Claims
[1] A cloth tensioning apparatus in an embroidering machine comprising a cloth feeding roller, a cloth winding roller, torque motors adapted to rotate the cloth feeding roller and cloth winding roller, respectively, front and rear cloth transfer rollers defining an embroidering section therebetween, and a head located in the embroidering section and adapted to perform a displacement in an X-axis direction of a cloth, the cloth tensioning apparatus comprising: a plurality of leftward and rightward movement LM guides provided at opposite sides of the cloth in the embroidering section and adapted to be moved leftward and rightward by first horizontal air cylinders; a plurality of forward and rearward movement LM guides mounted on the respective leftward and rightward movement LM guides and adapted to be moved forward and rearward by a second horizontal air cylinder; a pair of left and right nipper units connected onto the forward and rearward movement LM guides; a plurality of sensors installed at front and rear sides of the left and right nipper units and adapted to control a forward and rearward movement distance of the nipper units; and a controller to control operations of the LM guides, nipper units, and sensors.
[2] The apparatus according to claim 1, further comprising: a pair of pressure members installed near the left and right nipper units and adapted to be operated by vertical air cylinders, respectively, each pressure member having a pressure portion located inside an associated one of the left and right nipper units.
[3] The apparatus according to claim 1, wherein each of the first horizontal air cylinders for operating the leftward and rightward movement LM guides is installed between associated left and right ones of the leftward and rightward movement LM guides, and adapted to simultaneously move the left and right LM guides leftward and rightward.
[4] The apparatus according to claim 1, wherein the second horizontal air cylinder for operating the forward and rearward movement LM guides is connected to a connecting bar connecting between associated left and right ones of the forward and rearward movement LM guides, so as to simultaneously move the left and right LM guides forward and rearward.
[5] The apparatus according to claim 1 or 2, wherein each of the left and right nipper units comprises a lower nipper fixedly connected to blocks of the forward and rearward movement LM guides of the nipper unit, and an upper nipper adapted to be moved up and down by vertical air cylinders provided at the lower nipper. [6] The apparatus according to claim 1, wherein the leftward and rightward movement LM guides and the forward and rearward movement LM guides are operated by the first and second horizontal air cylinders, respectively, the first and second horizontal air cylinders being independent of each other, the left and right blocks of the forward and rearward movement LM guides are connected to each other by means of a connecting bar penetrating through guide pieces, so as to be simultaneously moved forward and rearward, and a pair of stop rings are provided at opposite ends of the connecting bar penetrated through the guide pieces, so as to control an outward movement width of the left and right nipper units. |
Description
CLOTH TENSIONING APPARATUS IN EMBROIDERING
MACHINE
Technical Field
[1] The present invention relates to a cloth tensioning apparatus in an embroidering machine, and more particularly, to a cloth tensioning apparatus capable of continuously imparting a constant tension to a cloth even in an X-axis direction of the cloth Background Art
[2] An inventor of the present invention has already developed a variety of kinds of embroidering machines, such as for example, an embroidering machine as disclosed in Korean Utility Model Registration No. 223005, in which a head is displaceable in an X-axis direction of a cloth to perform an embroidering operation, and an embroidering machine as disclosed in Korean Patent Laid-Open No. 2005-0111523 in which a tension is applied to a cloth in X-axis and Y-axis directions of the cloth during an embroidering operation.
[3] Specifically, in the above mentioned Korean Patent Laid-Open No. 2005-0111523, a tension is continuously applied to a cloth in a Y-axis direction of the cloth by torque motors, which are provided to rotate a cloth feeding roller and a cloth winding roller, and also, applied in an X-axis direction of the cloth by a plurality of elongated temples, which are transversely installed in an embroidering section defined between front and rear cloth transfer rollers. The above described conventional cloth tensioning structure, however, has a problem in that the temples have a difficulty to impart a sufficient tension in the X-axis direction of the cloth, although an appropriate tension can be applied in the Y-axis direction of the overall cloth due to the characteristics of the torque motors.
[4] Each of the temples includes an elongated supporting rod densely formed with oblique guiding grooves and a plurality of cloth expansion rings fitted in the respective oblique guiding grooves, each cloth expansion ring having needle rods circum- ferentially arranged therearound. In operation, if a cloth is moved in the Y-axis direction while coming into contact with each temple, the cloth expansion rings of the temple are rotated simultaneously by the needle rods thereof piercing the cloth, thereby allowing the cloth to be tensioned in the X-axis direction thereof. In this case, it will be understood that the temple must have a sufficiently long length to impart a sufficient tension to the cloth. However, the longer the length of the temple, the greater the damage to the cloth by the needle rods, and this results in deterioration in mer-
chantability. Furthermore, in a state wherein the cloth is rolled, there is a problem in that only a part of the cloth coming into contact with the temple is tensioned. Although this problem can be solved by providing the plurality of temples, the greater the number of the temples, the greater the damage to the cloth. Also, due to the fact that the temples should be installed so as not to interfere with needles of a head, the temples have a limit to apply a sufficient tension to the cloth in the X-axis direction of the cloth.
[5] In particular, when the cloth is tensioned by the temples, the tensioning width of the cloth is proportional to revolutions per minute of the cloth expansion rings provided at the temples. Therefore, if complex patterns are embroidered on the cloth and thus the cloth has an increase in the number of forward and rearward movements, an excessive tension may be given to the cloth. On the other hand, if very simple patterns are embroidered on the cloth or the patterns are arranged sparsely to have empty spaces therebetween and thus, the cloth has a decrease in the number of forward and rearward movements, a smaller tension may be given to the cloth. This makes it difficult to continuously apply an appropriate tension in the X-axis direction of the cloth. Also, the cloth may suffer from several problems, such as a difference in tension at different locations thereof, and this causes deformation of the embroidered patterns, resulting in poor merchantability. Moreover, providing an excessively large tension increases damage to the cloth by the needle rods of the temples, and results in many problems, such as deterioration in the value of products, etc.
Disclosure of Invention
Technical Problem
[6] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a cloth tensioning apparatus in an embroidering machine, which can continuously impart an appropriate constant tension to a cloth even in an X-axis direction of the cloth without the risk of damage to the cloth, thereby achieving a high quality embroidered cloth. Technical Solution
[7] In accordance with an aspect of the present invention, the above and other objects of the present invention can be accomplished by the provision of a cloth tensioning apparatus in an embroidering machine wherein: a pair of elongated nipper units are provided at left and right sides of an embroidering section where a head is located and adapted to be moved forward and rearward and leftward and rightward by LM guides, respectively; the left and right nipper units are moved a cloth along a Y-axis direction of the cloth to perform an embroidering operation in a state in which they apply an appropriate tension to the cloth in an X-axis direction of the cloth by seizing and pulling
opposite edges of the cloth; and if sensors detect that the nipper units are deflected forward via a continuous embroidering operation, the nipper units are returned to their returned positions in a state in which left and right pressure members press the edges of the cloth to keep the cloth in a tensioned state, thereby acting to again seize and pull the edges of the cloth in order to keep the cloth in the tensioned state at their returned positions.
Advantageous Effects
[8] The present invention provides a cloth tensioning apparatus in an embroidering machine, which includes left and right nipper units each having a long longitudinal length. According to the present invention, the nipper units can apply an appropriate tension to a cloth in an X-axis direction of the cloth as they are moved outward while seizing opposite edges of the cloth. Using the nipper units has the following several effects. Firstly, the present invention can apply an appropriate tension to a cloth even in an X-axis direction of the cloth without the risk of damage to the cloth. Secondly, according to the present invention, a constant tension can be continuously applied to the overall cloth located in an embroidering section of the embroidering machine regardless of a complexity of embroidery patterns, whereby there are no risk of deformation of the embroidery patterns due to a difference in tension at different portions of the cloth and consequently, a high quality embroidered cloth can be achieved. Brief Description of the Drawings
[9] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[10] FIG. 1 is a plan configuration view illustrating an embroidering machine according to an embodiment of the present invention;
[11] FIG. 2 is a perspective view of the embroidering machine according to the present invention;
[12] FIG. 3 is a perspective view illustrating important parts of the present invention;
[13] FIG. 4 is an enlarged partial perspective view illustrating the important parts of the present invention;
[14] FIG. 5 is a sectional configuration view of the important parts of the present invention; and
[15] FIG. 6 is a perspective view illustrating important parts of an embroidering machine according to another embodiment of the present invention. Best Mode for Carrying Out the Invention
[16] Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever
possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In the following description, detailed explanation of the known prior art or functions will be omitted to facilitate a better understanding of the invention.
[17] FIGS. 1 and 2 are a plan configuration view and a perspective view, respectively, illustrating an embroidering machine according to the present invention. As shown in FIGS. 1 and 2, the embroidering machine A comprises a cloth feeding roller 2, a cloth winding roller 4, torque motors 6 and 8 for rotating the cloth feeding roller 2 and the cloth winding roller 4, respectively, and a head 14 provided between a front cloth transfer roller 10 and a rear cloth transfer roller 12 and adapted to be reciprocally dis- placeable in an X-axis direction. The embroidering machine A may further comprise a cloth expansion roller 26 provided between the cloth feeding roller 2 and the front cloth transfer roller 10, or may further comprise a plurality of cloth feeding rollers, to fulfill functions as a quilting machine. Also, the head 14 have needles, which may be arranged in a single row, or in two or more rows if necessary.
[18] FIGS. 3 and 5 are a perspective view and a sectional configuration view, respectively, illustrating important parts of the present invention. In the present invention, a pair of nipper units 26 are disposed at opposite left and right sides of an embroidering section of the embroidering machine where a cloth B and the head 14 are located. The left and right nipper units 26 are adapted to be moved forward and rearward and leftward and rightward by operation of LM guides 18 and 20 and horizontal air cylinders 22 and 24. A pair of rear and front sensors 28 and 30 are provided at front and rear sides of each nipper unit 26 and adapted to detect a forward and rearward movement distance of the nipper unit 26. Also, pressure members 32 are provided near the nipper units 26, respectively, and adapted to be moved up and down. Each of the pressure members 32 has a pressure portion 32a disposed inside an associated one of the nipper units 26 at a higher height than that of the nipper unit 26.
[19] The LM guides 18 and 20 for moving the left and right nipper units 26 forward and rearward and leftward and rightward are arranged in such a manner that one LM guide 16 and one LM guide 18 make a pair, and two pairs of LM guides 16 and 18 are disposed, respectively, at left and right sides of the embroidering machine A to achieve a stability in the arrangement thereof. Of the LM guides 18 and 20, in particular, the LM guides 20, which are adapted to be moved leftward and rightward, are connected to an upper surface of a frame via rails so as to be arranged parallel thereto. Each of the leftward and rightward movement LM guides 20 has a block connected, at an inner side thereof, to a guide rod 36. The guide rod 36 is configured to have an appropriate length and is penetrated through a guide piece 34 on the frame. On the basis of two LM guides 20 arranged at left and right sides of the embroidering machine A, a pair of left
and right guide rods 36 are disposed between the facing left and right blocks of the two LM guides 20, and one of the horizontal air cylinders 24 is interposed between the left and right guide rods 36. With this configuration, the left and right blocks of the two LM guides 20 can be simultaneously moved leftward and rightward along the rails under operation of the horizontal air cylinder 24.
[20] On the other hand, the LM guides 18, which are adapted to be moved forward and rearward, are mounted, respectively, on the blocks of the leftward and rightward movement LM guides 20 that are installed to be moved leftward and rightward via the rails. Specifically, two pairs of the forward and rearward movement LM guides 18 are arranged parallel to each other at front and rear locations of the left and right nipper units 26, and a connecting bar 38 is connected between both facing blocks of the left and right forward and rearward movement LM guides 18 located at the front locations of the left and right nipper units 26. To the connecting bar 38 are connected the horizontal air cylinder 22 and guide rods 40 provided in front of or behind thee connecting bar 38, to achieve efficient forward and rearward movements of the nipper units 26. The nipper units 26 are able to be returned to their returned positions upon operation of the horizontal air cylinder 22.
[21] The left and right nipper units 26 are configured to have a relatively long longitudinal length and each nipper unit 26 is installed to the blocks of the front and rear LM guides 18 by means of connectors. Each of the nipper units 26 includes a lower nipper fixedly connected to the connectors, and an upper nipper connected to a pair of vertical air cylinders 42 that are installed on a bottom surface of the lower nipper and adapted to seize the cloth under operation of the vertical air cylinders 42.
[22] Preferably, each of the lower and upper nippers of the nipper unit 26 has a nipper portion formed with a toothed surface and a body portion formed with guiding protrusions and guiding grooves engaged with each other, so as to allow an even force to be applied to the overall lower and upper nippers each having a long longitudinal length. This has the effect of ensuring the nipper units 26 to seize the cloth with a high stability.
[23] Meanwhile, each of the left and right pressure members 32 includes the pressure portion 32a extending lengthwise in a longitudinal direction of the pressure member 32, which is connected to vertical air cylinders 44 by use of connectors. The vertical air cylinders 44 are fixedly erected on the upper surface of the frame. The pressure portion 32a is located inside the associated nipper unit 26 to avoid an operating space of the nipper unit 26.
[24] The sensors 28 and 30 of each of the nipper units 26 are arranged at front and rear locations of the nipper unit 26 to have an appropriate distance from front and rear ends of the nipper unit 26. The sensors 28 and 30 are connected, along with the air cylinders
22, 24, 42, and 44 provided at the nipper units 26 and the pressure members 32, to a controller, which is provided to control the overall operation of the embroidering machine A. In this case, the embroidering machine A of the present invention can be used to perform a quilting operation as well as an embroidering operation, on the basis of programs inputted in the controller. The controller and the input programs are commercialized known technologies and thus, the detailed description thereof is omitted herein.
[25] Referring to FIG. 6 illustrating another embodiment of the present invention, it can be seen that the LM guides 18 and 20 for moving the nipper units 26 leftward and rightward and forward and rearward may be operated by the horizontal air cylinders 22 and 24, which are independent of each other.
[26] In the present embodiment in which the LM guides 18 and 20 are operated by the independent horizontal air cylinders 22 and 24, the left and right blocks of the forward and rearward movement LM guides 18 are connected to each other by use of a connecting bar 38 penetrating through guide pieces of the blocks and adapted to be moved simultaneously forward and rearward. Preferably, at opposite ends of the connecting bar 38 penetrated through the guide pieces are provided a pair of stop rings 38a so that an outward movement width between the left and right nipper units 26 can be controlled by the stop rings 38a. Similar to the above described embodiment, the air cylinders 22, 24, 40, and 42 provided at the left and right nippers 26 and the pressure members 32 are operated by the programs inputted in the controller, so as to achieve desired forward and rearward movements as well as leftward and rightward movements of the nipper units 26.
[27] In the operation of the embroidering machine A having the above described configuration according to the present invention, if a cloth B is fed, the cloth B is able to be moved while being tensioned in a Y-axis direction thereof by the torque motors 6 and 8 provided at the cloth feeding roller 2 and cloth winding roller 4.
[28] Simultaneously, the cloth B is tensioned in an X-axis direction thereof by the left and right nipper units 26 according to the present invention. Specifically, as the blocks of the leftward and rightward movement LM guides 20 are moved inward along the rails by the horizontal air cylinders 22 in a state wherein the upper nippers of both the nipper units 26 are raised from the fixed lower nippers by the vertical air cylinders 42, opposite edges of the cloth B are introduced into gaps between the upper nipper and the lower nipper of each of the open nipper units 26. If the edges of the cloth B are introduced into the gaps, the upper nippers are lowered by the vertical air cylinders 42 such that the edges of the cloth B are seized by the left and right nipper units 26. Subsequently, as the left and right nipper units 26 are moved outward by the leftward and rightward movement LM guides 20 under operation of the horizontal air cylinders 24,
an appropriate tension can be applied to the cloth B in an X-axis direction of the cloth B.
[29] In this case, the horizontal air cylinders 24 for operating the LM guides 20 are installed between both the blocks of the left and right LM guides 20. Accordingly, the outward movement distances of the left nipper unit 26 and the right nipper unit 26 may be not equal to each other and be determined on the basis of the position of the cloth B seized by the left and right nipper units 26. As a result, the cloth B can be subjected to an appropriate tension in an X-axis direction thereof while maintaining a movement position thereof in a Y-axis direction thereof.
[30] The left and right nipper units 26 according to the present invention are designed so that they can seize opposite edges of the cloth B without interference of the needles of the head 14. Furthermore, by virtue of the long longitudinal length thereof, the nipper units 26 can apply a constant tension to the cloth B while seizing the overall cloth B located in the embroidering section.
[31] Once the cloth B is tensioned in an X-axis direction thereof by the left and right nipper units 26, an embroidering operation is performed as the cloth B is moved in a Y-axis direction thereof by the cloth feeding roller 2 and the cloth winding roller 4 and the head 14 having the needles is moved in an X-axis direction of the cloth B. Specifically, when the cloth B is moved in a Y-axis direction thereof, the left and right nipper units 26, which seize and pull opposite edges of the cloth B to thereby apply an appropriate tension to the cloth B in an X-axis direction of the cloth B, can be efficiently moved along the cloth B in a Y-axis direction of the cloth B as air valves of the horizontal air cylinders 22 provided at the forward and rearward movement LM guides 18 are opened.
[32] Subsequently, if the nipper units 26 are gradually moved forward via a continuous embroidering operation and thus, the front sensors 30 detect the nipper units 26, the controller stops the embroidering operation and simultaneously, lowers the vertical air cylinders 44. With the lowering of the vertical air cylinders 44, the pressure portions 32a of the left and right pressure members 32 act to press and keep opposite edges of the cloth B at fixed positions inside the left and right nipper units 26, so as to maintain the tension of the cloth B. Thereafter, the left and right nipper units 26 are moved rearward and returned to their returned positions as the LM guides 18 are operated by the horizontal air cylinders 22 in a state wherein the upper and lower nippers of the left and right nipper units 26 are disengaged from each other. Thereby, the nipper units 26 are again moved inward by the LM guides 20 and seize opposite edges of the cloth B at their returned positions. Then, as the pressure portions 32a of the pressure members 32 are raised and simultaneously, the left and right nipper units 26 are moved outward, the cloth B can be repeatedly subjected to an appropriate tension in an X-axis direction
thereof, and an embroidering operation can be again performed.
[33] It will be appreciated by those skilled in the art that the present invention may be applied to a quilting machine having a plurality of cloth feeding rollers as well as the above described embroidering machine, and the needles of the head may be arranged in a single row, or in two or more rows. In particular, under the assumption that the left and right nipper units 26 are connected to each other by means of the leftward and rightward movement LM guides 20 and the forward and rearward movement LM guides 18 and are movable along a cloth in a Y-axis direction of the cloth in a state wherein the cloth is tensioned in an X-axis direction thereof as they seize opposite edges of the cloth, various modifications, additions and substitutions of the present invention are possible without departing from the scope and spirit of the invention so long as the various modifications, additions and substitutions can be easily embodied by those skilled in the art. Industrial Applicability
[34] As apparent from the above description, according to the present invention, an embroidering machine is provided with left and right nipper units, each having a long longitudinal length, such that the nipper units can apply an appropriate tension to a cloth in an X-axis direction of the cloth as they are moved outward while seizing opposite edges of the cloth. Using the nipper units as tensioning means has the following several effects. Firstly, the present invention can completely eliminate the risk of damage to the cloth when applying a tension to the cloth in an X-axis direction of the cloth. Secondly, the present invention can continuously impart a constant tension to the overall cloth located in an embroidering section regardless of a complexity of embroidery patterns, thereby preventing deformation of the embroidery patterns due to a difference in tension at different portions of the cloth and consequently, achieving a high quality embroidered cloth.