US2827888A

US2827888A - Valve train assembly for internal combustion engines

Info

Publication number: US2827888A
Application number: US647831A
Authority: US
Inventors: Chadwell John
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-03-22
Filing date: 1957-03-22
Publication date: 1958-03-25
Anticipated expiration: 1975-03-25

Description

J. CHADWELL March 25, 1958 VALVE TRAIN ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed March 22, 1957 2 Sheets-Sheet 1 John Chadwel/ m m T m m 3, W 5 ..M# F n n March 25, 1958 J, CHADWELL 2,827,888

VALVE TRAIN ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Mm 22. 1957 '2 Sheets-Sheet 2 //2 /48- y /34 Fig. 6

I56 ,uz /42 I64 I I38 ma 0 Jo/m Chadhe/l IN V EN TOR. I

United States Patent VALVE TRAIN ASSEMBLY FOR INTERNAL COMBUSTION ENGINES John Chadwell, Cincinnati, Ohio Application March 22, 1957, Serial N 0. 647,831

4 Claims. (Cl. 123-90) This invention relates in general to new and useful improvements in internal combustion engines and more specifically to an improved valve train assembly.

At the present time, the return springs for the valve. of internal combustion engines are disposed concentric with the valve stems and are connected directly to the valves for the purpose of urging the valves to closed positions. However, the position of the springs is such that a large amount of heat is transferred to the springs, thus causing rapid deterioration of the springs with the result that the valves do not properly seat at high speeds after the internal combustion engine has been run for a period of time.

It is therefore the primary object of this invention to provide a valve train assembly for internal combustion engines wherein the return spring for the valve is positioned remote from the valve so as to eliminate the effect of heat on the valve spring, the valve spring being disposed in engagement with the rocker arm for the particular valve so as to urge the valve to a closed position through the rocker arm.

Another object of this invention is to provide an improved valve train assembly for internal combustion engines wherein the rocker arm is provided with a fitting which permits the positive connection, of a valve stem to the rocker arm and at the same time permits freedom of rotation of the valve so as to prevent burning thereof and to insure proper seating of the valve.

Another object of this invention is to improve valve train assembly for internal combustion engines, the valve train assembly including a rocker arm which is positively connected to a valve and which has engaged therewith a spring whereby the rocker arm is positively urged towards a valve closing position by the spring and the valve is urged to such a closed position by its positive connection with the rocker arm. a

Another advantage'of the present invention is that the "construction thereof'is such that the rocker arms may be constructed to have a greater ratio in order to efiect a greater travel of the valve, thus increasing the .valve opening and effectingbetter breathing of the internal combustion engine.

'"Another'object of 'this invention is to provide an improved fitting for positively connecting a valve stem to a rocker arm, the fitting including a ball member having a rodzextendiiig from one end thereof for attachment to the rocker arm and a socket fitting having a rod extending' from it in a 'direction generally opposite to the direcprojects above the head 16.

of the overhead valve type and shows the valve train assembly which is the subject of this invention;

Figure 2 is an enlarged, vertical, sectional view taken through the fitting connecting the rocker arm to the valve stem and shows the specific details of construction of that fitting;

Figure 3 is an enlarged, sectional view taken substantially upon the plane indicated by the section line 33 of Figure 2 and shows further the details of construction of the socket member of the fitting;

Figure 4 is an enlarged, fragmentary, elevational view of one end of the rocker arm and shows the details of the spring connection therewith;

Figure 5 is an enlarged, fragmentary, sectional view taken substantially upon the plane indicated by the section line 5--5 of Figure 4 and shows the relationship of hold-down bolts for the spring;

- Figure 6 is a fragmentary, sectional view similar to Figure 1 and shows a modified form of the invention;

Figure 7 is an enlarged, fragmentary, sectional view showing the adjustable connection between therocker arm and the push rod; and

Figure 8 is an enlarged, fragmentary, sectional view showing the connection between the spring retainer and the rocker arm.

Referring now to the drawings in detail, it will be seen that there is illustrated in Figure 1 a portion of an internal combustion engine which is of the overhead valve type, the internal combustion engine being referred to in general by the reference numeral 10. The internal combustion engine 10 includes a block 12 having a cylinder 14. Overlying theblock 12 is a head 16 which is provided in a combustion chamber 18 in alignment with the cylinder 14. Extending through the head 16 for selective communication with the combustion chamber 18 is a gas passage 20 which may be used for the entrance of a fuel-air gas mixture into the combustion chamber 18 or for exhaust gases. The flow of gases through the passage 20 is controlled by a valve 22 which includes a head 24 and a valve stem 26. The valve stem 26 is guidingly dis posed in a bore 28 in'the upper part of thehead l6 and In order to effect the actuation of the valve 22, the block 12 is provided with a bore 30 which is aligned with a bore 32 in the head 16. The

bores

30 and 32 have freely passing therethrou gh an elongated push rod 34 whose lower end is engaged with a follower (not shown) which is in turn engaged with a cam shaft (not shown) for vertical reciprocatory movement. It is to be noted that the push rod 34 extends upwardly above the head 16 a considerable distance.

Carried by the head 16 and projecting thereabove is the valve train assembly which is the subject of this invention, the valve train assembly being referred to in general by reference numeral 36. The valve train assembly 36 includes a plurality of longitudinally spaced, upstanding rocker arm shaft supports 38, only one of the supports 38 being illustrated. Extending longitudinal of the head 16 is a rocker arm shaft 40 which is supported by the supports 33. Mounted on the rocker arm shaft 40 for rocking movement is a plurality of rocker arms 42. It is to be understood that there is one rocker arm 42 and one push rod 34 for each of the valves 22.

Carried by the underside of the rocker arm 42 at one end thereof is an adjustable fitting 44 for engagement with the upper end of the push rod 34 so that the push rod 34 may urgethe rocker arm 42 to rock or rotate in a clockwise direction. The fitting 44 is adjustable so as to permit adjustment of the valve train as is necessary. It is to be understood that the fitting 44 may be of a conventional type. i Y i In order that the rocker arm 42 may control the position of the valve 22, :there is provided a fitting which is referred to in general vby .the reference .numeral46. The

fitting 46 is carried at the opposite end of the rocker arm 42 from the fitting 44 and is connected to the underside thereof. Thefitting 46 is also connectedto the upper end of the valve stem 26. The details =ofithe fitting 46 will be set forth hereinafter.

In order that the valve 22 may be continuously urged towards a closed position, there .is provided a spring assembly which is referred to in general by the reference numeral 48. The spring assembly 48 includes a .cup shaped lower :bearing member .50, as is best illustrated in Figure 4, which overliesthe one endof the rocker arm 42 generally in alignment with theifitting 44. Seated 1n theretainer $50.:isa heavy dutycoillspring 52 of the general "type used :in conjunction with'valves'for returning of the valves to closed position. Overlying the upper end of the spring 52 ..is .aniinverted,tcupashaped retainer 54. The spring :52 ;is retained .in a compressive state by "means "of a plate .56 'whichzoverlies :the retainer 54. I The plate 56 is positioned relative :tosthe head 16 Ibyrneans of a plurality :of elongated bolts :58 whose lower ends .are

anchored in .thehead 16and whose upper ends are provided with nuts 60 adjustablyxthreadedly engaged thereon. .By adjusting the nuts 60,the spring .52 may be adxzlosed position.

' Referring now to Figures 2 and Sin particular, it will be seen that there is illustrated the :details of the fitting 46. The fitting 46 includes a .ball member 62 which .has secured thereto an elongated rod :64 whose opposite end is externally threaded as at 6.6. Ihe.1ighthand.end of the rocker arm 42, as viewediniFigure .1,.has the lower part thereof provided with an internally threaded bore 68 inwhich the threaded portion '66 is threaded engaged. The rod 64 is retained in an' adjustedxposition relative to the rocker arm 42 by means of a lockwasher 70 and a lock nut 72, the :lock nut 72 being engaged with the threaded portion 66.

The fitting 46 also includes a socket member which is referred to in general by the referencenumeral 74. The socket member 74 includes an upper half 76 and a lower half '78. The

halves

76 and 78 are of identical construction with the exception that the upperhalf 76is provided with an opening 80 .for the passage of the :rod 64 and there is secured to the lower half in alignment with the center of the opening 80 an externally threaded :rod 82.

The rod 82 is:received in an internally threaded bore 84 in the upper end of the valve'stem 26.' .The rod 82 is locked in the bore 84 by meansofallock washer .86'and a lock nut 88.

Inasmuch as the halves 76' and 78 are identical with the exceptions set {forth above, only the half 78 will be described in detail. The half 78 includes a semi-spherical shell 90 which 'is provided with an annular connecting flange 92. The connecting flange 92 of the

halves

76 and 78 are connected together byaflplurality of circumferentially spaced fasteners94.

Each of the halves 76.and 78 :also'includes a generally semi-spherical ball retainer 96 which is disposed within the confines of the shell 90 and are concentric relative thereto. The ball retainer 96 is provided with a plurality of openings 98 for'the passage of portionsof'a plurality of balls 100 which are disposed between the ball retainer 96 and the shell 90. The balls 100 are so "disposed Where by they engage the ballmember 62 so as toposition the socket member 74thereon. It is to be noted that the ball retainer 96 is provided with a plurality oifradiating sockets 102 which-are internally threaded and which have received therein fasteners 104 carried by the shell, 90. The fasteners 104 serve to position the ball retainer '96 I 122 by means of 4. relative to the shell and also facilitate the assembly of

halves

76 and 78. 7

Although the rod 64 has been illustrated and described as being connected to the rocker arm 42 and the rod 82 has been illustrated and described as connected to the valve stem 26, it is to be understood that the fitting 46 may be inverted from its position in Figure 2.

By placing the spring assembly 48 remote from the head 16, the high temperatures-of the head 16 no longer affect the spring 52. This :assures a long life of the spring 52, as well as a constant spring pressure on the valve 22. On the other hand, the detrimental features normally resulting'from-the shifting of the valve spring are eliminated by providing the fitting 46. The fitting 46 not only serves topositively actuate the valve 22, but also permits relative rotation between the valve 22 and the rocker arm 42 even though the two are positively connected together.

The particular arrangement of the components ofthe valve train assembly 36 is such that the rocker arm 42 may extend further to the right, as viewed in Figure 1, than usual. By so increasing the length of oneend of the rocker arm '42, the ratio of the rocker arm 42 is changed,

and thus the valve 22 may be moved a greater distance fora like movement of the the opening of the valve 22, the valve push rod 34. Byincreasing a greater flow of gases past 22 is permitted, thus increasing the elficiency of the internal combustion engine 10.

The entire valve train assembly is covered by a rocker arm cover 106 of the usual typewhich is sealed with respect to the head 16 by means of a gasket 108 to prevent leakage of oil which is used to lubricate the valve train assembly. The cover 106 is retained in place by fasteners 110.

Referring now to Figures 6, 7 and 8 in particular, it will be seen that there is illustrated a modified form of valve train which is referred to in general by the reference numeral 112. The valve train .112 is mounted on a head 114 which includes a plurality of valves, both intake and exhaust, only one of the valves 116 being illustrated. The valve 116 includes a head 118 which is engaged with a seat 120 of the cylinder head 114 land a stem 122 which is guidingly disposed in a bore 124 formed in the upper part of the head 114.

For each of the valves 116, the head 114 is provided with a bore 126 therethrou'gh through which there extends an elongated push rod 128. The push rod 128is reciprocatedin timed relation by a cam shaft (not shown) and serves to actuate .theassociated one of the valves116.

Mounted on the head .114 and extending upwardly therefrom'is a plurality of -.longitu'dinally aligned .supports 130, only' one of which is illustrated. Suitably journaled in the supports 130 is a rocker shaftv 132 .on which there is mounted for rocking movement :a plurality of rocker arms 134. Only one rocker arm 134 is illustrated.

The rocker arm 134 is connected to the valve .stem a'fitting 136'which is identical with the fitting 46.

In order that .the valve .116 may automatically be returned to a closed position, .there isprovided a valve 'return spring 138. Thevalvereturnspring 138 extendsbetween the :rocker-arm- 134 and the .head 114. Secured to the upper surfaceofthehead .114 is :a' retainer 140 for the lowerendof the valve :spring138. .A similar retainer 142 is connected to the underside of'the rocker-arm :134

that the 'leftend of the rockerarm 134 is bifurcated to provide an upper flange 148 and a'ilower flange .150, the flanges 148'andJ150 being disposed in spaced, parallel relation. The flange 148 is provided with an internally threaded bore 152 which extends therethrough normal to the plane thereof and which has adjustably threaded therein a threaded shank portion 154 of a stop member 156. The threaded shank portion 154 is provided with a lock nut 158 to retain the stop member in an adjusted position.

The lower flange 150 is provided with a plug 160 which is removably threadedly engaged therein and which is provided with a bore 162 aligned with the internally threaded bore 152. Slidably disposed within the bore 160 is a shank 164 of a follower 166 for the upper end of the push rod 128. The follower 166 is provided with a spherical head 168 on the lower end of the shank 164, the head 168 being seated in a socket 170 formed in the upper end of the push rod 128.

In order that the spherical head 168 may be retained in the socket 170 at all times, there is provided a spring 172 which underlies the flange 150 and extends between the plug 160 and the spherical head 168. A spring retainer 174 is carried by the lower part of the shank 164 and rests upon the spherical head 168.

In order to assure the complete closing of a valve, it is necessary that there be provided a slight play in the valve train to compensate for elongation due to temperature changes. On the other hand, there should not be too much play in the valve train, inasmuch as this would permit battering of those parts between which there is relative movement. By permitting the upper end of the shank 164 to strike the stop member 156 so as to act as the tappet of the valve train, the desired adjustment of the valve train may be obtained by adjusting the position of the stop member 156 with respect to the upper end of the shank 164. 7

At this time it is pointed out that the adjustable connection between the rocker arm and the push rod will not be limited to the spring arrangement of Figure 6, but may be used in conjunction with the rocker arm 42 and the spring arrangement of Figure 1.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled inthe art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A valve train assembly for internal combustion engines comprising a rocker arm shaft, a rocker arm mounted on said rocker arm shaft, first means on the underside of said rocker arm at one end thereof for engaging a push rod, second means on the underside of closing position, said second means including a universal joint whereby a valve connected to said rocker arm is free to rotate while being positively actuated by said rocker arm.

2. A valve train assembly for internal combustion engines comprising a rocker arm shaft, a rocker arm mounted on said rocker arm shaft, first means on the underside of said rocker arm at one end thereof for engaging a push rod, second means on the underside of said rocker arm at the opposite end thereof for positive connection to a valve, said second means including a ball member having an attaching rod and a socket member having an attaching rod, said ball member being seated in said socket member with said attaching rods extending generally in opposite directions.

3. A valve train assembly for internal combustion engines comprising a rocker arm shaft, a rocker arm mounted on said rocker arm shaft, first means on the underside of said rocker arm at one end thereof for engaging a push rod, second means on the underside of said rocker arm at the opposite end thereof for positive connection to a valve, said second means including a ball member having an attaching rod and a socket member having an attaching rod, said ball member being seated in said socket member with said attaching rods extending generally in opposite directions, said socket member including a plurality of ball elements engaging said ball member.

4. A valve train assembly for internal combustion engines comprising a rocker arm shaft, a rocker arm mounted on said rocker arm shaft, first means on the underside of said rocker arm at one end thereof for engaging a push rod, second means on the underside of said rocker arm at the opposite end thereof for positive connection to a valve, and spring means engaged with said rocker arm for urging said rocker arm to a valve closing position, said second means including a ball member having an attaching rod and a socket member having an attaching rod, said ball member being seated in said socket member with said attaching rods extending generally in opposite directions.

References Cited in the file of this patent UNITED SEATES PATENTS 2,015,135 Brady Sept. 24, 1935 FOREIGN PATENTS 303,287 Italy Nov. 26, 1932 600,309 Germany July 19, 1934