Watertight plug structure for an aquarium

A structure for a watertight plug in an aquarium, having a positioning ring fitted in a neck portion of the aquarium, the watertight plug having a positioning ring and a ring flange so as to fit in the neck portion of a glass bowl of the aquarium, a flat portion on the top of the watertight plug having a plurality of buffer grooves, which have various and suitable shapes and sizes. Each of the buffer grooves has a thin film portion extending downwards from the groove mouth to form a curved bottom side, and then the thin film extends upwards and towards the center to form a separation plate. Such a structure can provide the glass bowl with a buffer effect to prevent the water from leaking out of the glass bowl or air being sucked into the glass bowl to form an air chamber.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a decorative aquarium, and particularly to a 
water tight plug, which can provide a buffer effect for ambient 
temperature variation. 
2. Description of the Prior Art 
A conventional aquarium usually comprises a glass bowl with neck portion on 
the bottom thereof, and a watertight plug having a positioning ring. The 
watertight plug is mounted in the neck portion of the glass bowl by means 
of the positioning ring and a ring flange; the water in the glass bowl is 
isolated from the atmosphere completely. The decorative aquarium is 
usually mounted in a round hole of a decorative body by means of the neck 
portion of the glass bowl, and silicone is used to glue them together. The 
bottom of the decorative body usually has a music assembly so as to 
provide visual and listening pleasure. 
In the conventional decorative aquarium, the glass bowl and the watertight 
plug are put into the water before being assembled together so as to 
remove air from the glass bowl. The watertight plug and the decorations 
therein have no air bubbles attached. After the neck portion of the glass 
bowl and the watertight plug are connected together, water cannot leak out 
because the watertight plug being is made of a resilient and sealing 
material. The inside of the glass bowl has no air left. However, variable 
ambient temperature may cause the pressure inside the glass bowl to vary; 
in the event of the increasing or decreasing pressure being higher than 
the connection and sealing force between the glass bowl and the watertight 
plug, the water in the glass bowl may leak out, or air might be sucked in 
to cause an air chamber to exist in the glass bowl. 
In the conventional decorative aquarium, the flat portion on the watertight 
plug has a plurality of grooves which are made of a thinner material so as 
to allow for the expansion or shrinkage effect under different 
temperatures. However, the expansion tolerance of the flat portion of the 
groove is limited; it can only improve the problem of a conventional 
aquarium to some extent without solving such problem completely. 
SUMMARY OF THE INVENTION 
The prime object of the present invention is to provide a watertight plug 
to fit in the neck portion of a glass bowl in an aquarium. The flat 
portion on the watertight plug has a plurality of buffer grooves, which 
can absorb the expansion and shrinkage of pressure in the glass bowl so as 
to prevent water from leaking out, or to prevent air from being sucked 
into the glass bowl to form an air chamber. 
Another object of the present invention is to provide a watertight plug, of 
which the flat portion has a plurality of elongate and curved buffer 
grooves; the thin film of the buffer grooves extends from the flat portion 
downwards a suitable length to form a bottom side and then extends towards 
the center thereof; since the curved thin film of the elongate and curved 
buffer groove has resilience to provide a buffer effect, the expansion or 
shrinkage can be absorbed and offset. 
Still another object of the present invention is to provide a watertight 
plug, in which the center of the elongate and curved buffer groove has a 
separation plate; the bottom side of the buffer groove extends towards a 
center and upwards; a separation groove is formed under the bottom side, 
and it is substantially an elongated hollow space to provide a buffer 
effect. 
A further object of the present invention is to provide a watertight plug, 
in which the center of the elongate and curved buffer groove has a 
separation plate, and the thin film on the bottom side extends towards the 
center thereof and upwards; the bottom side has an elongate hollow space. 
The resilience of the thin films and the up-and-down motion of the 
separation plate provides a buffer space. 
A still further object of the present invention is to provide a watertight 
plug, in which the top part thereof has a plurality of buffer grooves of 
various shapes, such as elongate and curved grooves, sector-shaped 
grooves, oblong grooves or round grooves. Since the curved thin film of 
the buffer groove is resilient and able to move up and down, it can 
provide a buffer effect.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
This invention relates to a structure of a watertight plug for an aquarium; 
as shown in FIG. 1, the aquarium 11 has the features of decoration and 
motion; on the base 13 thereof, there is a music assembly 14 mounted with 
a transmission mechanism 15. The base 13 is mounted under a decorative 
body 16. In a round hole 23 in the center of the watertight plug 12 is 
mounted a fixed disk 46, on which a turntable 47 is fitted; the spindle of 
the turntable 47 penetrates through a spindle hole of the fixed disk 46 
and then connects with the transmission mechanism 15 under the watertight 
plug 12. The glass bowl 20 is substantially a ball-shaped bowl, having a 
neck portion 17 to be mounted on the decorative body 16. During assembly, 
the top side of the turntable 47 must be glued to the decorations 19 
before the glass bowl 20 and the watertight plug 12 are put in a water 
tank so as not to have any air left in the glass bowl 20; the watertight 
plug 12 and the decorations will have no air bubbles attached. The 
watertight plug 12 is mounted in the neck portion 17 of the aquarium 11. 
Water in the glass bowl 20 provides the effect of enlarging the 
decorations 19. The turntable 47 in the center of the watertight plug 12 
is connected with a transmission mechanism 15 through a spindle, and then 
it is assembled together with the decorative body 16. The aquarium 11 is 
driven by means of the music assembly 14 through the transmission 
mechanism 15; the decorations 19 mounted in the glass bowl 20 will move 
upon rotation of the turntable 47. 
The watertight plug 12 mounted on the neck portion 17 of the glass bowl 20 
as shown in FIGS. 1 and 2 is made of a resilient and sealing rubber or 
silicone. The watertight plug 12 has a positioning ring 18, of which the 
size is similar to that of the neck portion 17. The outer surface of the 
positioning ring 18 has a ring flange 21, with which the positioning ring 
18 can be closely fitted in the neck portion 17 of the glass bowl 20. 
As shown in FIGS. 1 to 4, the watertight plug 12 has a lip portion 49 above 
the positioning ring 18; the lip portion 49 has flat portion 22 having a 
given thickness and a round hole 23 in the center thereof; the fixed disk 
is mounted and glued in the round hole 23. The spindle hole in the center 
of the fixed disk 46 is used for receiving the spindle of the turntable 
47, and the spindle extends to and under the watertight plug 12. Referring 
to FIGS. 5 to 7, the flat portion 22 on the watertight plug 12 has a flat 
surface 50 to provide a hermetic seal. The flat surface 50 of the 
watertight plug 12 is glued with decorations first, and then the 
watertight plug 12 and the glass bowl 20 are put in water; the neck 
portion 17 of the glass bowl 20 is sealed up with the watertight plug 12. 
The buffer grooves 25 on the flat portion 22 of the watertight plug 12 will 
provide a buffer effect upon temperature variation so as to prevent having 
a water leak or sucking air into the glass bowl 20 to form an air chamber. 
As shown in FIGS. 1 to 4, the flat portion 22 on the watertight plug 12 has 
a plurality of buffer grooves 25; the flat portion 22 has a suitable 
thickness, and a round hole 23 in the center thereof. Between the round 
hole 23 and the lip portion 49, there is a plurality of buffer grooves 25, 
of which each is an elongate and curved groove along the spaced between 
the round hole 23 and the lip portion 49. From the groove mouth 38 of the 
buffer groove 25, a thin film 34 extends downwards a suitable distance. 
The bottom side 29 of the thin film 34 extends to the center thereof to 
form a curved surface 35 with a suitable width. Then, a thin film 33 
having the same thickness extends upwards. The center part of the elongate 
and curved groove 25 has a curved separation plate 30; the separation 
plate 30 has a height slightly lower than that of the groove mouth 38, and 
has a thicker top part 32. The separation plate 30 extends towards the 
bottom side 29 of the buffer groove 25 by means of a curved thin film 33 
so as to form into a separation groove 31. By means of a space under the 
separation groove 31 and the resilience of the elongate and curved groove 
25, a suitable buffer effect can be provided. 
After the watertight plug 12 with buffer grooves 25 is mounted in the neck 
portion 17 of the glass bowl 20, the watertight plug 12 and the glass bowl 
20 are put in water simultaneously; in that case, no air bubbles will be 
produced in the glass bowl 20; the outer surface of the watertight plug 12 
will also have no air bubbles attached. During assembly, the watertight 
plug 12 is inserted into the neck portion 17 of the glass bowl 20 before 
fitting the ring flange 21 into the ring-shaped groove 48 of the neck 
portion 17 so as to have the ring flange 21 of the watertight plug 12 and 
the ring-shaped groove 48 of the neck portion 17 hermetically engaged. 
After the glass bowl 20 and the watertight plug 12 are assembled together, 
the water in the glass bowl has a considerable weight; by means of the 
neck portion 17 and the watertight plug 12, the glass bowl 20 becomes a 
hermetic space. Since the thin film of the buffer groove 25 has a suitable 
thickness, it will not deform. 
The elongate and curved groove 25 extending downwards from the flat board 
22 will provide a buffer effect. In fact, the buffer effect of the 
elongate and curved groove 25 is furnished by means of, first, thin film 
34 extending downwards from the groove mouth 38 and the flat portion 22; 
second, the curved surface 35 on the bottom side 29 of the ring-shaped 
thin film 34, and a separation plate 30 and a space under the separation 
groove 31; the ring-shaped thin film 34 is made of resilient material for 
absorbing the expansion or shrinkage of water in the glass bowl; third, 
the bottom side 29 of the elongate and curved groove 25, the inner thin 
film 33 and the outer thin film being formed into a curved surface 35, 
which all can provide a buffer effect by allowing the separation plate 30 
to move downwards. 
Referring to FIGS. 5 to 7, the flat portion 22 on the watertight plug 12 
has a sealed surface 50 glued to the bottom of the decorations. The flat 
portion 22 has a plurality of symmetrically arranged sector-shaped 
recesses 24. The sector-shaped recess 24 has curved thin film 34 extending 
downwards and curved surface 35 on the bottom side 29 thereof extending 
towards the center thereof. From the inner side of the curved surface 35, 
a thin film 33 with the same thickness as that of the thin film 34 extends 
upwards. The center of the sector-shaped recess 24 has a curved separation 
plate 30; the sector-shaped recess 24 can provide a buffer effect, the 
same as that of the elongate and curved groove 25 as mentioned above. 
Referring to FIGS. 5, 8 and 9, the flat portion 22 of the watertight plug 
12 is provided with a plurality of oblong symmetrically arranged buffer 
grooves 37. The oblong buffer grooves 37 have curved thin film 34 
extending from the flat portion 22 downwards, and a bottom side 29 
extending towards the center thereof to form a curved surface 35 with a 
suitable width. On the inner edge of the curved surface 35, a thin film 33 
with the same thickness as that of the thin film 34 extends upwards to 
form an elongate separation plate 30 in the center of the oblong buffer 
groove 37, which can provide a buffer effect the same as that of the 
aforesaid sector-shaped recess 24 or the elongate and curved groove 25. 
Referring to FIGS. 10 and 11, the flat portion 22 of the watertight plug 12 
has a plurality of round symmetrically arranged buffer grooves 39. A round 
thin film 34 from the groove mouth 38 extends downwards to form a bottom 
side 29 and a curved surface 35. Then a thin film 33 having the same 
thickness as that of the thin film 34 extends upwards to form into a 
tapered separation plate 30 in the center of the round buffer groove 39 so 
as to provide a buffer effect the same as that of the aforesaid 
sector-shaped recess 24, the elongate and curved groove 25, or the oblong 
buffer groove 37. 
The feature as disclosed in the aforesaid embodiments of the present 
invention is that the flat portion 22 of the watertight plug 12 has a 
plurality of buffer grooves 25, which has a suitable shape, and a groove 
mouth; a thin film 34 extends downwardly from the flat portion 22 and the 
groove mouth; the curved thin film 34 has a bottom side 29 with a curved 
surface 35; the thin film also extends to the center and upwards to form a 
separation plate 30, under which a separation groove 31 is located. By 
means of the resilient thin film, the shape of the buffer groove 25 and 
the buffer space, a buffer effect will be provided. 
According to the aforesaid description of the embodiments, it is apparent 
that the feature and structure of the present invention have been 
disclosed completely, i.e., the present invention has provided a prominent 
improvement for the watertight plug, and such feature has never been 
anticipated and shown by any one before; therefore, the present invention 
is deemed unique and novel.