US1774021A - Valve seat - Google Patents

Description

lPatented Aug. 2.6, 191,30

` UNITED. ls'nl'ras AUGUsT E. LEIPERT, or' COLLEGE POINT, New Yoitl'nAssI'GNoR froiNTnnNArrNAn Moron COMPANY, or NEW YORK, N. Y., A conronA'rroN or nErlAw-ARE@ j n VALVE ysEA'r original application filed January 3l, 192s, serial No. 250,941. niviaea'and this application inea-1Jaiiiialliyf l1, 1929. seria-l No.. 331,827.' Y .l v

The present application is the division of applicants applicationSer. No. 250,941, filed i January 31, 1928.`

vIn an endeavor to carry 0H the heat from i the valves of internall combustion engines To do this, the valve seat has been formed in several ways, for example, cast either with or after the casting of the main cylinder blocks, or fastened into place after the castlng alld machining operations have been completedi The present invention resides in providing an improved valve seat in situ in Which the material is expanded and rolled into place.

It is alsoicontemplated to vform'the valve con-` tacting portions of thevalveseat of greater Y density than the portion remotevfrom the section line as Figure l, but showing thev valve and adjacent lthe cylinder casting, whereby the life of the .seat will be increased and the heat froln the valve Acarried olf more rapidly. The seat as thus constructed, has essentially a holnogeneouspunion of the metal thereofwith the metal of the casting, thereby further insuring the most favorable ,conditions for heat conduction. f

Further objects and advantages of the invention will appear as the description proceeds and reference will now be had to the accompanying drawings, wherein:

Figure 1 is a view in section taken 0n line Vl--l of Figure 4, but showing the valve seat v before being rolled into position;

Figure 2 is a segmental view on the same valve seat rolled intol position so that it engages the underhooking edge of the casting.

lFigure 3 is a view similar to Figure 2, showing the valve seat after it has been rolled into the proper form. f i

Figure 4 is a plan view showing the valve seat after it has been rolled and formed.

Figure 5 is a segmental view in section taken on line 5-5 of Figure 4.

Figure Gis a view in section,sirnilar to Figure 1, but showing the valve engaging the finished valve seat. v j

Referring particularly to the above described iigures, a designates the cylinder castingefaii engine provided with' aalve' haie dercut as ata?V to provide groove ifntb which thematerial of the valve vseatis rolled.v This 'under-clit portion forms i a l'shoulder lwhich preventsl thev valveV seat froml being yremoved and 'receives Athe latter when'it isV installed inthe following mannen n j, y

The valve seat I), which vmay be of annular form, is placed asshown in Figure l. A suitable expanded c of well known7 construction is placed within vthe valve seat` and the latter is rolled and expanded into 'the under-,clit portion aifof the p cylinder wall fa. During this" rolling o]gv eration the material ofr the valve seat becomes denser. '.Thatport'ion of the lseat adjacent the valve .Will-.beef .relativelyV greater densityfthanthe portion of .the seat adjacent 'the underhooking edge.` This is true also in the next stepofrolling the ta; per in the valve seat afterit khasbeen forced into the .position shown in Figure 2. j Figure' 3 illustrates the valveseat with the tapering valve engageable surface formed Itherein. By forlning the seat adjacent the taperwith a very compressed .and v close-grained hstruc` ture, its life is greatly increased as well as its ability to carry olf the heat rapidly.

In order that the seat may be prevented from turning, serrations or recesses a3 are formed in the wall of the cavity receiving the seat and in the rolling of the seat into position, the material of the seat will be forced into the recesses to serve as a key to prevent 1 the'turning thereof. This is illustrated in portions b of the seat when it is rolled into a. The retainingwallzofthe'cylinder is un` position. Of course, the particular form of staking or means for securing the seat against rotation, is immaterial since any well known provision of this charactermay be utilized.

The metal constituting the valve seat may be of any composition capable of being expanded or rolled and` transferring heat better than cast metal. A copper aluminum bronze alloy, being homogeneous and not flaking, has been found to be satisfactory metal for these valve seats. The. particular means formed on the cylinder casting for` retaining the valve seat in position is immaterial, since shoulders and projections of many forms may be substituted for the under- `hooked groove to receive and engage the expanded seat material.

In practice it has been found that the metal of the seat, in being rolled, tends to be turned back at the upper edge and to be pulled away from thev rim ofthe horizontal portion of the groove. v"To reduce this action an expander is used having rollers,the outer surfaces of which always lie in planes parallel to the axis .ofthe expander. In fact it is sometimes necessary to secure a plate d to the block to confine the metal of the seat in its proper position and cause it to engage the horizontal portion of the groove intimately.

. Although the invention has been described with specific reference to the accompanying drawings, no limitation as to structure or means of applying the seat is to be placed upon it, save as defined in the appended claims. y

What I claim is: y

1; Al valve seat construction comprising a vcylinder casting formed with a groove and having a recess vin the wall of the groove, and a valve seat in the groove having a greater density adjacent its valve contacting area than its density elsewhere, said valve seat engaging in said recess.

2. Avalve seat construction comprising a cylinder casting formed with an undercut groove and having recesses in the wall of the a groove, a valve seat in the groove having a greater density adjacent the valve contacting portion than elsewhere, and portions on the seat extending in said recesses.

This specication -signed this 28th day of Decemberl A. D. 1928.

' AUGUST H. LEIPERT.

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