Machine terminology

Parts of Sewing M/C 

The parts of the lockstitch machine, which are identified below,

• Arm: the horizontal part of the head that houses the drive shafts.
• Bed: the working surface of the machine under which is located the mechanism that handles the lower thread. On a flat bed machine, the bed rests in the cut out of the table.
• Belt (motor belt or machine belt): the circular strap that that transmits motion from the pulley to the hand wheel, allowing the machine to operate.
• Bobbin mechanism: the parts – bobbin, bobbin case, and bobbin tension spring – that control the lower thread and its tension.
• Bobbin winder: the part that fills another bobbin while the machine is stitching.
• Check spring (tension spring or take-up spring): a small wire spring behind or at he top of the tension discs. It provides a small amount of tension on the needle thread and acts as a shock absorber. On the same machines, the check spring is mounted separately.
• Faceplate: the cover on the left side of the head that covers the needle bar and presser bar.
• Feed dogs (feed dog, feeder, or feed): the toothed mechanism beneath the presser foot that moves fabric toward and backward.
• Fittings: the parts – presser foot, feed dogs, and throat plates- that control the cloth during stitching.
• Hand wheel (balance or fly wheel): the part that control the motion of the machine manually and/or electrically.
• Head: the part of the machine above table, containing the stitching mechanism.
• Heel: the back of the presser foot.
• Hook (rotary hook or machine hook):  a rotating device that hooks the needle thread to carry it around the bobbin and form the “lock” on the lockstitch.
• Knee lift (knee lifter or knee press): a lever mounted at the right under the sewing table to lift and lower the presser foot with the right knee.
• Motor: the electrical unit that drive the machine.
• Needle: the part that penetrates the fabric. it carries the thread to the hook or shuttle and up again to make the stitch.
• Needle bar: a vertical bar that holds one or more needles and moves the needle up and down.
• Needle screw (needle bar clamp): the screw that holds the needle in the needle bar.
• Oil gauge: the part that indicates the amount if oil in self oiling machine.
• Pan (machine pan): the metal pan under the head that catches oil, lint and metal shards. On self lubricating machines, it holds the oil.
• Presser bar: the bar to which the presser foot is attached.
• Presser bar lifter: a lever at the back of presser bar to raise and lower foot by hand. It is used to raise the presser foot when winding a bobbin and not stitching.(its use is discouraged in industrial sewing because it wastes time and energy)
• Presser foot: a device that holds the fabric in place for stitching.
• Presser regulator (presser dial): control that regulates the amount of presser on the presser foot.
• Pretension: a simple tension disc used to regulate the thread so that it will feed into the tension assembly evenly.
• Pulley: the wheel attached to the motor. It transmits motion from the motor to the hand wheel by means of a leather belt.
• Rotary hook assembly: the part that holds the bobbin case.
• Shuttle: an oscillating device that carries the needle thread around the bobbin and forms the “lock” stitch.
• Slack thread regulator: a metal hook or bar near the tension discs.
• Slide plate (slide or bed slide): a removable cover at the left of the machine bed that allows access to the lower mechanism.
• Sole (shoe or slipper): the bottom part of the presser foot that contacts to the cloth.
• Stand: a metal structure upon which the table is mounted.
• Stitch hole (needle hole): the hole in the throat plate. The needle carries the thread into the hole so that it can interlock with the bobbin thread.
• Stitch regulator: a device that regulates stitch length.
• Switch (power switch): a key or button that turns the machine on or off.
• Table: the cabinet upon which the head rests. It generally has a drawer on the left side.
• Take-up lever: the part that first loosens the top thread during the stitch formation, then removes any slack to set or lock the stitch.
• Take-up lever guard: a piece of metal in front of the thread take-up lever.
• Tension discs: two concave discs that control the delivery of the upper thread from the spool to the needle.
• Thread guides (thread eyelets): the parts that guide the thread from the thread cone to the needle. They smooth the thread and protect it from abstraction.
• Thread retainer (pretension): a three-hole guide that applies a small amount of tension on the thread so it will flow into the tension discs uniformly.
• Thread stand: a metal device that holds thread cones.
• Throat plate: the smooth surface directly under the pressure foot that includes the stitch hole and surrounds the feed dog. It protects the lower mechanism from a build up of excess lint.
• Toes (prongs): the front end of the presser foot, or the part that faces the oncoming cloths. On feet such as the zipper foot, cording, and shirring foot, there is only one toe.
• Treadle (foot treadle): a metal platform on which the feet rests. (note: in case of an accident, the clutch control releases the hand wheel so that it can be turned )