US2331953A - Metalworking apparatus - Google Patents

Description

Oct. 19, 1943. R. w. ANDREWS, JR., ET A1.

METAL WORKING APPARATUS Filed Aug. 3, 1939 Q 11 RAYNAL W.

4 Sheets-Sheet l 1N VENT ORJ A Na Arr/fuk T. DLF/LY.

A ORNEY.

ANaRzws, JR.

METAL WORKING APPARATUS ATTORNY.'

R. W. ANDREWS, JR., ET AL oct. 19, 1943.,

METAL WORKING APPARATUS 4 sheets-sheet 3 Filed Aug. 3. 1939 INV ENTOR` W Anon-w, JR. AND ARTHUR TD5/Lx ATTORNE'Y.

Oct. 19, 1943. R. w. AND'R|-:ws, JR., ETAL METAL WORKING' APPARATUS Filed Aug. 5, 1939 4 Sheets-Sheet 4 .L L J l I 1 1- L INVENTOR. RAYNAL w ANnREwJ, JR. BY ARTHUR T. DEILY.

ATTORNEYy Patented Oct. 19, 1943 UNITED STATES PATENT OFFICE METALWORKING APPARATUS Raynal 'W. Andrews, Jr., New Kensington, and

Arthur T. Delly, Pittsburgh, Pa., assi gnors to Aluminum Company of America, Pittsburgh. Pa., a corporation of Pennsylvania Application August 3, 1939, Serial No. 288,16; 2 0 Claims. (Cl. 205-7) benches for drawing tubular shapes, rods and the like through a die. In one specific form the invention relates to a draw bench for drawing tubular shapes which employs a die and more than one mandrel rod and bulb.

The usual draw bench for tube drawing comprises a supporting frame or frames upon which are mounted a die, a mandrel and bulb, a draw chain or the like, and a carriage having jaws for gripping the work after it has been passed over the mandrel and bulb and insertedthrough the die. The carriage must be moved to draw the work through the die, and for this motion 'generally engages with,' and receives its drawing force from, a draw chain or similar device.

When tubular or hollow-shaped material is drawn, a mandrel or bulb designed to form the desired inner contour of the work isl usually attached to a mandrel rod which may 'be slidably mounted at the rear of the mandrel end of the draw bench. The mandrel is customarily supported manually while the work is threaded thereover. Ropes and cables have been used to force the mandrel rod, bulb, and work into registry with the die. These operations and such nonpositive methods of registering bulb and die have resulted in loss of useful production time and waste of material.

Also in former practices, production has been limited by the time required for the return of the drawing carriage to the die head and by the time required for passing new work over a mandrel rod and bulb.

The generan object of this invention is to im-y objects: The provision of a plurality of mandrelA Yunits, each `one of which may be employed-in registry with a die for forming a work-piece during a drawing cycle. The provision of such a plurality of mandrel unitsunder such conditions that a new work-piece may be passed over one mandrel unit while a preceding work-piece is being worked over another mandrel unit in a drawing" cycle.v The provision of positive automatic means for aligning a mandrel unit with a die. 'I'he provision of positive automatic means for forcing a mandrel rod and associatedbulb into registry with a die.

These and further objects and advantages of I.

this invention, either singly or in combination, are for purposes of convenience illustrated with respect to a specific mechanism which embodies all of the specic features of the invention. It

will be understood, however, that these features maybe available for single use, or in anysuitable combination, to improve the operation of draw benches or similar apparatus", which do not include all of said features.

In the drawings Fis. 1 isla partial plan view of the preferred form of a mechanism embodying the features of the invention, and showing two mandrel rods,

the die head, the drawing carriage, the draw.

same scale as Fig. 2, of the mandrel manipulat Fig. 4 is a section taken on the line IV-IV of I Fig. 3 showing the end mandrel supporting member, the tubular work and mandrel supporting structure, and the piping for the mandrel manipulating and rotating mechanisms;

Fig. 5 is a section taken on the line V-V of Fig. 3 showing the mandrel rotating mechanism and piping therefor; 4

Fig. 6 is a schematic diagram illustrative of the electric and pneumatic control system for the mandrel rotating and manipulating mechanisms;

Fig. 'I is a side elevation, to an enlarged scale, of the drawing carriage shown in Fig. 2, in which the work engaging jaws of the drawing carriage are in a closed position and the draw chain en-` -piece through the die.

gagingliook-is ina lowered position, in its first engagement withL the draw chain:

Fig. 8 is a fragmentary view; partly'in section,

. piece.

shown in Fig. '7, and to the same enlarged scale,

in which one-half is a section taken as indicated by the reference' line IXe-1X of Fiif. 8.

Briefly, the apparatus as shown comprises a draw bench frame, a drawing head or carriage,

a drawing die, and two work supporting mandrels. A hollow shape may bepassed over one mandrel within a protecting shell or other guiding support by hand or by suitable mechanical loading mechanism (not shown); the mandrels may be rotated to align one work-piece and mandrel with the die; the point of the work-piece may be inserted through the die; and the mandrel and work-piece may be forced into registry with the die conjunctve with the beginning of the drawing action. The drawing carriage and its work gripping jaws may be actuated to clamp the point of the hollow shaped work-piece, and may be /moved along the draw bench by suitable engagement with a draw chain to draw the work-A Upon completion of a draw, the work-piece may be released to a covenient rack or removal apparatus (not shown).

Endless return means are provided for vauto- Amatically traversing the drawing carriage back `to the die head after completion of a drawing operation. Such endless return means are preferably operable independently of the drawing chain and preferably lare adapted to control the position and rate of speed of the drawing carriage during its return movement.

It should be noted that the invention provides,

interV alia, for utilizing a plurality of mandrel rods rotatable to bring each, -in its turn, into position for drawing a Work-piece. As will appear more fully in the detailed description of the apparatus as shown, means have been provided throughout for automatic operation of the draw bench during at least one complete drawing cycle.

` Die section The die section of the draw bench will now be described` with special reference to Figs. 1 and 2 of the drawings. By the die section is meant that portion of the apparatus immediately head 3 may be removed from the frame by engagement of a crane hook with an eye-bolt 1. The die head may be suitably shimmed for alignment about the axis of draw in one or more planes, or a tilting die head, adjustable about either vertical or horizontal axes, can be employed if desired. 'Ihe work-piece, here a 'tube 8, is shown with its pointed end 9 inserted through die 4. As shown in the sectioned portion of Fig. 2, the

drawing operation has not started, and, there-v fore, mandrel rod I0 and bulb II are not shown lthe protective and supporting shell,

in full registry with die l. Asecond mandrel rod I2 and bulb I3 are located above and behind mandrel rod I0 and bulb I I. Said second mane drel rod and bulb are shown-ina fully vretracted position, adapted to receive an undrawn work- Bulbs II and VI3 are secured to mandrel rods I0 and I2,.rcspectively, by suitable threaded nuts I4, preferably tapered outwardly to facilitate passing of tubular 'and hollow-shaped stock thereover.

Means not necessarily forming part of this invention may be provided for placing a workpiece on the mandrel when it is in the position of mandrel I2. Means are shown, however, for rotating the mandrel rods to bring the mandrel lrod and work-piece from the position of mandrel rod I2 to the lateral position of mandrel rod IIJ; and means arev provided for advancing a mandrel rod and its work-piece to the die to occupy the position of mandrel rod III, bulb II, and tubular work-piece 8, as shown.

Means are provided for protecting and supporting a work-piece passed over a mandrel rod and bulb. 'I'hese means preferably take the form of tubular shells I6 supported at convenient intervals along their length by mandrel supports 24` intervals within the shells I 6 and provide fur-- ther points of support forthe work-piece. Tubular shells I6 are designed to protect the work against scratching and dirt and, with bushings I 8 and .22, to support work of considerable length. Where protection of the work from dirt is not a primary problem, the shells I 6 may take the form of spaced sections or rings rather than continuous lengths of tubing as shown.

Drawing section Referring to Figs. /1, 2, 7, 8 and 9, the drawing section of the draw bench is now described. This section of the bench is defined as that portion of thev bench, including the associated appa'- ratus, over which the stock is pulled or drawn fromv the die 4. The drawing section comprises generally frame I, draw head 30, and ytracks ,or rails 3| along whichthe carriage may move on carriage wheels 32. Gripping jawsI i "fand 34 are located in "draw head 30 and are adapted to engage the pointed end 9 of the tubular fworkpiece 8. Carriage hook 35 is adapted to engage endless draw chain 36. A pair of suitable return chains or other endlessdriving means 31 and 38 are connected to carriage 30 on either side l thereof and adapted to return the carriage to Locking are located along the main frame I, as shown.

These limit switches are arranged to control acceleration and deceleration'of drawing carriage 30 during its forward drawing and return move'- ments, and further to control various other operations to be hereinafter described.

Draw chain 36 is centrally located within l land 2), which drive coupling 48 is connected to the draw chain drive sprocket 46 through a drive shaft 49 held in frame I by bearings 50 and I. The draw chain maybe lubricated by continuous immersion in a suitable oil reservoir located in the path of the under portion of the chain, but not here shown. The idler sprocket 41 is located adjacent the die end of frame I and is mounted on an idle shaft 52 yjournalled in adjustable bearings 53. These bearings may be moved longitudinally of the draw bench by means of nuts 54 on screw threaded rods 55, for adjustment of the draw chain tension or for removal of the draw chain.

The draw chain 36 has preferably a short pitch, that is, the links are made as short as possible so that variation in linear velocityof the chain will be kept at a minimum; and the drive motors for the drawing chain preferably have rigid speed control soas to produce as nearly constant drawing velocities as are'feasible. By means of this preferred form of apparatus, the drawing speed may be Varied from practically a stop up to normal'speed, under no loadl up to heavy drawing load, with rapid and even acceleration, initiated by electrical control operable through limit switch 43.

Return chains 31 and 38 are iixed to4 carriage 38, through tie plates 56, and are supported and located on either side of frame I, being engaged by drive sprockets 51 adjacent the die end of said frame and by idle sprockets 58 at the opposite end of said frame. Drive sprockets 51 are mounted on a common drive shaft 59, which c arries belt pulley or sprocket 60, and is journalled in suitable bearings 6I. The drive shaft and sprockets are drivenhy electric motor 62 through drive belt or endless chain 53 and belt pulley or sprocket 60. The return chain idle sprockets 58 are located on common idle shaft 64 journalled in adjustable bearings 65. Means for adjusting the tension of return chains and for permitting their ready removal are here provided inthe form of threaded rods 66 and adjusting nuts 61 provided thereon. Return chains 31 and 38 are recessed in chain guards 68 for protection of both chains and operator. Suitable means may be provided for lubricating such chains,A

movement of the carriage on its return to theA die head is positively controlled, thus eliminating the necessity for employing previously used shock absorbers or cushioning devices to stop the carriage at the diehead. The two return chains 31, 38 are preferably provided 4to insure alignment of the drawing carriage with the die head upon its approach thereto, but a single chain or cable may be vused with satisfactory results. The acceleration and deceleration of the drawing carriage on its return travel may be accurately controlled through 'one or more of the aforementioned limit switches, as here shown by switches 40, 4I, and 42, which switches are actuated by the drawing carriage trip arm I8.

Other elements of the drawing section of the draw bench which should be noted at this point in the description are the two chain releasing cams 69 and`18. As aforementioned, the carriag'e 30 is positively connected to the draw chain 36 by a hook 35 carried by the carriage. Fixed upon the shaft which supports -hook is a hook release lever 1I (Figs. l and 9), which is mounted in a. substantially horizontal posi tionand extends forward of the drawing carriage on one side thereof. On the extremity of release lever 1I is. a cam follower in the form of a roller 12, adapted to engage and ride up the contour of cam 69 (Fig. 2) located adjacent the die head of the drawing section'of the draw bench, or of'stop cam-10 located at .the other extremity of the draw bench. At either cam the action of release lever 1I and its roller 12 is to lift hook 35 out of engagement with drawing c hain 36, thereby bringing carriage 30 to rest.

Cam 69 is provided for the purpose of releasing the carriage hook from the draw chain when the carriage jaws have failed to engage the workpiece or in case of breakage of the work-piece during forward travel of carriage 30. In either event, there is no drawing tension on the chain. If the carriage 30 has engaged work-piece 8 through the proper clamping engagement of jaws 33 and 34 upon the work, the drawing tension exerted on draw chain 36 will lift the chain and the engaging carriage hook 35 sufficiently high to\ permit hook release lever 1I and roller 12 to clear the cam 69. Thus the normal drawing operation will continue until the work-piece is free of drawing die 4. At this point, Idrawing tension isy immediately released and the draw chain tends to fall and disengage itself from the hook 35.

Cam 10 functions as a safety device and hook adjusting mechanism in the event that hook 35` does not, at the end of the drawing operation and when drawing tension is released, release itself from the chain but falls therewith. In such case, the release lever 1I and its cam follower 12 contact cam 10, with the result that the hook 35 is positively raised and disengaged from the chain 36, and reset in its raised position, thus preventing the continuously traveling chain 36 from dragging the draw head 30 oil the end of the bench,

or preventing otherA injury to the assembly.

Draw head in Fig. 9, and which are adapted to grip the-workpiece at the die head 3.` These jaws areso arranged that Vone jaw may advance` or adjust itself relative` to the other, and relative to the work-piece to grip the pointed end 9 thereof and exert an axial drawing force thereon despite any irregular formation or non-axial alignment of said Work-piece end. Further it maybe noted that the jaws are actuated through a linkage',

which will be described hereinafter, by means of Aapproach, thereto, and rise thereon the forces exertedby the draw chain 36 on the chain engaging hook 35.

The carriage or draw head 39 is provided with a transverse shaft 'journalled in lthe frame thereof. Centrally on said shaft is keyed the clevised end (see Fig. 9) of carriage hook 35. This hook has a link-engaging 'portion 16 which is arcuate in form (see Fig. 2) to conform with a link of the draw chain, the said arcuate portion being preferably adapted vto engage somewhat` more than 90 of arc on any particular link. Also keyed to shaft 15, at one end thereof, and located outside the frame of carriage 39, is the hook release lever 1| and its` cam contacting roller 12. The keyed angular relationship of hook 35 and hook release lever 1| on through shaft 15 is such that when lever 1| is in its lower position, its roller 12 would engage cam'69 or stop cam 19, on

thereby raising hook 35.

Also keyed to shaft 15 between forked portions of the clevised end of hook 35 is a crank lever 11 extending in a generally vertical direction above top .plate 18 of carriage 39, said hook 35 and crank lever 11 substantially forming a bell crank oscillatable with said shaft 15, in accordance with the forces imparted to the hook by means of the draw chain 36, or to the hook release lever 1| by means of the cams 69 or 19.

Disposed laterally and approximately centrally of carriage 39, above top plate 18, is pin 19 supported and retained in bearing blocks 80, 8|. Os-

cillatable on pin 19 is a centrally disposed crank 82 which extends upwardly therefrom in a generally vertical direction. Adjustable link 83 connects the upper extremities of crank 82 to crank lever 11, whereby crank lever 11, adjustable'link 83, and crank arm 82 form, with the frame of the. carriage, a quadricecrank linkage.

Preferably integrally formed with the lower portion of crank 82 is a projection forming a latch 84 adapted to be engaged by pawl 85, wherebS1 the quadric-crank linkage actuated by hook35 or release lever 1| may be latched with the hook in its raised position in a manner which will be more fully described hereinafter.

Also oscillatably mounted on pin 19, on either side of crank 82, are jaw- actuating levers 86 and 81, which levers have portions extending in a generally vertical direction above pin-19 in normally parallel relationship with crank arm 82, and jaw-actuating portions extending below pin |19 to act as lever arms. Jaw- actuating levers 86 and 81 are independently oscillatable on pin 19 .and are inter-related in their action by a double acting spring 88 and associated parts. At the lower extremities of said jaw-actuating levers are adjustable links 89 and 99 connecting to work-engaging jaws 33 and 34, respectively. Said jaws are slidable on converging ways 9| (see Fig. 9). The latterly described portion of the actuating linkage for each jaw may be referred to as a slider-crank linkage, said linkage comprising a jaw-actuating lever, an adjustable link, and a jaw slidable on a converging way.

To provide for convergence of the jaws, and for the angular movement of adjustable links 89, 99 with respect to levers 86, 81 and the jaws 33, 34, suitable ball-and-socket connections 92 have been provided between each of said levers and each of said adjustable links and between each of said links and each of said jaws.

Approximately central of the length of th crank 82 on either side, and in the directions of oscillation thereof. are recessed. concavebearing 2,331,953 'portions or seats 93, substantially semi-cylindrical inform. On the upper extremities of :lawactuating' levers `86, 81` on either side, and in the( directions of oscillation thereof, are similarv 5 recessed, concave bearing portions 94, substantially semi-cylindrical in form and adapted to lateral alignment with the corresponding bearing portions 93 on'crank 82.

level of recessed bearing portions 93, has an aperture 95 extending therethrough in a direction substantially/tangential to the arc of rotation thereof.` Extending through aperture 95, in approximately the same plane as contains the quadric-crank linkage and normally perpendicular to crank 82, isadjustable tie bolt 96 threaded at either end, to receive. adjusting nuts 91. Mounted preferably on the forward end of the tie bolt 96, in the direction of draw, is bearing mem- `ber 98 engaging crank 82 and jaw-actuating levers 86,' 81 in the aforedescribed bearing portions 93 and 94,*respectively. 'Ihe said bearing member 98, which is axially slidable on tie bolt 96 and positionable thereon by means of nuts 91, extends laterally across crank 82 and across the jaw- actuating levers 86, 81, and is adapted to engage with either of said jaw-actuating levers or said crank independently, or at times with all of them simultaneously. For engaging the opposite bearing portion of crank 82, or the opposite bearing portions in jaw- actuating levers 66, 81, is a second bearing member 99 similarly mounted on said tie' bolt 96. 'I'he two bearing members 98 and 99 are provided with semi-cylindrical or convex bearing surfaces adapted to engage in the aforesaid semi-cylindrical or concave bearing recesses of the crank and the levers.

'Ihe bearing member 99, slidableon tie bolt 96, serves further as a spring seat for double-acting spring 88, which spring is mounted surrounding the said tie bolt 96 on that portion of .the tie bolt which extends, to the left as viewed in Fig. 7, toward the jaw portion of the draw head 39. An opposing spring seat |99 is located at the end of tie bolt 96 and is slidable thereon, being adjustable for position by means of adjusting nuts 91. i Levers 86, 81 and crank 82 are cooperatively related by means of the aforementioned doubleacting spring, tie bolt, spring seats, and bearing members. The two-fold purpose of the spring ,and associated elements is, briey, (1) to tendjo keep levers and crank in the same axial line so that they may function substantially as one split lever oscillatable on the pin 19, and yet permit the levers to advance or retract relative to each other in response to movement of the crank, and in response to the relative positions assumed by the work-engaging jawsv as they positively and separately engage the work; and (2) to store jawopening energy by compression in the spring whereby the spring may effectuate movement of the levers to assist in the opening of the jaws, as will hereinafter be specically explained. Ad-

justabilities afforded in the various links, and the yieldability of the spring permit ready accommoldation of the apparatus to work and shape.

For engaging the aforementioned latch 84, the

pawl 85 is pivotally mounted on pin |9|, fitted in suitable bearings |92 located in the base of car` 7u riage or draw head 39. 'A spring |03 connects pawl 85 andan anchoring pin |94, and tends to lic-ld the pawl against either latch 84 (Fig. 7), or the base of crank 82 under the said latch. For moving said pawl from its latched position under latchl 84, a longitudinally-extending trip rod |95 Crank 82, at theof varying size ing movement of the said quadric-crank linkageV to take place.

The operation of the carriage will not be enlarged upon since it is fully set forth in our divisional application, Serial No. 341,677, above- .mentioned a Mandre'l section The preferred means of presenting work-pieces to die 4 will now be described with reference Vto Figs. 3, 4, 5, and 6, as well as to Figs. 1 and 2. Along the mandrel section of the bench, which is thatnportion of the bench located on the stock feeding` sideof the die head 3, are a plurality of mandrel-supporting members 24. The portion of the mandrel section of the bench between an end mandrel-supporting member 26, shown in Fig. 3, and the mandrel-supporting member 24 adjacent the die head 3, shown in Fig. 2, is not illustrated in the drawings, since it will be apparent that, regardless of the length of the on said rollers. Tubular shells I6 are mounted through apertures in block I.

IEnd mandrel-supporting member 26 (Figs. 3 ande) is associated with'and forms part of the mandrel end frame 21. Two' supporting .rollers II3 are journalled on end frame 21 and on them is rotatablal disc-like block I4 similar to bloks I II Vin the other mandrel-supporting members 24. On opposite sides of the axis of rotation of the block II4, suitably mounted in apertures ||5 are the ends of the tubublar shells I6. Also suitably journalled in restricted bushed portions ||6 of the'apertures are the end portions of the mandrel Y rods I0 and I2. These mandrel rod 'end portions extend through the said apertures to make connections to the mandrel manipulating mechanisms.

To impart stability to end mandrel-supporting member 26, a third upper supporting and restraining roller ||1 is mounted in a curved chana nel member IIB hingedly connected to one side' tubular shells I6, any convenient number ofv mandrel-supporting members 24 in the for shown in Fig. 2, may be provided. The end mandrel-supporting member`26, as shown in Figs. 3 and 4, is mounted upon a mandrel end frame 21. In the form of the invention illustrated, there are two sets of mandrel rods and cooperating tubular shells. These mandrel rods are preferably rotatable about a common axis located centrally therebetween so that either rmandrel rod I0 or mandrel rod I2 may be aligned with die 4. In Fig. 3 the lower mandrel rod I0 is shown in forward position corresponding to the eries will have a locus describing a frustum of a ber v26, are provided to support the tubuiarshells I6 and indirectly the mandrels, throughout their length, and for constraining the path of rotation thereof. a

Each mandrel-supporting member 24 comprises essentially a frame base structure25, on which are suitably journalled two supporting rollers III) adapted to support a disc-like block III, adapted to be rotated with its track portion I|2 bearing 24, including the end mandrel-supporting mem- 65 of the end frame 21, as at IIS, and retained in position over block I I4 by means of a pin connection, as at |20, with'a link |2| hingedly connected to end frame 21,'as'at |22, the link I2I having an extension thereof adapted to carry counter- YWeight |23.

. (see Figs. 3 and 5). Air cylinder |21, linkage. |28,

and angularly movable gear segment |29 in toothed engagement with pinion |26, are adapted to impart rotational movement to shaft '|24 and thereby to the mandrel rods, rst inpne direction and then in the other direction, through an angle of approximately 180. Adjustable stops |30, |3| e are located on end frame 21 in relation to gear segment |29 to limit4 the rotational movement of said gear segment in either direction. These adjustable stops maybe so arranged that when gear segment |29 is brought in contact with one or the other stop upon its rotation, a mandrel rod and bulb will be in proper alignment with the draw die 4.

Mounted on shaft |24 between the end mandrel-supporting member 26 and the mandrel rotating mechanism just describedis another-disclike block |32 bearing on rollers |33 suitably journalled on mandrel end kframe 21. This block I 32 is adapted to support manipulating mechanisms I'34, |35 for the mandrel rods I6 and I2, respectively. These manipulating mechanisms comprise suitable double acting' pistons and piston rods |36 and |31 adjustably connected to the end portions of the mandrel rods. The manipulating mechanisms are preferably operableby means pf compressedair but other suitable motive means may be employed. The adjustable couplings |38 between the end portions of mandrel4 rods |0,| 2 and the piston-rods |36,` |31 permit slight adjustment of the position of each mandrel tolocate its mandrel rod -bulb correctly with respect to thedie, but are primarily provided 4to make convenient the interchange of various sizes of mandrel rods.

The manipulating mechanisms |34 and |35 are adapted to longitudinally or axially move the mandrel rods and bulbs into and out-of registry with the die in response to control which will now be described. The mechanisms are adjustable for longitudinal position to initially correct any appreciable error in registry oi' bulb and die. This adjustment is obtained by means of suitable spanner nuts |33 located in apertures in the block |32, and adapted to engage threads on mechanisms |34 and |35, said mechanisms being keyed to shaft |24, as at |40, to prevent relative rotation, while permitting relative longitudinal adjustment.

To make clearthe function of the various elements of the mandrel section just described, certain parts of its operation will now be explained. Each manipulating mechanism |34, |35 is adapted to move a mandrel rod and bulb into registry with the die 4 at the beginning of a drawing operation. Upon the beginning of a'drawing operation the friction of the material being drawn over the mandrel rod bulb immediately places the mandrel rod in tension which must be resisted by the mandrel manipulating mechanism, the end mandrel-supporting member, and the thrust bearing provided on the end of the shaft |24. The channel member ||8 and upper roller ||1 in end mandrel-supporting member are adapted to maintain the block ||4 in vertical position and resist the overturning couple which may be imparted thereto by the drawing force on a mandrel rod and reacting force 'in theV shaft |24. vBushed portions IIB-have been provided in the apertures 5 in block ||4 to support and locate the mandrel rods |8 and I2, and to prevent overfiexing thereof and the transmission of iiexure to the mandrel manipulating mechanisms. i

Cil

Mounted on shaft 24 between end mandrelsupporting member 25 and manipulating mechanisms |34 and |35 are two limit switch dogs |4| and |42 in the form of radial amis extending in opposite directions albng approximately the same diametrical line. Located approximately centrally of mandrel end frame 21 beneathshaft |24 are two limit switches |43 and |41 adapted to be engaged and actuated respectively by limit switch dogs |4| and |42. Rotational movement of shaft |24 is adapted to bring one limit switch dog into position to actuate one limit switch, and opposite rotational movement ofL shaft |24 is adapted to reverse the position of that limit switch dog,while the other limit switch dog engages and actuates the second limit switch in alternate fashion. Limit switches |43 and |41 are electrically inter-connected with spring-held solenoid valves |48 and |43 which are in pneumatic circuit with the pressure source and the manipulating mechanisms |34 and |35. A thirdy solenoid valve '|50 is in pneumatic circuit with the pressure source and the air cylinder |21 for rmandrel rotating cylinder |21, and is connected across yan electric power source |5| through ratchet-type relay 52, which is actuated by a control circuit connected across power source 5| through both limit switch 44 and limit switch 45. Limit switch 45 may be replaced by or used in parallel with a push button |53, the latter alternative being illustrated in Fig. 6; and this limit switch 45, if employed as such, should be of the momentary contact type, whereas the other linut switches described herein are of the ordinary circuit making and breaking type. By positioning limit switch furtherA from the die head3 than limit switch 44, on the main frame of the draw bench: the successive action (45, then 44) of these limit switches (upon return movement of carriage 30) will energize and move the ratchet of the ratchet-type relay |52 to actuate solenoid valve |50, thereby directing air to one side of the mandrel rotating cylinder |21, and thenopen the circuit through relay |52; and upon the reverse successive opening (44, then 45) of the limit switches, they will have no eiect upon the mandrel rotating cylinder |21 until the-next cycle, switch 44 being moved only to select the circuit through relay |52.

For controlling the-supply of air to either side of the mandrel manipulating mechanisms |34 and |35, the solenoid valves |48 and |49 are also connected across the power source |5| through ylimit switches |45 and |41, respectively, and

through the opposite terminal of lixnit switch v44 on the main frame of the draw bench. Since the limit switches |45 and |41 are operable upon rov Y tation of the mandrel rods and shaft |24, their successive effect upon the system will be automatic following the actuation of mandrel rotating cylinder |21.

'I'he inter-relation of the electric and pneumatic control system for the mandrel rods will become more apparent as the operation of the draw bench generally is described in further detail hereinafter.

tating the mandrel rods. The pressure source V tioed nmit switches u and u on the main frame of the draw bench are inter-related-with the limit switches |45 and |41 on the mandrel end frame.

Solenoid -valve |50 controls the air, or other 52 movement of the carriage 30 toward the dieA head 3 will begin. The limit switclr dog 35 on carriage 30 will iirst'strike the limit switch 45 which, because of the previous closing of limit switch 44 on its first terminal in the circuit to solenoid |50 (as in Fig. 6) on movement of the 'carriage away from the die, will by momentary electrical contact (dotted position of switch 45, Fig. 6) energize the coil of ratchet-type relay |52, closing or opening the switch thereof. The push button |53 is shown as adapted to serve the 'same purpose as switch 45. The solenoid valvel |50 having been energized or de-energized and actuated by relay- |52 to direct air to the mandrel rotating cylinder |21, a piston therein.

A pressure medium, supply Vto either side of the mandrel rods I0 and |2 approach the end of dos,` e. g., dog |4|, will engage a limit switch, e. g.,4

their rotational movement, a limit switch |46, closing the 'same (as in Fig. 6) and thereby partially close the circuit tofa solenoidvalve,

e. g., 48, adapted to control the supply of air to` drel rod will be advanced upon the closing of' the limit switch 44 upon its second terminal (shown dotted in Fig. 6), later to be effected as the carriage moves toward the die, since when one limit switch |46 or |41 is closed, the other is necessarily opened, as here constructed.

At a position along the main frame of the draw bench nearer the die head 3, the limit switch dog 39 on the carriage 30 engages and operates limit switch 46. Upon the movement of limit switch 48, the eld control of the return drive motor 62 is, in the operation here described, modied to bring the return speed of the carriage to a substantially constant base value.

- At a position along`the main frame of the draw bench still nearer the die head, the said limit switch dog 39 engag'es and operates limit switch 44. Upon the movement of limit switch 44 to its second terminal (dotted position, Fig. 6), the energizing circuit to the mandrel rotating cylinder |21 is completely disconnected, without effect thereon since the circuit is normally open at' switch 45 or push button 153; and the circuit to the previously selected manipulating mechanism solenoid valve, -e. g., |48, is closed, whereupon a mandrel manipulating'mechanism, e. g., |34, is

operated to move a piston rod, e. g., |36, mandrel rod, e. g., 6, and bulb, e. g., connected thereto forward into registry with die 4, as shown in the gures, thereby moving a tube 8 substantially into drawing position in said die, At this position the pointed end 9 of the' tube extends through die 4 for engagement by the jaws 33 and 34 of the drawing carriage 30.

Upon further approach of the carriage 30 to the die head the limit switch dog 39 strikes and actuates successive limit switches 4|, 43, and 42, which in that order respectively decrease the speed of the return drive motor 62 by armature shunt control, decrease` the speed of vthe draw.

chain 36 to a pre-set initial drawing speed, and stop the motion of the drawing carriageas it approaches the die head byv applying `dynamic braking through the drive motor 62.

As carriage 36 comes to rest at die head 3, trip rod contacts the die head and releases pawl If stopped the draw chain would then be clamps the jaws 33 and 34 upon the pointed end 9 of the tube 8, and brings the mandrel-rod bulb into nal registry with the die 4.

' n Before continuing with the description of the operation, it may be pointed out that if the jaws should fail to engage4 the end ofthe tube there will be no tension Aon the chain 36 and the hook 35 will not be substantially raised. Rather'than permit Ythe carriage to travel out the full length of the frame, vmeans for stopping the car.- riage and returning it again to the die head are provided. The roller follower 120i hook release lever 1| will strike the cam 69, which will raise the hook release lever and will release the hook from the chain, whereupon the carriage 36 may have a short return travel back to the die head to re-engage tube 8. i

Assuming, however, that the jaws have engaged the end of the tube upon the falling of'hook 35 into the draw chain, the motion of the carriage outward under drawing tension will continue asv first actuate and engage Ilimit switch 42, resetting the same and electrically disconnecting from cir. cuit the return drive motor 6,2 so that the return chains 31 and 38, xedly connected to the carriage, may cause reverse rotation of4 the drive motor 62 against no electromagnetic forces.

The limit switch dog 39 will next resetthe'limit switch 43 and cause acceleration -of the drive chain 3 6 from its initialA slow speedl to normalv drawing speed. p v

The next limit switch 4|. will be merely reset without effect upon the cycle of operations.

Likewise the next limit switch 44 will be reset, toits first position (as shown in full line in 6) closing inpart the circuit to the ratchet-type relay |52 with asyet no effect thereon. But the.

resetting of this limit switch 44, however, opens the circuit to the solenoid valve, e. g., |48, which will then be spring actuated to'reverse the ow of air, o'r other 'pressuremedium to the opposite side of a piston in a. manipulating mechanism, e. g.,

|34. tending to withdraw a mandrel rod, e. g., l0,

and bulb, e. g., from registry-with'die 4. v'Ihis tendency, however, will remain ineffective while n there is drawing tension onla tube 8, but will be ing at a slow speed as here provided, immediately upon the engagement of the hook 35 with the draw chain, the carriage 30 begins its'travel away from the die head and the drawing of [the tube begins. Drawing tension through the chain, hook, carriage, jaws, tube, mandrel rod bulb, and mandrel rod raises the hook to its normal position, where crank 82 is latched by pawl85,

adapted to withdraw the mandrel rod and bulb upon completion of the drawingn operation.

The next limit switch `will be merely reset without effect upon the cycle of operations. The final limit switch will be reset to an in effective position without affecting :the cycleof operations, whereupon the electric and pneumatic control system will be then in condition for operation as described at the beginning ofthis drawing cycle. Y

' Before completing the description of the operation, it is to be `noted that vsuccessive drawing cycles differ in that the switch of relay |52 will be 'open' inv one ca'se andclosed inthe next; likewise solenoidv will bespring-held in one case and electro-magnetically-held.in the next; and likewise elements |4|, |46,- |48, |34, |33, I0, and will be factive in one case,vand correspondingy elements |42, |41, |49, |35, |31, l2, and-|3 respectively will be active in thev next, as far yas concerns the actual drawing operation'.

After passing these.limit switches, preferably located'wlthin a. distance from the die head corresponding to the minimum length oi.' tube to be handled, the carriage 30 will continue to be drawn out along tracks 3| on main frame I by draw chain 36 until tube 8 is drawn completely through die 4. When tube -8 makes its exitfrom die 4,

`there will be an immediate release of drawing tension throughout the draw bench; and the recoiling eiect of the tube 8 in connection with the stored energy in the spring 88 will immediately open the jaws 33 and 34 o! carriage, whereupon the tube 3 will'be released and allowed to fall onto any suitable unloading devices arranged therebeneath (not shown). At the same time the release of tension in the draw chain 3B will permit the chain to fall from engagement with the hook 35'and the carriage will come to rest. Also the pressure of air against the piston in the manipulating mechanisme. g., |34, will then be eiIective to move the mandrel rod and bulb out of registry with die 4 and to retract the same into and within its protective tubular shell I6.

The carriage is then in'position for a repetition of the cycle above described. Mandrel indexing in succeeding cycles will reset the manipulating mechanism selection switches |46 and |41, and it will be apparent to one skilled in the art that-the cycle of operations which may be employed with the lpresently disclosed draw benchl is adapted to a wide variation.

As may be understood from the foregoing de- `scription, the operation of the draw bench is sub.-

stantially' automatic. Certain special features may be particularly pointed out. To prevent accidental damage, both of the manipulating mechanisms |34 and |35 are normally retracted and only advance after the closing of two independent limit switches, and a mandrel rod bulb remains in the die only during the drawing operation. The work may be flood lubricated externally by a stream of oil from a suitable pipe supply, which may be arranged on the mandrel section of the draw bench, or, of course, the work may be iary devices with which this draw bench has been described are not essential to its useful operation, and that many other combinations and relations of the parts and associated devices may be employed without departing from the nature and scope of this invention as deilned in the appended claims.

What is claimed is:

1. In an apparatus for die drawing metal shapes including a die and movable drawing means for drawing a work-piece through said die, the combination comprising work-holding means adapted to support the work-piece as it is drawn through said die, means for moving said work-holding means bodily into and out of axial alignment with said die, and separate means actuated by the movement of said drawing means for initially advancing the work-piece into said die when in alignment therewith.

2. In an apparatus for die drawing metal shapes including a die and movable drawing means for drawing a work-piece through said die, the combination comprising work-holding means adapted to support the work-piece as it is drawn through saiddie, means actuated by the movement of said drawing means for moving said work-holding`means bodily into and out of axial alignment with said die, and separate means for initially advancing the Workpiece into said die when in alignment therewith.

3. In an apparatus -for die drawing metal shapes including a die and movable drawing means for drawing a work-piece through said die, the` combination comprising work-holding means adapted to support the work-piece as it is drawn through said die, means actuated by the movement of said drawing means for moving said work-holding means bodily into and out of axial alignment with said die, and separate means for initially advancingthe workpiece into said die when in alignment therewith, said work-advancing means being separately actuated by the movement of said drawing means.

4. In a metal working apparatus including a die and a movable draw head for pulling a metal shape through said die,v the combination comprlsing a plurality of work-holding members each adapted to support a metal shape adjacent said die, means for successively translating said Work- Vholding members bodily into a-nd out of axial alignment with said die, and separate means associated with each said work-holding member for initially advancing the supported shape to said die' when in alignment therewith.

5. In a metal working apparatus including a die and a movable draw head for pulling a metal shape through said die, lthe combination comprising a -plurality of work-holding members, means actuated by the movement of said draw head for positively moving each said work-holding member bodily into and out of axial ali-gnment with said die, and separate means associated with each said work-holding memb'er'for initially advancing a supported shape to said die when in alignment therewith.

6. In a metal working apparatus including a die and a movable draw head for pulling a metal shape through said die, the combination comprising a plurality of. work-holding members bodily rotatable around a common axis and means actuated by the movement of said draw head for positively indexing each said work-holding member into and out of axial alignment with said die.

7. In a metal working apparatus including a die and a movable draw head for pulling a metal shape through said die, the combination comprising a plurality of work-holding members, means actuated by the movement of said draw head for positively moving each said Work-holding member bodily into and out of axial alignment with said die, and separate means associated with each s'aid work-holding member and ing means bodily into and out of axial align- I ment with said die,separate means for advancresponsive to carriage movement.A

9. In an automatic draw bench, a die and a draw carriage, means for moving said carriage in the performance of a drawing operation, means for supporting material to be drawn adjacent said die, means for advancing and prometal shape through said die, the combination comprising a plurality of work-holding members, means for successively translating said "workholding members bodily into and out of axial,

alignment.. with said die, and separate means associated with each said work-holding member and actuated bythe movement of said draw head for initially advancing a supported shape to said die when in alignment therewith.

-. .11. In a metal working apparatus-including a die and a movable draw head -for pulling a metal shape throughsaid die, the combination comprisingv a plurality of work-holding members bodily rotatable around a common aids,.and

means for positively indexing each said workholding member by bodily rotating the same into and out of axial yalignment with said die throughout its work-supporting length. Y

12. In a metal working apparatus including a shape through said die, the combination comprising a plurality of work-holding members bodily rotatable about a common axis, means for positively indexing each said work-holding member into and out of axial alignment with said die,

and separate'means associated with eachl said work-holding member for initially advancing a supported shape to said die when in alignment therewith.

13. In a metal working apparatus including a -die and a movable draw head for pulling a metal shape through said die, the combination comprising a plurality of work-holding members bodily rotatable arond a common axis, means for positively indexing each said work-holding member into and out of axial alignment with said die, and separate means associated with each said work-holding member and actuated by the movement of said draw head for initially advancing a supported shape to said die when in alignment therewith. y

14. In a metal working apparatus including a die and a movable draw head for pulling a metal shape through said die, the combination comprising a plurality of work-holding members bodily rotatable around a common axis, means actuated by the movement of said draw head for Rositively indexing each said work-holding member into and out of axial alignment with said die, and separate means associated with each said workholding member and actuated by the movement die and a movable draw head for pulling a metal '4'5 of said draw head for initially advancing a supported shape to said die when in alignment therewith.

15. In a draw bench, a die, a draw device adapted to grip a work-piece projecting through said die and draw it through the die, a rotary carrier at the entry side of said die, means rotatably supporting said carrier with its axis par-.

allel to and laterally offset from the pass line of said die, a plurality of work supporting members incorporated in said carrier and diametrically arranged concentrically of the axis of rotation thereof,v for bodily movement in a circular path intersecting the pass line of said die. one of said supporting members being disposed in loading position to receive a work-piece and the other in axial alignment with said die to support the work-piece being drawn through said die, power means operatively connected to said carrier for rotating the same, to reverse the position of said supporting members, Y whereby the loaded supporting member is aligned with said die and the empty one is disposed in said loading position, and means for initially moving the work-piece in said die-aligned supporting member endwise into and through said die for gripping by said draw device.

16. In a* draw bench, a die, a draw device adapted to grip a tube projecting through said die and draw it through the die, a rotary carrier at the entry side of said die comprising a pair of' elongatev tubular members and a plurality of coaxial circular blocks spaced along said members, said members being diametrically arranged concentrically of the axis of rotation of said blocks, with one member in axial alignment with said die and the other member laterally oiset therefrom, means rotatably supporting said ,blocks at their peripheries, power means operatively connected to said carrier to rotate the same and reverse the position of said tubular members, manipulating devices coaxial with said members at the'ends thereof remote from said die, a rod connected to each vmanipulating device and extending through` the assoicate tubular member, and a mandrel secured to the forward end of each rod, a tube to be drawn being inserted endwise over said mandrel and supportingly received in the tubular member in-said offset position for delivery into axial alignment with the die upon actuation of said power means, the mandrel of the tubular member in alignment with the die being shifted forwardly by actuation of the associated manipulating device to push the tube thereon through the die for gripping by said draw device.

17. In a draw bench as deiined in claim 16,

wherein said tubular members are provided with a plurality of longitudinally spacedinternal 'guides for supporting the tube received therein 19. In a draw bench, a die, a rotary carrier including a plurality of work supporting members at the entry side of said die for presenting successive work-pieces to said die in longitudinal alignment therewith, a work-piece being loaded endwise into one of said supporting members at a point laterally offset from said die while another work-piece is being Withdrawn -from the other supporting member and drawn through said die, power means for rotating said carrier to bring the loaded supporting member into registry with said die, means operable. to advance a work-piece endwise into the die with its end projecting through the die, a draw head including means for gripping said projecting end, means for moving the draw head to draw the gripped work-piece through said die, and means actuated by movement of said draw head back toward said die for actuating said power means and said advancing means sequentiallyin the order named.

20. In a draw bench, a die, a rotary carrier at the entry side of said die and incorporating a pair of diametrically disposed work supporting members for alternate movement into longitu- 'dinal alignment with said die, means peripherally .supporting said carrier for rotative movement, power means operatively connected to said carrier to rotate the same and reverse the position of said supporting members, means associated with each of said supporting members for initially advancing a supported work-piece into .position 'projecting through said die when in alignment therewith, means actuated by rotation *of said carrier for preselecting said advancing means for alternate operation, a draw headv including means for gripping the projected workpiece, means for moving the draw head to draw the gripped work-piece through the die,means actuated by said draw head during return'movement thereof toward said die for actuating said power means to rotate said carrier and means subsequently actuated by said draw head during said return movement thereof. for actuating the preselected advancing means to advance the succeeding work-piece into position projecting throughl said die for subsequent drawing therethrough.

' RAYNAL W. ANDREWS., Ja. ARTHUR T. DEILY.

CERTIFICATE QF coRRETIoN.

.Pnt N o. 2,551,955. 'A octoberw, 1915.

' RAYNAL W. ANDREWS, JR.,'ET AL.

It is hereby certified that error appears inl the printed specification of the'above numbere patent requiring correction as fo-llws: Page 2, s'econd column, line 7l, for'. 'head 50" read 4 head' 5-; page 5,'second' column, line 11, for "tubublar" read -'tbular'; page 9, secoxxdoolumn, line h5, claim 16, for assoicat' read asociate; and that' the .said' Letters Patent -should be read with this correction therein that the same may' conform tothe record of, the case in .the Patent Office, I'

Sigled-andsealel this 7th day or D eqember, A. D'. 1915.

5 Henry Ven Arsdale, l (Seal) Actngcommissionerof Patents. b

. DlscL,-A|M.ER 2,331,953-f-Rayml W. Andrews, Jr., New Kensington, and Arthur 1'. Deug, Pimburgh, Pa.. METALwonII'NG APPARATUS. Patent dated Oct. 19, 1943. gisclgimer led Feb. 14, 1946, by the assignee, Aluminum `Company of manca.

\ Hereby gnters Athis.dilaimer to claims 44, 1 1, 12, and 15 of said'specicaton. l

[Ojm'alv Gazgug March 19, 1946.]

Images