Drilling jig

A jig for drilling all the dowel and fixture mounting holes for the 32 mm system of cabinet construction consisting of a pair of parallel rails having face and side, a third rail identical to the two parallel rails and attached perpendicularly to the parallel rails, a saddle which straddles the rails and containing a bushing that fits through the saddle and into the holes of the rails, two centering block assembles consisting of a bar with two dowels inserted perpendicularly into one side and a threaded rod inserted perpendicularly in the other side and a threaded knob which is screwed onto the free end of the threaded rod.

BACKGROUND OF THE INVENTION 
The present invention relates to the 32 millimeter ("mm") cabinetmaking 
system, which is a highly structured approach to cabinet construction. The 
32 mm system is used primarily in constructing kitchen cabinets and is 
often referred to as frameless construction due to the absence of a 
traditional face-frame. The system was developed in Europe as a means to 
mass produce cabinet components in a factory using melamine-coated 
particle board and other man-made sheet materials like plywood, ship the 
components disassembled to the construction site, and assemble the 
cabinets on-site with ease. The structural rigidity of cabinets made with 
the 32 mm system results from the very narrow tolerances maintained in 
panel size and dowel and fixture mounting hole location. 
By virtue of the sheer number of holes required for the typical 32 mm 
system cabinet and the dependence of the structural integrity of the 
cabinet on the accuracy of the placement of dowel holes, the 32 mm system 
does not lend itself well to being utilized where hand drilling is the 
only drilling method available. Large cabinetmaking shops often use 
expensive computer numerically controlled ("CNC") machines to cut and 
drill cabinet panels at phenomenal speeds. However, the cost of 
reprogramming CNC machines and the resulting down-time is prohibitive in 
small volume production. 
An alternative is less expensive pneumatically controlled machines. The 
set-up time for a pneumatically controlled machine, although a fraction of 
what its CNC counterpart requires, still represents a substantial amount 
of time and is prohibitive in producing cabinets in small volumes, is 
still too expensive for a small shop producing low volume, custom 
cabinets, and is simply out of the question for the industrious homeowner 
willing to tackle the manufacture of his or her own kitchen cabinets. 
A final alternative is to hand drill all holes. This option is inexpensive 
and requires virtually zero set-up time. However, because of the accuracy 
needed in the 32 mm system, hand drilling is not a viable alternative 
unless some sort of jig is used. Such jigs exist, but do little more than 
facilitate the drilling of one row of fixture mounting holes at a time, at 
specific intervals apart, on the face of the panel a set distance from the 
edge. Existing jigs do not have all of the features necessary to complete 
every aspect of the 32 mm system, such as providing a means to accurately 
drill the dowel holes in the ends and edges of a panel. 
SUMMARY OF THE INVENTION 
The present invention is a device for accurately drilling all the holes 
necessary in constructing cabinets using the 32 mm system. The 32 mm 
system jig of the present invention is a simple, inexpensive device which 
can be easily assembled and used by the small cabinet shop owner or the 
homeowner. 
The jig uses three rails with holes spaced 32 mm apart on their faces and 
which can be rigidly attached to each other. In use, two of the rails are 
fixed parallel to one another and centered on the side panel of the 
cabinet being constructed. The third rail is then attached perpendicular 
to the other two rails, and the entire assembly is clamped in position. 
Once clamped, the rails are used in conjunction with a saddle or drill 
guide to accurately position fixture mounting holes and dowel holes 
drilled at needed locations in the face of the panel. 
The third rail is then detached from the two parallel rails and located on 
the edge of the mating panel using two centering block assemblies to 
center the rail on the edge of the panel and a gauge assembly to properly 
locate the rail lengthwise. The saddle or drill guide is again used to 
properly position and center dowel holes drilled in the panel edge. 
The present invention allows for the accurate hand drilling of all the 
dowel and fixture mounting holes necessary in the 32 mm system, is easily 
and quickly disassembled and reassembled, can be quickly adapted to a wide 
variety of cabinet designs, and is easily affordable by the small shop 
owner or homeowner. 
Accordingly, one objective of the present invention is to provide a device 
that permits accurate hand drilling of all the dowel and fixture mounting 
holes for the 32 mm system of cabinetmaking. 
Another objective of the present invention is to provide an inexpensive 
device for accurately hand drilling all the dowel and fixture mounting 
holes for the 32 mm system of cabinetmaking. 
A further objective of the present invention is to provide a device for 
accurately hand drilling all the dowel and fixture mounting holes for the 
32 mm system of cabinetmaking that is easily and quickly set-up. 
Another objective of the present invention is to provide a device that is 
easily and quickly adaptable to a wide variety of 32 mm system cabinet 
designs. 
Another objective of the present invention is to provide a device which 
permits properly positioned and centered dowel and fixture mounting holes 
to be hand drilled in the edges of a panel. 
Still another objective of the present invention is to provide a device for 
accurately hand drilling all the dowel and fixture mounting holes for the 
32 mm system of cabinetmaking that is suitable for a low volume 
cabinetmaking shop or a homeowner. 
Other and further objectives of the present invention will become apparent 
from the detailed description and claims which follow.

DETAILED DESCRIPTION OF THE DRAWINGS 
The drilling jig 2 of the present invention, as illustrated in FIGS. 1 and 
2, permits drilling two parallel rows of holes spaced at the 32 mm 
intervals necessary in 32 mm system-style construction. This is 
accomplished by positioning a first rail 4 and a second rail 6 at desired 
distances from the side edges 22 and 24, respectively, of panel 26 and 
fixing rails 4 and 6 in place with clamping means 8. Each rail 4 and 6 may 
be fabricated of extruded aluminum and resembles a hat channel (as used, 
for example, in metal roofing) with holes 5 centered side-to-side in the 
top 3 on 32 mm centers end-to-end (or at other desired intervals such as 
one inch) and contains a cove or groove 46 on top 3 running the length of 
rail 4 and 6. 
Each clamping means 8 includes at least one clamping rod 10, which is 
threaded on one end 9. Clamping rod 10 can be made of any suitable 
material, but cold-rolled steel is preferred. Clamping rod 10 slides 
through a second set of holes 7 in the sides 1 of rails 4 and 6, the axis 
of holes 7 being perpendicular to the end-to-end centerline of holes 5, 
and through a hole 17 in fixed jaw 18. Fixed jaw 18 is a generally 
rectangular block, preferably made of aluminum, and is secured on clamping 
rod 10 by clamping screw 20, which threads through fixed jaw 18 to bear 
against clamping rod 10 in hole 17. 
The threaded end 9 of clamping rod 10 also slides through holes 7 and 
through a hole 15 in movable jaw 16, which is generally identical to 
clamping jaw 18 but does not carry a clamping screw. Movable jaw 16 is 
secured on clamping rod 10 by clamping nut 12, which has a threaded bore 
and is screwed onto threaded end 9 of clamping rod 10 to force jaw 16 
toward jaw 18 so that panel 26 is captured between the two jaws. Clamping 
rod 10 is secured to rails 4 and 6 by clamping screws 14, which thread 
through the tops 3 of rails 4 and 6 and bear against clamping rod 10. 
Clamping screw 20 and clamping nut 12 are tightened to secure the now 
connected rails 4 and 6 to panel 26. Clamping nut 12 and clamping screws 
14 and 20 are preferably made of brass or other suitable material such as 
steel or aluminum. 
If more than two lines of parallel holes along the longitudinal centerline 
of panel 26 are desired, additional rails (not shown) can be inserted on 
clamping rods 10 and secured by additional sets of clamping screws 14 (not 
shown). 
The location of the centerline of holes 5 of rails 4 and 6 relative to side 
edge 22 or 24 is established through the use of the gauge assembly 28 
illustrated in FIG. 1. Gauge assembly 28 is comprised of gauge head 29, 
which is substantially T-shaped, hollow in the middle, and contains a 
gauge rod 36 inserted in the front of gauge head 29. The horizontal 
portion of gauge head 29 slides over ruler holder 32. Ruler holder 32 is 
secured within gauge head 29 by gauge knob 30 which is screwed onto gauge 
stud 38. Gauge stud 38 slides through a hole in one side of the vertical 
member of gauge head 29 and is received into a threaded hole in the 
opposite side of the vertical member of gauge head 29. Further rotation of 
gauge knob 30 and gauge stud 38 presses the two vertical members of gauge 
head 29 together, thereby tightening gauge head 29 around ruler holder 32. 
Ruler holder 32 contains a fixed ruler 34 and a hole 35 in one end. Ruler 
34 is attached to ruler holder 32 such that the distance from the 
centerline of hole 35 to the free end of gauge rod 36 is equal to the 
reading on ruler 34 at point 39 where ruler 34 crosses the front edge of 
gauge head 29. In use, rule holder 32 is slid within gauge head 29 until 
point 39 of gauge head 29 crosses ruler 34 at the desired measurement. 
Gauge knob 30 is then tightened, preventing further movement of gauge head 
29. Gauge button 37 is then inserted through hole 35 and into one of the 
holes 5 near the end of rail 4. Gauge rod 36 is then placed in contact 
with edge 22 of panel 26, thereby locating that end of rail 4 with the 
centerline of holes 5 at the desired distance from edge 22. This process, 
and the tightening of clamping screws 14 to secure rails 4 and 6 on 
clamping rod 10 is continued sequentially until all four ends of rails 4 
and 6 are properly located. While gauge assembly 28 can be made out of any 
suitable materials, brass, aluminum, or steel are preferred. 
As can be seen in FIGS. 2, 3 and 4, a third rail 40, identical to rails 4 
and 6, is then mounted on and perpendicular to the two parallel rails 4 
and 6. Rail 40 allows dowel holes to be drilled one half the thickness of 
mating panel 84 from the ends 58 and 64 of panel 26. These dowel holes 
match holes in the end of panel 84 to permit panels 84 and 26 to be 
butt-joined. Rail 40 is located in relation to rails 4 and 6 so that the 
distance from the centerline of the last hole on each of the two parallel 
rails 4 and 6, to the centerline of holes on rail 40 is exactly 32 mm. 
This positioning is accomplished through the use of at least one end rail 
clamping assembly 48. Each end rail clamping assembly 48 includes one 
clamping block 50, which contains a channel in which clamping rod 10 is 
trapped by clamping screw 54 and a threaded bore 51 to receive the 
threaded end of end clamping rod 52. End rail clamping rod 52 can be made 
of any suitable material with cold-rolled steel being preferred. Clamping 
block 50 likewise made be made of steel or brass, but aluminum is 
preferred. Clamping screws 54 are preferably made of brass, but other 
suitable materials such as steel or aluminum also can be used. A fourth 
rail (not shown) parallel to third rail 40 may also be used. 
The threaded end of end rail 52 is first inserted in bore 51 of clamping 
block 50. The channel of clamping block 50 is then placed over clamping 
rod 10 and clamping screw 54 is tightened slightly. The smooth end of end 
clamping rod 52 is then inserted through one pair of holes 7 in the side 1 
of rail 40 and loosely secured by clamping screw 55. Once rail 40 has been 
movably secured to rails 4 and 6 by clamping assembly 48, a connector 42 
having a half round locating ridge 41 is installed so that ridge 41 is 
received in groove 46 in the top 3 of rails 4 or 6. Connector 42 has two 
holes 43, separated 32 mm on center. Two locating pins 44, are installed 
next so that locator pins 44 run through holes 43 into the end hole 5 in 
rail 4 and one of the holes 5 in rail 40. Connector 42 is preferably made 
of aluminum and locator pins are preferably made of brass, but another 
suitable material, such as steel, could also be used. Groove 46 on rail 4 
receives ridge 41 on connector 42 ensuring that hole 5 in rail 40 which is 
adjacent to the last hole in rail 4 is in the same end-to-end centerline 
of holes 5 in rail 4 and that the center of holes in rail 40 is exactly 32 
mm from the center of the last hole 5 in rail 4. This process of locating 
rail 40 by using connector 42 is then repeated on rail 6. Once rail 40 has 
been properly located, clamping screws 54 and 55 are tightened, ensuring 
that rail 40 is perpendicular to rails 4 and 6 and that the end-to-end 
centerline of holes 5 in rail 40 is exactly 32 mm from the end holes 5 in 
both rails 4 and 6. 
Once all the components are locked, the connector 42 and locating pins 44 
are removed. This assembly of three rails 4, 6 and 40 forms a rigid 
U-shape continuum of identically spaced holes. Clamp nuts 12 are loosened 
and the entire frame 56 is slid toward one end 58 or 64 of panel 26 until 
the centerline of holes 5 on rail 40 is one half the thickness of panel 84 
from end 58 or 64 of panel 26. This distance may be measured by use of 
gauge assembly 28 in a manner similar to that described above. Once frame 
56 is in position, clamp nuts 12 are retightened. 
With rails 4, 6 and 40 properly located, panel 26 can be drilled. The 
drilling of panel 26 is facilitated by bushing carrier, or saddle 60, 
which fits over and straddles the rails 4, 6, and 40 and has a hole 
centered therein for receiving interchangeable bushing 62. Bushing 62, 
which acts as a guide and ensures the dowel and fixture mounting holes are 
drilled perpendicular to the face of panel 26, is locked into the bushing 
carrier 60 by a setscrew 63, and has an outside diameter allowing a 
precise slip fit into holes 5 in the top of the rails. To prevent 
excessive wear, bushing 62 is preferably made of hardened steel, but other 
materials may be used. Bushing carrier 60, which may be made of aluminum, 
is placed with bushing 62 located in a hole 5 in the rails and the hole 
drilled. Bushing carrier 60 is then raised slightly and moved to the next 
hole along rails 4, 6 and 40 as the desired holes are chain drilled. The 
interchangeability of bushing 62 permits drilling of different size holes. 
For example, the holes drilled in connection with parallel rails 4 and 6 
are generally 5 mm, the normal size used for shelf supports and other 
mounting hardware. In contrast, dowel holes drilled in connection with 
rail 40 are generally drilled 8 mm in diameter. 
To drill the dowel holes on the end opposite to end 58 or end 64 (depending 
on which end was drilled first), frame 56 is unclamped from panel 26 by 
loosening clamp nuts 12 and frame 56 is rotated 180.degree.. Gauge 
assembly 28 is used to locate frame 56 so that the centerline of the row 
of holes in third rail 40 is one half of the thickness of panel 84 from 
panel end 58 or 64 in the manner described above. As can be seen in FIGS. 
1 and 2, while rotating frame 56, rail 40 does not drop down due to lip 66 
on the edges of rail 40, resting on the ledges 68 on the ends of parallel 
rails 4 and 6. 
In the alternative, an additional rail (not shown) could also be attached 
to rails 4 and 6 opposite to and in the same manner as rail 40 by using a 
second end rail clamping assembly 48 (not shown). 
If panel 26 is longer than rails 4 and 6, a gap without holes will remain 
in the middle of panel 26. Jig 2 can be repositioned to drill holes in 
this gap by loosening clamp nuts 12 and sliding frame 56 so that rails 4 
and 6 overlap the holes already drilled in each end 58 and 64 of panel 26. 
Rails 4 and 6 are located by inserting a locating pin 44 through one hole 
5 in the top 3 of either rail 4 or 6 and then through one of the 
previously drilled holes. This ensures the holes drilled in the gap will 
all be at 32 mm intervals with the previously drilled holes. Once frame 56 
is properly located, clamp nuts 12 are tightened, locator pin 44 removed, 
and the remaining holes are drilled in the gap. 
As can be seen in FIG. 6, dowelling jig 69 is used to drill the dowel holes 
in the edges of panel 84. Dowelling jig 69 uses one rail 4, 6 or 40, the 
bushing carrier 60, bushing 62, and a pair of centering block assemblies 
70. Each centering block assembly consists of a centering bar 72, having 
two sets of holes into which a pair of protruding centering pins 74 can be 
inserted. Centering guide stud 76, which is threaded on both ends, is 
screwed into a hole in the center of bar 72 on the side opposite from 
centering pins 74. Bar 72, centering guide stud 76 and centering pins 74 
are preferably made of steel but other materials such as aluminum may also 
be used. 
In use, a pair of centering block assemblies 70 are placed with studs 76 
inserted into two holes in any of rails 4, 6 or 40, spaced apart a 
distance slightly less than width 82 of panel 84. With rail 4 positioned 
against the edge of panel 84, block assemblies 70 are rotated clockwise 
until pins 74 register against the top and bottom face of panel 84. This 
aligns rail 4 with the centerline of edge 90 of panel 84. Centering guide 
knobs 78 are then tightened on the free ends of centering guide studs 76 
to lock block assemblies 70 in place. The clockwise turning effect of 
tightening guide knobs 78 on the block assemblies 70 ensures pins 74 
maintain intimate contact with the faces of panel 84. Gauge assembly 28 is 
inserted into the last hole of one end of rail 4 and adjusted as described 
above so that the distance from the edge 86 or 88 to the first hole 
drilled in the edge 90 of panel 84 will be exactly the same as the 
distance from panel 26 edge 24 to the last transverse hole drilled with 
rail 40. This is accomplished by sliding rail 4 along edge 90 of panel 84 
until the gauge rod 36 of the gauge assembly 28 engages edge 86 or 88 of 
panel 84. The dowel holes, typically 8 mm, may now be drilled using 
bushing carrier 60 and bushing 62. Only the matching dowel holes drilled 
at the ends of panel 26 with rail 40 need to be drilled. The first hole 
drilled is preferably opposite the gauge assembly. Once this hole is 
drilled, locator pin 44 can be inserted through hole 5 in top 3 of rail 4 
and then through the hole in the edge of panel 84. Locator pin 44 prevents 
rail 4 from sliding on edge 90 of panel 84 and gauge assembly 28 can be 
removed before the remaining holes are drilled. 
This description is given for purposes of illustration and explanation. It 
will be apparent to those skilled in the relevant art that modifications 
and changes may be made to the invention as described above without 
departing from its scope or spirit.