US90590A - Improvement in frofedlers - Google Patents

Description

airnt dtyiilirr.

Letters Patent No. 90,590, dated May 25, 1869.

IMPROVEMENT IN PROPELLERS.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known that I, CHRISTIAN, SHAnrs, of Philadelphia, Pennsylvania, have invented certain Improvements in Propellers, and in vessels for the same; and I do hereby declare the following to be a full, clear, and exact description of the same.

My invention consists of certain improvements, fully described hereafter, in the propeller for which Letters Patent were granted to Jacob Perkins, November 20, 1829, also of improvements in vessels for such pl'opellers.

The main object of my invention is to use a large propeller-wheel on a vessel of light draught, and to so adapt the vessel to the wheel as to obtain 'the best effects from the latter.

In order to enable others skilled in the' art to make and apyly my invention, I will now proceed to describe its construction and operation, reference being had to the accompanying drawing, which forms a part of this specification, and in which- Figure Il, Drawing N o. 1, is a side view ofthe stern and propeller of the boat.

Figure 2, a plan view.

Figure 3, a vertical section on the diagonal line 1 2, i 2.

gFigure 4, an inverted plan view.' v

Figure 5, a transverse section on the Vline 34, fig. 4.

Figures 6 and 7, Drawing No. 2, represent perspective views of the stern of the vessel and propeller.

Similar letters refer to similar parts throughout the several views.

A is the propeller-shaft, placed at an angle of fortyiive degrees, or thereabouts, in respect to the central line a: a: of the keel, as shown in fig. 2; and

B is the propeller, arranged to revolve in the direction of the arrows, having, in the present instance, live blades, each of which is arranged at s uch an angle, that when at its lowest point, the face of the blade, or of the greater portion of the same, shall be at right angles to the keel, as best observed on reference to fior. 4.

tThis arrangement of propeller was proposed by Jacob Perkins, and is illustrated in his patent of November 20, 1829. Y

In making experiments, with a view of perfecting this arrangement of propeller, I ascertained that it was necessary, in carrying the invention thoroughly into effect, not only to depart, to a considerable extent, from the construction and arrangement of the propeller itself, as proposed by Perkins, but toy make the stern of the boat of peculiar shape, in order that the best effect of the propeller might 'oe obtained.

It should be understood that my propeller is not submerged, as usual. Onthe contrary, its dip in the water is very limited, as my main object has been to obtain a large wheel ou a vessel of very light draught.

In carrying out my invention, I have found that the best results can be obtained bythe adoption of the following features:

First, it is necessary to make in the vessel, for thev reception of the propeller, an oblong opening, D, sit-uated at an angle in respect to the keel, as shown in tig. 4. The portion of the vessel at the rear of this opening should afford as little obstruction as possible to the free disposal of the water necessarily agitated by the propeller. Hence the vessel, at this point, consists of mere platform continuation, b, of the deck, (see fig. 3,) the under side of this platform being above the centre of the propeller-shaft, at the rear of the same. The top of the stern-postal is securedto this platform, and its lower end is connected to the keel by the bar e. While the platform, therefore, serves as a continua-V tion of the deck, and as a means of securing the sternpost and carrying the rudder, the space below it is so free and open as to permit the free disposal of the water agitated by the propeller-wheel.

Sec/1nd, I have found that the eiciency of the wheel, as a propelling-medium, is increased by cutting away the vessel below the-water-line, at that side of the keel where the blades enter the water. I therefore form on that side of the keel, and in the under side of the vessel, a recess, f, figs. 4, 5, and 7, this recess being deepest at or near the corner, m, of the opening D, fig. 5,V and gradually vanishing, in one direction, into the under side of the platform b, and in the opposite direction disappearing in a hull of the usual shape,

this being accomplished without detracting from the symmetrical appearancel of the vessel, and without weakening the overhangng platform, as the latter obtains efcient support from the rib h on the outside of the recess.

Third, as before observed, the dip of the blades into the water is very limited, while the wheel itself is of large diameter'. The result of this, with ordinary blades, would be the striking the ,Water abruptly, the

vjarring of the vessel, and the loss of propelling-power.

In order to prevent this, I curve each blade at the edge, w, where it enters the water, as shown in fig. 4, where the line H represents the lower edge of one of the blades, as it appears when it has reached the lowest point, the remaining portion of the edge of the blade, from t tot, being straight, and at right angles to the keel. Owing to this curve of theblades, and

to the peculiar position of the wheel, each blade in succession will dip gently into the water before it begins to act on the saine with its full propelling eect.

Fourth, I have found that the best results are obtained from so arranging the shaft that it shall be higher in front than at the rear, for, by this arrangementioned curving ofthe blades adding` to this impork Itent result, as will be readily observed on referring to iig. 6.

\ Another advantage of lthis arrzingement of the shaft is,thaJt the rear bearing, i, een be placed on the'endor side of the platform, and the front .bearing to the upper side of the salme, as seen in fig. 3, thereby per- -uiitting the shaft to be readily Withdrawn from its bearings in either direction.

I claim; as my invention, and desire to seeure byr Letters Patent- 1. A recess, f, on the under side of the vessel, et

the side of the keel, where the blades of the propeller enter the waiter, as herein set forth, for` the purpose specified.

2. The propeller-shalt, so arranged :is to he lower at the rear than in front, in combination with an inclined propeller-wheel, having,r :t limited dip in the water, as set forth, for the purpose specified.

In testimony. whereof, I have signed my name to this specification, in the presence of two subscribing witnesses. y

CHRISTIAN SHARPS.

Witnesses:

E. H. BAILEY, LOUIS BosWELL.

Images