A feed dog is a movable plate which pulls fabric through a
sewing machine
A sewing machine is a machine used to sew fabric and materials together with Thread (yarn), thread. Sewing machines were invented during the first Industrial Revolution to decrease the amount of manual sewing work performed in clothing companies. ...
in discrete steps between stitches.
Action
A set of feed dogs typically resembles two or three short, thin metal bars, crosscut with diagonal teeth, which move both front to back and up and down in slots in a sewing machine's needle plate: front to back to advance fabric gripped between the dogs and the presser foot toward the needle, and up and down to recess at the end of their stroke, release the fabric, and remain recessed while returning before emerging again to begin a new one.
Name
A
mechanical dog is named to suggest the jaw or teeth of a dog, the animal, clamped on to an object, refusing to let go.
This arrangement is called "drop feed" in reference to the way the dogs drop below the needle plate when returning for the next stroke.
Allen B. Wilson invented it during the time period 1850 to 1854,
[The date of 1850 is given by James Paton in his "Sewing Machines" article in the Encyclopædia Britannica 10th Edition, Retrieved 2010-08-06 from http://www.1902encyclopedia.com/S/SEW/sewing-machines.html, but as noted, Wilson's idea evolved over the course of his patents] while also developing the
rotary hook
The rotary hook (aka rotating hook) is a bobbin driver design used in lockstitch sewing machines of the 19th and 20th century and beyond. It triumphed over competing designs because it can run at higher speeds with less vibration. Rotary hooks an ...
. Wilson called it a "four-motion feed", in reference to the four movements the dogs perform during one full stitch: up into the fabric, back to pull the fabric along to the next stitch, down out of the fabric and below the needle plate, and then forward to return to the starting position.
Stitch length
Virtually all drop-feed sewing machines can vary their stitch length; this is typically controlled by a lever or dial on the front of the machine. They are usually also capable of reversing the feed dogs' motion to pull the fabric ''backwards'' to form a
backstitch
Backstitch or ''back stitch'' and its variants ''stem stitch'', ''outline stitch'' and ''split stitch'' are a class of embroidery and sewing stitches in which individual stitches are made backward to the general direction of sewing. In embroid ...
.
See also
*
Dog (engineering)
In engineering, a dog is a tool or part of a tool, such as a pawl, that prevents or imparts movement through physical engagement. It may hold another object in place by blocking it, clamping it, or otherwise obstructing its movement. Or it may c ...
References
Sewing machines
{{Fashion-stub