US573875A - Valve gear - Google Patents

Description

(NqModeL) 2 Sheets-:Sheet 1. O. P. HART.

VALVE GEAR. N0 573,875 Patented Dec. 29, 1896.

2 sheets-sneet 2.

(No Model.) 7

0, P.'HART'.

VALVE GEAR. No. 573,875. Patented Dec. 29, 1896.

WITNESSES: INVENTOR ATT EY5- U ITED STATES PATENT QFEICE.

TO JAMES L. RAINEY, SAME rLAoE.

VALVE- GEAR.

SPECIFICATION forming part of Letters Patent No. 57 3,875, dated December 29, 1896. Application filed June 27, 1896. Serial No. 597,142. (No model.)

To aZZ whom it may concern:

Be it known that l, OZIAs P. HART, residing at Murphysborough, in the county of J ackson and State of Illinois, have invented a new and Improved Steam-Engine Valve-Gear, of

which the following is a specification.

This invention relates generally to steamengines, and more particularly to an improved valvegear for regulating speed of said en- 1o gines.

The object of my invention is to provide a new form of valvegear which shall be exceedingly cheap in construction and easily applied and thoroughly efficient in operation.

Another object is to provide a valve-gear which can be applied to any of the machines now in use, and particularly to the engine of the Corliss type.

Another object of my invention is to provide a valve-gear which can be applied to engines provided with either a rotary or sliding valve.

Another object is to provide a valve-gear which shall be extremely quick and active,

2 5 and its movements thereby regulating the inlet of steam, and consequently the speed of the engine.

With these various objects in view my invention consists in the peculiar construction 0 of the various parts and in their novel combination or arrangement, all of which will be fully described in detail, and pointed out in the claims.

In the drawings forminga part of this speci- 5 fication, Figurel is a view showing my invention in use. Fig. 2 is a side elevation of the engine running at a low rate'of speed. Fig. 3 is a partial side elevation running at a high rate of speed. Fig. 4 is a sectional view 0 on the line 4 4 of Fig. 2. Fig. 5 is a partial top plan view.

In carrying out my invention I employ a bed A, upon which is located the steam-chest, the drive-shaft C, and all the operativeparts of the engine. The cylinder and steam-chest are shown incased and provided with rotary inlet and exhaust valves, and it will of course be understood that slide-valves can .be used if so desired. The drive-shaft O is provided with a crank portion, to which is attached the pitman D, operating the piston-rod. Upon Between the engine-bed and band-wheel an eccentric II is mounted upon the drive-shaft,

and between said eccentric and the band- I wheel is mounted a drum I, having a cam groovel.

Connected to the eccentric II is a pitman K, the forward end of which is pivotally attached to the upper end of a lever L, said lever being pivoted on a stub-shaft L, which projects laterally from the side of the engine body or frame.

A11 elbow-lever M is pivoted upon an arm M, projecting laterally from the engine body or frame at a point to the rear end of said stub-shaft L, the rear end of said elbow-lever being provided with an antifriction-rollerM which is adapted to travel in the cam-groove I of the drum I, and as the drive-shaft and drum revolve the elbow-lever is operated.

A short pitman-rod M is attached to the forward end of the elbow-lever, said pitman-rod in turn engaging the upper ends of a lever N, pivoted also upon the stub-shaft L, but upon the inner side of the lever L. The lower end of the lever L has a link-rod O pivotally. connected therewith, the .forward end of said rod being connected with thevalve-rod 0 through the medium of a wrist-pin O and .slide 0 in which said wrist-pin slides, the

said rod 0 being connected with the crank 0 carried upon the outer end of the exhaustvalve shaft, and this crank is connected with the opposite crank 0 by means of a link 0 whereby both exhau st-valves are operated simultaneously.

To the upper end of the lever L is attached 0 the link-rod P, said link-rod being pivotally attached to the upper end of a slotted link Q, said link having a grooved slot R, in which slides a block S, to which the rod T is attached, said rod Tbeing connected to the crank-arm 9 5 T, mounted upon the end of the steam-valve shaft, and this crank-arm T is connected with the opposite crank T by means of alink T so that both steam-valves operate in unison.

An automatic ball-governor U is mounted upon the arm U, which projects upwardly from the engine bed or frame, the shaft U of said governor being connected at its lower gear 7 through the medium of which the governoris revolved, and it willbe readily understood that as the speed increases the arms of the governor arethrown outward by centrifugal action and the shaft U is raised or drawn upward. This action raises the link Q, through the medium of the hanger U and thereby lifts the rod 'P to an upward position, so that its force'or thrust does not affect'the steam-valve, but, on'the contrary, the thrust of the rod V becomes direct-operating, and consequently operates the steam-rod.

Now'it will.bereadilyseen that the lever L is operated'from the eccentric upon the driveshatt and that the lever N is operated from the cam grooved drum upon the-drive-shaft, and it will'be understood that the eccentric is so shaped with reference to the cam-groove of the drum that the thrust of the lever M'will be greater than that of the lever N, so-that when-the link Q is elevated to the position shown in Fig. 3, orinfact'to any intermediate position, it is clear that the thrust of the lever L and rod P are'limited, and when the link'is raised to-its full limit the leverL ceases to have any effect whatever upon the steam? valve, but said valve is governed entirely by the-action ot the lever N. Thus it will be seen that asthe speed increases and the governor operates to lift thelink the steam is cutoff in proportion and the speed thereby.

regulated. Thus it will be seen that I provideranexceedingly cheap, simple, andefficient form of valve-gear, which acts with rapidity and accuracy, and onetwhich can be applied to any'of the engines now in use provided with either rotary or slide valves.

Ilavin g thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a valvegear for steam-ehgines the combination with the curved slotted link, of a governor connected therewith and adapted to raise and lower the same, the drive-shaft having an eccentric and a cam grooved drum, the pitman connected with the eccentric, the lever to which said pitman is connected the link-rods connected with the opposite end of said lever, one of which is connected to the upper end of the slotted link while the other is connected with the exhaust-valve mechanism, an elbow -lever operatively connect ed with the cam-grooved drum, a lever to which said elbow-lever is attached and the link-rod extending from said lever to the lower en'dof the slotted link all arranged substantially as shown and described.

2. In a valve-gear for steam-engines, the combination with the drive-shaft and wheels and the cylinder and steam-chest, of the governor constructed as described, the slotted link with which said governor is connected, the eccentric and cam-grooved drum, parallel levers pivoted upon the engine-bed and operatively connected with the said eccentric and drum, the inner lever having-a link-rod connected to its upper end, the forward end of which link-rod is connected to the lower end.

of the slotted link, the outer lever having a link-rod connected to its upper end, the forward end of which linki-rod connects with'the upper end of the slotted link, a link-rod connected to the lowerend of the-outer lever, the forward end of which connects with the ex haust-valve mechanism, and means forconnecting the slotted link with'the steam-valve mechanism all arranged substantially as.

to which said pitman is attached, the link rod connected tothe upper end of said lever and attached at its forward end to the upper end of the slotted link, thelihk-rod attached to the lower end of said lever and connected at its lower end with the exhaust-valve mechanism, the cam-grooved drum mounted also upon the drive-shaft, the elbow-lever adapted to engage said drum, a short pitman connected to said elbow-lever, a lever towhich said pitman is attached, a link-rod con.nect-, ing the said lever with the lower ends of the slotted link, the block sliding in theslot of saidlink and the steam-valve-operating rod attached to the said block and to the steam valvemechanism. and means for operating the governor-from the drive-shaft substantially as shown and described.

OZIAS P. I'IARTQ \Vitnesses:

EDWIN LOOSLEY, J 1 W W. OZBURN.

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