STIFFENED OSCILLATING FRAME SAW FOR CUTTING STONE BLOCKS

Abstract: The oscillating frame comprises a blade-holder frame (1) made to oscillate over the block (3) being machined by means of arms suspended on cursors (16) which slide in guides (18) in the columns (8) of the machine, a mechanism (2) to transmit reciprocating motion to the said frame (1), fixed cross-beams (9) to stiffen the columns, it presents a cross-beam (15, 27) joining the said cursors (16, 21, 26) and which is vertically mobile with them. In some versions, moreover, it presents: side members (60, 69, 84) for stiffening and joining the cursors (55, 65) or support structures (64, 67, 82) for the said suspension arms, which move vertically with them.

Description: STIFFENED OSCILLATING FRAME SAW FOR CUTTING STONE BLOCKS The invention relates to oscillating frame for cutting blocks made of granite and stone in general, having improved cursors and suspension arms, as well as system for stiffening the cursors, that is, a machine for cutting granite blocks into large slabs by means of a single sa- wing action, having a new type of cursor and suspension arm, a new type of cursor support structure and suspension arm support structure which improve productivity while simultaneously guaranteeing a long service life. Prior art comprises machines for cutting granite blocks with a horizontal rectangular frame carrying a series of blades sliding on and within the granite block, the oscillating motion being provided by a rotor and connecting rod mechanism. The forwards and backwards motion of the said blades pulls with them the abrasive elements of the cutting fluid with which they are continuously supplied, within the slots that are gradually formed in the block, thereby obtaining the cutting action; the blade-holder frame is suspended by arms hinged to cursors which move vertically on the columns of the machine, driven synchronously to impart the feed motion: the said cursors protrude from the columns on the f ont and rear sides . The granite block is positioned between the said columns . The production capacity depends on the length and fre- quency of the strokes of the said blade-holder frame and on the radius of the arms . With prior art frames there are those where the number of strokes, forward and return runs, is high, even over 80 per minute, alternatively there are frames which, in order to increase the distance covered by the blade, are con- structed with very long suspension arms, leading to very tall overall dimensions of the machine . There is also a machine having oscillating suspension arms are coupled to the lower part of the blade-holder frame . However, the prior art does not resolve the mechanical problems associated with the high mass of the blade-holder frame, due mainly to the high shear stresses applied by the connecting rod, and with the high frequency of the strokes, which put a considerable strain on the cursors in particular and on the whole machine in general, also due to the non-stop duty cycle of these machines. In fact the cursors consist of pivots at the ends of the suspension arms, sliding in vertical guides in the said columns of the machine, and protruding from them, suitably constructed with spherical roller bearings as they are often subjected to misalignment between each other and swing axis of the said arms . Such prior art may be subject to considerable improvement with a view to the possibility of ensuring that the said cursors are much less likely to take on an incorrect position due to the high stresses imparted by the blade-holder frame . From what has been said so far, the necessity arises of solving the technical problem of stiffening the said cursors to increase their service life and, simultaneously, to increase the productivity and the precision of the oscillating frame for cutting granite blocks . The present invention solves the said technical problem by adopting an oscillating frame for cutting blocks made of granite or stone in general, having improved cursors and suspension arms, comprising a blade-holder frame made to oscillate on the block being cut by means of arms suspended from cursors sliding in guides in the columns of the machines , a mechanism to transmit reciprocating motion to the said frame, cross-beams to stiffen the columns, characterised in that there is a cross-beam joining the said cursors and which moves vertically with them. The present invention, moreover, comprises: the said suspension arms provided with pins to couple them to the blade-holder frame and to the cross-beam positioned in a single longitudinal vertical plane on each side. The present invention, moreover, comprises: the said cursors being provided with an elongated structure extending upwards . The present invention, moreover, comprises: the said cur- sors are provided with double coupling to the guides in the columns . The present invention, moreover, comprises: the guides positioned on the internal side of the columns of the machine . The present invention, moreover, comprises: the guides positioned in the same vertical plane as the axes of the columns of the machine, coupling pins joining the arms and the frame, and coupling pins joining the cross-beam or the cursors . The present invention comprises another embodiment appl- yed jointly or separately with the previous embodiment: lateral members to stiffen and join together the said cursors or support structures for the said suspension arms, which move vertically with them, the front ones being joined to the rear ones on the same side of the machine. The present invention, moreover, comprises: a transverse cross-beam to join the cursors or support structures, which moves vertically with them. The present invention, moreover, comprises: the said cur- sors or support structures with an upward extension which enable long suspension arms to be used without lengthening the guides or increasing the height of the machine. The present invention, moreover, comprises: the said cur- sors or support structures on the same side of the machine joined to the side members by means of tie rods and/or braces . The present invention, moreover, comprises: the said cursors or support structures on the same side of the machine j oined by means of double side member, offset vertically. The present invention, moreover, comprises: the said cursors or support structures on the same side of the machine j oined by means of a stiffening space-frame structure. The present invention, moreover, comprises: the guides positioned on the external side of the columns. The present invention, moreover, comprises: the guides positioned in the same vertical plane as the axes of the columns of the machine, the pins coupling the suspension arms to the frame, the pins coupling the arms to the cur- sors or to the said extensions. The present invention, moreover, comprises: the guides positioned on the internal side of the columns . The present invention, moreover, comprises: the said cross-beam joining the said cursors or extensions positioned laterally with respect to the vertical plane containing the pins of the suspension arms. The present invention, moreover, comprises: the guides coupled to a sliding shoe having a slot to allow the pas- sage of a fixed protective covering. The advantages obtained with this invention are: the presence of the cross-beam joining the cursors enable the moment applied to them to be reduced, particularly in a vertical direction, due to the mass of the frame which du- ring its swing covers a vertical distance of between 20 and 40 mm; furthermore, the cross-beam enables the suspension arms to be fixed with pins in the same vertical plane as the coupling pins on the frame, further reducing the bending moment transmitted to the supporting columns; the extension of the cursors upwards enables longer suspension arms to be used giving a longer stroke in the horizontal direction and a shorter stroke in the vertical direction, this increasing the portion of stroke having favourable conditions for cutting and, due to the pulling effect, increasing the exchange of the cutting fluid. Finally, the arrangement of the pins of the suspension arms in a single longitudinal vertical plane enables machines to be obtained having ample frontage without the limits imposed by prior art cursors; so the side members stiffen the cursors, further reducing the bending moment transmitted to the supporting columns; moreover, the closed structure joining the cursors, made up of the side members and cross-beams, ensures they work together in re- ducing the misalignment and rotation caused by the forces of the blade-holder frame; furthermore, the guides being positioned on the external side of the columns prevents them from being sprayed with cutting fluid. Some embodiments of the invention are illustrated, purely by way of example, in the twelve tables of drawings attached. - Figure 1 is the cross-section side view of just one side of the improved machine as described. - Figure 2 the plan view of the machine as in Figure 1, similarly illustrating just the one side. - Figure 3 is the front view of the machine in the previous figures . - Figure 4 is an analogous front view of the machine with longer suspension arms . - Figures 5 and 6 are side and plan views as in the previous ones of the machine with the longer suspension arms in Figure 4. - Figures 7 and 8 are side and plan views as in the pre- vious ones of a machine with cursor guides inside the columns . - Figure 9 is the front view of the machine in Figures 7 and 8. - Figure 10 is cross-section X-X of the guide in Figure 9. - Figure 11 is the cross-section side view of just one side of the improved machine with the stiffened cursors. - Figure 12 the plan view of the machine as in Figure 11, similarly illustrating just the one side. - Figure 13 is the front view of the machine in the pre- vious figures . - Figure 14 is an analogous front view of the machine with longer suspension arms and without the stiffening crossbeam. - Figures 15 and 16 are side and plan views as in the pre- vious ones of the machine with the longer suspension arms in Figure 14. - Figures 17 and 18 are side and plan views as in the previous ones of a machine with cursor guides outside the columns . - Figure 19 is the front view of the machine in the previous Figures 17 and 18. - Figure 20 is cross-section XX-XX showing just the guide in Figure 19. - Figure 21 is the front view of a machine with cursor guides inside the columns . - Figures 22 and 23 are side and plan views analogous to the previous ones of the machine with the internal cursor guides in Figure 21. - Figure 24 is section XXIV-XXIV of Figure 14 showing just the support pin of the suspension arms able to support axial loads . The indications are as follows: 1, Figure 1, the horizontal oscillating blade-holder frame driven by the con- necting rod 2, coupled to it, in its forward and backward motion over and within the block 3 being cut; 4, Figure 2, the blades ixed to the structure 5 of the said blade-holding frame, that penetrate inside the said block by means of the abrasive action of the cutting fluid; 6, the trol- ley which may move on rails 7 for positioning the block within the cutting area of the frame 1; 8, the columns of the machine near the top of which there are the fixed longitudinal and transverse connecting beams 9; 10 and 11, respectively, the shafts and the mechanical gearboxes for the downward supply motion imparted to the said frame 1; 12, the suspension pins of the said blade-holding frame, joined by means of the suspension arms 13 and in turn coupled to the pins 14 of the cross-beam 15 joining the cursors 16; 17, the control screw for the vertical movement of the cursors along the guides 18 inside the column, open on the front side; 19, Figure 3, the roll-up protection in the cursor to protect the said guides from cutting fluid spray; 20, Figure 4, long suspension arms joined and coupled to the cross-beam positioned higher up by means of an elongation of the structure 21 of the cursors; 22 and 23, respectively lower and upper, the sliding cursors coupled to the internal guides 18 and to the control screw 17. The figures also show: 24, Figure 7, the suspension arms joined and coupled to the pins 25 of the internal cursors 26, which are in turn joined to the cross-beam 27; 28, the guides positioned on the internal side of the said columns 8, with U-shaped protective cover 29 fixed to the said columns; 30, Figure 8, the coupling shoe between the said cursor and the guide 28 and the control screw 31, Figure . . 10, enabling the passage of the said fixed protective cover; 32 the coupling block between the shoe and the screw; 33, the boxed structure of the column, with weight saving holes 34 in the internal walls; A, the side on which the protective wall is positioned to contain the spray of the cutting liquid; 35, the U-shaped slot in the shoe 30 to allow the passage of the said fixed protective cover 29; 36, the sliding surfaces of the guides 28 with transverse abutment 37 and the longitudinal abutments in the external sides of the coupling block 32; 38, the internal surface of the said columns 8. The figures moreover show, in the fourth version, 41, Figure 11, the horizontal oscillating blade-holder frame driven by the connecting rod 42, coupled to it, in its forward and backward motion over and within the block 43 being cut; 44, Figure 12, the blades fixed to the structure 45 of the said blade-holding frame, that penetrate inside the said block by means of the abrasive action of the cutting fluid; 46, the trolley which may move on rails 47 for positioning the block within the cutting area of the frame 41; 48, the columns of the machine near the top of which there are the fixed longitudinal and transverse connecting beams 49; 50 and 51, respectively, the shafts and the mechanical gearboxes for the downward supply motion imparted to the said frame 41; 52, the suspension pins of the said blade-holding frame, joined by means of the suspension arms 53 and in turn coupled by means of end pins 54 to the cursors 55, joined together by the cross-beam 56; 57, the control screw for the vertical movement of the cursors along the guides 58 inside the column, open on the front side; 59, Figure 13, the roll-up protection in the cursor to protect the said guides from the sprays of cutting fluid; 60, the longitudinal side members on the ex- ternal side 61 of the machine joining the front and rear . . cursors; A, the side of the machine where a dividing wall is generally positioned for protection against cutting fluid spray, in the side views of the various versions it is shown transparent. The figures also show, in the fifth version, 62, Figure 14, the long suspension arms joined and coupled to the extended structure 64 of the cursors 65 by means of the end pins 63 with axial thrust bearing: these are joined by the said side members 60, the front ones with the rear ones on the same side 61; B, Figure 24, the hub of the said arms 62 in which is lodged the pin P, in turn supported in the race C by means of the roller bearings D and E, adjusted by spacers F and ring nuts G; , the labyrinth protecting the seal T on the said pin P. The figures moreover show, in the sixth version, 66, Figure 17, the long suspension arms joined and coupled by means of end pins 54 to the extensions 67 joined together by the cross-beam 68; 69, the side members on external side 61 of the machine joining the front and rear extensions 67; 70, the guides positioned on the external side of the said columns 48, shielded by a protective U-shaped cover 71 fixed to the said columns; 72, Figure 18, the sliding shoe coupling the said side member 69, the guides 70 and the control screw 73, Figure 20, enable the passage of the said protective covering; 74, the coupling block between the shoe and the control screw; 75, the box structure with weight-saving holes 76 in the internal walls; 77, the U- shaped slot in the shoe 72 to allow the passage of the said fixed protective cover 71; 78, the sliding surfaces of the guides with transverse abutment and 79, the longitudinal abutments in the external sides of the coupling block 74; 80, the internal surface of the said columns 48. The figures finally show, in the seventh version, 81, Figure 21, the suspension arms joined and coupled by means end pins 54 to the internal extensions 82, in turn joined by the cross-beam 83; 84, the longitudinal side members on the internal to the side 61 of the machine joining the front and rear extensions 82; 85, the guides positioned on the internal side of the said columns 48, shielded by a U- shaped protective covering fixed to the said columns; 87, the shoe coupling the said internal extension 82, the gui- des 85 and the control screw, analogous to the screw 73 of Figure 20, allowing the passage of the fixed protective covering 86 : the said internal guides are identical to those described for the third version in relation to the parts visible in Figure 20. The oscillating frame with improved cursors operates as follows : in the first version in Figures 1 to 3 , the cursors 16, whilst sliding on guides 18 of known type and coupled to the control screw 17, are subject to reduced loads causing misalignment due to the centrifugal acceleration and the weight of the blade-holding frame 1, which arise with high oscillation frequency, cancelling out transverse bending moment ; furthermore, the upper pins 14 and lower pins 12 being vertically co-planar enables them to made identically without having to provide versions with end pins, which are inevitably much more expensive. The longitudinal moment arising due to the forward position of the pins 12 and 14 with respect to the guides 18, longitudinal off-set as in Figure 1, is supported, as with prior art solutions, by the reaction from the said guides. In the second version in Figures 4 to 6 the greater length of the suspension arms 20 is compensated by the higher position of the cross-beam 15 with pins 14 : the ex- tended structure 21 of the cursor increases the said Ion- gitudinal moment, which is counteracted by the double cursor 22 and 23 coupled to the said guides 18, the horizontal forces generated by the said moment is in this way better supported by the guides . The practical effect on the operation of the frame is such that there are considerable production advantages : the greater length of the arms 20 means that for a given vertical stroke there is a longer horizontal stroke of the blade-holder 1, or, vice- versa, for a given horizontal stroke there is a shorter vertical stroke; this has the effect of reducing the loads and therefore the associated moments and of increasing the working length of the horizontal stroke of the blades 4, immersed in the abrasive cutting fluid in the relative groove in the granite block 3. In the third version illustrated in Figures 7 to 10, the suspension arms 24 are coupled to the cursors 26 with end pins 25 of the known type, the cursor connecting beam, in this case positioned to the side of the said supports as is the front fixed cross-beam 9 to limit the height of the machine, ensures adequate stiffness against the limited bending moment that is generated there due to the pins 25, the pins 12 and the guides 28 inside the columns 8 being co-planar. The said internal guides are clearly visible in Figure 10 where the protective covering 29 completely covers the transverse abutment surface 36, whereas the longitudinal abutment surfaces 37, being inside the said guides, are protected as in a labyrinth from cutting liquid spray. The oscillating frame with the stiffening system operates as follows : in the fourth version in Figures 11 to 13 , the cursors 55, whilst sliding on guides 58 of known type and coupled to the control screw 57, they are subject to redu- ced loads causing misalignment due to the centrifugal ac- celeration and the weight of the blade-holding frame 41, which arise with high oscillation frequency, cancelling out both the transverse and the longitudinal bending moment . The longitudinal bending moment arising from the ad- vanced position of the pins 52 and 54 with respect to the guides 58, the longitudinal offset in Figure 11, is counteracted by the reaction of the side member 60 connected to the cursor 55 on the opposite side. Moreover, in the fifth version in Figures 14 to 16 the greater length of the suspension arms 62 is compensated by the higher position of the end pins with axial thrust bearings 63 : the extended structure 64 of the cursor 65 increases the said longitudinal moment, which is counterac- ted by the reaction of the side member 60 connected to the cursor on the opposite side, the horizontal forces thereby generated by the moment being better supported by the guides 58. The practical effect on the operation of the frame is such that there are considerable production advantages : the greater length of the arms 62 means that for a given vertical stroke there is a longer horizontal stroke of the blade-holder 41, or, vice-versa, for a given horizontal stroke there is a shorter vertical stroke; this has the effect of reducing the loads and therefore the associated moments and of increasing the working length of the horizontal stroke of the blades 44, immersed in the abrasive cutting fluid in the relative groove in the granite block 43. Moreover, the presence of the roller bearings capable of absorbing axial loads D and E in Figure 24 reduces the effect of the transverse moment in the two directions, due to the effect of the lowering and raising of the mass of the blade-holder frame 41, even if there is no cross-beam connecting the cursors 65 or the extended structures 64. n the sixth version illustrated in Figures 17 to 20, the suspension arms 66 are coupled to the extensions 67 with end pins 54 of the known type, the connecting cross-beam providing stiffness to counter transverse moment, and the side members 69, carrying the shoe 72 sliding on the gui- des 70, counter the longitudinal moment by means of the connection of the shoe 72 on the side 61 of the column 48 on the opposite side. The conformation of the said guides is clearly visible in Figure 20 where the fixed protective covering 71 completely cover the transverse abutment sur- face 78, whereas the longitudinal abutment surface 79 being inside the said guides are protected from the cutting fluid spray as in a labyrinth. In the seventh version illustrated in Figures 21 to 23, the suspension arms 81 are coupled to the internal extensions 82 with end pins 54 of the known type, the crossbeam 83, in this case positioned to the side of the said supports as is the front fixed cross-beam 49 to limit the height of the machine, ensures stiffness against the limi- ted bending moment that is generated there due to the pins 54, the pins 52 and the internal guides 85 inside the columns 48 being co-planar; the presence of the internal side members 84, joining the internal extensions 82, counteract the longitudinal moments arising from the greater height of the said pins with respect to the internal shoes 87. The conformation of the said internal guides 85 is illustrated in Figure 20. In practice the materials, dimensions and details of exe- cution may be different from, but technically equivalent to, those described without departing from the juridical domain of the present invention. To this end, though less advantageous, the said guides 28, 85 on the internal side of the columns 8, 48 may ad- vantageously be protected by flexible flaps on either si- de , to cover the necessary opening between the fixed protective covering 29, 86 and the side of the column, which in the absence of the shoe 30, 87 lie directly on the U- shaped protective covering; the said shoe may have angled surfaces to favour the coupling with the said flexible flaps .

Claims: CLAIMS . 1. Oscillating frame for cutting blocks made of granite and stone in general, having improved cursors and suspension arms, comprising a blade-holder frame (1) made to oscillate over the block (3) being machined by means of arms suspended on cursors (16) which slide in guides (18) in the columns (8) of the machine, a mechanism (2) to transmit reciprocating motion to the said frame (1) , fixed cross-beams (9) to stiffen the columns, characterised in that there is a cross-beam (15, 27) joining the said cursors (16, 21, 26) and which is vertically mobile with them. 2. Oscillating frame, as claimed in the preceding claim, characterised in that the said suspension arms (13, 20) have pins for coupling it the said blade-holder frame (1) and to the cross-beam positioned in a single longitudinal vertical plane (V) on each side. 3. Oscillating frame, as claimed in one of the preceding claims, characterised in that the said cursors have an elongated structure (21) extending upwards . 4. Oscillating frame, as claimed in claim 3 , characterised in that the said cursors (21) are provided with double coupling (22, 23) to the guides (18) in the columns (8) . 5. Oscillating frame, as claimed in one of the preceding claims 1 to 4, characterised in that it has the guides (28) positioned on the internal side of the columns (8) . 6. Oscillating frame, as claimed in one of the preceding claims 1 to 4, characterised in that it has the guides positioned on the external side of the columns (8) . 7. Oscillating frame, as claimed in one of the preceding claims 5 or 6, characterised in that it has the guides (18, 28) , the axes of the columns (8) of the machine, the pins (12) coupling the arms (13, 20, 24) to the frame (1) , 5 the pins (14, 25) coupling the arms and the cross-beam (15) or cursors (26) all positioned in the same vertical plane . 8. Oscillating frame for cutting blocks made of granite 10 and stone in general, having a system for stiffening the cursors, applyed jointly or separately with one of the previous claims 1, 2 or 3, comprising a blade-holder frame (41) made to oscillate over the block (43) being machined by means of arms (53) suspended on cursors (55) which 15 slide in guides (58) in the columns (48) of the machine, a mechanism (42) to transmit reciprocating motion to the said frame (41) , fixed cross-beams (49) to stiffen the columns, characterised in that there are side members (60, 69, 84) for stiffening and joining the said cursors (55, 20 65) or support structures (64, 67, 82) of the said suspension arms, and which move vertically with them, the front ones being joined to the rear ones on the same side (61) of the machine. 25 9. Oscillating frame, as claimed in the preceding claim, characterised in that there is a cross-beam (56, 68, 83) to join transversely the said cursors or support structures and which moves vertically with them. 30 10. Oscillating frame, as claimed in one of the preceding claims 8 or 9, characterised in that the said cursors or support structures are provided with an upward extension (64, 67, 82) enabling the use of long suspension arms (62, 66, 81) , without increasing the length of the guides or 35 the height of the machine . - - 11. Oscillating frame, as claimed in claim 10, characterised in that the said cursors or support structures are joined by means of tie-rods and/or braces on the same side (61) of the machine. 12. Oscillating frame, as claimed in claim 10, characterised in that the said cursors or support structures are joined by means of a double side member offset vertically on the same side (61) of the machine. 13. Oscillating frame, as claimed in claim 10, characterised in that the said cursors or support structures are j oined by means of stiffening space frame on the same side (61) of the machine. 14. Oscillating frame, as claimed in one of claims 8 or 10, characterised in that the said oscillation pins (63, P) of the arms (62) coupled to the cursors or support structures (64) consist of roller bearings with axial load capacity (D, E) . 15. Oscillating frame, as claimed in one of the preceding claims from 8 to 14, characterised in that the guides (70) are positioned on the external side of the columns (48) of the machine . 16. Oscillating frame, as claimed in one of the preceding claims from 8 to 15, characterised in that it has the guides (58, 70) , the axes of the columns (48) of the machine, the pins (52) coupling the arms (53, 62, 66, 81) to the frame (41) , the pins (54, 63) coupling the arms and the cursors (55) or the extensions (64, 67, 82) all positioned in the same vertical plane. 17. Oscillating frame, as claimed in one of the preceding claims 8 to 14, or 16, characterised in that the guides (85) are positioned on the internal side of the columns (48) of the machine . 18. Oscillating frame, as claimed in one of the preceding claims, characterised in that it has the said cross-beam (15, 27, 56, 68, 83) joining the cursors (16, 21, 26) or extensions (55, 64, 67, 82) positioned laterally to the vertical plane containing the pins (12, 14, 25, 52, 54, 63) of the suspension arms (13, 20, 24, 53, 62, 66, 81) . 19. Oscillating frame, as claimed in one of the preceding claims, characterised in that the guides (28, 70, 85) are coupled to a shoe (30, 72, 87) having a slot (35, 77) to allow the passage of a fixed protective cover (29, 71, 86) . 20. Oscillating frame, as claimed in the preceding claim, characterised in that the guides (28, 70, 85) consist of sections securely fixed to one of the lateral surface of the columns (8, 48) of the machine which protrude from the said surface; the said protective covering (29, 71, 86) has a U-shaped section with the ends pointing towards the surface of the column. 21. Oscillating frame, as claimed in one of the preceding claims 19, 20, characterised in that the said guides (28, 85) , when positioned on the internal side of the columns (8, 48) , are protected by flexible flaps on the two sides, to cover the necessary opening between the fixed protective covering (29, 86) and the side of the column.

Inventors: BERTI SERGIO, PEDRINI LUIGI, BERTI, SERGIO, PEDRINI, LUIGI
Applicants: BERTI SERGIO, PEDRINI LUIGI, BERTI, SERGIO, PEDRINI, LUIGI
Application year: 1998
Main classification: B28D1
IPC codes: B28D1