US401831A - Cut-off-valve gear - Google Patents

Description

(No Model.)

A. L. HARRISON. GUT-OFF VALVE GEAR.

Patented Apr.12s, 1889.

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UNTTED STATES PATENT "ANDREXV L. HARRISON, OF WILMINGTON, NORTH CAROLINA.

CUT-OFlF-VALVE G EAR.

SPECIFICATION forming part of Letters Patent No. 401,831, dated April 23,1889.

Application filed May 17, 1888.

To all whom it may concern:

Beit known that I, ANDREW LANGDON HAR- RISON, of lVilmington, in the county of lflanover and State of North Carolina, have invented a new and Improved Out-Off-Valve Gear for Engines, of which the following is a full, clear, and exact description.

My invention relates to a cut-off specially adapted for marine engines, and has for its objects to provide a variable cut-off which will work steam expansively at all points from the dead-center to the full stroke, and wherein the speed of the engine may be reduced at will without closing the throttle, and also to provide an improvement upon what is known as the Stevens cut-off.

The invention consists in the construction and combination of the several parts, as will be hereinafter fully set forth, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this speoification, in which similar figures of reference indicate corresponding parts in all the views.

Figure 1 is a front elevation of a rock-shaft, partly in section, with my improvement applied. Fig. 2 is an end view of the same, and Fig. 3 is a partial plan view.

In carrying out the invention the rook-shaft 10 is journaled in the usual manner and provided with fingers 11 near one end and a downwardly-extending arm, 12, at the opposite end. A second arm, 13, provided with a horizontal projection, 14, at the upper end, is attached to the rock-shaft and extends downward parallel with the aforesaid arm 12, the outer arm, 13, being connect-ed with the rock shaft, preferably, through themedium of bolts 15, passing through the outer arm into the end of said rock-shaft, as best illustrated in Figs. 1 and 2.

By reason of the projection 14 a space is made to intervene the contiguous faces of the arms 12 and 13, and the said arms, near their lower ends, are provided with aligning and straight rectangular longitudinal slots 16 and a vertical longitudinal bore, 17, which bore extends from the upper end of the arm 13,1ikewise the upper end of the rock-shaft, down through the lower ends of the said arms, as best illustrated in Fig. 1.

An eccentric -pin, 18, is projected trans= Serial No. 274,188. (No model.)

versely through the said slots 16, one end of which pin is threaded and extends beyond the inner arm, the opposite end being provided with a suitable cap or washer, 19. That portion of the pin 18 which is adapted to slide in the slots 16 is made rectangular and provided with a vertical aperture, 20, aligning the bore 17 of the respective arms.

Beneath the rectangular portion of the eccentric-pin nuts 21 are held to slide in the slots 16, the said nuts being adapted for the reception of a vertical rod, 22, threaded at its lower extremity, which rods are provided at their upper ends with a pinion, 23, and ext-end downward through the bore 17, the aperture 20 of the eccentricpin, and also out through the lower ends of the arms, at which point they are provided with a suitable lock-nut, 24.

A vertical rod, 25, is held to turn in an aperture produced in the arm projection or extension 14, the upper end of the said rod being provided with a hand-wheel, 26, and a gear, 27, below said hand-wheel, adapted to mesh with the respective pinions 23. The eccentric rod or hook, which is not shown, is attached to the eccentric-pin in the usual manner.

A washer, 28, is passed over the extended curved end of the eccentric-pin 18 to a bearing against the inner face of the arm 12, and the said washer is held in position by a nut, 29. lVhen the nut has been screwed up to proper position, the apertured end of a wrenchbar, 30,is passed over said nut and detachably secured thereon through the medium of a set screw or other approved or equivalent device. Thus,in operation, while the rock-shaft is yet in motion, by manipulating the hand-wheel 26 the eccentric-pin may be raised or lowered, as desired, and clamped in position by means of the wrench-bar 30.

It will thus be observed that I provide a mechanical device adapted for attachment to the end of the rock-shaft, whereby the adj ust-. ing of the lead of the steam-valves and taking off the lead and putting it on may be accomplished at will with the engine in motion, the said engine not having to be stopped. to roll the eccentric on the main shaft to secure this result, as is at present the case. As the slots in the arms are not cut on a radius from the center of the main shaft, when the pin is moved up or down in them the lead of the valves is changed, also the lift or throw of the valves. Consequently the steam is enabled to be cutoff shorter or longer to change the speed of the engine slow or fast, as desired, leaving the throttle-valve wide open at all times, and at the same time permitting the steam to be worked expansively at all times.

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

1. The combination, with the rock-shaft of an engine, of parallel spaced arms secured to one end of said rock-sh aft, provided with aligning and straight rectangular slots near their lower ends, an eccentric-pin sliding in said slots, a nut also sliding in the slots below the said pin, rods projected downward through the arms and the pins and engaging the nuts, and a means, substantially as shown and described, for manipulating said rods, whereby provision is made for changing the lead of the valves, and also the lift or throw of the said valves, as set forth.

2. The combination, with the rock-shaft of an engine and spaced arms secured at one end, provided with an aligning rectangular slot and a vertical bore extending longitudinally from end to end, of an eccentric-pin sliding in said slots, a nut also sliding in the slots below the pin,rods threaded at their lower ends and projected through the bore of the arms and engaging said nuts, pinions attached to the upper end of said rods, and a hand-wheel journaled in the rock-shaft above the pinion and provided with a gear-wheel meshing with the same, as and for the purpose specified.

3. The combination, with the rock-shaft of an engine and spaced arms secured at one end, provided with an aligning rectangular slot and a vertical bore extending longitudinally from end to end, of an eccentric-pin sliding in said slots, anut also sliding in the slots below the pin,rods threaded at their lower ends and projected through the bore of the arms and engaging said nuts, pinions attached to the upper end of said rods, a hand-wheel j ournaled in the rock-shaft above the pinions and provided with a gear-wheel meshing with said pinions, and means, substantially as described, for locking the eccentric-pin in a fixed position, as and for the purpose specified.

ANDREW L. HARRISON. Witnesses:

J osH. G. WRIGHT, S. J. BRYAN.

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