GB2126641A - Tank - Google Patents

Abstract

A fluid storage tank (10) (e.g. a domestic water cistern) has a lower portion (11) for containing fluid and an upper portion (14) for supporting fluid level control means, the upper portion (14) being of smaller cross-sectional area than the lower portion, when viewed in plan. In use, the fluid level is at or adjacent the top of the lower portion of the tank. The larger sides of the lower portion are provided with inwardly extending strengthening ribs 12. <IMAGE>

Description

SPECIFICATION Improvements in tanks The invention relates to fluid storage tanks of the type where fluid is kept at a predetermined level by means of a valve or other control mechanism. Such tanks will be referred to hereinafter as "tanks of the type defined". A typical example of such a tank is a domestic water cistern where the water level is normally kept constant by a ball valve.

According to the invention there is provided a tank of the type defined comprising a lower portion for containing fluid, and an upper portion for supporting water level control means, the upper portion being of smaller cross-sectionai area than the lower portion, when viewed in plan, the water level, in use, being at or adjacent the top of the lower portion of the tank.

The tank preferably has an inwardly turned peripheral ledge connecting the first portion and the second portion.

The tank may have strengthening ribs in the lower portion, and such ribs may extend vertically.

The tank may be rectangular when viewed in plan, and the ribs are preferably on the larger sides of the lower portion, but, particularly for larger tanks, ribs may be provided on the narrower sides also.

There may be a cover extending over part of the upper portion of the tank.

The tank may be a plastics moulding, and the ribs may be in the form of channels in the sides of the tank lower portion.

By way of example, one embodiment of a fluid storage tank according to the invention will now be described with reference to the accompanying drawings, in which:- Fig. 1 is a side view of a tank; Fig. 2 is a plan view of the tank of Fig. 1; Fig. 3 is an end view of the tank of Figs. 1 and 2; Fig. 4 is a sectional view along the lines A-A in Fig. 2; and Fig. 5 is a sectional view along the lines B-B in Fig. 2.

A fluid storage tank 10 is a moulding of plastics material and designed for use as a water cistern, for example, in a domestic water or central heating system.

The tank 10 has a lower portion 11 of rectangular cross-section when viewed in plan and is formed with inwardly extending ribs 1 2 for strengthening the larger sides of the lower portion 11 of the tank. The ribs 1 2 extend vertically. For larger tanks, strengthening ribs may also be formed on the smaller sides of the lower portion 11.

At the top of the lower portion 11 of the tank, the profile of the tank walls turns inwardly to provide a peripheral ledge 1 3. The width of the ledge 1 3 along the long sides of the tank corresponds to the depth of the ribs 1 2 as can be seen clearly in Fig. 3. The ledge 13 is narrower where the ledge extends across the narrow sides of the tank 10.

An upper portion 14 of the tank extends upwardly from the ledge 1 3. The majority of the upper portion is covered by an integral cover 1 5 but a circular opening 16 is provided at one end.

A circular cover (not shown) can be supplied for the opening 1 6. The profile of the tank surrounding the opening 1 6 can be seen in Fig. 5.

In use, the lower portion 11 of the tank contains fluid, the fluid being water in a domestic system. The upper portion 14 of the tank supports a valve mechanism for maintaining a desired water level, and a typical valve mechanism will comprise a ball float valve. The tank 10 is designed such that the fluid level should be at or adjacent the top of the lower portion 11 of the tank, that is at the level of the inwardly turned ledge 1 3. In this way, the upper portion of the tank 14 does not have to contain any water and can be formed without any strengthening ribs.

The presence of the ledge 1 3 also provides peripheral reinforcement of the tank to resist side wall deflection. This embodiment of the invention thus provides a significant saving in materials over conventional tanks of this type which have a generally continuous cross-section from top to bottom.

Claims (Filed on 20/6/83) 1. A tank of the type defined comprising a lower portion for containing fluid, and an upper portion for supporting fluid level control means, the upper portion being of smaller cross-sectional area than the lower portion, when viewed in plan, the fluid level, in use, being at or adjacent the top of the lower portion of the tank.

2. A tank as claimed in Claim 1 having an inwardly turned peripheral ledge connecting the first portion and the second portion.

3. A tank as claimed in Claim 1 or Claim 2 having strengthing ribs in the lower portion.

4. A tank as claimed in Claim 3 wherein the ribs extend vertically.

5. A tank as claimed in Claim 3 or Claim 4 wherein the tank is rectangular when viewed in plan, the ribs being at least on the larger sides of the lower portion.

6. A tank as claimed in Claim 5 having ribs on all four sides of the lower portion.

7. A tank as claimed in any one of Claims 3 to 6 wherein the ribs are in the form of channels in the sides of the tank lower portion.

8. A tank as claimed in any preceding Claim wherein the tank is a plastics moulding.

9. A tank as claimed in any preceding Claim comprising a cover extending over part of the upper portion of the tank.

10. A tank substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in tanks The invention relates to fluid storage tanks of the type where fluid is kept at a predetermined level by means of a valve or other control mechanism. Such tanks will be referred to hereinafter as "tanks of the type defined". A typical example of such a tank is a domestic water cistern where the water level is normally kept constant by a ball valve. According to the invention there is provided a tank of the type defined comprising a lower portion for containing fluid, and an upper portion for supporting water level control means, the upper portion being of smaller cross-sectionai area than the lower portion, when viewed in plan, the water level, in use, being at or adjacent the top of the lower portion of the tank. The tank preferably has an inwardly turned peripheral ledge connecting the first portion and the second portion. The tank may have strengthening ribs in the lower portion, and such ribs may extend vertically. The tank may be rectangular when viewed in plan, and the ribs are preferably on the larger sides of the lower portion, but, particularly for larger tanks, ribs may be provided on the narrower sides also. There may be a cover extending over part of the upper portion of the tank. The tank may be a plastics moulding, and the ribs may be in the form of channels in the sides of the tank lower portion. By way of example, one embodiment of a fluid storage tank according to the invention will now be described with reference to the accompanying drawings, in which:- Fig. 1 is a side view of a tank; Fig. 2 is a plan view of the tank of Fig. 1; Fig. 3 is an end view of the tank of Figs. 1 and 2; Fig. 4 is a sectional view along the lines A-A in Fig. 2; and Fig. 5 is a sectional view along the lines B-B in Fig. 2. A fluid storage tank 10 is a moulding of plastics material and designed for use as a water cistern, for example, in a domestic water or central heating system. The tank 10 has a lower portion 11 of rectangular cross-section when viewed in plan and is formed with inwardly extending ribs 1 2 for strengthening the larger sides of the lower portion 11 of the tank. The ribs 1 2 extend vertically. For larger tanks, strengthening ribs may also be formed on the smaller sides of the lower portion 11. At the top of the lower portion 11 of the tank, the profile of the tank walls turns inwardly to provide a peripheral ledge 1 3. The width of the ledge 1 3 along the long sides of the tank corresponds to the depth of the ribs 1 2 as can be seen clearly in Fig. 3. The ledge 13 is narrower where the ledge extends across the narrow sides of the tank 10. An upper portion 14 of the tank extends upwardly from the ledge 1 3. The majority of the upper portion is covered by an integral cover 1 5 but a circular opening 16 is provided at one end. A circular cover (not shown) can be supplied for the opening 1 6. The profile of the tank surrounding the opening 1 6 can be seen in Fig. 5. In use, the lower portion 11 of the tank contains fluid, the fluid being water in a domestic system. The upper portion 14 of the tank supports a valve mechanism for maintaining a desired water level, and a typical valve mechanism will comprise a ball float valve. The tank 10 is designed such that the fluid level should be at or adjacent the top of the lower portion 11 of the tank, that is at the level of the inwardly turned ledge 1 3. In this way, the upper portion of the tank 14 does not have to contain any water and can be formed without any strengthening ribs. The presence of the ledge 1 3 also provides peripheral reinforcement of the tank to resist side wall deflection. This embodiment of the invention thus provides a significant saving in materials over conventional tanks of this type which have a generally continuous cross-section from top to bottom. Claims (Filed on 20/6/83)

1. A tank of the type defined comprising a lower portion for containing fluid, and an upper portion for supporting fluid level control means, the upper portion being of smaller cross-sectional area than the lower portion, when viewed in plan, the fluid level, in use, being at or adjacent the top of the lower portion of the tank.

2. A tank as claimed in Claim 1 having an inwardly turned peripheral ledge connecting the first portion and the second portion.

3. A tank as claimed in Claim 1 or Claim 2 having strengthing ribs in the lower portion.

4. A tank as claimed in Claim 3 wherein the ribs extend vertically.

5. A tank as claimed in Claim 3 or Claim 4 wherein the tank is rectangular when viewed in plan, the ribs being at least on the larger sides of the lower portion.

6. A tank as claimed in Claim 5 having ribs on all four sides of the lower portion.

7. A tank as claimed in any one of Claims 3 to 6 wherein the ribs are in the form of channels in the sides of the tank lower portion.

8. A tank as claimed in any preceding Claim wherein the tank is a plastics moulding.

9. A tank as claimed in any preceding Claim comprising a cover extending over part of the upper portion of the tank.

10. A tank substantially as hereinbefore described with reference to and as shown in the accompanying drawings.