Grease supply structure for sewing machine hook

Abstract

To achieve a grease supply structure for a sewing machine hook which can suitably supply grease.SOLUTION: In a grease supply structure 100 for a sewing machine hook, an agitation member 11c can move in a grease storage part 11 to agitate grease G in the grease storage part 11 due to actions of a centrifugal force F1 caused by rotation of a shuttle race 1 and inertia forces F2, F3 caused by acceleration and deceleration of the rotation of the shuttle race 1 every time actuation and stop of a sewing machine are repeated. The agitation member 11c agitates the grease G in the grease storage part 11 to make the grease G hard to be separated so that a prescribed property is maintained. Thereby, the grease G is suitably fed out to the grease supply channel 12 from the grease storage part 11 by the centrifugal force F1 caused by the rotation of the shuttle race 1, and the grease G fed out to the grease supply channel 12 reaches a race groove 1a through a through-hole 5a of a core material 5, and the grease G can be suitably supplied to a sliding part (a race groove 1a, a race projection 2a) of a sewing machine hook 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a grease supply structure for a sewing machine bobbin case that supplies grease to a sliding portion of the sewing machine bobbin case.

Background Art

[0002] Conventionally, a grease supply structure for a sewing machine bobbin case is known in which grease is supplied to a sliding portion where an outer bobbin case and an inner bobbin case constituting the sewing machine bobbin case slide relative to each other, thereby suppressing heat generation, seizure, and wear of the sewing machine bobbin case (see, for example, Patent Document 1). This grease supply structure for a sewing machine bobbin case has a grease storage portion provided in the outer bobbin case. The grease storage portion includes an inner storage portion filled with grease, an outer storage portion near the sliding portion, and a communication storage portion that communicates the inner storage portion and the outer storage portion. When the outer bobbin case is rotated, grease is sent from the inner storage portion to the outer storage portion through the communication storage portion by centrifugal force, and grease is supplied to the sliding portion between the outer bobbin case and the inner bobbin case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the case of the technology of Patent Document 1 described above, there is a problem that the amount of grease supplied to the sliding portion of the sewing machine bobbin case varies, and the supply amount of grease may become too small. Since grease is a semi-solid in which base oil is dispersed by a thickener, when the outer bobbin case is rotated, the base oil and the thickener having different densities are separated by centrifugal force, and the thickener component that is easily affected by centrifugal force is excessively sent from the inner storage portion to the communication storage portion, making it difficult for the grease to pass through, and the supply amount of grease may become too small. Also, if there is a situation where a highly fluid base oil component is excessively supplied in a state where the grease is separated, the viscosity of the grease in the grease storage portion increases, and thus the subsequent grease supply amount may become too small.

[0005] An object of the present invention is to provide a grease supply structure for a sewing machine bobbin that can preferably supply grease.

Means for Solving the Problems

[0006] To solve the above problems, the invention according to claim 1 is A grease supply structure for a sewing machine bobbin having an outer bobbin connected to one end of a bobbin shaft and rotated in a predetermined direction, and an inner bobbin rotatably installed in the outer bobbin, the grease being supplied to a sliding portion where the outer bobbin and the inner bobbin slide relative to each other, The outer bobbin is provided with a grease storage portion filled with the grease, and a grease supply path for guiding the grease from the grease storage portion to the sliding portion, The grease storage portion is characterized in that at least one stirring member movable within the grease storage portion is provided.

[0007] The invention according to claim 2 is the grease supply structure for a sewing machine bobbin according to claim 1, The stirring member is characterized in that it is formed of a material having a density greater than that of the grease.

[0008] The invention according to claim 3 is the grease supply structure for a sewing machine bobbin according to claim 1, The grease storage portion is provided at a position outside the rotation center of the bobbin shaft in the outer bobbin, With the stirring member moving within the grease storage portion due to the centrifugal force accompanying the rotation of the outer bobbin, the grease is configured to be stirred.

[0009] The invention according to claim 4 is in the grease supply structure of the sewing machine hook according to any one of claims 1 to 3, wherein the stirring member is formed in a spherical shape.

[0010] The invention according to claim 5 is in the grease supply structure of the sewing machine hook according to any one of claims 1 to 3, wherein the stirring member is formed in a needle shape.

Advantages of the Invention

[0011] According to the present invention, grease can be suitably supplied to the sewing machine hook.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail. The grease supply structure of the sewing machine hook is for suppressing heat generation and seizure of the sewing machine hook disposed inside the sewing machine bed part and below the needle plate, and supplies grease to the sliding part where the outer hook and the inner hook constituting the sewing machine hook slide relative to each other.

[0014] The grease supply structure 100 of the sewing machine bobbin case according to this embodiment is, for example, as shown in FIG. 1, in a sewing machine bobbin case 3 having an outer bobbin 1 connected to one end of a bobbin shaft 10 and rotated in a predetermined direction, and an inner bobbin 2 rotatably installed inside the outer bobbin 1. Grease G is supplied to the sliding portion of the sewing machine bobbin case 3 where the outer bobbin 1 and the inner bobbin 2 slide relative to each other.

[0015] As will be described later, a race groove 1a is provided on the inner peripheral surface of the outer bobbin 1, and a race protrusion 2a is provided on the outer peripheral surface of the inner bobbin 2. The portion where the race protrusion 2a of the inner bobbin 2 is in sliding contact with and rotatably fitted into the race groove 1a of the outer bobbin 1 is the sliding portion of the sewing machine bobbin case 3. That is, the race groove 1a of the outer bobbin 1 and the race protrusion 2a of the inner bobbin 2 are the sliding portion of the sewing machine bobbin case 3, and grease G is supplied to the portion where the race groove 1a and the race protrusion 2a are rotatably fitted.

[0016] The bobbin shaft 10 is a drive shaft that is rotated by a sewing machine motor (not shown) and rotates the outer bobbin 1 connected to one end portion 10a thereof. The bobbin shaft 10 is rotatably supported by a shaft metal portion 20 via a bearing 20a.

[0017] The outer bobbin 1 is a part that houses the inner bobbin 2, and a race groove 1a is provided on its inner peripheral surface. The inner bobbin 2 is a part that houses a bobbin and a bobbin case (not shown), and a race protrusion 2a is provided on its outer peripheral surface. And the race protrusion 2a of the inner bobbin 2 is in sliding contact with and rotatably fitted into the race groove 1a of the outer bobbin 1, and the sewing machine bobbin case 3 is assembled.

[0018] The outer bobbin 1 is provided with a grease storage portion 11 filled with grease G, and a grease supply path 12 that guides grease G from the grease storage portion 11 to the sliding portion of the sewing machine bobbin case 3. The grease storage portion 11 is provided with a stirring member 11c together with the filled grease G. The grease supply passage 12 is provided outside the grease storage portion 11 in the outer pot 1.

[0019] As shown in FIGS. 1 and 2, the grease storage portion 11 is provided at a position outside the rotation center of the pot shaft 10 in the outer pot 1. Here, the grease storage portion 11 is provided at the base portion where the outer pot 1 is connected to the pot shaft 10. This grease storage portion 11 has a cylindrical space with an inner diameter of 5 mm. Since this grease storage portion 11 is located outside the rotation center of the pot shaft 10 in the outer pot 1, the grease G is sent from the grease storage portion 11 to the grease supply passage 12 by the centrifugal force accompanying the rotation of the outer pot 1.

[0020] In particular, at least one stirring member 11c that is movable within the grease storage portion 11 is provided in the grease storage portion 11. The stirring member 11 that is movable within the grease storage portion 11 has a size smaller than the internal space of the grease storage portion 11 and, of course, does not enter the grease supply passage 12. The stirring member 11c of the present embodiment is formed in a spherical shape, and one spherical stirring member 11c is provided in the grease storage portion 11. The stirring member 11c is a member formed of a material having a density greater than that of the grease G, for example, a metal material or an alloy material. In the present embodiment, a steel stirring member 11c is used, and a steel ball with a diameter of 2.0 mm is used as the stirring member 11c. Note that if the grease storage portion 11 can be filled with a predetermined amount of the grease G, two or more stirring members 11c may be provided in the grease storage portion 11.

[0021] Since this stirring member 11c is formed of a material having a density greater than that of the grease G, the stirring member 11c can move while being coated with the grease G even within the grease storage portion 11 filled with the grease G. And, as described above, since the grease housing portion 11 is provided at a position outside the rotation center of the kettle shaft 10 in the outer kettle 1, the centrifugal force associated with the rotation of the outer kettle 1 also acts on the stirring member 11c in the grease housing portion 11, and the stirring member 11c is caused to move within the grease housing portion 11 due to that centrifugal force.

[0022] Here, the movement of the stirring member 11c within the grease housing portion 11 due to the centrifugal force associated with the rotation of the outer kettle 1 will be described.

[0023] In a state where the sewing machine is not operating and the outer kettle 1 (kettle shaft 10) is not rotating, the stirring member 11c sinks into the grease G in the grease housing portion 11 due to gravity. Then, by an operation of operating the sewing machine, for example, as shown in FIG. 3, when the outer kettle 1 is rotated clockwise in the figure together with the kettle shaft 10, a centrifugal force F1 acts on the stirring member 11c in the grease housing portion 11, and the stirring member 11c is pushed outward within the grease housing portion 11. Also, when the outer kettle 1 (kettle shaft 10) is accelerating in rotation, the inertial force F2 at the time of that rotational acceleration acts on the stirring member 11c (see FIG. 3), and the stirring member 11c is pushed toward the rear in the rotational direction. Due to the action of such a centrifugal force F1 and inertial force F2, the stirring member 11c moves within the grease housing portion 11. As the stirring member 11c moves, the grease G in the grease housing portion 11 is stirred. Note that when the rotational speed of the outer kettle 1 (kettle shaft 10) becomes constant, the stirring member 11c is in a state of being pressed outward within the grease housing portion 11.

[0024] Next, when the rotational speed of the outer kettle 1 (kettle shaft 10) decreases by an operation of stopping the sewing machine, the centrifugal force F1 acting on the stirring member 11c weakens. Also, when the outer kettle 1 (kettle shaft 10) is decelerating in rotation, the inertial force F3 at the time of that rotational deceleration acts on the stirring member 11c (see FIG. 3), and the stirring member 11c is pushed toward the front in the rotational direction. Due to the action of such a centrifugal force F1 and inertial forces F3, the stirring member 11c moves within the grease storage portion 11. As the stirring member 11c moves, the grease G within the grease storage portion 11 is stirred. When the rotation of the outer pot 1 (pot shaft 10) stops, the stirring member 11c sinks into the grease G within the grease storage portion 11 due to gravity.

[0025] In this way, each time the operation and stop of the sewing machine are repeated, due to the action of the centrifugal force F1 accompanying the rotation of the outer pot 1 and the inertial forces F2, F3 accompanying the acceleration and deceleration of the rotation of the outer pot 1, the stirring member 11c moves within the grease storage portion 11 to stir the grease G within the grease storage portion 11. And by providing the stirring member 11c capable of stirring the grease G within the grease storage portion 11, it becomes difficult for the grease G within the grease storage portion 11 to separate. Therefore, the grease G is preferably sent from the grease storage portion 11 to the grease supply path 12 by the centrifugal force F1 accompanying the rotation of the outer pot 1, and as will be described later, it becomes possible to stably supply the grease G to the sliding portion of the sewing machine pot 3.

[0026] Further, the grease storage portion 11 is provided with a replenishment port 11a for replenishing the grease G, and a lid screw 11b that functions as a lid for the grease storage portion 11 is screwed to the replenishment port 11a. When replenishing the grease G to the grease storage portion 11, the lid screw 11b is temporarily removed from the replenishment port 11a. The replenishment port 11a of this grease storage portion 11 is provided on the outer peripheral surface side of the base portion of the outer pot 1. By doing so, the grease G can be replenished to the grease storage portion 11 without removing the outer pot 1 from the pot shaft 10.

[0027] As shown in FIGS. 1 and 4(a), the grease supply path 12 is an elongated flow path that communicates from the grease storage portion 11 to the race groove 1a. The grease supply path 12 of the present embodiment is a flow path that is bent in a substantially U shape when viewed from the side. At least a part of this grease supply passage 12 is provided with a core material 5 having a through hole 5a along the grease supply passage 12. Here, the core material 5 is provided at a position near the race groove 1a in the grease supply passage 12. The inner diameter of the grease supply passage 12 of the present embodiment is 1.0 mm, and a core material 5 having a diameter of 0.8 mm to 1.0 mm and a length of 4.0 mm is arranged in the grease supply passage 12 by adhesion or press-fitting.

[0028] The core material 5 is a plastic member, and at least one narrow through hole 5a is provided in the core material 5 along the axial direction of the core material 5. One through hole 5a is provided in the core material 5 of the present embodiment, and the axial perpendicular cross-sectional shape of the through hole 5a exhibits a branched shape in a mode of being branched into a plurality of branches as shown in FIGS. 4(b) and 4(c). Here, the branched shape is a mode in which, as shown in FIGS. 4(b) and 4(c), it is branched into a plurality of branches so as to exhibit a substantially F shape, and six substantially F-shaped portions are arranged radially. With such a narrow through hole 5a having a branched shape, the grease G can pass through little by little, and an appropriate amount of grease G can be supplied to the sliding portions (race groove 1a, race projection 2a) of the sewing machine bobbin 3. For example, if the width of this narrow through hole 5a is about 0.1 mm (about 100 μm), the grease G can pass through little by little without the thickening agent component of the grease G being clogged. The width of the through hole 5a referred to here corresponds to the width of each branch whose axial perpendicular cross-sectional shape exhibits a substantially F shape.

[0029] In addition, the plastic core material 5 has a certain degree of rigidity and is difficult to deform, so the shape of the through hole 5a of the core material 5 does not narrow, and the supply amount of the grease G to the sliding portions (race groove 1a, race projection 2a) of the sewing machine bobbin 3 does not vary, and the supply of the grease G can be stably performed. Note that the branched shape of the through-hole 5a of the core material 5 is not limited to the illustrated shape, and any other branched shape may be used as long as it allows the grease G to pass through little by little. Also, the shape of the through-hole 5a of the core material 5 is not limited to a branched shape as long as it allows the grease G to pass through little by little, and any other shape may be used.

[0030] With the grease supply structure 100 of the sewing machine bobbin of the present embodiment having such a configuration, each time the sewing machine repeats its operation and stop, due to the centrifugal force F1 accompanying the rotation of the outer bobbin 1 and the inertial forces F2 and F3 accompanying the acceleration and deceleration of the rotation of the outer bobbin 1, the stirring member 11c moves within the grease storage portion 11, and the grease G within the grease storage portion 11 can be stirred. Then, since the stirring member 11c provided in the grease storage portion 11 stirs the grease G within the grease storage portion 11, it becomes difficult for the grease G within the grease storage portion 11 to separate. Therefore, the grease G is preferably sent from the grease storage portion 11 to the grease supply passage 12 by the centrifugal force F1 accompanying the rotation of the outer bobbin 1. The grease G sent to the grease supply passage 12 reaches the race groove 1a through the through-hole 5a of the core material 5, and the grease G is supplied to the sliding portion (race groove 1a, race protrusion 2a) of the sewing machine bobbin 3.

[0031] That is, with the grease supply structure 100 of the sewing machine bobbin provided with the stirring member 11c that can move within the grease storage portion 11 filled with the grease G, it becomes difficult for the grease G within the grease storage portion 11 to separate. Therefore, it is possible to supply the grease G while maintaining a predetermined property, and the grease G can be stably supplied to the sliding portion (race groove 1a, race protrusion 2a) of the sewing machine bobbin 3.

[0032] Further, since the through-hole 5a of the core material 5 disposed in the grease supply passage 12 has a branched shape in which the cross-sectional shape perpendicular to its axis branches into a plurality of branches, the grease G passes through the narrow through-hole 5a little by little, and an appropriate amount of the grease G can be supplied to the sliding portion (race groove 1a, race protrusion 2a) of the sewing machine bobbin 3. In particular, by using the plastic core material 5, it becomes easier to maintain the shape of the axial vertical cross-section of the through-hole 5a of the core material 5. Therefore, the amount of grease G supplied to the sliding parts (raceway groove 1a, raceway projection 2a) of the sewing machine hook 3 does not vary, and the supply of grease G can be stably performed.

[0033] As described above, with the grease supply structure 100 of the sewing machine hook according to the present embodiment, grease G can be suitably supplied to the sliding parts (raceway groove 1a, raceway projection 2a) of the sewing machine hook 3. And if it is a grease supply structure 100 of a sewing machine hook capable of suitably supplying grease G to the sliding parts (raceway groove 1a, raceway projection 2a) of the sewing machine hook 3, heat generation and seizure of the sewing machine hook 3 can be suppressed, and the occurrence of problems in the sewing machine hook 3 can be reduced.

[0034] Note that the present invention is not limited to the above embodiment. For example, as shown in FIG. 5, the stirring member 11 provided in the grease storage portion 11 and movable within the grease storage portion 11 may be formed in a needle shape. Of course, the stirring member 11 having a needle shape is also formed using a material (metal material or alloy material) having a density greater than that of the grease G. Note that the needle shape means a so-called needle shape or a thin and short rod shape. In the present embodiment, for example, a stirring member 11c having a diameter of 1.5 mm and a length of 3.0 mm can be used. Even with the grease supply structure 100 of the sewing machine hook provided with such a stirring member 11c, the grease G in the grease storage portion 11 can be stirred, and the properties of the grease G can be maintained without separation. Therefore, the grease G can be stably supplied to the sliding parts (raceway groove 1a, raceway projection 2a) of the sewing machine hook 3. Also, as long as a predetermined amount of grease G can be filled in the grease storage portion 11, the stirring member 11c is not limited to one, and two or more stirring members 11c may be provided in the grease storage portion 11.

[0035] In the above embodiments, in the grease supply structure 100 of the sewing machine bobbin having the core material 5 provided with the narrow through hole 5a, although the example in which the stirring member 11c is provided in the grease storage portion 11 filled with grease has been described, the present invention is not limited thereto, and a stirring member may be provided in the inner storage portion filled with grease in the grease storage portion of the above-described prior art (Patent Document 1). By doing so, the grease filled in the inner storage portion of the grease supply structure of the prior art (Patent Document 1) becomes difficult to separate, and it becomes possible to suitably supply grease to the sliding portion of the sewing machine bobbin.

[0036] Further, in the above embodiments, the sewing machine bobbin 3 which is a so-called vertical bobbin has been illustrated, and the grease supply structure 100 of the sewing machine bobbin for supplying the grease G to the sewing machine bobbin 3 has been described as an example. However, the present invention is not limited thereto, and a grease supply structure of a sewing machine bobbin for supplying the grease G to a so-called horizontal bobbin may be used.

[0037] In addition, of course, other specific detailed structures and the like can be appropriately changed.

Explanation of Reference Numerals

[0038] 1 Outer bobbin 1a Race groove (sliding portion) 2 Inner bobbin 2a Race protrusion (sliding portion) 3 Sewing machine bobbin 5 Core material 5a Through hole 11 Grease storage portion 11a Refill port 11b Cover screw 11c Stirring member 12 Grease supply path 100 Grease supply structure of sewing machine bobbin G Grease F1 Centrifugal force F2 Inertial force during rotational acceleration F3 Inertial force during rotational deceleration

Claims

1. A grease supply structure for a sewing machine pan having an outer pan connected to one end of a pan shaft and rotated in a predetermined direction, and an inner pan rotatably installed inside the outer pan, wherein grease is supplied to a sliding portion where the outer pan and the inner pan slide relative to each other, the outer pan is provided with a grease storage portion filled with the grease and a grease supply passage for guiding the grease from the grease storage portion to the sliding portion, the grease storage portion is characterized in that at least one stirring member movable within the grease storage portion is provided. A grease supply structure for a sewing machine pan.

2. The grease supply structure for a sewing machine pan according to claim 1, wherein the stirring member is formed of a material having a density greater than that of the grease.

3. The grease storage portion is provided at a position outside the rotation center of the pan shaft in the outer pan, The grease supply structure for a sewing machine pan according to claim 1, wherein the grease is configured to be stirred as the stirring member moves within the grease storage portion due to centrifugal force accompanying the rotation of the outer pan.

4. The grease supply structure for a sewing machine pan according to any one of claims 1 to 3, wherein the stirring member is formed in a spherical shape.

5. The grease supply structure for a sewing machine pan according to any one of claims 1 to 3, wherein the stirring member is formed in a needle shape.

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