sewing machine frame 5 without increasing the weight as compared with the case where a middle plate having a curved surface is provided only on one of the bed frame and the arm frame 8.

[0049] When the longitudinal direction D of the leg column frame 4 is defined as the vertical direction, the leg column frame 4 has, at the lower end of the leg column frame 4, a leg column lower plate 110 that extends in a horizontal direction perpendicular to the vertical direction, and a rectangular leg column hole 111 having sides 113, 115 that penetrate in the vertical direction and are bent in a bottom view is formed in the leg column lower plate 110, and leg column plates 30, 43 having curved surfaces that extend upward from the bent sides 113, 115. The leg column frame 4 of the sewing machine frame 5 contributes to increasing the rigidity of the leg column frame 4 without increasing the weight as compared with the case where the leg column frame 4 does not have the leg column plates 30, 43. The leg column frame 4 of the sewing machine frame 5 can easily manufacture the leg column plates 30, 43 by pulling out the molding die downward.

[0050] When the longitudinal direction D of the leg post frame 4 is defined as the vertical direction and the direction orthogonal to each of the longitudinal direction D and the extending direction J is defined as the orthogonal direction W, the length L6 in the orthogonal direction W at the lower end of the leg post frame 4 is longer than the length L5 in the orthogonal direction W at the upper end of the leg post frame 4. The leg post frame 4 of the sewing machine frame 5 contributes to increasing the rigidity of the leg post frame 4 without increasing the weight as compared with the case where the length in the orthogonal direction W at the lower end of the leg post frame 4 is less than or equal to the length in the orthogonal direction W at the upper end of the leg post frame 4.

[0051] When the direction orthogonal to each of the longitudinal direction D and the extending direction J is defined as the orthogonal direction W, the arm frame 8 has arm ribs 86 to 89, 94 to 100 protruding in the orthogonal direction W from the extending intermediate plate 83. The leg post frame 4 has first leg post ribs 45, 46 having a thickness Q1 greater than the thickness F1 of the arm ribs 86 to 89, 94, 95 and the thickness F2 of the arm ribs 96 to 100 in the cross-sectional shape in the direction perpendicular to the orthogonal direction W, and first leg post ribs 31, 32, 39 having a thickness Q2. The leg post frame 4 has second leg post ribs 33 to 38, 47 to 58 having a thickness smaller than the thickness Q2 of the first leg post ribs 31, 32, 39 and the thickness Q1 of the first leg post ribs 45, 46 and having a shorter length in the longitudinal direction D than the first leg post ribs 31, 32, 39, 45, 46. The sewing machine frame 5 contributes to ensuring the rigidity of the leg post frame 4 where the load is likely to be applied while reducing the thickness of the arm ribs 86 to 89, 94 to 100 and achieving weight reduction as compared with the case where the leg post ribs 31 to 39, 45 to 58 and the arm ribs 86 to 89, 94 to 100 have the same thickness.

[0052] When the longitudinal direction D of the leg post frame 4 is defined as the vertical direction and the extending direction J is defined as the left direction, the arm frame 8 has a connecting curved plate 44 in an arc shape in the front view below the connecting portion 40 with the leg post frame 4, and the first leg post ribs 31, 32, 39, 45, 46 are formed on the tangent line of the connecting curved plate 44 in the front view. The leg post ribs of the sewing machine frame 5 contribute to ensuring the rigidity of the connecting portion 40 of the leg post frame 4 and the arm frame 8 where the load is likely to be applied.

[0053] The protruding amounts of the first leg post ribs 45 and 46 in the orthogonal direction W are larger than the protruding amounts of the arm ribs 86 to 89, 94, and 95 in the orthogonal direction W. The first leg post ribs 45 and 46 of the sewing machine frame 5 contribute to ensuring the rigidity of the connecting portion 40 of the leg post frame 4 and the arm frame 8 where loads are likely to be applied.

[0054] When defining the direction orthogonal to each of the longitudinal direction D and the extending direction J as the orthogonal direction W, the arm frame 8 has arm ribs 86 to 89, 94 to 100 protruding in the orthogonal direction W from the extending intermediate plate 83, and holes 90 to 93 penetrating in the orthogonal direction W along any of the arm ribs 86 to 89, 94 to 100 are formed in the extending intermediate plate 83. The holes 90 to 93 of the sewing machine frame 5 contribute to reducing the weight of the arm frame 8 compared to the case where a plurality of holes are not formed in the arm frame 8.

[0055] When defining the direction orthogonal to each of the longitudinal direction D and the extending direction J as the orthogonal direction W, the extending intermediate plate 83 is connected to the first extending plate 81 at portions separated from each of the both ends of the first extending plate 81 in the orthogonal direction W, and the extending intermediate plate 83 is connected to the first extending plate 81 at portions separated from each of the both ends of the second extending plate 82 in the orthogonal direction W. The extending intermediate plate 83 of the sewing machine frame 5 contributes to increasing the rigidity of the arm frame 8 without increasing the weight compared to the case where the extending intermediate plate 83 is formed only of a plane.

[0056] When defining the direction orthogonal to each of the longitudinal direction D and the extending direction J as the orthogonal direction W, the length R3 of the extending range of the extending intermediate plate 83 in the orthogonal direction W is smaller than 1 / 2 of the length L1 of the extending range of the first extending plate 81 in the orthogonal direction W and is also smaller than 1 / 2 of the length L3 of the extending range of the second extending plate 82 in the orthogonal direction W. The extending intermediate plate 83 of the sewing machine frame 5 contributes to increasing the rigidity of the arm frame 8 without increasing the weight compared to the case where the extending intermediate plate 83 is formed only of a plane.

[0057] The present invention is not limited to the above-described embodiments, and various modifications are possible. The sewing machine frame 5 may be a sewing machine frame of any type of sewing machine, such as a household sewing machine, an industrial sewing machine, a multi-needle sewing machine, and an embroidery sewing machine. The shape and size of the sewing machine frame 5 may be appropriately changed according to the type and configuration of the sewing machine 1. For example, when the sewing machine 1 does not include the projector module 20, the sewing machine frame 5 may not include the projector support plate 85. The definition of the direction of the sewing machine frame may be appropriately changed according to the sewing machine to which the sewing machine frame is attached.

[0058] Either the bed frame 6 or the arm frame 8 may be provided with a middle plate having a curved surface. The leg plates 30 and 43 may each not have a curved surface. The extending middle plate 83, the leg plates 30 and 43, and the bed middle plate 63 may each have a curved surface whose cross-sectional shape in the longitudinal direction D forms a curve. The shape of the first extending contour, which is the contour of the end 811 of the first extending plate 81, may be appropriately changed. For example, it may be linear in plan view. The shape of the second extending contour, which is the contour of the end 821 of the second extending plate 82, may be appropriately changed. For example, it may be linear in plan view. The end 811 of the first extending plate 81 may be the rear end of the first extending plate 81. The end 821 of the second extending plate 82 may be the rear end of the second extending plate 82. In the first extending plate 81, the portion 813 having the longest length in the orthogonal direction W may be located in the extending direction J relative to the portion 814 having the shortest length in the orthogonal direction W. In the second extending plate 82, the portion 823 having the longest length in the orthogonal direction W may be located in the extending direction J relative to the portion 824 having the shortest length in the orthogonal direction W. The leg base plate 110 may not be formed with a leg hole 111, or the leg hole 111 may be a polygon having only sides that are linear in bottom view, or may have a shape having a contour composed only of curves such as an ellipse and a circle. The number and shape of the leg plates 30 and 43 extending upward from the sides of the leg hole 111 may be appropriately changed. Only either of the leg plates 30 and 43 may have a curved surface. The leg plate 43 may not have a shape bent above the hole 422. The leg plate 30 may not have a shape bent above the hole 423. More specifically, the extending middle plate 83, the leg plate 43, and the bed middle plate 63 may be constituted by a single plate whose extending ranges in the orthogonal direction W are the same or similar to each other. The extending ranges in the orthogonal direction W being similar to each other means, for example, that when the extending range of the leg plate 43 in the orthogonal direction W is considered, more than 90% of the extending ranges of the extending middle plate 83 and the bed middle plate 63 overlap. The leg plate 30 may be constituted by a plate in a planar shape perpendicular to the orthogonal direction W. In these cases, the extending middle plate 83, the leg plates 30 and 43, and the bed middle plate 63 contribute to increasing the rigidity of the sewing machine frame 5 as compared with the case where the leg plates 43 and 30 are bent according to the configuration of the sewing machine 1.

[0059] When the longitudinal direction D of the leg post frame 4 is defined as the vertical direction and the direction orthogonal to each of the longitudinal direction D and the extending direction J is defined as the orthogonal direction W, the length L6 in the orthogonal direction W at the lower end of the leg post frame 4 may be equal to or less than the length L5 in the orthogonal direction W at the upper end of the leg post frame 4.

[0060] The shapes, numbers, protruding amounts, and arrangements of the arm ribs 86 to 89 and 94 to 100 may be appropriately changed. The arm ribs may be formed only on one surface of the extending intermediate plate 83 in the orthogonal direction W. The shapes, numbers, protruding amounts, and arrangements of the first leg post rib and the second leg post rib may be appropriately changed. The first leg post rib and the second leg post rib may be formed only on one surface of the leg post plates 30 and 43. The first leg post ribs 31, 32, 45, and 46 do not have to be formed on the tangent line of the connecting curved plate 44. A plurality of holes penetrating in the orthogonal direction W do not have to be formed in each of the leg post plates 30 and 43, the bed intermediate plate 63, and the extending intermediate plate 83. The number, shape, arrangement, and size of the holes formed in each of the leg post plates 30 and 43, the bed intermediate plate 63, and the extending intermediate plate 83 may be appropriately changed, and for example, they do not have to be formed along the ribs.

[0061] The extending intermediate plate 83 may be connected to one end of the first extending plate 81 in the orthogonal direction W. The extending intermediate plate 83 may be connected to one end of the second extending plate 82 in the orthogonal direction W. The bed intermediate plate 63 may be connected to one end of the first bed plate 61 in the orthogonal direction W. The bed intermediate plate 63 may be connected to one end of the second bed plate 62 in the orthogonal direction W. The length of the extending range of the extending intermediate plate 83 in the orthogonal direction W may be equal to or less than 1.2 times the thickness of the extending intermediate plate 83, or may be equal to or more than 1 / 2 of the length of the extending range of the first extending plate 81 in the orthogonal direction W, or may be equal to or more than 1 / 2 of the length of the extending range of the second extending plate 82 in the orthogonal direction W.

Explanation of Reference Numerals

[0062] 4: Leg post frame, 5: Sewing machine frame, 6: Bed frame, 8: Arm frame, 30, 43: Leg post plates, 31, 32, 39, 45, 46: First leg post ribs, 33 to 38, 47 to 58: Second leg post ribs, 44: Connecting curved plate, 61: First bed plate, 62: Second bed plate, 63: Middle bed plate, 81: First extension plate, 82: Second extension plate, 83: Middle extension plate, 86 to 89, 94 to 100: Arm ribs, 90 to 93: Holes, 110: Lower leg post plate, 111: Leg post hole, 112 to 115: Sides, 811, 821: Ends, 813, 814, 823, 824: Parts, D: Longitudinal direction, J: Extension direction, W: Orthogonal direction

Claims

1. A leg post frame, An extension frame extending from one end in the longitudinal direction of the leg post frame in an extension direction orthogonal to the longitudinal direction, A first extension plate extending in the extension direction, A second extension plate spaced apart from the first extension plate in the longitudinal direction, facing the first extension plate, and extending in the extension direction, An extension intermediate plate extending in the extension direction by spreading in the longitudinal direction and connecting the first extension plate and the second extension plate in the longitudinal direction, the extension intermediate plate having a curved surface, The extension frame having the above, A sewing machine frame characterized by comprising the above.

2. The extension intermediate plate has a curved surface whose cross-sectional shape in a direction perpendicular to the longitudinal direction forms a curve. The sewing machine frame according to claim 1, characterized by the above.

3. When the longitudinal direction of the leg post frame is defined as the vertical direction, The extension frame is an arm frame extending from the upper end of the leg post frame in the extension direction, The sewing machine frame according to claim 1, further comprising a bed frame extending from the lower end of the leg post frame in the extension direction and facing the extension frame.

4. When the longitudinal direction of the leg post frame is defined as the vertical direction and the direction orthogonal to each of the longitudinal direction and the extension direction is defined as the orthogonal direction, The orthogonal direction includes a first direction and a second direction opposite to the first direction, A first extension contour, which is the contour of the end of the first extension plate in the first direction, is a curve in plan view, The sewing machine frame according to claim 1, characterized in that a second extension contour, which is the contour of the end of the second extension plate in the first direction, is a curve in plan view.

5. In the first extension plate, the portion where the length in the orthogonal direction is the shortest is located in the extension direction with respect to the portion where the length in the orthogonal direction is the longest, The sewing machine frame according to claim 4, characterized in that in the second extension plate, the portion where the length in the orthogonal direction is the shortest is located in the extension direction with respect to the portion where the length in the orthogonal direction is the longest.

6. When the longitudinal direction of the leg post frame is defined as the vertical direction, The extension frame is an arm frame extending from the upper end of the leg post frame in the extension direction, A bed frame extending from the lower end of the leg post frame facing the extension frame in the extension direction, A first bed plate extending in the extension direction, A second bed plate that is spaced apart from the first bed plate in the longitudinal direction, faces the first bed plate, and extends in the extending direction. A bed intermediate plate that extends in the extending direction by spreading in the longitudinal direction and connecting the first bed plate and the second bed plate in the longitudinal direction, and has a curved surface in a cross-sectional shape in a direction perpendicular to the longitudinal direction. The sewing machine frame according to claim 1, further comprising the bed frame having the above.

7. When the longitudinal direction of the leg post frame is defined as the vertical direction. The leg post frame is At the lower end of the leg post frame, a leg post lower plate that spreads in a horizontal direction perpendicular to the vertical direction, and the leg post lower plate having a rectangular leg post hole that penetrates in the vertical direction and has a bent side when viewed from the bottom. A leg post plate having a curved surface extending upward from the bent side. The sewing machine frame according to claim 1, characterized by having the above.

8. When the longitudinal direction of the leg post frame is defined as the vertical direction and the direction perpendicular to each of the longitudinal direction and the extending direction is defined as the orthogonal direction. The sewing machine frame according to claim 1, characterized in that the length of the leg post frame at the lower end in the orthogonal direction is longer than the length of the leg post frame at the upper end in the orthogonal direction.

9. When the direction perpendicular to each of the longitudinal direction and the extending direction is defined as the orthogonal direction. The extending frame has an arm rib protruding in the orthogonal direction from the extending intermediate plate. The leg post frame has a first leg post rib having a thickness larger than the thickness of the arm rib in a cross-sectional shape in a direction perpendicular to the orthogonal direction, and a second leg post rib having a thickness smaller than the thickness of the first leg post rib and a shorter length in the longitudinal direction than the first leg post rib. The sewing machine frame according to claim 1, characterized by having the above.

10. When the longitudinal direction of the leg post frame is defined as the vertical direction and the extending direction is defined as the left direction. The leg post frame has a connecting curved plate in an arc shape when viewed from the front below the connecting portion with the extending frame. The sewing machine frame according to claim 9, characterized in that the first leg post rib is formed on the tangent line of the connecting curved plate when viewed from the front.

11. The sewing machine frame according to claim 10, characterized in that the protruding amount of the first leg post rib in the orthogonal direction is larger than the protruding amounts of the arm rib and the second leg post rib.

12. When defining the direction orthogonal to each of the longitudinal direction and the extending direction as the orthogonal direction, the extending frame has arm ribs protruding in the orthogonal direction from the extending intermediate plate, The sewing machine frame according to claim 1, wherein the extending intermediate plate is formed with a plurality of holes penetrating in the orthogonal direction along the arm ribs.

13. When defining the direction orthogonal to each of the longitudinal direction and the extending direction as the orthogonal direction, the extending intermediate plate is connected to the first extending plate at portions spaced apart from each of both ends of the first extending plate in the orthogonal direction, The sewing machine frame according to claim 1, wherein the extending intermediate plate is connected to the first extending plate at portions spaced apart from each of both ends of the second extending plate in the orthogonal direction.

14. When defining the direction orthogonal to each of the longitudinal direction and the extending direction as the orthogonal direction, The sewing machine frame according to claim 1, wherein the length of the extending range of the extending intermediate plate in the orthogonal direction is smaller than 1 / 2 of the length of the extending range of the first extending plate in the orthogonal direction and smaller than 1 / 2 of the length of the extending range of the second extending plate in the orthogonal direction.

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