US1599430A - Valve - Google Patents

Description

Sept. 14', 1926.

. F. w. OFELDT VALVE Filed March 11 1924 2 Sheets-Sheet 2 INVENTOR III/III],

: UNITED STATES z Patented Sept. 14; 1926,

PATENT orrrca;

FRANK w. orE-Lnrr, or rrr'rsnunen, PE NSYLV NIA; Ass'roNoa TO 0. an ooML.

PANY, INCORPORATED, or IITTSBURGH, P NNSYLV A, eooRroRArIoN or DELAWARE.

VALVE.

Application filed March 11, 1924. Serial No. 698,466.

7 'The present invention relates broadly to valves for internal combustion engines, and

i being understood more particularly to valves of the rotary and sliding types. V 4 A serious difliculty' encounteredin the use of valves of various types with internal combustion :engines is their tendency to warp due to the factthat different portions of the valves are, subjected to different amounts of heat, thereby'c'ausing non-uniform expansion or contraction throughout the bodies of the'va'lves.

By the present invention a'valve construction of such character that expansion may be subjected in use will tend to maintain the seating surface of the valve true. Inrthe accompanying drawings, there are shown, for purposes of illustration only, certain embodiments of my invention, it that the drawings do not define the limits of the invention, as changes may be made in the construction therein disclosed without departing from the spirit of the invention or scope of my broader claims.

In the drawings, Figure 1 'is a vertical sectional view through a portion of a cylinder head equipped with a rotary valve embodying my invention; v

FigureQ is a horizontal sectional'view on the line II-II of Figure 1;

Figure 3 is a .plan view of the shown in Figure .1; a i

Figure 4 is a vertical-sectional view through a equipped with a' sliding. valve embodying my invention; and

' valve Figure 5 is a plan view of the valve shown in Figure 4. I

Figures 1, 2 and 3 illustrate my invention embodied in a valve of the rotary-type. Referring to Figure '1, the referencecharacter 2 designates a cylinder head in which is mounted a valve-cage 3 provided with tw'o diametrically opposite intake ports 4 and two diametrically lop'p'ositeexhaust.

ports '5., The intake ports communicate with an intake manifold 6 and the exhaust ports with an exhaust manifold 7.

At its lower end the cage 3 has a convex V or spherical seating surface 8 'engaged'by a valve 9 carried by a valve stem 10. The

and contraction of the valve v under temperature conditions to which it portion of an engine. cylinder latter 7 connected at its upper endeto a diaphragm. 11: which-in turn"- is secured byscrews, 12- tofthe enlarged upper, portionu13 tates. A main bevel gear 15 is mounted upon the upper end of the portion 13 .by screws "of a-slceve 14: in whichthe: valvestemrof 16-. .This bevel gear is'driven by a pinion any tendency of the same to move away from its seat. j

The sleeve 14 rotates in a bearing 21 formed integral with the cage 3 but terminates short of the lower end of said bear, ing, The valve stem- 1O .fits, loosely in the sleeve 1 1 and has mounted thereon between the lower end of the sleeve and a shoulder 22, at the lower end-of thefbearing 21, a roller: 23 fitting loosely in thebearing; 7

The valve is provided with two diametricallyopposite ports 24:. It will be ap-, parent that when the valve is rotated the ports2 i will'be brought into communic'a tion first with. the intake ports 4 and then with the exhaust ports 5* once for every 180 degrees of rotationof the Valve. ..Furthermore, the valvenot only rotates about the axis of the valvestem 10, but also is a1:

q 1 engagement with "its seat and counteracts I have PIOVlClGd lowed to move bodil due to the loose fit of v present application to the diaphragm drive r the spring for counteracting for the valve,

the tendency. of the valve to move away from its seat,'or tot-he loose mounting of the valve stem enabling the; valve to have 'a gyratory motion, as these 'features constitu'te the subject-matter of Patent No. 1,551,209. Y

As'has already been pointed out; when a':

valve is subjected to the temperature conditions in actual use, there is a tendency for the valve to become warped. I have idiscover'ed'a wayto obviate thislaction by so constructing the valve that any tendency of the seating surface thereof to deviate from ing expansion or contraction of its opposite surface. I have found that if the surface 26 of the valve 0 aosite-its concave seatin 23 surface 25 is formed convex. any tendency of the seating surface to flatten out or otherwise change. its curvature when expanding or contracting is counteracted by the expansion or contraction of the convex opposite surface 26. In order to insure the maintenance of a true seating-surface on the valve during expansion or contraction thereof, it is preferable to form its concave seating surface and its opposite convex surface of such relative curvatures that the two surfaces either actually intersect at the periphery of the valve or'would intersect if extended. In other words, theseating surface 25 when expanding tends to become less concave or to flatten out, whereas the tendency of the surface 26 when expanding is to become more convex and to corresp nd ingly increase the concavity of the seating surface 2 5. The tendency of the seating surface to change its curvature-in expanding is, therefore, neutralized by the expansion of the opposite surface 26, and the same thing is true upon contraction of these surfaces.

In Figures 4 and 5, I have shown my invention embodied in a valve of the sliding type. The valve 27 shown in thesefigures, cooperates with a valve, seat 28 formed on a cylinder head 29. The valve is carried by a stem 30 which is pivoted at its lower end to thevalve and has its upper end connected to one end of a coil spring 31, the other end of said spring being connected to the end of a standard 32 forming part of a bracket 33 secured to the cylinder head by means of screws 34. Intermediate its ends the stem 30 is provided with 'alongitudinally extending slot 35 through which passes a pin '36 carried by the cylinder head. A stem 37 is sli-dably mounted in an arm 38 of the bracket and has one end pivotally connected to the upper end of the valve stem 30 and carries at its other end a roller 39. The roller 39 isengaged by a cam 40 carried on a shaft 41 journaled in an arm 42 of thebracket,

said cam being drivenfin any suitable-manner from the engine crank-shaft. A coil spring as surrounds the stem 57 and abuts at one end against the standard 32 and at the other end against washer 44 on said stem. The spring 43 maintains the roller 39 at all times in contact with the peripheral edge of the cam. The cylinder head 29 is pro-.

vided-with intake and exhaust ports 45 and 46, and the valve 27 is provided with ports 47 and 48 adapted to be moved into and out of communication with the ports 45 and 46 vex, and the relative curvatures of these surfaces are such that they intersect. att'h'e opposite endfledgcs ofthe valve. The valve 27 functions in the same manner as explained for the valve 29 to counteract :any-

tendency of the seating surface 49 to deviate from a true seating surface when the valve expandsand contracts.

The advantages of the present invention arise from the provision of a valve structure for rotaryor sliding valves of such chara-cter that tendency of the valve to warp inuse is counteracted. I i

l 'claim: I

1. A valve havinga concaveseating surface and :a convex opposite surface, the curvatures'of the two surfaces being eccentrio to each other, and having, radii of dif- 1 ferent lengt'l'is, the convex surface having a shorter radius of curvature than the con caved surface, substantially as described.

'2. A valve having a concave seating surface and a convex opposite surface, the relative curvatures of the two surfaces being such that they intersect at the periphery of the valve, substantially :as described.

3. A disk-shaped valve having a concave seating surface and a convex opposite surface, the relative curvatures of the two surfaces being such that they intersect, substantial'lyas described.

4. A disk-shaped valve having a concave seating surface and a convex opposite surface, the curvature of the convex surface intersecting the concaved surface at't'hepescribed.

5. A gyratory valve having a. concave seating surface and an eccentric convex opposite surface whose radius of curvature is shorter than that of the concave surface Whereby the valve is thicker at the center than at its periphery and wherein the relative curvatures of the two surfaces are such that the valve tends to maintain a true seatri-phery of the valve substantially as deing surface upon expansion or contraction thereof, substantially as described.

In testimony whereof I-have hereunto set my hand.

FRANK W. oFELnr.

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