Method and apparatus for automatic matching and sewing of pockets

Abstract: This invention consists of a method and assembly able to handle, recognize, match and sew automatically two parts of a garment, like a pocket and a shirt front part. The assembly includes basically a pick up and separation apparatus for big parts (8), another one for small parts (3), a vision processor system (5), a handling and positioning apparatus (6), a sewing device (7) and the adequate software and electronic computer and processor hardware to perform the control of the different components of the assembly and their integration. The method includes the data process required to attain the recognition and matching of a small part to a big part of a garment having a striped or checkered pattern using a videocamera and an image processor.

Description: The present invention relates to a method and assembly for automatic matching and sewing of different parts of a garment having or not a pattern. BACKGROUND OF THE INVENTION The main object of this invention is a method and assembly to match and sew automatically two different parts of a garment having a pattern, like a front part and a pocket of a shirt. This method incorporates the solution of a set of problems, solutions for some of them which are already known, and to find solutions for some other problems, are further objects of the present invention. For performing such a method first of all it is necessary to pick up a big or small piece of fabric from a pile of similar pieces and place it in an area, without wrinkles, where said piece can be recognized. This problem may be solved in several ways, but the one used must be compatible with the present invention. Further it is necessary to sew automatically the two parts which have been previously positioned in a determined way keeping their relative position while the sewing process. There are several systems in the market which solve this problem, but all of them require an operator for positioning each of the pieces one to one taking into account the respective patterns in order to match them. The recognition of a piece and its pattern having a plane shape, as a fabric pice of a garment and the matching with an other piece is also known at present time. Such systems are described par example in US-PS 4,853,866. In the DE 39 21 020 A1 a work piece setting apparatus is disclosed for stepwise matching and sewing together of at least two patterned garment pieces of different size with the aid of a preprogrammed host computer under the control of an operator whereby the apparatus comprising a sewing machine and a plane surface having a recognition area being observed by a video camera. The operator has to start the host computer and to actuate switches to initiate the different working steps and has to spread manually the shirt- and pocket-parts on the recognition area before a mismatch routine can be actuated in order to mismatch between the shirt part's pattern image and the pocket part's pattern image and the matching can take place by a correlation funktion having a iterativly looped algorithm. The operator has to supervise the matching result visually has to interrupt the procedure to reorientate the pocket's alignment again and to start matching again in order to get a aceptable matching. If the result is acceptable the operator has to set the start switch in on-condition. Thus the handling of the pieces to and from the machine has to be done by hand as well as the orientation of the first and second work piece. The operator has further to manipulate the two parts before they are fixed in order to favour accurate results. The operator has to supervise the matching procedure all the time and has to supervise the results and to marshal the method's progress by stepwise activating the steprelated switches. As the appartus, clamps, gauges and folders have to fit different pocket sizes a change in pocket size needs a change of these elements and of the base plate because a pocket size adapted needle grove is needed in order to guide sewing machine's needle during the stitching operation. Such adustments are time consuming and reducing the efficency of the apparatus. Therefore there is a need for attaining an automatic matching and sewing process for at least two pieces, especially for an apparatus able to place these pieces on the automatic sewing machine, substituing the operator function, that is, on the required position with the required precision according to the data previously stored in a computer which processes and compares these data with the data obtained by a recognition system. Therefore, this application contemplates the use of existing technologies in combination with a new manipulator of pieces of fabric in order to attain their automatic matching and sewing. SUMMARY OF THE INVENTION The present invention is directed to a method and apparatus to perform automatically the operation of matching and sewing of two different parts of a garment having a pattern which has to be matched once they have been sewn, like a pocket and a front part of a shirt. The apparatus works in combination with an automatic sewing machine, able to sew both parts if they have been well positioned in the assembly, and two manipulators, one of them able to receive pieces like shirt pockets one by one, and deposit them without wrinkles on a plane surface when required, and the other manipulator able to pick up a piece, like a shirt front part, from a pile of them and place it without wrinkles on said plane surface when required. The apparatus includes further a videocamera which takes a snapshot of the shirt pocket on the plane surface and then the image is processed by an image processor and a computer to look for the actual shape of the pocket, its location with respect to the videocamera axis, whose position with respect to the automatic sewing machine is previously known, the type of pattern if any, and the pattern location on the piece. In the meantime, the pocket is being moved automatically by the apparatus and positioned in the starting position of the sewing machine when the related data process is finished. Once the pocket leaves the plane surface of the recognition area the front part is placed on it and its image taken and processed in a similar way to that of the pocket, then allowing a positioner to move the front part through the automatic sewing machine in such a position that the pocket will be sewn to the front part on the required location, where the pocket pattern will match the front part pattern. The positioner that takes both the front part and the pocket from the plane surface and positions them on the automatic sewing machine, is also a part of this invention. The sequence of movements can be different according to the automatic sewing machine requirements. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of an apparatus according to the invention, integrated with an automatic sewing machine, an image processor incorporating a videocamera and pick up and separation systems for garment pieces. Fig. 2 is a side view of the positioner carriage of the apparatus according to Fig. 1. Fig. 3 is a plan view of the positioner carriage according to Fig. 2. Fig. 4 is a plan view of the clamping device of the positioner carriage according to Fig. 2. Fig. 5 is a front view of the clamping device according to Fig. 4 for fastening a pocket piece in the open position. Fig. 6 is a front view of the clamping device according to Fig. 5 in the closed position and Fig. 7 is a flow chart diagramm showing the operational steps of the inventive apparatus. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT It can be seen schematically in Fig. 1 the main parts of an apparatus able for matching and sewing automatically a pocket and a front part of a shirt. Usually, the pocket 1 will come from a previous operation, where its upper edge has been sewn, and therefore it will come one by one, for instance on a a conveyor belt 2. A pocket handling device 3 takes the pocket from the conveyor belt and places it in a recognition area 4, where the X-,Y-axis have been defined on a position similar to that of Fig. 1 that is with the most of the pocket in the quadrant by -X, -Y axis. This position has really a big tolerance and can only affect slightly the data process time. Once the pocket is in such a position, a videocamera 5 of the apparatus takes a snapshot of the pocket and the means - not shown - for image processing starts while the positioner 6 approaches the pocket and takes it, once it is located and the adequated orders - generated by a processor not shown - given to the positioner, to release the recognition area and place it in position on a folder 13 of a sewing machine 7. As soon as the pocket is removed from the recognition area, a handling device 8 incorporated with the apparatus takes a front part 9 from a pile of them and places it on the recognition area in such a way that the corner 10 of the front part lies in the quadrants formed by -X, -Y - -axis; and near the -Y-axis of the plan surface, and the edge 11 can be seen in the recognition area 4 approximately parallel to the X-axis. The tolerance position could be quantified with respect to a nominal position in about ± 25 mm, and can be easily performed by some handling devices - not shown - in combination with a position tolerance of the front part pile. A special requirement for the handling device is to separate one piece from the pile, and only one, and place it without wrinkles on the plan surface of the recognition area 4. The pile may come straight from a not shown cutting machine, as any intermediate operation is needed for the front part. Once the front part 9 is placed on the recognition area 4, the videocamera 5 takes a snapshot of it and the image processing starts to obtain the location of a matching point 12 which means a nominal point of the front part where a corresponding matching point of the pocket must coincide when both parts are sewn. The nominal position of these matching points is previously given to a computer - not shown - that controls the apparatus for each type of pocket and front part. Then, the first action of every image processing procedure is to determine the geometry of the piece in order to relate it to some of the models and sizes stored in the computer. The geometry is determined by referring it to an axis system related to each piece, which is defined for the pocket 1 by the upper bent edge and its mediatrice, and for the front part 9 by the edge 11 (see Fig. 1) and the perpendicular line to the edge 11 that contains the corner 10. Then once the axis and the matching point of the front part 9 are defined, the following step is to match in the computer memory the pocket and the front part in such a way that the pattern of both coincides, that means that both matching points being as near as possible. Predetermined criteria can be applied here in order to accept or not the pieces according to the correspondence between patterns (size, color) or the position tolerance between the mentioned matching points. After the matching data are generated and transferred into the computer memory, the following parameters are known by the computer: the initial pocket position, the final pocket position - centered on the folder 13 -, the actual front part position, and the final related position between pocket and front part. Then, the necessary movements for the front part are easily deduced by the computer according to a predetermined program and performed by the positioner 6 that moves the front part under the folder 13 to its final position. In that way, both parts are in the start position of the automatic sewing machine that can start to operate under computer control. Obviously, this series of sequenced operations - see Fig. 7 - can be overlapped to optimize the cycle time, or changed according to the automatic sewing machine requirements. The positioner 6 has two main functions as it has been mentioned above: the final positioning of the pocket 1 and the final positioning of the front part 9 after both pieces have been recognized by the videocamera and the sensed positions were transferred into corresponding data. The preferred embodiment uses only one recognition area 4. The pocket must be taken and lifted to be placed on the folder 13. The front part is preferably moved by sliding it along the surface between the recognition area and the area under the folder 13 where said front part must be positioned. Both movements imply a precision requirement of the order of ± 0,5 mm or less for the final position. A preferred configuration of the positioner 6 for performing the functions mentioned above includes a carriage 20 which can move along lineal guides 14 and 15, parallel to X- and Y-axis respectively, being the movements performed by adequate movement transmission means, including motor controlled position and the required electronic - all not shown -. Several different means well known can be applied to perform both movements with required precision and speed. The carriage 20 includes a stiff frame 19 which supports a position controlled motor 16 and an endless screw 17 (Fig. 3) connected to the motor 16. A threaded piece 18 is connected to the endless screw and guided by a guide bar 40 of the frame 19 so that said piece 18 is lineally moved along the endless screw, without rotation, when the motor 16 acts the endless screw. A lever 21 is connected to the piece 18 and joined to a pivot 41 mounted on the frame 19. The lever 21 rotates around Z axis, relative to the carriage 20, when the piece 18 moves along the endless screw. A clamping device 22 is connected to the pivot 41 so that said clamping device can move up and down, along Z axis, with respect to said carriage 20. Several other means can be applied to perform this movement along Z axis. The lower position is defined by contact between the bottom surface of the clamping device and the external surface 23 (Figs. 5/6) which can be either the recognition area 4, the folder 13 or the sewing machine surface under the folder 13. The upper position is limited by an end stop fixed to the frame 19. From the foregoing describtion it is clear, that the positioner 6 includes a clamping device 22 and adequate technical means to move it along X-, Y- and Z-axis and rotate it around Z-axis. The carriage 20 with the clamping device 22 performs different operations when the pocket or the front part has to be moved. When the pocket is to be moved, once its image is taken on the recognition area 4, the clamping device is placed above the pocket whereby the clamping device is in its upper position, then it is moved along Z axis to its lower position pressing the pocket and closing two blades 24 (see Figures 5 and 6) to fasten the pocket by both sides against edges 30 mounted on the clamping device (see Fig. 3) in such a way that possible movements between clamping device and a pocket piece are avoided, then the clamping device returns to its upper position and is moved to the required position above the machine folder 13, where it is moved again to its lower position and releases the pocket by opening the blades and returning to its upper position after the pocket is fastened by the folder. Dimensions A and B (Fig. 4) are respectively the distances between the blades 24 when in closed and open position, then allowing the fastening of any pocket whose width is intermediate between those dimensions. The lower surface of the clamping device which contacts with the pocket surface is provided with deformable or compression material 25 like foam, to guarantee a minimum pressure on a determined pocket surface which avoids the possibility of local displacements or deformations while the blades 24 are closing or opening. The blades 24 are moved simultaneously by the action of the endless screw 26 (Fig. 4) which is moved by a motor 27 and adequate movement transmission means 43, 44 controlled by the computer. The movement of the blades is guided by a part of lineal guides 28. The blades 24 can have small vertical movements with respect to their guides in order to contact better with the surface where the pocket is to be taken. When the front part 9 is to be taken, once the pocket 1 has been released on the folder 13, the clamping device in its upper position is placed above the front part on a determined relative position, then it is moved down to its lower position and press the front part mainly by four grip heads (points) 29 more distant from the rotation axis Z, being these main contact points provided with deformable or compression material 43 (Fig. 2), like foam. Then, the front part is moved by the clamping device to its final position, previously calculated by the computer, by sliding it along the intermediate surface between the recognition area and the start position of the sewing machine, maintaining approximately constant the contact pressure. In addition to contact points 29, other points near the rotation axis contact the front part with less pressure to avoid possibility of local deformation during the movement. The contact surface on the front part is determined by the area where the pocket is to be sewn in such a way that the clamp apparatus is approximately centered on that area. The larger area of the clamping device guarantees that when the front part is released, no wrinkles are transmitted to the pocket area. In this way it is not necessary to fasten the whole surface of the front part. From the foregoing it is clear that the positioner for handling the mentioned garment pieces includes a carriage with clamp means or apparatus comprising a set of pressing points to press the larger fabric piece on the surface of an area corresponding to said larger piece that includes the area (folder) in which the pocket piece is to be sewn, and means to keep a minimum pressure load on every pressing points when pressing on the larger piece while said piece slides along a horizontal surface of the apparatus, said clamp means further comprising a pressing piece having two edges to press the pocket near the two symmetrical edges of the pocket, two blades whose sharp edges are parallel to said pressing piece edges in the same horizontal plane, and means to move the blades from an open position in which the distance between the edges of the blades is larger than the distance between the edges of the pocket to a closed position in which the blades contact along the edges of the pressing piece, allowing to fasten a pocket piece by their symmetrical edges, said clamp means further comprising spring means to guarantee a minimum pressure of the blade edges against the surface where the pocket piece is to be taken while the blades are closing and against the pressing piece edges once the blades are closed both spring means associated with a limited capacity of rotation of the blades to guarantee optimum contact of the blade edges over the sliding surface and the pressing piece edges. Similar configurations can be applied to any operation where a plane piece must be matched to another plane piece in such a way that each piece pattern reach a predetermined relative position after the pieces have been joined.

Claims: Method for automatically handling, matching and sewing of at least two patterned garment pieces (1, 9) like a pocket (1) and a front part of a shirt under control of a host computer, whereby a video camera (5) and image processing means are used for generating reference data as the locations of a matching point of said garment pieces when placed on a recognition area (4) and means for positioning said garment pieces relative to each other according to the generated matching signals with reference to the matching points and the X- Y- and Z-axis of a predetermined starting position for sewing, characterized by the following steps: transporting the first garment piece (1) under control of said host computer into the recognition area (4), detecting position, shape and pattern and storing the derived data in said host computer, taking said first garment piece (1) from said recognition area (4) without wrinkles and moving said first garment piece into said starting position, transporting the second garment piece (9) under control of said host computer into the recognition area (4), detecting position, shape and pattern and storing the derived data in said host computer, moving said second garment piece (9) without wrinkles into that starting position underneath of said first garment piece (1), positioning the garment pieces (1, 9) relative to each other according to the generated matching signals with reference to the X- Y- and Z-axis in said predetermined starting position, and pressing both garment pieces (1, 9) together for maintaining said relative position which are defined by said derived matching data automatically sewing both garment pieces together under control of said host computer. Assembly for automatically handling, matching and sewing of at least two patterned garment pieces like a pocket (1) and a front of a shirt (9) according to the method of claim 1, comprising a host computer, a sewing machine (7), a video camera (5) with means for image processing, and a surface (23) with a recognition area (4), characterized by a pocket handling device (3) for taking pockets from a conveyor belt and placing in a recognition area (4) with defined x - y - axis, a handling device (8) for taking a front part of a shirt (9) from a pile and placing it in said recognition area, both devices (3, 8) being associated to said surface (23), a positioner (6) for taking the pocket (1) after image processing in position on a folder (13) in a predetermined starting position for sewing, whereby the positioner (6) is movable along the x-axis between the recognition area (4) and said predetermined starting position, said positioner (6) bearing a carriage (20) movable along the y-axis, comprising a clamping apparatus (22) movable along the x-axis and rotatable around z-axis, having clamp means (blades 24, edges 30) being movable from a upper fixed position to a variable lower position determined by contact between said clamp means (blades 24, edges 30) and the external surface (23) and being liftable to said upper position for transporting the clamped pocket (1) in said predetermined starting position, said clamping apparatus (22) further having grip heads (29) for taking the front part of the shirt after unloading of said pocket (1) from said clamp means (24, 30) at said predetermined starting position, after image processing and positioning in said predetermined starting position under control of said host computer. Assembly according to claim 2, characterized in that the clamping apparatus (22) having blades (24), to fasten the pocket (1) by both sides against edges (30) mounted on said clamping apparatus (22) , the blades (24) are parallel to said edges (30) and means (26, 28, 27, 43, 44) to move the blades (24) from an open position in which the distance (B) between the edges of the blades (24) is larger than the distance (A) between the edges of the pocket (1) to a closed position in which the blades (24) are in contact with the edges (30), said clamping apparatus (22) further comprising a set of four grip heads (29) for clamping the front part of the shirt (9) for transporting into the predetermined position underneath the pocket (1) for sewing. Assembly according to claim 2, characterized by further pressure means for keeping a minimum pressure load on every pressing point (29) when pressing the second garment piece (9) while said garment piece being slid over said horizontal surface (23) of the apparatus into said predetermined position.

Inventors: CRISTOS JUAN CARLOS, GALAN MARIO ANDRADA, JUAREZ JAVIER FERNANDEZ, CRISTOS, JUAN CARLOS, GALAN, MARIO ANDRADA, JUAREZ, JAVIER FERNANDEZ
Applicants: INVESTRONICA SA, INVESTRONICA S.A.
Application year: 1992
Main classification: D05B33
IPC codes: D05B33