US5129A - Operating cut-gee valves - Google Patents

Description

SPRAGUE BARBER, OF NEW YORK, Y.,'\ASSIIGNOR.TO` JAMES STEVENS, HOBOKEN,

NEW JERSEY.

' orERariNe cuir-OFF VALVES,

Specification ofLetters Batent IO; 5,129, dated May 22, 1847.

To aZZ whom it.' may concern.' y I lBe it known that I, SPRAGUE BARBER, of the city and county ofv New York, late` of Westerly Rhode Island, a citizen of the United States, have invented a new and use-` ful Improvement on VSteam-Engines, called a Cut-Off, of which the follow-ing is a fullI and exact description.

The object of this invention is tov con-l struct a less expensive and more perfect apparatus for lclosing the steam valves yat different portions of the strokev of the piston and thereby cutting o" the steam from the boiler and allowing it .to act eXpansively in the cylinder. This I mean to accomplish by means of what I call a drop slideplaced in the posit-ion represented in the drawing; this drop slide elevates the valve to its required height with the original lifting rod by means of its shoulder and then the shoulder being withdrawn by an attachment to some suitable portion of the machinery allows the valve to drop with any degree of velocity that may be found necessary on the curve of the drop slide. This will be more clearly explained by a reference to the drawing. l

In the drawings, Figure I represents an elevation or front view of the cylinder and steam chests of a horizontal engine with rock shafts, lifting rods and lifters together with my apparatus for cutting off the steam attached to each steam chest. Fig. II represents an end View of the same. Fig. III

represents det-ached portions of the cut off apparatus.

The letter a represents a lifter keyed fast to the ordinary lifting rod c, but not attached to the valve stem. The letter b represents an additional lifter not keyed-to the lifting rod but at liberty to slide on the lifting rod c and attached to the valve stem I.

Z represents the drop slide made with a vshoulderc and a curve Z as represented 1n and the other left handed. By means of i these screws the adjusting connection; can be drop slidey tov the; end m of the vrockershaft f f the end a of the lrocktrshaft-f can be connected to the walking beam at a suitable placey orcan be connected to a separate' eX- centric wheel on the'mainv shaftor 4to any part of the engine having a motion parallel to the motion'of the pistn rod and having a sufficient throw to move the arm m ofi the rocker shaft onv the steam chest Q, from lto 2 or on theirsteam chest I) from 3 toll while the piston is. moving from the top of the cylinder to the bottom. g 1

l g representsthehand gearvwhich-serves to force the catch lv under the lifter b, and by that means toconnect the lifters, @and b. The catch h is forced under the lifter b by disconnecting the hand gear g from the catch 0 this allows the engine to work whole y stroke and must always be done when workingby hand.

The operation of this cut-off is as follows: The'piston being supposed to be at the upper end of the cylinder, or at the end to which the steam chest Q is attached, the rocker f shaft R would by the ordinary mot-ion raise lthe lifting rod c and the lifter a which is firmly keyed to it. Now the' drop slide having been moved by the adjusting connection and rocker shaft f to the position as shown at the steam chest Q, the shoulder K connects the lifters a and b together so that when the lifter a is raised by the rocker shaft, itraisesthe lifter b and the valve I with it, admitting the steam on the upper or Q side of thepiston. Now as the piston moves from Q to P the arm attached to the rocker shaft f moves in the direction as marked from l to 2 withdrawing the shoulder K of the vdrop slide Zffrom under the lifter band thereby disconnecting a and b `and allowing the lifter b toffall gradually and kgently along the curve Z of thek drop slideuntil bot-h the shoulder and curve of the drop `slide is entirely withdrawn from y mences to close the valve) can be regulated by the adjusting connection e;by shortening e when it is desirable to cut off shorter and by lengthening e when it is desirable to cut ofi' longer.

The degree of curvature allowed to the curve Z must be made to suit the velocity. at which it is desirable that the valve should fall; the curve Jbeing made steep, when it is desirable t-hat the valve should fall rapidly. This curve maybe a section or portion of a circle or any other curvature that the fall' of the lifter or out olf Vmay require. The drawing represents the cutoff apparatus attached to a horizontal engine but it can, without altering the arrangement of the drop slide, sliding lifter, adjustable connection and rock shaft, be attached to an upright on to an inclined engine. f

It will be obvious from the foregoing'that thebeveled, inclined, or curved face of the drop slide for gradually arresting the downward motion of the valve as it drops is the essential feature of my invention by which the slamming of the valve is avoided, and that this feature of my invention may be applied to any kind of catch or slide which toseeure by Letters Patent is- 1. The method herein described of connecting the lifter ofthe valve with, and disconnecting it from the lifter of the lifting rod by means of the drop slide in combination with the lifting rod and lifter attached to the valve, the drop slide being op erated during the lifting of the, valve, substantially as described.

2. And I also claim the method of arresting the downward motion of the valve'by the inclined or curved face of the slide that holds and liberates the valve, whether it be the slide herein described, or any thing analogous or equivalent thereto, as described.

SPRAGUE BARBER.

Witnesses: p

A. G. MONTMOMERY, THos. LEE.

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