US2682864A - Valve lifter - Google Patents

Description

July 6, 1954' c. vooRHlEs 2,682,864

VALVE LIFTER Filed May 8, 1952 2 sheets-sheet 1 @en for C22/7? Vr es "f @M (am.

July 6, 1954 C. VOORHI'ES VALVE LIFTER 2 Sheets-Sheet 2 Filed May 8, 1952 Fey? Patented July 6, 1954 UNITED: STATES TENT D'FFICE VALVE LIFTER Carl Voorhies, Park Ridge, Ill.

Application May 8, 1952, Serial No. 286,845

(Cl. 12B- 90) 15 Claims.

This invention relates toa valve lifter or a tappet of the. hydraulic type and it includes a housing or barrel within which is mounted a plunger. A pushV rod contacts the plunger. Means areprovided'ior relative movement under controlled conditions of the plunger with respect to the tappet barrel or housing.

On'e: object of the invention is to provide means for controlling the relative movement of thelplunger and barrel portion of the tappet.

Another object is to provide a member of the general type indicated in which the valve parts within the tappet are of sulcient strength to act as their own stop members.

Another object is to provide a plunger of sturdy construction, a valve of sturdy construction, and a valve retainer of simple and sturdy construction by means of which the movement of iiuid in the desired direction Within the tappet or valve lifter is. positively and properly controlled.

Othern objects will appear from time to time in the course of the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

Fig. 1. is aplan view of one end of the tappet with the push rod in section;

Fig. 2 is a longitudinal section thru the tappet;

Fig; 3 is a transverse section taken at line 3, 3 of Fig. 2;

Fig. 4' is a side elevation of the valve retainer removed from the tappet; and

Fig. 5 is a section through a slightly modiiiedr form ofthe device;

Fig; 6 is a sideelevation of a modified form of spring;

Fig. is a longitudinal section showing a modied form of plunger.

Like parts are designated by like characters throughout the specification and drawings.

I' indicates a cylinder block or other means for guidingl and supporting a tappet or valve lifter. 2 is' a liner which may or may not be used. 3 indicatesa barrel portion, generally cylindrical, of. the tappet. It is provided with the. closed and integral portion 4; the outer face 5 of which is arranged to contact the cam 6 which is carried ena cam shaft 'I'. 3 is a plunger mounted within the barrel 3 of the tappet and in contact with the inner surface of the barrel. 9' is a snap ring positioned within a groove Ii! on the inner face of thefbarrel 3. IIhe snap ring is positioned to prevent accidental separation or dislodgement of the plunger from the'. tappet barrel. i! is a fluid duct through'which fluidisV supplied to the space Izffrom-which a perforation or passage I3 leads to the; inner faceof the liner 2. The plunger portion? 3 isprovided with an external annular groove or depression I d from which a'perforation I5 leads to the inner surface ofthe cylindrical portion 3 of the tappet barrel.

The plunger S isfprovided in its upper or outer end with a generally hemispherical depression or socket I6'. From this. socket a perforation I'I leadsto-an enlarged perforation or cavity It; The' cavity I8 extends to the inner end of the plunger. That is to say, the cavity It extends in thedirection of'the closedend-fl of the' tappet and the cavity Isis opened at its innerk end. An

annular' groove or depression I9- extends about thev plunger- 8 and may be in communication with the passage I5. A perforation 20' extends' from the groove I9 to^ the cavity I8. The plunger 8 is reduced adjacent its lower or open end as at 2| and thus ashoulder 22 is provided. A valve retainer 23'is positioned over they reduced portion 2l and is provided with a'laterally directed flange The- Z which is seated against theshoulder 22. valve'retainer is also providedat itsV opposite end with an inwardly'directed flange 25V and it is provided* in its walll with a; pluralityV of perforations Zt.

la;A valve '21 of substantial thickness is positioned within thevalve retainerl 23. It may bear at one end-against the reduced portion ZI of the plunger' S andis adaptedV to close the'lower end of the cavity I 8: The valve is retained against displacement by the inwardly directed flange 250i? the valveretainerrzti- The Valve portion or member 2'I is provided with an outwardly directed' generally central enlargement 2% which is ofsuch height or'thickness that' it' extends beyond the inwardly bent ange 250i the valve retainer 23 member 4. At the other end it bears upon the flange' 24 ofi the valve retainer 23' and in eiiect thusf exerts a pressure against the shoulder 22 of' the plunger' 8;

The'plungeril is, to all intents and purposes,

the same as the plungerA 3v in its action, excepty that it is apertured att-2; The operation is other'- Wise thefsame', and the arrangements of parts, to all intents and purposes, are the same.

.Althoughfll havey shown. an operative form of my invention, it will; bev recognized that many changes in the forni',` shape and arrangement of parts`v can bemadewithout departing` from the spirit of the invention, and my showing is, therefore, to be taken as, in a sense, diagrammatic.

In particular, the spring arrangement shown in Figures 2 and 5 might be modified by the use of the spring shown in Figure 6.

As shown in Figure 6 a spring 30 appears. This spring might be substituted for the spring 29 of the earlier figures. This spring is so shaped that certain of its coils throughout that portion of its length indicated at in Figure 6 are initially closer wound or shaped than are the other coils as indicated at y in Figure 6. The coils indicated in the area or length marked as may be considered as dampener coils and the functioning of this spring, when inserted for example, in the structure of Figure 2 will be described below in the general description of use and operation of the device.

As shown in Figure 7, the plunger is generally the same as shown in Figure 2, except that it is formed of two pieces; otherwise, the structure of Figure 7 is identical with that of Figure 2. The same reference numerals are used in both figures where the parts are identical, and identical parts will not be re-described in connection with Figure 7.

The plunger of Figure 7 comprises one part 83, reduced at 84 and provided with a wall of generally cylindrical shape 85; a shoulder 22 identical with the shoulder 22 of Figure 2 is formed by the reduced portion 84.

A second portion of the plunger comprises the member 86, reduced at 81 and provided with a perforation 88. An opening 89 is provided from the interior of the composite or two-part plunger to the spherical bearing portion 90. The reduced portion 81 provides a chamber or cavity 9 I. The two-part plunger functions at times identically with the unitary plunger of Figure 2. At other times, as will be described below, the two parts, 83 and 86, have or may have relative movement. The wall 85 corresponds generally to the wall I8 in the center of the plunger of Figure 2. The perforation or passage 88 corresponds to the passage 2 of the earlier figure, and the chamber 9i corresponds to the chamber I9 of the earlier iigure.

The use and operation of this invention are as follows:

The primary differences between the devices of Figures 2 and 5 is that in Figure 2 the oil under pressure from the engine lubricating system enters through the duct I I, the groove I2, the duct I3, the duct I5, the first supply chamber I9 where the oil is, to some extent at least, aerated, then through the duct 20 to the second oil supply chamber which is filled with substantially airfree oil. The ball and socket at IG is lubricated by oil reaching the ball through the duct I'I. Oil also passes down across the valve 2'I through. the ports 26 into the chamber below the end of the plunger until that chamber is substantially lled with oil, as pressure is applied between the cam and the ball I6 tending to compress the spring 29. The oil trapped below the valve 26 is unable to escape so there is a positive compression drive connection between the cam and the connecting rod. The valve 2T, with its extension 28, limits the bottoming eifect of the plunger 8.

The situation is much the same with regard to Figure 5. There the oil enters from above the plunger 8| through the ports 82, after which the passage of and operation of the oil is exactly the same as in connection with Figure 2.

The purpose of both of these arrangements iS to provide hydraulic means for taking up the slack between the cam and the push rod so as to provide silent valve operation as is characteristic of all hydraulic valve tappets heretofore used. The arrangement is a comparatively simple and inexpensive one. The plunger 8 or 8! provides inside its body an oil supply chamber wherein substantially air-free oil is found. Of course, if the oil is not air free it will do no good in providing a solid oil mass to transmit the valve actuating pressure because the air would yield and the rigidity of the hydraulic connection would be lost. Then, in each case, the oil enters the tappet area through the first supply chamber. The movement of the plunger 8 or 8|, and the supply of oil to the outside of this moving plunger will, of course, result in a certain amount of aeration in the oil. The fact that the passage between the first and second supply chamber in each case is at right angles to the length of the cavity I8 baiiles and limits oil surge. In other words, the back-and-forth movement of the mass of oil in the cavity I8 does not necessarily tend to expel oil, or at least the tendency to expel oil is baled and reduced to a minimum by the right-angle relationship between the cavity I8 and the passage 20.

The flattened portion of the spring I0 extendingr across the path of the plunger in each case insures against accidental loss of the plunger during assembly or in storage.

This arrangement provides a rugged design of hydraulic valve tappet, the valve closing the port at the bottom of the supply chamber in the plunger being sufliciently rugged and so placed as to limit bottoming of the plunger in the chamber when hydraulic fluid in the high pressure chamber below the valve is insuflicient to keep the plunger and valve above the bottom of the tappet cylinder.

Attention is called to the fact that the valve cage is a stamping held in place on the plunger by the spring within the high pressure chamber and so disposed that since the apertures in the stamping are intersected by the meeting planes of the valve and plunger a venturi action is provided, thus obviating the necessity of maintaining the valve in close proximity to the seat.

The drilled hole in the lower end of the plunger closed by the valve makes it possible to provide a ball and socket connection between the plunger and the connecting rod wherein the socket portion of the connection is integral with and not separate from the plunger.

The use and operation of this device are as follows:

When the spring 36 of Figure 6 is substituted for the spring 29 of Figure 2, a somewhat different action takes place during the operation of the device. The action of the spring of Figure 6 can be best described by reviewing the action of Figure 2 when the spring 29 is in place. When oil pressure is delivered through the passage I5 the upper and lower surfaces of the oil reservoir or chamber I9 are acted upon by the oil pressure equally, and the forces in this chamber are thus balanced.

When the oil enters through the passage 20, however, and moves into the chamber I8, the oil is then acting on the upper end of the chamber I8 and is acting equally on the valve 2'I at the bottom of that chamber and thus the oil pressure tends to move the valve open and to create a balanced pressure at this point. When, however, the valve 2'I is open, pressure is delivered through the open valve to the lower chamber aeszgeee below the-valveandbelow the lower end ofthe plunger illandthis pressure acts onan area equal to the outsider ciY theV plunger {1l-"minus: the area of the chamber I8.

It'acts ina-'direction tov push the plunger 8 out towards the open end ofthe cylinder 3. From this; it results that in operation the oil pressure within the cylinder' 3, and eiiective against the plunger 8; constantlyl tends to urge the plunger'y outwardftoward the open end of the cylinder and thusf alighter springA ZS'is required.

Asl the total ofthe :force of the oil and the iorce of' the spring becomes greater than the inertia force of lthel cylinder itself pump-up will occur andA will produce unsatisfactory performance.

When theel-igiene is stopped, the valve lifter leaks down completely to thev point at which the check' valve 21 rests `upon the bottom of the cylinder Si.l With the parts in this position when the engine is started, very often sticking of the plu-nger'l will occur 'and-a, relatively heavy spring is required to break or force the plunger loose in the cylinder in order to carry the valve lifted intoproperposition for operation without waitm ing for oil pressure to be delivered in suicient quantity. If the'spring action available is not sufficient toaccomplishv thisv movement of the plunger 8 within the cylinder 3, a noticeable starting noise may result.

It is one of the objects of the spring 30 as show-n in Figure to accomplish this result. In the spring 3@ a part of the coils is wound close together` and a part of the coils is spaced farther apart. This construction is indicated in the portions marked and y in Figure 6. When this spring is extended to the operating position, all of the coils are active and the rate of the spring is relatively low. Thus a very light load can be provided for the normal operating position.

When the engine is stopped and the valve lifter is in the position with the engine valve closed so that the valve 28 is resting on the bottom face of the cylinder 4, the coils ofthe spring indicated at rc are closedone against the other reducing the'spring to a lessernumber of coils indicated by y 'so that the rate of the spring is increased. The position of the plunger at which the coilsv indicated by ac reach the closed position is somewhat above the bottomed position of the valvek 28 so that for starting the engine a greater' spring load is provided for. breaking the plunger loose withcuthaving. excessively high spring load for the normal operation position.

The construction of the modified or two-part' plunger illustrated in Figure '7 may also be used' to solve the same problem of. oil pressure upon the plunger as discussed. above in connection withv the discussion of the action of the. spring 3B. When the plunger is made in the two parts, BSand 8E, the forcesacting on the plunger are balanced and the tendency of the oil pressure to push the plunger out of the cylinder is neutralized. Thus a heavier and more conventional spring as shown in Figures-2Y and 4 maybe usedsuccessfully. The spring design of Figure 6 and the two-part plunger design of Figure '7 are thus in a sense toA be considered as two solutions of the same problem. Under present conditions, the spring design' of Figure:` 6 is probably. preferable for reasons of economy.

I claim:

1. In' a hydraulic valve tappet, a hollow cylindricalbarrel open-at one end, a; plunger mounted for reciprocation therein, yielding means biasing saidIpllungen'awayg fromitlie bottom of? saidbarrel, thereA being? an"4 oili supply chamber associated with? theiupperl end'. of said plunger, a secondoil supply cl'iamlnervv within said plunger open. at its lower end; an-oild'uct between the two chambers perpendicular tothe' axis of said second chamber, a--valve` member: closing the lower end. of said second chamber; andfa` cage adapted to limit verticalandlhorizontal movement of said'valve member, said valve member having: an element extending' downwardly through saidcage tol bottom onf the.: bottomof said barrel.

2.'.Ena-lrydrau-li'e valve tappet, a hollow cylind'i-ieal'rbarrelopen at one end, a plunger mounted for.reciprocationthereing and yielding means biasin'gi said-plungeraway from the bottom of said barrel; there being. an oil supply chamber associatedfwithithe upper' endv of said plunger, a second'oil'supplychamber within said plunger open atitsf lower end,- an oil' duct between the two Chambers perpendicular to the axis of said second chamber, a valvemember' closing the lower endv of said secondl chamber, a valve-retaining cage adaptedgenerally to surround and hold said valve member in register with said chamber, said-cagebei-'ng general-lycup-shaped and having a generallycentrally apertured` bottom wall, said valve n'ieml'aer3 hav-ingan element1 extending downwrdly throughsaid-apertured'bottom cage wall to bottom onthe bottom of said barrel.

3'. In a--hydraulic valve tappet, a hollow cylin, drica-l barrel open at one end, a plunger mounted for reciprocationv therein, and yielding means biasing saidplunger away from the bottom of said i' barrel, there being an oil supply chamber associated withk thefupper end of said plunger, a second-oil supplyclia-mber within said plunger open at its lower end, an oil duct between the two chambers perpendicular to the axis of said secondV chamber', a valvemember closing the lower end ofsaid second'chamber, said valve member havinganelement extending downwardly to bottom-on the bottom of said barrel, and a valveretairring-fcage-associated' with said plunger, said cage having a flange portion extending inwardly benen-tha portion ofl said Valve member to hold said valveinworking relationwith the end of sai-d plunger.

4. In a hydraulicv valve tappet, a hollow cylindrical-barrel open at one end, a-plunger mounted for` reciprocation therein, and yielding means biasing said plunger away from the closed end ofsaid barrell there being an oil supply chamber associatedwith the upper end of said plunger, a second oil suppy chamber within said plunger. open at-its lower end, an oil duct between the two chambers perpendiculark to the axis of'said second chamber, a valve member closing the lower end of said second chamber, a valve-retaining cage havingportionslin contact with said valve member to limit vertical and horizontal displacement thereof and to hold said valve member in register with' saidchamber, said valve member having an element extending downwardly to bottomy on the bottom-ofsaid barrel, and said cage associa-ted'wi-thsaid'plunger adapted to hold said valve in working relation-with the end of said plunger.

5i Invafhyd-raulic'valve tappet, a hollow cylindri'eal-fbarrelopen atene end, a plunger mounted for reciprocation therein, there being an oil supply chamber associated with the upper end of s-aidplunger', a1 second oil-supply chamberv within said prl-unger vopen-at5 itslower end, an oil duct be-A tween the. two chambers perpendicular to the axis of said second chamber, a valve member closing the lower end of said second chamber, a cage adapted to hold said valve member in register with said chamber, said valve member having an element extending downwardly to bottom on the bottom of said barrel, said cage associated with said plunger adapted to hold said valve in working relation with the end of said plunger, and yielding means adapted to hold said cage against said plunger.

6. In a hydraulic valve lifter, a hollow cylindrical barrel closed at the bottom and open at the top, a plunger mounted for reciprocal movement therein, and yielding means biasing said plunger away from the closed end of said rbarrel, a hydraulic chamber in said plunger open at the bottom, adapted to receive liquid, a thin metallic valve cage encircling the bottom of said plunger and extending therebelow, and a valve plate held by said cage adapted to move therein toward and from the end of Said plunger and limited in its outward movement by said cage.

7. In a hydraulic valve lifter, a hollow cylindrical barrel closed at the bottom and open at the top, a plunger mounted for reciprocal movement therein, a hydraulic chamber in said plunger open at the bottom, adapted to receive liquid, a thin metallic valve cage encircling the bottom of said plunger and extending therebelow, a valve plate held by said cage adapted to move therein toward and from the end of said plunger and limited in its outward movement by said cage, and yielding means between said cage and the bottom of said barrel biasing said valve cage against said plunger.

8. In a hydraulic valve lifter, a hollow cylindrical barrel closed at the bottom and open at the top, a plunger mounted for reciprocal movement therein, a hydraulic chamber in said plunger open at the bottom, adapted to receive liquid, a thin metallic valve cage encircling the bottom of said plunger and extending therebelow, a Valve plate held by said cage adapted to move therein toward and from the end of said plunger, and yielding means between said cage and the bottom of said barrel biasing said valve cage against said plunger, said valve having a boss projecting downwardly below said valve cage adapted to engage the bottom of said barrel.

9. In a hydraulic vave tappct, a plunger, and yielding Imeans biasing it in one direction in said tappet, a connecting rod, a ball and socket connection between them, the socket portion of the connection being integral with the plunger, the plunger being longitudinally apertured and open at the end opposite to the ball and socket, a valve in opposition to said open end, and below the bottom of said plunger, said valve member having an element extending downwardly to bottom on the bottom of said barrel, the plunger and tappet together forming a pressure chamber for hydraulic liquid and valve-retaining means mounted on said plunger for movement therewith, said valve-retaining means including a portion underlying at least a portion of said valve to limit vertical separation between said plunger and said valve.

l0. In a hydraulic valve lifter, a hollow plunger adapted to receive hydraulic liquid and having an open end, and yielding means biasing said plunger in one direction in said valve lifter a valve adapted to close the open end of the plunger, the valve and plunger having mating surfaces generally perpendicular to the direction of movement toward and from the plunger, a

8 stamped valve cage encircling the plunger adapted to hold the valve in working relation therewith, a part of said valve extending beyond said cage.

11. In a hydraulic valve lifter, a hollow cylindrical barrel closed at the bottom and open at the top, a plunger mounted for reciprocal movement therein, and yielding means biasing said plunger in one direction in said valve lifter, a hydraulic chamber in said plunger open at the bottom, and a pressure chamber within said barrel and below said plunger, the two chambers being adapted to receive hydraulic liquid, a thin metallic valve cage encircling the bottom of said plunger and extending therebelow, a valve plate held by said cage adapted to move therein toward and from the end of said plunger and limited in its outward movement by said cage, and yielding means between said cage and the bottom o said barrel biasing said valve cage against said plunger, said yielding means comprising a dual rate spring.

12. In a hydraulic tappet a cylindrical member, means for supplying liquid to said cylindrical member, a plunger mounted therein for movement and a dual rate spring positioned to act upon said members and biased to give them relative longitudinal movement.

13. In combination in a hydraulic tappet, a cylinder and a plunger mounted therein for longitudinal relative movement with respect thereto and forming therewith a pressure chamber for hydraulic liquid, a passage communicative with the said pressure chamber and a check valve mounted to close said passage, a dual rate spring biased `to move said plunger with respect to said cylindrical member.

14. In a hydraulic valve lifter, a hollow cylinder closed at one end, a plunger mounted for relative reciprocation within said cylinder, a spring interposed between said plunger and said cylinder and biased to urge said plunger away from the closed end of said cylinder, means within the plunger deiining a passage to the area within said cylinder, a check valve for said passage, said check valve member having an element extending downwardly to bottom 0n the bottom of said cylinder and means for positioning said check valve with relation to said plunger including a generally cup-shaped member mounted for movement with said plunger, said cup-shaped member having a portion underlying at least a portion of said valve to limit the movement of said valve downwardly from said plunger, said valve positioning means being urged against said plunger by said spring.

15. The structure of claim 14 characterized by and including passage means in the wall of said valve positioning means, said passage means placing the area within said valve positioning means in communication with the area within said cylinder.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,798,938 Hallett Mar. 31, 1931 2,109,815 Best Mar. l, 1938 2,203,952 Eshbaugh June 1l, 1940 2,645,215 Moser July 14, 1953 FOREIGN PATENTS Number Country Date 988,202 France Apr. 25, 1951

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