[0001] The invention relates to miter saws.
[0002] Miter saws are power tools typically comprising a base assembly, a table rotatably
attached to the base assembly (for allowing the user to change the miter angle) and
a saw assembly pivotably attached to the table so that the saw assembly can move downwardly
for cutting. The saw assembly typically includes a blade and a motor driving the blade.
[0003] Examples of the prior art are disclosed in
US Patent Nos US4805504 and US5203245. In particular,
US5203245 discloses a chop saw according to the preamble of claim 1.
[0004] According to the present invention there is provided a chop saw comprising the features
of claim 1.
[0005] Additional features and benefits of the present invention are described, and will
be apparent from the accompanying drawings and detailed description below.
[0006] The accompanying drawings illustrate preferred embodiments of the invention according
to the practical application of the principles thereof, and in which:
FIG. 1 is an elevated front perspective view of a miter saw according to the invention;
FIG. 2 is an exploded view of the base assembly;
FIG. 3 is a cross-sectional view of the improved miter lock mechanism of FIG. 1, along
line III-III as shown in FIG. 1;
FIG. 4 is a partial cross-sectional view of the miter lock mechanism of FIG. 3, along
line IV-IV as shown in FIG. 3;
FIG 5 is partial cross-sectional view of the miter lock mechanism where FIG. 5A and
5B show different operational positions of the miter lock mechanism.
FIG. 6 is a partial front view of the bevel scale mechanism according to the invention.
FIG. 7 is side view of the bevel scale mechanism of FIG. 6;
FIG. 8 is a close up view of the pointer of FIG. 6 and 7;
FIG. 9 illustrates a second embodiment of the bevel scale mechanism according to the
invention, where FIG. 9A and 9B show different positions of the pointer;
FIG. 10 is a partial side view of the upper blade guard and pivot blade according
to the present invention;
FIG. 11 is a partial cross-sectional view of along line XI-XI as shown in FIG. 10;
FIG. 12 is a partial cross-sectional view along line XII-XII as shown in FIG. 10;
FIG. 13 is a partial cross-sectional view along line XIII-XIII as shown in FIG. 10;
FIG. 14 illustrates a first fixture mount according to the invention;
FIG. 15 illustrates a second fixture mount according to the invention; and
FIG. 16 is a partial cross-sectional view of the pivot plate/lower blade guard assembly.
[0007] The invention is now described with reference to the accompanying figures, wherein
like numerals designate like parts. FIG. 1 shows a power tool 10. Persons skilled
in the art should recognize that the power tool 10 may be a chop saw, miter saw, compound
miter saw, and/or sliding miter saw. For the purpose of clarity, a power tool 10 shall
be referred to herein as miter saw 10.
[0008] Miter saw 10 comprises a base assembly 11, a table 12 rotatably attached to the base
assembly, a saw assembly 30 pivotably attached to the table 12, and a fence assembly
20 fixedly attached to the base 11. Preferably, the fence assembly 20 comprises a
fixed fence 21 fixedly attached to the base assembly 11 and a slidable fence 22 slidably
attached to the fixed fence 21. Persons skilled in the art are hereby referred to
US Patent No. 5,297,463. A second fence 25 may also be fixedly attached to base assembly 11. Preferably fixed
fence 21, sliding fence 22 and/or a second fence 25 are co-planar.
[0009] The table 12 may have a cylinder 13, which is pivotably connected to the trunnion
junction 40. Trunnion junction 40 preferably includes a trunnion 41 which is pivotably
attached to the table 12 in a manner well-known in the art. Such pivotal connection
would enable a user to change the bevel angle of the miter saw 10.
[0010] Saw assembly 30 is pivotably attached to table 12 via the trunnion junction 40 and
cylinder 13. To enable a user to conduct the chopping operation, the saw assembly
has an arm 34 which is pivotably attached to the trunnion 41.
[0011] Saw assembly 30 may also include an upper blade guard 31 disposed on the arm 34,
motor housing 35 for housing a motor (not shown), a handle 36 disposed on the motor
housing 35 and/or upper blade guard 31 for allowing the user to move the saw assembly
30 downwardly, a blade 33 driven by the motor for cutting. The arm 34 may also include
a dust collector 37 as is well known in the prior art. Persons skilled in the art
are hereby referred to
US Patent No. 5,819,619.
[0012] Saw assembly 30 may also include a lower blade guard for covering the lower portion
of blade 33.
[0013] As mentioned above, the table 12 is rotatably connected to base assembly 11. Referring
to FIGS. 1 and 2, base assembly 11 may have a circular well 11W for receiving a wear
ring 14. The wear ring 14 may be disposed within a channel 11C defined in well 11W
by a wall 11WW. The wear ring 14 is not fixedly attached to base assembly 11. The
wear ring is preferably sandwiched between base assembly 11 and table 12.
[0014] Persons skilled in the art will recognize that the composition of wear ring 14 should
be an appropriate material, such as steel, rubber or any equivalent thereof, that
will enable rotation of table 12 on wear ring 14. Preferably wear ring 14 is L-shaped
so that it can be inserted into channel 11C and support table 12 at the same time.
[0015] Because the ring is not fixedly attached to base assembly 11 or to table 12, the
wear ring 14 is allowed to rotate as necessary while utilizing both contact sides
for longer life.
[0016] Referring to FIGS. 1 and 3-5, it is preferable to provide miter saw 10 with a miter
lock mechanism 50. As mentioned above, table 12 is rotatably attached to base assembly
11. A user can change the miter angle of the blade by rotating table 12 relative to
base assembly 11. In order to lock the rotational position of table 12, a miter lock
mechanism is required. In the prior art, a simple screw/knob assembly allowed users
to fix the rotational position of the table 12. However, such mechanism did not prevent
users from over-torquing the knob, thus causing damage to the miter lock mechanism,
the table 12 and/or the base assembly 11. An improved miter lock mechanism 50 is disclosed
herein.
[0017] Miter lock mechanism 50 may include a screw 51 threadedly engaged through table 12
and contacting base assembly 11 in the locking position. A knob 53 is operatively
connected to screw 51 for rotating screw 51. Miter lock mechanism 50 may also include
a clutch mechanism 56 for preventing the user from over-torquing knob 53. The clutch
mechanism 56 may include an auxiliary knob 52 fixedly attached to screw 51 for simultaneous
rotation therewith. Auxiliary knob 52 may have teeth 54. Teeth 54 may engage extensions
55 disposed on knob 53.
[0018] As shown in further detail on FIGS. 4 and 5, knob 53 preferably has extensions 55
which are resiliently connected to the knob 53 and are moveable between first position
contacting teeth 54, and a second position bypassing teeth 54. Extension 55 may include
a ramp 55R which moves along tooth 54 in the first position. Persons of ordinary skill
in the art will recognize that the shape and form of tooth 54, extension 55, and/or
ramp 55 will be designed in order to meet the desired torque requirements.
[0019] Persons skilled in the art will also recognize that, as the user rotates knob 53,
the protrusion 55 will cause rotation of auxiliary knob 54 unless a predetermined
torque limit is reached, upon which extension 55 will slide along tooth 54 until it
moves to the second position where extension 55 bypasses tooth 54.
[0020] Extension 55 may have a latching area 55L, which is preferably located on the rear
side of the ramp 55R. With such arrangement, when the user rotates the knob 53 for
unlocking the miter lock, the latch area 55L will latch onto tooth 54, causing the
knob 53 and auxiliary 52 to rotate together. Persons skilled in the art shall recognize
that the actual shape of the latching area 55L and tooth 54 should be designed so
as to minimize the movement of extension 55 between the first and second positions.
[0021] Persons or ordinary skill in the arts should also recognize that the extensions 55
and tooth 54 may be provided on the auxiliary knob 52, and knob 53, respectively,
in order to achieve the same results.
[0022] Referring to FIG. 14, the miter saw 10 may be provided with means for mounting fixtures
thereon. Fixture F may be attached on the miter saw 10 for supporting a workpiece
W disposed on table 12 and/or base assembly 11. Fence assembly 20 may be provided
with a hole FFH. Hole FFH may be either round or a slot, and should be of such size
to allow the user to put a screw FFB therethrough. Preferably, the hole size will
allow a number 8 screw therethrough. In other words, the hole FFH may have a diameter
of about 3/16 of an inch.
[0023] Preferably, hole FFH is provided on the sliding fence 21, thus providing the user
with moveable fixture F. Accordingly, the fence assembly 20 can be converted into
a movable end stop, allowing the end user to move the workpiece W to a first desired
position, then adjusting the sliding fence 22 to a second desired position, and moving
the workpiece W to that second desired position.
[0024] FIGS. 1 and 15 illustrate a different fixture mount. In miter saw 10, the fixture
F is preferably mounted to base assembly 11 and/or table 12 via bolts FB extending
through the fixture F. Bolt FB may screw onto base assembly 11 and/or table 12 directly
or into nuts F disposed underneath the base assembly 11 and/or rotatable table 12.
Persons skilled in the art should recognize that bolt FB may extend through hole FH
in base assembly 11 or through slot FS on table 12. Having a slot FS allow the user
to move table 12 without removing bolt FB or fixture F.
[0025] Persons skilled in the art shall recognize that the fixture mounting holes FH, FFH
and/or FS can be cast or machined into the different pieces.
[0026] Referring to FIG. 6, miter saw 10 may be provided with a bevel scale mechanism 60.
Bevel scale mechanism 60 may be used to indicate the bevel angle of miter saw 10.
Bevel scale mechanism 60 may include scale 62 on trunnion 41, and pointer 61 disposed
on cylinder 13. Persons skilled in the art should recognize that scale 60 may be disposed
on cylinder 13 and pointer 61 may be disposed on trunnion 41. Scale 62 may have indicia
62 I thereon to better denote the bevel angle.
[0027] It may be preferable to provide an adjustable pointer 61 to adjust the pointer close
to the scale 62 without contacting the scale 62. Referring to FIGS. 6-8, adjustable
bevel pointer 61 may include fixed portion 61 F and an adjustable portion 61A removeably
disposed on fixed portion 61 F. Screw 61 S may fix the location of adjustable portion
61A relative to fixed portion 61 S. The bevel pointer 61 may then be attached to cylinder
13 via screw 63.
[0028] Screw 61S may be threadedly extend through slots 61 N in adjustable portion 61A.
Screw 61S may threadedly engage a nut (not shown) disposed behind fixed portion 61
F or may be threadedly engaged into fixed portion 61 F.
[0029] By connecting pointer 61 to cylinder 13 via screw 63, pointer 61 is thus adjustable
via rotation about the longitudinal axis of screw 63 and/or moveable in a direction
parallel to the longitudinal axis of screw 63.
[0030] A second adjustable pointer 65 is shown in FIGS. 9A and 9B. The teachings of the
previous embodiments are wholly incorporated by reference, where like numerals refer
to like parts. In this embodiment, pointer 65 is again attached to cylinder 13 via
a screw 66 which preferably extends through pointer 65 and protrusion 13P of cylinder
13. Screw 66 may be threadedly engaged to a nut 68 behind the protrusion 13P. The
pointer 65 may be adjusted relative to the scale 62 by inserting washers 67 between
pointer 65 and protrusion 13P. It may be preferable to provide a fixed number of washers
so that the user may put some between screw 66 and pointer 65 and the remainder between
pointer 65 and protrusion 13P.
[0031] Referring to FIGS. 10-11, upper blade guard 31 may have a pivot plate 70 pivotally
attached to upper blade guard 31 via bolt 71 for rotatably supporting lower blade
guard 32. Pivot plate 70 may be locked in a fixed position relative to upper blade
guard 31 via bolt 73. Pivot plate 70 may also cover arbor A and must be pivoted in
order to provide access to arbor A. To do so, the user needs to unscrew screw 73 so
that it bypasses tab 71A. Once the screw 73 can bypass tab 71A, screw 73 will slide
along slot 72. Persons skilled in the art will recognize that slot 72 may be closed
slot as shown in FIG. 10 or an open slot so that the user can completely separate
the pivot plate 70 and screw 73. Persons skilled in the art will also recognize that
screw 73 is preferably threadedly engaged to upper blade guard 31.
[0032] Referring to FIGS. 11A-11B, persons skilled in the art should recognize that when
the head of the screw 73 is moved to bypass tab 71A, such position will block movement
of lower blade guard 32. Accordingly, if a user wants to lower blade guard 32, the
user will have to put pivot plate 70 in its original position and screw 73 thereon.
[0033] Pivot plate 70 may also have a tab 74 extending inwardly toward blade 33. Tab 74
extends inwardly so that it can contact upper blade guard 31 when the pivot plate
70 is pivoted. In other words, tab 74 limits the range of movement of pivot plate
70.
[0034] Referring to FIGS. 10 and 12, pivot plate 70 may have channel tab 75, which preferably
extends inwardly towards and parallel to blade 33. Upper blade guard 31 may extend
between pivot plate 70 and channel tab 75. Such arrangement prevents pivot plate 70
from moving laterally excessively.
[0035] Referring to FIGS. 10 and 13, pivot plate 70 may also have blade caliper tab 76.
Blade caliper tab 76 extends inwardly towards blade 33. Preferably, tab 76 extends
within several millimeters of blade 33. With such arrangement, tab 76 prevents blade
33 from moving laterally excessively during the rotation thereof, and from cutting
upper blade guard 31.
[0036] FIG. 16 illustrates the connection between pivot plate 70 and lower blade guard 32.
Preferably, a rotational spring 77 is captured between pivot plate 70 and lower blade
guard 32. Preferably, one end of spring 77 is shaped like a hook 77H. Preferably,
hook 77H is inserted through slot 32S and then released during assembly. Hook 77H
will then move towards the end of slot 32S providing a durable junction that is easy
to assemble.
[0037] Similarly, the other end of spring 77 may also be shaped as a hook and inserted through
pivot plate 70. Alternatively, the other end of spring 77 is shaped like a bent leg
77L, which then may be inserted through slot 70S in pivot plate 70.
[0038] Preferably, pivot plate 70 is connected to lower blade guard 32 via a screw 38. Screw
38 may be inserted through lower blade guard 32 and threadingly engage pivot plate
70. Alternatively, screw 38 may be inserted through pivot plate 70 and lower blade
guard 32 and threadingly engaged to a plate retainer 78. Preferably, a portion of
plate retainer 78 extends through lower blade guard 32 and/or contact pivot plate
70.
[0039] Persons skilled in the art may recognize other alternatives to the means disclosed
herein. However, all these additions and/or alterations are considered to be equal
inside the present invention.
1. Kappsäge, umfassend:
eine Basiseinheit (11) und
eine Sägeeinheit (30), die drehbar an die Basiseinheit befestigt ist, wobei die Sägeeinheit
einen oberen Klingenschutz (31), eine Platte (70), die drehbar an den oberen Klingenschutz
(31) befestigt ist, einen unteren Klingenschutz, der drehbar an die Platte befestigt
ist, und eine Schraube (73) umfasst, die in den oberen Klingenschutz eingreift, um
die Platte zu befestigen;
dadurch gekennzeichnet, dass mindestens einer des oberen Klingenschutzes und der Platte eine erste Lasche (71A)
neben der Schraube aufweist, die sich vom oberen Klingenschutz oder von der Platte
einen ersten Abstand erstreckt, wobei die Schraube einen zweiten Abstand vom oberen
Klingeschutz nach außen bewegt werden muss, wobei der zweite Abstand länger als der
erste Abstand ist, um über die erste Lasche hinauszuragen und die Platte zu drehen,
wobei der zweite Abstand länger als der Abstand zwischen dem unteren Klingenschutz
und dem oberen Klingenschutz ist.
2. Kappsäge nach Anspruch 1, wobei die Platte (70) eine zweite Lasche (74) aufweist,
die sich nach innen erstreckt, die beim Drehen der Platte mit dem oberen Klingenschutz
(31) in Kontakt kommt.
3. Kappsäge nach Anspruch 1, wobei die Platte (70) eine zweite Lasche (75) aufweist,
die sich nach innen erstreckt und einen Kanal definiert, wobei sich der obere Klingenschutz
(31) in den Kanal erstreckt.
4. Kappsäge nach Anspruch 1, wobei die Platte (70) eine zweite Lasche (76) aufweist,
die sich nach innen zu einer Platte (33) erstreckt.