U.S. patent application number 13/817765 was filed with the patent office on 2013-06-13 for convertible zero-clearance circular saw.
This patent application is currently assigned to Rylander & Associates P.C.. The applicant listed for this patent is Jacob Cuzdey. Invention is credited to Jacob Cuzdey.
Application Number | 20130145634 13/817765 |
Document ID | / |
Family ID | 45605436 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130145634 |
Kind Code |
A1 |
Cuzdey; Jacob |
June 13, 2013 |
CONVERTIBLE ZERO-CLEARANCE CIRCULAR SAW
Abstract
A portable zero clearance circular saw including a motor frame
portion with a transverse oriented drive shaft and arbor coupled to
the drive shaft, a handle portion with, a hand grip coupled to the
motor frame portion aft end, a planar blade deck on a first lateral
side, a movable blade shield rotatably mounted coaxial with the
drive shaft and having a sidewall with a edge face coplanar with
the blade deck, a trigger proximate the hand grip to move the blade
shield, and a blade couplable to the drive shaft against the arbor,
such that the blade outer surface is flush with the blade deck and
blade shield sidewall. The handle portion may be rotatably coupled
to the motor frame portion, and may include two laterally disposed
blade shield triggers operably coupled to the blade shield via a
dual pulley system.
Inventors: |
Cuzdey; Jacob; (Elma,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cuzdey; Jacob |
Elma |
WA |
US |
|
|
Assignee: |
Rylander & Associates
P.C.
Vancouver
WA
|
Family ID: |
45605436 |
Appl. No.: |
13/817765 |
Filed: |
August 18, 2011 |
PCT Filed: |
August 18, 2011 |
PCT NO: |
PCT/US11/48323 |
371 Date: |
February 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61401814 |
Aug 18, 2010 |
|
|
|
Current U.S.
Class: |
30/376 ;
83/835 |
Current CPC
Class: |
Y10T 83/9319 20150401;
B27B 5/08 20130101; B23D 61/025 20130101; B27B 9/02 20130101; B23D
45/16 20130101 |
Class at
Publication: |
30/376 ;
83/835 |
International
Class: |
B23D 45/16 20060101
B23D045/16; B23D 61/02 20060101 B23D061/02 |
Claims
1. A portable, circular saw adapted to receive a flush mounted
circular saw blade, the blade including a central mounting portion
having opposed first and second surfaces, and a cutting portion
with opposed first and second planar surfaces extending from the
central mounting portion to a cutting edge disposed along the blade
perimeter, the rotation of the cutting edge defining a blade arc,
the saw comprising: a. opposed forward and aft ends defining a
longitudinal direction; b. a motor frame portion having opposed
forward and aft ends, the motor frame portion including: i. a motor
connectable to a power source, the motor mounted to the motor frame
portion and operably coupled to a drive shaft, the drive shaft
projecting from a first lateral side of the motor frame portion,
the drive shaft defining a first transverse axis; and, ii. a blade
shield axle extending transversely from the motor frame portion
first lateral side coaxial with the drive shaft; c. a handle
portion coupled to the motor frame portion aft end, the handle
portion including a hand grip and a motor actuator to selectively
actuate the motor; d. a blade deck rigidly coupled to the motor
frame portion first lateral side, the blade deck including a planar
bearing surface; e. an arbor coupled to the drive shaft, the arbor
including a first mounting face adapted to mate to a blade central
mounting portion, the distance from the blade mounting face surface
to the blade deck planar bearing surface defining a blade offset
depth; f. a lower blade shield movable between a deployed position
and a retracted position, the lower blade shield having an arcuate
laterally projected sidewall circumscribing a portion of the blade
arc from a sidewall first end to a sidewall second end, the arcuate
sidewall including a facing edge coplanar with the blade deck
bearing surface, the lower blade shield rotatably coupled to the
blade shield axle; g. a base deck extending longitudinally from a
forward edge to an opposed aft edge and transversely from a first
lateral edge proximal the motor frame portion first lateral side to
a second lateral edge, the base deck edges defining a planar
bearing surface, the base deck pivotally coupled to the motor frame
portion about a second transverse axis and lockable at a plurality
of user selectable pitch angles about the second transverse axis to
adjust the blade cutting depth, the base deck further pivotally
coupled to the motor frame about a first longitudinal axis and
lockable at a plurality of user selected bevel angles about the
first longitudinal axis.
2. A circular saw as in claim 1, further comprising: a. the handle
portion rotatably coupled to the motor frame portion aft end to
rotate about a second longitudinal axis and lockable at a plurality
of user selected rotated positions, the plurality of handle portion
user selected rotated positions including at least 0.degree. and
90.degree..
3. A circular saw as in claim 1 or 2, further comprising: a. a
first lower blade shield trigger operably coupled to the lower
blade shield to move the lower blade shield between the normal
deployed position and the retracted position;
4. A circular saw as in claim 3, further comprising: a. the first
lower blade shield trigger mounted to the handle portion proximal
the hand grip such that it may be operated by a first thumb of an
operator while gripping the hand grip with a first hand.
5. A circular saw as in claim 4, further comprising: a. the first
blade shield trigger mounted to the handle portion along the first
lateral side of the handle portion proximal the hand grip; and, b.
a second lower blade shield trigger operably coupled to the lower
blade shield to move the lower blade shield between the normal
deployed position and the retracted position, the second lower
blade shield trigger disposed along the opposing lateral side of
the handle portion from the first blade shield trigger and proximal
to the hand grip such that it may be operated by the thumb of an
operator while gripping the hand grip with an opposed second
hand.
6. A circular saw as in claims 1 or 2, further comprising: a. a
circular saw blade removably couplable to the blade drive shaft,
the blade including a central mounting portion having opposed first
and second surfaces wherein the central mounting portion second
surface comprises a second mounting face adapted to mate to the
first mounting face, a cutting portion with opposed first and
second planar surfaces extending from the central mounting portion
to a cutting edge disposed along the blade perimeter, the rotation
of the cutting edge defining the blade arc; b. wherein, the
distance from the second mounting face to the blade first planar
surface is equal to the blade offset depth, such that the blade
first planar surface is coplanar to the blade deck planar bearing
surface.
7. A circular saw as in claim 6, further comprising: a. wherein the
central mounting portion is offset laterally from the circular saw
blade second surface.
8. A circular saw as in claim 6, further comprising: a. the arbor
further including a plurality of fastener receiving holes: b. the
blade central mounting portion having a having a first plurality of
mounting apertures, the first plurality of mounting apertures
countersunk on the mounting portion first surface, the first
plurality of mounting apertures aligned to the fastener receiving
holes; and, c. a plurality of bevel, head fasteners to engage the
blade to the arbor through the first plurality of mounting
apertures and fastener receiving holes, the fastener heads flush
with the mounting portion second surface when fully engaged through
the first plurality of mounting apertures.
9. A circular saw as in claim 8, further comprising: a. the blade
central mounting portion further having a second plurality of
mounting apertures, the second plurality of mounting apertures
countersunk on the mounting portion second surface, the second
plurality of mounting apertures aligned to the fastener receiving
holes, the plurality of fasteners engagable through the second
plurality of mounting apertures to be flush with the central
mounting portion second surface, such that the blade is
reversible.
10. A circular saw as in claim 1 or 2, further comprising: a. the
cross section of the drive shaft defining a shaft diameter; b. the
blade shield axle coaxial with and surrounding drive shaft, the
blade shield axle having an exterior bearing surface defining an
exterior blade shield axle diameter, the exterior bearing surface
to rotatably receive a lower blade shield over the blade shield
axle; c. the blade shield axle further including an interior
bearing surface defining an interior blade shield axle diameter
greater than the motor shaft diameter, the blade shield axle
interior bearing surface to rotatably receive an arbor first part;
d. the arbor further comprising: i. a first part comprising a
hollow axle to couple over the drive shaft and within the shield
axle interior bearing surface; and, ii. a second part extending
from the first part, the second part comprising a flange including
the first mounting face.
11. A circular saw as in claim 10, further comprising: a. wherein
the arbor flange diameter is greater than the blade shield axle
outer shaft diameter to retain the blade shield on the blade shield
axle.
12. A circular saw as in claim 10, further comprising: a. an arbor
cap having: i. a blade engagement projection to insert into and
engage a center mounting aperture through a blade central mounting
portion; ii. a surrounding arbor cap flange to go against a blade
central mounting portion first surface; iii. an arbor cap center
aperture to receive a fastener there through; and, b. a center
fastener to engage a blade against the arbor through the center
aperture.
13. A circular saw as in claim 12, further comprising: a. the arbor
cap having a depth dimensioned such that the arbor cap engaged
against a blade and the arbor does not protrude past the blade
cutting portion first planar surface.
14. A circular saw as in claim 1 or 2, further comprising: a. a
front deck portion having opposed forward and aft edges and a
planar bearing surface extending there between, the front deck
portion hingedly coupled proximate the front deck portion aft edge
to the base deck proximate the base deck front edge and pivotable
about a third transverse axis, the front deck portion lockable at
least at a first position, wherein the front deck planar bearing
surface is coplanar to the base deck planar bearing surface and
wherein the front deck portion forward edge extends forward of the
blade arc, and a second position, wherein the front deck planar
bearing surface is normal to the base deck planar bearing surface
and facing forward.
15. A circular saw as in claim 14, further comprising: a. the front
deck portion further including a locking pin to lock the front deck
portion in at least the first or second position and a front deck
aperture to access the locking pin, the front deck aperture
disposed to align, with the locking pin when the front deck portion
is in the second position.
16. A circular saw as in claim 1 or 2, further comprising a.
wherein the blade deck bearing surface extends forward to
circumscribe a portion of the blade arc, thereby defining a blade
deck interior edge, the distance between the blade arc and the
blade deck interior edge defining a blade gap to receive at least a
portion of the lower blade shield sidewall in the retracted
position.
17. A circular saw as in claim 1 or 2, further comprising: a.
wherein the lower blade shield is biased to the deployed
position.
18. A circular saw as in claim 5, further comprising: a. wherein
the first and second blade shield triggers are operable
independently from each other.
19. A circular saw as in claims 1 or 2, further comprising: a. an
electromagnetic brake to electromagnetically lock the motor
windings, the brake automatically actuated when the motor trigger
is released while the motor is connected to a power source.
20. A circular saw as in claim 1 or 2, further comprising: a. a
hinge block having a first end and opposed second end, the hinge
block first end pivotally coupled to the base deck distal from the
base deck aft edge along the first longitudinal axis to pivot the
base deck around the first longitudinal axis, the hinge block
second end pivotally coupled to the motor frame portion at a second
transverse axis to pivot the base deck around the second transverse
axis; b. dual axes hinge coupler mounted to the base deck proximate
the base deck first lateral edge distal from the base deck front
edge, the dual axes hinge coupler having a first portion comprising
a longitudinal hinge coupling aligned along the first longitudinal
axis to pivot the base deck around the first longitudinal axis and
a second portion comprising a transverse hinge coupling aligned
along a fourth transverse axis; C, a first sliding connector
comprising an arcuate track having a first end, a second end, and a
first closed channel extending from proximate the first end to the
second end, the first end coupled to the dual axes hinge coupler
second portion, the first closed channel to slidlingly receive a
stub axle there through; and, d, a stub axle extending from the
first lateral side of the motor frame portion to a free end, the
stub axle extending through the first closed channel and having a
first selectively releasable compression coupling coupled to the
stub axle to lockingly engage against the first arcuate track and
motor frame portion.
21. A circular saw as in claims 1 or 2, further comprising: a. a
hinge block having a first end and opposed second end, the hinge
block first end pivotally coupled to the base deck distal from the
base deck aft edge first longitudinal axis to pivot the base deck
around the first longitudinal axis, the hinge block second end
pivotally coupled to the motor frame portion at a second transverse
axis to pivot the base deck around the second transverse axis; b.
the base deck further comprising a dual axes coupler disposed
proximate the first lateral edge to couple the base deck to the
motor frame portion, the dual axes coupler having a first portion
comprising a longitudinal rotatable coupling aligned along the
first longitudinal axis to pivot the base deck around the first
longitudinal axis and a second portion comprising a transverse
rotatable coupling aligned along a fourth transverse axis; and, c.
a second sliding connector comprising overlapping first and second
arcuate portions: i. the first arcuate portion having a first end
coupled to the hinge block distal from the hinge block first end,
and a second end; ii. the second arcuate portion having a first end
coupled to the base deck distal from the base deck aft edge and
distal from the base deck first lateral edge, a second end, and a
closed channel extending from proximal the second arcuate portion
first end to second arcuate portion second end; and, iii. a second
selectively releasable compression coupling to selectively
lockingly engage the first and second arcuate portions against each
other.
22. A circular saw as in claim 1 or 2, further comprising: a. the
bevel angle continuously adjustable within a range of approximately
+65.degree. to approximately -10.degree., wherein the base deck
bearing surface oriented normal to the blade arc defines
0.degree..
23. A circular saw as in claim 1 or 2, further comprising: a. a
dust cover removably couplable to the saw to substantially enclose
the blade arc.
24. A circular saw as in claim 23, the dust cover further
comprising: a. an aft cover portion, a lower blade cover portion,
and a front cover portion; b. the aft cover portion removably
mountable to the blade deck and covering a portion of a mounted
blade; c. the blade cover portion removably mountable to the lower
blade shield and rotatably coupled to the aft cover portion coaxial
with the first transverse axis such that the blade cover portion
moves with the lower blade shield; d. the front cover portion
removably mountable to the base deck proximal the base deck forward
edge and movable with the base deck.
25. A circular saw as in claim 1 or 2, further comprising: a. the
motor further including a first brush access port on the motor
frame portion first lateral side; b. the blade deck further
including a first aperture aligned with the first brush access port
to provide access to a motor brush.
26. A circular saw as in claim 3, further comprising: a. a double
pulley rotatably coupled to the motor frame portion first lateral
side at a fifth transverse axis, the double pulley including a
first sheave having a first diameter and a second sheave having a
second diameter smaller than the first diameter; b. a first cable
operably coupling the first lower shield trigger to the first
sheave; and, e. a second cable operably coupling the second sheave
to the lower blade shield.
27. A circular saw as in claim 17, further comprising: a. a center
lever disposed between the first and second lower blade shield
triggers, the center lever including a transversely oriented bridge
portion, first and second legs extending from opposing ends of the
bridge portion to first and second leg ends, and opposed first and
second tabs extending transversely from the bridge portion opposed
ends, the center lever first and second legs pivotably coupled to
the handle portion coaxially to the first and second lower blade
shield triggers on a sixth transvers axis, the first and second
tabs overlapping the first and second lower blade shield triggers,
respectively, such that either the first or second lower blade
shield trigger will engage against its respective tab to move the
center lever when the respective trigger is depressed; b. a double
pulley rotatably coupled to the motor frame portion first lateral
side at a fifth transverse axis, the double pulley including a
first sheave having a first diameter and a second sheave having a
second diameter smaller than the first diameter; c. a first cable
operably coupling the center lever to the first sheave; and, d. a
second cable operably coupling the second sheave to the lower blade
shield.
28. A circular saw as in claim 26, further comprising: a. a biasing
spring coupled between the motor frame portion and the lower blade
shield to bias the lower blade shield toward the deployed
position.
29. A circular saw as in claim 27, further comprising: a. a biasing
spring coupled between the motor frame portion and the lower blade
shield to bias the lower blade shield toward the deployed
position.
30. A circular saw blade removably mountable to a zero clearance
circular saw having a motor coupled to a drive shaft, a blade deck
including a planar bearing surface, and a first mounting face
coupled to a drive shaft, the distance from the first mounting face
to the blade deck bearing surface defining a blade offset depth the
saw blade comprising: a. a central mounting portion having opposed
first, and second surfaces wherein the central mounting portion
second surface comprises a second mounting face adapted to mate to
the first mounting face; b. a cutting portion having opposed first
and second planar surfaces extending from the central mounting
portion to a cutting edge disposed along the blade perimeter, the
rotation of the cutting edge defining the blade arc; c. wherein,
the blade central mounting portion is offset laterally from the
blade cutting portion second surface and the distance from the
second mounting face to the blade cutting portion first planar
surface is equal to the blade offset depth, such that the blade
cutting portion first planar surface is coplanar to the blade deck
planar bearing surface when mounted to the saw.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to co-pending U.S.
Provisional Application Ser. No. 61/401,814, filed Aug. 18,
2010.
FIELD OF THE INVENTION
[0002] The present invention relates to portable circular saws for
zero-clearance or flush cutting, such as undercut saws.
BACKGROUND
[0003] Conventional portable circular saws are not capable of
safely making flush cuts--i.e. zero clearance--against a planar
surface. Conventional tools mount the saw blade using attachments
which project outward beyond the outside blade face, and the blade
guard extends at least partially over both blade faces, and no
bearing surface, or "deck", is provided to support the saw against
a first plane and the saw blade flush against a second plane.
Conventional tools also use a fixed forward blade guard which is
not adjustable, preventing the operator from inserting the saw by a
front entry which provides superior visibility and control from
"bucking", and prevents a smooth continuous transition through
different cutting directions--e.g. cutting along a floor edge and
then continuously upward along a door frame or wall corner.
Additionally, conventional designs do not provide effective
one-handed control of the movable blade guard, so operators are
either required to use one hand to operate the trigger and their
other hand to operate the blade guard--placing the operator's other
hand close to the moving blade--or they bypass the safety feature
by jamming something into the guard to hold it back--also quite
dangerous (but unfortunately very common).
[0004] None of the conventional tool designs provides the ability
to perform all of these functions in a safe and effective manner,
nor are they able to convert between conventional circular saw and
a flush cutting device. Conventional single-purpose tools have
other disadvantages. Generally, they are unable to make deep
cuts--e.g. through a double-deck comprising two or more layers of
two-inch thick stacked boards--and provide limited angular
adjustment to make beveled cuts.
[0005] A number of devices have provided an ability to perform
undercutting. For example, Crain Tools.TM. produces a conventional
"undercut saw", the model 820, capable of horizontal use to
undercut along base boards and door jams. However, it is not useful
for cutting vertical surfaces, lacking a deck, adjustable front
guard and bevel adjustment, and is not suitable for 360.degree.
contour cutting. Additionally, jam saws lack controllable blade
guards. Nor are conventional circular saws capable of conversion to
a flush cutting tool. Conventional designs are (safely) capable
merely of single purpose uses.
[0006] U.S. Pat. No. 5,481,806, to Pratt, is for a tongue
attachment to a lower blade guard of a portable electric circular
saw. During a cutting operation, that tongue attachment is intended
to prevent binding or snagging of the leading edge of the lower
blade guard on the nearest edge of a cut, bifurcated work. The saw
disclosed therein is no more capable of making a zero clearance cut
than any other portable electric circular saw.
[0007] U.S. Pat. No. 6,021,826 discloses a powered, chain saw
cutting system for cutting mortises in a work for making
mortise-and-tenon joints. Zero clearance cuts can be made with the
system only in a manner that the nose and of system's saw bar and
its entrained cutting chain is used to cut into a work piece in
order to create a mortise therein. The apparatus lacks a blade deck
bearing surface and adjustable base deck for use on vertical and
horizontal through-cuts and the retractable flush blade shield.
[0008] U.S. Pat. No. 6,606,930 B2 discloses a saw cutting guide for
a portable, electric, circular power saw that is intended as an aid
in cutting the of the excess ends of roof shingles and the like.
The disclosed saw cutting guide does nothing to permit a portable,
circular power saw to achieve a zero clearance cut, and nothing in
the disclosure would assist a person of ordinary skill to arrive at
Applicant's invention. U.S. Patent Pub. 2004/0035274 A is
similar.
[0009] U.S. Pat. No. 4,245,390 discloses a scoring attachment for a
portable, electric, circular saw. The attachment attaches to a
front end portion of a such portable saw and imposes a score upon a
surface of a wood article aligned with the rotating, circular saw
blade in order to reduce or eliminate splintering of the wood
during the cutting operation. The reference does not teach
solutions to the need for a zero clearance saw.
[0010] U.S. Pat. No. 6,568,088 B1 discloses a wheel attachment for
portable power cutting tools. The attachment mounts a pair of
laterally spaced-apart roller wheels at a front end of portable,
electric, circular power saw to reduce friction of movement of the
saw over a work piece during a cutting operation. The wheels are
placed all on the same side of the blade, but this is to enhance
stability of the saw, not for achieving a zero clearance cut.
[0011] U.S. Patent Pub. No. US 2007/0137446 A1 discloses a guide
for a hand-held power tool, which can include a portable, electric,
circular power saw. The guide is intended for making cross-cuts on
a work. No modifications to a circular power are made or even
suggested for achieving a zero clearance cut.
[0012] U.S. Pat. No. 5,121,545 discloses an improved base tilting
mechanism for a portable, electric circular saw, which is said to
improve stability of handling of the saw as well as more accurate
cutting. No modifications to a circular power are made or even
suggested for achieving a zero clearance cut.
[0013] U.S. Pat. No. 7,043,845 B2 discloses a trim attachment for a
portable, electric circular saw that provides a fence for cutting
accurate trims of a desired thickness and substantial length from
common elongated wood stock. The reference teaches only a
conventional circular saw with an attachement, but does not
disclose a saw capable of flush cutting.
[0014] Thus, there is a need circular saw that (1) is portable; (2)
provides zero clearance cutting capability; (3) provides continuous
360.degree. cutting capability; (4) provides one-handed trigger and
guard control using either hand; (5) is adjustable for bevel
cutting; (6) provides near-instantaneous stopping of the blade; (7)
can safely make deep cuts through multiple layers of lumber; (8)
provide ability to convert between conventional circular saw
arrangement and a zero clearance circular saw arrangement.
SUMMARY AND ADVANTAGES
[0015] A convertible zero clearance circular saw includes a motor
frame portion having a motor coupled to a drive shaft; a handle
portion coupled to the aft end of the motor frame portion, the
handle portion including a hand grip, motor actuator on the hand
grip, and one or two lower blade shield triggers proximate the hand
grip to be operable by an operator's thumb; a blade deck planar
bearing surface and circular cutting blade mounted to be flush with
the blade deck planar bearing surface; a lower blade shield movable
between a deployed position and a retracted position, disposed
between the blade and motor frame portion, the blade shield
including an arcuate sidewall partially circumscribing the blade
cutting edge and having an edge face coplanar with the blade deck
planar bearing surface; abuse deck pivotable about a transverse
axis and a longitudinal axis; and a front deck portion coupled to
the front end of the base deck to move between a flat deployed
position and a perpendicular position. The handle may be rotatingly
coupled to the motor frame portion to lock at least at 0 degrees
and 90 degrees. The saw may include a removable dust cover,
articulated to adapted to the saw movements. The saw may include an
offset blade or a flat blade with countersunk and beveled
connections. The blade shield triggers may be operable
independently from each other. The lower blade shield may be
operably coupled to the blade shield triggers through a double
pulley of dissimilar diameter sheaves. The saw may include an
electromagnetic brake for near instantaneous stopping of the blade.
The saw may convert to mount a standard fiat blade as well.
[0016] The convertible zero clearance circular saw of the present
invention presents numerous advantages, including: (1) 360 degree
flush cutting against a planar surface; (2) usable as a vertical
cutter or a undercut saw; (3) a remotely operated blade shield so
that operators do not place their fingers near the moving blade;
(4) provides greater bevel and pitch/depth adjustment than standard
saws; (5) may be used as a standard circular saw or a plunge cut
saw; (6) provides instantaneous braking of the blade for safety;
(7) provides easy access to motor internals for maintenance; (8)
independently operable blade shield triggers do not interfere with
the operator's hand grip; (9) provides for ambidextrous operation;
(10) allows for use of a dust cover; (11) may include a
pulley-operated blade shield system which reduces wear and
likelihood of binding.
[0017] Additional advantages of the invention will be set forth in
part in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The advantages of the invention may be realized and
attained by means of the instrumentalities and combinations
particularly pointed out in the appended claims. Further benefits
and advantages of the embodiments of the invention will become
apparent from consideration of the following detailed description
given with reference to the accompanying drawings, which specify
and show preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated into and
constitute a part of this specification, illustrate one or more
embodiments of the present invention and, together with the
detailed description, serve to explain the principles and
implementations of the invention.
[0019] FIG. 1 shows a perspective view of a first embodiment with
rotated handle portion at 90 degrees and dust cover installed.
[0020] FIG. 2 shows a perspective view of a first embodiment with
handle portion at 0 degrees and dust cover installed.
[0021] FIG. 3 shows a front view of a first embodiment with 0
degrees bevel.
[0022] FIG. 4 shows a front view of a first embodiment with
negative bevel.
[0023] FIG. 5 shows a front view of a first embodiment with
positive bevel.
[0024] FIG. 6 shows a left side view of a first embodiment with
positive pitch angle, front deck portion retracted.
[0025] FIG. 7 shows a right side view of a first embodiment with
positive pitch angle, dust cover installed, front deck portion
extended.
[0026] FIG. 8 shows an exploded view of a first embodiment.
[0027] FIG. 9 shows an exploded close up view of a drive shaft and
blade assembly.
[0028] FIG. 10 shows a plan view of an offset blade.
[0029] FIG. 11 shows a cutaway side view of an offset blade.
[0030] FIG. 12 shows perspective view of an offset blade.
[0031] FIG. 13 shows a perspective view of a flat blade of a second
embodiment.
[0032] FIG. 14 shows a cutaway side view of a blade mounting
assembly.
[0033] FIG. 15 shows a cutaway front view of a flush mount blade
assembly.
[0034] FIG. 16 shows a second cutaway front view of a flush mount
blade assembly.
[0035] FIG. 17 shows a perspective view of a lower blade shield
back side.
[0036] FIG. 18 shows perspective view of a blade deck.
[0037] FIG. 19A shows a plan view of an arbor cap.
[0038] FIG. 19B shows a side view of an arbor cap.
[0039] FIG. 20 shows a perspective view of a base deck.
[0040] FIG. 21 shows side view of a base deck.
[0041] FIG. 22 shows a side view of a second sliding connector
first part.
[0042] FIG. 23 shows a plan view of a second sliding connector
second part.
[0043] FIG. 24 shows a side view of a first embodiment with front
deck portion retracted.
[0044] FIG. 25 shows right side view of a first embodiment with
front deck portion extended and dust cover installed.
[0045] FIG. 26 shows bottom perspective view of a front deck
portion.
[0046] FIG. 27 shows top perspective view of a front deck
portion.
[0047] FIG. 28 shows a left side view of a first embodiment
indicating lower blade shield operation.
[0048] FIG. 29 shows left side view of a first embodiment with dust
cover installed.
[0049] FIG. 30 shows a perspective view of a front cover
portion.
[0050] FIG. 31 shows a front view of a front cover portion.
[0051] FIG. 32 shows an internal perspective view of a blade cover
portion.
[0052] FIG. 33 shows an external perspective view of a blade cover
portion.
[0053] FIG. 34 shows a side view of a second embodiment.
REFERENCE NUMBERS USED IN DRAWINGS
[0054] Turning now descriptively to the drawings, in which similar
reference characters denote similar elements throughout the several
views, the figures illustrate the of the present invention. With
regard to the reference numerals used, the following numbering is
used throughout the various drawing figures: [0055] 10 First
embodiment [0056] 12 Saw forward end [0057] 14 Saw aft end [0058]
16 Motor frame portion [0059] 18 Handle portion [0060] 20 Blade
deck [0061] 22 Base deck [0062] 24 Lower blade shield [0063] 26
First lower blade shield trigger [0064] 28 Arbor [0065] 30 Motor
frame portion forward end [0066] 32 Motor frame portion aft end
[0067] 34 Motor [0068] 36 Drive shaft [0069] 38 Motor frame portion
first lateral side [0070] 40 First transverse axis [0071] 42
Electrical cord [0072] 44 Lower blade shield axle [0073] 46 First
mounting face [0074] 48 Circular saw blade [0075] 50 Blade arc
[0076] 52 Blade teeth tips [0077] 54 Worm reduction gear [0078] 56
Second longitudinal axis [0079] 58 Hand grip [0080] 60 Motor
actuator [0081] 62 Electromagnetic brake [0082] 64 Blade deck
planar bearing surface [0083] 66 Blade offset depth [0084] 68 Base
deck forward edge [0085] 70 Base deck aft edge [0086] 72 Base deck
first lateral edge [0087] 74 Base deck second lateral edge [0088]
76 Base deck planar bearing surface [0089] 78 Second transverse
axis [0090] 80 First longitudinal axis [0091] 82 Base deck cut-out
[0092] 84 Lower blade shield journal bearing [0093] 86 Lower blade
shield journal bearing frustum [0094] 88 Base deck stiffening ribs
[0095] 90 Base deck back side [0096] 92 Blade shield sidewall
[0097] 94 Sidewall first end [0098] 96 Sidewall second end [0099]
98 Sidewall facing edge [0100] 100 Lower blade shield front side
[0101] 102 Lower blade shield back side [0102] 104 Lower blade
shield internal journal bearing surface [0103] 106 Lower blade
shield external sheave [0104] 108 Second cable pulley [0105] 110
Second cable pulley terminal end [0106] 112 Lower blade shield
anchor block [0107] 114 Lower blade shield bias spring [0108] 116
Lower blade shield bias spring first end [0109] 118 Lower blade
shield bias spring second end [0110] 120 [0111] 122 Drive shaft
diameter [0112] 124 Blade shield axle exterior bearing surface
[0113] 126 Blade shield axle exterior diameter [0114] 128 Blade
shield axle interior bearing surface [0115] 130 Blade shield axle
interior diameter [0116] 132 Arbor first part [0117] 134 Arbor
first part hollow axle [0118] 136 Arbor second part [0119] 138
Arbor second part flange [0120] 140 First shield trigger first leg
[0121] 142 First shield trigger first leg first end [0122] 144
First shield trigger first leg second end [0123] 146 First shield
trigger second leg [0124] 148 First shield trigger second leg
second end [0125] 150 First shield trigger finger tab [0126] 152
Handle portion first lateral side [0127] 154 Second lower blade
shield trigger [0128] 156 Handle portion second lateral side [0129]
158 Second shield trigger first leg [0130] 160 Second shield
trigger first leg first end [0131] 162 Second shield trigger first
leg second end [0132] 164 Second shield trigger second leg [0133]
166 Second shield trigger second leg second end [0134] 168 Second
shield trigger finger tab [0135] 170 Center lever bridge portion
[0136] 172 Center lever first leg [0137] 174 Center lever second
leg [0138] 176 Bridge portion first end [0139] 178 Bridge portion
second end [0140] 180 Bridge portion first leg end [0141] 182
Bridge portion second leg end [0142] 184 Bridge portion first tab
[0143] 186 Bridge portion second tab [0144] 188 Sixth transverse
axis [0145] 190 Double pulley [0146] 192 Fifth transverse axis
[0147] 194 Double pulley first sheave [0148] 196 First sheave
diameter [0149] 198 Double pulley second sheave [0150] 200 Second
sheave diameter [0151] 202 Center lever [0152] 204 First cable
[0153] 206 First lower blade shield trigger pivot axle [0154] 208
Second lower blade shield trigger pivot axle [0155] 210 Second
cable first end [0156] 212 Second cable second end [0157] 214 First
cable first end [0158] 216 First cable second end [0159] 218 Blade
central mounting portion [0160] 220 Central mounting portion first
surface [0161] 222 Central mounting portion second surface [0162]
224 Second mounting face [0163] 226 Blade cutting portion. [0164]
228 Blade cutting portion first planar surface [0165] 230 Blade
cutting portion second planar surface [0166] 232 Blade cutting edge
[0167] 234 Blade perimeter [0168] 236 Motor brush access port
[0169] 238 Blade deck first aperture [0170] 240 Dust cover [0171]
242 Exhaust port [0172] 244 Aft cover portion. [0173] 246 Lower
blade cover portion [0174] 248 Front cover portion [0175] 250 Dust
cover rotatable coupling connector [0176] 252 Hinge block [0177]
254 Dual axes coupler [0178] 256 Hinge block first, end [0179] 258
Hinge block second end [0180] 260 Base deck hinge block
longitudinal pivot coupling [0181] 262 Blade deck forward end.
[0182] 264 Hinge block second transverse hinge coupling [0183] 266
Dual axes hinge coupler [0184] 268 Dual axes hinge coupler first
portion. [0185] 270 Dual axes hinge coupler longitudinal hinge
coupling [0186] 272 Dual axes hinge coupler second portion [0187]
274 Dual axes hinge coupler transverse hinge coupling [0188] 276
Fourth transverse axis [0189] 278 First sliding connector [0190]
280 First arcuate track [0191] 282 First arcuate track first end
[0192] 284 First arcuate track second end [0193] 286 First closed
channel. [0194] 288 Stub axle [0195] 290 Stub axle base [0196] 292
Stub axle free end [0197] 294 First sliding connector first
compression coupling [0198] 296 Second sliding connector [0199] 298
Second sliding connector first arcuate portion [0200] 300 Second
sliding connector second arcuate portion [0201] 302 First arcuate
portion first end [0202] 304 First arcuate portion second end
[0203] 306 Second arcuate portion first end [0204] 308 Second
arcuate portion second end. [0205] 310 Second sliding connector
compression coupling [0206] 312 Second closed channel [0207] 314
Blade deck interior edge [0208] 316 Blade gap [0209] 318 Blade base
cutting depth [0210] 320 Blade plunge cutting depth [0211] 322
Front deck portion [0212] 324 Front deck portion forward edge
[0213] 326 Front deck portion aft edge [0214] 328 Front deck
portion planar bearing surface [0215] 330 Third transverse axis
[0216] 332 Front deck portion locking pin. [0217] 334 Front deck
portion hinge joint [0218] 336 Front deck portion aperture [0219]
338 Arbor cap [0220] 340 Bade engagement projection. [0221] 342
Center mounting aperture [0222] 344. Arbor cap flange [0223] 346
Arbor cap center aperture [0224] 348 Arbor cap center fasterner
[0225] 350 Arbor cap depth [0226] 352 Second hand grip [0227] 354
Cable sheath. [0228] 356 Dust cover lower blade cover portion snap
fitting [0229] 358 Dust cover lower blade cover portion sidewall
[0230] 360 Dust cover lower blade cover portion sidewall edge face
[0231] 362 Handle portion male locking portion [0232] 364 Motor
frame portion female locking portion [0233] 1010 Second Embodiment
[0234] 1028 Arbor [0235] 1360 Arbor fastener receiving holes [0236]
1362 First plurality of mounting apertures [0237] 1364 Countersunk
bevels [0238] 1366 Bevel head fasteners [0239] 1368 Fastener heads
[0240] 1370 Second plurality of mounting apertures [0241] 1372
Countersunk bevels
DETAILED DESCRIPTION
[0242] Before beginning a detailed description of the subject
invention, mention of the following is in order. When appropriate,
like reference materials and characters are used to designate
identical, corresponding, or similar components in differing figure
drawings. The figure drawings associated with this disclosure
typically are not drawn with dimensional accuracy to scale, i.e.,
such drawings have been drafted with a focus on clarity of viewing
and understanding rather than dimensional accuracy.
[0243] In the interest of clarity, not all of the routine features
of the implementations described herein are shown and described. It
will, of course, be appreciated that in the development of any such
actual implementation, numerous implementation-specific decisions
must be made in order to achieve the developer's specific goals,
such as compliance with application- and business-related
constraints, and that these specific goals will vary from one
implementation to another and from one developer to another.
Moreover, it will be appreciated that such a development, effort
might be complex and time-consuming, but would nevertheless be a
routine undertaking of engineering for those of ordinary skill in
the art having the benefit of this disclosure.
[0244] Referring to FIGS. 1-33, a first embodiment of a zero
clearance circular saw 10 is shown, having opposed forward and aft
ends 12 and 14, respectively, which define the longitudinal
forward-aft direction, and including a motor frame portion 16, a
handle portion 18, a blade deck 20, a base deck 22, a lower blade
shield 24, and a first lower blade shield trigger 26. In this
Specification, "longitudinal" refers generally to an axis or
orientation parallel to the forward-aft axis of the saw 10, and
"transverse" refers generally to an axis or orientation extending
perpendicular to the longitudinal direction.
[0245] Motor frame portion 16 includes opposed forward and aft ends
30 and 32, respectively, a motor 34 mounted to motor frame portion
16 operably coupled to drive shaft 36 projecting from a first
lateral side 38 of the motor frame portion 16, the drive shaft
defining a first transverse axis 40, in the embodiment, motor 34 is
connectable to a power source via electrical cord 42.
Alternatively, motor 34 could be powered by batteries, fuel cells,
internal combustion engine, or other power sources or combination
thereof. Arbor 28 is coupled to drive shaft 36 and includes a first
mounting face 46 adapted to mate to a second mounting face 224 of a
circular saw blade 48. In the embodiment, arbor 28 is a separable
from drive shaft 36, but may be integral to drive shaft 36 as well.
The rotation of rotary blade 48 mounted to saw 10 defines a blade
arc 50, equating to the perimeter traced by the teeth tips 52 of
blade 48. In practice, blade arc 50 will have a range of diameters
based on the size of the saw blade 48 selected. In the embodiment
motor 34 is mounted longitudinally, but could be mounted
transversely as well. In the embodiment, drive shaft 36 is coupled
to motor 34 through a reduction-worm gear 54, but other
configurations may be used, including by way of example, a
transverse engine mounting eliminating the worm gear, or a direct
coupling to motor 34 without reduction gears.
[0246] Referring again to FIGS. 1, 2, 8 and 28, handle portion 18
is rotatably coupled to motor frame portion 16 at its aft end 32 so
as to rotate about a second longitudinal axis 56. As seen in FIGS.
1 and 2, handle portion 18 is lockable at a plurality of user
selected rotated positions, including at least 0.degree. and
90.degree. relative to motor frame portion 16. An operator may
simply compress handle portion male locking members 362 to
disengage from motor frame portion female locking portions 364,
rotate the handle portion 18 until the male locking portions 362
snap into the female locking portions 364 again at the new
position, and the saw is ready. Handle portion 18 includes hand
grip 58, and finger operable motor actuator 60 to selectively
actuate motor 34. In this regard, 90.degree. may refer to clockwise
or counterclockwise rotation, depending on whether the saw 10 is
intended primarily for right-handed or left-handed operation, so
90.degree. refers to the direction away from the motor frame
portion first lateral side 38 where the saw blade would be mounted
and 0.degree. indicates handle portion 18 is aligned with hand grip
58 oriented parallel to blade arc 50.
[0247] In the embodiment, depressing motor actuator 60 activates
motor 34 at full speed and releasing motor trigger 60 activates
electromagnetic brake 62 to instantly and completely stop rotation
of drive shaft 36 and blade 48. In the embodiment, electromagnetic
brake 62 operates by applying DC current to the windings of motor
34, which is a permanent magnet AC motor in the embodiment, to lock
the motor in place.
[0248] Blade deck 20 is rigidly coupled to motor frame portion 16
on the motor frame portion 16 first lateral side 38. Blade deck 20
includes a planar bearing surface 64 parallel to arbor first
mounting face 46. The distance from first mounting face 46 to blade
deck bearing surface 64 defines the blade offset depth 66. In the
embodiment, motor 34 includes a first brush access port 236 on the
motor frame portion first lateral side, and blade deck 20 includes
a first aperture 238 aligned with the first brush access port 236
to provide access to an internal motor brush (not shown).
[0249] In the embodiment, blade deck 20 extends forward to blade
deck forward end 262 so that blade deck bearing surface 64 extends
forward to circumscribe a portion of blade arc 50, thereby defining
a blade deck interior edge 314, the radial distance between the
blade arc 50 and the blade deck interior edge 314 defining a blade
gap 316 to receive at least a portion of the lower blade shield
sidewall 92 in the retracted position.
[0250] Base deck 22 extends longitudinally from forward edge 68 to
opposed aft edge 70 and transversely from first lateral edge 72
proximal to motor frame portion first lateral side 38 to second
lateral edge 74, the base deck edges 68, 70, 72, 74 defining planar
bearing surface 76. Base deck 22 is pivotally coupled to motor
frame portion 16 about second transverse axis 78 and lockable at a
plurality of user selectable pitch angles about second transverse
axis 78 to adjust the blade base cutting depth 318 and plunge
cutting depth 320. Base deck 22 is also pivotally coupled to motor
frame portion 16 about first longitudinal axis 80 and lockable at a
plurality of user selected bevel angles about first longitudinal
axis 80. As seen in FIGS. 3-5, 8 and 22-23, in the embodiment, the
bevel angle is continuously adjustable within a range from
approximately -10.degree. to approximately +65.degree., where the
base deck bearing surface 76 normal to the blade arc 50 defines
0.degree. (see FIG. 3). Positive bevel angle is defined as base
deck 22 pivoted toward the exposed cutting portion of blade 48 (see
FIG. 5), and negative bevel angle is defined as base deck 22
pivoted away from the exposed cutting portion of blade 48 (see FIG.
4).
[0251] First lateral edge 72 is substantially parallel, to the
blade arc 50 and first longitudinal axis 80. In the embodiment,
base deck 22 includes a cut-out 82 along its first lateral edge 72
to provide clearance around lower blade shield journal bearing
portion 84 and frustum 86, as base deck 22 is pivoted about first
longitudinal axis 80 to adjust the bevel angle. In the embodiment,
other than cutout 82 the base deck first lateral edge 72 forms a
straight edge proximate blade arc 50 and first longitudinal axis
80, and so is described as "substantially" parallel. In the
embodiment, base deck 22 includes a plurality of longitudinal
stiffening ribs 88 along the back side 90, the back side 90 being
the opposed side from bearing surface 76.
[0252] In the embodiment, base deck 22 is coupled to motor frame
portion 16 by a forward mounted hinge block 252 and aft mounted
dual axes coupler 254. Hinge block 252 has a first end 256 and
opposed second end 258. Hinge block first end 256 is pivotally
coupled to base deck 22 by longitudinal pivot coupling 260 mounted
to base deck 22 distal from base deck aft edge 70 along first
longitudinal axis 80 to pivot base deck 22 around first
longitudinal axis 80, thereby adjusting the bevel angle. Hinge
block second end 258 is pivotally coupled to motor frame portion 16
at second transverse axis 78 to pivot base deck 22 around second
transverse axis 78. In the embodiment, hinge block second end 258
is directly coupled to blade deck 20 proximal blade deck forward
end 262 by transverse hinge coupling 264, and blade deck 20 is
rigidly coupled to motor frame portion 16, thereby coupling hinge
block second end 258 to motor frame portion 16. Hinge block second
end 258 could also be directly coupled to motor frame portion
16--the effect is the same. Dual axes hinge coupler 266 is mounted
to base deck 22 proximate base deck first lateral edge 72 distal
from base deck front edge 68. Dual axes hinge coupler 266 has first
portion 268 including longitudinal hinge coupling 270 aligned along
the first longitudinal axis 80 to pivot base deck 22 around first
longitudinal axis 80, and a second portion 272 including transverse
hinge coupling 274 aligned along fourth transverse axis 276.
[0253] In the embodiment, first sliding connector 278 couples
between dual axes hinge coupler 266 and motor frame portion 16 to
selectively set pitch angle controlling base cutting depth and
plunge cutting depth. First sliding connector 278 includes first
arcuate track 280 having first end 282, second end 284, and first
closed channel 286 extending from proximate first end 282 to second
end 284. First end 282 is coupled to dual axes hinge coupler second
portion 272. First closed channel 286 slidlingly receives stub axle
288 there through. Stub axle 288 extends from a base 290 connected
to motor frame portion first lateral side 38 to free end 292. Stub
axle 288 extends through first closed channel 286 and has first
selectively releasable compression coupling 294 coupled to stub
axle 288 to lockingly engage against first arcuate track 280 and
motor frame portion 16.
[0254] In the embodiment, a second sliding connector 296 couples
between base deck 22 and hinge block 252 to selectively set bevel
angle. Second sliding connector 296 includes overlapping first and
second arcuate portions 298 and 300, respectively, selectively
lockingly coupled by second compression coupler 310. First arcuate
portion 298 has a first end 302 coupled to hinge block 252 distal
from hinge block first end 256, and a second end 304. Second
arcuate portion 300 has a first end 306 coupled to base deck 22
distal from base deck aft edge 70 and distal from base deck first
lateral edge 72, and extends to a second end 308, with a second
closed channel 312 extending from proximate first end 306 to second
end 308. Second selectively releasable compression coupling 310
selectively lockingly engages first and second arcuate portions 298
and 300 against each other to set the bevel angle.
[0255] Compression fasteners 310 and 294 include finger levers for
easy and quick loosening and tightening.
[0256] In first embodiment, a front deck portion 322 movable
between a first extended position (shown in FIGS. 7, 25) and a
second retracted position (shown in FIGS. 6, 24) is provided to
permit accurate plunge cutting and the ability to cut along a
360.degree. path around a planar surface. Front deck portion 322
has opposed forward and aft edges 324 and 326, respectively, and a
planar bearing surface 328 extending there between. Front deck
portion 322 is hingedly coupled proximate front deck portion aft
edge 326 to base deck 22 proximate base deck front edge 68, and is
pivotable about third transverse axis 330. Front deck portion 322
is lockable at least at a first position (shown in Fig. xxx),
wherein front deck planar bearing surface 328 is coplanar to base
deck planar bearing surface 76, and wherein front deck portion
forward edge 324 extends forward of blade arc 50, and a second
position (shown in Fig. xxx), wherein, front deck portion planar
bearing surface 328 is normal to base deck planar bearing surface
76 and facing forward. In the embodiment, front deck portion 322
includes a locking pin 332 engageable with hinge joint 334 to lock
front deck portion 322 in the first or second position and a front
deck aperture 336 to access the locking pin 332, the aperture 336
disposed to align with locking pin 332 when front deck portion 322
is in the second position.
[0257] Lower blade shield 24 is movable between a deployed position
(see FIG. 29) and a retracted position (see FIG. 28). Lower blade
24 shield includes an arcuate laterally projected sidewall 92
circumscribing a portion of blade arc 50 from a sidewall first end
94 to a sidewall second end 96, the arcuate sidewall 92 including a
facing edge 98 which is approximately coplanar with blade deck
bearing surface 64. Lower blade shield 24 is rotatably coupled to
blade shield axle 44, coaxial to drive shaft 36. Lower blade shield
24 is movable between a deployed position, shown in FIGS. 6, 29,
circumscribing a substantial portion of the projecting blade arc
50, and a retracted position, as shown in FIG. 28, circumscribing
essentially no portion of the projecting blade arc 50. The
projecting blade arc refers to the portion of the blade arc 50
extending distally past base deck 22 and forward of the saw motor
frame portion 16, which will vary depending on the selected pitch
angle. In the embodiment, lower blade shield 24 circumscribes
substantially the entire bottom portion of blade arc 50 in the
deployed position, such that if saw 10 with blade 48 mounted to the
saw 10 were rested on the ground, the blade 48 would not contact
the ground.
[0258] In the first embodiment, the cross section of the drive
shaft 36 defines shaft diameter 122. Blade shield axle 44 is
coaxial with and surrounds drive shaft 36, the blade shield axle 44
having an exterior bearing surface 124 defining an exterior blade
shield axle diameter 126, the exterior bearing surface 124 to
rotatably receive lower blade shield 24 over the blade shield axle
44. Blade shield axle 44 includes an interior bearing surface 128
defining an interior blade shield axle diameter 130 greater than
the drive shaft diameter 122.
[0259] Arbor 28 includes a first part 132 having a hollow axle 134
to couple over drive shaft 36 and within shield axle interior
bearing surface 128, and a second part 136 extending from the first
part 132, the second part including a flange 138 having the first
mounting face 46. Blade shield axle interior bearing surface 128 is
adapted to rotatably receive arbor first part 132. In the first
embodiment, the diameter of arbor flange 138 is greater than blade
shield axle outer shaft diameter 124 to retain blade shield 24 on
blade shield axle 44. Blade shield frustum 86 flares out to provide
clearance for arbor 28 and arbor flange 138.
[0260] In the embodiment, an arbor cap 338 is provided to engage
blade 48 to arbor 28, and thereby to drive shaft 36. Arbor cap 338
includes a blade engagement projection 340 to insert into and
engage a center mounting aperture 342 through blade central
mounting portion 218; a surrounding flange 344 to go against
central mounting portion first surface 220; an arbor cap center
aperture 346 to receive a fastener 348 there through; and, a center
fastener 348 to engage bade 48 against arbor 28 through arbor cap
center aperture 342. In the embodiment, center fastener 348 is a
threaded bolt threading directly into the end of drive shaft 36 to
compress blade central mounting portion 218 against, arbor first
mounting face 46 to couple blade 48 to drive shaft 36, Arbor cap
338 has a depth 350 dimensioned such that with arbor cap 338
engaged against blade 48, arbor cap 338 does not protrude past,
blade cutting portion first planar surface 228 to facilitate flush
cuts. In the embodiment, blade engagement projection 340 is diamond
shaped to engage diamond shaped blade center mounting aperture 342,
but other shapes may be used.
[0261] Lower blade shield 24 includes front side 100 and opposed
back side 102, journal bearing portion 84 with internal journal
bearing surface 104 to go receive blade shield axle 44, and
external sheave 106 surrounding journal bearing portion 84 to
receive a cable. Blade shield axle 44 provides rotating bearing
surface for blade shield journal bearing 84, and receives the arbor
shaft 134 into an internal journal bearing 128 (the interior
bearing surface of blade shield axle 44) so as to stabilize drive
shaft 36 and blade 48 during rotation.
[0262] First lower blade shield trigger 26 is operably coupled to
lower blade shield 24 to move lower blade shield 24 between the
normal deployed position and the retracted position. In the first
embodiment, first trigger 26 is a lever arm having a first leg 140
extending from a first end 142 connected to a pivot axle 206 to a
second end 144, and a second leg 146 extending from first leg
second end 144 to a second end 148, with a finger tab 150 disposed
at second leg second end 148. First lower blade shield trigger 26
is disposed along a first lateral side 152 of the handle portion 18
proximal to motor actuator 60 such that it may be operated by a
first thumb of an operator while gripping the hand grip 58.
[0263] In the embodiment, a second lower blade shield trigger 154
is operably coupled to the lower blade shield 24 to move the lower
blade shield 24 between the normal deployed position and the
retracted position. Second lower blade shield trigger 154 is
disposed along the opposed lateral side 156 of the handle portion
18 from the first lower blade shield trigger 26 proximal to the
motor actuator 60 such that, it may be operated by the opposing
thumb of an operator while gripping the hand grip 58 with the
opposing hand. In the embodiment, second lower blade shield trigger
154 is a lever arm having a first leg 158 extending from a first
end 160 connected to a pivot axle 208 to a second end 162, and a
second leg 164 extending from first leg second end 162 to a second
end 166, with a finger tab 168 disposed at second leg second end
164.
[0264] In the embodiment, center lever 202 is disposed between
first and second lower blade shield triggers 26 and 154, to provide
independent operation. Center lever 202 includes a transversely
oriented bridge portion 170, first and second legs 172 and 174,
respectively, extending from opposing ends 176 and 178 of bridge
portion 170 to first and second leg ends 180 and 182, respectively,
and opposed first and second tabs 184 and 186, respectively,
extending laterally from the bridge portion opposed ends 176 and
178, respectively, the center lever first and second legs 172 and
174 pivotably coupled at first and second leg ends 180 and 182 to
the handle portion 18 coaxially to the first and second lower blade
shield triggers 26 and 154 on a sixth transvers axis 188. First and
second tabs 184 and 186 overlap first and second lower blade shield
triggers 26 and 154, respectively, such that either first or second
trigger 26 or 154 will engage against its respective tab 184 or 186
to move the center lever 202 when the respective trigger 26 or 154
is depressed. Double pulley 190 is rotatably coupled to the motor
frame portion first lateral 38 side at a fifth transverse axis 192,
the double pulley 190 including a first sheave 194 having a first
diameter 196 and a second sheave 198 having a second diameter 200,
the second diameter 200 smaller than the first diameter 196. First
cable 204 operatively couples center lever 202 to first sheave 194;
and, second cable 108 couples second sheave 198 to lower blade
shield 24 around lower blade shield sheave 106, as described
previously.
[0265] Lower blade shield triggers 26 and 154 are operably coupled
to double pulley 190 by first cable 204 coupled at a first end 214
to center lever 202 and wrapped around double pulley second sheave
198 at a second end 216. Lower blade shield 24 is operatively
coupled to double pulley 190 by second cable 108. Second cable 108
has a first end 210 wrapped around double pulley second sheave and
a second end 212 wrapped around sheave 106, with a terminal end 110
coupled to anchor block 112. A bias spring 114 is coupled at a
first end 116 to the motor frame portion 16 and at a second end 118
to blade shield 24 in order to bias lower blade shield 24 to the
deployed position.
[0266] Lower blade shield triggers 26, 154 moving independently of
each other allows ambidextrous use, wherein operating one trigger
will not bring the other trigger down in contact with the hand. The
lower blade shield 24 pulley and cable system permits locating the
operating parts virtually anywhere on the saw 10, and provides the
ability to use a rotatable handle portion 28, rather than the
direct lever couplings common in existing devices. Dual pulley
sheaves 194, 198 provide large shield movement for a small trigger
movement, due to greater diameter of the inner sheave 196. Second
cable 108 a distributes out of axis force substantially around the
perimeter of lower blade shield journal bearing portion 84, thereby
reducing trans-axial stress on the shield 24 and shaft 44, which
lessens the likelihood of binding.
[0267] Referring to Figs. xxx, an offset circular saw blade 48 of a
first embodiment 10 is shown. Saw blade 48 is removably mountable
to a zero clearance circular saw 10 having motor 34 coupled to
drive shaft 36, a blade deck 20 including planar bearing surface
64, and first mounting face 46 coupled to drive shaft 36. The
distance from the first mounting face 46 to blade deck bearing
surface 64 defines blade offset depth 66. Blade 48 includes central
mounting portion 218 and a cutting portion 226 extending outward
from central mounting portion 218. Central mounting portion 218 has
opposed first and second surfaces 220 and 222, the central mounting
portion second surface 222 including second mounting face 224
adapted to mate to first mounting face 46. Cutting portion 226 has
opposed first and second planar surfaces 228 and 230 extending from
the central mounting portion 218 to a cutting edge 232 disposed
along the blade perimeter 234. In the embodiment, saw blade 48 is a
unidirectional toothed saw blade so the cutting edge 232
corresponds to the teeth 52 disposed along the perimeter. Blade
perimeter 234 corresponds to or is coextensive to blade arc 50, as
the rotation of cutting edge 232 defines the blade arc 50. In the
embodiment, blade central mounting portion 218 is offset laterally
from blade cutting portion second surface 230 and the distance from
second mounting face 224 to blade cutting portion first planar
surface 228 is equal to blade offset depth 46, such that blade
cutting portion first planar surface 228 is coplanar to blade deck
planar bearing surface 64 when mounted to saw 10.
[0268] Second hand grip 352 is provided, oriented transversely, to
permit two-handed operation for increased stability. Second hand
grip 352 also provides a secure routing path for first cable 204.
First cable 204 runs through, a protective cable sheath 354 to
second hand grip 352.
[0269] Referring to Figs. xxx, a dust cover 240 of a first
embodiment is shown. Dust cover 240 is removably couplable to saw
10 to substantially enclose blade arc 50 in order to contain much
of the dust generated by cutting. Dust cover 240 includes exhaust
port 242 to connect to a dust collection system, for example a shop
vacuum cleaner or facility exhaust. In the embodiment, dust cover
240 includes an aft cover portion 244, a lower blade cover portion
246, and a front cover portion 248. Aft cover portion 244 is
removably mountable to blade deck 24 by snapping over the upper and
aft portion of blade deck 24 and covers a portion of blade 48
mounted to saw 10. Lower blade cover portion 246 is removably
mountable to the lower blade shield 24 using snap fitting 356, with
matching sidewall and edge face 358 and 360, respectively, to mate
against, blade shield edge face 98, and rotatably coupled to the
aft cover portion 244, the rotatable coupling connector 250 coaxial
with the first transverse axis 40, such that lower blade cover
portion 246 moves with lower blade shield 24 between the deployed
and retracted positions. Front cover portion 248 is removably
mountable to base deck 22 proximal base deck forward edge 68 and
movable with base deck 22. In the embodiment, forward cover portion
248 snaps over hinge block 252 to move with hinge block 252, which
in turn is coupled to and moves about second transverse axis 78
with base deck 22.
[0270] Referring to FIGS. 13 and 34, a second embodiment 1010 is
shown, generally similar to the first embodiment but having a
handle portion 1018 rigidly coupled to the motor frame portion
1016, and providing only a first blade shield trigger 1026, in the
second embodiment, a flat blade 1048 is mounted flush to blade deck
planar bearing surface 1064, through a first plurality of mounting
apertures 1362 having countersunk bevels on a first blade cutting
portion planar surface 1228, using bevel head fasteners 1366. Blade
1048 may include a second plurality of mounting apertures 1370
having bevels on an opposed cutting portion planar surface 1230 to
make blade reversible. This arrangement allows for a reversible
blade. Generally, blade cutting edges have unidirecional cutting
teeth, but some blades may have bidirectional cutting edges, for
instance simple triangular teeth, or blades that have a thin
grinding edge for a cutting edge, rather than teeth. Reversible
blade may be desirable to extend blade life, or to prevent
incorrect mounting (i.e. "idiot proofing").
[0271] In the second embodiment, the saw 1010 is adapted to mount a
flat blade 1048 flush for zero clearance cuts. In this regard, flat
blade means the blade depth 1066 is equal to the blade thickness.
Arbor 1028 includes a plurality of fastener receiving holes 1360;
the blade central mounting portion 1218 having a having a first
plurality of mounting apertures 1362, the first plurality of
mounting apertures 1362 countersunk 1364 on the mounting portion
first surface 1222, the first plurality of mounting apertures 1362
corresponding to the fastener receiving holes 1360; and, a
plurality of bevel head fasteners 1366 to engage the blade 1048 to
the arbor 1028 through the first plurality of mounting apertures
1362 and fastener receiving holes 1360, the fastener heads 1368
flush with the mounting portion second surface when fully engaged
through the first plurality of mounting apertures 1362.
[0272] In the embodiment, the blade central mounting portion may
also include a second plurality of mounting apertures 1370, the
second plurality of mounting apertures 1370 countersunk 1372 on the
mounting portion second surface, the second plurality of mounting
apertures 1370 corresponding to the fastener receiving holes 1360,
the plurality of fasteners 1366 engagable through the second
plurality of mounting apertures 1370 to be flush with the central
mounting portion second surface, such that the blade is
reversible.
[0273] Using the first embodiment 10 as an example, in operation a
blade 48 is mounted onto a saw 10 by fastening a center fastener
348 through the center mounting aperture 346 thread into drive
shaft 36, thereby compressing blade second mounting face 224
against, arbor first mounting face 46, Arbor 28 is rotatingly
engaged to drive shaft 36, and so rotates with the drive shaft,
stabilized within lower blade shield axle 44. To make a flush cut,
the operator lays the saw blade first planar surface 228 against
the flat surface to be cut to, supported by coplanar with blade
deck planar bearing surface 64 and blade shield sidewall edge face
98, actuates the motor using actuator 60, retracts the lower blade
shield 24 by compressing first or second shield trigger 26 or 254,
and drives the rotating saw blade 48 into the material. If the
operator first locks forward deck portion 322 into the second
position, then the operator may continue the cut through
360.degree.. For example, the operator may cut continuously along a
floor-wall interface, continuing up the far wall, along the
ceiling, and back down the near wall.
[0274] Alternatively, the operator may rotate handle portion 18 by
90.degree. to lay the blade 48 and planar bearing surface 64
horizontal for use as an undercut or "jam" saw.
[0275] Those skilled in the art will recognize that numerous
modifications and changes may be made to the preferred embodiment
without departing from the scope of the claimed invention. It will,
of course, be understood that modifications of the invention, in
its various aspects, will be apparent to those skilled in the art,
some being apparent only after study, others being matters of
routine mechanical, chemical and electronic design. No single
feature, function or property of the preferred embodiment is
essential. Other embodiments are possible, their specific designs
depending upon the particular application. As such, the scope of
the invention should not be limited by the particular embodiments
herein described but should be defined only by the appended claims
and equivalents thereof.
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