US1741230A - Poppet-valve action for internal-combustion engines - Google Patents

Description

Dec. 31, 1929. w. M. soonwm POPPET VALVE AcTIou r03 INTERNAL conauswxou ENGINES Filed Nov. 28, 1927 VE/V ran 5 Y MVM A TTL'JR/VEYE' Patented Dec. 31, 1929 WILLIAM M. GOODWIN, OF CENTRAL SQUARE, NEW YORK POPPET-VALVE ACTION FOR INTERNAL-COMBUSTION ENGINES Application filed November 28, 1927. Serial No. 236,195.

This invention relates to a poppet valve action for internal combustion engines of the multiple cylinder four-cycle type in which the valves areself-closing by means of suitable springs, but are adapted to be opened at regular intervals against the action of said springs by rotary cams acting upon the ends of the valve stems through the medium of What is commonly known as tappets and adj ustable connections between the valve stems and tappets for varying the length of the valve stem to con orm to the distance between the low points of the cam and valve seats and thereby to assure the proper closing of the valves when the low points of the cams are presented to their respective tappets.

These adjustable connections between the tappet and valve stem are also made to compensate for expansion and contraction of the valve stem under varying temperatures, and in order to maintain proper action of the valve under all temperature conditions it is customary to adjust the connections between the stems and tappets so as to allow a slight play or lost motion under relatively low temperatures sufficient to compensate for the expansion of the valve stem under higher temperatures without opening the valves" when the low points of the cams are registered with their respective tappets.

One of the objects of the present invention is to maintain a more uniform temperature of the valve mechanism than has heretofore been practised and thereby to reduce the va-- riations in the eifective lengths of the valves by expansion and contraction under varying temperatures of the engine.

Another object is to inclosc the cam shaft in a separate oil-containlng housmg so that 0 the bearings for the cam shaft and connections between the valves and 'valve stems may be automatically lubricated and the noise of operation of the valves reduced to a minimum,

Another object is to introduce and maintain the oil in the housing under sufficient pressure to hold the tappet connections with the valve stem in contact or against lost motion incidental to the diflerential lengths of the valve stem under varying t mperatures or rather to take upthe lost motion of said connections when the valve stem is contracted to its maximum degree under relatively low temperatures.

A further object is to provide the tappet with a relief passage communicating with the oil chamber in the housing to prevent undue opening of the valves by excess oil pressure in said housing.

Another object is to rovide one of the cam shaft journals with peripheral oil pockets adapted to successively re 'ster with the oil inlet port of the housing r causing, intermittent feed of the oil from the housing to the tappet connections with the valve stem and oil circulating ducts in said stem at regular intervals in the operation of the valves.

Other objects and uses relatin to specific parts of the valve action will be rought out in the following description.

In the drawings Figure 1 is a transverse vertical sectional view of a portion of an internal combustion engine'and one of the valve actions.

Figure 2 is a longitudinal sectional view of an end portion of the cam shaft housing and cam shaft therein together with the adjacent portions of the valve stems and tappets and oil inlet for supplying oil to the interior of the housing.

Figure'3 is a detail transverse sectional view of the valve stem.

Figure 4 is a transverse sectional view of the cam shaft housing showing a sli htly modified form of tappet connectlon with the valve stem.

The oil-containing housing for the cam shaft is similar in some respects to that shown in my pending applications Serial No. 160,406, filed January 11, 1927, and Serial No. 188,471, filed May 3, 1927, in that it consists of a closed tubular unit containing a quantity of oil and the cam shaft end adapted to be inserted into and removed from the 1M frame of the engine when the tappets and their connections with the valve stem are re i moved therefrom.

As illustrated, this device comprises a tubuable material having circular end heads 2- adapted to be supported in correspondlng circular openings -3 of the engine frame as -4-,- and held in operative position by set screws 5 engaging in threaded apertures in the walls of the openings 3 and also engaged in registering sockets in the peripheries of the heads -2-' as shown by dotted lines in Figure 1.

The tubular housing -1 is provided with an oil chamber 1 extending therethrough from end to end and having its axis eccentric to and preferably below the axis of the circular heads 2, the ends of the chamber being closed by removable cap plates 6- held in place by bolts 7-.

:The chambered portion of the housing 1 is provided with internal annular coaxial bearings -8 in axially spaced relation for receiving and supporting a rotary cam shaft --9-- having axially spaced journals -10 and 11 engaging the bearings 8--, said shaft being also provided with axially spaced cams 12 between the journals 10 and -11.

The upper side of the housing 1 is provided with guide openings 13-- radial to the axis off the cam shaft --9- and in radial alinement with the cams 12 for receiving cup-shaped piston tappets -14- which are reciprocally movable in their respective guide openings 13-- by their corresponding cams -12- and valve-operating springs -15- The guide openings --13 and piston tappets --14 are preferably cylindrical to permit relative rotation of the piston tappets for changing their lines of contact'withthe corresponding cams 12-. j

The lower ends of the piston tappets 14 are substantially flat and tangential to the circular portions of the cams -'12' and are provided with relief passages -16 of relatively small area connecting the oil chambers -5-- to the interiors thereof for the double purpose of lubricating the tappet connections and also for relieving the piston tappets from excessive pressure of the oil within the chamber 5 to reduce the liability of holding the valves open by such pressure on the undersideof the piston tappets. The tappet member -14- is provided wit a bearing member --17'- loosely resting upon the bottom thereof and provided'with a concave upper face --18 engaged by a correspondingly convexed lower end of a valve tappet --19 which 7 is screwed upon the lower threaded end of the valve stem -20 of the poppet valve -2l-- to form a continuation thereof and permit the valve stem to be lengthened and shortened by relative adjustment of the tappet 19 upon the stem as may be required to enable the valve to close upon its seat as -21 The tappet 19- is preferably hollow and threaded internally for receiving the lower end of the stem --20 and is provided with an oil passage 22 registering with the passage 16 to enable the lubricating oil to pass from the chamber 5- into the interior of the tappet 19 and thence through relieve excess oil pressure upon the lower end of the tappet which mightotherwise tend to hold the valve open.

A lock nut 23 is also engaged with a threaded lower end of a valve stem 20 and upper end face of the yoke -l9- to hold said valve stem and yoke in their relatively adjusted positions. I

A washer 24-- is loosely mounted upon the valve stem -20- and normally rests against the up er end of the lock nut 23 to form a seat or the lower end of the spring 15-, having its upper end abutting against the underside of a lateral projection 20- between the spring seat -24- andvalve head 21-- is divided by a lengthwise partition 27- into opposite compartments 28- and 29 having its lower end provided with a lateral ofl'set portion -30 closing the lower end of the compartments 29, the upper end of said partition being provided with a transverse opening 31 connecting the corresponding ends of the compartments .28- and -29.

The lower end of the compartment 28- communicates with the interior ofthe stem 20- below the offset portion -30 to allow oil which may pass through the passages 16 and 22- to flow upwardly into the compartment 28 and thence through the passage -3l and downwardly into the compartment 29 which is provided near its lower end with an outlet passage -32 just above the offset -30 and washer .24,- said washer being provided with an additional outlet '35 communicating with the outlet 32 to allow the oil which may escape through the outlet -32 to flow outwardly beyond the periphery of the valve tappet 19 and thence into the crank case of the engine.

oil shield on valve stem A frusto-conical sheet metal shield 36 is seated at its lower end on the upper face of the washer 24- at the outside'of the outlet openings and in spaced relation to the tube -20 and has its upper end secured to the periphery of said tube above the outlet opening 32 to prevent the oil from passing upwardly along the outside of'the valve stem or rather to direct the outlet of the fluid from the passage 32- through the passage -35 where it is free to escape" by gravity into the crank case around the outside of the housing -1--.

Oil under abnormal pressure may be supplied to the interior of the housing 1 from any available source of oil supply, as for example from the crank case of the engine, through a supply pipe '37 and passage 38 registering therewith, said supply pipe being engaged in a threaded socket in the outer end of the passage 38 and in the adjacent portion of the frame 4.

The oil supply passage -38- is preferably formed in the top wall of the housing 1- in radial ali'nement with the journal11 on the cam shaft -9'.

This journal -11is cylindrical and provided with peripheral oil pockets -39 and -39'- arranged in circumferentially spaced relation and eachhaving one end open and its other end closed.

That is, the pocket 39-is open at the end facing the cams 12- at'the left hand end of the journal 11 while the open ends of the pockets 39 face in the opposite direction or in the direction of the remaining two cams, not shown but at the opposite end sponding in this instance to a four cylinder of the journal 11-, the arrangement correengine, but it is evident that if six cylinders are used the journal bearings -11-'- will be interposed between. each pair of cams.

Each journal -11-'is provided with a number of pockets corresponding to the number of valves of the engine, 'one pocket for each valve and they are spaced circumferentially in such relation to each other and to their respective cams '12- that the pocket corresponding to any one of the valves and its operating cam will register with the oil inlet passage -38- at a out the time the valve is closing upon its seat or when the lower side of the cam is just beginning to register with the underside of. the corresponding tappet -14- and thereby to facilitate the entrance of a fresh charge of the oil' through the passa es 16 and --22- and thence upwardly t rough the passage -2 8I and return through the passages .31. and

29 through the outlets 3 2 and -35 for cooling the valve and its stem and thereby maintaining a more uniform temperature of the valve and stem to prevent excessive expansion and contraction thereof.

The passage -22-- in the lower end of the yoke -19- is controlled by a check valve -40- which is spring-pressed to its seat in r the upper end of said-passage by a light coiled spring -41--, Figure 1, to prevent back-flow of the oil from the interior of the valve stem in case the oil pressure in the houslng -1 should be excessively lowered or by suction Operation I The liquid oil may be fed through the pipe -37- into the interior of the housing -l-\ by pump pressure if desired to substantially fill the housing and thereby to supply the nee essary lubricant for the bearings of the cam shaft and also thebearings between the cams and tappets, which lubricant is also supplied under the same pressure to the interior of the upflow and return passages of the valve stem through the passages l6-x and 22-- to return to the crank case: from the down-flow passage 29 through the outlet passages 32 and 35-, it being-understood that the oil pressure from the source of supply through the passage -38 to the interior of the housing 1, is cut ofi' by the journal 11- except whenthe pockets 39- and 39'- for their particular valves are registered with said passage-38 In other words, the flow of the oil through the upflow and return passages in the valve stem is intermittent and coincident with the registration of the corresponding pocket in the journal 11- with the inlet passage This oil pressure in the housing 1 acts upon the lower ends of the piston-tappets -1 1 to hold the latter in contactwith the lower ends of the ta ppets 19 and serves to take up any lost motion between the tappets and thereby to reduce to a minimum the noise incidental to the operation of the valves by their respective cams aided by the presence of oil at the contact points between the cams and tappets 14 and also between the tappets.

It is to be understood, however, that the oil presure acting upon the lower ends of the tappets 14, is never sufiicient to openthe valves against the action of their closing springs -15. 1

'VVhat I claim is: v

1. In an internal combustion engine, a poppet valve having a tubular stem closed at its head and its opposite end opened, a partition extending diametrically across the interior of the tubular stem from side to side thereof for dividingthe interior of thestem into opposite cooling channels having a connecting passage adjacent. theclosed' end of the stem, one of the other channel being in open communication with the open end of the stem, and means for circulating a cooling liquid through said channels from the open end of the stem to said outlet.

2. In an internal combustion engine, a cam shaft housing having a cylindrical chamber containing oil under pressure and provided with a radial guide-opening leading from said chamber to the exterior of the housing, a cam shaft journaled in said chamber, a camactuated tappet slidably fitted in said guideopening and provided with a substantially flat inner end face adapted to be engaged by a cam on the shaft, a poppet-valve having a tubular stem in radial alinement with the guide-opening in the housing and having its inner end open and its outer end closed, a tappet-member adjustably secured to the open end of the valve stem and cooperating with the first-named tappet for transmitting motion therefrom 'to the valve, said tappets being provided with relatively small reliefpassages communicating with the oil-chamber of the housing and with the open end of the valve-stem to permit the passage of oil from said chamber to the interior of the valve stem for cooling purposes, said valve stem having an outlet passage leading from the interior to the exterior thereof to permit the escape of oil therefrom, the cross sectional area of the relief passages being considerably less than the area of the inner end of the firstnamed tappet to cause the oil pressure within said chamber acting upon the inner end of the piston to hold the first-named tappet in contact with the second-named tappet independently of the cam.

3. In an internal combustion engine, a rotary cam, ahousing for the cam having a guide-opening in one side, a tap et slidable in said guide-opening and actuate by said cam, a valve having a tappet bearing against the first-named tappet to transmit motion therefrom .to the valve, a spring for closing the valve and urging it and its tappet toward the cam, and means for introducing liquid under pressure into said housing, said liquid-pressure in the housing acting uponthe firstnamed tappet to hold the same in contact with the second-namejd tappet independently of the cam. v

4. In an internal'combustion engine, a rotary cam, a housing for the cam havin 1 a guide opening in one side, a tappet slida 1e in said guide opening and actuated by said cam,a valve having a tappet bearing against the first-named tap et to transmit motion therefrom to the va ve, a spring for, closing the valve and urging it and its tappet toward the cam, and means'for introducing liquid under pressure into said housing, said li uid pressure, in the housing acting upon'the rst-f named tappet to hold the same in contact with the second-named tappet independently of the cam, said tappet and valves having relatively small relief passage communicating with the interior of the housing to relieve

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