US2081258A - Method of making packing rings - Google Patents

Description

May 25, 1937. A. w. WENZ EL METHOD OF MAKING PACKING RINGS Filed Afiril 11', 1936 4 gamma/6oz Albert W1 Wenzei Patented May 25, 1937 y w I Q "UNITED STATES PATENT OFFICE 2,os1,25s a METHOD or MAKING PACKING mes Albert W. Wenzel, West Orange, N. J. Application April 11, 1936. Serial No. 73,837

- 9 Claims. (Cl. 29156.6)

. This invention relates to the method of manuboth on its outside and inside circumferences and facturing packing rings, and is a continuation in which is being compressed in accordance with the part of previously filed application S. N. 710,755 present invention; of February 10, 1934. Figure 6 is a sectional view on line 6-6 of Q The'objects of the invention are to provide an Fig. 5;

- 5 improved method for making rings of lasting Figures 7 and 8 are views similar to Figs. 5 quality; to provide a method which will produce and 6 showing a different compression tool; a ring subject to minimum distortion under se- Figure 9 is a similar sectional view of the ring vere heat conditions such as encountered in inafter completion of thecompression step;

10 ternal combustion engines; to provide a method Figure 10 isa similar sectional view of the ring 10 wherein the tension in the ring is made permew of Fig. 9 in a chuck as held ior grinding the side nent; to provide a method which afiects the mofaces of the ring; and g lecular structure to stabilize "the same beyond a Figure 11 is a) view similar to Fig. 8, showin point at which engine heat will cause no further a modified construction of ring and tool.

l5 disturbance; to provide a method which takes Haretofore i th manufacture of packing 15 into consideration 'the internal inequalities of rings, a method has been employed fo t tension of the molecular structure; to obtain a -ing the rings known as hammering.- The method closure of the ring and at the same time permit has applied a compressive stress at separated th ring to assume a natural Shape w ch it, aspoints along the inner circumference of the usual Sumes with free exercise of its internal stresses, normally expanded piston ring, but between the 20 p epa ato y to machining; to d e i g in its points 'of. compression the metal of the ring has natural shape which it assumed when closed while remained in its original'state. By virtue of the m hin n he same; o retain the inherent rehammered parts of the ring alternating with unsili'ency of the ring byutilization of pressure sufhammered parts, the molecular structure of the 5 ficient to disturb a part of the metal; to apply metal is irregularly disturbed, and while this has this disturbance throughout the length of one obtained a certain beneficial result in tensioning surface of the ring; to avoid applying a pressure the ring, it has had a detrimental efiect in that which will create'burrs; toapply a pressure withthe rings warp readily under engine heat. Acout fracturing the metal; to obtain a burnishing cording to the present invention, the ring is compression; to obtain a fiow'of the metalunder constructed to be a perfect circle when closed 30 action of the burnishing and a molecular rearand to have perfect tension throughout the length rans ntpto create the molecular disturbance of its treated surface. The usual piston ring is uccessive molecules in .a circumferential .iuxtreated on itsinner circumference so as to stand taposition; to reduce the heretofore necessary normal expanded, but other packing rings,

number of operations for makin'garing; to secure such as are to stand normally contracted, are 5 simplicity of construction, operation and fulfilltreated upon the outer circumference. It is likement f the v l S ps requis t0 h method; wise possible to treat the ring on its side or flat -and to obtain other advantages and results as faces, or upon one or more edge corner, or upon may be brought out inthe following description. a bevel or round. 'Therefore, whilethe selected 40 'In the accompanying drawing in which like illustration herein shows treatment on the inner 40 numerals of reference indicate similar, parts circumference, it is to be understood the inventhroughout the several .views: tion is not restricted thereby. I

Figure 1 is anelevation of a ring which has .In proceeding with the manufacture of rings been cut to provide the usual, expansion gap, but according to my invention, the blank may be an otherwise in its crude condition; iron casting' in the shape of an annulus. In 45 Figure 2 shows the ring of Fig. 1 drawn together Figure 1, I have illustrated such an annulus, destO 01089 the Said p; ignated by the numeral I 0 upon which the first Figure 3 illustrates the next step of the method operation has been performed, namely cutting the wherein one or more rings are held frictionally by same through at l I- so that the annulus may be their fiat surfaces ready to machine the outside resiliently compressed. While I have shown the cylindrical surface of the same; cut as made diagonally with respect to the radius, Figure 4 illustrates the next step wherein the any suitable cut may be made for obtaining the rings are similarly clamped to be internally madesired joint or overlap for the ends thus made. chined; After completion of this first step, the ring is Figure 5shows aring which hasbeen machined next drawn together under natural conditions,

as shown in Figure 2 by any suitable tool l2, here shown as including a band l3 which will extend around the annulus and the ends of which can have tension applied thereto in opposite directions. The tool will accordingly apply a closing tension to the ring in a circumferential direction enabling the ring to assume its natural shape henceforth to. be assumed when the ring is closed. In other words, if the internal stresses and strains tend to make the casting oval or lopsided, the ring assumes that shape while gripped by the tool before and while being introduced into the clamp of Figure 3 (described below) and retains that shape even after said clamp is applied. Then, when the outer surface of the ring is machined off, the ring becomes a perfect circle and thereafter will'always naturally assume its shape as a perfect circle when closed in an engine cylinder.

As indicated in general terms. above, while the ring is drawn together to its naturally assumed shape when closed, it is clamped by its side or flat faces with adequate force to retain the ring in exactly the shape it assumed under influence of the tool. The tool may then be removed and the clamping utilized to retain the ring both closed and in its assumed shape for the following machining operations. The clamping of the ring is illustrated in Figure 3, wherein numeral id indicates a base or clamping plate in the nature of' a face plate with a fiat face against which one side of the ring l0 may be engaged. A spider-like mandrel l5 positioned upon a central bolt I6 protruding from the face plate may be utilized for approximately centering the ring with respect to clamping or face plate M. In practice, I prefer to make the mandrel l5 and bolt l6 of sufficient length so that a plurality of rings may be applied at one time, said rings resting against each other side by side and being clamped by an outer clamping plate I! applied upon the bolt next the outermost ring and caused to squeeze the rings together by applying a nut I8 to the bolt. The outer clamping plate I! is of a diameter greater than the inner diameter of the ring, but of less diameter than the outer diameter of the ring. A margin of the ring next the outer circumference therefore may be seen projecting beyond the circumference of the outer clamping plate.

It will be understood that the outer curved surface of the several rings thus held by the clamp provides a substantially cylindrical surface. The clamp with the rings may then be put in a lathe or other suitable machine and the outer surface of the rings turned down to a depth below the chilled or spongy layer of the casting to a surface where the metal is healthy, for instance to surface .l9 where the crusty surface of the casting and the imperfections which exist in that part thereof have been eliminated. All of the rings are thus brought to a perfect cylindrical formation of desired size and healthy surface.

While outer clamping plate I1 still retains the machined rings secured in perfect cylindrical condition, a clamping collar 20 which has' a middle opening 2| large enough to receive clamping plate I! therein, is applied to the margin of the piston ring projecting beyond the edge of clamping plate l1, and is then secured by bolts 22 and nuts 21 with respect to the base clamping plate l4. After this clamping collar 20 is secured firmly, the outer clamping plate I1 and mandrel l5 as well as bolt l6 may be removed. This enables the inner surfaceof the several piston rings to be machined, if desired, for instance to a healthy surface 23, thereby taking off the crust of the castings at the inside of said rings and removing the imperfections of the chilled and spongy layer to a desired depth. When this operation is completed, the clamping collar 20 may be removed, if desired, and all further operations performed individually upon the rings.

As illustrated in Figures 5 and 6, the next operation upon the ring is to obtain a molecular disturbance substantially throughout the length of one surface of the ring. This operation may be performed upon such surface or surfaces of the ring as found desirable or necessary for the tension desired. The step in its preferred performance contemplates obtaining in the finished ring at least one surface which is compressed for the entire circular length of that surface. As one means of accomplishing this result upon a selected surface, for instance the inner circumference of the ring, a tool 24, shown in the shape of a roller, may be utilized. While this roller is also illustrative of a progressive application of the tension, it is not restricted thereto, as the tension may be otherwise applied, for instance by an expanding tool and progressive from several points or with a simultaneous pressure throughout the length of the surface.

Describing the illustrated embodiment, the tool 24 is shown as having a central bead 25 of less width than the ring. This tool is applied to the inner circumference of the ring. and caused to travel entirely around that circumference with suitable pressure so as to create a continuous depression or groove 26 in the ring. Bead 25, being of less width than the ring, avoids turning up a bur at the side face of the ring. However the molecular disturbance and compression is continuous throughout the length of the inner circumference and thus obtains a perfect tensioning without any likely distortion or warping in use. The molecular disturbance involves successive juxtaposed molecules in a direction circumferentially of the ring, and, for want of a better term, may be referred to as burnishing. It is within the scope of my invention to apply the burnishing action not only as above described,

but at successive intervals spaced by' unburnished intervals, as well as by a continuous burnishing terminating at a distance from one or both ends of the ring. A burnishing partly upon one surface and partly on another, a burnishing partly upon one corner edge and partly on another, as well as a combination 'of burnishing partly on a. face and partly on a corner or upon several faces and one or more corners'and conversely upon a plurality of corners and one or more faces may be utilized.

While in the above description I have referred to a tool under the specific designation of roller it is to be understood that tool does not have to have, and preferably does not have a rotative movement while being applied to the ring. I deem it within the scope of the invention to permit the roller to rotate freely, however, to have a partial rotation, should such be desired, but preferably not to rotate at all during the engagement in use with the ring. Its circular or roller shape has the benefit of enabling it to be readily applied in the machine and its angular disposition changed by the operator as the roller surface wears at any one spot. More than mere rolling the tool on the surface is required; there must be a flow of the metal, that is, a slight mound of metal forms in advance of the tool and groove or depression 26 .within the inner ma is pushed forward, like a wave, thereby obtaining a positive molecular displacement in the metal in a circumferential direction. This effect is best accomplished with no rotation of the tool being permitted. vThe tool has to be a blunt one so as not to cut the mound or "wave, and yet it may be less rounded than a roller. For instance, a fixed tool 24 is shown in Figures '7 and 8 with a downwardly directed rounded of beaded end 25% which will obtain the desired impression, flowing or burnishing of the'metal of the ring.

It is within thescope of .the invention to apply this pressure uniformly throughout the circular length ,cf the ring or to vary the pressure in such manner as to obtain greater compression diametrically opposite the split or joint, and progressively lessening'in both directions from this maximum pressure to a minimum pressure adjacent the split. Figure 9 illustrates the ring as having had the pressure applied continuously along the inner circumference, thereby forming burnishing,

whereas the circumference acted upon is originally substantially cylindrical. In any instance, I also deem it within the scope of the invention and within the meaning of the description when referring to a continuous pressure, to employ a burnishing tool or roller or other means such as hammering for obtaining a compression of the metal of. the ring at very close intervals, in other words, the roller if used does not have to be smooth, but may have its surface corrugated either in a circumferential direction or in an axial direction, or diagonally, -or with crossing corrugations comprising a combination of any of those just mentioned, so lose as to produce a substantially continuous e ect, and especially where a sliding compression is effected between tool and ring while the tool is in compressive contact with.

smoothing and truing operation upon the side" the ring. I

It is preferable, after the rolling, burnishing or compressing step above described, has been completed, to grind or otherwise finish the'flat or side faces of the ring, not only to remove any its circumference but from. which the ring projects at one side as clearly shown in Fig. 8. The projecting side of the ringis ground or otherwise treated and thereafter the ring is reversed so that the other side thereof can be similarly,

ground or treated. According to this invention, therefore, the ring is very accurate in all of its faces which engage either the piston or cylinder in use.

Obviously detail changes and modifications may be made in carrying out my improved meth- 0d of manufacturing Packing rings and in the apparatus employed in the accomplishment of that method without departing from the spirit or scope of the invention, and I do not wish to be understood as limiting myself thereto except as set forth in the following claims when construed in the light of the prior art.

Having thus. described my invention, I claim:-

1. A method of manufacturing packing rings comprising first closing the ring by a circumferential tension, clamping the ring fiatwise upon a member while thus closed, and machining said ring on both its outer and inner circumferences before releasing from said member.

2. A method of manufacturing packing rings which preferably engages the ring entirely around comprising first closing the ring by a circumferential tension, clamping the ring flatwise upon a member with the outer circumference of the ring' exposed, machining said outer circumference, and thereafter machining the inner circumference before releasing from said member.

3. A method of manufacturing packing rings comprising first closing the ring by a circumferential tension, clamping the ring fiatwise with the ing said outer circumfere ce, applying a clamp-to outer circumferences of tlge ring exposed, machinthe flat face of the ring outside of and without releasing the first clamp, removing the first clamp, and machining the inner circumference of the ring.

4. A method of manufacturing packing rings comprising applying a continuous sliding pressure throughout the length of one surface thereof with a difierential of intensity transversely of said surface for obtaining a continuous molecular disturbance of the material throughout said length.

5. A method of manufacturing packing rings comprising applying a continuous sliding pressure to the inner circumference thereof for obtaining a ence, said pressure being applied with maximum intensity parallel to and spaced from one longitudinal edge of said surface.

bur which the compression step may have raised, 6. A method of manufacturing packing rings,

but also to obtain a ring which has its side faces in planes and with the planes of ,the two side faces parallel to each other. It often occurs, upon compressing a ring to the shape which it assumes within a cylinder in use, that certain internal stresses cause the ring to warp or dish and thus have its side face or faces not truly within a plane, especially in rings of uneven crosssection. The warping may affect only the ends of the ring, or may affect the entire ring. It is therefore a feature of the present invention to perform, as a final step, a grinding or other faces of the ring underconditions of the ring as will exist when in'use. For this purpose, the ring is squeezed with. its ends substantially toether into a chuck or other holding means 2 8 cumferential direction for obtaining a molecular disturbance in the material of the said ring.

'1. A method of manufacturing packing rings comprising burnishing a groove with pressure throughout the length of one surface of the ring for obtaining a molecular disturbance of the material throughout said length.-

comprising applying a bumishing, sliding pressure 1 upon the inner circumference of the ring in a cir-' continuous molecular disturbance throughout said side of and without releasing the first clamp, relength. l moving the first clamp, machining the inner cir- 9. A method of manufacturing packing rings cumference of the ring, and applying a continuous comprising first closing the ring, clamping the pressure throughout the length of one surface of 5 ring flatwise with the outer circumference of the the ring forobtaining a molecular disturbance of 5 ring exposed, machining said outer circumference, the material throughout said length. applying a clamp to the flat face of the ring out- ALBERT W. WENZEL.

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