U.S. patent application number 11/650735 was filed with the patent office on 2007-05-17 for light beam alignment system.
This patent application is currently assigned to Eastway Fair Company Limited of Trident Chambers. Invention is credited to John Ka Ki Chan, Gerhard Josef Karl Weusthof.
Application Number | 20070107573 11/650735 |
Document ID | / |
Family ID | 22003475 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070107573 |
Kind Code |
A1 |
Weusthof; Gerhard Josef Karl ;
et al. |
May 17, 2007 |
Light beam alignment system
Abstract
A saw such as a chop saw, a circular saw, a compound miter saw
or a sliding compound miter saw having a rotatable saw blade is
provided with a laser arbor alignment system. The laser arbor may
include a power generator that generates power as the saw blade and
the laser arbor are rotated by a spindle. The generator may include
a stator comprising an electrical magnet or a permanent magnet
mounted on a fixed portion of the saw. The other portion of the
generator is a rotor comprising a coil that is rotated with the
laser arbor to generate power for the laser. Power may also be
provided to the laser by slip ring contacts from a stationary
source to the laser arbor.
Inventors: |
Weusthof; Gerhard Josef Karl;
(Tsuen Wan, HK) ; Chan; John Ka Ki; (Kowloon,
HK) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
Eastway Fair Company Limited of
Trident Chambers
Tortola
VG
|
Family ID: |
22003475 |
Appl. No.: |
11/650735 |
Filed: |
January 8, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10056297 |
Jan 25, 2002 |
7159497 |
|
|
11650735 |
Jan 8, 2007 |
|
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Current U.S.
Class: |
83/490 ;
83/520 |
Current CPC
Class: |
B27B 5/32 20130101; Y10T
83/7697 20150401; Y10T 83/7788 20150401; Y10T 83/828 20150401; B23Q
17/24 20130101; B23D 59/003 20130101 |
Class at
Publication: |
083/490 ;
083/520 |
International
Class: |
B23D 45/04 20060101
B23D045/04 |
Claims
1. A laser arbor for a saw having a spindle that rotates a saw
blade relative to a non-rotating portion of the saw, the laser
arbor comprising: a housing; a laser light disposed at least in
part within the housing; a circuit electrically connected to the
laser for providing power to the laser, the circuit providing power
for a voltage source that includes a portion secured to the
non-rotating portion of the saw.
2. (canceled)
3. (canceled)
4. The laser arbor for a saw having a spindle of claim 1 wherein
the circuit further comprises an inductively coupled power source
comprising a first induction coil that is rotated by the spindle
and a second induction coil that is on the non-rotating portion of
the saw, and wherein power for the laser is provided by the
inductively coupled power source.
5. The laser arbor for a saw having a spindle of claim 1 wherein
the circuit further comprises a power source electrically connected
by slip ring contacts that establish electrical contact between the
power source and the circuit, wherein the slip ring contacts
comprise a first set of contacts that rotate with the saw blade and
a second set of contacts that are stationary which contact the
first set of contacts.
6-13. (canceled)
14. A saw comprising: a motor having a spindle; a blade secured to
the spindle and rotated by the motor to cut a workpiece; a laser
arbor having a housing secured to the spindle for rotation with the
blade; a light source disposed in the housing, the light source
emitting a narrow beam of light adjacent the blade for providing a
visual indication of the alignment of the blade with the workpiece;
and an inductively coupled power source electrically connected to
the light source, wherein the power source includes a first
induction coil associated with and rotated with the housing and a
second induction coil secured adjacent to the housing, the second
induction coil inducing voltage in the first induction coil to
provide power to the light source.
15. The saw of claim 14 wherein the rotor is electrically connected
to a power conditioning circuit that provides power directly to the
light source.
16. The saw of claim 14 wherein the light source is a LED.
17. (canceled)
18. A saw comprising: a motor having a spindle; a blade secured to
the spindle and rotated by the motor to cut a workpiece; a laser
arbor having a housing secured to the spindle for rotation with the
blade; a light source disposed in the housing, the light source
emitting a narrow beam of light adjacent the blade for providing a
visual indication of the alignment of the blade with the workpiece;
and a power source electrically connected by a plurality of slip
ring contacts that establish electrical contact with the light
source, wherein the slip ring contacts comprise a set of rotating
contacts that rotate with the blade and a set of fixed contacts
that are stationary and are mounted on the saw to contact the first
set of contacts.
19. A laser arbor for a saw having a spindle that rotates a saw
blade relative to a non-rotating portion of the saw comprising: a
housing secured to the spindle; a laser disposed at least in part
within the housing; and an electric circuit for providing an
electrical connection between the laser and the voltage source,
wherein electric current to power the laser is generated solely by
rotation of the spindle with no electrical connection with the
non-rotating portion of the saw.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a saw having a light source
alignment system that does not require internal batteries to power
the light source.
[0003] 2. Background Art
[0004] Miter saws, portable circular saws, radial arm saws, chop
saws, and compound saws are used to precisely cut wood and other
materials. For example, miter saws and compound saws are used to
cut baseboards, crown moldings, cove moldings, and a wide variety
of trim pieces and structural members to exact dimensions. Such
circular saws generally have a blade that is rotated at a high rate
of speed to cut workpieces. The blade is guarded by a retractable
blade guard that covers the saw blade but is retracted as the blade
is brought into contact with a workpiece. The workpiece is retained
on a base and a turntable that, in conjunction with a fence, are
used to position the workpiece to be cut by the saw.
[0005] Before cutting, workpieces are generally marked with a
pencil at the intended cut location according to precise
measurements to assure accuracy. A common problem with these types
of saws is that it takes considerable skill and attention to
consistently align the workpiece with the saw blade so that the
edge of the saw blade cuts the workpiece at the desired location.
With prior art saws, it has not been possible to know if the saw
alignment is proper until the saw begins to cut the material. The
workpiece may be ruined if it is not set up at the correct
orientation when the saw blade contacts the workpiece.
[0006] A laser arbor for a circular saw has been proposed in U.S.
Pat. No. 5,862,727 to Kelly. The Kelly patent discloses the use of
a semiconductor laser arbor for a circular saw that is actuated by
a centrifugal switch and directs a line of laser beam on a
workpiece. The Kelly patent discloses a battery powered laser light
source. One problem with reliance upon batteries is that the
semiconductor laser light source draws substantial power from the
batteries to illuminate the laser, resulting in limited battery
life and requiring frequent battery changes. Similarly, U.S. Pat.
No. 6,035,757 to Caluori et al. discloses a similar semiconductor
laser light beam alignment device for a circular saw having a
focusing lens that causes the laser beam to be directed to the
blade cut line. The Caluori patent likewise relies upon a battery
power source that is carried by the laser arbor. This system has
the same problem of limited battery life as the Kelly patent.
[0007] The assignee of this application has marketed a battery
power laser alignment device which is described in copending U.S.
patent application Ser. No. 09/860,898 entitled "Miter Saw Having a
Light Beam Alignment System" which is incorporated by reference
herein for general background purposes.
[0008] Applicants have solved the battery life problem by their
development of a laser alignment system that utilizes a power
source external to the laser arbor.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the present invention, a miter
saw (or other circular saw) is provided that includes a motor with
a spindle to which a blade is secured and rotated by the motor to
cut a workpiece that is disposed on a turntable or saw table. The
motor is part of a saw head assembly that is supported relative to
the table by an arm. A laser or other directed light source
(hereinafter referred to as "laser" or "light source") is mounted
in a laser arbor housing that is secured to the spindle and rotated
by the motor along with the blade. The light source emits a narrow
beam of light from the housing to a location adjacent to the blade
for checking the alignment of the blade with the workpiece. Power
for the light source is provided by a source located outside the
laser arbor housing.
[0010] The invention may also be defined as a laser arbor for a
circular saw having a spindle that rotates the saw blade relative
to a non-rotating portion of the saw. The laser arbor comprises a
LED laser light and a circuit connected to the laser for providing
power to the laser. The circuit provides power from a voltage
source that includes a portion secured to the non-rotating portion
of the saw.
[0011] According to another aspect of the invention, the circuit of
the laser arbor for a circular saw may further comprise a generator
having a rotor associated with the spindle and a stator associated
with the non-rotating portion of the saw. Electrical energy is
generated as the spindle rotates the rotor relative to the
stator.
[0012] According to another aspect of the invention, the laser
arbor for a circular saw may have an inductively coupled power
source. The inductive power source may comprise a first induction
coil inside the laser arbor that rotates with the arbor and a
second induction coil mounted near the arbor that induces voltage
in the first coil. The first induction coil is electrically
connected to a power conditioning circuit that provides power
directly to the light source. According to another aspect of the
invention, the light source may be a LED laser.
[0013] Alternatively, the circuit may comprise a power source
electrically connected by slip ring contacts that establish
electrical contact between the power source and the circuit. The
slip ring contacts may comprise a first set of contacts that rotate
with the spindle and a second set of contacts that are stationary
and contact the first set of contacts. The circuit further
comprises a power conditioning circuit that provides power within a
predetermined voltage range to the laser.
[0014] These and other aspects of the invention and advantages of
the invention over the prior art will be better understood in view
of the attached drawings and following detailed description
provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a sliding compound miter saw
having a laser arbor including a power generator for powering the
laser;
[0016] FIG. 2 is a schematic fragmentary view of a circular saw
blade, laser arbor and blade guard to which a stator for a
generator is secured;
[0017] FIG. 3 is an exploded perspective view of a laser arbor
including a fixed induction coil secured to the blade guard and a
rotatable induction coil secured within the laser arbor;
[0018] FIG. 4 is an exploded perspective view of a laser arbor
including a generator having a permanent magnet stator connected to
the blade guard and a arcuate coil section secured within the laser
arbor; and
[0019] FIG. 5 is a diagrammatic view of a laser arbor having slip
ring contacts for providing power to the laser.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring now to FIG. 1, a saw 10 having a circular saw
blade 12 is shown. The saw 10 also includes a base 13 and a
turntable 14 that together comprise a supporting table generally
referred to by reference numeral 15. A fence 16 is provided on the
supporting table 15. A workpiece 18 is placed on the supporting
table 15 and held against the fence 16 as the workpiece 18 is cut
by the saw 10. An arm 20 connects the motor assembly 22 to the
turntable 14. The motor assembly 22 forms a part of the saw head
assembly, generally indicated by reference numeral 24. The motor
assembly 22 drives the saw blade 12. The saw blade 12 is shielded
by a fixed guard 28 and a retractable shield 30. A handle 32 is
provided for manipulating the saw head assembly 24.
[0021] The saw 10 shown in the illustrated embodiment is a sliding
compound miter saw having a miter angle adjustment mechanism 38 and
a tilt adjustment mechanism 40. While the illustrated embodiment is
of a sliding compound miter saw, the invention is equally
applicable to other types of circular saws such as a simple miter
saw, a compound miter saw, a chop saw, portable circular saw, or
radial arm saw. The saw head assembly 24 is pivotally connected to
the arm 20 and includes a spring (not shown) for biasing the saw
head assembly 24 normally out of engagement with the workpiece
18.
[0022] When an operator is ready to make a cut with the saw 10, the
operator grips the handle 32, depresses the trigger causing the
circular saw blade 12 to rotate, and pulls it down toward the
workpiece 18. The miter angle adjustment mechanism 38 permits the
turntable 14 to rotate relative to the base 13 to change the miter
angle of cut. The tilt adjustment mechanism 40 allows the saw head
assembly 24 to be pivoted to adjust the inclination of the blade 12
relative to the supporting table 15.
[0023] Referring now to FIG. 2, a saw 10 having a laser arbor 42 is
illustrated. The laser arbor 42 is mounted adjacent the saw blade
12 on the same spindle 44 as the saw blade. The laser arbor 42
directs a laser beam 48 outwardly from the laser arbor 42 as it is
rotated by the spindle 44. The light beam is slightly angled toward
the blade preferably at the top surface of the work piece where the
blade cuts the work piece. While the light source is described as a
laser, another light source such as a light emitting diode (LED)
laser, focused electric light bulb based system or other small
light could be used with the saw 10.
[0024] Referring now to both FIGS. 1 and 2, a stator 50 is secured
to the fixed guard 28 near the laser arbor 42. The stator 50 may
include an electrical magnet or permanent magnet that creates
magnetic flux through which the laser arbor 42 is rotated to
generate electricity, as will be more fully described below.
[0025] Referring now to FIG. 3, one alternative embodiment of the
invention is shown wherein a stationary induction coil 52 is
included as part of the stator 50 that is mounted on the fixed
guard 28. A housing 54 for the laser arbor encloses a rotating
induction coil 56. The housing 54 and rotary induction coil 56 are
assembled to a laser arbor washer 58 that supports a LED laser
module 60. The laser module 60 directs a beam of light through a
slot 62 formed on the washer 58. Electricity induced in the coil 56
is conditioned by a conventional inductively coupled power supply
circuit of the type commonly used in electric toothbrushes or the
like in order to power laser module 60. Stationary induction coil
52 is powered by an AC power source or a pulsed reversing polarity
or on-off DC source that induces a corresponding current through
the rotating induction coil 56 which is located within the magnetic
field of coil 52.
[0026] Referring now to FIG. 4, another alternative embodiment is
shown wherein a permanent magnet 64 is secured to the fixed guard
28. The permanent magnet 64 is preferably formed by a plurality of
arcuate segments (not shown) of a ceramic permanent magnet formed
of ferrite or other well-known magnetic ceramic material. A housing
66 is secured to a laser arbor washer 68. An arcuate coil 70 is
mounted on the laser arbor washer 68. The coil 70 is rotated with
the laser arbor module through the alternating polarity (N-S-N)
flux created by permanent magnet 64 thereby generating electricity
that is provided to the laser arbor module 72. Laser light is
emitted through a slot 74 formed in the laser arbor washer 68.
[0027] Referring now to FIG. 5, yet another alternative embodiment
is provided wherein a first set of contacts comprising contacts 80
that are provided on a hub 81 of a laser arbor washer 82 of a laser
arbor 84. A housing 85 is provided for enclosing the component
parts of the laser arbor 84. Contacts 86 are provided on the
spindle 88 that maintain contact with the contacts 80. A pair of
slip ring contacts 90 are provided on the spindle 88 at a location
spaced from the laser arbor 84. The slip ring contacts 90 connect
to contacts 91 and are electrically connected to the contacts 86.
The laser module 92 is supported by a laser arbor washer 82 and
directs a laser beam through a slot 94 formed in the laser arbor
washer 82.
[0028] In each of the embodiments described above with reference to
FIGS. 3-5, no batteries are required to provide power to the laser
modules.
[0029] A power conditioning circuit may be provided by a circuit
board 96 secured to the washer or could be built-in as part of
laser modules. In FIG. 3, an AC pulse reversing circuit 98 is
illustrated that may be provided as part of the power circuit.
[0030] While embodiments of the invention have been illustrated and
described, it is not intended that these embodiments illustrate and
describe all possible forms of the invention. Rather, the words
used in the specification are words of description rather than
limitation, and it is understood that various changes may be made
without departing from the spirit and scope of the invention.
* * * * *