An interlock is a feature that makes the state of two mechanisms or functions mutually dependent. It may be used to prevent undesired states in a finite-state machine, and may consist of any electrical, electronic, or mechanical devices or systems. In most applications, an interlock is used to help prevent a machine from harming its operator or damaging itself by preventing one element from changing state due to the state of another element, and vice versa. Elevators are equipped with an interlock that prevents the moving elevator from opening its doors, and prevents the stationary elevator (with open doors) from moving. Although both are idiot proof strategies, an interlock should not be confused with a simple safety switch. For example, in a typical household microwave oven, the switch that disables the magnetron if the door is opened is not an interlock. Rather, it would be considered an interlock if the door were locked while the magnetron is on, and the magnetron were prevented from operating while the door is open. Interlocks may include sophisticated elements such as curtains of infrared beams, photodetectors, a computer containing an interlocking computer program, digital or analogue electronics, or simple switches and locks.
An overlock is a kind of stitch that sews over the edge of one or two pieces of cloth for edging, hemming, or seaming. Usually an overlock sewing machine will cut the edges of the cloth as they are fed through (such machines being called “sergers” in North America), though some are made without cutters. The inclusion of automated cutters allows overlock machines to create finished seams easily and quickly. An overlock sewing machine differs from a lockstitch sewing machine in that it uses loopers fed by multiple thread cones rather than a bobbin. Loopers serve to create thread loops that pass from the needle thread to the edges of the fabric so that the edges of the fabric are contained within the seam.
Overlock sewing machines usually run at high speeds, from 1000 to over 9000 rpm, and most are used in industry for edging, hemming and seaming a variety of fabrics and products. Overlock stitches are extremely versatile, as they can be used for decoration, reinforcement, or construction.
Overlocking is also referred to as “overedging”, “merrowing”, or “serging”. Though “serging” technically refers to overlocking with cutters, in practice the four terms are used interchangeably.
To fit or clasp together securely.
A safety device that prevents activation in unsafe conditions.
“The demonstrator couldn’t figure out why the machine wouldn’t work, until he remembered that there was an interlock so it wouldn’t operate with the cover open.”
A edging, hemming or seaming.
To stitch in this manner.
To make the bolt of a lock go too far.
(of two or more things) engage with each other by overlapping or by the fitting together of projections and recesses
“their fingers interlocked”
lock or join (things) together
“the two planes were almost interlocked as they climbed together”
a device or mechanism for connecting or coordinating the function of different components
“a safety interlock to stop the blades spinning”
a fabric knitted with closely interlocking stitches allowing it to stretch
“a cotton interlock in black or plum”
“a dress in soft interlock”
strengthen and prevent fraying of (an edge of cloth) by oversewing it
“the seams are well stitched and overlocked to prevent fraying”