US1826544A

US1826544A - Blank and process for making valve tappets

Info

Publication number: US1826544A
Application number: US80426A
Authority: US
Inventors: Hervig Richard
Original assignee: RICH TOOL Co
Current assignee: RICH TOOL Co
Priority date: 1926-01-11
Filing date: 1926-01-11
Publication date: 1931-10-06
Anticipated expiration: 1948-10-06

Description

Oct. 6,1931. R. HERVIG 1,325,544

BLANK AND PROCESS FOR MAKING VALVE TAPPETS Filed Jan. 11, 1936 J71 a 10 18 IIIII 7J5 jozard @r/ .valve tappets are either excessivel ing the corresponding end Patented Oct. 6, 1931 UNITED STATES (PATENT OFFICE RICHARD HERVIG,

DETROIT,

OI DETROIT, MICHIGAN, ASSIGNORAW RICH TOOL COMPANY, OF

MICHIGAN, A CORPORATION OF MAIN E Application filed January 11, 1926; Serial No. 80,426.

Metals that can long endure in the heads of expensive to machine, or 0th, while or ver difficult y be readil machined, or can Y metals that can be purchased at reasonable cost, are not able to endure in the heads of valve tappets.

The principal object of this invention is to produce a tappet having its head and shank of different metals suited respectively to those portions and firmly united without stress or strain on the metals at, or adjacent to, the joint.

This object is attained by the structure and procedure illustrated in the accompanying 2 drawings in which Fig. 1 is a sectional view through a finished tappet of the preferred form; Fig. 2 is a sectional view through a head blank for producing the tappet shown in Fig. 1; and

Fig. 3 is a sectional view through the head and stem blanks and a bottom die suitable for forging them to the form and condition indicated in Fig. 1. v The preferred form of head blank 19, illustrated in Fig. 2, maybe roduced by casting, by forging a ball shape blank with suitable dies, by subjecting a bar to a Bradley hammer, or in any other way that may be selected. This blank roughly approximates the head of the finished tappet and requires no great amount of forgin to give the completely finished form and secure it to the surrounded by an annular flange 12, whereby ared for receiva tubular shank 14in the relation illustratedin Fig.-3. 1

With the parts assembled as indicated in this figure, the shank is supported at proper height by a knock-out plug 15 and the head blank 10 is acted upon by a hammer or flat die to force it to fill the cavity 16 in the bottom die 17.

The upper surface of the blank 10 1s provided with a disk-like recess 18 to cause the initial forging operation to affect the outer portion of the blank chiefly and causethe anan annular groove 13 is pre nular flange 12 to flow well down into the cavity 16 and around the end of the shank 14. The result of this operation is illustrated in Fig. 1, where the end portion of the shank has been forged to form a flaring flange 19 above a reduction, or constriction 20, and the boss 11 and flange12 are made to grip the flaring flange 19 and firmly secure it in What was formerly the groove 13.

Both the head and shank blanks should be heated during the forging operation so that in cooling they can shrink together and leave the metal of the two blanks in intermediate contact throughout the mating surfaces without stress or strain in either part. If, for example, the shankis, forged cold, there will be some movement along the surfaces of con- .tact as the head metal cools and shrinkage strains will remain in the head metal after coolmg which, to a greater or less. extent, vitiates the joint.

The blanks may be heated in any suitable manner, but preferably they are brought to a forging temperature after being assembled in the die by the application of suitable electric current. One electrode may be applied descends.

\ a The head metal may be of any material of suflicient hardness, or capable of having sufficient hardness imparted to it. Hi h speed tool steel or steel containing tung ten as a hardening material or wear resisting element is very sultable; cast material that is forgible when in cast form ma be used; an alloy composed of sixty (60%; percent cobalt, thirty percent chromium and the remainder chiefly iron, makes a very satisfactory head. Another alloy containing sixty per cent nickel, thirty (30%) percent chromium, seven (7%) percent aluminum, and the principal remainder iron, is also satisfactory.

The shank blanks may be made of a great variety of readily machined material, ordinarily .10% to .20% carbon steel, with or without three and one-half percent (3%%) nickel, is very satisfactory. This material can be readily. carburized after finishing and to the bottom die and the other to the head before forging. ;50% used and hardened in oil if carburizing is not resorted to to obtain suitable hardness.

I claim as my invention:

-\1. The process which includes forming a cad blank with an annular recess on the bottom, inserting a'tubular shank in the recess and forging a flange on the shank, and gripping the flange between portions of the head blank metal, the initial forging operation bein directed chiefly to the marginal portion 0 the head blank to force the metal downwardly and inwardly against the shank.

2. The process which includes forming a headblank with a boss on the bottom surrounded by a flange, and a marginal rojection on the top, resting the head blan i on a tubular shank and simultaneously forging a flange on the shank arid gripping the flange between the boss and the surrounding flange on. the head blank, the'marginal projection serving to provide extra metal in that area and to facilitate the movement of the metal in the bottom flange for the specified purpose.

3. A blank of the class described, having on the bottom a boss surrounded by aflange, and on top a m'ar inal flange.

In testimony w ereof I aflix my signature.

\ RICHARD HERVIGr;

carbon steel may be I