U.S. patent application number 10/442709 was filed with the patent office on 2003-10-23 for router table joint making machine.
Invention is credited to Hyde, Brent K., Tucker, Edwin C..
Application Number | 20030196726 10/442709 |
Document ID | / |
Family ID | 26838020 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030196726 |
Kind Code |
A1 |
Tucker, Edwin C. ; et
al. |
October 23, 2003 |
Router table joint making machine
Abstract
A machine for use with a table-mounted router to form a wide
variety of woodworking joints by manipulating a workpiece to engage
the router cutter in predetermined locations, in some instances by
reference to a joint element template, and in other instances by
reference to predetermined lateral locations, to form joint
elements with predetermined shapes and spacing.
Inventors: |
Tucker, Edwin C.; (Ottawa,
CA) ; Hyde, Brent K.; (Ottawa, CA) |
Correspondence
Address: |
JOHN S. PRATT
KILPATRICK STOCKTON LLP (LEE VALLEY TOOLS LTD.)
1100 PEACHTREE STREET
SUITE 2800
ATLANTA
GA
30309
US
|
Family ID: |
26838020 |
Appl. No.: |
10/442709 |
Filed: |
May 21, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10442709 |
May 21, 2003 |
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09990202 |
Nov 21, 2001 |
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6588468 |
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09990202 |
Nov 21, 2001 |
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09595742 |
Jun 16, 2000 |
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60140254 |
Jun 18, 1999 |
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Current U.S.
Class: |
144/372 ;
144/145.2; 144/87 |
Current CPC
Class: |
B27F 1/12 20130101; B23Q
3/005 20130101 |
Class at
Publication: |
144/372 ; 144/87;
144/145.2 |
International
Class: |
B27F 001/00; B27C
005/00; B27M 001/08; B27M 003/00; B27C 009/00 |
Claims
1. An apparatus for use with a router to cut woodworking joints,
comprising: (a) an elongated center guide for positioning relative
to the router, (b) a lower fence for sliding along the center guide
while positioned transverse to the direction of such sliding
motion, (c) an upper fence for sliding or fixed attachment to the
lower fence, (d) a clamp for securing a workpiece to the upper
fence, (e) a spacer tray for holding spacers and for attachment to
one of the upper fence or the lower fence, (f) a control block for
selectively fixing the position of the upper fence relative to the
lower fence by reference to the spacers.
2. The apparatus of claim 1, further comprising a tracer pin for
fixed positioning relative to the router, and at least one template
for alternative positioning relative to the upper fence for
controlling movement of the upper fence relative to the router by
moving the upper fence while maintaining contact between the
template and the tracer pin.
3. The apparatus of claim 1, wherein the tracer pin has a template
contact surface, the contact surface is conical, and a pin jack for
adjusting the height of the tracer pin relative to the template so
that different portions of the conical contact surface can be made
to contact the tracer.
4. The apparatus of claim 1, wherein the spacer tray comprises an
elongated channel within which multiple spacers, each containing at
least one index pin hole, may be locked.
5. The apparatus of claim 1 wherein the spacer tray comprises
structure having a plurality of locator holes.
6. The apparatus of claim 1, wherein the spacer tray may be locked
within the upper fence.
7. The apparatus of claim 1, further comprising an indexing pin
attached to the control block for contact with selected
spacers.
8. The apparatus of claim 1, further comprising a locking pin for
engagement between the control block and the upper fence to
selectively secure the control block to the upper fence.
9. The apparatus of claim 1, further comprising a lock for
selectively securing the control block to the upper fence.
10. The apparatus of claim 1, further comprising an auxiliary fence
attachable to project at a right angle to the upper fence.
11. The apparatus of claim 1, further comprising a stop secured to
the center guide to limit travel of the lower fence.
12. The apparatus of claim 1, further comprising an adjustable stop
secured to the center guide to limit travel of the lower fence.
13. An apparatus for use with a mounted router and router cutter to
cut woodworking joints, comprising: (a) a joint element template,
and (b) a workpiece holder for securing a workpiece and moving the
workpiece to engage the router cutter and sequencially form at
least two joint components on the workpiece, each by reference to
the template.
14. The apparatus of claim 13, further comprising a spacing
apparatus for sequentially positioning the template in multiple
positions relative to the workpiece.
15. An apparatus for use with a router to cut woodworking joints,
comprising: (a) a guide for positioning relative to the router, (b)
a first structure for sliding along the guide along a first axis,
(c) a workpiece holder for attachment to the first structure
alternatively fixed or for sliding along a second axis orthogonal
to the first axis.
16. The apparatus of claim 15, wherein the workpiece holder
comprises a clamp.
17. The apparatus of claim 15, further comprising a spacer
apparatus for positioning the workpiece holder relative to the
first structure.
18. The apparatus of claim 17, wherein the spacer apparatus
comprises: (a) a spacer tray for holding spacers and for attachment
to one of the workpiece holder or the first structure, and (b) a
control block for selectively fixing the position of the workpiece
holder relative to the first structure by reference to the
spacers.
19. The apparatus of claim 18, wherein the spacer tray comprises an
elongated channel within which multiple spacers, each containing at
least one index pin hole, may be locked.
20. The apparatus of claim 18, further comprising an indexing pin
attached to the control block for contact with selected
spacers.
21. The apparatus of claim 17, wherein the spacer apparatas may be
locked within the workpiece holder.
22. The apparatus of claim 15, further comprising a tracer pin and
at least one template, one of which pin and template may be fixed
in position relative to the router, and the other of which pin and
template may be fixed in position relative to the workpiece holder
for controlling movement of the workpiece holder relative to the
router by moving the workpiece holder while maintaining contact
between the template and the pin.
23. The apparatus of claim 22, wherein the tracer pin has a
template contact surface, the contact surface is conical, and
further comprising a pin jack for adjusting the position of the
tracer pin relative to the template so that different portions of
the conical contact surface can be made to contact the tracer.
24. The apparatus of claim 17, further comprising a locking pin for
engagement between the control block and the first structure to
selectively secure the control block to the first structure.
25. The apparatus of claim 17, further comprising a lock for
selectively securing the control block to the workpiece holder.
26. The apparatus of claim 15, further comprising an auxiliary
fence attachable to project from the workpiece holder parallel to
the guide.
27. Apparatus for use with a router cutter for shaping a wood
workpiece comprising: (a) a tapered pin for fixing relative to one
of the cutter or the workpiece; and (b) a fixture for securing a
pattern relative to the other of the workpiece or the cutter for
contact between the pattern and the pin during use of the
apparatus.
28. Apparatus for use in cutting wood using a rotating cutter,
comprising a workpiece holding structure movable so that the
workpiece can move laterially and longitudinally relative to the
cutter but cannot rotate.
29. Apparatus for use in cutting wood, comprising a workpiece
holding structure for permitting movement of a first workpiece only
longitudinally at a plurality of predetermined lateral
positions.
30. The apparatus for use in cutting wood of claim 29, further
comprising structure for permitting movement of a second workpiece
in a predetermined pattern at each of the plurality of
predetermined lateral positions.
31. An apparatus for cutting wood with a router bit, comprising
structure for permitting movement of a workpiece along two
orthogonal axes while preveinting movement along or rotation about
any axis orthogonal to the first and second axes.
32. The apparatus of claim 31, further comprising engagement
structure for constraining the first workpiece to move only
longitudinally at a plurality of predetermined lateral
positions.
33. The apparatus of claim 31, further comprising pattern and
follower structure for constraining a second workpiece to move
outside a predetermined shape at each of the plurality of
predetermined lateral positions and thereby remove material from
the second workpiece to leave workpiece material having at least a
portion of the predetermined shape.
34. A method for cutting workpieces using a router and router
cutter in order to form a woodworking joint joining the workpieces,
comprising: (a) securing an elongated guide relative to the router,
(b) securing a first workpiece to a first component, (c)
positioning the first component laterally relative to the guide by
reference to a first spacer, (d) sliding the first component and
workpiece along the guide to engage the router cutter at a first
position on the workpiece, (e) repositioning the first component
laterally relative to the guide by reference to a second spacer,
and (f) sliding the first component and workpiece along the guide
to engage the router cutter at a second location on the
workpiece.
35. The method of claim 34, further comprising: (a) securing a
tracing pin in a fixed position relative to the router, (b)
securing a template to the first component by reference to one of
the spacers, (c) securing a second workpiece to the first component
and moving the first component and workpiece to engage the router
cutter while maintaining contact between the tracing pin and the
template, and (d) repositioning the template relative to the first
component by reference to another of the spacers and moving the
first component and workpiece to engage the router cutter while
maintaining contact between the tracing pin and the template.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 09/595,742, filed Jun. 16, 2000, which claimed
priority to U.S. provisional application serial No. 60/140,254,
filed Jun. 18, 1999, each of which applications are incorporated
herein by this reference.
FIELD OF THE INVENTION
[0002] This invention relates to methods and apparatus for forming
woodworking joints, especially dovetail and similar joints, and it
relates more particularly to devices and techniques for enabling
such joints to be cut utilizing a router.
BACKGROUND
[0003] Wooden boxes, drawers and storage chests and a variety of
other wooden furniture and other objects often use dovetail joints
as a means of securely assembling the sides. Dovetails are used for
both their decorative nature and their high strength. Such joints
can be made without industrial machinery in one of two principal
ways, either using hands tools: saws and chisels, or using power
tools such as a router. In both cases, making such a joint requires
a high degree of skill and precision, and in the case of hand
tools, time. The desire to save time drives most woodworkers
towards the use of power tools, and the need for precision, often
in the relative absence of skill, makes jigs or machines that
control the power tools desirable.
[0004] There are two basic approaches possible when using a router.
The router can be held stationary and the workpiece moved relative
to the position of the router cutter, or the workpiece can be held
stationary and the router moved relative to the workpiece.
Additionally, in a variation of both basic approached, both the
router and the workpiece can be moved.
SUMMARY OF THE INVENTION
[0005] This invention is a machine that facilitates cutting of
dovetail and other joints such as box joints using an approach in
which the position of the rotating router cutter is maintained
stationary and the workpiece is moved relative to the cutter. The
machine is typically used with a router mounted upside down in a
router table so that the router bit or cutter protrudes through a
hole in the tabletop. Such a table is disclosed, for instance in
U.S. Pat. No. 5,715,880, but this invention is usable with a wide
variety of other router tables.
[0006] The machine of this invention utilizes an elongated track
called a guide that is clamped or otherwise fastened to the router
tabletop. Typically, this guide will be positioned so that a router
bit or cutter mounted in a router attached to the router table
protrudes through the hole in the guide, making it a "center
guide." A lower fence assembly positions a lower fence transverse
to the center guide with base wings attached to the lower fence and
contacting either side of the center guide so that the lower fence
can slide along the center guide and across the router cutter,
which passes through an opening in the lower fence. The opening may
be filled with sacrificial material such as wood or ultra high
molecular weight ("UHMW") polyethylene. An upper fence that
controls the lateral position of a workpiece slides along on the
top of the lower fence and can be locked (using a control block and
locks associated with it) in position relative to the lower
fence.
[0007] The position of the upper fence relative to the lower fence
can be fixed by reference to predetermined stops positioned by the
user in a spacer tray (or, alternatively, the user may make a
spacer stick) that is locked in the upper fence. The locations of
the stops determines the spacing of joint components and controls
movement of the machine components so that joint components are
formed in the desired locations on workpieces. In some aspects of
operation, such as when pins in through dovetail or finger joints
are formed, the upper fence is permitted to slide relative to the
lower fence during use of the machine.
[0008] Except when making half-blind dovetail tails, the machine
functions by clamping a workpiece against one face of the upper
fence so that the workpiece stands upright with its end resting
against machine wings that in turn rest just above the table top.
The lateral position of the upper fence (and therefore the position
of the workpiece clamped to it) is determined by interaction among
a control block, the upper fence and the lower fence.
[0009] The control block can slide along the upper fence or can be
locked to prevent such sliding motion. Alternative positions at
which the control block is locked to the upper fence are determined
by engagement between an indexing pin attached to the control block
and holes in spacers positioned in the spacer tray (or holes in a
user-made spacer stick), which tray (or stick) is locked into the
upper fence during use of the machine. The control block can also
be locked to the lower fence so that the relative positions of the
upper and lower fences may be secured in a manner limiting or
eliminating play between the two fences.
[0010] "Tails," such as the tails in a dovetail joint, are cut by
locking the control block to both the upper fence and the lower
fence, which locates the upper fence in selected predetermined
positions relative to the lower fence and prevents sliding movement
between the two fences, thereby fixing the lateral position of the
workpiece relative to the router cutter. The workpiece clamped to
the upper fence is then passed around a router cutter having an
appropriate shape, such as a dovetail-shaped cutter, by sliding the
workpiece and upper and lower fence assembly along the center
guide. The cutter exits the workpiece in a space in the lower fence
that may be filled with a replaceable block of ultra high molecular
weight polyethylene or other sacrificial material. The upper fence
is then repositioned to the next predetermined position by
unlocking the two fences and moving the upper fence so that the
indexing pin can be received in another hole in the spacers in the
spacer tray (or in the spacer stick), and a second cut is made.
Multiple tail boards or workpieces can be cut simultaneously,
limited only by the size of the machine and its capacity to hold
workpieces.
[0011] "Pins," such as pins in a dovetail joint, are cut by
mounting on the underside of the control block a template having
the shape and, typically, nominal size of each pin to be cut. The
control block is locked to the upper fence, but that fence is
permitted to move relative to the lower fence, allowing the
workpiece to move in two directions: (1) laterally relative to the
cutter, and (2) forward along the center guide and into the cutter
as described above. The workpiece clamped to the upper fence is
then forced into the router cutter while the template is rubbed
against a tracer pin located in a tracer pin jack secured to the
center guide, for instance, by screwing a threaded pin jack base
into a threaded hole in the center guide. Contact between the
tracer pin and template allows material to be cut away from the
workpiece except where the workpiece pin is desired. After
formation of a pin in one desired location on the workpiece by
removing the adjacent waste, the control block is repositioned on
the upper fence by moving the indexing pin to another hole in the
spacer tray, and the operation is repeated to form another pin at
another desired location. Since lateral positioning of the upper
fence is controlled in each instance by the spacer in the same
spacer tray (or hole in a spacer stick), joint pins and tails are
formed in the same locations.
[0012] The tracer pins have a conical shape and are used in
multiple sizes to make possible a wide range of joint component
sizes. The height of each tracer pin relative to the router
tabletop and the template is adjustable using the pin jack. This
makes possible adjustments in the size of joint pins produced using
a particular template, because changes in tracer pin height change
the effective diameter of the tracer pin in contact with the
template.
[0013] Joint tails in half-blind dovetail joints are cut with the
tail-containing workpiece face down on the wings that lie just
above the router table top. The lower fence is fixed in place on
the router tabletop, or a stop is utilized to fix lower fence
travel along the center guide, to thereby limit the distance the
dovetail cutter enters the workpiece as the workpiece travels
against the cutter. An auxiliary fence is secured to the upper
fence projecting at a right angle from the upper fence (parallel to
the center guide). With the upper fence positioned relative to the
lower fence with the indexing pin in one of the spacer holes as
described above, the workpiece is slid along the auxiliary fence
and into the dovetail cutter and then back out. Alternatively, if
the lower fence is permitted to move until it reaches a stop, the
workpiece is positioned against the auxiliary and lower fences, and
the workpiece and fences are slid so that the cutter enters the
workpiece until the stop is reached. The upper fence is then
relocated by moving the indexing pin to another spacer hole, and
the workpiece is again slid along the auxiliary fence and into the
dovetail cutter, or the workpiece and fences are slid as described
above, to make a second and subsequent cuts.
[0014] The track or guide and fence components can be made of
extruded aluminum, and most of the other components can be made of
a variety of metals, including steel, brass, and aluminum as well
as other materials, including plastics and other materials.
[0015] The machine and techniques of this invention facilitate
cutting the most common joints, through dovetail, half-blind
dovetail and finger joints. The machine can also cut rounded finger
joints, double-sided rounded finger joints, double sided dovetails
and rounded dovetails. FIG. 21 illustrates some of these joints.
With appropriately shaped cutters and templates other joint shapes
are also possible. Because it is necessary to have only one
template for a particular joint shape, it is practical for the user
of the joint-making machine of this invention to make templates and
create joints in any desired shape within the broad range of shapes
possible. It also makes it economical for a user to purchase
alternative templates because only one is need for any desired new
shape (within certain size limits for that shape).
[0016] This invention therefore provides a versatile joint making
machine for use with a router to make woodworking joints. This
invention is accurate, easy to use, and easy to set up for making a
wide range and variety of different joints with user selected
spacings of joint elements. Other advantages and benefits of this
invention will be apparent to those skilled in the art from the
drawings and the following description of the invention and claims.
For instance, the capabilities of this invention can be used not
only for creating joints but for creating repeating patterns in
items such as moldings, an operation that may be facilitated by use
of an apparatus controlling vertical positioning of the router bit
so that it can be lifted through the router table into the
workpiece when desired. Such a device for controlling the vertical
position of the router bit is disclosed in U.S. Pat. No. 5,918,652,
which is incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of the joint making machine of
this invention shown mounted on a router table top.
[0018] FIG. 2 is an exploded perspective view of the principal
components of the joint making machine of this invention.
[0019] FIG. 3 shows the relationship among a dovetail tailboard,
pin board, cutter, and template of this invention.
[0020] FIG. 4 depicts a user made spacer and the spacer tray of
this invention and joint components made with the illustrated
spacers.
[0021] FIG. 5 is a perspective of the controller and pin jack of
this invention, together with portions of the upper and lower
fences, and with lower fence locking screws shown exploded away
from the control block.
[0022] FIG. 6 is an exploded perspective view of the lower fence
assembly shown in FIGS. 1 and 2.
[0023] FIG. 7 is a cross-sectional end elevation view illustrating
locking components of the upper and lower fences shown in FIGS. 1
and 2.
[0024] FIG. 8 is an exploded perspective view of the upper fence
assembly shown in FIGS. 1 and 2.
[0025] FIG. 9 is a top plan view of one end of the upper fence
shown in FIG. 1 with a spacer tray located in the fence and the
fence lock engaging the end spacer.
[0026] FIG. 10 is a perspective view of the of the opposite end of
the fence shown in FIG. 9 illustrating the clamp shaft nut and the
trough in the upper fence in which it seats.
[0027] FIG. 11 is an enlarged perspective view of the center guide
assembly shown in FIGS. 1 and 2.
[0028] FIG. 12 is a top plan view of a portion of the lower fence
and a portion of the center guide assembly illustrating the
function of a stop on the proximate end of the center guide
assembly.
[0029] FIG. 13 illustrates the effect of adjusting the height of
the tapered tracer pins of this invention.
[0030] FIG. 14 is a perspective view of the pin jack shown in FIGS.
1 and 2 with part of the pin jack body broken away.
[0031] FIG. 15 illustrates setting up the spacer tray.
[0032] FIG. 16 shows locking the spacer tray in the upper
fence.
[0033] FIG. 17 is an exploded perspective view of the auxiliary
fence components and their relationship to the upper and lower
fences.
[0034] FIG. 18 is a top plan view of the upper and lower fences
positioned on the center guide, with the auxiliary fence mounted
and the adjustable depth stop shown mounted on the center
guide.
[0035] FIG. 19 is a front elevation view showing the relationship
between a tapered pin and a template during use of this invention
to form a pin in a workpiece.
[0036] FIG. 20 is a cross-sectional view of the control block and a
portion of the upper fence show the manner in which the control
block locks to the upper fence.
[0037] FIG. 21 depicts exemplary joints made with the joint making
machine of this invention.
DETAILED DESCRIPTION
[0038] FIG. 1 illustrates an exemplary joint making machine 101 of
this invention mounted on a router table top 619, and FIG. 2
illustrates the machine 101 in an exploded perspective view. For
simplicity, threads are not shown in the drawings on all of the
components in the exemplary embodiment that are threaded.
[0039] Operating Principles
[0040] For joints including a pair of panel shaped workpieces, each
workpiece end can be classified as either a tailboard or a pin
board. Tailboards, such as tailboard 102 in FIGS. 21 and 3, result
from passing a cutter through (or at least into) the board in a
straight line leaving a void having the profile of the cutter. Pin
boards, such as pinboard 104 in FIGS. 21 and 3 are the result of
removing material from a workpiece except where a template prevents
material removal. Template shape determines the end or cross
sectional shape of the pin board pins. Template shape is directly
related to the shape of the cutter used producing the tailboards.
This principle is illustrated in FIG. 3, which shows use of a 7/8"
14.degree. dovetail cutter 302 with a dovetail-shaped template 304
with 14.degree. sides 306 and a nominal width 308 of 7/8". The
template (such as template 304) determines the shape of the
dovetail pins, and the dovetail cutter determines the shape of the
tails.
[0041] Spacers are used to determine where the centers of both the
pins and tails will be located. They can be spaced at regular
intervals or at variable intervals. As is illustrated in FIG. 4, a
spacer tray 402 with movable spacers 404 or a user-made spacing
stick 406 may be used to control the spacing. Because of the use of
spacers to determine the locations of each pair of complimentary
joint components, only one template is needed for formation of
multiple pins, such as pins 110, in each joint. This simplifies
template-making as compared to many conventional joint-making
machines in which the template has to have a separate element
corresponding to each joint element.
[0042] The controller 502 illustrated in FIG. 5 is the part of this
invention that controls what type of cut is made. The controller
502 comprises three main components, the indexing pin or screw 504,
which rides in the controller body 503, the template arm 506 and
the tracer pin jack assembly 307.
[0043] The indexing screw or pin 504 engages the spacers 404 in the
spacer tray 402 or the holes 408 in a user made spacing stick 406.
The location of the indexing screw 504 determines where the center
of each pin and tail is located in the workpieces.
[0044] The template arm 506 is used to hold the template 304 that
is used when cutting joint pins. The shape of the template is
driven directly by the shape of the cutter used to cut the
tailboards. Among other shapes, templates may be shaped for through
dovetail, half-blind dovetails and finger joints. Experienced users
may make their own templates.
[0045] The pin jack 307 is used in conjunction with the templates
to create the pin boards. The tracer pin 305 traces around the
template (or, more accurately, the template 304 traces around the
pin 305) forcing the cutter to follow an identical path and remove
waste, thereby forming the pins 110 on the pin board. One template
is used for all the pins 110 in a particular joint.
[0046] The Lower Fence Assembly
[0047] The lower fence assembly 602, shown exploded in FIG. 6,
provides the connection between the front-to-back motion and the
left-to-right motions required to control the compound cuts that
form the shaped pins.
[0048] Fence assembly 602 has two wings 604 and 606 that slide back
and forth along the center guide assembly 202 (described below).
Wings 604, 606 do not directly contact the router table top but
rather rest on the center guide rail 204 (as may be seen in FIG.
19) and the tips of nylon thumb screws 624 that are positioned in
threaded holes in the wings 604 and 606 or are otherwise secured to
protrude from the bottom of the wings, such as, for instance, by
positioning nuts above and below the wing 604 or 606. The upper
part 203 of the center guide assembly 202 fits in the gap between
the wings 604 and 606. The edge 608 of each wing that slides along
the center guide may be rounded over to minimize the contact area.
The width of the gap 610 between edges 608 of wings 604 and 606 is
controlled using the two mounting screws 612 for each wing 604 and
606. The position of the left wing 604 is fixed by shoulder screws
612. The right wing 606 is allowed to move slightly by using
oversize holes 616 in wing 606 through which cap screws 614 are
positioned. This permits adjustment of the distance and parallelism
between the two wings 604 and 606. Typically the play between the
wings and the center rail should be about 0.003". This can be set
using a sheet of paper between the components when tightening
screws 614 in holes 616.
[0049] The lower fence 618 has a cutout 620 into which an UHMW
polyethylene block 622 or other sacrificial material such as wood
is inserted. Two screws (not shown) may be inserted from the top of
the guide to secure the block 622. The purpose of block 622 is to
provide a backing for the workpiece to prevent tear out from the
router cutter. Additionally, if the UHMW block 622 is positioned
proud of the lower fence 618 and flush with the upper fence 702
face 730, friction between the workpiece and the lower fence 618
will be minimized at the same time that tear-out is reduced.
[0050] Each wing 604 and 606 has a nylon thumbscrew 624 at the ends
of the fence 618. The ends of screws 624 contact router table top
619 and prevent rocking on center guide 202.
[0051] As may be appreciated by reference to FIG. 7, a cross
section taken through the lower fence 618 and a portion of the
upper fence 702, lower fence 618 has a longitudinal recess or
trough 628 (also identified in FIG. 6). Trough 628 has a small
ledge 704 protruding from one trough 628 wall 706. Link block 630
is an elongated bar having (in the illustrated embodiment) a
rectangular cross-sectional shape. Link block 630 rests on ledge
704 and is attached to the lower fence 618 with cap screws 632 that
are inserted from the front of lower fence 618 (see FIG. 6). The
purpose of link block 630 is twofold. First, it prevents the upper
fence 702 from rotating about a vertical axis. Second, it holds the
link foot 708 and link screw 710.
[0052] The link foot 708 and link screw 710, are used to control
the sliding fit between the J-hook 712 of upper fence 702 and lower
fence 618. Driving in link screw 710 (clockwise with a right-hand
thread) forces down link foot 708, which is a turned brass part
containing a cutout, the profile of which matches the profile of
the link screw. A narrow portion of the link foot 708 passes
through a hole in the link block 630. A button 707 of nylon or
other appropriately low friction material is pressed into a hole in
the lower end of the link foot 708 to provide a low friction
bearing surface against the J-hook 712 in the narrower portion of
the block. When the link screw is driven in, this button is pressed
down against J-hook 712, and the sliding resistance between upper
fence 702 and lower fence 618 is increased and the play is reduced.
By retracting the link screw 710 (counter-clockwise with a
right-hand thread) the pressure exerted on J-hook 712 by link foot
708 is reduced, the play is increased and the resistance is
reduced. Link screw 710 should be adjusted such that there is
almost no resistance but also minimal play. On the back of the
lower fence 618 a nylon tipped setscrew 714 is used to apply
pressure on the upper fence 702 by pressing J-hook 712 against the
link block 630 of the lower fence 618.
[0053] The Upper Fence
[0054] Upper fence 702 (shown exploded in FIG. 8) serves as a
workpiece holder and couples the workpiece 902 with the
shape-controlling components of the machine. While upper fence 702
is denominated a "fence" because of its shape in the embodiment
illustrated in the drawings, it could have an entirely different
configuration and still serve its function as a workpiece holder.
The only practical limitation on the width of joints that can be
formed on the joint-making machine of this invention is the
capacity of the upper fence 702 to hold a workpiece. In the form of
upper fence illustrated as 702 in the drawings, the width of the
upper fence limits the width of joint possible, but other workpiece
holders could accommodate wider joints.
[0055] FIG. 8 illustrates the major components of the upper fence
702. As noted above, the upper fence 702, which may be conveniently
fabricated as an aluminum extrusion, has a J-hook channel 712
protruding from its underside that connects upper fence 702 to
lower fence 618.
[0056] Front 714 of upper fence 702 has a slot 716 that accepts
either the spacer tray 402 or a user-made spacing stick 406. The
spacer tray 402 is held in position using the spacer tray lock
718.
[0057] In order to keep the spacer tray 402 aligned with the actual
workpiece 902, the spacer tray lock 718 is connected directly to
the right clamp bar 719 shaft 720 via the spacer tray arm 722. The
arm 722 is held vertical by two flats 724 on either side of arm 722
that engage in a rectangular hole 727 in the upper fence 702.
[0058] Internally threaded clamp rings 726 secure the threaded
clamp bar shafts 720 and 728 to the upper fence 702. Clamp rings
726 also serve to position the workpiece 902 laterally relative to
upper fence 702. By sizing the diameter of the end spacers 410 the
same as the diameter of the clamp rings 726, alignment of the
workpiece 902 and spacer tray 402 are automatic. This is
illustrated in FIG. 9.
[0059] The spacer tray lock arm 722 and a clamp ring 726 secure the
right clamp shaft 720. As is shown in FIG. 10, the left clamp shaft
728 is held in place by the clamp shaft nut 738 and a second clamp
ring 726. To prevent the nut 738 from turning when the clamp ring
726 disc is tightened, two protrusions 740 from the nut 738 engage
in a small trough 735 in the upper fence 702.
[0060] As is illustrated in FIG. 9, the workpiece 902 is placed
between the vertical face 730 of the upper fence 702 and the clamp
bar 719. Workpiece 902 is slid to the right until it contacts the
clamp ring 726 opposite the spacer tray lock 718. Clamp bar 719
slides along the two clamp shafts 720 and 728, and is tightened
against workpiece 902 using the two clamp knobs 734.
[0061] The Center Guide Assembly
[0062] The center guide assembly 202 illustrated in FIG. 111 is the
interface between the rest of the components of this invention and
the router table with which it is used. The center guide assembly
202 utilizes a center guide 204 having a longitudinal tee-slot 206
on the underside of the guide 204. This slot 206 accepts a pair of
mini c-clamps 209 that are used to attach the guide to a thin
router table like the table disclosed in U.S. Pat. No. 5,715,880 or
other similar tables. Alternative fastening arrangements can be
made for securing the center guide assembly 202 to other router
tables.
[0063] Guide 204 has one relatively large hole 208 within which the
router bit (744 in FIG. 18) is positioned. This router bit hole 208
is centered relative to the collet of the router (not shown) as
part of the setup procedure.
[0064] A second, threaded hole 210 in guide 204 holds the pin jack
307 that is used with the templates such as template 304 when
forming pins. A rubber stop 212 is secured with a screw 214 on the
top at the front of guide 204 so that when the lower fence 618 is
pulled back (typically toward the user) during the cutting process,
it is stopped by contact between wing 606 and stop 212 before lower
fence 618 contacts the pin jack 307.
[0065] The Pin Jack
[0066] The pin jack 307 is used to support the tapered pins 305
that trace around the templates. The pin jack 307 can be used with
different diameters of tapered pins 305. Additionally, each pin 305
has an incremental range of diameters that can contact the template
310 made available by adjusting the height of the pin 305, as is
illustrated in FIG. 13. FIG. 13 illustrates that at three different
heights 309, 311 and 312, the portion of pin 305 contacting the
template 310 has a slightly different diameter, thus causing travel
around template 310 along different paths 314, 316 and 318,
changing the size of the dovetail pin cut and thereby controlling
the fit. Such adjustability can also be used to produce joint
members having a desired amount of clearance between members so
that inlays or the like can be inserted between joint members. If
the tapered pin 305 has a 14.degree. taper, that is equivalent to a
ratio of 1 to 4. Therefore, by raising such a tapered pin 305 four
units of distance, the center of the pin 305 moves away from the
template 310 one unit of distance. Since this happens on both sides
of the template, the width of the pin is increased two units. This
is illustrated in FIG. 13.
[0067] As is illustrated in FIG. 14, the pin 305 is positioned in a
pin jack dial 320 that is threaded into, and positionable in, a pin
jack base 322 to accurately control the height of the tapered pins
305. The pin jack dial 320 is externally threaded and carries a
spring loaded positioner 324 such as a bullet catch that is
received in a series of flutes 326 (e.g., eight flutes) on the
inside of pin jack body 322 to provide a detent arrangement so that
pin jack dial 320 will be retained at a selected one of several
rotational positions. By rotating the pin jack dial 320, the
positioner 324 sequentially engages in each flute 326, temporarily
locking the dial 320 in that orientation and preventing
unintentional rotation. As the pin jack dial 320 is threaded into
the pin jack body 322, each time the positioner 324 engages, the
tapered pin 305 moves slightly up or down depending on which way
the pin jack dial 320 is turned. External threads (not shown) on
pin jack body 322 secure body 322 within threaded hole 210 in
center guide 204.
[0068] If the thread used on the pin jack dial 320 and inside pin
jack body 322 has 16 threads per inch, for each full revolution the
pin jack dial 320 will be raised by 0.0625". With eight flutes 326
in the pin jack base 322, each time the detent engages the height
will be changed by 0.0078". With a 14.degree. angle on the tapered
pin 305 this means that for each click of the detent, the width of
the joint pin cut is increased or decreased by 0.004"
[0069] The Spacer Tray
[0070] The spacer tray 402 shown in FIG. 4 is used to set the
spacing of the pins and tails. The end spacers 410 are used to set
the width of the material being worked; the intermediate spacers
404 are used to set the centers of the pins and tails. This
procedure is explained below and illustrated in FIG. 15.
[0071] 1. To set the spacer tray 402 begin by locking one of the
end spacers 410 in the spacer tray 402 using an appropriate tool
such as a hex key to adjust the set screw (not shown) to lock the
end spacer 410 in position.
[0072] 2. Decide upon the number of pins or tails in-the joint.
Slide that number of regular spacers 404 into the spacer tray 402.
There is no need to lock them yet.
[0073] 3. Slide a second end spacer 410 into the spacer tray
404.
[0074] 4. Position a workpiece board 412 on the tray 402 against
the locked end spacer 410 and slide the other end spacer 410
against the opposite edge of the board 412. Lock the second end
spacer 410.
[0075] 5. Remove the board 412 and set the positions of the pins
and tails using the regular spacers 404. Lock these spacers 404 as
well. Extra spacers 404 may be stored in the unused portion of the
spacer tray 402.
[0076] The spacer tray 402 slides into the mating slot 716 in the
upper fence 702. It is held in place by screwing the spacer tray
knob 718 into either of the end spacers 410 as illustrated in FIG.
17.
[0077] In order to cut symmetrical dovetails or other joint
elements, one joint must be cut with the spacer tray 402 inserted
one way, and the opposing joint is cut with the spacer tray 402
inserted in the opposing way. To flip the spacer tray 402, the
spacer tray lock 718 is disengaged, the tray 402 is, slide out,
turned around, and reinserted in the upper fence. Then they tray
402 is locked using the other end spacer.
[0078] The Control Block
[0079] The control block or controller 502 illustrated in FIG. 5
controls the type of cut begin made, the shape, the fit, and the
spacing.
[0080] When using the control block 502 in conjunction with the
templates, it is very important that the template be held in the
same position each time that it is used. It is for this reason that
the control block 502 has a lock 512 that may be understood by
reference to FIG. 20. Once the control block 502 has been moved
into position and the indexing pin or screw 504 has been engaged in
a spacer, the control block is locked to the upper fence 702 using
the control lock 512. As is illustrated in FIG. 20, control lock
512 is a screw threaded (threads are not shown in drawing) into
control body 503 to bear against control foot 528, which in turn
locks control body 503 to upper fence 702.
[0081] When tailboards are being cut, the controller 502 must be
locked to the lower fence 618. This is accomplished using the lower
fence lock screws 514, as illustrated in FIG. 5. The templates are
affixed to the control body 503 via the template arm 506. The
template arm 506 is secured to the control body 503 using the
template arm lock knob 516, which has a tapered point that is
driven into a mating tapered hole in the template arm 506. The
template arm is inserted in the slot 518 in the control block such
that it mates with the back surface of the slot 518 in control body
503. The holes for the arm lock 516 are positioned so that driving
in the lock 516 pushes the template arm 506 both inward and
down.
[0082] The template arm 506 has a window 520 in the center that
allows for greater visibility of the templates. The template arm
506 also has six counterbored and threaded holes 522 into which cap
screws 524 securing the templates are affixed. Each template may be
secured to the template arm 506 using a pair of template standoffs
526. The standoffs 526 preferably have cylindrical protrusions on
each end that insert into counterbores in the template arm 506 and
into matching holes in the templates. Other template securing
arrangements are, of course, possible.
[0083] The Template System
[0084] Depending upon the type of joint being cut, the style of
cutter used, and the material thickness, a different template
required for each different joint. Templates are used only for the
pin boards; the tail boards are cut using the shape of the cutter.
The type of joint is the first consideration that differentiates
the templates. Numerous sizes and shapes of templates are possible.
Generally templates for forming through dovetails will have a
portion with parallel sides joined to a tapered portion. Templates
for half blind dovetails will have parallel sides and a half-round
end. Templates for finger joints or box joints will have parallel
sides. As noted above, templates need not be one-piece structures
but can have two or more components to enable adjustment of the
width or other attributes of the joint element made with the
template.
[0085] Auxiliary Fence
[0086] In certain cases it is necessary to make cuts with the
workpiece laid horizontally. Such cuts are necessary for example
when half-blind tailboards are being made. FIG. 21 illustrates a
half-blind tailboard 106. In these circumstances it is necessary to
use the auxiliary fence 736. The auxiliary fence 736 is attached
directly to the upper fence 702 at the location shown in FIGS. 1,
17 and 18, by attaching an auxiliary fence support 738 to fence 702
with two screws 740. Auxiliary fence 736 is attached to one end of
support 738.
[0087] The auxiliary fence 736 is used in conjunction with the
depth stop 742 that mounts to the center guide 204, as illustrated
in FIG. 18. The depth stop 742 controls how far the bit 744
projects in front of the lower fence 618 when the fence 618 and
other components are pushed as far along center guide assembly 202
as possible. Depth stop 742 functions by contact between depth stop
bumper 746 at then end of stop shank 743 and wing 606, as
illustrated in FIG. 18. Adjustability may be achieved by rotation
of a threaded stop shank or screw 743 within a threaded hole in
stop body 745 or by other conventional structures providing an
adjustable stop.
[0088] When making joints that require this type of stopped cut,
the workpiece is laid flat on wings 604 and 606 with the workpiece
end abutting the lower fence 618 and the workpiece edge forced
against the auxiliary fence 736. Each cut is positioned using the
controller 502 and the spacer tray 402. Each cut is made by pushing
the workpiece into the bit 744 as the wings 604 and 606 and fence
618 slide upward in FIG. 18, causing the bit 744 to enter the
workpiece the distance permitted by adjustable stop 742.
[0089] Summary of Operation
[0090] Cutting of joint components begins with the setting the
spacers that determine where the centers of both the pins and tails
will be located. The tailboard is clamped to the upper fence, and a
bit appropriate in shape for the joint being cut is secured in the
router collet. Using the spacer engagement pin or screw, straight
cuts are made through the tailboard centered on each spacer.
[0091] The tailboard is then removed and the pin board is clamped
to the upper fence. A straight bit is secured in the router collet
or chuck, and the pin jack is positioned in the center guide. An
appropriate template that corresponds to the shape of the bit used
for the tailboard is then fastened to the control block using the
template lock. Using the spacer engagement pin to successively
locate the upper fence relative to the lower fence, the pins are
cut out of the end of the pinboard by moving the template and
workpiece around the pin jack.
[0092] Fine adjustment of the width of the pins may be accomplished
by adjusting the height of the tapered, height adjustable pin using
the pin jack. Raising or lowering the height of the tracer pin can
vary the width of the pins on the pin board by very small
increments.
[0093] Possible Modifications
[0094] As will be understood by those skilled in the art, the
principles of this invention can be practiced in a number of
alternative structures both similar and dissimilar in appearance
and construction to the exemplary embodiment of this invention
shown in the drawings and described above. For instance, while
anodized aluminum extrusions are excellent materials for several of
the guide, fence and control block or body components of this
invention, other materials, including machined metals and plastic
or plastic composite materials could also be used.
[0095] Wings 604 and 606 may be made of solid steel, aluminum or
other metals and could be solid plastic, plywood or other
materials, including composite sheet material having a
thermoplastic core bonded between two aluminum skins (e.g., 0.020
inch gauge aluminum sheets) and sold under the name AlucoBond.RTM.,
available from Alusuisse Composites, Inc., 55 West Port Plaza, Ste.
625, St. Louis, Mo. 63146.
[0096] Alternative components could also be used. For instance
different clamping arrangements can be used for securing workpieces
to the upper fence or for securing the center guide to the router
table being used. Spring loaded pins could be substituted for some
of the locking screws, and other alternative fasteners could also
be used. Cylindrical tracer pins could be used rather than the
tapered ones shown and described with sacrifice of only the ability
to change the effective diameter of the tracer pin by adjusting its
height. The ability to adjust joint element size can be achieved by
mounting the templates in a manner that permits them to slide back
and forth along the template arm. Templates can also be made with
adjustable widths by, for instance, making each template from two
or more pieces rather than from a single piece. This permits the
user to form workpiece pins of variable width by adjusting the
template pieces to have a width corresponding to the desired pin
width.
[0097] The lower fence could also be significantly different in
shape so long as it provides transverse movement of the workpiece
and accommodates lateral movement of the workpiece relative to
itself.
[0098] Different configurations of spacers are possible. For
instance, spacers could be mounted directly in or on the upper
fence rather than in a tray that is in turn mounted in the upper
fence. Engagement between the control block also does not need to
be a pin-in-hole arrangement but could be any of numerous
engagement or locking arrangements such as a foot or
tangent-in-slot arrangement. Indeed spacers could be entirely
dispensed with provided that alternative provision is made for
locating the places that the workpiece is to be machined. For
instance, the workpiece can be marked directly, or the control
block or its functional equivalent could be positioned before
locking to the upper fence by reference to measuring marks (on a
scale or rule) or by reference to stop components other than holes,
such as slots, screws, protrusions, edges or spacers or the
like.
[0099] Relocation of components is also possible. For instance,
while location of the pattern and tracer pin in the same lateral
location as the router cutter facilitates visualization by the
operator of cutter action, the pattern and tracer pin could also be
located in other locations relative to the router cutter, such as
offset to the side or inverted. It is simply necessary for the
relative location of the pattern and the portion of a workpiece
mounted in the machine being cut to be the same as the relative
locations of the pin and the router cutter.
[0100] Additionally, it is possible to swap the relative locations
of the tracer pin and the pattern. While the locations shown in the
drawings provide good logical mapping, it is possible to fix the
pattern in the center guide or elsewhere so that its position is
fixed relative to the router cutter and mount the tracer pin on the
control block so that the tracer pin traces around the pattern.
[0101] With appropriate modifications, the entire apparatus could
also be, in effect, inverted 180 degrees or rotated ninety
degrees--i.e., the router cutter could protrude down from the
router with the end of the workpiece being machined facing up, or
the router cutter could be positioned to rotate about a horizontal
axis. A dedicated machine 101 of the invention could also be
fabricated without a router table top and with appropriate
substitute support for the machine 101 components.
[0102] In another possible relocation, the center guide need not be
in the center of the router table aligned with the router bit. One
or more guides could be offset from the router bit; the important
requirement is simply that there be structure that permits linear
motion across the router table top or its functional equivalent so
that the cutter can enter and exit the workpiece along a straight
line (when tails are being cut).
[0103] All of these possible modifications, as well as others that
will be recognized as possible by those skilled in the art, are
intended to be included within the scope and spirit of the drawings
and description above and the following claims.
* * * * *