US2347175A - Machine for end tapering metal tubing - Google Patents

Description

s Sheet-Sheet 1 o a Q C. L. DEWEY MACHINE FOR END TAPERING METAL TUBING April 25, 1944.

Filed Aug. 29, 1942 Aprii 25, 39 (l v 21341232 5 MACHINE FOR END TAPERING METAL TUBING Filed Aug. 29, 1942 3 Shams-Sher"; 2

A ril 25, 1944. c. 1.. DEWEY MACHINE FOR END TAPERING METAL TUBING Filed Aug. 29, 1942 I s Sheets-Sheet s V chine;

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Patented Apr. 25, 1944 I UNITED- mourns roam 'ra'rnnmo METAL e TUBING T' ciuenee neweimh una August 29, 1842, Serial No. 456,58!

- comma (01.80-13) The machine ointhe present invention is particularly designed to step-taper the ends of comparatively short sections of metal tubing of the character employed in the production of propeller shafts for use in motor vehicles, or the like, and in which compactness of structure and ease and rapidity in operationare highly desirable. -In' the production of shafts of thecharacter in question it isdesirable to taperonly the ends of the shaft so that the range of movement required in the operation of the machine is relatively short and in view of the factithat such shaitsare ordinarily tapered at both ends, it is desirable to make provision for the simultaneous operation of the two groups of reducing or deforming elements which move inwardly in unison toward one anotherand to make provision for rigidly clamping theshait in the middle so that only the short end portions are exposedthereby so that-the danger of deflection of the projecting end portions of the shaft may be entirely eliminated by so'mounting the reducing elements that they will accurately center the opposite ends or the shait during the deforming operation.'

The invention also relates to the means employed for truing the interior oi the extreme ends of the tapered-shaft by the employment oi pilot mandrels which enter the ends ofthe shaft thus smoothing out the inside and accurately centering the ends to align with the medial or undeiormed portion of the tube.

The invention relates specifically to the configuring and mounting of .the forming rolls in such a way as to produce a step-tapered shaft. although the general structure of the machine is such that it may be advantageously employed with rolls configured to produce a smooth or uninterrupted taper. Further objects and details will appear from a description of the invention in conjunction with the accompanying drawings whereini Figure 1 is a side elevation oi the entire ma- Fig. 2 an end view thereof;

Fig. 8 a cross-sectional elevation taken on line HOIFILI;

Fig. a face view'mainly in elevation showing the mounting for the forming rolls and associated Fig. as detail of the 'clamp for engaging the middle of a tube section.

frame III which is provided along its upper edges withoarriage'slides or rails H which serve to slidably mount duplicate carriages ll each of a like character, so that a description of one will suilice ior both. Each 01' the carriages is provided along its edges wlthinwardly extending guide bars I: which underlie the rails 'l l and' serve to hold the carriages in position for accurate in and out travel toward one another. As shown, each of the carriages is fed iorwardly or backwardly by a ram ll having mounted, thereon a piston I! located within a hydraulic cylinder It, which arrange ment permits the two carriages to be operated in unison at any desired rate of travel. j.

Each carriage has mounted thereon a riser block H which carries a spindle mounting ll oi cylindrical formation, which spindle mounting is provided at each ell withroller bearings 58a which provide a mounting for a tubular spindle l9. which extends centrally through the spindle mounting with its ends projecting outwardly therefrom.

Each spindle is rotated by. a motor-driven sheave 20 which is bolted to asheave coupling 2| whichscrews onto the end of the spindle. The opposite end of the spindle is screwed into a flanged coupling 22 to the iaceoi which is bolted a circular disk-shaped driving head plate 23.

The hea" plate serves as a carrier for the mounting of three corrugated tapered rolls 24 the acting suriacesoi which are equally spacedoutwardly from the axis of the clearancespace to be occupied by the tubing and in circumferentially paced relation to one another. Each roll is mounted upon outer and inner roller bearings II and 26 carried by a spindle 21. The outer end of each spindle is socketed within a radially adjustable slide plate 28 having an inwardly projecting overhangi g arm II which has bolted thereto an inwardb projecting bracket plate SI which supports the inner end oi the spindle which is screwed into a bushing II. The bracket plate is bolted to the end of the arm 2! bythe headed bolts 32, and the slide plate II is clamped to the head plate by bolts a enteredthrough slots 53 which permit in and out adjustment of the respective slide plates with the corrugated forming rollers carried thereby. The adjustment oithe platesismaintainedbyscrews a entered through a surrounding flange 3' having the three-armed contour shown in Figure 5.

The bracket plates 3! extend radially inward asshownlnmlre5withtheirinnerendsfldlacenttotheaxis orthetubewallandroundedto The machine as a whole is mounted upon a Iaii'ord adequate clearance.

In order to rigidly sustain and center the tube at a point closely adjacent to the projecting end undergoing deformation,-a centering ring 31 is provided which is carried by a surrounding collar 38 being mounted for rotation on ball-bearings 39.

The collar is of the triple armed formation shown overhanging arrangement of the roll mountings .and the necessity of maintaining the centering ring 31 in accurate concentric alignment and at a point distant from its base of support.

The head coupling 22 in its center is provided with a boss 42' which sockets within a center bore 43 in the head plate, and the boss aflords a socket for a plug 44 carried by ball-bearings 45 which permit the spindle and roll frame ,to rotate without imparting rotation to the plug. The plug has screwed thereinto a center pilot mandrel 46 which is of a ize to fit snugly within the end of th tube when reduced and smooth out or iron out anyburrs or inequalities in the interior of the tube and true the tube end to concentric coincidence with the axis of the tube which is highly important in the reduction of tubing intended for power transmissionpurposes.

Each of the forming rolls 24 is of generally tapered formation and provided with concentric spaced corrugations or circumferential crests 41 separated by intervening valleys t8, the crests and valleys of the respective rolls being in common planes so that all will act equally upon the walls of the tube as the rolls are revolved around the tube axis and are rotated by frictional con-- tact with the tube which is held fixed against both rotary and longitudinal movement during the deforming operation.

The moddle portion of the tube is held by a clamp secured against longitudinal movement and comprising fixed and movable jaw- heads 49 and 50 respectively which jaw-heads are provided with opposed V-shaped channels which. receive serrated jaws adapted to grip the tube walls on four sides of the tube as shown in. Figure 6.

The fixed jaw head 49 is supported by standards 52 springing upwardly from the frame of the machine and the movabl jaw-head is provided with lugs 53 which mount pintles 54 carried by rods 55 having pistons 56 operable within cylinders 51', which permits fluid pressure to be applied for clamping and releasing the tubes as occasion may require.

In order to feed the tube sections in position to be clamped by the jaws, an inclined stationary runway 58 is provided down which the tube sections roll, the foremost section being restrained by an arresting arm 59 recessed at its upper end 30 and pivoted at 8|. A rocking'movement is imparted to the arresting arm 53 by a cylinder and piston arrangement Sta, the parts being so arranged that when the lower end of the arresting arm is drawn inwardly as in Figure3, the procession of the tubes will be arrested by contact with the projecting upper prong of the arm 59; but when the lower end of the arm is rocked outwardly, the tube at the head of the procession will be released to roll into the jaws and the next tube will be arrested until it is released by a reverse movement of the arm.

As shown, each of the sheaves 20 is operated by a'motor 82 and belt 63, the motor being mounted upon a shelf 64 carried by the carriage. As shown, the cylinders 51 are suspended from a beam 65 supported by standards 83 springing upwardly from the base of the machine, and the forming roll and mountings are. shielded and protected by arched housings .31 as shown in Figure 1'. v i

' Operation With the'carriages equally retracted, as shown in dotted lines in Figure l, to the extent necessary, a tube section is rolled into place and centrally. clamped by the jaws with its undeformed ends projecting equally in opposite directions. Power is thereupon applied to the spindle is which imparts rotation to the head plate 23 and the group of three rollers carried thereby, which are revolved around the tube axis as a center. Concurrently with the revolution of the rolls, the carriages will begin to move inwardly toward one another until the innermost ends of the rolls of each group engage the oppositely projecting ends of the tube. The innermost corrugations of the three rolls composing a group, being of a minimum diameter andail'ording the widest clearance, will effect a first step reduction in the tube wall and of the tube into short cylindrical portions of progressively decreasing diameter with the extreme tip of the tube displaying the maximum reduction. As the carriage advances to bring the endmost corrugations of the series into acting engagement with the tip end or the tube, the pilot mandrel 46 will advance, and the interior of the tube will be held in snug frictional contact therewith so that it will be restrained against rotation while at the same time serving to smooth out and accurately center the minimum end bore of the tube.

The reducing operation causes a redistribution of the metal, resulting in an elongation of the tube or a thickening of the tube wall, or both of these eflects, but the present invention is not concerned primarily with these results which are inherent in any tube reducingoperation, howsoever performed.

Ithas been found from experience that the use of circumferentially corrugated rolls of the character here shown possesses distinct advantages in operation, since each of the corrugations aii'ords a rounded periphery which advances against the shoulder evolving in the tube wall so that the metal is caused to flow down by minute increments in order to escape beneath the rounded periphery of the corrugation while the intervening channels ail'ord clearance spaces which break the reducing contacts into .a series of concurrent operations while affording clearance behind each corrugation, which assists in the redistributing of the metal and avoids chattering-or. galling of the metalsurfaces which may occur if continuous contacts are maintained. Furthermore the provision ofthe intervening channels provides for the distribution of a suitable liquid coolant and lubricant which may be forced upon the rolls 24 and around the ends of the tube and onto the pilot mandrel thus lubricating the rolls and holding the tube at a low temperature. This permits the cool rolling action of the rolls to greatly increase the tensile strength and hardness of the low carbon steel strip from which the electrically welded tube was made, it being advantageous to increase the strength and stiflness of the step-tapered tube ends when the tube is to be used as an automotive propeller drive shaft or the that the present operation does not require that the tube be exteriorly reenforced at or near the 31 is not employed for the purpose of confining the deformation to .the area in contact with the region of deformation and that the centering ring roll corrugations, but solely for the purpose of.

accurately holding the tube so that it will be concentrically reduced by the stepped forming rolls.

After the reduction of the tube has been completed, the tube is removed laterally by hand or by suitable mechanical means and the operations a repeated while it is not necessary to stop the rotation of the head plates, which need only be drawn back to the extent required to introduce another tube into position. I I

By revolving the rolls around a stationary tube it is possible to secure a high rate of production at lower costs since complications involved in the chuckingand rotating of the tube are avoided and there is no necessity for interrupting the continuity of the driving operation in order to permit the tubes to be introduced and removed.

As shown, the crests of the corrugations on the forming rolls in unison present a straight line of uniform tapering but, it will be understood cave configuration, or combinations thereof, or

variations in the angle of the taper line without departing from the principles of the invention.

Although the present machine has been designed in duplicate to operate upon both ends of a tube section simultaneously, it is not the intention, unlessotherwise indicated, to limit the profor concurrently tapering the for engaging the medial portion of a section of tubing in position to allow the ends of the tube section to project opp tely out ward from the clamp, duplicate sets of reducim vp r e. the

. that the crest lines may assume a convex or con- .of the respective shafts, a spindle for each set of rolls and means for rotating the V mountings to cause the rolls to revolve around an axis concentric with the tube axis concurrently with the advance of the carriage to progressively taperthe end of tube, and feeding devices oif-set laterally from the clamp for inwardly delivering the tubes laterally and singly into the bite of the clamp.

2. In a machine for tapering the ends of tubing, the combination of a clamp for eng n a tube at a point remote from the end to be tapered, a plurality of reducing rolls of progressively increasing diameter in the direction away from the end of the tube to be presented for tapering, the acting surfaces of the rolls being outwardly spaced from the axial center line of the tube to concurrently engage the tube wall in circumferentially spaced relation around the tube axis, a shaft for rotatably mounting each of the rolls, ahead plate and inwardly extending arms secured thereto for supporting the opposite ends carriage, and a pilot mandrel concentric with the tube axis and entered through the head plate in position to enter the reduced end of the tube to true and smooth the same.

3. In a machine for tapering the ends of tubing, the combination of a clamp for engaging a tube at a point remote from the end to be tapered, a plurality of reducing rolls of progressively increasing diameter in the direction away from the end-of the tube to be presented for taacting surfaces of the rolls being outwardly spaced from the axial center line of the tube to concurrently engage the tube wall in circumferentiaily spaced relation around the tube axis, a shaft for rotatably mounting each of the rolls, a head plate and inwardly extending arms secured thereto for supporting the opposite ends secured to the head plate and outwardly extending therefrom V and power means for rotating the spindle, a cena section of tubing, the combimechanisms each carried by a carriage and power means for oppositely advancing the carriages in unison inwardly-toward the projecting ends of the tubing and retracting the carriages in unison therefrom, each carriage supporting thereon a plurality of forming rolls of progressively increasing diameter in the direction away from the proximate end of the tube presented for tapering, the acting surfaces of the rolls being outwardly spaced from the axial centerline of the tube to concurrently engagethe tube wall along longitudinally converging lines 'in circumferentiaily spaced relation around the tube axis, a mounting tering ring adapted to surround the tube inward- 1y beyond the region contacted by the rolls and means for supporting the ring from the head plate, a carriage for mounting the spindle and parts carried thereby, means for advancing and retracting the carriage, and a pilot mandrel concentric with the tube axis and entered through the head plate in position to enter the reduced end of the tube to true and smooth the same.

4. In a machine for tapering the ends of tubing, the combination of a clamp for engaging a tube at a point remote from the end to be tapered, a phn'ality of reducing rolls of progr ively increasing diameter in the direction away from the end of the tube to be presented for tapering, the acting surfaces of the rolls being outwardly spaced from the axial center line of the tube to concurrently engage the tube wall in circumferentially spaced relation around the tube axis, a shaft for rotatably mounting each of the rolls, a head plate and inwardly extending arms secured thereto for supporting the opposite ends of the respective shafts, a spindle secured to the head plate and outwardly extending therefrom and power means for rotating the spindle, a centering ried thereby, and means for advancing and retracting the carriage. 5. In a machine for concurrently tapering the opposite ends of a section of tubing, the combination of a clamp for engaging the medial portion of a section of tubing in position to allow the ends of the tube section to project oppositely outward from the clamp, duplicate sets of reducing mechanisms each carried by a carriage and power means for oppositely advancing the carriages in unison inwardly toward the projecting ends of the tubing and retracting the carriages in unison therefrom, each carriage supporting thereon a plurality offorming rolls arranged in circumferentially Spaced relation around the tube axis and presenting their acting surfaces in progressively closer relation to said axis from the receiving to the discharge ends of the rolls; a mounting for each set of rolls and means for rotating the mountings tocause the rolls to revolve around said axis concurrently with the advance of the carriage to progressively taper the end of the tube, and feeding devices for delivering the tubes laterally and singly into the bite of the clamp.

6. In a machine for tapering the ends of tubing, the combination of a clamp tor engaginga tube at a point remote from the end to be tapered, a plurality of reducing rolls standing in circumferentially spaced relation around the tube axis and presenting their acting surfaces in progressively closer relation to said axis from the receiving to the discharge ends or said rolls, a shaft for rotatably mounting each 01' the rolls, a head plate and inwardly extending arms secured thereto for supporting the opposite ends of the respective shafts, a spindle secured to the head plate and outwardly extending therefrom, and power means for rotating the spindle, a carriage for mounting the spindle and parts carried thereby, means for advancing and retracting the carriage, and a pilot mandrel concentric with the tube axis and entered through the head plate in position to enter the reduced end of the tube to true and smooth the same.

CLARENCE L. DEWEY.

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