A Bowden cable is a cable mechanism utilizing a thin stranded wire that moves inside of a flexible outer housing. The Bowden cable has been in use since the late 1800s and was designed to take the place of complex cable and pulley mechanisms for bicycles and automobiles. The hollow outer housing of this device is usually constructed of spirally wound steel wire encased in a plastic sheath. The inner wire of this mechanism is typically used to perform a pulling movement although it is sometimes provides a pushing force in shorter applications. Bowden cables are most often used in automobile and motorcycle clutches and throttles.
The first patent for the Bowden cable was issued to Ernest Monnington Bowden in 1896. The cable was originally intended to be used as part of a braking mechanism for bicycles and was well received by cycling enthusiasts. The original Bowden brake mechanism consisted of braking stirrup containing a set of rubber pads mounted in line with the metal rim of the rear wheel. The stirrup was controlled by a Bowden cable connected to a lever mounted on the bicycle’s handlebars. This early mechanism required expert installation to provide reliable and effective braking force.
The outer housing of a typical Bowden cable is constructed of a tightly wound helix of either square or round steel wire. This housing is usually encased in some type of plastic material to prevent rust and corrosion from forming on both the outer and inner steel wires. Modern versions of this cable employ a plastic lining inside of the housing to further reduce the risk if corrosion and rust. Some form of dry lubricant is usually applied to promote smooth operation of the inner wire. Some outer housings have hollow threaded ends to facilitate adjustments in length when needed.
In pulling operations, the inner wire of this cable is typically made of stranded steel wire. Heavy duty cables may also have a solid steel wire in the center of the stranded wire. Bowden cables in pushing operations typically contain a single steel wire inside of a hollow plastic housing. A Bowden cable that pulls is generally much more flexible than one used for pushing. In braking and shifting applications, the ends of the inner wire typically have a small piece of metal attached for connection purposes.
Bowden cables are used in a wide variety of applications for automobiles, motorcycles, and bicycles. Pulling cables are commonly utilized for throttles, shifters, brakes, clutches, and cruise control devices. Pushing cables are often employed in lawnmower and tractor throttles and choke mechanisms. Bowden cables have many aircraft applications such as throttle controls, propeller pitch mechanisms, and flap adjustment.