Attachment for a miter gauge

An attachment for a miter gauge of the type having an arm slidably movable in the slot of a work table so that a wooden workpiece is moved into engagement with a table saw blade depending upon the angle of the arm with respect to the miter gauge body. The attachment is mounted on the miter gauge in such a manner that two workpieces one with a taper cut and the other with a miter cut can be successively cut and then joined along their bias edges to form a ninety degree joint, without readjusting the miter gauge.

BACKGROUND OF THE INVENTION 
This invention is related to an attachment for a miter gauge used for 
cutting and tapered cuts in wooden workpieces, and more particularly to an 
attachment for a miter gauge having a novel means for locking the 
attachment to the gauge body to form a workpiece-engaging surface having a 
ninety degree angle whereby a pair of workpieces can be successively cut 
and then joined together to form a ninety degree joint. 
Wooden miter joints are usually formed by employing a miter gauge having an 
arm slidably received in a slot in a work table, the arm being locked at a 
selected angle to the miter gauge body depending upon the angle of the 
edge to be cut in the workpiece. 
Sometimes the user desires to form a miter joint which requires him to cut 
two workpieces that are joined along their bias edges. A conventional 
miter gauge can be used to cut two such workpieces, however, it is 
difficult to precisely cut two workpieces so that they form a ninety 
degree joint where the miter angle of the first workpiece is different 
than the angle of the second workpiece. Conventionally, the user cuts the 
first workpiece using a miter gauge and then uses a taper jig to cut the 
second workpiece. If the adjustment is not precise, the two workpieces do 
not form a precise ninety degree joint. 
SUMMARY OF THE INVENTION 
The broad purpose of the present invention is to provide an attachment for 
a conventional miter gauge which permits the user to cut two successive 
workpieces, one having a tapered end, the other having a mitered end, 
without readjusting the miter gauge arm, in such a manner that the 
workpieces, when joined along their bias edges, form a ninety degree 
joint. The preferred embodiment employs a special locking means for 
adjusting the position of the attachment along the miter gauge body to 
accommodate various size workpieces. Preferably the attachment includes a 
fence that is connected to the miter gauge body. The fence has a 
channel-shaped slot. A stop is connected to the fence to a channel-shaped 
slot. A stop is connected to the fence to cooperate to form a ninety 
degree workpiece-engaging surface. The stop has a movable locking member 
with a tapered opening. A threaded fastener has its end received in the 
tapered opening to cam the locking member and to releasibly clamp the slot 
opening between the tongue and the locking member body. 
Still further objects and advantages of the invention will become readily 
apparent to those skilled in the art to which the invention pertains upon 
reference to the following detailed description.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, FIG. 1 illustrates a conventional table saw 
blade 10 mounted on a work table 12 having a slot 14. A miter gauge 16 has 
a body 18 with a semicircular gauge and indicia 20 marked along the edge 
of the gauge to indicate various angular positions. An elongated arm 22 is 
pivotally connected to body 18 and slidably mounted in slot 14. A handle 
24 is threadably connected to arm 22 to lock it in a selected angle to 
body 16 according to pointer means 26. 
The miter gauge body has an elongated face 30. A workpiece 11 engages this 
face and then is pushed along a path defined by slot 14 into cutting 
engagement with table saw blade 10. The angle of the cut depends upon the 
angle of the workpiece with respect to slot 14. Thus by adjusting body 18 
with respect to the slot, the user can select the bias angle of the 
finished workpiece. 
An attachment generally indicated at 32, is mounted on miter gauge body 18. 
The attachment includes a fence 34. Fastener means 36 and 38 connect the 
fence in abutment with miter gauge face 30. The bottom surface of the 
fence is aligned with the bottom of the miter gauge body. The fence has a 
channel-shaped slot 40 running the full length of the fence. The slot, as 
best illustrated in FIG. 6, has opposed walls 42 and 44, a base 46 and a 
neck 48. 
Referring to FIG. 2, a stop unit 50 is connected to fence 34. Stop unit 50 
has a body 52 with a work-engaging surface 54 disposed at a ninety degree 
angle with respect to work-engaging surface 56 of the fence. The bottom of 
the stop unit is also aligned with the bottom of the miter gauge body, 
both of which are disposed over arm 22. The stop unit also has a similar 
work-engaging surface 60 disposed at a ninety degree angle with respect to 
surface 56 of the fence so that a workpiece can be mounted on either side 
of the stop unit. An extension 57 is connected to stop unit 52 to 
accommodate the length of the workpiece 11. 
Referring to FIG. 7, the stop unit has a pair of elongated tongues 62 and 
64 receivable in the fence slot. The stop unit body has an opening 66 
disposed between tongues 62 and 64. A locking member 68 is slidably 
received in opening 66. The forward edge of the locking unit has a tongue 
70 with a cross-section similar to the shape of slot 40. 
A spring 72 is disposed in the stop unit to bias locking member 68 out of 
opening 66. The locking member has a tapered opening 74 aligned with a 
threaded opening 76 in the top of stop unit body 52, when tongue 70 is 
received in slot 40. A threaded adjusting member 78 having a handle is 
received in threaded opening 76. 
As best illustrated in FIG. 6, adjusting member 78 has a conical point 80 
which engages the rear wall of opening 74 to cam shoulders 82A and 82B of 
tongue 70 toward surface 84 of the stop body. The arrangement is such that 
as the user adjusts member 78, neck 48 is clamped between the tongue and 
body 52. 
To unlock the stop unit from the fence, the user unscrews member 78 to 
disengage it from the rear tapered wall of opening 74. The user can then 
slide the unit along slot 40 to either readjust the location of the stop 
unit or to separate it from the fence. 
In use, the user forms a 90.degree. joint from a pair of wood workpieces 90 
and 92 by placing first workpiece 11 into engagement with work-engaging 
surfaces 56 of the fence and 54 of the stop unit after he has adjusted the 
angle of arm 22 with respect to miter gauge body. He then moves the miter 
gauge body, the attachment and the workpiece into cutting engagement with 
the table saw blade to remove the corner of the workpiece as illustrated 
in FIG. 2. The angle can be any desired angle. He then places second 
workpiece 92 in abutment with the fence, as illustrated in FIG. 3, and 
cuts off the end of this workpiece. It is to be noted that the portions 
removed from both workpieces are such that by joining the two workpieces, 
as illustrated in FIG. 4, with their bias ends in abutment, they form a 
right angle joint. This is accomplished without readjusting the angle of 
arm 22 of the miter gauge body.