EP1011943B1

EP1011943B1 - Stiffened oscillating frame saw for cutting stone blocks

Info

Publication number: EP1011943B1
Application number: EP98919461A
Authority: EP
Inventors: Luigi Pedrini; Sergio Berti
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-24
Filing date: 1998-04-21
Publication date: 2004-06-30
Anticipated expiration: 2018-04-21
Also published as: ES2222585T3; DE69824864D1; DE69824864T2; PT1011943E; BR9808694A; WO1998047680A1; EP1011943A1; ATE270175T1

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

The invention relates to oscillating frame for cutting blocks made of granite and stone in general, having a system for stiffening the cursors, that is, a machine for cutting granite blocks into large slabs by means of a single sawing action, having 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 front and rear sides. The granite block is positioned between the said columns.

The production capacity depends on the length and frequency 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 constructed 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 (See e.g. FR-A-2 519 897).

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 the features of claim 1. Preferred details of the invention are defined in the claims 2 to 14.

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 during 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 reducing 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 drawings atttached, containing the figures 11 to 24.

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 previous figures.
Figure 14 is an analogous front view of the machine with longer suspension arms and without the stiffening cross-beam.
Figures 15 and 16 are side and plan views as in the previous 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 figures show, in the first 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 external 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 second 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; L, the labyrinth protecting the seal T on the said pin P.

The figures moreover show, in the third 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 fourth 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 guides 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 the stiffening system operates as follows: in the first 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 reduced loads causing misalignment due to the centrifugal acceleration 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 advanced 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 second 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 counteracted 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.

In the third 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 guides 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 surface 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 fourth 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 cross-beam 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 limited 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 execution 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, 85 on the internal side of the columns 48 may advantageously be protected by flexible flaps on either side, to cover the necessary opening between the fixed protective covering, 86 and the side of the column, which in the absence of the shoe, 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

Oscillating frame for cutting blocks of granite and stone in general, having a system for stiffening the cursors, 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 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) to stiffen and join the said cursors (55, 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.
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.
Oscillating frame, as claimed in one of the preceding claims, 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 the height of the machine.
Oscillating frame, as claimed in claim 3, 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.
Oscillating frame, as claimed in claim 3, 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.
Oscillating frame, as claimed in claim 3, characterised in that the said cursors or support structures are joined by means of a stiffening space frame on the same side (61) of the machine.
Oscillating frame, as claimed in one of claims 1 or 3, 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).
Oscillating frame, as claimed in one of the preceding claims, characterised in that the guides (70) are positioned on the outer side of the columns (48) of the machine.
Oscillating frame, as claimed in one of the preceding claims, 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.
Oscillating frame, as claimed in one of the preceding claims 1 to 7, or 9, characterised in that the guides (85) are positioned on the inner side of the columns (48) of the machine.
Oscillating frame, as claimed in one of the preceding claims, characterised in that it has a cross-beam 56, 68, 83) joining the cursors or extensions (55, 64, 67, 82) positioned laterally to the vertical plane containing the pins (52, 54, 63) of the suspension arms (53, 62, 66, 81).
Oscillating frame, as claimed in one of the preceding claims, characterised in that the guides (70, 85) are coupled to a shoe (72, 87) having a slot (77) to allow the passage of a fixed protective cover (71, 86).
Oscillating frame, as claimed in the preceding claim 12, characterised in that the guides (70, 85) consist of sections securely fixed to one of the lateral surface of the columns (48) of the machine which protrude from the said surface; the said protective covering (71, 86) has a U-shaped section with the ends pointing towards the surface of the column.
Oscillating frame, as claimed in one of the preceding claims 12, 13, characterised in that the said guides (85), when positioned on the inner side of the columns (48), are protected by flexible flaps on the two sides, to cover the necessary opening between the fixed protective covering (86) and the side of the column.