Патент USA US2411775код для вставки
NOV. 25., 19.46» ' w. B. BRONANDER, JR I ' VALVE 2,411,775 MEGHANISM Filed'July 21, 1944 »f / 31”” Jdf/ ff INVENTOR 2,411,775. Patented Nov. 26, 1946 UNITED As'irATrzs Partnr orties `Wilhelm B. Eronander, Jr., Montclair, N. J., assigner otono-half to Wilhelm B. .Bronanden Sr., Montclair, N. J. ApplicationvJuly 21, 1944, Serial No..545,996 " . ' 1 Claim. (Cl. 123-90) » 2 . This invention relates to valve -mechanisms for internal combustion engines and particularly to a method of balancing valve operating mecha nisms. y In the standard valve actuating mechanism thevva'lve is usually vactuated by a rocker arm vto open the valve, the rocker Aarm being actuated by suitable mechanism, such as a push rod, which Fig. 1 is an elevational yview showing the valve and valve mounting in section and illustrating the valve operating mechanism in elevation, this mechanism being constructedin accordance with the invention; and ' Fig. 2 is a top plan view, partly in section, of apart of the structure shown in Fig. 1. , In the particular embodiment of the structure for carrying out'the invention there is shown a in turn is operated by 4a cam. Springs are pro vided and operate on the valve stem to close the 10 portion `lil of a cylinder head having a valve guide ii in which is mounted a reciprocatable valve, return- the rocker arm `and push rod to valve having a stem l2 and a head I3 which seats their` initial or inoperative positions, and main on a valve seat lll. tain the push rod operating means in contact vwith A spring l5 surrounds the valve stem and en the cam. In case the valve freezes or sticks gages a ñxed Seat I6 at one end thereof and at 15 and does> not close, the valve spring action on its opposite end engages the upper end l1 of the rocker arm, push rod and tappet is suspended the valve stern I2. and the cam which operates the tappet-hammers The valve is actuated by a rocker arm which the tappet, causing serious damage. is mounted on a pin 20 mounted in suitable bear Internal combustion engines and particularly aircraft engines are operated at very high speeds 20 ings and the rocker arm comprises an >arm 2| having a roller 22 which engages the upper end and this has resulted in putting a great strain I1 of the valve stem and a rearwardly extending ~ on the valve mechanism and particularly on the arm 23 having a pivot socket 24 for receiving >the spring closing means. When the engine races spherical upper end 25 of a push rod 26. at high speed the inertia forces of the rocker arm, The rocker has a hub 30 which is mounted on 25 push rod and tappet overpower the valve spring a pair of sleeves 3i and 32, the inner sleeve being and the tappet does not follow the cam, again mounted on the pinv 2G which in turn is mounted causing a hammering action to take place. As in flanged bushings or bearings 33 and 34. usually operated, this spring closing mechanismv The lower> end of the push rod 26 is pivoted is relied on to overcome the inertia of the rocker arm and push rod as well as to close the valve. 30 at 35 to a cylindrical block 36 which is mounted in a bearing 3'! and has mounted on its lower This invention has for its salient object to endl a roller 38 engaging a cam 39. As the cam balance the reciprocating and oscillating inertia 3S is rotated the roller and block 35 are recipro forces of the rocker arm and push rod, thereby cated, thus actuating the push rod 28 and rocker relieving the valve spring from performing this operated thereby. function. ` Another object of the invention is to provide In the usual or common valve mechanism, a plurality of springs surround the valve stem and operate through the ñanged head I1 and valve ranged that the only work done by the valve stem to return the rocker and push rod to in spring is to close the valve, thereby permitting the use of a lighter valve and a lighter valve 40 operative position after the valve has been opened and closed. Obviously, with high speed engines spring. in which the valve is operated very fast, this Another’cbject of the invention is to provide puts an enormous strain on the valve stem and an independent and self-suñîcient rocker @rm valve spring and has necessitated the use of heav retracting means whereby the rocker arm, push rod and tappet will operate entirely independ 45 ier valves and heavier springs. Even withthese changes breakdowns have been frequent. More ently of the operation of the valve. over, as explained above, at excessively high Another object of the invention is to provide speeds the inertia forces or load on the rocker a method of balancing andretracting therocker arm, push rod and tappet overpower the valve arm and rocker arm operating mechanism in such a manner that the load on the rocker arm bear 50 spring and the tappet does not follow the cam. Also, when the valve freezes the rocker operation ing is substantially neutralized. _ by the valve spring is suspended. Further objects of the invention will appear In order to overcome this condition in the pres from the following speciñcation taken in connec ent invention, the rocker, push rod and push rod tion with the drawing which form a part of this 55 operating connection are moved to their retracted application, and in which a method of balancing valve mechanism so ar 2,411,775 3 position or inoperative position by a ñat coiled spring 49 having a loop 4| which engages the rearwardly extending arm 23 of the rocker and is coiled around the rocker hub 30, the free ends of this spring, shown at 42, engaging a fixed abutment 43 in the cylinder head. It should be noted that the spring 40 puts no load on the 4 maintains the roller 38 in engagementl with the cam 39. , By reason of the method above described the engine can be operated at much higher speeds without danger of breakdown. Although one specific embodiment of the in vention has been particularly shown and de bearings of the pin 20 but largely neutralizes the scribed, it will be understood that the invention load thereon. The flat coils of the spring 43 is capable of modification and that changes may which extend around the hub 30 on opposite sides 10 be made without departing from the spirit or of the rocker function as resilient thrust bearings and maintain the hub and rocker centered be scope of the invention, as expressed in the fol lowing claim. tween the flanges of the bushings or bearings 33 What Iv claim is: and 34. The rocker bearing is lubricated and In valve mechanism, a valve guide, a valve hav the oil also lubricates the contacting surfaces of 15 ing a valve stem reciprocatable in said guide, a the coils. This centering and thrust action is cylinder head having spaced bearings therein, a particularly important when the push rod block rocker having a pivot pin mounted in said bear 35 is not disposed in the plane of the socket 2fë ings and having an arm engaging the valve for and the push rod 26 is not disposed in the plane opening the valve, a spring for closing the valve, of the longitudinal axis of the rocker arm 2l. 20 and a coil spring encircling the rocker pin and The spring 4D takes the entire load of the engaging the end of the rocker remote from the rocker arm or rocker, push rod and push rod arm engaging the valve for substantially neu operating means and relieves the Valve spring tralizing the inertia load of the rocker arm and I5 from carrying this load, the sole function of returning the rocker to its inactive position dur the valve springl being to close the valve. Thus 25 ing the closing of the valve, said coil spring hav the rocker Will operate entirely independently ing ñat coils on opposite sides of the rocker and of the valve and the tappet will always contact between the rocker and said spaced bearings to and follow the cam. This obviously permits the take up thrust coaxial with the rocker pivot axis use of a lighter valve and of a lighter valve spring. and center the rocker between said spaced bear The inertia forces on the rocker and push rod are balanced by the spring 4i! which as stated ings. WILHELM B. BRONANDER, JR.