US1607051A - Engine valve - Google Patents

Description

Nov. 16 1926.

w. L. BRENNER a I ENGINE VALVE Fil ed Feb. 19, 1925 gwve'nfot Patented Nov. 16, 1926.

UNITED STATES WILLIAM L. BRENNER, OF DETROIT, MICHIGAN.

ENGINE VALVE.

Application filed February 19, 1923. Serial No.'620,061

My invention relates to puppet valves and more particularly to an automatic self centering valve which while hereinafter described and shown as adapted to explosive engine construction, is to be understood as being equally applicable to various other constructions wherein a puppet valve would ordinarilybe adaptable.

The invention contemplates a valve comprising an independent head and stem loosely connected for'relativeshifting movement into various eccentric relations. Such lateral shifting movement is afforded by providing in the valve head an enlarged hole through which the valve stem extends, the stem being provided with a fixed terminal head having a sliding seating engagement upon a bearing surface about the enlarged hole, the valve head being held in engagement-with the head of the stem by means of a spring washer engaging the opposite face of the valve head, thereby affording yielding frictional resistance to the lateral shifting movement of the valve head and stem in relation with each other.

Such shifting movement is for the purpose-- of enabling the Valve head to automatically center itself in relation with the valve seat in the event that the valve stem guide is not accurately centered with such valve seat or is worn to such extent as to permit side play or wa-bble movement to the valve stem. The valve head is further provided with an arcuate or rounded peripheral bearing surface for engagement with the straight conical valve seat, thereby insuring a narrow seating area and enabling the valve head to crush or wear away carbon deposits to insure a tight fit of the valve upon its seat.

It is necessary that valve stems be fitted loosely in their guides in order to -pre vent sticking and enable freedom of action. Such valve stem clearance permits a slight inclination of the valve stem by which the head-assumes an. eccentric relation to the valve seat much greater than the guide clearance. This eccentricity of the valve head and seat is further aggravated by the wear and further enlargement of the valve stem guide. A valve performs a double movement in its closing operation, particularly in the event that the stems or guide is worn. It possesses a reciprocatory movement to and from its seat and in addition thereto a lateral movement under influence of the retracting spring into marginal engagement with the seat. The former movement varies with the speed of the motor while the latter is substantially constant in time value. As the ratio of these movements changes at high speed the time of complete closure during each stroke is reduced. The valve being partially opened or having failed to find its seating contact during too great a portlon of the cycle results in excessive losses of fuel and compression. Moreover, the repeated seating of the valve in substantially the same position with the same side shifting movement to find its concentric seating relation causes the valve and seat to wear unevenly, especially as these 'parts frequently contain spots of different densities or degrees of hardness' Furthermore, the passage of flame of burning gases and superheated products of combustion between the valve and its seat during the momentary intervals of side shifts results in burning of these surfaces to such extent as to increase and aggravate wear andthe deposit of carbon.

It is obvious that if the valve head can be maintained at all times concentric with the valve seat the head will "strike the seat over its entire periphery simultaneously to effect an instantaneous closing without the wear and loss of fuel by the shiftingor sliding into place at each operation. This is effected in the present instance by enabling the valve head to automatically adjust itself in relation with the stem into such concentric relation with the valve seat even though the valve stem due to inaccuracies of manufacture or worn guides assumes an eccentric relation. Having once adjusted itself to concentric relation with its valve seat and eccentric relation with its stem the head will thereafter maintain such relation until conditions again change whereuponit will again accommodate itself to the new condition or adjustment.

A further feature of this invention is to enable the valve to automatically acquire an area of seating surface sufliciently narrow to permit it to penetrate carbon deposits upon the seat and yet amply wide enough to prevent wear. Valves having wide seats and especially those of the rigid type cannot crush the carbon deposit which accumulates upon the valve seat except perhaps upon the side on which the valve head initially strikes preparatory to its side 7 shift into closed position. Such side shift movement will have but little or' no crushing effect in retum due to the reaction of the spring will have been expended at the initial contact of the 'valve upon one side only. This permits a radual but ununiform accumulation of car on which tends to hold the valve elevated from its seat at one side thereby increasing compression and fuel losses.

In the present instance the valve is provided with a rounded or arcuate peripheral bearing surface for engagement upon the customary angular or conical valve seat. This affords a narrow seat contact. Since the valve automatically assumes a concentric relation with the valve seat it strikes upon such narrow contact area throughout its entire periphery. The force of impact being thus localized upon a reduced area excessive carbon deposits are prevented. Only a fine film of carbon uniformly distributed is permitted. Such uniform carbon film is advantageous in preventing wear. Such initially narrow seat may have a temporary tendency to widen but the wear ceases with the accumulation of such thin film of carbon deposit and the seat so formed is more accurate than can be produced by mechanical means and requires no grinding or resurfacing.

The capability of the present valve for automatic centering action in relation with the valve seat together with the interengagement of the convex and flat bearing surfaces of the valve and seat affording uniform full circular contact is conducive to quick and hermetic closing of the valve and consequent retention of the cylinder content which is much more essential in affording high efiiciency than is the accurate timing of the opening and closing movement of the valve. However accurately constructed andadjusted, the timing mechanism of engine valves cannot insure either a timely impulse or ultimate pressure or -uni formity of pressure without uniformity of compression, in each and every cylinder of a multicylinder engine. By insuring full and uniform compression the present valve will compensate to a considerable extent for inaccuracies of manufacture and adjustment of the valve operating mechanism whereby when the piston is at low .speed a considerable variation in the time of the valve openingv and closing movement will not to an appreciable extentafi'ectthe volumetric e ciency of the engine.

The object of the invention is to improve the structure as well as the means and mode of operation of such puppet valves whereby they will not only be cheapened in construction, but will be more efficient in use, automatic in action, uniform in operation, and unlikely to get out of repair.

' be adaptable.

A further object of the invention is to afford an accurately fitting quick operating and quick acting valve which will materially increase the efliciency of explosive engines particularly those of high speed type commonly employed in automobiles and airplanes.

A further object of the invention is to embody in a single valve great resistance to high degrees of temperatures, durability and long wearing qualities in combination with non-corrosive characteristics.

Another and quite important object of the invention is to provide a valve which will insure uniformity of compression upon which is dependent the rapidity of combustion and ultimate pressure, regardless of variations of valve timing.

With the above primary and other incidental objects in view as will more fully appear in the specification the invention consists of the feature of construction, the parts and combinations thereof, and the mode of operation or their equivalents as hereinafter described and set forth in the claims.

In the accompanying drawing, wherein is shown the preferred, but obviously not necessarily the only form of embodiment of the invention, Fig. 1 is a vertical sectional View of the valve forming the subject matter hereof together with its seat and valve guide as ordinarily employed to explosive engine constructions. Figs. 2 and 3 are detail sectional views illustrating modifications of the construction shown in Fig. 1. Fig. 4 is a sectional view of a modification of the bearing surfaces.

Like parts are indicated by similar characters of reference throughout the several viewsf While the valve construction forming the subject matter hereof has been shown and described in its adaptation to explosive engines, it is to be understood that it is not limited to this use but may find a wide range of usefulness in pumps, compressors, gas and liquid control systems and other installations wherein puppet valves might Furthermore, While the-preferred material for engine valve is cast iron for the headwith a carbon steel valve stem it is to be understood that the valve is not limited to any particular material and that the selection of material will depend somewhat upon the condition of use, to which municating with the exhaust passage. 2.

Below the exhaust passage is the usual valve stem guide 3 in which is freely mounted for reciprocatory movement the valve stem 4. In the present instance the stem 4 has been 4. This abutment sleeve 12 is but not necessarily a nut whic shown operative against the tension of the customary valve retracting spring seated at one end against the valve mounting and at its opposite end'against a collar 6 carried by the valve stem 4. At its upper end the valve stem 4 is provided with an integral head or peripheral shoulder-7 of comparatively small size in relation with the size of the port 1. Loosely mounted, upon the valve stem 4 immediately beneath the head or shoulder 7 is the valve head 8, which comprises a disc having therein a central orifice 9 of somewhat greater diameter than that portion of the valve stem extended therethrough. Surrounding the enlarged orifice 9 of the valve head 8 is an annular flat seating surface engaged by the head or peripheral shoulder 7--.of the valve stem.

The head or shoulder 7 of the valve stem and v the valve head 8 are capable of lateral shifting or sliding movement in relation with each while maintaining sliding contact between the seating surface 10 and the head 7 due to the enlargement of the central orifice 9 and the consequent clearance afforded about the enclosed portion of the valve stem. The head 7 possesses sufficient overlap upon the seating surface 10 that it will at all times effectively close the central orifice9 in all positions of eccentric adjustment of the head and stem. To maintain the head 7 and seat surface 10 in contact with each other and the orifice 9 closed at all times,-'there is provided beneath the valve head 8 a spring washer or collar 11, normally of a substantially concavo-convex form, which is placed under tension and caused to bear upon-the valve head 8 by the adjustment of an abutment sleeve or collar 12, preferably though not necessarily screw threaded upon the stem 1preferably may be secured in various positions of revoluble adjustment by means of a transverse pin 13. The spring tension exerted upon the head 8 by means of the washer or collar 11 not only maintains a tight contact between the head 7 and the seat 10, but also affords suflicient frictional resistance to the lateral shifting movement of the head and stem to yieldingly retain such parts in their adjusted relationr That is to say, while the valve head 8 is capable of such lateral movement to eccentric relation; when subjected to reasonable pressure, or force it is not entirely loose, or free upon the valve stem nor subject to rattle or clatter nor constant changeof relation. .The construction -is such that by its successive [engagement with the valve seat it 'willbe forced to a position of exact registry or concentric-ity with the valve seat even though thefguide sleeve'3 :may be uncentered, orthe sleeve or stem badly worn. Having achieved such concentric relation with the v'alve f sea t its automatic shifting movement it will retain such relation funtil vthe governing conditions change whereupon it'will readjust itself automatically meet the new con-f as a sharp instrumentor one'of reduced bearing may be driven into a body which will be unaffected by a blunt or flat implement under equal force. Thus this valve bearing surface not only overcomes vcarbon depositsbut vprovides for itself a wear resistantseat of extreme accuracy, Alth0ugh the preferred construction is to provide the convex bearing surface upon the valve head for engagement with a straight or angular seat, it is obvious that the relations might be reversed by pro riding a conical or .straightlbearing surface upon the valve for engagement with the convex or rounded valve seat as isshown in the modification Fig. 4. i The preferred construc tion is one in which the contacting faces of the seat 10 andhead 7 v are perfectly fiat and parallel with the plane of the valvehead. However, for certain conditions of useparticularly where the valve stem is free to assume extreme positions of 11101111312101] either due to enlarged or badly worn valve stem guides, the engaging surfaces between the seat 10 and head 7-may be of spherical form the center-of; such shperical faces being coincident with the axis. of oscillation of the valve stem whichordinarily will ,be found to be substantiallya mid length point of the valve stem guide 3. Thus if for any reason the valve stem has apermanent tilt the valve head may adjust itself automatically not only to concentric relation .with the valve seat,

-but also into parallel-relation therewith.

In Fig. 3 there is shown a further modification wherein the valve head seat 10 is shown concave and the o-stem he'ad or shoulder convex, the reverse ofthesphericalbearingdisclosed in Fig. 2, but affording asomewhat similareflfect. L

While the valvehead 8 maybe made of brass, aluminum, various metallic alloysor of nonmetallic substances according to the conditionsunder which it is to be used, the pre ferred material for internal; combustion :enginesis cast ironor what is known to th e trade as semi-steel. Such close; grain andwill readily-g withstandhigh mp tu e hai tmatar dt ridm iqa.

Not only for economy of manufacture, "but leaving intermediate these surfaces a large unfinished area. For the same reason and also to reduce the weight, the area ofthe underside of the valve head beneath the spring washer 11 is slightly relieved as at 16. The depth of the recess may be varied to meet different weight requirements. The underface of the valve head is recessed to receive the spring washer 11, and the bottom of this recess is machined or finished to afford only two annular spaced bearing faces 17 and 18 for the washer or collar, intermediate which the relieved portion 16 presents the original foundry surface. As is .well known the sand surface of the casting is of a more dense and impervious character than is the finished surface. The retention of as large an area of such original foundry surface materially increases the strength and durability of the valve head. For ordinary automobile engine purposes the ordinary thirty-five per cent carbon steel known to the trade as S. A. E. 1035, will be found quite suitable for valve stem constructions. However, for extraordinary or unusual conditions valve stems made of thirty-six er cent cent'nickle steel may be found desira le.

Cast iron (or semisteel) when used for valve heads is less subject to pitting or burning than steel of great density and higher melting temperature. The so-called burning is merely oxidization with the consequent scaling and gradual reduction of the surface in minute particles in very irregular manner, first evidenced by pitting of the seating surface. Cast iron ordinarily contains 3 or 4% of uncombined carbon in the form of graphite imbedded in continuity in the matrix of iron. On account of its porosity, it is subject to capillary action of oil. Since oil and oil vapors are always present in abundance in internal combustion engines the material, with the aid of the continual changes in temperatures, will absorb and retain the oils of heavier consistency. WVhen so saturated it is able to resist oxidiaation and its detrimental effects.

Whereas under some conditions cast iron wears more rapidly than steel, in a valve as here described the wear is almost imperceptible when sufficient area of seating surface is at once attained. For these reasons, cast iron is the most suitable material for exhaust valves in internal combustion engines.

From the above description it will be apparent that there is thus provided a device of the character described possessing 'the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing several modes of putting the invention into effect and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the ap pended claims.

Having thus described my invention, I claim:

1. A puppet valve comprising a disc like head and a stem therefor in relation with which the head is capable of lateral shifting movement to various eccentric positions whereby the valve head is capable ofassuming a concentric relation with its seat independent of the valve stem.

2. A puppet valve comprising a valve head, a valve stem having spaced shoulders thereon between which the valve head is mounted for lateral sliding movement.

3. A puppet valve comprising a disc like head having a central orifice surroundedby a seating surface upon the face of the valve, a valve stem extending loosely through the central orifice in said head whereby the valve head has suflicient play to enable it to assume eccentric relation with the valve stem, and a head upon the valve stem bearing upon the face seat of the valve to close said central orifice in the various positions of eccentric adjustment of the valve head.

4. 'A puppet valve comprising an annular valve head having a peripheral seat engaging surface and a central annular valve seat formed thereon, a valve stem, a valve head carried by the stem and seating upon the central seat of said annular head, and resilient means interposed between the annular valve head and the valve stem for holding the two valve heads in contact while permitting relative shifting movement thereof.

5. In a puppet valve construction, the combination with an annular valve seat. of a valve head comprising a plurality of sections slidingly adjustable one upon another in the plane of said head to various eccentric relations, and a valve stem common to all of the sections.

6. The combination of a valve seat, 'of an annular valve member seating thereon, and in turn possessing a seat surface, a valve Inn stem and a head carried by the valve stem seating upon the seat'surface of the valve member, the valve member and stem being capable of lateral shifting movement while maintaining the seating Contact of. the head, upon the valve member.

7. In a puppet valve construction, the combination with a valve seat, of anannular valve head seatable thereon, a stem having a head seatable upon the said valve member, said valve members andstem head being capable of lateral shifting movement in relation with each other to various eccentric relations while maintaining their interseating engagement.

8. In a puppet valve construction, a valve stem,a valve head and means for yieldingly clamping the valve head to said stem to maintain their operative engagement while permitting relative lateral shifting movement of the head and stem to various eccentric relations.

9. In a puppet valve, a valve stem, having a fixed head and a valve head having therein an enlarged hole closed by the fixed head carried by the valve stem, said heads having lateral sliding contact one upon the other by which they may assume various eccentric relations while maintaining the enlarged orifice closed. 10. In a puppet valve construction, a valve stem, a valve head capable of lateral shifting movement in the plane of saidhead to various eccentric relations with the valve stem,

- and resilient means for yieldingly clamping the head in any'of its assumed positions.

11. In a puppet valve construction, a valve stem, a valve head capable of lateral shifting movement in the plane of said head to various eccentric relations with the valve stem, a head upon said stem engaging one face of the valve head and a" 'spring'washer engagingthe other side of said valve head to frictionally resist such lateralshifting movement.

12. In a puppet valve construction, a valve stem, a valve head capable of lateral shifting movement in theplane of said head to various eccentric relations with the valve stem, and means for frictionally resisting such relative lateral shifting movement of the valve'head and stem.

13. In a puppet valve construction for explosive engines wherein the valve head is positively moved to and fromits seat, the combination with an internally beveled valve seat and a valve head having an external arcuate' seating surface for engagement with the valve seat and means for forcibly projecting the arcuate bearing surface of the valve head against the beveled seating tric relation with the valve seat substantially surface of the valve seat to enable it to penetrate and crus'h carbon deposits upon said seat to automatically provide for itself, an accurately conforming seating surface.

stantially tangentially disposed to the arcuate surface of the first member, the impingement of one of said contacting surfaces upon the other incident to the forcible engagement of the valve with its seat enabling the penetration of carbon deposited thereon to automatically insure a uniformly conforming seating. surface;

15. A puppet valve comprising a valve stem, a valve head movable radially in eccentric relation with the stem, and a spring washer for clamping the valve head to the stem.

16. A puppet valve comprising a valve stem, a valve head movable radially in eccentric'relation with the stem, and an adjustable abutment for subjecting the head to frictional resistance to shifting movement.

17. A puppet valve comprising afvalve head having a hole therein, concentric with its periphery, an angular seating surface around the hole, and a rounded seating surface on its periphery, a valve stemextend-' ing loosely through the hole in the valve head, a head on the stem to engage the annular seating surface on the valve head, a spring washer bearing upon the valve head to maintain frictional contact between the valve head and head of the stem yieldingly resistant to lateral displacement, and means for maintaining the spring washer under tension.

18. In apuppet valve,a valve stem, avalve head capable of lateral shifting movement.

in the plane of said head to various eccentric relations with said stem, and an adjust able abutment for said head by which the head is subjected to variable frictional resistance to its lateral shifting movement.

19. In a puppet valve, a valve stem, a valve head capable of lateral shifting movement'in the plane of said head to various eccentric relations with said stem, a fixed headas specified. r p 21. In a puppet valve construction, the combination with a valve seat, of a valve -head on said stem having sliding seating engagement on said valve member.

23. In a puppet valve construction, the combination with a valve seat, of a valve member seating thereon, a stem, the head and stem being slidingly connected for transverse shifting movement relative to the axis of the stem, to various eccentric positions relative to each other.

24. The combination with a valve seat, of an annular valve member seating thereon, an independent stem for the valve member, said valve member having therein a central orifice of greater diameter than the stem,,thru which thestem extends, and a head carried by the valve stem and slidingly engaging a seat upon the annular valve member to close the central orifice thereof.

25. The herein described method of insuring uniformity of contact between an explosive engine valve and its seat consisting in providing upon the valve and corresponding valve seat non-parallel contiguous faces engaging one'with tlie-otlfer upon a substantially line contact causing carbon deposits upon said surfaces to be penetrated and crushed to automatically conform the deposit to the engaged face.

26. The herein described method of utilizing carbon deposits to insure a leak tight seating joint between an explosive engine valve and its seat consisting in forming the valve and its seat with non-parallel contiguous faces which by impingement upon interposed carbon deposits over a narrow area conforms such carbon deposit to the contacting surface.

27. The herein described method of providing uniform seating surfaces for explosive engine valves consisting in utilizing a carbon deposit between the valve and its seat and providing upon one ofsaid members a narrow impingement surface capable of indenting the carbon deposit to automatically compensate for irregularities in the contiguous faces of the valve and its seat.

In testimony whereof, I have hereunto set my hand this 5th day of February A. D. 1923.

WILLIAM L. BRENNER.

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