Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates to the manufacture of equipment for sewing technologies and methods for the sewing industry, the embroidered goods industry, the knitted goods industry, the leather industry and the shoe industry. The present invention comprises a technology for obtaining a multi-thread single-line chain stitch line.
2. Description of Prior Art and Existing Problems
Existing at present, chain stitch lines (presented in U.S. Pat. Nos. 3,301,206; 3,753,410) have a limited number of threads (two threads only) being used in the line, and are limited in the variability of the structure of the stitch, which in turn limits the possibilities for adjusting the stitch line structure to the operational requirements. Likewise, the existing machines, manufacturing two-thread single-line chain stitch lines, have limited functional possibilities (as presented in U.S. Pat. Nos. 3,301,206; 3,753,410; 6,095,069).
The limited number of threads being used in the prior art strongly hinders the potential for changes in the parameters of the stitch, which are limited to changing the step of the stitch and the thread tension.
The contemporary chain stitch line used in sewing knitted goods is not very reliable, and tends to deform the seam, causing corrugation, which creates the appearance of a defect in the finished product.
Another problem in sewing technology is the optimization of stitch line properties along its length. The loads to which the stitch is exposed are different in different areas of a sewn article. In addition, the conditions of the stitch line operation are different, whereas the stitch line remains uniform along its length under the existing technology. For example, an article, such as a sleeve, is subject to various deformations in different areas—stretching at the elbow and corrugation at the bend. Also, the uniform stitch line often joins several layers of material, while the materials can be of different type (woven fabric, knitted fabric, leather, etc.). Thus, although the average properties of the uniform stitch line are intended to cover variable requirements, such factors ultimately limit the technological possibilities for creating new goods without the existing difficulties.
Further, the existing chain stitch structure results in uneven deformation under stretching, where alternating stretched and squeezed areas are created (stretched areas occur around the perforation in the material, i.e. in the point of conjunction of the top and bottom threads, while the squeezed areas occur in the interval between two perforations). Such uneven deformation of the seam causes corrugation.
Known stitch lines provide stretch ability due to the stretch ability of the threads used in the line and deformation of the sewn material.
Thus, the main drawbacks of the contemporary single-line chain stitch line, which limit its application and degrade its operational properties and appearance of the finished product, are as follows:
The aim of the present invention is a further improvement in the class of the chain stitch, due to the elimination of the drawbacks described above, by using the following principles:
These and other objects and advantages of this invention are described in detail in the description of the invention contained herein.
The present invention comprises variations in the manufacturing of chain stitch lines, with at least three threads involved, according to two main versions: one version consisting of top and bottom threads, which threads are conjoined at the material perforation points; and another version consists of top threads only.
In the first version, the top threads are joined with the bottom ones in a pre-determinable sequence, variable along the stitch line. This effect is obtained through the following:
The considered stitch line structure consists of a system of several top and several bottom threads joined through the perforations in the material. Such structure provides for a mutual compensation of stretched and squeezed areas of the material and eliminates corrugation of the seam. Another benefit is the potential for changing or transforming the structure along the length of the stitch line in the process of producing the stitch line. It permits the optimization of the properties of the seam in terms of its appearance, stretch ability, wear resistance, etc.
The sequence of interaction of the top and the bottom threads is determined by the required structure of the stitches. The sequence of interaction can be controlled mechanically or digitally. These methods of control and programming are well known and widely used—e.g., in knitwear fabrics manufacturing (U.S. Pat. Nos. 4,467,737 and 4,359,953).
The loading of every top thread into its needle and of every bottom thread into its looper can be provided by various methods used in conventional multi-thread sewing machines (U.S. Pat. Nos. 3,433,191 and 4,993,335).
A means for sequentially engaging a required needle and a means for sequentially engaging a required looper simultaneously, providing for the conjunction of one of the top threads with one of the bottom threads, is not known from the prior art. Such means could be provided in various ways. One of the ways is taught in the present invention. It comprises a needle unit (mechanism) and a looper unit (mechanism).
The needle unit comprises a revolver (needle revolver) with needle bars located along its periphery and oriented along its rotation axis. The looper unit also comprises a revolver (looper revolver), where the loopers are similarly located along its periphery. Both revolvers are equipped with a device which provides for enabling the current couple. Both revolvers are also provided with a means for turning and fixation. A Geneva wheel can be used for such purpose. (A Geneva wheel is a well-known mechanism in sewing machines; see, e.g., U.S. Pat. No. 4,702,183).
The utilization of both revolvers, due to the rotation of the needles and the loopers around the rotation axes of the respective revolvers, can provide for the respective intertwining of the top threads between each other and of the bottom threads between each other.
The second basic version of the present invention implies a multi-thread single-line chain stitch line, consisting of at least three top threads, each top thread forming a loop at the material perforation point in a predetermined sequence, such loop being conjoined with the consequent loop at the consequent perforation point by means of a looper, with no thread being loaded in the looper.
The present invention can be easily understood from the detailed description of the preferred embodiment by reference to the attached drawings.
After bringing a current couple into the operating position:
A—passing of top thread (3a) through material (1) by a needle (5a); passing the loop of the bottom thread (4a) by the looper (6a) through the loop of the top thread (3a);
B—extracting needle (5a) out of material (1) engaging top thread (3a) loop by looper (6a);
C—shifting material (1) to extend the bottom thread loop (4a) to the next sequential perforation point;
D—passing of top thread (3b) through material (1) by a needle (5b), further passing the needle (5b) together with the top thread (3b) through the bottom thread (4a) loop;
E—passing of bottom thread (4a) by looper (6a) through the top thread (3b) loop and extracting needle (5b) out of material (1).
After bringing a current couple into the operating position:
A—Passing of top thread (3a) through material (1) at perforation (p#1), by required needle (5a); engaging top thread (3a) by required looper (6a) with passing bottom thread (4a) into the top thread (3a) loop; thus forming the bottom thread (4a) loop inside of the top thread (3a) loop;
B—Extracting required needle (5a) out of material (1) at (p#1) and shifting material (1) to stretch the top thread (3a) loop by means of looper (6a); with this, the next current couple—needle (5b) and looper (6b)—provides interaction of top thread (3b) and bottom thread (4b); for which needle (5b) brings top thread (3b) through material (1) at (p #2), and looper (6b) brings thread (4b) through thread (3b) loop.
C—Shifting material (1) again; bringing needle (5a), which is another required needle, with the top thread (3a), which is another required thread, into the operating position for said cycle, forming another current couple with the looper (6a); with this, looper (6a) stretches thread (3a) loop to the area of the next perforation (p#3); needle (5a) brings thread (3a) through perforation (p#3) and provides interaction of thread (3a) loop by means of looper (6a) with threads (3a) and (4a); with this looper (6b) stretches thread (3b) loop.
D—Thread (3a) loop stretches thread (4a) forming an element of the stitch.
E—Looper (6a) brings thread (4a) through thread (3a) loop; with this, the next current couple (5b) and (6b) is being prepared.
F—Material (1) is shifted; with this, thread (3b) loop is stretched by looper (6b) to the area of perforation (p#4); whereas needle (5b) is bringing thread (3b) through perforation (p#4), providing interaction of thread (3b) loop with thread (4b).
G—Thread (3b) stretches thread (4b) loop to the area of perforation (p#2) forming another element of the stitch.
H—Looper (6b) brings thread (4b) through thread (3b) loop; with this, the next current couple (5a) and (6a) is formed.
I—Material (1) is shifted; looper (6a) stretches thread (3a) loop to the area of perforation (p#5), looper (6b) stretches thread (3b) loop as well; needle (5a) brings thread (3a) through perforation (p#5) and thread (4a) loop.
J—Looper (6a) throws off thread (4a) loop on needle (5a) and thread (3a).
K—Looper (6a) brings thread (4a) through thread (3a) loop; with this, the next current couple (5b) and (6b) is being formed, and the material (1) is prepared to be shifted with further repetition of the cycle described in A-G.
(Note: If intertwining is required, after each extraction of the needle the needle revolver rotates the required number of revolutions to provide intertwining).
The process of forming stitch lines according to the present invention can be performed by the following mechanisms and devices. The mechanism of discrete rotation of the needle revolver (10) turns needle unit (needle revolver) (8), bringing desired needle (e.g., 5a) into operating position; simultaneously, the mechanism of looper revolver discrete rotation (11) brings the desired looper (e.g., 6a) into operating position; thus, the current couple of needle (5a) and looper (6a) is enabled. With this, catching device (14) of mechanism (13) catches shoulder (15a), thus enabling needle bar (12a).
The sewing machine can be designed with:
The solid needle revolver (
The modular needle revolver (
The module (
The novelty of the present invention is in obtaining various and variable structures of chain stitch lines due to a pre-determinable conjunction of several top and several bottom threads. In the conventional chain stitch sewing machines, many methods are known for manufacturing conventional chain stitch lines. All of them are applicable to this invention with modification, providing for the individual interaction of needles and loopers, forming current couples.
While this invention has been described in terms of a specific embodiment thereof, it is to be understood that it is not limited thereto, but rather only to the extent set forth hereafter in the claims, which follow.