US1741678A - Valve-operating mechanism - Google Patents

Description

Dec. 31, 1929. R. w. A. BREWER VALVE OPERATING MECHANISM Filed July 15. 192.7 2 Sheets+Sheet l 7 INVENTOR m MZ-M ATTORNEY Patented Dec. 31, 1929 PATENT. OFFICE ROBERT W. A. BREWER, 0F JENKINTOWN, PENNSYLVANIA, ASSIGNOR TO HAROLD F. PITCAIRN, 0F BRYN ATHYN, PENNSYLVANIA VALVE-OPERATING MECHANISM Application filed July 15, 1927.

This invention relates to valve operating mechanism of the type in which the valve is actuated by a rocker arm in turn actuated by an operating rod.

One of the primary obj ects-of my invention is the provision of an improved valve operating device which is simple in construction, easy to assemble, and reliable in operation.

Another object of my invention is the provision of a device of the character described in which objectionable thrusts on the rocker arm are obviated.

Still another object ofmy invention is the provision of a device of the character described in which adjustments can be made in a very simple mann r. v

A more specific 0 ject of my invention is to provide a: device of the character described in which the movement of the operating rod is substantially axial. I

How the foregoing,together with such other objects and advantages as may hereinafter appear, or are incident to my invention, are realized, is illustrated in preferred form in the accompanying drawings, wherein- Fig. 1 is a fragmentary front elevational view of an internal combustion engine show ing my invention applied thereto, certain of the parts appearing in section.

Fig. 2 is a fragmentary side elevation of Fig. 1 looking toward the right of Fig. 1 with certain valve operating parts appearing in section. I

Fig. 3 is a fragmentary enlarged section taken on the line 33 of Fig. 1.

Fig. 1 is a section taken on the line 4-4 of Fig. 3, and

Fig. 5 is a plan view of Fig. 3 with the cover removed.

Referring now to the drawings and particularly to Figs. 1, 2 and 3, it will be seen that the reference letter A denotes one cylinder of a multiple cylindered internal combustion engine, such asthe radial type in which the valve operating rods are obliquely disposed with relation to the valve rocker, and the reference letter B denotes a portion of the crank case, the cylinder-being provided with a piston C. Each cylinder of the engine 'is providedwith an intake and an exhaust valve Serial No. 205,865.

located in the upper portion of the cylinder, and in Fig. 3 I have clearly illustrated oneof the valves, in this instance the intake valve of a the engine. Each valve is operated by a valve operating device indicated as a whole by the reference letter D.

Each valve operating device D comprises, in general, a rocker arm 6, (see Figs. 3, 4 and 5) and an operating rod 7. The operating rod 7 is actuated by a cam 8 which is driven from the crank shaft of the engine by means of suitable gearing provided for the purpose of causin opening and closing of the valves at the proper time as is well understood in the art. A tappet 9 carrying a roller is interposed between the lower end of the rod 7 and the cam 8, which tappet reciprocates in a sleeve member 10 in the casing B. The tappet is suitably socketed to receive the balled end of the rod 7.

At its upper end the operating rod 7 is soeketed in a lever 11 by means of its balled end and the rounded recess 12 in the lower surface of the lever. The lever 11 is pivotally mounted at 13 on the base member or support 14 and has its free end interposed be tween the operating rod 7 and the rocker arm 6. The upper surface 15 of the lever 11 is curved and contacts with the ball shaped roller 16 carried at one end of the rocker arm, whereby substantially rolling contactobtains as between the rocker and the lever.

The other end of the rocker arm is provided with a roller 17 which engages the valve stem of the valve 18, and the rocker is provided with a fulcrum 19 intermediate its ends on which it rocks as it is actuated by the operating rod 7. The manner of mounting the fulcrum 19 will appear hereinafter.

Referring now more particularly to Figs. 1 and 4, it will be seen that owing to the disposition of'the valves in the cylinders and to the central location of the earn 8, the operating rods 7 are obliquely disposed with respect to the rocker arms by virtue of which, without provision to the contrary, certain objectionable oblique thrusts would be imposed on the rocker arms. I aim to obviate objectionable thrusts onthe rocker by means of the lever 11 hereinbefore mentioned, the free end of which is interposedbetween the rod 7.and the rocker 6. By employing such a lever it will be seen that angular thrusts such as would be imposed on the rocker if the operating rod bore directly on the rocker are translated into thrusts in adirection to move the rocker without subjecting it to appreciable transverse stresses. The location of the pivot pin 13 of the lever 11 is such as to obtain this result. This is clearly illustrated in Fig. 4

by the arrow which shows the direction of cured to the cylinder casting in any convenient manner, as by means of screws 26. The

Y support 14 constitutes the base portion of what may be termed a rocker box, the remaining portion being constituted by the cover member 27, which cover is held in place by one of the screws 26 and bythe securing means 28.

In order to normally hold the shouldered portion 2 1v of the stud 23 against the seat 25, I have provided a'spring 29 interposed between the rocker box cover 27 and the nut or headwhich is secured to the post 23. In

this connection, it is pointed out that the stud also tends to seat by virtue of the upward thrusts on the rocker arm. The spring 29 merely serves to take up any lost motion between the rocker arm and its associated operating rod and Valve.

The rocker arm 6 is laterally positioned by means of the guides or horns 31, in this instance extending upwardly from the support 14C. In the operation of engines of the character described, it becomes necessary, from time to time, to adjust the relation of the rocker to the operating rod and valve and with the object in view of providing simple and readily accessible means for accomplislr ing this, I have extended the threaded stud 23 to project outside the cover 27 and have provided the nut 30 for rotating the stud. By rotating the stud the rocker may be raised or lowered as the case may be, and the desired adjustment effected. A suitable catch device as the snap spring 32 engaging notches 33 in the nut 30 is provided to hold the stud in its adjusted position. The exact vertical displacement of the rocker may be indicated by suitable gra'duations on the operating nut. The lateral guides 31 above mentioned hold the rocker against turning when adjustment is being made.

From the foregoing it will be seen that I have provided a very simple mounting for the rocker which is inexpensive to manufac ture and very reliable. Inthis instance, the rocker ismade of two flat plates bridged together at the ends by the pins 34 and 35 of the rollers 16 and 17, respectively. The fulcrum or rocker pin 19 is a simple round pin of a length corresponding to the width of the rocker and provided with a threaded aperture. The valve operating device D may be easily assembled and disassembled. To disassemble the device the nut 30 is first removed and then the cover or housing 27 is removed by taking out the screws 26 and 28. The

rocker arm 6-may then be removed by merely ing and provides a channel for-the passage of lubricating oil.

, In this connection, it is pointed out that by socketing the upper end of the operating rod in the lever 11 as hereinbefore described, the movement of the operating rod is almost wholly axial, any lateral movement at the upper end being very slight. By such an arrangement I am enabled to employ a shroud tube of relatively small diameter.

' I claim 1 I 1. A valve device for internal combustion engines comprising, in combination, a support, a valve,'a valve operating rod, a valve rocker having a pivot member, a rocker housing, a threaded rotatable stud on which the pivot member is secured, said stud having a shoulder adapted to engage said support, and means for holding said shoulder against said support. 2. A valve device for internal combustion engines comprising, in combination, a support, a valve, a valve operating rod, a valve rocker having a pivot member, a rocker housing, a threaded rotatable stud on which the pivot member is screwed, said stud having a shoulder adapted to engage said support, and resilient means for holding said shoulder against said support, together with means for preventing the rocker from rotating with said stud.

3. A valve device for internal combustion engines comprising; in combination, a support, a valve, a valve operating rod, a valve rocker, a rocker mounting, a rocker housing, and means extending through said mounting,

port

- support, a valve,

v rocker and its.

said support and said housing for holding the mounting inplace.

4. A valve device engines comprising, inv combination, a support, a valve, avalve operating 'rod, a valve rocker, a rocker mounting, a rocker housing, and means extending through said mounting, said support and said housing for holding the mounting in place, together with means of adjustment for said last-named means located exteriorly of said housing.

5. A valve device for internal combustion engines comprising, in combination, a fixed support, a valve, valve rocker, a rocker fulcrum, support, said fixed support having an aper.-- ture for receiving said fulcrum support,'said fulcrum support having a portion adapted to engage said fixed support, a rocker housing detachably secured to said fixed support, and means engaging said'housin'g and said fulcrum support crum support in engagement with the'fixed support.

6; A valve device for internal combustion engines comprising,

rocker, a rocker fulcrum, a fulcrum support, said'fixed support having an aperture for receiving said fulcrum support, said fulcrum support having a portion adapted to engage said fixed support, a rocker housing detachably secured to said fixed support, and means engaging said housing and said fulcrum support for normally holding the fulcrum support in engagement with the fixed support, to-

gether with means carried by said fixed supsaid valve rocker.

7. A valve device for internal combustion engines comprising, in combination, a fixed a valve operating rod, a valve rocker, a fulcrum pin for the rocker having a central screw threaded aperture, and a. screw threaded supporting stud for the engines comprising, in combination, a fixed support, a valve, a valve operating rod, a valve rocker, a fulcrum pm for the rocker 'havin g a central screw threaded aperture, and a screw threaded supporting stud for the rocker and its fulcrum pin, a housing detachably secured to the fixed support, and means" exterior of the housing for rotating said stud to move the rocker and its pin axially of said stud.

In testimony whereof I have" hereunto signed my name.

ROBERT w. A. BREWER.

for internal combustion a va'lve operatingrod, a a fulcrum for normally holding the ful-' in combination, a fixed support, a valve, a valve operating rod, a valve for preventing lateral displacement of fulcrum pin, said stud being rotatable to move the rocker and its pin. ax-

ially of the stud through the medium ofthe aforesaid screw threads.

8. A valve device for internal combustion

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