Apparatus and method for grooving a board-like material, a grooving tool therefor and a structure made by the method

Apparatus and method for forming V-shaped grooves in a board material including a grooving tool having a V-shaped leading cutting edge with a preselected included angle for cutting a V-shaped groove to a preselected depth in the board material, means for producing relative movement of said grooving tool and said board material to cut the V-shaped groove in said board material, guide means for inhibiting nonlinear relative movement of said grooving tool and said board material to cause a straight groove to be cut in said board. The board material thus grooved may be folded to form structures for use as boxes and in certain furniture applications.

BACKGROUND OF THE INVENTION 
The invention relates to forming V-shaped grooves in board materials such 
as paperboard, chipboard and particle board and more particularly to a 
method and apparatus for groove folding such board materials to form 
structures, such as boxes. 
In a desire to lower cost by using more plentiful materials, box makers and 
furniture makers are turning away from wood and the like in favor of 
composite board materials for forming both decorative and structural 
panels. It has been customary, in forming the four sides of a wooden box 
to join four panels together at their edges using a joint such as a butt 
joint or a dovetail joint. However, butt joints are relatively weak and 
dovetail joints involve manipulations which are detailed and therefore 
expensive. Dovetail joints require cutting or punching notches and 
projections in both ends of all boards, applying glue, fitting the 
interlocking notches and projections of the four panels together to form 
the sides of the box and blocking the four-sided structure in a 
rectangular shape until the glue sets. A further finishing operation to 
trim the projections may also be required. In addition to the cost of such 
an operation, the step of cutting or punching the notches and projections 
produces a large quantity of dust and small scrap material which must be 
collected and disposed of. 
Boxes have also been made by routing grooves in flake board with a rotating 
routing tool. Flake board is a dense, hard material made of wood shavings 
and chips bonded into a board. Routing the flake board produces large 
quantities of dust which may present a health hazard to those working with 
this process. 
Paper boxes or box-like structures of light weight paperboard or of 
corrugated paperboard may be fabricated by creasing a single piece of the 
board and folding the board along the crease lines which define the box 
corners. The fold or crease lines are produced by cutting partially 
through the material or by compressing grooves in the material. However, 
compression grooving is not effective to define corners on all thicknesses 
of solid paperboard or particle board. As board thickness increases, the 
stiffness of the board and its limited receptivity to creasing causes the 
board fibers at the outer radii of the corners to crack and break due to 
tension in the fibers. Even at lesser thicknesses, corners formed by 
compression grooving and folding are often unsatisfactory since they are 
rounded and not sharply defined. 
In order to bend thicker paperboard to produce reasonably square corners, a 
process known as step grooving has been used. Step grooving consists of 
removing a first relatively wide and shallow rectangular strip of material 
and then removing a relatively narrow and deep rectangular strip of 
material from the center of the wide and shallow groove. The paperboard is 
then folded along the line thus defined. 
However, step grooving has several disadvantages. Step grooving requires 
two grooves and produces a large amount of scrap. Also, the resulting 
grooves are generally ragged since shreds of paper fibers are attached to 
the walls of the grooves. In addition, the opposed edges of the step 
grooves abut in an irregular fashion when they are folded to form a 
corner. Furthermore, the outside edges of the corners so formed are not 
sharply defined. 
SUMMARY OF THE INVENTION 
The present invention overcomes the disadvantages of the prior art by 
providing a device which slides a V-shaped groove in thick board material. 
The V-shaped groove is cut at a predetermined included angle and is cut so 
that the sides of the V-shaped groove are smooth. Thus, the opposing sides 
of the V-shaped groove form a strong close fitting corner when folded 
together. By controlling the depth of the V-shaped groove in the board, 
the corner may be sharply defined to avoid the rounded corners obtained 
with many prior art methods. 
The present invention also reduces the health hazards associated with the 
dust formed during prior art processes, since each V-shaped groove of the 
present invention is formed by removing a single V-shaped fillet of board 
material which is easily disposed of. Furthermore, the present invention 
is more simple than prior art processes since it replaces the multiple 
grooves of the prior art with a single groove. In addition, by 
preselecting the included angle of the V-shaped groove, strong box-like 
structures having any number of sides and shapes may be formed. These 
structures may be used not only for packaging purposes but also for many 
furniture applications, such as, cabinets and tables. The structures may 
be covered with a decorative laminate to give them an attractive 
appearance. 
According to one aspect of the invention, an apparatus is provided for 
forming a groove in a sheet of board material. The apparatus comprises a 
grooving tool which is provided with a V-shaped leading cutting edge 
having a preselected included angle to cut a V-shaped groove to a selected 
depth in the board material. The board material is guided and maintained 
firmly against a support by a hold down and the V-shaped groove is formed 
by driving the board material relative to the grooving tool to cut the 
V-shaped groove in the board material. Optionally, the grooving tool is 
mounted on the hold down and is adjustable to vary the depth of the 
V-shaped groove formed. 
According to a feature of the invention, a method is provided for forming a 
groove in a sheet of board material. The groove is formed by guiding and 
advancing a sheet of board material relative to the V-shaped cutting edge 
of the grooving tool and cutting a V-shaped groove having a preselected 
included angle to a preselected depth in the board material. After the 
board material is grooved, box like structures may be formed by folding 
the board material along the grooves. 
In order to insure a properly formed groove, the method may also include 
supporting the sheet on a support and maintaining the sheet in firm 
engagement with the grooving tool as the sheet advances relative to the 
grooving tool. 
According to a further feature of the invention, a grooving tool is 
provided for forming a V-shaped groove in board material. The tool 
includes a body which is provided with a V-shaped cutting edge having a 
preselected angle. In one preferred embodiment, the tool includes a body 
having a shank portion and a shoe portion, the shank portion being adapted 
for fastening the grooving tool to a support and, the shoe portion 
preferably including a V-shaped bottom which is adapted for fitting in the 
V-shaped grooves. At the end of the shoe portion a V-shaped leading 
cutting edge having a preselected included angle is formed. Preferably, 
the inner contour of the shoe portion is curved to direct the V-shaped 
fillet cut from the groove away from the sheet. 
The above and other advantages of the invention will become apparent from 
the following description of the preferred embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 illustrates a grooving machine 10 according to an embodiment of the 
invention. Grooving machine 10 includes a base 12 and first and second 
side walls 14 and 16. A heavy roller 18, preferably of steel, is 
journalled in side walls 14 and 16 to rotate in the direction shown by an 
arrow 20. A superstructure 22 mounted between side walls 14 and 16 and 
above roller 18 supports a plurality of hold-downs 24 in a predetermined 
relationship to roller 18 and side walls 14 and 16. Hold-downs 24 may 
optionally be laterally displaceable using, for example, a dovetail 26 
which, although shown in cross section in FIG. 2 for clarity, extends 
substantially the full width below superstructure 22. Thus, hold-downs 24 
can be laterally positioned anywhere across the width of the grooving 
machine between side walls 14 and 16. Hold-downs 24 each include a 
hold-down wheel 66. A grooving tool 28 is affixed to certain hold-downs 
24. A board 30 to be grooved is supported on a platform 76 which is 
positioned tangential to roller 18. Roller 18 which rotates in the 
direction of arrow 20 is belt driven through a pulley 38 coaxial with 
roller 18. A guard 40 prevents accidental contact with pulley 38 or the 
belt. 
Board 30 is fed and pinched between wheels 66 and roller 18 and is thus 
forceably moved in the direction of an arrow 32. As board 30 is advanced 
relative to grooving tools 28, the grooving tools 28 cut V-shaped fillets 
34 from the surface of board 30 forming V-shaped grooves 36a through 36e. 
Although hold-downs 24 are shown in association with grooving tools 28, 
additional hold-downs 24' may be employed to securely pinch board 30 
between hold-down wheel 66 and roller 18. In a preferred embodiment, from 
3 to 6 additional hold-downs 24' are disposed between those shown. If 
insufficient hold-downs are provided, board 30 tends to turn or snake 
while being grooved resulting in curved V-shaped grooves 36. 
The rotating mass of roller 18 smoothly drives board 30 through the 
apparatus. Although it is normal to drive such a roller with a motor of 1 
or 2 horsepower, improved operation is achieved with higher power. In a 
preferred embodiment, a roller weighing about 700 pounds is driven by a 
7.5 horsepower motor. 
FIGS. 2, 3 and 4 illustrate a hold-down 24 maintaining the board 30 in firm 
contact with the roller 18 and maintaining the board 30 in firm contact 
with grooving tool 28 as the board 30 is driven past grooving tool 28. 
Referring to the top of FIG. 2, dovetail 26 is attached to superstructure 
22 using a number of countersunk screws 42 (one of which is shown in 
dashed lines). A slot 44 in hold-down 24 includes a beveled abutment 
surface 46 which is operative to abut a matching beveled surface 48 on 
dovetail 26. A holding member such as, for example, a rectangular plate 47 
is held by two pins 49 (one of which is shown) which pass through plate 47 
and are held fast in hold-down 24. Plate 47 is movable in the direction of 
arrow 51 on pins 49. A screw 50 is suitably threaded through hold-down 24 
and has its ends in stabilizing contact with plate 47 forcing the plate 
into abument with beveled tail surface 52 of dovetail 26. A forward flat 
upper surface 54 and a rear flat upper surface 56 of hold-down 24 are 
drawn upward into stabilizing contact with a flat lower surface 58 of 
superstructure 22 by forcing together the beveled abutment surface 46 and 
beveled surface 48 to securely hold and stabilize hold-down 24 against 
superstructure 22. 
In the lower left hand portion of FIG. 2, a pivoted member 60 within a 
cavity 62 in hold-down 24 is pivoted at an axis 64. Hold-down wheel 66 is 
a bearing which is rotatable on an axle 68 suitably screwed into pivoted 
member 60. A compression coil spring 70, in the right hand portion of FIG. 
2 and also shown in FIG. 3, is biased between the body of hold-down 24 and 
the trailing end of pivoted member 60 to urge pivoted member 60 in the 
clockwise direction of FIG. 2 about axis 64 and thus to urge hold down 
wheel 66 firmly against board 30. A limit screw 72 adjustable by a limit 
nut 74 passes through the helix of compression coil spring 70 to limit the 
outward travel of pivoted member 60 under the urging of compression coil 
spring 70. 
Hold-down 24 may be constructed without a spring-biased pivoted member. 
Satisfactory operation has been obtained using a rigid hold-down 24. The 
effect of a rigid hold-down may be achieved by fully tightening limit 
screw 72 and nut 74 or by fabricating a solid hold-down 24 (not shown) in 
which the hold-down wheel 66 is rotatably affixed to the body thereof. 
Referring also to FIG. 1, a platform or table 76 is provided at the run-in 
side of grooving machine 10 to support and feed board 30 to the nip 
between hold-down wheel 66 and roller 18. A suitable platform or table 
(not shown) may also be provided at the run-out side of the apparatus to 
receive board 30 after the grooving operation is completed. 
As illustrated in FIGS. 2 and 4, grooving tool 28 has a shank portion 78 
and a shoe portion 80. Shank portion 78 is substantially rectangular for 
close abutment to its support member which may be, for example, hold-down 
24 (FIG. 4). A plurality of capscrews 82, passing through slotted openings 
84, are threaded into threaded holes 85 (FIG. 3) in hold-down 24 to 
adjustably clamp grooving tool 28 against hold-down 24. As can be seen in 
FIG. 2, the range of adjustment of grooving tool 28 permits the depth of 
groove 36 to be adjusted to a preselected value which may be shallow or in 
the extreme, fully through board 30 whereby board 30 is severed. Thus, 
dimension d, measured from the bottom of groove 36 to the opposite surface 
of board 30, is controllable by loosening capscrews 82 and sliding 
grooving tool 28 upward and downward guided by slotted openings 84. 
Shoe portion 80 has a V-shaped bottom 86 having a substantially straight 
lower edge 87 and having an included angle 88 (FIG. 4) substantially equal 
to the included angle of fillet 34 and groove 36. V-shaped bottom 86 has a 
V-shaped sharpened leading or cutting edge 92 disposed to cut or slice 
board 30 when it is moved in the transport direction 32 (FIG. 2). The 
opposing sides of V-shaped bottom 86 are substantially coplanar with 
opposing sides of V-shaped edge 92. 
The grooving tool 28 is provided with an inner contour 94, shown dashed in 
FIG. 2 and solid in FIG. 4, which is curved to smoothly lift the V-shaped 
fillet 34 from the position at which it is severed by cutting edge 92 to 
the discharge position shown. 
To resist dulling by the abrasive nature of, for example, particle board, 
at least cutting edge 92 may be made of hardened material such as hardened 
tool steel. In the preferred embodiment, the entire grooving tool 28 is 
hardened tool steel. 
Bottom edge 87 of V-shaped bottom 86 may ride tightly in V-shaped groove 36 
or it may be tilted upward a small angle, such as angle 96. Angle 96 is 
preferably as small as two or ten degrees, inclusive but satisfactory 
operation has been achieved with angle 96 as large as 20 degrees. By 
keeping angle 96 small, cutting edges 92 perform a shaving action on board 
30 to produce a smooth clean V-shaped groove 36. Best operation is 
achieved with angle 96 about 7 degrees. 
The permissible values of included angle 88 of cutting edge 92 depend upon 
the thickness d from the bottom of V-shaped groove 36 to the outside 
surface of board 30. If d is very small (approaching zero), angle 88 may 
approach 90 degrees to form a square corner. As thickness d increases 
somewhat, angle 88 must increase to provide clearance for fibers pressed 
into the inner radius of the bend. An angle as large as 95 degrees has 
given satisfactory results for producing square corners with best results 
being obtained in the range of 91.5 to 93.5 degrees, inclusive. However, 
if d is permitted to grow too large, the corners formed may be rounded. 
In use, hold-downs 24 and attached grooving tools 28 having a preselected 
angle 88 are secured at desired positions along the length of dovetail 26. 
Additional hold-downs 24' may be provided to improve stability. In 
addition to maintaining the grooving tool 28 in firm engagement with board 
30 while cutting the grooves 36, the hold-downs 24 guide the board 30 to 
prevent the board from turning as the grooves 36 are formed. 
The number of grooving tools 28 utilized and the spacing between grooving 
tools 28 is dependent on the number of folds and the shape of the 
structure desired. In FIG. 1, five grooving tools 28 are illustrated and 
are positioned such that the distances between adjacent grooving tools are 
the same. 
Before feeding board 30 between roller 18 and hold-downs 24, the hold-downs 
24 and the grooving tool 28 are adjusted so that the grooves 36 are formed 
properly in the board 30. In order to adjust the tension of hold-down 
wheel 66 against the board 30, limit screw 72 is adjusted. By tightening 
limit screw 72, the coil spring 70 of hold-down 24 is compressed resulting 
in more tension between hold-down wheel 66 and roller 18. When limit screw 
72 is loosened, spring 79 relaxes and tension between wheel 66 and roller 
18 is decreased. Optimally, wheel 66 exerts just enough tension on board 
30 to prevent the board from turning as it passes between the roller 18 
and wheel 66. However, excess tension should be avoided to prevent 
excessive drag on board 30. 
The depth to which grooving tool 28 cuts is adjusted by loosening capscrews 
82 permitting grooving tool 28 to slide along the length of slotted 
openings 84 and move cutting edge 92 either closer to or away from roller 
18. Capscrews 92 are tightened in threaded holes 85 to clamp grooving tool 
28 against hold-down 24 when the desired adjustment is made. The cutting 
edge 92 may be brought close enough to roller 18 such that the cutting 
edge cuts entirely through board 30 and board 30 is severed. In FIG. 1, 
the two grooving tools 28 forming grooves 36a and 36e are adjusted to cut 
completely through board 30. The three interior grooving tools 28 forming 
grooves 36b, 36c and 36d are adjusted to cut to a preselected depth which 
is less than the thickness of the board. 
After the adjustments are made, the grooving machine 10 is operated by 
rotating roller 18 which is belt driven through pulley 38. As roller 18 
rotates in the direction of arrow 20, board 30, which is supported on 
platform 76, is fed between hold-down wheel 66 and roller 18. The board 30 
is driven in the direction of arrow 32 past grooving tools 28. Five 
grooves 36a,b,c,d and e are formed. Grooves 36b,c and d are V-shaped 
grooves and grooves 36a and 36e, which are cut entirely through board 30, 
form beveled ends 100. 
The board 30 with the grooves 36 formed therein is folded along grooves 
36b, c and d until the sides of each groove meet to produce three of the 
four corners of rectangular structure 98 (FIG. 5). The beveled ends 100 
are brought together and secured to form the fourth corner of the 
rectangular structure. 
FIG. 5 illustrates such a rectangular structure or box 98 partially 
assembled, of grooved board 30. Three V-shaped grooves 36, when folded 
until their sides substantially meet, produce three of the four corners of 
rectangular structure 98. The remaining beveled ends 100 of structure 98 
are mated as shown by the dashed line to form the fourth corner of the 
structure. Referring also to FIG. 1, ends 100 are formed by cutting 
V-shaped grooves 36a and 36e completely through board 30 to leave the 
substantially 45 degree beveled ends 100. Thus, when the box structure is 
closed, the beveled ends 100 closely abut each other to complete the 
structure. For strength, glue may be coated on the beveled surfaces of 
grooves 36 and ends 100 before folding into the shape shown in FIG. 5 
whereby the facing surfaces are bonded together. Other means of securing 
the beveled ends of box 98 together such as, for example, metal fasteners 
or flexible tapes, are included within the scope of the present invention. 
FIG. 6 illustrates an S-shaped board 101 used in making a four-sided box 
having a top and bottom. By cutting vertical grooves 102a,b,c and d, and 
horizontal grooves 104a,b,c,d,e, five panels A,B,C,D and E are formed. At 
points along the outer edge of S-shaped board 101, where grooves 102 and 
104 are not formed between two adjacent panels, the grooves 102 and 104 
bevel the circumference of S-shaped board 101 similar to beveled ends 100 
formed on board 30. 
In use, the S-shaped board 101 is driven past four grooving tools 28 of 
grooving machine 10 to form grooves 102a to d. The board 101 is then 
rotated 90 degrees and driven past five grooving tools of grooving machine 
10 to form grooves 104a to e and panels A to E. By folding panels B,C,D 
and E along grooves 104b,c, and d to bring outer edges 110a and 110b 
together, a four-sided structure is formed. Edges 110a and 110b may be 
secured in any convenient manner, such as with a metal fastener. Panels A 
and F form the top and bottom of the structure. Groove 102c between panels 
A and B forms a hinge 113a between panels A and B. Groove 102b between 
panels E and F forms a hinge 112b between panels E and F. When panels A 
and F are folded along hinges 113a and b to form the top and bottom of the 
structure, the beveled circumference of the S-shaped board 101 permits a 
tight fit between panels A and F and the structure formed by panels B,C,D 
and E. The three unattached sides of panels A and F may be attached to the 
structure formed by panels B,C,D and E in any convenient manner. In order 
to form a box which can be opened and closed, the three unattached sides 
of either panel A or panel F may be left unattached or one of the free 
sides may be secured to either panel B,C,D or E with a conventional 
latching device. 
Referring to FIG. 7, another board construction used for making a structure 
is illustrated. A rectangular board 105 is formed having five grooves 
106a,b,c,d and e. Grooves 106a and c at board edges 114a and b bevel the 
edges 114a and b in a manner like beveled edges 100 of board 30. Board 
edges 114c and d are not beveled. The board 105 is provided with two 
additional grooves 108a and b which are at 90 degrees to grooves 106. The 
portion of grooves 106b,c and d between groove 108a and board edge 114c 
and between groove 108b and edge 114d, passes through board 105 and forms 
six cuts 112 in the board 105. Thus, 12 panels, H through S are formed in 
board 105. Panels L, M, N and O may be folded along grooves 106b,c and d 
to bring edges 114a and 114b together to form a four-sided structure. 
Panels H, I, J and K and panels P, Q, R and S may be folded along grooves 
108a and 108b, respectively to form the top and bottom of the structure. 
In use, board 105 is driven past five grooving tools 28 of machine 10 to 
form grooves 106a,b,c,d and e. Cuts 112 may be formed, prior to or after 
grooves 106a to e are formed, by any conventional slicing method. 
Alternatively, cuts 112 may be formed by grooving tool 28 at the same time 
that grooves 106 are formed. However, this requires modifying grooving 
machine 10, by, for example, providing that superstructure 22 be slidable 
vertically relative to arrow 32 and suitably cammed to raise and lower 
grooving tools 28 at fixed intervals. As edge 114c of board 105 is fed 
between roller 18 and hold-down wheel 66, grooving tools 28 may initially 
be set to cut entirely through the board 105 for the length of cut 112. 
Superstructure 22 may slide up in response to a camming device to form 
grooves 106 and then slide down to form cuts 112 in edge 114a of board 
105. 
In order to make grooves 108a and b, the board 105 is rotated 90 degrees 
and driven past two grooving tools 28 of grooving machine 10. 
Once grooves 106 and 108 and cuts 112 are made, board 105 is folded along 
grooves 106b, c and d edges 114a and 114b are abuted next to each other 
and attached to form a box structure with four sides, panels L, M, N and 
O. Panels H, I, J and K may be folded along groove 108b to form the box 
top and panels P, Q, and S may be folded along groove 108b to form the box 
bottom. The top and/or bottom may be secured with glue or other suitable 
means. As an example, the top side of panels P and R may be glued to the 
bottom side of panels Q and S. 
Although FIGS. 5, 6 and 7 depict rectangular structures, it should be 
understood that structures having other shapes and having a different 
number of sides may be made by varying the number of grooving tools 28 and 
the size of included angle 88. 
Generally, the number of grooving tools utilized will directly relate to 
the number of sides of structure formed. If the grooving tools are used to 
form grooves in the interior of a board and also to bevel the edges of a 
board, as illustrated in FIG. 1, the number of grooving tools will be n+1, 
where n is the number of sides of the structure to be formed. If the 
grooving tools 28 are utilized only to form grooves in the interior of the 
board, and the edges of the board are not beveled, n-1 grooving tools will 
be utilized. 
The distance between grooving tools will determine the shape of the 
structure. For instance, in order to form a structure having n sides equal 
in length, the n+1 grooving tools should be provided with an equal 
distance between adjacent tools. To obtain a square structure, five 
adjacent grooving tools should be provided with an equal distance between 
them. A rectangular structure is formed by positioning five grooving tools 
such that the distance between the first and second grooving tools is 
equal to the distance between the third and fourth grooving tools. Also, 
the distance between the second and third grooving tools is equal to the 
distance between the fourth and fifth grooving tools. 
By changing the size of the included angle 88, the angle of the corners 
formed may be varied. Generally, to form a corner having an angle of X 
degrees, the included angle 88 of the grooving tool 28 will be X degrees 
plus an adjustment factor, between 0 and 5 degrees, inclusive. The 
adjustment factor depends upon the thickness d from the bottom of the 
groove to the outside surface of the board. In general, if d is very small 
the included angle 88 may approach the angle desired for the corner being 
formed. As d becomes thicker, the adjustment in the included angle must be 
made to provide for clearance for the fibers pressed into the inner radius 
of the fold. Thus, the angle 88 must be increased. The adjustment does not 
generally exceed 5 degrees. For a structure having n sides each equal in 
length, the included angle 88 will be (360/n) degrees plus the adjustment 
factor. 
Materials utilized with this invention are generally board materials, such 
as paper-based boards, paper board, corrugated paperboard or particle 
board. However, other types of board-like material, including foam board 
or plaster board are also suitable. 
The invention is also especially useful for grooving board materials which 
are generally thicker than those used in the art of box making from 
paper-based materials. It is particularly useful for grooving board 
material of at least 150 points (0.150 inches) and especially for 
materials with thicknesses of from 200 points to 300 points, inclusive. By 
grooving materials of these thicknesses, structures may be formed which 
possess the strength and durability of structures made from more expensive 
materials, such as, plywood or flake board. 
In one application of the invention, a rectangular piece of 250 point 
particle board (about 0.250 inches thick) was coated with a decorative 
vinyl film which simulated a wood grain. The board was grooved with five 
grooving tools in the manner described in FIG. 1. Each grooving tool had 
an included angle of 92 degrees. Adjacent grooving tools were spaced 
equidistant from each other and the first and fifth grooving tools were 
adjusted to cut completely through the board and vinyl film and bevel the 
edges of the board. The second, third and fourth grooving tools were 
adjusted to groove completely through the particle board down to the inner 
surface of the vinyl film. Thus, the board was hinged on the vinyl film 
such that folding the board along the grooves and abutting the two beveled 
edges produced four sharp clean corners. The facing surfaces of the 
grooves were glued and the abutting two beveled surfaces were attached. 
The precision grooving and folding produced a structure simulating a 
wooden cabinet having corners which were strong and accurately formed. 
The terms and expressions employed herein are terms of description and not 
limitation. There is no intention to exclude any equivalence of the 
features shown and described. It is recognized that various modifications 
are possible within the scope of the invention claimed.