Movement No. 107 is a variation of Movement No. 106, demonstrating a second type of grooved cam that converts continuous rotary motion into uniform reciprocating rectilinear motion. While No. 106 typically features a face-grooved disk cam, No. 107 employs a cylindrical drum cam — a cylinder with a continuous helical or shaped groove cut around its outer surface. A follower pin rides in this groove as the drum rotates, being driven back and forth along the axis of the cylinder. The enclosed groove provides positive control of the follower in both directions without the need for a return spring. The shape of the groove determines the motion profile — a uniform helical groove produces constant-speed linear travel, while a varied groove profile can create custom dwell and motion sequences. Cylindrical drum cams are widely used in automatic machinery, indexing tables, and cam-operated sequence controls.
106 and 107. Uniform reciprocating rectilinear motion, produced by rotary motion of grooved cams.