Description

A panel saw machine for panels made of wood or similar materials

Technical Field

This invention relates to a panel saw machine for panels made of wood or similar materials.

Background Art

At present, panel saw machines essentially comprise: a main frame comprising a first horizontal table; means for advancing the panels along a defined feed line and usually consisting of a crossbar mobile in parallel along said first horizontal table and equipped with clamps used for gripping the panel or panels to be sawn; a straight cutting unit or cutting front transversal to the feed line and comprising a beam that mounts one or two hold-down bars for pressing down on the panels, and a carriage, positioned near the beam and equipped with at least one mobile circular blade designed to cut the panels along a line transversal to the beam and usually passing between the hold-down bars; ' a second table, positioned in front of the cutting front, downstream of the cutting unit relative to the direction of panel feed on the first horizontal table, for supporting the panels and/or the respective panel lengths obtained by cutting.

Over time, these panel saw machines have been continually improved in all the parts described above in order to increase productivity, enhance panel cutting quality and make machine operation safer.

Thus, if on the one hand targets of high quality have been achieved, on the other, machine purchase and maintenance costs have risen proportionately. In practice, increased costs have restricted the range of potential machine buyers to companies with high productivity requirements that can quickly amortise the high initial cost of the machines, while individual craftsmen, one-person concerns and medium- to low-productivity companies cannot in most cases afford to buy machines of this kind.

For example, the panel hold-down beam (which this specification refers to in particular) positioned close to the blade carriage is one of the parts that tends to

increase machine cost considerably. That is because of the constructional complexity of the part, which consists of a monobloc bar that must be machined in different ways to make the grooves by which it can be coupled with the hold-down bars (to allow the blade to pass safely), the guides for coupling with respective uprights enabling the beam to be guided on both sides during the clamping-release movement of the panels to be cut.

In addition to this, the beam must not only be provided with mechanical accessories such as torsion bars and vertical movement systems to ensure correct vertical movement and secure clamping but also requires precision assembly of all its component parts.

Disclosure of the Invention

The Applicant has therefore designed and constructed a panel saw machine used for cutting panels made of wood or similar materials and whose reliability and good productivity are combined with a simplified structure of some of its parts in order to reduce machins costs, overall dimensions and weights.

According to the invention, this aim is achieved by a panel saw machine, especially a panel saw machine for panels made of wood or similar materials, comprising the technical characteristics described in one or more of the appended claims.

Brief Description of the Drawings

The technical features of the invention, with reference to the above aims, are clearly described in the claims below and its advantages are more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:

Figure 1 is a schematic top plan view of a panel saw machine according to the invention, for panels made of wood or similar materials;

Figure 2 is a front view, with some parts cut away in order to better illustrate others, of a part of the panel saw machine of Figure 1 ;

Figure 3 is a cross section through the line HI - HI of Figure 2, showing a hold-down unit on a work table in a non-operating configuration; Figure 4 is the cross section through the line in - El of Figure 2, showing a hold-down unit on a work table in a first operating configuration;

Figure 5 is a cross section through the line V - V of Figure 2, showing a

hold-down unit on a stack of panels in a first operating configuration;

Figure 6 is the cross section through the line V - V of Figure 2, showing a hold-down unit on a stack of panels in a second operating configuration;

Figure 7 is the cross section through the line V - V of Figure 2, showing a hold-down unit on a stack of panels and on a horizontal table in a first operating configuration;

Figure 8 is a scaled-up front view of a detail P from Figure 2;

Figure 9 is a scaled-up view of a detail Pl from Figure 3;

Figure 10 is a schematic exploded perspective view, with some parts cut away in order to better illustrate others, of the detail Pl of Figure 9.

Detailed Description of the Preferred Embodiments of the Invention

With reference to the accompanying drawings, in particular Figures 1 and 2, the machine according to the invention, labelled 2 in its entirety, is used for sawing panels 1 made of wood or similar materials.

The machine 2, as relevant in particular to this invention, essentially comprises: a horizontal table 3 for supporting the panels 1; means 4 for advancing the panels 1 along a feed line A and mobile in a direction parallel to and along the horizontal table 3 (illustrated schematically with gripper clamps 4p, being of customary type and not strictly relevant to this invention); a straight cutting unit or front 5 transversal to the feed line A and at least comprising presser means 6 for holding down the panels 1, and a carriage 7 positioned close to the hold-down presser means 6 and equipped with at least one mobile saw blade 8 (partly illustrated in Figure 2) designed to cut the panels 1 along a line T transversal to the feed line A.

As clearly shown also in Figures 3 to 7, the hold-down presser means 6 comprise at least the following: a first plurality of independent slats 9 positioned one after the other to form a first modular hold-down wall extending parallel to the transversal cutting line T, downstream of the blade 8 along the feed line A and slidably mounted on a respective frame 10; and first movement means 11 for modulating the position of the first independent slats 9, acting between the slats 9 and the frame 10, and designed to move them to at least two limit positions, between a first, raised idle position (see

Figure 3) where the slats 9 are away from the panels 1 and from the horizontal

table 3, and a second, lowered working position (see Figures 4 to 7 and arrows F), where at least some of the slats 9 are in stable contact with the panels 1 and the remaining slats 9 are in contact with the horizontal table 3 to form a partition wall on the latter. Figures 3 to 7 and 9 also show that the hold-down presser means 6 may advantageously comprise a second plurality of slats 12, positioned parallel to the first slats 9, to form a second modular hold-down wall upstream of the blade 8 along the feed line A and slidably mounted on the frame 10.

Since the structure is symmetrical, the second slats 12 are driven by second movement means 13 for modulating their position, which can be coordinated with the first movement means 11 and which act between the slats 12 and the frame 10 in such a way as to move them to at least the above mentioned two raised and lowered limit positions either successively or simultaneously with respect to the first slats 9: in this way, when the slat assemblies 9 and 12 are in the lowered position, a closed channel is formed on the panels 1 and on the horizontal table 3, on opposite sides of the saw blade 8.

In addition to the above, the hold-down presser means 6 may comprise second means 14 for adjusting the pressure of each slat 9, 12 and acting on the slats 9, 12, in such a way that the pressure of the slats 9, 12 on the panels 1 and on the table 3 is different, in particular when the blade 8 is in operation, that is to say, when the panels 1 are being sawn (as described in more detail below).

The numeral 15 in Figure 2 denotes means for transversely adjusting the frame 10, acting between the frame 10 and a fixed frame 16 of the machine 2, and designed to move the frame 10 in both directions (see arrows Fl 5) along a line T' perpendicular to the feed line A at least when the slats 9, 12 are in a lowered, working position, in such a way as to align the panels 1 laterally by moving the panels 1 against a longitudinal member 16 of the machine 2: this is achieved by pushing the slats 9, 12, which are in contact with the horizontal table 3 (as also described in more detail below), sideways. The frame 10 comprises the following (again with reference to Figures 3 to

7 and 9): a main, fixed plate 17 positioned transversally above the horizontal table 3 and supporting identical members symmetrically positioned on opposite sides of it, including two first supports 18, 18' positioned on both sides of, and associated with, the main plate 17 and respectively mounting the first and second means 11 and 13 for moving the slats 9 and 12;

two second supports 19, 19' positioned inside the two respective first supports

18, 18' and slidably associated with one side of the latter through respective first slides 20, 21, 24, 25 that engage respective first slots 22, 23 made in the first supports 18, 18'. The second supports 19, 19' are moved to and from the above mentioned raised and lowered positions by the first and second movement means 11 and 13 which are connected to the upper ends of the second supports 19, 19'.

The first and the second pluralities of slats 9, 12 are slidably associated with one wall of the second supports 19, 19', respectively. Each slat 9, 12 is driven by the movement of the respective second support 19 and 19' by at least one of the first, vertical movement slides 24, 25, the latter moving in a respective second slot 26 and 27 made in each slat 9, 12 and being positioned on each side of a first slot 22, 23, in such a way that the slats can move to the above mentioned raised and lowered limit positions. Each slat 9, 12 is provided with first means 28 for adjusting the position and pressure of the slats 9, 12 when they are in the lowered position.

These first means 28 comprise a first spring 28m for each slat 9, 12 positioned between a pin 29 associated with the top end of the slat 9, 12 and, at the bottom, with a second slide 30 integral with the first slide 24, 25 and designed to connect the respective slat 9, 12 to the slide 24, 25: in this way, the slat 9, 12 can be moved to a first stable position, where a first pressure is applied to the panels 1 or to the horizontal table 3 independently of the movement of the first and second movement means 11 and 13 by allowing the second slide 30 and the respective slat 9, 12 to slide partially relative to each other. In other words, the length of the upstroke/downstroke of the first and second movement means 11 and 13 may be fixed (distance D from the table 3), while the position of the slats 9 and 12 may vary according to whether panels 1 are present or not: thus, the slat 9, 12 stops on the panel 1, while the second slide 30, associated with the first slide 24 and 25, continues moving (see arrow F30, Figure 5) which, thanks to the first spring 28m, also causes the slats 9, 12 to apply a first slight hold-down pressure on the panels 1.

Further, each second support 19, 19' of the frame 10 houses a third support 31, 31', equipped with the above mentioned second means 14 for adjusting the pressure of the slats 9, 12 when they are in the lowered position. Each of the third supports 31, 31' is slidable relative to the second support

19, 19' through third movement means 32 positioned between, and associated with, the second and third supports 19, 19' and 31, 31' and forming part of the

second adjustment means 14, in such a way as to define at least two limit positions (see arrows F32 in Figure 6) where the third support 31, 31 is away from the horizontal table 3 (see Figures 3, 4, 5 and 7) and close to the horizontal table 3 (see Figure 6), respectively. In addition to the third means 32, the second pressure adjustment means 14 further comprise, a second spring 14m for each slat 9, 12, connected at each end to the above mentioned pin 29 associated at the top end with the slat 9, 12 and, at the other end, to the bottom end of the third support 31, 31' in such a way as to increase the contact pressure of the slats 9, 12 on the panels 1 and on the horizontal table 3 when the slats 9, 12 are in the lowered position and the third support 31, 31' is in the limit position close to the horizontal table 3: this stabilizes the panels 1 in the area where the blade 8 passes when they are being sawn.

As in the previous case, therefore, the second spring 14m creates traction on each slat 9, 12 when the third support 31, 31' moves down, thereby increasing the pressure on the slat 9, 12 and hence on the panels 1 and on the table 3.

Looking now at the structural details of the supports described up to now (see also Figure 10), each first support 18, 18' has a cross section in the shape of an upturned U.

The top horizontal wall of the U is associated with one part of the first and second movement means 11 and 13, while a vertical wall of the U, adjacent to and associated with the above mentioned main plate 17, has two consecutive first slots 22 and 23.

Similarly, each second support 19, 19' has a cross section in the shape of an upturned U. The top horizontal wall of the U is associated with the other part of the first and second movement means 11 and 13, while the vertical wall closest to the main plate 17 is associated with the first slides 20, 21, 24, 25 that run in the respective first slots 22 and 23 made, as stated above, in the vertical wall of the respective first support 18, 18'. Further, the top horizontal wall of each second support 19, 19' is associated with one part of the third movement means 32 acting on the third support 31, 31'.

Each of the third supports 31, 31', on the other hand, has a C-shaped cross section.

The top horizontal wall of the C is associated with the other part of the third movement means 32, while the bottom horizontal wall of the C has connected to it the second spring 14m enabling the pressure on the slats 9, 12 to be increased when the third support 31, 31' is in the lowered position.

As clearly shown in the accompanying drawings, the first and second movement means each comprise at least two actuators 11 and 13 positioned between and associated with the first and second supports 18, 18' and 19, 19' and connected to a main unit 33 for controlling the machine 2 (illustrated as a block in Figure 6, since it is of known type).

Similarly, the third movement means may comprise at least two second actuators 32 positioned between and associated with the second and third supports 19, 19' and 31, 31'.

Obviously, the number of actuators may vary according to the size of the machine and, hence, of the frame and supports, and also according to the pressure to be applied to the panels 1.

As mentioned above, the first supports 18, 18' are associated with the means

15 for transversely adjusting the frame 10, acting between the supports 18, 18' themselves and the fixed frame 16 of the machine 2, and designed to move the supports 18, 18' in both directions along a line T' perpendicular to the feed line A at least when the slats 9, 12 are in the lowered, working position.

More specifically, the transversal adjustment means 15 may comprise a third actuator 15a associated, at one end, with the fixed frame 16 and, at the other, with the first supports 18, 18' in order to perform the transversal movement. As shown also in Figure 8, the first supports 18, 18' may be provided with a plurality of rolling means or bearings 34, connected to the first supports 18, 18' and in contact with the top of the main plate 17 of the frame 10 in order to allow the transversal movement in both directions.

Obviously, the first supports 18, 18' have horizontal slot-like openings 50 made in them engaged by screws 17v associated with the plate 17 in such a way as to permit the transversal movements of the supports 18, 18'.

As regards the structure of the slats 9, 12, these have a bottom end 9e, 12e that is designed to come into contact with the panels 1 or with the horizontal table 3 and is made of a synthetic material to avoid causing damage on contact at high pressure.

Each slat 9, 12 also has a first, flat rod shaped top portion 9s, 12s and a second bottom portion 9i, 12i, wider than the first, to form the bottom end that comes into contact with the panels 1 or with the horizontal table 3 and giving it a "paddle"-like shape. The second slot 26, 27 is made in the second portion 9i, 12i of each slat 9,

12.

In practice, the panel saw machine 2 made as described above operates as

described below.

Once the panels 1 have been fed along the table 3 and positioned in the cutting area, the hold-down presser means 6, illustrated in working position in

Figure 3, are activated, that is to say, the first movement means 11 and 13 lower the slats 9 and 12 in such a way as to cover both sides of the cutting line of the blade 8, applying a slight pressure on the panels 1 and table 3 (Figures 4, 5 and 7).

If necessary, at this point, the transversal movement means 15 are activated, causing the panels 1 to abut against the longitudinal member 16, thanks to the pushing action of the slats 9, 12 positioned on the table 3, but adjacent to the panels 1 (this is possible precisely because the pressure applied to the panels 1 at this stage is slight).

Once this has been done, the third actuators 32 are activated to increase the pressure of the slats 9 and 12, thus holding down the panels 1 securely and enabling them to be cut safely. A machine constructed as described above therefore fully achieves the aforementioned aims thanks to the modular structure of the hold-down means, which has several advantages, including: improved assembly adaptability to user's requirements; improved distribution of pressure on the panels, thus achieving better quality cuts; multiple hold-down functions enabling the panels to be aligned laterally; improved efficiency of dust extraction system thanks to the closed channel created by the slats, which prevents dust from escaping; lower cost of hold-down means and, hence, reduced overall cost of machine thanks to the simple structure of the frame and supports, eliminating the need for complex machining processes for frame construction.

The invention described above is susceptible of industrial application and may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.