Rotary Transfer Press

In the manufacture of components made from shee metal usually at least three or four distinct operations are re quired for completion. Typical examples are drawn and ironed c (D&I) and drawn and redrawn cans (DrD) .

The manufacturing equipment has been evolving over the years according to the demand, from simple solutions comprising individual presses with single tools and manual tran fer of components, through designs whereby the transfer was mec nized, to single stream transfer presses in which the progress components between tools is carried out by gripper mechanisms, and to large presses capable of accepting more than one stream

1 components', the so-called multi-stream transfer presses.

In the case of high volume production the multi stream transfer presses, beingthe obvious solutions,have been de¬ veloped and successfully applied in practice, producing compone at an economic level. Low demands may be satisfied by single stream transfer presses, but at a higher cost because the ratio of capital investment per component produced is higher. This i due to the complexity of the mechanisms involved, revealing the need for cheaper and yet equally reliable solutions.

In any type of pressworking machinery, when con sidering the events during the time of making of one component, one cycle, useful work is performed during only a small fractio of -the cycle. Large flywheels are normally employed to provide required energy. During the working part of the cycle the flyw slows, down, losing energy, and the lost energy is recovered duri the idle part of the cycle as the flywheel angular velocity is i

creased once more to its idling value. By design, the transfer presses not only require larger driving mechanisms, but also must have the mechanical structure capable of withstanding the sum of the process loads in each tool. Hence the structures of transfer presses tend to be heavy and expensive. However trans presses have a small number of moving parts. In an attempt -to decrease the size of the driving mechanisms, it has been propos to use a series of "C" type crank presses operating out of phas with the crankshafts in line, and coupled together and driven by one power unit. This has the advantage of almost constant torq throughout the cycle and hence requires a smaller ^■ power unit. ever, each press, being independent, requires a suitable press frame with an appropriate amount of metal for stiffness, which performs a useful function for a small fraction of the cycle on

Most transfer presses are of vertical type with the punch moving down and up with the bottom dead center design for tool engagement. In such cases the component transfer mech operates in the horizontal plane, the tool array being arranged along a straight line, and the gripper pockets handling the com ponents stop when reaching the tool position. Hence the transf mechanism must provide a suitably controlled motion of the grip pockets, usually along a D shape path, with acceptable accelera and deceleration. The mechanism must be stiff enough to ensure precision of transfer. stiffer mechanism is stronger and hea and generates higher inertia forces, and is also inevitably mor expensive to set up. In some low speed applications, where the presses move horizontally, walking beam transfer mechanisms hav been used, whereby the transfer pockets are attached to a strai beam which performs a parallel rotary motion. The component is

collected by the gripper pocket at finite velocity and is also deposited in a suitable seat in the following tool at finite velocity. In this case the transfer mechanism is extremely simple, since rotary motion only is involved. The inevitable impact between the component, transfer pocket and tool nest is compensated by attention to detail design and by operating at low speed.

According to a first aspect of the present invention there is provided a method of mechanically treating ^" m components at a plurality of work stations arranged on a circul path and each provided with a tool, comprising advancing the components sequentially in stepwise fashion, each -from one .station to at least another station along said circular path, and applying force to the components by means of the tool at the respective work stations, said tools being operated cons cutively and each being subjected to a periodical recipro¬ cating action perpendicular to the directions in which component enter and leave the associated work station.

According to a second aspect of the present invention there is provided a machine for mechanically treating components, comprising means defining a plurality of work stati arranged on a circular path, a transfer mechanism for advancing the components sequentially in stepwise fashion, each from one station to at least another station along said circular

path, a plurality of tools provided at the work stations respec tively, each tool having a working part which is constrained to move perpendicularly to the directions in which components enter leave ^' the associated work station, and means for operating each tool while a component is disposed at the associated work statio

_ _. _^ ^

The present invention may be used to provide a transfer press having a tool array arranged along a circular path, the tools being actuated progressively by a single heavy duty cam provided with a suitable "lift" along the working part. The cam profile should ensure 'the lowest possible contact stresse between the cam followers attached to reciprocating rams, each ram carrying a different die. The cam profile includes also a "dwell" portion, which maintains the followers and the rams with dies in a stationary position during the part of the cycle when transfer of components takes place. The cam is rotably mounted o a cylindrical press stern around which ram carriers are equally spaced. The press stern is in a form of a robust thick walled tube, capable of resisting bending.whenthe load is applied by the cam and resisted by a circular bolster attached to the top of the stern. While the press is in operation, the stern is loaded con¬ tinuously as tools are being engaged successively. Likewise the driving provisions do not require any flywheel, since at any one time only one tool is in fully engaged position.

According to a third aspect of the present in¬ vention there is provided a transfer mechanism, for transferring components sequentially in stepwise fashion from one station to a least one additional station, said stations each defining, a cente and said centers being arranged on a first circle in equiangularl spaced relation, the mechanism comprising a carrier member, a plur of pocket members carried by said carrier member, each pocket mem ber being adapted to receive a component for transporting it as t carrier member rotates and defining a center, the centers of the pocket members being on a second circle in equiangularly spaced r lation, and support means supporting the carrier member so that t

- 5 - center of the second circle is spaced from the center of the first circle and so that the carrier member is rotatable about the center of the first circle without rotating about the cen ^¬ ter of the second circle, whereby the center of each pocket member moves in a circle passing through two adjacent stations.

The invention may thus be used to provide a transfer mechanism capable of transferring the components succe sively one component at a time from tool to tool, and of collec a blank from outside of the press and feeding it into the first tool, and ejecting the finished component from the- last tool. transfer mechanism may perform a "pericycloidal" motion around .tools, being based on a curved "walking beam" principle, taking the shape of a complete ring embracing the tool array, having a number of transfer pockets corresponding to the number of tools in ^' the press, or an integral, multiple of that number, leaving a least one idle position between the- tools in which the componen waits for the duration of one cycle. The transfer ring provide with suitable gripper pockets performs a rotary-parallel motion in such a way, that the center of each pocket passes through th axes of two tools, collecting the component from the first tool depositing it in the following tool, while moving along a circul path. The transfer ring is driven by a crank, which is intergea with the driving cam, and is also supported by at least two furt "idler cranks' ^* to guarantee the parallel-rotary motion. The len of the driving .crank, which is equal to the radius of the circul path along which the transfer pockets move, depends on the timin of the transfer; if for example half a cycle is allowed for tran

r — O — i.e. 180°, the crank radius would be equal to half of the distance between the tool axes, the distance between tools being related to the transfer path radius by the sine of half of the feeding angle. The gripper pockets are provided with holding features, either magnetic or vacuum-based, to ensure total control and reliability.

The transfer mechanism based on a "pericycloid motion" has speed limitations, due to finite contact velocity between the transfer pockets and the components, it is suitabl for low output requirements and ^' is inexpensive.

According to a fourth aspect of the present invention there is provided a transfer mechanism, for transfer components sequentially in stepwise fashion from one station t at least one additional station, said stations each defining a center and said centers being arranged on a first circle in eq angularly spaced- relation, the mechanism comprising a first ge having its pitch circle equal in diameter to said first circle and having the center of said first circle on its central axis, and a turret assembly comprising first, second and third turre each defining a plurality of pockets for receiving components, each pocket defining a center and the centers of the pockets o the three turrets being on first, second and third turret circl respectively, each turret also being provided with a gear havin its pitch circle equal in diameter to the respective turret cir and having the centre of the turret circle on its central axis, the gears of the first and second turrets being in meshing enga ment with the gear of the third turret, and the mechanism furt comprising support means whereby the turret assembly is suppor

so that the gears of the first ^' - and second turrets _^ are in meshing engagement with said first gear and the turret, assembly is rotatable about the center of said first circie, accompanied by rotation of the turrets, the pockets of the first and second turrets registering successively with said stations and with the pockets of the third turret, whereby a component can be collected from said one station by said first turret, transferr to the second turret by way -of said third turret, and deposited in said additional station by said third- turret.

The invention may thus be extended in accordanc with the fourth aspect to- provide a transfer mechanism suitable for high output requirements, capable of transferring component successively, up to five components at a time from tool to tool between operations, as well as collecting blanks from the outsi of the press and feeding them into the first tool or tools, and ejecting the finished components, from the last tool or tools. Such a transfer mechanism performs an epicycloidal motion and comprises a set of three turrets, two of which cooperate with t tool array and the third connects them, being intergeared. The set of these three turrets orbits around the tool array. There a stationary gear the pitch circle of which coincides with the p circle of the tools. The two turrets which cooperate with the array are driven by gears directly meshing with the stationary g The turret driving gears' pitch circles are equal to the pitch c of the turrets. Consequently the component is placed in tools a zero velocity, likewise it is collected from the tools at zero c tact velocity, and yet the set of the three turrets performs a c stant velocity epicycloidal motion, free of any intermittently-

operating cams and linkage mechanisms . The epicycloidal handling system of components may be employed for transfer of components at four different stages of treatment, and may be used to serve one, two or three sets of tools in the same press, thus satisfying high output requirements. The set of the three turrets can gyrate around the tool array at a speed of up to 200 revolutions per minute, and would provide a corres ponding output depending whether one, two or three sets of tools have been provided in the press. This is most desirable in production of two-piece cans. For adequate component contro during the transfer, the pockets in the turrets may be provided with magnetic and vacuum features, mechanical means not however .being excluded. The three turret handling system allows a long part of the cycle for the operation of tools, hence the cam may have a milder slope and higher lift.

The present invention may also be used to provi a "package deal" system for economic low output two-piece can bodymaking by Dsl and by DrD processes, the system incorporatin the basic, vertical multi-ram, rotary cam, single action press, and the circular beam transfer system with the number of pocket related to the number of rams, performing rotary parallel motio synchronized with the ram actuating cam, and suitable tools to out required operations dictated by the given process, these to

(Patent No. 3,924,437) being of KME design/or any other design suitable for single act operation. The system may be fed with individual blanks or wit metal sheet material in strip and coil form, the material being plain, lacquer coated or plastic film laminated tinplate, alumi blackplate and nickelplated steel; or lacquer coated and plasti

film laminated chromium plated steel known generally ^" as TFS. The system is capable of: feeding the material stock precisely using the same driving provisions as for the transfer mechanis cutting out suitable blanks, and ejecting the residual skeleto from the tool area after chopping to manageable fragments.

The present invention may also be used to prov a new configuration in press design, suitable for vertical typ and general application for .manufacture of products requiring multi-stage press operations, in which the. crank actuation has been superceded by cams and cam derivatives, capable of success operation of rams ^' with dies, through suitable followers.

The press stern may be central to correspond to . "C" frame design, or there may be four external pillars, simila to those in "H" press frame. Similarly the transfer system may be of external type embracing the tool array, as described; or it ^" may be within the tool array.

For a better understanding of the invention, an to show how the same may.be carried into effect, reference will now be made, by way of example, to the accompanying drawings ^' in which

Figure 1 shows diagrammatically a typical known multi-die "H" frame press with a heavy flywheel;

Figure 2a shows diagrammatically a known "C" frame press;

Figure 2b shows application of the "C" frame press to multiple tools;

Figure 3 shows diagrammatically a known gripper transfer performing "D" motion;

Figure -\ shows the principle of the known walking beam transfer mechanism: . '

transfer mechanism;

Figure 5 shows άiagrammatically, partly in elevation and partly in section, a transfer press according to the invention;

Figure 6a is an enlarged sectional view taken on the line Via- ia of Figure 5;

Figure 6b is a sectional view taken on the Vlb- Vlb of Figure 6a;

Figure 6c shows in simplified form successive positions of the components shown in Figure 6a;

Figure 7a shows diagrammatically a side elevati of a second transfer press according to the invention;

Figure 7b is a sectional view taken on the line Vllb-VIIb of Figure 7a;

Figures 8-1 to 8-6 shows plan views, at six consecutive positions,ofafirst transf r mechanism according to the invention;.

Figures 9a and 9bshow the principle of inter¬ action of certain components of the first transfer mechanism;

Figure 10 illustrates diagrammatically the re¬ lationship between feed angle and_cam lift angle;

Figure 11 shows a plan view of a modified trans mechanism according to the invention;

Figure 12 is a side elevation and Figure 13 is plan view of a mechanism for feeding strip material to the trans press;

Figure 14 is a diagrammatic side elevation of a mechanism for feeding coil material to the transfer press;

Figure- 15 shows .graphically the cam profile and the second derivative of the cam profile;

Figure 16 shows the cam lift relative to the tools at various cycle angles;

Figure 17 is a diagrammatic plan view of a- se transfer mechanism according to the invention;

Figure 18 is a 'side view, partly in elevation and partly in section, of a press equipped with the second tra fer mechanism;

Figures 19a-19i show in simplified form -nine successive operating positions of the second transfer system; .

Figures 20a-20i show in simplified form nine successive positions over one half of the cycle of the second t system operating with a press having two sets of four tools;

Figure 21 is a line diagram of component paths between operations in a press according to the invention fitted with two sets of four tools and the second transfer mechanism;

Figure 22 is a line diagram showing relative positions of components between operations in the system of Fig 21; and

Figure 23 shows the paths of components betwee operations in the second transfer system when applied to a pres having three sets of four tools-

Referring to Figure 1 which shows a scheme of typical multi-die "H" frame press, there is a stiff vertical pr structure 101 supported on _^ a press bed 102, and carrying press 103, all being clamped together by tie rods - (not shown), so str tures 101, 102, 103 are under compressive pre-load. Press crow is equipped with bearings which support crankshaft 104 provided two crankthrows 105 which actuate the crossh.ead 106 through con

rods 107 and gudgeon pins 108. The crosshead 106 is guided precisely by linear bearings 109. The crankshaft 104 is rotated by flywheel 110 which is driven by motor 111 through pulley 112 and vee-belts 113. Tools Tl, T2, T3 and T4 are attached to press bed 102 and- to. the crosshead 106. By rotating the crankshaft 104 crosshead 106 moves down and up and tools close and open in syn¬ chronism performing the allotted tasks. Since the tools move in synchronism, the tonnage which must be applied to the crosshead is equal to the sum of individual loads of the tools. The energy necessary is supplied by the flywheel 110, which slows when the tools close and regains its speed when the tools .separate. Such presses may operate more tools, being loaded then proportionally higher.

Figure 2a represents the "C" type press, of which the frame structure 201 is characterized by width. "W" opposite the throat between ram 202 and bolster 206 which accept tools 205. The ram 202 is actuated by crankshaft 203 through cσnrod 204. Ram 202 imposes a force "F" on tools 205 which in¬ duces a reaction R in bolster 206. Depending on the press load -rating, normally expressed in "tonnes", width "W" of the press frame is established to keep the bending stresses within safe limits and to maintain the deflection at acceptable low values. This means, that a volume of metal has to be contained in the fra for satisfactory performance. For the manufacture of products which require more operations, a separate press for each tool is required. Figure 2b shows diagrammatically the case of four pres the crankshafts of which may be arranged at advantageous phase an so that only one crankshaft at a time is turning through the work angle "α" ⁽ during which the punch penetrates the die ₎ .

At position 207 with ram 202 at BDC work has been com¬ pleted. .At the same time the second press crank apposition 208 is opening". The third press crank is fully open at positio 209, with the ram at TDC, while the forth unit with the crank ^¬ shaft at 210 position is closing. If the four crankshafts are coupled, then at any one time only one tool is operating, re¬ quiring only- ^' a medium size or small flywheel compared with that shown in Figure 1.

Figure 3 illustrates a gripper transfer mechan in which the transfer pockets move along a "D" shape path. Suc an arrangement is most suitable for transfer presses similar to that in Figure 1. Referring to Figure 3, blanks are stacked at position 300. Single units are delivered to tool 301 where (as shown in this case for clarity) it is drawn into a cup and promp moved into- tool 302 for first redraw operation, then to tool 303 for second redraw and 304 for- trimming operation to be then ejec into position 305 ready to. leave the-machine. The transfer arra ment operates in such a way, that the components at each stage o production move simultaneously from tool to tool, being embraced by half-pockets attached to gripper bars 306 supported at points 307 and 308, which move along "D" shape paths 309 and 310. Grip bars 306 carry half pockets 311, 312, 313, 314 and 315.

Figure 4 shows the principle of the so-called "Walking Beam" transfer mechanism. In this case cylindrical obj U00 roll down into a waiting position Ijoi which is in the form o semicircular nest. There are four treatment positions defined b semi-circular nests 402, 403, 404 and 405 in which objects IjOO r by means of gravity. There are five semi-circular transfer pock

__ - - ^{•" " " "} - 14- - 407, 408, 409, 410 and 411. T-he centers of these pockets move along circular paths passing through centers of the nests -.01, .02 403, 404 and 405. The transfer pockets are.attached to gripper bar 412 which is suspended in points 413 and 414. The two point 413 and 414 are guided along circular paths 417 and 418 traced by crankpins 415 and 416. Here the transfer pockets 407 to 411 meet the objects .00 at finite velocity and deposit them in εucc pockets also at finite velocity. During the travel from positio to position the force due ^' to gravity holds the objects in the tr fer ^' pockets. The last transfer pocket ^' 411 deposits objects -SCO the position 406, from which it is allowed to roll down. This type of transfer system is simple as it employs rotary and const velocity motion. Because of finite contact velocity the speed potential is limited. If applied in the horizontal plane, so th gravity could not be used to hold the objects in the transfer po kets, the objects may be held in the pockets by means of magnets or suction, and if the transferred objects have a low mass, then operating speed could be increased.

Figure 5 s ^" hows schematically the press accordin to the invention assuming a similar "tonnage" capacity to that o the press illustrated in Figure 2. In this case the press stern has diameter "D" which bears direct relationship with width W. 10 is surrounded by a number of ram assemblies 11 carrying dies cooperating with punches 12 attached to bolster 14 which is of c lar shape. Bolster 14 is clamped to press stern 10 by several t bolts 15, which maintain the press stern in a state of pre-loadi compression. Tie bolts 15 are anchored to the base of stern 10

split-collars 16 e bracing the ^' bolts 15 at suitably provided recesses and trapped in the fitting counterbores in stern 10. Nuts 18 mounted on the tie bolts secure a clamping plate 17 to base of the -stern 10. A.thrust bearing 19 is clamped between th plate 17 and a flange 21' of a cylindrical cam 21, and a thrus bearing 20 is clamped between the flange 21' and a shoulder 10' of the stern. Bearings 19 and 20 are located inside the cylin cal body of cam 21 which has a stroke "S" the value of which i closely related to the application and to the type of tools to operated. Cam 21 cooperates with the ram assemblies 11 throug follower rollers 22 and 23. Follower roller 22 has a substan diameter and width to suit the specified tonnage. Follower 23 smaller diameter maintains contact between cam 21 and follower Both followers are mounted in a fork 24 attached to cylindrical ram 25 which reciprocates in housing 26 provided with linear bearings 27 and 28. Housing 26 is formed with slots 29 and 30 to guide fork 24 particularly when side thrust is induced when follower 22 climbs cam 21. Housing 26 is rigidly clamped to pr stern 10 by bolts not shown. Ram assembly 11 represents theref a self contained unit actuated by cam 21. At ^' three positions a round press stern 10 and between ram housings 26, three legs 31 are attached by bolts and dowels not shown. Legs 31 support th press, stern and the ram assemblies, and also the. base casting 9 which retains lubricating oil and provides a guard for the cam mechanism and the drive gear at- the base of stern 10. Cam 21 i driven by internal gear 32, which meshes with gear 33 mounted o crankpin 34 attached at the end of long crankshaft 36. Four fo rolls comprising pins 35 rigidly mounted to retaining plate 17 a provided with respective rotatable sleeves

circular holes in gear 33 to -provide a necessary constraint for gear 33 to drive internal gear 32. Crankshaft 36 is driven on the --top of the press by a highspeed motor not shown. The re¬ quired reduction from say 1500 rpm to 60 rpm is ^" obtained by this set-up in one step. ^' _

Drive is also taken from gear 32 to which a sprocket 37 is attached and provides motion through chain- 38 to sprocket 39 at one to one ratio: Sprocket 39 is mounted at the end of long shaft 40, which carries at the top end a crank 41

» driving a circular "walking beam", described with reference to Figure 8. It can be seen .that the press shown in Figure 5 is mos compact, the rams being built around the press stern. --- --_ ^• Figure 6a shows a diagrammatic plan view and ^" Figure 6b a cress-section of the high reduction gear drive suit¬ able for the transfer press, according to the invention. Teeth and pitch liners and center liners are shown. There are two gea only, internal gear 32 attached to the rotating cam and gear 33 mounted on crank pin 34 attached to crankshaft 36. The speed re duction ratio i is given by the .formula: i = 32 ' ^t 32~ ^t 33 - Hence if gear 32 has -100 teeth and gear 33 has 96 teeth, then i = 25, which would reduce 1500 rpm to 60 rpm in one stage.

For clarity Figure 6a shows fewer teeth. Gear 33 has a central hole in which crank pin 34 turns; it also has fo holes 49 of diameter equal ^* to the sum of the diameter of the cra pin 34 pitch and the diameter of the stationary pin 35. The pins 35 prevent rotation of gear 33 about its own center, thus forcin it to perform a parallel rotary motion about the center of gear 3

In each revolution of gear 33 about the center of gear 32, the la

SADORIGINAL

is shifted angularly by the difference of teeth between gears

32 and 33. Since the mass of gear 33 gyrates on ^' a radius r, equal to the distance between the centers of the gears 32 and 33, it induces a centrifugal force, and balance weights 46 and 47 are provided to minimize the cyclic force on the crankshaft beari

48.

Figure 6c illustrates the progressive positions of the high reduction gear system. For clarity gear 32 is shown with 26 teeth and gear 33 with 22 teeth. The starting position of crankpin 34 is considered as 12 o'clock, the angle α between the radius to the crank pin center anda line extending vertically in Figure 6b is zero at that position. It should be noted that at ^' that position stationary pins 35 are at the bottom of circular ^• holes 49- Subsequent positions of crank pin 34 are equivalent to 3/22, 9/22, 12/22, 18/22. and 21/22 of 360° rotation of the crankshaft. It can be seen that gear 33 does not rotate, since the axes passing through circular- holes 49 remain vertical and horizontal. Angle of rotation 8 of gear 32 has been indicated at the progressive position showing clearly four teeth difference af 360°, i.e. 4/26 x 360°. ^"

Figures 7a and 7b show a modification of the Figure 5 press in which the central press stern is replaced by fou external pillars, thus providing a similarity with an "H" frame pr An extended bolster plate 50 on top is connected to the base plate

51 by four pillars 52. Hence the pre'ss loads are not taken by the tie bolts in the center stern, but by similar tie bolts placed in four pillars. The drive mechanism for the ram assemblies 11 is pl in box 53.

Figure 8 illustrates the principle of the circular walking beam transfer mechanism. For clarity, a six station unit is shown, with five tool positions designated Tl to TS ^' and an idle position designated 0. In Figure 8-1 the driving crank 41 is .in 12 o'clock position indicating zero cycle angle. The mechanism comprises a transfer ring 43 provided with three mounting pins 42. Two of the pins 42 are connected to idling arms 44 which are mounted on bearing posts 45 attached to the. press legs -31 (Figure 5) . The third pin 42- is connected to the driving crank 41. . Thus, as the shaft 40 rotates the ring 43 gyrates about the center of the press stern 10, the two idling arms 44 always maintaining a parallel relationship to the drivin crank 41. There are six ^" pockets, numbered PltoP6, attached to transfer ring 43. Figure 8-1 shows the. ring at a cycle angle (the angle between the crank 41 and a line bisecting the angle between the radii from the crankshaft 36 to the positions 0 and 5) of 0° with pocket 1 collecting a blank from the supply convey At the same time pocket 2 makes contact with the component in tool 1; ^" pocket 3 is in a midway position between tool 2 and tool 3; pocket 4 has just delivered a component into tool 4; tool 5 is in closing position (the cam peak is approaching tool 5) ; poc lcet 5 has left tool 5 and is on the way to tool 4; and pocket 6 has just delivered a component into the exit chute.

Figure 8-2* shows the transfer mechanism at a cy angle of 60°, the driving crank 41 having moved through 60° in c clockwise direction and the peak of cam 21 marked CP having likewise moved thr

60° in counterclockwise direction. Pocket 1 has reached the pos tion 0; pocket 2 is in midway position between tools 1 and 2;

BΛDORIGINAL J

3 has just delivered a component into tool 3; tools A and 5 are being operated (tool 4 is closing while tool 5 is opening) ; pockets 4 and 5 are on the return path to tools 3 and 4; and pocket 6 is approaching tool 5.

It will be seen from Figures 8-3 to 8-6, . illustrating the mechanism at cycle angles of 120°, 180°, 240° and 300°, that the same pattern of movement takes place. At a cycle angle of 300° (Figure 8-6) one completed component is delivered into the exit conveyor by pocket 6. The feed angle, i.e. the angle through which the crank 41 moves in order to tran fer a component from one tool to the next following tool, is one third of the total cycle angle and is thus equal to 120°, and to accommodate physically this feed angle, the cam dwell angle i 180°.

Figure 9a shows the principle of interaction be ween the transfer pockets of the ring 43 and locating rings at- ^• tached to the tools ^' . Although it is known in the art to provide "nests" for locating components in the tools, in the transfer press according to the invention, additional features have been included to ensure complete control of the components during transfer and particularly at the instants of delivery and locati in the tools. For clarity Figure 9a shows tools T2 and T3 dia¬ grammatically as circles. These tools are being served by trans the pocket P2 being fer pockets P2, P3 and P4,/shown in greater detail in Figure 9b.

Each tool is embraced by a locating ring 701. At one side each locating ring is provided with a locating surface 702, whic a segment of a cylindrical surface suitable to match the externa surface of the component. The locating surface is extended by t

prongs 703, 704 and 705, which ^" protrude upwards ^' . ^' Prong 703 is positioned centrally in relation to the locating surface 702, while prongs 704 and 705 are located on the ends of the lo¬ cating surface. Prongs 703, 704 and 705 are of a suitable widt and have gaps therebetween. The length of the prongs is at least 3/4 of the height of the component to be transferred. Transfer pocket. P2 is . in the form of a plateof suit able thickness to ensure adequate stiffness, and .is . pro¬ vided with a nesting surface 706, which fits the surface of the component to be transferred, being in a form of a segment of cy¬ linder extending through 120°. 'The nesting surface 706 is ex¬ tended downwards by means of three prongs 707, 708 and 709. Positioned centrally is prong 707, with prongs 708 and 709 at the ends of the nesting surface and spaced from the prong 707. The. length of prongs 707, 708 and 709 is similar to that of the prongs 703, 704 and 705. The gaps between prongs 707,.708 and 709 are wide enough to miss the die locating ring prongs 703, 704 and 705 while collecting the component from one tool and de¬ positing it in the next tool.

The design of transfer pockets will vary depend on the proportions of the component. The general rule is, that the pocket must suit the conditions of the tool into which the component is'to be deposited, since it is extremely important wh the tool is closing on the "component, that precise concentricity is maintained. After the forming operation, the component's dia meter may be smaller and the cylindrical wall will not be contac the nesting surface; it will however be concentric with the tool urged by a spring 713 having been pushed out of the die by a pad 710/and kept in con

I _m

- _r with the pad 710 by a magnet or a vacuum device 711. In this case the nesting surface of the transfer pocket will fit the com¬ ponent, and the prongs of the transfer pocket will be suitably located to miss the prongs of the locating ring. The transfer pocket is provided with a magnetic device to retain the com¬ ponent in the pocket.

The minimum cam dwell angle Δ is related . to the feed angle θ and the number N of tools by the following equation:

Δ = θ + 360 N

Figure 10 and the following Table clarify the relationship between the cam dwell angle, the feed angle and the number of tools. It has been assumed that the effective _. feed angle may vary between 90° and 180°, although at 180° feed angle, the dwell angle must be large, leaving little space for the cam lift. The particular example on Figure 10 shows 120° feed angle, which leaves 180° for the lift of the cam, identical to that in the case of Figure 8.

Table

Effective

Feed angle No. of Tools Cam dwell angle Cam lift a

90° 6 150° 210°

12 120° 240°

120° 6 180° 180°

12 150° -- 210°

150° 6 210° 150°

12 -■ 180° 180°

180° . 6 240° - 120°

12 210° 150

The diameter. dP of the transfer path is given by: dP = DT sin 180/N sin where DT is the diameter of the tool pitch circle, N is the number of -stations and of transfer pockets and θ -is the feeding angle.

The diameter DP of the transfer pocket pitch circle (and of the circle concentric with the tool pitch circle an upon which the centers of the" transfer paths are positioned) is gi

Figure 11 illustrates diagrammatically a twe pocket transfer mechanism, which is the most likely and preferred solution for the rotary transfer mechanism according to the invent It offers flexibility in application and minimum impact between th workpiece and handling elements. Above all it allows a sizeable c stern 10 of the press, the stern 10 being maintained in a state of compression by at least six tie bolts 15, which contribute to stif ness of the structure. Center stern 10 is embraced by transfer ri 43 supported on pivots 42. It carries twelve pockets, each of sui size to fit the exact dimensions of the component after being oper upon by the tool from which it is collected by the pocket.

There are a number of possibilities with this set-up. For higher outputs one could employ two sets of tools. I such a case the material blanks would be delivered into first and seventh station, and components would be extracted from fifth and eleventh tool, leaving stations 6 and 12 idle.

Alernatively, by employing six tools only, a idle station could be provided between each pair of successive tool

be- chieved by providing at each idle station a component . handlingnest whichis removable, and an exit chute comprising two guides (as shown in Figures 8-6) . ^' The transfer pocket feedin a particular idle station deposits a partly manufactured componen in the removable component handling nest and the nest is removed from the idle station by way of the exit chute. The component can then be inspected and the nest containing the component re¬ placed at the idle station. The nest must be replaced within one period of the cycle of operation of the press, since otherwise the nest would not be available to receive the next component and the next component would accordingly, be returned to the pre¬ ceding station and crashed between the prongs of the nest at that station. Inspection would- take place at regular intervals. Thus, it would be possible to inspect not only finished components but also ^' partly manufactured components, and this is important when it is desired to meet particularly high quality standards. Further possibilities are contemplated. For example, the material might. be supplied in short strip form or in continuous coil form, in which case the first pocket of. the rotary transfer collects a cup or blank from a cupping/blanking tool, which does not require a component locating nest and which would be placed in the idle stat 0 of Figure 8, or at each of the idle stations 6 and 12 of the Figure 11 arrangement employing two sets of tools . As finished components are ejected from the last tool, they would have to pass over the punch of the cupping tool. This is possible precisely be cause the latter tool is not provided with a nest.

The number of transfer pockets is primarily dictated by the capacity of the press, which requires suitable di¬ mensions for the center stern 10. In particular, when the press i

included the ram capacity at the early operations could be up to 12 tonnes. At one time for short, periods, one has to assume for safety in design, that- up to 3 tools could be developing the working loads, and the center stern must therefore be of .sufficient diameter and provided with a suitable number of tie bolts 15, to resist safely 36 tonnes. -Another important parameter, which in¬ fluences the size of the press is the pitch .between the tools, de¬ pending mainly on the size of the tools dictated by the component made♦

Figures 12 and 13 show diagrammatically the application of the strip-feeding to the press -according to the inve The purpose is to feed strip '50' to the cupping tool 51' located at t idle station 0 of Figure 8. Thi is achieved in a manner well know in the art by feed bar 5 ' and. auxiliary feed bar 53 ¹ . to which the strip 50' is supplied from the stack of strips (not shown) by mechan (not shown) _ Feed bars 52' and 53' are reciprocated by connecting ro 54 and 55 driven by a double eccentric 56, attached to crank 57 at end of ^" drive shaft 58. The double eccentric 56 is adjustable along crank 57 to ensure that the feed bars can be actuated at different strokes. It will be seen, that the auxiliary feed bar has a longer stroke. Crankshaft 58 has a driving sprocket 59 which is wrapped b chain 38 (Figure 13) taking the movement from driving sprocket 37, which also drives sprockets 39 and crankshaft 40 (Figure 5).

Handling of the strip is effected by means o pneumatic devices (not shown) , but the steering mechanism for contr operation ^' of the pneumatic devices has been illustrated on Figures

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12 and 13. The steering mechanism may take drive from any cyclic shaft for example shaft 40 to which driving sprocket 60 is attached actuating chain 61 wrapped also around sprocket 62. The ratio of teeth in sprockets 62 and 61 represents the number n of blanks in strip 50. Thus, while each revolution of the sprocket' 59, and hence of the sprocket 60, is associate with advancing the strip by one blank, n revolutions of the ^• sprockets 59 and 60 are required in order to rotate the sprocke 62 through one ^' revolution. Sprocket 62 drives steering shaft 63 to w.hich a "number of steering cams are keyed, each cam operating suitable pneumatic valves. ^' The pneumatic valves provide instruc tions for pneumatic cylinders . (not shown) which operate the stri handling mechanisms, before the strip reaches the auxiliary feed bar: position.

Hence cam 64 operates valve 65 controlling the movement of the vacuum sucker mechanism. Cam 66 operates valve 67 controlling the movement of the translator mechanism, .which shifts the strip 50 sideways into the path of auxiliary feed bar 53. Cam 68 operates valve 69 controlling the scrap ejecting rol Cam 70 operates valve 71, which controls the vacuum admission in the suckers. The arrangement shown in Figures 12 and 13 and des cribed above is one of many which could be employed as a strip feeder to the press according to the invention.

Figure 14 shows diagrammatically a coil feed mechanism. Narrow strip 80 is mounted on expanding mandrel 81. Pinch rolls 82 pull strip 80 and thus rotate the mandrel 81. Th rotation of ^' pinch rolls 82 is controlled by "dancer" roll 83, wh is provided with a switch (not shown) to switch "on" and "off" t

motor (not shown) driving pinch rolls 82. Another set of pinch rolls 84 driven intermittently'from the press through a suitable stop and move mechanism such as a Maltese cross mechanism (not shown) feeds strip 80 into the cupping tool 85 which is identical to cupping tool 51* in Figure 13. Strip 80 is guided by stripper plate 86. As shown in Figure 14, when the punch 87 is in its lowe dwell position, it leaves space between its top face and the stripper plate 86, for the rotary transfer pocket ejecting the finished component from the press through the idle station 0, as e plained previously.

Figure 15 shows diagrammatically the profile of the actuating cam 21. As discussed previously and illustrated in Figure 10, the value of the cam lift angle depends on the trans feed angle and the number of stations. The most likely and pre¬ ferred value of the cam lift angle will be between 180° and 240°. The lift of the cam depends on the height of the container and the

-type of the tools employed. It may be equal to three times the finished before trimming, height of the/container/ The cam shape or profile has a constrain in the form of the maximumincline angle at the nodal point N, whe normally acceleration changes to deceleration: at that point dy/d must not be greater than tangent 30° for smooth operation. This constraint dictates also the size condition for the cam 21, the di meter of which may have to be increased in order to decrease the slope of the cam at the nodal point N. In addition the cam lift angle must also be kept to maximum possible value. If the acceler tion curve is similar ^" to that shown in Figure 15, the slope of the cam at point N will be kept to minimum.

The design and features of cam 21 are an important point of the press according to the invention. It allows the ar¬ rangement of the tool array along a circular path, and successive

actuation of the tools. It leaves a suitable fraction of the cycle time available for feeding by the rotary transfer arrange ^¬ ment, which performs at constant velocity and does not require intricate intermittently operated mechanisms.

In order to explain clearly the relationship between the cam and tool positions as progressively shown in Figure 8,- reference will now be made to Figure 16, from which it can be seen that at zero cycle angle the cam peak CP is between idle posi¬ tion zero and tool position 5. At 60° cycle angle CP ^' is between to positions 4 and 5, and at subsequent cycle angles 120°, 180°, 240° and 300°, CP is between positions 3 and 4, 2 and 3, 1 and 2, 0 and respectively. Only a certain part of the cam rise near CP perform the "working" lift, the remainder serving an assembly function, i.e closing the tool, component and die together without deforming the component. Figure 16 illustrates clearly, that with the tools spac apart angularly by 60° (i.e. with five tool positions and one idle position), one tool at a time will perform useful work. This is de sirable for two principal reasons. First, it is essential that the component be centered accurately on the die, so that the punch may enter it. In the case of Figure 1, there is at any one time more than one tool developing a working load, and this results in deflecti of the structure 101 which may interfere with precise entry of the punc into the component. Figure 16 shows that during assembly of the component onto the punch, the press is not loaded and accordingly t relationship between the punch and die is not affected by other tool Second, if more than one tool performs useful work at a time, as in case of Figure 1, there may be an interaction between the tools resultin from the deflection which has to be compensated for, e.g. by setting some tools eccentrically to compensate for lateral deflection. In addition, power requirements are minimized. The number

be increased and the working lift of the cam rise would still operate on only one tool at a time, which is beneficial for the reasons explained, and also with regard to the press frame load magnitude. The dwell and lift angles shown in Figure 16 are equal and reference may be made to Figure 10 for further details.

For high speed applications, for example manufacture of two-piece cans by DrD method, an epicycloidal handl system', as illustrated in Figures 17 and 18, is suitable. In this case there are four tools Tl, T2, T3, T4 positioned along a circle which.coincides with the pitch circle of a stationary gear 501 whi is mounted on the bolster 14 (Figure 18) by means of tie bolts 535

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A carrier ring CR is mounted by _. means of a bearing 536 to rotate about the axis of the crankshaft 36. A reduction gear comprising elements 532, 533, 534 and 535 (corresponding to th elements 32, 33, 34 and 35 of Figure 6b) transmits drive from the motor M to the carrier ring CR, and thus causes the ring C to rotate about the center stern 10 at the same _. speed as the c 21.

The carrier .ring CR carries three turret hous H, of which only two can be seen in Figure 18. Each turret ho H is.hollow and has a shaft 539 extending axially therethrough, mounted in bearings 537,538. Three turrets 505, 506 and 507 a mounted on the lower ends of the shafts respectively, and thre gears 502, 503 and 504 are keyed to the shafts respectively at upper ends. The- gears 502 and 503 mesh with the gear 501 whil the gear 504 meshes with the gears 502. and 503, as shown in Fig IT. The angular; relationship between gear centers 502 and 50 also 503 and 504 is 25.87°. While gear- 501 is stationary, the gear set 502, 503 and 504 and the three turrets 505, 506 a.nd 50 gyrate counterclockwise and the turrets themselves rotate about their own axes, driven by the respective gears. The mass of th turrets is balanced by a balance member BL on the opposite side the carrier ring CR from the turrets.

Each turret has. four ^' pockets 1, 2, 3 and 4, w match exactly, the diameters of components at the four stages of manufacture. The turrets are arranged so that a given pocket o the entry turret 506 deposits a component into the tool of corr ponding diameter. Thus, a component enters the tool Tl from th pocket 1 of turret 506 with diameter 1 and after reduction to d meter 2 it is collected by pocket 2 of extract turret 505 and t

fer turret 507 to pocket 2 of _^ entry turret 506, which deposits it into tool T2. After reduction-to diameter 3 in tool. T2, the component is collected from tool T2 by pocket 3 of extract tur¬ ret 505 and deposited by pocket 3 of entry turret 506 in tool T After reduction to diameter 4 in ^" tool T3, the component is col¬ lected from tool T3 by pocket 4 of extract turret 505 and depos by pocket 4 of entry turret in tool T4'. Finally, after trimmin without diameter reduction, in tool T4, the component is collec by pocket 1 of extract turret 505 (which pocket is the same siz pocket 4 of turret 505) and is discharged from pocket 1 of trans turret 507.

One blank at a time is separated from stack of blanks 508 and transported along a circular blank transfer path by rotary pocket 51.0 provided with a suitable nest to fit diamet 1 and also another nest underneath to fit diameter 4. Rotary pocket 510 deposits blank 1 in transfer turret 507 at point 511, and also extracts a component of diameter 4 from ^" transfer turre 507 and places it on the exit conveyor 512. From point 511 the blank 1 travels to tool Tl along path 513. From tool Tl to T2 t components of diameter 2 travels along path 514. From T2 to T3 the component of diameter 3 moves along path 515. From T3 to T4 the component of diameter 4 moves along path 516. From T4 to po 511 the compone ^' ntof diameter 4 travels along the first half of pa 513. It should be noted, that the components are handled betwee the pitch circle of gear 501 and limit circle 517 by extract tur 505 and by entry turret 506. Outside-limit circle 517 component are handled by transfer turret 507. In this particular arrangem the ratio of the pitch diameter of gear 501 to the pitch diamete

of gears 502, 503 and 504 is 3:1.

Figure 19 illustrates the progressive posi of the epicycloidal handling systems and components in relation t tools at characteristic intervals. Figure 19a shows the starting position with blank 1 collected by transfer turret 507 and compon of diameter 4 ejected from turret 507. In Figure 19b, pocket 2 o extract turret 505 makes contact with component of diameter 2 in Tl. Between Figures 19b and 19c blank 1 is transferred into entr turret 506 approaching tool Tl, while component of diameter 2 is away from tool Tl in extract turret 505. In Figure 19c blank 1 is placed in Tl, whereas component of diameter 2 is moved into transf turret 507. Between Figures 19c and 19d it would be noted that th center line of transfer turret 507 has moved through 90° and compo of diameter 2 has assumed the extreme position in turret 507, corr ponding to the position of blank 1 in Figure 19a. It follows that in Figures 19d and 19e extraction ^" of component of diameter- 3 from by extract turret 505 takes place followed by deposition of a fres component of diameter 2 in tool T2 by turret 506. Between Figures and 19f extract turret, has moved through 180° and has component of diameter 3 in the extreme position. In Figures 19f and 19g the .pr of extracting component ^' of diameter 4 from tool T3 and depositing fresh component of diameter 3 in tool T3 takes place. Between Fig 19g and 19h the extract turret 507 has -moved through 270° and comp of diameter 4 is in the extreme position. Figures 19h to 19i illu unloading of tool T4 by pocket 1 of extract turret 505 removing co ponent of diameter , followed by loading of a fresh component of meter 4 from the pocket 4 of entry turret 506. ^' It will be appreci that the turrets 505 and 506 handle the components into and out of tools without any impact. Hence, the epicycloidal- handling system

a pocket in any of the three turrets has been designated to handle the component during a certain phase of manufacture, it always does so. -

Figure 20 illustrates progressive positions of a single epicycloidal handling system for two sets of four tools. There is a similarity to the case illustrated in Figure 19 , in as mu as there are three intergeared handling turrets, but the relative angle α between them is 35°. Also the ratio of pitch diameters of t to turrets is 2:1. The extract turret 505 and the entry turret 506 handle the components between pitch circle of gear 501 and limit cir 517, while the transfer turret 507 handles components outside the li circle 517. By examining the nine positions shown at Figures

20a to 20i over half a cycle, it can be seen that these positions ar repeated in the second half of the cycle. At position 20a blanks are placed into the system and finished components are extracted as shown clearly in Figure 21. Hence there are two blank supplies and two finished components extracts, which follows of course from there being two sets of tools available. Hence for on revolution of the press and handling system, two components are completed. It should noted that both in Figure 19 and in Figure 20 the cam dwell is equal to 2α, hence 52° and 70° respectively.

Figure 21 illustrates the paths of components between operations for the epicycloidal handling system with two set of tools and two blank feeding arrangements. It is evident that the blank after entering the handling system travels over 1.5 revolution hence the finished component leaves through the opposite entry/exit station from that at which the original blank entered.

Figure 22 illustrates the relative positions

seen that at the instant when an entry turret deposits a component into a tool, .there are five components in the "handling system.

Figure 23 shows how a single epicycloid handling system may be applied to three sets of four tools. With three in-feeds of blanks, it is in effect a tripling of the syste shown in Figure 17. Since the preferred solution of the ^' rotary cam press according to the invention would incorporate 12 working rams, use of three in-feeds is particularly advantageous.

The tool of each of said work stations ma either be a conventional drawing or ironing .tool, a ^' combination of both, or a multiple tool comprising several coaxially arranged ironing rings. It is to be understood that any other known type of tool suitable for metal working, such as stamping, trimming, flanging, beading etc. may also be- used within the protecting scop of the present invention.

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