Pivoting Lower Arm for Robotic Sewing Assembly

This application claims the benefit of U.S. Provisional Application No. 63/571,783 filed Mar. 29, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Exemplary embodiments of the present disclosure pertains to the art of robotic sewing assemblies for use in sewing processes.

Current robotic sewing technology often includes a sewing head with a lower arm post that is fixed in position (i.e., a fixed-position lower arm post). Due to the presence of the lower arm post and the fact that the lower arm post is fixed in position, it is often the case that the lower arm post makes sewing parts with complex geometries difficult. During sewing operations for parts with complex geometries, the lower arm post can impinge against the part itself or otherwise prevent the sewing head from accessing certain portions of the part. In these or other cases, the sewing head need to be adjusted or readjusted in order to allow the sewing head to complete the sewing operation.

In the manual sewing industry, especially within footwear and bag or luggage manufacturing, pivoting lower arm technology has been used. No such technology is available in robotic sewing technology.

According to an aspect of the disclosure, a robotic sewing assembly is provided and includes a sewing head body, an upper arm, a motor and a lower arm. The upper arm is attachable to the sewing head body and includes a sewing needle oriented along a first axis. The lower arm is rotatably attachable to the sewing head body to be rotatable about a second axis defined transversely with respect to the first axis by the motor. The lower arm includes a stitch plate, a butterfly looper and first and second drivetrains. The first drivetrain is extendable through the lower arm and configured to maintain a position of the stitch plate during lower arm rotation. The second drivetrain is extendable through the lower arm and configured to drive the butterfly looper during the lower arm rotation.

In accordance with additional and/or alternative embodiments, the upper arm, the sewing needle and the lower arm define an empty internal sewing region.

In accordance with additional and/or alternative embodiments, the lower arm is rotatable through 160 degrees of rotation about the second axis.

In accordance with additional and/or alternative embodiments, the lower arm and the first and second drivetrains are correspondingly U-shaped.

In accordance with additional and/or alternative embodiments, at least one of the first and second drivetrains includes concentric shafts.

In accordance with additional and/or alternative embodiments, a counterweight is disposable to reduce a lower arm torque requirement.

In accordance with additional and/or alternative embodiments, a bearing is supportively disposable on the sewing head body for lower arm support against the sewing head body.

In accordance with additional and/or alternative embodiments, wings are extendable outwardly from the sewing head body and roller bearings are attachable to the lower arm for lower arm support against the wings during the lower arm rotation.

In accordance with additional and/or alternative embodiments, a programmable control system is configured to robotically control the sewing head body, the upper arm, the lower arm and the lower arm rotation. The programmable control system includes a sensor system to gage distance between the lower arm and an article being sewn and the programmable control system is configured to modify a programmed operation of the sewing head body, the upper arm, the lower arm and the lower arm rotation in accordance with readings of the sensor system.

According to an aspect of the disclosure, a robotic sewing assembly is provided and includes a sewing head body, an upper arm, a motor, a lower arm rotation drivetrain and a lower arm. The upper arm is attachable to the sewing head body and includes a sewing needle oriented along a first axis. The lower arm is rotatably attachable to the sewing head body to be rotatable about a second axis defined transversely with respect to the first axis by the motor via the lower arm rotation drivetrain. The lower arm includes a stitch plate, a butterfly looper and first and second drivetrains. The first drivetrain is extendable through the lower arm and configured to maintain a position of the stitch plate during lower arm rotation. The second drivetrain is extendable through the lower arm and configured to drive the butterfly looper during the lower arm rotation.

In accordance with additional and/or alternative embodiments, the upper arm, the sewing needle and the lower arm define an empty internal sewing region.

In accordance with additional and/or alternative embodiments, the lower arm is rotatable through 160 degrees of rotation about the second axis.

In accordance with additional and/or alternative embodiments, the lower arm and the first and second drivetrains are correspondingly U-shaped.

In accordance with additional and/or alternative embodiments, at least one of the first and second drivetrains includes concentric shafts.

In accordance with additional and/or alternative embodiments, a counterweight is disposable to reduce a lower arm torque requirement.

In accordance with additional and/or alternative embodiments, a bearing is supportively disposable on the sewing head body for lower arm support against the sewing head body.

In accordance with additional and/or alternative embodiments, wings are extendable outwardly from the sewing head body and roller bearings are attachable to the lower arm for lower arm support against the wings during the lower arm rotation.

In accordance with additional and/or alternative embodiments, a programmable control system is configured to robotically control the sewing head body, the upper arm, the lower arm and the lower arm rotation. The programmable control system includes a sensor system to gage distance between the lower arm and an article being sewn. The programmable control system is configured to modify a programmed operation of the sewing head body, the upper arm, the lower arm and the lower arm rotation in accordance with readings of the sensor system.

According to an aspect of the disclosure, a method of operating a robotic sewing assembly is provided and includes programming the robotic sewing assembly to execute a sewing operation with respect to an article and driving the robotic sewing assembly in accordance with the programming. The driving includes operating an upper arm including a sewing needle oriented along a first axis, rotating a lower arm about a second axis defined transversely with respect to the first axis, driving a first drivetrain extending through the lower arm to maintain a position of a stitch plate of the lower arm during the rotating of the lower arm and driving a second drivetrain extending through the lower arm to drive a butterfly looper of the lower arm during the rotating of the lower arm.

In accordance with additional and/or alternative embodiments, the method further includes sensing a distance between the lower arm and the article, determining whether the distance is less than a predetermined distance and, in an event the distance is less than the predetermined distance, modifying the driving of the robotic sewing head in accordance with the programming to increase the distance.

Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed technical concept. For a better understanding of the disclosure with the advantages and the features, refer to the description and to the drawings.

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.

The present disclosure provides the ability to sew complex 3D planar parts with a robotic sewing cell as opposed to robotic sewing technology including a sewing head with a fixed-position lower arm post. Whereas a robotic sewing head with a fixed position post can be limited in its ability to sew parts with complex geometries, the present disclosure provides for a robotic sewing assembly with a lower arm that is rotatable about a horizontal axis. The rotatability of the lower arm makes it possible to rotate the lower arm about the horizontal axis while maintaining stitch plate position relative to the upper portion of the sewing head while actively sewing a part. Thus, as the part is being sewn, the lower arm can be maneuvered and repositioned to optimize the sewing head to fit the part geometry. The complex 3D planar parts can be instrument panels (IPs) for vehicles.

With reference toand, a robotic sewing assemblyis provided and includes a sewing head body, an upper armthat is attached to the sewing head bodyand includes a sewing needleoriented along a first axis Aand a footthrough which the sewing needleextends, a motor, a lower arm rotation drivetrainand a lower arm. The lower armis rotatably attached to the sewing head bodyto be rotatable about a second axis A. The second axis Ais defined transversely or perpendicularly with respect to the first axis A. Rotation of the lower armis drivable by the motorvia the lower arm rotation drivetrain.

The lower arm rotation drivetrainincludes a spur gearand pinion gearset and a right-angle gearboxpaired with the motor. The motordrives the right-angle gearboxand the right-angle gearboxin turn drives the spur gearvia the pinion gear. The spur gearis fixed to the lower armsuch that, with the spur geardriven by the pinion gear, the lower armis caused to rotate about the second axis A. The lower armis mounted to a horizontal mid-shaft, which protrudes from post sectionof the sewing head body. The lower armcan be mounted on a sleeve bearing such that the lower armis supported by but does not move with rotation of the horizontal mid-shaft.

In accordance with embodiments, the horizontal mid-shaftcan have a diameter of up to 16 mm or more to improve mechanism integrity and rigidity.

The lower armincludes a stitch plate, a butterfly looper, a first drivetrainand a second drivetrain. The first drivetrainis extendable through an interior of the lower armand is configured to maintain a position of the stitch platerelative to the sewing needleduring rotation of the lower arm. The second drivetrainis extendable through the interior of the lower armand is configured to drive the butterfly looperduring the rotation of the lower arm.

In accordance with embodiments, the lower arm, the first drivetrainand the second drivetraincan be correspondingly U-shaped. As such, the upper arm, the sewing needle, the footand the lower armcooperatively define a substantially empty internal sewing region. This substantially empty internal sewing regionprovides for ample space for accommodating portions of an article, such as an IP, being sewn. The rotatability of the lower armeffectively increases a size and utility of the substantially empty internal sewing regionby providing for movement of the lower armout of the way of the article during certain sewing operations.

The stitch plateis free-floating on a horizontal shaft. The first drivetrainincludes a bevel gear, a set of interconnected shaftsand a connection geardisposed underneath the stitch plateand to which the set of interconnected shaftsconnect. The bevel gearis fixed to the sewing head body. As the lower armrotates about the horizontal mid-shaft, the bevel geardrives the set of interconnected shaftsand the set of interconnected shaftsin turn drive the connection gear. As the lower armand the set of interconnected shaftsrotate, the connection gearcan be driven in a 1:1 ratio with respect to the lower arm. Therefore, as the lower armrotates, the stitch platerotates relative to the lower armand maintains its rotational position relative to the sewing needle, the footand rest of the sewing head body.

In accordance with embodiments and as shown in, the lower armis rotatable through up to 160 degrees of rotation or more about the second axis A. That is, the lower armcan be rotated clockwise through up to 80 degrees of rotation or more about the second axis Afrom a center position (see) and the lower armcan be rotated counter-clockwise through up to 80 degrees of rotation or more about the second axis Afrom the center position (see).

The butterfly loopercan be a butterfly-style looper that moves via continuous rotary motion. This stands in contrast to conventional sickle loopers and lockstitch mechanisms that are often used in most robotic sewing heads. The butterfly looperwas chosen over a lockstitch mechanism due to its compact packaging, ease of integration into the lower armand benefits of using chainstitch over lockstitch.

With continued reference toand with additional reference to, the second drivetraindrives the butterfly looperand is connected to bevel gearmounted to the horizontal mid-shaft. The second drivetrainincludes a set of interconnected bevel shaftsthat are driven by the bevel gear, a pulley, a beltthat transfers rotation from the set of interconnected bevel shaftsto the pulley, a stitch plate support and pulley casingand gearing. The butterfly looperis driven off the pulleythat in turn is driven by the belt. The butterfly looperis supported by the stitch plate, which maintains its rotational position relative to the sewing needle, the footand rest of the sewing head bodyvia the gearing. The stitch plateis mounted to the lower armby a structural componentthat includes a bearingthat allows the stitch plateto rotate while being constrained in multiple axis. A sheet metal shieldprevents material from touching the pulley.

With reference toand in accordance with embodiments, at least one of the first drivetrainand the second drivetraincan include concentric shaftsto reduce spatial requirements. That is, for the first drivetrain, at least a portion of the set of interconnected shaftscan include or be provided as the concentric shaftsand, for the second drivetrain, at least a portion of the set of interconnected bevel shaftscan include or be provided as the concentric shafts.

With reference toand in accordance with embodiments, the robotic sewing assemblycan further include a counterweight(the motorhas been removed for clarity). The counterweightcan be disposed on the lower armand can be configured to effectively reduce a torque requirement associated with rotation of the lower arm. The counterweightcan be oriented to not invade the substantially empty internal sewing regionor to limit invading the substantially empty internal sewing regionto a practical extent.

With reference toand in accordance with embodiments, the robotic sewing assemblycan further include a bearingwith a support elementthat are supportively disposable on the sewing head bodyfor support of the lower armagainst the sewing head body. The bearingand the support elementpermit the rotation of the lower armand can be disposed about the horizontal mid-shaft. In this configuration, the bearing elementand the supporteffectively replace a reliance of the lower armbeing mounted on the horizontal mid-shaft.

With reference toand in accordance with embodiments, the robotic sewing assemblycan further include wingsextending outwardly in opposite directions from the sewing head bodyto define a plane of support for the rotation of the lower armand roller bearings. The roller bearingsare attachable to the lower armand provide for support of the lower armagainst the wingsduring the rotation of the lower arm. The rotational length of the wingscan be at least sufficient to support the full rotational capability of the lower arm. Thus, where the lower armcan be rotated clockwise through up to 80 degrees of rotation or more about the second axis Afrom the center position, one of the wingsextends far enough to support the entirety of the clockwise rotation of the lower armand, where the lower armcan be rotated counter-clockwise through up to 80 degrees of rotation or more about the second axis Afrom the center position, the other one of the wingsextends far enough to support the entirety of the counter-clockwise rotation of the lower arm.

With reference to, the robotic sewing assemblycan include a programmable control systemand the programmable control systemcan include a sensor system. The programmable control systemcan include a processing unit, a memory for storing executable instructions that are readable and executable by the processing unit whereby the processing unit controls operations of the robotic sewing assemblyin accordance with readings of the sensor systemand an input/output (I/O) unit by which the processing unit is communicative with the robotic sewing assemblyand the sensor system. The programmable control systemcan thus be configured to robotically control the sewing head body, the upper arm, the sewing needle, the lower arm, the rotation of the lower armand the respective operations of the first drivetrainand the second drivetrainwithout operator involvement. The sensor systemcan be configured to gage distance between the lower armand the article being sewn. The programmable control systemcan be further configured to modify a programmed operation of the sewing head body, the upper arm, the sewing needle, the lower arm, the rotation of the lower armand the respective operations of the first drivetrainand the second drivetrainin accordance with readings of the sensor system. For example, to an extent that a size, a shape and/or a configuration of the article being sewn departs from a nominal size, shape and/or configuration whereby some portion of robotic sewing assemblyis at risk of impacting the article during sewing, the sensor systemwill be able to detect a possible impact and the programmable control system, upon being alerted of the possible impact by the sensor system, will be able to modify the programmed operation to avoid the possible impact.

While the various embodiments described above have been described separately, it is to be understood that they can be combined together in various combinations. It is to be further understood that other configurations besides those described above are possible. For example, the motorand the lower arm rotation drivetraincan be replaced by motorizing the roller bearingsof, which will in turn allow for corresponding modifications to the first drivetrainand the second drivetrain.

With reference to, a methodof operating a robotic sewing assembly, such as the robotic sewing assemblydescribed above, is provided. As shown in, the methodcan include programming the robotic sewing assembly to execute a sewing operation with respect to an article (block) and driving the robotic sewing assembly in accordance with the programming (block). The driving of blockcan include operating an upper arm including a sewing needle oriented along a first axis (block), rotating a lower arm about a second axis defined transversely with respect to the first axis (block), driving a first drivetrain extending through the lower arm to maintain a position of a stitch plate of the lower arm during the rotating of the lower arm (block) and driving a second drivetrain extending through the lower arm to drive a looper of the lower arm during the rotating of the lower arm (block). In accordance with further embodiments, the methodcan further include sensing a distance between the lower arm and the article (block), determining whether the distance is less than a predetermined distance such that there is a risk of a possible impact as described above (block) and, in an event the distance is less than the predetermined distance, modifying the driving of blockin accordance with the programming to increase the distance (block).

Technical effects and benefits of the present disclosure are the provision of a robotic sewing assembly that is capable of sewing complex 3D planar parts. The robotic sewing assembly has a rotatable lower arm that makes it possible to rotate the lower arm while maintaining stitch plate position relative to the upper portion of the sewing assembly and while actively sewing a part. Thus, as the part is being sewn, the lower arm can be maneuvered and repositioned to optimize the sewing assembly to fit the part geometry.

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.

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.

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.