# Patent

## Title
Pressure tank

## Abstract

A pressure tank includes a metallic vessel, a plastic liner received in the metallic vessel, a flexible diaphragm, two connectors and a nozzle coupled to the nipples respectively. The metallic vessel includes upper and lower shells. The upper shell defines a first planar area on a side thereof and a second planar area on a top thereof. The lower shell defines a third planar area therebottom. The flexible diaphragm divides the metallic vessel into a storage space and a pneumatic room. Each of the connectors includes a nipple and an anti-leak assembly. The nipples of the connectors are mounted on the side and top of the upper shell respectively and are in communication with the storage space. The two anti-leak assemblies provide leakproof connection between the nipples and the plastic liner. Additionally, the nozzle is mounted on the third planar area to be in communication with the pneumatic room.

## Background
CROSS REFERRENCE TO RELATED APPLICATION
This is a continuation of U.S. patent application Ser. No. 13/218,565, filed on Aug. 26, 2011, currently pending, which is a continuation of U.S. Pat. No. 8,033,416, filed on Oct. 28, 2008.


BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to a pressure tank and more particularly to a pressure tank having two connectors for connection with pipes.
2. Related Prior Art
Taiwan Pat. No. M250911 and Taiwan Pat. No. M312357 are exemplary of patents directed to pressure tanks of the type to which this invention is directed. Basically, the conventional pressure tank includes a flexible diaphragm through which the inside of the pressure tank is divided into an upper storage space and a lower pneumatic room. However, there is only nipple with one access opening in the pressure tank to be in communication with the storage space. The only nipple is then served as both an inlet and an outlet at different time. It takes huge time simply to access liquid into or out of the storage space. Moreover, since there is only one connector for access, residue dust or dirt may be easily accumulated on the bottom of the storage space, namely on the top surface of the flexible diaphragm, after a long time use.
SUMMARY OF INVENTION
Broadly stated, the present invention is directed to a pressure tank having two through-wall connectors for access in such a way that liquid may be efficiently accessed into and out of the pressure tank. In particular, the distinctive arrangement of the through-wall connectors prevents the pressure tank from contamination accumulation.
The pressure tank includes a metallic vessel, a plastic liner, a flexible diaphragm, two through-wall connectors and a nozzle. Each of the through-wall connector includes a nipple and an anti-leak assembly. The metallic vessel includes upper and lower shells joined together. The metallic vessel defines a first planar area on the hollow cylinder of the upper shell, a second planar area on the circular plate of the upper shell and a third planar area on a bottom of the lower shell. The plastic liner is received in the upper shell of the metallic vessel. The flexible diaphragm divides the metallic vessel into a storage space and a pneumatic room. The two nipples of the connectors are mounted on the side and top of the upper shell respectively and are in communication with the storage space. The two nipples are substantially identical to each other in construction and each includes an exposed tubular portion and an inner tubular portion. The exposed tubular portion has a threaded section, a polygonal section joined to the threaded section and a cylindrical section joined to the polygonal section. The inner tubular portion is joined to the cylindrical section of the exposed tubular portion and passes through the first (or second) planar area of the upper shell and the plastic liner to be in communication with the storage space. The cylindrical section of the exposed tubular portion is weld to an exterior surface of the first (or second) planar area of the upper shell. The inner tubular portion includes a base section and a neck section extending from the base section. The neck section is riveted in order to press the plastic liner on an interior surface of the first (or second) planar area of the upper shell. The two anti-leak assemblies of the connectors provide leakproof connection between the nipples and the plastic liner.
Additionally, the nozzle is mounted on the third planar area to be in communication with the pneumatic room and also provides efficient leakproof function.
As noted above, the present invention includes at least two through-wall connectors for connection with pipes. One of the connectors may be served as an inlet and mounted on the top of the metallic vessel while the other served as an outlet and mounted on the side. And, the flexible diaphragm is located exactly between the inlet and the outlet. In this manner, any residue dust or dirt can hardly left on the flexible diaphragm and can easily be swept away from the storage space via the side outlet, and thereby contamination accumulation is avoid.
The advantages of the present invention will be understood more readily after a consideration of the drawings and the Detailed Description.



BRIEF DESCRIPTION OF DRAWINGS
The invention is illustrated by the accompanying drawings in which corresponding parts are identified by the same numerals and in which:
FIG. 1 is an exploded view of a pressure tank in accordance with the preferred embodiment of the invention;
FIG. 2 is a cross section of the pressure tank of FIG. 1;
FIG. 3 is a fragmentary exploded view of the pressure tank, showing an arrangement among an upper shell and a first through-wall connector;
FIG. 4 is an assembled view of the parts shown in FIG. 3;
FIG. 5 is a fragmentary exploded view of the pressure tank, showing an arrangement among an upper shell and a second through-wall connector;
FIG. 6 is an assembled view of the parts shown in FIG. 5;
FIG. 7 is a fragmentary exploded view of the pressure tank, showing an arrangement between a nozzle assembly and a lower shell; and
FIG. 8 is an assembled view of the parts shown in FIG. 7.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, the pressure tank according to the present invention comprises a metallic vessel 1, a plastic liner 2, a flexible diaphragm 3, a fixing ring 4, two through-wall connectors and a nozzle 9. The first through-wall connector including a first nipple 5 and a first anti-leak assembly 6; and the second through-wall connector includes a second nipple 7 and a second anti-leak assembly 8.
As shown in FIGS. 1 and 2, the metallic vessel 1 includes an upper shell 10 and a lower shell 11 joined together, and preferably is made of stainless steel to conform to the requirements of Food and Drug Administration (FDA). The upper shell 10 is formed of a circular plate 12 and a hollow cylinder 13 extending from the periphery of the circular plate 12. The hollow cylinder 13 defines a recessed first planar area 14, as depicted in FIG. 2. A second planar area 15 is defined in the center of the circular plate 12 of the upper shell 10. Moreover, the lower shell 11 defines a third planar area 16 therebottom and formed with an inward tubular protrusion 17 extending inwardly from the third planar area 16, as depicted in FIGS. 7 and 8. The inward tubular protrusion 17 is provided with a hole 18 including a lower hole 181 and an upper hole 182 of diameter smaller than the lower hole 181 and thereby provides a projection 183 in the hole 18. It should be noted that opposite inner and outer surfaces of each of the planar areas 14, 15, 16 are flat and even in order to be easily and firmly weld/connected with the first, second nipples 5, 7 and a third nipple 90 of the nozzle 9.
As shown in FIG. 2, the plastic liner 2 is formed of a circular topwall 2a and a cylindrical sidewall 2b continuously extending from the periphery of the circular topwall 2a. The plastic liner 2 is received in the upper shell 10 and is formed with an inward protrusion 21 on an inner face of the circular topwall 2a and protruding toward inside of the metallic vessel. The cylindrical sidewall 2b of the plastic liner 2 has an inner surface that faces the inside of the metallic vessel and is continuous planar. As best seen in FIG. 6, the inward protrusion 21 of the plastic liner 2 defines an annular recession 23 therein.
Referring again to FIG. 2, the flexible diaphragm 3 is made of a rubber material and is disposed inside the plastic liner 2. The flexible diaphragm 3 and the plastic liner 2 co-define an upper storage space 30 therebetween. Likewise, the flexible diaphragm 3 and the lower shell 11 co-define a lower pneumatic room 31 therebetween. The fixing ring 4 is provided to hold the flexible diaphragm 3 against an inner peripheral wall of the plastic liner 2. Further, the flexible diaphragm 3 and the plastic liner 2 are tightly sandwiched between the fixing ring 4 and the upper shell 10 by applying rolling depression upon an exterior periphery of the upper shell 10 of the metallic vessel 1.
Referring to FIG. 3, the first nipple 5 of the first through-wall connector is mounted on the first planar area 14 and includes an exposed tubular portion 50 and an inner tubular portion 51. ... Referring to FIGS. 2 and 4, the inner tubular portion 51 passes through the first planar area 14 of the upper shell 10 and the cylindrical sidewall 2b of the plastic liner 2 and is in communication with the storage space 30.
Referring again to FIGS. 3 and 4, the first anti-leak assembly 6 of the first through-wall connector provides leakproof connection between the first nipple 5 and the plastic liner 2, and includes a seal washer 60, an O-ring 61 and a retainer ring 62. The seal washer 60 is placed around the inner tubular portion 51 of the first nipple 5 and placed in between the hollow cylinder 13 of the upper shell 10 and the sidewall 2b of the plastic liner 2. The O-ring 61 is also placed around the inner tubular portion 51 of the first nipple 5 and is placed in between the plastic liner 2 and the retainer ring 62. The retainer ring 62 consists of three portions, a disk-like flat portion (hereinafter named as annular disk 63), a flat wall portion (hereinafter named as inclined circumferential wall 63) and a flat flange portion (hereinafter named as ring flange 66). Specifically, as best seen in FIG. 4, the retainer ring 62 includes a ring body having an annular disk 63 and an inclined circumferential wall 64, and a ring flange 66 extending from the ring body. The annular disk 63 is placed around the inner tubular portion 51 of the first nipple 5. The inclined circumferential wall 64 extends outwardly from the periphery of the annular disk 63 and an arc connecting portion is formed between the annular disk 63 and the inclined circumferential wall 64 to connect the annular disk 63 and the inclined circumferential wall 64. The ring flange 66 extends and flares outward from the outer periphery of the inclined circumferential wall 64 and another arc connecting portion is formed between the inclined circumferential wall 64 and the ring flange 66 to connect the inclined circumferential wall 64 and the ring flange 66. The ring flange 66 has a flat surface which abuts against a planar area of an inner wall surface of the plastic liner 2. In other words, the flat flange portion (i.e. ring flange 66) of the retainer ring 62 is in contact with the continuous planar inner surface of the cylindrical sidewall 2b of the plastic liner 2. The annular disk 63 and the inclined circumferential wall 64 co-define an annular recession 65 for receiving the O-ring 61. Specifically, as seen in FIG. 4, the O-ring 61 is accommodated in the annular recession 65, and has a first peripheral area contacting with the continuous planar inner surface of the cylindrical sidewall 2b of the plastic liner2, a second peripheral area contacting with the flat wall portion (i.e. the inclined circumferential wall 64) of the retainer ring 6 and a third peripheral area contacting with the disk-like flat portion (i.e. annular disk 63) of the retainer ring 6. It is noted that the neck section 56 of the inner tubular portion 51 is thinner than the base section 55 and is bent to hold the first anti-leak assembly 6 and the plastic liner 2 against an interior surface of the first planar area 14 of the hollow cylinder 13 of the upper shell 10. Additionally, the O-ring 61 has a thickness slightly larger than a depth of the annular recession 65 of the retainer ring 62 in such a way that the O-ring 61 can be tightly held against the planar area of the inner wall surface of the plastic liner 2 and provides a better leakproof effect.
As shown in FIG. 5, the second nipple 7 of the second through-wall connector is substantially identical to the first nipple 5 in construction and is mounted on the second planar area 15 of the circular plate 12. Specifically, the second nipple 7 includes an exposed tubular portion 70 and an inner tubular portion 71 joined together. The exposed tubular portion 70 is formed with a threaded section 72, a polygonal section 73 joined to the threaded section 72 and a cylindrical section 74 joined to the polygonal section 73. The threaded section 72 is provided for connection with another pipe (not shown). The cylindrical section 74 of the exposed tubular portion 70 is weld to an exterior surface of the second planar area 15 of the circular plate 12 of the upper shell 10. The inner tubular portion 71 is formed with a base section 75 and a neck section 76 extending from the base section 75. Referring to FIG. 6, the inner tubular portion 71 passes through the second planar area 15 of the circular plate 12 and the inward protrusion 21 of the plastic liner 2 and is in communication with the storage space 30.
Referring back to FIG. 5, the second anti-leak assembly 8 of the second through-wall connector is placed around the inner tubular portion 71 of the second nipple 7 in order to provide a leakproof connection between the second nipple 7 and the plastic liner 2. Specifically, the second anti-leak assembly 8 includes a seal washer 80, an O-ring 81 and a retainer ring 82. The seal washer 80 is placed around the inner tubular portion 71 of the second nipple 7 and placed in between the circular plate 12 and the plastic liner 2. The O-ring 81 is also placed around the inner tubular portion 71, placed in between the inward protrusion 21 of the plastic liner 2 and the retainer ring 82, and lodged in the annular recession 23 of the inward protrusion 21 of the plastic liner 2. Likewise, the O-ring 81 has a thickness slightly larger than a depth of the annular recession 23 of the inward protrusion 21 of the plastic liner 2. As shown in FIG. 6, the neck section 76 of the inner tubular portion 71 is thinner than the base section 75 of the same and is bent to hold the second anti-leak assembly 8 and the plastic liner 2 against an interior surface of the second planar area 15 of the circular plate 12 of the upper shell 10.
Referring to FIGS. 2, 7 and 8, the nozzle 9 is mounted on the third planar area 16 of the lower shell 11 of the metallic vessel 1 and is in communication with the pneumatic room 31. Specifically, the nozzle 9 includes the third nipple 90, a third anti-leak assembly 96 and a one-way valve 99. The third nipple 90 is inserted in the hole 18 of the inner tubular protrusion 17 and has an exposed tubular portion 91 and an inner tubular portion 92. The inner tubular portion 92 has a protruding section 93, a cylindrical section 94 extending from the protruding section 93 and a threaded section 95 extending from the cylindrical section 94. The protruding section 93 is a shoulder section of the nozzle 9, which protrudes from an outer wall of the third nipple 90. The protruding section 93 of the inner tubular portion 92 is lodged in the lower hole 181 of the hole 18 of the inward tubular protrusion 17 of the lower shell 11. The threaded section 95 is formed on the outer wall of an end of the third nipple 90. The inner tubular portion 92 of the third nipple 90 passes through the third planar area 16 as well as the inward tubular protrusion 17 and is in communication with the pneumatic room 31.
Moreover, the third anti-leak assembly 96 of the nozzle 9 is placed around the inner tubular portion 92 of the third nipple 90 to provide leakproof connection between the third nipple 90 and the lower shell 11. The one-way valve 99 of the nozzle 9 is received in a passage formed in the third nipple 90, through which outside air or gas can be injected into the pneumatic room 31 to drive the flexible diaphragm 3. Specifically, the third anti-leak assembly 96 includes an O-ring 97 and a connecting member 98. The O-ring 97 of the third anti-leak assembly 96 is placed around the inner tubular portion 92 of the third nipple 90. And, the O-ring 97 is lodged in the lower hole 181 of the hole 18 of the inward tubular protrusion 17 of the lower shell 11 and is sandwiched between the projection 183 of the inward tubular protrusion 17 and the protruding section 93 of the inner tubular portion 92. The connecting member 98 of the third anti-leak assembly 96 defines a through hole 980 having an screw hole 20 and a receiving hole 19 for receiving the third nipple 90 and the inward tubular protrusion 17 of the lower shell 11. The screw hole 20 of the through hole 980 of the connecting member 98 is adapted for engaging the threaded section 95 of the inner tubular portion 92 of the third nipple 90, and thus a surface of the connecting member 98 abuts against an end face of the inner tubular protrusion 17 of the lower shell 11. The receiving hole 19 of the through hole 980 of the connecting member 98 includes an annular groove 191 defined in an inner peripheral wall surface of the connecting member 98 for reception of the inner tubular protrusion 17 of the lower shell 11. In particular, the receiving hole 19 of the through hole 980 of the connecting member is tapered in diameter from outside to inside of the lower shell 11, and the inner tubular protrusion 17 of the lower shell 11 is mated with the annular groove 191 of the receiving hole 19 of the through hole ... 980 of the connecting member 98. In other words, as best shown in FIG. 8, the screw hole 20 is defined through the connecting member 98 from a top surface 98a of the connecting member 98 to the bottom surface 98b of the connecting member 98 for the engagement of the threaded section 95 of the third nipple 90; the connecting member 98 further has a annular bump integrally formed with the connecting member 98; the annular bump extends downwardly from the bottom surface 98b and surrounds the receiving hole 19. When the connecting member 98 is engaged with the threaded section 95 of the third nipple 90, the bottom surface 98b of the connecting member 98 presses against an upper surface 17a of the inner tubular protrusion 17 at an end protruding inside of the metallic vessel 1. In such a way, the inner tubular protrusion 17 can be snugly wedged into the connecting member 98. In such a fashion, the nozzle 9 can be easily assembled and provides excellent leakproof function.
From the forgoing description, the present invention includes at least two connectors to connect with pipes. One of two connectors may serve as an inlet and the other as outlet for water or liquid so as to prevent the upper surface of the flexible diaphragm from accumulation of residue dust or dirt.
It will be appreciated that although a particular embodiment of the invention has been shown and described, modifications may be made. It is intended in the claims to cover such modifications which come within the spirit and scope of the invention.

## Claims

1. A pressure tank, comprising:
a metallic vessel;
a plastic liner enclosed by the metallic vessel, the plastic liner having a cylindrical sidewall, the cylindrical sidewall having a continuous inner surface; and
a first through-wall connector including:
a tubular body having an inner tubular portion, the inner tubular portion passing through the metallic vessel and the cylindrical sidewall of the plastic liner, the inner tubular portion having a neck section at an end thereof;
a washer placed around the tubular body and sandwiched in between the metallic vessel and the cylindrical sidewall of the plastic liner;
a retainer ring placed around the inner tubular portion of the tubular body and having a disk-like flat portion, an annular wall portion extending outward from outer periphery of the disk-like flat portion and a flat flange portion extending outward from a peripheral end of the annular wall portion, the flat flange portion being in contact with the continuous inner surface of the cylindrical sidewall of the plastic liner, wherein the retainer ring, the continuous inner surface of the cylindrical sidewall of the plastic liner and the inner tubular portion co-define an accommodation; and
an O-ring placed around the inner tubular portion of the tubular body, received in the accommodation, and sandwiched in between the retainer ring and the continuous inner surface of the cylindrical sidewall of the plastic liner, the O-ring having a first peripheral area contacting with the continuous inner surface of the cylindrical sidewall of the plastic liner, a second peripheral area contacting with the annular wall portion of the retainer ring and a third peripheral area contacting with the disk-like flat portion of the retainer ring;
wherein the neck section of the inner tubular portion of the tubular body is bent to hold the disk-like flat portion of the retainer ring.

2. The pressure tank of claim 1, wherein the plastic liner has a top wall continuously connected with the cylindrical sidewall, and the plastic liner further has an inward protrusion formed on an inner surface of the top wall and protruding toward inside of the metallic vessel.

3. The pressure tank of claim 1, wherein the annular wall portion extends obliquely outward from the disk-like flat portion, the retainer ring further has an arc portion formed between the disk-like flat portion and the annular wall portion to connect the disk-like flat portion and the annular wall portion.

4. The pressure tank of claim 3, wherein the retainer ring further has another arc connecting portion formed between the flat flange portion and the annular wall portion to connect the flat flange portion and the annular wall portion.

5. The pressure tank of claim 1, wherein the retainer ring further has an arc connecting portion formed between the annular wall portion and the flat flange portion to connect the annular wall portion and the flat flange portion.

6. The pressure tank of claim 2, wherein the metallic vessel includes an upper shell and a lower shell which are joined together, the plastic liner is received in the upper shell of the metallic vessel, the upper shell of the metallic vessel has a circular plate and a hollow cylinder extending from the periphery of the circular plate, and the first through-wall connector is secured on the hollow cylinder of the upper shell.

7. The pressure tank of claim 6, wherein the hollow cylinder of the upper shell of the metallic vessel defines a recessed area where the first through-wall connector is welded.

8. The pressure tank of claim 6 further including a second through-wall connector secured on the circular plate of the upper shell of the metallic vessel and passing through the upper shell of the metallic vessel and the inward protrusion of the plastic liner to communicate inside and outside of the metallic vessel.

9. The pressure tank of claim 8 further including a diaphragm disposed in the plastic liner, and a nozzle secured on the lower shell of the metallic vessel; wherein the plastic liner and the diaphragm together define a storage space therebetween; the diagram and the lower shell together define a pneumatic room therebetween; the first and second through-wall connectors are in communication with the storage space; and the nozzle is in communication with the pneumatic room.

10. A pressure tank, comprising:
a metallic vessel having a protrusion extending therefrom toward inside of the metallic vessel, the protrusion having a hole defined therethrough from an end of the protrusion where the protrusion extending from to an opposite end of the protrusion;
a nipple being at least partly received in the hole of the protrusion, the nipple having a shoulder section protruding from an outer wall of the nipple and a thread section formed on the outer wall of an end of the nipple, wherein the shoulder section sits in the hole of the protrusion, the thread section projects from the opposite end of the protrusion and is exposed inside the metallic vessel;
a connecting member having a top surface, a bottom surface opposite to the top surface and a screw hole defined through the connecting member from the top surface to the bottom surface, the connecting member engaging with the nipple by engagement of the thread section of the nipple with the screw hole of the connecting member, and the bottom surface of the connecting member pressing against the wall and against an upper surface of the protrusion at the opposite end thereof, wherein the upper surface of the protrusion is vertical to an interior surface of the protrusion surrounding the hole; and
an O-ring being placed around the nipple and sitting in the hole of the protrusion, the O-ring being sandwiched between the interior surface of the protrusion and the shoulder section of the nipple.

11. The pressure tank of claim 10, wherein the connecting member further has a receiving hole in communication with the screw hole thereof, and the diameter of the receiving hole is greater than the diameter of the screw hole; the protrusion of the metallic vessel is received in the receiving hole of the connecting member.

12. The pressure tank of claim 11, wherein the protrusion of the metallic vessel is tapered in diameter from the end thereof to the opposite end thereof; the receiving hole of the connecting member is tapered in diameter corresponding to the protrusion of the metallic vessel.

13. The pressure tank of claim 10, wherein the hole of the protrusion of the metallic vessel is provided with an upper hole and a lower hole communicating with the upper hole; the protrusion of the metallic vessel further has a projection projecting from an interior surface of the upper hole of the hole thereof; the shoulder section of the nipple sits in the lower hole of the hole of the protrusion; and the O-ring is sandwiched in between the projection of the protrusion of the metallic vessel and the shoulder section of the nipple.

14. The pressure tank of claim 10 further comprising a first and second through-wall connectors, a plastic liner, a diaphragm disposed in the plastic liner; wherein the metallic vessel includes an upper shell and a lower shell which are joined together; the protrusion extends from the lower shell of the metallic vessel; the plastic liner is received in the upper shell of the metallic vessel; the diaphragm and the plastic liner together define a storage space therebetween; the diaphragm and the lower shell of the metallic vessel together define a pneumatic room therebetween; the first and second through-wall connectors are secured on the upper shell of the metallic vessel and are in communication with the storage space; and the nipple is in communication with the pneumatic room.

15. The pressure tank of claim 14, wherein the upper shell of the metallic vessel has a circular plate and a hollow cylinder extending from the periphery of the circular plate; the first through-wall connector is secured on the hollow cylinder of the upper shell of the metallic vessel; the second through-wall connector is secured on the circular plate of the upper shell of the metallic vessel.