KR20020000529A - Device for controlling the pressure of fabric pressure shoes on sewing machines or the like - Google Patents

Abstract

PURPOSE: Provided is a device for automatically controlling the pressure of fabric pressure shoes on preferably industrial-type sewing machines, meaning those equipped with claw, roller or belt conveying system or other similar conveying system. CONSTITUTION: Automatic control device(1), installed above shaft(2) on which fabric pressure shoe(3) is mounted, basically consists of cylinder(4) in which piston(5) slides. The piston(5), which is connected to shaft(2) of the shoe through arm(6), mounts, along its external edge, a ring groove suitable for housing elastic ring or "O-ring" seal with a round and floating type cross-section. The seal is the type suited to exert floating sliding by the piston inside the cylinder chamber, therefore sliding with minimum friction and without any possibility of sticking to or gluing to the cylinder sleeve. The top part of the cylinder chamber is connected to tube(8) which terminates at pneumatic control system. A special pressure regulator belongs to this control system. This regulator is designed to control the pressure of the air circuit with great precision. This control is executed and performed by pressure regulator using a suitable reducing and stabilizing valve. The delivery rate of this valve can be varied using pressure regulator.

Description

Pressure control device for fabric pressure shoes of sewing machines or similar machines

The invention relates to an apparatus for automatically controlling the pressure of a fabric pressure shoe of an industrial sewing machine, ie a machine equipped with a claw, roller or belt conveyor or other similar conveyor arrangement.

This automatic control device basically uses a pneumatic device to control the pressure exerted on the axis of the fabric pressure shoe, and traditionally the pressure is acted by a spring device or in some cases always by a mechanical type device or by a spring pull. .

The automatic control device according to the invention has the advantage of having an improved thrust condition on the fabric pressure shoe at any thickness of the fabric being worked by greatly reducing the inertia and maintaining the proper working pressure at any speed compared to the known method. To provide.

A sewing machine is, as is known, in most common forms, a machine for sewing two fabrics mechanically. In the industry, it is recognized that different structural techniques are applied depending on the various operations they intend.

For example, single or multiple needle machines are generally known to be used to sew jeans or casual pants, work clothes, shirts or other garments.

Such industrial sewing machines can sew various fabrics, yokes, front and back crotch, knees or other various parts based on their different applications. They make special modifications for light or very heavy fabrics by increasing the pressure shoe height and expanding the stroke of the needle bar.

Typically all these variants are equipped with a fabric pressure shoe along a vertical axis that includes a mechanical pressure device designed to absorb the shoe impact. This device is necessary both to compensate for the thrust caused by different sewing speeds and above all to sew fabrics of different thicknesses.

1 shows such a conventional pressure device. As shown, the device comprises a pin A with a head B into which a spring C is inserted. Pin A slides on a special seat mechanized on axis D of shoe E, and the head of the pin itself is pressurized by pressurizer F. The height of this pressure can be adjusted by sewing pawl G.

By tightening pole G, it is certain that the spring creates greater pressure on shoe E.

This structural technique is used to absorb the impact forces acting on the fabric pressure shoes of most sewing machines and is a practical problem. This is mainly related to the difficulty of controlling pressure during operation. In all cases, it is very important for machines that experience a change in the thickness of the fabric during sewing.

In this case, the spring pressure mechanism does not adapt to the degree of accuracy required by the fabric. As is well known, the spring mechanism does not apply constant pressure during operation, on the contrary, the pressure increases when the working interval decreases.

This affects the quality of sewing and sewing speed. Speed must sometimes be greatly reduced in lost production time and in the price of the finished product. It is an object of the present invention to make an apparatus for automatic control of fabric pressure shoes which can overcome the above mentioned disadvantages. In other words, a constant shoe operating pressure is maintained during all sewing operations.

The fabric pressure shoe control apparatus according to the present invention maintains a constant shoe operating pressure during all sewing operations regardless of the thickness of the fabric. This allows any fabric to work at high sewing speeds.

As mentioned above, the problem of the present invention is based on the installation of a control device using a device of a completely pneumatic type. This provides the advantage of ensuring a constant working pressure at any working pressure with the initial setting of the shoe.

The above objects and advantages are all achieved by means of an automatic control of the fabric pressure shoe pressure acting on the sewing machine, especially in industrial sewing machines, the apparatus receiving a pneumatic device comprising one or more cylinders on which the piston slides. The piston is then connected to the fabric pressure shoe shaft via a particular connection, and the inner chamber of the cylinder is suitably set and connected via a suitable tube to a pneumatic control device comprising a particular pressure regulator with a stabilizing valve or similar device.

Other specific features of the present invention will be better understood with reference to the non-limiting embodiments and drawings.

1 is a schematic of a traditional control used to determine the pressure exerted by a known fabric pressure shoe.

2 is an overall schematic view of an apparatus according to the invention for the automatic control of pressure exerted by a fabric pressure shoe for an industrial sewing machine or similar machine.

Figure 3 is a detailed schematic diagram of the air pressure control device.

* Explanation of Drawings

1 ... Automatic controller 2 ... axis

3 ... shoe 4 ... cylinder

5 ... piston 6 ... arm

7 ... Encapsulation 8 ... Tube

9.Air pressure control 10,11,13 ... regulator

12 ... compensation device 14 ... second exit

Referring to the accompanying drawings, reference numeral 1 denotes the overall device according to the invention, which is a fabric pressure shoe of an industrial sewing machine, equipped with a claw, roller or belt conveyor device or any other similar conveyor device. It is a device for automatic control of pressure.

The automatic control device 1 installed on the shaft 2 on which the fabric pressure shoe 3 is mounted consists essentially of a cylinder 4 on which the piston 5 slides.

With reference to FIG. 2, the piston 5, which is connected to the shaft 2 of the shoe via the arm 6, receives an elastic ring or O-ring closure 7 with a round, floating type cross section along its outer edge. Has a suitable ring groove.

The sealer 7 is of a suitable type that is applied to float and slide by the piston inside the cylinder chamber. There is no sticking or adhesion to the cylinder sleeve and it slides with minimal friction.

The upper part of the cylinder chamber is connected to the tube 8 where the air pressure control device 9 ends. A special pressure regulator 10 belongs to this control. This regulator is designed to control the pressure in the air circuit very accurately. This control is performed by the pressure regulator 10 by appropriately reducing and stabilizing the valve. The delivery rate of this valve can be varied using the pressure regulator 11.

Compensation device 12 can be inserted between the cylinder 4 and the pressure regulator 10 if necessary. The device compensates for small changes in pressure before moving the valve of the pressure regulator.

With this control it is possible to set the air pressure in the upper chamber of the cylinder 4, which is the thrust due to the change in the thickness of the fabric under all conditions of the thrust applied by the axis 2 of the fabric pressure shoe 3. It keeps the pressure constant by compensating for the change of thrust or other thrust according to the sewing speed.

Small pressure changes can be absorbed in the compensation chamber 12, but all significant changes must be controlled by reducing and stabilizing the pressure regulator 10 and the valves contained therein.

As the fabric enters and exits, the rise of the shoe is also accomplished using air pressure controls. This is done through an appropriate change in the pressure exerted by the pneumatic device in the upper chamber of the cylinder.

Naturally, the entire device is controlled by computerized controls that enter and determine both different options and working variables.

The second outlet 14 is also provided at the bottom of the cylinder. This has the advantage that it can be connected to an additional pneumatic valve designed to assist the shoe lift as the fabric enters and exits.

It can be seen that the above-mentioned automatic control device greatly improved the thrust condition by greatly reducing the inertia and keeping the working pressure constant at any working speed or any thickness of the fabric to be worked. The method described above also shows the possibility of using the arm 6 by a direct connection between the compensator and the fabric pressure shoe shaft. However, this connection can also be done in parallel with a suitable mechanical connection or component coupling.

Those skilled in the art can make modifications and variations of the non-limiting embodiments described above, which fall within the protection scope of the technology described in the appended claims.

Claims (7)

In the device for the automatic control of the pressure applied by the fabric pressure shoe of the industrial sewing machine, The piston 5 has a pneumatic device comprising one or more cylinders 4 in which it slides, which piston is connected to the shaft 2 of the fabric pressure shoe 3 via a special connection 6, The internal chamber of the cylinder 4 is connected via a special tube 8 to an air pressure control device comprising a special pressure regulator 10 equipped with a stabilizing valve or similar device for variable setting. Device. 2. The piston (5) according to claim 1, wherein the piston (5), connected to the shaft (2) of the shoe via an arm (6), accommodates an elastic ring or O-ring closure (7) with a round and floating type short life along its outer edge. Automatic control device characterized in that provided with a ring-shaped groove designed for. 3. The cylinder chamber according to claim 1 or 2, wherein the cylinder chamber is connected to a tube (8) which terminates at the pneumatic control device (9) comprising a special pressure regulator (10) designed to precisely control the pressure of the air circuit at the top. Automatic control device characterized in that. The automatic control device according to claim 2, wherein the control is performed by a pressure regulator (10) through appropriate pressure reduction and valve stabilization, the delivery rate of which can be modified by the pressure regulator (10). An automatic control device according to claim 1, characterized in that an additional compensation device (12) is inserted between the cylinder (4) and the pressure regulator (10) and compensates for small changes in pressure before the pressure regulator is activated. . In the claim, a second outlet 14 can be installed at the bottom of the cylinder 4, and additional pneumatic valves can be designed and connected to assist in raising the shoe as the fabric enters or exits. Automatic control device characterized in that. The automatic control device according to claim 1, wherein the connection between the compensator and the fabric pressure shoe shaft is carried out via an arm (6), and can also be made in parallel with a suitable mechanical connection or component engagement.