Phonograph Speed Reducer

Phonograph Speed Reducer



      This inexpensive device allows blind people to play talking-book records, available from the Library of Congress and the American Printing House for the Blind, which play at 8-1/3 RPM, half the slowest speed of 16-2/3 RPM on conventional record players.  


      This adapter is based on the principle of a car tire.  The bottom of the tire is in contact with the road and therefore is not moving (“traveling” at 0 MPH).  If the car is driven at 30 MPH, the top of the tire must move at 60 MPH in order to catch up and go around again.  The important relationship is a 2:1 ratio between the 60 MPH top of the tire, and the 30 MPH axle.


Phono Adapter-3 top-bttm

      The speed reducer is made of three layers and drops onto the turntable like a record.  The top and bottom layers are attached to each other at the central hub.  The middle layer with protruding arm (shown in red below) is stopped from turning by the support for the stylus arm.  


     The turntable rotates at 16-2/3 RPM.  The axles of three small rubber wheels, are attached to the lower plate of the speed reducer.  The wheels ride on the 16-2/3 RPM turntable.  The weight of the red middle plate keeps the tops of the wheels from turning, causing the wheel’s axles to move at half speed of 8-1/3 RPM which turns the record being played at 8-1/3 RPM.  


       The American Printing House for the Blind declined to license the device because they would not be able to sell their more expensive record players, showing no concern for their blind members.  


      This is not a product for sale.  Do not contact us to purchase this product.  This project is shown only as an example of past projects.  Steve Hines currently offers consulting in the area of industrial design, novel solutions to your problems as well as a variety of licensable technology.  


Glendale, California, USA


phone: 818-507-5812