US1455591A - Marine propeller - Google Patents

Description

May 15, I923.

G. W. LAWSON MARINE PROPELLER Filed Oct. 1920 jfgi.

W/TIVES 8 ATTORNEYS Patented May 15, 1923. I v I i if UNITED srarss earsnrorrics.

Application filed (lctober 7, 1920. Serial No. 415,317.

7 '0 all whom it may concern: Figure 4 is'a similar view on the line 4 i 50 Be it known that I, GnonsnlV. LAwsoN, of Figure 1. i a citizen of the United States, and a resi- Figure 5 is a similar view on the line 5-5' dent of the city of New York, borough of of Figure 1. I 5 the Bronx, county of Bronx and State of Figure 6 is a similar view on the line 66 New York, have invented a new and 1mof Figure 1. proved Marine Propeller, of which the fol- Figure 7 is a similar view on the line 77 lowing is a full, clear, and exact description. of Figure 1. 7

This invention relates to propellers and Beferringto the drawings by characters 10 more particularly to an improvement in the of reference, 10 designates the hub of the construction of marine screw propellers. propeller and 11 the blades extending radi- The invention contemplates and aims for ally therefrom. The blades are of identical one of its principal objects to provide a formation and therefore a description of one construction which will increase the power will suffice to explain the features of con- 15 of any propeller of a given size with a ministruction of all of the same. Each blade is mum expenditure of energy, and to this end, provided with a substantially fiat working 65. one of the main features resides in forming face 12 having the desired pitch or angular the blades with a working face of substanrelation to the axis of the hub. The rear tiallythe same width throughout, from the face is properly curved as at 13 to produce 2 free end of each blade to the base, and in a stream line effect. The working faceof which the base at its juncture with the hub, the blade is of substantially the same width is of a greater pitch relative to the remainder throughout the length of the blade from its of the blade. outerfree end to its base. The forward or A further object in view is to construct a leading edge 14 of the blade is in advance-of '25 propeller in which the leading edge of the the forward end of the hub whereby the blade extends in advance of the forward end blade will obtain an initial purchase or grip of the hub to obtain an initial purchase or on the water forward on the hub to minigrip on the water forward of the hub to mize suction at this point. Immediatelyadavoid suction. jacent the juncture of the blade with the hub, 30 A still further object of the invention is the pitch ofthe same is increased as illusto provide a screw propeller having novel trated at 15. This increased pitch curves at 30 features of construction which materially a point where the proportionate distance add to the efiiciency of the same, without traveled is less than the distance traveled materially increasing the cost of producby the remainder of the blade, whereby no v 35 tion. substantial increase in resistance is offered i With the above mentioned and otherobat this point. The various cross sections jects in view, some of which will more taken through the blade shown in the sevclearly appear hereafter, reference is made eral views of the drawing, illustrate the to the following specification, the appended variations in the working surfaces of the 40 claim and the accompanying drawings blade to show the gradual increase of the forming a part of this application, in pitch from the outer free end of the blade which; to the base at the point of its juncture with Figure 1 is a front elevation of a prothe hub. The rear or following edge 16 of peller constructed. in accordance with the the blade is in advance of the rear end of 45 invention. the hub inorder to reduce to a minimum Figure 2 is a side view thereof. suction at this point caused by the action of Figure?) is a cross sectional view through the water leaving the following edge 16. one of the blades taken approximately on From the foregoing it is to be understood the line 3--3 of Figure 1. that the right is reserved to embodiments to the full extent indicated by the general meaning of the terms in Which the claim is expressed and by ology of the same.

Having thus described my invention, I claim as new and desire to secure by Letters Patent V A propeller comprising a hub, and a series of radial blades helically arranged thereto, each of said blades having a compound variations in the phrasepitch the leading edge of each ofsaid blades being convex and extending in advance of the forward end of the hub and the tip of the blade, each of said blades being so formed that the greatest convexity of the entering edge is located approximately at the greatest Width of the. blade and the greatest pitch of the blade initiates at the greatest Width of the blade and increases 20 therefrom to the following edge thereof.

GEORGE WI LAWSON.

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