US1977736A

US1977736A - Valve lifter mechanism

Info

Publication number: US1977736A
Application number: US654151A
Authority: US
Inventors: Theodore M Mueller
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-01-30
Filing date: 1933-01-30
Publication date: 1934-10-23
Anticipated expiration: 1951-10-23

Description

1934- T. M. MUELLER VALVE L IFTER MECHANISM INVENTOR.

nAA//////// Filed Jan. 50. 1935 miam $307 A ORNEY.

Patented Oct. 23, 1934 UNITED" STATES; psi-Ea OFFICE VALVE ur'ma mommies:

- Theodore M. Mueller, Pontiac, Mich.

Applicationlanunry 30, 1933, Serial No. 654,151

4 Claims. (01. 123 90) My invention'relates to improvements in a valve lifter mechanism in which hydraulic pressure is utilized for taking up tappet clearance to provide decreased noise of operation and the objects of my improvements are, first, to provide a valve lifter mechanism having a fluid valve mechanism located adjacent the lifted valve mechanism to decrease inertia forces exerted thereon; to provide a valve litter mechanism utilizing hydraulic pressure with means for efiectively sealing the valve lifter mechanism against leakage of the hydraulic medium; third, to provide a valve litter mechanism having a fluid valve actuated by a resilient member that will exert no thrust against the engine valve and its resilient actuating means; fourth, to provide a valve litter mechanism having a hydraulically actuated piston or cap member between the valve lifter mechanism and the engine valve mechanism; fifth, to provide a valve lii'ter mechanism having a flat or disc valve for controlling the flow of a hydraulic medium there.- with; sixth, to provide a valve litter mechanism having a hydraulically operated clearance take up, means connected with a source of hydraulic pressure only when the valve to be lifted is at or adjacent its closed position; seventh, to provide a valve litter mechanism having a hydraulically operated tappet clearance take up means from whichan amount of hydraulic medium is discharged, during the pressure or valve lifting stroke only, into the atmosphere outside of the valve lifter mechanism; and eighth, to provide a valve lifter mechanism containing a volume of hydraulic medium trapped or isolated from its source of supply.

I attain these objects by mechanism illustrated in the accompanying drawing, in which- Figure 1 is a vertical section 01 the valve lifter mechanism, together with an engine valve and its operating mechanism, in a closed position; Fig. 2,

' a vertical section of the valve litter mechanism,

together with the engine valve and its operating mechanism, in an open position; Fig. 3, a side elevation of the valve liiter mechanism as disclosed in Fig. 1 together with its valve liiter bracket; Fig. 4, a vertical section of my valve hit-- er mechanism adapted for use in an engine equipped with an overhead valve mechanism; .Fig. 5. a. side elevation of the member for limiting the movement of the hydraulic valve; and Fig. 6, an end elevation of the member disclosed in Fig. 5. I

Similar numerals refer to similar parts throughout the several views.

Theliiter plunger 1 is slldably mounted in the litter bracket 2 which is suitably mounted in the cylinder block 3 of anengine assembly, the cylinder block 3 being disclosed in partial section with the valve 4 having its stem 5 slidably mounted in the valve guide 6 which is pressed into the cylin'der block 3. The cylinder head 7 is suitably 'attachedto' the cylinder block 3 and thereby provides the combustion chamber 8 whichconnects with the valve passage 9 which is open and closed, relative to communication with the combustion chamber 8, by the valve 4.

The valve guide 6 may be provided with a portion extending into a conventional valve chamber or boxwhich surrounds and contains the valve lifter bracket-2 and the valve lifter mechanism. The valve guide 6 maybe provided with the shoulder 11 which may position the valve guide 6 in the cylinder 3 together with the retainer 10 there against, the retainer 10 further retaining and locating the upper end of the valve spring 13 concentrically with the valve guide 6.

The valve spring 12 is further secured in its operative position by the retainer member 13 which is retained by the members 14 which are constructed in halves to permit assembly in the shouldered portion 15 of the valve stem 5, the members 14 thus being secured to the valve stem 5 and absorbing the thrust of the valve spring 12 against the retainer member 13.

The above description of the conventional parts of an engine will aid in more clearly disclosing the essential features of,my valve lifter mechanism which is associated and operatively connected therewith. y

it is well known that the tappet clearance, necessarily incorporated in valve actuating mechanisms to accommodate the tendency of the engine valve and associated parts'to vary in their dimensions due to being subjected to varying temperatures, is the cause of objectionable noise in the operation of the valve mechanism of internal combustion engines as used in automotive ve- -'hicles and similar mechanisms.

Toeliminate objectionable noise and to assure 'quiet operation and efllcient control of the valve The lifter bracket 2 is provldedwith the pea-- sage 20 which communicates with the passage 18 of the connection 19 and the groove 21 which extends peripherally around the lifter plunger 1 and communicates with the passages 22 which further communicate with the chamber 16 of the lifter plunger 1, the groove 21 and the pasages 22 thus enabling the chamber 16 to always remain in communication with the passage 18 of the connection 19 in the closed position of the/engine valve 4, as disclosed in Fig. 1, even when the lifter plunger 1 oscillates about its axis as it will tend to in operation.

The chamber 18 is provided'with the threads 23, adjacent its open end, for, receiving the threaded end 24 of the adjusting screw 25 which is provided with the shoulder portion 23 for engaging a wrench.

The adjusting screw 25 is provided with the extension portion 27, adjacent its shoulder portion 26, the extension portion 2! being provided with the chamber 28 which communicates with the passage so which further communicates with the chamber 16 of the lifter plunger 1. 1

The inner end surface 29 of the chamber 2 forms a seat portion which is contacted by the fiat surface of the hydraulic valve 31, the passage 30 being thereby closed against. communication with the chamber 28 by the hydraulic valve 31 when maintained in contact with the surface 29 as hereinafter disclosed. The chamber 28 has an open end which is partially closed by the flange 32 of the member 33, the flange 32 being pressed or otherwise suitably secured in the open end of the chamber 28, so as to positioncthe inner end of the member 33 at a point adjacent the hydraulic valve 31, to permit the hydraulic valve 31 to raise from its seat contact on the surface 29 and allow the oil to be forced to flow under and around the hydraulic valve 31 into the chamber 28 as soon as thevalve a closes. I I

The hydraulic valve 31 will be preferably constructed of a fiat-disc 'of metal of sumcient size as to fit loosely in the chamber 28, the side wall surface of the chamber 28 and theinner end of the member 33 thus acting to maintain the hydraulic valve 31 in its proper position for opening and closing the passage 30.

' when the cam 34, of the camshaft 35, is in its closing position, relative to the engine valve 4, as disclosed in Fig. 1, the tappet clearance space 36 between the end surface of the extension portion 27 and the end surface of the chamber 37 of .the piston or cap member 38 is in communication with the chamber 28 by means of the passages or spaces 40 which are formed between the flatted sides 39 of the flange 32 of the member 33 and the inner side walls of the chamber 28 of the adjusting screw 25.. The piston 38 is movably mounted'on and extends over the end of the extension portion 27 of the adjusting screwllb enclosing the tappet clearance space 36, as disclosed in Fig. 1, and the piston 38 may be provided with the spherical surfacedl for contacting the end of the valve stem 5. when the engine and its valve lifter mechanism is operated at a very high rate of engine revolutions per minute, thc resilient member or spring 42 may be interposed between the hydraulic valve- 31 and the inner or under surface of the flange 32 to prevent the hydraulic valve 31 from being opened by inertia forces developed by ahigh rate of reciprocatim speed of the valve lifting mechanism.

It is also to be. noted that when the resilient member or spring 42, which may be of very light from the lubrication system of the engine through fills the tappet clearance 36 forcing the piston 41 weight and, tension, is used to counteract inertia forces acting on the hydraulic valve 31, no obv Jectionable resultant thrust loads or reactions are transmitted or added to the load of the valve spring 12 thus permitting the use of lighter weight valve springs than is the case where relatively heavy resilient members are used to control the operation of hydraulic valves in valve lift mechanisms.

Fig. 2, discloses the cam shaft 35, which may be suitably mounted, as having revolved to a point where the cam 34 is in an opening position relative to theengine valve 12, theoil which filled the tappet clearance space 36 having been displaced by the thrust of the valve lifter mechanism. the taking up of the clearance space 36 between the extension portion 2'7, of the adjusting screw 25, and the piston 38, tending to force some of the oil, in the tappet clearance space 36 out into the atmosphere in the valve chamber-or box enclosing the valve lifter mechanism, the oil being forced out between the outer surfaces of the extension portion 27 and the wall surfaces of the chamber 37 of the piston 38, the very slight amount of oil thus being forced out in the form of a light and almost invisible spray around the upper side of the shoulder portion 25 of the adjusting screw 25, as inclicatedby the arrows, at 44, in Fig. 2.

It is tobe noted that the groove 21 of the lifter plunger 1 is in alignment with the passage 20 of the lifter bracket 2 only when the lifter plunger 1 is in a position corresponding to the closed position of the engine valve 4 as disclosed in Fig. i in which position the oil is forced under pressure the conduit 17, the passage 18 of the connection 19, the passage 20 of the lifter bracket 2, and into the groove 21 of the lifter plunger 1 from where it passes through the passages 22 into the chamber 16 of the lifter plunger 1. From the chamber 16, the oil under pressure passes through the passage 30 and lifts the hydraulic valve 31 from its .seat and into contact with the end of the member 33, which limits the opening movement of the hydraulic valve 31, the oil passing under and around the hydraulic valve 31 and into the chamber 28 of the adjusting screw 25, the oil further passing through the passages 40 and into the tappet clearance space 38. The oil under pressure to raise and keep in contact with the lower end of the valve stem 5 andforms an-oil film between the flange 32 and the end wall surface of the chamber 37, the tappetclearance space 36 being enclolscd and sealed against leakage by the piston 88 being slidsbly or movably mounted with a good fit over the end of the extension portion 27. thus hydraulically taking up the tappet clearance spaceinthevalveliftingmcchanism. Assoonas the lifter plunger 1 is moved from its position in whichthcenginevalvc4is closed,asin1"ig. 1,to a position in which the engine valve 4 is balm opencd.asinl"k.2,thechamber ldanditsoonnecting passages and

chambers

30, 28, 40 and 36 become disconnected from the pressure line. of omam extension portion 27, the slight clearance space through which the oil is thus forced on the pressure stroke of the valve lifting mechanism also allowing for the escape of any air which may get into the connected chambers and passages of the valve lifting mechanism.

Thus it will be noted that my invention will provide a very efiicient and quietoperation of valve-lifter mechanism in which the hydraulic medium is retained without leakage in the valve lifter mechanism when the engine valve is in its open position thus resulting in no loss of oil pressure as registered on the oil pressure gauge connected with the engine and further only permits a very slight amount of oil to be displaced from the valve mechanism in the form of a light spray during the pressure stroke of the valve lifter mechanism.

The lock nut 52 is provided for locking the adjusting screw 25 in its adjusted position.

It is also to be noted that the piston 38 maybe constructed of very light-weight and bulk which will add substantially no inertia load to be absorbed by the valve spring 12, in high speed operation of an engine. Where it is desired to adapt my valve lifter mechanism to an engine equipped with overhead valves the adjusting screw mechanism is removed to a position adjacent the valves in the head and the lifter plunger 1, in Fig. 4, is provided with the passage 45 connecting with the chamber 28 which is formed in the extension portion 46 of, the lifter plunger 1,

the piston or cap member 47' slidably fitting over the end of the extension portion 46 in a manner similar to the piston 38 and the extension portion 27 of the adjusting nut 25 in Figaal and 2. The piston 4'? may be provided with the extension portion 48 having the chamber 49 for receiving the end of the push rod 50 which is operatively connected with the valve mechanism in the head of the engine.

The lifter plunger 1 is provided with the enlarged end 51 for engaging the cam 34.

It is to be understood that whereas a single valve lifter mechanism only is disclosed in the drawing, any member of valve lifter mechanisms may be connected with the oil pressure lubrication system of an engine and may be used with either inlet or exhaust engine valves.

Also it is to be understood that my invention may be adapted for use in mechanism, other than automotive units, where emcient control or quiet operation of tappet clearance means is desired.

It is also to be noted that the oil or other hydraulic medium which is trapped or isolated in the valve lifter mechanism of my invention forms a closed reservoir of oil which forms an absorbing cushion which will effectually dampen any tendency for noise between contacting surfaces without appreciable losses of the oil.

It is also to be understood that, when desired, the pistons 41 and 47 may be suitably mounted so as to extend within instead of extending over the outside of the portions 3'7.

I claim:

1. In a valve lifter mechanism, the combination of a litter member provided with a chamber having an open end adjacent the valve to be lifted, a fixed member suitably secured in the chamber of said lifter member, said fixed member having a portion extending to a point adjacent the other of the ends of said chamber, a valve suitably mounted to-open and close said other end of said chamber, said valve being contacted by said portion of said fixed member to limitthe opening movement of said valve, a piston member slidably mounted on the outside of said lifter member to form a clearance space between the end surfaces of said lifter and said fixed members and the inner surface of said piston member, said piston member engaging the valve to be lifted, and means providing communication between said clearance space and said chamber of said lifter member.

2. In a valve lifter mechanism, the combination of a litter plunger provided with a chamber, a fixed member suitably secured in said chamber, said fixed member having a flange portion for partially closing one end of said chamber, said fixed member having an extension .portion, a

valve member movably mounted to open and close the other end of said chamber, said valve member contacting the extension portion of said fixed member at the end of its opening movement, a resilient member surrounding the extension portion of said fixed member and opposing the opening movement of said valve member, and a pis-.

ton member slidably mounted on the outside of said lifter member, said piston member engaging the valve to'be lifted.

3. In a lifter mechanism for an engine valve, the combination of a valve lifter member provided with a chamber having openings at its ends, a piston member for closing one of the ends of said chamber, said piston member being mounted over the end of said valve lifter member and contacting the engine valve, .said valve lifter member and said piston member forming a tappet clearance space therebetween, a valve member mounted in and adapted to close the other end of said chamber, means for supplying hydraulic medium under pressure to said chamber during a portion only of the lifting movement of said valve lifter member, a member-fixedly mounted in said chamber and provided with a flange partially closing one of the ends of said chamber together with'an extension portion extending from said fiange to contact said valve member in said chamber to limit its lifting movement,

and resilient means for facilitating the closing of said valve member in said chamber, said resilient means being mounted around the extension of said valve member in said chamber.

4. In a valve lifter mechanism, the combination of a member provided with a chamber, means for supplying hydraulic medium under pressure to said chamber, a valve member suitably mounted in said chamber and controlling the flow of the hydraulic medium thereinto, said valve member loosely fitting within said chamber to permit said valve member to be guided in its movement by the walls of said chamber, a fixed member provided with a flange for partially closing one end of the chamber of said first mentioned member, said fixed member being provided with an extension portion for contacting said valve member to limit its opening move- THEODORE M. MUELLER.