Automatic edge positioning and fabric guiding for sewing machines

Abstract

Apparatus and methods are provided for automatic edge positioning and guiding of a moving web, such as a textile fabric or carpet, onto a conveyor system comprising manufacturing operations such as sewing, for example. More in particular an apparatus is provided including mechanics, optics and control for steering and positioning the side edges of the moving web in order to correct for misalignment, and hence sewing can occur appropriately.

Claims

1. An apparatus for steering an edge of a moving web, the apparatus comprising: a moving conveyor; and two pairs of rolls adjacent to at least one edge side of said moving conveyor, the two pairs of rolls comprising per pair of rolls a first roll above and a second roll below said moving conveyor, wherein: for each pair of rolls said first roll above and/or said second roll below can be moved along a vertical axis in relation to one another; said two pairs of rolls are mounted with their central axes perpendicular to the travel direction of said moving conveyor; and said two pairs of rolls comprise a first pair of rolls mounted in a fixed position along a transversal direction of said moving conveyor and a second pair of rolls movably mounted along said transversal direction of said moving conveyor, such that the distance between adjacent rolls of said first and second pair respectively above and below said moving conveyor is variable along said transversal direction.

2. The apparatus of claim 1, wherein said first roll and said second roll of said two pairs of rolls are configured to simultaneously move in opposite direction along said vertical axis, such that said first and second roll are at the same time, either moved closer, thereby closing a pair of rolls, or moved further away from one another, thereby opening said pair of rolls.

3. The apparatus of claim 2, wherein said two pairs of rolls are configured for simultaneously opening and closing in opposite directions.

4. The apparatus of claim 1, wherein only said first roll of said two pairs of rolls is configured to move along said vertical axis, such that said first roll is either moved closer, to said second roll, and thereby alternatively closing a pair of rolls, or moved further away from said second roll, and thereby alternatively opening said pair of rolls.

5. The apparatus of claim 4, wherein said second roll of said two pairs of rolls is fixedly mounted along said vertical axis, closely below said movable conveyor such that when said first roll above is moved closer, more in particular as close as possible, said first and second roll make contact with their outer surfaces.

6. The apparatus of claim 1, wherein said first pair of rolls is driven by a first motor for rotational movement of said first pair rolls, said second pair of rolls is driven by a second motor for rotational movement of said second pair rolls, and said second pair of rolls is further driven by a third motor for transversal movement of said second pair rolls.

7. The apparatus of claim 6, wherein said first and second motor further provide in translational movement of respectively said first and second pair of rolls along said vertical axis.

8. The apparatus of claim 1, comprising at least one photodiode along said edge side of said moving conveyor.

9. The apparatus of claim 8, wherein said at least one photodiode is located close to said first pair of rolls, more particularly just behind the contact surface of outer circle circumference surfaces of said first and second roll of said first pair.

10. The apparatus of claim 9, further comprising a further photodiode located in front of said two pairs of rolls.

11. A method for automatic alignment of an edge of a moving web, the method comprising: (a) guiding said moving web onto a moving conveyor, provided with two pairs of rolls adjacent to the same edge side of said moving conveyor, toward said two pairs of rolls; (b) holding said moving web at said edge by a first pair of rolls while at least one of the rolls of a second pair of rolls is lifted away from said moving web; and (c) holding and pulling said moving web toward said edge side of said moving conveyor by said second pair of rolls while at least one of the rolls of said first pair of rolls is lifted away from said edge of said moving web.

12. The method of claim 11, wherein (b) comprises moving said first and/or second roll of said first pair of rolls closer to said edge side of said moving conveyor, and when said first and/or second roll of said second pair of rolls are moved further away from said edge side of said moving conveyor, said first pair of rolls herewith holding said moving web against said edge side of said moving conveyor.

13. The method of claim 11, wherein (c) comprises moving said first and/or second roll of said first pair of rolls further away from said edge side of said moving conveyor, and when said first and/or second roll of said second pair of rolls are moved closer to said edge side of said moving conveyor, said second pair of rolls herewith holding said moving web against said moving conveyor and pulling said moving web toward or away from said edge side of said moving conveyor.

14. The method of claim 11, further comprising: (d) detecting and monitoring position of said edge of said moving web by means of at least one photodiode provided along said edge side of said moving conveyor; and (e) holding and pulling said moving web of (b) and (c) with said two pairs of rolls based on detected and monitored position of said edge in (d).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates schematically an embodiment of the apparatus for steering an edge of a moving web.

(2) FIG. 2 illustrates schematically an embodiment of part of the apparatus for steering an edge of a moving web, more in particular in the area of the sewing machine.

(3) FIG. 3 shows a picture view of an embodiment of the apparatus for steering an edge of a moving web.

(4) FIG. 4 shows another picture view of the embodiment of FIG. 3.

(5) FIG. 5 illustrates a flow chart of an embodiment of the edge alignment method.

(6) FIG. 6 shows a perspective view of an embodiment of the apparatus for steering an edge of a moving web.

(7) FIG. 7 shows another view of the embodiment of FIG. 6.

(8) FIG. 8 shows yet another view of the embodiment of FIG. 6.

DETAILED DESCRIPTION

(9) FIG. 1 shows an embodiment providing an apparatus 100 for steering the edges 201, 202 of a moving web 200, as for example a carpet. The apparatus 100 comprises a moving conveyor 101, such as for instance a conveyor table, driven by a motor 115 for moving forward the conveyor 101 in a travel direction t along the length L of the conveyor 101 and with a controllable speed. The carpet 200 is put onto the moving conveyor 101 for further processing, e.g. for broidery or sewing the carpet edges 201, 202. Therefore, the moving carpet 200 is to be aligned along its edges 201, 202 on the conveyor 101 such that further processing can be done appropriately and accurately. It is noted that the carpet 200 is folded away from its edges 201, 202 whereas it is too large to be entirely spread over the moving conveyor 101. As shown, the apparatus 100 further comprises two pairs 102, 103 of rolls adjacent to the edge side 104 of the moving conveyor 101.

(10) Although here in FIG. 1 two pairs 102, 103 of rolls are depicted at only one edge side 104, according to a further embodiment both edge sides 104, 114 have the pairs of rolls installed. The first pair 102 comprises the rolls 11, 12 whereas the second pair comprises the rolls 13, 14. All rolls are mounted such that the central axis 15, 16, 17, 18 of each of the rolls 11, 12, 13, 14 respectively is perpendicular to the travel direction t. In other words, the central axis 15, 16, 17, 18 of each of the rolls 11, 12, 13, 14 respectively is lying along (or parallel to) the transversal direction 1, being perpendicular to the travel direction t as indicated in FIG. 1 with the rectangle symbol.

(11) While referring now to FIG. 3, according to an embodiment each roll 11, 12, 13, 14 of both pairs 102, 103 comprises an outer circle circumference C and an outer edge surface E. Here, the outer circle circumference C is for all rolls the same, whereas the outer edge surface E can vary per pair since the edge thickness T of the rolls may vary.

(12) In an embodiment, as illustrated in FIG. 6, FIG. 7 and FIG. 8 the rolls of the first pair 102, i.e. the first pair rolls 11, 12 have a larger edge thickness T, and hence larger outer edge surface E than the rolls of the second pair 103, i.e. the second pair rolls 13, 14, whereas the first pair 102 is in essence related to holding and the second pair 103 is related to both holding and gripping functionality. Moreover each roll has a circle surface S1 and a parallel circle surface S2, whereas S1 being the surface closest to the edge side 104 of the moving conveyor 101.

(13) Returning back to FIG. 1, the first pair 102 of rolls is positioned at the outer edge side 104 of the conveyor 101, and comprises a first roll 11 above and a second roll 12 below the conveyor table 101. Next to the first pair 102, at a distance d, the second pair 103 of rolls is mounted, comprising also a first roll 13 above and a second roll below the conveyor table 101. The distance d is defined as the perpendicular circle surface-to-circle surface distance of the first rolls 11, 13, and or either of the second rolls 12, 14 respectively of the two pairs 102, 103. In other words, the distance d is the perpendicular distance between the circle surface S2 of the first pair first roll 11 and the circle surface S1 of the second pair first roll 13, and or either between the circle surface S2 of the first pair second roll 12 and the circle surface S1 of the second pair second roll 14. Or else, the distance d is the distance between first pair 102 and second pair 103 of rolls along the transversal direction 1. This distance d is moreover variable, which means that the second pair 103 of rolls can be moved closer to or further away from the first pair 102 of rolls along the transversal direction 1, whereas the first pair 102 of rolls is in fixed transversal position, as indicated in FIG. 1. The larger the distance d, the more the second pair 103 of rolls is moved toward the center of the conveyor 101. On the other hand, both first pair 102 and second pair 103 of rolls are movable along a vertical direction v, meaning that first roll 11, 13 of the two pairs is movable along this vertical direction v.

(14) The first roll 11, 13 of first 102 and second 103 pair respectively can be moved closer to or further away from the movable conveyor 101. Bringing the first roll 11, 13 closer to the movable conveyor 101, and hence bringing the first roll 11, 13 closer to the corresponding pair second roll 12, 14 is also referred to as closing the pair 102, 103 of rolls. Whenever both pairs 102, 103 are closed, the central axes 15, 17 of the first rolls 11, 13 are lying in line or coincide. Similarly, at the same time, the central axes 16, 18 of the second rolls 12, 14 are then also lying in line, or are coinciding. Moving the first roll 11, 13 further away from the movable conveyor 101, and hence moving in the first roll 11, 13 further away from the corresponding pair second roll 12, 14 is also referred to as opening the pair 102, 103 of rolls.

(15) According to an embodiment, the two pairs 102, 103 of rolls will never simultaneously open or close. On the contrary, the two pairs 102, 103 of rolls will always open and close in an alternating way, meaning that whenever the first pair 102 of rolls is closing, the second pair 103 of rolls will open and vice versa.

(16) According to a particular embodiment, the second roll 12, 14 of the two pairs is also movable along the vertical direction v. In combination with the vertical movement (along the vertical direction v) of the first roll 11, 13, the second roll 12, 14 of first 102 and second 103 pair respectively is moved closer to or further away from the movable conveyor 101. Bringing the first roll 11, 13 and the second roll 12, 14 closer to the movable conveyor 101, and hence bringing the first roll 11, 13 and the second roll 12, 14 closer to each other is now referred to as closing the pair 102, 103 of rolls. Whenever both pairs 102, 103 are closed, the central axes 15, 17 of the first rolls 11, 13 are lying in line or coincide. Similarly, at the same time, the central axes 16, 18 of the second rolls 12, 14 are then also lying in line, or are coinciding. Moving the first roll 11, 13 and the second roll 12, 14 further away from the movable conveyor 101, and hence moving the first roll 11, 13 further away from the second roll 12, 14 is now referred to as opening the pair 102, 103 of rolls.

(17) According to a more particular embodiment, the two pairs 102, 103 of rolls will never simultaneously open or close during edge alignment operation of the apparatus 100, but will always open and close in an alternating way, meaning that whenever the first pair 102 of rolls is closing, the second pair 103 of rolls will open and vice versa. During edge alignment, opening and closing of the two pairs 102, 103 of rolls is further accompanied by transversal displacement (direction 1) of the second pair 103 of rolls as further detailed below.

(18) In an embodiment, and as illustrated in FIG. 1, the first pair 102 of rolls is driven by a motor 105 for rotational movement of these first pair rolls 11, 12 whereas the second pair 103 of rolls is driven by another motor 106 for rotational movement of the second pair rolls 13, 14. Furthermore, the second pair 103 of rolls is driven by a motor 107 for transversal movement, i.e. movement along the transversal direction 1, of the second pair rolls 13, 14. All three motors 105, 106, 107, together also depicted in FIG. 7, can be connected or disabled separately. By means of the motors 105, 106 all rolls i.e. above and below the moving conveyor 101, of first and second pair 102, 103 are continuously driven for rotational movement.

(19) The rotational movement of the rolls 11, 12, 13, 14 is defined around their central axis 15, 16, 17, 18 respectively. The rolls 11, 12, 13, 14 rotate at a certain rotational speed being directly related or even synchronized with the travelling speed or velocity of the moving conveyor 101. The rotational speed of the rolls 11, 12, 13, 14 is hence adaptable, whereas the travelling speed or velocity of the moving conveyor 101 can be changed over time, along need and/or application, and is thus configurable by means of the motor 115 located and installed at the intake of the moving conveyor 101, for driving the conveyor 101 at desired or requested speed. Moreover, per pair 102, 103 of rolls the rotational speed of the rolls can further be slightly increased or decreased such that the rotational speed of the first pair rolls 11, 12 is slightly higher or slower than the rotational speed of the second pair rolls 13, 14. With transversal movement is meant the movement along transversal direction 1 as mentioned above.

(20) The motors 105, 106 may further provide in translational movement of respectively the first 102 and second 103 pair of rolls along the vertical axis v. The translational movement of the rolls along vertical axis v as described means that the rolls are lifted up or down, and thus moved closer toward or further away from each other. Hence, this translational movement is related to the opening and closing of a pair 102, 103 of rolls as defined previously.

(21) As illustrated in the picture views of FIG. 3 and FIG. 4, and further depicted in FIG. 6, FIG. 7 and FIG. 8, pneumatic cylinders 112, 113 are also part of the set-up, and are connected with the driving system, i.e. more in particular with either one of the motors 105, 106 respectively, while supporting the vertical translational movement for lifting up or down the rolls 11, 13.

(22) Further schematically depicted in FIG. 1 and FIG. 2, and shown in the picture views of FIG. 3 and FIG. 4, and illustrated in FIG. 8, are the photodiodes 108, 109, 110 along the edge side 104 of the moving conveyor 101. The photodiode 108 is located close to the first pair 102 of rolls, more particularly just behind the contact surface 19 of outer circle circumference surfaces of the first and second roll 11, 12 of the first pair 102. This contact surface 19 of the first and second roll 11, 12 of the first pair 102 is the area where the first and second roll 11, 12 make contact whenever the first pair 102 of rolls is closed. By closing the first pair 102, the rolls 11, 12 are positioned for holding the folded carpet 200 against the edge side 104 of the moving conveyor 101. A further photodiode 109 is located just in front of the two pairs 102, 103 of rolls. According to an embodiment, the apparatus 10 further comprises a sewing machine 300 as illustrated FIG. 2 and partly in FIG. 3 while referring to guiding roll 301 of the sewing machine 300. Yet another photodiode 110 is herewith depicted, more specifically at the intake of the sewing machine 300. The sewing starts at a distance D from the first pair 102 rolls contact surface 19. In an embodiment, this distance D is between 20 mm and 100 mm, i.e. not too far away from the edge alignment mechanism with the two pairs 102, 103 of rolls, and hence for having the correct edge alignment close enough to the intake of sewing, herewith not leaving the carpet 200 the opportunity to have its edge misaligned again when the manufacturing operation of sewing needs to take off.

(23) While referring further to FIG. 1, and FIG. 5 in particular, an embodiment of the method for automatic alignment of the edges 201, 202 of the carpet 200 is now described into more detail.

(24) As indicated with step 501 in the edge alignment method flow chart 500, the large carpet 200 is folded in the middle such that it can be put on the conveying table 101, having its edges 201, 202 brought as close as possible to the conveying edge sides 104, 114. Conveying is enabled by means of the motor 115 in the travel direction t.

(25) With step 502, the carpet 200 is then guided toward the rolls 11, 12, 13, 14 for edge alignment, such that correct positioning is achieved before intake of the sewing machine 300. Only the rolls 11, 12, 13, 14 at one edge side 104 are considered in the description although edge alignment at both edge sides 104, 114, and hence another two pairs of rolls at the other edge side 114 is understood according to an embodiment. Moreover, only the edge alignment of one edge 201 of the moving carpet 200 is further described, whereas edge alignment for both edges 201, 202 is understood according to an embodiment.

(26) Step 503 refers to detection and monitoring of the carpet edge 201, more particularly the position and alignment of the carpet edge 201 at the intake of the rolls 11, 12, 13, 14, and for which a photodiode 109 can be used.

(27) Following step 504 deals with transferring this detection and monitoring information toward a control and steering system, in connection with the driving motors 105, 106, 107 for the rolls 11, 12, 13, 14. This way, the rolls are controlled for holding and/or pulling the moving carpet 200 and herewith adjusting position against edge misalignment.

(28) Next step 505 refers to holding the carpet 200 by means of the first pair 102 of rolls, while at the same time the second pair 103 of rolls is not in contact with the carpet 200 but lifted or opened. The first pair 102 of rolls is closed meaning that first roll 11 of first pair 102 is brought closer to second roll 12 of first pair 102, or both first pair rolls 11, 12 are brought closer to each other, in such a way that the rolls 11, 12 together clamp and hold the moving carpet 200, while continuously rotating around their central axes 15, 16 and herewith guiding or propagating further the moving carpet 200.

(29) Consecutively, in step 506 the first pair 102 of rolls is opened, meaning that first roll 11 of the first pair 102 is lifted away e.g. lifted upward with motor 105 and/or pneumatic cylinder 112 from second roll 12 of first pair 102. Simultaneously, the second pair 103 of rolls is being closed, meaning that first roll 13 of the second pair 103 is brought down e.g. lifted downward with motor 106 and/or pneumatic cylinder 113 toward second roll 14 of second pair 103. Hence the second pair rolls 13, 14 are now holding the moving carpet 200, while continuously rotating around their central axes 17, 18 for further guiding the carpet 200.

(30) In addition, while referring to step 507, the second pair 103 of rolls is not only holding the carpet 200, but also pulling the carpet 200 while also driven by motor 107 for generating transversal movement (along direction 1). In other words, guidance of the carpet 200 is not only in the travel direction t due to control and steering of motor 106, but including in the transversal direction 1 and herewith guiding the carpet edge 201 toward the edge side 104 of the moving conveyor 101. The principle of edge alignment and correcting or adjusting for edge misalignment is herewith accomplished.

(31) As indicated with step 508, the position of the carpet edge 201 is further detected and monitored with another photodiode 108 in the area of the first pair 102 of rolls, such that further feedback for control and steering can be transmitted toward the driving motors 105, 106, 107 of the rolls 11, 12, 13, 14.

(32) Additional steps 509, 510, 511 refer to guiding the carpet 200 toward the sewing machine 300, detecting and monitoring position of the carpet edge 201 at the intake of the sewing machine 300 using photodiode 110, and starting sewing respectively.