US2635492A - Plug-handling mechanism for seamless tube mills - Google Patents

Description

M. S. GETTIG April 21, 1953 PLUG-HANDLING MECHANISM FOR SEAMLESS TUBE MILLS 3 Sheets-Sheet l Filed March 20, 1946 ImcNl/ INVENTOR Ill JW/vwvm i fwn April 2l, 1953 M. s. GETTIG 2,635,492

PLUG-HANDLING MECHANISM FOR SEAMLESS TUBE MILLS Filed March 20, 1946 3 Sheets-Sheet 2 INVENTOR Maf/075 6927@ A, mi?,

April 21, 1953 M. s. GETTIG 2,635,492

PLUG-HANDLING MECHANISM FOR SEAMLESS TUBE MILLS Filed March 20, 1946 5 Sheets-Sheet 5 fig. s.

IINVENTOR Mr/fn S. GIS/77g ma m I W Patented Apr. 2l, 1953 GFFICE PLUG-HANDLING MECHANISM FOR SE-AMLESS nlTUBE MILLS Y Martin S. Gettig,v"Youngstown, Ohio Application March 20, 1946, Serial N o. 655,7 37

' 2V Claims.

This invention relates to seamless tube mills and, in particular, to the so-called two-high or .plug mill in which pierced billets are rolled after being expanded and drawn out in a Mannesman mill, to bring them to iinal shape, size and wall thickness. Specifically, the invention concerns fa mechanism for placing a plug on the end of the mandrel and removing it therefrom and to a roll vfor supporting the mandrel to keep it properly centered relative to the pass between the mill rolls. Y

Mechanism for handling the plug used on a two-high pipe mill has been proposed heretofore but has not come into actual use for various reasons, .and the manual handling of the plug has continued to be the regular commercial practice. I have invented a novel form of plug-handling mechanism characterized by simplicity of construction and ease of operation, capable of satisfactorily handling plugs and eliminating fthe-strenuous labor involved in doing this work manually. In a preferred embodiment, my plughandling mechanism Y comprises an elongated member having a socket in one end adapted to receive a pin projecting from the plug. This plug-holding member is suspended on parallel pairs of links spaced therealong for movement from a position adjacentV the end of the mandrel to a position spaced and offset therefrom. Powler means such as a fluid-pressure cylinder and piston are provided for shifting the member from one position to the' other. My invention also lcontemplates novel means for supporting the mandrel oi a plug mill to center it properly in lthe roll pass and aline the mandrel with the axis of the-plug-handlingv mechanism.. This means includes a supporting roll disposed below the mandrel and mounted for movement toward and away from it. Means for operating the support roll include a toggle linkage and power means for extending or shortening it. Appropriate stops for the power means may be adjust ed to control the movement of the roll for various sizes of mandrels and various thicknesses of pipe wall. I also provide means for cooling the plug while in retractedposition, comprising a lspray ring movable from an out-of-the-way position into cooperative relation to the plug.

A complete understanding of the invention may be gained from the following detailed description which refers to the accompanying drawings illustrating the preferred embodiment.

In the drawings, v f .1 Figure 1 is a central vertical section through plus mill. .harina .the inveniien, ,incerprated therein;

.l showing a modified plug-handling apparatus Aincluding a movable spray ring; and

Figure 4 is a partial section taken along the plane of line IV-IV of Figure 3.

Referring now in detail to the drawings, a twohigh or plug mill for finishing seamless tubes vcomprises housings I0 and II having windows vtherein adapted to accommodate chucks I2 and I3 in which grooved upper and lower rolls I4 and I5 are journaled. The rolls have grooves IG therein defining circular passes. The upper roll I4 may be adjusted vertically by .screws Il and the lower roll by screws I8. The chucks I2 of the upper roll are held against the screws Il I9by counterbalance mechanism indicated at A pipe blank passing between the rolls is directed onto a mandrel 20 by guides 2I. The end of the mandrel remote from the mill is fixed, being secured to side frames 22 extending from the housings Il) and II. When the pipe has passed through the mill, the rolls thereof tare opened, as shown in the drawings, to permit the pipe to be run back through the mill by rolls .23.. These rolls are opened up when the pipe vadvances onto the mandrel and are closed onto the pipe to return it back through the mill.

The mechanism for opening and closing the rolls I4 and I5 includes wedge bars 24 cooperating with split blocks 25 between the screws and vthe bearing chucks. The wedge bars are operated by fluid-pressure cylinders and pistons 26 vmounted on brackets 2l secured to the housing I I.

The mill construction described above is conventional except that the wedge bars 25 have heretofore been used only for the upper roll.

As clearly shown in Figure l, the free end of the mandrel 20 extends through tubular guides 28 and terminates in a cap 29. This cap is drilled to receive one end of a pin 38 extending centrally through a plug 3|.' The mechanism of my invention for removing the plug from the mandrel to permit a tube which has been rolled to be backed ofi from the mandrel comprises a bar 32 disposed parallel to the mandrel and movable from a position adjacent and in alinement therewith to a retracted offset position, as shown in chain lines in Figure 1. The end of the bar 32 adjacent the mandrel has a socket adaptedto accommodate vthe forward end of the pin` 3i). The bar 32 isv supported by pairs of vparallel links 33 so that it remains horizontal when retracted. The links 33 are pivoted to a supporting bracket 34. The bracket 34 is carried by crossbars 35 extending between the housings l0 and Il. The bracket 34 may be adjusted along the crossbars to bring the axis of the bar 32 in the median plane through any one of the several grooves in the rolls. The links are pivoted to the bar 32 at points spaced along the length thereof. A huid-pressure cylinder' and piston 36 is provided for swinging the bar 32 from its position adjacent the mandrel to retracted position. The cylinder is pivoted to a downward extension 34a on the bracket 34. The piston rod is pivoted to the pair of links 33 nearer to the mill rolls.

The plug pin 3| has a reduced neck 3|a adjacent its forward end. A latch member 31 piv`` oted on the bar 32 is adapted to engage the reduced neck upon entering a hole intersecting the socket. A fluid-pressure cylinder and piston I8 is trunnioned on the bar 32 and is pivoted to the latch member 31 for swinging it from the position shown in Figure l to a retracted position in which it frees the mandrel pin. Fluid under pressure is admitted to and exhausted from the ends of the cylinder by a suitable valve through flexible hose connections.

It will be apparent from the foregoing that the bar 32 is normally held in retracted position by the cylinder and piston 36. After the pipe has paed through the mill and onto the mandrel, the bar 32 is permitted to swing (which it may do by gravity) down into position in alinement with the mandrel whereupon the plug pin enters the socket in the bar and is secured therein by latch member 31. The bar 32 is then retracted and the pipe is run back oif of the mandrel. When the pipe has been withdrawn from the mill, the bar 32 is again permitted to swing down to return the plug to the mandrel. It will be understood that the plug automatically returns to its position on the end of the mandrel and is left there on retraction of the bar 32 after the latch 31 has been released.

I may provide nozzles in suitable positions to discharge a spray of cooling water onto the plug when held by the bar 32 in the retracted position of the latter. A suitable baille disposed under the plug will prevent the cooling water from striking the pipe as it is being returned from the mill.

Since the mandrel 20 is fixed only at the end thereof remote from the mill, the end to which the plug is applied would tend to ride on the bottom roll |5. In order to center the mandrel and the plug thereon relative to the roll pass, I provide a support roll 40. This roll is journaled in bearings mounted on a base 4|. The base is mounted on a rocker arm 42 and is adjustable transversely thereof. The rocker arm 42 is fixed on a rock shaft 43 Journaled in the roll housings. The rock shaft is actuated by a bell crank 44 through a link 45 and an arm 46 rigid with the shaft 43. The bell crank is pivoted to a link 41 which is pivoted to a xed bearing 43 carried on one of the housings.

A fluid-pressure cylinder and piston 49 trunnioned on a frame member 50 has a piston rod extending therethrough, one end of which is pivoted to the bell crank 44. The other end has a bumper adapted to engage an adjustable stop 52. A fluid-pressure cylinder and piston 5I is also trunnioned on the frame member 50 and has a piston rod 54 extending therethrough,

one end of which is pivoted to the bell crank and the link 41. The other end is provided with a bumper adapted to engage an adjustable stop 55.

When the roll 40 is in its illustrated position, the mandrel 20 is properly centered relative to the roll pass for entry of a tubular blank. When a blank has entered the mill, the cylinder 53 is operated to lower the roll 40 by a distance approximately equal to the wall thickness of the pipe being made so that, after the leading end of the pipe passes the roll 40, the latter will engage the exterior thereof and continue to support the mandrel in properly centered position after the trailing end of the pipe has passed through the mill. This lowering of the roll 40 is accomplished by operating the cylinder 53 to shift its piston rod to the left until it engages stop 55. It will be apparent that this causes angular movement of the bell crank 44 which through the link and arm 46 causes counterclockwise rotation of the rock shaft 43.

When the pipe is stripped from the mandrel. the cylinder 53 is operated to shift its piston rod in the other direction after the leading end of the pipe passes beyond the roll 40 and before 'it passes out of the mill. As a result, the mandrel is again supported in properly centered position relative to the roll pass. The cylinder 43 is operated so that its piston rod is normally urged against the stop 52. If the mandrel 2B is replaced by one of different size. as for the purpose of rolling larger or smaller pipe, the stop 52 is adjusted so that when it is engaged by the piston rod 5|, the roll 4U will be at the proper position from the axis of the roll pass to support the mandrel prior to entry of the pipe length. A similar adjustment of the stop 55 may be made in case of a change in the wall thickness of the pipe being rolled,

Figures 3 and 4 illustrate a slightly modified construction including means for spraying jets of cooling liquid on the plug while it is supported by the bar 32 in retracted, offset position. Certain ofthe elements of the apparatus shown in Figure 3 are the same as those shown in Figures 1 and 2 and are designated by the same reference numerals. As clearly shown in Figures 3 and 4, the bracket 34 supported by the cross bars 35 has a downward extension 34h which provides a pivotal mounting not only for the cylinder and piston 35 but a similar cylinder and piston 58. The piston rod of this latter cylinder is pivoted to a lever 51. The lever is pivoted to the bracket 34 at 58 and is vactuated from the position in which it is shown in solid lines in Figure 3 to the chain-line position, by extension of the piston rod of cylinder 53.

A pipe ring 59 has a stud 60 welded thereto. The stud is adjustably disposed within a sleeve 6| forming part of the lever 51. The ring 59 may thus be secured to the lever in proper relation thereto by a set screw 62 threaded through a. tapped hole in the sleeve and engaging the stud 60. A lateral connection 63 from the pipe ring 53 is adapted to receive a flexible hose 64 extending to a suitable source of cooling water. The pipe ring 53 has holes 65 spaced circumferentially around the interior thereof whereby a plurality of cooling jets may be discharged onto the plug 3|. As illustrated, the pipe ring is of sufilcient inside diameter to embrace the plug with a substantial clearance therebetween. While a billet is being rolled in the mill, the lever Bland pipe ring 5l. of course, are held in their chain-line position by suitably actuating the cylinder 56. When the plug 3| has been removed and retracted to the position shown in solid lines in Figure 3 by operation of the cylinder 36, the cylinder 56 is operated to bring the pipe ring 59 into cooperative relation with the plug carried on the bar 32. The cooling water ls then turned on and the jets impinging on the plug quickly cool it, removing the heat picked up thereby during passage of the billet into the mill. When the rolled billet has been withdrawn and is ready for a second pass, the cylinder 56 is again actuated to swing the lever 51 and pipe ring 59 to their outof-theway position shown in chain lines after which the cylinder 36 is operated to restore c the plug to its working position on the end of the mandrel 20.

It will be apparent from the foregoing that the invention provides simple but effective means for handling plugs to and from the mandrel of a plug mill and for supporting the mandrel in properly centered position. All necessary movements of the parts in regular operation are effected by power means which can be easily controlled from any desired point. The strenuous labor involved in manual handling of the plugs is entirely eliminated. Normal operation of the mill in the customary manner is not interfered with.

The mandrel is properly supported centrally of the pass through the mill at all times and the supporting roll therefor is lowered sufficiently after the entry of a billet to accommodate the W-all thickness of the pipe into which the billet is converted by the rolling operation. Provision lis also made for cooling the plugs while out of i' the mill, the cooling means being movable into cooperative relation with the plug while it is supported in retracted position.

Although I have illustrated and described but a preferred embodiment of the invention, it will be recognized that changes in the details of construction disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. Apparatus for applying a plug to the mandrel of a plug mill and removing it therefrom comprising a plug-holding member, a support disposed at an elevation above the elevation of the plug when in position on the mandrel, mounting means carrying the plug-holding member, the mounting means comprising two parallel links respectively pivoted at their upper ends to the support about parallel axes dening -a generally horizontal plane and respectively pivo-ted at their lower ends to the plug-holding member about parallel axes dening a generally horizontal plane land spaced apart ya distance substantially equal to the distance which the rst mentioned parallel axes are spaced apart, a spray ring carrier also pivoted at its upper end to the support about a pivot whose axis is substantially parallel with said rst mentioned parallel axes and carrying a spray ring movable about the axis of the last mentioned pivot into and out of position generally surrounding a plug lmaintained by the plug-holding member at an elevation above the second mentioned elevation for spraying cooling fluid onto the plug.

2. A mandrel and removable plug mechanism comprising a mandrel, a, xed support supporting the mandrel adjacent one end, the mandrel being adapted to receive on its other end a plug tointernally shape a tubular blank passed over the plug onto the mandrel and which plug is removable from the mandrel when the blank is to be withdrawn from the mandrel, a plug-holding member, a second support in fixed position relatively to the xed mandrel support, a link pivotally connected to the plug-holding member and to the second support carrying the plug-holding member for swinging movement between a position relatively close to said other end of the mandrel and a position relatively remote therefrom, means cooperating with the plug-holding member and the second support for maintaining the laxis of the plug parallel to the axis of the mandrel during said swinging movement, said link when in its rst mentioned position being substantially perpendicular to the axis of the mandrel and of such length that the plug-holding member is disposed in said axis and moving the plug-holding member substantially in the axis of the mandrel to apply the plug to the lmandrel and remove it therefrom, and means for swinging the plug-holding member between its rst mentioned and second mentioned positions.

MARTIN S. GETTIG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 429,623 Heckert June 10, 1890 988,569 Harkness Apr. 4, 1911 1,036,309 Nowak Aug. 20, 1912 1,141,426 Simpkins June 1, 1915 1,243,407 Hawthorne Oct. 16, 1917 1,386,115 Jenkins Aug. 2, 1921 1,537,206 Wikstrom Mar. 12, 1925 1,764,736 Lowy June 17, 1930 1,766,573 Westin June 24, 1930 1,911,899 Judson May 30, 1933 1,919,390 Olson July 25, 1933 1,931,571 Burns Oct. 24, 1933 2,005,310 Bark et al June 18, 1935 2,101,236 Burton Dec. 7, 1937 2,263,744 Smith Nov. 25, 1941 2,303,314 Anater et al. Dec. 1, 1942

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