US908226A - Screw-propeller. - Google Patents

Description

O. P EGGAN. SCREW PROPELLER. APPLICATION FILED APE.6, 190B.

Patented Dec. 29, 1908.

awwantoz Witneooeo OLE P. EGGAN, OF SEATTLE, WASHINGTON.

SCREW-PROPELLER.

' No. ceases.

Specification of Letters Patent.

Patented Dec. 29, 1908.

Application filed April 6, 1908. 7 Serial No. 425,4;84.

' To'all whom it may concern: i

Be it known that I, OLE P. EGGAN, citizen of the United States, residing at Seattle, in the county of King and State of \Vashington, have invented new and useful Improvements in Screw-Propellers, of which the following is a specification.

My invention pertains to marine propulsion and more particularly to screw-propellers; and it has for its general object to provide a screw propeller. which, in proportion to its size, is possessed of large capacity both in propellin and backing a vessel, and one of such form that it will tend to slide oil of any object encountered in the Water and not be liable to be broken by the same, and which will take firm hold of the water at all times and consequently will not subject its driving machinery to sudden shocks and strains.

To the attainment of the foregoing objects my invention consists in apropeller which terminates at its rear end in a point, and which comprises a forward, longitudinal socket. designed to receive and be fixed on the shaft of a vessel, a longitudinal central body portion reduced. as compared with said socket and exteiiding rearwardly therefrom, and spiral blades which extend from the socket throughout the length of the longitudinal central body portion to a point adjacent to the rear end of said body portion and are gradually increased in width from their forward ends to points near their rear ends; the said spiral blades being relatively arranged to form spiral channels between them. It will be manifest that the peculiar arangement of the blades in combination with the longitudinal central body terminating in a point in rear of the rear ends of the blades, will enable the propeller to slip or slide past any obiect it 'may strike in the water, with the result that the liability of the propeller being broken while in service is reduced to a minimum.

'lhe details of the construction constituting the best practical embodiment of my invention known to me will be fully understood from the following description and claim when the same are read in connection with the drawings, accompanying and forming part of this specification, in which:

Figure l is a side elevation of my novel screw propeller taken from one view point, and Fig. 2 is a side elevation of the propeller taken from another view point and better illustrating the channels.

Similar letters designate corresponding parts in both'views of the drawings, referring to which:

A is the body or longitudinal central portion of my novel propeller which is preferabl reduced in size gradually toward its rear en a.

B is a socket which is preferably formed integral with the said body or longitudinal central portion A and is designed to receive a propeller shaft. lhe said socket may be fixed to the shaft through the medium of a set screw b or any other means consonant with the purpose of my invention.

In addition to the body or longitudinal central portion A my novel propeller comprises s iral blades C which extend from the socliet throughout the length of the body A to a point adjacent to the rear end of said body and are gradually increased'75 in width from their forward ends to points near their rear ends, as best shown in Fig. 1. It will also be noticed by reference to Fig. 2 that the spiral blades are relatively arranged to form between them spiral channels D. The body A extends about the proportional distance illustrated in rearof the adjacent rear portions of the blades 0 and has 1s rear terminal tapered as illustrated so as to assist the blades and the propeller as a whole in sliding out of engagement with or slipping past obstructions encountered in the water.

I prefer to have the blades 0 respectively comprise an inner portion 0 integral with the body A and an outer portion (Z, connected by rivets e or other suitable means to the inner portion, this being advantageous since in the event of an outer portion (i being broken it may be removed and replaced with a new outer portion (Z, and. in that way the period of usefulness of the propeller as a whole may be materially prolonged.

Having described my invcnticn, what I claim and desire to secure 1); Letters- Patent, is:

A screw propeller comprising a forward socket equipped with means for fixing it on a propeller shaft, a longitudinal central body portionformer integral with and extending rcarwardly from said socket and having a rear, tapered end, and spiral blades extending in the direction of the length of the body portion and increased in width from their forward ends to points near their relatively arranged to form spiral channels 10 rear ends and each having ,an'inner portion between them. integralwith the body portion and an outer In testimony whereof I have hereunto port1on attached to the inner portion and setmy hand in presence of two. subscribing '5' adapted to beremoved and replaced with witnesses.

.9; new outer portion when necessity'de- OLE P. EGGAN. mends; the said'ta ered rear end ,of the Witnesses: .body ortion exten ing in rear of the rear MARTIN J.'LUND, ends 0 theiblades, and the said blades being HENRY GULLIKsEN,

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