US2573082A - Oil control device for rocker arms - Google Patents

Description

Oct. 30, 1951 J. R. WINTER, JR

OIL CONTROL DEVICE FOR ROCKER ARMS Filed Feb. 24, 1949 IN V EN TOR.

' Patented Oct. 30, 1951 UNITED STATES PATENT OFFICE A 2,573,082 r OIL CONTROL DEVICE FOR ROCKER ARMS John R. Winter, Jr., Detroit, Mich., assignor, by direct and 'mesne assignments, to John R. Winter, Sr., Detroit, Mich.

Application February 24, 1949, Serial No. 78,217

8 Claims.

The present invention relates to rocker arm mechanisms such as are employed as a part of the valve actuating means of internal combustion engines of the Overhead valve type. The invention is particularly concerned with the controlled delivery of lubricant to the tappet-and push rod bearing ends of such rocker arms.

In overhead valve engines of the type wherein the cam shaft which actuates the valves is journaled in the engine block, the cam shaft acts stems is necessary; any over-lubrication results in wastage of oil and excessive oil consumption.

For various reasons, some of which will be considered herein, such over-lubrication has been difficult to prevent. succinctly stated, it is the primary object of this invention to provide simple, inexpensive and reliable means for preventing such over-lubrication, while insuring an adequate supply of lubricant to the ends of rocker arms and to the associated valve stems and push rods.

It is now most common to provide forced feed lubrication to the rocker arm bearings by way of an oil passage in the rocker shaft, interconnected passages being formed in the rocker arms for conducting the oil to the ends of the rocker arm. The difficulty involved in the delivery of acontrolled quantity of lubricating oil to the tappet end of the rocker arm and. the valve stem is aggravated by the fact that any excess oil which finds it way to this end of the arm tends to be sucked into the cylinder along the valve stem during the intake stroke of the piston, particularly after wear has occurred between the valve stems and their guide bearings.

The most successful method thus far devised for providing accurately metered-lubrication of rocker arm tappet bearings, valve stems, and push rods has been to provide lubricant conducting means of very restricted capacity but which is open to atmosphere, extending along the top edges of the rocker arm. One such system is disclosed in my copending application Serial No. 560,532, filed-October 27, 1944, now Patent Number 2,509,661. Another such system is disclosed in OHarrow Patent No. 2,288,831. While such systems effect. a great improvement and provide 2 efiicient oil control under ideal conditions, the effectiveness of control is not always complete,

particularly under high speed operation when the oil viscosity is low. Moreover, the effectiveness of such control diminishes as the engine becomes worn. Especially after wear has occurred between the rocker arm bearing and shaft, but

sometimes even in new engines, high speed operation causes oil to be discharged in the form of a jet from the top oil ports of rocker arms of the indicated types. This is highly undesirable because, due to the rapid reciprocatory movement I of the arm, some of the oil thrown in such jet discharge strikes the valve end of the rocker arm, or strikes and floods other parts of the rocker arms and is thereby thrown about inside the engine head cover. Excess oil is thereby delivered to the valve stems, whence it is drawn into the cylinder and burned, the oil consumption of the engine being thereby increased.

This undesirable jetting of oil is apparently due to a pumping action which creates instantaneous high pressures in the oiling system and which is the result of clearance between the rocker shaft and the rocker arm bearing. When the push rod descends, if undue clearance has developed between the rocker arm bearing and rock shaft, the push rod allows the rocker arm to drop on the shaft so that all such clearance is at thebottom, which is in the area of a part of the oil porting which connects the passages in the arm to the passage in the shaft. The

tappet at the other end of the rocker arm is held up by the valve springacting through the valve stem, and when the rocker arm drops to the extent permitted by the bearing clearance,

an increased quantity of oil is forced into the clearance space by the forced feed oiling system.

- When the push rod thereafter ascends, its first act is to lift the rocker arm, rocking it slightly about the tappet end to take up such clearance. Since this movement is very rapid, some of the oil which has accumulated in the bottom of the rocker arm bearing is forced upwardly through V the passages in the rocker arm and out through rocker arm, and adequate lubrication maintained.

In my copending application Serial No. 582,039 filed March 10, 1945, now "Patent ,Number 2,523,489, I have disclosed an improvedrocker arm construction which isalso capablecof overcoming the aforementioned difficulties, butthe upward jet discharge is of a relativelycostlyionepiece construction, and would of course have to be installed as replacement equipment'in order to correct the difiiculty in existing engines.

Another-object of the;present 'invention, therefore, is to provide, oil control means of the indicated characteradapted for installation uponthe rocker arms of engines ,in service without the necessity'of changing therocker arms or dis mantling any of the other working parts of the engine.

Still another object is to provide such oil control means in 1 the form of simple, inexpensive .sheet metal. clips, so constructed that they may be very easily and quickly installed upon the "rockenarms'of existing engines, merely by re- "movife the .e.ngine head cover and sliding the -ti-vely, of Figureland lookinginithe direction of the arrows;

'Figure isa=perspective view of one'ofmy improved oil control clips; and

. Figure 6 is re sectionalelevation -.taken substantiallyon the lineiG-eii of Figure-.2, andlookingdn-theadirection of the. arrows.

Referring' .-now Ltd the drawing, reference character LU fdesignates generally the-body-portion, of

-.a rocker .arm I constructed-in. general accordance ewithstheadisclosure of .:my, copending application =-SerialNo.-;56.0;532labovementioned. It will be .appreciatedthat the details of-construction of the trockerar-m itself..,-may:-be varied widely without departing from the: present invention, however. By way of example but not of limitation, it will be appreciated that ;.the ,oilwcontrol means of the present. invention is-eq-ually applicable to rocker arms.such-.as;,are shown in patents, Nos. 2,288,831

:and "2,176,083.

xRo'cker..-arms of;,the;general classindicated are provided with a -generally vertically extending oil :deliverypassage'asgl2;.through which oil is dis- -zcharged'into the space directlyabove therocker ar-m.

Iihave determined that .for best operation the oilshould fiowupwardly from-the mouth .ofopening l2 withoutrjettingtherefrom. ,In the :rockenarm construction shown,:the arm itself is dorrnedzof .aisinglepiece:ofsheet metal folded to iform:tw o:laminae.secured-together by suitable means such as by spot welding, as indicated at l4. Along their upper edges, the two laminae, considered cross sectionally, are inclined downwardly toward their central plane of juncture to define a shallow trough-like channel l5 for con- 5 veying oil to the opposite ends of the arm. The slight inclination which defines this channel may be formed by the unavoidable drawing of the metal which occurs during the stamping of the arms, as disclosed in my copending application serial No. 560,532,

In the area immediately adjacent the oil riser hole; 2,;a notchlikadepression 3D is formed, which extends completely across both laminations of the arm, constituting in efiect a transverse slot.

11:5 JBetween this-.slot-and the channeled portions l5 arm therein shown which is arranged to prevent leading to opposite ends of the arm are upstand- -ing-earsase3l'uwhich are bent outwardly away ,from-pne another to a slight angular divergence.

A narrow V-shaped channel 33, 33' of restricted cross-sectional area is thereby formed connecting the transversely slotted 'area 38 with the oil- "conducting channels l5. The 'ears "3| par-tially dam the oil, tendingto prevent-the flow -of--oil, except in limited-' quantities, -toward the ends of the: arm. "Itwill be-appreciated that by spreading the-earsfartherapart or moving them "-toward one another, the'capacity of-the channels betweenthem-maybevaried, all as 'more fully explained in "my previously filed applications .above referred to. Only'a limi ted quantity-of oil is'thus conveyed'along-the topof the arm to its ends. The excess oil is allowed to escape-through the opensidesof theilslotted; portion 3|. Another method'of controlling the'quantity of oil delivered ftothe ends of the, arm isbyreducing the width offthe top edge of the arm, as suggested; for example, in Patent "No. 2,288,831. 'Ihe point to be observed here,'however," is that neither of these methods of controlling the;quantity of oil-which 40 can flow along. the top of "the armis successful in preventing over-.oilingat the valveend due to the throwingotoil resulting'from the'jet-like dischargefromjthe oil riser. hole I 2.

iInaccordance with the present invention, I provide .aclip-likejcover,adaptedto be secured .to the. arm in su'chmanner that a bailling portion 20, -shown.;as substantially flat, extends transversely across and spacedly above the upper end vof. theoil riser .hole l2. The clip, which is inte- 5U .grallyfformedof sheet'metal,.is provided .with .,.four fric.tionally,, grippir 1g leg portions "as l6, .adapted Lto embrace. and bear inwardly against oppositersides of ,thelarm to .h0ld.the'c1ip-in position.

.Thertops-bafiling portion of the clip, which is generally rectangular whenviewed in, plan, 'preventso'il from squirting into the airabove'the arm. -Atboth ends.' of thebaffling portion/are zdownwardly .sloping control dam portions 122 -.f01m8d, as .continuationsof the ,portion 20, and v inclined downwardly to. such. extent that at' their extreme ends -transverseeedges. 24 are formed whichlie closely .adjacent the .upper, edge of'the .-.ar-m-.-and coact .with thelchannel [5- to define a Giyrestrictedbrifice through which only a limited quantity of oil will pass. I

:It willbe noted thatthecentral bafiie portion :20 is -so positioned. .as .to be substantially spaced -above;the mouth of the 0il..*h0le. l,2. With the .rocker arm construction shown, such space is automatically providedby the transverse slot30.

-A pair of deflecting portions 25 .extend angu- .1arly downwardly and outwardlyirom opposite ,sides. ofthew baillingportion 20 and are'substantially spaced from the sides of the arm, so'that substantial clearance is provided, affording side escape passages 26 of substantial cross-sectional area extending outwardly and downwardly from the space beneath the baflling portion 20, to permit free flow of excess oil to either side. Such laterally discharging passages 26 prevent the development of substantial pressures in the space 1 above -the arm and beneath the bafiie sectionZD.

By virtue of the provision of such vents of 'substantial size, the pressures in the aforementioned space 30 beneath the baffle cannot rise to a value which would cause the oil to squirt longitudinally along the top of the arm and beneath the end portions 24 of the clip.

It will be appreciated that the clip therefore not only prevents the discharge of the il jet in a direction which would permit it to be thrown or sprayed upwardly, but quickly relieves the pressure in the space under the bafile portion 20 and above the oil hole, thereby preventing squirting of the oil toward the valve stem along the top of the arm.

The deflecting portions may be of generally inverted channel form. Where the rocker arm is one having a transverse top slot such as the slot in the illustrated rocker arm, the deflecting channel portions 25 are preferably slightly narrower than the slot, so that near their upper ends the downturned side webs 28 of the deflecting channels may project into the transverse slot 30 to serve as locating means, preventing longitudinal displacement of the clip along the top of the rocker arm. The lower edges of the channel side webs 28 also tend to prevent the deflecting portions frombeing bent downwardly, although the clips are preferably formed of spring steel and hardened, so that such distortion is not likely to occur.

It has been found that with the use of oil control clips constructed in accordance with the present invention, substantial savings can be effected in the oil consumption of engines of the indicated type, even though the valve actuating mechanism is badly worn.

While it will be apparent that the preferred embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. An oil control device for rocker arms of the type having an oil riser hole terminating at its upper end at an upper edge of the arm in a discharge orifice having an upwardly opening mouth, said device comprising a bafile portion, fastening means for securing said device upon an arm with the baflie portion extending transversely over and spacedly above said mouth in position to intercept oil discharged from the mouth in the form of a jet r surge, oil diverting portions carried by said baflie portion and directed laterally away from the sides thereof, spacing portions for maintaining a substantial clearance between said diverting portions and the lateral parts of an arm to which the device is attached, and supplemental bafiling portions coacting with the ends of said first mentioned bafile portion and extending transversely and downwardly therefrom, whereby said supplemental bafiling portions may extend transversely with respect to such an arm and into close proximity to the top of the arm at two spaced positions between said mouth and the ends of the arm.

. .2. In; combination'with a rocker arm of the type having an oil riser hole terminating at its upper end at an upper edge Of the arm in a discharge orificewith an upwardly opening mouth, an oil control device comprising a bafiie portion,

. fastening means carried by said baflle portion and extending therefrom in a direction generally perpendicular to the plane of said baffle portion for securing said device upon an arm withthe baflle portion extending transversely over and spacedly above said .mouth in position to intercept oil discharged from the mouth in the form of a jet or surge, and a supplemental bafiling portion coacting with an end of said first mentioned baflle portion and extending transversely and downwardly therefrom in the same general direction as said first-mentioned bafiie portion, whereby said supplemental baflling portion extends transversely with respect to the arm and into close proximity to the top of the arm in a position between said mouth and an end of the arm.

3. In combination with a rocker arm of the type having an oil riser hole terminating at its upper end at an upper edge of the arm in a discharge orifice with an upwardly opening mouth, an oil control device comprising a bafile portion, fastening means carried by said baflle portion and extending therefrom in a direction generally perpendicular to the plane of said baflie portion for securing said device upon an arm with the baffle portion extending transversely over and spacedly above said mouth in position to intercept oil discharged from the mouth in the form of a jet or surge, and a supplemental dam portion coacting with an end of said first mentioned bafile portion and extending transversely and downwardly therefrom in the same general direction as said first-mentioned bafiie portion, whereby said supplemental baffling portion extends transversely with respect to the top of the arm.

4. In combination with a rocker arm of the type having an upwardly opening oil discharge orifice, an oil control device comprising a baffle member, and holding portions carried by and extending from one side of said member and securing such member to the top of the rocker arm.

5. In combination with a rocker arm of the type having an upwardly opening oil discharge orifice, an oil control device comprising a combined dam and baflie member, and holding portions carried by and extending from one side of said member and securing such member to the rocker arm.

6. In combination with a rocker arm of the type having an upwardly opening oil discharge orifice, an oil control device comprising a com bined dam and baffle member including integrally formed angularly disposed sheet metal dam and baffle sections, and holding portions carried by and extending from one side of said member and securing such member to the rocker arm with both of said sections positioned transversely with respect to the arm.

'7. An oil control device for rocker arms of the type having an upwardly opening oil discharge orifice, comprising a combined .dam and baflle member including integrally formed angularly disposed sheet metal dam and bafile sections, and holding portions for securing such member to a rocker arm with both of said sections positioned transversely with respect to the arm, said holding portions including legs also formed integrally

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