Sealed tag

A label in accordance with the present invention includes a base having a transparent window and an adjacent frame at least substantially surrounding the window, the frame being at least somewhat thicker than the window; a locating projection on the base for repeatably positioning an indicia bearing insert at least partially within the window; alignment holes on the frame; a cover having a transparent window portion and an adjacent frame portion at least substantially surrounding the window portion; alignment projections cooperating with the alignment holes for positioning the cover and base relative to each other with the transparent window portions of the cover and base at least substantially in registration; and at least one seal formed between the cover and the base at least substantially surrounding the window portions of the cover and the base for forming a sealed pocket for receiving an indicia bearing insert.

This invention relates generally to indicia bearing signs or tags and more 
particularly to a sealed tag assembly of particular utility in providing 
bar code labels in radioactive environments. 
Many industrial applications and particularly thermonuclear generating 
plants require tags or labels for various equipment, valves, switches and 
other apparatus and controls to enable operators to quickly identify, 
inventory or otherwise locate and select from among similar looking 
articles. 
Recently, it has become desirable to provide tags or labels with machine 
readable indicia such as bar codes, particularly for inventory purposes, 
but also for identifying equipment such as valves, pumps, instruments, 
tanks and the like that have been repaired or replaced, read in the case 
of instruments; or adjusted or the like in the case of valves and other 
controls. In areas where high levels of radioactivity are present it is 
important that the tags or labels be immediately readable both to 
operators and by bar code scanners. Operators must enter and leave 
radioactive areas quickly. Delay in reading a sign can cause the operator 
to be unduly exposed to excess radiation. This issue is called throughout 
the industry an ALARA concern (As Low As Reasonably Achievable). While 
sophisticated bar code scanners can eventually read even not very clear 
labels, providing a tag or sign having a high first time read rate may be 
critical in hazardous environments. 
Radioactive environments such as nuclear plants have additional stringent 
requirements on tags or signs. The signs must be UV stable, must not 
contain chlorine, and must be easy to decontaminate. Small or microscopic 
radioactive fleas tend to work their way into cracks and crevices, 
unsealed assemblies and the like. Fleas come from spent fuel. Fuel rods 
are highly radioactive. It is essential that tags or signs designed for 
use in a radioactive environment be resistant to picking up such fleas, 
and easy to decontaminate. Parts having crevices can spread the fleas to 
an operator. They are hard to detect, yet can cause sterility. 
Because extremely dangerous situations can be created by accidental 
mislabelling, as might occur if a marker falls off a control, or is 
intentionally altered by vandals, it is critical that tags in the nuclear 
industry be sturdy, permanently mounted and vandal resistant. Studies have 
shown that over 54% of accidents in nuclear plants are directly or 
indirectly related to improper or unreadable tags, including moved tags or 
vandalized tags. 
It is desirable to provide a tag or label that can be printed and assembled 
on site so as to provide the capability for immediately replacing a tag 
that has been accidentally destroyed, for labelling newly installed 
equipment and relabelling existing equipment as necessary due to changes, 
and the like. 
Heretofore, while tags or signs have been available that are more or less 
suitable for use by the nuclear industry, all such tags or signs have 
suffered from one or more disadvantages related to the above mentioned 
requirements. For example, a commonly employed sign is printed on paper 
which is then embedded in fiberglass. Such a tag has a number of 
disadvantages. Fiberglass is hydroscopic and the absorption of water makes 
the fiberglass hazy and any indicia on the tag, particulary bar code 
indicia, more difficult to read. Fiberglass blooms and the individual 
fibers become whiter after time. This also increases the difficulty of 
reading the indicia, particularly the bar code indicia. Fiberglass coated 
paper is, even in the absence of water absorption and blooming, more 
difficult to read than uncoated paper because the indicia are covered by a 
layer of material that is at best only close to transparent which must be 
optically penetrated by a bar code reader to read the coded indicia. In 
order to provide fiberglass embedded paper signs of sufficient strength to 
prevent their being easily broken, the signs must be quite thick, which 
further increases the difficulty of reading them. The fiberglass coating 
on printed paper labels causes the ink on the paper to bleed at least 
slightly and this makes the labels harder to read. Polyester based labels 
which exhibit significantly less bleeding cannot be used as an insert for 
fiberglass coated labels because the fiberglass does not penetrate the 
polyester and the overall assembly tends to fall apart. In addition, where 
the paper labels are printed on a laser printer, the toner tends to 
dissolve in the fiberglass embedment/coating process and this also causes 
bleeding. Fiberglass labels therefore provide less than ideal solution to 
labelling requirements. 
Another commonly employed label has a laminated printed label attached to a 
metal substrate. The process for making such a label is relatively 
complicated and includes the steps of laser printing the label, setting up 
a laminater, over laminating the label, renewing the laminater setup, 
underlaminating the label, setting up the die cutter, die cutting the 
labels, stripping premask from the metal substrate, aligning the label 
with the substrate and adhering the two, and punching the assembled tag 
with the required number of holes. The foregoing steps will produce a 
one-sided label. Where a two-sided label is needed, the laser printing, 
laminating and mounting steps must be repeated for each side. 
A label in accordance with the present invention overcomes many of the 
disadvantages of known labels in a tamper resistant sealed tag 
particularly designed for use in a radioactive environment, and including: 
a base having a transparent window and an adjacent frame at least 
substantially surrounding the window, the frame being at least somewhat 
thicker than the window; 
a first upstanding rib on the base for receiving and positioning an indicia 
bearing insert at least partially within the window; 
first alignment means on the frame; 
a cover having a transparent window portion and an adjacent frame portion 
at least substantially surrounding the window portion; 
second alignment means cooperating with the first alignment means for 
aligning the cover and base relative to each other with the transparent 
window portions of the cover and base at least substantially in 
registration; a recess in the cover for engaging the first upstanding rib; 
and 
at least one seal formed between the cover and the base at least 
substantially surrounding the window portions of the cover and the base 
for forming a sealed pocket for receiving an indicia bearing insert. 
A tag in accordance with this invention has a number of advantages over 
known tags. The tag is particularly well suited for providing information 
on one or two sides. A universal tag holder can readily be fabricated that 
will hold a two-sided or one-sided insert without change. 
The tag of the present invention utilizes easy to line up plastic inserts 
that can be laser printed on site and readily aligned on the base through 
the use of the locating means. The tag body is preferable made from 
polyester or a Lexan polycarbonate resin and the seals are formed by 
ultrasonically welding the cover and base in a loop formed in the frame 
portion of the cover and base, to seal the indicia bearing label within 
the tag. In an alternative construction, the tag of the present invention 
can be easily assembled on site and is particularly well adapted to the 
use of labels printed from computer data bases. The alternative 
construction is not sonically welded. It is assembled with pressure alone. 
The seals are formed at approximately the same locations as the ultrasonic 
seals, but are not welded, relying solely on pressure. 
The tag of the present invention is thicker at the edges than in the center 
and, even when it is provided with through holes in accordance with the 
present preferred embodiment of the invention is particularly strong in 
the otherwise potentially weakened region of the holes. 
The present tag is watertight and easy to decontaminate. The smooth outer 
profile and preferable double weld of the present tag make decontamination 
and removal of radioactive fleas much easier than is the case with 
previously known tags. 
The present tag allows easy customization for a wide range of mounting 
approaches, such as vertical or horizontal orientation. The tag can be 
readily made with a number of holes well suited for a variety of 
particular applications. 
The present tag can be readily manufactured in an adhesive stick-on 
configuration. The outer surface of the flat cover is particuarly well 
suited for receiving a layer of adhesive to adhere the tag to a flat 
surface. In a preferred embodiment of the invention, the top radius of the 
tag is smaller than the bottom radius of the tag, thereby making it more 
difficult to pry the tag off a door, tank or other piece of equipment. 
It is a feature of a preferred embodiment of the invention to provide a 
matte finish for reducing glare.

A sealed label or tag in accordance with this invention is shown in FIG. 1. 
The tag 10 (as used herein "tag" is intended to comprehend tags, signs, 
labels, and the like, having the construction described herein) is 
generally rectangular in peripheral shape, and has a generally rectangular 
frame 12 surrounding an at least substantially transparent viewing window 
14. A plurality of through holes 16 is provided in the frame for attaching 
the tag to an article to be labelled. Preferably, the tag is manufactured 
from clear thermoplastic material, such as polycarbonate resin of the type 
sold under the trademark Lexan. The material is selected to be chlorine 
free and suitable for ultrasonic welding. 
Preferably, the tag bears identifying indicia such as alpha-numeric indicia 
indicated by the series of X's and machine readable bar code indicia 18. 
The transparent window portion of tag 10 is selected to permit the bar 
code indicia 18 to be read by a conventional scanning wand or the like, 
and is preferably about 0.044 inches thick. 
The construction of the tag may be more readily appreciated by referring 
now to FIG. 2 in which the tag is shown in an exploded view. The tag 
includes a base 20, one or more indicia bearing inserts or labels 22 and 
24, and a cover 26. The base and cover are preferably formed from 
polycarbonate resin as mentioned, while the indicia bearing members are 
preferably formed from thin sheets of polyester selected to provide a high 
contrast surface when printed, for example, in a conventional laser 
printer. Like the housing, the indicia bearing members are selected to be 
free from chlorine. One or two indicia bearing members may be used. When a 
second is used, the indicia visible on the first is ordinarily duplicated 
on the second, so that the tag may be read from either side. In the 
alternative, one label printed on each of two sides could be used. 
A plurality of aligning pins 30 is provided on the inner surface of the 
cover member 26 for insertion into blind bores 32 formed in the frame 
portion of base member 20. A plurality of aligned through mounting holes 
16 is provided in the base and cover member respectively, for facilitating 
mounting of the tag by conventional fasteners, such as screws, wire, 
string or the like. 
The construction of the cover member is shown in more detail in FIGS. 3 
through 6A. As shown in FIGS. 3 and 4, the cover member has a relatively 
flat outer surface 40, with relatively sharp radius connections to short 
vertical side walls 42, to allow tamper resistant adhesive fastening to a 
flat surface. The short radius corners make it more difficult to pry the 
tag from such a surface. Aligning pins 30 are preferably spaced uniformly 
around the periphery of the tag, generally centrally within the width of 
the frame. Through holes 16 extend completely through the cover member, 
and are preferably provided with an enlarged countersunk recess on the 
inner surface of the cover member for mating with a projection on the base 
member, as shown and described below. 
A groove 46 surrounds the transparent, window portion 14 of the tag 10 for 
receiving an upstanding rib on the base member, as will also be described 
below. 
FIGS. 5 and 6 are enlarged segmental sections taken along corresponding 
section lines in FIG. 3, and show the through holes 16, groove 46 and pin 
30 in more detail. Preferably a groove 48 surrounds each pin 30, as shown 
most clearly in FIG. 6, for receiving a corresponding annular projection 
on the base member. 
As shown in FIGS. 5A and 6A, ultrasonic focusing projections in the form of 
rings 50 and 52 in the frame portion surrounding the window portion 14 are 
disposed on the inside surface of the peripheral frame portion of the tag 
for facilitating ultrasonic welding of the tag base and tag cover. Each of 
the focusing or concentrating projections forms a continuous loop on the 
surface of the frame portion of the tag for forming a sealed cavity for 
the printed label, which cavity is resistant to penetration by radioactive 
fleas or other particles, and likewise resistant to the entry of moisture 
and the like. As used in its broad sense herein, seal preferably refers to 
an ultrasonically welded seal, but also encompasses adhesive and other 
seals including pressure seals formed between flat surfaces. 
The base member of a tag in accordance with this invention is shown in more 
detail in FIGS. 7 through 12. 
FIG. 7 shows the base portion of the tag in top plan view (looking from the 
inside out). Like the cover, the base has a transparent window portion 70, 
which may be larger or smaller, but is preferably the same size and shape 
as the window portion 14 of the cover member. A peripheral frame 72 
surrounds the transparent window portion and, as shown in FIG. 8, is 
preferably somewhat thicker than the window portion, so that overall, the 
base, and the entire tag when assembled, have a cross-sectional shape 
somewhat like a doughnut with a depression in the center rather than a 
hole. The shape resembles a dog bone with one flat surface. The thicker 
frame portion 72 increases the strength of the tag, and provides for the 
aligning and joining members, as well as the mounting holes. A plurality 
of blind bores 32 is disposed centrally within the frame region 72 for 
receiving the pins 30 of the cover member, as shown in FIGS. 10 and 12. 
The base is provided with an inner label receiving area 80 in registration 
with the transparent window portion 70 and surrounded by an upstanding 
peripheral rib 82 for receiving a label and maintaining it in position 
during assembly of the tag. In accordance with a presently preferred 
embodiment of the invention, the label receiving area and rib 82 are 
generally rectangular with slightly rounded corners 83. The rim 82 extends 
upwardly from the base of a larger cavity 84 for receiving the cover 
member. The cavity 84 is circumscribed by an upstanding peripheral rim 86 
that guides and receives the cover member in registration with the base 
member, and preferably forms a snug fit for excluding particles and the 
like from entering the interior of the tag. The ribs 82 and rim 86 are 
shown even more clearly in FIGS. 9 through 12. The base member is also 
provided with through holes 16 in registration with the through holes 16 
of the cover member for forming mounting holes that extend completely 
through the tag for attaching the tag to an article, as described above. 
As can be seen most clearly in FIG. 12, when the base member and cover 
member are assembled, the completed tag forms an inner compartment or 
chamber 90 for receiving the labels. The chamber is isolated by a tortuous 
path over rib 82, the upstanding rim 88 surrounding blind bore 32, and rim 
86 of the base. In addition, seals are preferably formed at 92 and 94, 
either by gluing or more preferably ultrasonic welding, for which purpose 
focusing projections 50 and 52 are provided, as described above. Providing 
a dual weld is particularly advantageous for excluding contaminated 
particles. 
While the invention has been described in connection with a presently 
preferred embodiment thereof, those skilled in the art will recognize that 
many modifications and changes may be made therein without departing from 
the true spirit and scope of the invention, which accordingly is intended 
to be defined solely by the appended claims. For example, as mentioned, a 
contact adhesive or the like may be provided on the flat surface 40 of the 
cover for adhesively securing the tag to a labelled article. The frame 
portion of the tag may be color coded and/or finished in a matte or 
similar finish to provide a distinctive appearance.