AU758917B2 - A jacket for a water heater - Google Patents

Description

13/06 '00 TUE 17:57 FAX 61 2 9684 4270SOAHRPISIPASTIJ0 S011CHCORP IPIS 444 IP AUST 1a004 61 2 9684 4270

AUSTRALIA

Patents Act 1990 P/00/0 11 Regulation 3.2 COMPLETE SPECIFICATIONr- FOR A STANDARD PATEN r'

ORIGINAL

FOR OFFICE USE Name of Applicant: Address of Applicant: Actual Inventors: Address for Service: In-ventiOn tIC: TO BE COMPLE TED BY APPLICANT Seuthcop AwAutaia Pt+y LtdA AdJad 5 00 MALLIA, Daniel Michael bMr A -W-Th4ey IFQ.-k I n Rydanme~e-N W-2-6 41A JACKE~T FOR A WATER

HEATER"

The following statement is a full description of this inventiorn, including the best method of performing it known to me: RECEIVED TIMEI3. JUN. 18:56PRN TI 14JU. PRINT TIME14.JUN. 8:54

I

A JACKET FOR A WATER HEATER.

This invention relates to a jacket for a water heater.

In the mass production of water heaters, it is known to provide a storage tank for the water heater with an external layer of insulation to avoid heat loss, the insulation layer being protected and confined around the storage tank by a jacket. The most customary material used for jackets is cold rolled steel sheet, which may be galvanised and painted a suitable decorative colour.

Jackets have customarily included a cylindrical metal component referred to as the shell and two essentially symmetrical ends which are attached to the jacket shell by an overlapping flange around the periphery of the jacket end which overlie, in telescopic fashion, either end of the jacket shell, which may be, if desired, reduced in diameter locally in the region where the jacket end flange overlaps.

In the past, the assembly between the jacket end and jacket shell has been accomplished by the insertion and tightening of a substantial number of self tapping :0 screws, spaced around the periphery. This is a time-consuming operation which slows the production line of such heaters.

The present inventor proposes an alternative construction in which the jacket ends are firmly assembled to the jacket shell without requiring the use of self-tapping or other type of screws.

The invention consists of a jacket for a water heater having a jacket shell and at least inwardly directed locking channel extending circumferentially around the periphery of the shell, close to and parallel to the adjacent end(s).

The invention also includes a jacket end adapted to be connected to the jacket shell (in a assembly featuring greater tightness than that of the usual screwed connections) wherein the jacket end has locking lancings inwardly formed by cutting a short circumferentially extending length of jacket end material and deforming inwardly in a localised area the cut so formed to create a barbed shaped metal displacement capable of tight fitting inter-engagement with the above-mentioned locking channel upon assembly.

The locking lancing in the jacket end is preferably formed in the flange portion of a jacket end as a separate, off-line manufacturing step prior to the inter-assembly between the jacket end and the jacket shell.

It is preferable that there be at least three locking lancings formed in each jacket end but more preferably there should be a sufficient number of locking lancings so that the spacing between adjacent ones is no more than 600 apart. Preferably, in localised areas of the fit-up between the jacket shell and each end where the assembly of the water heater may impose an outward force on the material of the jacket upon assembly that may be concentrated in one particular region of the assembly, there may be provided a non-symmetrical concentration of locking lancings around the region where higher than average force is required to be resisted. For example, where the assembly of water heater storage tank and jacket is formed prior to a step of filling a space between the storage tank and the jacket with a foam-in-place form of heat insulation, known concentrations of internal pressure developed by the expanding and setting foam are associated with a filling hole and, accordingly, with this invention, additional jacket end locking lancings can S be formed and assembled adjacent to the filling hole.

One example of the invention is described in greater detail with reference to the accompanying illustrations in which: "m •Fig 1 is a perspective view of a jacket top having locking lancings according to the invention; Fig 2 is a part cross-sectional view of the jacket top and jacket shell inter-assembly.

Fig 3 is an elevation view of a complete jacket shell.

Fig 4 is a part cross-sectional view of the jacket top detail as referred from Fig 3 including a fragmentary plan view as well.

Fig 5 is an inclusive plan and elevation view of the jacket top shown in Fig 1.

Fig 6 is a part cross-sectional view of the jacket top viewed in at the section VI-VI as shown in Fig Fig 1 illustrates the modified jacket 10 according to one aspect of the invention, where four locking lancings 12 and 12' are visible, formed in a flange portion 14 of the jacket end. There are further identical lancings hidden from sight in the view shown. A filling hole 16 in the jacket end has two of the locking lancings 12' spaced closer together than the remaining locking lancings to better overcome a substantial pressure generation known to occur in that region when filling the space between the jacket and storage tank with foam-in-place insulation.

In Fig 1 each jacket end locking lancing is made by forming a horizontal cut typically 25mm in circumferential extent and then, with the aid of a locking punch and locking die block set, deforming inwardly material adjacent to the cut to protrude inwardly typically 2mm from the original undeformed position.

In Fig 2 the jacket shell 18 has formed in it an inward step 20, known as a joggle in the metalworking industries, so that the upper circumference of the jacket shell within typically 20mm of the end, is formed at a reduced diameter with respect to the remainder of the jacket shell. Within this approximately 20mm band at each end of S:the shell 18 an inwardly directed taper 22 is also formed to facilitate the assembly of "it. each jacket end 10 with the jacket shell. This process typically forms a sinusoidally shaped wrinkling of the marginal ends of the jacket but this does not provide a sufficient escape path for any significant quantity of the expanding foam insulation.

In addition, in the wall of the shell 18 between the end of the inward end of the taper 22 and the reduction in diameter associated with the joggle 20, a locking channel 24 is formed by any suitable variety of metalworking methods, including rolling the jacket shell between suitably shaped male and female dies to form the locking *channel in the shape as illustrated.

Significantly, the locking channel 24 has a form wherein the uppermost wall 26 has a horizontal portion in order to lock in a complementary fashion with a similar portion 28 in the jacket end locking lancings 12, 12'. This way, upon assembly of the jacket end 12 by moving axially inwardly relative to the jacket shell 18, the outward ends of the jacket shell resiliently deform radially inwardly during assembly but once the jacket end locking lancings 12, 12' pass the portion 26 of the locking channel 24, the locking channel springs back out to tightly engage the jacket end so that the jacket end cannot be readily disassembled from the shell.

Once assembled in this manner, the subsequent manufacturing step of forming foam-in-place insulation between the storage tank and the jacket can be completed and this step results in further tightening of the inter-engaging channel and lancings around either end as the foam insulation pressure forces the engaging surfaces tightly against each other in both radially outward and axially outward directions.

Fig 3 shows a cylindrical shell 18 with both ends, top and bottom, being joggled inwardly and formed with a locking channel according to the invention, shown in detail in Fig 4.

Fig 4 shows a detail of the top end of the shell 18 of Fig 3. Shown are the locking channel 24 bounded by the tip 22 of the shell and a reduced diameter portion 20 of the shell 18. The tip 22 becomes wrinkled during the rolling operation performed on the shell to form the locking channel 24.

Fig 5 shows a top end 10, indicating schematically by asterisks the locations of each locking lancing 12 around the periphery. The locking lancings 12' adjacent the filling hole 16 for admitting the foam-in-place heat insulation are asymmetric with respect to Stheir angular spacing from the other lancings 12, in order to better resist the internal pressure generated during the foaming reaction. This has been observed to be Shigher near the filling hole 16.

Fig 6 shows a section and elevation view of a typical locking lancing 12 in a top end, forming a surface 28 which tightly engages with the outward surface of the locking channel 24 of the shell 18.

Although the jacket shell 18 has been illustrated as being of cylindrical shape and the ends 10 circular, the invention is applicable also to a not illustrated square or rectangular jacket or other shape combining both square and rectangular portions and square, rectangular or other shaped jacket end to suit. The invention can also be applicable in reducing the number of screws used upon assembly rather than totally replacing screws as an assembly means if desired.

The jacket shell 18 as illustrated in Fig 2 has an inward joggle step 20 but the invention is equally applicable if there is no joggle present adjacent to either end of the jacket shell.

*o* e o** w

Claims (4)

1. A jacket for a water heater having a jacket shell and at least one jacket end wherein the jacket shell has formed in it close to at least one end an inwardly directed locking channel extending circumferentially around the periphery of the shell, close to and parallel to a plane containing the at least one end.

2. The jacket as claimed in claim 1 in which the jacket end has plural locking lancings inwardly formed by cutting a short circumferentially extending length of jacket end material and deforming inwardly in a localised area the cut so formed to create a each lancing, which is a barb-shaped metal displacement capable of tight fitting inter-engagement with the locking channel upon assembly.

3. A method of forming a jacket end as claimed in claim 1 or claim 2 in which each locking lancing in the jacket end is formed in the flange portion of a jacket end as a separate, off-line manufacturing step prior to the inter-assembly between the jacket end and the jacket shell.

4. The jacket as claimed in any one of the preceding claims in which the end io has at least three locking lancings formed in each jacket end. The jacket as claimed in any one of the preceding claims in which the number of locking lancings is chosen so that the spacing between adjacent ones is no more than 60 0 apart around the circumference of the end. S6. The jacket as claimed in any one of the preceding claims in which the lancings are spaced asymmetrically less than 60 0 around at least one region where higher than internal pressure is characteristically generated during filling of the shell with foam-in-place insulation. DATED this 13th day of June 2000 SOUTHCORP AUSTRALIA PTY LTD