USRE5364E - Improvement in screw-propellers - Google Patents

Description

Specification formin To all whom it may concern:

and State of New York, formerly of Baltimore, Maryland, have invented curingthe-surrounding cylinder by the aid of v of the blades,

projecting tenons, as aforesaid.

1 of. Fig. 3 is aperspective view of one blade "and hub segment. detachedfrom the shaft and v B are helical blades cast or forged separately,

, from the peripheries of the blades through inor- UNITE S ATES PATENT OFF CE.

.iA'MEs MONTGOMERY, OFISIN'G sine, NE w roan.

IMPROVEMENT IN SCREW-PROPELLERS.

g part of L No. 5,364, dated April 22, 1673;

Be it known that I, J AMES MONTGOMERY, in the eounty of Westchester of Sing Sing,

certain Improvements inScrew-Propellers, of l which the fol- Nature and Objects of thcInveatio-n. I This invention relates to screw-propellers in at the periphery, resist the tangential move ment' of the water, and prevent the fouling of the screw with cables, floating bodies, or other matter. My improvements consist,-first, in sesolid tenons projecting from the peripheries of the blades into mortise-s in the cylinder; second, in constructing the hub of the-screw of segments, each formed in one piece with one the said hub-segments affording ready means of securing the screw to the shaft by the aid of hub-bands and other appliances. The divided structure of the hub also facilitates the putting together of the screw within, an encircling band or cylinder secured upon U General Description. In the accompanying drawing, Figure l is an end vlew of a screw-propeller illustrating my BIVBIIlZIOZL, Fi-g. 2 1s a side elevationtherefrom-the surrounding cylinder.

A represents the shaft of the propeller'.. B

and each-formed in one piece with a segmental flange, b, which flanges are made to clasp the shaft, and are there firmly secured by bands D, so as to form, collectively, the hub of the screw. The bands. 1) D are, by preference, shrunk on the hub b b, or they may be formed with taper screw-threads adapted to fit corresponding screw-threads chased upon the hub. O is acylindrical casing surrounding the screw, secured by means of solid tenons c c projecting tises in the cylinder. It may also be riveted, as shown. This cylindrical casing afi'ords lllllette'rs Patent No. 23,598, dated April 19-, 1859; extended seven years reissue application filed March 28, 1873.

tual support to the ends of the blades and binds the whole structure firmly together in a similar manner to the tire of a carriage wheel, so that a strain or shock imparted to any one 'of the blades is equally sustained by all. The more rapid the motion of the vessel the coarser should be the pitch of the screw by which it is propelled. The obliquity of the blades will therefore be adapted to accord with the model of the boat or vessel for which the screw is in tended. The connection between the ends of the blades and the cylindrical casing is required to withstand a strain for which rivets alone would be entirelyinsufiicient. The tenons c are therefore formed in one piece with the blade, and, by engaging in corrcspondin g mortises in the casing, prevent such playe motion between the two as would sever and destroy the rivets. .When the blades are constructed of wrought-iron the cndsof the tenons will be upset or clinched on the outside of the casing, but with cast blades the tenons will be made in dovetail form and secured in the easin g bycalking or wedgin g from the out side. 1 I

A screw-propeller surrounded bya cylindrical band is prevented from fouling with tow-lines, drift-Wood, water-grasses, and other matters. banks, and the mutual support afforded by all the blades permits them to be made extremely light, so that the propeller meets with less resistance in cleaving the water, and is a less ponderous burden to the stern of the vessel. The casing is also very valuable in arresting or resisting the tangential motion of the water,

,which involves serious lossof power, and, in the case of canal navigation. is highly injurious to the banks.

I am aware that it has heretofore been proposed to apply surrounding bands or cylinders to screw-propellers in various ways, but I have, as before stated, devised a novel, practical, and efiicient mode of sccurin g and uniting such sn rrounding cylinders to the blades, and also an 'eflectivc practical mode of fabricating and putting together an incased screw and securing it \to its shalt.

01m ms.

The following is claimed as new:

It is also less liable to injure canaltises in the casing",

1. A Screw-propeller.eomposed'of a plurality of blades surrounded by a cylinder 0r easing, secured by means of solid tenons projecting from the peripheries of the blades intomorsubstantially as deseribed. 2. The propeller-blades B, each formed. in

ope piece with a segmenlgfi, of the hub, in

combination wibh'a surrounding cylindexyG,

gubstzmtia lly as set forth. 7 v

- JAMES MONTGOMERY;

Witnesses:

-WM. F, MqNAMAR-A,

WM. J. TURNER.

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