Machine for erecting strawberry lug

Method and apparatus for forming a tray are disclosed. The tray has at least one transverse hollow wall formed by a pair of substantially parallel, spaced flaps that are folded down from a transverse bridge. Each flap is secured to a tab folded upwards from the bottom of the tray. A pair of pivotally-mounted folding arms located above the tray rotate the two flaps downwardly while a mandrel located beneath the tray forces the two tabs upwardly into a substantially parallel, spaced relationship, whereby each tab contacts and becomes secured to its respective flap.

BACKGROUND OF THE INVENTION 
This invention is in the field of boxes and box-folding. More specifically, 
this invention relates to method and apparatus for erecting a tray having 
at least one transverse, hollow divider wall formed by two flaps folded 
downwardly from a transverse bridge into a substantially parallel, spaced 
relationship, wherein each flap is secured to a tab folded upwards from 
the bottom of the tray. For convenience, a tray having these features will 
be referred to as a "strawberry lug." One tray of this type is disclosed 
in U.S. Pat. application Ser. No. 881,169, filed Feb. 17, 1978, entitled 
"Shipping Container and Blank Therefor," hereby incorporated by reference. 
U.S. Pat. No. 3,965,804 discloses a ram-operated crease-breaker that forces 
the lower panel of a partially formed tray upwardly into a die. The die is 
formed by two planes intersecting at an angle and has a U-shaped recess 
located at the imaginery line of intersection of the two planes. The die 
is rigidily mounted within a housing that is moved up and down by a second 
ram. The combined action of the two rams (the bottom ram moving the 
crease-breaker up and the upper ram moving the die down) is to crease and 
fold the lower panel into two vertical walls, one wall for each of two 
separate compartments. 
U.S. Pat. No. 3,978,744 discloses a tray-forming machine having an 
expandable mandrel that forces a blank down into a die. While the 
expandable mandrel is disposed within the partially formed tray inside the 
die, a pair of pivotally mounted squeezer plates are brought into a 
substantially vertical position, thereby pushing connecting flaps against 
outer walls of the tray. 
U.S. Pat. No. 2,863,369 discloses a machine for erecting walls of 
paperboard containers. A vertical reciprocating member is hingedly 
connected to several pairs of rigid link members, and the other end of 
each link is pivotally connected to one of several folding plates that are 
hingedly connected to the frame of the machine. Downward movement of the 
vertical member causes the folding plates to rotate downwardly from a 
horizontal to a vertical position, thereby folding down cross-partition 
and inner end wall panels. 
U.S. Pat. No. 4,034,656 discloses a mandrel in a partition-straightening 
station of a box-forming machine, said mandrel having a plurality of 
downwardly pointing cones mounted on a support plate. Between each cone 
and the support plate is a die having the desired shape of its respective 
tray cell. Downward movement of the mandrel forces each cone and then its 
associated die between the partition walls, thereby aligning the walls of 
that cell. 
SUMMARY OF THE INVENTION 
Broadly, the present invention relates to method and apparatus for forming 
a strawberry lug. To erect such a tray, each tab must be folded upwards 
and held in position while its respective flap is folded downward, to 
allow securing of the tab to the flap. When glue is the securing means, 
the tab and flap must be brought into contact for a sufficient length of 
time to allow proper adhesion of flap to tab before the contacting means 
are removed. Additionally, the glue should not be visible in the finished 
tray. Finally, whatever securing means is used, tray erection should be 
rapid, foolproof, and economical. 
These and other objections are achieved by means of apparatus built in 
accordance with the present invention. One such apparatus is a machine 
having several forming stations wherein one station comprises tab-folding 
means for folding the tabs towards the transverse bridge into a 
substantially parallel, spaced relationship, and flap-folding means for 
folding the flaps towards the tabs. In a preferred embodiment, the 
tab-folding means of that station is a reciprocating mandrel (or ram) and 
the flap-folding means is a pair of rotatably-mounted folding plates, the 
mandrel and folding plates cooperating in a manner to be described. This 
station may be said to contain a "folding-ram assembly." 
None of the patents discussed above discloses such apparatus, let alone 
cooperating folding plates and mandrel.

DETAILED DESCRIPTION OF THE INVENTION 
This invention relates to method and apparatus for erecting a strawberry 
lug, and, in particular, for erecting the one or more hollow divider 
wall(s) of the tray. Such trays may be used for transporting produce, such 
as, strawberries, in small baskets. Several of these trays may be stacked 
within a box for shipping. 
These trays may be made from paper products, e.g., paperboard, or from 
other materials capable of holding the desired tray shape and having 
satisfactory physical properties, for example, tensile strength. The tray 
may be of any size, but generally is from 14 to 24 inches long, 8 to 16 
inches wide, and 2.5 to 6 inches deep and has the configuration shown in 
FIG. 6B (view 374). 
Blanks for a strawberry lug may be made by machine or hand, preferably by 
machine. Such blanks may be pre-printed, pre-folded, and stored until 
needed. 
One embodiment of the present invention is shown in the drawings, which 
embodiment is a lug-erecting machine having a folding-ram assembly for 
forming the hollow divider wall of the lug. 
For clarity, certain obvious elements have been omitted in the drawings. 
For example, the control panel, electrical wiring, pneumatic lines, most 
of the air supply system, the glue unit, tubing connecting the glue unit 
to the glue guns, the exit pusher assembly (which ejects the formed 
strawberry lug from the machine, over a waterfall, and onto the outfall 
tracks), and the outfall tracks are not shown. The construction, 
placement, and functioning of these and the other missing items will be 
obvious to one skilled in the art. Additionally, again for the sake of 
clarity, certain elements shown in one figure may not be shown in the 
other figures. 
Turning now to the drawings, FIGS. 1, 2, and 3 are, respectively, partial 
side, top, and end views of machine 20, which erects the strawberry lug. 
Not shown in FIGS. 1 or 3 are emergency stop button 128 or casters 122. 
Machine 20 comprises lower frame 22 and upper frame 142. The folding-ram 
station, indicated by reference numeral 400, is located at the left of 
FIGS. 1 and 2. A partially pre-folded blank is placed by an operator 
between infeed flap guides 94 (at the right of FIGS. 1 and 2), and the 
blank is pushed through all of the forming stations except the last (the 
folding-ram station) by one of six flight bars 54, which are attached to 
the two roller chains 50 by chain attachment links 56. (Six flight bars 54 
are shown attached to roller chains 50; however, more or less may be used, 
depending primarily on the width of the lug.) 
Motor 24, acting through torque limited 26, rotates sprocket wheel 28 in a 
counter-clockwise direction in FIG. 1. Roller chain 40 transmits this 
counter-clockwise motion to sprocket wheel 30 and, thus, to large sprocket 
wheels 38 (sprocket wheels 30 and 38 are rigidly mounted on shaft 32, 
which is itself rotatably mounted in bearings 34). Movement of sprocket 
wheels 38, in turn, causes counter-clockwise movement of roller chains 50, 
which ride on sprocket wheels 38, 44, and 46. Sprocket wheels 44 are 
rotatably mounted on idler arms 42 or outriggers 48, and sprocket wheels 
46 are rigidly attached to shaft 36, rotatably mounted in bearings 35. 
Flight bar aligners 64 are attached to flight bars 54 and ride on frame 
center panel 144 to maintain proper orientation of the flight bars (see, 
also, FIG. 8). Flap-scoring mandrel 66 is attached to upper frame 142 by 
support bars 140. Mandrel extension 126, shown only in FIG. 1, is attached 
to mandrel 66. A portion of air supply system 58 is shown at the left of 
FIG. 1. 
To fold the flaps of the blank, various plowbars, rods, and plates are 
provided. Inner flap scoring plows 72 are attached to inner flap plowbars 
134 by support plates 156 and are attached to upper frame 142 by forward 
supports 148 and rear supports 146. Plowrod hangers 76 connect top flap 
plowrods 74 to upper frame 142. Outside flap plowbars 78 are connected to 
lower frame 22 by rear, middle, and forward support bars 158, 160, and 
162, respectively, and top support brackets 70. Plowbars 78 are, for most 
of their length, rod-shaped, but become bar-shaped at one end. This is 
most easily seen in FIG. 1. Inner flap plowrods 136 are connected to 
supports 149, which are attached to supports 147, which, in turn, are 
carried by supports 146. 
Three pairs of glue guns apply glue to the lug as it is erected. Forward 
glue guns 104, having nozzles 110, are attached to lower frame 22 by 
mounting plate 88 and mounting supports 90. Internal glue guns 106, having 
nozzles 112, are attached to upper frame 142 by mounting plate 82 and 
supports 84. Rear glue guns 108, having nozzles 114, are attached to lower 
frame 22 by mounting plates 86 and supports 92. 
Three photoelectric cells, only two of which are shown, are used for 
control purposes. When the blank breaks a beam of light associated with a 
particular photocell, one or more machine functions are activated. 
Photocell assembly 100 (including a light source, a photoelectric cell, 
and a function circuit card) is attached to upper frame 142 by mounting 
plate 98. The reflector for this photocell assembly is mounted on frame 22 
below the assembly but is not shown in the drawings. Rear photocell 
assembly 132 is attached to upper frame 142 by mounting plate 130. 
Reflector 120, associated with photocell assembly 132, is attached to 
lower frame 22 by bracket 118. 
The locations of forward and rear glue shields 152 and 154, respectively, 
are shown in dotted lines. In FIG. 2, the normal location of glue unit 
102, which rests upon support bars 138, is shown in dotted lines. The 
location of the control panel 116 is also shown in dotted lines. 
Other support elements shown are supports 96, connecting infeed flap guides 
94 to upper frame 142, and top support base bars 68, to which top support 
brackets 70 are attached. Bars 68 sit above and are attached to 
flap-scoring mandrel 66. Air valves/mufflers 150 are also shown in FIG. 1. 
Finally, in FIG. 3 several parts of folding-ram assembly 400 are shown. 
Cranks 458 and 460 are rotatably mounted in frame 408 on shafts 436 and 
468, respectively, and are connected to one another by forward ocnnecting 
rod 422. Outer and inner folding plates 418 and 420, respectively are 
shown in their normal position, that is, folded down. 
FIG. 4 is a top view of folding assembly 404 of folding-ram station 400. 
Center shafts (jackshafts) 412 and 468 are rotatably mounted within frame 
408 and are functionally connected by meshed Boston gears 428. Outer 
shafts 436 and 466 are also rotatably mounted within frame 408. Four pairs 
of folding arms 410 connect outer folding plates 418 to outer shafts 436 
and 466 and connect inner folding plates 420 to center shafts 412 and 468. 
Crank 458 is rigidly attached to outer shaft 436 and rotatably connected to 
forward connected rod 412 through bearing 430 and bolt 432. Spacer 434 
separates the crank handle from the bearing. The other end of rod 422 is 
rotatably connected to center shaft 468 by a similar bearing, bolt, and 
spacer arrangement. 
Rotation of center shaft 468 causes counter-rotation of center shaft 412 
through meshed gears 428. Shaft 412 carries crank 462, which, in turn, is 
rotatably connected to rear connecting rod 456 by bolt 432 and bearing 
430, separated by spacer 434. The other end of rod 456 is rotatably 
connected to crank 464 by a similar bolt, bearing, and spacer arrangement. 
Crank 464 is rigidly mounted on shaft 466. 
Air cylinder 426 is pivotally connected to mounting plate 416 by means of 
clevis 454. Air cylinder 426, which is double air-actuated, normally keeps 
driveshaft 424 extended from the cylinder. Driveshaft 424 is rotatably 
connected to crank 414 by bolt 432 and bearing 430, with spacer 434 in 
between. The strawberry lug travels through folding-ram station 400 
between rollers 406, only one of which is labeled. 
FIG. 5 is a plan view of a preferred blank 300, from which a strawberry lug 
may be erected. Blank bottom assembly 304 comprises bottom end flaps 312 
and bottom wall panel 322. Glue flap 302 lies to the left of bottom wall 
panel 322. Blank bottom assembly 304 contains ventilation holes 324, 
center tab holes 326, and tab holes 330, tab holes 332, and center tabs 
328, separated by cut-score line 329. 
Blank top assembly 308 comprises top end flaps 316, transverse bridge panel 
334, center wall panel flaps 336, and inner end panel flaps 338. Cut-score 
lines 344 lie between each pair of inner end panel tabs 346 and center 
wall panel tabs 348. 
Side wall assembly 309 comprises side end flaps 314 and side wall panels 
306. Side wall assembly 310 comprises side end flaps 320 and side wall 
panel 318. Also shown are cut-outs 340, 341, and 358. 
Dashed lines in the drawing indicated score lines in the blank along which 
folding will occur. 
Before this blank can be erected by the machine of FIG. 1, the blank is 
folded along major score lines 360 and 362, and flap 302 is glued to side 
wall panel 318. The configuration of the blank following this step is 
shown as view 364 in FIG. 6A. The blank is then "squared up," that is, 
transversely compressed so that side wall panels 318 and 306 become 
perpendicular to top and bottom assemblies 308 and 304. Additionally, the 
trailing pair (and, optionally, the leading pair) of side end flaps 320 
are folded inwardly, as shown in view 366 of FIG. 6A, where both pairs of 
flaps 320 have been folded. (By "leading" or "trailing" is meant, 
respectively, closer to, or farther from, the discharge end of the 
machine, to the left in FIG. 1.) 
As will be appreciated, because the blank in view 366 occupies more space 
than in view 364, the blank is usually transported to the machine of FIG. 
1 while flattened (view 364). The blank is then squared-up, one or both 
pairs of side end flaps 320 are folded inwardly (view 366), the blank is 
placed on roller chains 50 between infeed flap guides 94, and the next 
available flight bar 54 starts the movement of the blank through the 
machine. 
View 368 of FIG. 6A shows center wall panel flaps 336 separated from inner 
end panel flaps 338. The center wall panel flaps have been moved up, away 
from bottom wall panel 322, and the inner end panel flaps have been 
rotated downwardly, towards panel 322. Additionally, glue 350 is being 
shot from glue guns 104 and nozzles 110 onto side end flaps 320 to form 
glue lines 352 (only one of which is shown). 
In view 370, bottom end flaps 312 have been folded upwardly to contact and 
adhere to side end flaps 320. Glue is being shot from internal glue gun 
nozzles 112 to form glue lines 356 on center wall panel flaps 336, which 
have been rotated upwardly. Glue lines 354 are being formed on the 
underside of top end flaps 316 by glue shot from rear glue guns 108 (only 
one of which is shown). 
View 372 of FIG. 6B shows top end flaps 316 rotated downwardly to contact 
and adhere to bottom end flaps 312. Also, center wall panel flaps 336 have 
been rotated downwardly, to a plane approximately parallel to bottom wall 
panel 322. 
The finished strawberry lug is shown in view 374. Center wall panel flaps 
336 have been folded downwardly so that they are substantially parallel to 
one another and are separated by transverse bridge panel 334. Center wall 
panel tabs 348 have been inserted into center tab holes 326, and center 
tabs 328 have been folded upwardly into a substantially parallel spaced 
relationship. Each center tab 328 is attached to its respective center 
wall panel flap 336 by glue line 356. Also, inner end panel flaps 338 have 
been folded downwardly so that they are substantially perpendicular to 
bottom wall panel 322, and are held in place by inner end panel tabs 346, 
which are inserted into end tab holes 330. 
FIG. 7 is a cross-sectional view of view 374 of FIG. 6B, taken along line 
7--7, and shows inner end panel flaps 338 lying next to side end flaps 
320. Bottom end flaps 312 lie between top end flaps 316 and side end flaps 
320. Center wall panel flaps 336 are substantially parallel to one another 
and are adhered to center tabs 328. The ends of inner end panel tabs 346 
and of center wall panel tabs 348 project below bottom wall panel 322. 
FIG. 8 shows the blank of view 366 having just been fed to the machine of 
FIG. 1 for erection. The blank rides on roller chains 50 and is being 
pushed by flight bar 54, which is connected to roller chains 50 by chain 
attachment links 56. Flight bar aligner 64 rides on frame center panel 144 
to maintain flight bar 54 in the proper orientation with respect to the 
blank. 
As the blank moves in the machine direction (from right to left, as 
indicated by the arrow), bottom end flap 312 will be moved upwardly by 
outside flap plowbars 78, and top end flaps 316 will be rotated downwardly 
by top flap plowrods 74. Glue will be shot from glue guns 104 through 
nozzles 110 onto side end flaps 320. Center wall panel flaps 336 will be 
rotated upwardly by inner flap plowbars 134, and inner end panel flaps 338 
will be rotated downwardly by inner flap scoring plows 72, thereby 
separating center wall panel flaps 336 from inner end panel flaps 338 at 
cut-score lines 344. 
FIGS. 9 to 14 are partial end views of the machine of FIG. 1, looking along 
the machine direction. Many elements are omitted from these drawings so 
that the co-action of the machine and blank during lug erection may be 
more clearly seen. Additionally, for clarity, only a sectional view of the 
blank, taken along line 7--7 of FIG. 6B is shown in these drawings. FIG. 9 
is a sectional end view of FIG. 8 (note that infeed flap guides 94 and 
glue guns 104 are not shown). 
FIG. 10 shows the blank moved farther along the machine. Top end flap 316 
and bottom end flap 312 have broken the light beam associated with 
photocell 100 (FIGS. 1 and 2), and this, in turn, has caused glue guns 104 
to shoot glue 350 at side end flaps 320. Additionally, bottom end flaps 
312 have been brought into contact with outside flap plowbars 78, causing 
those flaps to rotate upwardly. The leading edges of center wall panel 
flaps 336 have been pushed against inner flap plowbars 134, and inner end 
panel flaps 338 have been pushed against inner flap scoring plows 72. This 
has separated center wall panel flaps 336 from inner end panel flaps 338 
along cut-score lines 344, upwardly rotated the former, and downwardly 
rotated the latter. 
In FIG. 11, the blank has progressed sufficiently through the machine so 
that bottom end flaps 312 have contacted the end, bar portions of outside 
flap plowbars 78, causing bottom end flaps 312 to contact the glue 
previously applied to the outside of side end flaps 320. At this point, 
left top end flap 316 is no longer breaking the beam of light associated 
with photocell 100. This has caused rear glue guns 108 to apply glue to 
the underside of top end flaps 316 and internal glue guns 106 to apply 
glue to center wall panel flaps 336. The trailing portions of center wall 
panel flaps 336 are still contacting inner flap plowbars 134 (shown in 
dotted lines), thus holding center wall panel flaps 336 sufficiently 
upright for application of the glue. Inner end panel flaps 338 are still 
being depressed by inner flap scoring plows 72. 
FIG. 12 shows the blank at a point where top end flaps 316 are being forced 
against top flap plowrods 74, causing the flaps to rotate downwardly. The 
bar portions of outside flap plowbars 78 are still contacting bottom end 
flaps 312. Inner end panel flaps 338 are still being depressed by inner 
flap scoring plows 72, and transverse bridge panel 334 is lying against 
flap-scoring mandrel 66. Center wall panel flaps 336 are contacting inner 
flap plowrods 136, thereby downwardly rotating flaps 336, which no longer 
contact inner flap plowbars 134 as in FIG. 11. 
Further progression of the blank through the machine causes flaps 316 to 
contact, and thereby adhere to, bottom end flaps 312, and causes inner 
flap plowrods to rotate center wall panel flaps 336 downwardly to point 
towards bottom wall panel 322. Additionally, the leading edge of the blank 
interrupts the beam of light associated with photocell assembly 132 (see 
FIG. 2), causing air cylinder 426 (FIG. 13) to pressurize so as to retract 
driveshaft 424. This retraction pressurization ultimately causes outer 
folding plates 418 and inner folding plates 420 to rotate upwardly into a 
horizontal position, as will be explained below. Flight bar 54 continues 
to push the blank until the latter has entered the folding-ram station. 
(Because of reliability, it is preferred that air cylinders 426 and 442 be 
double air-actuated; however, either could be single air-actuated and 
contain biasing means, e.g., a spring, to keep its piston normally 
extended or retracted. Furthermore, solenoids or other reciprocating means 
could be used instead of air cylinders.) 
Referring to FIGS. 4 and 13, retraction of driveshaft 424 causes cranks 414 
and 458 and shaft 436, on which both cranks are rigidly mounted, to rotate 
clockwise. (In discussing operation of the folding-ram assembly, the 
directions "clockwise," "counter-clockwise," "right," and "left" are with 
reference to FIG. 13.) This moves forward connecting rod 422 to the right 
(in the same direction as driveshaft 424 moves when it retracts), causing 
clockwise rotation of left center shaft 468. 
Because of the interconnection of center shafts 468 and 412 by meshed gears 
428, clockwise rotation of shaft 468 results in counter-clockwise rotation 
of shaft 412. Crank 462 then rotates in a counter-clockwise fashion and 
pushes rear connecting rod 456 to the left (away from the air cylinder), 
which causes counter-clockwise rotation of crank 464 and left outer shaft 
466. The four folding plates, attached to shafts 436, 412, 468, and 466, 
are, thus, moved to the horizontal by retraction of driveshaft 424. 
Extension pressurization of air cylinder 426 causes the reverse of the 
movements described, resulting in downward rotation of the folding plates 
to the vertical. Note that clevis 454, attached to one end of air cylinder 
426, allows the other end and driveshaft 424 to move up and down with 
respect to the frame. Such up and down movement occurs as the folding 
plates go from the vertical to the horizontal, and vice versa, because the 
bolt connecting driveshaft 424 to crank 414 follows an arcuate path. 
Movement of the folding plates to the horizontal allows the 
partially-erected strawberry lug to be pushed into the folding-ram station 
by the flight bar. 
FIG. 13 shows the blank within the folding-ram station, the final station 
of the machine. Ram assembly 402 lies below the blank. Flanges 440 and 
stand-offs 450 are attached to plate 438, which is connected to lower 
frame 22. Mandrel 444 is attached to mandrel mount 446, which is connected 
to air cylinder shaft 452 and rods 448. Air cylinder shaft 452 moves 
within mandrel air cylinder 442 (double air-activated), and rods 448 move 
up and down within flanges 440. Standoffs 450 help gauge the spacing 
between the tip of mandrel 444 and the bottom of the blank. When mandrel 
444 is fully retracted, such spacing is preferably from 0.25 to 0.50 
inches. Also, the centerline of mandrel 444 preferably lies in the same 
vertical plane as the cut-score line between center tabs 328. 
In FIG. 13, inner end panel flaps 338 and center wall panel flaps 336 are 
all inclined towards bottom wall panel 322. The blank is no longer carried 
by roller chains 50 or pushed by flight bar 54, and instead, the blank 
rides between rollers 406. Center tabs 328 are positioned directly above 
mandrel 444, which is retracted. 
When the blank has completely entered the forming station, it no longer 
breaks the beam of light associated with photocell assembly 132 and 
reflector 120 (FIG. 14). This results in extension pressurization of 
mandrel air cylinder 442, which forces mandrel 444 upwardly, and in 
extension pressurization of air cylinder 426, which forces driveshaft 424 
outwardly, causing all four folding plates to rotate downwardly. 
Downward movement of outer folding plates 418 rotates flaps 338 downwardly 
and forces inner end panel tabs 346 into end tab holes 330. Downward 
movement of inner folding plates 420 rotates flaps 336 downwardly and 
forces center wall panel tabs 348 into center tab holes 326. The ends of 
tabs 346 and 348 project below the bottom of the strawberry lug. At the 
same time, upward movement of mandrel 444 pushes center tabs 328 from a 
horizontal to a vertical position. 
The combined effect of the upward movement of mandrel 444 and downward 
rotation of inner folding plates 420 is to force each center wall panel 
flap 336 against its respective center tab 328. Glue previously applied to 
each flap 336 (see FIG. 11) secures the flap to the center tab it 
contacts. 
In the finished strawberry lug, center wall panel flaps 336 are in a 
substantially parallel, spaced relationship, each secured to its 
respective upwardly folded center tab 328 and separated by transverse 
bridge panel 334. The hollow wall thus formed imparts greater strength and 
rigidity to the strawberry lug. 
The leading edge of the next blank carried by roller chains 50 towards the 
folding-ram station interrupts the beam of light reflected from reflector 
120 to photocell assembly 132. As explained above, this causes retraction 
pressurization of air cylinder 426, which, in turn, causes inner and outer 
folding plates 420 and 418 to return to the horizontal. Interruption of 
the light beam also causes retraction pressurization of mandrel air 
cylinder 442, which lowers mandrel 444 to the position shown in FIG. 13. 
Finally, movement of the next blank into the folding-ram station forces 
the strawberry lug just formed to move out of the station. The leading 
edge of the formed lug then breaks a light beam associated with a third 
photocell assembly (not shown). This activates a pusher assembly (not 
shown) to force the finished strawberry lug over a waterfall (not shown), 
from which it falls onto a stack of previously erected lugs. 
As will be obvious to one skilled in the art, many modifications and 
variations in the present invention can be made. The claims are intended 
to cover all such modifications and variations.