US2560934A - Reducing mill drive - Google Patents

Description

July 17, 195] :05 2,560,934

REDUCING MILL DRIVE Filed July 5, 1947 7 Sheets-Sheet 1 1900/ ofmocb/he INVENTOR ATTORNEYS July 17, 1951 G. a. COE

REDUCING MILL DRIVE '7 Sheets-Sheet 2 Filed July 5, 1947 INVENTOR George 5. Ge

ATTORNEYS July 17, 1951 s. B. coE

REDUCING MILL DRIVE '7 Sheets-Sheet 5 Filed July 5, 1947 Mr w Z 3 QQubk B xkox ll July 17, 1951 G. B. COE

REDUCING MILL DRIVE 7 Sheets-Sheet 4 Filed July 5, 1947 INVENTOR George B-Cbe ATTORNEYS mxxxuu xe B Il July 17, 1951 G. B COE 2,560,934

REDUCING MILL DRIVE Filed July 5, 1947 '7 Sheets-Sheet 5 V i AV R8 w 0 "0 0% E M w m m 7/ 5 0 me n A W m Wm ill/l lllll a? V w Jl g Wk \Nw QINX '7 Sheets-Sheet 6 G. B. COE

REDUCING MILL DRIVE July 17, 1951 Filed July 5, 1947 J W MW INVENTOR George 3. Cat.

July 17, 1951 G, B, COE 2,560,934

REDUCING MILL DRIVE Filed July 5, 1947 7 Sheets-Sheet '7 w k mg INVENTOR George 6. (be BY W7 aw m I ATTORNEYS Patented July 17, 1951 REDUCING MILL DRIVE George B. Coe, Upper Montclair, N. J., assignor to Tube Reducing Corporation,

Stamford,

Conn., a corporation of Delaware Application July 5, 1947, Serial No. 759,047

11 Claims.

In reducing mills of the character described in my Letters Patent No. 1,952,841, whereof the drawings illustrate a standard type used commercially for many years, cold metal stock is fed step by step to oscillating die-rolls by giving it an increment of feed, and a partial turn about its axis, during each cycle of the die-rolls. In such mills, the speed at which they are capable of operating is a prime factor in determining their efficiency. This, in turn, is so largely dependent upon the speed at which the stock feeding and turning mechanisms can be operated smoothly and with precision that, heretofore, the feeding and turning mechanisms have been referred to as the "bottle-neck of this type of mill. My present invention, accordingly, is directed to the improvement of these particular mechanisms of the mill with a view to relieving the bottle-neck.

In the drawings:

Figs. 1 and 1a are broken views, partly in section and partly in elevation, and taken together show the relation between some of the parts of a mill of this type from the forward end back to the rear end of the mandrel rod, with many of the parts, including most of the frame, the main drive-motor and driving connections therefrom, omitted; Fig. 2 is a plan and Fig. 3 an elevation, on a larger scale, of an intermediate part of the mill; Figs. 4 and 5 are respectively sections indicated by the lines 4-4 and 5-5 in Fig. 2; Fig. 6 is a detail view partly in section as indicated by the line 6-6 in Fig. 2; Fig. 7 is another detail view partly in section as indicated by the lin '|I in Fig. 3; Fig. 8 is a detail section taken on the line 8-8 in Fig. 5; and Fig. 9 is another detail section taken on the line 99 in Fig. 2.

Since tube mills of the type to which my present improvements belong are well known and since my present improvements are concerned only with the stock feeding mechanism and the stock and mandrel turning mechanism, only a brief description of the general character of such mills and their mode of operation will be needed before I describe my improvements. The metal stock S is fed forward step by step over a stationary mandrel M to and between a pair of cooperating rocker-dies D which constitute the reducing devices and reduce the stock by rolling it on the mandrel. The dies are mounted for oscillation or rocking in a reciprocating carriage C which causes them to roll forward on the stock and then back again once during each cycle of the die-carriage. The latter is driven from the main drive unit (not shown) and may be supported and driven, for example, in the manner shown in my Letters Patent No. 2,436,098. Once during each cycle of the dies, the stock is given an increment of feed along the mandrel, and both the stock and mandrel are turned through an angle of, say, from to and preferably, the increment of feed and the turning occur in alternation, that is, it is desirable that the increment of feed immediately precede the forward stroke of the dies and that the turning immediately precede their backward stroke. With this brief explanation of the general character and operation of the mill in which my improvements are to be embodied, I shall proceed now to describe my improved feeding mechanism for the stock.

I fasten the rear end of the stock firmly, as by a chuck Hi, to a longitudinally slidable crosshead i I, in which the chuck is rotatively held. To the rear end of the cross-head I secure, as by nuts l2, the forward end of a hollow threaded shaft I3 carrying a feed-nut If, all as substantially shown in my Letters Patent No. 2,388,251; but instead of mounting said nut so that it is axially immovable in the frame of the machine, as in that patent, I fit said nut to, and house it for rotation in, a carrier I5 which is longitudinally slidable in ways l5 formed in the frame of the mill and provide means, presently to be described, for rotating the nut continuously at a constant pre-determined speed in a direction to cause it to travel rearwardly on the shaft I3; and I also provide means, to be described presently, to cause the nut-carrier l5 to move rearwardly with, and at the same rate as, said nut for almost the entire period of each die-cycle and then to have a quick forward movement, during the remainder of the cycle, to impart an increment of feed to the stock. During the rearward traverse of the nut on shaft I3, the dies first bite upon the stock and roll forward upon it, and then roll back and up the tapered portion of the stock which has been formed by the forward stroke of the dies. This action of the dies upon the cold stock imparts very severe thrusts upon it which are transmitted therefrom to the nut l4 through the shaft l3; and these shocks occur in the following order: first a sudden kick-back on the stock the moment the dies bite upon it, then a forward thrust as the dies continue their forward stroke, and finally another sudden kickback followed by a continued rearward thrust after the dies are reversed to their backward stroke and roll up the taper of the stock. Therefore, to insure proper feeding of the stock under such conditions, 1 construct my feed mechanism so that it will act positively and effectively to resist these sudden shocks and continued thrusts rather than yield to them in any degree, and thus I obviate loss of control of accurate feeding which would otherwise occur.

Referring then to the means I provide for keeping the nut I4 in constant rotation for rearward traverse on the shaft I3, I take the motion from a shaft I6 driven from the main drive unit (not shown). Through a pair of bevel gears l1 (Fig. 3), a shaft I8 having an assembling coupling I8, and a, pair of bevel gears l9, power is transmitted from the shaft I6 to a shaft 20 upon which a cone gear cluster 2| having spur gears of different diameters, is secured. By means of gearing including a tumbler gear 22 journaled in a bracket 23 so that it can be slided axially and adjusted up or down to mesh with any one of the spur gears of the cluster ZI (Figs. 2, 3 and 6), said cluster is operatively connected to a longfaced gear 24 carried by a shaft 25. Fast on the shaft 25 is also a gear 26 which, through an idler gear 21, is operatively connected to a gear 28 fast on the rearward end of the feed-nut I4 (Fig. 4). Since during the operation of the mill, the shaft I6 will be continuously rotated by the main drive unit from which also, as will be understood, the reciprocating die-carriage C is driven as previously explained, the feed-nut I4 will also be rotated continuously in synchronized relation with the reciprocation of the die-carriage and at the constant speed for which it has been adjusted through the tumbler gear 22.

Next, I shall describe the mechanism which I provide to cause the nut-carrier or housing I (which as shown in Fig. 5 is made in two parts for assembling) to moverearwardly at the same rate as the nut I I which is fitted therein for rotation but is not otherwise movable in relation to this carrier housing, and in and by which mechanism I also provide the positive resistance to the shocks and thrusts imparted by the dierolls to which I have alluded. Referring then to Figs. 4 and 5, the nut carrier housing, which is fitted in the frame of the mill for sliding longitudinally between the frame parts'29, 29', has a pair of trunnions 30 which have their respective bearings in the upper ends of a pair of levers 3I fulcrumed respectively at intermediate points thereof on a second pair of trunnions 32 secured respectively to vertically adjustable slides 33 fitted in slide-way castings 34 formed in the main frame of the mill (see Fig. 8). Carried by and between the lower ends of this pair of levers is a roller 35 the axis of which, when the slides 33 are adjusted to their lowermost position in the frame, is the same distance from the fulcrumaxis of the levers as that axis is distant from the axis of trunnions 30. Said roller 35 is held in contact with and between the peripheries of two cams 36, 36' fastened respectively on shafts 31, 3'! which also carry respectively two pinions 38, 38'. Each of these pinions meshes with a common pinion 39 fast on a stub-shaft 40 which is rotated by the aforesaid drive-shaft I6 through a pair of bevel gears 4|. The roller, cams and gears just described may be housed in a casing 42 which, together with the shaft I6, is preferably so disposed in relation to the main frame F of the mill when the frame rests upon the floor of the plant or room where the mill is installed, the drive-shaft I6 and the pairs of the mechanism enclosed in the casing 42 may be disposed in a pit below the floor level, where also the main drive unit may be located as shown in my pending patent application Serial No. 678,193.

'lhe two cams 36, 36 are precisely alike in shape and size and are so disposed relatively to each other that the high point of one is directly opposite the low point of the other; and, due to the relation between their gearing and driving connections just described, each will rotate in the same direction (here indicated as counterclockwise) whereby each cam will always tend to turn the roller 35 in one direction here indicated as clockwise), whereby there will be no slippage between the cams and roller or tearing of their surfaces. Moreover, since the cams and roller take the shocks and thrusts of the dierolls heretofore alluded to and which are transmitted to them from the feed-nut I4 through the nut-carrier housing I5 and levers (H, the cams and roller will act to provide a positive and completely effective resistance to, and thus insure against, any movement of the threaded shaft I3 which said shocks and thrusts would otherwise produce or tend to produce. Furthermore, with respect to the single increment of feed given the stock during each die-cycle, and which takes place in the interval during which the dies reverse their direction and preferably occurs in the interval during each cycle which directly precedes their forward stroke, it will be clear that the maximum speed at which the mill can be run, and which is a controlling factor of its efliciency, will depend to a large extent on how short the interval for the feeding of the stock can be safely made. And this, in turn, will depend upon the rapidity with which the feeding mechanism can be made to operate smoothly and with precision.

Through the main drive-unit connections to the feeding mechanism on the one hand, and the connections from the main drive-unit to the diecarriage on the other, the feeding cycle, .which consists of one complete rotation of the cams 36, 36', can obviously be made to take place synchronously with the die-roll cycle which consists of one complete reciprocation of the diecarriage. The periphery of the cam 36 is so related to the roller 35 that directly as the low point of that cam passes the roller, said cam causes the levers 3| to move the nut-carrier housing I5 forward and thus impart an increment of feed to the stock through the threaded shaft l3 and the cross-head II; and the peripheries of the cams are so formed that this forward movement of the nut-carrier housing is completed while the cam 36 is rotated from the low point of its periphery through an angle of about 60 to the high point thereof where its periphery begins and continues to taper down gradually and uniformly during the remaining 300 of its rotation until its low point is again reached. And during that 300 rotation of the cam 36, the cam 36' through the roller 35 and levers 3|, causes the nut carrier housing to travel rearwardly to match the rearward traverse of the feed-nut I 4 on the threaded shaft I3. This mechanism produces a very smooth and accurate feeding of the stock step by step along the mandrel and at the same time enables each increment of feed to be performed with such rapidity, while the dies are changing from their backward to their forward stroke, that it is not necessary to limit the speed of the dies to insure smooth and precise feeding of the stockthereto.

The precise length of each increment of feed, depending as it does upon the length of the forward stroke of the nut-carrier housing I5, may be regulated through adjustment of the slides 83 up or down in the frame of the mill, by applying a crank to either of the square ends of a shaft 48 to rotate the same; for this shaft, through bevel gears 44 at its ends, is operatively connected with screws 45 the shanks of which are joumaled in the frame of the mill and their threads engaged by stationary nuts 48 respectively housed in hubs 41 secured to the respective upper ends of the slides 33; and the trunnions 32 secured on the lower ends of these slides are joumaled in square blocks 48 slidable respectively in vertical slots 49 formed in the levers 3 I. When adjusted in the position shown in Figs. 4 and 5, the blocks 48 are at the lower ends of the slots 49, in which case the trunnions 30 and the roller 35 are equidistant from the trunnions 32. With the slides in that position the levers impart the maximum range of movement to the nut-housing l5; and by adjusting the slides upwardly from that position this range of movement will be decreased as the result of shortening the length of the weight arms of the levers and increasing the length of the power arms. And since the rate at which the nut-housing travels in its rearward stroke must match that of the rearward traverse of the feed-nut I4 on the shaft I3, holes 50 for the insertion of dowel pins to engage and hold the slides 33 in their adjusted position, may be provided in proper locations ,inthe slide-way castings 34 (Fig. 3). These holes may be suitably marked to indicate the needed adjustment of the slides to cause the rearward movement of the nut carrier housing to match that for which the feed-nut l4 has been set through manipulation of the tumbler-gear adjustment bracket 23. And inasmuch as it would be practically impossible to get these two movements to match precisely, a slip-friction device 5| is so mounted on the shaft 25 (Figs. 2 and 9) as to allow the longfaced gear 24 sufiicient slippage on that shaft to compensate for any difference in these two movements and thus prevent breakage.

When, in operating the mill, the threaded shaft l3 carrying at its forward end the cross-head II with the chuck ID in which the rear end of the stock S is secured, has advanced to its foremost position, said shaft is retracted to its starting position for the insertion of a fresh length of stock. For this purpose the idler gear 21, which remains constantly in mesh with the gear 28 on the rear end of feed-nut i4 and is also normally in mesh with the gear 28, may be mounted so as to be shiftable from its normal meshing position with gear 26 to a position to mesh with a gear 52 on the shaft of an auxiliary high speed motor 53; so that after the shaft of an auxiliary high speed motor 53; so that after the shaft l3 has reached the limit of its forward position and the rear end of the stock released from the jaws of the chuck l0, and the gear 21 swung into mesh with the gear 52, the auxiliary motor may be started to turn the feed-nut [4 in a direction to cause the threaded shaft and cross-head to be retracted rapidly to their starting position for the insertion of a fresh length of stock. For shifting the gear 21, the latter is held in a swivel support bracket 54 (Figs. 4 and 6) so as to be revolvable about the axis of the feed-nut -I4, and its shifting movement may be controlled by a camslide 55 which engages a roller 58 carried by said bracket, the cam-slide in each case to be pushed manually in the proper direction or that slide may be automatically operated at the proper times by the piston of a pressure cylinder 81 as in my aforesaid Letters Patent No. 2,388,251.

I shall now describe the mechanism for tumin the stock and mandrel which, as I have said, is to be eflected once in each die-roll cycle during the momentary interval which occurs while the dies are reversing their stroke and preferably while they are reversing from their forward to their backward stroke. This mechanism includes a long turn-shaft 58 extending fore and aft of the mill as shown in Figs. 1 and 1a, said shaft being geared at 59 to the rear end of the mandrel rod M and at 68 to the rotatable stockholding chuck III in the longitudinally slidable cross-head H, all as substantially shown and described in my aforesaid Patent No. 2,388,251.

Thus, when the shaft turns, both the mandrel and stock turn with it. Embracing the tumshaft 58 (Figs. 2, 3 and 7) and having its inner member secured thereto is an over-running or one-way clutch 8| whose outer member is geared by pinions 82 to the outer member of a similar clutch 83 which is off-set from the shaft 58 and has its axis parallel to that of the clutch GI. and the inner members of both clutches bein geared together by pinions 84. These clutches are so disposed relatively to each other that when the outer. member of clutch 63 is actuated to move it in its free running direction, it causes the clutch 8|, through the pinions 62, to move in the direction to grip its inner member and turn the shaft 58 to which, as before stated, the inner member of clutch 8| is secured. Any tendency of the inner member of clutch 6| to over-travel after the movement of clutch 83 ceases and is held stationary, will be instantly checked by the inner member of that clutch gripping its outer member which. as before stated, is geared to the outer member of clutch 63 by pinions 62 and therefore cannot move if the outer member of clutch 88 is held stationary. Where, as heretofore, a friction brake is used to prevent overtravel of the shaft 58, extra force is neccessary in turning that shaft to overcome the resistance of the brake. The present mechanism eliminates that necessity and ensures absolute precision in the turning of the stock and mandrel.

The operation of this turning mechanism is controlled by a cam 65 (Figs. 3 and 7) fast on shaft l8 whereby the actuation of the clutch 8| can not only be timed to operate during the momentary interval aforesaid of the die-roll cycle which occurs while the dies are reversing from their forward to their backward stroke, but also in proper timed relation with the movement of the levers 3| which, as before explained, operate to cause an increment of feed to be given the stock during the momentary interval of the dieroll cycle which occurs while the dies are reversing from their backward to their forward stroke. The periphery of cam 65 rides against rollers 86 mounted on a cam-slide 61 at opposite sides of said cam and is so formed as to cause the slide to move upward and back once during each rotation of the cam, said slide carrying with it a vertical rod 88 attached thereto and slidable in the upper. end of a casing 69 in which said cam, slide and rollers are housed. This rod is connected bya link to a rocker arm ll pivoted to a bracket 12 secured on the frame of the mill; and a link I3 connects the other end of said arm to the outer member of clutch 83. Through these operative connections between the cam 85 and the clutch 8|, the latter is not only actuated at the proper times but at all other times is held stationary by the cam, its rollers and slide.

I claim as my invention:

1. The combination with a threaded shaft, a feed-nut threaded to said shaft, a carrier to which said nut is fitted for rotation therein but in relation to which said nut is otherwise immovable, and means to rotate said nut in a direction to cause it to traverse said shaft rearwardly, of means including a lever connected to said carrier and a cam maintained in operative relation to said lever to impart movement to said carrier and control the direction and'degree of said movement, and characterized by this: that the operative face of said cam is formed so as to cause a rearward movement of said carrier to match the rearward movement of said nut and then a forward movement of said carrier to impart an increment of feed to said shaft.

2. The combination defined in claim 1 and further characterized by this: that the means for rotating said nut are adjustable to impart different speeds of rotation thereto, and that said lever has an elongated slot in which its fulcrum is adjustable to difierent positions to change the relative lengths of its weight and power arms and thereby cause the rearward movement of said carrier to match the rearward movement of said nut in accordance with the speed of rotation for which said nut has been set.

3. The combination defined in claim 1 and further characterized by this: that the means to rotate said nut include a gear secured to and coaxial with said nut, and change-speed gearing operatively related to said gear.

4. The combination defined in claim 1 and further characterized by this: that the means to rotate said nut include a gear secured to and co-' axial with said nut, a long-faced gear operatively connected to the gear on said nut, a cone gear cluster, a tumbler gear to connect said long-faced gear with any gear of said cluster, and a slipfriction device.

5. The combination defined in claim 1 and further characterized by this: that the means to rotate said nut include a gear secured to and coaxial with said nut, an idler gear constantly in mesh with the gear on said nut, an arm swingable about the axis of the gear on said nut and carrying said idler gear, a gear normally in mesh with said idler gear, a high-speed reversing gear, means to shift said idler gear from its meshing position with the gear with which it is normally in mesh to a position to mesh with said reversing gear.

6. The combination with a rotatable chuck and a turn-shaft secured to said chuck, of two similar over-running clutches one of which is co-axial with and has its inner member secured to said shaft and the other offset from said shaft with its axis parallel to that of the first named clutch and having its outer and inner members geared directly to the respective outer and inner members of the first named clutch so that the outer member of each clutch will always turn in a direction opposite to that of its inner member, and means to actuate one of said clutches to cause said shaft to turn.

7. The combination with a mandrel, a rotatable chuck, and a turn-shaft geared to both said mandrel and said chuck, of two similar over-running clutches one of which is co-axial with and has its inner member secured to said shaft and. the other offset from said shaft with its axis parallel to that of the first named clutch and having its outer and inner members geared directly to the respective outer and inner members of the first named clutch so that the outer member of each clutch will always turn in a direction opposite to that of its inner memben'and means to actuate one of said clutches to cause said shaft to turn.

8. The combination defined in claim 6 and further characterized by this: that the said means to actuate one of the clutches is operatively connected to the outer member of the clutch which is offset from said shaft.

9. The combination defined in claim 6 and further characterized by this: that the said means to actuate one of the clutches includes a cam, a cam-slide controlled by said cam, and unyielding connections between said cam slide and the said clutch operated thereby, whereby upon each operation of that clutch, said shaft will be turned with exact precision since any tendency of that shaft to over-travel will be instantly checked by said clutches and the connections between them and their connections with said cam. I

10. The combination with a threaded shaft, a rotatable chuck secured to said shaft, a feed-nut threaded on said shaft, a carrier in which the feed-nut is rotatably held, and a tum-shaft geared to said chuck, of an over-running clutch the inner member of which is secured to said turn-shaft, a drive-shaft, and separate operative connections respectively from said drive-shaft to said feed-nut, from said drive-shaft to said carrier. and from said drive-shaft to said over-running clutch.

11. The combination with a threaded shaft, a feed-nut threaded to said shaft, a carrierto which said nut is fitted for rotation therein but in relation to which said nut is otherwise immovable, and means to rotate said nut in a direction to cause it to traverse said shaft rearwardly, of means for imparting movement to said carrier including two cams, a pair of levers fulcrumed on a common axis and having their weight arms connected to said carrier, and a roller carried by the power arms of said levers and disposed between and in working contact with the working surfaces of both cams, whereby said carrier is caused to move rearward to match the rearward movement of said nut and then forward to impart an increment of feed to said shaft.

GEORGE B. COE.

REFERENCES CITElj The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 563,444 Boucharat July 7, 1896 737,541 Williams Aug. 25, 1903 916,624 St. Mary Mar. 30, 1909 1,780,713 McEwan Nov. 4, 1930 1,952,841 Coe Mar. 27, 1934 2,226,677 Vikhman Dec. 31, 1 940 2,258,475 Sinclair Oct. 7, 1941 2,318,814 Strong May 11, 1943 2,403,378 Kilpela July 2, 1946

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