The purpose of the invention is to saw particularly hard stones with two parallel blades tensioned in a frame having an almost vertical oscillating motion.
For hard stone sawing like granites, one commonly uses sawing machines with one or more blades, animated by a straight reciprocal or oscillating movement. The blades used are either steel ones, sprinkled with water and abrasive grits (like sand, steel shot or silicon carbide) either ones with diamond segments.
Some of those machines only have one blade animated by a horizontal axis oscillation while the stone blocks are in horizontal traverse movement. The blade is tensioned in a frame to avoid deviations during the sawing. It is better to place the blade laterally in order to accomodate blocks of unlimited width.
The major inconvenience of such machines is that one has to cut one slab at a time, rendering the sawing slow and expensive. Another inconvenience is given by the asymmetrical disposition of the blade in tne frame, introducing a bad equilibrium of the tensions in the machine and this creates deviations during the sawing.
Machines having several blades are also well known. Those blades are tensioned parallely in a frame which is animated by a horizontal axis oscillation or a straight reciprocal vertical movement, with a horizontal traverse movement for the block to be sawn. The distance between the blades is chosen in order to saw the slabs with a desired thickness. The evident advantage of such machine is that series of slabs can be sawn in one operation.
The inconveniences of such machine are unfortunately numerous. The tensioning of the blades in the frame is, indeed, a long and arduous operation and it is not possible to modify the distance between the blades as one would like. The width of the sawn slabs can not be regulated in accordance with clients' demands and one has to be satisfied with standard width.
Another inconvenience of multiblade machines lies in the frame wherein the block to be sawn has to pass through. One can thus see that the frame dimensions are determined for those of the blocks. In particular, the width of the blocks has always to be below the inside width of the frame.
It must also be observed that the construction of such kind of multiblade machine is sophisticated and always expensive.
The object of the hereby invention is to remedy the above mentioned inconveniences, realizing a double blade sawing machine, giving the opportunity of simultaneous sawing of two slabs with arbitrary thickness in two independent blocks placed on both sides of the machine. One realizes like this a symmetrical machine, fast and economical.