Patent Application
20090064510
This application is based upon and claims a priority from prior Japanese Patent Application No. 2007-233397 filed on Sep. 7, 2007, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
An aspect of the present invention relates to portable cutting machines and, in particular, to a portable cutting machine adjustable in cutting depth.
2. Description of the Related Art
There have conventionally been portable cutting machines achieved by making cutting machines portable for cutting and processing to-be-processed members such as lumber. Such portable cutting machines, which consist mainly of a circular saw blade and a motor as a drive unit, are easily taken anywhere and thus used generally not only in manufacturing plants but also at construction sites and the like.
Since lumber to be cut by portable cutting machines has respective different thicknesses, it is necessary that various types of boards, from thick to thin boards, can be cut suitably. Conventional portable cutting machines are arranged in such a manner that a saw cover or a housing on which a circular saw blade is supported is rotatable with respect to a base to be brought into contact with lumber and the amount of rotation thereof determines the amount of protrusion of the circular saw blade from the base.
For example, in the portable cutting machine 901 shown in
However, forming the link 907 along the broken line B causes the saw cover 904 that covers the link 907 to grow in size. Hence, the link 907 may be formed by an elastic thin plate in such a manner as to be housed in the saw cover 904 as shown in
Hence, the portable cutting machine disclosed in JP-UM-H03-29221-A is provided with a dust case connected with a saw cover to prevent chips from attaching to the link by sucking chips from the saw cover into the dust case.
However, the arrangement disclosed in JP-UM-H03-29221-A has a high possibility that chips are not sucked completely due to, for example, reduction in the suction power of the dust case. Leftover chips will attach to the link to become resistance when the movement restricting part slides, resulting in a reduction in the operating efficiency.
It is therefore an object of the present invention to provide a small-sized portable cutting machine whereby the operating efficiency can be improved.
In order to achieve the foregoing object, the present invention provides a portable cutting machine including: a housing; a motor housed in the housing; a cutting blade adapted to be driven by the motor to cut to-be-processed members; a saw cover provided in the housing to cover approximately the half of the outer periphery of the cutting blade; a base adapted to rotatably support the saw cover or the housing and to be brought into contact with the to-be-processed members; and a protrusion amount changing mechanism capable of changing the amount of protrusion of the cutting blade from the base toward the side opposite to the saw cover, in which the protrusion amount changing mechanism has an adjustment guide extending from the base in the rotation direction of the saw cover and a movement restricting part for restricting the movement of the adjustment guide with respect to the saw cover, and in which the portion of the adjustment guide on the side farther from the base with respect to the movement restricting part is arranged outside of the saw cover.
It is preferable to further include a guide cover for covering the portion of the adjustment guide on the side farther from the base with respect to the movement restricting part.
It is preferable that the guide cover is formed detachably to the saw cover.
It is preferable that the saw cover is defined with an opening portion formed in the surface on the side farther from the motor and an air passage communicating from the front of the cutting blade in the cutting direction to the opening portion, and a guide portion for guiding air from the side nearer the motor toward the side farther from the motor is formed in the air passage in the vicinity of the opening portion.
It is preferable that the housing is formed with a handle part protruding from the housing toward the side opposite to the cutting blade, and the handle part and the guide cover are each formed of resin.
According to the portable cutting machine of the first aspect of the invention, since the portion of the adjustment guide on the side farther from the base with respect to the movement restricting part is arranged outside of the saw cover, chips generated inside of the saw cover cannot attach to the portion of the adjustment guide on the side farther from the base with respect to the movement restricting part. Therefore, chips cannot attach to the portion of the adjustment guide on the side farther from the base with respect to the movement restricting part to interfere with the sliding of the movement restricting part. Also, since there is no need to ensure a space for housing the adjustment guide inside the saw cover, the size of the saw cover can be reduced. Further, the guide member on the side farther from the base with respect to the movement restricting part can be replaced, if desired, without dismounting the saw cover from the base, which exhibits an improved assemblability.
According to the portable cutting machine of the second aspect of the invention, since there is further provided a guide cover formed detachably to the saw cover and adapted to cover the portion of the adjustment guide on the side farther from the base with respect to the movement restricting part, extraneous shocks can be absorbed by the guide cover, which can prevent the adjustment guide from being deformed. Although the portable cutting machine is often used in environments where dust such as wood debris circulates, the provision of the guide cover can prevent dust circulating outside from attaching to the adjustment guide.
According to the portable cutting machine of the third aspect of the invention, since the guide cover is formed detachably to the saw cover, maintenance operations such as cleaning of the adjustment guide and saw cover can be performed easily by dismounting the guide cover from the saw cover, which exhibits an improved workability.
According to the portable cutting machine of the fourth aspect of the invention, since a guide portion for guiding air from the side nearer the motor toward the side farther from the motor is formed in the air passage in the vicinity of the opening portion, chips generated when cutting to-be-processed members with the cutting blade pass through the air passage defined inside the saw cover to be guided away from the motor by the guide portion, and then discharged through the opening portion. This arrangement makes it less likely that chips stay inside the saw cover, which reduces the possibility that chips attach to the adjustment guide and movement restricting part, etc. Further, since housings with a motor housed therein do not have a planar shape, but rather often have a shape corresponding to that of the motor, it would be difficult to remove chips that may be discharged on the side nearer the motor. Meanwhile, on the side farther from the motor, there are no obstacles to interfere with removal of chips, whereby chips can be easily removed.
According to the portable cutting machine of the fifth aspect of the invention, the handle part and guide cover are each formed of resin. Therefore, even if the portable cutting machine may be placed on an installation surface such as a floor in such a manner that the vicinity of the handle part and guide cover is in contact with the installation surface, the installation surface is less likely to be damaged, which exhibits an improved convenience.
Embodiments of the present invention will be described in detail based on the following figures, wherein:
A portable cutting machine according to an embodiment of the present invention will be described with reference to
The housing 2 consists mainly of a housing part 21 with a motor 2A housed therein and a handle part 22 formed integrally with the housing part 21. Also, a drive system (not shown in the drawings) adapted to be driven by the motor 2A is provided inside the saw cover 4, and the drive system allows rotation of the circular saw blade 3.
The handle part 22 is made of resin, and is provided with a switch (not shown in the drawings) for controlling the drive of the motor 2A and a stopper (not shown in the drawings) for keeping the switch ON.
The saw cover 4 is connected and provided on the side of the handle part 22 opposite to the housing part 21 in the housing 2. As shown in
The saw cover main body 41 is made of metal, and as shown in
As shown in
According to the arrangement above, chips generated when cutting to-be-processed members with the circular saw blade 3 pass through the air passage 41c defined inside the saw cover main body 41 to be guided away from the motor 2A by the guide portion 41C, and then discharged through the opening portion 41b. This makes it less likely that chips stay inside the saw cover main body 41, which reduces the possibility that chips attach to the link 7 and movement restricting part 5, etc. Further, since the housing 2 with the motor 2A housed therein often has a shape corresponding to that of the motor 2A, it would be difficult to remove chips that may be discharged on the side nearer the motor 2A. Meanwhile, on the side farther from the motor 2A, there are no obstacles to interfere with removal of chips, whereby chips can be easily removed.
As shown in
The guide cover 43 is made of resin, and is provided detachably to the upper surface of the saw cover main body 41.
As shown in
As shown in
As shown in
As shown in
As shown in
The guide portion 71A is formed with an elongated hole 71a extending in the longitudinal direction of the lower guide member 71, through which the bolt 51 is to be inserted and slide. The base end portion 71 is formed with an axis hole 71b having a diameter approximately greater than that of the rotation pin 65A, through which to be connected with the base 6. As shown in
As shown in
As shown in
As shown in
Each axis portion is engaged with each connecting portion so that the guide members are connected rotatably with each other. Specifically, as shown in
Further, as shown in
As shown in
As shown in
As shown in
Meanwhile, when the bolt 51 of the movement restricting part 5 is positioned within the passage 72a of the middle guide member 72 and the saw cover 4 and the middle guide member 72 are fastened so that the movement of the middle guide member 72 is restricted with respect to the saw cover 4, the upper guide member 73, which is rotatable with respect to the middle guide member 72, is in contact with and supported by the upper surface of the saw cover 4.
Also, when the bolt 51 of the movement restricting part 5 is positioned within the elongated hole 73a of the upper guide member 73 and the saw cover 4 and the upper guide member 73 are fastened so that the movement of the upper guide member 73 is restricted with respect to the saw cover 4, the upper guide member 73 is fastened to the saw cover 4 while being pulled with a force applied by the movement restricting part 5 in the direction from the rotation support axis 62 toward the movement restricting part 5, as is the case with the middle guide member 72 when the saw cover 4 and the middle guide member 72 are fastened. In this case, the middle and lower guide members 72 and 71 are fixed together non-rotatably with respect to the base 6.
In the conventional arrangement in which the movement restricting part is positioned farther from the base with respect to the rotation support portion when the link is divided vertically and the amount of protrusion of the cutting blade is maximum, since the lower link is not used for changing the amount of protrusion of the cutting blade but serves only as a support for the upper link, the lower link is formed as small as possible. However, if the upper link is formed in a larger size to ensure a sufficient movable range for the movement restricting part, a larger space is required to house the upper link, resulting in an increase in the size of the portable cutting machine.
Meanwhile, according to the circular saw 1 of the foregoing embodiment of the present invention, since the movement restricting part 5 is positioned nearer the base 6 with respect to the rotation support axis 62 at least when the amount of protrusion of the circular saw blade 3 is maximum, the elongated hole 71a of the lower guide member 71 constitutes part of the guide passage 7a within a range which the movement restricting part 5 can slide. That is, it is only required that the lower, middle, and upper guide members 71, 72, and 73 provide a movable range equivalent to that for the movement restricting part by the conventional upper link, and there is no need to increase the size of the circular saw 1 even if the lower guide member 71 may be formed in a larger size. Further, at least when the amount of protrusion of the circular saw blade 3 is maximum, only a smaller space may be required to house the middle and upper guide members 72 and 73 by rotating the middle and upper guide members 72 and 73 with respect to the lower guide member 71, whereby the size of the circular saw 1 can be reduced. In addition, the tensile force by the movement restricting part 5 can be reduced by rotating the middle and upper guide members 72 and 73, which allows the movement restricting part 5 to slide smoothly, resulting in an improvement in workability.
Also, the guide member positioned nearer the base 6 with respect to the guide member, the movement of which with respect to the saw cover 4 is restricted by the movement restricting part 5, is fixed non-rotatably with respect to adjacent guide members, whereby the link 7 and the saw cover 4 are fixed to each other with no loosening at a given position. Further, since multiple guide members and multiple rotation support portions are included, the link 7 can be deformed freely through the rotation of each guide member even if it may not have elasticity, which allows the movement restricting part 5 to be guided smoothly. Consequently, there is no need that each guide member should be formed by an elastic thin plate, and the strength can be increased using a thick plate.
In addition, the guide member positioned farther from the base 6 with respect to the guide member, the movement of which with respect to the saw cover 4 is restricted by the movement restricting part 5, is rotatable with respect to adjacent guide members, only a smaller space may be required to house the guide members, whereby the size of the portable cutting machine can be reduced.
Also, since the guide members are supported along the outer periphery of the circular saw blade 3 in a plane including or parallel to the side surface of the circular saw blade 3, the movement restricting part 5 can be guided smoothly along the guide passage 7a when moved away from the base 6.
Moreover, the movement restricting part 5 is adapted to restrict the movement of the link 7 with respect to the saw cover 4 by rotating the rotation operating part 53 and thereby moving the axis portion 51A relatively in the axial direction so that the link 7 is engaged with the collar portion 51B, whereby the movement of the link 7 with respect to the saw cover 4 can be easily restricted by operating the rotation operating part 53.
Furthermore, since the guide members are each formed to have approximately the same thickness in the direction where the axis portion 51A of the movement restricting part 5 protrudes, there is no need to prepare a specific movement restricting part 5 for each guide member. Specifically, since the axis portion 51A moves by the same distance when restricting the movement of the link 7 with respect to the saw cover 4, identical movement restricting parts 5 may be used.
Also, since the guide member positioned farther from the base 6 with respect to the guide member, the movement of which with respect to the saw cover main body 41 is restricted by the movement restricting part 5, is arranged outside of the saw cover main body 41, chips generated inside of the saw cover main body 41 cannot attach to the guide members. Therefore, there is no possibility that chips attached to the guide members become resistance to interfere with the sliding of the movement restricting part 5 with respect to the guide members. Also, since there is no need to ensure a space for housing the guide members inside the saw cover main body 41, the size of the saw cover main body 41 can be reduced. Further, the guide member positioned farther from the base with respect to the guide member, the movement of which with respect to the saw cover main body 41 is restricted by the movement restricting part 5, can be replaced, if desired, without dismounting the saw cover main body 41 from the base 6. Furthermore, the guide member positioned farther from the base with respect to the guide member, the movement of which with respect to the saw cover main body 41 is restricted by the movement restricting part 5, can also be replaced, if desired, without dismounting the saw cover main body 41 from the base 6, which exhibits an improved assemblability.
Further, extraneous shocks can be absorbed by the guide cover 43, which is formed detachably to the saw cover main body 41 to cover the guide member positioned farther from the base 6 with respect to the guide member, the movement of which with respect to the saw cover main body 41 is restricted by the movement restricting part 5, which can prevent the link 7 from being deformed. Although the circular saw 1 is often used in environments where dust such as wood debris circulates, the provision of the guide cover 43 can prevent dust circulating outside from attaching to the guide member positioned outside of the saw cover main body 41.
Also, since the guide cover 43 is formed detachably to the saw cover main body 41, maintenance operations such as cleaning of the link 7 and saw cover main body 41 can be easily performed by dismounting the guide cover 43 from the saw cover main body 41, which exhibits an improved workability.
In addition, the housing 2 is formed with the handle part 22 that protrudes from the housing 2 toward the side opposite to the circular saw blade 3, and the handle part 22 and guide cover 43 are each formed of resin. Therefore, even if the circular saw 1 may be placed on an installation surface such as a floor in such a manner that the vicinity of the handle part and guide cover is in contact with the installation surface, the installation surface is less likely to be damaged, which exhibits an improved convenience.
It is noted that the portable cutting machine according to the present invention is not restricted to the above-described embodiment, and it will be appreciated that various modifications may be made within the scope of the claims. For example, the arrangement shown in
According to the arrangement above, since the link 170 is provided on a plane parallel to the side surface of the circular saw blade 3 and at a position not to be in contact with the circular saw blade 3, the adjustment guide 170 can be formed smaller than the outer periphery of the circular saw blade 3. This allows the saw cover 140 to be formed in a smaller size, and thereby the size of the circular saw 100 can be reduced.
Also, the portable cutting machine 1 according to the above-described embodiment is arranged in such a manner that when the middle guide member 72 is fastened to the saw cover main body 41 and the movement with respect to the saw cover main body 41 is restricted by the movement restricting part 5, the upper guide member 73 positioned farther from the base 6 with respect to the guide member, the movement of which with respect to the saw cover main body 41 is restricted, is supported on the upper surface of the saw cover main body 41, but not restricted thereto. For example, as shown in
According to the arrangement above, it is possible to prevent the link 170 from coming into contact with the circular saw blade 3 due to excessive rotation of the guide members toward the circular saw blade 3 even if the link 170 may be provided inside of the saw cover 140.
Further, the restriction piece 172A is provided on the connecting portion of the middle guide member 172, which can prevent an increase in the number of parts as well as define a range within which the upper guide member 173 can be rotated at low cost.
The circular saw 1 according to the above-described embodiment is also arranged in such a manner that one middle guide member 72 is provided between the lower and upper guide members 71 and 73, but multiple middle guide members may be provided between the lower and upper guide members 71 and 73. This arrangement allows the link to be deformed more freely, and thus the movement restricting part 5 can be guided more smoothly.
It is noted that the embodiment employs an arrangement that the movement of the link 7 can or cannot be restricted with respect to the saw cover main body 41 by rotating the operating part and therefore the bolt 51, but the present invention is not restricted thereto, and another arrangement may be employed that the movement of the link can or cannot be restricted with respect to the saw cover by, for example, rotating the operating part and using cam means or the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-233397 | Sep 2007 | JP | national |
