Abstract: The present invention is an improved winch drum design which improves the gripping action of the drum on a rope by departing from the traditional belt-pulley theory. The winch drum has a series of depressions at spaced intervals around the circumference of the drum. The portion of the drum between the depressions is smooth, producing a low coefficient of friction with the rope. The rope deforms as it bends over a portion of the drum between depressions at a relatively sharp angle, causing the rope to resist lengthwise movement. At the same time, the smooth surface allows the rope to easily move parallel to the spin axis of the drum, thereby facilitating the necessary climbing action of the rope from working to tailing ends. The gripping action is provided because the rope is compressed and bent between depressions, thereby making it difficult for the uncompressed portion of the rope resting over a depression to propagate lengthwise of the rope.

Abstract: A deck winch having provision for removal of the main shaft without removal of the winch base from the deck is disclosed. The winch includes a flat keeper member disposed radially to the main shaft and which seats semi-circumferentially in a circumferential groove in a main shaft. This keeper member is normally kept in the shaft-retaining position by the pinion shaft, which is spaced from the main shaft. An opening through the keeper member is positioned over the pinion shaft just above the upper gear and below a portion of the base structure, so that when the winch drum is removed and the pinion shaft is removed following extraction of a cotter pin, the keeper member may be easily pulled out to permit removal of the main shaft.

Abstract: A deck winch provides three separate speed ratios for its drum when its main shaft is turned. With an external control lever in a neutral position a high speed ratio is attained by rotation of the main shaft in a first direction, resulting in a low drum speed. A medium speed ratio is attained by rotation of the main shaft in a second, opposite direction. With the control lever in its active or low gear ratio position, rotation of the main shaft in the first direction moves the drum at its highest speed relative to the main shaft. When the control lever is in this active position and the main shaft is rotated in the second direction, the control lever is automatically shifted to its neutral position and the medium speed ratio is established. The control lever is connected internally to engage and disengage an idler gear that mechanically interconnects the main shaft with one or several driving gears for the drum.

Abstract: A self tailing winch with which a rope can be automatically pulled and paid out has a clamping ring attached to a rotary winch drum for rotation therewith. The ring has a central hub portion with a cylindrical surface that defines an annular groove with the end of the drum. The ring is yieldably urged against the end of the drum to clamp the rope. The rotary drum may be driven by a gear train from a rotated input shaft. A stationary annular plate fixed to a stationary frame is attached above the clamping ring and supports a downwardly and outwardly extending projection for deflecting the rope from the drum to the groove and also supports a device for paying out rope from the groove as the drum and ring are turned.

Abstract: A self tailing winch with which a rope can be automatically and properly pulled and paid out. A facing pair of clamping rings splined to a rotary winch drum for rotation therewith and define a generally angular shaped groove between them, one of the clamping rings having a smooth face and a cylindrical extension defining the winding diameter for the rope and the other ring having a serrated face, the two being yieldably urged together by an elastic member, a spring or springs. The rotary drum may be driven by a gear train from a rotated input shaft. A stationary annular plate anchored to a stationary frame lies adjacent to one clamp ring and supports a feeding device for feeding the rope from the drum to the groove and also supports a guide device for paying out rope from the groove.