JPH0630705B2 - Sewing machine balance device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a balance device for a sewing machine.

As is generally well known, the balance moves up and down in the slit formed in the frame with the upper shaft in a state where the upper thread is passed through the eye hole, and tightens and loosens the thread necessary for seam formation. In most cases, threading through the eyelet is performed by directly inserting the free end of the thread, but it is performed through the eyelet to facilitate threading. Some have slits and some have notches.
In any case, in the conventional balance, the thread must be threaded through the eye hole at the time of sewing, and the work for threading the thread through the eye hole is required. When threading the eyelet, the eyelet must also project outside the frame.
In recent years, various attempts have been made to conceal by incorporating a device that protrudes outside the frame from the viewpoint of design and safety, but the locus of the eye hole is at least part of it in order to thread the eye hole. Had to project outside the frame, and therefore the balance could not be built in so that it would never project outside the sewing machine.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in view of the above problems, and an object thereof is to provide a balance device that does not require threading through eye holes.

Therefore, according to the present invention, in the present invention, an engaging portion for thread is formed in a balance which reciprocates in conjunction with an upper shaft, and an engaging hole is formed in the forward movement start side of the balance for thread passage. The guides are arranged so as to sandwich the drawn path, and the engaging portion engages with the yarn passing between both guides during forward movement of the balance and captures and pulls the yarn, while the engaging portion engages with the yarn during forward movement. The engagement is canceled.

Here, the engaging portion preferably has a hook shape so that the engaged thread is not easily disengaged from the engaging thread during the forward movement.

The balance is configured to perform a reciprocating linear motion along a guide or a swinging motion around a fixed point. The balance may also reciprocate while protruding outside the frame, but is preferably adapted to reciprocate within the frame. When concealed by reciprocating in the frame,
Not only is it preferable from the standpoint of design and safety, but a guide plate is attached to the inside of the sewing machine frame to prevent the loose thread from being deflected by the sewing machine frame and the guide plate from both sides when the balance is returning. Further, the guide can be provided between the guide plate and the sewing machine frame to eliminate the protrusion so that the slackened yarn is not caught and entangled.

Example In a bracket 2 which is arranged in parallel with the frame in the frame 1 with an appropriate gap, a slot 3 is formed, and a guide 4 for sandwiching the slot is formed inside the slot 3 by bending. The guide 4 has a width corresponding to the above-mentioned gap, hits the frame 1, is positioned corresponding to the slit 5 formed in the frame, and the thread is passed through the slit 5. A guide rod 6 is attached to the bracket 2 in parallel with the slot 3.
A balance 7 is slidably attached to the balance 7, and the balance 7 is connected via a link 11 and a lever 11 that swings by a deflection pin 9 that rotates in conjunction with an upper shaft 8. 6 is reciprocated along the line 6, the tip of which is formed in a hook shape and protrudes into the above-mentioned gap from the slot 3, and engages with the yarn between both guides 4 in the forward movement and captures the yarn. It is designed to be towed (the tow is released during the backward movement, causing the yarn to sag).

FIG. 3 shows another embodiment, in which one end formed in a hook shape is projected from the slot 3 of the bracket 2,
Balance lever 15 with the other end pivotally attached to the sewing machine body
Is connected by a link 16 to a lever 16 at an intermediate portion thereof, and the lever 16 is swung by an end face cam 18 fixed to the upper shaft 8 so that the hook portion at the tip of the balance lever 15 is moved in an arc.

Effect of the Invention As described above, the thread balance device of the present invention does not require threading to the thread balance, so threading work prior to the start of sewing is facilitated accordingly, and a complete concealment of the thread balance device is possible. This makes it possible to prevent it from protruding outside the sewing machine at all. In addition, the yarn is caught by the engaging portion and pulled in a V shape when the thread is moving forward, but is guided from the beginning when the thread is caught by the guide provided on the forward movement start side of the thread take-up, so that the thread is taken in. Since the amount of movement is increased, the amount of reciprocating movement of the balance can be reduced, and since the thread is passed through the eye hole of the guide and its movement is restricted, the thread is always pulled at the same position by a certain amount. Therefore, it is possible to always secure the thread amount necessary for forming the seam.

[Brief description of drawings]

FIG. 1 is a perspective view of a balance device according to the present invention, FIG. 2 is a plan view of the balance device, and FIG. 3 is a plan view of another embodiment. 1 ... Frame, 2 ... Bracket 3 ... Slot, 4 ... Guide 5 ... Slit, 6 ... Guide rod 7 ... Balance, 17 ... Balance lever

Claims (4)

[Claims] 1. A thread engaging portion is formed on a balance that reciprocates in conjunction with an upper shaft, and eye holes for threading are provided on the forward movement start side of the balance with a locus drawn by the engaging portion. The guide is arranged so that the engaging portion engages with the yarn passing between both guides when the balance moves forward, and catches and pulls the yarn, while the engagement of the engaging part with the yarn is canceled during forward movement. A balance device for a sewing machine characterized by the above. 2. The balance device for a sewing machine according to claim 1, wherein the engaging portion has a hook shape. 3. A frame is formed with a slit that passes through both guides, and the entire device is built in the frame so that the balance does not protrude from the frame.
A balance device for a sewing machine according to the item. 4. The balance device for a sewing machine according to claim 3, wherein the balance has a tip protruding from a slot formed in a bracket arranged in parallel with the frame.