NZ205976A - Rotary valve operated by float and lever - Google Patents

Description

205976 18 OCT 1984 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL NO: 205976 DATED: 17 October, 1983 FLOAT VALVE We, ENGINEERING SERVICES (HHAMGAREI) LIMITED, a New Zealand Company of 1 Colenso Street, Kamo, New Zealand, do hereby declare the Invention for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement: o . -2- 20597.' ITiis invention relates to a float valve.

In the past# float valves have generally comprised a float arm which has operated a plunger to open and close a valve.

It is an object of the present invention to provide an alternative form of float valve.

Accordingly, in a first aspect, the present invention broadly consists in a float valve including a valve housing having an inlet, em outlet, and a valve seat, a rotatable valve member moveable relative to the housing towards or away from the valve seat, a float arm operatively connected to said rotatable valve member, said rotatable valve member having a main screw thread thereon, said housing having complementary thread means thereon for engagement with said main screw thread, and at least one cleaning groove provided within the turns of the main screw thread, so that in use up-or-down movement of the float arm will cause the rotatable valve member to move towards or away from the valve seat to decrease or increase flow through the valve whilst the cleaning groove will allow some of the liquid flowing through the valve to pass along the cleaning groove to assist in deeming the interengaging portions of the rotatable valve member and the housing.

The above gives a broad description of the present invention, a preferred form of which will now be described with reference to the accompanying drawings, in which: Figure 1 is a side view of a float valve of the present invention; Figure 2 is a diagrammatic part-sectional view through the valve body of the float valve of Figure 1; Figure 3 is a sectional view through part of the valve body, shown at A in Figure 2; and Figure 4 is an end view of the arrangement shown in Figure 3.

Illustrated in the drawings is a float valve 1 comprising a float arm 2, which includes a float 3, and a valve 4. The valve 4 comprises a NEW ZEALAND JAN 1987 PATENT OFFICE 205976 » f valve body 5, with a valve seat 6 and outlet passage 7, and a valve member 8.

Although only one outlet passage 7 is illustrated, a plurality of radial outlet slots 7 are preferred where the valve is to be used as a flow oontrol valve.

The valve member has an engaging portion 9 which engages the valve seat 6 to close the valve, and a screw threaded driving portion 10, to which the float arm 2 is attached. Typically, the valve member is attached to the float arm via a spline machined onto a drive shaft 11 which, in turn, is keyed to the valve member.

Typically, the float arm 2 operates between a position forty-five degrees below horizontal and a position forty-five degrees above, so that the valve member rotates through ninety degrees between its closed and fully open positions. The pitch of the screw thread therefore must, in such circumstances, be such that the valve member travels far enough back from the valve seat in ninety degrees of rotation to allow fluid to flow unimpeded. However, the pitch must not be so great that it becomes too difficult for the float arm to operate.

The number of threads (starts) on the valve member will depend upon the shear strength of the valve member material. The illustrated valve member has two threads, and is envisaged to be made of a synthetic material such as UHMW polyethylene or nylon, although many other materials may be used. The valve body may be made of stainless steel, brass or any other suitable materia]..

Preferably there is sufficient clearance between the screw threads of the valve member and the complementary threads of the valve body to allow some liquid to pass between them to clean the co-acting surfaces and prevent the valve from sticking.

Cleaning grooves 12 are machined in the valve member to ensure that when cleaning fluid is directed into the valve a reasonable quantity of it can travel at sufficient velocity to clean the valve member and the body thread. The cleaning grooves typically run between the ridges 13 of the screw thread, although various arrangements of cleaning grooves cure possible.

JEW ZEALAND 20 JAN 1987 TEMTOFRCE 205976 Ttiis valve arrangement has a number of advantages over the older type of float valve, in which a plunger operates a linearly moving valve member. For example, when the valve is used in a milk vat or the like, there is nowhere for milk fat to accumulate where it can remain to breed bacteria or interfere with the operation of the valve. (It cannot lodge between the plunger and the valve member because there is no plunger.) Furthermore, there are no complicated parts which are difficult to clean.

The valve has particular application in the food and chemical industries, where cleanliness is important, and where vigorous cleaning of fluid conduits anid associated parts has to take place periodically.

The valve of the present invention can be constructed to any of a wide variety of sizes and specifications.

Various modifications to the above may be made without departing from the 8cope of the present invention as broadly defined in the following claims. For example, Ihe float arm may take many different forms. Hie angle through which the float arm is designed to operate may differ considerably. Hie valve itself may comprise any of many different types of rotary tap or valve, and may include any of a wide variety of seating arrangements.

The valve member and float arm may be formed as an integral unit.

The valve body could be welded or otherwise secured onto a suitable fitting to attach it to an existing valve arrangement. Alternatively, it could be secured directly to a water pipe or to the wall of a water tank or cistern.

: NEW ZEALAND 20 JAN 1987 ■T OFFICE

Claims (8)

-5-• • WHAT WE fTAIM IS: 205976 }

1. A float valve including: a valve housing having an inlet, an outlet, and a valve seat; a rotatable valve member moveable relative to the housing towards or away from the valve seat; a float arm operatively connected to said rotatable valve member; said rotatable valve member having a main screw thread thereon; said housing having complementary thread means thereon for engagement with said main screw thread; and at least one cleaning groove provided within the turns of the main screw thread; so that in use up-or-down movement of the float arm will cause the rotatable valve member to move towards or away from the valve seat to decrease or increase flow through the valve whilst the cleaning groove will allow some of the liquid flowing through the valve to pass along the cleaning groove to assist in cleaning the interengaging portions of the rotatable valve member and the housing.

2. A float valve as claimed in claim 1, wherein the rotatable valve member has at least two main screw threads thereon, each of which has its own cleaning groove.

3. A float valve as claimed in claim 1 or claim 2 wherein the rotatable valve member is formed of a plastics material. ■J

4. A float valve as claimed in any one of the preceeding claims, wherein the valve housing is formed of stainless steel.

5. A float valve as claimed in any preceeding claim, wherein the outlet comprises • a plurality of radial slots formed in the "housing adjacent the valve seat.

6. A float valve as claimed in any preceeding claim, wherein the inlet comprises a single axial inlet. NEW ZEALAND 20 JAN 1987 PATENT OFFICE .1) 205976 ! -V »

A float valve as claimed in any preceeding claim, wherein the float arm la directly connected to the rotatable valve member.

8. A float valve substantially as herein described with reference to the acoompanying drawings. W A k£*\i\Qx -(?obM&*v JAMES W PIPER AH) 00. Attorneys for the Applicant ENGINEERING SERVICES (WHAN3AKEI) LIMITED NSW ZEALAND 70 JAN 1987 T OFFICE