US607058A

US607058A - Valve-gear

Info

Publication number: US607058A
Authority: US
Publication date: 1898-07-12
Anticipated expiration: 1915-07-12

Description

a 9 m m w u 1 B t n B t a P 8 MA F- G IL Ln 3 5 7 o 6 m N (Application filed Jan. 24, 1898.)

2 Sheets-Sheet I.

(No Model.)

Inventor DU, as;

Atfiorney Witnesses:

, No. 607,058. Patented July l2, I898.

L. A. LANG.

VALVE GEAR.

4 (Application filed Jan. 24, 1898.)

2 Sheets-Sheet 2.

(No Modl.)

Inventor 015% (1 Attorney UNITED STATES ATENT Enron.

LINooLN A. LANG, or YULE, Nonru'D'AKo'rA, ASSIGNOR on ONE-HALF TO EDWARD FREEMAN WALSH, OF sr. PAUL, MINNESOTA.

VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 607,058, dated July 12, 1898.

Application filed January 24, 1898. Serial No. 667,721. (No model.)

To aZZ whom it may concern:

Be it known that I, LINCOLN A. LANG, of Yule, Billings county, North Dakota, have invented certain new and useful Improvements in Valve-Gears, of which the following is a exemplifying my invention, and Fig. 2 a perspective View thereof.

In the drawings, 1 indicates the main shaft of an engine; 2; an eccentric fast thereon; 3, the eccentric-strap, which is entirely without the usual rigid eccentric-rod; 4, the valve-rod whose reciprocations are to be transmitted to the valve; 5, that end of the valve-rod distant from the shaft and adapted for any of the usual systems of connections with the valve-stem or valve-stem rocker; 6, alinkhaving a mean radius equal to the length of the valve-rod, the link lying in the plane of the eccentric-strap and the back of the link being as close to the eccentric-strap as is consistent with non-interference of the parts as they move; 7, the block of the link, the same sliding in the link, as usual, the inner end of the valve-rod being pivoted to the block; 8, a pivot in a fixed position in the plane of the mean tangent of the link; 9, an arm free to oscillate on pivot 8 and lying alongside the link; 10, link-supporting pivot carried by the free end of arm 9 and engaging an intermediate portion of the link, the link-block 7 to be capable of adjustment in the link to one side and the other of supporting-pivot 10 by any usual or suitable adjusting mechanism; 11, a pivot carried by eccentric-strap 3 as far inwardly upon the strap as is practicable; 12, an arm I rigid with arm 9 and having its outer end connected with pivot 11; 13, the bell-crank thus formed by rigidly-connected arms 9 and 12, these arms being at such an angle to each other as the expediency of construction brings about; 14, a pivot carried by the eccentricstrap on that side of the shaft opposite pivot 11; 15, a pivot carried by one end of the link;

16, a coupling-barconnecting

pivots

14 and 15, and 17 an exemplifyingsuspender for adjusting and supporting the valve-rod.

Referring to Fig. 1, it is obvious that one effect of the motion of the eccentric-strap is to oscillate the bell-crank and shift pivot 10 and the link to and from the shaft, thus giving reciprocating motion to the valve-rod. Arm l2restrains the rotation of the eccentricstrap and limits the movement of pivot 11 to that of an arc toward and from the shaft. Pivot 14 describes a distorted ellipse whose maj or axis represents the degree of oscillation of the link upon pivot 10. The movement of pivot 10 toward and from the shaft is to be equal to twice the lap plus twice the lead of the valve, and the bell-crank and the throw of the eccentric are to be constructed accordingly. Pivots 14 and 15 are to be so related to the strap and link as to give to the link the oscillation proper for the desired maximum port-opening when the block is at full gear.

hen the eccentric center crosses a line joiningthe shaft center and pivot 11, then pivot 10 will be at one extreme of its movement and the mean tangent of the link will be perpendicular to the mean plane of the valve-rod 4, and the valve-rod may then be moved to sweep the block throughout the length of the link without changing the position of the valve. half-turn and pivot 10 will be thrown to its other extreme of motion, and again the block can sweep the length of the link without changing the position of the valve. Pivot 14 effects the oscillation of the link upon pivot 10, while pivot 11 causes themovement of pivot 10 and the link, the resulting functional movement of the link-block and valve being sharply concentrated at opposite points of the cycle of movements, leaving long dwells in the intervals between those movements. The functional results are extraordinary, as will be hereinafter indicated.

A mere survey of Fig. 1 shows that the entire system which reciprocates the valve-rod is concentrated close to the main shaft, thus permitting of the use of a long valve-rod and permitting the system of mechanism to be 100 Give to the eccentric a.

kept with a small field near the shaft. The entire system may be disposed at any angular position about the shaft, thus permitting the valve-rod to lead off in any desired direction for connection to the valve-stem or valverod, the system thus being peculiarly adapted for use under conditions Where there is but limited room and where obstructions may prevent leading the valve-rod directly toward the valve. The construction also permits the link to lie in the plane of the eccentric, thus permitting the direct transmission of the working strains. It is obvious without analysis that the device With a single eccentric has all of the capacities of the ordinary doubleeccentric link-motion, so far as variability of cut-off and reversibility of engine are concerned; that the comparatively long valverod permits of a correspondingly straight link; that the transmission of strains is peculiarly direct and the mechanisms comparatively free from joints and offset connections productive of side strains; that a light valverod instead of a heavy link needs to be adjusted; that the block is practically free from slip; that the strap friction of but one eccentrio is involved; that the eccentric needs but short throw, and that evils of rod angularity are nullified.

An analysis of the system by those skilled in the art will develop the following extraordinary qualities: first, an extremely-rapid opening and closing of ports at all gears, back or forward, the motion being so prompt as to be completed in, say, two inches of piston travel where the latter is twenty-four inches; s'econdfsuch prompt action in opening and closing gives long periods for entry and exhaust of steam, and thus permits of less portopening and consequently of less valve travel, with consequent economy in valve -moving energy; third, such prompt action avoids exhaust lead, if desired, and avoids back-pressure and compression evils; fourth, the lead is constant, and, what is of the highest importance, this constancy of lead is secured Without any sacrifice of port-opening; fifth, a sharp cut-off is secured within any practical desires, it being practicable to out off at any point within two inches of each end of the stroke in the case of an engine having tWenty-four-inches stroke and without any concomitant sacrifices in distribution. So far as known to me these results have not heretofore been attained in linkmotion valvegears.

I claim as my invention- 1. In a valve-gear, the combination, substantially as set forth, of a single eccentric, a rodless strap therefor, a first pivot and a second pivot carried by said strap, a pivot fixed near the eccentric, a link-supporting arm mounted thereon, a link-pivot carried by the free end of said arm, a link pivoted on said link-pivot, a block adjustable in said link, a connecting-bar pivoted to the link and to the first pivot of the eccentric-strap, a connection from the second pivot of the eccentric-strap to said fixed pivot to restrain the turning of the eccentric-strap, and a connection between the second pivot of the eccentricstrap and said link-pivot whereby said linkpivot is moved toward and from the eccentric.

2. In a valve-gear, the combination, substantially as set forth,.of a single eccentric, a rodless strap therefor, a first pivot and a second pivot carried by said strap, a pivot fixed near the eccentric, a link-supporting arm mounted thereon, a link-pivot carried by the free end of said arm, a link pivoted on said link-pivot, a block adjustable in said link, a connecting-bar pivoted to the link and to the first pivot of theeccentric-strap, and an arm mounted on said fixed pivot and 0011- nected with the second pivot of the eccentricstrap and rigidly connected with said linksupporting arm.

3. In a valve-gear, the combination, substantially as set forth, of a single eccentric, a rodless strap therefor, a first pivot and a second pivot carried by saidstrap, a pivot fixed near the eccentric, a bell-crank mounted on said fixed pivot and having one of its arms connected with the second pivot of the cocentric-strap, alink pivoted to the other arm of the bell-crank, a link-block adjustable in said link, and a connecting-bar pivoted to said link and to the first pivot of the eccentrio-strap.

4. In a valve-gear, the combination, substantially as set forth, of a single eccentric, a rodless strap, a link, a link-block adjustable therein, a connection pivoted to the link and to the eccentric-strap to impart an oscillating movement to the link, and a bell-crank interposed between the link and eccentric and serving to reciprocate the link and to restrain the turning of the eccentric-strap.

5. In a valve-gear, the combination, substantially as set forth, of a single eccentric, a rodless strap therefor, a link-supporting pivot mounted near the eccentric and capable of movement to and from the eccentric, mechanical connections between said pivot and strap for causing said pivot to move toward and from the eccentric, a link mounted on said pivot, a block adjustable in said link, and a connection pivoted to said strap and link for oscillating the link upon said supporting-pivot.

LINCOLN A. LANG.

WVitnesses:

J. IV. SEE, FRANK P. RICHTER.