US2594126A - Mill for reducing metal stock - Google Patents

Description

April 22, 1952 cog MILL FOR REDUCING METAL STOCK 10 Sheets-Sheet 1 Filed Nov. 5, 1949 MN w mmf OE Wk INVENTOR aolrqa ATTORNEYS p 22, 1952 cs. B. COE 2,594,126

MILL FOR REDUCING METAL STOCK Filed Nov. 5, 1949 10 Sheets-Sheet 2 INVENTOR Y FM ATTORNEYS April 22, 1952 G. B. COE 2,594,126

MILL FOR REDUCING METAL STOCK Filed Nov. 5, 1949 10 Sheets-Sheet 3 F |G.2b.

INVENTQR an 5' Ge L: B I w M 7 140 ATTORNEY-S April 22, 1952 I G. B. COE 2,594,126

MILL FOR REDUCING :METAL STOCK Filed Nov. 5, 1949 10 Sheets-Sheet 4 QINVENTOR m BY ATTORNEYS April 22, 1952 G. B. coE 2,594,126

MILL FOR REDUCING METAL STOCK 5 A INVENTOR m saw 4, Ge

6% 7w] We 7 4910 ATTORNEYE' April 22, 1952 e. B. cos 2,594,126

MILL FOR REDUCING METAL STOCK Filed NOV. 5, 1949 10 Sheets-Sheet 7 F168. 6 9/ m7 M4 /0 I 94 95 m2 1:. u r

m I 92. v 95 I i. l0? 2 42 E 6/ FIG.|2. w axrzm ATTORNEYS April 22, 1952 G. B. COE 2,594,126

MILL FOR REDUCING METAL STOCK 10 Sheets-Sheet 8 Filed NOV. 5, 1949 1%}?! H 5 NIH 4 30 E 25 L E I a INVENTOR BY (M, y; i I MVM ATTORNEYS April 22, 1952 COE 2,594,126

MILL FOR REDUCING METAL STOCK Filed Nov. 5, 1949 10 Sheets-Sheet 9 INVENTOR geowe G BY 6W WW7 Manor-e M ATTORNEY-5' A ril 22, 1952 G. B. COE

MILL FOR REDUCING METAL STOCK 10 Sheets-Sheet 10 Filed Nov. 5, 1949 INVENTOR ATTORNEYS Patented Apr. '22, 1952 MILL FOR REDUCING METAL STOCK George Bertram Coe, Upper Montclair, N. J assignor to Tube Reducing Corporation, Stamford, Conn., a corporation of Delaware Application November 5, 1949, Serial No. 125,770

The above named applicant has made an invention or discovery of which the following is a specification.

The present invention relates to improvements in mills of the type shown in my Letters Patent No. 1,952,841, that is to say, to mills for the cold reduction of metal stock, such as tubes or rods, wherein the stock to be reduced is fed intermittently, step by step, to the reducing devices which act upon the stock while cold to reduce it in diameter and, in the case of tubular stock, to reduce it in diameter or gage or both. In such mills, as in that of my Letters Patent aforesaid as well as in the mill shown and described here, the reducing devices generally comprise a single pair of oscillating die-rolls mounted on a reciprocating carriage so that on each forward stroke of the carriage they roll upon a short section of the stock while the latter is stationary, and on each rearward stroke of the carriage roll back again upon that same section of stock, whereupon the stock is then given an increment of feed to advance it between the rolls before the nextreciprocation of the carriage occurs. Thus, forleach cycle of the die-rolls, there is an increment of feed; and, in addition, the stock (and also the mandrel which is generally used in the case of tubular stock) is given about a quarter turn about its axis. This quarter turn usually occurs in the interval directly following the forward stroke of the carriage and before its backwardstroke begins, and the increment of feed takesplace in the interval'directly following thebackward stroke; and since during each of said intervals the movement of the carriage is reversed in direction, the latter during each said interval is momentarily stationary.

Since the efliciency of these mills depends, in large part, upon the speed at which it is practicable to operate them, it is obvious that their efficiency-will, in turn, depend upon the rapidity at which the mechanisms provided for feeding the stock and for turning the stock and mandrel, can be made to operate smoothly and effectively duringthe relatively short intervals while the carriage is stationary; for it-is the operation of those said mechanisms which limits the time allowable between the respective strokes of the carriage. The principal object of the present invention, accordingly, is to relieve this bottle-neck, so to speak, in this type of mill, by providing an improved mechanism for feeding the stock to the rolls, and an improved mechanism for turning the stock and the mandrel, Other objects areto provide a fluid system 11 Claims. (01. 80-14) for operating these mechanisms and other parts of the mill, and to coordinate the fluid system with the driving mechanism for the rolls and carriage.

The said improved mechanisms and fluid system havebeen incorporated in the ,mill shown in the accompanying drawings wherein Figs". 1, 1A and 1B are plan views respectively of the front, rear and intermediate portions of the mill; Figs. 2, 2A and 23 side elevations of the same portions corresponding respectively to Figs. 1, 1A and 1B; Figs. 3 and 4 larger scale views in plan and vertical section respectively of the intermediate portion of the mill, the'plane of the sectional view being indicated by the line 4-4 in Fig. 3; Fig. 5 a view partly in elevation and partly in section on a plane indicated by the line 5- -5 in Fig. 4; Fig. 6 a detail section the plane of which is indicated by the line 6-6 in Fig. 3; Fig. 7 an enlarged scale view partly in elevation and partly in section, the plane of the section being indicated by the line 1-1 in Fig. 1; Figs. 8 and 9 detail sectional views taken respectively on planes indicated by the lines 88 and 9-9 in Fig. 7; Fig. 10 a view partly in elevationand partly in section, the plane of the section being indicated by the line l l'|l0 in Fig. 2; Figs. "11, 12 and 13 similar views on a larger scale takenon planes indicated respectively by thelines l l--\| i in Fig.

' 1,-l2--l2 in Fig. 1B and [3-13 in 1; Fig. 14

a section taken on a plane indicated by the line i4 'l4'inFig. 11; and Fig. 15 a diagram of the fiuidsystem by which certain partsof the mill are] operated, and showing the relation -of the fiuidmotorsjthe fluid circuits and the control valves in said system, to the timing cam and the fluid reservoir. r I v The reducing devices here shown comprise a pair of die-rolls (Figs. 11 and 14) mounted for oscillation in a reciprocating carriage 2| and being geared together by two pairs of gears 22. A pair of gears 23 rigidly connected respectively to the gears of one of the pairs 22, mesh respectively with racks 24 secured, one on each'side of thecarriage, to the frame of the mill whereby. as the carriage reciprocates on the frame, the rolls will be oscillated. Secured. at each side of the carriage, to the upper part of the mill frame are tracks 25 which run lengthwise of the frame and from which the" carriage is suspended, said carriage being supported ,on said tracks by hearing rollers 26 journaled on heavy studs 21 fast to the carriage fore and art and on each side thereof. so that as the carriage is 'reciprocatecl said rollers travel back and forth upon said tracks. Fast to each roller 26 so as to rotate therewith are gears 28, these gears meshing respectively with other racks 29 also secured, one at each side of the carriage, to the mill frame so as to extend along and beside said tracks, the purpose of these gears 28 and racks 29 being to prevent slippage of said, rollers on their tracks and the resultant wear and consequent flattening of the peripheries of these rollers when the carriage reverses the direction of its movement at the end of each half cycle of its reciprocation.

The carriage is reciprocated by the main driving motor 30, the shaft of which is directly coupled to the main driving shaft 3! (Figs; 1 and 2) whereby said shaft is driven at the same speed as the motor shaft. Fast on said main shaft is a relatively small pinion 32 which is connected by gears 32' to a relatively large gear 33 fast on a countershaft 34. On one side of the large gear 33 a crank arm 35 is attached to said countershaft, and a connecting rod or link 36 connects the crank arm to the lower end of a rock arm 31 fulcrumed at 38 on the front end of the mill frame forward of the die-roll carriage. As shown in Figs. 2, and 11, the upper end of this rock arm is forked and each fork is so connected t6 the forward end of the carriage 2| by links 39 that the pivotal connections 40-40 of these links to the carriage and rock-arm, lie substantially in the horizontal plane C--D (Fig. 11) in which the opposing faces of the die-rolls meet,'and which plane, is coincident with the axes of mandrel M and the stock S. Thus, during the forward or working stroke of the carriage and die-rolls, the links 39 are under tension rather than under compression and the carriage is pulled forward rather than pushed forward during the working stroke. Where, as heretofore, the carriage is pushed rather than pulled during its working stroke, there is a tendency of the forward bearing rollers 26 to lift from their supporting tracks and unless the mill is run at very slow speed, this produces a whipping action of the rollers upon the tracks and not only causes excessive vibration but also excessive wear and tear on the rollers and tracks thus requiring them to be replaced frequently. By driving the carriage in the manner above described this tendency is counteracted. To provide sufficient operating space for the large gear 33 and its associated crank arm and connecting rod 36 and leave ample room for thereciprocation of the die-roll carriage, said gear and connectin rod. may be disposed below a horizontal plane passing through ornear the base plate ofthe mill (Fig. 2,) so that they may be housed ina pit underneaththe main body of the mill and below the floor level of. the room wherein the mill is installed.

' The, stock S which may be either tubular or solid-and which, for purposes of description and illustration, will be assumed to be tubular as shown in the drawings, is gripped and held at its rear end by a chuck 4| (Figs. 13,213 and 12). rotatable in a longitudinally movable head 42 which isengaged by; the forward end of a longitudinally movable but non-rotatable threaded shfiit 43 (Figs. 3 and 4) housed within a cylindrical casing 44. Threaded to this shaft is a feed-nut 45 (Figs. 4 and 5) mounted for rotation in a bracket 46 on the millframe and restrained thereby from movement in an axial direction, a gear 41 through which said nut is rotated being secured tofits rear end. The mechanism just de'scribed,.namely "the parts 4l to 41 inclusive, comprise the feeding mechanism for the stock;

4 and this mechanism is operated by the fluid system, hereinafter described, to advance the stock step by step to and between the die-rolls.

As previously explained, the stock and, in the case of tubular stock where a mandrel is usedto assist in reducing the same, the mandrel as well as the stock are turned about their axes more or less, during each short interval when the die-roll carriage is stationary immediately prior to the beginning of its forward or working stroke. fhe mandrel, denoted at M in Fig. 11, is adapted to be attached to the forward end of a mandrel-rod M (Figs. 13 and 4) but hereinafter the term mandrel, when that term is used, will be understood to include both the mandrel per se and the'rod M to which it is attached. During the reduction of the stock, the mandrel, except for its intermittent turning movement, is otherwise stationary, being firmly held at its rear end against the rearward thrust of the die-rolls, by a bearing block 48 in which itsv rear end is journaled, the said block being secured to a slidable carriage 49 which, while the stock is being fed forward along the mandrel tothe die-rolls, is rigidly held by latch-slides 49 against dis placement by the backward thrust of the. dierolls (Fig. 3). The mechanism which imparts to the mandrel, as well as to the stock, their intermittent turning movements aforesaid comprises a rotatable shaft 50 having an extension 5! coupled to its rear end; and said shaft is journaled at its rear end in the frame member 53' (Fig. 4) and has a gear 54, through which it isturned, fast on its forward end (Fig. 2) and a gear 55 fast on its rear end. The gear 55 meshes with an idler gear 56 which, in turn, meshes with a gear 57 integral with the journal 58, which is rigidly secured to the rear end of the mandrel. In addition, the said turning mechanism includes a gear 59 (Fig; 12) carried by the movable head 42 and splined to the shaft 50 so as to be movable along said shaft, and this gear meshes with an idler gear 60 also carried by the head 42, the latter gear, in turn, meshing with a gear 6| fast on the rotatable chuck 4! which, as before stated, grips and holds the rear end of the stock S. Thus, when the shaft 50 'is turned by the gear 54, the mandrel and stock will be turned at the same time and in the same direction and degree by the gears 55, 56 and 57 and the gears 59, Gil and El respectively. The stock and mandrel turning-mechanism, like the stock feeding mechanism, is operated by. the fluid system alluded to above and presently to be described.

In Figs. 3, 4 and 5 the mandrel M and the threaded feed-shaft 43 are shown in operative position in relation to a length of stock which is being reduced. When this length of stock has been fed forward far enough to bring its rear end a short distance. from the reducing rolls, it is released from the jaws 62 (Fig. 12) of the chuck 41 by turning a hand-wheel 6.3 (Fig. 13) fast on a threaded shaft 64 meshingwith a'worm 65, thereby loosening the. grip ofthe jaws on the stock; and a fresh length of stock may vthen be introduced into the mill for reduction. To introduce this new length of stock, thefeed nut 45 is first rapidly rotated, by means here? inafter described, in a direction reverse to that of its rotation for feeding the stock forward to the reducing rolls, thus causing the feed-shaft 43 and its attached head 42 to be returned'to their starting positions; and the mandrel is drawn rearwardly from its position shown in Fig. '4 to its position shown in Fig. 2A, by an endless'chain 66, after withdrawing the latch-slides 49 from their locking engagement with the sliding carriage 49. The chain 66, which is secured to said carriage at 6?, passes over sprockets 68, 68, the latter of which is fast on one end of a shaft 69 to the other end of which a gear is secured and driven by an auxiliary motor I I5 (Figs. 3 and 5). To sustain the free end of the mandrel when the latter is inits rearward position, a support I2 freely movable along a track I3 may be providedin a'position to be engaged by a lug'l4 on said chain and moved rearwardly thereby to support the mandrel at or near its forward end when the mandrel has reached its rearward position.

Having withdrawn the mandrel to its rearward position and having returned the feedshaft 43 and its attached head 42 to their starting positions, the fresh length of stock is now introduced, its rear end shoved into the jaws of the chuck M, and the hand-wheel 63 turned to tighten the jaws on the stock; then the motor H5 is again operated, this time in the re verse direction, to push the mandrel forward through the stock and thus restore the mandrel to its operative position. The latch-slides 49' are then moved into position to engage the carriage 49, and the mill is again ready for further operation. The movement of the latchslides, both into and out of their latching positions, is effected by the pistons of cylinders I6 to which these slides are respectively secured and which, together with the motor II5, are operated by the fluid system before alluded to as I length is no longer gripped and held by the jaws.

of the rotatable chuck 4 I, it will not be subjected to the action of the turning mechanism previously described. Accordingly additional turning mech anism is provided for gripping and holding the out-going previous length of stock. For this purpose, a second rotatable chuck TI is provided (Fig. 13 forward of the reducing rolls and to which a gear I8 is connected to turn this chuck intermittently the same as in the case of the chuck 4i previously referred to. The jaws I9 of said second chuck H are at all times, during the normal operation of the mill, held in sufficient frictional engagement with the outgoing previous length of stock S to cause the latter to be turned by the gear I8 and, notwithstandingthe frictional grip of said jaws, permit said stock to be fed forward through the engagement of its rear end by the forward end of the new length of stock. As shown in Fig. 13, this second chuck has a sleeve 80 and a collar 8| attached to said sleeve and through both of which the outgoing previous length of stock S passes, the said jaws I9 being retained between said sleeve and collar and within a wedge-ring 82. The gear I8 is slidably keyed to the sleeve 80 so that if it is desired for any reason to relax the grip of the jaws on the stock S, this can be done by giving the sleeve a slight sliding movement through said gear I8 6" in a rearward direction; and this sliding movement of the sleeve may be effected by admitting fluid under pressure to a cylinder 83 having a piston connected to a rod 84 whereby the latter, when moved by the piston against the action of a spring 85, rocks a lever 86 fulcrumed on the-mill frame. The lever 86 is connected by a clevisl'l, to said sleeve so that when said rod is moved by said piston against the action of said spring, the jaws will release the stock but are otherwise continuously held by said spring in frictional engagement with the stock. 1 The said fluid system will now be described, and first those parts of this system which operate the. stock and mandrel turning mechanism and the stock feeding mechanism; and since these said parts of said system are to operate in synchronism with the die-rolls, their actuation may be controlled by a cam 90 (Figs. 1, '7, 8 and 15) which is fast on the countershaft 34 and which reciprocates a slide SI in a casing or box 92 secured to the mill frame. Referring more particularly to the diagram of Fig. 15, the parts of said fluid system for operating the turning mechanism for the mandrel and stock and also the turning mechanism for the out-going previous length of stock, comprise a pair of hydraulic rams 93, 93' secured to the mill frame and having their respective plungers directly connected at 94 to one end of the cam slide SI and their respective cyl inders communicating, through pipes 95, 95', with the respective intake ports of a pair of fluidoperated motors 96, 96. The respective outlet ports of these motors are connected to a reservoir Q! for oil or other fluid used in the system, by pipes 58, 98'. Return pipes 99, 99 areprovided to directly connect the reservoir with the respective cylinders of said pair of rams to complete the fluid circuits through said motors; and each of said pipes 99, 99 has a check-valve therein to prevent backward flow from said cyilnders to the reservoir. The other end of the cam-slide BI is op-eratively connected to a single hydraulic ram I00 on the mill frame, by a linkage which, as here shown, includes a member such was a clevis IIiI directly secured to the cam-slide, a lever I02 fulcrumed on the mill frame, a link I013 connecting the clevis to one end of said lever, a block I04 slidably supported on the mill frame and directly connected to the plunger I00 of the ram I00, and a link I05 connecting this slide or block I04 to the other end of said lever. To change the relative lengths of the arms of said lever so as to adjust the length of stroke of the plunger I00 to that desired, the fulcrum of said lever may consist of a trunnion I06 slidable along said lever and the frame and to which an adjusting screw I0! is threaded, and nuts I08 to clamp the trunnion to the lever and frame in its adjusted posi tion; and to support the lever while said adjustment is being mad-e, a link I09 is pro'vided one end of which is pivoted to the frame and its other end connected to the lower end of said lever by a pivot or connecting pin Iie which is 'fitted to and passes through bores in the link I09 and lever respectively. To prevent the parts just described from cramping during the operation of the mill, the diameter of the bore in the link me through which the connecting pin I I 0 passes, is greater than the diameter of the bore for said pin in the lower end of said lever (Fig. 9). z

The parts of the fluid system for operating the turning mechanism include the ram I00 afor said and its plunger I00, a pipe IIO connecting the cylinder of that ram with the intake port 01 valve therein and directly connecting the reservoir with the cylinder of ram IUII.

"The; motor H2 is operatively connected to the.

gears-Hon the feed-nut 45 of the stock feeding mechanism,.;the motor 96 is operatively connected tortheshaft 59' of the stool; and mandrel turn-- ing-mechanism, and the-motor 96 is operativelygeonnected to-the gear 18 by which the outgoing previous length of stock is turned. And asindicatedin the diagram of Fig. 15, the cylinder of the rams Hit), 93 and. 93 by which the motors] [2,96 and 66 arerespectively actuated, are disposed below the reservoir 91. The latter is an open. reservoir, i. e. the fluid therein is not under pressureand thus is freeto flow bygravity through the respective pipes H4, 96 and 99' to said cylinders to keep them filled and so maintain the rams in operative condition at all times. Hence since there is no back-pressure from the reservoir to resist the flow of fluid through said motors and. back to the reservoir, and since these motors are, and remain, continuously in operative engagement with the respective feeding and turning mechanisms 45, 5t and 18, the latter are instantly responsive to the action of the rams.

In addition to the motors 96, 96' and I I2, th

fluid-operated motor H5 isincluded in the fluid system, for driving the chain 66. For this purpose, fluid. from the reservoir is delivered to saidrmotor H5 by a pump H6, driven by an auxiliary motor H1, and having a pressure-relief value (not shown) opening into the reservoir. A pipe H8 connects the discharge end of said pump to one side of a 4-way valve H9, a return pipe I connects, the opposite side of said valve to the reservoir, and pipes I2I connect said valve to the respective ports of the motor H5, whereby in one position of the 4-way valve, said pump will cause fluid to flow through said' motor in a direction to move the chain 65 so as to draw the sliding carriage 49 and mandrel rearwardly, while, in another position of said 4-way valve, the pump will cause fluid to flow through said motor in the reverse direction to return the mandrel again to said operative position. It will of course be understood that before the carriage 49 can be drawn rearwardly, the: latch-slides 49' must be withdrawn from their locking positions with the carriagej and to effect this, power is supplied from the pump H6 to the aforesaid cylinders 16 through a pair of -way valves I22 (only one of which is shown in the drawings, Fig. 15).. Pipes I23 connect one side of each of said pair of valves I22 to the,

discharge end of said pump, return pipes I24 connect the opposite sides of said pair of valves I22 to the reservoir, and pipes I25 connect said pair of valves I22 to each end of the respective cylinders 16, whereby fluid is caused to be deliveredto either end of said cylinders to move their pistons and attached latch-slides in one direction or the other for locking and unlocking the sliding-carriage 48. Each oi the three 4-way valves H9, I22 has three positions, nameiv, a closed position which shuts off all flow through the valve, and two open positions one of which, designated as open position 1, permits flow in one direction either to the motor H5 to draw the mandrel rearwardly or to the cylinders 16v to withdraw thelatch-slides, and the other of which open-positions, designated as openposition II, permits flow either to said motor or to said cylinders in the reverse direction to restore the mandrel to its operative position to their closed 'positionsand the valve H9 to its open position I, whereby the motor H5 will, cause the carriage 49 and mandrel to move rearwardly. To return the mandrelto its operative position again, the valve H9 is set to its open position II, while b othof the valves I22 are-left in their closed positions; and after themandrel has thus-been restored to its operative position, the valve I I9 is shifted to its. closed position and: both of the valves I22 to their open positionsv II, whereby the latch-slides will be moved into.-

position again to lock the carriage 49; and the pump is then stopped.

For rapidly returning the feed-shaft 43 to its starting position, an additional pump I26, similar to the pump. H6, is provided in the fluid system and also adaptedto be driven by said auxiliary motor H1. The intake of this pump, like that of pump H5, is. connected to the reservoir. ,A. pipe I21 connects. the discharge end of this pump I26 to one side of a 3-way valve I21 the opposite side of which is connected to the. aforesaid outlet port of the fluid-operated motor, H2. The inlet port of said motor H2 is connected to one side of a second 3-way valve H0 the opposite side of which is connected to the pipe I It leading from the cylinder of ram I00. Each of these 3-way valves is connected to the reservoir by the pipe H3 aforesaid and each said valve has two positions which may be designated as position I and position II respectively. When, as indicated in Fig. 15, the valve III] is in position Iand the valve I21 in position II, fluid impelled by the ram IUD will pass through. the motor I I2 in one direction while the pump I26 is cut off from saidmotor; when the valve H0 is shifted to position II and the valve I21 to position I, fluid impelled by the pump I26 will pass through said. motor in the reverse direction while the ram I03 is cut off from said motor. Thus, when the feed-shaft 43 is to be returned to its starting position, the valve I III is adjusted to position II and the valve I21 to position I and the pump I26 tarted in operation; and after the feed-shaft has been restored to its starting position, the pump I26 is stopped and the valve:

I21 shifted back to position II and valve H0 to position I again.

While the fluid-operated motors H2, 96 and 96 are preferably of the rotary type such as that commercially known as Vickers constant displacement type fluid motor. they, as well as the fluid-operated motor H5, may be of any rotary type or, indeed, of anon-rotary type such, for example, as the cylinder and piston type shown herein for operating the latch-slides 49'. Hence, the term fluid-operated motor. wherever used herein, is not to be construed in a literal or restrictive sense.

I claim as my invention:

1. In a mill for reducing metal stock and. having stock feeding mechanism which includes a feed-shaft and an axially immovable feed-nut threadedthereon to advance the feed-shaft, and said mill also having a fluid system for operating said stock feeding mechanism, said fluid system including a reservoir for the fluid, a ram, a fluid-operated motor operatively connected to the feed-nut to rotate the latter, a pipe connecting the cylinder of the ram with the intake port of the motor, a pipe connecting the outlet port of the motor with the reservoir, a return pipe having a check-valve therein and connecting the reservoir with the cylinder of the ram, a pump the intake end of which is connected to the reservoir, a pipe connecting the discharge end of the pump with the outlet port of the motor, a

pipe connecting the intake port of the motor with the reservoir, and control valves in the first, second, fourth and fifth named pipes, whereby said valves may be set either to cause fluid impelled by the ram to pass through the motor in one direction to advance the feed-shaft or-to cause fluid impelled by the pump to pass through the motor in the reverse direction to return the feed-shaft to its starting position.

2.; The mill defined in claim 1 and in which the said control valves comprise a pair of 3-way valves one of which is placed in the first and fifth named pipes to control their connection with the inlet port of the motor and the other of which is placed in the second and fourth named pipes to control their connection with the outlet port of the motor.

3. In a mill for reducing tubular metal stock, the combination with a reciprocating carriage, reducing devices mounted on the carriage, a mandrel mounted for turning on its axis, mechanism for feeding the stock along the mandrel to the reducing devices, mechanism for turning both the stock and the mandrel about their axes, means to reciprocate the carriage, a slidable carriage upon which the mandrel is mounted, and

latches for locking the slidable carriage to hold the mandrel in its operative position, of a fluid system for operating said stock feeding mechanism, said stock and mandrel turning mechanism, said slidable carriage, and said latches, and characterized by a fluid reservoir, a fluid-operated motor for operating the stock feeding mechanism, a hydraulic ram, a pipe connecting the cylinder of said ram with the intake port of said motor, a pipe connecting the outlet port of said motor with the reservoir, a return pipe connecting the reservoir with the cylinder of said ram and having a check-valve to prevent the backflow of fluid from that cylinder to the reservoir, operative connections between said motor and the stock feeding mechanism, a second hydraulic ram, 9, second fluid-operated motor, a pipe connecting the cylinder of said second ram with the intake port of said second motor, a pipe connecting the outlet port of said second motor with the reservoir, a return pipe connecting the reservoir with the cylinder of said second ram and having a check-valve to prevent backfiow of fluid from that cylinder to the reservoir, operative connections between said second motor and the. stock and mandrel turning mechanism, a third fluid-operated motor operatively connected to said slidable carriage, a pump the intake of which is connected to the reservoir, a 4-way valve, a pipe connecting the discharge end of said pump to one side of said 4-way valve, a pipe connecting the opposite side of said 4-way valve with the reservoir, pipes from said 4-way valve to the respective ports of said third motor, fluidoperated cylinders the pistons of which are attached to said latches, a pair of 4-way valves, pipes connecting the discharge'end' of said/pump respectively to one side of each of said pair of 4-way valves, return pipes connecting the opposite side of each of said pair of 4-way valves'respectively with the reservoir, pipes from each of said pair of 4-way valves to the respective ends of said fluid-operated cylinders,v and means for synchronizing the operation of said rams with each other and with the reciprocating carriage.

4. A fluid system for controlling the operation of the stock feedingand stock turning mechanisms of a mill of the type described and having a timing cam, which system comprises a fluidoperated motor in continuousoperative engagement with the feeding mechanism and. provided with a fliud inlet port and a separate fluid outlet port, a hydraulic ram, a reservoir forfluid, :a pipe connecting the reservoir with the cylinder of said ram, said reservoir being open to the atmosphere and disposed above said ram so that fluid may freely flow by gravity through said pipe from the reservoir to the cylinder of said ram, a check valve in said pipe to prevent backwardfiow of fluid through said pipe to the reservoir, a pipe connecting the cylinder of said ram to the inlet port of saidmotor, a pipe connecting the outlet port of said motor with the reservoir, a second fluid-operated motor in continuous operative engagement with the turning mechanism and provided with a fluid inlet port and a separate fluid outlet port, a second hydraulic ram disposed below the reservoir, a pipe connecting the reservoir and the cylinder of said second ram for the flow of fluid to the latter and having a check valve to prevent backward flow to the reservoir, a pipe connecting the cylinder of said second ram to the inlet port of said second motor, a pipe connecting the outlet port of said second motor with the reservoir, operative connections between the plunger of the first named ram and the timing cam, and operative connections between the plunger of said second ram and the timing cam.

5. The fluid system defined in claim 4 and further characterized by a third fluid-operated motor in continuous operative engagement with another of said turning mechanisms and provided with a fluid inlet port and a separate fluid outlet port, a third hydraulic ram disposed below the reservoir, a pipe connecting the reservoir and the cylinder of said third ram for the flow of fluid to the latter and having a check valve to prevent backward flow to the reservoir, a pipe connecting the cylinder of. said third ram to the inlet port of said third motor, a pipe connecting the outlet port of said third motor with the reservoir, and operative connections between the plunger of said third ram and the timing cam.

6. The fluid system described in claim 4 and further characterized by this: that the operative connections between the plunger of the first named ram and the timing cam include a lever fulcrumed to the frame of the mill and having means to vary the relative lengths of its arms.

'7. The fluid system defined in claim 4 and further characterized by this: that the connections between the plunger of the first named ram and timing cam and between the plunger of said second ram and timing cam include a slide reciprocated by the timing cam, that one end of. said slide is directly connected to the plunger of said second ram and that the other end of said slide is connected to the plunger of the other ram by a linkage including a lever fulcrumed to the frame and having means to vary the relative lengths of its a ms.

8. The fluid system defined in claim 4 and further characterized by this: that the operative connections between the first named ram and the timing cam include a slide reciprocated by said cam, a member fast to said slide, a lever, a link connectings'aid member to one end of said lever, a trunnion adjustable on said lever tovary the relative lengths of the lever arms, means to clamp the trunnion to both the lever and the frame of the mill, a slide fast to the plunger of said first named ram, and a link connecting the 'last named slide to the other end of said lever.

ther characterized by this: that the stock feeding mechanism comprises a longitudinally movable head, a chuck carried thereby 'for gripping and holding the stock, anon-rotatable threaded shaft the forward end of which engages the head, a

feed-nut threaded to the non-rotatable shaft and restrained from movement in an axial direction, and a-gearon the feed-nut operatively connected to the first named motor.

'10. The fluid system defined in claim 4 and further characterized by this: that a rotatable chuck is provided to grip and hold the stock and 12 that the stock turning mechanism comprises a rotatable shaft geared to the chuck and operativel-y connected to said second motor.

11. The fluid system defined in claim 4 and further characterized by this: thatthe stock feeding mechanism comprises a longitudinally movable head, arotatable chuck carried thereby-for .gripping and holding the stock i'anon-rotatable threaded shaft engaging the head, a 'feed-nut threaded to the non-rotatable shaft and restrained from movement in an'axial direction,

that the stock turning mechanism comprises a rotatable shaft geared to said chuck, and that said feed-nut is operatively connected to the first named motor and saidrotatable shaft geared to Number Name Date 1,952,841 Coe Mar. 27, 1934 2,387,515 Inslee Oct. 23, 1945 2,388,251 Coe Nov. 6, 1945

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