US3633260A - Method of forming a spacer-expander - Google Patents

Method of forming a spacer-expander Download PDF

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US3633260A
US3633260A US39264A US3633260DA US3633260A US 3633260 A US3633260 A US 3633260A US 39264 A US39264 A US 39264A US 3633260D A US3633260D A US 3633260DA US 3633260 A US3633260 A US 3633260A
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United States
Prior art keywords
strip
strut
bending
blanking
spacer
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US39264A
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English (en)
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Frank G Warrick
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SPX Corp
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Sealed Power Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/06—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass piston rings from one piece
    • B23P15/065—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass piston rings from one piece from metal strip
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/16—Making other particular articles rings, e.g. barrel hoops
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/84—Making other particular articles other parts for engines, e.g. connecting-rods
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49229—Prime mover or fluid pump making
    • Y10T29/49274—Piston ring or piston packing making
    • Y10T29/49279—Piston ring or piston packing making including rolling or die forming, e.g., drawing, punching

Definitions

  • This invention relates to piston rings and more particularly to an improved method of forming a spacer-expander adapted to be used with one, but preferably two, thin metallic rails of a piston oil ring assembly for an internal combustion engine.
  • An object of the present invention is to provide an improved method of forming a spacer-expander of the type disclosed in U.S. Pat. No. 3,477,732, issued Nov. 1 1, I969 in the name of Frank G. Warrick, inventor herein, and assigned to Sealed Power Corporation of Muskegon, Michigan, assignee of the present application.
  • the present invention provides a method of forming the spacer-expander shown and described in connection with FIGS. 1-5 in the aforementioned patent in a manner which is economical, reliable, accurate, which lends itself to progressive die blanking and bending operations, which permits mass production of the spacer-expanders on a reliably repetitive basis with close tolerances in automatic machine setup, and in which the blank strip stock starting material is worked and stressed in blanking and bending it into the final product in a manner which cooperates with the various functions of the respective structural portions of the spacer-expander in its finished form.
  • FIG. 1 is a plan view of an oil ring assembly incorporating one embodiment of a spacer-expander made by the method of the present invention and having portions broken away to illustrate details thereof.
  • FIG. 2 is an enlarged vertical sectional view taken on the line 2-2 of FIG. 1 with the oil ring assembly installed in the oil ring groove of a piston and compressed to operating diameter by the wall of the engine cylinder in which the piston is installed.
  • FIG. 3 is a fragmentary perspective view of the spacer-expander and associated rails of the oil ring assembly.
  • FIG. 4 is a fragmentary perspective view of a strip of the initial ribbon stock from which the spacer-expander is formed.
  • FIGS. 5, 6, 7, 8, 9, 10, 11 and 12 are fragmentary perspective views showing in sequence the progressive die blanking and bending steps of the method of the invention.
  • FIGS. 13 and 14 are sectional views taken respectively on the lines 13-13 and 14-14 of FIG. 12.
  • FIGS. l5, l6, l7, l8 and 19 are fragmentary vertical sectional views taken on the lines 15-15, 16-16, 17-17, 18- 18 and 19-19 of FIG. 12 illustrating in more detail the progressive strut bending steps and associated tooling for performing the steps to impart the progressive bending of the strip illustrated in FIG. 12.
  • FIGS. 20, 21 and 22 are enlarged fragmentary views of the left-hand bend portion of the strut and illustrating respectively the progressive zone working of the strut imparted in FIGS. 15-19 inclusive.
  • FIG. 23 is a fragmentary side elevational view of an induction heat treat step.
  • FIG. 24 is a fragmentary plan view of the progressive coiling step of the method.
  • FIG. 25 is a fragmentary plan view illustrating the strip cutoff step of the method.
  • FIG. 26 is a fragmentary plan view of a joint trim step of the method.
  • FIG. 27 is a fragmentary plan view of a joint bending step of the method.
  • FIGS. 1, 2 and 3 illustrate a spacer-expander 58 used in connection with one or two rails 60 and 62 to form an oil ring assembly for use in the groove 54 of a piston 52 reciprocable in a cylinder 50, as set forth in more detail in the aforementioned U.S. Pat. No. 3,477,732, the disclosure of which is incorporated herein by reference.
  • FIGS. 1, 2 and 3 correspond respectively to FIGS. 1, 5 and 3 of said patent except that the end joint structure consists of the T-shaped pad 275 disclosed in conjunction with FIGS. 12, I4 and 15 of said patent.
  • spacer-expander 58 Since the function and structure of spacer-expander 58 is fully set forth in the aforementioned patent, and the reference numerals used herein are the same as in FIGS. 1-5 of said patent, spacer-expander 58 will not be described in detail herein except as is incidental to the description of the method of forming the same pursuant to the present invention.
  • the first step of the method of the invention is the provision of a strip of thin flat ribbon metal stock (FIG. 4) which may be supplied from a suitable coil 102 of such stock for feeding in a generally straight horizontal path through a series of blanking and bending operations which preferably are continuously and automatically performed in a machine constructed pursuant to the disclosure of a copending U.S. Pat. application of Roy E. Overway and Frank G. Warrick, Ser. No. 39,499, filed on even date herewith, and entitled Machine for Forming Spacer-Expanders".
  • Strip 100 preferably is made of stainless steel, and when being formed into spacer-expander 58 for use in a dual rail oil ring assembly 58-60-62 having a nominal operating diameter of 4 inches for use in a groove 54 having an axial width of 0.188 inch, strip 100 has, by way of example, a unit length of I 1.833 inches, a width of 0.434 inch and a thickness of 0.0 l 2 inch.
  • strip 100 is oriented such that its upwardly facing side 104 remains so oriented throughout the steps of the method described in conjunction with FIGS. 4-22 inclusive, assuming that the blanking punches and bending dies are positioned above the strip and travel downwardly perpendicular to the plane of the strip on their working strokes. Also the upwardly facing surface 104 and strip 100 becomes the radially inner or interior surface of spacer-expander 58 in its final form.
  • the punch on its working stroke will first strike surface 104 of strip 100 on a shearing stroke and will travel downwardly through the strip so that the burrs are formed on the underside of the strip, which later becomes the outer exterior surface of the spacerexpander 58.
  • burrs will be stressed in compression when the spacer-expander is coiled to operating configuration in the step illustrated in FIG. 24.
  • the burrs will be exposed at the outer periphery of spacer-expander 58 where they may be readily removed by chemical and/or mechanical polishing equipment. With this orientation the scrap material removed from the strip falls by gravity and thus is easily collected in a suitable container.
  • the punching and bending of the strip from above simplifies the construction, mounting and support of the backup dies for these operations.
  • Another feature of the method is to feed strip 100 lengthwise simultaneously through a series of blanking and bending stations which perform blanking and bending operations on strip 100, the strip being intermittently advanced a distance equal to two sections or pitches, a pitch as used herein meaning an incremental distance lengthwise of the strip corresponding to the repeat of the pattern seen in blank 68 of FIG. 7 wherein the pitch length is labeled P" and represents the lengthwise or longitudinal distance from the center of one strut portion 74 to the center of the next adjacent strut portion 74.
  • P the pitch length
  • one section is one pitch length long and contains one leg portion 76, one leg portion 78, and one strut portion 74.
  • leg portion 76 is joined integrally to band 72 and the outer end of leg portion 78 is integrally joined to band 70.
  • the free or inner ends of leg portions 76 and 78 terminate short of the opposite band.
  • the strip length per spacer-expander is made equal to 26 times P," plus two additional pitch lengths for a total of 28 P to provide material for the end joint tabs 275 mentioned previously.
  • each blanking and bending operation is performed upon two adjacent pitches at a time, and strip 100 is fed lengthwise between each operation for a distance of two pitch lengths which may represent a distance of 0.600 inch.
  • the strip is held stationary between each advance in accurately located position for registry with all of the punching and/or bending dies required to perform a different operation at each station corresponding to the separate figures shown in sequence herein in FIGS. 5, 6, 7, 8, 9, l and 11, and this same advance occurs in the operations of FIGS. 12-25 inclusive.
  • the first punching operation consists of simultaneously punching six parallel slots I06, 108, 110, 112, 114 and 116 which extend perpendicular to the length of strip 100 and are equally spaced lengthwise of the strip, the distance between the center of slot 106 and slot 112 being equal to the pitch length P.
  • the material removed in this step consists of the six punchings 106-116 as shown in FIG. 5.
  • Strip 100 is then indexed to advance it to the right as viewed in FIGS. 1-12 inclusive a distance of two pitch lengths. Then another six slots are punched in the strip. In the example given a total of 13 strikes of the six slot punches occur in sequence to form a total of 156 slots.
  • strip 100 is advanced another two pitch increment but the six slot punch step of FIG. 5 is skipped to thereby leave a blank end joint portion 118 (FIG. 6) in strip 100 from which two end tabs 275 are subsequently formed, one tab becoming the trailing end tab and the other the leading end tab of two adjacent spacer-expanders being sequentially formed from strip stock 102.
  • an interim operation is performed on the end joint portion 118 wherein, as shown in FIG. 6, a pair of short tandem slots 120 and 122 are punched in portion 118 in the space where slot 112 otherwise would have been punched.
  • the punching of slots 120 and 122 produces the punchings 120' and 122 shown in FiG. 6.
  • Slots 120 and 122 serve as locator slots in conjunction with a pawl stop mechanism (not shown) of a suitable strip-advancing mechanism utilizing the principle of strip overfeed and pull back to provide intermittent strip advance.
  • a pawl stop mechanism (not shown) of a suitable strip-advancing mechanism utilizing the principle of strip overfeed and pull back to provide intermittent strip advance.
  • One such mechanism is disclosed in U.S. Pat. No. 2,925,847, particularly in connection with FIGS. 4-9 thereof.
  • the pawl stop mechanism is designed to catch the fourth slot 112 in each successive six-slot, two-section increment.
  • slots 120 and 122 in the end joint section 118 are likewise caught by the pawl stop when section 118 comes into registry with the stop mechanism.
  • the next step in the method of the invention is to punch out a portion 76' of the strip located between slots 106 and 108, and a similar portion 78' located between slots 108 and 110.
  • a similar punching operation is performed simultaneously on the adjacent pitch between slots 112 and 114 and 116. This punching operation thus forms in each pitch a leg 76 between slots 106 and 108 and a leg 78 between slots 108 and 110.
  • the material remaining between slots 110 and 112 and between slots 116 and 106 of the preceding six-slot series thus forms the two struts 74 in the two adjacent pitch lengths.
  • the first of two joint blanking operations is performed on skip portion 118 wherein six punches are employed to simultaneously blank out eight punchings 130, 132, 134, 136, 138, I40, 142 and 144.
  • the portions of the strip 100 removed by this blanking operation leave intact the two marginal bands 70 and 72 as well as a center strip 146 running from the leading strut 74 of one spacer-expander blanking to the trailing strut 74 of the next preceding spacer-expander blanking.
  • This blanking operation also leaves two cross strips 148 and 150 which are properly located to subsequently provide material for the cross bars 281 of the end tabs 275 as disclosed in the aforementioned U.S. Pat. No. 3,477,732 in conjunction with FIGS. l2, l4 and 15 thereof.
  • FIG. 9 The first bending step of the method of the invention is illustrated in FIG. 9 wherein an upwardly inclined foot 82 is formed on the free end of each leg portion 76, and a similar upwardly inclined foot 84 is formed on the free end of each leg portion 78.
  • the foot-bending operation of FIG. 9 is performed simultaneously on the four leg portions of two pitch lengths. This operation produces a bend line 82 between the foot 82 and the remaining portion of leg 76 which continues to lie in the plane of strip 100.
  • a similar bend line is formed between foot 84 and leg portion 78. This operation is repeated for a total of 13 strikes in the example given above.
  • a third punching or blanking operation is performed on skip portion 118 wherein punchings 70 and 72 are removed from the strip, leaving the center longitudinal strip 146 and the cross bars 281 of what will subsequently become the T-shaped pads 275.
  • the continuity of the marginal longitudinal bands 70 and 72 is retained in the continuous strip 100 through the several stations leading up to FIG. 10. This preserves the longitudinal strength of strip 100 as long as possible, the retention of the continuity of the side bands 70 and 72 thus reducing the tendency of the strip to buckle as it is pushed forward.
  • strip 100 is advanced through the blanking and bending operations of the method by pushing the strip 100 in a strip feeding station located upstream of all the blanking and bending operations.
  • a strip-feeding mechanism is disclosed in U.S. Pat. No. 2,925,847, which is also incorporated herein by reference for this aspect of its disclosure as well as for skip station punch and die structure.
  • the next step is to bend the legs 76 and 78 in each section upwardly from the plane of strip 100 about a bend line located close to the inner edge of margins 70 and 72 to form the bends 88 and 90 in the legs 76 and 78 respectively.
  • this bending is performed in a single stage so that the final angle between legs 76, 78 and the plane of strip is the same as that between leg 76 and band 72 and leg 78 and band 70 as in the free-state condition of the spacerexpander 58 as shown in FIG. 4 of the aforementioned U.S. Pat. No. 3,477,732.
  • the next step in the method of the present invention comprises a sequence of strut-bending operations as shown in FIGS. 12-22 inclusive wherein the flat strip 100, with the legs 76 and 78 bent up from the plane of the strip per the operation of FIG. 11, is progressively curled to impart a generally U- shaped channel configuration to the strip, as best seen in FIG. 14.
  • this is accomplished by progressively bending struts 74 in two bending zones equally spaced outwardly from the center of strut 74 as the strip is advanced through a progressive die-bending station equipped with a series of die punches and cooperating die shoes as well as a backup and stripper shoe as shown in FIGS. 15-22 inclusive.
  • these punches and dies may range in even number multiples from about 10 to about 20 punches. Assuming, for example. that these punches are numbered consecutively 1-10 inclusive in the direction of strip travel, the odd numbered punches operate on a leading strut 74 of one two-pitch length increment while the even numbered punches operate on a trailing strut 74 of this increment, all punches preferably operating simultaneously through one working cycle per each two-pitch index of the strip. 1
  • FIGS. 15-19 inclusive illustrate the progression of the first strut 74 of the two adjacent struts 74 and 74 of each two pitch increment through this progressive bending station.
  • FIG. 20 illustrates the progressive bending of strut 74 imparted successively in the operations of FIGS. 15, 16 and 17 with respect to the left hand bending zone of the strut as viewed in FIGS. 15, 16 and 17.
  • FIG. 21 illustrates the further bending progression imparted in the operation of FIG. 18, and
  • FIG. 22 illustrates the still further bending progression imparted in the operation of FIG. 19.
  • leading strut 74 is shown after it has been bent by being struck by the second punch 150 against its associated left and right die shoes 152 and 154 respectively and backup punch 156.
  • this leading strut 74 Prior to being so struck this leading strut 74 is advanced while in its flat unbent condition (shown at the left hand end of strip 100 in FIG. 12) into registry with the flat flush horizontal surfaces 158 and 160 of shoes 152 and 154 respectively.
  • this strip advance punch 150 is raised clear of the strip and backup punch 156 is elevated so that its upper surface 162 is raised slightly above the plane of surfaces 158 and 160.
  • backup punch 156 extends continuously through all punch stations and is elevated to its raised position when the respective upper punches are raised to their uppermost position so that the central portions of struts '74 and 74 can slide along surface 162 during each increment of strip advance, the strip thereby being elevated clear of the forming shoes at each station.
  • Each of the two bends in loading strut 74 are formed at the same time in progressive working stages shown herein by way of example as five stages identified as A, B, C, D, and E cor responding to punch stations Nos. 2, 4, 6, 8 and 10. Accordingly, strut 74 is operated on at stations Nos. 2, 4, 6, 8 and 10 by the tooling shown in FIGS. 15, 16, 17, 18 and 19 respectively.
  • station No. 2 the horizontal separation between punches 152 and 154, the radius R and R (FIG. of shoes 152 and 154 and the width as well as radii at the lower corners of punch 150 are properly correlated to produce a first bending of strut 74, changing it from its flat shape to the configuration shown in FIG. 15.
  • This first bend is completed when punch 150 is bottomed on its downward working stroke against the strip stock and bottomed backup punch 156, this being the position of the parts shown in FIG. 15.
  • This change in configuration of strut 74 from its flat horizontal position to the first upwardly inclined position labeled A is shown in broken and solid lines respectively in FIG. 20, only the angular inclination of the left portion of strut 74 being shown in FIG. 20.
  • the bending forces imparted by the tooling in station No. 2 are concentrated in a small segment of strut 74, labeled A in FIG. 20, causing segment A to be bent, thereby cold working and permanently deforming only this portion of the strut.
  • portion A of strip 74 being bent upwardly against the innermost angular increment 164 of thercorner radius of punch 150.
  • the remaining portion of strip 74 outwardly of segment A extends tangentially from radius segment 164 up wardly and outwardly to its tangential contact with the radius R of shoe 152.
  • segment zone working is imparted to the right-hand bend zone of strut 74 (not shown in FIG. 20) in station No. 2.
  • FIG. 15 illustrates the amount of bending imparted in station 1, which may be on the order of 15 upwardly from horizontal, whereas the amount of bending imparted to the leading strut 74 in station 2 may be on the order of 30 upwardly from the horizontal as shown in FIG. 15.
  • strut 74 is bent in station No. 4 from its configuration A of FIG. 15 to a configuration B illustrated in FIG. 16 by a punch 166, associated die shoes 168 and 170 and backup punch 1172.
  • the tooling employed in station No. 4 has the same shape and size as the tooling in station No. 2, the only difference being that punch 166 and backup punch 172 bottom farther downwardly below the horizontal plane of the upper surfaces 174 and 176 of shoes 168 and 170.
  • Strut 74 is thus bent in a localized zone of working contiguous with and outwardly of segment A, causing permanent deformation of only segment B in this station as the strut is bent against the increment 178 of the corner radius of punch 166.
  • strut 74 moves into registry with the tooling at station 6 wherein it is operated upon by punch 180, associated shoes 182 and 184 and backup punch 186. Again this tooling is the same as that used in the previous bending stations but punch bottoms even further downwardly from the plane of the upper surfaces 188 and 190 of shoes 182 and 184, thereby bending strut 74 from its B (FIG. 16) to its C configuration (FIG. 17). In so bending, strut 74 is cold worked in still another localized zone of working contiguous with and outwardly of segment B, again causing permanent deformation of only segment C in this station as strut 74 is bent against the increment 192 of the corner radius of punch 181). This sequence of zone working is best indicated in the composite view of FIG. 20.
  • FIGS. 20, 21 and 22 The progressive narrowing of the punches and the smaller spacing between the associated die shoes which occurs in stations 8 and 10 relative to station 6 is illustrated schematically in the vertically aligned views of FIGS. 20, 21 and 22 wherein the vertical phantom lines 186, 196 and 214' represent extensions of the left edge of the backup punches 186, 196 and 214 in stations 6, 8 and 10 respectively.
  • the side surfaces 216 and 218 of punch 212 are formed to the final angle to which the strut 74 is shaped as shown in FIG. 19.
  • the further narrowing of the punch in station No. 10 causes the next localized zone of working to occur contiguous with segment D and inwardly thereof as shown in FIG. 22 wherein strut 74 is bent from the shape D (broken lines) to the shape E (solid lines). This bending occurs against the innermost increment 220 of the corner of punch 212, causing pennanent deformation of segment E while bringing segments D, A, B, and C against the comer of punch 212.
  • the final additional bend produced in segment E provides a total bend of 100 thereby bringing the portion 96 of strut 74 against the inwardly inclined side surface 218 of punch 212.
  • portions 96 and 98 are brought to their final shape E wherein they are inclined towards one another even through the working strokes of the punches all occur in a vertical direction and there is no horizontal movement of the associated shoes 208 and 210.
  • the 100 zone of working in the two bending zones of strut 74 is accomplished in approximately equal increments, preferably in five stages.
  • the strut is stressed through successive increments to produce a relatively large zone of cold working and permanent deformation without being overstressed, i.e., without causing cracking or breakage, even though it has been bent about a relatively small radius through more than a right angle.
  • a stripper plate 222 is provided as shown in broken lines in FIG. 19 which extends horizontally between the punches of stations Nos. 9 and 10 and preferably also of stations Nos. 7 and 8. Plate 222 is maintained stationary at a given elevation just above raised level of the strip during strip advance. Thus when punch 212 is lifted, margins 70 and 72 will strike plate 222 to stop further upward movement of the strip while punch 212 is lifted further until the nose of the punch has been cleared from between bands 70 and 72.
  • the 10 inclination of its side surfaces 216 and 218 serves to cam apart the portions 96 and 98 of the strut so that the punch nose can clear the strip, the spring material of the strip allowing it to yieldably flex apart and causing it to spring back to the final configuration once the punch has cleared the same.
  • FIG. 23 The next step in the method of the invention is illustrated in FIG. 23 wherein the now U-shaped strip 100 is advanced lengthwise through a suitable induction heating coil 224 to provide a stress relieving heat treatment in a conventional manner.
  • the next step of the method is the coiling of the channel shaped strip into the circular configuration of the spacer-expander 58 shown in FIG. 1, this coiling operation being partially illustrated in FIG. 24.
  • the strip still is being intermittently advanced two pitch lengths at a time in the direction of the arrow in FIG. 24.
  • the strip is brought between suitable bending dies which operate on a portion 230 of the strip to impart the proper radius to this portion of the strip in a single stroke operation which is repeated on successive increments 230.
  • the trailing joint portion 234 comes into registry with a joint cutoff station located just upstream from the strip coiling dies.
  • the strip is guided as it is fed out of the coiling station so that the leading joint portion 232 is offset to one side of the strip being fed into the coiling station.
  • the lead signal of the spiral is so small that this does not permanently deform the strip out of a plane perpendicular to the axis of the coiled spacer-expander.
  • the joint zone 118 of the strip is subjected to a joint cutoff operation as illustrated in FIG. 25.
  • a suitable shearing die set severs the strip by cutting portion 146 midway between portions 281 along a cut line indicated by the arrow in FIG. 25. This operation is performed after the last portion of the strip adjacent the trailing end 234 has been coiled in zone 230 to the radius of the coiling die set.
  • control of the strip is maintained and it is advanced from coil 102 (FIG. 4) through all of the blanking and bending operations of FIGS. 524 as a continuous length of material, the individual spacer-expanders finally being severed from the strip at the cutoff station of FIG. 25.
  • each spacer-expander 58 a final trimming and bending operation is performed on the end joints of the spacer-expander after severance of the continuous strip 100.
  • the coiled spacer-expander is suitably fixtured and the portion of strip 146 extending from the cross tab 281 to the free end of strip 146 is removed by a suitable blanking operation to thereby impart the T-shaped configuration of pad 275 as shown in FIG. 12 of the aforementioned Warrick U.S. Pat. No. 3,477,732.
  • strip 146 is bent as shown in FIG.
  • the spacer-expander 58 thus formed by the abovedescribed method may be subjected to further electrical or chemical polishing operations to deburr and finish the same, and also may be plated or given other conventional surface treatments as desired.
  • a method of making a spacer-expander comprising the steps of:
  • each section comprises two parallel bands extending lengthwise of the strip and defining the side margins thereof, a transverse strut spaced lengthwise of the strip equidistant from the struts of adjacent sections and at least one leg with said leg extending parallel to said strut and offset lengthwise of the strip from said strut, one end of said leg being connected to one of said first and second bands and the free end of the leg terminating short of the opposite one of said first and second bands;
  • step (3) is performed in advance of said step (4) such that said legs of each section assume their final position in said spacer-expander as said strip is curled to said channel-shaped configuration by said bending of said struts in said step 4).
  • step (3) performing said bending operation of step (3) by bending said legs up from the plane of said strip about a bend line adjacent the associated marginal band.
  • a method making a spacer-expander comprising the steps of:
  • each section comprises two parallel bands extending lengthwise of the strip and defining the side margins thereof, a transverse strut spaced lengthwise of the strip equidistant from the struts of adjacent sections and first and second legs with the legs extending parallel to said strut and offset lengthwise of the strip, one end of said first leg being connected to said first band and one end of said second leg being connected to said second band and the free ends of the legs terminating short of the opposite band;
  • step (3) performing said bending operation of step (3) by bending said legs up from the plane of said strip about a bend line adjacent the associated marginal band.
  • strip stock is oriented horizontally with the surface thereof which faces the interior of said spacer-expander in its finished form facing upwardly and said blanking and bending operations are performed by punch means operating in vertical strokes in cooperation with associated die means.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
US39264A 1970-05-21 1970-05-21 Method of forming a spacer-expander Expired - Lifetime US3633260A (en)

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BE (1) BE767306A (fr)
BR (1) BR7102932D0 (fr)
CA (1) CA971345A (fr)
ES (1) ES391559A1 (fr)
PH (1) PH9958A (fr)
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3745627A (en) * 1969-07-12 1973-07-17 Nippon Piston Ring Co Ltd Spacer expander and process therefor
DE2714462A1 (de) * 1976-04-01 1977-10-13 Ramsey Corp Verfahren und vorrichtungen zur herstellung eines gewalzten metall- kolbenrings
US4799694A (en) * 1986-12-18 1989-01-24 Goetze Ag Piston ring and method of making the same
WO2001051833A1 (fr) * 2000-01-13 2001-07-19 Andrei Alexeevich Alexandrov Segment de piston compose, dispositifs et procedes de fabrication de ce segment
CN102489574A (zh) * 2011-11-29 2012-06-13 重庆大学 一种板材渐进成形加工控制回弹的方法

Citations (7)

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US2482990A (en) * 1948-02-09 1949-09-27 Sealed Power Corp Piston ring blank
US2697865A (en) * 1949-08-19 1954-12-28 Thompson Prod Inc Piston ring making machine and process
US2834096A (en) * 1949-08-18 1958-05-13 Thompson Prod Inc Method of making piston ring stock
US2837385A (en) * 1956-08-08 1958-06-03 Mcquay Norris Mfg Co Piston ring element and method of making same
US3181875A (en) * 1958-06-30 1965-05-04 Muskegon Piston Ring Co Inc Piston rings
US3477732A (en) * 1965-04-14 1969-11-11 Sealed Power Corp Spacer-expander

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US2111258A (en) * 1936-01-15 1938-03-15 Z Flex Piston Ring Corp Piston ring expander
US2482990A (en) * 1948-02-09 1949-09-27 Sealed Power Corp Piston ring blank
US2834096A (en) * 1949-08-18 1958-05-13 Thompson Prod Inc Method of making piston ring stock
US2697865A (en) * 1949-08-19 1954-12-28 Thompson Prod Inc Piston ring making machine and process
US2837385A (en) * 1956-08-08 1958-06-03 Mcquay Norris Mfg Co Piston ring element and method of making same
US3181875A (en) * 1958-06-30 1965-05-04 Muskegon Piston Ring Co Inc Piston rings
US3477732A (en) * 1965-04-14 1969-11-11 Sealed Power Corp Spacer-expander

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3745627A (en) * 1969-07-12 1973-07-17 Nippon Piston Ring Co Ltd Spacer expander and process therefor
DE2714462A1 (de) * 1976-04-01 1977-10-13 Ramsey Corp Verfahren und vorrichtungen zur herstellung eines gewalzten metall- kolbenrings
US4799694A (en) * 1986-12-18 1989-01-24 Goetze Ag Piston ring and method of making the same
WO2001051833A1 (fr) * 2000-01-13 2001-07-19 Andrei Alexeevich Alexandrov Segment de piston compose, dispositifs et procedes de fabrication de ce segment
CN102489574A (zh) * 2011-11-29 2012-06-13 重庆大学 一种板材渐进成形加工控制回弹的方法

Also Published As

Publication number Publication date
BR7102932D0 (pt) 1973-05-10
BE767306A (fr) 1971-11-18
PH9958A (en) 1976-06-14
ES391559A1 (es) 1973-07-01
CA971345A (en) 1975-07-22
ZA713118B (en) 1972-12-27

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