Bench circular saw machine

A bench circular saw machine for cutting a material including a base upon which the material is supported, an arm interconnected to the base, a tube member, and a main body having a circular saw for cutting the material and a motor operatively associated with the circular saw for driving the circular saw. The main body is pivotally supported on the arm such that the main body can be pivoted toward the base and the circular saw can cut the material. The main body has a discharge port through which sawdust formed by the circular saw during a cutting operation is discharged from the main body. The tube member is disposed adjacent to the discharge port and is associated with the discharge port so as to guide the sawdust into the discharge port. The tube member is also pivotable relative to the material such that an angle of the tube member relative to the material can be varied.

FIELD OF THE INVENTION 
The present invention relates to a bench circular saw machine that 
comprises a base on which a material to be cut is held, a support arm 
disposed behind the base, and a main body, having a circular saw, that is 
disposed in front of the arm and is allowed to pivot in an upward-downward 
direction. 
BACKGROUND OF THE INVENTION 
A discharge port for sawdust is formed behind the circular saw of the main 
body in the machine. A sawdust accommodating bag, a sawdust accommodating 
element or the like is connected with the discharge port through which the 
sawdust propelled rearward from the circular saw is collected into the 
sawdust accommodating bag. It is disclosed in JP-A 3(1991)-108401(Utility 
Model) and JP-A 3(1991)-112301(Utility Model) that a machine comprises a 
guide plate for guiding the sawdust to a discharge port thereof. The guide 
plate is rotatably disposed under the main body, and the guide plate has a 
U shape cross-section. The guide plate is raised for contacting a material 
to be cut in a case where the material is thick. An inclination angle of 
the guide plate is thereby variable to improve collection efficiency of 
the sawdust. 
In the above-mentioned machine, however, there is a large possibility of 
damaging the material to be cut due to contact between the guide plate and 
the material. The damage to the material may be aggregated, in particular, 
by a slide type bench circular saw machine that is driven as sliding the 
main body and guide plate on the material. 
Furthermore, sawdust directed into the guide plate at an angle deviated 
from the angle of the guide plate may be directed on a out through an open 
side of the plate because of the plate U shape cross section of the plate. 
This sawdust is not guided into the sawdust accommodating bag. It can not 
be expected to improve collection efficiency of the sawdust. 
Improved sawdust guiding elements are shown in U.S. Pat. Nos. 5,063,802 and 
5,445,056. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide a bench 
circular saw machine that has an improved collection efficiency of the 
sawdust without a possibility of damaging a material to be cut. 
The machine according to the present invention includes a base on which the 
material to be cut is supported, a main body, supported on the base or on 
a turn table which is disposed on around the base in a rotatable manner, 
having a circular saw for cutting the material and a motor for driving the 
circular saw, a hinge for supporting the main body in a rotatable manner, 
a discharge port formed behind the circular saw of the main body, a tube 
member for guiding the sawdust into the discharge port, wherein the tube 
member is pivotally disposed to enable the inclination of the tube to be 
varied in a rearward-backward direction. 
Furthermore, an opening of a lower edge of the tube member may be formed as 
inclining forward and facing toward the circular saw. 
Additionally, it is possible to change an angle of the tube member 
according to a graduation on the main body. 
Yet, furthermore, it is possible to have the main body slide on the turn 
table in a forward-rearward direction with the hinge. 
The sawdust is collected effectively by the tube member by adjusting the 
inclination angle of the tube member with respect to a path of the exiting 
sawdust. 
The tube member is configured so that the tube member transfers the sawdust 
that is collected at an angle slightly deviated from the right its 
thereof. The tube member is independently variable in angle thereof so 
that it is not in contact with the material to be cut. Therefore, the 
material is never damaged. 
The width of the opening of the tube member can be effectively widened by 
arranging the lower edge of the tube member at a forward inclination, that 
is, arranging the lower edge of the tube member so that the lower edge 
faces the circular saw. 
It is furthermore possible to adjust the angle of the tube member quickly 
and correctly with respect to thickness or the like of the material to be 
cut by having the angle of the tube member vary in angle with regard to 
the graduation on the main body. 
In a case where the main body is disposed on a turn table and is able to 
slide in a forward-rearward direction, the tube member is not in contact 
with the material to be cut so that the material is never damaged by the 
sliding.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
An embodiment of the present invention is described hereinbelow with regard 
to the attached drawings. 
FIG. 1 is an elevational view of a bench circular saw machine 1, shown in a 
slide-type configuration. A turn table 3 is disposed around a base 2. A 
slide bar 4 is inserted into the turn table 3 and is allowed to slide in a 
forward-rearward direction (description will be made hereinbelow as the 
forward direction is the right direction of FIG. 1 and the rearward 
direction is the left direction). A movable arm 5 is disposed at the rear 
end of the slide bar 4. The arm 5 is allowed to move in the 
forward-rearward direction together with the slide bar 4 and to rotate in 
a circumferential direction about the slide bar 4. Position of the movable 
arm 5 in the circumferential direction with respect to the turn table 3 is 
desirably set by handling a fixing lever 6 behind the arm 5. 
A main body 8 is rotatably disposed at a front end of the arm 5 such that 
the main body 8 can move in an upward-downward direction about a support 
element 7. The main body 8 comprises a circular saw 10 driven by a motor 
not shown, a blade case 9 for protecting the saw 10 and a safety cover 11. 
The main body 8 is continuously biased in the upward direction by a 
torsion spring (not shown) provided on the support element 7. 
The blade case 9 has a body portion 12 in which a guide pass 14 for sawdust 
is formed therethrough in the upward-downward direction. A connecting 
plate 15 is connected to an upper opening 14a as a discharge port of the 
guide pass 14. The plate 15 supports a cylindrical elbow 16 in a rotatable 
manner. The elbow 16 is so designed to allow a hose from a sawdust 
accommodating bag or the like to connect thereto. 
FIG. 2 shows a configuration viewed downward from the body portion 12. A 
guide tube 17 of a rectangular cross-section is provided in the guide pass 
14. A width between a left end and a right end of the tube 17 is almost 
equal to a distance between a left wall 13a and a right wall 13b of the 
body portion 12 and a width between a front end and a rear end of the tube 
17 is almost equal to a diameter of the elbow 16. An upper portion of the 
guide tube 17 together with the wall 13a of the body portion 12 is screwed 
by a thumbscrew 18. A lower end of the guide tube 17 can be rotated in the 
forward-rearward direction around the thumbscrew 18 as a center as 
loosening the thumbscrew 18 and is fixed at a desirable angle by 
tightening the thumbscrew 18. The lower end of the guide tube 17 is formed 
in an inclined shape to configure an opening 19 that faces the circular 
saw 10. The opening 19 therefore has a wide area facing the saw 10, so 
that the opening 19 can easily to collect the sawdust. 
The bench circular saw machine 1 thus configured is driven as follows. When 
a handle (not shown) of the main body 8 is pulled down, pivots downwardly 
the main body 8 about the support element 7 to cut the material on the 
turn table 3 with the circular saw 10. In a case where the material has a 
wide width in the forward and backward direction, the main body 8, 
together with the slide bar 4 and movable arm 5, is moved forward by 
manipulating the handle to start the cutting operation. 
The flying direction of the sawdust varies depending on thickness of the 
material to be cut in the cutting operation. As shown in FIG. 3, the 
sawdust flys in the direction shown by an arrow "a" when the material is 
relatively thin, whereas as shown in FIG. 4, the sawdust flys in the 
direction shown by an arrow "b" when the material is relatively thick. 
Therefore, when the relatively thin material (the arrow a) is subjected to 
cutting, as shown in FIG. 3, first loosening the thumbscrew 18 to move the 
lower end of the guide tube to the rearmost position of the guide pass 14 
and thereafter tightening the thumbscrew 18 is diserable. Almost all the 
sawdust is collected through the opening 19 and is guided towards the 
elbow 16 through which the sawdust is directly collected and into the 
sawdust accommodating bag. On the other hand, when the relatively thick 
material (the arrow b) is subjected to cutting, as shown in FIG. 4, the 
lower end of the guide tube 17 is moved forward and the guide tube 17 is 
fixed at the position where the opening 19 is nearest to the circular saw 
10. The sawdust is collected by the opening 19 and is guided through the 
guide tube 17, of which direction is almost consistent with the direction 
of sawdust's path, to the elbow 16 and is collected into the sawdust 
accommodating bag. In this embodiment, as mentioned above, the guide tube 
17 is variable in angle at the position where it will not in contact with 
the material to be cut. The sawdust collecting operation is performed 
effectively without damaging the material to be cut by adjusting the angle 
of the guide tube 17 to the direction of the sawdust's path. Particularly, 
as the guide tube 17 is constructed as a tube member that has an even or 
constant cross section, the sawdust collected into the opening 19 is 
guided towards the elbow 16 regardless of the sawdust's entrance angle 
with respect to the opening 19. 
In the embodiment mentioned above, the guide tube 17 has a rectangular 
cross section. The guide tube 17 may be configured as another polygonal 
cross section or a cylinder. The fixing means of the guide tube 17 shown 
in FIG. 5 can be used as well as the thumbscrew 18. In FIG. 5, a screw 
member 18a such as a thumbscrew is so screwed into a wall 13a of the body 
portion 12 so as to permit the screw member 18a to press and fasten one 
side of the guide tube 17a by a top end of the screw member. A projection 
portion 20 is formed from the other side of the guide tube 17a fitted into 
a recess of the other wall 13b of the body portion 12. Other types of 
fixing means, such as a rivet or the like that supports the guide tube in 
rotatable manner and around which the guide tube rotates, can be utilized. 
Furthermore, rotational operation of the guide tube becomes easy by forming 
an arc like slit on one of or each of the walls of the body portion and 
disposing a projection member on a side or each side of the guide tube 
that penetrates through the slit. 
In the embodiment, the guide tube is separated from the elbow and is able 
to rotate. It is possible to construct the guide tube and the elbow as a 
single piece wherein and the piece is rotated by the rotation means 
mentioned above. In this case, the inclination angle of the guide tube is 
varied by means of the elbow by gripping and moving it and the number of 
the elements is thus reduced to achieve a rationalal structure. 
Next, an embodiment in which angle of the guide tube is varied in a more 
preferable manner. 
FIG. 6 is a view of the body portion 12. FIG. 7 is a view taken along an 
arrow A in FIG. 6. FIG. 8 is a view taken along an arrow B in FIG. 7. A 
tube portion 22 is projected from a side of a guide tube 21 disposed in 
the body portion 12 as shown in FIGS. 6 and 7. A tube like knob 23 is 
disposed outside the body portion 12 and is coaxial with the tube portion 
22. A connecting recess portion 22a determined by two surfaces is grooved 
in the tube portion 22 as shown in FIG. 6. On the other hand, a connecting 
projection portion 23a determined by two surfaces is bulged directing to 
the connecting recess portion 22a. The tube portion 22 and the knob 23 are 
fixed by fitting the connecting recess portion 22a and the connecting 
projection portion 23a. A boss 29 is projected from a guide tube 21 on a 
side opposite to the tube portion 22. The boss 29 is loosely inserted into 
a wall 13b of the body portion 12. A screw 24 is so provided to penetrate 
through the tube portion 22 from the knob 23 and the screw 24 is coaxial 
with the boss 29. The angle of the guide tube 21 is varied as rotating 
around the screw 24 as a center. The rotation of the guide tube 21 is 
conjoint with the rotational operation of the knob 23. A female screw 
portion engaging to the screw 24 is only formed at the tube portion 22 of 
the guide tube 21. A flange 25 having an indicator 25a is extended from 
the knob 23 as shown in FIG. 8 that is viewed along the arrow B in FIG. 7. 
On the other hand, graduations 26 indicating thickness (10 to 90 mm in the 
embodiment) of the material to be cut is formed on an outer surface of the 
wall 13a of the body portion 12. The graduations 26 indicates a position 
to which the knob 23 should be rotated. Numeral 27 in FIG. 7 depicts a 
compression spring that biases the main body upward. Numeral 28 depicts a 
linkplate connecting to the safety cover 11 and the linkplate 28 makes the 
safety cover 11 open as the main body goes down. 
According to the present embodiment, the screw 24 is loosened to change the 
angle of guide tube 21. When an operator grips the knob 23 and rotates the 
indicator 25a toward the graduation 26 indicating the thickness of the 
material to be cut, the guide tube 21 then rotates conjointly, an angle of 
the guide tube 21 preferable to the thickness of the material to be cut is 
set automatically. Thereafter, the guide tube 21 is fixed by tightening 
the screw 24. That is, the guide tube 21 moves toward the knob 23 due to 
engagement between tube portion 22 and the screw 24 and rotation of the 
screw 24. The wall 13a is then pinched between the tube portion 22 and 
knob 23 and the guide tube 21 and knob 23 are fixed at this position. As 
mentioned above, the rotational operation of the guide tube 21 is carried 
out by the knob 23 and additionally angle adjustment with regard to the 
thickness of the material to be cut is carried out quickly and correctly. 
Configuration of the guide tube 21 of the embodiment shown in FIGS. 6 to 8 
can be modified if it had a polygonal cross section. In the 
above-mentioned embodiments, the bench circular saw machine of the slide 
type having the movable arm is shown to explain the present innovation. 
The present invention, as a matter of course, can be applied to a bench 
circular saw machine in which the stationary arm is projected from the 
turn table. 
Although the invention has been disclosed in the context of certain 
preferred embodiments, it will be understood that the present invention 
extends beyond the specifically disclosed embodiments to other alternative 
embodiments of the invention. Thus it is intended that the scope of the 
invention should not be limited by the disclosed embodiments, but should 
be determined by reference to the claims that follow.