.~ Dwell defined only by "dead-center" of rotating crank
DEFINITION
Classification: 83/258
(under subclass 202) Device wherein the work-feed means is driven from a constantly rotating crankshaft through a Scotch yoke or connecting rod with no provision for work dwell other than the momentary halts that occur when the yoke or connecting rod passes through its extreme positions.
(1) Note. The yoke or rod may drive work-feed rolls through a double pawl-and-ratchet arrangement, whereby the feed is driven at each forward and each return stroke of the pitman (no half-revolution idle period as in a single-ratchet drive).
SEE OR SEARCH THIS CLASS, SUBCLASS:
235, for work-feed dwell caused by imposing reverse motion on a portion of flexible moving work, where all machine parts may be in motion during the dwell.