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US 4,470,360 AGranted
Sewing machine
OwnerLeif Gerlachinventor
Life of this patent
Estimating the term…
Abstract
A quilting machine employs bobbin holders which support bobbins each having a conical lower portion ending in a point. A plurality of hooks are driven in an eliptical path to engage and pull down a loop of thread formed by insertion of a needle through a needle plate and the partial withdrawal thereof. The hooks keep the loop open and pull it down so that it passes over the pointed lower end of the bobbin. In order to facilitate engagement of the loop over the bobbin, the bobbins are maintained in sloped fashion. A thread take-up mechanism pulls up the loop of thread with one of the strands of the loop passing behind the bobbin between the bobbin and the bobbin holder to form a lock stitch.
Claims9
A sewing machine, comprising:
- a needle plate having at least one needle hole therein;
- at least one needle having an eye proximate its point;
- means for entering said point through said needle hole whereby a thread loop is formed below said needle plate;
- at least one bobbin adapted for holding a supply of thread and for feeding out said thread under a controlled tension;
- at least one stationary bobbin basket adapted to freely gravity support said bobbin;
- means for preventing withdrawal of said bobbin from said bobbin basket;
- hook means for drawing said thread loop over an end of said bobbin;
- means for disengaging said hook means from said thread loop;
- means for withdrawing excess thread in said thread loop whereby one of a descending strand and an ascending strand passes between said bobbin and said bobbin basket to form a lock stitch with thread from said bobbin;
- and
- said means for preventing withdrawal of said bobbin including means for permitting said bobbin to be displaced in said bobbin basket by said thread sufficiently to allow said excess thread to pass between said bobbin and said bobbin basket.
8 more elements
A method for forming a stitch, comprising:
- forming a thread loop with a needle below a needle plate;
- freely gravity supporting a bobbin containing a thread in a stationary bobbin basket below said needle plate;
- engaging said loop with a hook;
- holding open and pulling down said loop with said hook;
- drawing said thread loop over an end of said bobbin;
- disengaging said hook;
- withdrawing excess thread in said loop to form a lock stitch with thread from said bobbin;
- and
- permitting said bobbin to be displaced in said bobbin basket by said thread sufficiently to allow said excess thread to pass between said bobbin and said bobbin basket.
6 more elements
A quilting machine, comprising:
- a needle plate;
- a plurality of spaced-apart needle holes in said needle plate;
- a plurality of needles aligned with said needle holes;
- means for controlling a supply of thread to an eye proximate a point of each of said plurality of needles;
- means for concertedly penetrating said plurality of needles through said needle holes whereby a plurality of thread loops is formed below said needle plate;
- a plurality of bobbins below said needl plate, each of said bobbins being associated with one of said plurality of needles;
- each of said bobbins containing a supply of thread and including means for feeding said thread out at a predetermined tension;
- a plurality of stationary bobbin baskets freely supporting said bobbins, said bobbin baskets surrounding at most a portion of a surface of said bobbins;
- an enlarged diameter portion on each of said bobbins engaging its associated bobbin basket to support said bobbin in its bobbin basket by gravity;
- a conical lower end ending in a point on each of said bobbins, said point being free of said bobbin basket;
- said bobbin baskets being disposed to position said point of each of said bobbins below its associated thread loop;
- a plurality of hooks, one hook associated with each of said needles;
- means for concertedly entering each of said hooks into the thread loop formed by its associated needle and for enlarging said thread loop and for drawing said thread loop over said point on said bobbin;
- means for disengaging said hooks from said thread loops;
- means for withdrawing excess thread in said thread loops through said needle holes, one of a descending and an ascending strand of each of said thread loops passing between its associated bobbin and bobbin basket whereby a lock stitch is formed;
- means for preventing removal of said bobbins from said bobbin baskets during withdrawal of excess thread;
- and
- said means for preventing removal including means for permitting said bobbin to be displaced in said bobbin basket by said thread sufficiently to allow said excess thread to pass between said bobbin and said bobbin basket.
15 more elements
Dependencies are inferred from the claim text.