Board sawing apparatus.

Abstract: Sawing apparatus, comprising a frame (1) with means for supporting on or against it a board for sawing, and first guide means (9) which are designed for supporting and guiding in a first direction a coupling part (11) on which are fixed second guide means (12) intended for supporting and guiding a machine saw (14) in a second direction crossing the first direction, so that the machine saw can be moved in a plane running parallel to the board. Extraction means have a suction nozzle (17) provided at the front side of the board, for extracting particles of the board escaping during the sawing. An extraction channel (23) is fixed at one end of the second guide means, running parallel to the second guide means and, after positioning, running behind the board, which channel is connected to an inlet of the extraction means and has an elongated opening running in the vicinity of a saw cut to be made in the second direction, for the extraction of particles released from the board at the rear side of the board at the saw cut. The supporting means have supporting elements which are designed for supporting the board, and which are movable by means of stop means of the extraction channel in a third direction crossing the board, in order to allow passage of the channel and the stop means.

Description: The invention relates to a sawing apparatus as described in the precharacterizing portion of claim 1. A sawing apparatus of this type is disclosed by GB-A-2139556. A frame of the prior art apparatus is bounded by two vertical columns and two horizontal girders connected firmly at the lower and upper ends of the vertical columns. A guide post is arranged through the intermediary of rollers and rails on the two horizontal girders so that the guide post can be moved in a first (horizontal) direction along the total length of the frame. A sawing unit is attached to the guide post. The sawing unit is slidable in a second (substantially vertical) direction perpendicular to said first direction along the guide post. In addition the sawing unit can be pivoted over 90°, so that the circular saw blade assumes a horizontal or vertical cutting position. A suction nozzle of a housing of the sawing unit covering the sawing blade is connected to vacuum extraction means. A horizontal exhaust duct, or extraction channel, is guided with vertical sliding mobility on the two columns of the frame. The exhaust duct is provided with a slot extending along the total length of the exhaust duct for receiving therein an end part of the circular sawing blade which has passed a board to be sawn positioned and supported between the sawing unit and the exhaust duct. Both the sawing unit and the exhaust duct are engaged by cables and counter weights to compensate the weight of the sawing unit and for easily manually guiding the sawing unit along the guide post, and for maintaining the horizontal exhaust duct at a position opposite the sawing unit while keeping the sawing blade received in the exhaust duct. With the prior art apparatus a board to be sawn is supported on rollers arranged on the lower horizontal girder and an upper edge part of the board is clamped by clamp claws arranged on the upper girder. In this position the board lies against, or is supported by the horizontal exhaust duct. In the reference it is considered that such construction provides a poor supporting of the board. Therefore, preferably, the exhaust duct is provided with a plurality of support arms, extending from the duct to above only, and the upper girder is provided with similar support arms extending from the girder downwards between the support arms attached to the exhaust duct. The length of the support arms is about one third of the frame height. The support arms are intended to provide additional support to the board to be sawn. However these support arms provide only additional support for an upper part of the board, i.e. above a saw cut to be made. The support for the lower part of the board, below the saw cut, remains poor. Another drawback is that the height at which the horizontal saw cut can be made is limited by the presence of the supporting arms. For making a vertical saw cut in the board, the board needs to be moved from said frame with the horizontal exhaust duct to a complementary auxiliary device having a fixed vertical channel with a vertical slot for passing through a sawing blade of an auxiliary sawing device, the latter channel being connected to vacuum extraction means. This makes the whole arrangement for making horizontal as well vertical saw cuts very large, taking much valuable room in a working place, and makes the whole arrangement even more complex and expensive. From DE-A-1528001 there is known a sawing apparatus having slightly inclined posts for supporting a board to be sawn against it. At the lower end of each of post there is provided a roller. The board is supported on several, but not all, of said rollers. At the upper part of the frame of this prior art apparatus there are arranged first guide means, a coupling part and second guide means and a sawing unit connected to the second guide means as with the apparatus described in the precharacterizing portion of claim 1. With this prior art apparatus there is connected a guiding member having run-on edges extending parallel to the board. Each post is provided at the upper end thereof with an additional roller at such a height to only engage a run-on edge if the post and the guiding member are aligned and such roller and the guiding member are pushed against each other. If a roller of a post is engaged by the guiding member when displacing the guiding member horizontally the post is forced downwards and backwards, the latter movement providing room for moving the sawing unit vertically without the sawing blade interfering with such post lying opposite it. The posts are moved downwards and backwards against the force of springs arranged between the frame and the posts. The prior art apparatus disclosed by DE-A-1528001 is not provided with saw dust extraction means. With the art apparatus disclosed by DE-A-1528001 the springs arranged between the frame and the posts must be rather strong, since it must be prevented that the weight of a board to be sawn only can have the result that the posts are pushed backwards, instead of only by the guiding member pushing against the upper end of the post of concern. Therefore said springs must be designed for even the heaviest allowed board and/or board with maximum allowable dimensions, requiring relatively strong springs with respect to situations in which just light weighted or small boards need to be sawn. Also, if the springs are insufficient strong the board to be sawn, supporting on rollers at the lower ends of the posts, can inadvertently move downwards, making a selected or adjusted height of the sawing cut less accurate, or making sawing even hazardous because of the poor support. Since during sawing the sawing blade exerts a force also against the working of said springs, the design of the arrangement and the tension of the springs should have taken into account such sawing forces, which are dependent on the materials to be sawn and the type of the saw blade and which are therefore at the long term unpredictable. Therefore this prior art apparatus is difficult to design, complex, difficult to maintain, difficult to use when sawing light or small boards, and expensive to manufacture. It is an object of the invention to solve the drawbacks mentioned above. Said object is according to the invention obtained by a sawing apparatus having the features of claim 1. Each of the plurality of supporting members, distributed across a board to be sawn needs only to be designed to be able to support a board area supported by it. Therefore, if such supporting member is spring loaded, the spring need not to be as strong as with the prior art. The extraction channel can move very smoothly and easily, without applying great forces, between the supporting means and the board to be sawn, while pushing the supporting members out of its way when engaging them. The board to be sawn will not move inadvertently in any direction enabling sawing cuts, which accurately follow predetermined or selected trajectories on the board. A sawing cut can be made across virtually the whole area bounded by the frame. The invention is explained with reference to the drawings. In the drawings: Fig. 1 shows in perspective a part of a sawing apparatus according to the invention; Fig. 2 shows, on a larger scale, a part of supporting means of the apparatus shown in Fig. 1; Fig. 3 shows an alternative embodiment for the supporting means shown in Fig. 2; Fig. 4 shows a cross-section of the apparatus shown in Fig. 1 along the line IV-IV, in which a board is placed; Fig. 5 shows a cross-section like that of Fig. 4 of another embodiment of the apparatus according to the invention. The apparatus shown in Fig. 1 comprises a frame 1 on which a number of horizontally running rectangular tubes 2 are disposed above one another. Elongated openings 3 are formed at regular intervals in the tubes 2. Through each opening 3 projects a supporting element 4 which is pretensioned by means of spring means, such as a leaf spring 5 (Figs. 4 and 5) in the direction indicated by the arrow 6 (Fig. 2). A board 8 (not shown in Fig. 1, but shown in Figs. 4 and 5) can be placed on movable supporting blocks 7 against the supporting elements 4. The tubes 2 and the supporting elements 4 are disposed in such a way that the board 8 runs essentially vertically. Hereinafter, the side of the board 8 resting against the supporting elements 4 is called the rear side, and the other side of the board 8 is called the front side. Guide means 9, which are suitable for moving a coupling part 11 in a first direction, indicated by the double arrow 10, are provided at the top side of the frame 1. Connected to the coupling part 11 are second guide means 12, which are suitable for moving a machine saw 14, which can be locked to the second guide means 12, in a second direction, indicated by the double arrow 13. The machine saw 14 comprises a motor 15 for driving a circular saw blade 16 (Figs. 4 and 5), situated in an essentially closed housing 17. At the side of the tubes 2 the housing 17 has an opening 18 through which an end part 19 of the saw blade 16 projects. The housing 17 has a tubular connection piece 20 which is connected by means of a hose 21, a tube 22 and a pipe (not shown) to extraction means (not shown). The result is that during the sawing of the board 8 particles of the board released at the front side of the board 8 can be extracted efficiently by the extraction means. An elongated extraction channel 23, running opposite the second guide means 12, is also fixed on the coupling part 11. The extraction channel 23 is bounded (Fig. 4) by an elongated chamber 24 and a wall part 25 with an elongated space or opening 26 between them which is suitable for receiving therein the end part 19 of the saw blade 16. In the extraction channel in the vicinity of the end part 19 of the saw blade 16 provision is made for short partitions 27 which prevent deformation of the chamber 24 during sawing, and which ensure a good seal between the rear side of the board 8 and the walls of the channel 23 lying against it. When the machine saw 14 makes a vertical saw cut, particles from the board 8 escaping at the rear side of the board 8 will essentially fall downwards. In most cases it is therefore sufficient to provide a connection opening 28 at the bottom side of the extraction channel 23, which opening is connected by means of a hose 29 to extraction means which can be the same extraction means as those with which particles of the board 8 released at the front side of the board 8 are extracted. By means of a guide roller 30 and a pull cord 31, to which pulling means (not shown), for example spring-loaded means, are connected, the hose 29 can be held in the orientation shown in Fig. 1, in which the hose 28 does not go in the way of the board 8 or of the machine saw 14. When the machine saw 14 is rotated through 90° for making a horizontal saw cut, in which the saw blade 16 (also) turns in the direction indicated by the arrow 32 (Fig. 4), particles of the board released at the rear side of the board 8 will be thrown both downwards and upwards. In this embodiment of the device it is therefore preferable to provide a connection piece 33 also on the top side of the extraction channel 23, connected by means of a hose 34 to the extraction means. In an alternative embodiment a vertical partition 35 is fitted in the channel, dividing the channel on either side of the partition 35 into 2 sub-channels 36, 37. The partition 35 does not run right to the bottom side or right to the top side of the extraction channel 24. When the suction opening 28 and the hose 29 connected to it are not provided (the channel is closed at the position of the opening 28), use of the partition 35 will mean that extraction takes place both at the bottom side and at the top side. The supporting elements 4 have run-on surfaces 38 opposite the rear side of the board 8. The extraction channel 23 has run-on surfaces 39 opposite the tubes 2. When the part of the sawing apparatus, comprising the coupling part 11, the guide means 12 with the machine saw 14 and the extraction channel 23, is moved in the direction of the arrow 10, the supporting elements 4 will be moved away from the rear side of the board 8 when the run-on surfaces 38 of the supporting elements 4 and the run-on surfaces 39 of the extraction channel 23 push against each other, with the result that the above-mentioned part of the device can pass the pushed-away supporting elements 4. The extraction channel 23 and the partitions 27 have run-on surfaces 40, 41 respectively opposite the board 8, by means of which a board 8, which may not be entirely flat, can be pushed easily over the supporting elements 4 and the extraction channel 23 prior to sawing. Various modifications are possible within the scope of the invention. For example, Fig. 3 shows an alternative to the tubes 2 with supporting elements 4. According to Fig. 3, C-sections 41 are used instead of tubes, through which sections supporting elements 42 project, which elements are retained on the inside of the section 41 by shoulders 43 of the supporting elements 42, while the supporting elements 42 are pressed in the direction of the board 8 by means of a leaf spring 44. Other spring-loaded means can, of course, also be used instead of the leaf springs 5 and 44. Instead of the supporting elements 4 and 42, it is also possible to use hinged elements which are forced by spring means in the direction of the board 8, and which can be turned by the extraction channel 23 out of its way. The extraction channel 23 can also have a number of connection openings distributed in direction 13, which are connected to the extraction means. A better distribution of the suction force in the direction 13 can be obtained in this way. A valve can be fitted in the connection between a connection opening and the suction means, for shutting off said connection if the board to be sawn is not in the vicinity of the connection opening. The extraction channel 23 can also be divided, for example by means of partitions like the partition 35, into a number of sub-channels which, on the one hand, open out at various levels into the elongated opening 26 and, on the other hand, can open out at one or more connection openings distributed in the direction 13. It is also possible to make the extraction channel 23 symmetrical relative to the saw blade 16. If the sawing apparatus is intended only for making vertical saw cuts, the embodiment shown in Fig. 5 can be used, with a narrow elongated opening 45 instead of the wide elongated opening 26 of Fig. 4. It is also possible within the scope of the invention for the sawing apparatus to be intended only for making horizontal saw cuts, in which case the machine saw 14 can be securely fixed to the guide means 12. The sawing apparatus can also be designed for supporting and sawing a board in any direction between vertical and horizontal. In an apparatus according to the invention it is possible to select a direction of rotation of the saw blade 16 which is opposite to the direction 32. Then too, the particles released from the board 8 can be extracted efficiently both at the front side and at the rear side of the board 8.

Claims: Sawing apparatus, comprising a frame (1) with means (2, 4, 7, 41, 42) for supporting flat on or against it a board (8) to be sawn, the frame (1) having first guide means (9) which are designed for supporting and guiding in a first direction (10) a coupling part (11) to which are coupled second guide means (12) designed for supporting and guiding a machine saw (14) in a second direction (13) crossing the first direction (10), both directions (10, 13) running parallel to the board (8), so that the machine saw (14) can be moved in a plane running parallel to a rear or front main side of the board (8) and that during operation of the machine saw (14) a saw blade (16) thereof, according to the movement of the machine saw (14), can make a saw cut through the board (8) from a front side of the board (8), and extraction means with a suction nozzle (18) provided at the front side of the board for extracting particles of the board (8) released during the sawing, whereby an extraction channel (23) which is coupled to the second guide means (12) extends parallel to one of said directions and, after positioning, behind the board (8), which channel (23) is connected to an inlet of the extraction means and which has an elongated opening (26) extending along the channel (23) and in the vicinity of a saw cut to be made, for the extraction of particles released from the board (8) at the rear side of the board (8) at the saw cut, and the supporting means (2, 4, 7, 41, 42) have supporting elements (4, 42) which are designed for supporting the rear side of the board (8), characterized in that the extraction channel (23) is coupled to the coupling part (11), each supporting element (4, 42) has dimensions which are minor with respect to maximum allowed dimensions of the main sides of the board (8), the supporting elements (4, 42) are distributed across a supporting area of the supporting means, each supporting element (4, 42) is movable in a third direction crossing the board (8), and by that, viewed in the first direction (10), before and after the channel stop means (39) are present on the channel (23) which on movement of the machine saw (14) in the first direction (10) move supporting elements (4, 42) which push against the stop means (39) in the third direction away from the board (8), in order to allow passage of the channel (23) and the stop means (39). Sawing apparatus according to claim 1, characterized in that each supporting element is an element (4, 42) which is pretensioned against a spring force of spring-loaded means (44). Sawing apparatus according to claim 1 or 2, characterized in that each supporting element is an element which is hinged to the frame (9) and turns away from the board (8) when it is hit by the stop means (39). Sawing apparatus according to any of the preceding claims, characterized in that each supporting element (4, 42) and/or the stop means (39) which can push against the supporting element (4, 42) have run-on surfaces (38, 39) which gradually push the supporting element (4, 42) away from the board (8) when they are encountered. Sawing apparatus according to any of the preceding claims, characterized in that the supporting element (4, 42) and stop means (39) have run-on surfaces (38, 40, 41) which push an edge of the board (8) knocking against them away from said run-on surfaces (38, 40, 41). Sawing apparatus according of any of the preceding claims, characterized in that the machine saw (14) can be turned over 90° and over an axis crossing the board (8) and the opening (26) of the channel (23) extends so far in the first direction (10) that the machine saw (14) can make a saw cut in the first direction (10). Sawing apparatus according to any of the preceding claims, characterized in that the channel (23) has a number of connection openings distributed in the second direction (13) for connection to an inlet of the extraction means. Sawing apparatus according to any of the preceding claims, in which the first and second directions (10, 13) are horizontal and vertical directions respectively, characterized in that the channel (23) has at least in a lower part thereof a connection opening (28) for connection to the extraction means. Sawing apparatus according to any of the preceding claims, characterized in that the channel (23) has at each end thereof a connection opening (28, 33) for connection to an inlet of the extraction means. Sawing apparatus according to any of the preceding claims, characterized in that the channel (23) is divided into a number of sub-channels extending in the second direction (13), which sub-channels open out at various locations of the elongated opening (26) of the channel (23) and are connected to one or more connection openings distributed in the second direction (13), for connection to an inlet of the extraction means. Sawing apparatus according to claim 10, characterized in that the channel (23) is provided with a partition (35) extending from one end of the channel (23) across part of the channel (23) viewed in the second direction (13), and the extraction means being connected to said one end of the channel (23).

Inventors: MEIJER PIETER, MEIJER, PIETER
Applicants: ELCON MASCHF BV, ELCON MACHINEFABRIEK B.V.
Application year: 1992
Main classification: B23D59
IPC codes: B27B5, B23Q11, B23D47, B23Q1, B23D59