Bottle cap

The present application discloses a bottle cap for a medicine bottle, such as a small bottle or vial or the like, in which the cap main body and a removable member made of the same metallic material are securely fixed to each other by cold pressure welding while forming therein pressed concave portions in an annular shape. Said cap main body and said removable member are provided within said pressed concave portions in the annular shape thereof with upwardly expanded portions. Thus, the present invention provides a good airtight cap which is easy to be manufactured and which can be heat-sterilized.

BACKGROUND OF THE INVENTION 
Generally a vial is used in such a way that a rubber stopper press-fitted 
to the vial neck is covered with a cap, a predetermined portion of the cap 
is then removed, and an injection needle is passed through such removed 
portion. 
In a conventional cap, a through-bore has been formed in the top plate of 
the cap main body made of metallic material and a resinous removable 
member has been attached on this through-bore of the top plate. When 
intending to open the cap, this removable member is raised up to break the 
attached portions thereof. With such arrangement, however, the attached 
portions may not be provided with good airtightness and it is not possible 
to heat-sterilize the cap with the removable portion remained as attached 
to the cap main body, since the removable member is made of resin. 
Accordingly, such cap has not sealingly been fitted in the aseptic 
condition to the rubber stopper and subsequently the rubber stopper 
portion through which an injection needle is passed, has not been covered 
in the aseptic condition. This has required a sterilization method other 
than heat-sterilization, so that complicated and therefore expensive 
sterilizing equipment has been necessary. Moreover, since such 
conventional cap comprises a metallic cap main body and a resinous 
removable member, complicated manufacturing equipment has also been 
required. 
OBJECTS OF THE INVENTION 
It is an object of the present invention to provide a bottle cap in which, 
by merely pushing up the periphery of the removable member with the thumb 
of the hand holding a bottle, a predetermined portion of the top plate of 
the cap main body may be broken, so that the removable member may be 
removed with one hand, thereby to facilitate the cap opening procedures to 
a great extent. 
It is another object of the present invention to provide a bottle cap in 
which the cap main body and the removable member may be formed by stamping 
and securely fixed to each other by cold pressure welding, thereby to 
provide good airtightness to prevent the entrance of bacteria, as well as 
to facilitate the manufacturing of such cap. 
It is a further object of the present invention to provide a bottle cap in 
which the cap main body and the removable member are made of the same 
metallic material such as aluminium, thereby to facilitate fixing of the 
cap main body to the removable member by the cold pressure welding and to 
permit such cap to be heat-sterilized just before sealingly fitted to a 
vial after having been delivered from factory, whereby such cap may 
sealingly be fitted in the aseptic condition to a rubber stopper, thereby 
to simplify cap sterilizing equipment and to facilitate sterilizing 
procedures. 
It is still another object of the present invention to provide a bottle cap 
in which upwardly expanded portions are formed within the inside of the 
pressed concave portions in the annular shape formed in the removable 
member and the cap main body, thereby to easily absorb expansion of the 
rubber stopper due to the internal pressure in a vial. 
It is a still further object of the present invention to provide a bottle 
cap in which pressed concave portions in the annular shape formed by cold 
pressure welding for securely fixing the top plate of the cap main body 
and the base plate of the removable member to each other, are formed thin 
so that, when opening the cap, the annular pressed concave portion of the 
top plate of the cap main body is easily broken to facilitate the opening 
procedure. 
It is a still further object of the present invention to provide a bottle 
cap in which annular scores are formed in the under surface of the pressed 
concave portion of the top plate of the cap main body, thereby to permit 
the cap to be easily opened with a small and constant opening force, and 
such scores may be formed simultaneously with forming the pressed concave 
portions for fixing the cap main body top plate to the removable plate, 
thereby to facilitate the manufacturing of such cap. 
It is a still further object of the present invention to provide a bottle 
cap in which an annular projection is formed at the under surface of the 
top plate of the cap main body at the outside of the annular pressed 
concave portion thereof so as to be press-contacted to the upper surface 
of a rubber stopper press-fitted to the bottle neck, whereby the top plate 
of the cap main body perfectly come in close contact with the rubber 
stopper, thereby to prevent the entrance of foreign matter such as 
bacteria or dust into the pressed concave portions from the clearance 
between the rubber stopper and the top plate. 
It is a still further object of the present invention to provide a bottle 
cap in which a rolled-in ring is formed at the periphery of the removable 
member, thereby to reinforce the periphery of the removable member, 
simultaneously with forming a contact member to which the finger is 
applied when intending to remove such removable member, thereby to 
facilitate the removing operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The description will first be made of a first embodiment of a bottle cap 
according to the present invention, with reference to FIGS. 1 and 2. 
A cap main body 1 made of metallic material such as aluminium has a top 
plate 2. A side wall 3 is formed by downwardly turning the periphery of 
the top plate 2. A removable member 4 is made of the same metallic 
material, such as aluminium, as material of the cap main body 1. This 
removable member 4 has a base plate 5. A side plate 6 is formed by 
upwardly turning the periphery of the base plate 5. A rolled-in ring 7 is 
outwardly turned at the upper edge of the side plate 6. Pressed concave 
portions 8 and 8' are formed in the annular shape at the center portions 
of the top plate 2 of the main body 1 and the base plate 5 of the 
removable member 4 by cold pressure welding of the base plate 5 of the 
removable member 4 overlapped onto the top plate 2 of the cap main body 1. 
Thus, the cap main body 1 is integrally secured to the removable member 4 
by such pressed concave portions 8 and 8' formed by the cold pressure 
welding. It is to be noted that the pressed concave portions 8 and 8' are 
formed thin. Expanded convex portions 5' and 2' of a generally spherical 
shape are formed within the annular pressed concave portions 8 and 8' of 
the base plate 5 and the top plate 2. The outer diameter of the rolled-in 
ring 7 is preferably the same as or slightly larger than the outer diamter 
of the side wall 3 of the cap main body 1. 
A description now made of the cap shown in FIGS. 1 and 2 fitted to a vial, 
with reference to FIG. 3. 
Mounted to the neck 10 of a vial 9 is a rubber stopper 12 having a 
cylindrical portion 11 press-fit to the inner wall of the neck 10. The cap 
main body 1 of a sterilized cap is then put on the rubber stopper 12 and 
the vial neck 10. The lower portion 13 of the side wall 3 of the cap main 
body 1 is rolled in to the lower surface of the vial neck 10 for 
preventing the rubber stopper 12 from coming up from the neck 10, as well 
as for sealingly fitting the cap to the neck 10 through the rubber stopper 
12. 
When opening the cap, the vial 9 is held with one hand and the rolled-in 
ring 7 is obliquely pushed up. The thin pressed concave portion 8 of the 
top plate 2 of the cap main body 1 is then broken, so that the expanded 
portion 2' of the top plate 2 is removed from the top plate 2, thereby to 
form a circular bore in the top plate 2. 
Accordingly, with the thumb of the hand holding the vial to which the 
bottle cap according to the present invention is sealingly fitted, the 
periphery of the removable member 4 may be pushed up, and such pushing 
operation alone permits the predetermined portion of the top plate 2 of 
the cap main body 1 to be broken away, thus realizing a one-handed removal 
of the removable portion thereby to facilitate the cap opening operation 
to a great extent. 
Since the cap main body 1 and the removable member 4 may be formed by 
stamping and securely fixed to each other by cold pressure welding, a good 
airtightness may be provided to prevent the entrance of bacteria and also 
the manufacturing may easily be done. 
Furthermore, since the cap main body 1 and the removable member 4 are made 
of the same metallic material, such as aluminium, they may readily be 
fixed to each other by cold pressure welding and be sterilized, for 
example by heating, just before being fitted to a bottle after having been 
delivered from the factory, thereby to simplify sterilizing equipment and 
to facilitate the sterilizing procedures. 
In addition, since the upwardly expanded portions 2' and 5' are formed 
within the annular concave portions 8 of the cap main body 1 and the 
removable member 4, it is possible to absorb expansion of the rubber 
stopper 12 due to the internal pressure in the bottle. 
Moreover, since the rolled-in ring 7 is formed at the peripheral edge of 
the removable member 4, the periphery of the removable member 4 may be 
reinforced and such rolled-in ring 7 may also serve as contact portion for 
the finger at the time of the cap opening operation, thereby to facilitate 
the opening procedures. 
Although, in the embodiment discussed hereinbefore, the side plate 6 of the 
removable member 4 has been formed by upwardly turning the peripheral edge 
of the base plate 5, such side plate may also be formed by downwardly 
turning the peripheral edge of the base plate 5 so as to form a rolled-in 
ring by outwardly turning the lower edge of the side plate and to be 
press-contacted to the side wall 3 of the cap main body 1. Such 
press-contact serves to prevent the entrance of dust or dirt into the 
clearance between the top plate 2 of the cap main body 1 and the base 
plate 5 of the removable member 4. 
It is to be noted that, when the cap main body 1 and the removable member 4 
are made of Alumite, the stability of the press-welding by the cold 
pressure welding may be improved. 
The description will then be made of a second embodiment of the present 
invention with reference to FIGS. 4 and 5. 
A cap main body 14 is made of metallic material such as aluminium. This cap 
main body 14 has a top plate 15 of a circular shape. A cylindrical side 
wall 16 is formed by downwardly turning the peripheral edge of the top 
plate 15. An annular projection 17 is formed at the under surface of the 
top plate 15 near the peripheral edge thereof. A removable member 18 is 
made of the same metallic material, such as aluminium, as material of the 
cap main body 14. A circular base plate 19 of the removable member 18 has 
an inclined portion 20, which is formed by upwardly turning the peripheral 
edge of the base plate 19 on a slant. A side plate 21 is formed by 
downwardly turning the peripheral edge of the inclined portion 20. A 
rolled-in ring 22 is formed by inwardly turning the lower edge of the side 
plate 21. There is disposed a clearance 23 between the rolled-in ring 22 
and the side wall 16 of the cap main body 14. Pressed concave portions 24 
and 24' for the fixing purpose are formed in the annular shape at the 
center portions of the top plate 15 and the base plate 19 by cold pressure 
welding of the base plate 19 of the removable member 18 overlapped to the 
top plate 15 of the cap main body 14. By these pressed concave portions 24 
and 24', the cap main body 14 is securely fixed to the removable member 
18. Expanded convex portions 15' and 19' of a generally spherical shape 
are formed within these annular pressed concave portions 24 and 24' of the 
top plate 15 and the base plate 19'. 
Scores 25 of an annular shape are formed in the under surface of the 
pressed concave portion 24 of the top plate 15 at the positions near the 
peripheral edge thereof, and such scores 25 are formed at the same time of 
forming the pressed concave portions 24 and 24' formed by cold pressure 
welding. 
A description is now made of the cap shown in FIGS. 4 and 5 fitted to a 
vial, with reference to FIG. 6. 
Mounted to the neck 27 of a vial 26 is a rubber stopper 29 having a 
cylindrical portion 28 which is press-fit to the inner wall of the neck 
27. The cap main body 14, which is sterilized is fitted to the rubber 
stopper 29 and the neck 27. The lower end 30 of the side wall 16 of the 
cap main body 14 is rolled in to the bottle neck 27, thereby to prevent 
the rubber stopper 29 from coming up from the bottle neck 27, as well as 
to sealingly fit the cap to the bottle neck 27 through the rubber stopper 
29. 
When opening the cap, the vial 26 is held with one hand and the rolled-in 
ring 22 of the removable member 18 is obliquely pushed up. The center 
portion of the top plate 15 is then pushed up together with the base plate 
19 and the scores 25 are broken, so that the center portion of the top 
plate 15 is removed from the top plate 15, thereby to form a circular bore 
in the top plate 15. 
Accordingly, the second embodiment shown in FIGS. 4 and 5 may provide other 
effects in addition to those provided in the first embodiment shown in 
FIGS. 1 and 2. Since the scores 25 are formed in the under surface of the 
pressed concave portion 24 of the top plate 15 of the cap main body 14, 
namely since the scores 25 are formed in the under surface of the pressed 
concave portion 24 to which a cap opening force is directly applied, cap 
opening procedures may be easily performed with a small and constant force 
alone. 
Moreover, the scores 25 may be formed simultaneously with forming the 
pressed concave portion 24 thereby to facilitate the manufacturing of the 
cap to a great extent. 
Furthermore, since the annular projection 17 is formed at the under surface 
of the top plate 15 of the cap main body 14, this annular projection 17 is 
fittingly pressed to the upper surface of the rubber stopper 29, so that 
the top plate 15 perfectly comes in close contact with the rubber stopper 
29, thereby to prevent dust or bacteria from entering the scores 25 from 
the clearance between the top plate 15 and the rubber stopper 29.