EP0539635A1

EP0539635A1 - Stone sawing machine

Info

Publication number: EP0539635A1
Application number: EP91310072A
Authority: EP
Inventors: Armando Pedro Luis
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-01
Filing date: 1991-10-31
Publication date: 1993-05-05
Also published as: BR9003763A; PT93025A

Abstract

The present invention concerns an alternative machine for cutting stone blocks with a laminated diamond tool, in which the cutting is done vertically during the descendent stroke, the inverse stroke movement being passive for the cutting.

Besides, the support structure of the diamond blades is compensated statically by another structure having the same mass which can be passive or active to cut if it bears or not a diamond tool and which describes a parallel movement to the first one but with a phase difference of half cycle.

The present machine is useful to cut ornamental stones.

Description

INVENTION DESCRIPTION

A - BACKGROUND OF THE INVENTION
B - WORKING PRINCIPLE
C - BRIEF DESCRIPTION OF THE EQUIPMENT
D - FINAL CONSIDERATIONS

A - BACKGROUND OF THE INVENTION

Traditionally, the linear cutting of stone blocks is done using 2 distinct tools which can be classified into 2 groups:

a) Diamond tools, used actually in the cutting of the smoothest stones, such as marble and similar ones, consisting of a series of diamond segments joined by soldering to steel blades adapted to a rectangular structure usually called "frame" to which an alternative linear movement is transmitted.
b) Tools without diamond, used in the cutting of the hardest stones, such as granite and similar ones, which cut by abrasive cutting and do not dispense the introduction of steel granules between the tool and the stone.

In conformity to the above mentioned diamond tools, these blades are adapted to a "frame" to which an alternative linear movement is transmitted.
These two processes have as a common situation the fact that both the strokes of the alternative cycle are useful for cutting.
In the known cases, the "frame" movement is made on a horizontal, vertical or oblique plane and is transmitted through mechanisms of rod-crank type but without compensation of the mass in alternative movement.
The object of this invention is to provide a machine for cutting hard stones with diamond tools having a vertical alternative linear movement, only the descending stroke of which being useful.
The machine accomplishes the presupposition that every working parameter inherent to the cut may be varied in function of the stone nature to be cut, block dimensions and thickness of the sections to be obtained.

B - WORKING PRINCIPLE

It was considered that the adequate methodology to attain the above mentioned aims passes through the vertical cut of the stone block along its length.
The cutting device comprises a set of steel blades having a constant rectangular cross-section, one of the longitudinal edges of which having diamond cutting segments with a convenient shape and spacing, each assembled to the other parallelly and removably fixed to a vertical structure, which is called "frame", to which an alternative linear movement is transmitted.
The cutting is carried out only during the strokes from up to down of the "frame". Therefore, the frame in addition to the vertical movement has also a transversal movement which permits the approximation of the blades set to the block during the stroke from up to down and its backward movement during the inverse strokes.
The cutting advance is obtained by the horizontal movement of the stone block against the "frame".

C - BRIEF DESCRIPTION OF THE EQUIPMENT

The machine to cut stone blocks with diamond tools is totally built of steel and comprises mainly two units:

C.1. Structure for the stone block support and movement;
C.2. Cutting assembly unit.
- C.1. STRUCTURE FOR THE STONE BLOCK SUPPORT AND MOVEMENT (It comprises):
  - C.1.1. The structure for the whole stone block support and movement which is anchored in the ground, being arranged frontally and before the "frame". It contains the system for the block approximation.
  - C.1.2. Structure for the block reception after being cut which is arranged vertically after the "frame". It is susceptible of longitudinal movement and is used to receive and move the cutted sections of the block.
- C.2. CUTTING ASSEMBLY UNIT (It comprises):
  - C.2.1. Fixed structure of closed ring portico type anchored in the ground and useful for supporting and guiding the movable structure.
  - C.2.2. Movable structure which is made of the three next assemblages:
    - C.2.2.1. Structure called "rocking lever". It is a closed ring structure in a horizontal position, pivotable approximately in the middle according to the transversal direction which receives an alternative movement received from a double motion mechanism of rod-crank type driven by an electro-hydraulic system.
    - C.2.2.2. Structure called "frame". It is the structure already referred having the shape of a closed ring, upperly pivotably linked to the "rocking-lever" by means of an axle parallel to the axle defined by the articulation of this and having a vertical guiding solidarized with 2 columns to the portico as defined under C.2.1. The "frame", as already referred, is the support for the diamond blades which are the cutting tools and simultaneously acts as the longitudinal stretching device of the blades.
    - C.2.2.3. Statical compensating structure of mass, called "counterweight".
      It is a structure pivoted to the "rocking lever" on a parallel axle defined by the pivotable axle of this and in opposition to the "frame". It has a vertical guiding solidarized by 2 columns to the portico as defined under C.2.1.

D - FINAL CONSIDERATIONS

Besides the functional scheme of the itself machine which we think is new in this kind of equipment, it is important to point out that it is the cutting principle in the vertical direction and only during the descending stroke which deserves a special attention, because besides its innovatory character, it allowed to obtain very encouraging results concerning the speed and economy of the cutting operation as the already done test runs have have shown.

Claims

A granite and/or similar stone blocks sawing machine having a diamonded tool with reciprocating vertical movement, being useful for the cutting only the descending stroke, which comprises a statically balanced supporting structure for the cutting tool by means of another non-cutting structure with the same weight having parallel movement to the first one, both being articulated on a common structure (crankshaft) which causes a difference of phase of 180 degrees, characterized by the fact that the vertical structure is comprised by two metallic rectangular shaped frame structures, one being contained in the other.
The sawing machine according to claim 1, characterized by the fact that the assembly made by both exterior and interior frames has an alternative vertical movement whereas the interior frame has an independent movement perpendicular to the vertical movement of the assembly.
The sawing machine according to anyone of claims 1 and 2, characterized by the fact that the interior frame is supported on the exterior frame by means of several linear bearings, each of which also support two linear single acting hydraulic actuators which oppose each other and position the interior frame relative to the exterior frame in the horizontal movement.
The sawing machine according to anyone of claims 1 to 3, characterized by the fact that the driving system of the interior frame relative to the exterior frame is a hydraulic system generating a pressurized flow of a hydraulic fluid which causes the simultaneous extension and retraction of each pair of the opposing single acting hydraulic actuators.
The sawing machine according to anyone of claims 1 to 4, characterized by the fact that the hydraulic system which drives the interior frame relative to the exterior frame is driven by the crankshaft which causes the alternating movement of the frames and comprises
a) two linear hydraulic actuators working as alternative pumps each driven simultaneously by said crankshaft and each having equal volumes;

b) an electrically actuated bypass valve which is opened only for the starting up and shutting down procedures to interrupt cutting;

c) two hydraulic fluid accumulators, the maximum volume of each being equal to the total volume of the corresponding linear hydraulic actuators at maximum stroke for a preset regulated pressure;

d) a flow regulator which connects both volumes of said two hydraulic actuators according to a) so as to regulate the corresponding hydraulic fluid flow;

e) some pressure regulators which limit the maximum fluid pressure delivered to said hydraulic actuators and return the excess fluid to a storage tank;

f) said two linear hydraulic actuators as described above in claim 3, each of which are provided with a mechanical stop:

g) two unidirectional control valves which allow that the hydraulic fluid pump (i) to pressurize the hydraulic circuit at a preset pressure;

h) a pressure relief valve which assures a supply of hydraulic fluid at a preset pressure and prevents an excessive pressure; and

i) a hydraulic pump for pressurizing the hydraulic circuit at a preset pressure.
The sawing machine according to anyone of claims 1 to 5, characterized by the fact that said linear hydraulic actuators as described at claim 5. a) are provided with an angular position adjustment relative to the centerline of the crankshaft support bearings.
The sawing machine according to anyone of claims 1 to 6, characterized by the fact that the advance of the granite block toward the cutting tools is discontinuous and occurs only during the upstroke of said exterior and interior frame assembly, at which time the inner frame is in a retracted position.
The sawing machine according to anyone of claims 1 to 7, characterized by the fact that the pressure required to cut the granite block is applied hydraulically at a constant, regulated, adjustable rate during the cutting stroke.
The sawing machine according to anyone of claims 1 to 8, characterized by the fact that the blade construction is arranged in segment groupings which consist of an even number of segments and an uneven number of spaces which is one less than the number of segments.
The sawing machine according to anyone of claims 1 to 8, characterized by the fact that the diamonded tool segments are installed on each blade according to the following relationship: Stroke length of blade(s) S = 155 mm Individual segment length 1 = 20 mm Individual space length v = 25 mm Space between segment groups V₁ = 60 mm Number of segments per group N = 4 Number of spaces per group n = 3 Total length of segments per group L = N x 1 = 80 mm Total length of internal spaces per group V = n x v = 75 mm Total length of spaces per group V₂ = V₁ + V = 135 mm Total length of the segment group G = L + V = 155 mm
The sawing machine according to anyone of claims 1 to 10, characterized by the fact that the vicinal segments are mounted offset to the centerline of the blade.
The sawing machine according to anyone of claims 1 to 11, characterized by the fact that the major surface of each vicinal segment is at same level of the major surface of the blade.