Elements of Brass Instrument Construction:  Allen Valves Allen Valves This valve type is characterized by long slender rotors; the tubing entering and exiting the rotor is flatter and longer than a normal rotary valve. Its design is attributed to Joseph Lathrop Allen, a Boston brass instrument maker, who produced his first valves of this type sometime after 1853. Allen's intention was to create a quicker action by reducing the diameter of the rotors. Its seemingly effortless movement helped the Allen valve become quite popular among 19th-century American players. Allen Valve Mechanism Valve construction seen from the left side Parts of an Allen valve (letters refer to diagrams above and below): a = valve casing b = rotor c = valve loop with slide d = main tubing e = port f = touchpiece k = push rod l = rotor spindle or shaft bearing m = pin stop n = stop cork o = valve cap p = reciprocal driver pivot q = screw to hold rotor in place r = pulley s = string t = return spring u = screw to hold string in place Allen Valve Case Diagram Right:  Arrangement of closed valve case Left:  Valve disassembled (from right to left):   rotor with cork buffers inside; disc with stopping protrusion; rotor spindle nut with attached reciprocal driver pivot; topping screw Return to Elements of Brass Construction National Music Museum The University of South Dakota 414 East Clark Street Vermillion, SD 57069 ©National Music Museum, 2007-2009 Most recent update: January 21, 2009 You are the 4,496th visitor to this page since September 20, 2007. The University of South Dakota Return to Top of Page