Sonic sealed bias seam

Details Sonic sealed bias seam Sonic sealed bias seam

1999-02-08

2001-05-08

Sells, James (Department: 1734)

Adhesive bonding and miscellaneous chemical manufacture

Methods

Surface bonding and/or assembly therefor

C156S073100, C156S193000, C156S203000, C156S267000

Reexamination Certificate

active

06228195

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a process and apparatus for forming a bias seam, and more specifically, to a process and apparatus for forming a bias seam using an ultrasonic sealing apparatus.
Bias binding containing a bias seam, or a seam on the bias, is generally used to bind edges or cover seams to give a product a finished look. The bias binding is arranged such that the threads or yarns of the fabric run on an angle from the edge rather than parallel or perpendicular to the edge. This permits the binding to have some elasticity or stretch enabling the binding to go around curves or comers and lay flat without puckering. A straight binding, i.e., not on the bias, would appear unappealing if sewn other than in a straight line as it would pucker when sewn around curves.
To prevent fraying of the edges. the edges to be sewn together are folded under to produce a “clean finish.” An apparatus for folding the binding edges is attached to the sewing machine. The apparatus folds each edge and guides it to the needle. The presently used sewn bias binding thus has two butterfly edges on the reverse side of the seam. The two-ply butterfly edges create bulk which can have difficulty passing through finishing attachments. In addition, the sewn seam has holes from the sewing needle and spaces between the stitches regardless of how close they are together. Hence, the seam is subject to leakage.
The folding apparatus described above is capable of accommodating single bindings and multiple bindings. When the seams of the bindings are passed through the folding apparatus, the butterflies on the back of the seam, especially with multiple bindings, cause considerable friction in the folding apparatus, which results in inconsistent feeding, irregular stitches and defects. Still further, there are times when the butterflies are caused to be turned back at the entrance of the folding apparatus resulting in three-ply bulk, thereby making the problem of friction even worse.
Sewn bias seams also have a tendency to pull apart slightly at the edges as it is impossible to lock either the first stitch or the last stitch.
Ultrasonic bonding is a well-known process in which high frequency vibrations are imparted into two or more plies of a thermoplastic material with a horn. The horn vibrates adjacent to an anvil which supports the material. The vibrations develop frictional heat at the seam interface, subsequently bonding the material together. Materials may also be cut or slit with an ultrasonic horn while sealing the edges. The ultrasonic horn couples mechanical vibrations into the material, while the anvil supports the material during the sealing process.
A review of the ultrasonic binding art indicates a need for a process of and an apparatus for forming a bias seam using an ultrasonic sealing apparatus.
U.S. Pat. No. 3,666,599 to Obeda describes an ultrasonic seaming apparatus in which the feed rate of the workpiece through the seaming station and the velocity of the resonator are interconnected in such a manner that both are varied in a predetermined relationship.
U.S. Pat. No. 3,852,144 to Parry describes an ultrasonic seaming and cutting apparatus having a resonant horn, a rotating anvil wheel and a cutting surface disposed in juxtaposition with the anvil wheel. The apparatus is adapted to simultaneously cut and fuse the material adjacent the seamed area without excessive wear in the instrumentality providing such cutting action.
U.S. Pat. No. 4,333,791 to Onishi describes an ultrasonic seam welding apparatus for seam welding at least two sheet-like work pieces piled one above the other. The seam welding is carried out by imparting the ultrasonic oscillation to the workpieces from the converter-horn assembly with the aid of the roller.
U.S. Pat. No. 4,373,982 to Kreager et al. describes an ultrasonic sealing apparatus where plastic film in sheet form is supplied to a forming unit which forms the plastic film into tubular form with overlapping edges. The edges are caused to pass along an anvil and the horn of an ultrasonic sealing unit for effecting ultrasonic sealing of the edges. The edges of the film are passed through a gap between the horn and the anvil.
A publication by Sonobond Ultrasonics Company titled “Ultrasonic Techniques for Thermoplastic Fabrics and Apparel” describes the ultrasonic sealing process in connection with thermoplastic fabrics and apparel. Under Cut and Seal Edge Finishing, the company describes sealing of the ends of a bias tape to prevent raveling using an ultrasonic apparatus. This process is unrelated to forming a bias seam.
For details concerning the design and construction of the ultrasonic sealing apparatus, reference is made to the book entitled “Ultrasonic Engineering” by Julian R. Frederick, John Wiley & Sons, Inc., New York, N.Y. (1965).
All patents and publications cited in the specification are herein incorporated by reference.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a process and apparatus for forming an ultrasonic bias seam that overcomes the above-described problems in the prior art.
It is another object of the present invention to provide a process and apparatus for forming an ultrasonic bias seam in which the resulting seam is strong, has a single ply, has a clean finished look and is sealed such that leakage is prevented through the seam.
The ultrasonic sealing operation is substantially faster than the sewing operation. Hence, the sonic sealed bias seam realizes another advantage over the prior art in being produced at a much faster rate of production. As a result, however, many adaptations had to be developed, especially in the feeding of the fabric, to accommodate the ultrasonic sealing apparatus.
These and other objects are obtained by providing a process of forming a sonic sealed bias seam using an ultrasonic sealing apparatus having an ultrasonic sealing head and an anvil. The process includes the steps of folding the fabric such that two edges are substantially adjacent one another periodically ensuring that the ultrasonic sealing apparatus is accurately tuned, sealing the edges with the ultrasonic sealing apparatus, thereby forming a tube of fabric, and cutting the tube of fabric in a spiral pattern at a predetermined angle.
In another aspect of the present invention, the process further includes, simultaneous with the sealing step, the steps of cutting selvage from the tube of fabric with the anvil and separating the selvage from the tube of fabric.
In another aspect of the present invention, the process further includes the step of feeding the selvage to a selvage disposal apparatus with a selvage feeding device, the selvage feeding device feeding the selvage at a speed substantially equal to a feed speed of the fabric.
In still another aspect of the present invention, the process further includes the step of controlling air pressure on the anvil. The air pressure is provided by an air pressure source. The controlling step further includes the steps of driving the anvil with the air pressure source to change its contact position relative to the horn, raising and lowering the anvil with the air pressure source, and cooling the anvil and the horn with the air pressure source.
In yet another aspect of the present invention, the cutting step includes the steps of feeding the tube of fabric over a supporting device, the supporting device supporting the tube of fabric in a tubular form, and rotating the supporting device while feeding the fabric in a direction parallel to a longitudinal axis of the tube of fabric through a knife assembly.
The apparatus of the present invention provides unique structure for performing the above-described process steps. In addition, the anvil is disposed within a housing. The selvage feeding device includes a pair of rollers adapted to pull the selvage to the selvage disposal apparatus, the rollers being driven by a motor. The selvage disposal apparatus includes a tube connected to a vacuum source, wherein the rollers feed the selvage in

Affiliated with

Also associated with

Rating

Sonic sealed bias seam does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Sonic sealed bias seam, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sonic sealed bias seam will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2454685