US1998241A - Method of making valve mechanism - Google Patents

Description

April 16, 1935.

Filed-Jan. 26, 1935 2 Sheets-Sheet 1 Fig.1.

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METHOD OF MAKING VALVE MECHANISM Filed Jan. 26, 1933 2 Sheets-Sheet 2 Patented Apr. 16, 1935 1,998,241 METHOD or MAKING VALVE MlilClIANIdM John Keen and Thomas F. Sinnott,

Philadelphia, Pa. 1

Application January 26, 1933, Serial No. 653,598

9 Claims.

This invention relates to an improved method of forming a one piece valve seat. 1

While we have shown our present invention in connection with a substantially balanced valve of a type applicable to locomotive poppet valve mechanisms,yet itwillbeunderstoodthat the specific embodiment of the invention shown and the principles employed therein are applicable to different types of valves whether of the balanced or unbalanced type or whether they have single or double seats or are used for locomotive valve mechanisms,throttle valves or other purposes. In double seat poppet valves of the balanced or substantially balanced type, it is of course necessary that the seat areas should be substantially equal but this involves complications due to the inability to pass a single piece valve cage seat over the valve or vice versa due to the valve cage-seats and valve having, of necessity, an overlapping seating relation. Heretofore, in order to obtain a balanced or substantially balanced valve, the valve cage or the seat'has been made in two parts and the parts fastened together, but this arrangement has obvious objections which would not be present in a seat made from a single piece. In other prior arrangements the valve cage seat is cast as an integral part of the valve and then later separated therefrom but this injects the uncertainties incident to cast metal and other difiiculties.

It is an object of our invention to provide an improved method of forming a single piece valve cage seat for a substantially balanced valve. In one aspect of the invention we accomplish this by placing an annular blank of forgeable material around the valve and then forge, compress, shrink or otherwise suitably work and machine the blank to its normal dimensions, the internal diameter thereof being less than the outside diameter of the valve; In another broad aspect our improved method consists in forming a valve cage seat element and a cooperating valve element by first passing one over the other and then forging, pressing or otherwise manipulating one of said elements, followed by a finishing operation thereon, so that both elements are brought into permanent overlapping seating relation.

- Other. objects and advantages will be more apparent to those skilled in the art, and it will also be understood by such persons that the advantages of our improved article and method may be obtained by various modifications to the structure and order of. steps for making the same. Hence it is not'desired that our invention shall be limited to the specific form and method disclosed in the accompanying drawings wherein:

Fig. 1 is a vertical section of one formof valve mechanism to which our invention has been applied merely ior purposes of illustration;

Fig, 2 is a vertical section through a valve and blank valve cage seat in the first step of our improved method;

Fig. 3 is a vertical section of the valve and valve seat cage showing the second step in our method;

Fig. 4 is a vertical section showing the finishing or machining step in our improved method.

For purposes of illustrating one application of our improved method and the valve resulting therefrom, 'we will describe briefly the form of valve mechanism shown in Fig. 1 which comprises a usual valve housing I having suitable exhaust ports and passages 2 and 3 although the invention is equally applicable to and in fact is used for intake valves as well. This housing is provided withacylindrical valve cage 4 having a lower ring portion 5 engageable with a suitable shoulder 6 formed between passages 2 and 3 while an upper annular portion 1 has an upper valve cage seat 8. The cylindrical portions 5 and l are connected'by suitable vertical ribs 9 spaced apart to provide lateral passages through the valve cage. The lower ring 5 has an internal ey lindrical surface l to'receive, by a forced fit, our improved valve cage seat element ll having an annular shoulder [2 to engage a suitable ofiset recess in ring while a lower valve cage seat I3 is of substantially the same diameter and area as the upper seat 8. l

A valve generally indicated at M has an annular body l5,"of semi-cylindrical form in cross section, terminating in an upper seat l5 and a lower seat II. The periphery of this body has an annular recess [8 while the inner periphery of the valve body is connected by a series of radial webs i9 to a central hub 20 which is secured to the reduced portion'o'f a valve stem generally indicated at 2|. The lower end of this valve stem is provided with a guide pin 22 axially slidable in a suit-' able guide bearing generally indicated at 23 while the upper end of the valve stem is adapted to be actuated by any suitable mechanism such as a cam or cam lever engaging a suitable head 24. The upper portion of valve stem 2| is guided in a suitable sleeve 25 secured in a valve cage cover 26 to which the valve cage is secured by suitable studs, screws or the like. To hold the valve assembly in position, an outer cover or plate 21 engages cover 26 as at 28 and is secured to valve housing I by suitable bolts, this detail not being shown for purposes of simplicity. Suitable holding screws 29 may have threaded engagement with outer cover 2i for engaging cover 26 and thus positively hold the valve cage to its seat 5.

From the foregoing disclosure it is seen that the valve cage seat element II which is formed as a single integral piece has an internal diameter less than the external diameter of either the upper or lower valve seats l5 or H, and hence cannot be removed from the hollow portion [8 of the valve nor passed over the valve seats to effect assembly therewith. Our improved method is adapted to solve this problem in an improved and ingenious manner, and it will be seen from the disclosure herein that our improved method and apparatus may be employed with a valve where similar conditions might be met with whether or not the valve was of the double seat balanced type or of various other types.

In our improved method we first provide an annular blank 35 of any suitable material, preferably steel. This blank has an internal diameter 3| slightly larger than the outer diameter of the lower valve seat I! thereby permitting the blank to be passed over the valve seat and within the recess N3 of the valve although it will of course be understood that the internal diameter 3| may be slightly less than the outer diameter of valve seat I! in which case when the blank 30 is heated, it will expand to permit insertion of the valve within the blank but in either case the blank is heated to a desired forging temperature and then the valve inserted within the blank.

The next step is to apply a set of split annular dies 32, having a shoulder 33, to the outside of the blank to press or forge the same in inward radial directions, the dies or blank being preferably relatively rotated between successive pressing or forging operations thereby causing the blank to maintain a substantially annular form. It is found that with some practice a workman may manipulate the heated blank with ease and accuracy so that the same may be readily machined or finished to the proper size which is the next step.

The finishing step, which may include both machining and grinding if desired, consists in supporting the valve hub upon a suitable lathe mandrel 34 while the blank now of reduced size from the original blank 30, is held by the usual jaws 35 of a lathe chuck 36. Any suitable cutting tools may then be employed to turn blank 39' into the finished form of valve cage element 1 I as shown in dotted lines in Fig. 4. The outer and inner cutting tools are shown at 36 and 31. After the blank 35' has been machined as far as possible during one setting of jaws 35, the blank and valve will be taken out and turned around whereupon the jaws 35 will clamp the machined portion of the valve seat element to permit the machining operation to be completed.

From the foregoing description of our improved method, it is seen that we have provided a relatively simple means whereby a single piece valve cage seat may be placed in permanent cooperating relation with a valve which is of such a type as to prevent normal assembly of the valve with its finished valve cage seat. By our arrangement we are able to make the valve cage seat of any desired forgeable steel or workable material, thereby insuring proper wearing of the valve seat with minimum possibility of breakage or warping.

It will of course be understood that various changes may be made in our improved method and apparatus without departing from the spirit of the invention as set forth herein wherein a valve element is insertable within a valve cage seat element and one of said elements is thereafter suitably forged, shaped or otherwise worked to bring the two elements into normal cooperating seating relation.

We claim:

1. The method of providing a valve seat for a valve having an annular valve seat engaging surface, consisting in inserting said valve within a blank, then reducing said blank so that its inner perimeter is less than the outer circumference of said annular surface, and finally finishing said reduced blank to form a seat for said valve surface.

2. The method of providing a valve seat for a valve having a peripheral groove, consisting in inserting said valve Within a seat blank, then reducing said blank so that it is non-removably disposed within said groove, and finally finishing said reduced blank to form a seat for the valve.

3. The method of providing a valve cage seat for a valve having a peripheral groove, consisting in inserting said valve within a heated substantially annular blank, then compressing said blank to a smaller size than the outer diameter of said groove, and finally machining said blank in the form of a valve cage seat.

4. The method of providing a, valve cage seat for a valve having a peripheral groove, consisting in inserting said valve within a heated substantially annular blank, then compressing said blank to a smaller size than the outer diameter of said groove, and then rotatably supporting said blank and valve in fixed relative relation and machining said blank in the form of a valve cage seat.

5. The method of providing cooperating valve seat and valve elements, consisting in having one of said elements in substantially incomplete form and the other element in substantially complete form and of such relative dimensions that one of said elements may be inserted within the other, then inserting one of said elements within the other, and then completing said incomplete element while it remains associated with said other element in spaced relation thereto and thereafter is adapted normally to have movement relative thereto.

6. The method of providing cooperating valve seat and valve elements one of which has a form other than its normal form and one of which has a peripheral groove, consisting in inserting one of said elements substantially within said groove,

and then forming said abnormal element into its 4:-

normal form with such relative dimensions between said elements that one is loosely disposed within the other but constitutes a normally inseparable assembly.

7. The method of assembling and forming a valve mechanism including a cage and a one piece valve cage seat and a valve, consisting in inserting a valve within an incompleted one piece valve seat, completing said seat so as to'render it non-removable from but loosely disposed around said valve, and then inserting said valve and its valve seat within the valve cage to form a unitary valve assembly.

8. The method of providing a valve cage seat for a balanced double seat poppet valve, consisting in inserting said valve within a heated valve seat blank, the blank being disposed between said double seats, then compressing said blank inwardly from all radial directions to reduce its inner diameter to less than that of either of said seats, and finally supporting said valve upon a lathe mandrel and chucking said blank and then machining said blank to its finished form.

9. The method of providing a valve cage seat for a balanced double seat poppet valve, consisting in inserting said valve Within a heated valve seat blank, the blank being disposed between said double seats, then compressing said blank inwardly from all radial directions to reduce its inner diameter to less than that of either of said seats, and finally supporting said valve upon a lathe mandrel and chucking said blank and then machining said blank to its finished form and then inserting said valve and seat member within a valve cage and making a pressed fit between said seat member and cage.

JOHN S. KEEN.

THOMAS F. SINNOTT.

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