US310489A

US310489A - arnold

Info

Publication number: US310489A
Authority: US
Publication date: 1885-01-06
Anticipated expiration: 1902-01-06

Description

(No Model.) 2 lSheets--Sheet 1.

W. S. ARNOLD.

STEAMl ENGINE. No. 310,489. Patentedv Jan. 6, 1885.`

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(No Model.) 2 Sheets-Sheet 2.

"W. s. ARNOLD.

STEAM ENGINE.

No. 310,489. Patented Jan. 6, 1885.

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VILLIAM SAXON ARNOLD, OF CHATHAM, ONTARIO, CANADA.

STEAM-ENGINE.

SFECIFICATION forming part of Letters Patent No. 310,489, dated January 6, 1885.

Application filed March 31,1884. (Xo model.)

To all whom, t may concern:

Beit known that I, WILLIAM Saxon AR- NOLD, a citizen of Canada, residing at Chatham, in the county of Kent and Province of Ontario, Canada, have invented a-new and useful Steam-Engine, of which the following is a specification.

My invention relates to improvements in steam engines in which steam is used eXpansively, and the crank is used as a medium for convertingthe reciprocating motion of the piston into the rotary motion of the crank-shaft.

In engines using steam expansively by cutting off early in their stroke, the pressure is greatly reduced in the cylindcrsoon after cutting off and before the crank is in the best position for work, and the objects of my improvements are, first, to apply the power which is transmitted through the piston to the crank when said crank is in a more advantageous position to transmit power than with the present practice; second, I avoid compression on exhaust side of cylinder, and

thereby prevent accidents from the accu1nu` lation ot' water. I attain these objects by the mechanism illustrated in the accompanying drawings, in which- Figure l is a longitudinal section of cylinder, steam-chest, and pistons. Fig. 2 isatop view of cylinder, steam-chest, side bars, crossliead, and piston-rods as they appear after the removal of steam-chest cover and valve. Fig. 3 is a plan of the entire engine. Fig. 4 is an enlarged-scale side elevation of the cammotion. Fig. 5 is an enlarged elevation of the slotted rocking lever, with its sliding block, wrist-pins, and connecting-rod.

Similarletters refer to si mi lar parts throughout the several views.

Cylinder A, with the steam-chest M, steamports N, exhaust-ports O, and exhaust-pipe P, constitute the cylinder proper of the engine. The cylinder is provided with three pistons, the center one being the main piston B, andis connected to the main piston-rod E, which transmits power to the crank with the usual connections. The movable piston heads C and I) are externally connected to each other by means of the end piston-rods, F F F, cross-heads G G, and side bars, H H. The side bars, H H, are provided with wrist-pins I l, to w ich connecting-rodsmm are attached,

that have a reciprocating motion adapted to the time and travel of the piston-heads C D. The slide-valve L controls the admission of steam only, and through its valve-rod Kis operated by any suitable system of expansiongear. The exhaust-ports O O are so situated in the bottom of cylinder that the pistonheads O D in their travel control the'eXit of steam. In the center of piston-head Gis an ordinary stuffing-box, U, through which the main piston-rod E passes. Vhen in operation, the main piston B makes aportion of its stroke before steam is admitted to the cylinder; the piston-heads O D, having simultaneously traveled the same distance and in the same direction, then stop, and are firmly held in place. This position is show n in the drawings, Fig. 1, the dotted lines designating the reverse position of main piston and pistonheads. The exhaust-port O being uncovered by piston-head1) and steam then admitted by the steam-valve L, the main piston B continues the remainder of its stroke.

The piston-heads() D are held in position and operated as follows: On the main crankshaft a is secured the disk Z1, on which is a segmental projection, c. Against the face of disk Z), and free to slide across the diameter of shaft c, is the plate d, which is provided with two segmental projections, c c". To the plate d is attached one end ot' the rod g, the other end connecting with the pin lz. This pin 7L projects from the side of the upper end of a slotted rocking lever, i, the lower end of rocking lever being pivoted from the bed-plateof engine by thepivot a. Across the end ot' engine bed-plate farthest from the shaft a is jonrnaled the small crank-shaft k, said crankshaft being provided at each end with cranks Z Z and wrist-pins o p. Frein pins o p are connecting-rods m m, which connect with wrist-pins I l on the side bars, H H. The wrist-pin p is extended through the sliding block j, the said block being free to slide in the slot of the rocking lever fz. 'Vhen the main piston B is at that end of the cylinder nearest to the main shaft, the projection c on disk b comes in Contact with the projection c on the plate (l, thereby causing the plate d to move toward the cylinder. This motion is transmitted to t-he rocking lever t' by the connecting-rod g. The said levert' will, there- IOO fore, through the medium of the sliding block I j and eXtended wrist-pin l), throw the crankshaft k one half-revolution, and thus (as the wrist-pins o p and I I are connected by the rods m on) give proper motionto the pistonheads C D. When the end ot' the projection c on the disk b ceases its contact with the end of the projection c on the plate d, the outer circumference of the projection c revolves against the inner circumference of the projection c, and thereby prevents motion in the plate d until the projection c comes in contact with the lower projection, e, on the plate d. At the point where the segmental projection c on the disk b ceases its contact with the end of the projection c the cranks ZZ have been thrown to their opposite extremes, and the piston-heads C D have reached the extent of their travel and are held rigid in place, owing to the position of the cranks ZZ. It is at this point steam is admitted to the cylinder. The return-stroke is performed in a similar manner to the foregoing by the segmental projection c on the disk b coming in contact with the lower projection, e, on the plate d.

I am aware that prior to my invention steam-engines have been made with more th an one piston and with separate steam and exhaust ports. I therefore do not claim such a combination, broadly; but

I I, the cross-heads G G, carried by said side I bars, the piston-rods F F F. secured to crossheads G G, the piston-heads C D, secured to piston-rods F F F, all having an intermitting reciprocating motion derived from and operated by the mechanism consisting of the disk b, with its projection e, said disk being secured to the shaft c, the plate el, with its projections c e, the rod g, which connects the plate d to the upper end of the slotted rocking lever t', the sliding block .7', the wrist-pins o p, the cranks Z Z, the crank-shaft k, and the connecting-rods m m, which connect the wrist-pins o p with the wrist-pins I I on the side bars, H H, all substantially as described, for the purposes speciiied.

2. In a steam-engine cylinder, the combination of the piston-heads C D with the steamports N N and the exhaust-ports O O, substantially as shown, and for the purposes specified.

WILLIAM SAXON ARNOLD.

Vitn esses XV. F. RUTLnY, T. J. A. RU'rLnY.