US2721543A

US2721543A - Self-adjusting contactor for valves

Info

Publication number: US2721543A
Application number: US280588A
Authority: US
Inventors: Frank W Johnson
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-04-04
Filing date: 1952-04-04
Publication date: 1955-10-25
Anticipated expiration: 1972-10-25

Description

F. W. JOHNSON Filed April 4, 1952 3/) INVENTOR.

BY fZ'd/IkWx/OfiI/JW A TTOR/VE 7-.

SELF-ADJUSTING CONTRACTOR FOR VALVES 20 lg? lg Oct. 25, 1955 United States Patent SELF-ADJUSTING CONTACTOR FOR; VALVES.

Frank W. Johnson, Kansas City, Mo. Application April 4, iasasensmq. 280,588

6 Claims. (Cl. 1-23'-.-90)

This invention relates. toaself-adjusting contactor for poppet-type; valves as used in internal combustion engines and has for, its principal object to.provide a hydraulic; unit of thischaracter that is readily applied toa conventional valve operating mechanism. as. a. single; unit and which involves no alteration of the existing; parts of an. engine with the exception of shortening thetappetor push rod,

Other objects of the invention are to provide a selfadjusting contactor which ispositive in action; is of simple construction and easily assembled: to form a sealed, selfcontained unit.

In accomplishing these and other objects of, the invention hereinafter pointed out, I haveprovided. improved structure, the preferred formof which isillustrated in. the accompanying drawing wherein:

Fig. l is a'vertical sectional view through an engine having the valve gear equipped with a. self-adjusting; con.- tactor constructed in accordance with the present inventron.

Fig. 2 is an enlarged vertical sectional view of theselfadjusting contactor.

Fig. 3 is. a perspective view of the working parts of th self-adjusting contactor shown in disassembled spaced relation.

Fig. 4 is a. horizontal section: through the contactor on the-line 44 of Fig. 2. 7

Referring more in detail to the drawings:

1 designates a conventional type. internal combustion engine having a cylinder block 2 containing a piston cham her 3 in which apiston- 4' is. reciprocablymounted for actuation by. a connecting rod 5-and crank shaft 6.

The engine also includes a cylinder head 7 having a combustion chamber 8 in connection. with the cylinder chamber. The engine illustrated. is of the overhead valve type and has exhaust and intake valves, one, of which, is designated 9 for controlling the passageway 10. The valve 9. has a stem 11 that is. slidably mounted, inv av bore 12 in the head 7. The head of. the, valve is retained in position on a seat 13by a coil spring14 having one end engaging a seatingwasher 15 that is secured to.the. stem 11 and the. other end engaging a seat 16 in. the cylinder head.

The valve 9 is actuated by a rocker arm 17. having one arm. 18 engaging the end. of the stem. 11 and an arm 19 carrying an adjusting screw 20, which. ordinarily engages the end of a push rod 21. The other end. of the push. rod has a ball and socket connection 22. with a plunger 23 which is operated by a cam shaft 24. havinga cam. 25.

It is. well known that clearance must beprovidedin. the tappet' portions of the valve gear to assure. that the'valves seat properly. Consequently, such valve gears are noisy in. operation. In the modern engines, this difficulty is overcome by hydraulic valve lifters. which. are actuated by pressure fluid. from the pressure oiling systems of such engines. Such valve lifters. are built into. the. engine. at the time: of its construction and are subject tooperational diflicnlties because of foreign particles. usually contained in the lubricating oil.

"ice

These difliculties, are overcome through the-present invention by providing the valve gear with a self-contained, adjusting unit 26 for automatically taking up clearance and providing silent operation of the valve gear.

In? the illustrated instance, the unit 26 includes, a cylindrical body'member 27 having an annular wall 28 which is provided} with, an internal, annular shoulder 29 for sup- PQItting a spring seating washer 30 later described. The lower end of the cylinder body is closed by a head 31 having an annular shoulder 32. which has a press fit within the cylinder to provide a leak-tightjoint therewith. The head has a. fixed piston element 33 that projects into the cylinder and which is of smaller diameter than the inner diameter of the cylinder to leave an annular passageway 34 therebetweem The fixed piston 33 is of cylindrical shape and has annular groovev 35 formed in the periphery thereof to seat piston rings. 36 which form a. seal with. a movable piston element 37. The inner end 38 of the stationary piston is substantially flat and the axial center thereof is provided with a bore 39: to accommodate a pilot 40 on a valve plunger 41' later described. The outer, lower end of the cylinder headv 31 has an axial recess 42' which is adapted toreceive the upper end of the push rod; 21 as best shown in Fig. 2.

The movable piston. element 37 includes a cylindrical skirt.- portion. 43; that is. sleeved over the stationary piston element 33 and has a head. 44' to cooperate with the inner end of the fixed piston in forming a pressure chamber 45' of variable capacity, depending upon the position of the movable piston relative to thefixed piston.

A suitable liquid is admitted intoand discharged from the pressure chamber 45, through an axial port 46 in the head 44: of the movable piston 37, and the periphery of the port forms a seat 47 for a beveled annular valve face 48 on the valve plunger 41.

The head 44: of the movable piston 37 has: a laterally extending annular periphery 49* that is loosely positioned Within: the inner wall. of the cylinder to form an annular seat 50; for one endv of a coil spring 51' that encircles the skirt portion: of the movable piston and has its other end engaging a seat 52' on the. cylinder head 31 immediately encircling the fixed. piston 33 (shown in Fig. 2).

The valve plunger 41 includes a stemportion 53 that projects through a head 54.which closes the opposite end of-the cylinder. Thehead 54- has an annular flange portion. 55 which hasa pressed fit over that end of the cylinder to form a leak-tight joint and to retain a washer 56 in: engagement with a packing ring 57 that is inset within a. counterbore 58' on the inner side of the head and encircling anv opening 59? through which the end of the plunger projects. Thepacking ring thus forms a liquidtight seal about the stem of the plunger and prevents leakage of the operating liquid 60 from the cylinder during actuation ofthevalve gear;

Thevalve plunger moves through an opening 30. in the spring seat 30 and; is lifted from itsseat 47 during a portion of the operation of the, valve gear by-means of a coil spring 61 seating on the washer 30 and having the other end engaging asplit washer 6 2- that' is, retained in. an annular groove 63. oi the plungerstern. (see. Figs. 2 and 3). The, washer 307 has a. plurality of. openings 64 by which fluid is. transferred toa-nd from the respective, sides or the seating washer thereby providingmaxi'rnum: fluid capacity for a given size mechanism.

The pilot recess. is vented into the pressure chamber through a port 65 of the pilot so as; to avoid trapping of liquid under the pilot.

The outer end of thevalve plunger is provided with a conical seat 66 for receiving the conical end. 67 of the adjusting screw 20, previously described.

In assembling the parts of the self-adjusting contactor,

the piston rings 36 of the fixed piston element 33 are inserted in the grooves 35 thereof. The coil spring 51 is then sleeved over the fixed piston element 33 to engage the seat 52. The movable piston element 37 is applied by sliding the skirt portion 43 thereof between the coil spring 51 and the fixed piston element 33. The seating washer 30 is inserted through the opposite end of the cylinder. The split washer 62 is then slid in the groove 63 of the valve plunger 41, and the spring 61 is sleeved over the pilot end 40 of the plunger 41, after which the valve plunger 41 is moved into position with the pilot 40 passing through the opening 30 in the seating washer 30 and through the valve port 46 of the movable piston element 37, the pilot 40 sliding into the pilot recess 39 to provide a guide in retaining axial alignment of the valve face 48 of the plunger with the valve seat 47 in the head of the movable piston element 37.

All of the space within the cylinder is then filled to the level of the upper end thereof with a lubricating oil 60.

The washer 56 is then applied to the open end of the cylinder, and the head 54 carrying the packing ring 57 is sleeved over the projecting end 53 of the valve plunger 41 with the skirt 55 being pressed tightly over the wall of the cylinder to complete the assembly.

In fitting the adjuster to the valve gear of an existing engine, a suificient amount of the push rod 21 is cut off so that when the upper end thereof is engaged in the axial recess 42, there is SllffiClCHt room to accommodate the adjuster below the arm 19 of the valve rocker 17. The adjusting screw 20 is then moved into position so that the conical end 67 thereof engages in the recess 66 of the valve plunger 41 to take up all of the slack in the valve gear. After the slack has been taken up, the adjusting screw 20 is given an additional partial turn. This maintains a positive seat between the valve plunger 41 and movable piston element 37 against action of the spring 51.

When the plunger 23 is engaging the low portion of the cam shaft 24, the spring 61 lifts the valve plunger 41 so that liquid flows through the port 46 to fill the pressure chamber 45. When the plunger and push rod are lifted by the high lobe portion 25, the push rod 21 lifts the entire unit 26. The pressure of the valve plunger 41 acting against the rocker arm seats the face 48 of the valve plunger against the seat 47 to trap the liquid in the pressure chamber 45 so that movement of the valve is effected through the liquid trapped in the pressure chamber 45 which eliminates the slack that produces noise in conventional valve gear.

While the invention is particularly adapted for use as an attachment for valve gear of existing engines, it is obvious that it is also suitable for use in the valve gear of any internal combustion engine.

While I have particularly described the invention as applied to an overhead type of valve gear, it is obvious that the complete unit may be inserted between the valve stem and tappet of any L head type engine by shortening the valve stem.

What I claim and desire to secure by Letters Patent is:

1. A self-adjusting contactor for insertion between an operating member and an operated member in a valve gear for a poppet type valve including a cylindrical member, a fixed piston closing one end of the cylindrical member and having a recess to receive the operating member therein and having a piston element extending into the cylindrical member, a movable piston element having a skirt portion slidable over the first named piston element to form a variable capacity pressure chamber therebetween, the movable piston element having a port in connection with the pressure chamber, a head closing the other end of the cylindrical member, a plunger having a valving face normally closing said port during actuation of the operating member to trap liquid in the pressure chamber for taking up any slack in the valve gear and having an end projecting through the head for connection with the operated member, and

spring means for moving the plunger from closing relation with the port and maintaining said pressure chamber when slack occurs in the valve gear to effect filling of said pressure chamber upon closing of the poppet valve by said valve gear.

2. A self-adjusting contactor for insertion between an operating member and an operated member in a valve gear of a poppet type valve including a cylindrical member, a fixed piston closing one end of the cylindrical member and having a recess to receive the operating member and having a piston element extending into the cylindrical member, a movable piston element having a skirt portion slidable over the first named piston element to form a variable capacity pressure chamber therebetween, said cylindrical member having an inner shoulder spaced from the movable piston element, a spring seat on said shoulder and having an axial opening registering with a port in the movable piston element, a head closing the other end of the cylindrical member, a plunger having a valving end normally closing said port during actuation of the operating member to trap liquid in the pressure chamber for taking up any slack in the valve gear and having an end projecting through said head to engage the operated member, a spring having one end seated on the spring seat, resilient means engaging the movable piston element to maintain the pressure chamber and a spring seat carried by the plunger for engaging the other end of the spring to lift the plunger for passing liquid into the pressure chamber when slack tends to occur in the valve gear.

3. A self-adjusting contactor for insertion between an operating member and an. operated member in a valve gear of a poppet type valve including a cylindrical member, a fixed piston closing one end of the cylindrical member and having a recess to receive the operating member and having a piston element extending into the cylindrical member, a movable piston element having a skirt portion telescoping the first named piston element to form a variable capacity pressure chamber therebetween, said cylindrical member having an inner shoulder spaced from the movable piston element, a spring seat on said shoulder and having an axial opening registering with a port in the movable piston element, a head closing the other end of the cylindrical member, a plunger hav ing a valving face normally closing said port during actuation of the operating member to trap liquid in the pressure chamber for taking up any slack in the valve gear and having an end extending through said head to engage the operated member, resilient means engaging the movable piston element to maintain the pressure chamber, a spring having one end seated on the spring seat, a spring seat carried by the plunger for engaging the other end of the spring to effect lifting of the plunger for passing liquid into the pressure chamber when slack tends to occur in the valve gear, and packing carried by said head for sealing about the plunger.

4. A self-adjusting contactor for insertion between an operating member and an operated member in a valve gear of a poppet type valve including a cylindrical member, a fixed piston closing one end of the cylindrical member and having a recess to receive the operating member and having a piston element extending into the cylindrical member, a movable piston element having a skirt portion telescoping the first named piston element to form a variable capacity pressure chamber therebetween, said cylindrical member having an inner shoulder spaced from the movable piston element, a spring seat on said shoulder and having an axial opening registering with a port in the movable piston element, a head closing the other end of the cylindrical member, a plunger having a valving face normally closing said port during actuation of the operating member to trap liquid in the pressure chamber for taking up any slack in the valve gear and having an end extending through said head to engage the operated member, resilient means engaging the movable piston element to maintain the pressure chamber, a spring having one end seated on the spring seat, a spring seat carried by the plunger for engaging the other end of the spring to effect lifting of the plunger for passing liquid into the pressure chamber when slack tends to occur in the valve gear, packing carried by said head for sealing about the plunger, and a pilot at the other end of the plunger slidably mounted in a recess of the fixed piston element.

5. A self adjusting contactor adapted for insertion between an actuated and an actuating member of a poppet type valve gear including a member having support on the actuating member and having a liquid containing chamber, movable piston means in said liquid containing chamber, one of said piston means having a peripherial portion slidable in sealing contact with the other piston means to provide a pressure chamber between said means, the movable piston means having a port therein in connection with the pressure chamber, resilient means engaging the movable piston means and seated on a part of said member having the liquid containing chamber to maintain the pressure chamber between the piston means, a plunger having a valving face for closing the port in the movable piston means and adapted to engage the actuated member on the plunger closing side of said port, and a spring having one end fixed relative to the member having the liquid containing chamber, and the other end engaging a part of the plunger to lift the plunger when slack tends to form in the valve gear to allow liquid to flow in the chamber to take up said slack upon reseating of the valving face of the plunger.

6. A self adjusting contactor adapted for insertion between an actuated and an actuating member of a poppet type valve gear including a member having support on the actuating member and having a liquid containing chamber, relatively movable piston elements carried within said liquid containing chamber and having heads, one of said piston elements having a skirt encircling the head of the other piston element to provide a pressure chamber between the heads of said elements and to provide a sliding seal for the pressure chamber, one of the piston elements having a port in connection with the pressure chamber, resilient means urging the piston elements apart to maintain said pressure chamber and a clearance between the heads of the fixed and movable piston elements to allow for action of the valve gear, a plunger having a valve portion for closing said port and adapted to engage the actuated member on the plunger closing side of said port, and a spring having one end fixed relative to the member having the liquid containing chamber and the other end engaging a part of the plunger to lift the plunger when a greater amount of clearance tends to form in the valve gear to allow liquid to flow through said port into the pressure chamber to take up slack upon reseating of the valve portion of the plunger.

References Cited in the file of this patent UNITED STATES PATENTS