JPS598695Y2 - Thread guide for sewing machines that use spools - Google Patents

Description

[Detailed description of the invention] This invention relates to a thread guide for sewing machines that use a spool, such as overlock sewing machines and chain stitch sewing machines.

In a sewing machine that uses a spool, thread is drawn from a stationary spool in an axially upward direction of the spool, passes through a guide wire above the spool, reaches a thread tension regulator, and is then sent to a needle and a looper.

Here, since the thread is released from the spool in a spiral manner, it is twisted when it is elongated on the way to being pulled up.

The twisted thread often absorbs the loose thread and is sent to the thread tensioner in a laterally twisted state.

The thread thus sent to the thread tension device is passed through the tension discs that are pressed by the spring, but at this time the thread is twisted, and a part of the thread that has contracted and accumulated is formed near the entrance of the discs. .

In many cases, the part where the twist has contracted is pulled and passes through the thread tensioner while the amount of twist accumulated is small, but the problem is that the part where the twist has accumulated further absorbs the loosened thread above, causing abnormalities. The thread forms a loop or becomes tangled, and in this state it is gradually drawn into the tension disc through the curved guide surface around the tension disc, and passes through the thread tension device.

In other words, the predetermined tension is no longer applied to the thread after passing through the thread tension device.

Previously, in a utility model registration application dated June 2, 1971, the present applicant provided a thread guide with numerous protrusions in front of a thread tension device, and the thread to be sent to the thread tension device was placed between the protrusions in advance. He proposed a method of handling the thread by threading it through, removing twists and loops in the thread, and preventing the formation of tangles and loops in the thread just before the thread tension device.

The purpose of this invention is to provide a thread guide that provides better results in removing yarn tangles and loops and is structurally simple.

The explanation will be given below according to the drawings. In Fig. 1, 1 is a sewing machine, behind which a thread stand (not shown) is installed, and the thread stand is further provided with several spool pins 2 and supports 3. There is.

4 is a thread spool that is inserted into the spool pin 2, and 5 is a guide wire that is attached to the upper end of the column 3.

On the other hand, on the front of the sewing machine are thread guides 8, 9 for single threads and double threads (details will be described later) and a thread tension regulator 6 according to the present invention.
and a thread hook 7 are shown, and the thread fed out from one of the several bobbins passes through a guide wire 5 above the bobbin winder and is hung on a single yarn thread guide 8, a thread tension device 6, and a thread hook 7. The thread that is then sent to the upper needle and let out from the other spools passes through the thread guide 9 for double threads and is sent to the looper via a thread tension adjustment device (not shown).

Next, the thread guide 8 for single yarn shown in FIGS. 2 to 4 will be explained. Reference numeral 10 is a housing made of a plate bent into a trapezoidal shape, and a single cut groove 11 is formed on the upper surface and the bent portions on both sides. The tongue piece 12 is provided to form a tongue piece 12, and this tongue piece is slightly bent downward to function as a presser for the thin plate described later, and one side of the ""-shaped cut groove is slightly bent downward. It is shaped to follow the tongue piece 12 (see Figure 2).

The housing 10 is further provided with a mounting part 13 projecting downward from one side thereof, and this mounting part is fitted into a horizontal hole (not shown) drilled in the front face of the sewing machine and is attached to a frame inside the sewing machine. , the housing is attached to the front of the sewing machine.

14 is a thin film-like plate inserted into the upper housing 10, and is made of metal. It is shaped by punching out celluloid or hard resin sheets.

15 is a porous sponge such as foamed urethane that is approximately the same size as the thin plate 14 and is inserted into the housing following the thin plate 14, and is compressed when the housing is attached to the front of the sewing machine as described above. , substantially the entire surface of the thin plate 14 is brought into elastic contact with the tongue piece 12 with a force smaller than the elastic contact force between the tone plates of the tone device 6.

Next, the thread guide for double threads shown in Figures 5 and 6 will be explained. This thread guide is arranged so that the thread guide for single thread described above is arranged symmetrically, and has a trapezoidal bent shape. A cut groove 21 is provided in the upper surface of the housing 20 and the bent portions on both sides to form a pair of tongues 22 symmetrically, and one side of the housing is attached to a sewing machine frame. The attachment part 23 is in a protruding shape, and the lower ends of the side plates are bent and overlapped on both sides, and the tip part is formed into a threading finger whose tip is upward from the vicinity of the elongated hole end of the cut groove 21 and inclined toward the groove end. Piece 24
, 24.

Further, as shown in FIG. 5, the central portion of the long groove is formed into a concave shape along a pair of tongues 22, 22 that are slightly bent downward.

The thin plate 14 and the sponge 15 are sequentially inserted into the housing 20 in the same manner as in the single yarn guide described above.

Threading through these thread guides is carried out by inserting the thread guide 8 for single threads through the cut groove 11 into the tongue piece, that is, between the tongue piece 12 and the thin plate 14, and for the thread guide 9 for double threads. This is carried out by further hooking the thread passed between the tongue piece 22 and the thin plate 14 onto the threading finger piece 24 at the end of the long groove.

However, during sewing, an abnormally looped or twisted thread with accumulated torsion occurs just before the thread guides 8 and 9, as described above, but the tongue pieces 12 and 2 of the thread guides 8 and 9 are prevented by the porous sponge. The thin plate 14 and the tongue piece 12 that are in light elastic contact with the
When the thread passes near the entrance to the thread 22, it is lightly loosened by the edge of the thin plate 14, and the thread becomes an evenly twisted state, passes through the thread guides 8 and 9, and is sent to the thread tension device.

The thread between the thread guides 8, 9 and the thread tension device is given a weak tension by the porous sponge of the thread guides 8, 9 that does not affect the thread tension of the thread tension device, so it may not get twisted or abnormal. A stable thread can be supplied to the thread tension device without forming a loop.

As described above, this invention uses a film-like thin plate, which is extremely simple in structure, to prevent the thread from becoming tangled or looped just before the thread tension device, and the thread generally only experiences frictional resistance at the edge of the thin plate. Since the tension is applied by the thread guide, there is almost no tension applied by the thread guide, and the required tension can be set exclusively by the thread tension device.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a sewing machine equipped with a thread guide according to the present invention, Fig. 2 is an exploded side view of the thread guide for single threads, Fig. 3 is a front view of the same, Fig. 4 is a longitudinal sectional view of the same, and Fig. 4 is a longitudinal sectional view of the sewing machine. FIG. 5 is a side view of the thread guide for two threads, and FIG. 6 is a front view thereof. 4... bobbin winder, 6... thread tension device, 8,
9... Thread guide, 10... Housing, 11.
... Cut groove, 12 ... Tongue piece, 13 ...
... Mounting part, 14 ... Thin plate, 15 ...
...Sponge, 20...Housing, 21...
・Cut groove, 22... tongue piece, 23...
Attachment part, 24...Threading finger piece.

Claims (1)

[Scope of utility model registration request] It has a spool stand, a spool pin 2 that stands upright from the spool stand, and a support 3. A spool 4 is fitted and supported on the spool stand 2, and a thread hook 5 is attached to the support 3 above the spool. In this sewing machine, the thread let out from the bobbin spool is pulled upward in the axial direction of the bobbin spool in a stationary state, and is sent to the thread tension device 6 via the thread hook 5. Thread guides 8 and 9 are arranged between the thread tension device 6 and the thread guides include a thin film-like plate 14 and a thin film-like plate 14.
An elastic body 15 is provided which brings the thread into elastic contact with the tongue pieces 12 and 22 forming a part of the thread guide with an elastic contact force smaller than the elastic contact force between the thread tension disks of the thread tension device 6, so that the thread is connected to the thin plate and the tongue. A thread guide for a sewing machine using a thread spool, which is passed between a thread and a thread and is unraveled near the entrance of the thread.