Pullstring

String, cord, or chain wound on a spring-loaded spindle that engages a mechanism when pulled

A pullstring, pullcord, or pullchain is a string, cord, or chain wound on a spring-loaded spindle that engages a mechanism when it is pulled. It is most commonly used in toys and motorized equipment. More generally and commonly, a pullstring can be any type of string, cord, rope, or chain, attached to an object in some way used to pull or mechanically manipulate part of it.

This keyword could refer to multiple things. Here are some suggestions: