Spencer Heath Archive

Item 2743

Photocopy of a printed card inviting demonstration of the Universal Propeller at Heath’s factory in Baltimore until January 15, 1922.

 

 

 

 

 

There is now on demonstration at the works of THE AMERICAN PROPELLER & MFG CO., 233-249 E. Hamburg St., Baltimore, Md. until January 15, 1922, a

 

UNIVERSAL PROPELLER

 

designed by Spencer Heath and now in operation on a 4,000 pound land machine under full load and power conditions. The blades of this propeller can be adjusted universally in their sockets for any angle of forward or reverse pitch while the engine is running, the power of the engine itself being used to effect the changes of pitch. A light pull or pressure on a button is all that is required to produce any change of pitch desired. When the engine is at rest the pitch may be altered or reversed by turning a small hand crank located conveniently to the operator. The machine accelerates or decelerates or travels forward or backward in response to changes of pitch. At all times and during all changes of pitch the exact position of the blades is graphically shown by an indicator on the instrument board.

 

 The speed of the engine is automatically controlled by the indicator mechanism so as to give the correct throttle position for every possible blade position and thus prevent racing or  stalling the engine by manipulation of the pitch. The engine is subject at all times, however, to manual control of the throttle which may at any time interrupt and supervene upon the automatic throttle control. The entire operating mechanism is entirely disengaged and the blades securely locked at all times except during change or adjustment of the pitch.

 

 You are invited to observe the operation of this Universal Paragon Propeller by appointment at any time until after January 15^th.