A planing machine

Abstract: A planing machine is provided with at least one drive head (3), predisposed to plane tiles, slabs and the like (2) translated by a planing line (1) comprising a slat conveyor belt (4) formed by a plurality of slats (5) constrained one consecutively to another by flexible joints (6). A wheel (8), on which the slat conveyor belt (4) is partially wound, can be displaced with a vertical direction component. A cam (10), solidly associated to the wheel (8), rests on a fixed roller (11), and is shaped so that a flexible joint (6) joining a first slat (5) interacting with the wheel (8) and an adjacent slat (5) not interacting with the wheel (8) is not subject to vertical displacements.

Description: The invention relates to a planing machine, in particular for slabs, tiles and the like. The prior art teaches planing machines, specially used for planing ceramic tiles in general and/or marble slabs, granite slabs, aggregates, which machines comprise a plurality of heads provided with frontal grinders or sanders, predisposed in a line to operate on tiles or slabs translated thereon with a predetermined infeed motion. Prior art realisations exhibit numerous drawbacks and disadvantages. A first series of drawbacks originate in the conveying systems in use, which convey the slabs or tiles in ordered succession to positions below the various heads. These systems, when formed by articulated continuous conveyors, are subject to rapid hinge wear, which negatively influences the correct functioning of the transport system and inevitably requires expensive and frequent maintenance. Other drawbacks and disadvantages can be traced to the high number of work heads, each of which bears a planer, used in the prior art to carry out the planing process. An unresolved problem in present continuous conveyors formed by rigid plates hinged consecutively one to another is constituted by the impossibility of keeping the plate or plates transported by the upper branch of the conveyor perfectly aligned when in the proximity of the drawing organ which gives them their necessary advancement motion. The main aim of the present invention is to obviate the above-described drawbacks by providing a functionally simple and economical solution. The stated aim is fully achieved by the present invention as it is defined in claim 1. The dependent claims 2-14 describe further embodiments of the invention. Further characteristics and advantages of the present invention will better emerge from the detailed description that follows of a preferred but non-exclusive embodiment of the invention, illustrated purely by way of nonlimiting example in the accompanying figures of the drawings, in which: figure 1 shows the invention in a schematic lateral view in vertical elevation, partially sectioned according to line H-H of figure 2; figure 2 shows a schematic plan view from above of the invention, partially section according to line I-I of figure 1. With reference to the figures, 1 denotes in its entirety a planing line, constituted by a horizontal transport plane, along which slabs or tiles 2 which are to be planed are translated in a line, at a predetermined conveyor speed. The upper branch of a continuous slat conveyor 4 supports and transports the slabs or tiles. The slat conveyor 4 is formed by a plurality of slats 5 constrained one behind another by flexible joint elements 6. On the upper branch, the slats 5 rest on a roller plane formed by a plurality of identical rollers 14, situated at short distances one from another and arranged parallel, with horizontal axes perpendicular to the advancement direction of the slats, as schematically indicated by the arrow 35.The roller plane 14 has the task of supporting the slats 5 in movement, maintaining them on a fixed reference plane of the machine. The slats 5 are identical and superiorly exhibit a rest surface for the slabs or tiles 2, which rest surface has low side walls 12, the height of which is lower than the height of a tile or slab 2. The connection between the slats 5 is realised by means of flexible joint elements 6, having a strip shape, and being preferably made of friction rubber and fixed to the slats by screws 13. Transmission of motion to the conveyor 4 (and thus transport of the slats in the direction of arrow 35) is done by a drawing device 7 which comprises at least one wheel 8, on which the slat conveyor is partially wound. The drawing device 7 has a plurality of projecting drawing elements 9, in the form of cogs, angularly equidistanced and predisposed to interact mechanically with the slats 5, inserting perfectly into housings 15 afforded in the lower surface of the slats themselves. The arrangement of the drawing elements 9 on the wheel 8 is such that any two consecutive drawing elements 9 interact with two consecutive slats 5. The wheel 8 can be displaced in at least one direction which is perpendicular to said reference plane constituted by the roller plane 14. A cam 10 is provided, solidly constrained to the wheel 8, for this purpose. The cam 10 has its active surface resting on a fixed-axis roller 11 and is subdivided into a plurality of equal portions whose number is identical to the number of said drawing elements 9. The portions are also positioned at an angle with respect to the drawing elements 9 so that the joint element 6 joining the first slat 5 interacting with the wheel 8 and the slate adjacent thereto and not yet interacting with the wheel 8 is not displaced perpendicularly to the reference plane (i.e. the roller plane 14) by effect of the rotation of the wheel 8. In other words, by effect of the rotation, the cam 10 produces a cyclical raising and lowering movement of the wheel 8 which compensates for the lowering and raising inflicted on the flexible joint element 6 joining the slat 5 engaged by the wheel 8 with the immediately following slat 5. This means that during the planing operation the configuration of the rest plane bearing the slats 5 and therefore the tiles or slabs 2 can be kept perfectly flat and constantly fixed. The possibility of vertical displacement is made constructively possible by the fact that the shaft 19 of the wheel 8 is supported at the free ends of two oscillating arms 20, forming a fork, which arms have the other two ends constrained one to another and hinged on a single pivot 21 having a rotation axis which is parallel to a rotation axis of the wheel 8. In the illustrated embodiment, the wheel 8 has a regular polygonal shape (a pentagon in the example), in which a drawing element having the shape of a cog 9 is predisposed at the centre of each side. Each side of the regular polygon is predisposed so that part of the lower surface of each slat 5 rests thereon. Obviously the cam 10 is also subdivided into five equal portions. The conveyor belt 4 is ring-wound and stretched between the wheel 8 represented in the enclosed figures and a similar wheel, not shown in the figures. The belt 4 tension can be screw-regulated using a screw 18 operating between the frame 17 of the machine and a support 16 on which the whole drawing train 7, comprising the wheel 8, the roller 11, the oscillating arms 20 and the pivot 21 with relative support to which the two arms are hinged, is mounted. Two tool heads 3, aligned according to the direction indicated by arrow 35, bearing the tools for planing the slabs or tiles 2 resting on the slats 5 are arranged above the upper branch of the slat conveyor belt 4. Each of the tool heads 3 comprises a first hollow spindle 22 bearing a mobile platform 23 to which a plurality of plane chuck spindles 24 are rotatably constrained, to each of which in turn a front-acting plane 25 is associated as well as a pulley 26. A second spindle 27, provided with an internal coaxial channel 28, is predisposed coaxially internally and rotatably of the first spindle 22, and inferiorly bears a pulley 29. The pulley 29, solid in rotation with the second spindle 27, draws the plane chuck spindles 24 in rotation by means of a belt transmission 30. A tube (not illustrated) is inserted in the coaxial channel 28 of the second shaft 27, having the task of conveying a fluid (in the present embodiment, water) on to the slabs or tiles 2 predisposed on the slats 5 of the upper branch of the conveyor belt during planing. The first spindle 22 is mounted rotatably internally of a sleeve 31 which is axially displaceable with respect to the frame 17 of the machine, in a parallel direction to the axis of said spindles 22 and 27, so that the planers 25 can be height-adjusted. The first spindle 22 and the second spindle 27 are driven in rotation by separate mechanical transmissions 36 and 37 which engage pulleys 38 and 39, not shown in the figures. The types of transmission used, which are independent, enable the rotation speed of the spindles 22 and 27 to be differentiated according to need. The chuck spindles 24 of each drive head 3 are arranged in a crown fashion around the axis of the platform 23 and at a distance therefrom which is greater than half the external diameter of the pulley 26 which is solidly constrained to each chuck spindle 24, plus the external diameter of the pulley 29 being solidly constrained to said second spindle 27. In particular, the pulley 29 which is solidly constrained to the second spindle 27 functions as a drive pulley for the drive transmission, through belts 30, to the pulleys 26 which are solidly constrained to the chuck spindles 24. Thus the working drive direction of a single drive head 3 on the slabs or tiles 2 results from the composition of the single planer 25 rotation directions about axes thereof and the orbital drive of the planers themselves about the rotation axis of the rotating platform 23. The pulley 29 which is solidly constrained to the second spindle 27 and the pulleys which are solidly constrained to the chuck spindles 24, together with the transmission belts 30, are sealedly housed internally of a chamber 32 which is solidly associated to the platform. From the bottom side of the chamber 32 the following debouch: at the centre, the lower end of the second spindle 27 with the outlet mouth of the relative coaxial channel 28 and, peripherally, the lower ends of the chuck spindles 24 bearing the front-acting planers 25. In this way the drive transmission from the second spindle 27 to the chuck spindles 24 can be protected, and the necessary liquid can be distributed centre-outwards on the slabs or tiles 2 being planed beneath the planers 25. The belt drive transmission means that the noise level during functioning is kept low. By arranging a plurality of planers 25, with drive directions as indicated, on a single head, it is possible to reduce (with respect to the prior art) the number of drive heads predisposed in series along the planing line 1 (i.e. the upper branch of the conveyor belt 4) of the tiles or slabs 2.

Claims: A planing machine for slabs, tiles and the like, comprising: a planing line (1) along which slabs, tiles and the like (2) are translated in a predetermined direction; at least one tool head (3) bearing tools for planing, arranged superiorly to said predetermined direction, arranged above the planing line (1) and predisposed to operate on said slabs, tiles and the like (2) conveyed on said planing line (1); characterised in that said planing line (1) comprises: a slat conveyor belt (4), formed by a plurality of slats (5) equidistanced and constrained one consecutively to another by flexible joint elements (6); said slat conveyor belt (4) exhibiting an upper branch on which are arranged means for supporting the slats (5) in movement, and maintaining said slats on a reference plane; at least one drawing device (7) for transmission of drive to said conveyor belt (4), which device comprises: at least one wheel (8) on which said slat conveyor belt (4) is partially wound, having a plurality of drawing elements (9) which are angularly equidistanced one from another and which are predisposed for mechanically interacting with the slats (5), two consecutive drawing elements (9) interacting with two consecutive slats (5), said wheel (8) being constrained to make displacements which have at least one direction which is perpendicular to said reference plane; a cam (10) solidly constrained to the wheel (8) and exhibiting an active surface which rests on a fixed-axis roller (11) and which is subdivided into a plurality of parts a number of which is equal to a number of said drawing elements (9), said plurality of parts being angularly positioned with respect to the drawing elements (9) in such a way that the joint (6) connecting a first of the slats (5) interacting with the wheel (8) and a slat (5) which is adjacent thereto and not yet interacting with the wheel (8) is not subject to displacements that are perpendicular to said reference plane by effect of a rotation of the wheel (8). The machine of claim 1, characterised in that said slats (5) superiorly exhibit a rest surface for the slabs, tiles and the like (2) which rest surface is laterally bordered by side walls (12). The machine of claim 1, characterised in that said flexible joints (6) are strip-shaped, preferably made of rubber, and are fixed to the slats (5) by screws (13). The machine of claim 1, characterised in that said means for supporting the slats (5) comprise a roller plane formed by a plurality of identical rollers (14), situated side-by-side at a short distance one from another and arranged parallel with axes perpendicular to the advancement movement of the belt (4). The machine of claim 1, characterised in that said drawing elements (9) are cog-shaped and predisposed to engage in seatings (15) made in bottom surfaces of the slats (5). The machine of claim 1, characterised in that said drawing device (7) is mounted on a support (16) a position of which with respect to the frame (17) of the machine is adjustable by means of a screw-adjustment (18) in the advancement direction of the belt (4). The machine of claim 1, characterised in that said wheel (8) exhibits a shaft (19) supported at free ends of two oscillating arms (20) forming a fork, other ends of which arms (20) are reciprocally solidly constrained and hinged on a same pivot (21) having an axis which is parallel to a rotation axis of the wheel (8). The machine of claim 1, characterised in that a peripheral surface of said wheel (8) is shaped as a regular polygon in which at a centre of each side thereof a drawing element (9) is predisposed. The machine of claim 8, characterised in that each said side is predisposed in such a way that a part of the bottom surface of each said slat (5) rests thereon. The machine of claim 1, characterised in that the drive head (3) comprises: a first hollow spindle (22) bearing a mobile platform (23) to which are rotatably supported a plurality of chuck spindles (24), each of which inferiorly bears a front-action planer (25) and is provided with a pulley (26); a second spindle (27), provided with a coaxial internal channel (28), rotatably and coaxially predisposed internally of said first spindle (22) and inferiorly bearing a pulley (29); rotation of the chuck spindles (24) being achieved by means of the pulley (2) which is solid in motion with said second spindle (27) by means of a belt transmission (30); the coaxial channel (28) of the second spindle (27) being provided for conveying a liquid on to the slabs, tiles and the like (2) arranged on said planing line (1); the first spindle (22) being rotatably mounted internally of a sleeve (31) which is axially slidable with respect to the frame (17) of the machine in a parallel direction to the axis of said first and second spindles (22 and 27); separate mechanical transmissions being provided for independently drawing in rotation, on command, said first spindle (22) and said second spindle (27). The machine of claim 10, characterised in that the plurality of chuck spindles (24) are disposed crown-fashion about an axis of the platform (23) and at a distance therefrom which is greater than half an external diameter of the pulley (26) which is solidly associated to said spindle (24) combined with an external diameter of the pulley (29) which is solidly associated to said second spindle (27). The machine of claim 11, characterised in that the pulley (29) solidly associated to said second spindle (27) functions as a drive pulley for drive transmission, by means of belts (30), to the pulleys (26), which are solidly associated to said chuck spindles (24). The machine of claim 12, characterised in that the pulley (29) solidly associated to the second spindle (27) and the pulleys (26) solidly associated to said chuck spindles (24) together with the drive transmission belts (30) are sealedly housed internally of a chamber (32) which is solidly constrained to said platform (23); from the bottom surface of said chamber (32) there exit: at a centre of said bottom surface, a lower end of said second spindle (27) with an outlet mouth of a relative coaxial channel (28) and, peripherally of said bottom surface, a lower end of said chuck spindles (24) bearing the front-acting planers (25). The machine of claim 10, characterised in that said separate mechanical transmissions for drawing independently in rotation, on command, the first spindle (22) and the second spindle (27), are of a belt-transmission type and act on pulleys (38), (39) fixed to upper ends of the first spindle (22) and the second spindle (27).

Inventors: GIOVANARDI UMBERTO, GIOVANARDI, UMBERTO
Applicants: R P S R L, R.P. S.R.L.
Application year: 1998
Main classification: B24B7
IPC codes: B24B7, B24B41, B23Q7