Patent Description:
Currently, application of a decorative live stitch to pre-shaped automotive components can be accomplished via manual or automated stitching methods. Manual stitching is normally utilized on smaller components with relatively linear stitch paths. As part size, weight and stitch path complexity increase, it becomes more difficult for an operator to manually articulate the pre-shaped part under a stationary sewing machine and thus automation becomes more practical. An automated cell using a six-axis robot is commonly utilized with a sewing machine as the end effector. The sewing machine is designed to access required areas of the part within the range of motion of the robot.

As the trend to apply live stitching to pre-shaped automotive components continues to gain in popularity, the placement and type of stitching required is evolving as well. As the desired stitch path increases in length and/or covers a larger portion of the shaped part surface, additional movement of the sewing head around the outside of the part is required. Movement the sewing head around the outside of the part can present a problem when fixturing the part, however, and the movement can often exceed a range of motion of the robot as well. In addition, automotive manufacturers often prefer unique stitch types, patterns and thread sizes that are not easily provided by conventional sewing systems. Examples of prior art sewing machines are disclosed in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

According to the invention, a sewing machine for sewing a stitch into an article is provided. The sewing machine includes first and second heads, which are each movable relative to the article, a first head and a second head. The first head includes a coupler rotatable about an axis extending through the first and second heads, a first actuator element to rotate with the coupler and to translate relative to the coupler in first and second directions transverse to the axis, a second actuator element to rotate with the coupler, to translate in the first and second directions with the first actuator element and to rotate relative to the first actuator element about an axis along a third direction and a third actuator element to rotate with the coupler, to translate in the first and second directions with the first actuator element, to rotate with the second actuator element about the axis along the third direction and to translate relative to the second actuator element in the third direction. The second head includes a coupler rotatable about the axis in the third direction, a first actuator element to rotate with the coupler and to translate relative to the coupler in the first and second directions and a second actuator element to rotate with the coupler, to translate in the first and second directions with the first actuator element, and to translate relative to the first actuator element in the third direction.

In accordance with the invention, the first head includes first and second stitching elements.

In accordance with embodiments, the first stitching element includes a looper or a spreader and the second stitching element includes a punch or awl.

In accordance with additional or alternative embodiments, the first actuator element drives translations of the first stitching element relative to the coupler of the first head in the first and second directions, the second actuator element drives rotations of the first stitching element relative to the first actuation element and the third actuator element drives translations of the second stitching element relative to the first stitching element in the third direction.

In accordance with additional or alternative embodiments, a controller is configured to control and coordinate rotations of the coupler and translations and rotations of stitching elements of each of the first and second heads.

In accordance with additional or alternative embodiments, the controller includes a scanner to scan positions of a feature on the article and is configured correct for deviations between actual and allowable needle positions in accordance with predefined stitching instructions and the positions of the feature.

In accordance with additional or alternative embodiments, a first stitching element of the first head includes a looper or a spreader and a second stitching element of the first head includes a punch or awl.

In accordance with additional or alternative embodiments, a first stitching element of the second head includes a needle.

In accordance with additional or alternative embodiments, the first and second heads are coupled to first and second independently articulable robotic arms.

In accordance with additional or alternative embodiments, the first and second heads are coupled to a support structure.

In accordance with additional or alternative embodiments, the support structure includes a spine and first and second elongate members extending from the spine, the first and second elongate members having distal ends to which the first and second heads are coupled, respectively.

As will be described below, a sewing machine is provided with capabilities that meet current sewing demands. The sewing machine is intended for use in automated stitching applications and incorporates independent but synchronized upper and lower head rotations to eliminate a need to locate a machine body at a position perpendicular to the sewing path at all times. As a result, an ability to sew closed loop stitch paths is enhanced as is the capability to stitch curves having smaller radii into remote areas of a part. The sewing machine includes sewing heads that are each capable of +/-<NUM>° rotation and movement which can be driven mechanically, electro-mechanically or completely electrically. The sewing machine is designed such that the sewing heads are compact in size to allow for maximum maneuverability around a part. Functional capabilities of the machine are enhanced such that the following stitching technologies can be executed with only minor machine reconfiguration: single or double needle double thread chain stitch through soft materials; single or double needle single thread chain stitch through soft materials; single or double needle single thread chain stitch through rigid substrates; and single needle multi-thread embroidery stitching through soft materials. The sewing machine can also be designed such that the sewing heads can be decoupled with upper and lower heads attached to separate robots for further application flexibility.

With reference to <FIG>, a sewing machine <NUM>, not according to the claimed invention, is described and is capable of sewing various types of stitches into an article <NUM>. The sewing machine <NUM> includes a support structure <NUM>, which is movable relative to the article <NUM> and which is rotatable about an axis A1 that extends through the article <NUM>. The support structure <NUM> is movable in forward and back directions (i.e., first directions defined axially relative to the axis A3), side to side directions (i.e., second directions defined axially relative to the axis A1) and up and down directions (i.e., third directions defined axially relative to the axis A2).

In accordance with examples, the support structure <NUM> may include a spine <NUM>, a first elongate member <NUM> extending from a first end of the spine <NUM> and a second elongate member <NUM> extending from a second end of the spine <NUM> to be substantially parallel with the first elongate member <NUM>. The first elongate member <NUM> has a distal end <NUM> at its far end from the spine <NUM> and the second elongate member <NUM> has a distal end <NUM> at its far end from the spine <NUM>.

The sewing machine <NUM> further includes a first stitching head <NUM>, which is coupled to the support structure <NUM> at the distal end <NUM> of the first elongate member <NUM> and a second stitching head <NUM>, which is coupled to the support structure <NUM> at the distal end <NUM> of the second elongate member <NUM>. The first stitching head <NUM> can include or be provided with a first stitching element <NUM>. The first stitching element <NUM> can include a needle. The second stitching head <NUM> can include or be provided with a second stitching element <NUM>. The second stitching element <NUM> can include a looper.

The sewing machine <NUM> also includes a first actuation assembly <NUM>, a second actuation assembly <NUM> and, in some cases, a third actuation assembly <NUM>.

The first actuation assembly <NUM> is at least partially disposed within the support structure <NUM> and is configured to actuate sewing element <NUM> of the first stitching head <NUM> and the sewing element <NUM> of the second stitching head <NUM>. Actuation of the sewing element <NUM> occurs axially along axis A2 while actuation of the sewing element <NUM> occurs rotationally about an axis in parallel to axis A1. The first actuation assembly <NUM> includes a motor <NUM>, a mechanical linkage <NUM> that extends through the support structure <NUM>, a first coupling unit <NUM> by which the mechanical linkage <NUM> is coupled to the first stitching head <NUM> and a second coupling unit <NUM> by which the mechanical linkage <NUM> is coupled to the second stitching head <NUM>. The second actuation assembly <NUM> is at least partially disposed within the support structure <NUM> and is configured to drive respective rotations of each of the first stitching head <NUM> and the second stitching head <NUM> about axis A2. The second actuation assembly <NUM> includes a motor <NUM>, a mechanical linkage <NUM> that extends through the support structure <NUM>, a first coupling unit <NUM> by which the mechanical linkage152 is coupled to the first stitching head <NUM> and a second coupling unit <NUM> by which the mechanical linkage <NUM> is coupled to the second stitching head <NUM>.

Where it is available, the third actuation assembly <NUM> is configured to drive rotations of the support structure <NUM> about a second axis A1, such that the first stitching head <NUM> can operate above or below the article <NUM> and the second stitching head <NUM> can operate below or above the article <NUM>. In accordance with further examples, the sewing machine <NUM> may further include a scanner <NUM> that, prior to sewing, is configured to detect the relative position of a feature on the article <NUM> located along the stitch path, and provide feedback to the robot controller which in turn will adjust the coordinates of the predefined stitch path prior to sewing, resulting in part sewn in compliance with predefined stitching constraints.

With reference to <FIG>, a sewing machine <NUM> is provided for sewing a stitch into an article <NUM>. The sewing machine <NUM> includes a support structure <NUM>, which is movable relative to the article <NUM>. The support structure <NUM> is movable in forward and back directions (i.e., first directions defined linearly relative to axis A3), side to side directions (i.e., second directions defined linearly relative to the axis A1) and up and down directions (i.e., third directions defined linearly along the axis A2). The support structure <NUM> is also rotatable about the axis A1 and the article <NUM>.

In accordance with embodiments, the support structure <NUM> may include a spine <NUM>, a first elongate member <NUM> extending from a first end of the spine <NUM> and a second elongate member <NUM> extending from a second end of the spine <NUM> to be substantially parallel with the first elongate member <NUM>. The first elongate member <NUM> has a distal end <NUM> at its far end from the spine <NUM> and the second elongate member <NUM> has a distal end <NUM> at its far end from the spine <NUM>.

The sewing machine <NUM> further includes a first stitching head <NUM>, a second stitching head <NUM> and a drive assembly <NUM>. The first stitching head <NUM> is coupled to the support structure <NUM> at the distal end <NUM> of the first elongate member <NUM>. The second stitching head <NUM> is coupled to the support structure <NUM> at the distal end <NUM> of the second elongate member <NUM>. The first stitching head comprises a first stitching element <NUM> and a second stitching element <NUM>. The first stitching element <NUM> can include a looper or a spreader. The second stitching element <NUM> can consist of a punch or awl. The second stitching head <NUM> can include or be provided with a third stitching element <NUM>. The third stitching element <NUM> can include a needle.

The first stitching head <NUM> includes a coupler <NUM>, a first actuator element <NUM>, which is rotatable with coupler <NUM> about axis A2 and which is translatable relative to the coupler <NUM> in the first and second directions, a second actuator element <NUM> and a third actuator element <NUM>. The second actuator element <NUM> is translatable with the first actuator element <NUM> in the second and first directions along axes A1 and A3, is rotatable relative to the first actuator element <NUM> about axis A2 and is also rotatable with coupler <NUM> about the axis A2. The third actuator element <NUM> translates the second stitching element <NUM> relative to second actuator element <NUM> in the third direction along the axis A2, is translatable with the first actuator element <NUM>, is rotatable with the second actuator element <NUM> about the axis A2 and is also rotatable with the coupler <NUM> about the axis A2.

The second stitching body <NUM> includes a coupler <NUM>, a first actuator element <NUM>, which is rotatable with coupler <NUM> about the axis A2 and which is translatable relative to the coupler <NUM> in the first and second directions along axes A3 and A1, and a second actuator element <NUM>. The second actuator element <NUM> is translatable with the first actuator element <NUM> in the second and first directions along axes A1 and A3, is translatable relative to the first actuator element <NUM> in the third direction along the axis A2 and is rotatable with the coupler <NUM> about axis A2.

The drive assembly <NUM> is at least partially disposed within the support structure <NUM> to drive rotations of the first and second stitching heads <NUM> and <NUM> about the axis A2. The actuation assembly <NUM> includes a motor <NUM>, a mechanical linkage <NUM> that extends through the support structure <NUM>, a first coupling unit <NUM> by which the mechanical linkage <NUM> is coupled to the first stitching head <NUM> and a second coupling unit <NUM> by which the mechanical linkage <NUM> is coupled to the second stitching head <NUM>.

An additional drive assembly <NUM> is provided to drive rotations of the support structure <NUM> about the axis A1 during sewing. The additional actuation assembly <NUM> is also utilized to drive the rotations of the support structure <NUM> about the second axis A2 such that the first stitching head <NUM> can operate above or below the article <NUM> and the second stitching head <NUM> can operate below or above the article <NUM>.

In accordance with further embodiments, the sewing machine <NUM> may further include a scanner <NUM> that, prior to sewing, is configured to detect the relative position of a feature on the article <NUM> located along the stitch path, and provide feedback to the robot controller which in turn will adjust the coordinates of the predefined stitch path prior to sewing, resulting in part sewn in compliance with predefined stitching constraints.

With reference to <FIG>, a sewing machine <NUM> is provided for sewing a stitch into an article <NUM>. The sewing machine <NUM> includes a first head <NUM>, which is movable relative to the article <NUM>, and a second head <NUM>, which is movable relative to the article <NUM>.

The first head <NUM> includes a first actuator element <NUM>, which is rotatable about an axis A2 extending through the article <NUM> and the first and second heads <NUM> and <NUM>, a second actuator element <NUM>, a third actuator element <NUM>, a fourth actuator element <NUM>, and a first stitching element <NUM> that includes a looper or a spreader. The second actuator element <NUM> rotates with the first actuator element <NUM> and is translatable relative to the first actuator element <NUM> in first and second directions along axes A3 and A1 directions. The third actuator element <NUM>, which is directly coupled to the first stitching element <NUM>, rotates with the first actuator element <NUM>, is translatable with the second actuator element <NUM> and rotates relative to the second actuator element <NUM>. The fourth actuator element <NUM> translates a second stitching element <NUM> in the third direction along the axis A2, rotates with the first actuator element <NUM>, translates with second actuator element <NUM> and rotates with the third actuator element <NUM>.

The second head <NUM> includes a first actuator element <NUM>, which is rotatable about the axis A2, a second actuator element <NUM> and a third actuator element <NUM>. The second actuator element <NUM> rotates with the first actuator element <NUM> and is translatable relative to the first actuator element <NUM> in the first and second directions along the axes A3 and A1. The third actuator element <NUM> includes a third stitching element <NUM> and rotates with the first actuator element <NUM>, translates in the first and second directions along axes A3 and A1 with the second actuator element <NUM> and is translatable relative to the second actuator element <NUM> in the third direction along the axis A2.

As shown in <FIG>, the sewing machine <NUM> may be connected, via tool changers <NUM> and <NUM>, to first and second independently articulable robotic arms <NUM> and <NUM> to which the first and second heads <NUM> and <NUM> are coupled, respectively. The robotic arms <NUM> and <NUM> can allow the first and second heads <NUM> and <NUM> to operate at various positions and attitudes relative to the article <NUM> and to be disposed above or below the article <NUM>.

With reference to <FIG>, the first and second heads <NUM> and <NUM> can be coupled to a support structure <NUM>. The support structure <NUM> may include a spine <NUM>, a first elongate member <NUM> extending from a first end of the spine <NUM> and a second elongate member <NUM> extending from a second end of the spine <NUM> to be substantially parallel with the first elongate member <NUM>. The first elongate member <NUM> has a distal end <NUM> to which is the first head <NUM> is coupled at its far end from the spine <NUM> and the second elongate member <NUM> has a distal end <NUM> to which the second head <NUM> is coupled at its far end from the spine <NUM>.

Additional drive assembly <NUM> is provided to drive rotations of the support structure <NUM> about axis A1, as required in order to position the sewing machine <NUM> in it optimal position for stitching. The robot controller can be configured to drive the rotations of the support structure <NUM> about the axis A1 such that the first head <NUM> can operate above or below the article <NUM> and the second head <NUM> can operate below or above the article <NUM>.

Technical effects and benefits of the present disclosure are the provision of a sewing machine incorporating upper and lower sewing heads for use in automated stitching applications to eliminate a need to locate a machine body at a position perpendicular to the sewing path at all times and to enhance an ability to sew closed loop stitch paths and curves having small radii, such as the case when embroidering. In addition, the sewing machine provides for closed loop chain stitch patterns on large contoured parts that have no internal feature openings (which are normally required for sewing head access) as well as start and stop positions that are perfectly aligned to create the effect of multiple components sewn together. The sewing machine also provides for intricate and complex chain stitch patterns that are placed on large countered parts, stitching capabilities around entire perimeter and interior portions of such products (where the products contains minimal or no openings internal to the part for sewing head access) and patterns that can be programmed to create an image, logo or text on products (embroidery) requiring very tight directional changes and turning radii (e.g., in-plane turning radii or the stitch turning radius on the surface of the flat or contoured part of less than <NUM> and in some cases less than <NUM>) where the turning radii is dictated by stitch length and an ability to rotate/turn the needle and hook within short periods of time and over short distances.

Claim 1:
A sewing machine (<NUM>) for sewing a stitch into an article (<NUM>), the sewing machine (<NUM>) comprising:
first (<NUM>) and second heads (<NUM>), which are each movable relative to the article (<NUM>),
the first head (<NUM>) comprising:
a coupler (<NUM>) rotatable about an axis (A2) extending in a third direction and through the first (<NUM>) and second (<NUM>) heads and the article (<NUM>);
a first actuator element (<NUM>) to rotate with the coupler (<NUM>) and to translate relative to the coupler (<NUM>) in first and second directions transverse to the axis (A2);
a second actuator element (<NUM>) to rotate with the coupler (<NUM>), to translate in the first and second directions with the first actuator element (<NUM>) and to rotate relative to the first actuator element (<NUM>) about an axis along the third direction; and
a third actuator element (<NUM>) to rotate with the coupler (<NUM>), to translate in the first and second directions with the first actuator element (<NUM>), to rotate with the second actuator element (<NUM>) about the axis along the third direction and to translate relative to the second actuator element (<NUM>) in the third direction; and
the second head (<NUM>) comprising:
another coupler (<NUM>) rotatable about the axis (A2) extending in the third direction;
another first actuator element (<NUM>) to rotate with the another coupler (<NUM>) and to translate relative to the another coupler (<NUM>) in the first and second directions; and
another second actuator element (<NUM>) to rotate with the another coupler (<NUM>), to translate in the first and second directions with the another first actuator element (<NUM>), and to translate relative to the another first actuator element (<NUM>) in the third direction,
wherein the first head (<NUM>) comprises first (<NUM>) and second (<NUM>) stitching elements.