US1820891A

US1820891A - Valve actuating mechanism

Info

Publication number: US1820891A
Application number: US382265A
Authority: US
Inventors: William R Spiller
Original assignee: White Motor Co
Current assignee: White Motor Co
Priority date: 1929-07-30
Filing date: 1929-07-30
Publication date: 1931-08-25
Anticipated expiration: 1948-08-25

Description

Aug. 25 1931.

w. R. SPILLER VALVE ACTUQTING MECHANISM Filed July 50, 1929 2 Sheets-Sheet l a, 5 4 H s x O m M M A WHil m 7 l A HI w \l| kkkkk 1 w i I hm 4 am I MM m. I 227 Aug. 25, 1931. w. R. SPILLER 1,820,891 I VALVE ACTUATING MECHANISM Filed July 30. 1929 2 Sheets-Sheet 2 FSIIYVEfVTOR.

BY; I Miami/534% Patented as. 25,1931

* UNITED STATES- PATENT? ossrcs mien a. alumna, or, cmvnmnn, onro, assrcnon so me warm comm, or cnnvnnann, 10, a coaronarron or one s me VALVE AOTUATING MECHANISM Application tiled July 80,

This invention relates to valve actuating mechanism, and is articularly adapted for I use with valves suc as are used in internal combustion motors. f d An object of the invention is to provide an improved valve mechanismwhich will automatically adust itself.

Another 0 ject is to provide a self-adjusting valve mechanism which will compensate for expansion and contraction of its parts i and of the associated parts of the motor.

' Another object is to provide a self-adjusting valvemechanism in which the; adjustment is entirely effected while the valve is seated.

7 Other objects will hereinafter appear.

The invention vwill be better understood from the description of one practical em-' bodiment thereof'illustrated the accompanying drawings, in which;

go re 1 is a fragmenta transverse sec-- tiona view of a motor of t e valve-in-head type, having a valve operating mechanism embodying the invention;

' Fi re 2 is a fra fentary transverse sec- 25 tiona view of the va ve tappet and cam shaft .of Figure 1 but showing the arts to a larger scale and in the position t ey occupy immeldiately preceding the opening of the va ve' Fighres 3 and are views taken on the line III-III of Figure 2, showing the arts in positions that they occupy, respective y, when the valve is opened or unseated, and when the agjustfiient of the mechanism is being efiecte an Figures 5 and 6 are transverse sectional views taken on the lines V-V and VI'-VI respectively of Figure 2.

The. motorillustrated has a crank case 1 withinwhich is journaleda crank shaft (not shown) arranged to be rotated by connecting rods 2 attache at their upper ends to, pistons .3 which reciprocate in cylinders 4 formed within a cylinder block 5. The u per end of the cylinder block .is closed by cy inder head 6 provided with valves 7 each having a stem 8 y which it' may be actuated. The valves are maintained closed by springs 9 surrounding the stems.

A rocker arm 10 bears, thi'ough closure 11 1929. Serial R'o. 882,285.

upon the upper end of the valve stem, the rocker being pivoted at 13 to the cylinder head. A push rod 14: is arranged to raise. the opposite end of the arm, and is actuated from cam shaft 15, journaled within the crank case by means of a cam 16.

Between the cam 16 and the push rod 14 is located the tappet mechanism, best shown in Figures 2 to 7, which is so designed that it will automatically adjust itself tocompen: sate for expansion or contraction of the valve mechanism or associated parts of the motor, thereby insuring proper operation of the valve at all times.

This ta pet operates in a'guide 17 having a nera y c lmdrical outer surface provi ed with a ange 18 which seats 11 on the upper surface of the crank case, an is retained in position by a bolt threaded into the crank case and extending through a notch 19 in the flange. 1

Interiorly, the'guide is formed with two cylindrical bearing faces 20 and" 21 terminat ing at chordally extending faces 22, the cylindrical faces being arranged to take the side thrust imposed upon the tappet by the pres-' sure of the cam. The upper part of the tappet' consists of a bar 23 having two cylindrical edges 24 fitting the c

lindrical surfaces

20 and 21, and interme iate flat surfaces 25 which en age the chordal surfaces 22 and so prevent t e bar from turning. The upper end of the baris formed with a recess 26 receiving the lower end of push rod 14. An axial bore 27 extends from the bottom of the rod to near its top, and is threaded with a thread" of small pitch 28. Threaded into this bore is the shank 29 of a bolt, the head 30 of which bears upon the cam 16. The head 30 is of large diameter and of almost flat convex conical shape on its under surface, being provided with an upwardly extendin marginal flange 31. Surrounding the sh and positioned upon the upper surface of 1 the head 30- is a spiral sprin 32 having one end connected as at 33 wit the marginal flange of the head, and its other end connected as by means of a dowel pin 34 to the'bar 23. This spring is arranged to rotate the screw 29 v v in a manner to extend it from the bar, the cam I 16 has a point substantially in alinement with the center ofthe screw, 'so that when'this ,point travels across the under surface of the head there is no appreciable tendency to rotate the latter. The tendency to rotate the head is further reduced by its conical shape,

as the cam travels along an element of the cone in alinement with the axis of the tappet. The low'side of the cam is cut away at 35 on the part of this side which contacts the tappet first, so that a projecting flange 36 is left, which is disposed to one side so that it will contact with the head adjacent its edge at the side which will allow friction between the cam and the head to rotate the screw in a manner to cause the screw to enter the bar and shorten the tappet.

The operation of the tappet is as follows: The head 30 rests upon the cam and is elevated thereby as the cam shaft rotates, there being no relative rotation between the screw and bar until after the point of the cam has passed beyond the head and the valve is seated. When this has happened, the head bears only upon the flange 36 and the friction between these surfaces rotates the screw,

shortening the tappet as long as there is any pressure between the head and the cam, or even further, if there is suflicient inertia in the head, so that the head assumes the position somewhat like that shown in dotted lines in Figured After the flange 36 has passed the head, the spring 32 rotates the 'screw in the opposite direction, extending the same until thehead just bears upon the base circle portion 37 of the cam, at which time all slack has been taken out of the valve actuating mechanism, and as the point of the cam comes in contact with the head the tappet is raised and the valve is again opened. It will be noted that not only is the-tappet self-adjusting but that all adjustment takes place during the time that the valve is closed, and the tappet operates as one integral part during the opening and closing of the valve.

While I have described the illustrated 'embodiment' of my invention in some particularity, obviously many others will readily occur to those skilled in the art, and I do not, therefore, limit myself to the precise details shown and described, but claim as my invensaid parts immediately after the valve closes,

and becoming inoperative before the valve commencesto open, and a spring for rotating the parts relatively in the opposite direction.

2. In a valve actuating mechanism, a tappet comprising a reciprocating member held against rotation, a screw threaded therein and v having a head'above the cam shaft of the motor, a cam on said shaft having a point centrally alined with said screw, and a projecting flange on its base circle en aging said head near its outer edge whlle t e valve is and a spring between the reciprocating mem-' her and screw for rotating the parts relatively in a direction 0 posite that in which they are rotated by the ange.

4. A valve actuating mechanism comprising a tappet consisting of a reciprocating part slidable in a guide and prevented thereby from rotation, a screw threaded into the bottom of said reciprocating part having an enlarged head on its, lower end, a spring surrounding said screw and connected to said head and to the said reciprocating part, a cam shaft beneath the head, a cam thereon having a'point in alinement with said screw and having a flange on the base circle portion thereof first engaging the tappet and arranged to contact the head of the screw near the edge thereof.

5. In a valve actuating mechanism, a tappet comprising two telescopically arranged parts,

rotating means telescoping the parts to shorten the tappet immediately after the valve has closed, and resilient means extending the parts thereafter and before the valve starts to open. 7

.6. In an internal combustion motor, valve actuating mechanism comprising a two-part tappet, the parts of which are relatively rotatable, means rotating one of said parts relative the other to shorten the tappet operative while'the valve is closed, and means thereafter rotating said first mentioned part in theopposite direction also operative while the valve is closed.

1 7. In a valve actuating mechanism, a two part tappet, the parts of which are rotatable Illi relative. each other, meansfor rotating one of said parts relative the other while the valve is closed and rendered inoperative for a portion of the' time ,while the valve is closed,and spring. means for returning said first mentioned part relative the second while the first mentioned means is inoperative. y

8. Valve actuating mechanism comprising a two-part tappet, the parts of which are threaded together, means'a'ctuated by a cam rotating one of said parts immediately after i the valve clos'es, and becoming inoperative before thevalve commences to open. 9. In a valve actuating mechanism, a tapeaaeer pet comprising two telescopically arranged parts, one of which bears upon a valve actuating cam, means carried by said cam for rotating said part to shorten the tappet immediately after the valve is closed, and means extending the parts thereafter, and before the valve starts to open.

10. In a valve actuating mechanism, a tappet comprising two telescopically arranged parts, one of which bears upon a valve actuat ing cam, means carriedby said cam for rotating said part to shorten the tappet immediately after the valve is closed, and spring means extending the parts thereafter and before the valve starts to open.

11. In an internal combustion motor having a cam shaft, a cylinder, and a valve controlling communication with said. cylinder, valve actuating mechanism including two parts which are relatively rotatable, means I for rotating one of said parts relative the other while the valve is closed, and means thereafter rotating said first mentioned part in the opposite direction also operative while the valve is closed.

'12. In an internal combustion motor having a cam shaft, a cylinder, and a valve controlling communication with said cylinder, valve actuating mechanism between said valve and shaft comprising two parts which are simultaneously relatively rotatable and translatable, means for rotating one of said parts relative the other while the valve is closed and rendered inoperative before the valve commences to open, and spring means for returning said first mentioned part rela tive the second before the valve'commences to open.

i 13. In an internal combustion motor. comprising a cam shaft, a cylinder, and a valve signature.

WILLIAM R. SPILLER.

controlling communication with said cylinder, valve actuating mechanism between said shaft and valve comprising two relative= ly rotatable telescopically arranged parts, means carried by a cam for rotating one of said parts relative the other to cause them to telescope immediately after the valve is closed, and means extending the parts thereafter and before the valve commences to open. 14. In an internal combustion motor comprising a. cam shaft, a cylinder, and valve controlling communication with the cylinder,

, valve actuating mechanism comprising two threaded parts, means actuated .by the cam shaft for rotating one of said parts relative the other immediately after the valve closes,

and becoming inoperative before the valve commences to open.

15. In an internal combustion motor comprising a cam shaft, a cylinder, and valve controlling communication with the cylinder, valve actuating mechanism comprising two threaded parts, means actuated by the cam shaft for rotating one of said parts relative the other immediately after the valve closes