Apparatus for forming shaped edges

An apparatus for forming shaped edges which includes a support table, means for securing components to be shaped to the support table, and shaping means which are mounted upon the table and can be moved relative to the table. The shaping means is guided for at least part of its travel by cam means which are arranged to guide the shaping means so as to cut profiles of pre-determined shape in the components to be shaped.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to apparatus for forming shaped edges which 
co-operate to form a neat, high-precision joint. The apparatus of the 
present invention has been designed with especial reference to the cutting 
of bench top components which are to be joined together with a "masons 
mitre" type of joint, and will be described with especial reference to 
this application, but it will be appreciated that the apparatus could be 
used in any application where similar requirements apply. 
2. Description of the Prior Art 
Bench tops generally are made of wood or wood product board such as 
"Customwood" (Trade Mark) or particle-board. The edge of the bench 
generally is reinforced to double-thickness, and the top surface of the 
board generally is clad with a laminate such as "Melteca" or "Formica" 
(Trade Marks). Thus, cutting a shaped edge of precise shape is not easy: 
the cutter must cut accurately through a considerable thickness of board, 
without splintering the laminate or the board. Any inaccuracy or roughness 
will result in an ill-fitting and unsightly joint. 
Hitherto, joints of this type have been cut with a spindle-moulder, and 
hand-finished with a file or a plane, or cut with a hand-held router, in a 
jig. Both methods are relatively slow, and need a skilled operator for 
consistently good results. 
BRIEF SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide apparatus 
capable of overcoming the above-described drawbacks. 
The present invention provides apparatus comprising: a support table; means 
for securing components to be shaped to said table; and shaping means 
mounted upon said table and movable relative thereto; said shaping means 
being guided for at least part of its travel by cam means arranged to 
guide said shaping means to cut in said components profiles of 
predetermined shape. 
Preferably, said shaping means includes a frame supporting two routers, 
mounted so that the router blades rotate in opposite senses. 
Preferably also, two components are cut simultaneously: one component is 
secured to one side of the table, the other components to its other side, 
and the shaping means is arranged to travel between said components, in a 
slot formed down the centre of the table.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to FIGS. 1 and 2 and a first preferred embodiment, the apparatus 
2 comprises a table 3 which provides two co-planar surfaces 4 for 
supporting the bench components (not shown) to be shaped, and shaping 
equipment 5 mounted between said surfaces 4. The surfaces 4 are 
substantially horizontal, and bench components to be shaped lie flat, one 
on each of said surfaces, with the edges to be shaped adjacent the 
inner-edges 4a of said surfaces. In use, the bench components are held in 
place by pneumatically-operated clamps (not shown) which press the bench 
components down into tight engagement with the surfaces 4. 
The shaping equipment 5 includes a pair of routers 6, 7, of known type, 
both mounted in a supporting frame 8 with the router blades vertical, and 
with one router above the table and the other below, so that the blades of 
both routers contact the corresponding bench component to be cut in the 
same direction of rotation: it is important for the formation of a clean 
cut that the router blade rotates so as to push the bench component away 
from the blade, or the component will tend to catch on the blade, and the 
cut will be ragged. The directions of rotation of the router blades are 
indicated by arrows A and B in FIG. 1. 
The supporting frame 8 is mounted on bearings 9 which travel on spaced 
parallel rails 10, extending along the length of the table 3. The frame 8 
is moved along the rails 10 by a pneumatic ram 11 mounted between the 
table 3 and the frame 8. 
FIG. 2 shows in detail the mounting of one of the routers 6; the other 
router 7 (not shown) is mounted in exactly the same manner, but in 
reverse, with the body of the router below the table. The router 6 is 
supported upon a plate 12, with the longitudinal axis of the router blade 
vertical. The plate 12 is rigidly secured to a pair of arms 13, each of 
which is rigidly secured to the body of one of a pair of parallel 
pneumatic cylinders 14. The cylinders 14 are of the through-rod type, and 
the ends of the rod are secured one to each of a pair of parallel vertical 
plates 15, mounted on the bearings 9. A cam plate 16 having the required 
profile for the bench component to be cut by the router 6 is mounted on 
the arm 13 adjacent the end of the table 3; in the starting position of 
the apparatus, said cam plate 16 bears against one of a pair of co-axial 
cam followers 17, 18, mounted on the adjacent end of the table. 
A second cam plate 19, secured to a corresponding arm 20 associated with 
the router 7 (not shown in FIG. 2) bears against the cam follower 18. 
The pneumatic cylinders associated with both routers 6, 7 are set to bias 
each of the cam plates 16, 19, firmly against the corresponding follower. 
The above-described apparatus is used as follows: the two board components 
to be shaped are placed one on each surface 4, with the inner edge of each 
board component projecting inwards of the edge of said surface 4, and are 
clamped in these positions by the pneumatically-operated clamps. 
The shaping equipment 5 is initially in the starting position shown in FIG. 
1, in which both cam followers 17, 18 are in contact with the initial 
straight portions 16a, 19a, of the respective cam plates. The routers 6, 7 
are started, to rotate the cutting blades, and then the ram 11 is operated 
to push the shaping equipment 5 along the rails 10, down the length of the 
table (arrow C). As the shaping equipment 5 is moved, the cam plates 16, 
19, are still being biased into contact with the followers 17, 18, so the 
arms 13, 20, to which the cam plates 16, 19 are secured, move in response 
to the shape of the respective cam plate a the shaping equipment 5 travels 
along. 
Thus, the routers 6, 7 are moved in the manner dictated by the profile of 
the corresponding cam plates 16, 19, cutting the appropriate profiles in 
the board components. 
The speed of the ram 11 is increased once the required profiles have been 
cut and the cam followers reach the end of the corresponding cam plates. 
This speed increase may be effected by the operator, or arranged to occur 
automatically once the ram 11 has reached a predetermined point in its 
travel. 
Referring to FIG. 3 and a second preferred embodiment of the invention, a 
single cam plate 30 is arranged to bear against a cam follower 31 secured 
to one end of the support table (not shown). The cam plate 30 is rigidly 
secured to the side of a rectangular frame 32, which is supported in a 
vertical plane by through-rods 33 mounted between plates 34 (only one of 
which is shown) which are secured to the bearings (not shown) as described 
with reference to FIGS. 1 and 2. 
The frame 32 is movable in a horizontal plane by a pneumatic cylinder 35 
secured to the centre of one end 38 of said frame 32 and bearing against 
the plate 34. The travel of the cylinder 35 is limited by a limiting screw 
(not shown) which extends through an aperture 36 in the opposite end 37 of 
the frame. The screw is adjustable in length. One router 6 (not shown) is 
attached to, and moves with, the frame 32. 
The other router 7 (not shown) is attached to and moves with the second 
frame 40, only part of which is shown. The frame 40 and its associated 
through-rods 41 and pneumatic cylinder (not shown) are directly above, and 
a mirror image of, the lower frame 32 and its associated equipment. 
A stop 45 is rigidly secured to one end wall 42 of the frame 40, and the 
end of the stop is arranged to contact the outer surface of the end wall 
38 of the frame 32. 
Except as described above, the remainder of the apparatus is the same as 
the first preferred embodiment. 
The above-described apparatus is used as follows: as described above for 
the use of the first preferred embodiment, the pneumatic cylinders are 
arranged to bias the cam plate 30 into engagement with the follower 31, 
the routers are started, and the ram 11 is operated to push the shaping 
equipment down the length of the table. 
As the frames 32, 40 and the associated routers 6, 7 move down the length 
of the table, the frame 40 is urged in the direction of arrow D by its 
pneumatic cylinder, and this presses the stop 45 hard against the frame 
32, so that both frames 32, 40, and their routers follow the contour of 
the cam plate 30, and the routers therefore cut complementary profiles on 
each of the associated board components. 
The fact that only a single cam plate is used means that any minor 
inaccuracies in the cam profile are self-compensating, since they appear 
in both components. 
In the case of a typical bench-top, only part of the cam profile is 
required to be cut on the upper board component, and this is achieved 
simply by limiting the stroke of the upper pneumatic cylinder, using the 
limiting screw. Once the end of the cylinder contacts the limiting screw, 
the cylinder, and hence the associated frame and router, can travel no 
further in the direction of arrow D, and the lower frame and router 
continue on their own, since the lower pneumatic cylinder has not yet 
reached the end of its stroke. 
It will be appreciated that the shape of the profile cut in each board 
component (for either embodiment) may be varied as required, simply by 
altering the corresponding cam shape.