Adaptive control for transport and sewing of material

Abstract

Various examples are provided related to transporting and sewing material in, e.g., the automated production of sewn products. In one example, a system includes a sewing machine including a sewing needle; a material holding assembly; and a translation system. The material holding assembly can include mechanical fingers that can contact material adjacent to the sewing needle to secure a relative orientation and position of the material during sewing; and a structural grounding system supporting the mechanical fingers. The material holding assembly can include a cam profile positioning system that can adjust position of a cam profile with respect to the sewing needle. The translation system can be attached to the structural grounding system to transport the material on a sewing plane via the mechanical fingers.

Description

ADAPTIVE CONTROL FOR TRANSPORT AND SEWING OF MATERIALCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to, and the benefit of, U.S. provisional application entitled “Adaptive Control for Transport and Sewing of Material” having serial no. 63 / 664,993, filed June 27, 2024, which is hereby incorporated by reference in its entirety.BACKGROUND

[0002] Often in the production of sewn products, stitches must be sewn with a high degree of accuracy onto one or more flat pieces of material. These stitches may be decorative, structural, or both, and may not follow features of the materials themselves. Because of the above mentioned nature of these seams, human operators are not well suited to the task, and instead a pattern sewing machine is often used.

[0003] Pattern sewing machines utilize custom made templates to clamp onto layers of materials prior to initiating the sewing procedure. These templates are then loaded onto a pattern sewing machine. The pattern sewing machine will move these templates with clamped layers of materials to the sewing needle. The pattern sewing machine will then follow a predefined path and sew seam lines within the manufactured open shapes of the template (at high speeds). Often more complicated products will require several of these templates for each size, style, and manufacturing step, reducing manufacturing flexibility and increasing tooling cost.

[0004] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.SUMMARY

[0005] Aspects of the present disclosure are related to transporting and sewing material in, e.g., the automated production of sewn products. In one aspect, among others, a system for transporting and sewing material comprises a sewing machine including a sewing needle; a material holding assembly comprising: mechanical fingers configured to contact material on a sewing plane adjacent to the sewing needle, the mechanical fingersconfigured to secure a relative orientation and position of the material during sewing of the material; a cam profile positioned to engage with followers of the mechanical fingers; a cam profile positioning system supporting the cam profile, the cam profile positioning system configured to adjust position of the cam profile with respect to the sewing needle; and a structural grounding system supporting the mechanical fingers, where clearance around the sewing needle is provided by repositioning individual mechanical fingers around the sewing needle in response to the cam profile; and a translation system attached to the structural grounding system, the translation system configured to transport the material on the sewing plane via the mechanical fingers, where the mechanical fingers move in response to repositioning of the structural grounding system and interaction of a surface of the cam profile with the followers of the mechanical fingers. In one or more aspects, the surface of the cam profile can comprise a projecting portion, where the mechanical fingers linearly translate away from the sewing needle in response to engagement with the projection portion. The cam profile positioning system can be configured to linearly translate the cam profile horizontally, vertically or both. The cam profile positioning system can be configured to adjust position of the cam profile in three-dimensions.

[0006] In various aspects, each of the mechanical fingers can comprise a passive belt system that extends from a proximal end to a distal end that is positioned adjacent to the sewing needle, where the passive belt system contacts the material to secure the orientation and position. The passive belt system can comprise a belt extending between at least one pulley attached to the proximal end of the mechanical finger and a plurality of angled turns at the distal end of the mechanical finger, each of the plurality of angled turns defined by a corresponding pulley or low friction guide, wherein the belt passively rotates about the at least one pulley and rotates about the corresponding pulley or slides about the low friction guide of each of the plurality of angled turns during linear translation of the mechanical finger. The plurality of angled turns can comprise a first angled turn adjacent to the material and a second angled turned turn over the first angled turn opposite the material. A distance between the at least one pulley and the first angled turn can be greater than a distance between the at least one pulley and the second angled turn. The first and second angled turns can be defined by corresponding pulleys. The first and second angled turns can be defined by at least one low friction guide. The at least one low friction guide can comprise a low friction guide surface. The low friction guide surface can comprise an ultra high molecular weight polyethylene plastic or teflon coating. A lower section of the belt can be secured in a fixed position with respect to the structural grounding system by a belt grounding mechanism of the structural grounding system.

[0007] In another aspect, a material holding assembly comprises mechanical fingers configured to contact material on a sewing plane, the mechanical fingers configured tosecure a relative orientation and position of the material during sewing of the material, where each of the mechanical fingers comprises a passive belt system that extends from a proximal end to a distal end and contacts the material to secure the orientation and position, the passive belt system comprising a belt extending between at least one pulley or low friction guide attached to the proximal end of the mechanical finger and a plurality of angled turns at the distal end of the mechanical finger, each of the plurality of angled turns defined by a corresponding pulley or low friction guide, where the belt passively rotates about the pulley and rotates about the corresponding pulley or slides about the low friction guide of each of the plurality of angled turns during linear translation of the mechanical finger; and a structural grounding system supporting the mechanical fingers. In one or more aspects, the plurality of angled turns can comprise a first angled turn adjacent to the material and a second angled turned turn over the first angled turn opposite the material. A distance between the at least one pulley or low friction guide and the first angled turn can be greater than a distance between the at least one pulley or low friction guide and the second angled turn. The first and second angled turns can be defined by corresponding pulleys. The first angled turn can be defined by a pulley and the second angled turn can be defined by a low friction guide. The first and second angled turns can be defined by at least one low friction guide. The at least one low friction guide can comprise a low friction guide surface. The low friction guide surface can comprise an ultra high molecular weight polyethylene plastic or teflon coating. In various aspects, a lower section of the belt can be secured in a fixed position with respect to the structural grounding system by a belt grounding mechanism of the structural grounding system.

[0008] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings illustrate various examples of systems, methods, and embodiments of various other aspects of the disclosure. Any person with ordinary skills in the art will appreciate that the illustrated element boundaries (e.g., boxes,groups of boxes, or other shapes) in the figures represent one example of the boundaries. It may be that in some examples one element may be designed as multiple elements or that multiple elements may be designed as one element. In some examples, an element shown as an internal component of one element may be implemented as an external component in another, and vice versa. Furthermore, elements may not be drawn to scale. Non-limiting and non-exhaustive descriptions are described with reference to the following drawings. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating principles. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0010] FIG. 1 illustrates an example of a robotic system, according to various embodiments of the present disclosure.

[0011] FIGS. 2A-2G illustrate an example of the robotic system comprising a translation system and material holding apparatus, according to various embodiments of the present disclosure.

[0012] FIGS. 3A-3E illustrate examples of mechanical fingers, according to various embodiments of the present disclosure.

[0013] FIGS. 4A-4C illustrate another example of movement of mechanical fingers on a structural grounding system of the material holding apparatus, according to various embodiments of the present disclosure.

[0014] FIGS. 4D and 4E illustrate an example of the translation system and material holding apparatus utilizing multiple arrays of mechanical fingers, according to various embodiments of the present disclosure.

[0015] FIGS. 5A and 5B illustrate an example of a structural grounding system comprising air cylinders, according to various embodiments of the present disclosure.

[0016] FIGS. 6A-6D illustrate examples of cam profile positioning systems repositioning a cam profile, according to various embodiments of the present disclosure.DETAILED DESCRIPTION

[0017] Disclosed herein are various examples related to transporting and sewing material in, e.g., the automated production of sewn products. The present disclosure is generally related to an apparatus capable of securing the orientation and position of layered materials in order to be sewn with an automated sewing machine. For example, an adaptive apparatus can enable sewing multiple material layers of various designs and sizes since it can adapt to arbitrary seam shapes. The adaptive apparatus can clamp down on layered materials and prevent them from puckering, slipping or shifting their relative positions and orientations during a sewing operation. Reference will now be made in detail to thedescription of the embodiments as illustrated in the drawings, wherein like reference numbers indicate like parts throughout the several views.

[0018] The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.

[0019] It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the preferred systems and methods are now described.

[0020] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Embodiments of the claims may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.

[0021] Referring to FIG. 1 , shown is an example of a system that can be used for material manipulation and sewing. As illustrated in the example of FIG. 1 , the system can comprise a robotic system 102, which can include a processor 104, memory 106, an interface such as, e.g., a human machine interface (HMI) 108, I / O device(s) 110, networking device(s) 112, material mover(s) 114, secondary operation device(s) 116, a local interface 118, sensing device(s) 120, and an automated sewing machine 122. The sensing device(s) 120 can comprise one or more sensor and / or camera 124. The robotic system 102 can also include operational control(s) 126, which can be executed by the robotic system 102 to implement manipulation and / or processing of materials. The automated sewing machine 122 can comprise, e.g., a translation system 128, a cam profile 130, cam profile positioning system 131 , material holding apparatus 132, mechanical fingers 134 and a structural grounding system 136. The automated sewing machine 122 also includes a sewing machine with at least one sewing needle at the sewing head as will be discussed.

[0022] The processor 104 can be configured to decode and execute any instructions received from one or more other electronic devices or servers. The processor can include one or more general-purpose processors (e.g., INTEL® or Advanced Micro Devices® (AMD) microprocessors) and / or one or more special purpose processors (e.g., digital signal processors or Xilinx® System on Chip (SOC) field programmable gate array (FPGA) processor). The processor 104 may be configured to execute one or more computer-readable program instructions, such as program instructions to carry out any of the functions described in this description.

[0023] The Memory 106 can include, but is not limited to, fixed (hard) drives, magnetic tape, floppy diskettes, optical disks, Compact Disc Read-Only Memories (CD- ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, Random Access Memories (RAMs), Programmable Read-Only Memories (PROMs), Erasable PROMs (EPROMs), Electrically Erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media / machine-readable medium suitable for storing electronic instructions. The Memory 106 can comprise one or more modules (e.g., operational control(s) 126) that can be implemented as a program executable by processor(s) 104.

[0024] The interface(s) or HMI 108 can accept inputs from users, provide outputs to the users or may perform both the actions. In one case, a user can interact with the interface(s) using one or more user-interactive objects and devices. The user-interactive objects and devices may comprise user input buttons, switches, knobs, levers, keys, trackballs, touchpads, cameras, microphones, motion sensors, heat sensors, inertial sensors, touch sensors, visual indications (e.g., indicator lights or meters), audio indications (e.g., bells, buzzers, etc.) or a combination of the above. Further, the interface(s) can either be implemented as a command line interface (CLI), a graphical user interface (GUI), a voice interface, or a web-based user-interface, at element 108. The interface(s) can also include combinations of physical and / or electronic interfaces, which can be designed based upon the environmental setting or application.

[0025] The input / output devices or I / O devices 110 of the robotic system 102 can comprise components used to facilitate connections of the processor 104 to other devices such as, e.g., material mover(s) 114, secondary operation device(s) 116, sensing device(s) 120 and / or the automated sewing machine 122 and can comprise one or more serial, parallel, small system interface (SCSI), universal serial bus (USB), IEEE 1394 (i.e. Firewire™) connection elements or other appropriate connection elements.

[0026] The networking device(s) 112 of the robotic system 102 can comprise the various components used to transmit and / or receive data over a network. The networking device(s) 112 can include a device that can communicate both inputs and outputs, for instance, a modulator / demodulator (i.e. modem), a radio frequency (RF) or infrared (IR) transceiver, a telephonic interface, a bridge, a router, as well as a network card, etc.

[0027] The material mover(s) 114 of the robotic system 102 can facilitate material manipulation between operations. The material mover(s) 114 can move, stack, or position the materials prior to the next operation. In some embodiments, the material mover(s) 114 may transport materials into a predetermined alignment prior to a sewing or other operation.

[0028] In some embodiments, the material mover(s) 114 can comprise a manipulator capable of spatial motions and one or more material handling components. These material handling components, depending on the material being handled, can utilize various gripping technologies such as, e.g., air flow, vacuum, mechanical gripping, such as a clamp, pinching, pins, or needles, electro-adhesion, adhesion, electro-static forces, freezing, brush, or hook and loop, etc. In various embodiments, the material mover(s) 114 can comprise end effector(s) which can be manipulated through one or more manipulator(s) such as, e.g., industrial robot(s) or other manipulator or appropriate manipulation assembly. Industrial robots include, e.g., articulated robots, selective compliance assembly robots (SCARA), delta robots, and cartesian coordinate robots (e.g., gantry robots or x-y-z robots). Industrial robots can be programmed to carry out repetitive actions with a high degree of accuracy or can exhibit more flexibility by utilizing, e.g., machine vision and machine learning. For example, a material mover can be moved to engage with the material and manipulate its position and / or orientation for processing by the robotic system 102. When the desired processing of the material is complete, movement of the material mover 114 can transport the material out of the work area. This automated motion can be very beneficial in many repetitive processes. The secondary operation device(s) 116 can include destacking device(s), stacking device(s), folding device(s), label manipulation device(s), and / or other device(s) that assist with the preparation, making and / or finishing of the sewn product.

[0029] The local interface 118 of the robotic system 102 can be, for example, but not limited to, one or more buses or other wired or wireless connections, as is known in the art. The local interface 118 can have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers, to enable communications. Further, the local interface 118 can include address, control, and / or data connections to enable appropriate communications among the components, at element 122.

[0030] The sensing device(s) 120 of the robotic system 102 can facilitate detecting the movement of the product material(s) and inspecting the product material(s) for defects and / or discrepancies before, during or after a sewing and cutting operation or other process operation. Further, the sensing device(s) 120 can facilitate detecting markings on the product before cutting or sewing the material. A sensing device 120 can comprise, but is not limited to, one or more sensor and / or camera 124 such as, e.g., an RGB camera, an RGB-D camera, a near infrared (NIR) camera, stereoscopic camera, photometric stereo camera (single camera with multiple illumination options), time of flight camera, Internet protocol (IP) camera, light-field camera, monorail camera, multiplane camera, rapatronic camera, stereo camera, still camera, thermal imaging camera, acoustic camera, rangefinder camera, etc., at element 120. The RGB-D camera is a digital camera that can provide color (RGB) and depth information for pixels in an image. The sensing device(s) 120 can also include one or moremotion sensor(s), temperature sensor(s), humidity sensor(s), microphone(s), ultrasound device(s), radar or lidar device(s), RF receiver(s) and / or other environmental or electronic sensor(s).

[0031] An automated sewing machine 122 is a sewing system that can include a computerized sewing machine, a material securing assembly to secure one or more layers of material, and computer-controlled actuators that can move the material securing assembly relative to the sewing machine to facilitate the sewing of the secured material(s). The translation system 128 can include elements responsible for the relative motion between the material securing assembly and the sewing machine of the automated sewing machine 122. In one embodiment, this motion could be achieved with an XYZ cartesian motion system (e.g., cartesian coordinate robots, gantry robots or x-y-z robots), where the XY motion is planar and on a sewing plane (or worksurface) 209, and the Z motion lifts or drops the material securing assembly onto the material(s). In another embodiment, the translation system 128 can use a polar motion system. In yet another embodiment, the translation system 128 can be any of a number of styles of industrial robot.

[0032] The material securing assembly of the automated sewing machine 122 can include a material holding apparatus 132 that can adapt during operation of the automated sewing machine 122. The material holding apparatus 132 is capable of changing its contact points on the material(s) during the sewing process to allow the sewing machine access to some, most or all of the surface of the material. Mechanical fingers 134 attached to the structural grounding system 136 can clamp onto multiple layers of material which can adapt to different styles and sizes and sew arbitrarily shaped seam lines at high speeds. A cam profile 130 can be a body held or supported in space (e.g., affixed to the sewing machine 203), allowing followers of the mechanical fingers 134 to move on the cam profile to produce finger displacement. The shape of the cam profile 130 can be designed to produce a desired motion of the followers and thus the mechanical fingers 134 e.g. to avoid contact with the sewing needle. The structural grounding system 136 can be configured to support and allow movement of the mechanical fingers 134 to maintain uniform contact of the belt with the layered material, e.g., during finger translation, and therefore preserve their relative position and orientation. The displacement of the mechanical fingers 134 can provide space around the sewing needle to allow the sewing machine to produce a stitch that can hold the layered material together.

[0033] As shown in FIG. 1 , the robotic system 102 includes operational control(s) 126 which can control the robotic system 102, as will be discussed. The operational control(s) 126 can include one or more process modules that can be executed in order to control operation of various components of the robotic system 102 such as the automated sewing machine 122.

[0034] Functioning of the material securing assembly will now be discussed with reference to FIGS. 2A-2F. One skilled in the art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.

[0035] Referring to FIG. 2A, shown is an example of a translation system 128 and material securing assembly of the automated sewing machine 122. The automated sewing machine 122 can comprise a sewing machine 203 with a sewing needle 206 (e.g., a computerized JUKI® sewing machine), the translation system 128 and the material holding apparatus 132 with the mechanical fingers 134 over a sewing plane 209. The sewing plane 209 is the work area in which a material can be sewn utilizing a single array or multiple arrays of mechanical fingers 134 of the material holding apparatus 132, that can translate relative to material pieces 212 being sewn without the unsewn material pieces altering their relative position and orientation. For example, two arrays of mechanical fingers 134 can be positioned opposite (or facing) each other to facilitate sewing of the material pieces 212. The translation system 128 which can produce XYZ motion in which the XY motion is planar motion on the sewing plane 209 and the Z motion is up and down motion. The translation system 128 is attached to the material holding apparatus 132 allowing it to move in an XY motion. The linear array of mechanical fingers 134 acts as a means of transporting layers of material on a planar surface of the sewing plane 209 without altering their relative position and orientation.

[0036] Referring to FIG. 2B, shown is an expanded view of the material securing assembly including the array of mechanical fingers 134 supported by the structural grounding system 136 attached to the translation system 128. The structural grounding system 136 can include a support frame comprising metal brackets 215 attached to the translation system 128 and extending through the mechanical fingers 134. The mechanical fingers 134 include a belt 218 configured to contact with the layered material 212 to preserve their relative position and orientation. In the example of FIG. 2B, a belt 218 is used, however it can be any contact element which enables continuous rotation around two rotational axes such as, e.g., a chain, material strip, rubber strip, timing belt, etc. Motion (linear displacement) of the mechanical fingers 134 can be achieved by first transporting the layered material 212 to the sewing needle 206 in the XY plane using the translation system 128. Then followers 221 of the mechanical fingers can engage with the cam profile 130 which causes finger displacement. As seen in FIG. 2B, the cam profile 130 can comprise a surface along which the followers 221 travel as the material holding apparatus 132 isrepositioned with respect to the sewing needle 206. The surface can include flat (or linear) portions and one or more projecting portion(s) that extends away from the flat portion. In the illustrated example, the flat portions are provided by a mounting bracket 231 (e.g., an L- shaped metal bar) and the projecting portion can be provided by a tapered cam 232 affixed to the bracket 231 , or integrated as part of the mounting bracket 231. As the mechanical fingers 134 are repositioned sideways along the bracket 231 (see arrow 224), the follower 221 moves across the flat portion, and the corresponding mechanical finger 134 remains extended in the same position. As the follower 221 moves across the projecting portion, the corresponding mechanical finger 134 is pulled back away from the sewing needle 206. The cam 232 can be shaped to provide sufficient clearance between the fingers and the sewing needle or other system components, as needed. The cam profile 130 can be reconfigured by adding or removing cams 232 attached to the bracket 231 , or by utilizing cams 232 with different shapes and taper designs.

[0037] As can be seen, the sewing needle 206 extends toward the layered materials adjacent to the mechanical fingers 134. The material holding apparatus 132 is attached to the translation system 128 allowing the mechanical fingers 134 to be moved using the movement of the translation system 128. The sewing needle 206 sews the layered materials 212 together without interference from the mechanical fingers 134. The linear array of mechanical fingers 134 acts as a means of transporting layers of material 212 on the planar surface of the sewing plane 209 without altering their relative position and orientation. This can also be achieved using a belt grounding mechanism that rigidly connects a belt of the mechanical finger 134 to the translation system 128 via the metal bracket 215, yet allowing the mechanical finger 134 to translate onto and off of the material because of the cam profile engagement.

[0038] The translation of the mechanical fingers 134 can use a passive belt drive system that allows the belt 218 to rotate about the finger and does not alter the layered material 212 relative position or orientation. The mechanical fingers 134 can be displaced linearly in order to provide the clearance around the sewing needle 206 to sew stitches. In some embodiments, a clearance may be created for other operations to be performed on the material(s) 212 such as, e.g., vision inspection, hole punching, or laser etching. The structural grounding system 136 can utilize a cam-follower combination to passively displace the mechanical fingers 134 linearly to create clearance around the sewing needle 206. This feature may also be accomplished using, e.g., motors or other appropriate mechanism in each mechanical finger 134 to produce linear displacement of each mechanical finger 134.

[0039] Referring now to FIG. 2C, shown is a side view illustrating the relationship between the cam profile 130, the mechanical fingers 134 of the material holding apparatus 132, and the sewing needle 206. The cam profile 130 can be fixed in position with respect tothe sewing needle 206 by, e.g., attaching the mounting bracket 231 to the sewing machine 203. As a follower moves along the surface of the cam profile 130, the mechanical finger 134 to which it is attached can be linearly displaced away from the sewing needle 206. As can be seen in FIG. 2C, the mounting bracket 231 of the cam profile 130 can be attached to the sewing machine 203 by a bolt, screw, fastener or other appropriate fastening technique (e.g., welding, adhesives, etc.). The mounting bracket 231 can be detachably attached to allow for the cam profile 130 to be replaceable. The tapered cam 232 can be attached to the mounting bracket 231 by a bolt, screw, or other appropriate fastening technique. In some embodiments, the cam 232 can be an integral part of the mounting bracket 231 .

[0040] As shown in FIG. 2C, a mechanical finger 134 is retracted with respect to the other mechanical fingers 134 as the follower 221 moves across the projection of the cam profile 130. This passive cam-follower system can cause the mechanical fingers 134 to displace linearly in order to provide the clearance around the sewing needle to sew stitches. This passive system can displace specific mechanical fingers 134 as needed to create clearance around the sewing needle 206, and then allow them to return to their original position after passing by the sewing needle 206. In some embodiments, this movement may be accomplished by using motors in each mechanical finger 134 to produce the linear displacement.

[0041] The relationship of the mechanical fingers 134 with respect to the cam profile 130, the location of the sewing needle 206, and the material 212 is further illustrated in the top (or overhead) view of FIG. 2D. As the mechanical fingers 134 are repositioned, the follower 221 moves across the cam profile 130 (as illustrated by arrow 224). The linear array of mechanical fingers 134 can independently translate (as illustrated by arrow 227) onto and off the layered unsewn material pieces 212 without altering their relative position and orientation. The linear array of mechanical fingers 134 can also transport the layers of material 212 on the planar surface of the sewing plane 209 without altering their relative position and orientation. This can be achieved using a belt grounding mechanism that is rigidly connected with the mechanical finger belt and the translation system 128 via metal bracket 215. This connection allows the mechanical finger 134 to translate onto and off of the material 212 based on the cam profile 130.

[0042] The mechanical fingers 134 can utilize a belt 218 with a high coefficient of a friction in combination with a low friction worksurface or sewing plane 209 (e.g., a belt with a coefficient of friction about twice (or more) than the coefficient of friction of the sewing plane 209). This combination aids the material holding apparatus 132 to transport layered materials 212 on the planar surface of the sewing plane 209 without altering the materials relative position and orientation. The interaction of the followers 221 with the cam profile 130causes the mechanical fingers 134 to displace linearly in order to provide the necessary clearance around the sewing needle to sew stitches in the materials 212. This passive system utilizes the cam-follower system to individually displace the fingers linearly to create the clearance around the sewing needle. In some embodiments, this movement can be achieved using motors in each mechanical finger 134 to produce independent linear displacement of each mechanical finger 134.

[0043] Referring next to FIG. 2E, shown is an array of six mechanical fingers 134 supported by a structural grounding system 136. The mechanical fingers 134 are supported by the metal brackets 215 of the structural grounding system 136, which are configured to attach to the translation system 128. The mechanical fingers 134 utilize a compliant belt 218 made of material that can compress to come into contact with multiple layers of material 212 to improve gripping performance for transporting the layered material 212 on a planar surface of the sewing plane 209 (see, e.g., FIG. 2A). The belt 218 can include ridges or can be textured to improve compliance and contact with the material 212.

[0044] Additional details are illustrated in FIGS. 2F and 2G, which displays a cross section of the mechanical fingers 134. A mechanical finger 134 can comprise a finger body 230, a rear pulley 233, follower 221 , coil spring 236, transport carriage 239, belt grounding mechanism 242, linear guide rail 245, belt tensioning screw 248, front pulley 251 and a belt 218 extending between the rear and front pulleys 233 and 251. While a coil spring 236 is illustrated in this example, other appropriate positioning or tensioning devices (e.g., a piston or cylinder as illustrated in FIGS. 5A and 5B) can be utilized. The belt 218 is shown extending across the layered materials 212 on the sewing plane 209. The mechanical fingers 134 can secure the layered materials 212 in a specific position or orientation so that the layered materials 212 can be sewn together.

[0045] The finger body 230 is the structure of the mechanical finger 134 supporting the rear pulley 233 and front pulley 251 that allow the belt 218 to stay in contact with the layered materials 212 without altering the orientation or position of the layered materials 212. The rear pulley 233 can be mounted to the finger body 230 and the front pulley 251 can be mounted to a pulley carriage 254 located at a distal end of the mechanical finger 134. The pulley carriage 254 can be mounted to the finger body 230 in a fixed position or can be configured to movably engage with the linear guide rail 245. For example, the linear guide rail 245 can include two rails on opposite sides of a slot or linear opening, which can extend along at least a portion of the axial length of the finger body 230 as illustrated in FIG. 2F. A belt tensioning screw (or bolt) 248 can apply pressure to the pulley carriage 254 to tension the belt 218 looped over the rear and front pulleys 233 and 251 . In other embodiments, a belt tensioning screw (or bolt) can tension the belt 218 via the rear pulley 233.

[0046] A transport carriage 239 can be attached to a bracket 215 of the structural grounding system 136 that extends across the finger body 230 and rigidly connects to the belt 218. The transport carriage 239 can be configured to movably engage with the linear guide rail 245 to support the mechanical finger 134 during operation. The follower 221 allows the finger body 230 to move out of the way of the sewing needle 206 based upon the design of the cam profile 130. A coil spring 236 (or other appropriate tensioning device such as, e.g., a spring, elastic band or piston) can be attached to the finger body 230 and the bracket 215 of the structural grounding system 136. The coil spring 236 or other tensioning device provides tension to maintain the follower 221 against the surface of the cam profile 130 as shown in FIG. 2D. The tension provided by the coil spring 236 allows the mechanical finger 134 to return to the extended position after passing over the projecting portion of the cam profile 130. Other mechanisms can also be used. For example, a captive cam can be used to constrain both the extension and retraction of the mechanical finger 134.

[0047] The translation 227 of the mechanical finger 134 without altering material layer position and orientation is possible using the passive belt system, which can rotate about the pulleys 233 and 251 as the finger body 230 moves. The belt 218 can be toothed or flat and can be endless or of discrete length. The mechanical fingers 134 utilize a compliant belt material that can compress to contact with multiple layers of material 212 to improve gripping performance for transporting the layered material on the planar surface of the sewing plane 209. In some embodiments, the belt 218 may be replaced with another type of contact element enabling continuous rotation around two rotational axes such as, but not limited to, a chain, material strip, rubber strip, or timing belt.

[0048] The linear array of mechanical fingers 134 can act to transport layers of material 212 on the planar surface without altering their relative position and orientation to each other. This can be achieved by utilizing the belt grounding mechanism 242 of the mechanical finger 134 to enable the automated sewing machine 122 XY translation. The belt grounding mechanism 242 comprises a securing element or member that engages with a lower section of the belt 218 to secure it in a stationary or substantially stationary position with respect to the structural grounding system 136. In some implementations, the securing element or member can be a fastener (e.g., a screw, bolt, rivet, or other appropriate fastener) that extends through the belt 218 and is attached to the bracket 215 of the structural grounding system 136 as illustrated in FIG. 2G. For example, the belt grounding mechanism 242 can be a screw that passes through an opening (e.g., a hole) in the belt 218 and the slot or linear opening in the finger body 230 and is affixed to the bracket 215 via a threaded opening or nut. In other implementations, the securing element or member can comprise a block or band that is adhered to or clamped to the lower section of the belt 218 and attached to the structural grounding system 136. In some embodiments, the securingelement or member can be embedded into the belt 218 (e.g., molded into the belt by the manufacturer) and configured for attachment to the structural grounding system 136. By fixing the position of the belt 218 with respect to the bracket 215 of the structural support system 132, bunching and wrinkling of the material 212 during movement of the mechanical fingers 134 can be avoided. As a mechanical finger 134 is linearly displaced by the cam profile 130, contact with the material(s) 212 remains the same because of the fixed relationship with the structural grounding system 132. The belt grounding mechanism 242 is free to move within the slot or linear opening extending along the length of the finger body 230. By holding the belts 218 of the mechanical fingers 134 in position, the translation system 128 can transport the materials 212 on the sewing plane 209. The contact points of the belt 218 remain fixed on the layered materials 212 during sewing. The belt grounding mechanism 242 can also prevent the buildup of static charge during operation of the automated sewing machine 122.

[0049] Referring next to FIGS. 3A-3E, shown are perspective and cross-sectional view of examples of mechanical fingers 434 of a material holding apparatus 132. A mechanical finger 134 can comprise a finger body 230, one or more rear pulley 233 and / or low friction guide, linear guide rail 245, front pulley assembly 451 and a belt 218 extending between the rear pully 233 and front pulley assembly 351. For example, the pulley assembly 351 can include a plurality of angled turns at a distal end of the mechanical finger 134, each of the plurality of angled turns defined by a pulley or low friction guide as illustrated in the examples of FIGS. 3B-3E. The mechanical finger 134 can also include other features as illustrated and described with respect to FIGS. 2F and 2G. The belt 218 can extend across layered materials 212 on a sewing plane as previously described. The mechanical fingers 134 can secure the layered materials 212 in a specific position or orientation so that the layered materials 212 can be sewn together.

[0050] The configurations of the pulley assembly 351 in FIGS. 3A-3E allows the contact surface of the belt 218 to engage with the material 212 closer to the sewing needle 206 while maintaining space between the belt 218 for the translation system 128 and other features of the mechanical fingers 134. By using a plurality of pulleys, one or more low friction guide, or a combination of both, the angled turns can be arranged in a variety of ways to open up space. FIG. 3A is a perspective view showing an example of a mechanical finger 134 with a pulley assembly 351 comprising two pulleys arranged in an offset fashion with a first angled turn adjacent to a lower surface contacting the material 212 and second angled turn over the first angled turn opposite the material. In the example of FIG. 3A, the first and second angled turns are defined by pulleys. FIG. 3B shows a cross-section view illustrating the placement of the belt 218 extending over the rear pulley 233 and first and second pulleys 354a and 354b of the pulley assembly 351 . By arranging the first and second pulleys 354aand 354b such that the belt path between them is substantially vertical (or substantially perpendicular to the worksurface) or angled back away from the sewing needle (e.g., at an angle < 90 degrees with respect to the worksurface), additional clearance can be provided. Using a smaller pulley (with a smaller radius of curvature) can increase the contact with the material adjacent to the sewing needle. By having the distance between the rear pulley 233 and the first pulley 354a of the pulley assembly 351 greater than the distance between the rear pulley 233 and the second pulley 354b of the pulley assembly 351 , additional clearance can be provided for the sewing needle 206 while increasing the contact with the material adjacent to the sewing needle 206.

[0051] Positioning of the second pulley 354b can be varied as needed. For example, the second pulley 354b can be positioned substantially vertically over the first pulley 354a as illustrated in FIG. 3C, or can be located further aft from the distal end of the mechanical finger 134. In some implementations, the second pulley 354b can be placed near the middle of the mechanical finger 134, making a triangular shape of the belt 218. In some cases, the second pulley 354b can be locate even further away from the distal end of the mechanical finger 134, leaving the first pulley 354a at the distal end.

[0052] FIGS. 3D and 3E illustrate examples where one or more pulley of the pulley assembly 351 has been replaced by a low friction guide 357. The low friction guide 357 can comprise a low friction surface (with a coefficient of friction of < 0.3) such as a UHMW (ultra high molecular weight polyethylene) plastic or teflon coated part or surface configured to guide the belt 218 around the angled turn. In FIG. 3D, the second pulley 354b has been replaced with a low friction guide 357 that directs the belt 218 around the second angled turn and the first pulley 354a directs the belt 218 around the first angled turn. In other implementations, both the first and second pulleys 354a and 354b of the pulley assembly 351 can be replaced by a corresponding low friction guide 357. This can comprise two separate low friction guides 357, one for each of the pulleys, or this can comprise a single low friction guide 357 configured to define both the first and second angled turns as illustrated in FIG. 3E.

[0053] In addition, the rear pulley 233 can be replaced with a pulley assembly comprising a plurality of angled turns at the proximal end of the mechanical finger 134, each of the plurality of angled turns defined by a corresponding pulley or low friction guide. The rear pulley 233 can also be replaced by a low friction guide that guides the belt 218 around one or more angled turn. While the upper and lower sections of the belt 218 are shown as being parallel in FIGS. 3A-3E, as can be appreciated these sections can be configured in other orientations relative to each other.

[0054] Functioning of the structural grounding system 136 and cam profile 130 will now be discussed with reference to FIGS. 4A-4C. One skilled in the art will appreciate that,for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined operations are only provided as examples, and some of the operations may be optional, combined into fewer operations, or expanded to include additional operations without detracting from the essence of the disclosed embodiments.

[0055] Beginning with FIG. 4A, the structural grounding system 136 is in an initial position with the material holding apparatus 132 shown positioned with the mechanical fingers 134 on the layered material 212 as illustrated in FIG. 2F. The mechanical fingers 134 extend around the sewing needle 206 of the sewing machine 203 based upon the interaction of the followers 221 with the cam profile 130. As the translation system 128 is repositioned during the sewing process from an initial position in FIG. 4A to a second position in FIG. 4B, the structural grounding system 136 is extended to move the layered material 212 forward under the sewing needle 206. As can be seen by comparing FIGS. 4A and 4B, the layered material 212 extend further out from the sewing needle 206 but the positions of the mechanical fingers 134 (FIGS. 2A-2F) remain the same because of the fixed position of the cam profile 130 with respect to the sewing needle 206. During the translation of the mechanical fingers 134, the belt 218 (FIGS. 2A-2F) is always in contact with the layered material 212 and therefore preserves their relative position and orientation. This motion of the structural grounding system 136 exposes the layered material 212 to the sewing needle 206. As shown in FIG. 4C, further movement of the structural grounding system 136 by the translation system 128 continues to extend the layered material 212 under the sewing needle 206, while the position of the mechanical fingers 134 do not change. After a seam is made in the layered material 212, the mechanical fingers 134 can translate back onto the layered material as shown in FIG. 4A. The layered material 212 can also be repositioned under the sewing needle 206 using the translation system 128.

[0056] While material(s) 212 can be sewn on the sewing plane 209 utilizing a single array of mechanical fingers 134 of the material holding apparatus 132 as illustrated in FIGS. 4A-4C, multiple arrays of mechanical fingers 134 can also be used to hold the material(s) during sewing. For example, as shown in FIGS. 4D and 4E the material holding apparatus 132 can comprise two arrays of mechanical fingers 134 positioned, e.g., on opposite sides of the sewing needle 206 to facilitate sewing of the material pieces 212. The transportation system 128 can be configured to independently position the arrays of mechanical fingers 134 to contact the material(s) 212. The mechanical fingers 134 of each array can linearly translate away from the sewing needle 206 to provide the needed clearance using a corresponding cam profile 130. The use of multiple arrays of mechanical fingers 134 can assist in the handling of larger pieces of material 212 or better supporting less rigidmaterials. By contacting the material 212 on two or more sides of the sewing needle 206, the material can be securely held in position during sewing.

[0057] FIGS. 4D and 4E provide top and perspective views of the automated sewing machine 122 comprising material holding apparatus 132 with the two arrays of mechanical fingers 134 extended beyond the sewing needle 206 at the sewing head of the sewing machine 203. The automated sewing machine 122 includes a translation system 128 that allows the material holding apparatus 132 to move in an XY motion. The linear array of mechanical fingers 134 acts as a means of transporting layers of material on a planar surface of the sewing plane 209 without altering their relative position and orientation. With the material holding apparatus 132 positioned with the two arrays of mechanical fingers 134 on the material, the translation system 128 can move the material under the sewing needle 206 via the material holding apparatus 132. As the arrays of mechanical fingers 134 are advanced toward the sewing needle 206, individual mechanical fingers 134 on opposite sides of the sewing needle 206 are retracted to provide clearance around the sewing needle 206 as it sews the material. For example, each array of material fingers 134 can use a cam profile 130 to retract material fingers 134 in the vicinity of the sewing needle 206 as previously disclosed. In other implementations, individual position control (e.g., pneumatic piston or cylinder, linear motor, etc.) can be used to reposition individual material fingers 134 as will be discussed.

[0058] Referring now to FIGS. 5A and 5B, shown is another embodiment of a structural grounding system 136 to control linear positioning of the mechanical fingers 134 of the material holding apparatus 132. For example, if the mechanical fingers 134 have individual position control (e.g., pneumatic piston or cylinder, linear motor, etc.) then their positions can be individually controlled as the structural grounding system 136 translates the material 212 during sewing. Control of the individual finger positions can be provided by, e.g., closed-loop electrical or pneumatic control systems. In this embodiment, translation of the mechanical fingers 134 can be accomplished with or without a cam profile 130.

[0059] As illustrated in the embodiment of FIG. 5A, the structural grounding system 136 can comprise a piston or cylinder system attached to the translation system 128 in order to provide the linear translations for each of the individual mechanical fingers 134. Each mechanical finger 134 can be controlled individually by a corresponding piston or cylinder 503. In some embodiments, the piston or cylinder system can use servo-pneumatic air cylinders with proportional air valves to control the positions of each of the individual mechanical fingers 134. An air cylinder can be a mechanical device which uses the power of a compressed gas to produce a force in a reciprocating linear motion. In various embodiments, the cylinder may be a pneumatic cylinder which utilizes a gas in order tomove the piston of the cylinder in the desired direction. In other embodiments, an electromechanical device 506 can be used to produce the linear translation.

[0060] FIG. 5B illustrates an example of a single pneumatic cylinder 503 of an air cylinder system. The air cylinder 503 is connected to the finger body of an individual mechanical finger 134 and controls the linear movement of the mechanical finger 134. In some embodiments, the air cylinder 503 can be a servo-pneumatic air cylinder with proportional air valves to control the positions of each of the individual mechanical fingers 134. The air cylinder 503 can control the translation of the mechanical finger 134 by the application or release of a compressed gas to produce the linear motion. Where a cam profile 130 is used, the air cylinder 503 (instead of the coil spring 236 of FIG. 2F) can maintain pressure on the finger body to ensure contact of the follower 221 with the surface of the cam profile 130. In some embodiments, the piston or cylinder system can comprise a rotary motor with linear drive train mechanism, linear motors, magnets, electromagnets, that can be used to create the linear displacement of the mechanical fingers. FIGS. 4D and 4E show an example of arrays of mechanical fingers 134 utilizing the piston or cylinder system.

[0061] In some examples, the system can include a cam profile positioning system 131 supporting the cam profile 130. The cam profile positioning system 131 can be configured to adjust positioning of the cam profile 130 with respect to the sewing needle 206 and sewing machine 122. The cam profile positioning system 131 can be configured to linearly translate the cam profile 130 horizontally, vertically or both. In some cases, the cam profile positioning system 131 can translate the cam profile in three dimensions using, e.g., computer controlled actuators. FIGS. 6A-6D illustrate various examples of cam profile positioning systems 131 that can be utilized with the mechanical fingers 134 of the system.

[0062] FIGS. 6A-6D illustrate examples of cam profile positioning systems 131 repositioning a cam profile 130 vertically and horizontally. The structural grounding system 136 includes a support frame with a metal bracket 215 extending through the mechanical fingers 134 that is attached to the translation system 128. As shown in FIGS. 6A-6D, the cam profile 130 is attached to a separate cam profile positioning system 131 configured to support and reposition the cam profile 130. Movement of the cam profile 130 can be independent of the mechanical fingers 134 by the translation system 128 or can be synchronized with movement of the mechanical fingers 134 by the translation system 134. The cam profile positioning system 131 can comprise, e.g., one or more actuators (e.g., pneumatic, electric, etc.) and / or articulated arms to facilitate movement and positioning of the cam profile 130.

[0063] FIGS. 6A and 6B illustrate an example of vertical adjustment of the position of the cam profile 130. In FIG. 6A, the mechanical fingers 134 can be in contact with material on a work surface with the mechanical fingers 134 extending around the sewing needle. Aspreviously described, translation of the mechanical fingers 134 while maintaining the position of the cam profile 130 can move the material along the work surface causing the mechanical fingers 134 to move around the sewing needle during the sewing process. As shown in FIG. 6B, the cam profile 130 can be vertically lifted by an actuator (e.g., pneumatic, electric, etc.) to provide room to lift the mechanical fingers 134. The movement of the cam profile 130 and the mechanical fingers 134 by the translation system 128 can be coordinated to maintain contact of the followers 221 of the mechanical fingers with the surface of the cam profile 130. In some embodiments, the cam profile positioning system 131 can be spring loaded to hold the cam profile 130 down on the mechanical fingers 134. Alternatively, the cam profile 130 can be held down with air, springs or gravity. When the mechanical fingers 134 are lifted, they (or another feature) lift the cam profile 130 as well. Once the mechanical fingers 134 are lifted, the material can be repositioned or replaced under the mechanical fingers 134. In other implementations, the work surface may be lowered to provide space under the mechanical fingers 134. Movement and repositioning of the cam profile 130 by the cam profile positioning system 131 with respect to the mechanical fingers 134 can also provide access to the mechanical fingers 134 for maintenance, repair or replacement.

[0064] FIGS. 6C and 6D illustrate an example of horizontal adjustment of the position of the cam profile 130. In FIG. 6C, the mechanical fingers 134 can be in contact with material on a work surface with the mechanical fingers 134 extending around the sewing needle. As shown in FIG. 6D, the cam profile 130 can be horizontally translated by an actuator (e.g., pneumatic, electric, etc.) to shift the mechanical fingers 134 away from the sewing needle as illustrated. The mechanical fingers 134 can be removed from the material area by moving the cam profile away, thereby shifting all of the mechanical fingers 134 together. While the examples of FIGS. 6A-6D are shown with movement of the entire cam profile 130, in other implementations a portion of the cam profile 130 may be repositioned while another portion of the cam profile 130 remains stationary. A combination of actuators or articulated arm(s) can be utilized to allow for movement of the cam profile 130 in three dimensions. This can allow the cam profile 130 to mimic movement of the mechanical fingers 134 by the translation system 128.

[0065] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

[0066] The term "substantially" is meant to permit deviations from the descriptive term that don't negatively impact the intended purpose. Descriptive terms are implicitlyunderstood to be modified by the word substantially, even if the term is not explicitly modified by the word substantially.

[0067] It should be noted that ratios, concentrations, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of “about 0.1% to about 5%” should be interpreted to include not only the explicitly recited concentration of about 0.1 wt% to about 5 wt%, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicated range. The term “about” can include traditional rounding according to significant figures of numerical values. In addition, the phrase “about ‘x’ to ‘y’” includes “about ‘x’ to about ‘y’”.

Claims

CLAIMSTherefore, at least the following is claimed:

1. A system for transporting and sewing material, comprising: a sewing machine including a sewing needle; a material holding assembly comprising: mechanical fingers configured to contact material on a sewing plane adjacent to the sewing needle, the mechanical fingers configured to secure a relative orientation and position of the material during sewing of the material; a cam profile positioned to engage with followers of the mechanical fingers; a cam profile positioning system supporting the cam profile, the cam profile positioning system configured to adjust position of the cam profile with respect to the sewing needle; and a structural grounding system supporting the mechanical fingers, where clearance around the sewing needle is provided by repositioning individual mechanical fingers around the sewing needle in response to the cam profile; and a translation system attached to the structural grounding system, the translation system configured to transport the material on the sewing plane via the mechanical fingers, where the mechanical fingers move in response to repositioning of the structural grounding system and interaction of a surface of the cam profile with the followers of the mechanical fingers.

2. The system of claim 1 , wherein each of the mechanical fingers comprises a passive belt system that extends from a proximal end to a distal end that is positioned adjacent to the sewing needle, where the passive belt system contacts the material to secure the orientation and position.

3. The system of claim 2, wherein the passive belt system comprises a belt extending between at least one pulley attached to the proximal end of the mechanical finger and a plurality of angled turns at the distal end of the mechanical finger, each of the plurality of angled turns defined by a corresponding pulley or low friction guide, wherein the belt passively rotates about the at least one pulley and rotates about the corresponding pulley or slides about the low friction guide of each of the plurality of angled turns during linear translation of the mechanical finger.

4. The system of claim 3, wherein the plurality of angled turns comprises a first angled turn adjacent to the material and a second angled turned turn over the first angled turn opposite the material.

5. The system of claim 4, wherein a distance between the at least one pulley and the first angled turn is greater than a distance between the at least one pulley and the second angled turn.

6. The system of claim 4, wherein the first and second angled turns are defined by corresponding pulleys.

7. The system of claim 4, wherein the first and second angled turns are defined by at least one low friction guide.

8. The system of claim 7, wherein the at least one low friction guide comprises a low friction guide surface.

9. The system of claim 8, wherein the low friction guide surface comprises an ultra high molecular weight polyethylene plastic or teflon coating.

10. The system of any one of claims 3-9, wherein a lower section of the belt is secured in a fixed position with respect to the structural grounding system by a belt grounding mechanism of the structural grounding system.11 . The system of any one of claims 1-10, wherein the surface of the cam profile comprises a projecting portion, where the mechanical fingers linearly translate away from the sewing needle in response to engagement with the projection portion.

12. The system of any one of claims 1-11 , wherein the cam profile positioning system is configured to linearly translate the cam profile horizontally, vertically or both.

13. The system of any one of claims 1-12, wherein the cam profile positioning system is configured to adjust position of the cam profile in three-dimensions.

14. A material holding assembly, comprising: mechanical fingers configured to contact material on a sewing plane, the mechanical fingers configured to secure a relative orientation and position of thematerial during sewing of the material, where each of the mechanical fingers comprises a passive belt system that extends from a proximal end to a distal end and contacts the material to secure the orientation and position, the passive belt system comprising a belt extending between at least one pulley or low friction guide attached to the proximal end of the mechanical finger and a plurality of angled turns at the distal end of the mechanical finger, each of the plurality of angled turns defined by a corresponding pulley or low friction guide, where the belt passively rotates about the pulley and rotates about the corresponding pulley or slides about a low friction guide of each of the plurality of angled turns during linear translation of the mechanical finger; and a structural grounding system supporting the mechanical fingers.

15. The material holding assembly of claim 14, wherein the plurality of angled turns comprises a first angled turn adjacent to the material and a second angled turned turn over the first angled turn opposite the material.

16. The material holding assembly of claim 15, wherein a distance between the at least one pulley or low friction guide and the first angled turn is greater than a distance between the at least one pulley or low friction guide and the second angled turn.

17. The material holding assembly of claim 15, wherein the first and second angled turns are defined by corresponding pulleys.

18. The material holding assembly of claim 15, wherein the first angled turn is defined by a pulley and the second angled turn is defined by a low friction guide.

19. The material holding assembly of claim 15, wherein the first and second angled turns are defined by at least one low friction guide.

20. The material holding assembly of claim 19, wherein the at least one low friction guide comprises a low friction guide surface.21 . The material holding assembly of claim 20, wherein the low friction guide surface comprises an ultra high molecular weight polyethylene plastic or teflon coating.

2. The material holding assembly of any one of claims 14-21 , wherein a lower section of the belt is secured in a fixed position with respect to the structural grounding system by a belt grounding mechanism of the structural grounding system.

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