US3908615A - Ball ended push rod with controlled oil flow - Google Patents

Abstract

A thin-wall hollow push rod has in it a co-axial tube of small bore running from end to end through the hollow interior thereof. The bore of the tube is sufficiently large to permit a controlled stream of oil under pressure to flow therethrough, and sufficiently small as to prevent churing of the oil which produces a foam having bubbles in the oil stream. This hinders return of oil to the crank case. Ball surface bearings with bores therethrough are affixed at each end of the tube, and the ends of the tube are disposed in counterbores in the ball surface bearings.

Description

United States Patent 11 1 Hayward 1 1 Sept. 30, 1975 15 BALL ENDED PUSH ROD WITH 3.066658 12/1962 Gondek 123/90.61 CONTROLLED OIL FLOW 3,086.507 4/1963 Mooney... 123/9061 3.094,]07 6/1963 Gondek 123/90.61 [76] Inventor: Norman G. Hayward. 1141 3.191.290 6/1965 Knox 123/9061 Mercury Dr., Manassas, Va. 221 10 3.299.986 l/1967 Briggs 123/9035 3.301.241 967 1k Z3 [22] Filed: May 2 1974 1/1 5 endcndn l /90 61 [21] Appl. No.: 466,209 Primary Emminer-Charles J. Myhrc Related Application Data Assistant E.\'aminerDaniel J. OConnor [63] Continuation-impart of Ser. No. 394,805, Sept. 6.

1973 [57] ABSTRACT A thinwal1 hollow push rod has in it a co-axial tube of UsS. i small bore running from end to end through the ho]- 1 1 1/06 low interior thereof. The bore of the tube is suffi- 1 Field of Search 123/90-61- ciently large to permit a controlled stream of oil under 123/90-36- 9055' 90-63, 308/5- 9 pressure to flow therethrough. and sufficientIy small as to prevent churing of the oil which produces a foam 1 References Cited having bubbles in the oil stream. This hinders return UNITED STATES PATENTS Kishline 123/9().61

Morsch .v 123/9().61

Almen i 123/9061 Mannerstedt.. 123/9061 Wuest 123/9061 of oil to the crank case. Ball surface bearings with bores therethrough are affixed at each end of the tube, and the ends of the tube are disposed in counterbores in the ball surface bearings.

7 Claims, 2 Drawing Figures US. Patent Sept. 30,1975

BALL ENDED PUSH ROD WITH CONTROLLED OIL FLOW RELATED APPLICATION- FIELD OF INVENTION Internal Combustion Engines, Poppett Valve Operating Mechanism, Rod.

PRIOR ART Almen US. Pat. No. 1,823,419; Mannerstedt US. Pat. No. 2,878,796.

OBJECTS Hollow push rods for actuating valves of internal combustion engines have been known for many years, a typical example of which is shown in FIG. 30f the Almen patent (supra). These thin-wall rods are usually open at the ends to permit oil to pass therethrough. Not only does the oil add to the inertia of the usual hollow rod, but also, due to the rapid reciprocation of the rod in high-speed engines, the oil churns back and forth so much that air bubbles in the oil stream are produced, and these air bubbles make it difficult to return the oil to the crank case. One solution to the bubble problem might appear to be the use of a solid push rod with a smaller oil passage theregthrough, such as the one shown in Mannerstedt (supra). However, solid rods are heavier and, if they are made with the same amount of metal as a hollow rod, they are not so strong. Another solution, which has been attempted by racing car mechanics, is to insert pipe cleaners into the hollow interiors of push rods. These reduce churning, but there remains the weight of the oil which fills the rods, with resultant inertia, the oil flow through the rod is impeded, and there is a resultant danger of foreign substances from the pipe cleaners getting into the oil stream. Also, the twisted metal rod of the pipe cleaner may enter the hole at the end of the rod and clog it up. My object is to produce a push rod for valves which conducts oil from end-to-end, which is almost as light as the ordinary hollow rod, which is strong or stronger than the ordinary hollow rod, but in which the oil cannot churn so as to produce air bubbles in the oil stream. To this end, it is intended now to provide a thin-wall hollow push rod having a relatively small hollow tube running coaxially therethrough from end to end controlling the flow of oil therethrough. More specifically, it is pre ferred that the bore of this tube be capillary in nature.

Application Ser. No. 394,805 discloses a hollow push rod with hollow ends having holes therethrough sufficiently large to accommodate the ends of a capillary tube which extends coaxially therethrough from endto-end. However, some makes of automobiles use hollow push rods with ball surface bearings welded into the ends, the ball surface bearing having bores across them through which oil flows. It is to this type of push rod to which the present invention is addressed.

It is the object of this invention to provide a hollow push rod having ball surface bearings secured in the ends thereof, each bearing being solid but for a bore which extends therethrough, wherein the bores having counterbores in the ends thereof which face the interior of the hollow push rod. A small hollow tube, preferably having capilary characterisitcs as regards lubricating oil, e.g., a thin-wall tube having a bore of about one-sixth inch diameter, has its ends engaged in the counterbores of the bearings. This not only provides a finished surface for the bearings, unbroken save for the bore ends, but, perhaps more importantly, a great manufacturing advantage in assembling. Because the ends of the tube engage closely into the counterbores in the bearings, the rod can be assembled by engaging one end of the tube into the counterbore of a first bearing, then the free end of the tube is inserted end-wise through the hollow rod until the first bearing engages into an end of the hollow rod, then the counterbore of the second bearing is engaged over the free end of the tube and, witli'the bearings engaged into the respective ends of the hollow rod,'the bearings are welded into place, Alternatively, an end of the tube can be welded into the bore of the first bearing before the free end of the tube is inserted through the hollow rod. However, this pr eliminary welding step is not absolutely necessary because, once the bearing balls are welded into place, the tube is locked into place, and, furthermore, if the bearings are affixed into the ends of the hollow rod by inductive welding, the ends of the tube can be simultaneously welded to the bearing balls.

These and other objects will be apparent from the following specification and drawing, in which:

FIG. 1 is a perspective view of the push rod in typical environment of use; and,

FIG. 2 is an exploded view of the parts of the push rod. 7

Referring now to the drawings, in which like reference numerals denote similar elements, the hollow push rod 2 is formed of a hollow rod 4 whose'inner edges 6 are beveled at both ends for receiving bearings which in this example are balls 8 and 10 which are welded as at 1 1. to the beveled edges. The bearings balls 8 and 10 engage against concave seats 12 and 14 in a valve lifter 16 anda rocker arm 18, respectively. Oil under pressureis supplied via a cross passage 20 and longitudinal bore 22 in the lifter, thus oil flowing through bores 22 in the bearing ball, through the hollow push rod and to an oil hole 24 in the rocker arm. As thus far described, the hollow push rod is conventional for certain makes of automobiles and in a typical example the push rod would be about 6 "4 inches long, about 5/16 inches outer diameter and about 13/64 inches inner diameter. These dimensions, of course, change in accordance with engine specifications. The valve lifter and rocker arm form no part of the invention and may partake of various forms so long as some sort of mating pressure oil supply is provided for one end of the rod, and some sort of mating oil receiving means is provided for the other end of the rod. The problem solved by this invention is that ordinarily oil fills the interior of the hollow rod and, because of rapid reciprocation, churns and form bubbles which are harmful to the libricating system of an engine, and extremely difficult to get rid of.

According to this invention, each ball is provided, in addition to the transverse bore 26, a counterbore 28, and tightly engaging in the counterbores 28 are the ends of a thin wall tube 30. Although dimensions may change from model to model, in the example being described, the outer diameter of tube 30 is about 3/32 inches, the wall 32 is about 1/64 inch, and the axial bore 34 is about 1 16 inch. The counterbore 28 in bearing balls 8 should be, in this case, about 3/32 inches in diameter to provide a tight fit over the ends of tube 30.

In assembling rod 2, one end of tube 30 is inserted into the counterbore 28 of one bearing ball, such as ball 8, the then free end of tube 30 is inserted through hollow rod 4, the counterbore 28 of other bearing ball is fitted over the free end of tube so that both bearing balls are firmly steated against the beveled end edges 6 of hollow rod 4, and then both bearing balls are joined to the rod ends by welds 11. With some welding processes, such as inductive welding. the ends of the tube 30 can be simultaneously welded in place. Otherwise, if needed to provide a leak-proof joint between the ends of the tube 30 and the bearing balls a sealing compound may be used, it being preferred that no oil enter the hollow space 36 between the tube 30 and the inner wall of hollow rod 4, because this would add to the weight of the rod.

The diameter requisite for the bore 34 of tube 30 is that it be sufficiently small that lubricating oil, a somewhat viscous liquid, will not churn enough to form bubbles. It is preferred that the bore of the tube be capillary in nature so that lubricating oil will adhere to its sides and thereby tend to reciprocate with the tube, rather than undergo cavitation with resultant entrainment of air. In some hollow push rods, the ball surface bearings are not entirely speherical but, rather, are somewhat bullet-shape, with substantially hemispheri' cal bearing surfaces at the exposed ends.

I claim:

1. A push rod for actuating a poppet valve of an engine and for transmitting oil, comprising an elongate hollow tube having abutment means at opposite ends thereof, and means providing a capillary passage from end-toend through said tube and said abutment means,

the means providing a capillary passage comprising a second tube whose outer diameter is substantially less than the inner diameter of the first-mentioned tube, and means securing the opposite ends of the second tube in said abutment means, the space between said diameters being hollow.

Lil

LII

2. A push rod as defined in claim 1, said abutment means comprising bearing members respectively secured in opposite ends of said hollow tube, said bearing members each having bore means extending therethrough in the axial direction of the tube, and each having an inner end portion open towards the interior of the tube and an outer end portion open oppositely therefrom, the ends of said second tube being respectively secured in the inner end portion of the bore means in the bearing members.

3. A push red as defined in claim 2, the outer end portions of the bore means having a diameter substantially equal to the inner diameter of the second tube and the inner end portions of the bore means having a diameter but slightly larger than the outer diameter of the second tube whereby the ends of said second tube engage snugly in the inner end portions of the bore means.

4. A push red as defined in claim 2, said bearing members being spherical.

5. A push rod for actuating a poppet valve of an engine and for transmitting oil, comprising an elongate hollow tube having abutment means at opposite ends thereof, and means providing a passage from end-to-end through said tube and abutment means,

the means providing a passage comprising a second tube whose outer diameter is less than the inner diameter of the first-mentioned tube, and means securing opposite ends of the second tube in said abutment means, the space between said diameters being hollow.

6. A push rod as defined in claim 5, said abutment means comprising bearing members respectively secured in opposite ends of said hollow tube, said bearing members each having a bore therethrough, the ends of said second tube being respectively secured in the bores of the bearing members.

7. A push rod as defined in claim 6, said bearing members being spherical.

Claims (7)

1. A push rod for actuating a poppet valve of an engine and for transmitting oil, comprising an elongate hollow tube having abutment means at opposite ends thereof, and means providing a capillary passage from end-to-end through said tube and said abutment means, the means providing a capillary passage comprising a second tube whose outer diameter is substantially less than the inner diameter of the first-mentioned tube, and means securing the opposite ends of the second tube in said abutment means, the space between said diameters being hollow.

2. A push rod as defined in claim 1, said abutment means comprising bearing members respectively secured in opposite ends of said hollow tube, said bearing members each having bore means extending therethrough in the axial direction of the tube, and each having an inner end portion open towards the interior of the tube and an outer end portion open oppositely therefrom, the ends of said second tube being respectively secured in the inner end portion of the bore means in the bearing members.

3. A push rod as defined in claim 2, the outer end portions of the bore means having a diameter substantially equal to the inner diameter of the second tube and the inner end portions of the bore means having a diameter but slightly larger than the outer diameter of the second tube whereby the ends of said second tube engage snugly in the inner end portions of the bore means.

4. A push rod as defined in claim 2, said bearing members being spherical.

5. A push rod for actuating a poppet valve of an engine and for transmitting oil, comprising an elongate hollow tube having abutment means at opposite ends thereof, and means providing a passage from end-to-end through said tube and abutment means, the means providing a passage comprising a second tube whose outer diameter is less than the inner diameter of the firstmentioned tube, and means securing opposite ends of the second tube in said abutment means, the space between said diameters being hollow.

6. A push rod as defined in claim 5, said abutment means comprising bearing members respectively secured in opposite ends of said hollow tube, said bearing members each having a bore therethrough, the ends of said second tube being respectively secured in the bores of the bearing members.

7. A push rod as defined in claiM 6, said bearing members being spherical.

Images