Apparatus for winding helical wire coils

Abstract

Apparatus for winding helical wire coils which can be subdivided into discrete spiral binders for insertion into the perforations of steno pads, exercise books or like stationery products has a rotary mandrel whose periphery is adjacent to several rows of rotary wire guiding pins defining a helical path extending around the periphery of the mandrel. The axes of the pins are slightly offset with reference to radial positions relative to the mandrel so that the pins can readily rotate in response to lengthwise movement of the wire therealong and their inner end faces can be placed sufficiently close to the periphery of the mandrel so as to prevent a thin wire from penetrating into the space between the end face of a pin and the periphery of the mandrel. When a feeding device supplies a continuous length of wire into the inlet of the helical path, the wire is entrained by the periphery of the mandrel and is caused to advance along the helical path with attendant conversion into the convolutions of a coil moving axially of the mandrel under the action of the pins which rotate in response to movement of the wire therealong. Those end portions of the pins which are immediately adjacent to the mandrel may resemble conical frusta. The pins are mounted in holders which are adjustable axially of the pins, and each pin is adjustable axially in the respective holder.