US986982A - Steam-engine. - Google Patents

Description

N. G. HERRESHOPF.

STEAM ENGINE.

APPLICATION FILED JULY 31, 1907. RENEWED DBO. 2a, 1909.

Patented Mar. 14, 1911.

4 SHEETBSHEET 1.

FIG. 1

N. G. HERRESHOFF.

STEAM ENGINE. APPLICATION FILED JULY 31, 1907. RENEWED p120. 28,4909.

986,982. Patented Mar.14, 1911.

4 SHEETS-SHEET 2.

FIG. 2

Wbbvmooa v E?! 1400 who-z //m imam M N. G. HERRESHOFF.

STEAM ENGINE.

APPLICATION FILED JULY 31, 1907. RENEWED DEC. 28, 1909.

986,982; Patented Mar. 14, 1911.

4 SHEETS-SHEET 3.

FIG. 3

A 4 i l i l 15071, M 5 v0 whoa l -l.j i lii,

1 1 l J A 1 o 1. a H1.

l o I N. G. HERE FF.

STEAM EN E.

EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE DEC. 28, 1909. 986,982. Patented Mar. 14, 1911.

INVENTOH I mwm UNITED STATES PATENT OFFICE.

' NATHANIEL GREENE HERRESHOFF, OF BRISTOL, RHODE ISLAND.

STEAM-ENGINE.

Specification of Letters Patent.

Application filed July 31, 1907, Serial No. 386,439.

Patented Mar. 14, 1911. Renewed December 28, 1909. Serial No. 535,361.

mand for engines of great power with little bulk or weight.

I have discovered that it is practicable by combining features before used separately to produce an engine eminently adapted for swift vessels and various other work developed by modern progress including flying machines.

The improvement may be used with the super-heated vapor of water or other fluids, but I will'describe it as working with steam from any generator with means of superheating. I prefer that the pressure and temperature of the steam used be much higher than in ordinary engines.

The invention is more especially applicable where quick-acting, reversing engines of small size are required; I will describe it as applied on a motor boat, but it is also applicable in a motor carriage or car.

The cranks are formed in one with the shaft, the whole being forged or otherwise produced of suflicient thickness and strength to serve without bearings between the cranks, and extending the metal from each crankpin to the next directly in straight lines. And I have discovered that it is practicable to make such cranks, of the form, which we term undercut when applied to ordinary cranks so that each crank pin is longer and affords a wider bearing for the. connection than would be otherwise practicable. I can employ many cranks. I will show and describe three. The six cylinders are matched together in pairs, steeply inclined like the sides of the letter V. I connect both the piston-rods of each pair to one crank-pin.

The following is a description of what I consider the best means of carrying out the invention.

The accompanying drawings form a part of this specification.

Figure 1 is a vertical section in the plane' of the axis of one of the cylinders and of the accompanying valve and valve-stem, and an elevation of other parts. Fig. 2 is a longitudinal, vertical, section on the line 22 in Fig. 1. Fig. 3 is a plan view, with the upper portion of the top casing and the midw dth portlon of the bottom casing removed. Fig. 4 1sa cross-section of a detail on the line 44 in Fig. 2 proportioned to serve wlth a small number of cylinders. Figs; 5

and 6 are on a larger scale. Fig. 5 indicates the front elevation partly in section, though on a larger scale, of a part shown in Fig. 2 but proportioned to serve with a larger number of cylinders by allowing less lost motion in reversing. I Fig. 6 is a vertical section of a portion corresponding to Fig. 2. It shows the forward end of the cam shaft and adjuncts. Fig. 7 is a perspective view showing a crank shaft and cranks more slender than are used in practice, to exhibit the relation of the parts. Fig. 8 is 2. corresponding end view. Fig. 9 is a side view partly in vertical section of an engine having eight cylinders. Fig. 10 is a corresponding end View partly in vertical cross-section, showing the relations when carried out with eight cylinders. In all these small diagrams the cylinders are shown wide apart and the cranks are more widened than is desirable in practice.

Similar letters of reference indicate like parts in all the figures where they appear.

A is a fixed framing of cast-iron or other suitable material, certain portions being designated by supermunerals.

A is a cylinder. Each cylinder is separately formed and the cylinders being alike, 2. description of one with its adjuncts will suflice for all.

A is abottom casting, which can be removed for examination and repairs. After disconnecting by ordinary means, not shown, the entire engine with the casing A, A, can be lifted out of its connection with the other parts, and turned on its side or inverted. The pan A which is at the bottom when in use can then be removed and easy access obtained.

B is an extension of the shaft, shown as integral with the cranked portion.

B is a portion of the metalextending from the center line of the shaft; C is a portion at right angles thereto, serving as the first crank-pin.

12; is a portion extending at right angles to C is a second crank-pin.

B is a portion of the metal extending from the latter crank-pin to the next and last crank-pin C, andB is an extension of the inetal from C, inward to the shaft proper.

" and resting in a stout adjacent part-s B, B etc. As shown, there are six. connecting-rods, six cylinders, and sixpistons, all alike, coupled 1n palrs Descrlblng' only one-E is a connecting-rod, taking hold to the respective crank-pins.

of half the length of the corresponding crank-pin C and connecting to a pm G in the trunk-piston G. The construction is intended to make the bearing afi'ordedby the brasses snfliciently extended to allow the enine to work with its full force for an indefinite. period with the efiiclent lubrlcatlon which I provide. The exteriors of the p1s-.

5 tons,.and the interiors of the cylinders are v is in the lower side of the cylinder.

finished truly,.and my experiments indicate that theparts will work together for a long period'without abrasion or appreciable leak- I age. There is no movable part termed an exhaust-valve, unless I the piston shall, itself, be given that name.

The exhaustporta extendsfa considerable portion of the distance around the cylinder, the metal be-' 3mg, of courseybridged across at short distances to maintain the. strength. This I" is a pin set in the cam-shaft P. It plays in a recess which extends about half way around in the interior of the loosely mounted gearwheel D, which latter is thus free to revolve to a limited extent,somethingless than halfofa revolution,on the cam-shaft. c

S, S are pins permanently 'set at opposite points in the loose gear wheel D and extending parallelto the axis into the plane of the disk K.. At opposite points in the circumference of the latter wheel are shal ,low recesses 70, h, each deep enough to receive the corresponding pin S and'of the width required to allow the wheel D to turn freely to the extent prescribed. There are, thus shown twomeans for connecting the wheel D having'a limited looseness with the shaft P. I can use both of these two means of engagement, one being the pin P set in the shaft P and playing in an approximately segmental'recess in the wheel D, and the other being the two pins S set in such wheel D and playing in the two broad spaces k in the circumference in the wheel K, which latter is fast on'iP. The efiect of either or bothis to communicate motionreliably from the engine to the cam shaft P and to allow thus sufiicient lost motionto insure that the position of the cams relatively to the valves will be right for revolving in either direction.

M is the induction-valve,one for each cylinder. These arethe only valves, strictly so-callod, except the necessary stop-valves,

in the entire engine. When a valve M is opened, the steam comesfrom above through the steam-pipe, and flows downward through the valve-seat and impels the piston with force until the valve is allowed to close by the retreat of the cam, after which it eont-inues to impelby its expansion until near the end of the stroke when its surplus above atmosphere escapes through the port a and the connected thin metal pipe a. It will be understood that thesourceof power of the engine lies in the excess of the favorable action thusinitiated and continued on the upper side of the piston, during its descent,

over the resistance due to the compression which the piston meets during its upstroke.

The valve M is a single pup et of liberal area controlled by the aid. of t e valve-stem M. A high degree of compression ofvthe exhaust steam under the valve aids in raising it. t This is very important when working with high pressure or high speed or both. The valve stem is actuated by a block containing an anti-friction roller M" on its lower end which is subjected to the action of the cam P? in the cam-shaft P. This latter shaft is'supported in stationary bearings and rotated by the aid of a nicely cut gearwheel D which receives the action of an intermediate gear-wheel O,- which latter receives its motion from the gear-wheel B keyed to the main shaft B. The only exhaust which is obtained is the expansion of the steam contained in the cylinder when the piston approaches and passes the lower center and commences to rise again. The liberal opening provided by my extended port a allows the steampressure to descend, theoretically, to atmospheric'pressure, while the piston is at its lowest point. During the rising motion of the piston the thin steam remaining. in the cylinder above the piston is compressed. The clearance, bywhich term I includejall the space above the piston, when the iston is in its highest osition, is so litt e that the pressure wi raised by the compression nearly up to the high pressure of the boiler. Reversin is effected atwill by the force of the hand of the attendant. This effect is due to a just suflicient amount of lost motion in the connection of the gear-wheel D to the camshaft. I, l

on the overhanging end of the cam-shaft ,P, nearest the engineer, is fixed a handwheel Pt, This is important in reversing. To reverse the enginethe steam is temporarily shut off by an ordinary stop-valve, not

shown, and the engineer turns the wheel P forvard,-relatively to its previous direction of rotation, as far as it will go by hand,

either directly or through the agency of a in such direction with the same efliciency and economy as before. The engine has been reversed.

The strong casing A which incloses the cranks and the cam-shafting and gearing is bolted upon the keelsons, not shown, and receives and holds the lower ends of the cylinders. It serves as-the bed-plate or foundation framing for the engine. The lower portion A, is an inverted cap, detachably secured by bolts, not shown. A* is another casing o lighter construction. It conveys the gaseous products of combustion from the steam generator, not shown, and utilizes their heat in warming the engine. 1t envelops in the hot bath thus obtained, the upper portions,the working portions,of the cylinders and of the valves and valve-stems, leaving the cranks and the shaft unaffected. The hot casing A is approximately arch-shaped and envelops the higher part of the cylinder, the valve boxes and the steam pipes, and extends down each side enveloping the exhaust ipe a for a litttle distance horizontally. See Fig. 3.)

I J are springs secured to the fixed framework and acting each on a cross-pin M in the corresponding valve-stem. The duty of these springs is to hasten the closing of the valves.

I attach importance to the arrangement of the pairs of cylinders so that the two which connect to one crank are not directly opposite, but one is in advance of the other so that the crank boxes are side by side on the one crank pin because it'allows them to transmit force in direct lines and avoids making offsets in the connecting rodsand valve stems.

T is a hand-wheel, controlling a large, light valve, mounted in the manner long practiced with dampers,-it is in fact, a damper which may at will be caused to control the flow of the hot gaseous products rate casings A, A and A, the lowermostA stout and cold serving to defend the cranks and valve motions from injuring or being injured and allowin for lubrication by holding a liberal stocc of suitable oil, and also as a bed for the engines, and the uppermost A thin and arch formed carried on the cylinders and valve uides, out of contact with the cold enve 0 A but so connected by the cylinders and valve guides as to be removable therewith when required for examinations or repairs, with connections for flowing the hot gases through it. The considerable space a with liberal ventilation between these casings retards the flow of. heat from the hot to the cold chamber, and I attach importance to the fact that this hot upper casing A extends down and envelops the exhaust pipe a. so as to maintain the high temperature of the escaping steam, and make it more efficient for any useful purpose as blowing the fire 0r warming distant portions of the vessel.

I attach importance to the oppositely inclined positions of the cylinders because such arrangement is compact while allowing access and facility for attention to any one as required; to the eduction ports on the lower sides because it effectually drains out water or oil; to the lower casing A A because it keeps the cranks cool and well supported, and when the engine is lifted and turned over, easily accessible; to the hot casing A and its connections because it warms the main portions of the several cylinders; to the hand wheel -T and its connections because it allows the hot gases to be excluded to avoid over-heatin engine is stopped; to the reversing gear because of its efliciency and convenience, and

when the used both at once if re uired because it gives great security against derangement.

I claim as my invention: 1. In a steam engine having plural cylinders arranged in pairs with the members standing inclined from each other, a shaft having corresponding multiple cranks with the two pistons of each pair connected to one crank pin; so inclosed in casings as to produce two chambers, one chamber inclos ing the effective parts of the cylinders and the valves and valve stems, filled with the hot products of combustion, a space between serving to retard conduction, and a second chamber arranged below inclosing the cranks and shaft and the lower ends of the cylinders and connecting rods welldefended from the heat.

2. A steam engine having plural sets of cylinders in pairs inclined apart, in combieach crank-pin, with the cranks undercut,

allowing broad bearings for the connecting rods, the cranks working in a stron and relatively cool casing A A and wit the bathed in the hot and-with provisions for shuttlng oil such main portions of the several cylinders products of combustion,

I heating meanswhen required.

3. A steam engme comprising plural sets of cylinders inclined in pairs, with the exnation with a shaft having a corresponding number of cranks about equally spaced, an

casings providing two chambers at dif-.

ferent levels, the uppermost heated by the 15 products of combustion and thelowerrnost protecting the main bearings from heat and servmg the additional function of a bed casting.

Signed at Bristol, Rhode Island, this 20 6th day of July, 1907.-

NATHANIEL GREENE nrmmsn'orr.

Witnesses:

NEWELL B. SHELDON, F. P. BRIGHTMAN.

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