US125205A - Improvement in devices for propelling canal-boats - Google Patents

Description

THOMAS K. M cDONELL. Improvement in Device for Propelling Canal Bo ats.

No*.125,205. Pa'tentedApr'|\2,1872. I

o G) v Vitness'es Inventor X I A UNITED STATES PATENT Orrrcn.

THOMAS K. MCDONELL, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT lN DEVICES FOR PROPELLING CANAL-BOATS.

Specification forming part of Letters Patent No. 125,205, dated April 2, 1872.

SPECIFIGATIO N.

To all whom'it may concern:

Be it known that I, THOMAS K. MoDoNELL, ot' the city and county of San Francisco, State of California, have invented an Improved Device for Propelling Vessels; and I do hereby declare the following description and accompanying drawing are suficient to enable any person skilled in the art or science to which it most nearly appertains to make and use my said invention or improvements .without further invention or experiment.

My invention relates to a novel device for propelling vessels through the water, and is more particularly applicable for propelling canal-boats. My device relates to wings or blades hinged at the extremity of a shaft which passes through the stern of the boat into the water, and which is given a reciprocating motion from the interior of the vessel by any suitable power, so that the blades will be caused to fly open and take hold upon the water on the backward stroke, but will close together on the reverse motion or stroke, so as to pass readily through the water without retarding the progress of the boat in any considerable degree.

In order to more fully illustrate my invention, reference is had to the accompanying drawing forming a part of this specification, in which-- A represents a vessel of any class. B is a shaft which extends from the interior of the vessel through the stern and into the water, and is given a reciprocating motion by any suitable power inside the boat. The outer extremity F of this shaft is made conical, as shown, and a cup-shaped paddle or blade, 0, is hinged at each corner or angle of the triangular head, so that they can open and close freely. The opening of the blades is limited by proper means, so that they will only open to a position at right angles to the shaft where they will be in the best position for taking hold upon the water. A circular plate, D, is fixed to the end of the shaft B, which serves a double purpose: first, it prevents the hinged paddles from closing entirely on the reverse stroke, so that when the shaft is driven backward the water will have sufficient hold upon them to throw them open and, secondly, it serves, when the concave paddles are open, as another paddle to aid in propelling the boat. The shaft B points downward from the stern of the boat, and its movement is consequently in that direction, so that upon the back stroke, when the paddles open and push against the water, they produce no surface agitation of any consequence. The movements of the shaft B will cause the paddles to open and close in accordance with the direction in which it moves, the resistance of the water tending to close the paddles on the reverse stroke, while it causes them to open on the back or propelling stroke, thus giving great propelling power with small resistance to the forward motion of the boat. A similar arrangement canbe placed in the bow of the boat, which can be protected with a housing of proper shape when not in use, so as to avoid any resistance, in order to permit the boats being backed when necessary.

Owing to the peculiar shape of the head F of the shaft it is a prolongation of the planes of the blades 0 when they are closed, and it merges into the shaft about on the lines of such prolongation. This construction allows of su-fficient room for hinging the blades on the end of the shaft, and at the same time greatly lessens the resistance against the closed blades on the return stroke, as the blades and shaft-head together then form a cone, the apex dividing the water, and avoiding the loss of momentum in the vessel.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, lS

The shaft B, provided with the conicalshaped head F, and having the end-plate D fixed at its extremity, in combination with the hinged concave blades or paddles G, substantially as and for the purpose above described.

In witness whereof I have hereunto set my hand and seal.

THOMAS K. MODONELL. [L. s.]

Witnesses:

J. L. BOONE,

J Aims H. DAVIS.

Images