US37063A - John teempejk - Google Patents

Description

J. TREMPER. GUT-OFF GEAR FOR STEAM ENGINES.

No. 37,063. Patented Dec. 2, 1862.

Ill

ii I I'FJ win/aspen, I japan/for tion with the aforesaid tripping-levers for the purpose of enabling the steam to be continued ATNT Orricn.

TREMPER, 0F BUFFALU, NEW YORK.

iiiiPiliJVElilENT IN VARlABLE CUT-OFF GEARS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 3?,0'63, dated December 2, 1862.

iii? n25 whom' it may concern.-

it known that 1, Joan TREMPER, of But this, in the county of Erie and State of New York, have invented a new and Improved Variable Cut-0h" Gear for Steam Engines; and I do hereby declare that the following is a full, clear, and exact description of the same, referenoe being had to the accompanying drawings, forming part of this specification, in which 7 h Figure l is a front view of the cut-off gear and the shell which contains the cut-off valve. Fig. 2 is a side view of the cut-oh gear, omitting such parts of the framing as would conceal the working parts. Fig. 3 is a front view illustrating the addition of a device for continuing the operation beyond half-stroke. Fig. i is a plan, on a larger scale, of some of the details of the addition shown in Fig. 3.

5 is an end view of the same.

Similar letters of reference indicate corresponding parts in the several figures.

This invention consist-s in a certain novel mechanism composed of two toothed lifters or tripping-levers jointed to two arms of a rock-shaft, and operating in combination with a toothed .block on the upright stem or rod of the cut-off valve, and with a cone or wedge connected with a governor or otherwise made adjustable, whereby I obtain a gradual opening of the cnt-of valve for the admission of steam to the engine-cylinder, and a sudden closing of the same to out off the steam at such pointas may be required during the first half of the stroke of the piston; and it also consistsin certain means applied in combina on the piston to diiierent points beyond halfstroke.

To enable others skilled in the art to make and use my invention, 1 will proceed to describe it with reference to the drawin s.

A is the shell, which contains the cut-oi? valve. This valve may be of anyknown kind, though ll prefer to use one 'thatis perfectly inalanced when cxposedto the action of the steam. v

a is the rod by which the valve is operated, constituting in the example represented the stem of the valvegbut it may be connected "with the valve in any suitable manner to the valve by its upward movement, the said rod working through a suitable fixed guide. 6, which keeps it upright, and havingapplied to it bet-ween the said guide and a collar, 0, on its'lower part, a spring, d, which exerts a a constant downward pressure, and thereby tends to' close the valve. On the upper part of the said rod there is firmly secured a lifting-block, B, on opposite sides of which there are two teeth, e e, which are acted. upon by the tripping-levers to open the valve, and on another side of which there is formed a tongue, f, working between guides g g, to prevent the rod from turning.

D is the rock-shaft by which the opening movement of the valve is effected, arranged horizontally in abearing ina frame. M. erected upon the shell A, with its axis in the same plane with the axis of the valve-rod a. This rock-shaftha-s fast upon it at the end farthest from the valve-rod an arm, h, by which the connection is made with the eccentric on the main shaft of the engine, and it has also fast. upon it at the end next the valve-rod two arms,

E E, to which are attached the lifters or-tripping-levers F F, which operate upon the teeth 6 e to lift the rod and open the valve. The arms E E have a downward inclination from each other and from the rock'shaft at an angle from ninety degrees to one hundred and twenty degrees, or thereabou-t. The tripping-levers F F are attached by their lower ends by pivots't' z" to the ends of the arms E E, and are arranged on the two opposite sides of the valve-rod on which the teeth 6 e of the lifting-block B are situated, and each has formed upon its-inner side a tooth, j orj, to engage with the tooth e or e on the corresponding-side of the lifting-block, and the parts of the inner sides of the said levers above their teeth jj have backward and up ward inclination, to correspond with the profile of the cone G, which may be either attached to the governor in such manner as to be thereby depressed when the speed of the engine increases. and vice versa, for the purpose of governing the engine by the variation of the point of cutting off steam, or may be adjusted by any other means tocause the cutting off of the steam at any fixed point in the first half of the stroke of the engine-piston. This cone, when usedin connection with a t'romithe main shaft of the engine, causes this thecone until its tooth escapes from the corand the highest position to which they rise is governor, may be arranged to turn freely on the lower part of the upright rod k, which connects it; with the governor, or through which the governor operates to raise and lower it. Whichever way the said cone may be turned, it is in condition for operating on the tripping-levers, and in this respect it is superior to a simple-wedge, which would require some. contrivance to prevent it from turning and keep-its edges opposite to the trippinglevers. The two tripping-levers'are connected by a spring, I, which acts to prevent them from falling or slipping backward. The rocking motion of the arms E E, produced by the osnot be effected at any point in the stroke of cillating motion of the rock-shaft -derived 1 tripping-levers each to rise and fall once during each revolution of the engine, and each one, by the action of itstooth j or j, upon the corresponding tooth e or e of the lifting-block, lifts and opens the cut-off valve at the proper. time for the induction of steam to the cylinder.' As each tripping-lever rises, if the cone G is in a sufficiently-low position the inclined inner surface ofthe part of the said lever above its tooth yorj cornesin contact with and slides up the cone, and as it continues to rise it is forced outward by the wedge-like action of responding tooth of the lifting-block and permits the valve to be closed suddenly by the spring and the steam to be thereby cut ofi. This escape of the tooth of the tripping-lever from the tooth of the lifting-block takes place at an earlieror later point in the stroke of the engine-piston, according as the cone is more or less depressed, and hence when the speed of the engine begins to increase and the cone is thereby caused to be depressed, the escape of the tripping-lever takes place at an earlier point in the stroke, and when the speed is di- 'minislied and the cone allowed or caused to rise the escape of the tripping-lever takes place later, and in this way the cut-off is made to regulate the speed of the engine. In the downward movement of the tripping-pieces with the arms E E they are gradually drawn toward the lifting-block by the springlas fast as permitted by the cone, and their teeth slip over and pass under the teeth of the lifting block ready for a'new lift.

By the arrangement of the arms E E at such an angle to each other below the rock-shaft, as hcreinbcfore described, their operation is caused to be within the lower halfof a circle,

not above a horizontal one, and hence their movement is at first very slow and gradually faster, and they are thereby caused to open the valve with a. very slow movement, corresponding ncarl y with that of the engine-piston at the commencement of its stroke, and 'as the piston is moving faster the valve opens quicker to produce a desirable progressive increase in the supply of steamto the cylinder. In order to stop the cut-oft when closed withoutviolent concussion, the upper part of the guide b is hollowed out concentric with the rod or in the form of a cup, and has applied within the cuplike cavity a ring or rings, n, of vulcanized india-rubber, cork, or other elastic material, to form a cushion, and the bottom of the lift ing-block B is made of a form to enter thesaid cup, and so arranged or of such depth that it will come in contact with the cushion it when the valve in its descent arrives in a closed condition. The lifting-block is thus made to serve the additional purpose of a stop to the valve. As the liberation ofthe valve by the action of the cone on the tripping-levers canthe piston beyond half-stroke, I propose to use in connection with them, in engines inwhich it is desirable to cut 05 beyond half-stroke, the contrivance shown in Figs. 3, 4, and 5. In those figures N is a short bar secured lirml y to one side of the frame. M, and projecting horizontally therefrom toward the rod a and tripping-levers F Fin a direction perpendicular to the planes of oscillation of the said leversi This bar is slotted horizontally, for the reception of portions of two slides, P l",which are fitted toit in such manner as to be capable ofsliding toward and from the sides ofthe tripping-levers, and these slides-are connected rigidly together by ashort transverse pin, 1), which crosses the central verticalslot, r, of the bar N. This slot receives within it a plate, Q, (see Fig. 3,) which is suspended vertically from 1- suitable connection with the governor in such manner as to move up and down with the cone G. This piate contains a vertical slot 8, which is fitted to a fixed pin, t, secured across the slot-r of the bar N, and the said plate also contains an oblique slot, 8, which fits to the pin 2, and as the said plate is caused to move upward and downward with or by the governor the slot .9 and pin tkeep it vertical, and the faces of the oblique slots act as wedges upon the nin p, and cause it to move theslides I P P from and toward the tripping-levers, one of them being arranged opposite to each of said levers. To the twoslides there are attached by pins u u two laterally-swinging toes, R B, one to each slide. These toes have applied to them springs r a, which tend to press them toward each other and hold them within grooves provided in slides for their reception; but portions of the said toes project beyond the ends of the slides toward the tripping-levers, and these portions-are beveled on their inner sides, as shown at w w in Fig. 5, and on their outer sides, as shown at x w in same figure, the bevel on the outer side being oblique, both in a direction lateral andlongitudinal to the said toes, and making the upper sides, 3 3 of the taper form shown in Fig. 1. These, upper sides are also slightly beveled,to give them a downward inclination toward the outer side, as shown in Fig. 5. In each one of the tripping-levers there is secured a pin, 6, which operates in the following manner, in combination with the toes R R: The valverod is brought down by the spring (I to such a position-as to bring the pins 6 6 below the toes, and when the tripping-levers are not thrown out by thecone before the ascent of the said levers is completed, the pins are "brought to position above the toes. In moving upward the said pins work in contact with the inner beveled faces, 10 w, of the toes andpnsh them aside,- and,;when the said pins rise above thetoes thelatt-er springbackagain into or toward the slides PP, and thepins have to descend onisideof 'the toes, and in such descent they are pressed outward in such manner as to throw aside the tripping-levers from the lifting'block and liberate the valve, It has been before stated that the plate Q moves up and down with the cone G, and in that moving upand down it moves the slides .P P and their attached toes R R longitudinally toward and from the.tripping-levers, and the lower it is depressed by the governor-the farther the toes will be pushed toward the tripping levers and under the pins 66. When the toes are presented far under the pins as is the case when the plate Q and cone Gare depressed nearly far enough to make the latter throw off the tripping'levers, the pins, iii-being brought down into contact with the wide portion of the upper inclinedsnrlaces, y y, of the toes, are

caused to slip'qnickly across the said surfaces and drop over the outside of the toes, and so made to throw the trippinglevers from under, the lifting'bloclr almost as soon as the descent of the tripping ielvers commences, and hence permit the valve to remain open very little longer than if the tripping-levers had been thrown out by the cone; but when the toes are presented a less distance under the pins, as is the case when the plate Q and cone G are not so much depressed, the pins descend on the narrower portions of the surfaces 3/ y, and, though they slip quickly across those portions of the surfaces, they are caught by the surfaces was, down which they pass more gradually,and by which they are caused to draw the tripp nglevers more gradually from under the liftingblock, and so keep the valve open during a longer portion of the stroke.

What I claim as my invention, and desire to secure by Letters Patent, is

l. The attachment of the lifters or trippinglevers F F by pivot-joints to two arms, E E, which are soar-ranged upon a roelrshaft or its equivalent as to work below the axis thereof, and-socanse the opening of the valve slowlyat first and with agradually-increasing velocity,- substantially as and for the purpose herein specified.-

2. The combination of the lifters or trippinglevers F F, applied as above specified, the lifting-block B, and the cone G, substantially as and for the purpose herein set forth.

3. The arrangement of the lifters or trinpinglevers F F and the toothed lifting-block B, in combination with the rock-shaft D andacone, G, connected with the governor or otherwise controlled, substantialiy as herein specified.

4s. The mechanism shown in Figs. 3, 4, and 5, and herein described, for tripping the levers F F in their downward motion, substantially as and for the purpose herein set forth.

JOHN TREMPER. Witnesses:

JAMES LAIRID, It. GAWLEY.

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