Pedrazzoli band and circular sawing systems
Pedrazzoli offer a wide range of sawing methods and equipment. The range starts from simple pull down circular saws, to fully automatic cutting lines using either bandsaw, circular saw or knife cutters.
Pedrazzoli’s machines are characterised by extreme sturdiness and long work-life; their structure is entirely made of cast iron with high precision machining. Cutting heads are perfectly balanced to give a pleasant and effortless cutting action. They are supplied in one-speed, two-speed or with steplessly variable speed drive unit. Integral cutting table with rotating disk provides excellent support for material even the case of very short lengths while reducer’s screw has a double support on ball bearings and an elastic joint which ensure a perfect vibration-free cut and consequent long blade life.
Pedrazzoli’s semi-automatic cutting machines are very fast and noiseless thanks to particular constructive design of the screw-ring transmission, the double screw support on bearings and the original design of clutch unit. The infinitely variable speed drive unit gives excellent results in varied work conditions even when the blade’s diameters is quite small. Head tilts on adjustable self-lubricating bushings, anti-burr vice is reversible and can be connected both on left-hand and right-hand side. The pneumatic head movement unit is complete with hydraulic brake . This enables operator to adjust blade descent speed according to type of material and type of cutting blade used. Also these models can be fitted with blade cleaning devices, inversion of blade rotation direction unit, pedestals and loading-unloading tracking.
These extremely versatile machines are supplied with feeders which allow to keep cutting pieces until bar finishes. 45° cuts both left and right can be carried out in semi-automatic mode , while the version for aluminium cutting can also perform mitre cuts off the vertical up to 45°. Rotation of graduated disc is upon tempered balls with automatic stops in 90° and ± 45° positions and manual stops in intermediate positions. The vices move freely in horizontal direction and head tilting upon adjustable self-lubricating bushings makes machines reliable even on large cutting capacity with ø 350 mm blades. The feeder carriage is complete with clamping cylinder with adjustable closing pressure which allows to securely grip piece with no deformation; the 600 mm stroke can be selected as single or multiple step and adjustable speed. Machines with feeder can also be used in semi-automatic cycle, with single step feeling or in totally automatic cycle.
The automatic cutting lines are complete with loader, feeling unit, cutting unit and discharge selector. Pedrazzoli can supply version for tube, full bar and profile cutting, for ferrous materials, light alloys and structural steelwork. Type of loader can be chosen between chute loaders, toothed loader for full bars, bunker loaders with belt loading for tubes and chain loading for heavy profiles.
Discharge units can also be supplied according to cutting line’s application, with maximum discharge lengths which go from 500 mm to 7000mm and structures to ensure correct discharge both of light tubes and heavier pieces. We can also supply automatic systems to separate scraps and trim cuts from good pieces and to check cut lengths by means of magnetic bands.
Cutting lines can be completed by adding automatic swarf extractors, deburring machines, cleaning systems and automatic stacking devices for cut pieces.
In this group of machines we can define 4 main sub-groups with a specific application:
Manual models feature a band start button on handle and automatic return of cutting head to rest position the moment operator interrupts cutting process. Machines are also fitted with adjustable hydraulic brake, an indispensable accessory as it makes head descent independent from operator so improving quality of cut and increasing band life.
Vices allow rapid nearing and clamping thus ensuring a strong and secure grip on piece which combined with the jaw and mobile back rest guarantee that material is always resting correctly during cutting. The head hinge pin is fitted on conical roller bearings and is adjustable to allow compensation of any axial play. Transmission of motion from motor to band is by means of reducer in oil bath. Machines are furthermore complete with dampened limit switch for bow return. Extractable swarf collection vat, lockable switch, safety micro switches on band covers, and variable speed drive unit are standard equipment. Loading, unloading tracking is also available.
Semi-automatic model can make single cuts without presence of operator. The wide circular base is fitted on ball track and this makes rotation and positioning extremely fast and precise also thanks to adjustable mechanical stops. Machines have bow inclined upon the vertical by 35°, inclination which together with big diameters of flywheel limit as far as possible the yielding of the band; to this we can add the adjustable blade guide device which noticeably reduces wear on band. Semi-automatic band saws can be supplied with two-speed selector or with variable speed drive unit. All machines are supplied with rapid band tensioning device, very practical and reliable it immediately gives a constant tension of 600 kg. Standard equipment is the band rotation sensor which allows control unit to check work overload, excessive reduction of number of revolutions or to stop machine in case of band breakage. One can adjust position and speed of the hydraulic head movement unit. Position of bow is read by a linear potentiometer by means of which one can set cutting start and end position. The PLC which controls this series of semi-automatic machines has been developed especially to obtain the correct sequence of cutting and to give all the extremely useful diagnostic messages. The control panel is complete with membrane key-pad with can be used even in critical environments with no risk of wear. Digital display with large characters and icon commands make use of this machine simple and intuitive.
Machines with automatic feeder are designed to cut single bars or whole bundles unassisted until material is exhausted: this makes them very flexible machines which can be used even for particularly exacting work. This family of machines can be supplied with two axis numeric control and electronic blade speed rotation. Adjustment of descent speed, control of cutting head’s position by means of linear potentiometer and the proximity switches which in every moment monitor the state of machine guarantee sturdiness, long working life and flexibility of use. Models available include 45° left and 60 ° right mitre cutting models, with head supported upon bearings which eliminate any axial play and make cutting unit adaptable even to most exacting working conditions. Moto-reducer is placed in vertical position to reduce rear dimensions of machine, cutting bow is balanced and step feeder has been designed so as to reduce end scrap to minimum. Here again the control panel, with large visual display and icon keys allows one to easily access, in an intuitive manner all machine functions, with simultaneous visualisation of the various diagnostic messages. The presence of a rotation sensor guarantees an extremely high level of safety which together with the mechanical structure involved in band’s movement, preserve motor from overloads and makes band’s life much longer. The machines also come with a wide range of accessories such as vertical anti-burr vice, loading/unloading tracking, laser pointer for cutting position and bundle cutting device.
Tool cutting systems are used in cutting lines to obtain high productivity , above 3200 pieces/hour, with noise limited to sole cut piece falling.
There are two different cutting techniques:
The first uses a circular knife rotating on itself at a high speed while simultaneously rotating round the tube’s circumference. Second technique uses two orthogonal knives mechanically synchronized: the horizontal knife removes a thin layer of material from upper part of tube after which vertical knife slices through remaining tube thickness to finish job. Both kinds of machine are suitable for working big batches in fast and silent manner with very limited intervention by operator and limited wear on tools. They can be connected to complete deburring systems and stacking systems for cut pieces which makes them suitable for the most diverse cutting requirements.