US656164A - Valve-gear for engines. - Google Patents

Description

No, 656,164. k l Patented Aug. 2|, |900.

A. w. .1. BEST.

VALVE GEABFOR ENGINES."

(Apphcation led Nov, 17, 1899. (No Model.) 2 Sheets-Sheet l.

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VALVE GEAR FOR ENGINES." (Appl'ication filed Nav. 17, 1899.)

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'Nieren STATES ANDREV W. J. BEST, OF MACON, GEORGIA.

VALVE-GEAR Fon ENGINES.'

SPECIFICATION forming part of Letters Patent No. 656,164, dated August 21, 1900. Application filed November 17, 1899. Serial No. 737,308. (No model.)

To allzu/"tom, it may concern'.-

Be it known that I, ANDREW W. J. BEST, a citizen of the United States,residing at Macon, in the county of Bibb and State of Georgia, have invented a new and useful Valve-Gear for Engines, of which the following is a specid ication.

This invention relates to steam-engines in general, and more particularly to the duplex type and it has for one object to provide a construction in which the usual arrangement of cut-off mechanism is omitted and in Which the cylinders are so disposed as to eliminate the necessity of cross-heads for the pistonrods, thus saving the friction and the expense of such construction.

A further object of the invention is to so arrange the parts that the highest efficiency of the engine Will be secured.

In the drawings forming a portion of this specication, and in Which similar numerals of reference designate like and corresponding parts in the several views,A Figure 1 is a side elevation showing the complete engine with the valves set for movement of the fly- Wheel to the right. Fig. 2 is a View similar to Eig. 1 With the cut-off mechanism reversed to rotate the fly-Wheel to the left. Fig. 3 is a view, partly in section and partly in elevation, showing the cut-off valves and their arrangement upon one of the cylinders. Fig. 4 is a section on line 4 4 of Fig. 3. Eig. 5 is a detail elevation of one of the rockers of the cut-olf mechanism.' Fig. 6 is a section on line 6 6 of Eig. 5. Fig. 7 is a section Online 7 7 of Eig. 6.

Referring now to the drawings, 10 represents the bed-plate or casting of the engine, having upwardly-extending portions 11 and 12 at its ends, which portions have circular openings therethrough in axial alinement for the reception ofthe cylinders 13 and 14 These cylinders have each a peripheral iiange 15 and 16, respectively, Which are adapted to lie against the outer faces of the upwardly-extending portions 11 and 12, and against which faces they are secured bymeans of screws17. The outer ends of the cylinders 13 andl 14 are'closed, while the inner'ends are open, and Within each cylinder is disposed a piston 18 and 19, respectively. PilloW-blocks 2O are formed upon the bed-plate 10, and in the bearings thereof is disposed a crank-shaft 21, having at one end, exteriorly of the bed-plate, a fly-Wheel 22, and at the opposite end, exteriorly of the bedplate, a crank-disk 23. The shaft 21 has also a crank 24 between the sides of the bed-plate, and connected With this crank are pitmen 25 and 26, leading from the pistons 13 and 19, and through the medium of which motion is conveyed from the pistons to the shaft 21.

In order to supply steam to the cylinders 13 and 14 and to exhaust therefrom at the proper time, the outer end of each cylinder has the stem of a T-Way connected therewith, which TWays are shown at 28 and 29. Connected With one end of the head of the T-Way 28 is a valvecasing 30 and With the other end a valve-casing 3l, the casing 30 having communication with a feed-pipe 32 through the medium of a pipe 33, While the casing 31 is connected with an exhaust-pipe 34 through the medium of the pipe 35.

The casing 30 has a valve-seat 36,7Whilethe casing 31 has a valve-seat 37, these seats being adapted to receive valves 33 and 39, respectively, the valve 38 being adapted to open against the head of steam supplied to the cylinder, While the valve 39 opens against the head ofthe exhaust-steam. These valves are provided with stems 40 and 4l, which are adapted for reciprocation in extensions 42 and 43 of the valve-casings, and upon the outer ends of the stems 40 and 41 are fixed caps 44 and 45, against the rear faces of which bear the outer ends. of springs 46 and 47, which encircle the stems 40 and 41 and the extensions 42 and 43 and bear at their opposite ends against the casings 30 and 31, the tendency of these springs being to hold the valves seated.

The connection 29 upon the cylinder 14 has valve-casings 50 and 51 connected with the opposite ends of its head, -which casings oontain valves having the same construction and arrangement as those above described, the stems 52 and 53 of these valves being extended through extensions 54 and 55 ofthe valvecasings and provided With heads 56 and 57 at their outer ends. Helical springs 53 and 59 encircle the extensions and the valve-stems and bear at their outer ends against the caps 56 and 57 and at their inner ends against thc casings 50 and 51, thus tending to hold the valves seated.

In order to operate the cut-olf valves to cause proper admission and exhaust of steam to and from the cylinders, it is necessary that the valve of the casing 30 and the valve of the casing 51 be opened simultaneously and that this opening ofthe valves of the casings 30 and 51 be made alternately with the opening of the valves of the casings 31 and 50, which latter are opened simultaneously. Thus while steam is being admitted to one of the valve-casings to supply the cylinders connected therewith, the steam is being exhausted from the opposite cylinder, it being of course understood that the steam-pressure is exerted upon but one face of each piston. In order to thus operate the several cut-oftl valves, two rockers GOvand 61 are pivotally mounted upon the bed-plate 10 adjacent the cylinders 13 and 14, respectively, and each of these rockers has a cushion G2 at one end and a second cushion G3 at the other, these cushions being adapted for engagement with the caps of the valve-stems alternately as the rockers are operated.

In order to oscillate the rockers, a connecting-rod 64 has a bearing at one end upon the crank-pin 65 of the crank-disk 23, while its opposite end is slidably connected with the rocker GO. This rocker GO consists or" a plate having a groove GG in itsinner face, one wall G7 of this groove being lower than the opposite wall G8, and upon the outer face of this higher wall 68 is secured a second plate G9, through the medium of which the rocker is secured to the bed-plate 10 by means of a bolt 70. The end of the connecting-rod 64E has an enlarged head 71, which is disposed within the groove GG and in which it has slidable movement, the connecting-rod being eX- tended outwardly between the lower wall 67 and the plate 69. By this means the connecting-rod Get may be shifted to engage the rocker adjacent either its upper end or its lower end, and in order to thus shift the connecting rod a hand-lever 72 is pivotally mounted upon an extension 73 of the bedplate, and this lever has an arm 74, the outer end of which is connected with the connecting-rod by means of the link 75. Thus as the lever 72 is oscillated the outer end of the arm 74 will be raised and lowered and will correspondingly move the headed end of the connecting-rod. The extension 73 has a segmental slot 76, through which is passed a headed bolt 77, which is continued through the perforation of the lever 72 and is provided with a hand-nut 7S, by means of which the head of the bolt may be drawn against the rear face of the extension 73 to hold the level' in its adjusted position.

Vith the lever 72 (shown in Fig. 1 of the drawings) the upper end ofthe rocker GO will strike the cap 45 simultaneously with the striking of the lower end of the rocker G1 upon the cap 57, and this striking will occur just before the piston 1S has reached the limit of its motion in the direction of its closed outer end of the cylinder 1.3, the caps 44 and 5G having been previously engaged by the rockers to exhaust the prior charge from the cylinder 13 and to supply steam to the cylinder 14. Il", however, the position of the lever 72 be reversed, as shown in Fig. 2, the time of operation of the several valves will be reversed, and instead of the cylinder 13 exhausting, which it would do when the parts are as shown in Fig. 1, the valve 38 will be pressed from its seat and the piston 18 will be moved toward the open end of the cylinder and will thus move the fly-wheel 22 to the left instead of to the right, the valve in the casing 51 at the same time being opened to permit the steam from the cylinder 14 to exhaust.

In order to transmit motion from the rocker GO to the rocker 61, a connecting-rod 80 has one end pivotally connected with the lower end of the rocker 60, While the other end is similarly connected with the lower end of; the rocker (3l.

From the foregoing description it will bc seen that the present structure employs no cross-heads whatever, the pistons being connected directly with the crank-shafts through the medium of their pitmen or piston-rods, and also that instead of the usual link-motion and slide-valve for supplying and exhausting and for reversing is employed a structure having less friction and greater efficiency.

Vhat is claimed is- 1. In a steam-engine, the combination with oppositely-disposed cylinders and a common crank-shaft, of pistons in the cylinders connected with the crank-shaft, a steam-supply pipe connected with the cylinders, valves between the supply-pipe and the cylinders, an exhaust-pipe connected with the cylinders, valves between the cylinders and the exhaustpipe and rockers operatively connected with the crank-shaft and adapted to open an inletvalve and an outlet-valve simultaneously and alternately with the opening of the remaining inlet and outlet valves.

2. In an engine, the combination with oppositely-disposed cylinders, and a crankshaft, of pistons in the cylinders, pitmen connected wit-h the pistons and with the crankshaft, steam supply and exhaust pipes connected with the cylinders, inlet-valves bctween the supply-pipes and the cylinders, outlet-valves between the exhaust-pipes and the cylinders, mutually-connected rockers adjacent the cylinders and adapted to open an inlet-valve and an exhaust-valve simultaneously, and alternately with the opening of the remaining inlet and outlet valves, and connections between the crank-shaft and one of the rockers for moving the rockers.

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crank-shaft to move the rocker, and means for shifting the connecting-rod with respect to the attached rocker to reverse the engine.

In testimony that I claim the foregoing as 15 my own I have hereto affixed my signature in the presence of two Witnesses.

ANDREW W. J. BEST.

Witnesses:

F. F. BEST, E. P. JoHNsToN.

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