US1660982A

US1660982A - Internal-combustion engine

Info

Publication number: US1660982A
Application number: US641333A
Authority: US
Inventors: Lionel M Woolson
Original assignee: Packard Motor Car Co
Current assignee: Packard Motor Car Co
Priority date: 1923-05-25
Filing date: 1923-05-25
Publication date: 1928-02-28
Anticipated expiration: 1945-02-28
Also published as: FR577833A; GB216493A

Description

Feb. 2s, 192s. 1,660,982

L. M. WOOLSQN INTERNAL COMBUSTION ENGINE Filed May 25, 1925 INVENTOR, Lionel Z. Woolson.,

A TTORNEY.

Fig. 3

Patented lF eb. 28, 19.28.

UNITED STATES.

PATENT OFFICE.

LIONEL IAL WOOLSO, OF DETROIT, MICHIGAN, ASSIGNOB T PACKABDMOTOR .CAR COM- 'PANY, OF DETROIT, MICHIGAN,

A CORPORATION 0F .MICHIGANZ i INTERNALCOMBUSTION ENGINE.

Application filed May 25,

This invention relates to a valve mechanism for internal combustion engines, and more particularly to the springv mechanism whereby the puppet or mushroom valves pf suchzengines are seated and against the action of which they are opened by the valve operating mechanism.

It has for an object toprovidc a mechanism of the character designated in which VOther objects and structural details Will be apparent from the subjoined description, in connection with the accompanying drawing in which:

Fig. 1 is a vertical section thru a portion of an internal combustion engine constructed in accordance With the invention; Fig. 2 is a section on the line 2-2 of Fig. 1;

Fig. 3 is an elevation of the guide pin assembly, and; Fig. 4 is a sembly showing a modification of the invention.

It has been discovered that valve spring failure under the high speeds used in mod- .ern practice is almost invariably caused by the synchronizing of the natural frequency of the valve springs with the fundamental period of the engine. To avoid this difficulty, this invention provides a means whereby the natural frequency of the springs is raised beyond the engine period at any possible speed. The periodicity of any given spring is a' fixed characteristic of that spring, and changes in the number of coils, or in the size of Wire forming the coils-has but little effect thereon. factors determining this characteristic, the radius of curvature of the spring coils is controlling. In the present invention these objects are accomplished by using a considera'ble number of relatively small springs, so located as to dispose their combined load vertical section thru a valvel as Ofy the 1923'. Serial No. 6,111,333.

about' the valve stem. The tot-al spring strength is thus divided between a number of springs, and the stress in each spring is correspondingly lowered, so that simple, untreated spring Wi're maybe used instead of theheattreated alloy steel nowr required.

Inthis manner the liability to failure thru faulty workmanship is diminished. At the same time, as the load is divided among a plurality ofsprings, a number ofthesemay break Without affecting the operation of the engine.

Referring to the drawing, 10 represents an internal combustion engine having a cylinder 11 in which a piston 12 is adapted to operate, and ahead portion 13 secured to the` upper end of the cylinder in any appropriate way as bythe bolts 14. -The upper portion ofthe head 13 is provided With'a to be closed by a detachable cover plate 17,

providing a housing for the valvey operating mechanism of the engine.

Suitably journaled in the housing is 'a camshaft 18,.adapted to be driven from the engine crankshaft in timed relation thereto, in the Well known manner, and provided with suitable cams 19 to actuate the engine valves. The head portion is also provided With suitable passages, Such as 21, for the fuel mixture and for theexhaust. The head portion 13 supports a combustion head 22 above the cylinder 11, provided in its central portion with a port 23, the inner edge of which is chamfered to rovide a valve seat 211, and which communicates with the passage v21. The combustion head 22 is also provided With suitable tapped openings for the reception of spark plugs 26.-

Located above and in line with the port 23, is a valve guide 27, preferably mounted in the head 13 by pressing into a web 28 formed therein, 'and provided intermediate its ends with an internalshoulder 29. The valve guide 27 is adapted to receive and support the vertically disposed stem 31 of a puppet or mushroomvalve 32, which cooperates with the valve seat 24 to control the port 23 in the usual manner. end of the valve stem 31 is adapted for coop- The uppereration with anadjustable tappet member 33, secured t0 a crosshead 34, which recipropressure and open the port 23, in a manner Well understood in the'art to which this invention relates.

Adapted to surround the valve guide 27 land restingagainst the shoulder 29, is an annular member 38, having upwardly directed circumferential flanges 39 and 41. Secured to the member4 38 and preferably evenly spacedabout the axis thereof are a number of upwardly disposed guide pins 42, arranged parallel to the valve stem 31. The guide pins 42 are preferably formed With necks at their lower ends, which project thru holes in the member 38, and are riveted over as indicated at 43, so that the member 38 and the pins 42 form a unit assembly, as clearly shown in Fig. 3.

'The member 38 provides a iiXed spring abutment between which and the annular collar 37 are disposed a plurality .of coil springs 44, of relatively small radius; one of the springs 44 being placed around each of theguide pins 42. The combined pressure of the springs 44 acts upon the stem 31, thru the collar 37, to urge the valve 32 to its seat as Will be readily understood. The pins 42 support the springs 44 and prevent lateral bending thereof, but terminate short of the lowermost position of the 'collar 37 when the valve 32 is Wide open.

The operation of the invention is apparent. On the rot-ation of the camshaft 18, they 'cam 19, acting thru the erosshead 34 and the tappetl member 33, depresses the valveste'm 31 against the collective action of the springs 44, each of which is compressed and slides upon'its guide pins 42. 0n continued rotation of the camshaft 18, 4the pressure of the cam 19 on the crosshead 34 is released, when 451 the springs`44 return the valve 32 to its seat.

In Fig. 4 is shown a modilication of the invention in which the guide pins 42 are of greater length to extend thru appropriate holes 46 in the'eollar 37. In this manner complete support to prevent lateral lexure of the springs 44 is provided, the collar 37 being; also guided by the pins 42. In this case,'ho\vever, the valve will not be freely rotatable on its oivn axis While it recipro- Cates in the valve guide 37.

It wil'l be apparent that this invention provides a valve spring mechanism in which the total spring load is divided between a number of small springs, the radius of curvature of each of which is relatively small. The unitstress in each spring is `there-fore relatively lovv, permitting the use of less eX- pensive and more uniform material =for the springs. At the same time, because. of the 'smaller radius of curvature, the natural period of each of `the springs is greatly" inl 1. In an internal combustion engine, the` combination of av valve, means for positively opening the valve, and means for yieldingly closing the valve comprising a considerable number of relatively small springs arranged about the valve stem.

2. In combination with an internal combustion engine, a valve having'a single integral stem, and a plurality of compression springs disposed in spaced relation about the stem.

3. In combination with an internal combustion engine, a valve having a sing'le integral stein, and a plurality ofcompression springs of relatively small radius disposed about the stem.

`4. In combination lvvith an internal'combustion engine, a valve having a stem mounted in a iXed guide, an annular abutmentsecured to the guide, an annular abutment secured to the stem, and a plurality of springs disposed in spaced relation between the said abutments.

5. In combination with an internal combustion engine, a valve, an abutment secured thereto, a plurality of guidepins disposed about the valve axis and parallel thereto, a coil spring surrounding each of said pins a-nd engaging the abutment, and a secondabutment for said springs.'-

6. A -Puppet valve forv internal'v combustion l engines having a lstem mounter'l-,'infal xed guide, a. shouldermountedon the gnidefan annular abutment surroundig the guide and:

resting on the" shoulder, i plurality ofA guide pins secured -fto the-abutmentin spaced relal tion, an abutment secured to the valve stem,- and a coll spring surrounding each pin be-l tween saidabutments.

7. In combination with a puppet valve for internal combustion engines, an apertured annular abut-ment securedto the stem thereof, a plurality of guide pins mounted to project thru the aperture in the abutmenta i coil spring surrounding each' pin and disposed to exert 'pressure on the abutment, and

rounding each said guide abutment for the springs.

9.' In an engine, in combination, valve guiding means, a puppet valve having a stem in said guiding means, an abutment on the valve stem, a stationary abutment, and a plurality of valve springs spaced `around the valye stem between 'said abutments.

10. In an engine, in combination, a valve guide having a shoulder, an annular abutment surrounding the guide and resting-on the shoulder, a valve having a stem extending through Vsaid guide., an' annular` abutment mounted on the valve stem in op l osition to the iirst said abutment, and a p urality of coil springs arranged between said abutments and disposed in spaced relation about said valve stem. y

11. The method of constructing the spring structure of the mushroom valve of an inpin, and a second ternal combustion engine, characterized by forming the springs so that the naturalffrei 'quency of said springs is considerably in excess of the frequency of any vibration likely tobe set up in the engine to which said valve is fitted.

12. The method as claimed in claim 11 in' which the desired high frequency oi vibration of the springs is obtained byy forming said springs of relatively small diameter.

13. Themethod as claimed in claim 11 comprising the provision of a relatively large number of springs of small diameter arranged circumferentially about the valve stem.

14. A valve structure comprising a mushroom valve and a plurality of springs eachV `having a period of vibration considerably higher than that of the engine in which it is incorporated, said springs being disposed symmetrically around the stem of said valve and 4acting against a common abutment on the valve stern.

'15. In an internal combustion engine, the

valve guide, an annular abutment surrounding said guide and resting on the shoulder, a series of guide pins secured to the'abutment in spaced relation,`an abutment se-v cured to the valve stem, and a coil'spring surrounding each pin between said abutments.

17. A valve structure comprising a mushf room valve and a plurality of springs each having a period of vibration' considerably higher than that of the engine in which it is incorporated, an apertured annular abutment secured to the valve stem,- a plurality of guide pins mounted to project through the apertures in the abutment, and a coil spring surrounding each pin and disposed to exert pressure on the abutment;

18.' A valve structure comprising a mushroom valve and a plurality of springs each having a period of vibration considerably higher than' that of the engine in which it is incorporated, a shoulder mounted on 'the valve guide, an annular abutment surrounding and removably attached to said guide and resting on the shoulder', .a series of guide pins secured to the abutment in spaced relation, an abutment secured to the valve stem, and-a coil spring surrounding each pin between said abutments.

19. As an article of manufacture a valv spring device comprising upper and lower substantially ring-shaped membershaving alining apertures therethrough adapted to receive a valve stem, and a plurality of compression springs between t-he upper and lower members in spaced axial relation with respect to each other outwardly of the lining apertures of said members. i

20. g In a valve spring construction for engines a substantially ringshaped member adapted for abutment against a stationary partof an engine and having a Central opening therethrough, a pluralityof rods carried by the member extending in spaced parallel relation transversely of the plane of the' ring-shaped member and laterally of the opening through said member, a second ringshaped member having a central screw threaded opening therethrough and laterally of said central opening having a plurality of `other transverse openings adapted to slidabl receive therethrough the free ends of saidr rods which are carried by the first mentioned member, and individual spiral compression springs on each of said rods under compression between said two ring-shaped members, and in abutment at their `ends therewith. q

21. vIn a valve spring construction for en gines the combination with an engine includ ing an engine casing,a valve including a re'- ciprocable stem having a screw threaded portion thereon, and means to reciprocate said valve stem for adjusting the last mentioned member longitudinally of the valve stem, a

Ap'lurality 4of spaced rods supported by the -first mentioned member in right angled par' allel relation entirely laterally of the opening of said member, the second mentioned member having a plurality of spaced openvmeans on the screw threaded portion of the ings thereabout laterally of the opening in member `vvllereloy to force the first mentioned which the valve stem is slidably mounted, member against the engine casing to e stafor slidably receiving the free ends of said tionary position, and to force the valve stem 10 rod-s, and relatively small diametered spiral into a valve seating relation.

compression springs engaging at similar lln testimony whereof I ailix my signature. l

ends the first mentioned member and at theopposite similar ends the second mentioned LIONEL M. WOOLSON.