US2521621A - Rocker arm - Google Patents

Description

p 9 1950 J. R. WINTER, JR 2,521,621

ROCKER ARM Filed Nov. .21, 1949 ill? IN VEN TOR.

77 Tray/V1345.

Patented Sept. 5, 1950 ROCKER ARM John R. Winter, Jr., Detroit, Mich., assignor to John B. Winter, Sr., Detroit, Mich.

Application November 21, 1949, Serial No. 128,623

10 Claims.

The present invention relates to the construction of rocker arms of the character employed for actuating the valves of internal combustion engines of the overhead valve type. The primary object of the invention may be stated broadly as comprising the provision of such a rocker arm which afiords better control of the supply of lubricant to the end of the valve stem which is engaged by the rocker arm.

Another object is to provide such an improved rocker arm which is adapted to be constructed of sheet metal in a rapid and economical manner.

Other objects and advantages of the invention will become apparent upon consideration of the present disclosure in its entirety.

In the drawing:

Figure 1 is a side elevational view of a rocker arm constructedin accordance with the present invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a sectional elevational view taken substantially on the line 33 of Fig. 2 and looking in the direction of the arrows; and

Figs. 4 and 5 are sectional views taken substantially on the lines 44 and 5--5, respectively, of Fig. 1 and looking in the direction of the arrows.

Referring now to the drawing, my improved rocker arm construction includes a tubular hub portion generally designated l0, and a laminated body portion generally designated l2. The general mode of construction and assembly of the hub and body portions preferably correspond to the disclosure of my copending application Serial No. 701,150 filed October 4, 1946, to which reference may be had for a more complete consideration of the construction and assembly of these parts. Rocker arm structures of this general class having laminated body portions with tubular hubs have now been in large scale production for a number of years and are well known in the art, so that detailed re description of such general features will not be required here. With respect to such general features of construction, however, it should be noted that the tubular sheet metal hub portion I is provided withbulges I I, I4 on opposite sides of, and which bear inwardly against, theflat sides of the laminated arm body to lock the hub to the arm portion. An internal bearing sleeve I is tightly held in the hub and adapted to .be journaled upon the rocker arm shaft (not shown). One or more internal communicating oil passages as l1, l3 extend through the bearing sleeve l5 and hub l0 and communicate with a riser oil passage 20 which extends upwardly through the laminar arm, the upper end of the riser passage being open and located in a depression or transverse notch 22 formed in the top edge of the arm.

At its valve end, the body of the arm carries a push pin 25 having a head portion 24 adapted to engage the end of the valve stem. The pin 25 is tightly frictionally held in the end of the arm, which is formed as a loop 21 to provide a retaining opening for the pin. The looped portion 21 is joined to the flat laminar portions of the arm by inclined portions which converge gradually toward one another to form a V-shaped passage 29 between the laminations on the side of pin 25 toward the hub. The V-shaped passage 29 extends farther toward the hub than does the head 24 of pin 25, to provide a small opening at the point designated 30 beside the head 24 of the push pin, so that oil flowing downwardly through the passage 29 can pass through the opening 30 and flow down the side of the head of the push pin and onto its valve-stem engaging bottom surface.

The pin 25 is somewhat shorter than the axial length of the looped, pin-retaining portion 21. The space above the pin bounded by the walls of looped portion 21 thus forms a depression or pocket 32. Pocket 32 communicates with the notch 22 by means which is adapted to limit the quantity of oil which can flow to the valve end of the arm. Such communication is provided by a groove 33 which extends along the top edge of the arm and which terminates at its outer end at the juncture of the pocket 32 and the V'-shaped downflow feed passage 29.

At its inner end groove 33 communicates with a V-shaped slot 34 forming an inward continuation of the channel 33. V-slot 34 is defined by the space between a pair of upstanding divergent ears 35, 36, formed upon the top edge of the arm, one ear being formed integrally with each lamination. These ears will be recognized as analogous to the damming and metering ears disclosed in my aforementioned application Serial No. 101,150,

and which have become well known in the art.

The sloping inner edges 31 of the ears constitute of the oil-holding capacity of the channel, as it extends outwardly toward the end of the arm, achieves an important benefit and overcomes a difficulty which arises in the operation of arms of this class which are not equipped with such a tapered groove. This difliculty, which is particularly observed at high speeds, is a tendency on the part of the oil to pile up in the channel, and flow over the sides of the arm. The action of a tapered groove or channel corresponding to the channel 33 is described in greater detail in my copending application Serial No. 128,621; filed November 21, 1949.

I have found that it is practical to form the tapered channel 33 by striking the edge of the arm blank before it is folded. A ehamfered edge is thereby formed which becomes a channel when the two sides are folded together, as will be apparent. Such chamfered portion may be continued around the looped section 21 of the arm, so as to provide an inclined or chamfered wall portion 38 at the top of the pocket 32. Retention of oil against escape over the sides of the arm seems to be superior where the chamfer is continued around the top edge of the pin-retaining loop 21 in this manner.

For conducting oil to the push-rod end of the arm, I preferably provide an internal passage 40 which is defined by complemental grooves, so formed in the laminar wall portions which are folded together when the blank is folded upon itself as to register to define a passage of substantially circular cross section. The passage 49, at its inner end which communicates with the notch 22, is enlarged, as indicated at 42, to provide a mouth which is generally funnel-shaped. The enlarged mouth 42 occupies a large proportion of the rear wall of the notch 22. The passage 40 is also of relatively large cross section, and inclines downwardly toward its outer end, where it terminates in a substantially vertical passage 44, of generally triangular cross section, which lies alongside the adjustable push-rod engaging screw 45. The passage 44, like the passage 29, is formed as a V-shaped opening by, and as a. result of. the bending of the metal of the laminations to form a generally cylindrical opening, which in this instance is for reception of the screw 45. Beyond the screw 45, the metal is again made to converge and is welded together to secure the laminatiens against separation. It will be appreciated that the oil which enters the mouth portion 42 can flow through the communicating passages 40, 44 and thence downwardly along the side of the screw 45 and over the head 41, to lubricate the point of engagement between the head 41 and the push rod.

The passage 44 is also of relatively large cross section, and the oil path provided by the enlarged mouth 42 and the passages 40, 44 is one through which the oil can flow freely. The arrangement is such that under the usual operating conditions, substantially all of the excess oil which does not flow to the valve end of the arm enters the enlarged mouth "and passes down the passages 40, 44. Little or no such excess oil flows laterally from the notch 22 and down the sides of the arm. Although during operation the oil appears in substantial quantity in the notch 22, the viscosity and surface tension of the oil, and the action of the arm. are such that virtually all of the oil tends to flow into the mouth 42 and through passages 40, 44. Despite careful observation of these arms in operation, I have not been able to determine the exact action which takes place.

4 The sloping wall area 31 on either side of the V- slot 34 appears to toss the oil rearwardly and into the mouth 42 during the rapid oscillation of the arm. I have found that if the rear wall 31 is made more abrupt, that is, more nearly vertical, less of the excess oil enters the mouth 42 and more of it flows laterally from the ends of the notch 22 and down the sides of the arm. The slope of the wall 31 thus seems to be related to the funnel- mouthed passage 40, 42 and to the action which results from the oscillation of the arm and in effect, as noted previously, the wall tends to throw the oil into the funnel-like mouth 42. Since in my preferred construction the passages 4D, 44 are large enough to accommodate the excess oil, all such excess oil is carried entirely away from any part of the arm which might cause the oil to be thrown, or allowed to flow, toward the valve end of the arm where oil consumption difficulty would be apt to ensue. In any event the capacity of the rearwardly extending passageway system 42, 40, 44 and the action of the parts are such that none of the excess oil finds its way to the top edge of the arm in the area between the notch 22 and screw 45, or to the upper portion of the screw 45. Thus no oil can be tossed from the rear end of the arm toward the valve end.

As pointed out in my copending application Serial No. 701,150, previously referred to, great difliculty has been encountered in so controlling the flow of oil that only a predetermined and relatively limited quantity will reach the valve stem and the valve stem-engaging end of the arm. Where the oil delivery to the valve stem is excessive, the engine consumes an undue quantity of oil, particularly after it becomes worn, because of the tendency of the reduced pressure in the cylinders during each intake stroke to draw oil downwardly along the valve stem. Previous arms of this general class have incorporated open-topped channels leading both to the push pin at the valve end of the arm, and to the screw at the push rod-engagin end of the arm. The provision of the tapered channel leading to the valve end, in combination with the damming and meteringears 35, 36, effectively controls the rate at which lubricant flows along the top of the arm to the valve end, but I have found that under some conditions of engine wear and operation, there is also a tendency to throw oil through the air from the push-rod end to the valve end, particularly where an open-topped channel is employed leading from the riser opening to the push-rod end. Under such conditions, particularly with a worn engine operating at high speed and with lubricant of low viscosity (the viscosity is, of course, reduced at high engine operating temperatures) 011 moving toward the push-rod end of the arm through an open-topped groove or channel is sometimes thrown upwardly and in an are back toward the valve end. Frequently, in such cases the oil first flows upwardly to the top of the push-rod screw (corresponding to the screw 45) and then is tossed upwardly into the air. Due to the rocking character of the movement of the arm, such oil is usually thrown in an arc, back toward the valve end, and under some operating conditions this are is of such proportions as to define a small jet which throws oil in substantial volume toward, and frequently actually strikes, the valve end of the arm. It then flows down the outside of the arm and push pin and results in overoiling of the valve stem. This condition has been observed in actual tests of arms which would ordinarily provide very eilective control of the flow of oil to the valve end. With the improved construction herein disclosed, the oil is prevented from reaching the upper edge of the part of the arm which extends toward the push-rod end, and the oil which is intended for lubrication of the push rod, therefore, cannot be tossed overtoward the other end of the arm to cause overoiling at the valve end in the manner indicated.

Although I have disclosed and described herein my preferred metering means, consisting of the ears 35, 36 and metering slot 3-4 therebetween, and have also disclosed my preferred tapered channel means (33) for conducting oil to the outer end of the valve end of the arm; it will be appreciated that the invention could be practiced, and substantial benefits obtained, with different metering and oil conducting means for the valve end of the arm (leading to the pushpin For example, the metering and oil conducting means might take the form disclosed in the OHarrow Patent No. 2,288,831, wherein the oil simply flows along the top edge of the arm leading to the valve end, adhesion being relied upon, with no defined channel for this purpose, and the metering means consisting of narrowed or chamfered sections formed upon the top edge of the arm and interposed between the riser hole and the pushpin or valve end of the arm. In the claims appended hereto, the terms open-topped oil conducting means and metering means," where not expressly limited to the preferred types herein disclosed, are intended to encompass other known oil conducting means and metering means, such as, but not restricted to, the types shown in the OHarrow patent as well as the types shown in my Patent No. 2,509,661, issued May 30, 1950.

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

What is claimed is:

i. In a rocker arm construction for internal combustion engine valve mechanism or the like in combination with a hub and a body having arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top of said body, an open-topped oil conducting portion providing communication between said opening and an outer end of one of said arms, and a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, said portion d fining the covered channel including a part located adjacent to said riser passage and extending upwardly above the top of the riser passage, and metering means interposed between said opening and the outer end of said arm which incorporates the open-topped oil conducting means.

2. A structure as defined in claim 1 wherein said covered channel is provided with a mouth portion located on one side of said opening in said part which extends above the riser passage, 1

said mouth portion extending substantially the full width of the arm.

3. Ir. a rocker arm construction for internal combustion engine valve mechanism or the like, in combination with a hub and a body having arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top of said body,-an open-topped oil conducting means interposed between said opening and the outer end of said valve actuating arm, said covered channel being substantially unrestricted.

4. In a rocker. arm construction for internal combustion engine valve mechanism. or the like, in combination with a hub and a body having arms projecting from said hub in generally op-. posite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top of said body, an open-topped channel-defining portion providing communication between said opening and an outer end of one of said arms, a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, said opening being defined by transverse walls forming a notch-like area located appurtenant to the upper edge of said body, that one of said walls on the side toward said open-topped channel being inclined outwardly from the vertical toward the top of said notch-like area, said wall having a restricted longitudinal opening therethrough defining metering means interposed between said opening and said open-topped channel.

5. In a rocker arm construction for internal combustion engine valve mechanism or the like, in combination with a hub and a body having arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top of said body, an open-topped oil conducting portion providin communication between said opening and an outer end of one of said arms, a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, one of said arms comprising a valve actuating arm and the other of said arms comprising a push-rod actuatable arm, said coveredpassage extending through the interior of said last-mentioned arm, and metering portions interposed between said opening and the outer end of said valve actuating ar'm, said covered channel extending angularly downwardly toward the outer end of said push-rod actuatable arm.

6. In a rocker arm construction for internal combustion engine valve mechanism or the like, in combination with a hub and a body havin arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top of said body, an open-topped channel-defining portion providing communication between said opening and an outer end of one of said arms, and a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, said opening comprising transverse walls extending upwardly above and on either side of the upper end of the riser passage and defining a notch-like area located appurtenant to the upper edge of said body, at least one of said walls being inclined outwardly away from the riser passage toward the top and located at the rear end of said open-topped channel and having a restricted longitudinal opening therethrough defining metering means interposed between said opening and said open-topped channel, said covered channel having a mouth on the other side of said opening from said inclined wall and being sub-- stantially unrestricted.

7. In a rocker arm construction for internal combustion engine valve mechanism or the like, in combination with a hub and a body having arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top of said body, an open-topped channel-defining portion providing communication between said opening and an outer end of one of said arms, and a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, said opening comprising transverse walls extending upwardly above and on either side of the upper end of the riser passage and defining a notchlike area located appurtenant to the upper edge 01' said body, at least one of said walls being inclined outwardly away from the riser passage toward the top and located at the rear end of said open-topped channel and having a restricted longitudinal opening therethrough defining metering means interposed between said opening and said open-topped channel, said covered channel being provided with an enlarged mouth on the other side of said opening and extending angularly downwardly away from the opening and being substantially unrestricted.

8. In a rocker arm construction for internal combustion engine valve mechanism or the like, in combination with a hub and-a body having arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top 01' said body, an open-topped oil conducting portion providing communication between said opening and an outer end of one of said arms, a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, one of said arms comprising a valve actuating arm and the other of said arms comprising a pushrod actuatable arm, said covered passage extending through the interior of the last-mentioned arm, and metering portions interposed between said opening and the outer end or said valve actuating arm.

9. In a rocker arm construction for internal combustion engine valve mechanism or the like, in combination with a hub and a body havin arms projecting from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the top or said body, an open-topped oil conducting portion providing communication between said opening and an outer end 01' one of said arms, a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part oi said other arm, one of said arms comprising a valve actuating arm and the other of said arms comprising a pushrod actuatable arm, said covered passage extending through the interior of said last-mentioned arm, said opening comprising an open-topped notch-like depression formed in the upper edge of said body, and metering means interposed between said depression and the outer end of said valve actuating arm, said covered channel having an enlarged mouth communicating with said depression.

10. In a rocker arm construction for internal combustion engine valve mechanism or the like. in combination with a hub and a body having arms projectin from said hub in generally opposite directions, a lubricant riser passage extending upwardly from the hub through the body and terminating in an opening located near the .top 01' said body, an open-topped oil conducting v portion providing communication between said opening and an outer end of one of said arms, a portion in the other of said arms defining a covered channel terminating at one end at said opening and terminating at the other end at an outer part of said other arm, said portion defining the covered channel including a part located adjacent to said riser passage and extending upwardly above the top of the riser passage, said opening comprising an open-topped, notchlike depression formed in the upper edge of said body, metering means interposed between said depression and the outer end of said valve actuating arm, said covered channel having an enlarged mouth at its end which terminates at said depression and being substantially unrestricted.

JOHN R. WINTER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,278,195 Noack Sept. 10, 1918 2,176,083 Leake Oct. 17, 1939 2,259,905 Moncrieff Oct. 21, 1941 2,288,831 O'Harrow July 7, 1942 2,415,213 Leake Feb. 4, 1947 2,478,130 Ronfeldt Aug. 2, 1949 2,482,312 Bachle Sept. 20, 1949 FOREIGN PATENTS Number Country Date 349,508 Great Britain May 26, 1931

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