US1769376A - Piston mechanism for internal-combustion engines - Google Patents

Description

July l, 1930. ,Jj c'. LEARY: 1,769,376

PISTN MECHASM FOR INTERNAL COMBUSTION ENGINES Filed July 24, 1924 F1a1- y Flag I NVEN TOR.

Patented 'July l., 1930 JOHN c. LEAnY, Orsini rzaanorsoo, onLIFonnI-n l Application filedy July a4,

v invention'relatesto, means for lquickly and easily removing thefpiston-head from an internal combustion engine andor varying the compression space in saidv vinternal combustion engine. n u' An object of the invention'is to provide a piston-head that Can be readily detached from the wristpin, and withdrawn through what is generally called the head end of an .internal combustion engine, without disturbing the crank-ease or crank-pin bearings. Another object. is toy provide a meansvby which the compression space vcan be readily varied.V VY; y Y

The invention possesses other objects` `and featnres ofadvantage, some of which'with` the foregoing will be setfortli in the following description of the preferred form of my invention, which is illustrated inthe drawings accompanying and forming part of the specification. lt is to be understood that'l do not limit `myseliifto the showing made byV the said drawings and description, as I may in the Claim.

lReferring to the drawings.

Fig. 1 is a front elevation of an ordinary internal combustion engine with shell broken with my preferred device.

, Fig. 2 is a sectional view of what will hereafter'be referred to as the outer shell.

Fig. 3 is a plan view of the Vhead of this shell. Y

`F ig. 4 is a sectional side view of what is called the inner shell (or spider) showing Wrist pin bearings, bosses for bolts, andfconnecting rod suspended.

Fig. 5 is a. plan view oiithis inner shell. Fig. 6 is the outer'shell of a piston with a straight bore referred to in specifications.

Fig. 7 is a sectional view of inner shell or spider for Fig. 6.

ing` when once screwed'up.

Fig. 9 is an alternative device for keeping bolts romturning.

" k Figure 10 is a perspective View of a distance adopt variations from the preiierredl forni n Within the scope of my invention, as set forth to show a sectional view of a piston equipped'- Jofrnixtnre can be obtained.

1.99.4.' .serial"Nof'zzzes f piece for use in the embodiment oli' Figures Gand?.

. Probably, one of theniost annoying'troubles of the ordinary internal combustion engine, is a leakyk piston or pistons. Due to the general construction, these kvpistons are very hardandfdisagreeable tojget at. The'crank case with all lits bolts has to oe removed,"the

connecting rod disconnected, y,andthe piston pulled -down through the,v cylinder, or up through the head; then when the. trouble isr remedied; all these parts'and bolts have to bev i replaced, new g allbolts tightened upwell. n I

All this timethe" mechanic 'doing'the work is in a very disagreeableand-awkwardposi# y tio1'1,',whether the machine onlskids, or over` apit,"or he lyingon his back on the ground.

` vIt will bel readily seen byfglancing'at the drawings that all this .disagreeable work is gaskets probably installed `done away` with. ihezei'ankcase would only have tov be disturbedy in overhauling the crank pin and lmain bearings,` whichis rare, as these parts practically' run in oil, and'have little wear, and then again lthe'tlirust in this ltype of engine is always down, with the 'exception of the" suction stroke, and ythat/due to the weight'of they piston `androd is practicallyy p nil The savingA intime` and expense in "removing pistons should be readily discerned. In the 'designing offintern'al; combustion engines, the designor Y"generallyilays out'the compression space to suit aselose as possible all localities', butit frequently lhappensl that a motor that gives excellent resultsatpa low .altitude will not act the saine in' highaltitildes@l This .is due to rthedil'er/e'nee in atmospheric pressure as the air will not' flow in as' fast gasfin the lower altitudes. By '90 screwing theouter shell up or downj as in the vembodim".ent of Figures 1 to 5, or by using a distance piece as' in Fig. 6`the proper density ,My vimprovemeini l`s "what might be ytermed a Apiston'within afpiston, in tha fthe Fig. 8 isa devlce to keep bolts from lturnc spider'that lits int-othe'outer shell and is secured therein. rI he "termj spider alluded to,l isv to be'understoodf'as a lmethod of lightlioo ToveXaInine rings.

ening up the structure to the eXtent that the inner shell need not lit the outer shell but here and there, but still have suicient bearing surface for strength and rigidity.

Referring again to the drawings.

No. 1 is a cylinder showing piston mounted for reciprocation. It will be observed that the outer. shell No. 2 is drawn line to line where it meets inner shell No 3 on top, showing that the piston is set for a maximum compression space. :Bolts No. 4 are'shown tightened up. It may be well to state here that the dili'erent figures are all drawn halt' size or" an engine ot this type, scale being 1/2 to 1". Actual sizesV of cylinder being 3% bore and 4 stroke,V connecting rod 7 center to center. It will be noticed that the piston rings in shell No. 2 are l/S lower than inFig. which would amount to 1/4 full size,. and which is considered ample and which would allow plenty ot bolt hold when head, is raised up to lessen the compression space and still. leave piston rings below top of cylinder.

Both outer shell No. 2 andA inner shell No. 3: are turned" to a good sliding fit at No. 5. Shell No. 2 has an internal thread cut into it at No. 6 and. inner shell No. 3 an external thread at 6 with this threadlongerand lower in the shell topermit it being raised and' all necessary threads be in service.

Take out bolts No. e, screw outer shell outot threads and pull out.

To alter compression. Take out bolts No. 4r, unscrew outer shell to the desiredposition andy replace bolts No. 4. Piston should be on. upper center when this is done.A Two stray bolts entered in boltl holes of outer shell and a bar between them for a lever enables this to be done very easily.

Where pistons are supplied with the shells threaded at No. 6, two bolts preferably the two parallel with the wrist pin, are sufficient. Thisalso.v applies to pistons where the connecting rods has a bolted. on cap. on the wrist pin end. In this case the two bossesthatfare in way. ot the swinging of the captare also lett out.

DepressionsNo. 8V are preferably hexagon shaped and it isessential that thebolt heads therein be prevented from turning, and crystalizing trom heatV as muchy as possible. A- nonburnable cement placed between the bolt head sides andthe heXagon shaped depressions, should. accomplish this purpose. I have designed metal` protection and holding members 11. and 12fwhich are respectively A disclosed in developed form in FigureshS and 95 either of saidmembers being arranged to be engaged about/a4 bolt head after the latter is in a depression` 8.

The embodiment shown in Figures 6 and 7 can also-be made with orwithout the variable compression features. Drawing (No. ,6) shows the nonvariable in. that the "upper piston rings are closer to the top.y To be variable, the upper rings should be lower as in Fig. 1 and what is generally spoken ot'as a Vdistance piece inserted between the bosses on shell No. 3 and where they meet shell No. 2. As here shown, the distance piece, or spacing member, 13 is in the form ot an an-V nular ring perforatedv to loosely receive the bolts 4. There being no threads on this type, shell No. 3 is turned all the way, eX-v cepting between where-it may be spidered, to a nice sliding lit. As a precaution against accidents, all'tour bolts are used in this design. Y

Dotted circles No. 9 may not be used at all. Theyrepresentthe position Awhere rivets may be ifit is desirous of usingfan. old style pistonshell. rlhese shells are generally very thin, .therefore theyV wouldhave to be reint'orced by riveting a piece onto themtormed v for that purpose.

vIvclaim--l In a piston for. a reciprocating'engine, an exterior member defining the piston. walls and piston head, anv interior member arranged 'for threaded engagement with and vwithin saidv exterior member whereby' rel-V ative axial adjustment of said members in a plurality oiV predetermined relative positions may be effected upon relative rotation ot the members through rotative angles of less than 360 degrees, a wrist pin mounted in said interior memberand a bolt operable from; the head end of said piston and arrang'c-idv to axially draw `said members together to thereby lock them againstaxial and rotative displacement.

JOHN c. LEAs-Y.

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