Title:
Rocker arm
United States Patent 2345822


Abstract:
My invention relates to rocker arms and more particularly to the type used to operate the valves in an internal combustion engine. Heretofore all the rocker arms used in combination with an internal combustion engine have been of a solid structure. Originally the rocker arms were either castings...



Inventors:
Leake, James M.
Application Number:
US40775041A
Publication Date:
04/04/1944
Filing Date:
08/21/1941
Assignee:
Leake, James M.
Primary Class:
Other Classes:
123/90.39, 184/6.9, 384/155
International Classes:
F01L1/18
View Patent Images:



Description:

My invention relates to rocker arms and more particularly to the type used to operate the valves in an internal combustion engine.

Heretofore all the rocker arms used in combination with an internal combustion engine have been of a solid structure. Originally the rocker arms were either castings or forgings. My former stamped rocker arm disclosed in Patent No. 2,176,083, gave much more strength per unit of weight than did the older types of rocker arms which were cast or forged. This was due to the fact that my former stamped rocker arm was constructed from a sheet metal material that has greater strength than cast or forged metal.

This type of rocker arm comprises a laminated sheet metal arm member with a solid crosssectional area. My improved rocker arm combines the use of a sheet metal material with a hollow shaped cross section thus giving still more strength per unit weight that was obtained in my former stamped rocker arm.

My improved rocker arm finds great utility when applied to the present day high speed internal combustion engine as it has the attributes of rigidity and strength coupled with comparatively little weight. Especially,with the higher speed engines it is very essential that the oscillating weight of the rocker arm be reduced to a minimum. Furthermore it is very essential that the reduction in weight be accomplished without any increase in cost.

One object of my invention is to provide a stamped rocker arm whose shape-gives the maximum strength per unit weight.

Another object of my invention is to provide a stamped rocker arm that requires little or no expensive machining operations.

Another object of my invention is to provide a rocker arm adapted to be made of material of high strength characteristics. Another object of my invention is to provide a rocker arm that readily adapts itself to quantity production.

Another object of my invention is to provide a rocker arm that requires a minimum amount of 41 skilled help.

Another object of my invention is to provide a rocker arm that is especially adapted to the present day higher speed engines.

Another object of my invention is to provide a 6( rocker arm that controls or meters the lubricant to the contacting bearings.

Another object of my invention is to provide a rocker arm with an oil reservoir.

Another object of my invention is to provide 5i a rocker arm with a maximum of rigidity and strength with minimum weight and cost.

With these and other objects in view, my invention consists in the construction, combination and arrangement of the various parts of my 61 improved device as described in the specification, claimed In the claims and illustrated in the accompanying drawing.

In the drawing: Fig. 1 is a pictorial view of my improved rocker arm without the adjustable contacting bearing.

Fig. 2 is a side elevation partially in section of a rocker arm embodying the novel features of my invention.

Fig. 3 is a plan view of my novel rocker amn.

Fig. 4 is a section taken on line 4--4 of Fig. , looking in the direction of the arrows.

Fig. 5 is an end elevation of my novel rocker arm.

Fig. 6 is a sectional view taken along line 6-6 of Fig. 3.

Fig. 7 is a sectional view taken along line 7-W of Fig. 3 showing the cross-sectional area and the oil regulating slot.

Fig. 8 is a section taken along line 8-- of Fig. 2 showing the shape or cross-sectional area of the arm member.

Fig. 9 is a pictorial view of one of the members forming the hub of my novel rocker arm.

Fig. 10 another form of the hub used in my novel rocker arm.

Referring to the drawing in more detail, in Fig. 1, I have shown the stamped or pressed metal arm member 10 of my novel rocker arm. This arm member 10 is pressed or stamped from a fiat piece of sheet metal. The sheet metal blank is pressed into an arm member 10, as shown in Fig. 1, with two vertical side walls spaced substantially apart and lower Wall joining the side walls thus providing an arm member with a Ushaped cross-section as shown in Figs. 6, 7 and 8.

The ends of the arm member are provided with vertical walls integral with the side walls and the bottom wall. One end of the arm member is provided with a curved surface I adapted to act as a contacting bearing. It will be noted that the curved surface I is an integral part of the arm. The lower surface of the curved surface I may be hardened to resist wear. The opposite end of the arm member i0 is formed into a partially hexagonal hollow prism 12. A nut 20 is fastened in the prism portion 12 of the arm member by welding, brazing or any other suitable means. An adjustable contacting bearing 20 is inserted through an opening in the arm member ) 10 just below the nut 20 and is then screwed into the nut 20 until the desired position is reached. The adjustable contacting bearing is then locked in position by means of the lock nut 23. The position of the contacting bearing can 5 readily be adjusted by loosening the lock nut 23, adjusting the position of the threaded stem 22 and then locking it in its position by tightening the lock nut 23.

Holes are punched in the side walls of the Sarm member 10 intermediate its ends. These holes are adapted to receive a hub member as shown in Fig. 4. The hub comprises two cylindrical flanged members 13 as shown in Fig. 9.

One flanged member 13 is iiiserted from the outer side of the arm member 10 through the holes in the opposite side walls. The inner ends of the flanged cylindrical members meet as shown at 14 in Fig. 4. The annular inner ends of the hub members 13 are welded, brazed or otherwise fastened together. The annular flanges of the hub members 13 are also welded, brazed or other- 1 wise fastened to the aim member 10 as shown at points 29, or the entire flange may be welded to the arm member. The hub members 13 are provided with notches or semi-cylindrical holes 15. The hub members 13 are placed so these notches 15 are juxtaposed thus forming an oil passageway 16. A bushing or bearing 11 is pressed into the assembled hub members 13. The bearing is provided with a hole 18 coinciding with the oil passageway 16. The oil passageway 6 may also be made by drilling a hole through the hub and bushing after the hub members 13 and the bushing 16 are assembled.

Fig. 10 discloses hub of my novel rocker arm in another form. The hub 19 is all in one piece.

When this form of hub is used a tube or hollow cylindrical member is inserted through the holes in the side walls of the arm member 10. The annular flanges 24 are in this form of my invention formed after the tube member is inserted in the arm member 10. The flanges 24 may likewise be welded to the arm member 10. This form of the hub is also provided with an oil passageway 16.

When the rocker arm is installed in an internal combustion engine the bearing 1I operates or oscillates on a rocker arm shaft. Oil is provided by pressure from a suitable source to the rocker arm shaft. The iocker arm shaft is provided with an oil passageway to lubricate the bearing 17. Oil from the rocker arm shaft is also fed through the oil hole or passageway 16 into the oil reservoir 25. The oil reservoir 25 is formed by the lower part of the arm member 10. This lower part is located below the hub.

The bottom wall of the arm member 10 is provided with a drain hole 26. The drain hole 26 may be placed at varying levels by varying the position of the hole on the curved bottom wall of the arm member 10. The level of the oil or the amount of oil retained in the reservoir 26 will thus depend uppn the position or level of the drain hole 26.

One end of the arm member 10 is provided with an oil passageway or slot 21 adapted to lubricate the contacting bearing 11. The other end of the arm member 10 is provided with an oil passageway or slot 28 adapted to lubricate the adjustable contacting bearing 21. The size of the oil passageways or slots 21 and 28 can be varied to regulate or meter the amount of oil fed to the contacting bearings II and 21. In some cases it is desirable only to lubricate one of the contacting bearings. In this case one of the slots is omitted.

In operation the rocker arm oscillates and thus the oil flows from end to end of the arm. A port'on of the oil finds its way through the oil passageways 27 and 28 as they arein the low position thus intermittently and alternatingly lubricating the contacting bearings II and 21. The quantity of oil fed to the bearings depending on the oil level and the size of the oil passageways 27 and 28.

With my improved type of rocker arm the oil reservoir 25 provides lubricatioh immediately when the engine starts. In the old type of rocker arm in which no oil reservoir is provided, the contacting bearings are not lubricated until the oil pump circulates sufficient oil to reach the contacting bearings.

Fig. 6 discloses the U-shaped cross-sect'on of my novel rocker arm along line 6-6 Fig. 3. Similarly Figs. 7 and 8 disclose the U-shaped crosssection of my improved stamped rocker arm along lines 7-7 and 8-8 respectively. It will readily be noted that the cross-sectional area of my improved rocker arm is substantially U-shaped at any point. Thus it will be seen that in the construction of my novel rocker arm the metal is located away from the center line where greater strength is obtained. This type of construction provides the greatest possible strength for the material used. This is readily explained that a hollow tube is stronger than a solid rod with the same cross-sectional area. Likewise, an I-beam is stronger than a round or square bar of the same cross-sectional area. Many various shapes are made to increase the strength per unit weight. Furthermore, my improved stamped rocker arm is made from sheet metal which has more strength per unit area than does cast or forged metal. Since my rocker arm is made from the type of metal that provides greater strength and also provides a shape that gives the maximum strength for the amount or weight of metal used, it will readily be seen that my improved rocker arm gives more strength for the same weight than do other types of rocker arms.

At the present time tractor engines, tank eng'nes, airplane engines and many other army, naval and industrial engines are being speeded up in order to obtain greater speed and power.

Experiments have proven that when the present internal combustion engine is speeded up, stronger and heavier valve springs have to be used in order to operate the valves properly. Heavier valve springs result in greater cost, heavier engines, and increased wear, all of which are undesirable features. When my improved stamped rocker arm was used, the engine operated very satisfactorily with the original or lighter and weaker valve springs. My improved rocker arm has proven to give less engine wear and conse80 quently longer life to the engine. This is due to the fact that my rocker arm is lighter and consequently the inertia of the oscillating arm is less.

The weaker and lighter valve springs that can be used with my improved rocker arm further create less pressure which results in less wear of the parts. Also, greater brake horse power is obtained when my improved rocker arm is used.

This is due to the fact that less engine power is required to oscillate my lighter weight rocker arm o6 than the present type of heavy rocker arm and less power is needed to operate the lighter valve springs used with my improved rocker arm than is required to operate the heavier valve springs that must be used with the old type of rocker arm. While I have described the details of one form of my invention, I do not wish to be limited to the particular form shown and described as it will be apparent that many modifications therein may be made without departing from the scope of my invention as set forth in the appended claims.

Having thus described my invention what I claim is: 1. A stamped metal rocker arm having a substantially U-shaped cross-section, a hub interII mediate Its ends comprising a plurality of tubular members extending through the side walls of said rocker arm, the inner ends of said tubular members being abutted and fastened so that said pluSrality of tubular members are in axial alignment the outer ends of said tubular members having annular flanges extending radially adjacent the outer surfaces of said side walls, a contacting bearing at the proximity of either end of said rocker arm, an oil reservoir in said rocker arm, an oil passageway in said hub for feeding oil to said oil reservoir, a plurality of oil ducts for feeding oil from said oil reservoir to contacting bearings and a means for metering the flow of oil to said contacting bearings.

2. A rocker arm comprising; a sheet metal arm member of substantially U-shaped cross-section; annular holes provided in the side walls of said U-shaped arm member; a hub intermediate the ends of said U-shaped arm member, said hub comprising a plurality of tubular members inserted in said annular holes and abutted in axial alignment, said tubular members being provided with a plurality of annular flanges extending radially therefrom; a means for fastening said hub in said arm member; and a bushing within said hub member.

3. A rocker arm comprising a sheet metal arm member of substantially U-shaped cross-section; a pair of annular holes in axial alignment, one hole being located in either side wall of said Ushaped arm member; a hub intermediate the ends of said U-shaped arm member, said hub comprising a plurality of tubular members one of said tubular members being Inserted in said annular holes, the inner ends of said tubular members 'being abutted and fastened together in axial alignment, a plurality of annular flanges struck radially from said tubular members, one of said annular flanges fastened to either side walls of said U-shaped arm member, a bushing within said hub, a contacting bearing comprising a curved surface on the under side of said Ushaped arm member, a nut fastened between the .walls and near the end of said U-shaped arm member, adapted to aed to austably secure a contacting bearing; an oil reservoir within said U-shaped arm member, an oil duct in said hub to feed oil to said reservoir and a means for metering oil to on% or both of said Contacting bearings.

4. A rocker arm comprising a sheet metal arm member of substantially U-shaped cross-section; a hub comprising a plurality of tubular members extending through annular holes on either side of said arm member and annular flanges extending radially from said tubular member adjacent the outer surface of said arm member and fastened thereto.

5. A rocker arm comprising a sheet metal arm member of substantially U-shaped cross-section; a curved surface, on the under side of and near one extremity of said arm member, providing a contacting bearing; a substantially hollow prism portion provided by said arm member at its other extremity; a nut fastened in said hollow prism portion; a second contacting bearing, provided with a threaded stem, threaded into said nut; a lock nut for locking said second contacting bearing in a predetermined position; a hub comprising a plurality of tubular members extending through annular holes on either side of said arm member, the inner ends of said tubular members being abutted and fastened in axial alignment, and annular flanges extending radially from said S tubular members adjacent the outer surface of said arm member and fastened thereto; an oil reservoir provided in said U-shaped arm memS5 ber; an oil duct in said hub to feed oil to said reservoir; and an oil passageway adapted to feed a predetermined quantity of oil to one of said contacting bearings.

6. A rocker arm comprising a sheet metal arm member of substantially U-shaped cross section; a curved surface, on the under side of and near one extremity of said arm member, providing a contacting bearing; a substantially hollow prism portion provided by said arm member at its other extremity; a nut fastened in said hollow prism portion; a second contacting bearing, provided with a threaded stem,' threaded into said nut; a lock nut for locking said second contacting bearing in a predetermined position; a hub comprising a plurality of tubular members extending through annular holes on either side of said arm member, the inner ends of said tubular members being abutted and fastened in axial alignment, and annular flanges extending radially from the outer ends of said tubular members adjacent the outer surface of said arm member and welded thereto; an oil reservoir provided in said U-shaped arm member; an oil duct in said hub to feed oil to said reservoir; a passageway adapted to feed a predetermined quantity of oil to said first contacting bearing and a second passageway adapted to feed a predetermined quantity of oil to said second contacting bearing.

7. A rocker arm comprising a sheet metal arm member of substantially U-shaped cross-section; a curved surface, on the under side of and near one extremity of said arm member, providing a contacting bearing; a substantially hollow prism portion provided by said arm member at its other extremity; a nut fastened iad in said hollow prism portion; a second contacting bearing, provided with a threaded stem, threaded into said nut; a lock nut for locking said second contacting bearing in a predetermined position; a hub comprising a plurality of tubular members extending through annular holes on either side of said arm member and the inner ends of said tubular members abutted in axial alignment, annular flanges extending radially from the outer ends of said tubular members adjacent the outer surface of said arm member and fastened thereto; an oil reservior provided in said U-shaped arm member; an oil duct in said hub to feed oil to said reservoir; a means for controlling the oil level in said oil reservoir and an oil passageway for metering oil to either of said contacting bearings.

8. A rocker arm for operating the valves of an internal combustion engine comprising a sheet metal arm member of substantially U-shaped cross-section; a plurality of annular holes in axial alignment in the side walls of said arm member intermediate its ends; a hub comprising a plurality of tubular members inserted in said annular holes, the inner ends of said tubular 05 members being abutted and fastened together in axial alignment, a plurality of annular flanges struck radially from the outer ends of said tube members adjacent the side walls of said side walls of said U-shaped arm member; a bushing in 7® said hub; an oil reservoir within said U-shaped arm member and a plurality of passageways for metering oil to said contacting bearings.

JAMA at LEAKE.