U.S. patent application number 12/767687 was filed with the patent office on 2010-10-28 for portable cutting device with on-board debris collection.
Invention is credited to Charles B. Martin.
Application Number | 20100269353 12/767687 |
Document ID | / |
Family ID | 42990800 |
Filed Date | 2010-10-28 |
United States Patent
Application |
20100269353 |
Kind Code |
A1 |
Martin; Charles B. |
October 28, 2010 |
PORTABLE CUTTING DEVICE WITH ON-BOARD DEBRIS COLLECTION
Abstract
A portable cutting device having a cutting tool for cutting a
material. The cutting device includes a motor driving the cutting
tool and a shroud at least partially enclosing the cutting tool.
The shroud defines a debris accumulation chamber for gathering
debris created by the cutting tool cutting the material. An
impeller is operatively coupled to the motor and driven by the
motor to create suction pressure to draw the debris out of the
debris accumulation chamber and into a collection bag.
Inventors: |
Martin; Charles B.;
(Washington, IL) |
Correspondence
Address: |
HOWARD & HOWARD ATTORNEYS PLLC
450 West Fourth Street
Royal Oak
MI
48067
US
|
Family ID: |
42990800 |
Appl. No.: |
12/767687 |
Filed: |
April 26, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61172607 |
Apr 24, 2009 |
|
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Current U.S.
Class: |
30/124 ; 30/374;
30/390 |
Current CPC
Class: |
B23D 59/006 20130101;
B27B 9/02 20130101; B27G 19/04 20130101 |
Class at
Publication: |
30/124 ; 30/390;
30/374 |
International
Class: |
B27G 3/00 20060101
B27G003/00; B27B 9/00 20060101 B27B009/00; B27G 19/04 20060101
B27G019/04 |
Claims
1. A cutting device comprising: a material cutting blade; a shroud
which at least partially encloses the blade and relative to which
the blade is supported for relative movement; a debris accumulation
chamber within the shroud in fluid communication with the blade and
into which material debris generated by the blade during cutting is
received; a source of vacuum in fluid communication with the debris
accumulation chamber; a pressure equalization chamber in fluid
communication with the source of vacuum; a plurality of vacuum
conduits extending between the debris accumulation chamber and the
pressure equalizing chamber, each conduit having an inlet and an
outlet, the debris accumulation chamber having an opening into a
conduit inlet, the pressure equalization chamber having an opening
into a conduit outlet; wherein airflow induced by the source of
vacuum is drawn from the conduit inlets to the conduit outlets,
material debris received in the debris accumulation chamber carried
by the induced airflow toward the vacuum source and the pressure
equalization chamber.
2. The cutting device of claim 1, further comprising a vacuum
housing having an exhaust port from which the induced airflow and
material debris carried thereby exits the vacuum housing.
3. The cutting device of claim 2, wherein the source of vacuum is
contained in the vacuum housing, and the induced airflow and
material debris carried thereby is expelled from the exhaust port
under a pressure greater than the pressure in the pressure
equalization chamber.
4. The cutting device of claim 2, further comprising a collection
container attached to the exhaust port and into which the induced
airflow and material debris carried thereby is received, material
debris received in the collection container retained therein.
5. The cutting device of claim 4, wherein the collection container
is a collection container having a wall through which the induced
airflow received thereby passes.
6. The cutting device of claim 5, wherein the collection container
includes a porous inner container disposed within a porous outer
container, the porosity of the inner container being less than the
porosity of the outer container.
7. The cutting device of claim 1, wherein each outlet of the
plurality of vacuum conduits opens individually into the pressure
equalization chamber.
8. The cutting device of claim 1, wherein the inlets of the
plurality of vacuum conduits are sequentially positioned along the
path of blade travel within the shroud.
9. The cutting device of claim 8, wherein the blade is a circular
saw blade rotatably supported within the shroud, the perimeter of
the saw blade having a circumferentially distributed plurality of
teeth, the inlets of the vacuum conduits positioned at locations on
the shroud that are sequentially passed by each saw blade
tooth.
10. The cutting device of claim 9, wherein the shroud substantially
surrounds an upper portion of the circular saw blade and further
comprising: a lower blade guard connected to the shroud, the lower
blade guard having movement relative to the shroud between an
extended position in which it substantially surrounds the perimeter
of the lower portion of the saw blade, and at least one retracted
position into which it is received in the debris accumulation
chamber and at least partially exposes the perimeter of the lower
portion of the saw blade, the lower blade guard having a surface in
which is provided at least one aperture that is moved substantially
into alignment with a vacuum conduit inlet in a retracted position;
and wherein material debris generated by the blade during cutting
is carried with the induced airflow into the conduit inlet from a
location between the saw blade perimeter and the blade guard
through the aperture substantially aligned with the conduit
inlet.
11. The cutting device of claim 1, further comprising: a deck plate
through which the blade extends and to which the shroud is
connected; a base plate attached to the deck plate and through
which the blade extends, the base plate being positioned between
the deck plate and a material-engaging portion of cutting blade;
the shroud and the base plate having selective cut depth positions
in which the distances from the base plate to which the
material-engaging portion of cutting blade extends are varied; the
shroud and the base plate having selective cut angle positions in
which the relative angle between the base plate and the
material-engaging portion of cutting blade is varied; wherein the
blade is disposed in a space defined by a surrounding wall
extending between the base plate and the shroud that is
substantially sealed against air leakage through the wall,
throughout the operating ranges of cut depth and cut angle
positions.
12. The cutting device of claim 11, wherein substantially all of
the air drawn by the vacuum source into the debris accumulation
chamber substantially solely through an opening in the base plate
through which the blade extends.
13. The cutting device of claim 11, wherein the surrounding wall
includes a expandable first bellows located between the deck plate
and the shroud, the first bellows being correspondingly expanded
and compressed between different cut depth positions with
corresponding relative movement between the deck plate and the
shroud.
14. The cutting device of claim 11, wherein the base plate and the
deck plate are pivotably attached to each other, and the
surrounding wall includes a expandable second bellows located
between the deck plate and the base plate, the second bellows being
correspondingly expanded and compressed between different cut angle
positions with corresponding relative movement between the deck
plate and the base plate.
15. The cutting device of claim 11, wherein the surrounding wall
includes a transparent window located between the deck plate and
the shroud, the cutting blade and material being cut visible to an
operator through the window during cutting operations.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and all benefits of U.S.
Provisional Application No. 61/172,607, filed Apr. 24, 2009,
entitled "PORTABLE CUTTING DEVICE WITH ON-BOARD DEBRIS COLLECTION,"
the complete disclosure of which is hereby incorporated by
reference. The complete disclosure of U.S. application Ser. No.
10/939,440, filed Sep. 14, 2004, entitled "SELF-CONTAINED VACUUM
SAW," now U.S. Pat. No. 7,328,512, is also hereby incorporated by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a portable cutting device
for cutting a material such as wood, drywall, concrete, roof tiles,
slate, etc, which creates debris. More specifically the present
invention relates to the portable cutting device having an on-board
debris collection system.
BACKGROUND OF THE INVENTION
[0003] Portable cutting devices are well known in the art of
carpentry and construction. Such devices include portable circular
saws, concrete saws, routers, and the like. When using these
devices to cut through materials such as wood, drywall, concrete,
roof tiles, slate, etc., cutting debris is created, e.g., saw dust,
concrete dust and larger particles. In most cases, protective gear
is needed to avoid health hazards associated with this debris.
Additionally, the debris accumulates in the area in which the
cutting device is being used making clean-up time consuming and
difficult. Accordingly, there is a need for portable cutting
devices with debris collection systems to collect the dust and
larger particles.
[0004] Prior art portable cutting devices have been developed to
include debris collection systems. These systems typically include
a housing defining a debris accumulation chamber and a collection
port on the housing for connecting to a vacuum source. The vacuum
source draws the debris through the collection port into a
collection area. The vacuum source is off-board, meaning that the
vacuum source is separate from the cutting device. As a result,
when transporting the cutting device between work sites, a vacuum
source must be made available at each of the work sites.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0005] A portable cutting device having a cutting tool for cutting
a material is provided. The cutting device includes a motor driving
the cutting tool and a protective housing at least partially
enclosing the cutting tool. The protective housing defines a debris
accumulation chamber for gathering debris created by the cutting
tool. An impeller is operatively coupled to the motor and driven by
the motor to create suction pressure to draw the debris out of the
debris accumulation chamber and into a collection bag. A vacuum
housing protects the impeller and the collection bag is coupled to
the vacuum housing. The impeller and collection bag form part of an
on-board debris collection system thereby eliminating the need for
a separate off-board vacuum source and debris collection area.
[0006] The present invention provides a cutting device that
includes a material cutting blade, a shroud which at least
partially encloses the blade and relative to which the blade is
supported for relative movement, a debris accumulation chamber
within the shroud in fluid communication with the blade and into
which material debris generated by the blade during cutting is
received, a source of vacuum in fluid communication with the debris
accumulation chamber, a pressure equalization chamber in fluid
communication with the source of vacuum, and a plurality of vacuum
conduits extending between the debris accumulation chamber and the
pressure equalizing chamber, each conduit having an inlet and an
outlet, the debris accumulation chamber having an opening into a
conduit inlet, the pressure equalization chamber having an opening
into a conduit outlet. Airflow induced by the source of vacuum is
drawn from the conduit inlets to the conduit outlets, material
debris received in the debris accumulation chamber carried by the
induced airflow toward the vacuum source and the pressure
equalization chamber.
[0007] Certain embodiments of the cutting device include a vacuum
housing having an exhaust port from which the induced airflow and
material debris carried thereby exits the vacuum housing.
[0008] In certain embodiments of the cutting device, the source of
vacuum is contained in the vacuum housing, and the induced airflow
and material debris carried thereby may be expelled from the
exhaust port under a pressure greater than the pressure in the
pressure equalization chamber.
[0009] Certain embodiments of the cutting device include a
collection container attached to the exhaust port and into which
the induced airflow and material debris carried thereby is
received, material debris received in the collection container
retained therein.
[0010] In certain embodiments of the cutting device, the collection
container may have a wall through which the induced airflow
received thereby passes. The collection container may include a
porous inner container disposed within a porous outer container,
the porosity of the inner container being less than the porosity of
the outer container.
[0011] In certain embodiments of the cutting device, each outlet of
the plurality of vacuum conduits opens individually into the
pressure equalization chamber.
[0012] In certain embodiments of the cutting device, the inlets of
the plurality of vacuum conduits are sequentially positioned along
the path of blade travel within the shroud.
[0013] In certain embodiments of the cutting device, the blade is a
circular saw blade rotatably supported within the shroud, the
perimeter of the saw blade having a circumferentially distributed
plurality of teeth, with the inlets of the vacuum conduits
positioned at locations on the shroud that are sequentially passed
by each saw blade tooth.
[0014] In certain embodiments of the cutting device, the shroud
substantially surrounds an upper portion of the circular saw blade
and the cutting device may include a lower blade guard connected to
the shroud, the lower blade guard having movement relative to the
shroud between an extended position in which it substantially
surrounds the perimeter of the lower portion of the saw blade, and
at least one retracted position into which it is received in the
debris accumulation chamber and at least partially exposes the
perimeter of the lower portion of the saw blade. The lower blade
guard has a surface in which is provided at least one aperture that
is moved substantially into alignment with a vacuum conduit inlet
in a retracted position. In such an embodiment, material debris
generated by the blade during cutting may be carried with the
induced airflow into the conduit inlet from a location between the
saw blade perimeter and the blade guard through the aperture
substantially aligned with the conduit inlet.
[0015] Certain embodiments of the cutting device include a deck
plate through which the blade extends and to which the shroud is
connected, a base plate attached to the deck plate and through
which the blade extends, the base plate being positioned between
the deck plate and a material-engaging portion of cutting blade.
The shroud and the base plate have selective cut depth and
positions in which the distances from the base plate to which the
material-engaging portion of cutting blade extends and the relative
angle between the base plate and the material-engaging portion of
cutting blade are respectively varied. In such an embodiment, the
blade may be disposed in a space defined by a surrounding wall
extending between the base plate and the shroud that is
substantially sealed against air leakage through the wall,
throughout the operating ranges of cut depth and cut angle
positions.
[0016] In certain embodiments of the cutting device, substantially
all of the air drawn by the vacuum source into the debris
accumulation chamber is solely through an opening in the base plate
through which the blade extends.
[0017] The surrounding wall of certain such embodiments includes an
expandable first bellows located between the deck plate and the
shroud, the first bellows being correspondingly expanded and
compressed between different cut depth positions with corresponding
relative movement between the deck plate and the shroud.
[0018] In certain such embodiments of the cutting device, the base
plate and the deck plate are pivotably attached to each other, and
the surrounding wall includes a expandable second bellows located
between the deck plate and the base plate, the second bellows being
correspondingly expanded and compressed between different cut angle
positions with corresponding relative movement between the deck
plate and the base plate.
[0019] In certain embodiments of the cutting device, the
surrounding wall includes a transparent window located between the
deck plate and the shroud, the cutting blade and material being cut
visible to an operator through the window during cutting
operations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Other advantages of the present invention will be readily
appreciated, as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0021] FIG. 1 is a right-side, front perspective view of a portable
cutting device;
[0022] FIG. 2 is a right-side front perspective view of the
portable cutting device in an angled state;
[0023] FIG. 3 is a left-side front perspective view of the portable
cutting device in an angled state;
[0024] FIGS. 4A and 4B right-side front perspective exploded views
of the portable cutting device;
[0025] FIG. 5 is a front view of drive train components and blade
of the portable cutting device;
[0026] FIG. 6 is a left-side rear perspective view of the motor
casing of the portable cutting device;
[0027] FIG. 7 is a right-side front perspective view of the motor
casing of the portable cutting device;
[0028] FIG. 8 is a left-side front perspective view of the
left-hand handle half;
[0029] FIG. 9 is a right-side front perspective view of the
right-hand handle half;
[0030] FIG. 10 is a partial right-side front perspective exploded
view of vacuum housing-related components of the portable cutting
device;
[0031] FIG. 11 is a left-side rear perspective exploded view of the
vacuum housing of the portable cutting device;
[0032] FIG. 12 is a right-side front perspective view of the vacuum
housing of the portable cutting device;
[0033] FIG. 13 is a right-side front perspective view of the
impeller and its drive shaft;
[0034] FIG. 14 is a right-side front perspective view of the upper
blade enclosure;
[0035] FIG. 15 is a fragmented sectional view of the upper blade
enclosure and the retracted lower blade guard, and the saw
blade;
[0036] FIG. 16 is a partially sectioned, front view of the drive
train components and vacuum conduits of the portable cutting
device;
[0037] FIG. 17A is a right-side front perspective exploded view of
the lower blade guard and its bearing;
[0038] FIG. 17B is a left-side view of the lower blade guard and
its bearing;
[0039] FIG. 18 is a right-side front perspective view of the
transparent side window of the portable cutting device;
[0040] FIG. 19 is a right-side front perspective view of the main
bellows;
[0041] FIG. 20 is a right-side front perspective view of the
transparent blade window;
[0042] FIG. 21 is right-side front perspective view of the rear
bellows;
[0043] FIG. 22 right-side front perspective view of the lower
bellows;
[0044] FIGS. 23A and 23B are fragmented front views of the portable
cutting device in a zero angled state, at comparatively greater and
lesser blade depth positions, respectively;
[0045] FIGS. 24A and 24B are fragmented front views of the portable
cutting device in a 45-degree angled state, at comparatively
greater and lesser blade depth positions, respectively;
[0046] FIG. 25 is an enlarged, fragmentary front view of the
portable cutting device in a 45-degree angled state; and
[0047] FIG. 26 is a fragmented front view similar to that of FIG.
24B, but with a portion of the base plate removed to reveal the
lower bellows.
[0048] It is to be noted that the Figures are not necessarily drawn
to scale. In particular, the scale of some of the elements of the
Figures may be exaggerated to emphasize characteristics of the
elements. It is also noted that the Figures are not necessarily
drawn to the same scale. Elements shown in more than one Figure
that may be similarly configured have been indicated using the same
reference numerals.
[0049] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and may herein be described in
detail. It should be understood, however, that the drawings and
detailed description thereto are not intended to limit the
invention to the particular form disclosed, but on the contrary,
the intention is to cover all modifications, equivalents and
alternatives falling within the spirit and scope of the present
invention as defined by the appended claims.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0050] Referring to the Figures, wherein like numerals indicate
like or corresponding parts throughout the several views, a
portable cutting device for cutting a material M such as wood,
drywall, concrete, roof tiles, slate, etc., is generally shown at
30. The cutting device 30 is defined as being portable because of
the ability to easily move the cutting device 30 between work
sites. The cutting device 30 preferably weighs less than 50 lbs,
more preferably less than 35 lbs, and most preferably less than 20
lbs. The cutting device 30 is also preferably handheld, such that
it can be maneuvered, lifted etc. with a single hand.
[0051] Referring to FIGS. 1 and 2, the cutting device 30 includes
saw casing 31 in which is disposed a motor 32 which drives a
cutting tool 34. The motor 32 is preferably electrically powered
and energized by a 110-volt outlet through a conventional
electrical cord C, but the motor 32 could also be battery operated.
The motor 32 has a main drive shaft 36 and the cutting tool 34 is
operatively coupled to the main drive shaft 36 to rotate upon
operation of the motor 32.
[0052] The cutting tool 34 shown is a circular saw blade 34 that
rotates counterclockwise, in the direction of arrow 24, to cut up
through the material M. The saw blade 34 could be configured for
cutting through wood, metal, concrete, roof tiles, slate, and the
like. The saw blade 34, which is of a common type known to those of
ordinary skill in the art, is generally circular and defines a
central aperture for engaging a rotational saw shaft 116, as best
shown in FIGS. 2 and 20.
[0053] Referring to FIGS. 2 and 20, the main drive shaft 36 drives
the saw shaft 116 through a transmission 33. The transmission 33
includes a first gear 320 fixed to the main drive shaft 36 and a
second gear 322 fixed to the saw shaft 116. The gears 320, 322 are
preferably configured to step down rotational speed of the saw
shaft 116 compared to the main drive shaft 36. The transmission 33
is disposed in transmission casing 35 (described further below)
that covers, secures, and protects its gears 320, 322, with a
sealed bearing disposed in transmission casing 35 to support the
saw shaft 116. The motor casing 38 and transmission casing 35
together form a drivetrain housing.
[0054] A gear plate 51 defines part of the transmission casing 35
and includes a fixed collar 206 that covers and supports the sealed
bearing 204, through which extends saw shaft 116 supported thereby.
The gear plate 51 includes a base 53 on which outer fixed collar
206 is disposed and from which collar 206 extends laterally
outwardly. Saw blade 34 is clamped between an adjacent flange 55
and a bolt or nut 37 that engages threads formed in or on the end
of the saw shaft 116 in the well-known manner, thereby rotatably
fixing the saw blade 34 to the saw shaft 116.
[0055] Referring to FIGS. 2-4, the motor 32 includes a motor casing
38 that encloses and supports the motor components, e.g., brushes
32a, stator 32b, and rotor 32c. The motor casing 38 defines a motor
cavity 39 for receiving the stator 32b and rotor 32c and a pair of
cavities 41 for receiving the brushes 32a. The motor components
32a, 32b, 32c are secured in the motor cavities 39, 41 using
methods well known to those skilled in the art, such as by
fasteners, clips, snap-fits, interference-fits, and the like. The
motor casing 38 is preferably formed of metal and includes a vent
40 for exhausting heat generated by the motor 32. In other
embodiments, the motor casing 38 could be formed of a rigid plastic
material suitable for supporting the motor 32.
[0056] Referring to FIGS. 2-6, a handle 42 is fixed to the motor
casing 38. A user grasps and holds the handle 42 to manipulate,
maneuver and operate the cutting device 30 during use. A trigger 44
energizes the motor 32 using conventional methods. The handle 42
supports the trigger 44 for actuation by the user. As shown in
FIGS. 5 and 6, the handle 42 is preferably formed in two mating
halves 42a/42b that are locked together (via adhesive, mating
studs/bores, and/or the like). The handle 42 defines a rear cable
port 48 for receiving the cord C.
[0057] The motor casing 38 defines a cylindrical outer surface 50
(see FIG. 3). The handle 42 defines a cylindrical inner surface 52
that surrounds and engages motor casing surface 50. A suitable
adhesive could be used to secure the handle 42 to the motor casing
38. Mid-body motor casing enclosure 46 is disposed on motor casing
38 adjacent to left-hand handle part 42b, and forms part of saw
casing 31. Mid-body motor casing enclosure 46 has inner cylindrical
surface 47 that surrounds and engages motor casing surface 50. A
suitable adhesive could be used to secure enclosure 46 to the motor
casing 38.
[0058] Referring back to FIGS. 1 and 2, a lower platform assembly
54 is coupled to the motor casing 38. The lower platform assembly
54 comprises an upper plate or deck plate 56, and a lower plate or
base plate 58, which are pivotally coupled together through
pivoting or hinged joints 60. The upper plate 56 defines a
generally rectangular blade opening 62 for receiving a lower
portion of the saw blade 34. The lower plate 58 similarly includes
a generally rectangular blade opening 64 for receiving the lower
portion of the saw blade 34. The lower plate 58 is adapted to
contact and slide along the material M being cut by the saw blade
34.
[0059] A depth adjustment block 66 is fixed to the upper plate 56.
The depth adjustment block 66 defines an elongated slot 68 for
receiving an adjustment screw 70 therethrough. A corresponding
depth adjustment bracket 72 (FIG. 4B) is fixed to handle 42. The
depth adjustment bracket 72 defines a threaded bore 74 for
threadably receiving the adjustment screw 70. The adjustment screw
70 has a graspable head or pommel 69 and a threaded shaft wherein
the threaded shaft fits through the elongated slot 68 and threads
into the threaded bore 74. When tightened, the graspable head 69
frictionally engages an outer surface of the depth adjustment block
66 to hold the depth adjustment block 66 in one of a plurality of
adjustable positions by frictionally securing the depth adjustment
block 66 between the depth adjustment bracket 72 and the graspable
head 69. As a result, the lower platform assembly 54 can be
adjusted for depth relative to the motor casing 38 via the
adjustment screw 70.
[0060] Referring to FIGS. 1, 2, and 7, a first angle adjustment
block 71 is fixed to the upper plate 56 and a second angle
adjustment block 73 is fixed to the lower plate 58. The first angle
adjustment block 71 defines a bore 76 for receiving an angle
adjustment screw 78. The angle adjustment screw 78 has a threaded
shaft and a graspable head 81 configured to form a lever. A wing
nut 80 threadably engages the threaded shaft of the angle
adjustment screw 78 on a rear surface of the first angle adjustment
block 71. Wing nut 80 may be welded or permanently fixed to the
first angle adjustment block 71. Alternatively, bore 76 may be
threaded to engage the threads of screw 78, with wing nut 80
omitted altogether. The second angle adjustment block 73 defines a
second elongated, arcuate slot 88, preferably semicircular in shape
and centered about the axis of pivot joint 60, in which is received
the threaded shaft of the angle adjustment screw 78. When
tightened, the graspable head 81 frictionally engages a front
surface of the second angle adjustment block 73 to hold the lower
plate 58 in one of a plurality of angular positions by frictionally
securing the second angle adjustment block 73 between the first
angle adjustment block 71 and the graspable head 81.
[0061] The second angle adjustment block 73 is preferably graduated
with angular markings 79 such that the lower plate 58 can be
pivotally adjusted relative to the upper plate 56 at a known angle
therebetween. The angular markings preferably include graduations
of 1 degree spanning from zero to 45 degrees. This allows the user
to cut the material at a known angle. For instance, the user can
cut through wood trim pieces at a 45-degree cut angle.
[0062] Referring to FIGS. 2 and 8-10, a vacuum housing 90 is
coupled to the motor casing 38 and a blade shroud or upper blade
enclosure 110, with bolts. The vacuum housing 90 forms part of saw
casing 31 and includes a main housing portion 92, an impeller
housing portion 94, and a impeller cover 97. The main housing
portion 92 defines a pressure-equalizing chamber 96 (or pressure
chamber 96) and the impeller housing portion 94 and impeller cover
97 together define an impeller chamber 98 (see FIG. 10). The
generally cylindrical impeller housing portion 94 forms a
substantially tangentially extending exhaust port 95. The impeller
cover 97 is mounted to the impeller housing portion 94 using
fasteners F disposed in through bores T defined in the impeller
cover 97 and threaded into bores B in the impeller housing portion
94. Cover 97 has gear housing 136 formed on its exterior planar
surface. Housing 136 may, in some embodiments, have a separately
attached outer planar cap 138 to facilitate cover 97 being molded
with the side walls of housing 136.
[0063] A plurality of through bores 101 are also defined through
the main housing portion 92 are mated to holes 105 in impeller
housing portion 94, which receive fasteners (not shown) to mount
the main housing portion 92 to the motor casing 38 at a first end
of the motor casing 38.
[0064] An impeller 100 is rotatably supported in the impeller
chamber 98 on a stub shaft 135, which extends through aperture 106
of cover 97 and into gear housing 136, wherein it is rotatably
supported and axially fixed relative to central hub 103 of cover
97, by a sealed bearing 104 mounted on the outward side of hub 103,
within gear housing 136. The axially outward end of stub shaft 135
disposed in gear housing 136 has worm gear 336 formed thereon,
which is enmeshed with worm 338 provided on the end segment 129 of
flexible shaft 128, which is attached to gear housing 136. The
motor 32 rotatably drives the impeller 100 through flexible shaft
128 in the direction indicated by arrow 26 to create airflow and
corresponding vacuum pressure in the pressure-equalizing chamber
96. The impeller 100 can be formed of metal or plastic materials
such as Lexan.RTM., nylon, or other relatively rigid plastic
materials.
[0065] Referring specifically to FIG. 8A, a bore 99 is defined
through end cap 118 of saw casing 31, which is fixed to motor
casing 38. Attached to end cap 118 is end segment 102 of flexible
drive shaft 128 (see FIG. 2). Drive shaft end segment 102 is
adapted for receipt into bore 99 and rotatably fixed to motor drive
shaft 36. Flexible drive shaft 128, which includes rotating,
torque-carrying flexible cable disposed within a flexible
surrounding, nonrotating casing or sheath, is of a type well-known
in the power transmission art that is available from a number of
sources such as, for example, S.S. White Technologies, Inc. of
Piscataway, N.J., or Suhner Manufacturing, Inc. of Rome, Ga.
[0066] Referring to FIGS. 10-12, the impeller 100 has circular
plate 122 that superposes the inside planar surface of cover 97,
and to which a plurality of blades 124 or fins are interconnected.
Circular plate 122 has a central hub 130 extending normally
therefrom which defines a central hub 130 to which blades 124 are
also interconnected, and from which they extend radially outwardly.
Hub 130 defines a central bore into which stub shaft 135 is
inserted, with impeller 100 and stub shaft 135 rotatably and
axially fixed together. Impeller 100 and shaft 135 may be
interfixed through an interference fit, clamped engagement, or
through fasteners, for example.
[0067] Planar wall 120 of housing portion 94 defines an aperture
126 that approximates a size of the pressure-equalizing chamber 96
such that the pressure-equalizing chamber 96 opens directly into
the plurality of blades 124. The pressure-equalizing chamber 96
opens into the impeller chamber 98 in a direction generally
transverse to, and preferably perpendicular to, plate 122 of
impeller 100.
[0068] Referring specifically to FIGS. 2, 8A, 8B, a plurality of
vacuum conduits 406 are disposed about the saw casing 31 and extend
laterally therealong, between saw blade shroud or upper enclosure
110 and main housing portion 92 of vacuum housing 90. In the
depicted embodiment, three vacuum conduits 406 are utilized. The
vacuum conduits 406 communicate with the pressure-equalizing
chamber 96 through openings 109 in the main housing portion 92 (see
FIG. 10). It should be appreciated that more or fewer vacuum
conduits 406 could be employed. The vacuum conduits 406 extend
between upstream ends located at enclosure 110, and downstream ends
located at main housing portion 92. The pressure-equalizing chamber
96 assists in equalizing the vacuum or suction pressure drawn in
each of the vacuum conduits 406 by providing a volume of space,
upstream of the impeller 100 and downstream of the vacuum conduits
406, in which a suction pressure can be established.
[0069] In the depicted embodiment, the vacuum conduits 406 are
formed in multiple segments defined by casing components or other
components that define the conduits. These components may be
connected together by being sealably interfitted, or through the
use of adhesive and/or couplers, and/or the like. The sequentially
encountered sections of conduits 406 along the general direction of
airflow are described as duct heads 408, tubes 410, right-hand
handle passages 412, left-hand handle passages 414, mid-body
passages 415, and vacuum housing passages 422. Mid-body passages
415 are defined by the cooperating semi-cylindrical surfaces 416
formed on mid-body motor casing enclosure 46 and semi-cylindrical
surfaces 418 formed defined by mid-body window 420 attached to
enclosure 46. Passages 422 in main housing portion 92 of vacuum
housing 90 define individual outlets of vacuum conduits 406 that
each open into pressure equalization chamber 96.
[0070] The vacuum conduits 406 preferably have a generally circular
cross-section, but their cross-sections may instead be generally
rectangular in shape or other shapes, and can vary in
cross-sectional shape over their lengths. Each of the vacuum
conduits 406 preferably has a cross-sectional area at the blade
shroud or upper enclosure 110 that is larger than the
cross-sectional area at the main housing portion 92. The
cross-sectional area may taper gradually from the upper enclosure
110 to the main housing portion 92. Three vacuum conduits 406 are
illustrated and include a first or leading vacuum conduit 406a, a
second or center vacuum conduit 406b, and a third or trailing
vacuum conduit 406c.
[0071] Referring to FIGS. 2, 13 and 13A, the upper enclosure 110 at
least partially encloses an upper portion of the saw blade 34, and
defines an upper section of a debris accumulation chamber 112 (see
FIG. 22). The upper enclosure 110 has a generally semi-circular
shape that approximates the shape of the saw blade 34. The upper
enclosure 110 is generally U-shaped in cross-section taken in
planes containing the axis of rotation of saw shaft 116, except at
the openings to vacuum conduits 406.
[0072] The inlets to the first 406a and second 406b vacuum conduits
are disposed at a front section of the upper enclosure 110. The
inlet to the third vacuum conduit 406c is disposed at a rear
section of the upper enclosure 110. The front section is defined as
the front half of the upper enclosure 110, while the rear section
is defined as the rear half of the upper enclosure 110. The first
vacuum conduit 406a is preferably located at the frontmost location
on the front section to collect debris at the front of the debris
accumulation chamber 112. The third vacuum conduit 406c is
preferably located on the rear section to collect debris at the
rear of the debris accumulation chamber 112. Together the vacuum
conduits 406a, 406b, 406c define separate vacuum paths for the
debris.
[0073] A plurality of duct heads 408a, 408b, 408c are integrally
formed with the upper enclosure 110 (or alternatively can be formed
separately), and define inlets to their respective conduits 406a,
406b, 406c. The duct heads 408a, 408b, 408c each have a surrounding
collar adapted to receive and sealably engage the respective
upstream ends of tubes 410a, 410b, 410c. The upstream ends of tubes
410 may form an interference fit with the collars or be adhesively
bonded to the collars.
[0074] Referring to back to FIG. 2, an inner side 150 of the upper
enclosure 110 is mounted to the transmission casing 35 to close the
debris accumulation chamber 112 on the inside. More specifically,
inner side 150 is integrally connected to an outer rim 145, which
surrounds intermeshed gears 320, 322 of transmission 33, and
integral wall 146. Gear plate 51, outer rim 145, and wall 146
together define transmission casing 35. In the blade-surrounding
portion of enclosure 110, the inner side 150 and an outer side 152
of upper enclosure 110 are interconnected by integral,
semi-circular shoulder 155.
[0075] Outer side 152 of the upper enclosure 110 defines a
semicircular opening 153 in which is disposed a side window 160
that closes the opening 153 and the outward side of debris
accumulation chamber 112. The side window 160 includes a
transparent section 162 formed of transparent plastic and has a
semicircular outer periphery 164 in which is a circumferential
distribution of holes 166. The transparent section 162 allows the
user to view the saw blade 34. The outer periphery 164 interfaces
and abuts the inner surface of outer side 152 along the periphery
of opening 153 that is provided with holes 168 that correspondingly
align with holes 166. Fasteners (not shown) extend through aligned
holes 166, 168 to secure window 160 to enclosure 110. Side window
160 includes arcuate slot 170 centered abut the axis of rotation of
blade 34. The slot 170 is adapted to receive shaft 172, the end of
which is fixed to outer side 205 of manually retractable lower
blade guard 200. The outward end of shaft 172 is provided with knob
174 which may be grasped by the operator to manually move shaft 172
along slot 170 to retract lower blade guard 200 into upper blade
enclosure 110 to expose the edge of blade 34, which is desirable
for making plunge cuts into the surface of material M, rather that
from an edge thereof. Lower blade guard 200 may be rotatably biased
into its extended position in which it shields the edge of blade
34, by a tension spring 175 operably engaged with enclosure 110 and
guard 200, in a conventional manner well-known in the circular saw
art.
[0076] Upper blade enclosure 110 defines bottom edge 182 and side
window 160 defines bottom edge 176. Bottom edges 176 and 182 are
substantially flush and lie in a plane. Referring to FIGS. 2 and
17, a flexible main bellows 180 interconnects bottom edges 176, 182
along a corresponding upper rim or edge 188. The flexible bellows
180 is flexible and expandable between compressed and extended
states to accommodate differing cutting depths, i.e., when the
lower platform assembly 54 is raised and lowered relative to blade
34 to provide more or less blade cutting depth. Flexible main
bellows 180 has opposite longitudinal ends 194, 195 that face each
other, and slidably engage respectively interfacing, parallel
planar sides 196, 197 of blade enclosure 110. Bellows 180 has lower
rim or edge 186 that is interconnected with corresponding upper rim
or edge 190 of transparent blade window 192. Blade window 192 has
the same general shape as main bellows 180, and may be molded of a
suitable transparent, substantially rigid plastic material, to
allow the operator to view the cut line. Bosses 193 are formed in
blade window 192 through which fasteners F extend to secure blade
window 192 to deck plate 56. Bottom edge 198 of blade window 192 is
closely received into blade opening 62, and its outward side has a
shoulder 199 that abuts deck plate 56 along the outer longitudinal
edge of opening 62. Blade window 192 has opposite longitudinal ends
212, 213 that face each other, and abut and seal against
respectively interfacing, parallel planar sides 196, 197 of blade
enclosure 110.
[0077] More particularly, upper rim 188 of main bellows 180 may
define a peripheral groove adapted to receive the bottom edges 176,
182 of side window 160 and upper enclosure 110, and lower rim 186
of main bellows 180 may similarly define a peripheral groove
adapted to receive upper edge 190 of transparent blade window 192.
The bottom edges 176, 182 and the upper edge 190 may be
press-fitted and adhesively sealed in the respective peripheral
groove of bellows 180. In one embodiment, the flexible bellows 180
has an accordion shape. In other embodiments, the flexible bellows
180 is formed of a stretchable plastic material capable of
stretching greater than 100% such as polyurethane. The flexible
bellows 180 is also preferably transparent.
[0078] Additionally, the portion of the upper surface of deck plate
56 immediately below transmission casing 35 of enclosure 110 and
along the longitudinal inward edge of blade opening 62 is recessed
below the adjacent portions of the deck plate upper surface. The
recessed portion 218 of deck plate 56 defines a planar floor 220
that is parallel with planar bottom surface 222 of transmission
casing 35, which extends between its opposed sides 196, 197.
Extending the entire length of recessed portion 218 and surface 222
is rear bellows 178. Top surface 224 of rear bellows 178 is
sealably attached to transmission casing bottom surface 222; bottom
surface 226 of rear bellows 178 is sealably attached to floor 220.
Thus, the blade-containing space between blade opening 62 in deck
plate 56 and chamber 112 of upper blade enclosure 110, is
substantially sealed against air leakage through its enclosing
walls.
[0079] Referring back to FIGS. 2 and 7, the inward longitudinal
edge of blade opening 64 in base plate 58 is laterally distanced
from blade 34 to an extent that it is positioned on the side of
recessed portion 218 that is opposite the blade 34. Extending the
length of blade opening 64 is U-shaped lower bellows 181, which may
be of a material similar to main bellows 180. The legs 228, 229 of
lower bellows 181 extend substantially perpendicularly from its
elongate body 230; top and bottom surfaces 231, 232 of lower
bellows 181 are respectively sealably attached to the interfacing,
superposed surfaces of deck plate 56 and base plate 58. As lower
platform assembly 54 is adjusted about pivoting joints 60, to angle
deck plate 56 and base plate 58 between zero and 45 degrees, lower
bellows body portion 230 is expanded and contracted, while at the
terminal ends of legs 228, 229 bellows 181 remains compressed to a
substantially consistent degree regardless of saw blade angle.
Thus, bellows 181 is arranged to enclose a portion of the space
between plates 56, 58 into which blade opening 64 communicates.
[0080] On the outward lateral side of blade 34, elongate,
substantially planar slider plate 61 extends along the entire
length of blade opening 64 in base plate 58. The opposed ends 234,
235 of slider plate 61 are pivotally attached to deck plate 56 near
the upper slider plate edge 236, which slidably abuts elongate
sealing flange 240 integrally formed on the deck plate and
projecting upwardly and outwardly from its upper planar surface at
an angle, away from blade opening 62. The opposed ends 234, 235 of
slider plate 61 are closely fitted between a pair of upstanding
planar sealing flanges 242, 243 located at opposite longitudinal
ends of blade opening 64. The lower slider plate edge 237 is in
sliding engagement along its length with the adjacent planar
sealing surface 244 of base plate 58 located between its upstanding
flanges 242, 243. As slider plate 61 pivots relative to deck plate
56, with relative angular movement between deck plate 56 and base
plate 58 about pivot joints 60, slider plate lower edge 237
sealably slides along base plate sealing surface 244, and slider
plate ends 234, 235 sealably slide along the adjacent sealing
surface of their respective flanges 242, 243. The opposed ends 234,
235 of slider plate 61 may be slidably linked, for example, via
pin-in-slot joints, with flanges 242, 243, to ensure sealing
engagement between slider plate lower edge 237 and base plate
sealing surface 244. Alternatively, slider plate 61 may be
pivotably biased relative to deck plate 56, for example by a
torsion spring (not shown), to ensure sealing engagement between
slider plate lower edge 237 and base plate sealing surface 244.
Alternatively, slider plate 61 may rely on gravity and/or the air
pressure differential between its opposite planar sides during saw
operation to ensure sealing engagement between slider plate lower
edge 237 and base plate sealing surface 244. Thus, the
blade-containing space between blade opening 64 in base plate 58
and chamber 112 of upper blade enclosure 110, is also substantially
sealed against air leakage at locations below deck plate 56. The
above-described sealing of the blade containing space against the
influx of air leakage downstream of (i.e., above) blade opening 64
in lower plate 58 helps to maintain general sealing of the debris
accumulation chamber 112 when the lower plate 58 is pivoted for
angled cuts. In other words, during saw operation a working vacuum
pressure is maintained in the debris accumulation chamber 112 to
draw the debris out of the debris accumulation chamber 112 at all
cutting angles and depths.
[0081] Referring to FIGS. 2 and 18-19, a lower blade guard 200 is
pivotally mounted to the fixed collar 206 of the gear plate 51. The
lower blade guard 200 includes an inner side 203 and an outer side
205. The lower blade guard 200 includes a hub 202 on the inner side
203 for supporting a sealed bearing 204. The sealed bearing 204 is
disposed over the fixed collar 206 and is fixed to the fixed collar
206. The saw shaft 116 rotates within bearing 204 of the fixed
collar 206. Thus, the fixed collar 206 is fixed from rotation. As a
result, the lower blade guard 200 pivots about the fixed collar 206
via the sealed bearing 204. The lower blade guard 200 at least
partially encloses a lower portion of the saw blade 34. The lower
blade guard 200 also defines a plurality of openings 208 in the
inner side 203 and part of the shoulder 210. When guard 200 is
fully retracted, the openings 208, which generally correspond in
size and location to the inlets to conduits 406 in the upper
enclosure 110, become aligned with the duct heads 408. A bottom
shoulder 210 spaces the inner side 203 from the outer side 205.
[0082] This lower blade guard 200 rotates further into the upper
enclosure 110 as the saw blade 34 cuts through the material M in a
conventional manner. Referring to FIG. 18A, when the lower blade
guard 200 is rotated into the upper enclosure 110, the openings 208
assist in providing aligned airflow paths to carry the debris to
the vacuum conduits 406. This is best illustrated in FIG. 18A. When
the lower blade guard 200 is rotated into the upper enclosure 110,
it still surrounds the saw blade 34, just now at an upper portion
of the saw blade 34. As a result, there is a need for airflow from
the debris accumulation chamber 112 to easily penetrate through the
lower blade guard and remain relatively unimpeded as it continues
to the vacuum conduits 406, and openings 208 assist in this
effort.
[0083] Referring back to FIGS. 1 and 2, a collection bag 300 is
releasably mounted to the exhaust port 95 with a clamp or collet
302. In other embodiments, the collection bag 300 can be mounted
with a cinching string, elastic band, and the like. The collection
bag 300 is preferably flexible, collapsible, and easily disposable.
In other embodiments, the collection bag 300 is washable for coarse
work such as cutting materials like wood. The particular type of
collection bag 300 utilized to catch and collect fine debris such
as that produced in drywall cutting are in common use in the
industry and are well known in the art. The collection bag 300 is
generally porous to allow airflow therethrough, while still
trapping debris deposited in the collection bag 300 during
operation.
[0084] In one embodiment, shown in FIG. 3, the debris collection
assembly includes an outer container 301 and an inner container
303, both clamped about the exhaust port 95 and preferably being
bags that are flexible and collapsible. In this embodiment, the
inner bag 303 may be formed of disposable filter materials such as
a Style C Genuine Multi-Filter bag for an Electrolux Tank. The
inner bag 303 may be formed with a maximum pore size configured to
prevent pass-through of particle diameters of 100 microns or less,
more preferably 10 microns or less, most preferably 5 microns or
less, and even some embodiments capable of preventing pass through
of particles with diameters of 1 microns or less. The outer bag 301
may be fabricated from a synthetic or natural cloth material and be
formed with pore sizes configured to prevent pass through of larger
material such as wood chips, etc., preferably on the order or 0.5
inches in diameter or less, 0.1 inches in diameter or less, and
preferably from about 100 microns to about 0.1 inches in
diameter.
[0085] During operation, the motor 32 drives the main drive shaft
36 (and flexible shaft end segment 102). Referring to FIG. 20, the
first gear 320 is fixed to the main drive shaft 36, while the
second gear 322 is fixed to the saw shaft 116. The gears 320, 322
are preferably configured to step down rotational speed of the saw
shaft 116 compared to the main drive shaft 36.
[0086] Referring to FIG. 23, as the motor 32 drives the impeller
100, the impeller 100 rotates to generate airflow. This airflow
creates a vacuum or suction pressure in the debris accumulation
chamber 112 to draw debris from the debris accumulation chamber 112
into the vacuum conduits 406. From the vacuum conduits 406, the
debris travels into the pressure-equalizing chamber 96 and then
through the inside plate 120 of the impeller 100. The impeller 100
then directs the debris out of the exhaust port 95 and into the
collection bag 300. In FIG. 22, the arrows show the direction of
airflow and the direction of travel of the debris.
[0087] The saw blade 34 preferably has a plurality of teeth
arranged circumferentially about a perimeter of the saw blade 34.
Each of the teeth includes a flat section protruding radially
outwardly from the main body of the saw blade 34 that has a width
that generally approximates the width of the main body and is
usually integrally formed with the main body out of a metallic
material such as steel or composites thereof. In some embodiments,
the saw blade 34 may be 10 inches or less in diameter, preferably
between 6 inches and 10 inches, and more preferably between 6
inches and 8 inches. The width of the saw blade 34 is 3 mm or less,
more preferably 1.5 mm or less, and most preferably between about
0.2 mm and 2.0 mm. Other embodiments may have varying sizes
depending on the particular application or material to be cut.
[0088] Each of the teeth has a kerf face that defines the kerf
formed by the saw blade 34 during cutting. The blade's kerf face
can take on many different shapes depending on the particular
cutting application. In some embodiments, the kerf is 2 mm or more,
while in other embodiments, the kerf is 2 mm or less. In one
particular embodiment, the kerf is about 2 mm. In some embodiments
carbide tips define the blade's kerf face, with the carbide tip
fixed to the flat section in a conventional manner, such as by
welding, adhesive, etc. A gullet is defined between the teeth. The
gullet for a saw blade of about 10 inches in diameter or less is
preferably less than 1 inch, more preferably less than 0.75 inches,
and most preferably between 0.25 inches and 0.75 inches. For larger
diameter saw blades, the gullet may be deeper.
[0089] Each of the teeth may also include an embossed portion on
opposing sides of the flat section that preferably extends from the
carbide tip onto the main body of the saw blade 34. The height of
the two embossed portions and width of the flat section in total
preferably equal or are less than the kerf width of the teeth, more
preferably less than about 95% of the kerf width of the teeth. The
maximum height of each of the embossed portions in one embodiment
may be 1 mm or less, more preferably 0.5 mm or less, and most
preferably between 0.1 mm and 0.5 mm. In different applications,
the height may differ.
[0090] The dimensions of the various elements can be varied
according to the uses and designs of the cutting device 30. For
example, the debris accumulation chamber 112 may be from 0.5 inches
to 10 inches in width. In some embodiments, the upper enclosure
110, blade window 132, side window 160, and bellows 180 may be
unitary and formed in one-piece of plastic. The motor casing 38,
vacuum housing 90, and upper enclosure 110 could also be formed in
one-piece and could be formed of metal, plastic, or any
combinations thereof. Additionally, the vacuum conduits 406 (also
referred to as debris carrying ducts 406) could be integrated into
a single duct (not shown) partitioned into separate paths to
accomplish the same objectives as the present invention.
[0091] As additional enhancements, lighting could be provided
inside the debris accumulation chamber 112. Referring to FIGS. 13
and 13C, one or more LEDs 645 could also be positioned inside the
debris accumulation chamber 112 and actuated by a separate switch
650. In FIG. 13, the LEDs 645 are mounted inside the upper
enclosure 110 on the front side. Additional LEDs 645 could be
mounted on the opposite side of the upper enclosure 110 (see FIG.
13). The LEDs could be glued to the upper enclosure 110, snap fit
into sockets integrally formed in the upper enclosure, or otherwise
fastened to the upper enclosure 110 using screws, rivets, and the
like. The LEDs 645 could be configured to automatically operate
(light up) when the motor 32 is actuated by switch 44, or could be
separately operated by switch 650 (see FIG. 13C). Further, a laser
guide 700 could be incorporated in the cutting device 30. In FIG.
13, the laser guide 700 is mounted to an outside of the upper
enclosure 110 along the upper shoulder 155. Like the LEDs, the
laser guide 700 could be configured to automatically operate when
the motor is actuated by switch 44, or could be separately operated
by switch 702. The laser guide 700 could also be separately battery
powered.
[0092] While the invention has been described with reference to
exemplary embodiments, it will be understood by those skilled in
the art that various changes can be made and equivalents can be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications can be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment(s) disclosed herein, but that the invention
will include all embodiments falling within the scope of the
appended claims.
* * * * *