US1298548A - Packing-ring. - Google Patents

Description

A. J. MUMMERT '6: J. T. WOODBRIDGE.

PACKING RING.

APPLICATION FILED 1uLY21. 19w.

Patented Mai. 25, 1919.

WI IWESSES:

- we. i ns 1 UNITED STATES i PATENT or Io Y ARDEN MUMME R'L' AND JESSE T. WOODBRIDGE, OF 8'1. LOUIS,MISSOUBI, ASIGNOBS A TO MOQUAY-NORBIS MANUFACTURING COMPANY, OF ST. LOUIS, MISSOURI,

PORATION OF MISSOURI.

To all whom it may concernr Be it known that we, ARDEN J. MUMMERT and JESSE T. Woonnnmon, citizens of the United States, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements in Packing-Rings, of

which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part 10 hereof. I

Our invention has relation to improvements in piston-head packing rings; and it consists in the novel features of construction more fully set forth in the specification and pointed out in the claims.

The present is an improvement on the packing ring forming the subject-matter of U. S. patent issued to Arden J. Mummert, numbered 1,210,674, and bearing date of January 2, 1917 and has for its object to overcome the objection of uneven wear in herent not only in the patented structure but in all rings of similar character whichare provided with oil-collecting grooves or 25 basins on one side only. As fully indicated in the patent aforesaid, the ringcomprises an imperforate resilient split band, such a band, as well understood in the art, being Specification of Letters Patent. V

'- may be A. COB- PACKING-RING.

Patented Mar. 25, 1919.

Application filed m 21, 1911; Serial ms. 101,999.

sults from a distortion or strain imparted to the ring by the stresses to which it :is sub ected, said distortion being due to the uneven distribution of the molecules of the ring about a medial plane perpendicular to the axis of the ring, in which plane the stresses are supposed to operate. The ring compared to a beam subjected to flexure under a load. As well understood in mechanics and in the science of stresses, the bending moment of a force acting on a beam causes the beam to bend with its concave side in the direction toward which the moment acts, and with its, convex side in the opposite direction, it, being understood that the layers subjected to the stress are disposed perpendicular to the plane in diate surface termed} the neutral surface subjected to stresses operating in a plane or o planes transverse or at right angles to the axis'of the ring and of the piston carrying thesame, the said stresses tending to ex-- pand thering, and causing the outer face thereof to hug the inner walls of the cylin- 5 der in which the piston operates. It is of course desirable that a ring subjected to the stresses in question should expand; contract, or otherwise yield in planes parallelto the planes in which the force is exerted, so that- 0 the outer rubbing face or; periphery of the ring shall bear evenly against-the cylinder walls throughout the width of the ring. A

rin with a single oil-collecting groove or basin (or its equivalent) disposed adjacent 45 to one side of the ring, as in the patent aforesaid does not in practice; wear uniformly, the ring having a tendency .to bear more heavily against the cylinder walls at .points in the region of the groove than at -50 any other portion of the ring periphery, the

result being that the rear. cutting or oil scraping edge of the basin shows the first ring wears unevenly and loses itseeifeetive- 55 ness. The uneven pressure referred t? rewhich is neither lengthened nor shortened: At any cross-section of the beam the .neu tral surface intersects said cross-section on a line known as the neutral axis, said axis traversin the center of magnitude'ofthe cross-sect1on. Where the surface. represented by the cross-section has a center of figure (as would be the case for example with a square, parallelogram, circle,'el11pse, I hexagon and the-like) the center of magmtude would be coincident with the center of figure. In compound figures and polygons having no center of figure, the center of magnitude is ascertained by fixedmathematical rules not necessary hereinto discuss. For our immediate urpose we need only to concern ourselves with the neutral axisandwith the bending moment of the force operating in a central plane across said axis or at right angles to the neutral surface m which said axis is disposed. The present 1 0 tracting throughout.

wear and the outer face of the application of the principles of moments to the ring in question, the result beinga perfectly balanced ring, expanding and conits width in planes parallel to the plane in which the stresses are exerted, that is to say, in planes perpendicular to the neutral axis of the crosssection of the ring, the ring bearing with evenpressure against the inner walls of the 110 cylinder, throughout its entire width whereby an'even wear results and a maximum life for the ring is assured. Theadvantages of .the improved ring will be fully apparent .from the following detailed description in connection with the accompanying drawings in which Figure-1 represents a-longitudinal section J of a; gas engine cylinder, Wlh the piston in elevation, ,showing the improved ring applied thereto; Fig. 2 is an enlarged crosssection on the line 22 of Fig. 4C;"Fig. 3,

is an outer face or edgeview of the ring;

are cross-sections of modifications of the invention; Fig.7 is an outhne cross-section Fig. 4 is a plan of the ring; Figs 5 and 6 of a ring with perfectly balanced stresses and in which the center of figure and center of magnitude are coincident; and Fig. 8 is an outline cross-section of a ring formed 'with a single oil basin adjacent to one side a of the ring showing the strain or distortion produced therein'by --the same is subjected; t

Referring to the drawings, and for the present to'Figs. 1 to 4 inclusive, C represents the engine cylinder and P, the piston,

the latter being'herein shownwith one of the improved oil sealing and packingrings in con unction with-ordinary lubricating and packing rings common in the art. The

improved ring comprises a resilient imperforate'annular split band 1 which is depositthe ban ed (as well understood in the art) in the annulargmripheral groove k of the jpigton, to expan or' normally ,tendin dilate and hence to hug t e walls of the .fbylinder when thepiston with its" .band are inserted thereinto. The stresses which cause the band to expand or contract act in planes transverse or at right angles to the axis of the band; and when a. resilient band ofthe character here indicated is confined by the inner walls ofthe cylinder and thereby held .rmg, saidneutral surface intersecting cross-section of the ring along. the neutral contracted, or restrained against further ex- .pansion, the bending moment of the restraining force tends-to impose tension on the outer layers of the ring and compression on the inner layers the same as would a' load acting on a beam--supported or fixed at one end, 'or the opposite to the action of a load acting'on a-beam supported at both ends.-' In a ring subjected to stremes of the character referred to, there will necessarily be resent a. neutral surface 12. Figs.'2, 4 between the inner and outer faces of tlhe t e axis of said cross-section as shown in Fig. 2, sald axis be by said cross-section. The bending momentof the stresses may be assumed to operate in the plane indicated by the line t in Fig. 2,

said plane being perpendicular to the neuthe stresses to which backward stroke, the same as, and as supposed to traverse the. center of magnitude of the area represented anemia 'tral surface a of the ring and bisecting the neutral axis of the cross-section taken at any a medial'plane through the ring and transverse to the axis thereof. Disposed on ops posite sides of said medial lane t along the outer cylindrical face oft e ring orband, and contiguous to the sides thereof, or at point along the ring, and corresponding to what correspond to the outer corners of the band are (preferably) annular oil-collecting basins, grooves or equivalent chambers or receptacles a the opposite walls 10, 'w, whereof terminate respectively in cutting or shear-- ing edges e which scrape the oil or lubricant from the inner walls of the cylinder, and

with edges 6' which clear said walls, leaving a passage-way or clearance 03 throu h which the oil is free to pass to and from t e basin. The basins a, a, are disposed symmetrically about and at equal distances from the medial plane t of the moments involved in the stresses to which the ring is subjected,

the result being that in the cross-section of v the ring (Fig. 2) the molecules of the mass are evenly distributed relatively to said me dial plane t. It follows therefore that the stresses through the ring will be perfectly balanced, the molecules yielding or respond ing to the bending moment uniformly'and evenly throughout the entire cross-section of the ring, whereby the outer face of the ring will bear evenly at all points against the inner walls of the cylinder and hence wear evenly, thereby prolonging the life of the ring. Both sides of the rin being alike (or substantially alike, an absdl ute corres 0ndence not necessarily being required to ring the ringwithin the scope and spirit offour invention), it follows that the ring is re-' -versible and it makes no difference in mountthis basin which is depended on to scrape the down or forward .stroke of the piston, the oil being released from the ba'sin the oil from the walls of the cylinder with and spread over said walls on then -or described in the patent aforesaid. Preferably, the basinsa, a, should be so formed i and disposed that the cone elements m which bisect the respective basins (or which blsect the angle between the basin walls where such walls are not opposite or parallel) shallintersect in the medial moment plane 1% as indicated in Fig. 2. Where kerosene or hydrocarbons-1 0f high igniting or flashing tern V perature' are employed in admixture with gasolene as-the motor fluid, the unconsumed.

liquid portions of the kerosene or hydroor that facing the combustion chamber are revented by the inner inclined wall of such asin from coming in contact with the comparatively cool walls of the cylinder and accordingly prevented from cooling to the point where they will give rise to engine trouble b the carbonization of particles not complete y or sufiiciently consumed. The object sought of course is to prevent an undue cooling of these heavy hydrocarbons, such cooling being inevitable were "the liquid particles accumulating in the upper basln a permitted to come in direct contact with the cool cylinder walls: Another advantage of the upper basin (2 is, that the heavy hydrocarbons accumulating therein are prevented from working their way into the crank-case and in an even and uniform pressure of the outer face of the ring against the inner walls of the cylinder. A typical example of an evenly and uniformly stressed'ring is shown in Fig. 7 wherein the cross-section of the 'ring 10 is a parallelogram, the neutral axis a of which passes through the center of figure and through the center of magni-v tude coincident therewith, the central plane of moments being indicated by t. It is perfectly obvious that a ring (or beam) having at all points a symmetrical and uniform cross-section as' shown in this figure, will flex or yield to the bending moment evenly and uniformly and in planes parallel to the medial plane t'- in which the bending inoment or force is supposed to act, and the. inner and outer faces 1', 1", of the ring (or the corresponding faces of a beam) will remain parallel and permanently at right angles to said plane it. In other words the ring (or beam) will suffer no distortion or strain under the stresses to which the same is sub1ected. The moment however that we excise or remove from one corner of a ring I of the cross-section shown in Fig. 7, suflicient material so as to form a ring 20 with a basin a as shown by the outline cross-section in Fig. 8 (corresponding in cross-section to the ring forming the subject-matter -of the patent aforesaid), the inner and outer faces an, m, of such ring, when the rin is under stress will no longer remain perpen ieular to the planet along which the force or bending moment acts, but the ring will suffer a strain or distortion as shown by the dotted position of the parts in said figure, the outer face of the ring being brought to an incline toits ori 'nal position due to a spreading of the W55 of the basin a, and causing'most of the wear to center on the oil-scraping edge e", the major portion of the outer face. of the rin operating clear of the inner walls of the cy inder C. The distortion suffered by the rin thus causes the ring to wear unevenly an in a comparatively short time the ring is useless. This distortion or tilting is due to the unevenness of the stresses through the cross-section of the-ring resulting from the uneven distribution of the molecules of the rin about the medial moment plane 25", the t icker' portions of the cross-section of the ring onone side of such plane offering more resistance than the reduced portions disposed on the opposite side of said plane. In this ring the neutral axis n" no longer passes through the center of figure.

We need. not of course adhere to the crosssection of ring shown in Figs. 1 to 4. For

example, in Fig. 5 is shown a ring 30 with oil collecting basins b where the opposing walls of the basin are not strictly parallel. In Fig. 6 we show a ring 50 with corner oil basins b" substantially V-shaped in crosssection. Other modifications are possible. Like in the main form described, the bisectrices m of the basins incline toward and meet in the central moment plane of the ring. Thus, in Fig. 5,-the bisectrices m meet in the moment plane and in Fig. 6 they meet in the moment plane y". In Figs. 1 to 4, the basin walls w, w, are parallel and inclined to the axis of the ring and to the me dial moment plane t. 1

It is to be understood that we may depart from the details and structures shown, in many particulars without departing from the nature or spirit of our invention. For example the peripheral basins or grooves 11 need not be continuous but may extend only partially around the ring; they may have various depths; their walls may assume various inclinations to each other and to the medial moment plane. Whatever be the form of the oil collecting basin however, the cutting and clearing edges of its walls should be disposed in different transverse planes through the axis of the ring.

Having described our invention what we' claim is:

1. A piston packing ring comprising a resilient split band provided with'peripheral oil-collecting basins at the outer-corners of the band, the outer wall of each basin or that walls of the cylinder with a given strokeof at the outer corners of the band; said basins 7 having opposing walls inclined to the plane of moments by which the band is stressed when in service, the outer of said walls terminating in an edge clearing the walls of 'the cylinder in which the piston is to operate, and the inner of said walls terminating in a cutting edge for scraping the oil from the cylinder walls with a given stroke of the piston.

' A piston packing band'provided on opposite sides of a medial a resilient split band prO-p ring for engine cylinders COIIIPI'lSlIlg a resllient imperforate split mes es circumferential line .with an annular basin bounded on one side by an outer wall inclined to the plane of moments by which the band is stressed when in service,v and ter- 25 the cylinder in which the piston is to oper-' minating in an edge clearing the walls of ate, and bounded on the opposite side by an inner wall terminating in a cutting operating to scrape the oil from the walls of the cylinder vinto the basin with a given stroke of the iston, the oil be' free to flow into'the in past the clearing edge aforesaid.

In testimony whereof we aflix our signatures, in presenceof two witnesses.

' ARDEN J. MUMMERT. 1

JESSE T, Witnesses:

Emu. STAREK, Jos. A. Mrcm r woonBRmGn

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