Abstract: A machine for winding a filament, such as wire, on a normally stationary mandrel, the machine having a single winding element provided with guides for forming a filament loop on one side only of a rotational axis. Non-rotating feeding means supplies the filament to the rotating loop and means are provided for removing the turns from the mandrel. A binding or positioning element is fed from a supply located outside the zone of rotation of the winding element, the binding or positioning element being fed down inside the filament coils to secure them for removal from the mandrel. The binding or positioning element may be a wire or a solid rod supported by an extension of the mandrel which projects towards the filament feed. The mandrel extension may be an enlongated tube mounted in bearings in one or more fixed supports between the winding element and the filament feed.

Abstract: A machine is provided for coiling wire about a core filament, particularly for producing heat exchanger coils. The machine comprises a main frame, two coiling elements spaced from each other and mounted in the frame for rotation about substantially the same axis, a hollow mandrel on which the wire is to be coiled, the longitudinal axis of the mandrel substantially coinciding with said axis, and a wire guide on each of the coiling elements spaced from the said axis whereby a loop of wire may be formed with its ends substantially on the said axis and the remainder thereof spaced from the said axis. The machine further comprises means for rotating the two coiling elements in a substantially synchronous fashion so that wire guided about the elements is coiled on to the mandrel, means for preventing the mandrel from rotating relative to the frame, and means for feeding a core filament through the hollow mandrel.