JPS6014455Y2 - Feed dog height adjustment device for sewing machines - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for adjusting the amount of protrusion of the feed dog from the upper surface of the throat plate.

In the conventional adjusting device shown in Fig. 4, by loosening the nut a with a wrench and moving the eccentric shaft, the engagement between the roller C and the vertical feed link d is loosened, and from this state, the eccentric shaft is turned to move the feed base e. The amount of protrusion of the feed dog f from the throat plate g is adjusted through the feed dog f.

However, since the head of the eccentric shaft and nut a are separated laterally, in the free-arm type sewing machine shown in Fig. 1 in which the hook and feed mechanism are covered with a machine frame, the throat plate base that forms the bed surface is Unless 1 was removed, the nut a could not be gripped with a spanner.

That is, a free arm type sewing machine is provided with an opening 2 for replacing the bobbin case, but the size of this opening 2 is limited from the viewpoint of strength, so the nut a is hidden inside the machine frame.

Since the adjustment cannot be made with the throat plate 3 set, it is necessary to set and check the throat plate 3 and repeat the adjustment several times, which has the disadvantage of requiring a long time for this type of adjustment. .

This idea eliminates the above conventional drawbacks with a simple configuration,
The purpose is to improve operability.

Examples of this invention will be described below with reference to the drawings.

Reference numeral 4 denotes a well-known feed table, which is rotatably supported at the upper end of a horizontal feed arm (not shown) that swings in synchronization with the stitch forming mechanism of the sewing machine, and has a feed dog 5 fixed to its free end. .

An eccentric cam 6 is fixed to a shaft 7 that is linked to the main shaft, and rotates in synchronization with the horizontal feed arm.

8 is a vertical feeder whose base portion is rotatably supported on a horizontally fixed shaft 9, and a contact portion 10 facing the outer circumferential surface of the eccentric cam 6 is formed in the middle.

Reference numeral 12 denotes a screw shaft having a shaft portion 12a, a threaded portion 12b at one end on the axis, and a collar portion 12c at the other end, and the threaded portion 12b is screwed into the free end of the vertical feeder 8 parallel to the shaft 9 to support it. .

Reference numeral 13 denotes an eccentric body having a shaft portion 13a, a collar portion 13b having a hexagonal outer periphery, and a small hole 13c penetrating through these and offset from the central axis of the shaft portion 13a. It is loosely fitted into the shaft portion 12a of the screw shaft 12 adjacent to the flange portion 12c.

Reference numeral 14 denotes a roller having a hole 14a concentric with the outer periphery and loosely fitted to the shaft portion 13a of the eccentric body 13, on which the free end of the feed table 4 is placed.

Reference numeral 11 denotes a coil spring, which is normally stretched between the feed bar 4 and the machine frame so that the feed bar 4 engages with the roller 14.

Note that the relationship between these elements is as shown in FIG.
A roller 14 is loosely fitted between the flange 13b and these are fixed together by a screw shaft 12, and when the lid 15 on the front of the sewing machine bed is opened, the screw shaft 12 is placed in front of the opening 2. and each collar portion 12a, 13b of the eccentric body 13
are now facing each other.

This invention has the above-mentioned configuration, and when the sewing machine is driven, the vertical feed body 8 oscillates about the shaft 9 by the rotation of the eccentric cam 6 in synchronization with the horizontal feed arm, so that the feed table 4 can feed the cloth. As well as reciprocating in the direction, the feed dog 5 swings up and down about the connecting portion with the horizontal feed arm, and as a result, the feed dog 5 moves in and out of the upper surface of the throat plate 3 and performs four well-known movements.

In addition, when the screw shaft 12 is loosened to loosen the fixation between the eccentric body 13 and the vertical feed body 8, and from this state, when the eccentric body 13 is rotated by pinching the cap portion 13b, the roller 14 is moved by the displacement of the eccentric portion 13a. Through this, the feed bar 4 rotates slightly around the connecting portion with the horizontal feed arm against or pulled by the coil spring 11, thereby reducing the amount of protrusion of the feed dog 5 from the upper surface of the throat plate. changes slightly.

Therefore, in order to adjust the amount of protrusion of the feed dog 5 from the upper surface of the throat plate 3, open the lid 15 and enter the opening 2 through the collar 13b of the eccentric body 13.
Hold down and rotate the screw shaft 12 to loosen these connections, then rotate the eccentric body 13 while looking at the top surface of the throat plate 3, and rotate the feed dog 5.
When the screw protrudes by a predetermined amount, the eccentric body 13 is held down again and the screw shaft 12 is tightened.

As described above, in this invention, the flange of the eccentric body that supports the rollers and the flange of the screw shaft that supports them on the vertical feeder are adjacent to each other, making it easy to operate the screw shaft and the eccentric body. Especially in free-arm type sewing machines, by placing these on the lid side, you can operate from the bobbin replacement opening without removing the throat plate base, so you can quickly and accurately adjust the amount of protrusion of the feed dog from the top of the throat plate. There are effects that can be adjusted.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a sewing machine, FIG. 2 is a vertical sectional view of the main parts, FIG. 3 is an exploded perspective view of FIG. 2, and FIG. 4 is a vertical sectional view of the conventional main parts.

Claims (1)

[Scope of Claim for Utility Model Registration] A cam body 6 that is rotatable about a fixed axis in synchronization with the seam forming mechanism, and a fixed horizontal axis that moves the free end up and down in conjunction with the cam body. A vertical feeder 8 that swings at the center, a cylindrical roller 14 having a hole 14a concentric with the outer periphery, a shaft portion 13a that loosely fits into the hole of the roller, a collar portion 13b that engages with one end surface of the roller, and the shaft. an eccentric body 13 having a small hole 13c that is offset along the central axis of the eccentric body; a central shaft portion 12a that loosely fits into the small hole of the eccentric body; a threaded portion 12b at one end on the axis; and a collar portion at the other end. 12c,
A screw shaft 12 whose flange is adjacent to the flange of the eccentric body and whose threaded portion is horizontally screwed into the free end of the vertical feed body and supported; and a horizontal support shaft which reciprocates along the upper surface of the throat plate in synchronization with the cam body. A feed dog height adjusting device in a sewing machine, comprising a feed table 4 having one end supported on a roller, the other end placed on a roller, and a feed dog 5 fixed to the other end.