U.S. patent number RE38,612 [Application Number 10/092,960] was granted by the patent office on 2004-10-05 for router table fence system.
This patent grant is currently assigned to Lee Valley Tools, Ltd.. Invention is credited to Leonard G. Lee, John S. Lynn, Michael S. McGuire, Edwin C. Tucker.
United States Patent |
RE38,612 |
Tucker , et al. |
October 5, 2004 |
**Please see images for:
( Reexamination Certificate ) ** |
Router table fence system
Abstract
A router table fence having three nesting aluminum extrusions or
spars, two of which lie under a longer third spar. By positioning
the inner ends of the two lower spars adjacent to a router cutter
protruding through a router table, it is possible to provide a
fence, particularly when the lower spars are used with wood facings
or sub-fences, that can be adjusted to closely surround the cutter.
Lateral movement of the fence assembly adjusts the amount of cutter
that contacts a workpiece manipulated past the cutter while
contacting the fence. The cross sectional shapes of the spars are
identical and are generally square, with structure that permits the
upper, longer spar to rest on top of, and be attached in a manner
permitting it to slide against, the lower two spars. T-shaped slots
in each face of the spars accept fasteners that connect the spars
together and also accept fasteners for a variety of accessories,
such as hold-down devices and shields. Fence locks attach the fence
to a variety of router table tops without the need for
fence-receiving structures separately attached to the router table
or table top. A micro-adjust stop can be used in cooperation with
the fence locks to make very accurate and predictable adjustments
in the position of the fence on a router table top. By using a shim
behind one of the sub-fences in order to position it parallel to,
but slightly offset from, the other sub-fence, it is possible to
joint a surface of a board using a "straight" cutter.
Inventors: |
Tucker; Edwin C. (Ottawa,
CA), McGuire; Michael S. (Ottawa, CA), Lee;
Leonard G. (Almonte, CA), Lynn; John S. (Ontario,
CA) |
Assignee: |
Lee Valley Tools, Ltd. (Ottawa,
CA)
|
Family
ID: |
26681827 |
Appl.
No.: |
10/092,960 |
Filed: |
February 28, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
791818 |
Jan 30, 1997 |
05779407 |
Jul 14, 1998 |
|
|
Current U.S.
Class: |
409/218;
144/252.1; 144/253.1; 269/303; 409/226 |
Current CPC
Class: |
B27C
5/06 (20130101); B23Q 3/005 (20130101); B23Q
3/002 (20130101); Y10T 409/309072 (20150115); Y10T
409/308624 (20150115) |
Current International
Class: |
B27B
31/00 (20060101); B23C 1/00 (20060101); B23C
1/12 (20060101); B27B 031/00 (); B23C 001/12 () |
Field of
Search: |
;15/300.1,301,306.1
;144/251.2,252.1,253.1,253.2,135.2 ;269/303,304,315
;409/218,226 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
CMT Tools Catalog 18, 1995-96, p. 44.* .
Highland Hardware Early Fall 1993 Sale Catalog, pp. 46-48.* .
Lee Valley Catalog entitled Fine Woodworking Tools 1991-92, p.
108.* .
McFeely's Square Drive Screws Catalog, .COPYRGT.1995 McFeely's, pp.
60-61.* .
The Woodworker's Store.RTM. 1993-94 Catalog #C-93, pp. 99-100.*
.
Trend-lines.RTM. Woodworkers Warehouse.TM. Catalog 508H,
.COPYRGT.1993 Trend-Lines, Inc., pp. 10, 42.* .
Woodcraft.RTM. Jan. 1996 Catalog, p. 74.* .
Woodhaven Catalog entitled Uncommon Woodworking Tools,
.COPYRGT.1995, Woodhaven, Inc., pp. 3, 5, 10-13.* .
Woodworker's Supply, Inc., Catalog #76, Aug. 1992, p. 36.* .
Jul. 2, 2001 letter to R. Warren Comstock, Esq. from Roger D. Greer
of Greer, Burns & Crain, Ltd. .
Exhibit 1: CRAFTMAN.RTM. Professional Router Table Fence, Owner's
Manual Model No. 9-26472. .
Exhibit 2: U.S. Pat. No. 5,553,644 to Adams, entitled Fence for
Woodworking Machine, issued Sep. 10, 1996. .
Exhibit 3: Scheppach Katalog, 1994. .
Exhibit 4: Taunton's Fine WoodWorking, Fence and Chip-Collection
System, Oct. 1991 No. 90. .
Exhibit 5: Taunton's Fine WoodWorking, Smart Fence Plus,
Advertisement from Join Tech, Oct. 1994 No. 108. .
Exhibit 6: Bench Dog. .
Nov. 7, 2001 letter to R. Warren Comstock from John D. Gould of
Merchant & Gould. .
Exhibit 1: U.S. Pat. No. 5,779,407 to Tucker et al., entitled
Router Table Fence System, issued Jul. 14, 1998. .
Exhibit 2: CRAFTMAN.RTM. Professional Router Table Fence, Owner's
Manual Model No. 9-26472. .
Exhibit 3: CRAFTSMAN.RTM. table fence photographs. .
Exhibit 4: JoinTech, SMART FENCE.RTM. Plus Model SF-32 photographs.
.
Exhibit 5: JoinTech, SMART FENCE.RTM. Plus Model SF-32, Owners
Manual. .
Exhibit 6: JoinTech, Smart Fence Plus Mounting Brackets, SF-MB2,
Parts List with instructions. .
Exhibit 7: Taunton's Fine WoodWorking, Oct. 1994, p. 123 showing
SMART FENCE.RTM. advertisement. .
Exhibit 8: Taunton's Fine WoodWorking, Oct. 1991, showing SMART
FENCE.RTM. advertisement. .
Exhibit 9: American Woodworker Magazine, Reprint from Aug. 1995
Issue. .
Exhibit 10: U.S. Pat. No. 5,553,644 to Adams entitled Fence for
Woodworking Machine, issued Sep. 10, 1996. .
Exhibit 11: ShopNotes, 1992, No. 1, entitled Complete Router Table.
.
Exhibit 12: Prototype of Exhibit 11 Photographs..
|
Primary Examiner: Rosenbaum; Mark
Attorney, Agent or Firm: Kilpatrick Stockton Pratt; John S.
Johnson; Kristin L.
Parent Case Text
REFERENCE TO PROVISIONAL APPLICATION
This application claims the benefit of U.S. Provisional application
Ser. No. 60/010,975, filed Feb. 1, 1996, the entire contents of
which are incorporated herein by this reference.
Claims
We claim:
1. A router table fence for use with a router table top,
comprising: (a) a top spar having a first length and a front face,
(b) two bottom spars having front faces, and (c) connectors for
attaching the bottom spars to the top spar so that: (i) the front
faces of each of the top spar and the two bottom spars are in
substantially the same plane and (ii) opposed ends of the two
bottom spars may be positioned either: (x) abutting, or (y)
separated by a selected distance.
2. The router table fence of claim 1, further comprising two
sub-fences, one of which is attached to the front face of each of
the bottom spars, and each of which sub-fences has a working face
for contact with workpieces.
3. The router table fence of claim 2, wherein the sub-fences are
made of a material that can be machined with a router cutter.
4. The router table fence of claim 1, wherein the cross-sectional
shape of each of the top and bottom spars is substantially
identical.
5. The router table fence of claim 1, wherein the cross-sectional
shape of each of the top and bottom spars is substantially a
rectangle.
6. The router table fence of claim 1, wherein the cross-sectional
shape of each of the top and bottom spars is substantially a
square.
7. The router table fence of claim 1, wherein one of the top spar
or the bottom spars has at least one rib that may be received in a
depression in the other of the bottom spars or the top spar so that
the bottom spars may slide longitudinally relative to the top spar
while the bottom spars maintain vertical alignment relative to the
top spar and each other.
8. The router table fence of claim 1, further comprising means for
engaging the bottom spars with the top spar so that the bottom
spars may slide longitudinally relative to the top spar while
maintaining vertical alignment relative to each other.
9. The router table fence of claim 2, further comprising means for
positioning the working face of one of the sub-fences in a plane
parallel to but displaced from the plane within which the working
face of the other sub-fence is located so that a straight cutter
positioned to rotate tangent to the working face plane of the one
sub-fence can produce a substantially flat surface on a workpiece
fed from the other sub-fence face, into the cutter and onto the one
sub-fence face.
10. The router table fence of claim 1, wherein the top spar has a
top face orthogonal to the front face, the front faces of the
bottom spars are in substantially the same plane as the top spar
front face and the bottom spars each have a bottom face
substantially orthogonal to the bottom spar front faces.
11. The router table fence of claim 10, wherein each of the top
spar front and top faces and the bottom spar front and bottom faces
have a longitudinal T-slot therein.
12. The router table fence of claim 1, further comprising means for
fixing the fence to a router table top.
13. The router table fence of claim 12, wherein the fixing means
comprises at least one clamp for attachment to the fence and
engagement with the router table top.
14. The router table fence of claim 12, wherein the fixing means
comprises two clamps, each of which clamp has a body for contact
with the top of the router table top, and, attached to the body:
(a) a projection having a T-shaped cross section to be received in
a T-shaped slot in the fence and (b) a foot through which a
threaded rod extends to exert pressure against the underside of the
router table top generally opposite the clamp body.
15. The router table fence of claim 1, further comprising a dust
chute comprising: (a) an inlet for positioning adjacent to the
fence, (b) a tubular extension communicating with the inlet for
attachment to a dust removal system or vacuum cleaner and (c) at
least one magnet affixed to the chute for attachment of the chute
to ferrous metal surfaces.
16. The router table fence of claim 1, further comprising a safety
shield for attachment to the fence, the shield comprising a
substantially transparent shield member attached to a vertical arm
for fixation to the front of the fence in a position so that the
shield member is positioned generally above a router cutter
protruding through the router table top.
17. The router table fence of claim .[.1.]. .Iadd.16.Iaddend.,
wherein the safety shield is made of polycarbonate plastic.
18. The router table fence of claim 1, wherein the fence has a
front and the fence further comprises a hold-down assembly for
mounting on the fence, the hold-down assembly comprising a body to
which there is attached: means for exerting pressure against a top
of a workpiece to urge it against the top of the router table top,
and means for exerting pressure against a side of a workpiece to
urge it against the front of the fence.
19. The fence of claim 18, wherein the fence has at least one
T-slot and the hold-down assembly attaches to the fence by engaging
a T-slot in the fence.
20. The router table fence of claim 1, further comprising a
micro-adjust stop for accurately repositioning one end of the
fence, comprising a stop body for attachment to the router table
top and a positioning screw threaded through the body for contact
with a face of the fence in a range of locations determined by the
position of the screw within the body and the location of the body
on the router table top.
21. The router table fence of claim 20, further comprising
longitudinal and rotational position indicating means on the
positioning screw and, attached to the body, a cursor for
establishing the longitudinal and rotational position of the screw
relative to the body by reference to the position indicating means
so that changes in position of the screw can be accurately
determined.
22. The router table fence of claim 20, further comprising spaced
apart longitudinal marks around the circumference of the
positioning screw and spaced apart annular rings on the positioning
screw and, attached to the body, a transparent plate having cursor
marks for establishing the longitudinal and rotational position of
the screw relative to the body by reference to the longitudinal
marks and the annular rings so that changes in position of the
screw can be accurately determined.
23. The router table fence of claim 1, further comprising a fixed
stop usable to establish the position of the fence on the router
table top to make it possible to remove the fence from the router
table top and later return it to the same position, comprising: a
section of rod penetrated by a slot within which an edge of the
router table top may be received and a screw threaded into an
axial, threaded hole in one end of the rod section so that an end
of the screw may be tightened against a surface of the router table
top when the edge of the router table top is received within the
slot.
24. A router table fence for use with a router table top,
comprising: (a) a top spar and (b) two bottom spars, each of which
spars: (i) has a top face, bottom face and two side faces and (ii)
is fabricated of extruded aluminum having a generally square
cross-sectional shape with a laterally centered, longitudinal
T-shaped slot in each face, and (iii) first structure on a first
face of one of the spars for engagement with second structure on an
opposite face of another of the spars so that the one spar can
slidingly engage the other spar with at least a second face of the
one spar maintained in substantially the same plane as a second
face of the other spar.
25. The router table fence of claim 24, wherein the first structure
comprises a pair of longitudinal ribs and the second structure
comprises a second pair of longitudinal ribs in a position
laterally offset from the first pair of ribs.
26. A method of accurately positioning a router table fence on a
router table top relative to a router cutter protruding above the
router table top, comprising the steps of: (a) fixing the router
table fence in a first approximately correct position on the router
table top with fence locks that attach to the fence and table top
on opposite sides of the table, (b) taking a first test cut in a
workpiece by passing a portion of the workpiece through the
revolving router cutter while maintaining the workpiece in sliding
contact with the fence, (c) positioning a micro-adjust fence stop
against the front or back of the fence at one edge of the router
table top (d) loosening the fence lock adjacent to the one edge of
the router table top, (e) measuring on the workpiece a distance the
fence position needs to move relative to the router cutter, (f)
using the micro-adjust stop to reposition the fence contacting the
micro-adjust stop by twice the distance, and (g) tightening the
fence lock adjacent to the one edge of the router table top.
.Iadd.
27. The router table fence of claim 1, wherein in use substantially
the entire top spar is positioned higher above a router table than
the bottom spars..Iaddend..Iadd.
28. The router table fence of claim 1, wherein in use the bottom
spars rest on a router table and the top spar rests on the bottom
spars and does not contact the router table..Iaddend..Iadd.
29. The router table fence of claim 1, wherein the top spar is
positioned substantially entirely above the two bottom
spars..Iaddend..Iadd.
30. The router table fence of claim 29, wherein the bottom spars
each have a top face substantially orthogonal to the bottom spar
front faces, and the top spar has a bottom face substantially
orthogonal to top spar front face, wherein the top faces of the
bottom spars and the bottom face of the top spar engage so that the
bottom spars can slide relative to the top spar..Iaddend..Iadd.
31. The router table fence of claim 30, wherein the bottom face of
the top spar comprises at least one rib and the top face of each of
the bottom spars comprises at least one depression, wherein the at
least one rib fits into the at least one depression of each bottom
spar..Iaddend..Iadd.
32. The router table fence of claim 30, wherein the bottom face of
the top spar comprises at least one depression and the top face of
each of the bottom spars comprises at least one rib, wherein the at
least one rib of each bottom spar fits into the at least one
depression of the top spar..Iaddend..Iadd.
33. The router table fence of claim 30, wherein the top face of
each bottom spar comprises a slot and the connectors comprise at
least two screws, wherein each screw is positioned at least
partially through the top spar and substantially parallel to the
front face of the top spar and protrudes from the bottom face of
the top spar and is positioned in the slot in the top face of one
of the bottom spars..Iaddend..Iadd.
34. The router table fence of claim 1, wherein each of the spars is
an extrusion..Iaddend..Iadd.
35. The router table fence of claim 1, wherein each of the spars is
aluminum..Iaddend..Iadd.
36. The router table fence of claim 1, wherein each of the spars is
substantially the same width..Iaddend..Iadd.
37. The router table fence of claim 1, further comprising a plastic
end cap attached to an end of at least one spar..Iaddend..Iadd.
38. The router table fence of claim 37, wherein the cross-sectional
shape of the at least one spar forms a slot having an arcuate wall,
wherein the plastic end cap is attached to the end of the at least
one spar by at least one screw received in the
slot..Iaddend..Iadd.
39. The router table fence of claim 1, wherein the fence has a back
side and separation of the opposed ends of the two bottom spars by
a selected distance defines an opening between the opposed ends of
the two bottom spars through which workpiece chips and dust may be
removed from the back side of the fence..Iaddend..Iadd.
40. The router table fence of claim 39, further comprising a dust
chute attachable to a vacuum positioned at the opening on the back
side of the fence..Iaddend..Iadd.
41. The router table fence of claim 1, wherein the each of the
bottom spars further comprises a back face and the top spar further
comprises a back face and a top face, wherein each of the bottom
spar front and back faces and the top spar front, back, and top
faces has a longitudinal tee slot therein..Iaddend..Iadd.
42. The router table fence of claim 1, further comprising a safety
shield for attachment to the top spar, wherein the safety shield
comprises a substantially transparent shield
member..Iaddend..Iadd.
43. The router table fence of claim 1, further comprising a first
structure on a first face of one of the bottom spars for engagement
with a second structure on an opposite face of the top spar so that
the bottom spar can slidingly engage the top spar with at least a
second face of the bottom spar maintained in substantially the same
plane as a second face of the top spar, wherein each spar is
fabricated of extruded aluminum having a generally rectangular
cross-sectional shape..Iaddend..Iadd.
44. The router table fence of claim 1, wherein a contact surface
for a workpiece is associated with each of the two bottom spars,
and the two contact surfaces are alternatively positionable in the
same plane or in parallel planes..Iaddend..Iadd.
45. A router table fence for use with a router tab top, comprising:
a. two bottom spars, each fabricated of extruded aluminum having a
generally rectangular cross-sectional shape, each having
substantially the same width, and each comprising a front face, a
top face comprising at least one depression, and a back face,
wherein the front, top, and back faces of each of the two bottom
spars has a longitudinal tee slot therein; b. a top spar
substantially the entirety of which is positioned above the two
bottoms spars when the fence is in use, wherein the top spar has a
first length and is fabricated of extruded aluminum having a
generally rectangular cross-sectional shape and having a width
substantially the same as the width of each of the two bottom
spars, wherein the top spar comprises a front face, a top face, and
a back face, each face having a longitudinal tee slot therein and
wherein the top spar further comprises a bottom face having at
least one rib, wherein the at least one rib fits into the at least
one depression of each bottom spar so that the bottom spars can
slide relative to the top spar; and c. connectors for attaching the
bottom spars to the top spar so that: (i) the front faces of each
of the top spar and the two bottom spars are in substantially the
same plane and (ii) opposed ends of the two bottom spars may be
positioned either: (x) abutting, or (y) separated by a selected
distance to define an opening between the opposed ends of the two
bottom spars through which workpiece chips and dust may be removed
from a back side of the fence..Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates to router tables and fences for use with
router tables.
Because of their versatility, electric routers are very widely used
in woodworking, particularly in home and small commercial shops.
Such routers use a powerful electric motor in a housing to which
handles are attached for holding and manipulating the tool. The
motor shaft terminates in a collet adapted to receive the shank of
a router bit or cutter, and a base attaches to the housing and
surrounds the cutter so that a portion of the cutter may protrude
beyond the base, which bears against a workpiece during use of the
router. The position of the base is adjustable up and down parallel
to the rotating axis of the collet and cutter, and in plunge
routers the relative position of the base and router cutter can
change during use of the tool in order to "plunge" the cutter into
the workpiece. Electric routers are generally intended to be used
by moving the router relative to a stationary workpiece, with a
portion of the router base bearing against the workpiece.
Substantial additional versatility can be achieved by mounting a
router in an inverted position with the router cutter protruding up
through an opening in a relatively large, flat work surface to
provide, in effect, a shaper. With this arrangement, a workpiece
lying on top of the work surface can be manipulated relative to the
stationary router and a rotating router cutter, the position of
which does not move relative to the workpiece. Such router tables
are commercially available in a variety of configurations, and
numerous plans for homemade router tables are also available.
Many commercially available router tables are provided with fences,
and fences for both commercial and homemade router tables are
frequently made by users by clamping or otherwise fixing a length
of wood to the router table top. Because most router table
operations using a fence require that only a portion of the router
cutter protrude beyond the face of the fence, provision typically
needs to be made for locating the fence at least partly around the
cutter. This is sometimes accomplished by machining a slot or
recess in the fence within which a portion of the cutter is
positioned.
Such shop-made fences, and many of the commercially manufactured
fences, suffer from a variety of deficiencies. For instance, many
are difficulty to position, reposition or adjust accurately. Some
have insufficient strength to resist deformation during use, and
many do not easily accommodate chip and dust removable accessories.
It is very typically desirable to use work hold-down and safety
shield accessories with router table fences, and many fences accept
attachment of such accessories only with difficulty, if at all.
It is thus among the objects of the present invention to provide a
router table fence that is straight, rigid, easily adjusted and
which accommodates good chip escape.
It is a further object of the present invention to provide a router
table fence that can be easily used in jointing a work surface.
It is another object of the present invention to provide a router
table fence that will easily accommodate a wide variety of
additional shop-made and commercially available accessories.
These and other objects of the present invention will become
apparent from the following description of the invention, the
accompanying drawings and the claims.
SUMMARY OF THE INVENTION
The router table fence of the present invention uses three nesting
extrusions or spars, two of which lie under a longer third spar. By
positioning the inner ends of the two lower spars adjacent to a
router cutter protruding through a router table, it is possible to
provide a fence, particularly when the lower spars are used with
wood facings, that can be adjusted to closely surround the cutter.
Lateral movement of the fence assembly adjusts the amount of cutter
that contacts a work piece manipulated past the cutter while
contacting the fence.
The cross sectional shapes of the spars are typically identical and
are generally square, with structure that permits the upper, longer
spar to rest on top of, and be attached in a manner permitting it
to slide against, the lower two spars. Tee-shaped slots in each
face of the spars accept fasteners that connect the spars together.
Such tee-shaped slots also accept fasteners for a variety of
accessories, such as hold-down devices and shields. Fence locks
attach the fence to a variety of router table tops without the need
for fence-receiving structures separately attached to the router
table or table top. The fence locks of the present invention can be
used for many top thicknesses but work particularly well with thin
tops.
A micro-adjust stop can be used in cooperation with the fence locks
to make very accurate and predictable adjustments in the position
of the fence on a router table top.
Wood sub-fences attached to the lower fence spars can be cut by a
router cutter to fit very closely around the profile of the cutter
to facilitate chip removal and to reduce tear-out in the work
piece. By using a shim behind one of the sub-fences in order to
position it parallel to, but slightly offset from, the other
sub-fence, it is possible to joint a surface of a board using a
"straight" cutter.
Among the shields easily attached to the fence of the present
invention is one that can be formed from a single sheet of suitable
plastic like polycarbonate or acrylic with a 90.degree. bend
joining a semicircular (horizontal) portion that lies above the
router cutter in use to a rectangular (vertical) portion with two
screw-receiving vertical slots for receiving screws that are
threaded into nuts within one of the fence tee-shaped slots to
mount the shield where needed. The shield can be mounted directly
against the fence when the cutter being shielded is in that
location. In other instances, particularly where wood sub-fences
are used, longer screws can pass through the shield and then
through stand-offs that position the shield at a desirable location
(above the router cutter) away from the fence.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the front and left end of the
router table fence of the present invention, shown positioned on a
router table top.
FIG. 2 is a perspective view of the rear and right end of the
router table fence of the present invention, also shown positioned
on a router table top together with the micro-adjust fence
positioning stop of the present invention.
FIG. 3 is a top plan view of the fence of the present invention
shown on a router table top and with two fixed stops and the dust
chute of the present invention; FIG. 3A is a top plan view similar
to FIG. 3 illustrating use of the micro-adjust fence positioning
stop; and FIG. 3B is a fragmentary, enlarged view of the fence of
the present invention in the vicinity of the router cutter.
FIG. 4 is an elevation view of the right end of the router table
fence of the present invention together on a router table top with
the micro-adjust fence stop of the present invention.
FIG. 5 is a top plan view of the micro-adjust fence stop shown in
FIG. 4.
FIG. 6 is a rear elevation view of a fixed fence stop of the
present invention shown on a router top edge fragment together with
a fragment of the fence.
FIG. 7 is a perspective view of a portion of the face of the fence
of the present invention showing a fence-mounted safety shield
mounted directly to the fence.
FIG. 8 is a perspective view of a portion of the face of the fence
of the present invention with wood sub-fences mounted in place and
the safety shield shown in FIG. 7 shown positioned away from the
fence with spacers.
FIG. 9 is a perspective view of a portion of the face and top of
the fence of the present invention shown with a work hold-down
mounted thereon.
DETAILED DESCRIPTION OF THE DRAWINGS
The router table fence system 10 of the present invention is
illustrated in front and rear perspective views in FIGS. 1 and 2,
respectively. The system 10 includes a fence 12, micro-adjust stop
14, fixed stop 16, and dust chute 18. The figures illustrate use of
the system on a relatively thin router table top 42 that is
typically steel.
A safety shield 100 is shown mounted directly to the fence 12 in
FIG. 7 and spaced away from fence 12 in FIG. 8. A hold-down
assembly 120 is illustrated mounted on fence 12 in FIG. 9.
As is illustrated in FIGS. 1, 2 and 4, fence 12 includes an
extruded aluminum upper spar 20, extruded aluminum lower spars 22
and 24, two fence locks 26, sub-fences 28 and 30, and jointing
spacers 33.
As will be appreciated by reference to FIG. 4, the cross-sectional
shapes of upper spar 20 and lower spar 22 are identical. Each spar
20 and 22 is generally a rectangle in cross-section, having four
sides, opposed pairs of which are equal. As illustrated in the
figures all sides of the cross-sectional shape of the spars 20 and
22 may be substantially equal, resulting in a square cross-section.
A longitudinal T-slot is centered in each of the four faces of the
spar. Each spar, 20 and 24 also has two upstanding ribs 34.
Upstanding ribs 34 on the top of the lower spars 22 and 24 that are
received in longitudinal slots or depressions 36 in the bottom of
upper spar 20, so that lower spars 22 and 24 may slide
longitudinally relative to each other while maintaining vertical
alignment with upper spar 20.
Screws 38 having a long rod-shaped head connect the upper spar 20
to lower spars 22 and 24 by passing through spar 20 and into nuts
39 located in the upper T-slot 32 in spars 22 and 24.
Plastic end caps .[.(not shown).]. .Iadd.41 (FIGS. 1 and 2)
.Iaddend.on the ends of the spars prevent T-nuts from falling out
of T-slots 32 and seal the lower spars 22 and 24 to improve dust
removal.
As will be appreciated by reference to the figures, particularly
FIG. 2, the ability of lower spars 22 and 24 to move toward or away
from each other permits upper spar 20 and lower spars 22 and 24 to
be positioned in a variety of desirable locations relative to a
router cutter 40, including locations where a portion of the cutter
40 is surrounded by the fence 12.
Fence 12 is locked in position on a router table top 42 by fence
locks 26 that have a cross-sectional shape permitting a head 44 of
fence lock 26 to be received in a T-slot 32 on the bottom of one of
lower spars 22 or 24. A foot 46 of fence lock 26 protrudes under
router table top 42 and carries a threaded rod 48, preferably
brass, to which a gyratory handle 49 is attached in order to rotate
threaded rod 48 in order to press its tip 51 against the underside
of table top 42.
Fixed stops 16 may be used to establish the position of fence 12 in
order to make it possible to remove fence 12 and later return it to
exactly the same position. Each fixed stop 16 is essentially a
section of round rod 50 penetrated by a slot 52 that fits around an
edge of router table top 42. An axial threaded hole receives a
screw 54 with a knurled head 56.
Accurate adjustment of the position of fence 12 may be accomplished
with the assistance of micro-adjust stop 14, which is shown in side
elevation and top plan views in FIGS. 4 and 5, respectively. In
order to accomplish such adjustment, one end of fence 12 is fixed
in position by locking the associated fence lock 26, and the other
end of the fence is located in approximately the desired position.
Micro-adjust stop 14 is then positioned on the edge of table top 42
with micro-adjust stop screw 58 end 60 in contact with the rear
face 62 of fence 12.
Micro-adjust stop 14 includes a stop body 64 that is locked in
position on an edge of router table top 42 with knurled head screw
66. Body 64 is penetrated by screw 58, preferably brass, that has a
conical or round end 60 for contact with face 62 of the fence and,
on the other end, a knurled knob 68 a barrel 70 marked with a ring
72 to establish lateral position and rotational position marks 74.
A reference cursor 78 that may be a piece of acrylic or other clear
plastic extends from body 64 over barrel 70. Cursor 78 has a
longitudinal mark 80 and hash marks 82 transverse to longitudinal
mark 80 which are separated from each other by 0.100 inches.
The thread on screw 58 is a double-start, twenty turns per inch
thread, so that one complete revolution of screw 58 advances it by
0.100 inches. With the remote end of the fence 12 clamped in
position, the center point of the fence (adjacent to the router
cutter 40) will move 0.050 inches when the micro-adjust screw 58 is
rotated one revolution and therefore moves by 0.100 inches the face
62 of fence 12 against which screw 58 end 60 bears. Barrel 70 is
not threaded into screw 58 but rather can rotate or "float" on
screw 58. Barrel 70 is held in position by a bent washer 71 between
the barrel 70 and knurled head 68 and by a knurled nut 65. This
permits barrel 70 to be rotated in order to "zero" it after contact
with fence surface 62 is established. Each full rotation of screw
may be read from the barrel 70 and cursor 78 markings as 0.050
inches of movement of the fence relative to cutter 40 at cutter
40.
Wood sub-fences 28 and 30 are typically used with fence 12 by
fixing them to the appropriate face of each of lower spar 20 and
22. By sliding the sub-fences 28 and 30 toward cutter 40, when
cutter 40 is rotating, the cutter 40 will cut the ends of the
sub-fences 28 and 30 so that a "zero-clearance" relationship is
established between the cutter and sub-fences 28 and 30. This
reduces workpiece 90 tear-out, and also facilitates dust ejection
by causing most of the material removed from workpiece 90 be
ejected between the opposed ends of lower spars 20 and 22.
Such dust may be gathered with dust chute 18, which includes a
generally rectangular housing 84 that may be conveniently
positioned on ferrous metal router table top 42 with powerful rare
earth (such as neodymium-iron-boron) magnets located on the bottom
86 of housing 84. Housing 84 attaches to a tubular extension 88, to
which a dust removal system or vacuum cleaner may be attached.
Alternatively, a short hose or length pipe may be attached to
tubular extension 88 and terminated in a dust bin. With such an
arrangement and positioning of sub-fences 28 and 30 as described
above, most material removed from workpiece 90 will be driven into
the receiving bin.
As will be appreciated by those skilled in the art, in many routing
or shaping operations, including, in particular, formation of
ornamental edges on workpieces, sub-fences 28 and 30 should
desirably be located in the same vertical plane. However, by
positioning the surface of infeed sub-fence 30 within the cutting
radius of a straight cutter 40, as shown in FIG. 3B, and
positioning the surface of outfeed sub-fence 28 in alignment with
the same cutting radius of cutter 40, it is possible to use the
router table fence system 10 of the present invention for edge
jointing. As will be appreciated by one skilled in the art by
reference to FIG. 3B in particular, this will result in removal
from a workpiece of a small amount of material and will provide an
appropriately positioned outfeed reference surface.
In the present invention, such relative positioning of the
sub-fences 28 and 30 may be rapidly and accurately accomplished by
dropping a jointing spacer 33 (shown in FIG. 1 exploded away from
the system 12) into position between outfeed sub-fence 28 and lower
spar 24. Jointing spacers 33 may be made of a variety of materials
and in a variety of thicknesses. The materials may include wood,
metal and plastic. As can be seen in FIGS. 3 and 3B the amount of
material removed from a workpiece in such a joining operation is
established by the thickness "y" of the jointing spacer 33.
FIG. 7 illustrates safety shield 100 affixed directly to the front
face 102 of fence 12 by passing screws 104 through washers 105 and
vertical slots 106 in the vertical arm 108 of shield 100 and into
T-nuts 110 received in a T-slot 32. This fixes vertical arm 108 of
shield 100 directly against the front face 102 of fence 12 so that
horizontal arm 112 of shield 100 extends horizontally out from the
front face 102 of fence 12 above a router cutter (not shown)
positioned immediately adjacent to fence 12 (or partially
surrounded by fence 12). Safety shield 100 may be made of
polycarbonate or acrylic plastic or a variety of other suitable
materials, although transparent materials are preferable.
When safety shield 100 is used with fence 12 with sub-fences 28 and
30 (or the cutter is for some other reason spaced out from the
front face 102 of fence 12), stand-off spacers 114 may be used with
longer screws 116 as illustrated in FIG. 8 to appropriately
position shield 100.
A hold-down assembly 120 may be easily positioned on fence 12 by
affixing the body 122 to the top 124 of fence 12 by passing body
cap screw 126 through body 122 and in to a tee-nut 110 in the
T-slot 32 on the top 124 of fence 12, as illustrated in FIG. 9.
Body 122 grasps two arms 128 and 130, each of which are round rods.
Top spring arm 128 grasps, in a slot 132 in one end of arm 128, a
top spring 134, which is a leaf spring having a curved end 136
positioned to press against the top of a workpiece (not shown) to
urge it against the router table top 42. Arm 128 may be rotated
within body 122 to increase or decrease the pressure exerted on a
workpiece by spring 134.
Side spring arm 130 is also held within body 122 by positioning arm
130 in a bore 123 through body 122 and fixing it in position with a
forward cap screw 127 threaded into body 122 to press against arm
130, permitting arm 130 to be moved in a direction normal to the
front face 102 of fence 12. Side spring arm 130 has a transverse
bore 138 that receives side spring post 140, which is fixed in
position with a post screw 142 threaded into the end of arm 130 so
that it intersects bore 138 and presses against post 140. Side
spring 144 is fixed in a slot 146 in the lower end of post 140.
Side spring 144 is a leaf spring similar to top spring 134, and it
has a similar curved end 148 that is positioned to press against
the side of a workpiece (not shown) opposite the front face 102 of
fence 12 to thereby maintain constant contact between the fence and
the workpiece during machining of the workpiece.
The router table fence and accessories of the present invention are
not confined to the embodiments described herein but include
variations and modifications within the scope and spirit of the
foregoing description, the accompanying drawings and the following
claims.
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