US2691419A - Propeller - Google Patents

Description

Oct; 12, 1 954 c. ANDERSEN PROPELLER Filed March 10 1950 INVENTOR. C/m EL E5 AA/az/esE v m I ,4 TTO/P/VEX Patented Oct. 12, 1954 ggg sggg UNITED STATES PATENT OFFICE PROPELLER Charles Andersen, New York, N. Y. Application March 10, 1950, Serial No. 148,987 1 Claim. (01. 170-165) 1 My invention relates to propellers for impartdescribed, when rotation occurs as indicated at ll, ing motion to boats or vessels in a fluid medium. the fluid engaged by the inboard blades is More particularly my invention pertains to propassed without substantial turbulence into the bite pellers especially adapted for imparting motion to of the blades of the outboard propeller 5, where, marine craft. Generally my inventive idea is ap- 5 due to the form of the blade profile the initial plicable to propellers whether employed for imthrust of the outboard propeller is not only mainparting motion to a craft or for imparting motained but substantially augmented and accelertion to a fluid in which the propeller is operating. ated. In the disclosure but two propellers are Among the objects of my invention is to proshown and discussed but it should be understood vide a propeller that may be economically opthat the novel principle herein described may be erated at high efliciency. It is also an object to applied to more than two tandem propellers suitprovide a substantially non-cavitating propeller ably spaced apart and angularly set relative to capable of exerting a powerful thrust. Further each other. While the full benefit of the inobjects and the unique advantages of my invenvention is best realized when the propellers are tion will be brought out as the following specidriving in their intended direction the system fication is read in conjunction with the drawings may be operated in the reverse direction. In a forming a part of this application, in which: marine application, for example when going Figure 1 is a front elevation of a propeller emahead, water forced 01f the driving faces of the bodying my invention. blades lb of the inboard propeller 6 is driven Figure 2 is a side elevation of Fig. 1, partly in to the back side of the blades l5 of the outboard section, on line 2-2 of Fig. 1. propeller 5, thereby increasing the overall thrust Figure 3 is a series of profile sections of a blade of the unit and increasing the driving speed or of a propeller made according to my invention propulsion travel rate. In Fig. 2, the sleeve 1 taken on the lines A-A, B-B, C-C and D-D. carrying the propeller blades 5 and 6, is shown Figure 4 is a series of profile sections of an- 2 as having a tapered bore it fitted to a similarly other blade of my propeller taken on the lines tapered portion 9 of a shaft 10, carried in a suit- E-E, F-F, G-G and HH. able bearing II, the sleeve 1 being secured upon Referring to Fig. 1 of the drawing 5 are the the tapered portion of the shaft by means of a nut blades of the outboard or first propeller, and 6, 5 l2 screwed onto the threaded portion l3 of the are the blades of the inboard or second propeller. 3O shaft I0 and covered by the can M. As may be It will be noted that both propellers are carried noted in the views, the leading edges of blades 5, 5, by a single sleeve 1 and that one set of blades 8, 6 etc., are indicated at l 5, I 5, while the leading is set at an angle of about degrees in advance edges of the other blades 6, 6, etc., are noted it, of the blades 5, 5 of the other. Obviously in place [6, inasmuch as the normal rotation of the proof the single sleeve 1, each propeller, complete with pellers occurs in the direction indicated in Figi s wn sleeve, y be stru t d d pend ntly ure 1 by arrow l1. Having described and il1usand thereby re ly Set at an ppropriate relatrated a preferred embodiment of my invention tive angle. A purpose of the two propellers, set h t I 1m as new i one behind the other and having their blades In a propeller system, a first or outboard prosuitably profiled, is to develope the utmost efpeller mounted upon a drive shaft, said first profective power from the motive force imparted to peller consisting of three identical blades, said it and to reduce to a minimum the amount of slip blad being equi-angularly spaced from each and drag. As indicated by the series of p il s other, each of said blades having concave driving (Fig. 3) the blades of the outboard propeller 5 surfaces and convexly curved back. surfaces, a may be formed in the usual manner, the outersursecond or inboard propeller mounted upon the f e be li t y convex and the under surface same drive shaft as said first propeller, said first being dished or concave so that in operating relaand second propellers being spaced apart and potive to a fluid medium a screw-like path is desitioned in tandem, the said second propeller con- Scri dhe oa propeller owever, which sisting of thre identical blades, said last meniS Set w y from the other p p r a p ed tioned blades of the second propeller being equitermined distance, as indicated in Fig. 4 prefangularly spaced from each other, each of said erably is formed to provide a different set of blade latter blades having fiat driving surfaces and lint profiles 1. e.: the outer faces of same being subback surfaces, said blades being tapered from stantially flat and tapered in cross section, the their front edge to their rear edge on said back entering edge being relatively thin. By the means surfaces, said second propeller being spaced angu- I! 12 larly behin said first propeller whereby to pro- Number vide a space to allow water to go through, both 1,767,786 of said propellers being of substantially the same 1,954,309 diameter. 2,128,780

5 References Cited in the file of this patent UNITED STATES PATENTS g g Number Name Date 1,021,822 Broussouse Apr. 2, 1912 10 Name Date Engstrand June 24, 1930 Cutolo Apr. 10, 1934 Lefi Aug. 30, 1938 FOREIGN PATENTS Ceuntry Date Great Britain 1912

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