AU610604B2 - Loader for sequential positioning of manufactured products - Google Patents

Description

El'

H-

AUS'TRALA9 61060 L1 PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORTGINAL)

FOR OFFICE USE Short Title: In2. Cl: Application Nnmer: Lodged: Complete Specificaticii Lodged: Accepted: Lapssd: Ott' Published: too PrLority: 0 0 j 0 0 0 t 0 00 00 S.0 0 Related 0 0 Narie of Ng~qicart: 0000o 0 ;i'hi L Ucuniont covit1tins tctt D1iil2'r1d0ihis T1h'UC I'L !I 2o ?t I t and~ is cUri.C)P(Y ra TO BE COMPLFlD BY APPICANT S.T.I.M.A. ENGINEERING DI MANIA DCYT, ING. ION C. S.n. c.

Address of AWp~icant: Actual Inventors: Address for Service: via Ripalta Arpina 26012 Castelleone, Cremona.

ION MANIA CALLINANS, Patent Attorneys, of 48-50 Bridge I Richmond 3121, Victoria, Australia CcrWjlete Specification for the invention entitled "LOADER FOR SEQUENTTAL POSITIONING OF MANUFACTI'UREI} PRODUCTS" The following statement is a full description of this inve-/tion, including the best method of performing it known to me:- Delete for Non-Convention Application.

Insert place and -t L of signature.

4. Tihe basgic; app~ication(Wreferred to in paragraph 2 ef this Deelaratio 1 WasiWere the finsi V t 4: it Delare atn() ma i Declared at C Ie in a on..vCti. f le uu n inv .u V1 uuJI remona this 24th day of June, 1988.

SIGN X HERE *r rw~, -w This invention relates to an improved loader for positioning, in sequence and with accuracy, manufactured products to be submitted to grinding, on machine tools, preferably with numeric control. Loaders are generally known in the techniques of the sector. They substantially comprise a structure on which is transferably arranged an "arm" provided with taking and releasing grippers for manufactured products submitted to the working process, the taking and releasing operations being carried out by a bench associated with said structure.

The product fixed on the bench is transferred from a starting position to a working position depending on tEh operating characteristics of the machine tool.

Thus if, for example, the manufactured product to be processed is a rotor to be subjected to grinding operations of the shoulders, since the "stroke" of the tool is predetermined with respect to the position of the rotor between the 09 0 "01" fixing means of the machine tool, it is necessary to check, by known equipment, 0000 ,ooo the values of the shoulders. If these values do not correspond to that of said 00 g stroke necessary for carrying out the grinding, the fixing means are translated to aOfo" an extent depending on the material which is removed during the grinding.

0 These repeated and indispensable controls with optional relative repositionings, 0O even if they are automatically operated, involve a loss; of time that leads to high economic damage in the processing cycle, besides the cost of control equipment, due to the influence of so called "dead time".

0o Therefore, the present invention seeks to provide an improved leader for the above purposes, which makes it possible to insert the "manufactured product or piece in the machine tool, previously positioned, said o positioning being carried out and deterrlined during transfer of the piece to be O processed, to eliminate the substantial reproduction of said dead time. More 00 Q, S"specifically, the invention seeks to provide an improved loader for sequeatial positioning, with accuracy, the manufactured products, generally submitted to grinding, on machine tools preferably having a num'eric control.

-2-

S;

According to the present invention tnere is provided a loader for sequential positioning, with accuracy, manufactured products to be submitted to grinding on machine tools with numeric ccntrol and provided with a slide or motorised table with rmeans to fix said manufactured products, said loader including: a composite along which an arm bidirectionally traverses with preestablished strokes, including gripping and releasing members for said manufactured products; a bench associated with said structure and provided with two sur .cimposed shelves, a lower of said shelves being for arrival of said manufactv products to be processed and the upper of said shelves being for the moving away of already processed products; and a plurality of motors and a control station to operate and control said movements, wherein downstream of said bench there is provided a unit partly vertically movable and provided with means to withdraw and lift the manufactured products to be process from said lower shelf up to a predetermined position in which said gripping members grip !Soo and carry said products in correspondence with a tracer point associated with Soo 'said composite structure, said tracer point memorising in the same control *0 9 station the positional dimension/dimensions in which said manufactured product o is subsequently placed and held between said fixing means with respect to the o 00 O predetermined displacement of said tool so that, during transfer of the manufactured product, said control station transmits the memorised data to the operating and controlling system of said machine tool, which presets said slide in the position in which said manufactured product is processed.

9 0 'o Characteristically said unit, which is also associated with the 0 composite structure, substantially consists of a hydrodynamic .ylinder on which a framework is placed, said framework comprising "points" susceptible, on command, to alternative approach and retreat by the action of a small oP 6hydrodynamic cylinder with double effect, placed in the body supporting each 0 S of said points, everything to ensure that the manufactured product withdrawn is held between said points.

Advantageously, at least one of said points is provided with an intermittent rotary movement around its axis to ensure correct centering, also in -3the angular direction, of the product between said points. Th:- movement is controlled by a photo-electric cell and determined by the displacement of a rack, also operated by a small hydrodynamic cylinder, which is engaged in teeth provided in the shank of said point, said small cylinder and rack being both placed in the body supporting said point.

The bidirectional movements of said arm on the structure are advantageously defined by a ball system which ensures their precision.

Furthermore, the gripping, withdrawal and transfer means of the product include at least two grippers positioned at approximately 300 with respect to said arm and placed at the lower end of said arm, said grippers alternately contrasting and having an inclination which facilitates the practically simultaneous grip of the product to be processed and, respectively, the release of the already processed product.

Another feature of the invention consists in a new arn- original l 0 1i.oo. structure of the grippers. The opening and closing of each gripper is detexmined by a straight operation of two opposed small pistons which stress to Sg 0 6 rotate the pins carried by a disc, two of which pins slidingly engage into o 1O',ocoheren' seats provided in the small pistons, while another two pins, placed a crosswise with respect to the first pins, also slidingly engage into corresponding coherent seats provided in the relative "bolts", also opposed, associated with the jaws of the same grippers, so that the rotating movement of said disc is A transformed into a radial movement of the jaws of these grippers, assuring a 0o -more effective and precise grip of the product.

Finally, the improved loader of the present invention includes 'known circuital and electronic means which ensure the synchronisation of the relative complete movements.

c In order that the invention may be more clearly understood and put Sinto practical effect there shall now be described in detail a preferred embodiment oi a loader in accordance with the invention. The ensuing description is given by way of non-limitative example only and is with reference ,to the accompanying drawings, wherein: -4i il_ i~ L~ i-ij)iiii i I__iY~:~_l;lll..iX-i..iii*-L:LI .~Ui~ Fig. 1 shows a perspective view of the improved loader of .le present invention; Fig. 2 is a schematic side view of the loader shown in Fig. 1 connected to a machine tool, schematically and pariially reproduced; Fig. 3 is a schematic front view of the unit provided with points to grip the bench of the piece or product; Fig. 4 is a schematic section of the body supporting one of the points provided with both rotary movement around its axis and alternative straight movement; Fig. 5 is a schematic fragmentary section of the structure of the grippers; Fig. 6 is a schematic section made by a plane passing along line VI- VI of Fig. 5; and Fig. 7 shows the diagram for transfering the piece to be processed to the slide of the machine tool with the coherent surveys and relative o memorisations.

With reference to Fig. 1 the loader 10, for feeding products or ,0,pieces to be processed into machine tools, includes an arm 12 associated with 0 0 0 omotorised wagons having a. horizontal traverse 14 and a vertical traverse 16.

Arm 12 carries at its lower end grippers 18 and 20, placed at 300 with respect to said arm 12.

The loader 10 includes a bench 22 carrying two s-'perimposed S 0 ,o'oshelves 24 and 26, the lower one 24 of which is assigned to the arrival of the products 28 to be processed, and the upper one 26 to carrying away the 25 *products 28' already processed.

The loader 10 is completed by a plurality of motor means 30 for its and by a control station 32 for the operating and controlling movement.

The above substantially corresponds to what is known in the art.

The improved loader according to the present invention comprises, downstream from bench 22 and associated with the composite structure, a unit t i 34 composed of a framework 33 vertically movable by the action of a 1 hydrodynamic cylinder 35. On the framework 33 are integrated bodies 37 and 39 supporting a couple of points 40 acting as counterpoints to lift the single pieces 28 to a predetermined height. The pieces 28 are subsequently withdrawn from one of the two grippers 18 or 20, and placed in correspondence of a tracer point 42, also associated with said composite structure. This tracer point 42 transmits data (transmission being schematised by line L) to the control station 32, in the present case prepared also for data memorisation for the purposes specified below.

Fig. 2 shows how a piece 28, after being withdrawn from the points 40, is placed by grippers 20 in correspondence with the tracer point 42 which, as already said, transmits its data, by memorising the same at control station 32.

Piece 28 is then transferred (in the case illustrated) between point and counterpoint 46 and 58 (Fig. 7) of a motorised slide 50 (which can be substituted by a table) of a machine tool 52, partially and schematically shown in the same 1 V ooFig. 2.

Fig, 3 illustrates in detail how said hydrodynamic cylinder So operates the vertical movement of the framework 33 on which are placed said .o o, bodies 37 and 39 supporting the points 40, which can move away from and Sapproach the relative supporting bodies to grip and release the products 28 to be 0o a >.U processed.

This movement, essentially straight and alternative in the axis of the opoints 40, can be particularly observed in Fig. 4, in which only one point is 0 0 oillustrated and is also assvineii as having a movement of intermittent rotation around its axis. The intermittence is controlled by a photo-electric ceil (not 0shown as already known) which determines its circular rotation around its axis relatively to the position piece 28 must assume, thus guaranteeing ,.fect Pt*icentering, also angular, of said piece 28 between said points 40. Shank 41 of the 2 point 40 is contained in supporting body 37, made integral to the framework 33.

Said shank 41 includes a toothed zone 43 engaging with a rack 45 which, driven by a small hydrodynamic cylinder 47, causes said rotation of the point 40, while the straight alternative displacement is determined by a further small -6- 4 C, Irp P' A' hydrodynamic cylinder 49.

The position of the small hydrodynamic cylinders contained in the supporting body 37 is not described in detail, since it is clearly deducible from the drawing shown in the same Fig. 4. Obviously, the other point 40 contained in the supporting body 39 can similarly move in a straight line in the same way since it has a similar structure even if not provided rith rotating movement but, if necessary, could be, by structuring it like that contained in supporting body 37.

The structure of grippers 18 and 20, which is a further original feature of the invention, is illustrated in Figs. 5 and 6. Each set of grippers 18 and 20 (only one is described as they are similar) comprises an external body 62 rotatable around the inclined axis (at 300 with respect to arm 12). In said body 62 there is arranged a couple of small opposite pistons 64 and 66 which engag' between coherent grooves 64' and 66', pins 68 and 70 belonging to a disc 72.

0 'The disc 72 further includes another two pins 74 and 76 engaged in coherent grooves 78 and 80 provided on opposite bolts 78' and 80', placed crosswise with Srespect to said small pistons 64 and 66. The straight movement of said pistons 6 0 S64 and 66 determines a rotation of disc 72, returning it to a straight line with S0 a respect to said bolts 78 and 80, to which jaws 82 which move radially are also connected.

Finally, Fig. 7 schematically shows how a piece to be processed, e.g.

a rotor 28 submitted to grinding of the shoulders: is withdrawn from bench 22 a 0 a-oe of loader 10 by points 40. Then by means of grippers 18 or 20, the piece is "00 0 o placed in correspondence with the tracer point 42 which transmits numerical and 2" odigital information to control station 32, by means of the L-connection. Said control station 32 memorises this information and, during the transfer of piece 0 'ooo 828 carried out by the straight displacement with pre-established stroke and S° °o indicated with X of arm 12, transmits the data to driving and controlling unit of the machine tool. This unit ensures that the slide (always in the case illustrated) provided with point 46 and counterpoint 48 is placed in the exact position suitable to receive piece 28 to be subjected to the grinding operation by -7- I i_ a tool 100 whose stroke is also predetermined. In practice, the slide is positioned in relation to the amount of maLerial to be removed from piece 28 without further dimensional checks and consequently without interrupting the production cycle. The structure of stops, raceways and ducts is well known and, therefore, does not form part of the invention. The movement of the wagons is facilitated by a ball system that ensures precision of displacement.

The products to be processed may be shafts, flanges, bushes etc. and they may be subjected to any other type of processing besides grinding.

f 0 C Ct 0000 o0 o 00 00 0 00000 0 00

QQCC(

00 0 agCCCC a 0 1 3

'N

-8-

Claims (7)

1. A loader for sequential positioning, with accuracy, manufactured products to be submitted to grinding on machine tools with numeric control and provided with a slide or motorised table with means to fix said manufactured products, said loader including: a composite along which an arm bidirectionally traverses with pre-established strokes, including gripping and releasing members for said manufactured products; a bench associated with said structure and provided with two superimposed shelves, a lower of said shelves being for arrival of said manufactured products to be processed and the upper of said shelves being for the moving away of already processed products; and a plurality of motors and a control station to operate and control said movements, wherein downstream of said bench there is provided a unit partly vertically movable and provided with means to withdraw and lift the manufactured products to be process from said lower shelf up to a predetermined position in 'S which said gripping members grip and carry said products in correspondence OQwith a tracer point associated with said composite structure, said tracer point g° rmemorising in the same control station the positional dimensiorJdimensions in .which said manufactured product is subsequently placed and held between said ofixing means with respect to the predetermined displacement of said tool so that, during transfer of the manufactured product, said control station transmits the memorised data to the operating and controlling system of said machine tool, which presets said slide in the position in which said manufactured product is y'processed. 0 2. The loader according to claim 1, wherein said unit includes a 'hydrodynamic cylinder on which is placed a framework provided with points susceptible, on command, tc alternative approach and retreat, t:o ensure that the wo "~ithdrawn manufactured product is ield between said points. So3. The loader according to claim 2, wherein at least one of said points is equipped with an intermittent rotary movement around its axis to ensure centering, also in an angular direction, of the manufactured product between said points. -9- _I51 I -i-L-rUusmspue~r+~

4. The loader according to claim 2 or claim 3, wherein said alternative approach and retreat of said points is determined by the action of a small hydrodynamic cylinder with double effect, placed in a body supporting each of said points.

5. The loader according to claim 4, wherein said intermittent rotary movement of said point is determined by displacement of a rack, which is engaged in teeth provided on a shank of said point, said small cylinder and said rack being placed in said body supporting said point.

6. The loader according to any one of claims 3 to 5, wherein the intermittent rotary movement of said point is controlled by a photo-electric cell. 7, The loader according to any one of the preceding claims, wherein said arm is bidirectionally transferable on the composite structure by means of a ball system.

8. The loader according to any one of the preceding claims, wherein Ii,, said gripping, withdrawal and transfer means include at least two sets of grippers positioned at approximately 300 with respect to said arm and placed, at o" the lower end of said arm, said gripper alternatively contrasting and having an Soinclination which facilitates the simultaneous grip of the manufactured product ,to be processed and, respectively, the release of already processed product.

9. The loader according to claim 8, wherein the opening and closing of each set of gripping and releasing members are determined by a straight .operation of two opposed small pistons which stress to rotate pins carried by a oO%,odisc, two of said pins being engaged into seats provided in said small pistons, o while two other pins, placed crosswise with respect to said first pins, are 23 Oengaged into seats provided in the bolt means, also opposed, associated with the Sjaws ci said grippers, so that the rotating movement of said disc is transformed o 1. nto a radial movement of the jaws of said grippers. o0 40. The loader according to any one of the preceding claims, including circuital and electronic systems ensure synchronisation of the movements.

11. An improved loader for sequential positioning, with accuracy, manufactured products to be submitted to grinding, on machine tools having numeric control, substantially as descr" ,i~n with reference to the accompanying drawings. DATED the 30th day of January, 1991 S.T.I.M.A. ENGINEERING DI MANIA DOTT. fNG. ION S~n.c, by their Patent Attorneys CALLINAN LAWRIE 0 C OC 00 00