Untitled record

G. F. BROWN..

SCREW PROPELLER.

No. 9,849. Patented July 12, 1853.

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UNITED STATES PATENT OFFICE.

CHARLES F. BROWN, OF WARREN, RHODE ISLAND.

ADJUSTABLE SCREW-PROPELLER.

Specification, of Letters Patent No. 9,849, dated July 12, 1853.

To dll whom it may concern:

Be it known that I, Charles F. Brown, of Warren, in the county of Bristol and State of Rhode Island, have invented cer5 tain new and useful Improvements in ScrewPropellers ; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of 10 this specification, in which—

Figure 1, is a side elevation of part of the framing of the stern of a vessel fitted with a screw propeller having my improvements. Figs. 2 and 3 are horizontal sections of the 15 same taken through the axis of the propeller. Fig. 4, is a transverse section of the propeller shaft in the line x, y, of Figs. 1, and 2. Fig. 5, is a transverse section of the hub of the propeller.

Similar letters of reference indicate corresponding parts in each of the several figures.

This invention relates more particularly to the description of screw propeller which 25 has its blades adjustable in the hub for the purpose of altering the pitch of the screw, and for bringing them to a position to offer no material resistance to the vessel’s progress when under, sail alone.

It consists 1st. In an improvement in the method of fitting or . arranging the adjustable blades in the hub, 2nd. In so operating one of the blades that when it is brought into a proper position and the revolution of the 35 propeller stopped, it will act as a rudder in case of the vessel’s rudder being disabled, and will serve to steer the vessel under sail.

To enable those skilled in the art to make and use my invention I will proceed to de40 scribe its construction and operation.

A, A, A, is the framing of the vessel in which are the bearings of the propeller shaft B. C, is the hub which may be made solid with the shaft or may be cast separate and 45 fitted and secured to the shaft as may be thought convenient. The shaft B is bored from the front end nearly to the back end, the bored part extending all through the hub; and in this bore is fitted a rod a, b, 50 which is furnished at that part which passes • through the hub with a rack d, the said rack being formed by turning grooves in the rod or by raised rings. The object of this rod and rack will presently be explained. The 55 hub is bored through transversely to receive the pivots c, o', of the propeller blades D,

D'; these pivots are not radial to the hub but pass through the hub at equal distances from the axis on opposite sides of it (see Fig. 5). Each one of the pivots carries a qq small toothed pinion e, gearing into the rack d, on the rod a, b. The hub is perfectly solid except where it is bored to receive the rod a, b, and the pivots c, o', and where it is slotted from the outside to the center bore to 65 allow of the pinions e, e, to be inserted. The pinions are secured to the pivots and the pivots are confined in the hub by the pinions or by other suitable means.

It will be understood that if the rod a,b, 70 is moved longitudinally that the rack d, will turn the pinions e, e, and thus may be made to bring the blades D, D', to any position either in line with or parallel to the axis of the screw or at any pitch or inclina- 75 tion in either direction, so as to make a right or left handed screw—the pinions are geared with the rack so as to cause each blade to occupy the same position in relation to the axis of the shaft. The rod a, b, is 80 moved from the deck E, of the vessel by the following means. A shaft F, is placed vertically in suitable bearings near one side of the propeller shaft, its upper end reaching above the deck and carrying a purchase §5 wheel G: opposite the propeller shaft, it carries a toothed pinion /, which gears into a rack c/; this rack is attached to·. a collar h, i, which fits to, but is capable of moving longitudinally on the propeller shaft. 90 The collar is prevented turning on the shaft by flanges /, /, above and below the rack which embrace the pinion and keep the rack in gear. There is a recess in the collar i, which divides it into two parts, and in this 95 recess is fitted another collar k, fitting to the shaft so as to be capable of sliding on it, but this collar is caused to turn with the shaft by a pin m, through it and the shaft, and through the rod a, b; slots shown 100 in dotted lines in Figs. 2 and 3, (see also Z, Z, Fig. 4) are cut in the shaft to allow of the longitudinal movement of the pin. By turning the wheel G, the pinion /, is caused to move the rack &lt;7, longitudinally and the 105 collar h, i, moving with the rack moves the collar k, and the pin m, moving with k, moves the rod a, b, and causes the rack to act upon the pinions e, e. This can be done either while the propeller is revolving or 110 while it is stationary. A dial 0, is placed upon the deck and a pointer, P, on the

9,849 shaft F, by which the position- of the blades may be seen on deck.

The rod a, b, as far as I have described my invention, and as far as relates to the adjustment of the blades may be considered a single rod, but for the purpose of using the blade of the propeller as a rudder it is divided longitudinally into two parts a, and b\; these are bolted together (as shown in Fig. 2) by a screw bolt, n, at the front end which projects through the crank end or front end of the shaft, while the propeller is in use; the part «, carries that part of the rack which gears with the pinion on the pivot e, of the blade D, and the part δ, carries the part of the rack gearing with the pinion on the pivot c-', of the blade D'.

The blade D, is the one intended to serve as the rudder, and for that reason its portion a, of the rod, is made the largest and also for· the additional reason that when the other blade is riot in use, it is necessary that the pin m,, work clear of the pari, b. The first thing to be done to use the blade D, as the rudder, is to bring the blades, or at least that one D, to a vertical position, D, being turned downward as there it will have most effect. This is done by stopping the engine in the proper position; then the blades are brought in line or parallel with the keel, and O', is secured in that position by a set screw q which passes through the shaft B, and into a recess in the part δ, of the rod; the bolt n, is unscrewed from a, and a, is then left free to be moved independently of the other part of the rod, this will be best understood by reference to Fig. 3; by turning the wheel G, the blade D, may be brought into the various positions necessary to enable it to steer the vessel. The superiority of this mode of arranging and adjusting the blades consists chiefly in the depth of bearing or socket obtained for the pivots of the blades by fitting them right through the hubs. The common arrangement is to make the pivots c, c', radial and to turn. them by bevel gearing; this prevents their being carried through and requires the hubs to be quite hollow to re- 50 ceive the gearing and unless it is of great size or has very large bosses where the pivots pass through there is not sufficient depth of bearing for the pivots to keep the blades firm and steady, but by my arrange- 55 iment the pivots can have a sufficient depth of bearing without unreasonably increasing the size of the hub.

A greater number than two blades, as ishown, can be employed if considered de- 60 sirable, all being operated in the same mantier by the rack d.

ί I am aware that others have tried to effect ithe same object by placing the blades one •behind the other, but this arrangement 65 renders it necessary to cut much more of •the after part of the vessel and weaken it Immecessarily and to a very dangerous extent, as is the case in the arrangement •shown in the London Mechanics Magazine, 70 h’ol. 49, page 241.