Method and apparatus for automated ornamental decorative stitching
12320050 ยท 2025-06-03
Assignee
Inventors
Cpc classification
D05B61/00
TEXTILES; PAPER
D05B57/02
TEXTILES; PAPER
International classification
D05B57/02
TEXTILES; PAPER
D05B61/00
TEXTILES; PAPER
Abstract
Disclosed is an ornamental chain stitching head, including: an upper head assembly, the upper head assembly controls movement of a needle bar and a walking foot mechanism; a walking foot eccentric configured to allow adjustment of a foot lift while a stitch length eccentric is configured to allow for adjustment of both a walking foot and a needle bar advancement via regulation of a rock frame the determines a length of a stitch created by the ornamental chain stitching head; a lower head assembly; and a needle bar cam assembly that drives rotation of the needle bar during each stitch cycle of the ornamental chain stitching head to achieve desired stitch patterns, the needle bar cam assembly is driven directly by an upper shaft through a pair of gears that reduce the needle bar cam assembly speed according to a size ratio of the pair of gears.
Claims
1. An ornamental chain stitching head, comprising: an upper head assembly, the upper head assembly controls movement of a needle bar and a walking foot mechanism; a walking foot eccentric configured to allow adjustment of a foot lift while a stitch length eccentric is configured to allow for adjustment of both a walking foot and a needle bar advancement via regulation of a rock frame the determines a length of a stitch created by the ornamental chain stitching head; a lower head assembly; and a needle bar cam assembly that drives rotation of the needle bar during each stitch cycle of the ornamental chain stitching head to achieve desired stitch patterns, the needle bar cam assembly is driven directly by an upper shaft through a pair of gears that reduce a speed of the needle bar cam assembly according to a size ratio of the pair of gears.
2. The ornamental chain stitching head as in claim 1, wherein two different cam profiles are machined into the needle bar cam assembly.
3. The ornamental chain stitching head as in claim 2, wherein a cam follower engages one of the two different cam profiles which in turn drive a linkage that connects to a drive gear.
4. The ornamental chain stitching head as in claim 3, wherein lateral movement of the linkage is managed by two bearing blocks that engage a guide rail.
5. An ornamental chain stitching head, comprising: an upper head assembly, the upper head assembly controls movement of a needle bar and a walking foot mechanism, the needle bar having a pair of needles; and a lower head assembly, the lower head assembly including: a pair of loopers each having a scarf facing each other; and a pair of spreaders, the lower head assembly configured to move pair of loopers towards the pair of spreaders and away from the pair of spreaders during a stitching sequence of the ornamental chain stitching head and the lower head assembly configured to move the pair of spreaders towards and away from each other during the stitching sequence of the ornamental chain stitching head.
6. The ornamental chain stitching head of claim 5, wherein the pair of needles are received within the pair of loopers during the stitching sequence of the ornamental chain stitching head.
7. The ornamental chain stitching head of claim 5, wherein the lower head assembly further comprises a pair of concentric shafts rotatably secured to each other such that one of the pair of concentric shafts rotates about the other one of the pair of concentric shafts rotates and the other one of the pair of concentric shafts rotates within the one of the pair of concentric shafts, one of the pair of concentric shafts being operably secured to the one of the pair of spreaders and the other one of the pair of concentric shafts is secured to the other one of the pair of spreaders such that rotation of the pair of concentric shafts with respect to each other causes the pair of spreaders to move towards and away from each other during the stitching sequence of the ornamental chain stitching head.
8. The ornamental chain stitching head of claim 7, wherein the pair of concentric shafts are rotated by a spreader cam that engages a spreader cam follower which is directly connected to a bearing block, wherein rotation of the spreader cam causes rotation of the pair of concentric shafts with respect to each other.
9. The ornamental chain stitching head of claim 8, wherein the bearing block rides on a guide rail.
10. The ornamental chain stitching head of claim 8, wherein the bearing block further comprises a pin that serves as a hub for rotatably receiving one end of each of a pair of connecting rods and an opposite end of each of the pair of connecting rods is rotatably secured to one of a pair of crank arms, one of the pair of crank arms is secured to one of the pair of concentric shafts and the other one of the pair of crank arms is secured to the other one of the pair of concentric shafts.
11. The ornamental chain stitching head of claim 10, wherein linear movement of the bearing block causes rotational movement of the pair of concentric shafts with respect to each other.
12. A method of providing a stitch to a part with an ornamental chain stitching head, comprising: moving a pair of needles up and down with an upper head assembly; and engaging an upper thread of each of the pair of needles with a pair of loopers of a lower head assembly during a stitching sequence of the ornamental chain stitching head, the pair of loopers each having a scarf facing each other; and engaging a lower thread of each of the pair of loopers with a pair of spreaders during the stitching sequence of the ornamental chain stitching head, the lower head assembly moving the pair of loopers towards the pair of spreaders and away from the pair of spreaders during the stitching sequence of the ornamental chain stitching head and the lower head assembly moving the pair of spreaders towards and away from each other during the stitching sequence of the ornamental chain stitching head.
13. The method of claim 12, wherein the pair of needles are received within the pair of loopers during the stitching sequence of the ornamental chain stitching head.
14. The method of claim 12, wherein the lower head assembly further comprises a pair of concentric shafts rotatably secured to each other such that one of the pair of concentric shafts rotates about the other one of the pair of concentric shafts rotates and the other one of the pair of concentric shafts rotates within the one of the pair of concentric shafts, one of the pair of concentric shafts being operably secured to the one of the pair of spreaders and the other one of the pair of concentric shafts is secured to the other one of the pair of spreaders such that rotation of the pair of concentric shafts with respect to each other causes the pair of spreaders to move towards and away from each other during the stitching sequence of the ornamental chain stitching head.
15. The method of claim 14, wherein the pair of concentric shafts are rotated by a spreader cam that engages a spreader cam follower which is directly connected to a bearing block, wherein rotation of the spreader cam causes rotation of the pair of concentric shafts with respect to each other.
16. The method of claim 15, wherein the bearing block rides on a guide rail.
17. The method of claim 15, wherein the bearing block further comprises a pin that serves as a hub for rotatably receiving one end of each of a pair of connecting rods and an opposite end of each of the pair of connecting rods is rotatably secured to one of a pair of crank arms, one of the pair of crank arms is secured to one of the pair of concentric shafts and the other one of the pair of crank arms is secured to the other one of the pair of concentric shafts.
18. The method of claim 17, wherein linear movement of the bearing block causes rotational movement of the pair of concentric shafts with respect to each other.
19. The method of claim 12, wherein movement of the pair of loopers and the pair of spreaders is limited to an area defined by a stitch plate having a width of 35 mm or less and a length of 56 mm or less during the stitching sequence of the ornamental chain stitching head.
20. The method of claim 12, wherein the pair of needles are received within the pair of loopers during the stitching sequence of the ornamental chain stitching head and the lower head assembly further comprises a pair of concentric shafts rotatably secured to each other such that one of the pair of concentric shafts rotates about the other one of the pair of concentric shafts rotates and the other one of the pair of concentric shafts rotates within the one of the pair of concentric shafts, one of the pair of concentric shafts being operably secured to the one of the pair of spreaders and the other one of the pair of concentric shafts is secured to the other one of the pair of spreaders such that rotation of the pair of concentric shafts with respect to each other causes the pair of spreaders to move towards and away from each other during the stitching sequence of the ornamental chain stitching head.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
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DETAILED DESCRIPTION
(11) A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
(12) As mentioned above and when a decorative ornamental stitch is desired on an automotive trim panel and as the part size and/or shape increases, manual sewing of such parts becomes more difficult. As such and as part size and shape complexity increase, particularly in the case of instrument panels, manual sewing of such parts becomes more difficult and at times impossible, driving the need for automation.
(13) Disclosed herein is a method and apparatus for robotically sewing a decorative ornamental stitch onto the surface of a 3D shaped part. Non-limiting examples of the three dimensional part include, vehicle interiors, vehicle instrument panels, any automotive interior surfaces or any other part that has limited access on an opposite side of the item to be sewn due to the configuration of the part or panel to be sewn. The part or panel to be sewn may comprise several layers or only a single layer, in one embodiment, the part or panel may have as an exterior show surface having a substantially smooth outer surface and an underside facing away from the outer surface. The exterior show surface may be formed of a plastic material, vinyl, thermoplastic olefin TPO, leather etc. of substantial flexibility and aesthetically pleasing character.
(14) In order to enhance the softness of part or panel, a layer of cushioning support material may be added to the part or panel before or after the part is sewn. The part or panel may also include a substrate panel of dimensionally stable plastic or other suitable material applied before or after the stitching process. Still further and in one embodiment, the part or panel may only comprise a single layer of the structural panel.
(15) The ornamental stitch sewing head utilizes chain stitch technology to eliminate the need for frequent lower thread bobbin changes.
(16) Lockstitch technology can also be utilized with consideration of the need for lower bobbin changes and a redesign of the post assembly to accommodate hooks in lieu of loopers.
(17) The sewing head is attached as an end effector to a 6-axis robot which serves to position the sewing head as required relative to the part to be sewn.
(18) Alternatively, the sewing head can be stationary while the robot positions the part relative to the sewing head to execute the stitching process.
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(29) Referring to
(30) As shown in
(31) A needle bar cam 7 assembly drives rotation of the needle bar 3 about an axis A during each stitch cycle to achieve desired stitch patterns 8 illustrated in
(32) A cam follower 12 engages one of the two cam profiles 11a, 11b which in turn drive a linkage 13 connected to the cam follower 12 at one end and the linkage 13 is connected to a drive gear 14 at another end via a pin 50 such that linear movement of the linkage in the direction of arrows 52 causes rotational movement of gear 50. Smooth lateral movement of the linkage 13 in the direction of arrows 52 is managed by two bearing blocks 15 that engage a guide rail 16 that slides between the two bearing blocks 15. A portion of the guide rail 16 is illustrated by the dashed lines in
(33) Alternatively, needle bar rotation can be controlled via pneumatic or electrical actuation in lieu of the aforementioned cams.
(34) The lower head assembly 2 is shown in
(35) In
(36) At the top of the bearing block 25 in
(37) A description of a stitch formation cycle using the ornamental chain stitch sewing head 100 of the present disclosure is shown in at least
(38) In
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(46) Also illustrated, is that the loopers 31 move between the rearward and forward positions in the directions of arrows 108.
(47) In one embodiment and in view of the configuration of the present disclosure, the stitch plate 36 width W by length L can be 35 mm56 mm or less to allow for passage of the stitch plate 36 through restricted or small areas of three-dimensional parts during sewing. This configuration also eliminates any tendency for the thread to untwist during sewing.
(48) While the aforementioned configurations of a width W of 35 mm by a length L of 56 mm has been shown to provide desired results the present disclosure is also contemplated for use dimensions smaller or greater than the aforementioned dimensions.
(49) Frequency of needle bar rotation and the use of one versus two needles dictates the type of stitch pattern produced.
(50) Referring now to
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(56) Through elimination of parts and simplification of the needle bar rotation and spreader drive system, this robot sewing head design will be compact enough to provide access to stitch all but the most remote areas of a preformed automotive trim component.
(57) The term about is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, about can include a range of 8% or 5%, or 2% of a given value.
(58) The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms a, an and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms comprises and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
(59) While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.