Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: FLOATING BENCH SAW GUIDE
FIELD OF THE INVENTION
This invention pertains to portable circular saw guides and more
particularly it pertains to circular saw guides which have universal saw
mounting cradles, reversible guiding edges and rulers.
BACKGROUND OF THE INVENTION
It can be difficult for a carpenter to carry a conventional table saw
from one job site to another. This can be particularly difficult when the
project involves the working on a roof or on other parts of a building
requiring the transport of tools in stairs, in ladders or on scaffolding. This
inconvenience with conventional table saws has created a need for a
portable device that is compact, lightweight and that can be used to
perform substantially the same work as can be done on a conventional
table saw.
In the past, several circular saw guides have been developed and
used with varying degrees of success. The known circular saw guides
belong to two groups wherein the devices in each group have common
characteristics. The main feature of the saw guides in the first group
consists of an anchor device which attaches to the skid plate of a portable
circular saw. A guiding edge is mounted on a stem which is telescopically
movable in a socket mounted to the anchor device. The circular saw is
used in a conventional manner but with the guiding edge following the
straight edge on the panel being sawn. Examples of circular saw guides
belonging to the first group are described and illustrated in the following
documents:
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US Patent 4,128,940, issued on Dec. 12; 1978 to Jose K. Ong;
US Patent 4,397,089, issued on Aug. 9, 1983 to Mason E. Pease;
US Patent 4,628,608, issued on Dec. 16, 1986 to Gerhard Kuhlmann et al.;
US Patent 5,035,061, issued on Jul. 30, 1991 to Timothy Bradbury et al.;
US Patent 5,815,931, issued on Oct. 6, 1998 to Todd Cleveland, and
US Patent 5,901,450, issued on May 11, 1999 to Thomas P. James.
The second group of circular saw guides of the prior art is
characterized by the mounting of the portable saw in a cradle which is
movably supported or fixedly attached to a pair of rails. A guiding edge
or the saw itself is movable along the rails so that the relative positions of
the guiding edge and the saw are adjustable, for sawing a panel or a board
at selected places. Examples of saw guides of the second group are
illustrated and described in the following documents:
US Patent 3,434,514, issued on Mar. 25, 1969 to Charles E. McManama;
US Patent 4,016,649, issued on Apr. 12, 1977 to James R. Kloster;
US Patent 4,135,419, issued on Jan. 23, 1979 to Everett E. Chapin;
US Patent 4,237,762, issued on Dec. 9, 1980 to Kevin J. Winter;
US Patent 4,852,257, issued on Aug. l, 1989 to Kenneth D. Moore;
US Patent 4,909,111, issued on Mar. 20, 1990 to Walter E. Noble;
US Patent 5,080,152, issued on Jan. 14, 1992 to Michael Collins et al.;
US Patent 5,107,736, issued on Apr. 28, 1992 to James O. Albrecht, and
US Patent 5,921,161, issued on Jul. 13, 1999 to Robert M. Newell.
Although the circular saw guides of the prior art deserve undeniable
merits, these devices are believed to be deficient in at least the features of
being capable of accommodating various makes and models of circular
saws, and being readily adjustable for use without having to measure the
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position of the saw blade relative to the guiding edge. Such lack of instant
positioning means can lead to errors in sawing and can cause irreparable
damage to expensive wood boards or panels.
As such, it will be appreciated that there continues to be a need for
a new and improved circular saw guide which is readily usable with
various models of saws, without having to measure using a measuring tape
and laboriously adjust the position of the saw blade relative to the guiding
edge.
SUMMARY OF THE INVENTION
The present invention provides a floating bench saw guide which
has a compact configuration and a saw cradle in which the portable saw is
readily positional for use without subjective measurement using a
measuring tape.
Broadly, in accordance with one feature of the present invention,
there is provided a floating bench saw guide for guiding a portable circular
saw along a workpiece while sawing the workpiece. The floating bench
saw guide comprises a cradle for retaining a portable circular saw, a saw
plane across the cradle, and a guide lip movably affixed to the cradle. A
pair of gage blocks are affixed to the cradle or to a structure adjacent the
cradle. The gage blocks have a certain thickness and are positioned along
the saw plane. The gage blocks define the saw plane. The provision of the
gage blocks on the cradle is particularly advantageous for allowing the use
of a straight edge such as a carpenter square for easily positioning the
blade of a circular saw along the saw plane without having to use a
measuring tape to measure the position of the saw blade within the cradle.
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In accordance with another feature of the present invention, a pair
of spaced-apart parallel rails are affixed to the cradle. The rails have a
common length of about thirty six inches and extend away from the saw
plane. The guide lip is movably affixed to the rails and is reversible
relative to the saw plane. Moreover, the guide lip overhangs its mountings
to the rails such that it is positional relative to the saw plane over a
distance
ranging from about zero inch to about forty-eight inches from the saw
plane. The floating bench saw guide is thereby relatively compact in size
when the guide lip is positioned in a forward orientation nearest to the saw
plane.
In accordance with yet another feature of the present invention, each
rail has a ruler affixed thereto. A pointer is affixed to the guide lip and
overhangs one of the rulers. The ruler on one rail has a graduation set
which is a continuation of the graduation set on the other ruler. The
pointer indicates the position of the guide lip relative to the saw plane
whether the guide lip is positioned in a forward or reverse orientation.
In accordance with a further feature of the present invention, the
guide lip is mounted to an intermediate position along the rails, and a
muter support member is removably mounted to the far ends of the rails
relative to the saw plane. The router support member has a structure which
allows its mounting over the cradle. The router support member has
clamping means to retain a router over the cradle in place of a circular saw,
such that the floating bench saw guide is usable with several carpentry
tools.
Still another feature of the floating bench saw guide according to
the present invention is that it is susceptible of a low cost of manufacture
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with regard to both materials and labor, and which accordingly is then
susceptible of low prices of sale to the consumer, thereby making such
floating bench saw guide economically available to the public.
Other advantages and novel features of the present invention will
become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of this invention is illustrated in the
accompanying drawings, in which like numerals denote like parts
throughout the several views, and in which:
FIG.1 is a perspective side and top view of the preferred configuration of
the floating bench saw guide according to the present invention;
FIG. 2 is a plan view of the floating bench saw guide;
FIG. 3 is a plan view of the base frame of the floating bench saw guide;
FIG. 4 is the bottom view of the base frame of the floating bench saw
guide;
FIG. 5 is a cross-section view of the base frame, as seen along line 5-5 in
FIG. 3;
FIG. 6 is a cross-section view of one of the rails in the floating bench saw
guide, as seen along line 6 in FIG. 2;
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FIG. 7 is a plan view of the saw holding plate in the floating bench saw
guide;
FIG. 8 is an end view of the saw holding plate;
FIG. 9 is an enlarged side view of the toggle clamp mounted on the saw
holding plate;
FIG. 10 is a plan view of the movable guide member comprised in the
preferred floating bench saw guide;
FIG. 11 is a cross-section view through the movable guide member as
seen along line 11-11 in FIG. 10;
FIG. 12 is an enlarged top view of a slide block comprised in the movable
guide member;
FIG. 13 is an end view of the slide block shown in FIG. 12;
FIG. 14 is a plan view of the sight glass affixed to the movable guide
member;
FIG. 15 is another plan view of the floating bench saw guide showing
specific reference dimensions, and showing the movable guide
member mounted in a forward orientation nearest to the saw plane;
FIG. 16 is yet another plan view of the floating bench saw guide wherein
the movable guide member is mounted in a reverse orientation
farthest from the saw plane;
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FIG. 17 is a side view of the floating bench saw guide with the movable
guide member mounted in a forward orientation;
FIG. 18 shows a plan view of the router support member which is
optionally comprised with the preferred floating bench saw guide;
FIG. 19 is an end view of the router support member;
FIG. 20 is a cross-section view through the router support member as seen
along line 20-20 in FIG. 18;
FIG. 21 is another cross- section view through the router support member,
as seen along line 21 in FIG. 18;
FIG. 22 is a side view of the floating bench saw guide with a router in
place of a circular saw;
FIG. 23 illustrates a method, using the floating bench saw guide with a
circular saw mounted therein, for sawing a wedge-shaped shim;
FIG. 24 illustrates a method, using the floating bench saw guide with a
router mounted therein, for making book case ends;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While this invention is susceptible of embodiments in many
different forms, there is shown in the drawings and will be described in
details herein a specific embodiment, with the understanding that the
present disclosure is to be considered as an example ofthe principles ofthe
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invention and is not intended to limit the invention to the embodiment
illustrated and described.
Referring firstly to FIG. 1 the major components of the floating
bench saw guide according to the preferred embodiment comprises a saw
cradle 30, a base frame 32, comprising a base plate 34 and a pair of rails
36, 38 extending from the base plate 34. A movable guide member 40 is
engaged with, and movable along the rails 36, 38. A router support
member 42 is removably engaged into the far ends of the rails 36, 38 and
is optionally mountable over the saw cradle 30 for supporting a router in
place of a circular saw 44.
The structural details of the base frame 32 will now be described
with reference to FIGS.1-6. The base plate 34 is affixed to the near ends
of the rails 36, 38, flush with or slightly raised from the bottom of the
rails
as seen in FIG. 5. The preferred base plate 34 is about 1 /4 of a inch thick
and the rails 36, 38 are preferably made of aluminum tubing 1 inch by 1
inch square by 0.120 inch wall thickness. A rectangular opening 50 in the
base plate 34 allows the passage of a saw blade and a saw blade guard on
a circular saw 44. This rectangular opening 50 is at the near end of the
base frame 32. A circular indentation 52 is provided in the rectangular
opening for clearance around the chuck of a router (not shown), as will be
understood from the following description of the preferred embodiment.
An array of threaded holes 54 is provided in the base plate 34 to retain the
saw holding plate thereto as will also be explained later. A central hole 56
through the base plate 34 is usable to retain the router support member 42
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to the base plate 34. Each of the holes 54, 56 in the base plate as well as
in the other parts of the preferred floating bench saw guide is reinforced
with a threaded insert 58 known in the field of machine design as a PEMTM
fasteners or a NUTSERT TM.
Each of the rails 36, 38 has a longitudinal slot in the inside wall
thereof, such that it forms a C-shaped configuration as best illustrated in
FIGS. 5 and 6. The slide blocks along the saw holding plate and the
movable guide member are movably engaged inside this C-shaped
configuration as seen in FIG. 6. Each rail also has a ruler printed thereon
or affixed thereto. The ruler 60 on the right side rail 36 is graduated from
0 - 24 inches. The ruler 62 on the left side rail 38 is graduated from 24 -
48 inches.
Most importantly, there are two gage blocks 64, 66 affixed to the
upper walls of the rails, at the near ends of the rails. These gage blocks 64,
66 define a saw plane 68 against which the saw blade of the circular saw
44 is positioned in the saw cradle 30, and from which both rulers 60, 62
are referenced. The utility of these gage blocks will be further explained
when making reference to FIG. 15.
Transverse slots 70 are provided through the underside walls of
both rails near the far edge of the base plate 34, for evacuating sawdust
which may accumulate inside the rails during use of the floating bench saw
guide. If not removed, the sawdust can hinder the movement of the
movable guide member 40.
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The saw cradle 30 consists of the base plate 34 and the saw holding
plate 80 mounted over and overlapping the base plate 34. The saw holding
plate has a C-shaped configuration and a pair of sliding block 82, 84
mounted along the edges thereof. The slide blocks are dimensioned to slide
precisely but freely inside the rails 36, 38 as illustrated in FIG. 6. The saw
holding plate 80 has a thickness of about 1/8 of an inch, and the
rectangular opening 90 therein has dimensions to partly enclose the skid
plate of a circular saw 44. On the forward side of the saw holding plate,
there is provided a clamp bar 92 which is affixed to the saw holding plate
80 by screws 94. The saw holding plate 80 is retained to the base plate 34
by means of two thumb screws 96, 98 through adjustment slots 100, 102
in the saw holding plate, and through two of the series of holes 54 in the
base plate 34. The slots 100, 102 and the series of holes 54 provide
adjustment to accommodate the holding of various models and sizes of
circular saws in the cradle 30.
In use, the skid plate of a circular saw 44, is placed over in the base
plate 34 of the floating bench saw guide and inside the rectangular opening
90 of the saw holding plate 80. The forward edge of the skid plate is
inserted under the clamp bar 92, and is clamped down against the base
plate 34 using the thumb screw 104 through the clamp bar 92. The rear
end of the skid plate 110 of the circular saw 44 is held down against the
base plate 34, by a toggle clamp 112 on the saw holding plate, near the rear
end of the saw holding plate 90. This type of toggle clamp 112 is available
from Carr-Lane Manufacturing Co., a company from St. Louis, Missouri,
USA. A wing nut 114 is provided on the bumper 116 of the toggle clamp,
for easy height adjustment of the bumper 116 to accommodate various
thicknesses of skid plates 110.
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Also as illustrated in FIG. 7, a slot 124 is provided in the clamp bar
92. In use, the slot 124 is positioned to coincide with any raised
deformation that may be present on the skid plate 110 of a portable saw 44.
The movable guide edge 40 will now be described with reference
to FIGS. 10-17. The movable guide edge 40 comprises a guide lip 130
formed on the edge of an guide-carrier plate 132. A channel-like member
134 is affixed to the top side of the guide-carrier plate 132 and encloses a
pair of slider blocks 136, 138. These slider blocks have dimensions for
sliding freely but precisely inside the rails 36, 38. The guide-carrier plate
132, is held below the slider blocks 136, 138, such that it moves under
both rails 36, 38 as shown in FIG. 17, under the base plate 34 and under
the router support member 42.
A handle 140 is provided on the channel-like member 134 to
facilitate the adjustment of the movable guide member and to support the
preferred floating bench saw guide in use.
Each of the slider blocks 136, 138 has a slider portion 150 which
has a similar cross-section as the inside dimensions of one of the rails, and
an anchor portion 152 which has dimensions for precise insertion inside
one end of the channel-like member 134, and attachment to the channel-
like member. The slider portion 150 is retained to the anchor portion 152
by a thin portion 154 having substantially a same thickness as the width of
the slot in each of the rails. There is further provided in each of the slider
blocks 136, 138, a quarter-turn lock nut 156, 158, each having a stem
extending through the slider portion 150 of each slider block. These lock
nuts are used to selectively clamp the wall of the rails between the slider
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portion 150 and a washer 160 under each lock nut, for the purpose of
locking the movable guide member 40 to the rails 36, 38. The quarter-turn
lock nut 156 on the right side of the preferred floating bench saw guide has
a clockwise thread, and the quarter-turn lock nut 158 on the left side has
a counter-clockwise thread as represented by arrows 162 and 164
respectively in FIG. 10. These lock nuts are thereby easily loosened and
tightened in a common direction for adjusting the position of the movable
guide edge member 40 along the rails 36, 38.
The exact position of the movable guide edge 40 along the rails 36,
38 is easily confirmable by means of a sight glass 170 affixed to the
channel-like member 134 and extending above one of the rulers 60, 62 on
the rails of the preferred floating bench saw guide. A first hairline 172
indicates the position of the guide lip 130 relative to the saw plane 68. A
second hairline 174 indicates the position of the guide lip 130 relative to
the position of the tool bit when a router is used in place of the saw 44.
The second hairline 174 indicated the position of the guide lip 130 relative
to the center of the circular indentation 52 in the base plate 34.
Referring back to FIG. 10, there are two threaded holes 176, for
optionally retaining the thumb screws 96, 98 and preventing these screws
from becoming lost when the saw holding plate 80 is removed from the
base plate 34.
Reference is now made to FIGS. 1, 15 and 16 to explain some of
the most important features of the floating bench saw guide according to
the preferred embodiment. The mounting of a portable circular saw 44 in
the saw cradle 30 is preferably effected while using a carpenter square 180
laid against the gage blocks 64, 66 as illustrated in FIG. 15. The saw
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guard of the circular saw 44 is moved up, and the saw blade 182 is moved
against the carpenter square 180. Then the skid plate 110 of the circular
saw is clamped down against the base plate 34 as previously explained.
This procedure ensure that the outside face of the saw blade 182 is aligned
with the saw plane 68.
Although a carpenter square 180 has been suggested for adjusting
the position of the saw blade along the saw plane 68, it will be appreciated
that any straight edge such as a piece of molding or a piece of board can
also be used to obtain the same result.
The right side ruler 60 is positioned such that the distance 'A'
between the zero mark on the ruler and the saw plane 68 is a same distance
as the measurement 'B' between the guide lip 130 and the left hairline
172 on the sight glass 170. Therefore the actual distance 'C' between the
guide lip 130 and the saw plane 68 is read under the hairline 172.
The guide-carrier plate 132 has a substantial length measured along
the rails, to provide the option of bringing the guide lip 130 close to the
saw plane 68 if required. When the movable guide member 40 is in the
forward orientation as illustrated in FIGS. 15 and 17, the guide lip 130 is
movable to a distance 'D' of about 1 /8 inch or less from the saw plane 68.
Both slide blocks 136, 138 on the movable guide member 40 are
symmetrical and parallel, such that the movable guide member is reversible
in its mounting inside the rails 36,38 as shown in FIG. 16. When the
movable guide member 40 is mounted in this position, referred to herein
as the reverse orientation, the distance 'E' between the near side of the
guide lip 30 and the saw plane 68 is a same distance as read on the left side
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ruler 62 under the hairline 172. For this reason, the zero mark on the left
side ruler 62 is set at a distance 'F' from the saw plane 68 which
corresponds to the distance 'A' plus the thickness of the guide lip 130.
The structure of the router support member 42 is illustrated in
FIGS. 18-22. The router support member 42 comprises a thick plate 190
made of plastic material for example, and has a hole 192 through its center.
The hole 192 may have a shoulder 194 to conform to the shape of a router
body. The plate 190 is made in two pieces which are joined together by a
pair of clasps 196 extending over a tongue-and-groove parting line 198.
The hole 192 has dimensions to provide a tight fit over a router body, such
that a router body may be retained to the plate 190 when the clasps 196 are
closed. A handle 200 is also provided to assist in operating the preferred
floating bench saw guide with a muter in place of a circular saw.
Each of the side edges 202 of the thick plate 190 has a shape and a
groove on its upper surface to mount into one of the slotted rails 36, 38.
The lower surface of the thick plate 190 is planar and smooth such that it
can be inserted into the near ends of the rails and over the base plate 34, in
place of the saw holding plate 80. When not used, the router support
member 42 is preferably inserted in the far ends of the rails and left there
to keep the rails in parallel alignment and to prevent damage to the far ends
of the rails in use.
A level gage blade 204 is affixed to the front edge of the thick plate
190 and is used when a router 210 is installed in the preferred floating
bench saw guide in place of a circular saw. The level gage blade 204 is
adjustable up and down relative to a working position of the router support
member, by means of a pair of slots 206 and two wing nuts 208. The level
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gage blade 204 is advantageous for leveling the preferred floating bench
saw guide along a workpiece when the guide lip 130 is made to slide in a
router-made shallow groove for example, and to ensure that the next
groove will be truly perpendicular to the surface of the workpiece. The
utility of the level gage blade 204 will be further explained when making
reference to FIG. 24.
The router support member 42 is adjusted and retained to the base
plate 34 by means of a thumb screw 212 mating into the threaded hole 56
in the base plate 34. The position of the screw 212 and the hole 56 in the
base plate 34 are calibrated with the number sets on the rulers 60, 62 such
that the center of the router bit 214 relative to the guide lip 130 is
indicated
on one of the rulers, under the hairline 174 on the sight glass 170.
As may be understood from the foregoing detailed description, the
preferred floating bench saw guide is used while holding the circular saw
44 in one hand and the handle 140 of the movable guide member in the
other hand. The guide lip 130 is brought against a straight edge of the
workpiece and the saw is driven through the workpiece to cut the
workpiece at the exact measurement from the guide l ip 130 as is indicated
on one of the rulers under the hairline 172.
While a right-handed circular saw 44 has been illustrated, it may be
appreciated that the all the components of the preferred floating bench saw
guide are symmetrical and can be reversed to accommodate a left-handed
circular saw. Similarly, Braille rulers may also be used to accommodate the
visually impaired users of the floating bench saw guide according to the
preferred embodiment.
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The floating bench saw guide according to the preferred
embodiment of the present invention can also be used to perform non-
conventional work such as sawing a workpiece along an acute angle for
example, as illustrated in FIG. 23. In this case, the work is performed on
a table 220 or on carpenter benches. A piece of lumber 222 is temporarily
affixed to the table 220 or to the benches. The workpiece 224 to be sawn
is placed against the piece of lumber 222 with the largest finished end 226
of the workpiece resting against the piece of lumber. A saw mark 228
indicating the width 'G' at smallest finished end of the workpiece 224 is
moved away from the piece of lumber 222 a distance 'H' equal to the
finished width of the workpiece at the large finished end 226. The
workpiece 224 is then temporarily affixed to the table 220. The cut is then
effected with the preferred floating bench saw guide as explained before,
that is with the guide lip 130 sliding against the piece of lumber 222.
A second application of the preferred floating bench saw guide is
illustrated in FIG. 24. In this application, a router 210 and router support
member 42 are used in place of a circular saw. 7'he preferred floating
bench saw guide is used to cut shelving seat grooves in a pair of bookcase
ends. The first groove 232 is effected while manipulating the preferred
floating bench saw guide as previously explained, that is with the guide lip
130 sliding against the ends 234 of the bookcase ends. The second and
subsequent grooves 236 are effected while sliding the guide lip 130 into
the adjacent groove 232. Depending upon the depth at which the grooves
are made, the level gage blade 204 may be adjusted to maintain the rails
36, 38 parallel with the surface of the workpiece and to maintain the
second and subsequent grooves true with the surface of the bookcase ends.
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Reference may be made again to FIG. 22 to better understand the
adjustment of the level gage blade 204 . In the case of the bookcase ends
230 as just explained, the level gage blade 204 is set higher than the
bottom edge of the guide lip 130 by a dimension 'J' which is equivalent
to the depth at which the first groove has been made.
It will be appreciated from the examples illustrated in FIGS. 23 and
24 that the applications of the floating bench saw guide according to the
preferred embodiment in carpentry work are limited only by the
imagination of the users. As such, it is believed that further explanation
relative to the manner of usage and operation of the floating bench saw
guide according to the present invention would be considered repetitious
and is not provided.
While only one embodiment of the present invention has been
illustrated in the accompanying drawings and described herein above, it
will be appreciated by those skilled in the art that various modifications,
alternate constructions and equivalents may be employed without departing
from the true spirit and scope of the invention. Therefore, the above
description and the illustrations should not be construed as limiting the
scope of the invention, which is defined by the appended claims.
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