Patent Publication Number: US-8522656-B2

Title: Table cutting machine

Description:
This application claims priority to Japanese patent application serial number 2008-74221, the contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a table cutting machine adapted to move a cutting machine body provided with, for example, a round grind stone or a rotary blade such as saw tooth downward for carrying out a cutting operation or the like to a cut material fixed on a table. 
     2. Description of the Related Art 
     This type of cutting machine includes a table supporting a cutting material thereon and a cutting machine body vertically movably supported on the table. The cutting machine body includes an electric motor as a drive source and also includes a circular rotary blade rotatably driven by the motor. In order to perform a cutting operation, an operator fixes the cutting material onto the tale and downwardly moves the cutting machine body while the rotary blade rotates, so that the rotating rotary blade cuts into the cutting material. 
     In order to enable various modes of cutting operations, various improvements have been made to the cutting machine. One improvement is to enable the cutting machine body to tilt leftward or rightward as viewed from the side of the operator, so that it is possible to perform an inclined cutting operation in which a cutting direction of the rotary blade into the cutting material is inclined as viewed from the front side. In general, in order to enable the inclined cutting operation, a body support member supporting the cutting machine body on the table has a fixed-side support member on the side of the table and a pivotable-side support member on the side of the cutting machine body, which is rotatably connected by a pivotal shaft. A fixing screw extends between the fixed-side support member and the pivotable-side support member and can fix the inclined position of the cutting machine body as it is tightened. A fixing lever is mounted to a head of the fixing screw and is operable to pivot by the operator. In the know cutting machine, the fixing lever is positioned on the rear side of the body support member away from the operator. Therefore, in order to hold the fixing lever, it is necessary for the operator to extend his or her hand to the fixing lever. 
     In general as a fixing lever, a single-lever type fixing lever having one grip portion is used as disclosed in Japanese Laid-Open Patent Publication No. 8-332605 (U.S. Pat. No. 3,277,307) and No. 2004-330618. In order to improve the operability, there has been proposed a triple-lever type fixing lever having three grip portions arranged at intervals of an angle of 120°. 
     In the case of the single-lever type fixing lever, it is difficult for the operator to look at the grip portion, because the grip portion is hidden on the rear side of the body support member. Therefore, it is necessary for the operator to feel for the fixing lever for operating it. In addition, the hand of the operator, who is a right-handed person or a left-handed person, is difficult to reach the fixing lever. 
     In the case of the triple-type fixing lever, there is a possibility that the fixing lever becomes difficult to be operated when the lowest one of the grip portions contacts the floor or the ground on which the cutting machine is installed. In order to avoid this problem, it is necessary to set the lengths of the grip portions to be small, resulting in lowering the operability of the fixing lever. 
     Thus, there is a need in the art for a configuration in which a fixing lever for fixing the inclined position of a cutting machine body can have a length capable of being easily held by an operator and can be operated by the operator who takes a comfortable position. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention can include a cutting machine having a table supporting a workpiece, a cutting machine body able to move vertically and laterally, the cutting machine body is supported on the table by a body supporting member. The body supporting member includes a fixed-side support member, a tilting-side support member connected to the fixed-side support member by a lateral tilt shaft, a fixing screw capable of fixing the tilting-side support member to the fixed-side supporting member, a fixing lever capable of rotating the fixing screw, the fixing lever has two grips capable being held for operating the fixing lever, and the two grips are arranged to extend upward in a V-shape from a head of the fixing screw. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a general side view of a table cutting machine according to an embodiment.  FIG. 1  shows a left side view viewed from a user.  FIG. 1  shows a state in which a cutting machine body is held at an upper waiting position. 
         FIG. 2  is a general side view of a table cutting machine according to the embodiment.  FIG. 2  shows a state in which the cutting machine body is moved downward to a lower end position. 
         FIG. 3  is a general side view of the table cutting machine according to the embodiment.  FIG. 3  shows a state in which a cutting operation is carried out on a cut material by a rotary blade by moving the cutting machine body downward and then sliding the same rearward.  FIG. 3  shows a state in which a rearmost position of the cutting machine body is limited by an intermediate stopper mechanism and is held at a position where a front portion of the auxiliary cover is in the course of moving over top of the positioning fence. 
         FIG. 4  is a general side view of the table cutting machine according to the embodiment.  FIG. 4  shows a state in which the cutting machine body is moved downward and then slid to the rearmost position of the sliding movement.  FIG. 4  shows a state in which the intermediate stopper mechanism is released. 
         FIG. 5  is a vertical cross-sectional view of the table cutting machine according to the embodiment.  FIG. 5  shows a state in which the cutting machine body is moved downward and then retracted to an intermediate position of an entire sliding range by the intermediate stopper mechanism.  FIG. 5  also shows a state in which the front portion of the auxiliary cover is in the course of moving over top of the positioning fence. 
         FIG. 6  is a back view of the table cutting machine according to the embodiment.  FIG. 6  shows a state in which the table cutting machine is viewed from the right side as viewed from the user. 
         FIG. 7  is a perspective view of the auxiliary cover as a single unit. 
         FIG. 8  is a plan view of the auxiliary cover as a single unit. In  FIG. 8 , a portion of the auxiliary cover near a portion which supports a turning movement is shown in an exploded state. In  FIG. 8 , part of a fixed cover and part of a link lever are shown by double dashed lines, respectively. 
         FIG. 9  is a vertical cross-sectional view of the auxiliary cover taken along the line (F 9 )-(F 9 ) in  FIG. 8 .  FIG. 9  shows a state in which a shielding edge on the left side when viewed by the user is viewed from inside. 
         FIG. 10  is a perspective view of an upper sliding mechanism and a periphery thereof viewed obliquely from above on the rear side.  FIG. 10  shows a state in which the cutting machine body is slid to a frontmost position of the sliding movement with respect to the upper sliding mechanism. 
         FIG. 11  is a perspective view of the upper sliding mechanism and the periphery thereof viewed obliquely from the front.  FIG. 11  shows a state in which the cutting machine body is slid to the frontmost position with respect to the upper sliding mechanism. 
         FIG. 12  is a view of a bearing holder and a rib thereof from the front in the direction indicated by arrows (F 12 )-(F 12 ) in  FIG. 11 . 
         FIG. 13  is a rear view of a fixing lever and the periphery thereof viewed from the rear in the direction of arrow indicated by (F 13 ) in  FIG. 1 . 
         FIG. 14  is a perspective view of an inclined angle display device viewed from the left front side.  FIG. 14  shows a state in which the cutting machine body is held at a right-angle cutting position with an angle of inclination of zero. 
         FIG. 15  is an enlarged view of a second angle scale and a second indicator. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide improved cutting machines. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in conjunction with one another, will now be described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Moreover, various features of the representative examples and the dependent claims may be combined in ways that are not specifically enumerated in order to provide additional useful embodiments of the present teachings. 
     Referring now to  FIG. 1  to  FIG. 15 , an embodiment of the present invention will be described.  FIG. 1  to  FIG. 5  show a table-type cutting machine  1  according to the embodiment in general. In  FIG. 1  to  FIG. 5 , a user is positioned on the right side of the cutting machine  1 . In the following description, the front and rear of the respective members and the configurations are defined such that the right side in  FIG. 1  (near side of the user) corresponds to the front side and the left side corresponds to the rear side. 
     The cutting machine  1  includes a substantially circular table  20  for placing a cutting material W, a base  30  for supporting the table  20  so as to be capable of rotating horizontally and a cutting machine body  10  arranged above the table  20  via a body supporting member  40  provided at a rear portion (left side portion in  FIG. 1 ) of the table  20 . Hereinafter, a so-called crown-mold material W 1  to be cut in a state of leaning against a positioning fence and a cut material W 2  formed into a normal flat board which is cut in a state in which the widthwise direction thereof is oriented upright at a right angle along the positioning fence are exemplified as the cut materials W. Both the cut materials W (W 1 , W 2 ) have a height from the upper surface of the table higher than normal, so that a large cutting depth is required for a rotary blade  12 . 
     As shown in  FIG. 5 , the table  20  is supported on the upper surface of the base  30  so as to be capable of rotating horizontally via a shaft  33 . The rotational position of the table  20  is adjusted quickly and precisely according to the operation by two-system stopper mechanism. In the drawings, reference numerals  21  and  22  designate operating levers of the two-system stopper mechanism. Both the operating lever  21  and  22  are respectively arranged at a front end portion of the table  20 , where the user is able to operate easily. 
     Both left and right end portions of the base  30  are protruded sideward from the table  20 , and the protruded portions correspond to base seats  31  and  31 . Upper surfaces  31   a  and  31   a  of the left and right base seats  31  and  31  are aligned to be flush with the upper surface of the table  20 . A positioning fence  32  is mounted to the upper surfaces  31   a  and  31   a  of the left and right base seats  31  and  31  so as to extend across therebetween. The front surface of the positioning fence  32  corresponds to a positioning surface  32   a  to which the cutting material W is to be abutted. As shown in the drawing, the exemplified positioning fence  32  has the positioning surface  32   a  at a relatively high position. The positioning surface  32   a  matches the center of rotation of the table  20  (the axial center of the shaft  33 ), and is orthogonal to the upper surface of the table  20 . The positioning fence  32  enables positioning of the cut material W 1  in a state of leaning against the positioning surface  32   a  and the upper surface of the table  20  so as to extend therebetween as shown in the drawing. 
     The cutting machine body  10  is supported via the body supporting member  40  so as to be capable of sliding in the fore-and-aft direction and of tilting in the vertical direction. As shown in  FIG. 1 , a position in which the cutting machine body  10  is returned to the uppermost end corresponds to the waiting position. When the cutting machine body  10  is moved downward from the waiting position (a state shown in  FIG. 2 ) and then the cutting machine body  10  is slid rearward as shown in  FIG. 3 , the rotary blade  12  is caused to cut into the large cut material W 1  for cutting operation. 
     The cutting machine body  10  is adapted to be able to change the cutting angle of the rotary blade  12  with respect to the cutting material W angularly leftward or rightward in plan view by rotating the table  20  leftward or rightward by an adequate angle. Hereinafter, this cutting state is referred to as angular cutting. In this angular cutting, the axis of rotation of the rotary blade  12  (the axis of rotation of a spindle  18 ) is maintained in parallel to the upper surface of the table  20  (the direction of the table surface). In this angular cutting operation, the rotary blade  12  advances so as to cut into the material obliquely with respect to the positioning surface  32   a  of the positioning fence  32 . When the rotary blade  12  advances so as to cut into the material in the direction orthogonal to the positioning surface  32   a , a right angle cutting is achieved. This right angle cutting is used most frequently. 
     In contrast, the cutting machine body  10  is adapted to be able to carry out the cutting operation by advancing the rotary blade  12  so as to cut into the cutting material W obliquely when viewed from the front (user side) by being inclined leftward or rightward by a tilt supporting mechanism  50  of the body supporting member  40 , which will be described later. Hereinafter, this cutting state is referred to as an oblique cutting. In this oblique cutting, the axis of rotation of the rotary blade  12  is maintained in a non-parallel state with respect to the upper surface of the table  2  (the direction of the table surface). The angle of inclination of the rotary blade  12  in this oblique cutting is displayed by an inclined angle display device  60  described later. The right-angle cutting is achieved in a state in which the axis of rotation of the rotary blade  12  is positioned in parallel to the upper surface of the table  20  and the rotary blade  12  is vertically positioned (at an angle of inclination of zero). 
     In this manner, the cutting machine body  10  is supported by the body supporting member  40  so as to be capable of tilting in the vertical direction, to be capable of sliding in the fore-and-aft direction, and to be capable of tilting in the lateral direction. The body supporting member  40  includes upper and lower sliding mechanisms  41  and  42  at two levels for supporting the cutting machine body  10  so as to be capable of sliding in the fore-and-aft direction and the lateral tilt mechanism  50  for allowing the cutting machine body  10  to tilt in leftward and rightward when viewed from the user. The slide mechanism  41  on the lower side includes two lower slide bars  41   a  and  41   a  supported in parallel at a certain distance in the lateral direction. As shown in  FIG. 5 , both the lower slide bars  41   a  and  41   a  are supported via the bearings  41   b  mounted to the lower surface of the table  20  respectively so as to be capable of sliding in the fore-and-aft direction. The lateral tilt mechanism  50  is mounted at rear end portions of both the lower sliding bars  41   a  and  41   a.    
     The lateral tilt mechanism  50  includes a fixed-side supporting member  52  and a tilting-side supporting member  53  coupled via a lateral tilt shaft  51  so as to be capable of mutual rotation. The rear end portions of the lower slide bars  41   a  and  41   a  are coupled to the fixed-side supporting member  52 . Therefore, both the lower left and right slide bars  41   a  and  41   a  slide integrally in parallel to each other in the fore-and-aft direction, whereby the cutting machine body  10  slides in the fore-and-aft direction. 
     The cutting machine body  10  is tilted in the lateral direction when the tilting-side supporting member  53  rotates by a certain angle leftward or rightward about the lateral tilt shaft  51  with respect to the fixed-side supporting member  52 . A positioning mechanism for positioning the cutting machine body  10  at a right angle position, at a 45° inclined position or the like (so-called positive block mechanism) is integrated between the fixed-side supporting member  52  and the tilting-side supporting member  53 . 
     The rotational position of the tilting-side supporting member  53  with respect to the fixed-side supporting member  52 , that is, the leftward or rightward tilted position of the cutting machine body  10  is fixed by tightening a fixing lever  55 . The tilted position of the cutting machine body  10  is quickly and precisely read by the inclined angle display device  60 . 
     The fixing lever  55  is arranged on the rear side of the tilting-side supporting member  53 . As shown in  FIG. 13 , the fixing lever  55  assumes a V-shape with a left grip  55   a  on the left side and a right grip  55   b  on the right side when viewed from the user coupled to each other at the lower ends thereof. In the case of this example, the left and right grips  55   a  and  55   b  are coupled to each other at an angle of approximately 80° as shown in  FIG. 13 . Both the left and right grips  55   a  and  55   b  have a length that the user is able to grip easily with one hand. A fixing screw  56  is mounted to a coupled portion between both the grips  55   a  and  55   b . The angle formed between both the grips  55   a  and  55   b  may be set arbitrarily within a range from 60° to 100°, in addition to the angle of approximately 80° described above. As described later, an angle of 60° or larger formed between both the grips  55   a  and  55   b  ensures the easy visibility of both the grips  55   a  and  55   b  from the user and allows the user to grip one of them easily. An angle of 100° or smaller ensures prevention of interference of one of the grips with a floor or the ground when rotating the other grip. 
     As shown in  FIG. 5 , the fixing screw  56  penetrates through the tilting-side supporting member  53  and is screwed into the fixed-side supporting member  52 . The fixing screw  56  is arranged below the lateral tilt shaft  51  in parallel thereto at a certain distance therefrom. When the fixing lever  55  is turned to the tightening direction (for example, clockwise in  FIG. 13 ), the fixing screw  56  is tightened with respect to the fixed-side supporting member  52  to fix the tilting-side supporting member  53  so as not to be able to rotate with respect to each other, whereby the cutting machine body  10  is fixed at the oblique position or the right-angle position. When the fixing lever  55  is turned in the loosening direction (for example, counterclockwise in  FIG. 13 ) by an adequate angle (for example, about 30°), the fixing screw  56  is loosened with respect to the fixed-side supporting member  52  and, consequently, the tilting-side supporting member  53  is brought into a state of being capable of rotating with respect to the fixed-side supporting member  52 , which allows the cutting machine body  10  to tilt leftward or rightward. 
     The fixing lever  55  in this example is easy to tilt either in the tightening direction or in the loosening direction by gripping one of the left and right grips  55   a  and  55   b . Therefore, if the user is right-handed, he/she is able to tilt the fixing lever  55  easily by reaching out with his/her right hand to the rear side of the body supporting member  40  via the right side of the cutting machine  1  and gripping the right grip  55   b . In contrast, if the user is left-handed, he/she is able to tilt the fixing lever  55  easily by reaching out with his/her left hand to the rear side of the body supporting member  40  via the left side of the cutting machine  1  and gripping the left grip  55   a.    
       FIG. 13  shows a state in which the fixing lever  55  is firmly tightened (obliquely fixed state), a state in which the tilting-side supporting member  53  is fixed with respect to the fixed-side supporting member  52 , and a state in which the cutting machine body  10  is fixed in terms of the lateral tilt position. As shown in the drawing, in this obliquely fixed state, a state of attaching the fixing screw  56  with respect to the fixing lever  55  is adequately set so as to achieve a state in which the left and right grips  55   a  and  55   b  are inclined at the substantially same angle leftward and rightward with respect to the supporting arm portion  57 . Therefore, the user is able to view both the left and right grips  55   a  and  55   b  easily and is able to grip both the left and right grips  55   a  and  55   b  easily by reaching out with the left hand or the right hand to the rear side. 
     With the exemplified V-shaped fixing lever  55 , since the left and right grips  55   a  and  55   b  protrude leftward and rightward with respect to the supporting arm portion  57 , respectively, the user is able to view easily and is able to grip in a comfortable posture. 
     Further, with the fixing lever  55  in this embodiment, the two grips  55   a  and  55   b  are arranged in a V-shape extending upward from a head of the fixing screw  56 , and hence there is no portion protruding downward. Also, since the fixing screw  56  functions sufficiently by being rotated in the tightening direction or the loosening direction by approximately 30°, the fixing lever  55  needs not to be rotated to a position where the grips  55   a  and  55   b  protrude downward from the fixing screw  56 . Therefore, in the exemplified fixing lever  55 , since the sufficient length of the respective grips  55   a  and  55   b  which allows the user to grip easily is secured, and they are coupled in the V-shape opening upward, the problems as in the related art do not occur. 
     Subsequently,  FIG. 14  shows the inclined angle display device  60  for displaying the lateral position or inclination of the cutting machine body  10  in detail. 
     The inclined angle display device  60  in this example includes a first angle scale  61  mounted to the fixed-side supporting member  52  and a second angle scale  62  mounted to the tilt supporting member  53 . The first angle scale  61  in this embodiment is displayed on a sheet material, which is attached along the peripheral surface of the fixed-side supporting member  52 . Therefore, scale markings of the first angle scale  61  are displayed substantially in parallel to the center axis of tilting movement of the cutting machine body  10  (the axial line of the tilt shaft  51 ), and are adapted to be legible mainly from above (visibility from above). The first angle scale  61  includes scale markings displayed thereon at every 5° in angle of inclination of the cutting machine body  10 . A first indicator  63  for reading the first angle scale  61  is mounted to the tilt supporting member  53 . 
     The second angle scale  62  is displayed on a substantially fan-shaped scale panel  62   a  as shown in the drawing. The scale panel  62   a  is mounted from the front so as to protrude radially upward along the upper portion of the tilt supporting member  53 . Therefore, the scale markings of the second angle scale  62  are displayed along the radial direction with respect to the center axis of the tilting movement of the cutting machine body  10  (the axial line of the tilt shaft  51 ), and are adapted to be legible mainly from the front (visibility from the front). 
     When the mounting precision of the second angle scale  62  with respect to the front surface of the upper portion of the tilting-side supporting member  53  and the mounting precision of the first angle scale  61  with respect to the outer peripheral surface of the fixed-side supporting member  52  are compared, the latter is able to be attached at a higher mounting precision. In the former case, since the scale panel is generally formed of a metal plate or a sheet material and is attached on the front surface of the tilting-side supporting member  53 , the positional precision (mounting precision) with respect to the lateral tilt shaft  51  is more difficult to be ensured at the time of assembly. In contrast, in the latter case, since the first angle scale  61  is attached on the peripheral surface of the fixed-side supporting member  52 , assembly with the high precise positioning and the concentricity of the first angle scale  61  with respect to the lateral tilt shaft  51  is easily achieved at the time of assembly by being attached along the peripheral surface thereof as long as the peripheral surface of the fixed-side supporting member  52  is manufactured at a high degree of precision in terms of position and concentricity with respect to the lateral tilt shaft  51 . 
     The second angle scale  62  is arranged on the outer peripheral side which is spaced more from the tilt shaft  51  in the radial direction than the first angle scale  61  and hence the pitch of the scale markings for the corresponding angles is larger than the pitch of the first angle scale  61 . Therefore, in the case of the second angle scale  62  in this example, the scale markings are displayed at an increment of 1° for the angle of inclination of the cutting machine body  10 , and the sufficient visibility is ensured for the respective scale markings. A second indicator  64  for reading the second angle scale  62  is mounted to the fixed-side supporting member  52 . 
     In this manner, the inclined angle display device  60  in this embodiment is largely characterized in that the first angle scale  61  is on the radially inner peripheral side and the second angle scale  62  is on the radially outer peripheral side with respect to the center of tilting movement of the cutting machine body  10  (the lateral tilt shaft  51 ). The precision in mounting position of the first angle scale  61  is higher than that of the second angle scale  62 , while the display precision in scale markings of the second angle scale  62  is higher (the finer angular display) than that of the first angle scale  61 . 
     In addition, since the second angle scale  62  whose scale markings are displayed with finer display precision is legible mainly from the front and the first angle scale  61  is legible mainly from above, the user-friendliness is remarkably improved in that both the angular scales  61  and  62  may be selectively used depending on the operating posture of the user, or depending on the precision required for the angle of inclination of the cutting machine body  10 . In particular, since the user may obliquely look down at the first angle scale  61 , the user is able to view in a comfortable posture, and hence a superior visibility is achieved. 
     As shown in the drawing, the second angle scale  62  includes angles of inclination of 22.5° and 33.9° which are useful for some cutting operation in addition to the scale markings of 0°, 15°, 30° and 45° on both leftward and rightward respectively in the indications of numerical values. 
     Furthermore, as shown in  FIG. 15 , the second indicator  64  includes a secondary scale indicated thereon. As regards the second angle scale  62  as a primary scale, for example, two secondary scale markings of 0.5 at pitches of 0.9°, which is an angle obtained by dividing 9° equally by 10, for example, and a reference line zero are indicated on the second indicator  64 . Therefore, the angle of inclination of the cutting machine body  10  is adapted to be read precisely at pitches of 0.5° with the second angle scale  62 . 
     The supporting arm portion  57  is provided on top of the fixed-side supporting member  53  so as to extend upward. An upper slide mechanism  42  is provided on top of the supporting arm portion  57 . The upper slide mechanism  42  includes a pair of left and right upper slide bars  43  and  43  extending in parallel to each other. Both the upper slide bars  43  and  43  are supported by the bearings  44  so as to be slidable in the fore-and-aft direction. Both the bearings  44  and  44  are held by a bearing holder  45  provided on top of the supporting arm portion  57 . Front ends of both the upper slide bars  43  and  43  are coupled to each other by a tilting bracket  46 . The cutting machine body  10  is supported by the tilting bracket  46  via the vertical tilt shaft  11  so as to be capable of tilting in the vertical direction. Rear ends of both the slide bars  43  and  43  are coupled to each other by a connecting bracket  47 . Therefore, the upper slide bars  43  and  43  slide integrally in the fore-and-aft direction in a state of being fixed in parallel to each other. The cutting machine body  10  slides in the fore-and-aft direction in association with the fore-and-aft sliding movement of both the slide bars  43  and  43 . As shown in  FIG. 6 , an upper slide fixing screw  48  is provided on the side portion of the bearing holder  45 . When the upper slide fixing screw  48  is tightened, both the upper slide bars  43  and  43  are unslidably fixed to the bearing holder  45 , so that the sliding movement of the cutting machine body  10  by the upper slide mechanism  42  is brought into a locked state. By loosening the upper slide fixing screw  48 , the cutting machine body  10  is allowed to slide in the fore-and-aft direction by the upper slide mechanism  42 . 
     In this manner, with the body supporting member  40  including the upper and lower sliding mechanisms  41  and  42  at two levels and the lateral tilt supporting mechanism  50 , the cutting machine body  10  is supported so as to be capable of sliding in a stroke which is long in the fore-and-aft direction and to be capable of tilting movement in the lateral direction independently from this sliding movement. 
     The upper slide mechanism  42  includes an intermediate stopper mechanism  70  for constraining the retracting operation (rearmost sliding position) of the cutting machine body  10  at a midpoint of the entire sliding range integrated therein. The intermediate stopper mechanism  70  is illustrated in  FIG. 10  and  FIG. 11  in detail. The intermediate stopper mechanism  70  includes a stopper body  71  mounted to one of the upper slide bars  43 . The stopper body  71  includes an annular supporting portion  71   a  which allows insertion of the upper slide bar  43  in a state of being capable of rotating with respect to each other without rattling or obstruction, a stopper shaft portion  71   b  and a switch lever portion  71   c  provided integrally with the periphery of the annular supporting portion  71   a , respectively. 
     As shown in  FIG. 10 , the stopper body  71  is held so as to be capable of turning within a certain angular range about the an axis of the upper slide bar  43  at a position in which the annular supporting portion  71   a  is accommodated in the inner peripheral side of the tilting bracket  46  and the upper slide bar  43  is inserted on the inner peripheral side of the annular supporting portion  71   a  (between the tilting bracket  46  and the upper slide bar  43 ). A fitting screw  72  is tightened at an upper portion of the tilting bracket  46 . The annular supporting portion  71   a  is held so as to be capable of turning in a certain range about the axial line of the upper slide bar  43 , but not to be capable of moving in the axial direction by the engagement of the distal end portion of the fitting screw  72  with the annular supporting portion  71   a.    
     The stopper shaft portion  71   b  is provided so as to extend in parallel to the upper slide bar  43  and rearward via an arm portion  71   d  extending radially outwardly from the annular supporting portion  71   a . The switch lever portion  71   c  is arranged so as to be capable of being moved in a certain angular range radially on the outside of the tilting bracket  46 . Rotating the switch lever portion  71   c  at a certain angle about the axial line of the upper slide bar  43  allows the annular supporting portion  71   a  to rotate at a certain angle coaxially, thereby allowing the stopper shaft portion  71   b  to rotate and move in the vertical direction within a certain range. 
     The stopper shaft portion  71   b  retracts integrally with the retracting movement of the cutting machine body  10 . Abutment of the rear end portion of the stopper shaft portion  71   b  with a center rib  45   a  of the bearing holder  45  restrains the retracting movement of the cutting machine body  10  at a midpoint of the entire sliding range of the upper slide mechanism  42 . As shown in  FIG. 11  and  FIG. 12 , three ribs (upper rib  45   a , center rib  45   b , lower rib  45   c ) are provided on the front portion of the bearing holder  45  substantially in parallel and equidistantly in the vertical direction. 
     When the cutting machine body  10  is retracted in a state in which the switch lever portion  71   c  is moved to the intermediate locking position (downward in this embodiment), the stopper shaft portion  71   b  comes into abutment with the front end surface of the center rib  45   b  from among the three ribs  45   a ,  45   b  and  45   c  and hence the retracting movement is restrained, whereby the cutting machine body  10  is brought into a state in which the retracting movement thereof is restrained at a midpoint within the entire sliding range of the upper slide mechanism  42 . In contrast, when the switch lever portion  71   c  is moved to an unlocked position (upward in this embodiment), the stopper shaft portion  71   b  moves downward from the abutted position as shown by a double-dashed line in  FIG. 12 . Therefore, when the cutting machine body  10  is retracted in this state, the stopper shaft portion  71   b  enters a space between the center rib  45   b  and the lower rib  45   c . In this state, the retracting movement of the stopper shaft portion  71   b  is not restrained, and hence the cutting machine body  10  is allowed to slide to a rearmost position of the sliding movement within the entire sliding range of the upper slide mechanism  42 . The function of the intermediate stopper mechanism  70  will be described later. 
     The cutting machine body  10  is supported at a distal end side of the body supporting member  40  above the table  20  in a state of being capable of tilting in the vertical direction about the vertical tilt shaft  11 . As shown in  FIG. 6 , the cutting machine body  10  is provided with the circular rotary blade  12  which is rotated by the electric motor  16  arranged on the rear side (right side when viewed from the user). The electric motor  16  is mounted in a posture inclined in the direction in which the rear end side is displaced upward. The rotary blade  12  is mounted to the distal end portion of the spindle  18  by a mounting flange  17 . 
     The upper portion of the rotary blade  12  is always covered with the fixed cover  13 . The rear end portion of the fixed cover  13  is supported by the tilting bracket  46  of the upper slide mechanism  42  so as to be capable of tilting in the vertical direction via the vertical tilt shaft  11 . The electric motor  16  is mounted on the rear side of the fixed cover  13 . The rear portion of the fixed cover  13  is provided with a dust collecting port  19  for mounting a dust box for collecting dust. 
     The lower portion of the rotary blade  12  is covered with a movable cover  14  which is opened and closed in association with the vertical movement of the cutting machine body  10 . The movable cover  14  is opened and closed by the relative displacement of the link lever  23  in association with the vertical movement of the cutting machine body  10 . The rear end portion of the link lever  23  is supported by the front portion of the tilting bracket  46  via a shaft  24  so as to be capable of turning in the vertical direction. The approximate midpoint of the link lever  23  (in terms of the longitudinal direction thereof) is provided with an arc-shaped relief groove  23   b . An engaging shaft  25  provided on the fixed cover  13  is inserted in the relief groove  23   b  so as to be relatively displaceable. A front end portion  23   a  of the link lever  23  is in abutment with an abutment wall portion  14   a  provided on the movable cover  14 . The link lever  23  provided in this manner tilts in the vertical direction in association with the vertical movement of the cutting machine body  10 . When the link lever  23  tilts downward in association with the downward movement of the cutting machine body  10 , the front end portion  23   a  thereof presses the abutment wall portion  14   a  while displacing around the center of turn of the movable cover  14 , so that the movable cover  14  is gradually opened. In contrast, when the link lever  23  tilts upward in association with the upward movement of the cutting machine body  10  and the front end portion  23   b  is displaced in the opposite direction around the center of turn of the movable cover  14 , the abutment wall portion  14   a  is not pressed by the front end portion  23   a  in the opening direction, and hence the movable cover  14  is closed by its own weight and an urging force in the closing direction. 
     The electric motor  16  is provided with a handle portion  15  which allows the user to grip on the side portion of the front side thereof. In the case of the embodiment, the handle portion  15  is provided in the lateral direction so as to extend leftward and rightward (the direction along the axis of rotation of the rotary blade  12 ). 
     As shown in  FIG. 5  and  FIG. 6 , a rear edge portion  13   b  of the fixed cover  13  on the rear side of the spindle  18  is recessed upward by a dimension L with respect to the front edge portion  13   a  thereof which corresponds to the end on the opening side and on the front side of the spindle  18 . Hereinafter, the rear edge portion  13   b  of the fixed cover  13 , which is recessed upward by the dimension L is also referred to as the relief portion  13   b  of the fixed cover  13 . With the position of the relief portion  13   b  on the rear side, the range of height of the rotary blade  12 , which is disposed from the rear side (the cutting depth), is increased. 
     With the configuration in which the cutting depth on the rear side of the spindle  18  (the center of rotation of the rotary blade  12 ) is increased in this manner, downward movement to the lowermost position is achieved without interference with the positioning fence  32  being relatively high from the table  20 , whereby the cutting operation of the cut material W 1  by a large cutting depth is achieved by placing the cut material W 1  so as to lean obliquely against the positioning surface  32   a  of the positioning fence  32  as shown in the drawing, or by placing the cut material W 2  upright along the positioning surface  32   a.    
     Also, with the arrangement of the relief portion  13   b  on the fixed cover  13 , even when the cutting machine body  10  is moved upward to fully close the movable cover  14 , part of the peripheral edge (cutting edge) of the rotary blade  12  is covered neither with the fixed cover  13  nor the movable cover  14  at the relief portion  13   b . In this configuration, part of the cutting edge of the rotary blade  12  which is covered neither with the fixed cover  13  nor the movable cover  14  is adapted to be covered by an auxiliary cover  80 . 
     As shown in  FIG. 5 , the auxiliary cover  80  is supported inside the fixed cover  13 . The auxiliary cover  80  is supported by the fixed cover  13  in a state of being capable of tilting in the vertical direction via a shaft  81 . The auxiliary cover  80  is urged in the direction to rotate downward (closing side, clockwise in  FIG. 5 ) by a torsion spring  82  interposed between the auxiliary cover  80  and the fixed cover  13 .  FIG. 7  to  FIG. 9  illustrate the auxiliary cover  80  as a single unit. 
     The auxiliary cover  80  includes a pair of left and right shielding edges  83  and  84 . Both the shielding edges  83  and  84  are coupled to each other in parallel by partitioning walls  85  and  86  at two points, that is, at a midpoint and a point near the rear end portion in terms of the longitudinal direction thereof. As shown in  FIG. 9 , on the inner surface of the left shielding edge  83  (when viewed from the user) is provided with a guiding wall portion  87  so as to extend from an approximate midpoint of the partitioning wall  85 . A dust collecting channel  88  is defined by the front and rear partitioning walls  85  and  86  and the guiding wall portion  87 . The upper portion of the dust colleting channel  88  is directed toward a dust collecting port  19  at the time of cutting operation carried out by the downward movement of the cutting machine body  10  as shown in  FIG. 5 . In this manner, the auxiliary cover  80  has a function for guiding (correcting) chips generated by the cutting operation toward the dust collecting port  19 . The guiding wall portion  87 , defined continuously from the partitioning wall  85 , is formed into a shape extending into an angular shape in cross section, and a inclined surface  87   a  on the front side thereof (the left inclined surface in  FIG. 9 ) is formed in a more gradual angle in comparison with the inclined surface on the rear side. With this gradually inclined surface  87   a , the chips blown upward from the cutting portion are collected more smoothly and reliably into the dust colleting channel  88 . The dust colleting channel  88  formed between both the partitioning walls  85  and  86  is curved obliquely rearward and upward, and the dust collecting port  19  is arranged to extend therefrom. In this configuration as well, the efficiency of dust collection is improved. 
     The front portion of the auxiliary cover  80  with respect to the partitioning wall  85  on the distal end side of the tilting movement includes both the shielding edges  83  and  84  protruding forward in parallel to each other in a bifurcated shape. As shown in  FIG. 8 , the cutting edge of the rotary blade  12  can enter between both the shielding edges  83  and  84  formed into the bifurcated shape to achieve the shielding thereof. 
     The shielding edge  84  (which is the right side when viewed from the user) is provided with a restraining shaft  89  on the outer surface thereof so as to project sideward. The restraining shaft  89  is inserted into an arc-shaped restraining groove  13   c  formed on the rear side of the fixed cover  13  (the right side portion when viewed from the user) so as to be displaceable with respect to each other as shown in  FIG. 6 . The auxiliary cover  80  is adapted to be able to turn in the vertical direction within a range in which the restraining shaft  89  is displaceable in the restraining groove  13   c , whereby the uppermost position (opened position) and the lowermost position (closed position) of the auxiliary cover  80  are restrained. As shown in  FIG. 7 , the outside surface of the shielding edge  83  on the left side is provided with an engaging projection  83   a . Correspondingly, the link lever  23  is provided with a restraining projection  23   c  on the side portion thereof so as to protrude sideward as shown in  FIG. 1  to  FIG. 4 . In a state in which the cutting machine body  10  is located at the uppermost position as a waiting position as shown in  FIG. 1 , the auxiliary cover  80  is held at a closed position at the lowermost side by the urging force of the spring. In this state, the restraining projection  23   c  of the link lever  23  is located above the engaging projection  83   a . Therefore, turn of the auxiliary cover  80  in the opening direction is restrained, so that the auxiliary cover  80  is reliably held at the closing position. 
     Further, as shown in  FIG. 2  to  FIG. 4 , when the cutting machine body  10  is moved downward, the link lever  23  tilts downward accordingly. Therefore, the restraining projection  23   c  is retracted from above the engaging projection  83   a  toward the front, whereby the auxiliary cover  80  is brought into a state of being capable of turning upward toward the opened position. However, as described later, the auxiliary cover  80  is held at the closed position by the torsion spring  82  unless the auxiliary cover  80  interferes with the cutting material W or the positioning fence  32  during the cutting operation. As shown in  FIG. 3 , when the cutting machine body  10  is slid rearward by the upper and lower sliding mechanisms  41  and  42  in the two levels and, in the course of the sliding movement, the lower end portion of the auxiliary cover  80  interferes with the upper portion of the cutting material W or the positioning fence  23 , and the cutting machine body  10  is continuously slid rearward in this interfered state, whereby the auxiliary cover  80  is opened upward against the torsion spring  82 . 
     The lower end portion of the auxiliary cover  80  is formed into an angular shape protruded downward as shown in the drawing. A top  80   a  of the lower end portion is arranged near the end portion of the guiding wall portion  87 . Hereinafter, the front side of the auxiliary cover  80  with respect to the top  80   a  (the left side in  FIG. 9 ) is referred to as a front lower end  80   b , and the rear side thereof with respect to the top  80   a  (the right side in  FIG. 9 ) is referred to as a rear lower end  80   c . Both the lower ends  80   b  and  80   c  each are formed into a flat shape, and extend to each other to the top  80   a  at an obtuse angle. The top  80   a , the front and rear lower ends  80   b  and  80   c  are constituted in the same manner for both the left and right shielding edges  83  and  84 . 
     When the cutting machine body  10  is positioned at the uppermost position as shown in  FIG. 1 , the auxiliary cover  80  is in a state of being locked at the closed position. In this state, the lowermost position (closed position) of the auxiliary cover  80  is further adequately set by the position of the restraining groove  23   b  or the like so that the rear lower end  80   c  of the auxiliary cover  80  extends substantially in parallel (horizontal) with respect to the upper surface of the table  20 . On the other hand, at this time, the front lower end  80   b  of the auxiliary cover  80  enters inside the movable cover  14  and is positioned at the end portion of the movable cover  14 . Accordingly, the entire circumference of the rotary blade  12  is substantially completely covered with the fixed cover  13 , the movable cover  14  and the auxiliary cover  80  without exposing the rotary blade  12  to the outside. 
     In the state in which the auxiliary cover  80  is positioned at the closed position described above, the front lower end  80   b  is positioned substantially in parallel to the rear edge portion  13   b  of the fixed cover  13 . The closed position of the auxiliary cover  80  is restrained by the abutment of restraining shaft  89  with the lower end portion of the restraining groove  13   c  as shown in  FIG. 6 . 
     As shown in  FIG. 2  and  FIG. 6 , the auxiliary cover  80  is not opened by the downward movement of the cutting machine body  10 , and is maintained at the closed position over the entire range of the vertical movement thereof. Therefore, even when the cutting machine body  10  is located at the lowermost position and hence the movable cover  14  is completely opened as shown in  FIG. 2 , it is held at the closed position by the torsion spring  82 . However, in this state, the restraining projection  23   c  of the link lever  23  is retracted from above the engaging projection  83   a  and the locked state is released, whereby the auxiliary cover  80  is in a state of being capable of turning toward the opened position (upward). 
     As shown in  FIG. 2  and  FIG. 6 , when the cutting machine body  10  is moved downward substantially to the lowermost position in a state of being slid to the frontmost side (the near side of the user) by the upper and lower sliding mechanisms  41  and  42  and then the cutting machine body  10  is slid rearward by the operation of the upper and lower sliding mechanism  41  and  42 , the rotary blade  12  cuts into the cut material W 2  to achieve the cutting operation thereof. 
     When the cutting machine body  10  is slid rearward and hence the cutting operation proceeds, the rear lower end  80   c  of the auxiliary cover  80  interferes with the cut material W 2  or the upper portion of the positioning fence  32 , and the cutting machine body  10  is slid further rearward in this state, so that the auxiliary cover  80  is pressed upward and opened. In this manner, the front lower end  80   b  is oriented horizontally when the auxiliary cover  80  is at the closed position, and hence the rear lower end  80   c  is positioned in an inclined state in which the rear side is higher and serves as a guiding inclined surface, thereby opening smoothly in association with the rearward sliding movement of the cutting machine body  10 . 
     In the intermediate stopper mechanism  70 , in a state in which the switch lever portion  71   c  is switched to the intermediate locked position, the rearward sliding distance of the cutting machine body  10  is restrained to the midpoint. A state in which the rearward sliding distance of the cutting machine body  10  is restrained to the midpoint of the entire sliding distance (via the upper and lower sliding mechanisms  41  and  42 ) by the intermediate stopper mechanism  70  is shown in  FIG. 3 . As shown in the drawing, the stopper shaft portion  71   b  of the intermediate stopper mechanism  70  abuts against the center rib  45   b  and the retracting distance of the cutting machine body  10  is restrained to the midpoint, so that the cut material W 2  (placed so as to lean obliquely between the positioning fence  32  and the table  20 ) is completely cut off by the rotary blade  12 , and interference of the protruded portion  13   d  of the fixed cover  13  with respect to the cut material W 2  is avoided in advance, whereby damage of the cutting material W is avoided in advance. In the state of being restrained to the midpoint, the top  80   a  of the auxiliary cover  80  passes from the front side to the rear side with respect to the positioning fence  32 , and the front lower end  80   b  thereof is restrained to a state of moving halfway on the upper end of the positioning fence  32 . Accordingly, the intermediate stopper mechanism  70  is settled in a state in which the front lower end  80   b  of the auxiliary cover  80  is moving halfway on the upper end portion of the positioning fence  32 , where the entire auxiliary cover  80  functions for avoiding the rearward movement of the positioning fence  32 . In this manner, with the arrangement of the intermediate stopper mechanism  70 , since the entire auxiliary cover  80  is prevented from moving to the rear side of the positioning fence  32 , the auxiliary cover  80  is abutted against the back surface of the fence  32  in the stage of returning the cutting machine body  10  to the front side and, consequently, the forward sliding operation of the cutting machine body  10  is avoided from being hindered in advance. 
     Further, in a state in which the switch lever  71   c  of the intermediate stopper mechanism  70  is switched to the unlocked position in advance, the cutting machine body  10  is allowed to be slid to the rearmost position in the entire sliding range by the upper and lower sliding mechanisms  41  and  42  as shown in  FIG. 4 . In this case, for example, by placing the cut material W 2  (of a flat board shape) upright along the positioning plane  32   a  of the positioning fence  32  with the widthwise direction thereof oriented in the vertical direction as shown in the drawing, which is different from the case of the cut material W 1 , the cutting operation is achieved in a state of being fixed with a significant height. When the cutting machine body  10  is slid to the rearmost position in the entire sliding range, the rotary blade  12  is passed completely through the lower end of the positioning surface  32   a , so that the rotary blade  12  can completely cut off the lower end portion of the cut material W 2 , whereby the cutting operation thereof is reliably achieved. In this regards, when the rearward sliding distance of the cutting machine body  10  is retrained to a midpoint thereof by the intermediate stopper mechanism  70  as shown in  FIG. 3 , even when the rotary blade  12  does not pass completely on the side of the lower portion of the positioning surface  32   a , it is not a cause for concern because in this situation the cutting operation is for cutting material W 1  in the state of being placed obliquely (so as to lean against the upper surface of the table and the positioning fence  32 ). 
     The rearmost position of the entire sliding range is set so as to prevent the height of the protruded portion  13   d  of the fixed cover  13  from interfering with the high cut material W 2  or the positioning fence  32  even when the intermediate stopper mechanism  70  is released to the unlocked side and the cutting machine body  10  is able to slide to the rearmost position of the entire sliding range. 
     When the intermediate stopper mechanism  70  is switched to the unlocked side, and the cutting machine body  10  is able to slide to the rearmost position of the entire sliding range, the entire auxiliary cover  80  is moved to the rear side of the fence  32  as shown in  FIG. 4 . Consequently, the front lower end  80   b  moves apart from the upper end portion of the positioning fence  32  to the rear, and the auxiliary cover  80  is returned to the closed position by the urging force of the torsion spring  82 . In this case, interference of the auxiliary cover  80  with respect to the positioning fence  32  may be avoided by moving the cutting machine body  10  upward first and then sliding the same toward the front. 
     Although it is not shown in the drawing, by additionally providing the auxiliary cover  80  with a guiding surface which is inclined in the direction to cause the auxiliary cover  80  to turn toward the opened position when interfered with the upper portion of the positioning fence  32  at the time of the forward sliding movement of the cutting machine body  10 , the cutting machine body  10  is allowed to be returned to the front side in the state of being positioned at the lowermost position while avoiding obstruction of the auxiliary cover  80  with respect to the back surface of the positioning fence  32 . 
     The detailed configuration of the auxiliary cover  80  will be summarized here. 
     (Arrangement of Auxiliary Cover  80 ) 
     (1) The auxiliary cover  80  moves integrally with the cutting machine body  10  from in front of the positioning fence  32  (the position shown in  FIG. 2 ) to a position where it is entirely passed therethrough to the rear (the position shown in  FIG. 4 ) over the entire sliding range of the cutting machine body  10 .
 
(2) With the configuration of the intermediate stopper mechanism  70 , the rearmost position of the auxiliary cover  80  does not pass completely through the positioning fence  32  but the front lower end  80   b  thereof is restrained to a position halfway on the upper end portion of the positioning fence  32  (the position shown in  FIG. 3 ).
 
(3) In the state in which the front lower end  80   b  of the auxiliary cover  80  is approximately halfway on the upper end portion of the positioning fence  32 , the front lower end  80   b  is inclined in the direction in which the front side is higher as shown in  FIG. 3 . Consequently, when the cutting machine body  10  is returned to the front side from this state, the auxiliary cover  80  is turned to the opened side (upper side) against the torsion spring  82 , so that the forward sliding movement of the cutting machine body  10  is smoothly achieved.
 
(4) The rear lower end  80   c  of the auxiliary cover  80  functions as the guiding surface against the positioning fence  32  when retracting the cutting machine body  10  as described above.
 
(5) The auxiliary cover  80  is supported inside the fixed cover  13 . Therefore, the auxiliary cover  80  is stored inside the fixed cover  13  when being turned to the upper opened position. Accordingly, interference of the auxiliary cover  80  with the cutting material W or the positioning fence  32  is avoided during the oblique cutting operation carried out with the cutting machine body  10  inclined leftward or rightward.
 
(6) When the auxiliary cover  80  is in the closed position, the front lower end  80   b  is positioned substantially horizontally, and is protruded to the substantially same level as, or to a lower level than, the front edge portion  13   a  of the fixed cover  13 . Accordingly, the auxiliary cover  80  is provided with a higher dust collecting function.
 
     Further, turning the end of the auxiliary cover  80  toward the opened position allows for a position entirely set or stored inside the fixed cover  13 . Therefore, the auxiliary cover  80  is able to turn until the top  80   a  thereof is displaced upwardly of the rear edge portion  13   b  of the fixed cover  13 . Accordingly, the auxiliary cover  80  is prevented from hindering the sliding operation of the cutting machine body  10 . Also, the cutting depth increasing function of the rear edge portion  13   b , which is recessed upward by the dimension L with respect to the front edge portion  13   a , reliably functions. 
     (Shape of Auxiliary Cover  80 ) 
     (7) The lower portion of the auxiliary cover  80  is formed into an angular shape protruding downward. The front lower end  80   b  and the rear lower end  80   c  are formed on the front side and the rear side of the top  80   a , respectively, and each function as a guiding surface against the positioning fence  32  or the cutting material W when sliding the cutting machine body  10  as described above.
 
(8) The width of the auxiliary cover  80  is set to a width smaller than that of the movable cover  14 . Therefore, when the cutting machine body  10  is positioned at the uppermost position, the movable cover  14  is fully closed and the auxiliary cover  80  is positioned in the closed position as shown in  FIG. 1 , the front lower end  80   b  of the auxiliary cover  80  enters inside the movable cover  14 .
 
     In this manner, since the width of the auxiliary cover  80  is set to the width smaller than that of the movable cover  14 , at the time of the oblique cutting operation carried out by inclining the cutting machine body  10  leftward or rightward as described above, interference of the auxiliary cover  80  with the cutting material W or the positioning fence  32  is avoided, and hence the oblique cutting operation can be achieved at a sufficiently large angle. 
     (9) The lateral distance between the rotary blade  12  and the left shielding edge  83  of the auxiliary cover  80  is larger than the distance between the rotary blade  12  and the right shielding edge  84  of the auxiliary cover  80 . Thus, when rotary blade  12  is removed, the left shielding edge  83  does not interfere with rotary blade  12 .
 
(10) As shown in  FIG. 2 , in the course of sliding the cutting machine body  10  rearward in a state of being positioned at the lowermost position, there is no fixed portion of the cutting machine body  10  that protrudes downwardly of the front lower end portion  13   a  of the fixed cover  13  (at a position on the rear side of the auxiliary cover  80 ). Accordingly, a larger cutting depth is reliably achieved in the area on the rear side of the center of rotation of the rotary blade  12  (the mounting flange  17 ) than in the front area.
 
(Operation of Auxiliary Cover  80 )
 
(11) In a state of placing the cutting machine body  10  at the uppermost position, the auxiliary cover  80  is locked to the closed position. In this example, the restraining projection  23   c  is provided on the link lever  23  for opening and closing the movable cover  14  and the engaging projection  83   a  is provided on the auxiliary cover  80 , so that the upward (in the opening direction) turn of the auxiliary cover  80  is restrained and hence the auxiliary cover  80  is locked at the closed position by positioning the engaging projection  83   a  downwardly of the restraining projection  23   c.  
 
     Since the auxiliary cover  80  is locked to the closed position at the uppermost position of the cutting machine body  10 , the accidental opening operation of the auxiliary cover  80  is reliably prevented. 
     (12) The auxiliary cover  80  is supported with respect to the fixed cover  13  via the shaft  81  so as to be capable of turning in the vertical direction. The auxiliary cover  80  is opened by being turned upward, and is closed by being turned downward. The auxiliary cover  80  is supported by the shaft  81  at the rear end portion thereof so as to be capable of turning. The movable cover  14 , may be configured to support the same so as to be capable of turning in the vertical direction about the front end portion. The auxiliary cover is not limited to the configuration to turn in the vertical direction, and an auxiliary cover which moves between the closed position and the opened position by moving in parallel in the vertical direction is also applicable.
 
(13) The auxiliary cover  80  is urged by the torsion spring  82  toward the closed position (downward). By employing the torsion spring as the urging means, a compact configuration is achieved by using the shaft  81 . An extension spring, a compression spring, or a damper may be used instead of the torsion spring  82  to urge the auxiliary cover  80  to the closed position.
 
(14) As exemplified above, in addition to the configuration in which the restraining groove  13   c  is provided on the fixed cover  13 , and the restraining shaft  89  is provided on the auxiliary cover  80 , so that the opened position of the auxiliary cover  80  is restrained by the abutment of the restraining shaft  89  against the upper end of the restraining groove  13   c  and the closed position of the auxiliary cover  80  is restrained by the abutment of the restraining shaft  89  against the lower end of the restraining groove  13   c , a configuration in which stopper projections for restraining the opened position and for restraining the closed position respectively are provided on the fixed cover  13 , so that the opened position and the closed position of the auxiliary cover are restrained, is also applicable.
 
(Dust Collection Function of Auxiliary Cover)
 
(15) The exemplified auxiliary cover  80  includes the dust colleting channel  88 . The dust colleting channel  88  is positioned between the portion where the chips are generated (mainly the rear side of the rotary blade  12 ) and the dust collecting port  19 , so that the generated chips are guided to the dust collecting port  19  further reliably and collected efficiently.
 
(16) The dust collating channel  88  is formed between the partitioning walls  85  and  86 . The front partitioning wall  85  may be adapted to function as a wall portion for preventing the generated chips interacting along the direction of rotation of the rotary blade  12 .
 
(17) The guiding wall portion  87 , having the gentle inclined surface  87   a  on the front side, is continuously provided on the lower side of the front partitioning wall  85 . The chips generated at the cutting position are smoothly guided into the dust colleting channel  88  with the inclined surface  87   a  on the front side of the guiding wall portion  87 .
 
(18) As shown in  FIG. 5 , the dust collecting port  19  is arranged to extend from the dust colleting channel  88  that is curved obliquely and upward on the rear side. Accordingly, the dust collecting efficiency may further be enhanced.
 
     According to the cutting machine  1  configured as described above, the fixing lever for fixing the inclined position of the cutting machine body  10  has two grips  55   a  and  55   b  that are arranged to form a V-shape together, in which the grips  55   a  and  55   b  extend upward and define an angle of approximately 80° therebetween. The fixing screw  56  is mounted to a coupled portion (lower end portion) between the grips  55   a  and  55   b . Therefore, the operator can easily hold the grip  55   a  or  55   b  in a comfortable position from either of the left and right sides. Hence, it is possible to improve the operability for rotating the fixing lever  55 . 
     Further, at least one of the grips  55   a  and  55   b  may not be hidden behind the body support member as in the case of the single-lever type fixing lever. Therefore, the operator can easily look at at least one of the grips  55   a  and  55   b , and therefore, the operability of the fixing lever  55  is improved also in this respect. 
     In particular, the mounting position of the fixing lever  55  to the fixing screw  56  is set such that the grips  55   a  and  55   b  are positioned to be symmetrical with each other in right and left directions with respect to the supporting arm portion  57  when the inclined position of the cutting machine body  10  is firmly fixed by tightening the fixing screw  56 . Therefore, during the cutting operation, the operator can easily look at both of the grips  55   a  and  55   b . For this reason, the operator can easily hold the grip  55   a  or  55   b  from the left or right side for loosening the fixing lever  55 . Hence, the operability, in particular the operability for the loosening the fixing lever  55 , is improved. 
     The above embodiment can be modified in various ways. For example, although, in the exemplified construction, the two grips  55   a  and  55   b  are arranged in V-shape at an angle of approximately 80° therebetween, the angle between the two grips  55   a  and  55   b  may be arbitrarily determined. For example, the angle may be 45°, 90°, 120° or any other angles. However, setting the angle between the two grips  55   a  and  55   b  allows both of the grips  55   a  and  55   b  to be easily looked at by the operator and to be easily held. Setting the angle to be less than 100° allows to loosen and tighten the fixing screw  56  by rotating the fixing lever  55  by a suitable angle while the operator holds one of the grips without causing interference of the other of the grips with the floor or the ground. In view of this, the angle between the grips  55   a  and  55   b  is preferably set between 60° and 100°, and in particular at approximately 80°. 
     Further, although the grips  55   a  and  55   b  of the exemplified fixing lever  55  have the same length, the grips  55  and  55   b  may have different lengths from each other to form a V-shape.