US2726561A - Apparatus for shaping tubular stock - Google Patents

Description

06. 13, 1955 r w, HM 2,726,561

APPARATUS FOR SHAPING TUBULAR STOCK Filed March 19, 1951 2 Sheets-Sheet l 5 m ae E I E: E k GE] 4 V 44 35' 2 l7 fl INVENTOR.

Dec. 13, 1955 w 2,726,561

APPARATUS FOR SHAPING TUBULAR STOCK Filed March 19, 1951 2 Sheets-Sheet 2 IN V EN TOR.

WHITE? P- lV BY k KW! United States Patent APPARATUS'FOR SHAPENG TUBULAR STGCK Walter. P.. Hill, Pontiac,rMich., assignor to Calumet &

' H'ecla,.Inc.,.a corporation of Michigan Application March 19, 1e51, Serial No. 216,421

5 Claims. .cl..7s-s9 Thisinventi'on. relates; generally to an improved. apparatus for. shaping stock to conformthelatter to thecontour off-a ,partof a tool.

It. is an object of. this invention to provide an apparatus. rendering it possible. to deform workable stock to a. substantial. degree without the, danger of. overheating or appreciably altering the preferred characteristics of the. stock. 7

One instancewhere this invention finds particular utility isin. the manufacture of casings,. containers, or tubes having one or both ends closed or .partially closed. The present invention enablesproducing such products from tubular stock of workable material. by reducing one.or. both ends ofthe. stock torthe desired. degree, and accomplishes. this. .result regardless. of whether the stock is ofa ferrous metal such as steel and alloys of steel, or. islot. anonferrous metaLsuch for example, ascopper, copper alloys,..aluminum. or similar materials.

With. the above in view, it is. anotherobject. of this invention. to, reduce .one or both. ends of a length of tubular stock by exerting. aro'lling, pressure on. successive circumferentially extending portions. of the. stoclcof limited area,. whileleaving the portions of the stock out of contact with thepressure applying means free tov deform in response to the rolling pressure. Although; they stock out of direct: contact with the pressure applyingmeans is free to deform during the rolling'operation, neverthel'ess', the tool is of a. nature to confine the stock so that the "latter is etfectively reduced. Also with the above arrangement, the area of the stock subjected at any one time to a the rolling-reducing pressure is "restricted; and -in the event the stock to be" reduced isstill or some similar metal, this area is preferably verysma-ll, so that substantial deformation of the stock may be accomplishod without damaging: or overheat-ingthe stock. The areasof contact of: the pressure applying means with the stock may be increasedsomewhat 'in-cases where more ductile.- metals: are used; but even when. such metals-are to be. reduced, it is preferred to restrict the area of'the stockcontacted at. any one time by the pressure applyingm'eans inworder to obtain proper distribution of the stock;

It is still another object of this invention to initially exert :a: circumferential rolling pressure in a generally radiallyinwardE direction: on limited areas of the stock extending around the circumference of the stock, and finallyexerting the rolling pressure in a generallyaxially ext'ending-direction=toclosethe end ofthe stock.

It is: a further object of this invention to provide 'stock' reducing apparatus having a reducing tool freely rotatably supported about anaxis ofis'et laterallyfrom the-axis of the tubular stock tobe'reduced, and having an eccentric mounting for the tool adjustable to vary the degree of eccentricity between the axis of the stock and the axis-of the tool; Thus tubular stock-of different diametersmaybe redueed-hy the'tool and the'reducing 2,726,561 Patented Dec. 13, 19 55 2 pressure or .thearea. of. thestock. contacted at any one time by the toolmay bevariedo It is; a. still further object of this invention to provide a reducing. tool. of the above. type having. a. cavity con-.- centric. with the tool axis. for receiving. one. end; of the stock. and having at least a portion of the cavity-pro.- gressively decreasing: in crosssectional. area. axially of the tool. Thus the tool is. actually in. the term of an internal. roll. which not only has a rollingcontact with limited areas of. the stock,.but in addition, confines, the stock. in order: to: effectively reduce the. latter.

It is a still further objectof: this invention to provide an apparatus of the. abovegeneraltype whereinthe. tool life is appreciably increased even though the reducing tool. isv formed of "an inexpensive mild steel, and even thoughv the stock to be reduced is .formed ofsteel-or some equallydifiicult material to shape. Inworking steel. or steel. alloys, the metal. is preferably: heated to a temperature where oxides are. formed on the surface of the stock. Such heating not only renders the. stock more workable, but in addition, enables; the oxide; to impregnate the rolling. surface of the tool. and greatly improve the wearing. qualities of the. tool.

The foregoing as well. as other objects of this. invention willbe. made. more apparent as this description pro.- ceed's, especially when considered in connection with the accompanying drawings, wherein:

Figure l is a semidiagrammatic side elevational view of reducing apparatusformingthe subject matterof this invention;

Figure 2' is a sectional view of one of the reducing headsof the apparatus, theaxis of the tool holder being ShOWlIJlIli its; zero: position, i. e.. coinciding with the axis of rotation; ofi-the; head;- I

Figure 3' is an end; elevational view of the: reducing head shown; in Figurel;

Figure. 4 is, a semidiagramrnatic viewshowing: the relationship between the stock, andreducing tool in. the head;

Figure 5 is a semidiagrammatic sectional view taken on the linev 5-5 of Eigure 4;. and

Figure 6 is a view similar to Figure 5 showing the completion ofthe reducing operation.

The method and apparatus about tobe described may 'beused' to advantage for shaping stock to various different' contours regardless of whether the stock is of ferrousmetal such-as steel or is ofa more ductile metal such as copper, copper alley or aluminum. However the present invention is especi'allyapplicable when" employed for'reducing' one or'both ends of alength ohmbular stock to form casings, containers, or other tubular products; such for example, as primer tubes; Accordingly' the apparatus selected" herein for" the purpose of i1- lustrationis ofthe-typefound especiallysatisfactory for reducing'either or both ends of a length of tubular stock;

Itwill further be understood as this description proceeds that the present'invention renders it possible tocornpl'etely close-either or both ends of the tubular stock and i's-capableof "eifectively accomplishing; this result in connection' with relatively large diameter stock formed of steel; steel alloys, copper, copper alloys, aluminum or similar relativelyductile" metals. Tubularstock of ferrous metals, such for example, as steel is particularly difficult to-reduce; especially where the extent of reduction must be sufficient to completely close one or both endsof the stock; In accordance with this invention-one or both ends' of'alength of'tubular stock may be com- 'ple't'ely closed in a relatively short interval of time'and with amini'mum amount ofwearof the tools by-exertihg a" rolling pressure onsuccessive circumferentially extend? ing portions of limited area of the stock. Thus only a relatively small area of the stock is subjected to the rolling reducing pressure at any one time, and the remainder of the stock is free to deform in response to the rolling pressure. In instances where the stock is formed of steel or steel alloys, it is preferred to preheat the'portions of the stock to be reduced prior to subjecting the stock to the rolling pressure. The temperature to which the steel or steel alloy stock is preheated depends to some extent on the characteristics of the stock; but in any case, is heated to a temperature sufliciently high to cause oxide to form on the outer surface of the stock and to render the stock workable under the prevailing rolling pressures. The advantage of forming an oxide on the outer surface of the stock prior to introducing the stock into the tool will be more fully hereinafter explained. Briefly this oxide becomes embedded in the adjacent wall of the tool, and provides a hard wear resisting surface on the tool even though the latter may be formed of a mild coldrolled steel, for example. In instances where the stock is of a ductile metal, such for example, as copper or copper alloy, it is possible to satisfactorily reduce a length of tubular stock to completely close one or both ends without preheating the stock.

With the above in view reference is now made more in detail to the drawings, wherein Figure l diagrammatically illustrates one type of apparatus found highly satisfactory for reducing one or both ends of a length of tubular stock, regardless of whether the latter is formed of ferrous or nonferrous metals. The apparatus comprises a pair of axially aligned reducing heads spaced from each other in the direction of their axes and respectively secured to suitable drive shafts 11. The drive shafts 11 are driven by a suitable prime mover, and are supported for relative axial movement to enable the heads 10 to be fed toward and away from one another. The means for rotating the drive shafts 11 and for feeding the same in the direction of their axes are not shown herein, as this mechanism forms no part of the present invention.

The numeral 12 indicates a length of tubular stock which may be of a ferrous metal such as steel or of a nonferrous metal such for example as copper, copper alloy or other ductile metals. In any case the length of stock 12 is shown diagrammatically in Figure 1 as supported intermediate the ends on a carriage 13 and as secured against rotation by a clamp 14 on the carriage. The carriage 13 is movable in a direction perpendicular to the axes of rotation of the reducing heads 10, and the means I for operating the same is not shown herein. It will suffice to point out that the length of stock is mounted on the carriage 13 in a manner to enable the stock to be positioned between the reducing heads 10 in axial alignment with the latter.

The reducing heads 10 are identical in construction and a description of one will suflice for both. As shown in Figures 2 and 3 of the drawings, each head comprises a housing 15, a carrier 16 and a tool holder 17. The housing has a recess 18 formed in the inner end and has a bore 19' extending axially of the head from the base of the recess to the outer end of the housing. The bore 19 .is fashioned to receive the inner end of the adjacent drive shaft 11 and is internally threaded for attachment to the drive shaft 11. The recess 18 has a bearing 19 concentric with an axis 20 offset laterally with respect to the axis 21 about which the head 10 rotates and on which the length of tubular stock 12 is supported during the reducing operation. Thus the bearing 19 is eccentrically located with respect to the axis of rotation of the head, and the purpose of such an arrangement will become apparent as this description proceeds. In order to compensate for the eccentricity of the bearing 19 rela tive to the axis 21 of rotation of the head, a portion of the housing 15 is cut away at the outer end as at 22 in Figure 2.

The carrier 16 is in the form of a sleeve having a cylindrical part 23 journalled in the bearing 19 and having a bore 24 eccentrically located with respect to the bearing 19 or cylindrical part 23. The axis of the bore 24 is indicated in Figure 4 of the drawings by the reference character 25, and the relationship between the several axes is such that the axis 25 of the carrier may be moved from a position in coaxial relationship to the axis 21 of rotation of the head 10 (Figure 3) to any one of several selected positions which are laterally offset different degrees from the axis 21.

In Figure 3 of the drawings the axis 25 of the carrier 16 is shown in its zero position; or in other words, coincides with the axis 21 of rotation of the head 10. In use however the axis 25 of the carrier 16 is offset laterally with respect to the axis 21, and this is accomplished by merely rotating the carrier relative to the housing on the bearing 19. In this connection it will be noted that the carrier has a radially outwardly extending flange 26 at the inner end, and this flange abuts the inner end of the housing 15. It will be noted from Figure 3 of the drawings that the flange 26 is formed with a plurality of circumferentially spaced notches 27, and these notches are selectively engaged by a pin 28 in the form of a stud secured to the inner end of the housing 15. It follows therefore that the carrier 16 is normally secured to the housing by the pin 28 and rotates as a unit with the housing about the axis 21. It also follows that the carrier 16 may be secured to the housing in any one of a number of different angular positions with respect to the housing so that different degrees of eccentricity of the axis 25 relative to the axis 21 may be obtained.

The tool holder 17 is in the form of a shaft journalled in bearings 29, which in turn, are respectively secured in the bore 24 of the carrier 16. The bearings 29 are spaced axially from each other by an annular shoulder 30 extending radially inwardly from the carrier intremediate the ends of the latter.

The outer end of the tool holder is threaded for receiving a lock nut 31, and the inner end of the tool holder has a recess 32 therein. The lock nut 31 cooperates with a suitable lock washer 33 to prevent inward displacement of the holder 17 relative to the carrier and outward displacement of the holder is prevented by an enlargement 34 positioned on the holder to engage the inner bearing 29. A suitable oil seal 35 is secured in the inner end of the bore 24 in the carrier 16 to close the space around the tool holder 17.

Attention is called to the fact that the bearings 29 support the tool holder 17 for free rotation about the axis 25 of the carrier 16. It is important to note that the tool holder 17 is not directly driven, but on the other hand, may rotate freely relative to both the housing 15 and the carrier 16. It will also be noted that since the tool holder 17 has the same axis 25 as the carrier 16, it is angularly adjusted relative to the housing 15 as a unit with the carrier 16 to vary the degree of eccentricity of the tool holder relative to the axis 21 of rotation of the head 10.

Removably secured within the recess 32 at the inner end of the tool holder 17 is a reducing tool 36. The reducing tool is removably held in the recess by a set screw 37 threaded in the enlargement 34 of the tool holder 17. A bore 38 extends axially of the tool holder from the base of the recess 32 to the outer end of the tool holder, and is adapted to receive a knock-out tool when it is desired to remove the reducing tool 36 from the recess 32.

The reducing tool 36 is in the form of a block of metal havinga cavity 39 in the inner end thGI'COfg The cavity 39 has a straight cylindrical section 40 at the entrant end which is concentric to the axis 25 of rotation of the tool holder; and progressively decreases in cross section from the cylindrical part 40- to the axis 25", as clearly shown in Figure '5 of the drawings.

In use the carrier -16--is angularly adjusted relative to the housing to locate the axis' of the tool holder 17 in olfset relationship'to the axis 21 of rotation of the head10 (see Figures 4-6). Since the length of tubular stock 12 is' supported in coaxial relationship to the axis 21-, it will be'noted that onlya limited area of'one side of the stock is engaged. by the wall of the cavity '39, as clearly shown in Figure 5. ofthe drawings. As pointed out above the length of stock 12 is secured against rotation on the carriage 13 by the clamp 14 so that rotation of the head 10 results in a frictional engagement between the stock and wall 39 of the cavity. This frictional contact imparts rotation to the tool holder 17 and the wall of the cavity 39 has a rolling engagement with limited areas of the stock extending circumferentially of the latter.

Where both ends of a length of tubular stock 12 are to be reduced, the stock and heads 10 are relatively positioned on the axis 21, and the heads 10 are fed toward one another to project the opposite ends of the stock into the respective tool cavities 39, as indicated in Figure 5, of the drawings. The heads 10 are then fed in directions toward one another, and at the same time, are rotated. Although the axis of the tool 36, indicated at 25, is oifset or eccentric with respect to axis 21 of the head, it is readily apparent that tool holder 17 will be caused to revolve about axis 21 of the head as the latter rotates. When the head 10 is advanced sufliciently to cause wall 39 of the tool civity to engage the stock, it is apparent that the rotation of the head together with the fricional engagement between the tool cavity and stock causes a rotation of tool holder 17 about its own axis, whereby cavity 39 has a continuous rolling engagement with the stock about successive limited areas extending circumferentially thereof. This can be more clearly understood by referring to Figures 4-6. Thus, for example, when the head is rotated 180 degrees so that the axis 25 of the tool lies on the opposite side of axis 21 (see Figure 4), it will be apparent that the cavity 39 of the tool will engage the stock at a limited circumferential area diametrically opposite to that subjected to the action of the tool cavity shown in Figure 4. During initial relative movement of the heads 10 toward one another, the reducing tools 36 exert a rolling pressure in a generally radially inward direction on the stock to progressively reduce the diameter of the latter, and finally exert a rolling pressure in a generally axial direction on the stock to completely close the ends of the stock. If desired the axial rolling pressure may be continued after the ends are closed in order to in effect upset the metal at the ends of the stock as indicated by the reference numeral 41 in Figure 6 of the drawings. The line 42 at the end of the stock indicates the joint which results when the metal at the end or ends of the stock are brought together. Since the reducing pressure is applied successively to only limited circumferentially extending areas of the stock, the remaining areas being out of contact with the tool, the temperature of the stock is maintained well below any temperature which might injure the stock or cause a welding together of the metal at joint 42. Therefore, in practice, although the metal is intimately joined at the closed end or ends of the stock, the joint 42 nevertheless remains, although not readily apparent. It will, of course, be understood that the rolling-reducing pressure may be discontinued prior to completely closing the ends of the stock if it is desired to leave restricted openings at the ends of the stock.

It is important to note that during the reduction of the stock, the wall of the cavity 39 freely rotates around the stock, and the reducing pressure is successively applied to limited areas extending circumferentially of the stock. Thus the remaining portions of the stock, or in other words, the portions of the stock out of contact the rolling pressure.

with the reducing tool, are free to -deform in response to This arrangement 'afi'ords-amore uniform: control of the flow of themetal during: the reducing operation, and maintains the temperature of the stock well. below any. temperature: that may. injure the stock. It is alsoimportant to note,,however, that while the metal out of direct contact Witl'r'tlie wall of the cavity 39 is freeto deform, nevertheless, the stock is confined by the cavity 39; and asa result, is etfectivelycontracted or reduced during the rolling operation.

It willfurther be noted. that the stock need; notbe heated by an external source during the reducing operation. Practically the only heating obtained during the reducing operation results from the friction, and since this friction is somewhat reduced during the final stages of the reducing operation, it follows that the stock is cooled to some extent. However when reducing ferrous metals, such for example as steels, it is preferred to preheat the ends of the stock prior to subjecting the latter to the reducing operation. The temperature to which the stock is preheated depends largely on the nature of the stock; but in any case, preheating is effected to such a temperature that the stock is not only rendered more readily workable by the rolling pressures to be applied, but also to a temperature high enough to provide a coating of oxide on the surface of the stock. In practice this oxide flakes off and becomes lodged in the wall of the cavity 39 during the rolling operation. This is especially true in cases where the tool is formed of a relatively mild cold rolled steel, for example; and provides a wear resisting surface on the tool or wall of the cavity 39. When reducing stock of copper, copper alloys or similar ductile materials, it is not essential to preheat the stock, as the heat normally generated during the reducing operation is sulficient to render such materials workable What I claim as my invention is:

1. Apparatus for reducing stock comprising a head rotatable about a first axis, a carrier rotatable as a unit with said head and having a cylindrical bearing, a reducing tool mounted in said bearing for free rotation about the axis of said bearing and having a stock receiving cavity concentric with said bearing, at least a portion of said cavity progressively diminishing in cross-section axially of said tool and the wall of said cavity being adapted for rolling contact with the stock to be reduced, and means for mounting said carrier on said head in different positions of transverse adjustment with the axis of said bearing generally parallel to the axis of rotation of said head, whereby to locate said bearing in various positions laterally offset from the axis of rotation of said head.

2. The apparatus defined in claim 1, in which said last-named means includes a bearing on said head mounting said carrier for rotation about a third axis laterally offset from the first and second axes.

3. The apparatus defined in claim 2 in which the third axis is so located with respect to the first and second axes that rotation of the carrier about the third axis relative to the housing varies the degree of eccentricity between the first and second axes from zero to a predetermined maximum.

4. Apparatus for reducing stock comprising a head having a housing rotatable about a first axis and having an eccentric cylindrical bearing in said housing, means for rotating said housing, a carrier rotatable as a unit with said housing and having a peripheral bearing surface journalled in the eccentric housing bearing, said carrier having an eccentric cylindrical bearing, and a reducing tool journalled in the last-named cylindrical bearing for free rotation and having a cavity concentric with said last-named cylindrical bearing for receiving one end of a length of stock to be reduced, at least a portion of said cavity progressively diminishing in cross-section axially of said reducing tool and the wall of said cavity being adapted for rolling contact with the length of stock, and

References Cited in the file of this patent UNITED STATES PATENTS Ide Jan. 18, 1876 Nason Dec. 1, 1885 Ritchie Apr. 13, 1886 10 Kennedy Aug. 18, 1891 8 Oster Oct. 8, 1918 Hamacheck Ian. 17, 1928 Hill Mar. 9, 1943 Montgomery June 24, 1943 Gage et a1. Feb. 1, 1944 Enghauser Jan. 20, 1948 De Wilde et a1. June 15, 1948 Johnson Sept. 7, 1948 Fessler Aug. 15, 1950 Woldman et a1. May 6, 1952

Images