US2113316A - Method of making valves - Google Patents

Description

April 5, 1938. J. BUGATTI METHOD OF MAKING VALVES 2 Sheets-Sheet 1 Original Filed May 23, 1935 A7 a 4 j April 5, 1938. J T 2,113,316

METHOD OF MAKING VALVES Original Filed May 23, 1935 2 Sheets-Sheet 2 I .mm V 7 Wha'uw f il MM Patented Apr. 5, 1938 METHOD OF MAKING VALVES Jean Bugatti, Molsheim, France Original application May 23, 1935, Serial No. 23,100, now Patent No. 2,072,615, dated March 2, 1937. 15, 1936, Serial No. 90,813. 25, 1934 6 Claims.

The present invention which is a division of the U. S. patent application Ser. No. 23,100, filed May 23, 1935, Patent Number 2,072,615, issued. March 2, 1937, relates to valves of the mushroom type, and its object is to provide an improved valve of this type.

The essential feature of the present invention consists in giving the valve head a laminated structure, that is to say composed of a plurality of laminas superposed in adjacent relation and which, individually, possess a certain elasticity or a certain freedom of movement while the assembly of the whole possesses the required rigidity.

Owing to the elasticity thus obtained, the valve head is always applied in a fiuidtight manner against its seat, even under unfavorable condition, that is to say, for instance, when this seat is not uniformly worn or is subjected locally to expansions different from the expansions in other points. Furthermore, when the valve is utilized in an engine operated through a fluid at a high temperature, for instance an internal combustion engine, the cooling of the valve according to the present invention is considerably improved because it has been found that most of the heat transmitted to the valve head is evacuate-d through the seat, and in the present case there is an intimate contact between said seat and the valve head over the whole periphery thereof.

Since the valve head is elastic, the sudden shock that occurs when the valve is closed is partly absorbed since the energy (kinetic force) of the pieces in movement is partly absorbed by the elastic deformation of said valve head. Therefore the hammering of the seat by the valve is avoided, which is important for the good preservation of these delicate pieces. As the valve closes Without any important shock, its working is much less noisy than that of ordinary valves.

The arrangement according to the present invention is particularly well adapted to the case of double head valves, that is to say of valves provided, on a common stem, with two heads or discs located at a certain distance from each other and intended to be applied each against its respective seat. Valves of this type are often employed with high pressure fluids because they can be balanced with reference to the action of the pressure thereon and they are accordingly easier to control. Now, such valves work generally in a medium in which variable, and most often very high, temperatures exist. They may Divided and this application July In France May therefore dilate in a nonuniform manner or they may not be applied accurately on the corresponding seats when these various elements expandi Furthermore, as the valve discs and the corresponding seats are machined separately, small differences often exist between the distance between the seats and the distance'between the valve discs. Consequently, it is always diflicult to ensure and to maintain fluidtightness between valve discs of this kind and their'respective seats.

In this case, the present invention consists essentially, in order to obviate the drawbacks inherent in known valves of this kind, in making at least one of the valve discs elastic, as above explained, so that it can compensate for the slight axial difference in the distance between the seats.

In a preferred embodiment of the invention, the valve head is divided, in a direction at right angles to the axis of the valve stem, into a rigid portion and an elastic portion, which, at least in its peripheral zone where it is to bear against the seat, is at a very small distance from this rigid portion, the latter acting as an abutment for said elastic portion. I

Another feature of the present invention consists in providing a double valve of the type above referred to arranged to permit a certain relative displacement of the valve heads with respect to heads with each other may be reduced in order to render this portion of the stem elastic. But this feature cannot be employed in many cases. This is due to the fact that the distance between the valve heads is necessarily in relation with their diameters and it is necessary to leave a suflicient cross section of the valve stem for keeping the end valve head in proper axial position.

In a preferred embodiment of the invention, each of the valve heads is provided with a distinct stem and the stem of the end valve head is engaged into the hollow stem of the other valve head and is fixed at the bottom of said hollow stem through any suitable means (by screwing, keying, etc). With this arrangement, the end valve head can be provided with a sufficiently long and flexible stem. It is preferably made elastic in the manner above stated. Therefore,its deformability compensates for the lack of perpendicularity of itsdisplacements with re- '55 spect to the axis of the other valve head. Besides this defect is of very little importance due to the great distance of the end valve head to the point where the stem thereof is fixed.

Other features of the present invention will result from the following detailed description of some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 is an elevational view, partly in axial section, of a first embodiment of a valve according to the present invention;

Fig. 2 is a view similar to Fig. 1 and corresponding to another embodiment;

Fig. 3 is an elevational View, partly in section, of a double head valve according to the present invention;

Figs. 4 and 5 are partial sectional views illustrating the method of manufacturing the elastic valve head of Fig. 3, said valve head being shown at two different times of its manufacture;

Fig. 6 is a longitudinal sectional view of a valve provided with two valve heads connected together through a flexible stem according to the present invention.

In the embodiments of Figs. 1 and 2, each valve head includes three elastic laminas I, 2 and 3, obtained for instance by making nicks in the metal at 4 and 5. In the embodiment of Fig. 1, laminas l and 3 have been curved toward each other at their periphery so that the valve head has the usual shape. The intermediate lamina 2, which is shorter than the other ones, is provided with a substantially conical surface 6. The intervals between these laminas and the thicknesses thereof are such that, if lamina 3 is deflected at its periphery, it comes to bear against lamina 2 and then the whole is applied, through the peripheral edge of 3 against the third lamina l. Of course, the valve could be so devised that part 3 first comes into contact with part I, and then with part 2, or with both simultaneously. In any case, it will be readily understood that the elasticity of the valve head is gradually variable. of course, it is necessary that the deflection of these three laminas I, 2, 3, working in parallel should be limited in such manner that the valve head can always perform its function, which is to stop the hole limited by its seat.

In the embodiment shown by Fig. 2, the three laminas are made of substantially the same external diameter, and in this embodiment also the elasticity of the composite valve head is gradually variable as above explained.

Of course it should be well understood that the invention is not in any way limited to the embodiment just above described. It can be applied as well to explosion engines as to combustion engines, to steam engines, to compressors, and so on.

The invention can obviously be applied to the case of a valve the stem of which carries a plurality of valve heads, and in this case all or a part of these valve heads may be made according to the invention as above stated.

Figs. 3 to 6 relate to the case of double head valves. In the embodiment of Figs. 3 to 5, the valve, which includes a stem 7 and two valve heads 8 and 9, controls the inflow of fluid from a chamber l into another chamber I I. The valve element 9 includes a rigid portion 12 and a flexible portion 13. I have shown at IS a removable plug which permits to examine the valve system and to remove it in case of need.

When machining the element 9 of the valve, I first leave a very thick disc. Then this disc is divided into two portions I2 and 13 by providing an annular groove [4 (Fig. 4) of a suitable width and extending radially as far as the diameter of the rod or stem. Finally the elastic portion I3 is bent in the hot state in the direction of the rigid portion, a small play being provided at l (Fig. 5) so as to permit the elastic compensation above referred to. Portion I3 has been thinned down in the central portion so as to obtain the required elasticity.

In the embodiment shown by Fig. 6, the stem I 8 of the elastic valve head I! is provided with a cylindrical bore I9 in the bottom of which the stem 2| of the other valve head 22 is fixed, for instance by screwing at 20. A sufficient play is provided between the inner wall of bore l9 and stem 2|, in such manner as to permit this last mentioned stem to be deformed, for instance as shown in dotted lines. Such deformations permit the two valve heads I! and 22 to be applied against their seats in a satisfactory manner even when said valve heads or said seats are not quite exactly parallel. As shown in the drawings, valve head 22 is elastic, which permits a correct application of this valve head against its seat in spite of the lack of perpendicularity of said valve head with respect to axis X-Y when the valve is deformed as shown by the dotted lines.

While I have, in the above description, described what I deem to be practical and efilcient embodiments of the present invention, it should be well understood that I do not Wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What I claim is:

1. In the manufacture of an elastic valve head, the steps which consist in machining a peripheral groove into a disc-like blank of elastic metal to divide the latter into two spaced apart flanges projecting substantially radially from an integral center part, and thinning down one of the said flanges to render it flexible.

2. In the manufacture of a valve, the steps which consist in forming with an elastic metal a blank including a thick head and a stem integral with said head, projecting centrally therefrom; machining a peripheral groove into said head in a plane substantially at right angles with said stem so as to divide the head into two spaced apart flanges integral with a common center part; and thinning down one of the said flanges to render it flexible.

3. In the manufacture of valves, the steps consisting in forming a peripheral groove into a head blank made of an elastic metal so as to produce two flanges spaced apart from one another but still attached integrally to a common center, thinning down one of the said flanges to render it flexible, and hot drawing the peripheral portions of said flanges near to one another.

4. In the manufacture of valves, the steps consisting in forming a peripheral groove into a head blank made of an elastic metal so as to produce two flanges spaced apart from one another but still attached integrally to a common center, and thinning down the center portion in one of the said flanges to render it flexible.

5. A method for the manufacture of a valve which comprises forming a relatively thick disclike blank on a valve stem, cutting an annular Wide groove into said disc from the edge thereof towards the center part of the disc to divide it into two rigid flanges spaced apart from one another but attached integrally to a common center part, thinning down the center part of one of the flanges to render it flexible, heating said thinned flange and bending the thinned flange while hot, to draw its peripheral portion towards the peripheral portion of the other flange.

6. A method for the manufacture of an elastic form an elastic valve head having its peripheral 10 portion thinner than its central portion.

JEAN BUGATTI.

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