US1504774A - Valve-operating mechanism - Google Patents

Description

Aug. 12, 1924. ,7 1,504,774

v c. Hi MARTIN VALVE OPERATING MEUIIAIII SM Filed July 17. 1923 INVENTOR Patented Aug. 12, 1924;

UNITED STATES PATENT OFFICE.

CLYDE H. MARTIN, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO DURANT MOTOR-S INCORPORATED, A CORPORATION OF DELAWARE.

VALVE-OPERATING MECHANISM.

Application filed July 17,1923. Serial No. 652,016.

To all whom it may concern:

Be it known that I, CLYDE H. llLfARTIN, a citizen of the United States, and a resident of. Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Improvements in Valve-Operating Mechanism, of which the following is a specification.

The invention relates to mechanism for operating valves, and particularly to the devices for operating the poppet valves of an explosion motor. Such mechanism ordinarily operates through a pair of rods, one the valve stem and the other what is known as a push rod, either with an interposed lever arm, or without such lever arm, and it is the primary object of the invention to provide an improved device of this kind, (1) which can be applied to the standard engine construction of the type specified without difliculty and at a very slight expense, (2) which can be readily adjusted to take up the lost motion in the series of connections, and thus eliminate the noise incident to. such lost motion ordinarily present in one or more of the plurality of sets of such mechanism in a multi-cylinder engine, and (3) which, when once adjusted to take up the lost motion, remains substantially permanently in the condition of adjustment, so that the ordinary requirement for frequent adjustments is avoided. Certain embodiments of the invention are illustrated in the accompanying drawings wherein:

Figure 1 is a partial vertical .section through a cylinder with the improvement applied thereto. Fig. 2 is an enlarged dctail section through the upper end of the push rod. Fig. 3 is a partial vertical section through a modification.

Referring to Figs. 1 and 2, 1 is the cylinder of a gas engine provided with a piston 2, 3 is the cylinder head, and a is one of the cams carried by the cam shaft for operating the-valve, the showing of these parts being conventional and constituting no part of my invention which relates particularly to the means for operatingthe valve from the cam. I

j The valve 5 1s Of thepoppet type, having a stem 6 guided in the bearing 7 in the cyllnder head, and normally held closed by the spring 8 bearing. against the collar 9, a cotter pin 10 serving to hold the collar in position.

Mounted on the cylinder head upon the shaft 11 is pivoted the'lever 13 which at one end bears against the upper end of the valve stem 6. The other end 14 of the lever is formed into the usual plate, whose lower surface 15 is flat and plain as indicated in the drawing, or slightly curved, the term substantially flat being intended to cover both conditions.

. Between the end 14 of the lever and the cam 4; 18 the push rod, comprising a lower part 16, slidably guided in the cylinder cast mg, and an upper part in the form of the rod 17, guided in the cylinder head at 18, the lower end of the rod fitting in a socket in the part 16 and being free to turn therethe nut lock 20. The upper end of the adjusting member is provided with a ball socket which carries the hardened steel ball 21. The ball is preferably held against accidental removal from its socket by peening or bending over the side walls of the socket as indicated at 22. This ball bears against the lower flat or curved surface 15 at the end of the lever. V

In operation, to adjust the device, the nut lock 20 is loosened and the adjusting member 19 turned to take up the lost motion and bring the ballinto contact with the surface 15, after which the nut lock istightened. hen once adjusted there is practically no wear at the'ball contact, as the ball is free to turn, and the turning of the ball or the rod 17 does not tend to introduce lost motion, as is the case where the ordinaryv contactinvolving the engagement of the end of a rod with the lever is .employed. In the latter construction, there is apt to be a high spot on theend of the rod,

1 so that when it is turned, in the course of negligible 0a.

is caused, or the valve does not close tightly,

there is a relative sliding movement between the contact surfaceof the'leve'r and the end of the rod. My construction avoids all of these difficulties, as there i sno change in elevation of the ball contact surface due to the rotation of the rod or ball, and the wear is distributed over the" ball and its socket to" avoid producing. lost motion. In practice, the device maybe used indefinitely Without adjustment Another advantage of the construction is" incident a; as: applicability" to standard engine; construction ata All of the parts of the construction shown in both embodiments ofthe invention, are standard; except the adjusting" member, so all that is necessary to" apply the device is; to thread thepush rod, and screwon the lock nut and adjusting member. The device can, therefore, be readily applied to existing engine structures at slight expense, since no machining of the lever end, or other part cooperating with the ball, is required, such as is the case Where a ball is applied between opposing sockets.

Other advantages .of the construction will be apparent to those skilled in the art'.

Fig. 3 illustrates a modification in which thelever 18 of Fig. 1 is omitted, the push rod being placed in line with the stem 23 of the valve 24 and. acting directly to open it. In this construction, 25 is the cylinder, 26, the piston,'27 the cylinder head', and 28 the operating (5am, The push rod 29 is guided in the bearing 30,,andi's provided with a screw threaded socket 31 into which is" threaded the adjusting member, comprising a stem 32 and a head 33, the letterheingprovided with a socket carrying the ball 34. After the adjusting member is screwed by the ant-100k 37. The valve is normally closed by thespring 35,-bearingagainst the collar 36 secured to the stem of the valve.

Vvhalt I claim is:

1,111 combination in an engine structure provided with" an operating cam and a valve, having a stem, normally held closed by means of spring, of operating means for the stern comprising a lever fulcrurned intermediate its ends andengaging. the stem at one end and having: at its other end a substantially flat surface, av push rod operated' swaths cam at one end, means for guiding said push rod in sliding. movement parallel to-t he of the enginecylinder, an adjusting member screw threaded on the other end of the push rod and provided with a ball socket, a ball in said socket, free to termediate itsends and engaging the stem atone end and having at its other end a substantially flat surface, a push rod operated from the cam at one end, means for guiding ada ter rod insliding movement parallel to the azris of the engine cylinder, an adjusting; member screw threaded on the other end of the push rod and provided with a ball socket, a ball in said socket free to rotate, but held against lateral movement by the walls of the socket and engaging said fiat surface on said lever, and, a nut lock for said adjusting member, also threaded on said push rod, the side edges of the adjusting member'being peened or bent over to hold said ball in place in said socket. v

3. In conibin'ationin an engine structure provided with an operating cam and a valve, having a stem, normally held closed by means-of a spring, of operating means for the stem comprising a lever fulcrumed intermediateits ends and engagingthe stem at one end and having at its other end a substantially flat surface, a push rodoperated from the cam and comprising an inner member, means for guiding said push rod in sliding movement parallel to the axis of the engine cylinder engaging the cam at one end and having a socket at its other end, and an outer member fitting at one end in said socket free to turn therein, an adjusting member threaded on the other end of said outer member and provided with a ball socket, a ball in said socket free to rotate, but held against lateral movement by the walls of the socket and engaging said flat surface on said lever, and a nut lock for said adjusting member, also threaded on 7 said outer member.

in sliding movement parallel to the axis of the engine cylinder engaging the cam at one end and having a socket at its other end, and an outer member fitting at one end in said socket free to turn therein, an adjusting member threaded on the other end of said outer member and provided with a ball socket, a ball in said socket free to rotate, but held against lateral movement by the Walls of the socket and engaging said flat surface on said lever, and a nut lock for said adjusting member, also threaded on to hold said ball in place in said socket.

In testimony whereof, I have hereunto subscribed my 1923.

name this 19th day of June,

CLYDE H. MARTIN.

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