JPH03149088A - Full turning hook - Google Patents

Abstract

PURPOSE:To reduce a frictional force between the rail of an inner hook and an inner hook presser member, and drive an outer hook for the rotation thereof smoothly and at a high speed without generating any high hook noise by applying the constitution wherein the outer hook comprises an outer hook body and the inner hook presser member fitted to the outer hook body, and a synthetic resin film of low frictional resistance is formed on the inner hook presser member. CONSTITUTION:A synthetic resin film 9 of low frictional resistance is formed on the inner surface 8 of an inner hook presser member 6 faced to a rail 4. When an outer hook is rotating, an inner hook 3 is prevented from rotating in an outer hook rotational direction 11 with the projection of an inner hook locking member 28 coupled into an inner hook locking well 19. Even when an outer hook 12 is driven for rotation in the arrow direction 11, the film 9 is in slidable contact with an outer hook releasing end or an edge 20. Consequently, a frictional force acting on the rail 4 coupled within a groove 5 can be reduced and the outer hook 12 can be smoothly rotated without generating any hook noise. Even when the film 9 is worn, a screw 7 is removed and the inner hook presser member 6 can be easily changed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a full rotary hook provided in a lockstitch sewing machine or the like.

2. Description of the Related Art Conventionally, lockstitch sewing machines are provided with a lower shaft that is rotationally driven around a horizontal axis of rotation. An outer hook is fixed to this lower shaft. A track groove into which the inner hook rail is fitted is formed on the inner circumferential surface of the outer hook, and the rail groove is formed by the outer hook body and an inner hook holding member fixed to the outer hook body. In a state where the rail of the inner hook is fitted into such a raceway groove, the inner hook is prevented from being pulled out from the outer hook by the inner hook holding member. The outer hook is rotationally driven around a common rotational axis by the rotation of the lower shaft, and at this time, the inner hook is prevented from rotating in the outer hook rotating direction by an inner hook rotation preventing member fixed to the body of the sewing machine.

Problems to be Solved by the Invention In such prior art, the inner hook holding member made of a metal material such as iron or stainless steel is in direct contact with the rail of the inner hook, so when the outer hook rotates, the inner hook is rotated. There is a problem in that a relatively large frictional force is generated between the rail and the inner hook holding member, and this makes it impossible to rotate the outer hook at high speed. Moreover, if the frictional force between the rail and the inner hook holding member is large, a thick hooking sound will be generated when the outer hook is rotated, which is undesirable for some wholesalers.

Therefore, an object of the present invention is to reduce the frictional force between the inner hook rail and the inner hook holder so that the outer hook can be rotated smoothly and at high speed without producing loud hook sounds. The purpose is to provide a rotary hook.

Means for Solving Problems The present invention provides a full-rotation hook in which the outer hook is driven to rotate around its rotational axis with the inner hook rail fitted into the outer hook raceway. , includes an outer hook body and an inner hook holding member attached to the outer hook body, and the inner hook holding member is made of synthetic resin I! with low frictional resistance. ! There is a full-rotation hook that indicates the formation of a film as a TI sign.

Function According to the present invention, a synthetic resin coating with low frictional resistance is formed on the inner hook holding member, so that the rail of the inner hook fits into the track groove formed by the outer hook body and this inner hook holding member. Even when the outer hook is rotated in the closed state, the inner hook holding member does not come into direct contact with the rail, but the coating contacts, so the frictional force generated between the rail and the inner hook holding member is reduced. This allows the outer hook to rotate smoothly.

Embodiment FIG. 1 is an enlarged sectional view of an embodiment of the present invention. In a full-rotation hook 1 installed in a lockstitch sewing machine or the like, the outer hook body 2 is attached to the outer hook body 2 by an inner hook presser member 6 using a screw 7 or the like in order to hold the rail 4 of the inner hook 3 within the rail groove 5.
Fixed. The inner hook holding member 6 is formed roughly in an inverted shape, and the inner surface 8 facing the rail 4 is coated with a synthetic resin coating 9 having relatively low frictional resistance, such as Teflon (trade name). It is formed.

FIG. 2 is a perspective view of the full-rotation hook 1, and FIG. 3 is a sectional view of the full-rotation hook 1. The full-rotation hook 1 is a vertical full-rotation hook that is driven to rotate around a horizontal rotation axis l, and an axis common to this axis l, ! The lower shaft 10 having an arrow mark 1 is rotationally driven in the direction of the arrow 11. The outer hook 12 is constituted by the outer hook main body 2 and the inner hook holding member 6, and is fixed to the lower shaft IO by a screw 13-. Therefore, the outer hook 12 is rotationally driven in the direction of arrow 11 by the rotation of the lower shaft 10. In addition, the outer hook 12 has a tip 14,
The needle tip 14 captures the needle thread brought by the needle 15 which is reciprocated up and down in synchronization with the rotational movement of the lower shaft 10 to form a needle thread loop, which is held in the inner hook 3 by the bobbin case 16. The lower thread 18 of the bobbin 17 formed by the lower thread 18 forms a seam. During such rotation of the outer hook, the inner hook 3 is in a state in which the protrusion of the inner hook rotation stopper member 28 fixed to the sewing machine is fitted into the inner hook rotation prevention recess 19 formed in the inner hook. , rotation of the inner hook 3 in the outer hook rotation direction 11 is prevented.

In the full-rotation hook 1 constructed in this way - the outer hook 1
2 is driven to rotate in the direction of arrow 11.

Since the coating 9 slides on the end face 20 of the rail 4 on the outer hook open end side, that is, on the right side in FIG. As a result, the outer hook 12 can be rotated smoothly without producing a large hook noise. Furthermore, even if the coating 9 becomes worn, the inner hook holding member 6 can be easily replaced by removing the screw 7.

FIG. 4 is an enlarged sectional view of another embodiment of the invention. In the embodiment described above, the coating 9 was formed on the inner surface 8 of the inner hook member 6 over the entire length in the radial direction.
The coating 9 may be formed in the circumferential direction so as to have l[dl up to the bottom of the raceway groove 5 in the radial direction, thereby achieving the embodiment shown in FIGS. Compared to , the amount of coating 9 is reduced by di-d2, and the coating B9 is
It is possible to reduce the amount of protrusion of the inner hook holding member 6 toward the open end of the outer hook by the thickness t. Further, as another embodiment of the present invention, as shown in FIG.
The coating 9 may be formed over the entire length of the rail 4, thereby making it possible to reduce the coating M9 by the width d2-d3 compared to the embodiment shown in FIG. can be reduced to reduce frictional resistance.

Furthermore, as another embodiment of the present invention, as shown in FIG. 6, a plurality of coatings 22 having a width d3 in the radial direction and a length may be formed at intervals in the circumferential direction. As a result, a gap can be formed between the open end side end surface 20 of the rail 4 and the inner surface 8 of the inner hook holding member 6, and air can pass through this gap as shown by the arrow 23. This makes it possible to achieve a cooling effect for the rail 4.

Effects of the Invention According to the present invention, since a synthetic resin coating with low frictional resistance is formed on the inner hook holding member, it is possible to reduce the vibration force generated with the rail when the outer hook is rotated. This allows the outer hook to rotate smoothly and at high speed, and does not produce loud hook sounds.Furthermore, the friction between the rails and grooves is reduced, so lubricating oil, etc. There is no need to supply lubricating oil between the lubricant and the groove, and therefore no mechanism for supplying lubricating oil is required, making it possible to significantly simplify the configuration.

[Brief explanation of the drawing]

Fig. 1 is an enlarged sectional view of a part of an embodiment of the present invention, Fig. 2 is a perspective view of a full-rotation hook, and Fig. 3 is a perspective view of a full-rotation hook.
R side view, FIG. 4 is an enlarged sectional view of a part of another embodiment of the present invention, FIG. 5 is an enlarged sectional view of a part of still another embodiment of the invention, and FIG. FIG. 7 is an enlarged perspective view of a part of still another embodiment. 1...Full rotation hook, 2...-Outer hook body, 3...-Inner hook, 4...Rail, 5...Rail groove, 6...Inner hook holding member, 9゜22... Film, 12... Outer Hook Agent Patent Attorney Function Keiro No. 1 Figure 2 Figure 3 [! 4 Figure 5 N'')S+-4 Figure 6

Claims (1)

[Scope of Claims] A full-rotation hook in which the outer hook is driven to rotate about its rotational axis with the inner hook rail fitted into the outer hook raceway, wherein the outer hook has an outer hook main body; A full-rotation rotary hook comprising an inner rotary hook retaining member attached to the outer rotary rotary rotary hook body, the inner hook retaining member being coated with a synthetic resin coating having low frictional resistance.