This invention relates to improvement in or relating
to Seals for LPG Gas Cylinders.
This invention more particularly relates to tamper proof
Seal for LPG Gas Cylinder.
It is already known to Seal the plug on top of the gas
outlet mouth of a LPG gas Cylinder by different types of Seals
before delivering the Cylinders to Customers.
One type of such a Seal is adhesive paper strip with
characteristic printed matter.
Another type of such a Seal is a strip of plastic thus
film with characteristic printed matter.
The first type is used after plugging the gas outlet in
the usual manner. The paper strip is tightly covered covering the
withdrawal prong like pin so that the pin is not exposed for
withdrawal. One has to break the paper Seel before tampering
with the pin.
The second type is also similar to the first with the
only, differences that the plastic film has its ends fused.
In both the cases, it is very easy to tamper with the
Cylinder and refix the plug using substitute identical paper
strip or plastic film which can be easily manufaeturedvery
cheaply.
A third variety is now very cpomonly used to avoid the
drawbacks of the first two varieties.
This is in the form of an aluminium or tin cap and rubber
plug with a tearable strip portion already punctured or marked
by weakened lines running vertically down the side of the Cap.
This Cap is usually inserted on the top of the mouth of the
Gas Cylinder and its lower ends are crimped to hold on to the

under surface of the nut on the top of the mouth.
Though this construction or seal has solved the problems
and drawbacks associated with the above two mentioned seals,
nevertheless it has its own drawbacks.
One such drawback is that the punctured head of the
tearable strip lying horizontally along the top surface of the seal
is not in a lifted condition as otherwise it will cause injuries
to the fingers while handling. It lies flush with the top horizontal
surface and has to be first punctured using instrument,like a
small knife or screw driver and then lift the head.
another
And/drawback is that the tearable portion, in majority
of instances does not get torn right from the top end to the
tail end and again some small instrument is needed to remove the
untorn portion before removing the cap. This is possibly
because the tearable portion russ from the top horizontally, takes
a 90® bend to run along the vertical side and again takes a 90°
bend to run the small horizontal portion of the crimped region
under the nut . Handling such an imperfect metal Cap can cause
injury to the fingers.
It is therefore an object of this invention to propose
such a Cap or seal for LPG Cylinders which will overcome all
the above drawbacks and ensure a smooth operation without any
chance of injury to the fingers.
It is another object of this invention to suggest such
a seal which can be relied upon and can not easily duplicated.
It is yet another object of this invention to propose
such a seal, which after use, can be recycled, thus making the
manufacturing cost cheap and economical, and at the same time avoi-
ding pollution problem to a great extend.

These and other objects of the invention will be apparent
from the following paragraphs.
There is provided according to this invention,
a pilfer proof Cap/Seal made of resilient plastic as
herein described for LPG Cylinder comprising a cylinderically
formed Cap/Seal, having a vertical side wall having an open
lower end with its top end merging with a flat top wall portion,
said top wall portion having a centrally formed opening with a ride
alaround housing the head of a tearable flat strip portion, the
portion of the ride forming part of the tearable strip having
weakend sections along both sides of the tearable strip, said
weakend section running continuously vertically down the side
wall, until the lower most end, the inner side of the cylinderical
side wall having provided thereon a plurality of locking rims
diametrically opposite to one another, and the portion of the
inner side wall forming the breadth of the tearable portion and
also the diametrically opposite portion of the inner side wall
being free of the locking ribs.
The Flat top portion and the top end of the side wall
meet at 90°.
A part of the ridge of the horizontal top wall portion is
ened
formed as a part of the tearable strip with weak side section
and wherein the head of the tearable strip extends horizontally and
lie in the circular opening.
The under side of the head of the tearable strip has a
bulbous portion adapted to seal the mouth of the gas outlet
of a LPG cylinder when the Cap/Seal is placed in position.

The weakened tearable section is formed of a series of
punched holes or slots or serrations or thin wall.
The weakened section is preferably formed on the inner
surface of the side wall.
The lower end of the side wall is formed as a slightly
flared section.
The inner surface of the side wall is provided with a
set of locking ribs, preferably at the junction of the vertical
portion and the beginning of the flared portion of the side
wall.
The locking ribs are formed diametrically opposite to
each other.
The locking ribs are preferably two in number and/or
formed circumferentially along the inner wall of the cap.
These two ribs are formed diagonally opposite each other.
The longth of each locking rib is specially adjusted for
successfully performance of the cap. The portion forming the
earable strip and the two adjacent weakened portion one or either
side of the strip are free of the locking ribs. Similarly, the
portion diametrically opposite the earable strip is also free of
the locking strip.
The shape of the locking strip is also carefully formed
in that its cross section resembles that of a Right angle
triangle with hypotenuse formed as a curbed portion. That is
one side of the Right angle portion lies along the vertical
inner wall and the other Right angle side extends vertically
from the upper end of the other vertical side when viewed from
the top side of the cap.

When in operation, the cap is simply pressed downwards
on the mouth of the cylinder. In view of the curbed portions
of the locking ribs, these ribs simply glide or slip along the
nut.
The distance between the under surface of the top wall
and upper surface of the ribs is equal to or slightly more than
the distance between the top of the mouth of the gas outlet and
the under surface of the nut on the mouth of the cylinder.
In view of this; as soon as the cap in position the top
vertical side of these two locking ribs lie under the under
surface of the nut. It is now possible to pull out the cap. To
remove the cap the tearable portion is to be removed.
The ribs are integrally moulded in the cap.
The invention will now be more fully described with
reference to the accompanying drawings where s
Figure 1 illustrates a Front side View of the article.
Figure 2 illustrates a Top View of the article.
Figure 3 illustrates a Bottom View of the article.
Figure 4 illustrates a Right Side View of the article.
Figure 5 illustrates a Top Prospective View of the article.
Fiaure 6 illustrates a Bottom Perspective View of the
.^ article.

The steal is madd of a resilient plastic thin sheet material
and
of suitable thickness, moulded to required size/shape. It can thus
be made of plastics like PVC, TEFLON and other such suitable
material.
It will be seen from the various figures of the drawings

that the seal 1 has a top horizontal circular portion 2 and a

substantially vertical wall portion 3, the outer horizontal portion
2 and the top vertical portion meeting at 90°.
The horizontal portion 2 is provided substantially with

a central circular opening 4 leaving a circular rim 5. A part
r
of the horizontal portion is formed as a part of a tearable
strip 6^with the head, lying flush in the cut out opening 4.
The both the sides 6a & 6b of the head of the tearable
portion are provided with narrow weakened portions 7a and 7b
facilitating tearing when necessary.
The weakened portions 7a & 7b 'continue as portions 8a & 8b
vertically along the side wall 8 of the seal. The weakened portions
7a,7b, 8a & 86 are preferably formed as continuous small notches
along the interior wall of and top of the seal, though these can
be formed externally. For aesthetic purposes these are formed
along the interior wall and top.
It is not beyond the scope of the invention to form such
weakened portions in the form of a series of clos punctured
holes or slets or serrations or other equivalent or any combination
of these forms.

The lower end of the side wall 8 is formed as a slightly-
flared portion 8e for purposes explained hereinafter.
The interior of the side wall 8 is provided with a pair of
locking ribs 8c and 8d disposed diametrically opposite to each
/formed right angled triangle
other. Each rib 8c and 8d is almost semicircular/inshape and is
/ and has the hypotenuse facing the interior.
of a thin section, /Theselocking ribs 8c and 8d are preferably
formed internally at the place where the flared portion 8c of the
side walls starts. However, the distance between the inner side of
the horizontal top wall and the rib is preferably such that the
ribs lie under the nut on the mouth of the outlet opening in a
locking manner. This distance may however be slightly larger,
though not necessarily so.
The thickness 8e of the ribs is uniform and is judiciously
selected to satisfactorily lock underneath the above said nut.
The locking ribs 8c & 8d are not continuous and are two
independent means. The portion forming. the tearable strip and
the diametrically opposite portion in the inner wall of the cap
are free of these locking ribs for satisfactory operational and
functional reasons.
The operation of thebseal/cap is as follows.
When a LPG Cylinder is to be sealed, the seal/cap is held
vertically on top of the top gas outlet and just pressed down
until the locking ribs reach the under surface of the nut on the
mouth of the cylinder. After pressing it is just left the
locking the gas outlet. The under side of the head of the tearable
portion is provided with a bulbous portion 6c adapted to seal
the mouth of the gas outlet.
The slightly flared portion of 8c of the side wall facilitate

the insertion of the Cap/Seal and also resiliently acts on the
locking ribs pressing these twowards the under surface of the nut.
The Cap/Seal can not be just pulled out because of the combined
functions of the locking ribs and the flared wall portion.
When the Gap/Seal is desired to be removed, the head of the
temrable portion is lifted, held between the thumb and the next
finger and pulled.
The tearable strip starts breaking or freeing itself along
the weakened lines until it reaches the lower most end and is
freed. Because there is no crimpring of the lower end as in the
metal Cap/Seal, the removal of the tearing portion is easy.
Moreover, as it is a pliable plastic, the elastic strength allows
uniform tearing throughout and not breaking at intermediate locations a
as in the metal Cap/Seal.
The Cap/Seal can be easily removed. The used plastic can be
recycled for making fresh Caps/Seals.
To add to aesthetic value, the caps can be conveniently
made of translucent material which may be coloured as desired.
It is also possible to have the tear tab heed running
from the lower end to the top end, or horizontally or from one
end to the other end. diagonally cross-wise. Preferably the
horizontal tear strip can be located at the position of locking
ribs, so that the locking ribs are also removed when the tear
is pulled out.

We Claim:

1. A pilfer proof Cap/Seal made of resilient plastic as
herein described for LPG Cylinders comprising a cylinderically formed
Cap/Seal, having a vertical side wall having an open lower end with
its top end merging with a flat top wall portion, said top wall
portion having a centrally formed opening with a ridge alaround
housing the head of a tearable flat strip portion, the portion
of the ride forming part of the tearable strip having weakened
sections along both sides of the tearable strip, said weakened
section running continuously vertically down the side wall, until
the lower most end, the inner side 6£ the cylinderical side wall
having provided thereon a plurality of locking ribs diametrically
opposite to one another, and the portion of the inner side wall
forming the breadth of the tearable portion and also the
diametrically opposite portion of the inner side wall being
free of the locking ribs.
2. A Pilfer proof Cap/Seal as claimed in Claim 1, wherein
the flat top portion and the top end of the side wall meet at 90o .
3. A pilfer proof Cap/S eal as claimed in Claim 2 wherein a
part of the ridge of the horizontal top wall portion is formed
as a part of the tearable strip with weakened side section and
wherein the head of the tearable strip extends horizontally and
lied in the circular opening.
4. A pilfer proof Cap/Seal as claimed in Claim 3 wherein
the under side of the head of the tearable strip has a bulboua
portion adapted to seal the mouth of the gas outlet of a LPG
cylinder when the Cap/Seal is placed in position.

5. A Pilfer proof Cap/Seal as claimed in Claims 1 to 4 wherein
the weakened tearable section is formed of a series of punched
holes or slets or serrations or thin wall.
6. A Pilfer proof Cap/Seal as claimed in Claim 5 wherein the
weakened section is formed on the inner surface of the side wall.
7. A Pilfer proof Cap/Seal as claimed in Claim 5 wherein the
weakened section is formed on the external surface of the side
wall.
8. A Pilfer proof Cap/S eal as claimed in Claims 1 to 7 wherein
the lower end of the side wall is formed as a slightly flared section.
9. A Pilfer proof Cap/Seal as claimed in Claim 8 wherein the
inner surface of the side wall is provided with a set of locking
ribs, preferably at the Junction of the vertical portion and the
beginning of the flared portions of the side wall.
10. A Pilfer proof Cap/Seal as claimed in Claim 9 wherein the
locking ribs are formed diametrically opposite to each other.
11. A Pilfer proof Cap/Seal as claimed in Claim 10 wherein the
locking ribs are xxxxxxxxx formed. as right angled triangle
with the hypotenuse facing the interior.
12. A Pilfer proof Cap/Seal as claimed in Claim 11 wherein the
distance between the under surface of the top wall and upper
surface of the ribs is equal to or slightly more than the distance
between the top of the mouth of the gas outlet and the under
surface of the nut on the mouth of the cylinder.
13. A Pilfer proof Cap/Seal as claimed in Claims 1 to 12,
locking
wherein the / ribs are two in number and are diametrically
opposed to each other.

14. A Pilfer proof Cap/Seal as claimed in Claims 1 to 13
wherein each locking rib has a cross section resembling a right
angled triangle with the hypotenuse facing the interior of
the cap.
15. A Pilfer proof Cap/Seal as claimed in Claim 14, wherein
the hypotenuse is of slightly curved shape.
16. A Pilfer proof Cap/Seal as claimed in Claim 14, wherein
one vertical side of the triangular portion lies along the
interior wall of the cap while the other vertical side extends
at 90° c from the top of the other vertical side.
17. A Pilfer proof Cap/Seal for LPG cylinder substantially
as herein described and with reference to the accompanying
drawings.

A pilfer proof Cap/Seal made of resilient plastic as
herein described for LPG Cylinders comprising a cylinderically formed
Cap/Seal, having a vertical side wall having an open lower end with
its top end merging with a flat top wall portion, said top wall
portion having a centrally formed opening with a ridge alaround
housing the head of a tearable flat strip portion, the portion
of the ride forming part of the tearable strip having weakened
sections along both sides of the tearable strip, said weakened
section running continuously vertically down the side wall, until
the lower most end, the inner side 6£ the cylinderical side wall
having provided thereon a plurality of locking ribs diametrically
opposite to one another, and the portion of the inner side wall
forming the breadth of the tearable portion and also the
diametrically opposite portion of the inner side wall being
free of the locking ribs.