US142820A - Improvement in screw-propellers - Google Patents

Description

n. K. STEVENS & s. 'm LLEB.

' Screw Propellers.

P atented Sept'ember16,1873.

UNITED STATES. PAT NT "OFFICE ENEY K. STEVENS AND SOLOMON MILLER, 0F WATERLOO, NEW YORK;

SAID MILLER ASSIGNOR To SAID STEVENS.

lMPROlIEMENT m SCREW-PROPE'LLE'RS.

Specification forming part of Letters Patent No. 142,820, dated September 16, 1873 application filed March 13, 1873 which we denominate the Hercules Propel-V ler, of which the following is a specification: The first part of our invention consists in the construction of the blades of the propeller,

; by which, with a greater number of blades than is now used we have a larger and freer water space for the passage of the water through the wheel than any propeller heretofore oonstructedwith which we are acquainted, thereby furnishing a larger amount of water for the propelling surfaces to act upon, by which the Slip is decreased when the wheel is in rapid motion.

The second part of our invention is the coupling for uniting the driving-shaft with the propeller.

The construction of the propeller is as follows, referringto the accompanying drawing, in which- Figure 1 is a general View of the propeller. Fig. 2 is a side elevation. Fig. 3, the coupling joint.

.The hub a is of ordinary form tapered at each end. "The blades b. are six in number, and are joined to the hub at an angle of about thirty-five degrees to the shaft. The center line of the blade b is curved backward. It starts at an angle from a radial line at that point, curving upward at right angles to the line of the base, inclined backward to the center of the length of the blade; and thence curving forward to the outer periphery of the blade, as clearly seen in the drawing. The rear edge of the blade has a nearly similarcurve, rounding ofi' at the periphery. front edge of the blade curves much more, extending forward of a radial line, and expandin g out the outer circumference of the blade to about double the breadth at the hub, and terminating forward in a rounded point, as clearly illustrated in Fig. 1. Both faces of the blade are convex in their cross-section, tapering to an edge in front and rear, the thickness also diminishing from the hub to thetip.

The form we thus give to our propellerblades allows much greater space for water motion. This action of our propeller decreases.

the wash on the sides.

I The axis of our propeller is hung in bearings in a stout metal rudder-frame, c, having fenderbraces 01 projecting horizontally therefrom, which surround the propeller. This rudder-frame is pivoted to the sternpost of the boat, or to Outriggers e, and is so connected with the tiller f above as 'to be readily swung to the right or left thereby.

The driving-shaft h of the engine projects out through the stern-post of the vessel, and is coupled with the axis of the propeller by a flexible coupling-joint, constructed so as to give freedom of motion, and at the same time sufficient strength for the purpose. To effect this I form two jaws upon the shaft h, circular on their face 'i, as seen in the drawing. Similar jaws are aflixed to the axis of the propeller, which couple into those on the shaft h. These jaws are united by joint-pins to hold them in place, thewhole strain coining upon the jaws. Having thus fully described our invention, what we claim, and desire to secure by Letters Patent, is-

' 1. The propeller constructed and arranged as herein described, having the blades formed I and aflixed to the hub, as herein specifically set forth in the above description, and for the purposes Specified.

2. The joint herein described, for coupling the propeller, withthe driving-shaft composed of strong jaws united together and held in place by pins, as herein described.

In testimony whereof we hereto set our hands. HENRY K. STEVENS. SOLOMON MILLER.

In presence of- HUGH MONTGOMERY, H. VAN AMBURGH.

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