US2858817A

US2858817A - Tappet mechanism

Info

Publication number: US2858817A
Application number: US638035A
Authority: US
Inventors: Gerald D Line
Original assignee: Eaton Manufacturing Co
Current assignee: Eaton Corp
Priority date: 1957-02-04
Filing date: 1957-02-04
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

. Nov. 4, 1958 G. D. LINE 2,858,817

TAPPET MECHANISM Filed Feb. 4. 1957 I2 I I INVENTOR.

F 19.3 GERALD D. LINE BY 1 I Q 38 W7 ATTORNEY United States Patent g TAPPET MECHANISM Gerald D. Line, Royal Oak, Mich., assignor to Eaton Manufacturing Company, Cleveland, Ohio, a COI'POIEl-r tion of Ohio Application February 4, 1957, Serial No. 638,035

' 7 Claims. c1.123-90) This invention relates to tappet mechanisms and moretappet mechanism. The invention in this application per tains to the above structure and through the useof a simplified novel spring means provides for a compact onepiece unit insertable in tappet mechanisms efiectiv'e to serve a dual function. a i i An' object of this invention is to providein a tappet mechanism comprising a tappet body and a piston; or plunger member, a novel one-piece spiral spring means secured to the tappet body adapted to receive one end of a push rod for maintaining the push rod in extended relation from the tappet body. I

Another object of this invention is to provide a tappet mechanism of the above 's'ort wherein the spiral spring means limits the axial movement of the piston orplunger member.

' A further object of this invention is to providea tappet I mechanism of the above nature wherein the spiral spring means, adaptable to receive the push rod, is capable by structural limitations of restricting or allowing'relative rotative' moti'on occurring between the'tappet' body and push rod during operation of the mechanism.

A still further object of this invention is to provide a" dual purpose spiral spring means that is simple in structure and'economical to produce having inherent characteristics of sustained operating life. I J

This invention can be further brifly summarized as containing novel and practical combinations and arrange ments of parts hereinafter described and particularly set out in the claims hereof.

Further objects and advantages of the invention will appear from the following description takenin connection with the drawings forming a part of the specification and in which,

Figure 1 is a side view of the tappet actuating means and includes an enlarged cross-sectional view of the tappet mechanism containing the dual purpose spiral spring means. i

Figure 2 is a top view of the dual purpose spiral spring means in its unassembled form.

Figure 3 is a fragmentary cross-sectional view of the push rod and tappet structure with a conical or spiral spring means modification.

Figure 4 is a top elevational viewof the spiral spring means modification in its unassembled form.

Referring to the drawings for more specific details of the invention, a hydraulic tappet structure 10, shown more distinctly in Figure 1, comprises a cylindrical body 2,858,521? Patented Nov. 4, 1958 member 12, a base portion 14 formed as a part thereof, and an opening 16 formed by the body at the extreme end opposite the base portion. A

Radially inwardly of the tappet body 12 is a piston member 18, axially movable within the tappet body and responsive to fluid pressure supplied to a high pressure chamber disposed between the piston and body wherein upon rotation of a cam member 20 a reciprocating motion is imparted to the tappet body and consequently, to the movable piston memberthrough the medium offluid trapped in the high pressure chamber. I I

The movable piston member is so constructed asto provide for a hollow fluid chamber 22, oneend of which provides for a fluid passage 26 forming a valve seat 28. A circular disk-shaped valve member 30 is positioned axially between the base portion 14-and the fluid passage 26and is resiliently held in intimate contact with thevalve seat 28 by a spring member 32 interposed between the cage bottom 34 and the valve member 30. The piston member 18 is biased outwardly of tappet body 12-by a resilient spring 36.

At the opposite end of the fluid opening of the movable piston member is an end piece 38, formed of a certain cup-like curvature, having its convex side opposite the fluid opening 26 and the concave side facing the tappet body opening '16, the end piece 38 being so constructed as to provide a curved area adapted to receive the end portion 40 of a push rod 42. The push rod end is formed of a lesser diameter than a body portion 43 of the push rod 42 so as to provide a shoulder portion 44 for receiving a normally flat spiral spring means 46. The spiral spring means 46 is formed to provide atits inner periphery an opening 48 for engageably receiving the shoulder portion 44 of the push rod 42. The outer periphery 50 is fixedly secured to the tappet body 12- allowing limited axial movement of the plunger or piston"member 18, preventing the piston from an overly;

extended outward movement. i a

-A rocker arm 52, pivotal in a slot 56 formed by a fixed member -54, is .in constant engagement with one end of the push rod member 42.

mal operation, the tappet mechanism serves to function to maintain zeroor a predetermined small clearance-in the valve-gear train between the valve being actuated;

and the motivating cam, the spring function of meansv 46'serves-to insure a maintenance of engagement between: oneend of push rod 42 and one arm of rocker arm 52.1 In this manner should the tappet piston for any reason;

become bottomed in thetappet body the resilient action of means 46 isever present to hold the push rod axially extended relative to the tappet body with one end engaging the push rod. It will be thus recognized that the push rod by reason of not being attached to the rocker arm is prevented from falling out of series related engagement therewith as part of the valve gear train and as a further'relationship, the spring through the trans mitted action of the push rod maintains the rocker arm in constant contact at its fulcrum point and at its valve stem contacting point, thus minimizing valve gear failure.

Figure 3 shows the aforementioned tappet mechanism and push rod member combined and connected with a normally conical spring means 60 from overextending outwardly from the tappetbody. The conical spring means being of a resilient nature maintaining the piston 18 and the push rod 42 in a continuous contact position tending to eliminate clearance caused if piston sticking occurs. This particular figure demonstrates a possible modification of the dual purpose spiral spring means idea as used in valve actuating mechanisms.

drawings, it can be seen that the valve mechanism disclosed contains certain novel and practical features of simple and economical construction. Summarily, the tappetmechanism containsa one-piece spiral spring means which acts as a limiting means for the movable piston member and also as a resilient means maintaining the push rod in. a constantly extended position in relation to the tappet'body.

Furthermore, it will be seen that the spiral spring mains of a practical design nature and the ease of its assemblance into the tappet mechanisms facilitates largescale production.

While the. invention has been described in connection with certain-specific embodiments, the mechanism involved is susceptible of numerous other applications that will readily, occurto men skilled inthe art. Therefore, the invention is limited" only as indicated by the scope of the appended claims.

* Whiat"I;claim is:

1' ll A valve actuating mechanism including a pivotal rocker" arm, a push rod engageable with one end of said rocker'arm, a rotating member imparting reciprocal motion to a tappetmechanism, saidtappet mechanism being axially spaced between and in intimatecontact withsaid rotating means and said push rod, said tappet including abody member; a movable piston member therein, and a oneapiece spiral springmeans fixedly secured to said tappet'body, said'spring means having its inner periphery of*s'uitable diameter adapted to engage one end'of said pusli rod and so arranged on the tappet body as to maintain 'said piston fromoverextending outwardly from said tappet body while simultaneously biasing the push rod axially awayfromthe body member.

2. A valve actuating mechanism including a pivotal rocker arm, a push rod, engageable with one end of said'rocker arm, a rotating means imparting reciprocal motion to atappet mechanism, said tappet mechanism being axially spaced between and in. intimate contact withsaid rotating means and said push rod, said tappet including a body member, a movable piston member therein and a' one-piece spiral spring'means fixedly secured to said tappet body maintaining said pistonfrom overt-extending" outwardly from said tappet body, said springmeans ha'ving its inner periphery of suitable diameter adapted'to receive one endof sai'd push rod, and providing aresilient action for maintaining said push rodincontinuous-contact with said rocker arm.

' 3 A valveactuating mechanism including a pivotal rocker'arrn; a; push'rod engageable with One end of said rocker arm; a rotating means imparting reciprocal motion t'o' a tappetmechanism, said tappet mechanism being axiallyspaced between and in intimate contact with said rotatin'g'means andsaid'push rod, said tappet including a body member, a movable piston member therein, and a one-piece spiral spring means fixedly secured to said I r r 4 tappet body allowing limited axial movement of said piston member outwardly of the body, said spring means having its inner periphery of suitable diameter to engageably receive one end of said push rod and maintaining said push rod in extended relation from said tapped body.

4. A valve actuating mechanism including a pivotal rocker arm, a push rodengageable with one end of said rocker arm, a rotating member imparting reciprocal motion to a tappet mechanism, said tappet mechanism being axially spaced between and. in intimate contact with said rotating means and said push rod, said tappet including a body member, a movable piston member therein, and a one-piece spiral spring means fixedly secured to said tappet body, said spring means having its inner periphery of suitable diameter adapted to engageably receive one end of said push rod, said inner periphery so adapted as to frictionally maintain said push rod and said tappet in non-rotatable relationship to one another and to bias thepush rod axially away from the body.

5. A valve actuating mechanism including a pivotal rocker arm, a push rod'engageable with one. end of said rocker arm, arotating-member imparting reciprocal motion to atappet mechanism, said tappet'mechanism being axially spacedbetween and in intimate contact with said rotatingmeansand said push rod, said tappet including a body member, amovable. piston member therein, and a one-piece. spiral. springmeans fixedly. secured to said tappet body, said means having its inner periphery of suitable; diameter: forengageably receiving one end of said. push rod'with .saidinner periphery-so adapted as to provide.relativerotatable.motionbetween said push rod and'tappet mechanisms.

6. A valve actuating mechanism including a tappet body, a. movable. piston. member therein: and a conical spiralfsp'ring means fixedly secured. to said tappet body, said'sprin'g means: adaptableto receiveone. end of-a push rod, maintainingsame inextendedvrelation from said-tappet body, said'piston member-axially movable within said tappet body being limited from excessive outward motion by said conical springmeans. p

7. A valve actuating mechanism including. a. tappet body, a 'member axially movable. in said'body, apush rod having one extremity engageable with said member, a spring means disposed betweensaidbody and vsaidzp ush rod biasing said push rodaxially away from said body and limiting axial outward movement of: said. memberrelative to saidbody, said spring means: being of av spiral configuration with its largest diameter portion secured to said tappet body and its smallest diameter portion in. engagement with .said push rod.

References Cited inthe-file. of. this patent UNITED STATES PATENTS 2,719,515 Archangeli, Oct.. 4, 1955