US1350046A - Packing-box for piston-rods - Google Patents

Description

' A. 0. VAN DERVOHT.

- PACKING BOX FOR PlsToN Roos.

APPLICATION FILED'OCT. 22,1919.

Patented Aug'. 17,1920.

3 sHEETs-sHEET-l.

' nvezor: 14d/whiz ya efaor y/zs c/ZZ) A. 0. VAN DERVORT. PACKING Box FOR PlsToN Roos.

APPLICATION FILED OCT. 22, 1919.

Patented Aug. 17, 1920.

3 SHEETS-SHEET 2.

Al 0. VAN DEHVORT. PACKING BOX FOR PSTON RODS. APPLICATION FILED ocr. 22, 1919.

Patented Aug. ,17, 1920,

3 SHEETS-SHEET 3.

nvenar: ai-z'afz 0. vanuezwar UNITED STATES PATENT OFFICE.

ADRIAN 0. VAN DERVORT, OF TROY, NEW YORK.

PACKING-BOX FOR PISTON-RODS.

To all whom it may concern.' y

Be it known that I, ADRIAN O. VAN Dna voRT, a citizen of the United States, residing in Troy, in the county of Rensselaer and State of New York, have invented certain new and useful Improvements in Packing Boxes for Piston-Rods, of which the following is a specification.

This invention relates more especially to means for packing the piston-rods of highpressure steam engines, and a principal 0bject of the present improvements is to furnish for use on superheater locomotives a packing box of a simple character and a few parts, and which shall provide for effectively meeting the peculiarly exacting requirements appertaining to said classes of engines. A further object is to vaccomplish the foregoing object and results by means whereby the packing ring shall be relieved (as hereinafter more fully explained), of certain strains normally inimical thereto, and shall be subjected without material detriment thereto, to a progressive and re-formative action during the gradual wearing away thereof, and thereby maintain in a continuous manner the high efiiciency which is particularly needful in said service.

ln the accompanying drawings forming a part of this specification, Figure 1, is a side view of a packing box made in accordance with my present invention, the portion above the upper line of the rod being in section.

Fig. 2, an end elevation as seen from the left-hand in Fig. 1, but with the usual retaining cap partly broken away. thereby showing` the vibrating-casing; this casing is also shown partially broken away to show in side view the upper part of the packing ring. which is contained within a packing ring chamber in the interior of the casing.

Fig. 3 is an enlarged View of a portion of Fig. 2, and shows an upper part of the vibrating casing, an upper part of the rod, an upper part of the two ring segments, and these joining by lapping ends at a chamber, which is within the casing wall.

nigga, 5, aan7 s, 9, fr, 10,11, i5, ic, i7, 18 and 19 are a series of diagrammatic and explanatory views illustrative of various details and functions as hereinafter more fully described.

Fig. 12, is a plan view of the two-segment ring `as employed in a preferred embodiment of my invention, and in lapping relation.

Specification of Letters Patent.

Application filed October 22, 1919.

Patented A110. 17, 1920.

serial No. 332,408.

Fig. 13, is a pla-n View showing a pluraliity of more than two ring segments and in lapping relation.

Fig. 14, is a plan view of a single-member ring the coactive ends of which are in lapping relation.

The embodiment of my invention herein illustrated comprises the retaining cap B,

the vibrating-casing C, the spring actuated follower D, the packing ring E, preferably in two segment form, and the rod R.

The ring-chamber or space, is preferably form ed within a member, which is arranged to have a movement in directions laterally of the rod when the rod (operating in a well-known manner, and from unavoidable causes), is deflected, or sprung sidewise. This mode of action, or vibratory movement (which is often both rapid and intense), is provided for in the form of construction shown in Figs. 1 and 2, by means of the usual flange and suitable holding means therefor. The ring-inclosing member when thus supported for the described sidewise movements is commonly designated as the vibrating case,7 heretofore denoted by C, it being intended for use on piston rods which ordinarily, and almost constantly while in operation, are subjected to a considerable amount of lateral vibration.

Since said vibrating-ririg-case C, which comprises a hoop-surmee 2@ necessarily, in practice, has an internal diameter greater than the external diameter of the roth-in 1 order to slide freely over the roth-and since the packing ring is necessarily kept closed-in to fit the rod tightly, (to prevent leakage), therefore, as will now be evident, a lateral movement of the rod acts initially against the metal of the ring, in the present instance a moldable metal, and thus moves the case itself. Thus, in practice, it may be said that the rod operates as an impact device or member, and so tends to drive outwardly the ring-metal-tirst on one part and then on another part f the circumference of the ring-and thereby facilitates and accelerates the re-formative action in the case of a moldable ring to which the ring is simultaneously subjected by the steam-pressure, heat and friction.

. The packing-ring E especially for the more usual requirements, may he forme-1l of two similar segments, as QCcand 3, Fig. 12, which together extend entirely around the rod li. These segments each have one end Y Yticularly advantageous.

of a different construction from the other end, but constructed i'or a novel and effective coaction by a peculiar method and principle.

rihus, reference being had to Fig. l2, the right hand segment 2C is provided as shown, at substantially the upper' point of vertical diameter of the packing ring E when in packing position, with an overlapping end 2f, and at the lower point of vertical diameter of the packing ring E with a projecting end 2g, and the left hand segment 3e is provided With an overlapping end 3l, and at the upper point of vertical diameter of the packing ring ivith a projecting end 3g, the segments 2@ and 3@ relation to each other.

il chamber G, which for purposes of description l term a relief chamber, is formed at substantially the upperl point of vertical diameter of the packing ring E, as shown in Fig. l2, by a portion of the vibrating case C, indicated by the dotted line, the curved portion of the overlapping end 2f of the segment 2e, and a portion of the projecting end 3f of the ring segment 3f. A similar relief chamber is formed at substantially the lower point of the packing ring l. b a iortion of the vibratino` case C the Y 1 Ci 7 curved portion of the overlzuiping end Noi the ring segment Se, and a portion ot the projecting end 2g of the ring segment 2O, the purpose of the relief chambers being hereinafter explained.

Said coacting segment ends, as 20 and 3 (Fig. l2) may be considered as constituting',

respectively, the ends of a pair of coacting levers; For instance, in Fig. 3, the efthand segment-end 3g, has bearing at point 3h Which is in the nature of a fulcrum, with relation to 'which that portion of said end S15-at the right-hand of the radial line V3j, constitutes a projecting lever-end the outivard movement of which is prevented by a force or resistance that is limited to such fulcrun point. Similarly, the right-hand segment-end 2l' has a bearing at the point 2h, which is in the nature of a fulcr'um in relation to the adjoining portions of said end 2f, when this is considered as functioning after the manner of a lever. rthese rclations and their proportionate effects are indicated in Fig. 3, by netted lines whichr also illustrate certain geometrical, or kinematic relations in the preferred form of embodiment of my present improvements, and areY later referred to. v

The diagram Fig. 1l, illustrates preferred construction which in superheater locomotives, and With the packing-ringV segments, 2e and 8e, made Vof a composition substantially one half vcopper and one half lead,-has been found in practice to be par- In this -view the arcual extent or length (circumferentially being coactive in of the ring) of the overlap of segment ends' 2f and 3g, is shown by the arc line 762, and the arcual length of the relief chamber G, by the longer arc line les. The two engagingV faces of said segment ends 2f and 3g, respectively, are of equal lengths, and the tip, or point 3l of said under-lapping segment-end, or Wedge-end 3g, is held doivn in a positive manner against the rod-surface by 'a reaction force applied to the lWedge-point at 31 in the direction of the line 754, which is at about right-angles to the engaging face line of the ring-segments. These geometric relations, bring the centerpoint of said engaging faces of the seg- Yment-ends in a line It Vwhich is substantially central of said arc it, so that the tivo arcual lengths 7a2 and la may be said in this instance, to be symmetrically disposed, or arranged.

es shown in said Fig. Ll, the entire 'faceline of said underlap )ing segment-end (when said engaging faces are true planes),

entends from said Wedge point 3l te the point 3 on the outer circle and is thus considerably longer than the portion thereof which normally engages-the coacting face, of said overlapping segment-end 2. in this arrangement, and owing tothe position of said pressure-line 7c", the extreme point, asl

- segment-end, 2f, is materially favored as regards there-forming action to which these segment-ends are subjected.V ln this forl of the construction the lines forming the Vangle K, make such angle of about 45 degrees, which results in the segment-end 2f being sufficiently obtuse to afford a proper resistance, While not unduly resisting the reforming of the segments under the combined action of heat and pressure, and the friction and vibration of the piston rod.

A further feature of the preferred construction shoivn in Fig. 5, is a symmetrical arrangement of' the'center-point, as g, of the shaded normally unstable portion, of

the segment-end 3g, With relation to the tivo Y fulcrum points 2h and 3 of the segmentends 2f and 3S, respectively. VThe line ,72 drawn throughthe'point 3h to the central radial line, subtends the anglefvs720 VWith relation to the central VradialV line and a similar angle V21 is subtended by theV line g drawn through the point 2h to the Vradial line. In this arrangement if an outwardlyacting force be applied, or centered, at the point gV such force Will be transmitted throughthe metal of the coactive segmentends and to the tension-hoop 2C of the vibrating case C, and if directly so transmitted such forces would naturally and mainly follow the divergent lines g2, g3, and be sustained by said hoop at the points 2h 3h. However, the metal between the three points g 2h and 3h may be said to be arranged on the principle of an inverted arch, of which the bases are at (or near) points 2h, 3 and the crown of the arch is at point gli; the proximate transmission and distribution of the forces and pressures thus sustained are diagrammatically indicated by dotted arch-lines gt and g5. This diagram, therefore, illustrates how the total amount of work is performed a part by one method and means, and a part in a different way, since the overlap-end or lever-end 2f is here shown as substantially. unaffected by such forces as may be transmitted in the Zone between said arch lines. Thus any weakening of the packing ring considered as a whole, which might seem, apparently to be due to the presence of the relief chamber Gf, is clearly overcome or avoided by the peculiar manner in which the described devices are organized and the highly effective mode of action thereof.

ln Fig. that portion of segment 2e which lies between said arch-lines g2, g3, constitutes, in effect, a directly-acting compression member or brace between the extreme point-portions, or zone of the projecting end 3g of the segment 8e, and the hoop surface 2C at 2h; this being also the fulcrum 2 of the overlap end 2f, when this is considered as a lever-end, as more fully explained in connection with Fig. 3. During the wearing` away of the metal while the packing box is in use, said brace-forming portion is normally maintained in length by the reforming of the segments, already described. Said point portion or Zone of the projecting end 23g of its acute-angle form, is found in practice to be of insufficient strength for itself resisting outward flexure, and to require a bracing means of a powerful character for holding the same in place; such means is effectively supplied by the construction herein explained.

ln the mode of action here described (F 8 and l0), one important feature is not fully shown in any one View, but is evident from all the diagrams and sectional views when these are duly compared :--The lever-end 2f on being slid forward and forced upward as in Fig. 10 and when this is done (as usually may happen) while the packing ring metal is highly heated and hence relatively mobile and iexible,-the follow-r D Fig. l, is forced back by the coaction of said lever-end 2f with three faces, 3k, 2J', 2d (all relatively inclined cach to the other) with the result of bending upwardly the lever-end, while the main portion of the ring-segment is held closely down to the rod, this action being permitted by the relief chamber G. If, now, said leverend 2f, reti-acts to the position indicated by dotted line in Fig. l0, a normal result would be to leave said lever-end bent upward to the position indicated by solid line in Fig. l0, but at this time the follower by acting against the conically formed side surface 2d Fig. 8, of the ring-segment in the lever-end portion thereof, coacts with the casing cone-surface 3 and thus strongly tends to rebend said lever-end back to its position shown by said dotted line. Thus the described reformative'action or process, when carried into effect by the means herein set forth, comprises a restorative element which being often repeated, tends to prolong the life of the ring-segments.

In Fig. 9, the underlapping end, 3e', of a ring-segment 3e, is shown located within the strain-band 2C (here only partially shown), so that the extreme fulcrum-point 3 indicates how that band normally resists any outward movement of the projecting wedgeend 3g, of said segment, due to the action of steam (or other hot fluid) tending to force its way between the surfaces at '23,-- that is, between said wedge-end and the surface, indicated by line r3, of a piston-rod l. Under these conditions, and for the uses already stated, it is found in practice, that the met-al in the shaded Zone, is normally non-stable, being too weak for resisting rapid deformation due to the causes herein explained.

The curved line, (Fig. 9), is deemed to closely approximate the boundary,-as occurring most commonly in these rings as used in recent locomotive practice,-between the normally stable and the normally nonstable Zones, of the end 3g of the underlapping ring segment. The extent of said nostable zone, along the face-line 3k, of said end 3g is ordinarily about two-thirds, or not less than one-half of said face line, as indicated by the distance line w", Fig. 8, and hence this distance along` said face-line must be held in place by some coacting means, but this means must be so positioned and conditioned as not to interfere with the required gradual reduction and continuallyreforming action which should taire place slowly during the life of the packing ring.

The lever-like function, or mode of action, is shown in a diagrammatic manner in Fig. 3. The radial line 4j, extending through said fulcrum point 2h, may be said to show that the left-hand end portion 2f of the segment ring 2@ constitutes one end of a lever the other end of which is comprised within the mass of metal at the right-hand of said line. That is, this mass of metal in that part of the segment 2e, is necessarily an excess over the requirements for a mere leverllO action, owing to the well-known parabolic principle, as regards the normal proportions v3 to show how a right-hand lever-arm might be fulcrumed at said point 2h, and resisted at its end by the rod-surface r3 at point r4. ln practice, of `course, the forces and strains transmitted by the projecting lever-end' 2f to the right-hand of said line tj, will not be actually centered or applied at any one suoli position, as rt, but will be transmitted throughout a more extended portion of the metal, and thus, in one sense, be dissipated through the entire mass. It will beevident, however, that said overlapping segment-end 2f has the same lever-like character and function, as if it were provided with an opposite lever-arm such as represented by said dotted lines. I

This peculiar lmode of action is rendered feasible, it will now be obvious, through the provision of the relief chamber Gr, whei'eby the described outward movement of the overlap-end 2f is pi'oducible by the coaction of the three pairs of coacting and inclined faces, and is uiiopposed except by its said inclined faces 3C, 2d, Fig. 8, and the only 4moderate 'resistance to flexure of the segnient due to pacity of tlie copper therein), and thereby temporarily but suddenly to subject the metal of the ring to a heavy comiiressivc or crushing action. This action as l have discovered tends greatly to accelerate the otherwise slow but constant rate of progress of the well-known disintegratory action, or process, to which such packing-metals, notwithstanding their practical superiority in other respects,-are unavoidably subject.

Y vrl`he arcual length, as V21 Fig. 5, of the relief chamber Gr, may be'varied in practice and to some extent, in accordance with the varying requirements in different cases, but a Vrange of lengths of from one and oiiehalf to three times the arc, V20, occupied by the overlap face 2f, is deemed sufficient for all ordinary requirements; but in the practical demonstrations thus far made, l have Y joint faces 2j, 3k, Fig. 10, the inclined inelosing walls 3C 2d, are effective, of course, only for the diametrical height as y, Fig. 9, which practically coincides with that of the face-line as V. Thus'the entire underlapping wedge-point,ror Zone 2g, which is at right-hand of radial line 1g in Fig. 9, consists of the relatively non-stable portion of the segment-end 3g, which may be said to be inclosechas if in a box,rby these several walls or faces; at the left-hand by the more stable portion of said segment end, (at about the line 1g), the rod. surface r3, the two iiicliiied side walls 3C and 2d, Vand the face as V, of the overlapping lever-end 2f.

In thusy retracting, or driving back the follower D, the overlap-end 2f in advancing upwardly on the wedge face 3g, as already indicated, (acts after the Vmanner of a wedge) operating in two directions and for `retractingrthe follower, butthis action, or

tends (owing to the described mobile character of the metal) materially to accelerate the reforming of said portion, 2f, of the ring or segment. As a result of these coinplex conditions,and when the packingbox is in use under heavy steam pressure,

t-lie overlap-end 2f after being forced forward VYinto the relief-chamber Gr, (as eX- plained in connection with Figs. S andV 10), rapidly reforms into a modified shape, and this is accomplished in a manner further indicated in Fig. 15, theV outline of said parts as shown in Fig. 11, being here shown in dotted lines for' theV purpose of compariso-n.

It will, ofl course, be understood, that said Figs. 10, 11 and 15, are drawn (in order to facilitate comparison), to show an amount of said reforming action which does not, ordinarily or always, take place as one instantaneous shift or change, but which may proceed in a gradual manner, so that the relations shown in Fig. 3 may gradually change to those of Fig. 15 without a distinctive developme-nt of the 'intermediate stage as especially shown in Fig. 11; in this case, said intermediate position orV arrangement may be said to be progressively transformed as rapidly as formed, so that while occurring and being effective, itis not a clearly distinguished intermediate arrangement.

However, when the change of temperature and pressure conditions occurs quickly, the

^ overlap-end 2f may be forced upwardly into the relief-chamber G more rapidly :thansaid reforming action can follow, so that for a brief time a space, as 2k, (Fig. 10), may be opened between sai-l end 2f and the rod surface large enough for steam to flow between. This result, when it thus occurs, operates to heat that part of the ring with great rapidity, and thus operates to accelerate the reforming of the coactive ends 2f 3g into a newly perfected form and bearing of the modified arrangement, or proportions as illustrated by Fig. 15, and thereby rapidly close said steam outlet or leakage at said space 2k.

lVith the packing-rings constructed of about the proportions as shown in Figs. 1, 2 and 8, and used on high-pressure locomotives, it has been found that under the conditions here explained, (and the ring-metal being copper and lead, very nearly one-half of each), the original width, co2, Fig. 8, is gradually reduced to thenarrower width, as fw, while the height, is maintained the same as at first and the original relief# chambers Gr were little if any more than one-half filled up. Furthermore, it was found that the rod packing function was continuously maintained in a highly effective manner, while the usual final breakingup,-or disintegration,-of the ring-metal was materially delayed in proportion to the service rendered. These valuable results are believed to result from or to be materially enhanced by a peculiar mode of action by means. of which the follower ring D is temporarily forced back at a certain time, by a temporary increase of the aforesaid overlap, already referred to in connection with Fig. 15.

Referring, now, to Figs. 10, 11 and 15, it will be evident on comparison thereof, that when the overlap-end 2f is forced upwardly on the face 3k of the coacting segment end 3g the inclined side faces at 3, 2d, of said overlap-end will be moved outwardly; this action is diagrammatically illustrated in Fig. 7, where said 2f is shown advanced through the distance S, the corresponding outward movement of the side-faces 3", 2d, being shown in Fig. 'l'u by the distance t. To accommodate these surface-portion changes, the follower D normally moves back by the corresponding distance t2, (see Fig. 7), being forced in that direction by said overlap-end 2f, acting outwardly, after the manner of a wedge), against the forward inc-line 3k as an abutment, and thus operating as an actuator against said follower face 2d. Thus the two segment faces opera-te to force outwardly the overlap-end 2f, while this, by its faces forces apart the inclosing faces 3, 2, thereby retract'ing or moving back the follower D in the manner and for the purposes herein set forth.

W hen the packinci ing has been employed Aunder o beve explained, a fur@ ther result of importance has been found to occur, in practice as regards the favorable manner in which the inner ring surface conforms to the roll surface during thc described progressive narrowing and reforming of the ring. ln F 6, said inner surface is indicated (in accordance with oberved results) as closely bearing on the rod R two Zones n, n2, whereas in the midrone n3 said surface, (as seen in the cross section), is upwardly curved. Thus a space, or a Zone of low pressure, appears normally to be formed between the two Zones n., an, so that in operation the rod is packed in two separated annular zones between which the lubrication material may collect in sullicicnt quantity to materially improve the quality of the action and the durability of the coacting members.

The results and mode of action here eX- plained are believed to he due to some cause not as yet fully understood, but T apprehend that the progressive reforming of the ring metal, as to the width thereof as seen in cross-section, (see Figs. 6 and 18), may take place in connection with lines of force, or pressure-lines, having an arrangement indicated by thc lines ai, rc2, in Fig. 18. By this eansA` and the co-action thereof with the relief from circumferential compression afforded by the relief chambers G, the crushing action due to the pressure of follower D is believed to be diverted,-in the midwidth Zone indicated, to a considerable extent outwardly, thereby causing the outer part at n, 'n2 to be kept up to a full size or diameter, as limited only by the inclosing hoop or casing-band 2. Thus the inner mid-portion at a3 appears to be in a normally lowspressure condition favorable to the peculiar mode of action here described. And thus the behavior of the metal while the ring is service, differs in a radical manner from rings of similar section as used 4in the old kinds of packingsf in these, as is well-known, the wear extends practically uniformly, over the entire inner surface of the ring-member.

The precise manner in which the movement, or liowage7 of the metal probably occurs within the mass, or body, of the ring, is not as yet fully understood, but from a study of observed results of numerous instances of the rod-packing` used on locomotives, it clearly appears that owing to the low circumferential compression and the relief obtained by means ofl the relief chambers, (as specially described in connection with Figs. 10, 11 and 15), the metal is further relieved of restraint as regards the flowage thereof in planes transverse to the ring, and is thus enabled, or permitted, to continually readjust itself for replacement of metal worn away by the rod, in said zones a, a2, And, it also appears that under the complex conditions above indicated,rsuch worn-away metal is mainly supplied or replaced, by a flowage inwardly of the metal in the mass adjacent to the inclined` faces 3C 2d.' This mode of action seems to be favored by some force-line action as indicated by arrow-lines 2 and z2 Fig. 17, showing how such an inward movement. of the metal at m and x2 may be in directions nearly vertical to opposing faces at 3C and 1 respectively.

AsV a result of' practical investigation, it appears that the line n (see Fig. 8) indicates, approximately the manner in which the side portions tend slowly to move inwardly under the continued co-action of the wear and the pressure, and of the friction and heat while in use. This action operates, it seems evident, in wearing away most rapidly, the outer Zones, of the inner face of the ring, so that the relative wearing away of the face may be indicated by a reverselycurved line a7, (Fig. S). This wearing away of the ring-metal is compensated for, gradually during the reduction of the mass of the ring in part by a tendency of the ring to close inward to a smaller diameter under the action of said inclined end faces Bc, 2d, and further, by a slow but effective reforming of that mass as to its cross-sectional proportions. For instance, if the ring metal should be worn away to the extent shown by line m7, in order to maintain both the outer and inner diameters thereof, the length of said cross-section (Fig. 8) would have to be shortened to the amount shown by line as; and in practice, this reformation seems actually to occur; the described shortening being in the nature of a secondary action which continuously follows said gradual mass reduction as effected by the wearing away of the inner zone of the cross-section.

The aforesaid modes, of action, or effects, while believed to be concurrent` and continuous, apparently are not at all times of precisely the same ratio; furthermore, in accordance with principles well understood, the metal on the inner surface, as at a7 appears to tend to move (under said reforming action) or broaden out, not only lengthwise of the piston, but also circumferentially thereof, thereby tending to lengthen the ring segments, with the result of sliding forwardly the overlapping end 2f, as indicated by the solid-line position thereof in Fig. 11. This movement, however, is opposed by the compressive and wedging-in actions of the faces 3, 2d; but this opposing action is lim-v ited in its effect by the relatively low power of resistance of the ring-metal while in a heated condition, so that, in practice, the extent, of said overlapping is found to gradually increase, especially under severe service, but not to such an extent as to entirely fill the relief-'chamber space, YGr (Fig. 15).

These complex actions and reactions evidently have from time to time, different ratios; or degrees of co-action, under the. widely and rapidly varying conditions of use. For instance, thevringsegments 3e, when heated, more quickly than the inclosing-hoop 2C, (as must often occur in locomotive practice) tends to lengthen and thus increase said overlap distance, which, later and normally would lbe reduced. Y Thus, the relief-space atGrV permits of a Vtemporary and excessive overlap deformation of said overlapping ends 2f, 3f of the segments, this result 'beingone of importance as regards the life of the ring. Y

These effects are further modified or limited, by the inclosing hoop 2C. This member is necessarily a strong and stable one, and hence is preferably made of steel, or of a rigid metal highly contrasting with that of the ring-segments; and, hence, in practice, said hoop member will ordinarily have a ratio of expansionV by hea-t, much less than that of the ring-metal.

In Fig. 9a, dot-ted lines are drawn for indicating a series of zones in the lever end 2f, and, in the wedgefend 2g and are shown curved in arrangement for suggesting the manner in which metal of similar forms, and especially when considerably heated, tends to flow, or be driven off, when subjected to a suflicient intense and concentrated pressure. Said Zonesgpas thus drawn run from a normally stable Zone, as f3, at one end of a series, to a normally unstable zone, as t, at the other end of the series. Thus the stable zone 252 of the lever-end 2f is complemental to the unstable zone t4 of said wedge-end; and, this complemental relation extends to the other pairs of the two series, as clearly shown by this diagram, since said series of lZones are progressive from the maximum to minimum stability in opposite directions, respectively, so that a more stable Zone of one series coacts with a weaker, or less stable zone of the other series. Thus all of these zones are so related as to produce nearly equal co-acting pairs of them, as regarcs their stabilities.

In Fig. 15, the successive dash lines (ma, m4) further indicate the nature of the progressive reformation of the overlapping lever-end portion 2f, during a considerable period of use. At first, the fulcrum point being at about the point 2, the segment-end 2f bears on the wedge-end 3g only up to the point x5, but as the reformative action progresses, this bearing extends slowly upward, and the fulcrum point moves along toward Vthe center-line as for instance, to the point ehr-thereby reducing the freedom ofaction, and of co-action for the required functioning, to such an extent that the packing-ring should then be replaced by a new one.

In the form and proportions thereof as shown in Figs. 10, ll and l5, the lever-end portion of the segment 2f has its fulcrum point, as 2h, in such a position that a line, as 7s? Fig. 9 therefrom, is vertical to the plane of the wedge-end face, (of the co-acting segment-end 8e) at a point at or near to the inner end of said face. Also, it will be noted that the underlapping end 8g, has an outer zone at US of the inclined face thereof, free from contact with said overlapping lever-end 2f, but so arranged that the latter member can slide outward therewith, during successive stages of the exianding and contracting movements to which, (as already explained in connection with Figs. lO, ll and l5) these members are repeatedly subjected while in use, and during the reformative action to which the packing-ring metal is subjected.

when the packing ring is intended for use with locomotive piston-rods of ordinary sizes, and for use under temperatures of from L00 to TOO degrees, (Fahr.), and is composed of the described half and half i mixture of copper and lead, l have found that a favorable position, or angular relation to the two contacting faces 3, 21' Fig. l() of the underlapping and overlapping ends 8g, 2f, respectively, may be suitably proportioned by making said faces in a plane,-as shown in Fig. 19,-coinciding with a chord-line m which is so positioned that the chord (from point m2 to point m3) of the outer circle is twice the length of the chord (from point m'L to point m5) of the inner circle. This construction makes the distance m equal to the distance m7, and this is also the proportion as shown in Figs. 2 and il, but those proportions may be varied.

The provision of the necessary reliefchambers may be effected, in practice, in two ways, preferably as in Figs. l2 to 14, inclusive, and in sonne instances as shown in Fig. le. ln the construction illustrated by Figs. l), to l-l, inclusive the packing ring regardless of the number of segments coinprise-d therein,-is free to gradually work around, or turn within the packing-ring chamber, which is deemed te be desirable, since this action clearly tends to equalize wear and strains. However, to provide for said chambers the necessary room by this construction, the thickness or" the ring seginents,-diametrically of the ring,-is preferablj-.f made greater than otherwise would be essential.

ln Fig. 16 the relief-chamber, G2, is shown located as before inside the hoop 2C, but is here located in a position exteriorly (instead of interior-ly) of the inner circle thereof, and the ring segments 2e, 3@ are of a reduced thickness. In this case, however, the fulcrum points, as 2, 3" are related both as to position and function,-to the coacting` segment-ends 3f", 2l', in the saine manner as already explained in connection with Figsv and i2; this is further indicated by the diagram lines of Figs. l1 and l5 as reproduced in this view. ln this construction (Fig. 1G) it is, of course, necessary to provide means for preventing the circumferential slipping out of place of the segments; this may be done by using an ordinary dowei-pin, as F, preferably placed about midway of the length of each segment.

The number of segments comprised in a complete packing-ring, may vary in different instances, according to requirements. For instance, in Fig. l2, two segments 2e, 3e, (preferably duplicates) are shown, each having one lever-end, as 2f, or 3f overlapping a wedge-end, as 3g or of the companion segment, and there being a reliefchambcf (t, at each such pair of co-active segment-ends, when the ring is assembled in the packing box,

In Fig. 1?), a multiplex construction is shown, comprising the three duplicate seginc-nts such as 2, 3u. and each segment having a lever-end and an iu'iderlapping wedgeend, all arranged and co-active in the manner illustrated in Figs. l0, ll and l5, already described. A. particular advantage of such a larger number of segments (more than two), is that the effect of the yielding and reformative actions described in connection with Figs. l0, 1l and l5 is multiplied, thus providing for the requirements of extreme cases, as for instance, for use on large piston rods which are subjected to unusual changes et temperature or of steam-pressure, or both.

In some instances, the packing ring may be a single-piece member and one such form is illustrated in Fig. 14. In this ease, however.l the ring may still be regarded as comprising two segments, as 2 and 30, integrally joined at the dotted line and coactiveiy joining each other at the reliefchamber (il, where the lever-end 2f and the wedge-end are arranged and function in the manner explained in connection with said Figs. l0, 1l and l5; accordingly this understanding of said construction of Figs. 10, ll and l5 has been adopted in and for the purposes of this description.

By a comparison of the several diagrams and the foregoing explanations thereof, it will now be evident how the packing-ring comprises segments joining', at each segment-lap thereof, by a pair of lapping segment-ends (as 2e, 3Q, Fig. 3) one of which, as 3g, is underlapping and the other of which, as 2f, is overlapping; and, how said segments,-these being composed of a compound of metal'of suitable resistance to reformation,-are slowly reformable in cross-section under the combined action of the described follower-ring pressure and heat while subjected to the friction (and, of course, to the resistant surface and pressure) of a moving piston-rod to which the packing box shall be applied; and Vhow said action and results take place in connection with a relief-chamber, (as G, Fig. 3) formed components in a copper-lead packing ring.

may be varied, in practice, to some extent without preventing the proper mode of action of the ring; and it should be understood that small quantities of other metals or substances, in the nature of adulterants, may be present inthe copper-lead composition without destroying the reforming capacity thereof. In the case of some of those compositions, it appears that a slight reduction of mass may gradually occur by reason of oxidation or other chemical action, and also by a kind of compacting together of the ingredients when the mass, as initially formed, has some degree of porosity. Thus the packing ring when put into actual service may have, or be subject to a loss (usually relatively small in amount) of substance or reduction of mass of volume, in addition to that directly due to the wearing away thereof by the friction of the steam heated piston rod.

Having thus described my invention I claim:

1. In a .rod-packing, in combination, an annular packing ring chamber comprising an outer wall forming a tension hoop, and two annular end walls each facing toward the other; a follower ring of which the inner face thereof constitutes one of said end-walls; means for actuating the follower ring in a direction for subjecting a packing ring in said chamber to a width-contracting pressure; and a packing ring in said chamber consisting of co-acting segments composed of a metal mixture moldable under the action of the pressure and heat of superheate'd steam, said segments each having one underlapping wedge-end, and also having one overlapping lever-end bearing upon and extending only partially over the wedgeend of a co-acting segment, and the rod packing having between the tension hoop and the lapping wedge-end and lever end, a relief chamber occupying an arcual length circumferentially of the ring Ygreater than the arcual length of the bea-ring of a said lever end upon said wedge-end. u Y Y 2. In a rod-packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension hoop, and two annular end walls each facing toward the other; a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the fol-l lower-ring in a direction for subjecting a packing-ring in said chamber to a widthcontracting pressure; and, a packing ring in said chamber and consisting of co-acting segments composed of a two-'metals mixture moldable under the action of the pressure and heat of super-heated steam, said segments each having one under-lapping wedge-end, and also having one overlapping lever-end bearing upon and extending only partially over the wedge-end of a co-acting segment, and the rod-packing having between the tension-hoop and the lapping wedge-end and lever-end, a relief chamber occupying an arcual length circumferentially of the ring greater than the arcual length of the bearing of a said lever-end upon a said wedge-end.

3. In a rod-packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annular end walls each facing toward the other; a follower-ring ofY which the inner face thereof` constitutes one of said end-walls means for actuating the followerring in a direction for subjecting a packingring in said chamber to a width-contracting pressure; and, a packing ring in said chamber and consisting of co-acting segments composed of the metals copper and lead proportioned substantially one-half of each of said metal, and segments each having one underlapping wedge-end, and also having one overlapping lever-end bearing upon and extending only partially over the wedgeend of a co-acting segment', and the rodpacking having between the tension-hoop and the lapping wedge-end and lever-end, a relief chamber occupying an arcual length circumferentially of the ring greater than the arcual length of the bearing of a said lever-end upon a said wedge-end.

4L. In a rod-packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annular and conical walls oppositelydisposed and Voutwardly converging; a follower-ring of which the inner face thereof constitutes one 'of said end-walls; means for actuating the follower-ring iny a direction for subjecting a Vpacking-ring in said chamber to a width-contracting pressure; and a packing-ring in said chamber and comprising co-acting segments consisting of two-metals mixture moldable under the action of the pressure and heat of superheated steam and comprising the metals copper and lead proportioned substantially one-half'of each said metal, said segments each having one underlapping wedge-end, and also having one overlapping lever-end bearing upon and extending only partially over the wedge-end of a co-acting segment, and the rod packing having between the tension-hoop and the lapping wedge-end and lever-end, a relief chamber occupying an arcual length greater than the arcual length of the bearing of a said lever-end upon a said wedge-end.

5. In a rod-packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annularand conical end walls oppositely-disposed and outwardly converging; a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the follower-ring in a direction for subjecting a packing-ring in said chamber to a width-contracting pressure; and a packing ring in said chamber and comprising co-acting segments consisting of a two-metals mixture moldable under the action of the pressure and heat of superheated steam and comprising the metals copper proportioned substantially one-half of each said metal, said segments each having one underlapping wedge-end, and also having one overlapping lever-end bearing upon and extending only partially over the wedge-end of a Vco-acting segment, and the rod-packing having between the tensionhoop and the lapping wedge-end and leverend, a relief-chamber occupying an arcual length, circumferentially of the ring of between one and one-half and three times the arcual length of the bearing of a said leverend upon a said wedge-end.

6. In a rod-packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annular and conical end-walls oppositely-disposed and outwardly converging; a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the follower-ring in a direction for subjecting a packing-ring in said chamber to a width-contracting pressure; and, a packing-ring in said chamber and comprising co-acting segments consisting of a copper and lead composition slowly moldable under the combined action of the pressure and heat of superheated steam and the friction and vibration of a heated pistonrod, said segments each having one underlapping wedge-end, and also having onel overlapping lever-end bearing upon and extending only partially over the wedge-end of a co-acting segment, and the rod-packing having between the tension-hoop and the lapping wedge-end and lever-end, a reliefchamber substantially as and for the purpose, set forth.

7. In a rod-packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annular and conical end walls oppositely-disposed and outwardly converging; a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the follower-ring in a direction for subjecting a packing-ring in said chamber to a width-contracting pressure; and, a packing ring in said chamber and comprising co-acting segments consisting of a copper and lead composition slowlyr moldable under the combined action of the pressure and heat of superheated steam and the friction and vibration of a heated pistonrod, said segments each having one linderlapping wedge-end, and also having one overlapping lever-end bearing upon and extending over less than two-thirds of the face. length of a wedge-end of a co-acting segment, and the rod-packing having between the tension hoop and each pair of lapping segment ends, a relief chamber occupying an arcual length circumferentially of the ring greater than the length of the contact of a said lever-end upon the face of a said wedge-end.

8. In a rod packing, in combination, an annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annular and conical end walls oppositely disposed and outwardly converging; a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the follower-ring in a direction for subjecting a packing-ring in said chamber to a width-contracting pres sure; and, a packing ring in said chamber and comprising co-acting segments consisting of a material moldable under the combined action of the pressure and heat and the friction and vibration of a piston-rod, said segments each having one underlapping wedge-end, and also having one overlapping lever-end bearing'upon and extending over a portion of the face-length of a wedge-end of a co-acting segment, and the rod packing having between the tension-hoop and each pair of lapping segment ends, a relief chamber extending circumferentially of the ring.

9. In a rod-packing, in combination, an annular packing-ring chamber comprising an'outer wall forming a tension-hoop, and two annular and conical end walls oppositelydisposed and outwardly converging; a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the follower-ring in a direction for subjecting a packing-ring in said chamlber to a width-contracting pressure; and, a

metal packing ring in said chamber and comprising co-acting segments, the metal of said ring-segments being moldable under the combined action of the pressure and heat when subjected to the friction and vibration ofa piston-rod, saidcsegments each having one underlapping wedge'end, and also having one overlapping lever-end bearing upon and'extending over a portion oi the face-length oli a wedge-end oit a (2o-acting segment, and the rod-packing having vbetween the .tension-hoop and each pair of lapping segment ends` a relief chamber eX tending circumferentially of the ring.

ll0. Ina rod-packing, in combination, an. annular packing-ring chamber comprising an outer wall forming a tension-hoop, and two annular and conical end walls oppositely-disposed and outwardly converging;

a follower-ring of which the inner face thereof constitutes one of said end-walls; means for actuating the -follower ring in a direction for subjecting a packing-ring insaid chamber'to a width-contracting pres sure; and, a packing-ring in said chamber and-comprising co-acting segments consisting of a composition slowly moldable under the Ycombined action of the pressure and heat when subjected Vto the friction and vibration of a piston-rod, said segments each having one underlapping wedge-end, andalso having one overlapping lever-end bearing upon and extending over a portion of the face-length of a wedge-endoit a ooacting segment7 and the rod-packing havin(Y between the tension-hoop and each pair or lapping segmentfends, a .relief chamber occupying anarcual `length circumferentially of the ring sufficient for 4permitting said moldable action of the heat and pressure ifipon the segment ends, 'substantially as set orth.

"ADRIAN VAN DERVORT.

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