US1718525A - Automatic feathering propeller - Google Patents

Description

June 25, 1929. I EY 1,718,525

AUTOIIATIC FEATHERING PROPELLER Filed March 5, 1927 "Ifuullmlnun \illlllll 'mllllllll H CAD Patented June 25, 1929.

MAJOR J'. CASEY, OF NEW BEDFORD, MASSACHUSETTS.

AUTOMATIC FEATHERING PROPELLER.

Application filed March 5,

This invention relates to propellers of that type in which the blades are automatically adjustable by the pressure of the water thereon to proper position to drive the boat ahead or astern, depending on the direction of rotation of the shaft, or in a position offering minimum obstruction when the shaft is stationary and the boat is being propelled by other means. such as by sails or when in tow.

The object of this invention is to provide an improved construction effectivefor the purpose, easy and certain in action and simple in construction.

For this purpose the blades of the propeller are journaled on longitudinal eccentric axes in a sectional casing which may be attached to the propeller shaft, cooperating means being provided on shaft and blades for causing the blades to be held in proper angular positions for propelling when the shaft is rotatedjn either direction, while permitting the blades to turn to a different angular position where they offer the minimum resistance to the motion of the boat or to water currents when the shaft is stationary.

F or, a more complete understanding of this invention, reference may be had to the accompanying drawings in which I Figure 1 shows in perspective a propeller constructed according to this invention, the blades being shown in propelling position.

Figure 2 is a side elevation to an enlarged scale, one of the blade holding casing parts being removed.

Figure 3 is an end elevation to the scale of. Figure 1, but showing the blades in feathering position.

Figure 4 is a fragmentary elevation similar to the position shown in Figure 2.

Referring first to the construction shown in Figures 1 to 3, 1 indicates a hollow shaft which may be fixed to the usual propeller shaft (not shown), a keyway 2 being shown therein by which the shaft 1 may be fixed to the propeller shaft to be rotated thereby.

This shaft, 1 is shown as provided with a pair of spaced annular shoulders 3 to hold in axial position thereon a sectional casing comprising parts 4, journaled on the end port'ons 5 of the shaft 1 outwardly of the shou ders 3. The outer ends of the casing sections are threaded to receive the'reover I internally threaded retaining collars 6 which 1927. Serial No. 173,175.

hold the casing parts in assembled relation on the shaft 1. The collars may be locked in position as by means of screws 7. As shown the casing is formed in two parts to cooperate with a pair of propeller blades 10 extending substantially radially to the shaft 1, though should more than two propeller blades be used, the casing would be divided into a correspondingly greater number of parts: this for the reason that the mating edge portions of the parts have recesses 11 therein, which, when the casing is assembled, form journal openings for the blade members. Each of the blade members, as shown, comprises the active propeller portion 12, a base portion 13, the outer face of which forms substantially a continuation of the surface of the adjacent casing parts, a portion 14 of reduced diameter journaled in the journal openings formed by the mating recesses 11 in the casing section edges, and an enlarged head portion 15 hearing on the inner face of the casing parts and which carries one or more elements cooperating with elements on the shaft 1 as will later appear. The casing parts thus hold ,the

blades against detachment while permitting their rotation about longitudinal axes eccentrically disposed relatively to the active propeller portion.

The base section 13 is shown as'provided with an outwardly extending stop lug 16 movable between stop lugs 17 and 18 of the casing parts. When the lug 16 is against the stop 17, the active blade portion 12 is in such angular relation to the propeller shaft 1 that it will act to propel the boat on the rotation of this shaft in either direction, while when the stop 16 is against the lug 18, as illustrated in Figure 3, the por-' tions 12 of the blades are arranged in such angular relation as to impose minimum resistance to motion of the boat either ahead or astern, the propeller shaft being stationary. This position is illustrated in Figure 3.

Means for holding the blade portions 12 in propelling angular relation while the propeller shaft is being rotated may comprise, as shown in Figure '2', a rib 20 extending inwardly from the inner face of the portion 15 of each blade and a pair of series of lugs 21 and 22 extending radially from the shaft 1 between and adjacent to each of the ribs 20.

When the propeller shaft is rotating in one direction, the lugs 21 engage oneend of each of the ribs 20 and rock the propeller blades into and hold them in their propelling position. When the shaft is rotated in the .opposite direction, the lugs 22 act on the other ends of the ribs 20 on the opposite side to rock and hold the propeller blades in the same position. It will be noted, however, that there is a lost motion connection between the shaft 1 and the propeller blades, there being a considerable angular turning of the shaft permitted when'changing from one to the other direction of rotation after the lugs at one end are brought out of contact with the ribs 20 and before the lugs at the other end are brought into contact with .these ribs. This lost mot-ion permits an angular turning of the propeller bladeswhen the propeller shaft is stationary and without the necessity of the blades rotating about the axis of -the propeller shaft sufiic1ent to bringthe stop 16 thereon into contact with the stops 18 so that the blades are in feathering position where they offer the least possible obstruction to the progress of the boat,

' the center of pressure exerted by the water on the blades, being eccentric to the axis ti f-60 about which the blades are journaled, tending to bring the blades to this feathering position as the boat is propelled while the propeller shaft is stationary. This eccentricity of the center of pressure is due to the fact that there are unequal areas of blade surface on o posite sides of the axis 'wm, the blade surface shown to the right of this axis in Figure 2 being larger than that to the left of this axis. When the boat is moving either forwardly or rearwardly and the propeller shaft is stationary, the total pressure of the water on the larger area overcomes that on the smaller area so that the blade is turned to feathering position where the pressure on opposite faces of the blade is equal.

Instead of placing the ribs on the propeller blades and the cooperating driving lugs on the shaft 1 these parts may be reversed as shown in Figure 4 in which the driving lugs 25 and 26 are carried bythe head portion 15 of each of the blades and a cooperating'rib 27 is arranged somewhat spirally lengthwise and around the shaft 30. The rib 27 is shown as arranged inv spiral formation so as to permit the desired lost' motion between engagement of the lugs 25 and 26 thereagainst. It is tobe understood, of course, that one rib 27 will beutilized for each of the propeller blades. The action of this construction is similar to that of the construction heretofore described, the ribs 27 acting against the lugs 25 to hold the propeller blades in driving fposition during one direction of rotation o the shaft 30 and those ribs acting against the lugs 26 to hold against axial movement therein,

feathering.

It will thus be seen that the mechanism is extremely simple and rugged and that the propeller blades are held in propelling position during rotation of'the propeller shaft in either direction and are permitted to turn to feathering position by the pressure of the water thereon when the shaft is stationary-and when the boat is being moved by other means.

Having thus described certain embodi ments of this invention it should be evident to those skilled in the art that various changes and modifications may be made therein without departing from its spirit or scope as defined by the appended claims.

1 claim:

1 A device of the class described comprising a shaft member, a sectional casing surroundlng and rotatably carried by said shaft member, a propeller blade .member ournalecl about an eccentric longitudinal axis between sections of said casing, a rib on one of said members, a pair of spaced lugs projecting from the other of said members, alternate lugs and said ribs contacting on turning of said shaft in opposite directions through a predetermined angle, and then tending to turn said blade member about said axis, means for limiting said axial-turning of said blade member to propelling angular position, said predetermined angle being sufficient to permit free rotation of said blade member to feathering position when said shaft is stationary, and means for holding said casing sections in assembledrelation on said shaft. 2. A device ofthe class described comprising a shaft having a pair-of spaced annular shoulders, a sectional casing embracing said shaft outwardly of said shoulders,saidsec tions having mating recesses forming journal openings when said casing is assembled, propeller blades journaled about eccentric longitudinal axes in said openings and held 'a rib pro ectmg from the inner end of each blade toward said shaft, a series of lugs extending outwardly from said shaft adjacent to and between said shoulders, the lugs of each series being spaced angularly of said shaft to respectively engagenand then turn said ribs on turning of said shaft in saidcasing in opposite directions through a predeter mined angle, stops to limit the turning of said blades bysuch. turning of said shaft, said angle being sufiicientto permit said blades to turn to feathering position when pair of lugs on the other of said members 10 extending on opposite sides bf said rib on opposite sides of said axis, and a sectional casing for holding said blade member assembled with said shaft member.

In testimony whereof I have afiixed my 15 signature.

MAJOR J. CASEY.

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