Pivoting lower arm for a robotic sewing system

Abstract

Robotic sewing device comprising: a sewing head body; an upper arm attachable to the sewing head body and including a sewing needle aligned along a first axis; an engine; and a lower arm rotatably attachable to the sewing head body to be rotatable by the motor about a second axis defined transversely with respect to the first axis, the lower arm comprising: a needle plate; a butterfly gripper; a first drive train extendable through the forearm and configured to maintain a position of the throat plate during forearm rotation; and a second drive train extendable through the forearm and configured to drive the butterfly gripper during forearm rotation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 571,783, filed March 29, 2024, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND

[0002] Exemplary embodiments of the present disclosure relate to the technology of robotic sewing devices for use in sewing processes.

[0003] Current robotic sewing technology often includes a sewing head with a forearm column that is fixed in position (i.e., a fixedly positioned forearm column). Due to the presence of the forearm column and the fact that the forearm column is fixed in position, it is often the case that the forearm column makes it difficult to sew parts with complex geometries. When sewing parts with complex geometries, the forearm column may strike the part itself or otherwise prevent the sewing head from accessing certain sections of the part. In these or other cases, the sewing head must be adjusted or readjusted to allow the sewing head to complete the sewing operation.

[0004] In the manual sewing industry, especially in the manufacture of shoes, bags, and luggage, pivoting forearm technology is used. No such technology is available in robotic sewing. SHORT DESCRIPTION

[0005] According to one aspect of the disclosure, a robotic sewing device is provided that includes a sewing head body, an upper arm, a motor, and a forearm. The upper arm is attachable to the sewing head body and includes a sewing needle aligned along a first axis. The forearm is rotatably mountable to the sewing head body for rotation by the motor about a second axis defined transversely with respect to the first axis. The forearm includes a throat plate, a butterfly gripper, and first and second drive trains. The first drive train is extendable through the forearm and configured to maintain a position of the throat plate during forearm rotation. The second drive train is extendable through the forearm and configured to drive the butterfly gripper during forearm rotation.

[0006] According to additional and / or alternative embodiments, the upper arm, the sewing needle and the forearm define an empty inner sewing area.

[0007] According to additional and / or alternative embodiments, the forearm is rotatable 160 degrees about the second axis.

[0008] According to additional and / or alternative embodiments, the lower arm and the first and second drive trains are correspondingly U-shaped.

[0009] According to additional and / or alternative embodiments, at least one of the first and second drive trains comprises concentric shafts.

[0010] According to additional and / or alternative embodiments, a counterweight may be arranged to reduce the torque requirement of the forearm.

[0011] According to additional and / or alternative embodiments, a bearing may be arranged supportingly on the sewing head body for supporting the lower arm against the sewing head body.

[0012] According to additional and / or alternative embodiments, wings are extendable outwardly from the sewing head body, and roller bearings are attachable to the forearm to support the forearm on the wings during forearm rotation.

[0013] According to additional and / or alternative embodiments, a programmable control system is configured to robotically control the sewing head body, the upper arm, the forearm, and the forearm rotation. The programmable control system includes a sensor system for measuring a distance between the forearm and an object to be sewn, and the programmable control system is configured to modify a programmed operation of the sewing head body, the upper arm, the forearm, and the forearm rotation according to measured values from the sensor system.

[0014] According to one aspect of the disclosure, a robotic sewing device is provided that includes a sewing head body, an upper arm, a motor, a forearm rotation drive train, and a forearm. The upper arm is attachable to the sewing head body and includes a sewing needle aligned along a first axis. The forearm is rotatably attachable to the sewing head body for rotation by the motor via the forearm rotation drive train about a second axis defined transverse to the first axis. The forearm includes a throat plate, a butterfly gripper, and first and second drive trains. The first drive train is extendable through the forearm and configured to maintain a position of the throat plate during forearm rotation. The second drive train is extendable through the forearm and configured to drive the butterfly gripper during forearm rotation.

[0015] According to additional and / or alternative embodiments, the upper arm, the sewing needle and the forearm define an empty inner sewing area.

[0016] According to additional and / or alternative embodiments, the forearm is rotatable 160 degrees about the second axis.

[0017] According to additional and / or alternative embodiments, the lower arm and the first and second drive trains are correspondingly U-shaped.

[0018] According to additional and / or alternative embodiments, at least one of the first and second drive trains comprises concentric shafts.

[0019] According to additional and / or alternative embodiments, a counterweight may be arranged to reduce the torque requirement of the forearm.

[0020] According to additional and / or alternative embodiments, a bearing may be arranged supportingly on the sewing head body for supporting the lower arm against the sewing head body.

[0021] According to additional and / or alternative embodiments, wings are extendable outwardly from the sewing head body, and roller bearings are attachable to the forearm to support the forearm against the wings during forearm rotation.

[0022] According to additional and / or alternative embodiments, a programmable control system is configured to robotically control the sewing head body, the upper arm, the forearm, and the forearm rotation. The programmable control system includes a sensor system for measuring a distance between the forearm and an object to be sewn. The programmable control system is configured to modify a programmed operation of the sewing head body, the upper arm, the forearm, and the forearm rotation according to measured values from the sensor system.

[0023] Further features and advantages are realized by the techniques of the present disclosure. Further embodiments and aspects of the disclosure are described in detail herein and are considered part of the claimed technical concept. For a better understanding of the disclosure, including the advantages and features, reference is made to the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in conjunction with the accompanying drawings and detailed description, in which like reference characters represent like parts: Fig. 1A, Fig. 1B and Fig. 1C are perspective views of a robotic sewing device with a rotatable forearm according to embodiments; Fig. 2 is an enlarged and partially cutaway perspective view of parts of the robotic sewing device, including the rotatable forearm of Fig. 1, according to embodiments; Fig. 3A, Fig. 3B and Fig. 3C are side views of a sewing needle and a throat plate assembly of the robotic sewing device of the Fig. 1 and Fig. 2 according to embodiments; Fig. Figure 4 is a side schematic view of concentric shafts of drive trains of the robotic sewing device of the Fig. 1 and Fig. 2 according to embodiments; Fig. 5 is a perspective view of the robotic sewing device, including the rotatable forearm of the Fig. 1 and Fig. 2, with a counterweight according to embodiments; Fig. 6 is a perspective view of the robotic sewing device, including the rotating forearm of the Fig. 1 and Fig. 2, with a bearing and a support element according to embodiments; Fig. Figure 7 is a perspective view of the robotic sewing device, including the rotating forearm of the Fig. 1 and Fig. 2, with wings and roller bearings according to embodiments; Fig. 8 is a schematic diagram of a robotic sewing device, a programmable control system, and a sensor system according to embodiments; and Fig. 9 is a flowchart illustrating a method of operating a robotic sewing device according to embodiments. DETAILED DESCRIPTION

[0025] A detailed description of one or more embodiments of the disclosed device is given herein by way of example and not by way of limitation with reference to the figures.

[0026] The present disclosure provides the ability to sew complex, flat 3D parts with a robotic sewing cell, in contrast to robotic sewing technology that includes a sewing head with a fixed forearm column. While a robotic sewing head with a fixed column may be limited in its ability to sew parts with complex geometries, the present disclosure provides a robotic sewing device with a forearm rotatable about a horizontal axis. The rotatability of the forearm allows the forearm to rotate about the horizontal axis while maintaining the needle plate position relative to the upper part of the sewing head while a part is actively being sewn. Thus, while the part is being sewn, the forearm can be maneuvered and repositioned to optimally adapt the sewing head to the part geometry. The complex, flat 3D parts may be instrument panels (ITs) for vehicles.

[0027] With reference to the Fig. 1A, Fig. 1B and Fig. 1C and Fig. 2, a robotic sewing device 101 is provided, which includes a sewing head body 110, an upper arm 120 attached to the sewing head body 110 and having a sewing needle 121 aligned along a first axis A1 and a foot 122 through which the sewing needle 121 extends, a motor 130, a forearm rotary drive train 140, and a forearm 150. The forearm 150 is rotatably attached to the sewing head body 110 such that it is rotatable about a second axis A2. The second axis A2 is defined transversely or perpendicularly with respect to the first axis A1. The rotation of the forearm 150 is drivable by the motor 130 via the forearm rotary drive train 140.

[0028] The lower arm rotation drive train 140 includes a set of spur gear 141 and pinion 142, and an angle gear 143 coupled to the motor 130. The motor 130 drives the angle gear 143, and the angle gear 143, in turn, drives the spur gear 141 via the pinion 142. The spur gear 141 is attached to the lower arm 150 such that when the spur gear 141 is driven by the pinion 142, the lower arm 150 is caused to rotate about the second axis A2. The lower arm 150 is attached to a horizontal center shaft 144 that protrudes from the column portion 145 of the sewing head body 110. The lower arm 150 may be mounted on a plain bearing so that the lower arm 150 is supported by the horizontal center shaft 144 but does not move with it as it rotates.

[0029] According to embodiments, the horizontal center shaft 144 may have a diameter of up to 16 mm or more to improve the integrity and rigidity of the mechanism.

[0030] The forearm 150 includes a throat plate 160, a butterfly gripper 170, a first drive train 180, and a second drive train 190. The first drive train 180 is extendable through the interior of the forearm 150 and configured to maintain a position of the throat plate 160 relative to the sewing needle 121 during rotation of the forearm 150. The second drive train 190 is extendable through the interior of the forearm 150 and configured to drive the butterfly gripper 170 during rotation of the forearm 150.

[0031] According to embodiments, the lower arm 150, the first drive train 180, and the second drive train 190 can be U-shaped, respectively. Thus, the upper arm 120, the sewing needle 121, the foot 122, and the lower arm 150 together define a substantially empty inner sewing area 201. This substantially empty inner sewing area 201 provides sufficient space for accommodating portions of an object to be sewn, e.g., an instrument panel. The rotatability of the lower arm 150 effectively increases the size and utility of the substantially empty inner sewing area 201 by allowing the lower arm 150 to be moved out of the path of the object during certain sewing operations.

[0032] The throat plate 160 is cantilevered on a horizontal shaft. The first drive train 180 includes a bevel gear 181, a set of interconnected shafts 182, and a connecting gear 183 disposed below the throat plate 160 and to which the set of interconnected shafts 182 is connected. The bevel gear 181 is attached to the sewing head body 110. As the lower arm 150 rotates about the horizontal center shaft 144, the bevel gear 181 drives the set of interconnected shafts 182, and the set of interconnected shafts 182, in turn, drives the connecting gear 183. As the lower arm 150 and the set of interconnected shafts 182 rotate, the connecting gear 183 can be driven at a 1:1 ratio to the lower arm 150.Therefore, when the lower arm 150 rotates, the needle plate 160 rotates relative to the lower arm 150 and maintains its rotational position relative to the sewing needle 121, the foot 122, and the rest of the sewing head body 110.

[0033] According to embodiments and as described in the Fig. 1A, Fig. 1B and Fig. 1C, the forearm 150 is rotatable about the second axis A2 by up to 160 degrees or more. This means that the forearm 150 can be rotated clockwise from a central position by up to 80 degrees or more about the second axis A2 (see Fig. 1B), and the forearm 150 can be rotated counterclockwise from the center position by up to 80 degrees or more about the second axis A2 (see Fig. 1C).

[0034] The 170 butterfly hook is a butterfly-like hook that moves through a continuous rotary motion. This contrasts with conventional crescent hooks and lockstitch mechanisms commonly used in most robotic sewing heads. The 170 butterfly hook was chosen over a lockstitch mechanism due to its compact design, easy integration into the 150 forearm, and the advantages of using chainstitch over lockstitch.

[0035] With further reference to Fig. 2 and with additional reference to the Fig. 3A, Fig. 3B and Fig. 3C, the second drive train 190 drives the butterfly hook 170 and is connected to a bevel gear 191 mounted on the horizontal center shaft 144. The second drive train 190 includes a set of interconnected bevel shafts 192 driven by the bevel gear 191, a pulley 193, a belt 194 that transmits rotation from the set of interconnected bevel shafts 192 to the pulley 193, a throat plate support and pulley housing 1945, and a gear train 195. The butterfly hook 170 is driven by the pulley 193, which in turn is driven by the belt 194. The butterfly hook 170 is carried by the throat plate 160, which maintains its rotational position relative to the sewing needle 121, the foot 122 and the rest of the sewing head body 110 via the gear transmission 195.The throat plate 160 is attached to the lower arm 150 via a structural component 196, which includes a bearing 197 that allows the throat plate 160 to rotate while being constrained in several axes. A sheet metal shield 198 prevents material from contacting the pulley 193.

[0036] With reference to Fig. 4, and according to embodiments, at least one of the first drivetrain 180 and the second drivetrain 190 may include concentric shafts 401 to reduce space requirements. That is, in the first drivetrain 180, at least a portion of the set of interconnected shafts 182 may include or be provided with the concentric shafts 401, and in the second drivetrain 190, at least a portion of the set of interconnected tapered shafts 192 may include or be provided with the concentric shafts 401.

[0037] With reference to Fig. 5 and according to embodiments, the robotic sewing device 101 may further include a counterweight 501 (the motor 130 has been removed for clarity). The counterweight 501 may be disposed on the forearm 150 and may be configured to effectively reduce the torque requirement associated with rotation of the forearm 150. The counterweight 501 may be oriented so as not to intrude into the substantially empty interior sewing area 201 or to limit intrusion into the substantially empty interior sewing area 201 to a practical extent.

[0038] With reference to Fig. 6 and according to embodiments, the robotic sewing device 101 may further include a bearing 601 with a support member 602, which may be supportingly disposed on the sewing head body 110 to support the forearm 150 against the sewing head body 110. The bearing 601 and support member 602 enable rotation of the forearm 150 and may be disposed around the horizontal center shaft 144. In this configuration, the bearing member 601 and support 602 effectively replace a support for the forearm 150 mounted on the horizontal center shaft 144.

[0039] With reference to Fig. 7 and according to embodiments, the robotic sewing device 101 may further include wings 701 extending outwardly from the sewing head body 110 in opposite directions to form a support plane for the rotation of the forearm 150 and the roller bearings 702. The roller bearings 702 are attachable to the forearm 150 and provide support for the forearm 150 against the wings 701 during rotation of the forearm 150. The rotational length of the wings 701 may be at least sufficient to support the full rotational capability of the forearm 150.When the forearm 150 can be rotated clockwise from the center position by up to 80 degrees or more about the second axis A2, one of the wings 701 extends far enough to support the entire clockwise rotation of the forearm 150, and when the forearm 150 can be rotated counterclockwise from the center position by up to 80 degrees or more about the second axis A2, the other of the wings 701 extends far enough to support the entire counterclockwise rotation of the forearm 150.

[0040] With reference to Fig. 8, the robotic sewing device 101 may include a programmable control system 801, and the programmable control system 801 may include a sensor system 802. The programmable control system 801 may include a processing unit, a memory for storing executable instructions that can be read and executed by the processing unit, the processing unit controlling the operations of the robotic sewing device 101 according to measured values from the sensor system 802, and an input / output (I / O) unit via which the processing unit communicates with the robotic sewing device 101 and the sensor system 802.The programmable control system 801 can thus be configured to robotically control the sewing head body 110, the upper arm 120, the sewing needle 121, the lower arm 150, the rotation of the lower arm 150, and the respective operations of the first drive train 180 and the second drive train 190 without operator intervention. The sensor system 802 can be configured to measure a distance between the lower arm 150 and the article to be sewn. The programmable control system 801 can further be configured to modify a programmed operation of the sewing head body 110, the upper arm 120, the sewing needle 121, the lower arm 150, the rotation of the lower arm 150, and the respective operations of the first drive train 180 and the second drive train 190 according to the measured values of the sensor system 802.For example, to the extent that a size, shape, and / or configuration of the object to be sewn deviates from a nominal size, shape, and / or configuration, thereby creating a risk that a portion of the robotic sewing device 101 will impact the object during sewing, the sensor system 802 is capable of detecting a potential impact, and the programmable control system 801 is capable of modifying the programmed operation to avoid the potential impact when alerted to the potential impact by the sensor system 802.

[0041] Although the various embodiments described above have been described separately, they can of course be combined in various combinations. It is further understood that configurations other than those described above are also possible. For example, the motor 130 and the forearm rotary drive train 140 can be motorized by motorizing the roller bearings 702 according to Fig. 7, which in turn enables corresponding modifications to the first drive train 180 and the second drive train 190.

[0042] With reference to Fig. 9, a method 900 for operating a robotic sewing device, such as the robotic sewing device 101 described above, is provided. As in Fig.9, the method 900 may include programming the robotic sewing device to perform a sewing operation with respect to an article (block 901) and controlling the robotic sewing device according to the programming (block 902). The controlling according to block 902 may include operating an upper arm with a sewing needle aligned along a first axis (block 9021), rotating a forearm about a second axis defined transversely with respect to the first axis (block 9022), controlling a first drive train extending through the forearm to maintain a position of a needle plate of the forearm during rotation of the forearm (block 9023), and controlling a second drive train extending through the forearm to drive a gripper of the forearm during rotation of the forearm (block 9024).According to further embodiments, the method 900 may further comprise detecting a distance between the forearm and the object (block 903), determining whether the distance is less than a predetermined distance such that there is a risk of potential impact as described above (block 904), and, if the distance is less than the predetermined distance, modifying the control of block 902 according to the programming to increase the distance (block 905).

[0043] Technical effects and advantages of the present disclosure lie in the provision of a robotic sewing device capable of sewing complex, flat 3D parts. The robotic sewing device has a rotatable lower arm, which allows the lower arm to be rotated while maintaining the needle plate position relative to the upper part of the sewing device while actively sewing a part. While the part is being sewn, the lower arm can thus be maneuvered and repositioned to optimally adapt the sewing device to the part geometry.

[0044] The term "approximately" is intended to encompass the degree of error associated with the measurement of a particular quantity based on the equipment available at the time the application is filed. For example, "approximately" may encompass a range of ± 8%, 5%, or 2% of a particular value.

[0045] 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" include the plural forms unless the context clearly indicates otherwise. It is further understood that the terms "comprising" and / or "including" throughout this specification specify the presence of certain 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.

[0046] Although the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements without departing from the scope of the present disclosure. Moreover, 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 of the disclosure. Therefore, it is intended that the present disclosure not be limited to the particular embodiment contemplated as the best mode for carrying out the present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 571,783

[0001]

Claims

[1] Robotic sewing device comprising: a sewing head body; an upper arm attachable to the sewing head body and including a sewing needle aligned along a first axis; an engine; and a lower arm rotatably attachable to the sewing head body to be rotatable by the motor about a second axis defined transversely with respect to the first axis, the lower arm comprising: a needle plate; a butterfly gripper; a first drive train extendable through the forearm and configured to maintain a position of the throat plate during forearm rotation; and a second drive train extendable through the forearm and configured to drive the butterfly gripper during forearm rotation. [2] The robotic sewing device of claim 1, wherein the upper arm, the sewing needle and the forearm define an empty inner sewing area. [3] Robotic sewing device according to claim 1, wherein the lower arm is rotatable 160 degrees about the second axis. [4] Robotic sewing device according to claim 1, wherein the lower arm and the first and second drive trains are respectively U-shaped. [5] The robotic sewing device of claim 1, wherein at least one of the first and second drive trains comprises concentric shafts. [6] The robotic sewing device of claim 1, further comprising a counterweight that can be arranged to reduce a torque requirement of the forearm. [7] A robotic sewing device according to claim 1, further comprising a bearing that can be supportively arranged on the sewing head body to support the forearm against the sewing head body. [8] Robotic sewing device according to claim 1, further comprising: wings extendable outwardly from the sewing head body; and Roller bearings that can be attached to the forearm to support the forearm against the wings during forearm rotation. [9] The robotic sewing device of claim 1, further comprising a programmable control system configured to robotically control the sewing head body, the upper arm, the forearm, and the forearm rotation, wherein: the programmable control system comprises a sensor system for measuring a distance between the forearm and an object to be sewn and the programmable control system is configured to modify a programmed operation of the sewing head body, the upper arm, the forearm and the forearm rotation according to measured values of the sensor system. [10] Robotic sewing device comprising: a sewing head body; an upper arm attachable to the sewing head body and including a sewing needle aligned along a first axis; an engine; a forearm rotary drive train; and a lower arm rotatably mounted on the sewing head body to be rotatable by the motor via the lower arm rotation drive train about a second axis defined transversely with respect to the first axis, the lower arm comprising: a needle plate; a butterfly gripper; a first drive train extendable through the forearm and configured to maintain a position of the throat plate during forearm rotation; and a second drive train extendable through the forearm and configured to drive the butterfly gripper during forearm rotation. [11] A robotic sewing device according to claim 10, wherein the upper arm, the sewing needle and the forearm define an empty inner sewing area. [12] Robotic sewing device according to claim 10, wherein the lower arm is rotatable 160 degrees about the second axis. [13] Robotic sewing device according to claim 10, wherein the lower arm and the first and second drive trains are respectively U-shaped. [14] The robotic sewing device of claim 10, wherein at least one of the first and second drive trains comprises concentric shafts. [15] A robotic sewing device according to claim 10, further comprising a counterweight that can be arranged to reduce a torque requirement of the forearm. [16] Robotic sewing device according to claim 10, further comprising a bearing which can be arranged supportingly on the sewing head body for supporting the lower arm against the sewing head body. [17] Robotic sewing device according to claim 10, further comprising: wings extendable outwardly from the sewing head body; and Roller bearings that can be attached to the forearm to support the forearm against the wings during forearm rotation. [18] The robotic sewing device of claim 10, further comprising a programmable control system configured to robotically control the sewing head body, the upper arm, the forearm, and the forearm rotation, wherein: the programmable control system comprises a sensor system for measuring a distance between the forearm and an object to be sewn and the programmable control system is configured to modify a programmed operation of the sewing head body, the upper arm, the forearm and the forearm rotation according to measured values of the sensor system.

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