NZ537530A - Sealing cap - Google Patents

Abstract

A sealing cap which has a substantially cylindrically shaped inner wall surface with one end (4) closed and the other end (3) open; having an internal threaded portion (6) on the inner wall and having an annular sealing rib (16) on the internal surface of the closed end concentric with the axis of the threaded portion and projecting towards the open end of the cap, and grip means on the outer wall surface.

Description

53753 0 FORM 5 NEW ZEALAND S.9 Reg.19(4) Fee: $250.00 PATENTS ACT 1953 Insert number of Provisional Specification(s) (if any) and date(s) of filing; otherwise leave blank Number: Date: Insert Title of Invention SEALING CAP COMPLETE SPECIFICATION Insert full name, full street address and nationality of (each) applicant I, DAVID JOHN PICTON, a British citizen, of 356 Point View Drive, R.D. 1, Papatoetoe, Auckland, New Zealand °€% £ o: r^'*> / <&. u % £ o 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 jarticularly described in and by the following statement:- This invention relates to a sealing cap which has been specifically designed for use in the plumbing trade.

It is good plumbing practice, when plumbing fittings have been installed in a structure, to test the installation to ensure that it is leakproof. Usually this will involve pressurizing the system to about 220 psi (15.4 kgP/cm2; 1517 kPa ) and checking that the gauge on the test equipment maintains that pressure for at least 30 minutes.

Where wingback fittings have been installed then traditionally these would be female fittings (although a range of male fittings might also be available). A female fitting is versatile because the plumber would simply cut a portion of threaded brass tube of a suitable length to give the required projection from the wingback fitting beyond the structure face surface. Having installed such a length of brass tubing in a female wingback fitting, or where a male wingback fitting is used, it remains to test the installation to ensure it does not leak. The traditional method has been to temporarily put galvanised caps on the protruding thread, introduce water into the system (assuming that one is dealing with a new installation) and then commence to pressurize the system, which will involve loosening the caps to bleed air out of the system and then retightening them to check that there are no leaks over the requisite observation period.

Intellectual Property Office of N.Z. 2i, DEC 200't received.

The above technique allows any bled water escaping from the system to be caught well away from the structure's face surface.

One of my patent specifications describes an improved form of testing device where the same arrangement of flange sealing washer, thread and handle are provided but the whole device is hollow and is provided at the end of the handle portion furthermost from the flange with a further male threaded portion and optionally next to that a hexagonal cross-sectioned area to enable the device to be gripped by a spanner or similar tool. The cap of this invention is designed to seal such a projecting threaded portion and has a sealing means adapted to sealingly mate with the threaded portion.

As well, the cap has grip means provided externally, facilitating its threading onto and off such a threaded area.

The present invention consists in a sealing cap which has a substantially cylindrically shaped inner wall surface with one end closed and the other end open; having a threaded portion on the inner wall and having an annular sealing rib on the internal surface of the closed end concentric with the axis of the threaded portion and projecting towards the open end of the cap, and grip means on the outer wall surface.

One preferred form of the present invention will now be described with reference to the accompanying drawings in which - Figure 1 shows a perspective view of a preferred form of cap from an open end thereof.

- Figure 2 shows a perspective view of the cap from a closed end thereof.

- Figure 3 shows an end view of the closed end.

- Figure 4 shows a side view of the cap.

- Figure 5 shows a central longitudinal cross section.

- Figure 6 shows a side view of a spanner able to be used with the cap.

Referring to Figure 1, the cap has a substantially cylindrically inner and outer surfaced wall 2 which is open at the end 3 and closed at the opposite end by a wall 4 (Figure 2). A skirt 5 provides a suitable lead-in to a female threaded portion 6 and on the external surface of the cylindrical wall there are preferably a number of projections such as 7, 8, and 9.

As can be seen from Figures 2, 4 and 5, the junction between the closed end 4 and the substantially cylindrical outer surface of the wall 2 is relieved at 13 by a chamfer or rounding. The projections are also preferably six in number (7-12 inclusive) and are equally spaced. The ends of those, nearest the wall 4, are also relieved such as at area 14 indicated on projection 10 and they are set back a little way from the junction of the end wall 4 and the outer surface of the wall 2.

Projections 7 - 12 are all elongated and are coaxial with the threaded portion 6. They are preferably semi-cylindrical in cross section. The cap is preferably injection moulded from a plastics material. A suitable spanner for use with the cap as shown in Figure 6 is also preferably injection moulded. The spanner is the subject of one of my patent specifications.

The relieved portion 13 allows the spanner to be easily centred on the cylindrical outer surface of the wall 2, the projections being set back from the lead-in portion to facilitate proper engagement of the spanner on to the cap. Then when the spanner is to be engaged with the projections 7-12 inclusive, the relieved portions such as 14 further enable the spanner to be easily aligned, and slid onto the projections. Furthermore, the substantially cylindrical outer wall surface may be slightly greater in diameter towards the open end 3 of the cap to prevent the tool 15 from being pushed too far onto the cap. The correct tolerances would see the tool centred along the length of the projections 7 - 12 in normal use. Instead of the cylindrical surface being tapered, the projections themselves could taper outwardly towards the open end 3 of the cap or there could be some other stop means provided on the outer surface of wall 2 towards the open end 3. The tapered arrangement, however, means that the spanner 15 can be placed on the cap 1 and will stay there via frictional forces during loosening or tightening of the cap, if it does not need to be repositioned on the cap.

A feature of the cap is the provision of an annular internal rib 16 (Figure 5) which is preferably triangular in cross-section with an included angle of substantially 55°. The side of lesser diameter is inclined at an angle of 15° to the threaded portion axis but it is the other side which effects the sealing when it engages with a suitable 40° chamfer provided at the end of a male threaded tube which is designed to co-act with the cap. Such a tube is the subject of two of my patent specifications.

In a case where the cap was not to be injection moulded from a plastics material then the sealing rib would be a suitable insert either as a resilient washer spanning the whole internal face of the end 4 or in the form of a resilient ring suitably located in or on the inner surface of the end 4 to effect the necessary sealing function.

The internal diameter of the tip of the rib 16 is 14mm. The internal diameter of the skirt 5 is 22mm and the thread 6 is inch BSP and the projections preferably have a radius of 1.75mm, but obviously different dimensions would be used for % inch BSP threaded caps.

The caps may also be modified with a central hole through the end wall so that they can function as nuts on braided hoses designed to co-act with a wingback of my design, and the subject of one of my patent specifications, which has the appropriate matching chamfer.

Claims (15)

WHAT I CLAIM IS:

1. A sealing cap which has a substantially cylindrically shaped inner wall surface with one end closed and the other end open; having an internal threaded portion on the inner wall and having an annular sealing rib on the internal surface of the closed end concentric with the axis of the threaded portion and projecting towards the open end of the cap, and grip means on the outer wall surface.

2. A cap as claimed in claim 1 wherein there is a skirt at the open end of the inner wall surface which is unthreaded and provides a guide for a mating male thread, in use, to be engaged with the female thread within the cap.

3. A cap as claimed in claim 1 or claim 2 wherein the outer wall surface is substantially cylindrical and has a number of elongated straight projections which lie parallel to the thread axis.

4. A cap as claimed in claim 3 wherein the projections are equally spaced.

5. A cap as claimed in claim 4 wherein the projections number six.

6. A cap as claimed in claim 5 wherein each projection is semi-cylindrical in cross-section.

7. A cap as claimed in any one of claims 3-6 wherein the ends of the projections nearer the closed end of the cap are relieved.

8. A cap as claimed in any one of claims 3-7 wherein the external substantially cylindrical wall of the cap tapers slightly to an increased diameter towards the open end of the cap.

9. A cap as claimed in any one of claims 3-7 wherein the height of the projections increases slightly towards the open end of the cap.

10. A cap as claimed in claim 3 or any one of the preceding claims when dependent on claim 3 wherein the junction of the closed end of the cap and the external wall surface is relieved so that it is not sharp.

11. A cap as claimed in claim 10 wherein the projections are set back from the relieved junction.

12. A cap as claimed in any one of the preceding claims wherein the annular sealing rib is triangular in cross section with an included angle at the tip of substantially 55°.

13. A cap as claimed in claim 12 wherein the face of the rib of lesser diameter makes an angle of substantially 15° with respect to the thread axis.

14. A cap as claimed in any one of the preceding claims wherein the tip diameter of the rib is 14mm.

15. A cap substantially as herein described with reference to the accompanying drawings. C, Oshornt DAVID JOHN PICTON By his authorised agents J.D. HARDIE & CO. J INTELLECTUAL PROPERTY OFFICE OF N.Z. - 7 APR 2006 RECEIVED 9