Electronic musical keyer with touch responsive volume control employing a mechanical electrical transducer

Claim 1

A keyboard device for an electronic musical instrument comprising a plurality of keys swingable about a fulcrum, a lever located near each of said keys, a pivot shaft swingably supporting said lever, a weight disposed near the free end of said lever, a mechanical-electrical transducer including a movable element attached to the free end of said lever and a fixed element disposed in such position that one of said movable and fixed elements applies varied effects on the other of said elements depending on the relative positions thereof, drive means disposed on said key to transmit the depression of said key to said lever, a bridle rod disposed on said key to return said lever when said key is released, and means providing friction force between said lever and said pivot shaft, said friction force being sufficient to hold said lever in a depressed position in accordance with the key depressing strength, said key, lever, pivot shaft, drive means and bridle rod being arranged to meet the following conditions: (a/b)> (x/y) where: a the distance between the fulcrum of the key and the bridle rod, b the distance between the fulcrum of the key and the drive means, x the distance between the pivot shaft and the bridle rod, and, y the distance between the pivot shaft and the drive means.