SU755917A1 - Device for cutting needle thread on sewing semiautomatic machine - Google Patents

Description

The invention relates to the garment industry, in particular to devices for pinching the thread while simultaneously trimming it at the beginning of casting on the sewing machine for sewing buttons.

A device for trimming a needle ^{5 * * * *} thread on sewing machines is known, comprising a fixed knife mounted on the inner side of a needle plate having a central hole for the needle, and a power knife mounted to rotate in a ¹⁰ plane parallel to the needle plate plane and kinematically connected with a semi-automatic copier disk [1].

However, in the process of sewing buttons

Skipping of the initial stitches and the presence of the needle thread end on the front side of the product are possible.

The purpose of the invention is to improve the quality of products by trimming the initial end of the needle thread and fixing it at the beginning of sewing.

The goal is achieved in that the device contains a fixed knife mounted on the inner side of the needle plate, having a center

ral needle hole, and a power knife mounted to rotate in a plane parallel to the plane of the needle plate, kinematically connected with a copier disk to semi-automatic machines and made plate-like in the form of a frame, whose inner edges are pointed, and its axis of rotation is perpendicular to the needle plate, moreover The frame is located coaxially with the central hole of the needle plate, while the fixed knife is spring-loaded relative to the drive knife.

FIG. 1 shows a sewing machine; Fig 2 - needle plate with fixed and driven knives; in fig. 3 shows section A-A in FIG. 2; in fig. 4 shows a section BB in FIG. 2

A device for trimming a needle thread on a semiautomatic sewing machine contains a drive knife 2 mounted under the needle plate 1 and a fixed knife 3.

Fixed knife 3 fixed in the middle

parts of the needle plate 1 with screws 4. The cutting edge 5 of the doge 3 interacts with the inner cutting edge 6 of the drive755917

knife 2, made in the form of a frame located coaxially with the central hole 7 for the needle 8 in the needle plate 1.

To ensure sustainable trimming of the thread 9, the fixed knife 3 is constantly pressed with spring ₅ to the plane of the knife 2, which is hinged on the axis 11 of the needle plate 1.

Pa opposite the end of the knife 2 has a groove 12 which includes a stone 13 connected to a double-arm lever 14 mounted 10 pivotally on an axis 15 in the body of the machine 16.

The other end of the two shoulders lever 14 is connected by means of a ball-shaped drawbar 17 to the lever 18, the upper end of which is provided with a roller 19 entering the groove 20 of the cam disc 21. 15

The device works as follows.

When the machine is turned on, the coi disc 21 is set in motion and the needle 8 begins to fall into the lower position with the needle 9.

Before the needle 8 approaches the needle plate 1 - 20

The copier disk 21 will turn on the axle 11 a power knife 2 by means of a lever 18, a ball-shaped drawbar 17 and a two-armed lever 14 so that the needle passes into the hole of the knife 2.

The thread 9, held by the needle 8 into the hole 25 of the needle plate 1, is captured by the hook or the knotter 22,

When the thread feeder (not shown) is lifted to the highest position, the needle 8 will exit the needle plate 1 and the copier disk 21 30

by means of the lever 18, the ball tongue 17, the two shoulders lever 14 will rotate the knife 2, ensuring the pinching of the thread 9 between the plane of the needle plate 1 and the knife. 2, and the remaining end of the thread is cut off with a fixed knife 3. 35

At the second needle prick 8, normal looping takes place. In order that the tied thread is not pulled out of the clamp

during the second injection of the needle 8 to the formation of the first stitch, the device provides for the release of the thread tension regulator 23, which is affected by the release of the thread 24, kinematically connected with the copier disk 21.

After the second needle injection 8, the regulator 23 closes and remains in this position until the end of the operating cycle.

Claims (1)

Claim A device for trimming a needle thread on a semiautomatic sewing machine, for example for sewing buttons, containing a fixed knife mounted on the inside of a needle plate having a central hole for the needle, and a driving knife mounted rotatably in a plane parallel to the plane of the needle plate and kinematically connected with a semi-automatic copier disk, characterized in that, in order to improve the quality of products by trimming the initial end of the needle thread and fixing it at the beginning of the thread, the drive knife is removed flap plate in the form of a frame, the inner edges of which are pointed, and its axis of rotation is perpendicular to the needle plate, with the frame aligned coaxially with the central hole of the needle plate, while the fixed knife is spring-loaded relative to the drive knife.