Sewing – Method of sewing – On specified product
Reexamination Certificate
1999-11-18
2001-05-01
Nerbun, Peter (Department: 3741)
Sewing
Method of sewing
On specified product
C112S470140, C112S470350
Reexamination Certificate
active
06223668
ABSTRACT:
The invention relates to manufacture of sports balls, in particular, inflatable sports balls, formed of stitched panels.
BACKGROUND OF THE INVENTION
Inflatable sports balls, such as for soccer and volleyball, are formed of multiple panels stitched together at seams formed along adjacent panel edges to form a cover, within which an inflatable bladder is placed prior to closure. The panels of these sports balls are typically stitched together by hand, although a pending application by the present inventor, as well as U.S. Pat. No. 5,759,123 and U.S. Pat. No. 5,772,545, describe air-inflatable sports balls with at least some of the panels joined by machine stitching.
The traditional hand stitch process is often facilitated by a device that consists of a triangular frame, formed, e.g., of bamboo or other suitable material, and open at the apex. A pair of panels to be stitched together is placed in the opening with the edges to be stitched and the stitch holes in alignment (typically the stitch holes are formed through both panels in a single punching or piercing operation). The worker then uses his or her legs to apply inwardly directed pressure to the opposite sides of the frame to grip the panels while he or she uses two hands to pass opposite ends of a stitching fiber or yarn through the holes, and to tighten the stitching fiber by pulling the ends in opposite directions. When stitching of an edge is completed, leg pressure against the frame is released, the stitched pair of panels is removed, and another pair of panels is placed within the frame opening for hand stitching.
The intensive hand labor required to hand stitch an inflatable sports ball dictates that manufacturing operations using traditional methods be conducted in countries with relatively low labor costs, i.e., countries of the Far East and Asia, such as China and Pakistan. The labor intensity of hand stitching also generally limits production to about four balls per working day for an average worker.
SUMMARY OF THE INVENTION
According to one aspect, the invention features a method for hand stitching of multi-panel sports balls. The method includes (a) moving the free ends of opposed gripping arms of a panel gripping assembly into an open position; (b) positioning a pair of panels to be stitched to form a multi-panel sports ball between the free ends, with edges of the panels and holes formed along the edges being in position for stitching; (c) allowing the free ends to move from the open position to a closed position; (d) forming a first stitch in the panels by passing a stitching fiber through a first set of aligned holes in the panels; (e) engaging opposite ends of the stitching fiber in first and second gripping members disposed at opposite sides of said gripping arms; (f) tightening the first stitch by actuating a pneumatic cylinder associated with the first and second gripping members to move the first and second gripping members relatively apart; (g) removing the opposite ends of the stitching fiber from the first and second gripping members; and (h) repeating the stitch-forming and stitch-tightening steps to form subsequent stitches, until stitching along the edge is completed.
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The method includes the further step of replacing or repositioning the panels after stitching along the edge is completed, so that a second edge is positioned for stitching, and repeating the stitch-forming and stitch-tightening steps until stitching along the second edge is completed. The method further includes stitching along subsequent edges to form a ball cover. The method further includes the step of allowing the opposite ends of the stitching fiber and said first and second gripping members to align in common horizontal and vertical axes during the tightening step. The method further includes the step of allowing the first and second gripping members to adjust axially relative to the panels held in the gripping arms to accommodate the opposite ends of the stitching fiber having different lengths. The tightening step includes actuating the pneumatic cylinder by depressing a foot pedal to move the first and second gripping members relatively apart, e.g. under pressure preadjusted by a control valve mounted to the apparatus. The step of moving the free ends of the gripping arms into the open position includes applying pressure to the lever arm. The step of allowing the free ends to move from the open position to the closed position includes releasing the pressure from the lever arm.
In another aspect, the invention features an apparatus for hand stitching of multi-panel sports balls. The apparatus includes a panels gripping assembly including (a) a pair of opposed gripping arms having opposed free ends mounted for relative movement between a first, closed position gripping a pair of panels to be stitched and second, open position for releasing a stitched pair of panels and receiving a pair of panels to be stitched, (b) a biasing member urging the opposed free ends toward the first, closed position; and (c) a lever arm urging the free ends toward the second open position in response to pressure applied by a user; and a stitching fiber tensioning assembly including (a) a first string gripping member and a second string gripping member disposed at opposite sides of said pair of opposed gripping arms and positioned to releasably hold opposite ends of a stitching string in generally common horizontal and vertical planes during stitch tensioning; and (b) a pneumatic cylinder adapted, when actuated by the user, to urge the first and second string gripping members apart with a predetermining tensioning force during stitch tensioning, said first and second string gripping members being slidably mounted upon said frame relative to said pair of gripping arms, wherein, during tensioning of the stitching string, said first and second gripping members slide relative to said pair of gripping arms to accommodate application of uniform tensioning to opposite ends of a stitching string having different lengths.
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The first and second string gripping members are mounted for axial movement on a pair of substantially parallel posts, so that as stitching of the panels progresses, the axial positions of the gripping members adjust as tension is applied to the stitching fiber by the pneumatic cylinder. The biasing member includes a spring. At least one of the opposed gripping arms is hinged to allow rotation between the open and closed positions.
The invention thus provides an apparatus and method for hand stitching multi-panel sports balls with increased uniformity and quality of stitching and tension, and also with improved efficiency.
Other features and advantages will be apparent from the following description of a presently preferred embodiment, and from the claims.
REFERENCES:
patent: 3151584 (1964-10-01), Fossa
patent: 4248165 (1981-02-01), Addy
patent: 4403557 (1983-09-01), Dietrich
patent: 5772545 (1998-06-01), Ou
Fish & Richardson P.C.
Joyful Long Industries, Ltd
Nerbun Peter
LandOfFree
Method and apparatus for hand stitching of sports balls does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for hand stitching of sports balls, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for hand stitching of sports balls will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2506201