The underwriter's knot is used in
electrical wiring as
strain relief to prevent a
cable
Cable may refer to:
Mechanical
* Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof
* Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...
from being pulled from
electrical terminal
Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection betwee ...
s when the cable is yanked.
History
Clifford Ashley
Clifford Warren Ashley (December 18, 1881 – September 18, 1947) was an American artist, author, sailor, and knot expert.
Life
Ashley was born in New Bedford, Massachusetts, son of Abiel Davis Ashley and Caroline Morse. He married Sarah Scudder ...
listed it as an electrician's knot in 1944. He suggested it be used "where rough treatment is expected" and described it as a two-strand
wall knot.
The name may come from its use by fire underwriters, who understood its importance in electrocution and fire prevention.
Function
The knot is typically used as a
stopper knot
Stopper may refer to:
* Bung, a plug used to stop the opening of a container
** Laboratory rubber stopper, a specific type of bung
* Plug (sanitation), used to stop a drainage outlet
* Defender (association football), in soccer (association foo ...
where a lamp or appliance cord passes through a hole or slot of a plug or socket. Its purpose is to "reduce strain on the screw terminal connections—where the metal parts of the wires connect to the socket or plug—and prevent the wires from pulling free."
See also
*
List of knots
This list of knots includes many alternative names for common knots and lashings. Knot names have evolved over time, and there are many conflicting or confusing naming issues. The overhand knot, for example, is also known as the thumb knot. The ...
References
External links
How to tie an Underwriter's Knot. ''Animated Knots.''
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Climbing knots
Double knots
Cables