SAWING MACHINE INCLUDING A SAWDUST REMOVING DIVICE

Abstract: A device (27) for removing chip on a saw blade (21) in a sawing machine. A cleaner support member (35) movable in directions of approaching and separating from the saw blade (21) is provided on a saw blade housing (11) for supporting the saw blade, and overlapping area adjusting devices (51,53, 55 and 57) are provided for adjusting the overlapped area of a cleaner (37) and the saw blade (21) in such a manner that the overlapped area of the cleaner (37) supported by this cleaner support member and the saw blade (21) is constantly kept at a substantially proper one.

Description: Technical Field This invention relates to a device for removing sawdust adhering to a saw blade of a sawing machine, including a saw band and in particular to a sawdust removing device provided with a cleaning instrument such as a brush for which a suitable overlap with respect to the saw bade is always maintained so that the sawdust is always removed from the saw blade. Background Art In the prior art, a sawdust removing device for a sawing machine, such as a circular rotary wire brush, overlaps the saw blade and is rotated to clear the sawdust from the saw blade. However, such a rotary wire brush fails to remove the sawdust from the saw blade due to abrasion after being used for many hours. Hence, the operator of the sawing machine must watch the abrasion of the wire brush and adjust the overlap between the brush and the saw blade when the brush is worn to a certain extent. Finally, when the wear on the wire brush reaches a preset limit, the operator must replace the wire brush. When the wire brush wears to a certain extent as mentioned above, the operator adjusts the overlap between the wire brush and the saw blade to a suitable amount. However, the amount of the adjusted overlap tends to differ, depending on the individual preferences of the operators. Furthermore, the operator may sometimes forget to adjust the overlap. In order to resolve these problems, a technique has been developed as shown, for example, in Japanese patent (A) 1-177912, for automatically detecting the amount of abrasion of the wire brush and adjusting the amount of overlap between the saw blade and the wire brush. In the above Japanese patent, an available automatic sawdust removing device is disclosed. The device is equipped with a wire brush which moves from a position where it clears the sawdust from the saw blade to another position where the amount of abrasion of the wire brush is automatically detected. After the amount of abrasion is detected, the position of the wire brush is adjusted according to the detected amount. Thus, the amount of overlap is automatically adjusted and is always maintained within a certain suitable value. There are, however, some drawbacks in the device to be overcome. In the device, the amount of abrasion of the wire brush is periodically detected even if the brush is not badly worn, resulting in wasted effort. On the other hand, the adjustment of the overlap is sometimes not carried out regardless of heavy abrasion which has occurred in a short time and which causes the wire brush to fail to clear the sawdust from the saw blade. The degree or rate of abrasion of the wire brush differs according to the type of a saw blade used, detect the amount of abrasion of the wire brush. FR-A-2.537.826 discloses a sawing machine including a device for removing sawdust adhering to a saw blade of the sawing machine, comprising the features of the preamble of independent claim 1, i.e. a supporting member attached to a saw blade housing in which said saw blade is mounted, the supporting member being energised so as to move towards said saw blade; and a disc shaped cleaning instrument supported on said supporting member, the cleaning instrument being rotatable for removing sawdust from the saw blade. In Fig. 5 of this document a brush is applied against the front face of a driving wheel. According to the invention, the sawing machine further comprises : a limiting member distinct from the driving wheel and the following wheel for moving the saw blade and adapted to contact the outer periphery of the disc shaped cleaning instrument, during operation of the device for removing sawdust, for stopping the movement of the supporting member, the limiting member being mounted on the housing so that the cleaning instrument overlaps with the blade to a predetermined degree when the limiting member contacts the outer periphery of the cleaning instrument. The sawdust adhering to the saw blade is removed by the cleaning instrument by moving the supporting member towards the saw blade so that the cleaning instrument supported by the supporting member can overlap the saw blade. A suitable overlap between the saw blade and the cleaning instrument is always maintained, and the cleaning instrument is actuated, thus the sawdust is positively removed from the saw blade. Brief Description of Drawings Fig. 1 is a front view showing a sawing machine provided with a sawdust removing device of the present invention. Fig. 2 is an enlarged front view showing a part of the sawing machine, taken in the direction of the arrow II in Fig. 1. Fig. 3 is an explanatory drawing showing an embodiment of the device of the present invention in a side view. Fig. 4 is an explanatory drawing showing another embodiment of the device of the present invention. Fig. 5 is an explanatory drawing showing another embodiment of the device of the present invention. Fig. 6 is an explanatory drawing showing another embodiment of the device of the present invention. Best Mode for Carrying Out the Invention In order to make it easy to understand the device of the present invention, the general constitution of a sawing machine will first be described. Fig. 1 shows a lateral-type band saw machine 1 as one type of sawing machine. The band saw machine 1 is mounted on a box-shaped base 3. A worktable 5 and a pair of vices 7a, 7b respectively for supporting and securing a workpiece W to be cut are positioned on the base 3. The first vice 7a is fixed, and the second vice 7b is movably provided relative to the first vice 7a (to the right and left in Fig. 1). The worktable 5 is a component of the base 3. A vertically rotatable housing 11 is mounted on the base 3 through a hinge shaft 9, while a cylinder 13 for rotating the housing 11 is attached to the base 3. The upper end of a piston rod 15 of the cylinder 13 is suitably connected to the housing 11. Another configuration may be alternatively used for vertically moving the housing with respect to the base 3. For example, the housing may be guided along upright guiding posts supportend on the base. A drive wheel 19 and a follower wheel 17 are rotatably mounted in the housing 11, and an endless band saw blade 21 is engaged with the drive and follower wheels 19 and 17. A drive device (not shown) is connected to the drive wheel 19 to rotate the drive wheel 19. The housing 11 is provided with a beam 23 to which a pair of movable saw blade guides 25a, 25b are attached. The saw blade guides 25a, 25b hold the saw blade 21 perpendicular to the workpiece W supported on the worktable 5. The first saw blade guide 25a is fixed, while the second saw blade guide 25b is movably provided relative to the first guide 25a (to the right and left in Fig. 1). The vice 7b is moved towards the vice 7a to secure the workpiece W on the worktable 5, and then the rotating device (not shown) is actuated to run the band saw blade 21. At the same time, the cylinder 13 is actuated to rotate the saw blade 21 downward. Therefore, the workpiece W is cut by the band saw blade 21 guided and held by the guides 25a, 25b perpendicular to the workpiece W. The housing 11 is provided with a device 27 for removing sawdust produced during the cutting of the workpiece W and adhering to the saw blade 21. Referring now to Figs. 1 and 2, the sawdust removing device 27 is mounted on the saw blade housing 11 which supports the saw blade 21. In the sawdust removing device 27, a bracket 29 is suitably attached to the saw blade housing 11 by a plurality of bolts. A motor 31 is suitably mounted on the bracket 29, and a guide bracket 33 is integrally attached to the bracket 29. The guide bracket 33 supports a supporting member 35 which bears a rotary cleaning instrument 37. The cleaning instrument 37 is in the shape of a disk and is made of a suitable material such as rubber, soft metal, or the like, or is a circular resin or wire brush and serves to remove sawdust adhering to the saw blade 21. The cleaning instrument 37 is detachably mounted on a rotary drive shaft 39 provided on the supporting member 35. The supporting member 35 is provided with a torque transmission rotary shaft 41 which transmits the torque of the motor 31 to the drive shaft 39. The torque transmission shaft 41 is connected to a drive shaft 45 of the motor 31 through a universal joint 43 so that the torque transmission shaft 41 can be rotated by the motor 31. The torque of the transmission shaft 41 is transmitted to the drive shaft 39 through, for example, a bevel gear, etc. The sawdust removing device 27 is designed as mentioned above, therefore the sawdust adhering to the saw blade is removed while the outer edge of the cleaning instrument 37 overlaps the saw blade 21, and the cleaning instrument 37 is rotated by the motor 31. In order to cause the cleaning instrument to overlap with the saw blade to a predetermined degree, the supporting member 35 is provided for reciprocatingly moving towards and receding from the saw blade 21 and the sawdust removing device comprises a limiting member for ensuring said overlap. In the configuration of the sawdust removing device 27 as is better shown in figures 2 and 5, the guide bracket 33 is formed with an arched rack as well as an arched guide hole 49 for guiding the supporting member 35 through a plurality of guide rollers 47 attached to the supporting member 35 in the direction relative to the saw blade 21. A suitable motor 53 is secured to the supporting member 35, and a pinion 55 driven by the motor 53 engages the rack 51. Hence, the supporting member 35 can be moved towards and away from the saw blade 21 along both the guide hole 49 and the rack 51 by suitably controlling the motor 53, and therefore the amount of overlap of the cleaning instrument 37 is adjusted with respect to the saw blade 21. A sensor 59 is provided on the guide bracket 33 of figure 5. The sensor 59 detects the abrasion of the cleaning instrument 37 which has reached a limit value within which the cleaning instrument 37 can be used. The sensor 59 may be a limit switch, proximity sensor switch, or the like. The sensor 59 is activated by the supporting member 35 when the supporting member 35 approaches closest to the saw blade 21. Hence, the activation of the sensor 59 means that the cleaning instrument is worn to the limit value and is to be replaced. In the embodiment described above, with reference to figure 2, the means for moving the supporting member 35 relative to the saw blade 21 mainly consist of the rack 51, the pinion 55, and the torque motor 53. However, an actuator such as a fluid cylinder may be alternatively used. Fig. 3 shows a schematic drawing of an embodiment of the present invention. In this embodiment, the rotatable supporting member 35 on which the rotary cleaning instrument 37 is supported is mounted through a pin 65 on the bracket 29 secured to the saw blade housing 11. The supporting member 35 is energized by the weight of the motor 31 so that it can move towards the saw blade 21. A limit member 67 is provided on the bracket 29 close to the saw blade 21, for obtaining a suitable amount of overlap between the cleaning instrument 37 and the saw blade 21. In this configuration, the edge of the cleaning instrument 37 comes into contact with the limit member 67 since the energized supporting member 35 moves towards the limit member 67. Hence, the overlap between the cleaning instrument 37 and the saw blade 21 is always maintained at a suitable value. The limit member 67 is in the shape of a plate in the drawing, however, the limit member 67 may be a roller mounted on the bracket 29, or in particular, a limit switch in connection with the above embodiment. As has been understood in this embodiment, the cleaning instrument 37 is automatically moved towards the saw blade 21 an amount equal to the wear, and is always maintained in a position where it contacts the limit member 67. The sensor 59 for detecting the limit of use of the cleaning instrument 37 is provided in this embodiment. The sensor 59 detects the wear of the cleaning instrument in the same manner as described above. Fig. 4 shows another embodiment of the sawdust removing device of the present invention. In this embodiment, a guide bracket 69 is attached to the bottom of the saw blade housing 11. The bracket 69 is formed with an arched guide hole 71, and a limit member 73 is attached to a free end of the guide bracket 69. A cover 75, which supports a rotary drive shaft of the cleaning instrument 37, is disposed for sliding along the arched hole 71. A weight 77 is attached to the cover 75, for helping the cover 75 to move towards the saw blade 21. The use of the weight 77 may be omitted if the cover 75 can move of its own weight towards the saw blade 21. As can be understood from the above configuration, the cleaning instrument 37 is energized by means of the weight 77 to move towards the saw blade 21, and comes into contact with the limit member 73. Therefore, the overlap is maintained at a suitable amount between the cleaning instrument 37 and the saw blade 21. An elastic member such as a coil spring, windup spring or the like can alternatively be used for energizing the cleaning instrument 37 to move towards the saw blade 21. For example, a tensioned coil spring 79 may be disposed between the bracket 29 and the cleaning instrument 37 as shown in Fig. 3. Fig. 5 shows a further embodiment of the sawdust removing device 27. In this embodiment, a tensioned coil spring 79 is provided between the supporting member 35 and the bracket 29, and a roller 73A, which serves as a limit member, is attached to the guide bracket 33. In this design, the cleaning instrument 37 contacts the roller 73A by means of the energized coil spring 79 so that the overlap is always limited or maintained at a suitable value between the cleaning instrument 37 and the saw blade 21. Fig. 6 shows a further embodiment of the sawdust removing device 27 similar to that shown in Fig. 5. In this embodiment, a windup spring 79WS is used instead of the coil spring 79 to thrust the supporting member 35 against the saw blade 21. Furthermore, a dog block 35D is provided for cooperating with the sensor 59 for detecting the limit of use of the cleaning instrument 37. This configuration has the same function as those described above.

Claims: A sawing machine (1) including a saw band, a driving wheel (19) and a follower wheel (17) for moving said saw band, and a device (27) for removing sawdust adhering to said saw band (21) of the sawing machine (1), comprising : a supporting member (35) attached to a saw blade housing (11) in which said saw band (21) is mounted, the supporting member being energized so as to move towards said saw band (21) ; and a disc shaped cleaning instrument (37) supported on said supporting member (35), said cleaning instrument (37) being rotatable for removing sawdust from the saw band (21) ; characterized in that the sawing machine further comprises : a limiting member (67, 73, 73A) distinct from said wheels (19, 17) adapted to contact the outer periphery of the disc shaped cleaning instrument (37) during operation of the device for removing sawdust, for stopping the movement of the supporting member (35), the limiting member (67, 73, 73A) being mounted on the housing (11) so that the cleaning instrument (37) overlaps with the band (21) to a predetermined degree when the limiting member contacts the outer periphery of the cleaning instrument (37). The machine (1) of claim 1, wherein said device includes a sensor (59) for detecting proximity of said cleaning instrument (35) closest to said saw blade (21) and as a result detecting wear in said cleaning instrument, said wear reaching a limit within which said cleaning instrument can be used. The machine (1) of claims 1 or 2, wherein said supporting member (35) for moving towards said saw blade (21) is energised by a spring (79, 79 WS). The machine (1) of claims 1 or 2, wherein said supporting member (35) for moving towards said saw blade (21) is energised by an actuator (61, 53) comprising one of a fluid cylinder and a torque motor. The machine (1) of claims 1 or 2, wherein said supporting member (35) for moving towards said saw blade (21) is energised by weight of parts (31) which make up said supporting member.

Inventors: SADAHIRO TORU, SADAHIRO, TORU, SADAHIRO, TORU 36-6, HIGASHINARUSE
Applicants: AMADA CO LTD, AMADA COMPANY, LIMITED
Application year: 1991
Main classification: B23D59
IPC codes: B23Q11