US112366A - Improvement in propellers - Google Patents

Description

y a ALEXANDER o. MARSHALL,

or' wAnnnNroN, VIRGINIA.'

Letters Patent Na. 112,366, dated umh' 7, 1871; mitad March e, 1871. i

IMPROVEMENT IN PROPELLERS.y

The Schedule referred tou theseI Letters Patent and making prt of the same.

, I, ALnXA'nnnR J.-`MAns`HALL, of Warrenton, in the county of Fauquier and State of Virginia, have invented' certain Improvements in the Application' of Steamflower to -thePropulsion of Boats upon the Watersof Canals .as well Aas upon-,other waters, of which thefollowng is aspeciication. 1

Nature and Olyeotsvof the Intention.

The iirst part of my invention relates tothe form, l to the mounting, and to the operation of the paddles Por propellers of boats, iu' such a manner that theysvhall present theiwrilat` or .concavesurfaces and shall be driven by the'force of steam directly in right lines against-the water in the rear of the boat, and that allel to, the4 surface, andyet so far below it, that it shall not`-be greatly agitated by' their motion, while the water Where the propellersdooperate will have its power of resistance to, them vgreatly increased by' theweight of the waterjaboveit; and furthermore, .Q

that the propellers shall be driven againstthe water alternately, so that, while lone is driven as aforesaid, @the other shallbe-withdrawn edgewise.

The second part of 'my invention relates to the construction, location, and arrangement of thesteam cylinders in the stern of the boat, in such a manner that the paddlesor propellers shalleach. be hinged upon a` frame which shallbe fastened upon the outerV end of a plunger,'which ismerely an elongation of the piston, and be driven and withdrawn by it without any intermediate Inachinery. L l

` Description ofthe Accompanying Drawing.

g Figurel is a ground-planlof the rear section of a boat with my improvements shown in it.

y 1 Figure 2 `is 'adongitudinal vertical Vsection of the same.

ton, paddle, andthe frame in, which it is mounted.

1 General Description. v The letters AA A indicate the sides and O the sternproper of the boat,"and K thebottoin, and the part-i` tion C and the sides AA` exten led, together with li, constitute a second ,or false stern, which isprovided niei'el y to protect the paddles or propellers from injury j 'or obstruction such as may be caused hy dritt or by .coming in contact with the banks, the gates of locks, and the like. This false stern isplanked up from bei low the surface of `the water, so "the true stern, and should be suilicientlystrong to serve the purpose designed.

The guides II their fhrward ends bolted down upon the cross-timbers M'Maiter passing throughthe partition O, and are thus h eld rividlyin position,

they shall be so driven against the water in lines par-.y

Figure?) is a detached view, in perspective, of a pisas to appearto he and extend to the openings o r, between the end piece B, and O 0 the brace for the sides -of the -outer stern. .l The outside guides are provided with beveled edges on their inner sides, and the middle guide is provided.

with `like edges on both its sides to fit the grooves ff v in the cross-heads F F. These guides and cross-heads, should be made 'of metal of sujcient hardness and tremities, and the paddle-braces H H should be let into the cross-head or cast together with it in one piece, so that their outer surfaces. shall be flush with each other, to the end that when the paddles G G are' driven against the waterl there shall be an equal pressnre against both, and the center of each paddle should abut` against thefcenter of each plunger.

The uprights HH should have the form shown in figs. 2 and 3. The parts' ,-HI' act as stops to prevent the lower ends ofthe paddles from being thrown bythe action of thewater, or otherwise, quite as high 4' as the lupper ends';` 'orit' Ithe lower edges were to be raised higher than .the upper, it, might be thrown` upward A instead of downward when its plunger was forced outward against the water.

.The paddles should be made of metal, of theform, or about the form, shown in' the drawing. The pins upon which the paddles turn in the upper parts'oi` the,

. braces maybe in one piece with the 'paddle itself', or

otherwise.

In g. 2, G is the paddle in position to Vloe' driven` against the water, and in iig.A 3 the same' letter indicates the paddle as being withdrawn edgewise by the plunger.

`Asa certain means of inducingthe -outer end of the paddle to be thrown down instead of up, the lower and outer edge mightbe in the beveledform shown 'in iig. 3, Its own weight, however, will` always tend to r give it adownward inclination.

The steam-cylindersv D D 'maybe imbedded in timbers, in any lsuitable manner, in the boat.l

As to'the location of the-boiler in which the steam is to be generated, and the 1mechanical contrivances by which the steam isto be so applied as to draw out and draw in the pistonsE E alternately, these things may be done'in many dilerent ways, and I do not herein make any claim for` any-of` them.

In the drawing the pistons are provided with` stuffing-boxes Where they pass through Vthe partition or ,bulkhead Unas shown at L, iig. 2, to prevent the admission of water `into the boat.- Y i Itwill appearin the drawing that the steam-'cylinders are placed with their back ends against the partition C, and it is obvious, therefore, that when a piston is driven out against the water a portion of it will be in-contaot with and be cooled in some degree by .the water, and that, when again it enters its cylinder,

it will condense the steam therein to some extent. That result may be easily avoided by placing the cylinder so much further forward in the boat that no portion of the piston which will come in contact with the water will reach it.

I have not attempted in this specification to give the dimensions or the proportions of the various parts to each other. They should, of course, be varied according to the conditions and circumstances existing when and where my improvements are used.

1 will suggest; however, that the lower edges of the paddles should, in the outward'push against the water, move in a line but a few inches above that of the bottom of the boat, for the reason that the further they operate below the surface the greater will be the resistance of the water and the less will it be thrown into waves upon the surface, and the less will be the injury done to the banks of canals and other bodies o f water.

These improvements are especially designed for the propulsion of boats upon the waters of canals, but it is believed that their use will be found expedient upon lakes and rivers also.

It is obvious that my prol 1ers or paddles may be` operated by animal or other power as well as that of steam, and that any number of them may be used to propel a single boat.

I do not claim to be the first inventor of a propeller to be driven back in a right line with the line of direction of the boat to be propelled against the water in the rear of the same, nor of the described mode of connecting the propeller immediately with the piston of a steam-cylinder located inthe boat; but

(lo claim- The paddle G, formed and hinged as shown, and its cross-head F, the uprights H H, with their projections H H and their grooves ff, when each is constructed and all are arranged and combined substantially as and for the purpose described.

A. J. MARSHALL.

Witnesses O. J. Heumen, A. M.- STOUT, Jr.

Images