US2247863A - Pipe swaging machine - Google Patents

Description

July 1, 1941- J. B. TIEDEMANN PIPE SWAGING MACHINE 5 sheets-sheet 1 Filed Kay 27, 1939- Julius B. Tiedemann I INVENTOR.

ATTORNEY.

y 1, J. B. TIEDEMANN 2,247,863

' PIPE SWAGING MACHINE Filed Ilay 27; 1939 5 Sheets-Sheet 2 INV ENT OR.

ATTORNEY.

JuliusB. Yiedemann July 1, 1941- J. B. TIEDE MANN PIPE SWAGING MACHINE Filed Nay 2'7, 1939 5 Sheets-Sheet 5 I II Ll. u

Julius B. fiedemann INVENTOR ATTORNEY.

y 1941- J. B. TIEDEMANN PIPE SWAGING MACHINE Filed May 27, 1939' 5 Sheets-Sheet 4 Julius B. 'Hedemann ATTORNEY.

July 1, 1941. J. B. TIEDEMANN 2,247,863

PIPE SWAGING MACHINE Filed May 2'7, 1939 5 Sheets-Sheet 5 Julius B. Tz'edemann INVENTOR.

ATTORNEY.

Patented July 1, 1941 UNITED STATE PIPE SWAGING MACHINE Julius 'B'. Tiedemami, Milwauk Wis.,

to A. 0. Smith Corporation, Milwaukee. corporation of New York Application May 27, 1939, Serial No. 270,!

Claims.

This invention relates to a pipe swaging machine and provides a machine which can be economically employed in the swaglng-of relatively large diameter thin wall pipe to pipe of smaller diameter and thicker walls. V

Heretofore pipe swaging, as accomplished by the piiger mills and so called tube reducing mills, has been utilized to thin the wall of pipe and in some instances to change its diameter either to a larger or a smaller diameter. Such mills, however, have been expensiveto build and slow in operation. I

In the pilger mills the pierced billet or blank has to be reciprocated a substantial distance during each working stroke of the rolls, 1. e. the rolls in their partial rotation move the blank in one direction and then release it and the blank has to be moved back almost the same distance before the rolls start another working stroke. Where oscillating roll segments are employed the same movement of the pipe is necessary although with them it is possible to obtain two working strokes of the dies for each cycle of reciprocation of the blank. The mass of the blank, combined with the distance of its reciprocatory movement, results in a necessarily large amount of energy being consumed in the mov-' ing of the blank and in changing its direction of movement. It is impossible to obtain any sub.- stantial rapidity of stroke or of reciprocation and the cycle of operation is usually limited to less than one or only a few reciprocation cycles per minute. I

With the tube reducing mills, which have been employed only on relatively small diameter tubing of easily workable material, the frame on which the rolls or die segments are mounted is reciprocated and the blank held stationary except for a small feed between every other working stroke. Again the operation is necessarily slow due to the relatively large mass being reciprocated and the distance of its movement.

The principal object of the present invention is to provide a practical and efllcient machine for swaging pipe and in which neither the machine nor the pipe will have any substantial relative reciprocation.

Another object of the invention is to provide a machine for swaging pipe in which the mandrel may be held relatively stationary and the movement of the dies will tend to break the blank loose from. the mandrel at the end'of each operating stroke.

Another object of the invention is to providea machine for swaging pipe in which the moveusignor. Win. a

ment of the dies is utilized to obtain'the whole or a part of the necessary feed of the blank between the working strokes.

Another object is toprovide for dies of larger radius thereby giving a longer more gradual swaging per working strokewith less wear on the dies and making-it possible to more efilciently and more accurately swage pipe of large diameter.

Another object is to provide a pipe swaging machine which will operate eiiiciently with over one hundred strokes per minute and produce accurately formed pipe at such a rate.- i

Other objects and advantages of the invention will be set forth hereinafter .in connection with the description of the preferred embodiment of the invention illustrated in the accompanying drawings. h

In the drawings: 7 V

Figure 1 is a side elevation of themachine, partly in section;

Fig. 2 is a top plan view of the machine, a part shown in section on the line 2-2-01 Fig.

Fig. 3 is a top plan view of a part of the machine showing the counterbalancing mechanism;

Fig. 4 is an end elevation of the machine;

Fig. 5 is a transverse horizontal section on line I! of Fi 4; v

Fig. 6 is a vertical section on the line 6-6 of Fig. 4 showing the die mountings, parts being omitted;

Fig. 7 is a schematic view showing a section through the center of the dies at the beginning of a working stroke;

Fig. 8 is a view similar to Fig. 7 showing the dies at the centerline of their stroke;

Fig. 9 is a view similar to Fig. '7 showing the dies as they approach the end of their stroke;

Fig. 10 is a view similar to Fig. 7 showing the dies as they lift clear of the blank on the return stroke; and

Fig. 11 is a view similar to Fig. 6 showing, schematically, a modified form of die holder.

The machine comprises, in general two upright side frame members I and 2, an upper drive shaft 3 extending transversely between the frame members I and 2, a similar lower drive shaft 4, extending transversely between the frame members I and 2, and parallel to the upper shaft 8, and upper and lower die segments 5 and 0, respectively, disposed at the center of the machine.

The drive shafts 3 and l are geared together and driven from a common source of power, which is preferably a motor I.

The upper die segment is hung from the upper drive shaft 3 by means of links 8 and 9. The link 8 has bifurcated ends,.the upper ends forming two spaced bearings Ill operating on eccentric cranks II on shaft 3, and the lower ends being pivotally connected to the forward end of the upper die 5 as at l2 and I3 on each side of the die. The link 9 has a single upper hearing I 4 operating on 'an eccentric crank 5 on shaft 3. between the cranks H, and a bifurcated lower end pivotally connected to the rear end of the upper die 5 as at l6 and I1 on each side of the die.

The lower die 6 is similarly supported above the lower shaft 4 by means of links l8 and 9. The link l8 has bifurcated ends, the lower ends forming two spaced bearings operating on eccentric cranks 2| on shaft 4, and the upper ends being pivotally connected to the forward end of the lower die 6 as at 22 and 23 on each side of the die. The link 9 has a single lower bearing 24 operating on an eccentric crank 25 on shaft 4, between the cranks 2|, and a bifurcated upper end pivotally connected to the rear end of the lower die 6 as at 26 and 21 on each side of the die.

The two die segments 5 and 6 are connected to the side frame member by means of pivotal links 28 and 29, respectively, and to the side frame member 2 by means of similar pivotal links and 3|, respectively. The links 28, 29, 30 and 3| serve to keep the dies in alignment and to prevent the die faces from moving endwise relatively to each other. The links, however, have another very important function which will be described hereinafter in connection with the operation of the machine. In the embodiment illustrated in Figures 1 to 10, the pair of links 28 and 29 have a common pivotal attachment to the frame I and likewise the pair of links 30 and 3| have a common pivotal attachment to the frame 2.

In order to prevent wear on the drive shaft' 3 by reason of the weight of the die 5 and alternate working forces, the die 5 is supported by a balancer so that the links 8 and 9 are constantly lifted upwardly against the cranks II and I5 thereby removing all slack in the drive.

The balancer comprises an X-shaped cross head 32 pivotally supported on a horizontal shaft 33 on top of the machine and having depending pivotal arms 34 extending from the ends of the cross head and pivotally secured to the die segment 5 at about its four corners, respectively.

The shaft 33 is mounted for vertical movement in slots in guide brackets 35 and is supported on a piston rod 36 extending upwardly from a piston 31 provided in a large vertical cylinder 38 on top of the machine.

By supplying compressed air or other suitable compressible fluid in the cylinder 38, piston 31 can be forced upwardly thereby tending to lift the die member 5 against the shaft 3. The pivotal mounting of the cross head 32 allows for the free rocking motion of the die 5.

The importance of this balancer for the upper die is realized when it is appreciated that it greatly lengthens the life of the cranks H and I5 and the bearings of shaft 3, since the wear on these parts will be reduced to frictional or surface wear as distinguished from wear produced by a pounding of the parts as, would be obtained if slack were allowed to develop.

In conjunction with the machine it is necessary to employ a feeding device for feeding the blank. This is illustrated in Fig. 1 as comprising a feeder 39 at the left hand end of the machine and feeder 40 at the right hand end of the machine, the feeders being operated from the machine drive so as to insure synchronism between the feeding of the blank' and the operation of the dies. The blank passes through the feeder 39 and into the machine, and then out through feeder 40. The detail construction of an improved feeder is set forth in co-pending application Serial No. 286,627, filed July 26, 1937, by the present inventor, it being understood that the feeder constitutes no part of the present invention and therefore, is illustrated herein only in general as any suitable feeding device.

A mandrel 4| is provided with a tapered section 42 in the working zone between the dies and with a tapered end head 43 for entering into a blank as the latter enters the machine. The mandrel 4| is supported at the right hand end by a cushion or spring mounting 44 which is detachable to allow a section of pipe to be stripped from the mandrel after the pipe has been swaged. The mandrel is preferably water cooled, particularly for hot forming operations, and its internal construction for this purpose is more specifically set forth in co-pending application, Serial No. 294,254, filed Sept. 11, 1939, by the present inventor.

The mandrel 4| comprises a long tubular member 45 extending between the tapered section 42 and the mounting 44 at the outer end of the member, the length of the member being suflicient to allow for the completion of the swaging of a section of pipe before the detaching of the mounting in stripping the pipe from the mandrel. Suitable rolls 46 beneath the member 45 are adaptedto receive and support the pipe as the latter emerges from the swaging machine and to remove the pipe from the mandrel after completion of the swaging operation. When the mounting 44 is detached from the mandrel 4|, the latter is held against longitudinal movement by a forked holder 41 located between the feeder 39 and the swaging machine, and which is caused to engage the head 43 of the mandrel during stripping.

The forked holder 41 and the detachment of the mounting 44 are operated by suitable air cylinders, 48 and 49, respectively, the control valves for which may be operated by cams driven by the movement of the pipe as it leaves the swaging machine.

The mounting 44 comprises pivotal jaws 50 adapted to receive the head 5| on the mandrel stem, and are positioned on opposite sides of a stationary ring 52 which supports the mandrel and through which the pipe moves in stripping it from the mandrel. The movable jaws 50 are mounted on pivots 53 and are operated by links 54 connecting them to the air cylinder 49, the links standing vertical when the jaws engage the mandrel stem. One of the jaw members engages the end of head 5| and has a suitable passage 55 for admitting water to the tubular mandrel stem for cooling purposes.

The jaws 50 and their operating mechanism are mounted on a slidable base 56 having an end cross plate 51 to the center of which is secured a bolt 58 extending forward parallel to the mandrel stem. The bolt 58 passes through an opening in a stationary cross member 59 suitably secured to a concrete foundation and a nut 68 on rearwardly toward the the bolt securesjhe mandrel against movement machine. A- rubber cushion blockwas'her II is provided between the nut and stationary member I! to ailowa limited movement of the mandrel'in' case the die; should have a slight rearward feedidurina any part of the working stroke,

The bolt' II extends forward from nut 00 through an opening in plate I2 and nut "on theinner side of plate It allows the bolt to move to the left freely with respect to the plate, but presses against the plate when the bolt moves to the right, or forward. The plate 82 is held movable on two bolts 63- and is pressed to the left by two relatively strong'springs 64 located on the respective bolts 03. Any movement of the mandrel forward with the dies of themachine will move plate 82 forward and compress the springs 64. The limited movement allowed the mandrel is enough to decrease any severe shock on it or the machine and still effect proper breaking of the pipe from the mandrel in the action of the dies.

The machine has been applied to the manufacture of heavy walled relatively small diameter,

i. e. from 4% to 13 inchesin diameter, casing for oil wells, from welded pipe of thinner walls and larger diameter. The pipe sections employed are approximately 40 feet long to start with and the swaging operation lengthens them to about '50 feet. At the same time the wall thickness of the pipe is increased from about one-fourth to about one-half inch.

In operation of the machine where large reductions in diameter of the pipe are desired it is preferable to swage it hot and for this purpose a suitable furnace 65 is employed to heat,

the pipe section before it is fedto. the machine. The temperature to be employed will depend largely upon the type of steel being swaged as is well known in the metallurgical art. The dies are kept cool by spraying water on them as from a spray pipe 66.

Where the machine is employed for making relatively small reduction in diameter of the pipe, as in sizing, the operations are preferably carried out without previous heating of the pipe.

" inclusive.

.gther at their forward ends bringing the comdie faces and the mandrel.

groove faces of dies from right to left onto the blank firsteffects a conical shaped reduction of the pipe at the end.- As this conical end of the'pipe passes the center-line ll of the machine it-entersthe working zone where it ispressed between the blank 01 is moved forward it is turned 90 by the feeders l9 and 40 so as to effect pressing in different radial directions alternately.

As the end of the pipe reaches the desired diameter it enters thecurved'groove III and then the cylindrical section 68 of the groove in the die faces. It emerges step by step from the cylindrical section as a straight cylindrical section of pipe of the desired diameter.

The steps of a single typical cycle of operation of the machine are illustrated in Figures 7. to 10 In Fig. 7 themes I and 8 come toplementary cylindrical groove section 69 of the die faces into engagement with the pipe. Then the tiles are caused to rock to the rear, up the taper of the mandrel as shown in Fig. 8. After the contact between the dies and pipe passes to the rear (left) of the center line H and leaves the working zone the die faces are caused to move forward (to the right), thus tending to feed the pipe forward to a slight extent, as illustrated in Fig. 9. -This slight forwardfeed of the pipe loosens it from the mandrel. Then the dies lift clear from the pipe as in Fig. 10 and return to the starting position while the pipe is fed forward a few inches and turned as described above. I

It is possible to change the wall thickness obtained by the swaging operation by moving the mandrel 4| the required distance forward or to Referring to Figures 7 to 10, inclusive, a pipe section 61 is fed into the machine from left to right over the mandrel 4|, and between the dies 5 and 6. The dies 5 and 6 have a tapered circular groove 58 in the complementary working faces of their removable die blocks, corresponding in the working zone to the taper 42 on the mandrel and having its larger diameter at the left end and its smaller diameter at the right end. The right end of the dies contain a cylindrical section 69 forming an extension of the groove 68, and the two are merged by a short curved section 10.

The principal working zone is to the right or ahead of the center line H of the machine, the conical section 42 of the mandrel being positioned in this zone. This is the only zone in which the mandrel is designed to contact with the pipe, since the function of the mandrel is primarily to support the pipe against collapse in the working zone and to effect more uniform thickening of the pipe walls. In cold sizing and certain other operations the mandrel may be disposed with entirely.

As the pipe blank 61 is fed into the machine in therear. If it is moved to the rear it is possible that the forward feeding movement of the dies will begin before the dies have cleared the working zone on the mandrel. In such case the mandrel will be given a strong forward impulse in breaking the pipe from it. In any event some forward impulse will be given to the mandrel at the time the pipe is broken loose from it.

The cushioning of mounting 44 as previously described operates'to allow the mandrel to move with the pipe to a limited extent, relievesthe mandrel from shock resulting from forward impulses and prevents breaking of the mounting.

The die faces are constructed on a radius several times that heretofore employed in practice for pilger rolls and without necessitating heavier frame work or drives. By reason of this fact a more gradual forming of the pipe is obtained with less severe working.

The neutral axis of the die face at which the pipe is neutral to the surface of the die is approximately at two-thirds of the depth of the semi-circular groove in the face. At the bottom of the groove there will be a tendency towards slippage between the surfaces of the pipe and g of the die as the latter rocks on the pipe, and

at the edges of the groove there will be a tendency towards slippage in the opposite direction. The distance of the neutral axis from the axis of the pivotal attachment of links-28, 29, 30 and 3| to the respective dies is one of the determining factors in effecting the forward feed of the pipe as the dies approach the end of a working stroke. Another factor is the length of the links 28, 29, 30 and 3|. By employing links of different length it is possible to obtain different die movements. Longer links tend to reduce the the dies and the rocking of the 1 Each time the pipe feeding movement while shorter links tend to increase it.

It is possible to separate the links so that their pivotal attachment to the frames are at vertically separated points as illustrated in Fig. 11. However, with such a construction the feeding movement of the dies is increased and will begin ahead of the center line ll. This type of construction may be used without a mandrel as for cold sizing.

Various embodiments may be employed within the scope of the invention as set forth in the accompanying claims.

The invention is claimed as follows:

1. In a machine for swaging pipe, a pluralit of swaging dies disposed to rock longitudinally on the pipe and having complementary recesses therein for receiving and forming the pipe, said recesses combining to provide a substantially conical working section for reducing the diameter of the pipe as the dies are caused to operate on successive sections of the pipe and a substantially straight cylindrical section for straightening and sizing the pipe to final dimensions as it leaves the machine, means toreciprocate the dies together to reduce the diameter of the pipe in short successive increments, the dies closing onto the pipe at the end of said cylindrical section first and thereafter on said conical section, and means for feeding the pipe intermittently to the machine between successive strokes of the dies.

2. In a machine for swaging pipe, a pair of swaging dies disposed to rock longitudinally on the pipe and having complementary recesses therein for receiving and forming the pipe, said recesses combining to provide a substantially conical working section for reducing the diameter of the pipe as the dies are caused to operate on successive sections of the pipe and a substantially straight cylindrical section for straightening and sizing the pipe to final dimensions as it leaves the machine, said dies being disposed to close on the pipe first at said cylindrical section and then at said conical section.

3. In a machine for swaging operations, a die member disposed to rock longitudinally on the article being swaged, a constantly rotating drive shaft therefor extending transversely of the same, a driving connection between said shaft and said die member including a crank on the shaft connected by a link to one end of the member and another crank on the shaft connected by a link to the other end of the member, said cranks extending in different directions from the axis of the shaft to eifect a rocking movement of the die member from end to end.

4. A machine for swaging operations comprising a pair of complemental die members disposed to rock longitudinally on the article being swaged, a constantly rotating drive shaft for each member, a driving connection between one of said shafts and its corresponding die member including a crank on the shaft connected by a link to one end of the member and another crank on the shaft connected by a link to the other end of the member, said cranks extending in different directions from the axis of the shaft to effect a, rocking movement of the die member from end to end, a similar driving connection between the other of said shafts and its corresponding die member, and means holding said die a members to a predetermined complementary movement relative to each other and to the article being swaged.

5. In a machine for swaglng operations, a die member disposed to rock longitudinally on the article being swaged, a. constantly rotating drive shaft therefor extending transversely of the same, a driving connection between said shaft and said die member including a crank on the shaft connected by a link to one end of the member, another crank on the shaft connected .by a link to the other end ofthe member, said cranks extending in diflerent directions from the axis of the shaft to eflect a rocking movement of the die member from endto end, and a link pivoted to said die member at one end of the member and to a stationary member, the direction and length of said link providing a curvature of movement of its connection to said die member eflecting a. substantially true rocking movement of said die upon the article being swaged for the major part of the swaging movement of the die.

6. A machine for swaging operations comprising a pair of complemental die members disposed to rock longitudinally on the article being swaged, a constantly rotating drive shaft for each member, a driving connectionbetween one of said shafts and its corresponding die member including a crank on the shaft connected by a link to one end of the member and another crank on the shaft connected by a link to the other end of the member, said cranks extending in different directions from the axis of the shaft to effect a rocking movement of the die member from end to end, a similar driving connection between the other of said shafts and its corresponding die member, and means holding said die members to a predetermined complementary movement relative to each other and to the article being swaged, said last named means including a link pivoted to each die member at one end of the member, the other ends of the links being pivoted to a stationary member on a common axis lying in the central transverse plane of the dies and at a point preferably near to the opposite ends of the die members from those to which the links are pivoted.

7. In a machine of the class described, a pair of complemental swaging dies disposed to cooperate in swaging operations, a plurality of rotary drive shafts operating in bearings and having cranks thereon, pivoted links connecting respective cranks to the respective die members to effect a rocking movement of the latter as said shafts rotate, and means pressing said die members outwardly against the respective bearings and pivot connections to take up any slack between the same.

8. In a machine .of the class described, an upper horizontal rotary drive shaft, cranks disposed thereon and links depending from said cranks, a die member connected to the lower ends of said links and disposed to be rocked by the movement thereof, a cross head pivoted at its center to a frame member and connected at its ends to said die member to support the same, and means pressing the pivot of said cross head upwardly relative to said rotary drive shaft to carry the weight of said die member and prevent slack developing in the several cranks and bearings.

9. In a machine of the class described, a stationary frame, an upper horizontal rotary drive shaft mounted in bearings in said frame and having cranks thereon, a die member disposed for rocking movement beneath said shaft, pivoted means connecting said cranks and die member to drive the latter when the shaft is rotated.

means connecting said cranks and die member to drive the latter when the shaft is rotated, a cross head pivoted on top of said frame, links connecting the outer arms of said cross head to the opposite ends of said die member, and fluid pressure means tending to lift said cross head at its pivot point to carry the weight of said die member.

JULIUS B. TIEDEMANN.

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