US2570589A - Transfer mechanism - Google Patents

Description

Oct. 9, 1951 H. F. PHILLIPS TRANSFER MECHANISM 8 Sheets-Sheet l Filed March 20, 1947 Oct. 9, 1951 HfF. PHILLIPS 2,570,589

TRANSFER MEcHANrsM Filed March 20, 1947 8 Sheets-Sheet 2 INVEN TOR. #f1/PRY f Pff/UPS -----IITV |||||.\H a l lllTml Oct. 9, 1951 H. F. PHILLIPS 2,570,589v

TRANSFER MECHANISM Filed Maron 2o,- 1947 a sheets-sheet s Ti Z.

/9 7' TUF/VE Y 181 'Sheets-Sheet 4 H. F. PHILLYIPS TRANSFER MECHANISM Oct. 9, 1951 Filed March 20, 1947 Oct. 9, 1951 H. F. PHILLIPS TRANSFER MECHANISM 8 Sheets-Sheet 5 Filed March 2O, 194'? Oct 9, 1951 H F. PHILLIPS 2,570,589

TRANSFER MECHANISM Filed March 20, 1 947 8 Sheets-Sheet 6 INVENToR. ,fm/PPV f P/f/L/P BY @w71 Oct. 9, 1951 H. F. PHILLIPS TRANSFER MECHANISM Filed March 20, 1947 8 Sheets-Sheet 7 INVENToR. HAPPY PH/L/Ps O Ct 9, 1951 H. F. PHILLIPS 2,570,589

, TRANSFER MECHANISM Filed March 20, 1947 8 Sheets-Sheet 8 Byvzm v INVENTOR. JCI-l- #4f/PPV F Pff/MP5 Patented Oct. 9, 1951 TRANSFER MECHANISM Harry F. Phillips, Springfield,"Ma'ss., assigner to Bausch Machine Tool Company, Springfield, Mass., a corporation of Massachusetts Y Application March 20, 1947, Serial No. '736,034

My'present invention relates to almechanism whereby work pieces to'be machined may be transferred in ordered sequence through one or more stations relative to machines and may be accurately positioned at each station.

In the mechanism of my invention Work pieces are successively placed in starting position by an operator and are then transferred from one position or station to the next without further intervention by the operator except to start or stop the mechanism or the machines associated with it. Any number of mechanisms and their associated machines may be arranged in sequence and the work pieces are then transferred automatically from one mechanism to a succeeding one.

Each transfer mechanism is under the control of the machine associated with it so that a Working station it is'located accurately by locating devices, such as hydraulically actuated pins, Which move into accurately positioned openings or holes in the Work piece when it is in correct position. When the Work piece is located in a station by the locating pins it is clamped securely work piece is not moved to the working station Y until the machine, such as a drilling machine, is ready to start the machining operation at that station and is not moved to the next succeeding station until the machine has completed its operation and is ready to receive a succeeding piece. When transfer mechanisms are arranged in sequence, the starting or loading station of one mechanism must be vacant before the preceding mechanism is set in operation to deliver a work piece.

It will be apparent, therefore, that no work piece can be moved into a station until the machine is ready yto receive it and until the machining operation on a preceding work piece has been completed. The successive mechanisms are thereby timed to the slowest machine although each mechanism may itself vbe otherwise independent.

Inasmuch as each transfer mechanism is a complete and separate entity, any number of mechanisms may be combined with a corresponding number of machinesto accomplish any desired number of machining operations and may be readily changed about or adapted to changes in the order or types of machines and machining boring machine, planer or Shaper or profiler, orga4 machine for turning the work piece to a different position for a succeeding operation, or it' may be apparatus for inspecting the work accomplished in preceding machines.

in position by hydraulically actuated bushing or clamping'plates which hold it throughout the machining operation.

The transfer element may carry a transfer pin, or similar mechanism, Which is depressed when the clamping or bushing plate is depressed and which may, therefore, move underneath the path of the Work piece when the transfer bar moves reversely and to engage a work piece and move it from one station to the next when the clamping plate or element is released.

These various mechanisms are preferably controlled by valves so arranged that each element may move only in its proper sequence and timing. Thus, the valves are so arranged that the clamping plate is lowered into clamping position only when the locating pins or elements have movedl to locating position. The transfer element moves y reaches its rearmost or starting position it then operates a control valve to cause the clampingl plate and the transfer pin to rise and the locating pin to be retracted, whereupon the transfer bar Ymoves forwardly carrying with it the work piece f 'clamping plate to clamp the work piece in its trol switches at the loading stations of the mechlocated position.

These hydraulically operated valve mechanisms insure that each of these movements Will take place in its proper sequence and only when the 'preceding operation has been successfully and fully completed, I

These hydraulic mechanisms are in turn elec-v trically controlled jointly by the machine associated'with the transfer mechanism and by conanism and the one next succeeding. This control circuit releases the hydraulic mechanism to advance a work piece when the machine has completed its' operation and Withdrawn, when the loading station is loaded and that of the next succeeding machine is empty. It also comprises a starting switch for the machine actuated by the clamping of the clamping mechanism and a switch actuated by the withdrawal of the locating pins to permit forward movement of the transfer element. l

The various features of the invention are illustrated, by way of example, in the accompanying drawings in which- Fig. 1 is a side View of a transfer mechanism embodying a preferred form of the invention, parts being broken away to more clearly show the construction; I

Fig. 2 is a plan view, and Fig. 3 is an end view of the mechanism shown in Fig. l; n i

Fig. 4 is a transverse sectionona largerscale on line 6 4 of Fig. 2, showing the transmission mechanism for the transfer bar and pin;

jFig. v is a horizontal section takenon line 5 -5 offFigjB, showing transmission 'ele'rlientsl for "the clamping plate, 'tfansjfeibr andlatifigps Fig. 7 isa verticalsect'ion'takn'fromftne right ofwFig. 5' ofu a hydraiilic cfylinder and a lpa'tfofa transfer forthe transferbar; A

Fig. 8'is aodetail ofY the 'transferbr and trans'- m'isiciis..

Fig.v '9 `a Aside nview \of` a Voer'tziin valve control mechanism; y d n n Fig. lqis a diagrammatic 'outli'f' fof tliehydraulic controluvalves and connections;

Fig. Y 12 Vis a'wiringdiagram showingtlie' controls for the hydraulic valve control system shown in Fig. 10.

Referring toA the Yenb dment 'the vinvention Shcwii iii ihccccciiipeiiyiis die iiigs. c wcik piace iiiicccciic. the stcriiriaiicsiticcc icfiiccicc ci .1..5-Fic- 1, @gemir .ci Scpccriiiicrcilc..iciid Il ities.- .lcnd ii. which. csiciid .tricv i.cil .iccg'ih ci the. ,machine-...T csc rails crccccpcricc. cnc ircirici4 Wiiiciii i in is ciciiiitccciigcccbiiii [9l Figslfandgjw ich may contain allor partY The Work 'piece ,ic mcvciiircm the.. iiqsiiicii shcirn ai. I5 .Successi/cls'-tty ,sicticiic indicated@ @and 2i, twostiicns @eine shcwiiby ci cianplc, and tiicnccic c .Startins Sicticc Qc c Succeeding machin? .2.3` br .means cf c Suitable transfer` mcchcnism .which mcrcsc. Slisics. .the Work piece on the rails I6 and l1 fromv one station icihcncxt- ...The vwcrk pieces. crc guided against ,Sidcwicc displacement in moving over thesupportingwrails I6 and 1 by means of guide rails 24 and 2 5 mounted above the rails I6 and 1 1 by' r n`eans of scitcblelcrcckccc and. 2.1. .'ilicisiiidc icilcmcy bvelged@ ih? Qntlalends! dfatqt 28.1ar1d 29, in cider icrcccivc cwcrk piece cvn thcugh it may ,bc ciiicwhac Gignac@ It will be understood that thegiiide 'railsugd ccc-.c2c ,iiccd' cci iccA ,ccctiiicccs ihic shccc -ih'c length cf che machin@ bctiiicrlccciadc. iii'cc.- tions and also secured 4otherwise than by the brackets 26 and 2'l.

Transfer 'bar'undfp'in 32 extending from the supporting rails I6 and l1. These anges support the transfer bar 30 and enable it to slide longitudinally between the rails i6 and Il' for a limited distance equal to the distance between the respective stations I5 and 2l and 26 and 2|. In the advance position of the transfer bar it extends from its rear end, shown at 3 3 in Fig. 2, to* the opposite endfofthe supporting rails I6 and l1. When in reverse position vthe end 33 would be at the front or starting end 'of the rails I6 and l1.

Thetra'n'sfer bar is driven alternately in forward and reverse directions by means of a hy- Yd1"afilic'ally operated piston 34 in a cylinder 35 attachedtothesiderof the frame i8, Figs. 2, 3 and li. Y The piston is provided with a stem 36 extending ifin'tda yVc'a'sing 31 having an adjusting screwjt at its end to adjust the limit of movement of the piston and stem.

rfhepiston stem S6 is provided with rack teeth 3,9'y which fmesh withjpinion 4teeth `l46 --on a cross shaft l, Figs. 13 and 4;*extedng 'into the fra-nie le and tematica-therein :ma bearing'fefz. fiche Y sh'jftll may alsobejjcurnalled in ah'alf bearing i3 in the casingS. As the piston *36 andis'ter'n3'6 reciprocate they vgive Aalternately reversed V'rotations to 'thei'shaftL i Arme opposite endof mechant-i s-securdija pirfionil which "meshes with iarra'ckfi 'secured to "the 'undersnrface of lthe 'transferbar S'so 'that the reciprocating movements 'of the pistons-34 are 'transferred throug'hthegshaft fil-I to recipr`o`' eating vlon'gitiidinal Amovements wof lthe transfer bar an.

1t willbe "understood, as indicated vby the different diameters of the pinions 46 A"andtl,jtl'iat the movement of I'th'epistcin''may be shorter than that of the transfer 'barl or 'may beincany relative proportion tlii't. Thlllh tldalt'elate'- ciprocations ofthe pston'in the cylinder 35, the transfer '-bar V`is moved forward `to thepdsitin shown l2, or`r`versely,' to a'startingfpo'si'- tion at the starting or'frontend nof' the 'machine Y @hev transfer bar isbelow'the level'ofth'e n'lr surfaces of the railslBland"lfandftherefore, t of contact with thejwork piecesfthereon. 'Ic engage and carry forwardthe workpieces'with each forward movement-ofthetransfer bar vertioal'slidable transfercpins `46, 41 and 48 are provided, there-being one for each 4of the stations I5, 2i! and'Zl. -The transferpins 46 andyll'lare spaced va distanceegual to the distance between thestations l'and 2Q or20 and2|. AThe transi feripin dais; providedf'at its-upper -end with-abifurcated horizontal extension 49, the frontend of whichis'distant =from'the vpini-i8 byI a` distance equal t'o the distancelbetweenvthe separate "stations, f this 'distanceY being sufficient f to i cause this extension to project"over-"the=` 'endof the machine andfto'v the starting position' "of thefnextv machine.

Vifh'e extension piece 4:9 being f'bfurcated provides iai slot "to receive ffa'v transfer Vpin-'56 4'of j-the succeeding machine 2,3 so that the worki'pie'ce may i bel picked! 'upf-byf tl'iefltra'nsfermechanism of the succeeding machine.

downwardly acting clamping mechanisms Wh-ich.

Clamping mechanism The clamping mechanism of the stations 20 and 2| respectively comprises vertically movingv clamping plates y5| and 52, the construction and operating mechanisms of which are substantially identical.

`Referring more particularly to the clamping mechanism of station 28, the clamping plate 5| is supported by a pair of vertically movable rods or shafts 53 and 54 at diagonally opposite positions of the plate 5I which slide in suitable guiding grooves in a supporting frame 55.Y The up- Ward movement for unclamping the plate 5| and the downward movement for clamping it are imparted to the lower ends of the supporting and operating rods 53 and 54 by means of a reversely driven shaft 56 extending transversely of the machine below and secured to the frame I8, as shown in Fig. 6, and provided with gear teeth 51 and 58 at its opposite ends that mesh with rack teeth 59 and 60 on the lower ends of the shafts 53 and 54.

The lower ends of the vertical movable rods 53 and 54 extend through or into housings 6I and 62 which are secured to the lower surface of the frame I8 and also carry the ends of the shaft 56 and the gear teeth thereon. Through the crossshaft 56, therefore, both of the rods 53 and 54 are moved simultaneously and for the same dista'nce with each rocking of the shaft 56.

A rocking movement is imparted to the shaft 56 by means of a hydraulically operated piston 63 in a cylinder 64 to the piston stem of which is attached a rack 65 meshing with suitable gear teeth 66 in the mid part of the shaft 56. In this way the vertical movement of the hydraulic piston 63 is imparted equally to the lifting rods 53 and 54 and uniformly to the clamping plate 5| or 52 respectively, it being understood that each clamping mechanism has its own individual operating piston and transmission mechanism.

Also secured to the clamping plate 5| is a pair ofvertical slide rods 61 and 68, Figs. 1 vand 2,V which extend downwardly into the frame I8 to the position shown in Figs. 1, 3 and 4. These rods 61 and 68 being secured to the plate 5I move upwardly and downwardly with it, being guided by suitable guides 68 in the framework 55.

The rods 61 and 68 extend below the rails I6 and I1, as shown in Fig, 1, and have clamped Vat their lower ends brackets 18 and 1I which serve to raise and lower the transfer pins 46, 41 and 48 through a suitable transmission mechanism.

As shown more particularly in Figs.3 andv 4 the brackets 18, 1| carry a vertically movable grooved guiding bar 12 which extends below the transfer bar 38 a distance at least equal to the distance between the two stations.

.At the lower end of the transfer pin 48 is mounted a roller 13, Figs. 3 and 4, which extends into the groove 14 of the bar .12 so that as the bar 12 is raised and lowered by the bracket 1 10, rod 6I and clamping plate 5I, the transfer pin 46 will be raised andl loweredaccordingly, at the same time the transfer pin 46 may move with the transfer bar vSII, longitudinally of the lifting guide 12, the roller 13 moving 1ongitudi` nally in the groove 14. In this way the pin 46 is caused to move upwardly when theclamping..

plate is raised and downwardly when the clamping plate is lowered in clamping position.

The upward and downward movementof theY pin 46 is transferred simultaneously to the pins Y 5 f; 41 and 48 by means of a shaft 15, Figs. 2, 3 and 4,' carried in the transfer bar 38 and extending longitudinally thereof and having gear teeth that mesh with rack teeth 16 on each of the respective transfer pins so that all rise and lower simultaneously and equally.

It will be apparent, therefore, that the clamping plates control the transfer pins, that the transfer pins are lowered and may be moved reversely to starting position when the clamping 15. plates are down holding the respective work pieces, and that the transfer pins rise to engage their respective work pieces and move them' forwardly only when the clamping plates or bushing plates are lifted or unclamped.

# Locating mechanism When a work piece is moved into the station 28 or 2| it is accurately located in positionbe- 1 fore being clamped so that it may be in exact position for the machining operation at that station. For this purpose the work piece isprovided with locating openings, preferably two, which are engaged by locating pins 11 and 18, one for each station, and positioned to move upwardly and' 3o .lit closely into the locating openings of the work piece when the latter has been brought into the respective station by the transfer bar and pins.y Preferably the upper ends of the locating pins 11 and 18 are rounded or pointed so that they will nd the locating openings of the work pieceA if the latter is slightly displaced from the proper position and will thereby move it into the exact position it is to occupy for machining.

The locating pins are raised and lowered through a suitable transmission mechanism by means of a hydraulically operated piston 19 in a cylinder 80 mounted on the lower face of the frame I8 as indicated in Fig. 7. The piston 19 is provided with a stem 8| having rack teeth that mesh with suitable gear teeth on a shaft' 82 extending longitudinally of the machine below the respective stations 20 and 2|.

The shaft 82 is provided with gear teeth 83- and 84 respectively that mesh with corresponding rack teeth in the locating pins 11 of the respective stations 28 and 2|, causing the pins 11 to lower when the piston 19 is raised and, reversely, to raise the locating pins when the piston 19 is lowered, the piston rod 8| being on the opposite side of the shaft from the locating pins 11.

The rocking movement of the shaft 82 is transferred to a second shaft 85 parallel to the shaft 82 by4 means of a transverse rack bar 86, Figs. 5

and 1l, sliding in a housing 81 on the undersurface of the frame I8 and having rack teethA that mesh with gear teeth 88 and 89 respec-v tively on the shafts 82 and 85.

Through the rack bar 86 the movements o the shaft 82 are transferred to the shaft 85.

These movements are in turn transferred from the shaft 85 to the locating pins 18 by suitable gear teeth that mesh with rack teeth inthe pins 18 so that the pins 18 of both of the stations move simultaneously with the pins 11. In theY g event that the pins 11 and 18 cannot rise into the locating openings in the work piece, either due to displacement of the work piece or other causes, the'pressure on the upper vside of the piston 19 will be insufficient and the piston will 75,*notbe able Yto drop and lower the piston rod 8Il.'J

. Hydraulic 'control :mechanism The'transfer elements, the clamping elements and the locating mechanisms'are loperated'in relative sequence by an V'interlocking hydraulic system. A

vThe system so controls Vthe admission offluid to the cylinders 35, 84 and 80 'that veachofl the elements operates in its appropriate relation to theo'thers. Thus, before the transferpin can move to starting position 'the clamping Aplates mustbe lowered, and 'with them the'transfer pins, so that each work piece'in any jworking station is held securely while the transfer'pin is free to-move reversely. The parts remain 'in these positions Vuntil vthe 'transfer bar has completed its rearward movement, thereupon theA locating pins are withdrawn and in timed 'relation thereto the clamping plates are lifted orunclamped raising the transfer pins.

When these operations have been completed iluid vis admitted to the cylinderr35 in such a manner as to cause the transfer barand transfer pins to advance moving each work piece to the .next `succeeding station. 'The locating pins thereupon rise to locate the work pieces accurately.

'If' for any reason 'the locating pins fail to rise, the clamping plates cannot be lowered and no further operation can take place. If the pins do rise, properlyA locating the work piece, the clamping` plates lower also lowering the transfer pins and remain lowered until the machining operation is completed, thereupon the cycle of operation is repeated.

"The fluid under pressure for operating the hydraulic mechanisms andv for operating the various fluid control elements is drawn from a supply tank, indicated at', by means of a pump 9| driven by a motor 92 and supplied to a supply main 93. The pressure in the supply main 93 is limited byineans of a relief valve 94 which opens upon generation of pressureabove a predetermined limit to admit fluid from the main 93 through a return circuit 95leading back to the supply tank 90.

The main 83 leads to a distributing valve SB controlled alternatively by a pair of electro-magnets 91, 98. The electro-magnet or solenoid 91 is energized by an electrical system when the station 22 of the next succeeding machine is .empty and the station at I is lled, when the bush-ing plates are clamped, when the locater pins are raised and whenth'e rear limit Vswitch of the machine tool mechanism is in its back or withdrawn` position.

When the solenoid 91 is energized the valve 9S opens communication from .pipe 93 through a branch pipe 99 to a distributing pipe |08, Aall of these pipes being of relatively large ksize as, .for example, in diameter, through which .fluid is supplied through timing valves to the cylinders 35, 64Iand 8G.

Fluid. is also suppliedthrough asmaller control line *IUI to a pair of kcontrol valves |82 and `I|3 which are alternately opened and closed by mechanism connected to the clamping plates 5| and 52, the valve |82 being open when the Aclamping plate is down and closed whenthe clamping' plate is up, and the valve |83, reversely, beingclosed when the clampingplates are down landf'open when they are up. Y

As shown in Figs. l, 5 and `9, the rod51 of.rthe. clamping :plate is `extended. throug'hfthe :base of "the, frame' I8 zand into the .cabinet-CIS being...

guided in,.a1suitable .guide boX IM,l secured to the underfaceof the baseroftheframe I8. VTherod 81Jis positioned vaboverthe valve |82 and has an extension :.I051to x .contact withthe stem of .the yvalve |82,

ftocontactwiththestem of the valve |83.

Throughthe abovemeehanism the valves|02 and |83 are controlled and operated in opposite directions from the clamping plate 5|. Whenthe clamping. plate-is!dow-nv the valve |92 ismoved .in

such a "-directiontasfto permitthe passage of .pressure fluidV from the1line|| .to a control line V|139 leading .to the lower end of a valve il and acting toopen lthis Valve. Y

The-.solenoid91 .being activated the pressure fluid flows-from thezpipe 9.9 into .a-pipe I -leading to the valve |10 and through `'this valve throug'hline I |2 and forwardly through a check valve I |3 and line H8 to the left hand side of the cylinder-35, the cylinder `is thereby forced 4right and, reVerSely, Ycarries the .transfer bar 35 to star-ting I position.

The movements Yof the transfer bar 38 -are transmitted to the hydraulic control system-by means of a suitable mechanism which comprises :a bevel gear'I |5,1Figs. 1 and Y4, xed on andv ro-Y tating with the shaft *C12-and meshing with a bevel gear IIS xed ona vertical` shaft I|1 which eX- tends below the base of the frame I8, as shown in Figs. 1 and -5. The rotation in either direction of the shaft ||1 is `transmitted vby means of bevel gears IIS and IIB to a horizontal shaft |28 and lthence through bevel'gears |2|, |22, to a shaft On the front end of the shaft |23 is a pinion |24, Fig. 7., .which meshes with a gear '|25 on a' shaft |28 which also carries va control disc |21. Mounted on the disc `|21.are a pair of adjustable cams |28 Vand |29 which, as the disc |21 rotates throughout somewhat lessthan a full revolution, contact alternatively, and open, .hydraulic valves |38 and |3| respectively,"Fig. 9.

The mechanism is so arranged that when .the transfer bar moves in reverse directionto the startingY position the valve |30 will be opened and valve |3i closed at the end of vthe stroke, and when it moves forwardly to theend Aof its forward stroke valve I.3| will be opened and Valve |30 closed.

When the valve I3v8is open pressure fluid flows from the line|| through a branch lead line |32 throughrthe valve |35 ,and thence to line |33' through a control valve |34, opening this valve. Fluid then `flows from the line Iii through fa branch line |35 and'through the open valve |34 and line |36 to the lower ends of clamping cylinders 54 'raising thesecylinders and unclamping thek clamps and alsoflifting the transfer bar pins. The lifting of therbushingwclamps Vserves `te reverse the' valves "|82 Iand |83, through the mechanism described above, opening va'lve'i'i and closing .valve 182. Fluid thereupon flows from 'the line IBI througha loranchline |31 and thence through the `open valve |03 to line |38 into the' bottom. of a control valve |39 vand opening this valve. :the `valve. is opened `fluid flows Vfrom the branch II35"through the valve and througha branch lineV VHill "to the :lower end of the locater' pin of cylinder' 80,1-for'cing upwardly the-piston f rod 8|.;andlowering thelocating pins`l11'and'1'8.

At this stage the Work piece is unclamped, the locating pins are withdrawn and the transfer pins are raised in position to engage their respective workpieces.`

When the locating pins are lowered a limit switch is tripped energizing the solenoid 99 and thus reversing the valve 96, pressure fluid Y'then ows through a pipe |4| and line |42 to the right hand side of the cylinder 35 forcing it to the left to advance the transfer bar and at the same time forcing the uid from the left hand side of the cylinder 35 reversely through the line ||4.V The check valve ||3 vprevents the passage of the fluid directly to the line 2 and forces it through a branch line |43 and a speed controlling valve |44 to the valve and thence through the control valve 96 t0 an exhaust pipeY |45 leading Ytothe tank 90.

When the transfer bar 30 has completed its forward movement the cam |29 will have reached the stem of the valve |3| depressing it and opening the valve. The valve. |3| `now being opened and valve |30 being Closed pressure fluid flows from the line or pipe |00 through a branch line |46 and thence through the valve 3| and delivery line |41 to the lower end of a control valve |48, opening this valve. Fluid then ilows from the line |00 through the valve |48 and through a line |49 to the upper end of the cylinder 80 thereby depressing this cylinder and lifting the locating pins 21 when the piston rod 8| is lowered to raise the lowering pin 11.

Corresponding rotational'movement is transmitted to a cross-shaft |50 which has gear teeth meshing with rack teeth on the piston rod. From thence the rotation of the shaft |50 is transmitted through a similar rack and pinion arrangement at the end of the shaft to a vertical rack bar immediately above a control valve |52 thereby lowering this valve and opening it.

As the valve |52 opens control pressure fluid is admitted from the line |49 through a branch line |53 and through the valve leading to a line |54 to a control valve |55, opening the latter; thereupon fluid flows from the line |49 through valve |55 and a pressure control valve |56 -to a line |51 leading to the upper ends of the clamping piston 64 and thereby depressing this piston and lowering the vclamps to clamping position. The transfer pins are also lowered at the same time.

It will be evident from this control, therefore, that the clamping plates cannot lower to clamping position until the locating pins are in fully raised position. If there is any obstruction that would prevent the locating pins from rising and accurately locating the work pieces in position, the clamping plates cannot lower to clamping position.

As the bushing plate clamps the valve |02 is opened and valve |03 is closed tripping a limit switch which controls the movement of the machining mechanism, such as a drilling orboring machine or whatever machine is at the par.- ticular station. o

The parts remain in this position until the machining operation is completed and the machining mechanism returns to its starting position. As the machining mechanism returns to its starting or back position it trips a limit switch which will again de-energize solenoid 98 and energize solenoid 91. When the loading station 22 of the next machine is empty and a new work piece is placed in the station I5 the vGyle 0f operation is repeated. I

Electric control The electric control for the solenoids 91 and 98 is shown diagrammatically in simplified form in Fig. 12 the positions of control switches being indicated dagrammatically in Fig. 1.

In this diagram-electric energy is supplied to a line |58 through a suitable start and stop switch mechanism and transmitted to the solenoid 91 by a branch circuit which comprises in series an electric switch |59 closed when a part is in the starting station 5; a switch |60 which is open when the starting station 22 of the next machine is filled and closed when it is empty; switches |6| and |62 which are closed when the clamping plates are lowered; a switch |63 which is open when the locating pins are down and closed when they are up. Electric energy is, therefore, only supplied to energize the solenoid 91 and permit reverse movement of the transfer bar, when station 22 is empty, station I5 is filled, locating pins are up and clamping plates are down in clamped position. The opposite side of the solenoid 91 is connected through a line |65 to a return mainV Electric energy is supplied to the solenoid 98 from the main |58, a switch |64 which is closed when the machining mechanism associated with the particular transfer mechanism is in withdrawn or back position and through a switch |61 which is closed when the mechanism of the succeeding machine is in withdrawn position, the opposite side of the solenoid 99 being connected through a branch |68 to the line |65 and return main |66.

It will be obvious, therefore, that this soleno1d cannot be energized to advance a work piece until the next machine is in position to receive a work piece. Any suitable start and stop mechanism may be employed to control the supply of electric energy from a main |69 to the line |58.

As illustrated in Fig. 12 this may comprise a master stop switch |10 in a branch circuit I 1| having a shunt circuit |12 containing a starting switch |13. The circuit |1| comprises an electromagnet |14 which closes a switch |15 from the shunt circuit |12 to the line |58 wheneverand while current passes through the line I1 When -both switches |10 and |13 are closed current flows through therbranch line |12 energizing an electro-magnet |16 to'close a relay switch |11 in a shunt circuit |10. This circuit leads through a control solenoid |19 which when energized closes a switch in the branch 1| As current ows through the two solenoids |15'and |19 the switch |11 is closed and then the switch |80 closes. When switch |80 is closed current flows continuously and at all times through the solenoid |19 maintaining a continuous closed circuit s o long as the master stop switch |10 remains closed. When this circuit has once been established it remains whether the starting switch |13 is closed or open. However, once the master stop switch |10 is opened the circuit is not re-established upon releasing it but the starting switch |13 must again be closed. It will be understood, however, that this is merely one way of establishing a starting and stopping control circuit and that other alternative systems may be employed. v

It may be noted also that the switches I5 and |62 may lbe double switches tocontrol the starting of the machining mechanism upon the completing of the clamping operation.

In the above mechanism it will be observed that the transfer mechanism once started will continue in operation as long as v work, pieces are supplied to the'startingfposition or station I5,

'and that if this position should not besupplied the machine will stop, but be .in readiness Ytostart immediately upon placinga-fworl: piece in the starting station.'

Notransfer will take place until the receiving position 22 of the next'machine isi-empty and readyto receive a workpiece. Inthe event .that anygmachine should stopas, for-example, by the breaking -of a drill or toolor for any otherreason l.

and should; thereforeinotreturn .to its starting position, the transfer mechanisms of an entire 'setor train will stop 'until this YdefectI is corrected andr the respective machine returns to its original position.

It will be notednalsoV that no machining operation. canA start. until` thesclamping plates. are lowered to clamp` th'e vwork pieceiin position and thatthis clampingv operation cannot take place until the .locating pins have been .lifted to Ylocate beingv necessary that the delivery-end off eachl mechanism as, for example, that from the station 2| ltothe station 22ifshould befsuch Ethat a work piece will slide fromithef rails of the .transfer mechanism to the rails of the next andthat it comegwithin the widened'ends--of theguide -rails 24rand 250i a succeeding machine.

As fthe-f mechanism'.A of each :transfer 'machine operates independently of the mechanism of a Asucceedingmachine vany difficulties,y due to the failure of any particular mach-ine, may be traced to that machine.

As the wiring and hydraulic systems areA relativelyv simple for eachimaohine anyfdiiicultyin anymachine may beieasily identiedi or traced and corrected.4

Thefact that'- each transfer-machine is self maintained enables itto be-readily adjustedf to changes iinv the assembly' line; For example; the positions of av drilling machine; or"boringma chine, or. other vtype ofmachineztooll maybe interchanged; additional transfer machines may be added when it is desired to' accomplish 'additional machining operations, or they may-be subtracted from an assembly 'line when fewer operations-are to take place. Y

The-clamping. platesor bushings arefgenerally made with an open top so 'that 'id-rilling or'boring operations may take place. vertically asl well as horizontally.

Rswnil A cycle of operationof'a mechanism or a' train of mechanisms is as follows:

At the beginning-'of the operation the various machines will be-running'as, for example, in a drilling machinethe drills will be rotating and inV their withdrawn' or starting position, the clamping plates 5| and 52 will bein lowered position and through thefpush' rod |05 will open the valvev |02, Figs.v l and l0.' The transfer pins 40 will also be1 loweredf by the elements 6| and 16 connected' to the clamping plates, Figs. 3 and 4, so that they may slide horizontally below the level of the supporting rails I 6 and l The locating pins 11 and` |B will also bein locating position and through theA transmission "12 elements |50 and |5I,' Figs. 5'and 10, willA depress and'iopen the hydraulic valve |52." The transfer bar-or element 30 will be in its forward position and through the transmission elements |5,|2'| will depress and open the valve |3|.

If the load station 22 of the succeeding machine 231s empty Athe switch |60, Fig. 12, will be closed. The switches|6| and|62 are closed by therlowering of the clamping plates, and the switch |63 Ais closed by the locating pins in raised position,

and the switch |64 is closed by the machine 'elements, such as drills, etc., being in their withdrawn` or rearmost position.

If awork piece is now placed in the load station at |5zthe switch|59 isclosedand aVV circuit completed through thesolenoid 91, whereupon fiuidipressure is admitted from the pipes 93' and 99 through the valve 96 to the supply pipe III, Fig. l0,.and'thence to thevalve V| ill.`

The'valve |92' being opened uid also flows through the'line |0|, valve |02 and line |09`to the. lower p-art of Vvalve H0, .opening this valve. Fluidjthen `flows through the line |2, check valve ||3 and line ||4 tothe left-hand. side of the cylinder: 35 causing the .transferelement30 to moveto 'the ileft.

As Athe transfer bar moves 4to the left it rotates the transmission mechanisms IIE-|21 to close valve |3| and open valve |30. Fluid thereupon ows from the pipe through the'line' |32 to the open valve |30 and thence through the line |33 to the lower part of valve |34, opening this valve, thereupon fluid ows through the pipe through the branch pipe |35', valve |34 and pipe V|36 to the lower parts of clamping` cylinders 64,

pushing upwardly the piston 63, Figs. 5 and 6, and through the transmission elements 60-66 raising the clamping plateY rodsV 53 and 54 'and also raising the transfer pins to extend'above the supporting rails I6 and As the bushing plate rises .the valve |02 is released and closed and the valve |03 vis depressed andopened; thereupon pressure fluid flows from the pipe' |91 through the branch pipe |31 yand thenceV through the open valve |03 andv branch line |38 to the lower part of valve |39, opening this valve. Fluid then ows from-the pipe |35 through the opened valve |39 and branch pipe |40to the locating pin cylinder', causing the locating pins and 18 to be lowered through the transmission mechanisms 8 I-BB. As the locating pins are lowered the-'movement of the'piston is transmitted through the' transmission elements |50 and |5I, Figs. 5 and 10, to depressand close the valve |52. At the same time the switch |61, Fig. 12,is closed by the lowering of the locating pin and the solenoid energized.

Inasmuch as the switches |6| and |62 hav been opened by the lifting lof the clamping plates, solenoid9`| will be de-energiZed-.the Vposition of the-valve V96-vvill, therefore, be. lreversed Aclosing the supply of iuid to ,the pipe and opening it.. to the pipe. |03. Pressure fluid, therefore,

flows through the valve to the pipe |00 tothe right hand 'side of the transfer barof cylinder 35. forcing this bar to the right andthe transfer pin in forward direction. The movement is retarded by the closinggof the check valve ||3 shunting the return iluid through thespeed control valve |44. The transfer element, therefore, moves forwardly'and as'the transfer pins l.are raised each work piece is; advanced from one station to the next.

As the transfer bar moves-forwardly the valve |30 is closed and at the end of the movement lthe valve |3| is opened Athusv returning` these valves to their initial position. Pressure fluid thereupon ows from the pipe through the branch line |46 and the opened valve |3| to the lower part of the control valve |48, raising and opening this valve. Pressure fluid thereupon flows from the pipe |00 through the Valve |48 to the upper end of cylinder 80 causing the locating pin to rise and depressing and opening valve |52.

Upon the opening of the valve |52 pressure uid flowing through valve |48 and branch line |49 is admitted through and to the valve |52 and line |54 to the lower end of valve |55, opening this valve. Valve |48 still being open, pressure fluid flows through the valve |55 and through a pressure regulating Valve |56 and pipe |51 to the upper part of cylinder 64, depressing the piston 63 and the clamping plates and clamping the pieces in position.

It will be apparent that pressure can only be admitted to the clamping plates as long as the valve |48 is opened, and accordingly, only while the locating pins are in raised position.

As the clamps are depressed they release and close valve |03 and depress and open valve |02 through the transmission mechanism above described.

The lowering of the clamping plates also serves to close the starting switch of the machines, such as drilling machines, or boring machines, etc., so that these machines advance to perform a machining operation. As these machines complete their operation and return to starting position the cycle repeats.

Having described the invention, what I claim is:

1. Transfer mechanism for moving a work piece in successive steps from a loading station to a work station of a machine and from said work station to a receiving station which comprises a reciprocating transfer means having means to engage a work piece at the loading station and a work piece at the work station, means to actuate said transfer means forwardly a distance equal to the distance between said loading station and said work station and reversely, locating means for engaging and positioning said work piece at said work station, means for securing said work piece at said work station, means controlled by the loading of a piece at said loading station and by the withdrawal of said posi- 14 tion and securing means to actuate said transfer means forwardly and means positioned to be actuated by a work piece at said receiving station to interrupt forward actuation of said transfer means.

2. Transfer mechanism for moving a work piece from a loading station to a work station and from a work station to a receiving station which comprises work piece supporting and guide rails extending from said loading station to said work station and to a receiving station, a reciprocating element extending longitudinally of said rails and movable forwardly and reversely a distance equal to the distance between said stations, pins carried by and movable with said reciproeating element and movable transversely into and out of position to engage a work piece at each said work station and loading station, positioning means at said work station movable to engage a work piece and place it in position for work, clamping means to secure said Work piece in position at said work station, said clamping means being connected to and movable with, said pins, uid operated means to move said reciprocating element forwardly and an electric circuit to control the admission of fluid for the forward movement of said reciprocating element and having a switch positioned to be actuated by a work piece in said loading station for the admission of said fluid and a switch positioned to be actuated by a work piece at said receiving station to prevent the admission of said uid.

HARRY F. PHILLIPS.

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

UNITED STATES PATENTS Number Name Date 1,435,046 Birnstock Nov. 7, 1922 1,560,373 Birnstock Nov. 3, 1925 1,597,536 Murray Aug. 24, 1926 2,120,966 Clark June 21, 1938 2,160,476 Kampmeier May 30, 1939 2,193,840 Oberhoffken et al. Mar. 19, 1940 2,238,921 Waldsmith Apr. 22, 1941 2,302,878 Muhl et al Nov. 24, 1942 2,438,999 Hartley et al. Apr. 6, 1948

Images