The present invention relates to a pressure vessel and relates particularly but not exclusively to a pressure vessel such as a gas cylinder having a separable protective outer casing or jacket which, in some aspects, is tamper proof whilst still being removable without destruction of major portions thereof and is at least partially re-usable without re-cycling of the materials.
A gas cylinder typically comprises a thick-walled steel pressure vessel. Such a gas cylinder is heavy and cumbersome. Lighter weight gas cylinders have been introduced in which the pressure vessel is wound with strengthening fibres, thus enabling its walls to be much thinner. In order to protect the vessel, or ‘liner’ as it is sometimes called, and its winding from damage, the vessel is located in an external plastics jacket.
It is known from U.S. Pat. No. 6,386,384 to provide a protective device for gas cylinders to protect the cylinder itself from damage which is both light weight and does not affect the required heat exchange between the cylinder and the atmosphere. The arrangement includes a top portion and a bottom portion which, in operation, surround the cylinder whilst leaving an upper and a lower surface of the cylinder exposed to the atmosphere such as to allow for the desired heat exchange with the atmosphere. The portions are each made of synthetic material and are interconnected during the assembly process by a standard functional clipping device. The clippings are integral with the upper and lower portions and must be broken in order for the casing to be removed, to allow visual inspection of gas cylinder itself. The two portions are then broken and must be sent for recycling before the material can be used again.
U.S. Pat. No. 7,287,663 also provides a protective device for gas cylinders in which a gas cylinder is surrounded by a metal outer casing comprising an upper and a lower portion. The upper portion surrounds all but an outlet area whilst the lower portion completely surrounds and encases the lower portion of the cylinder. An overlap between the upper and outer portions is accommodated by a dislocation of the upper portion such that the lower portion fits therein such as to present an edge of the upper portion which may be secured to the lower portion by means of a circumferentially extending weld. The arrangement whilst being very secure does not lend itself to easy removal of the jacket for the purpose of inspecting the inner cylinder and requires the addition of a complex collar portion surrounding the outlet area of the gas cylinder and being formed of metal is both heavy and prone to corrosion. The additional weight is a particular disadvantage when employed in combination with light weight composite pressure vessels such as domestic or medical grade gas bottles. The use of welds whilst making the arrangement tamper-proof may prevent the major components being re-used after separation as the removal of the weld will inevitably also damage the protective casing which is clearly very undesirable.
It will be appreciated from the above that there exists a need for a protective casing or jacket for gas cylinders and the like which is both light weight, robust, tamper-proof but removable to allow inspection and maintenance of an encased cylinder and which does not require re-cycling or re-finishing of major components before they can be re-used.
According to the present invention there is provided a pressure vessel comprising an outer protective jacket having an open end and a closed end within which is contained a fibre wound inner pressure vessel receiving a valve assembly enabling the contents of the inner pressure vessel to be controllably discharged, and a wheel base, wherein the wheel base comprises a main body having an open end for receiving the base of the jacket, a releasable catch operable to attach the main body of the wheel base to the jacket when the base of the jacket is inserted into the open end of the wheel base; and wheels rotatably attached to the main body of the wheel base wherein when the jacket is mounted to the main body of the wheel base, the jacket and the wheel base are operable to be transferred between locations using the wheels.
In some embodiments the wheels may be rotatably mounted on an axle and a slot is provided in the main body of the wheel base operable to receive said axle. A clip may be provided within the slot to retain the axle within the slot. Where the open end of the main body is substantially circular the slot provided in the main body may be offset from the centre of the circle defined by the open end of the main body.
The releasable catch may comprise a claw catch or similar operable to engage with a ridge provided on the exterior of the jacket. In some embodiments the releasable catch may comprise a pair of catches provided on opposite sides of the wheel base.
The open end of the main body of the wheel base may be complementary in shape to the exterior of the base of the jacket, the shape of the base of the jacket being such that the jacket may only be mounted to the wheel base in a number of set orientations. A lid may be provided at the end of the jacket remote from the base.
An embodiment of the present invention with now be described with reference to the accompanying drawings in which:
The pressure vessel 1 comprises a cylindrical outer protective jacket 3 having an open end and a closed end within which is contained a fibre wound inner pressure vessel (or ‘liner’) 5 (not visible in
The protective jacket 3 is mounted on a wheel base 9 which comprises a main body 11 and a pair of wheels 13 attached to an axle 15. A lid 17 which in this embodiment comprises a handle assembly, is attached to the end of the protective jacket 3 remote from the wheel base 9.
When fixed to the protective jacket 3 and the protective jacket 3 is mounted on the wheel base 9, the handle assembly on the lid 17 provides a pair of handles 21 which enables the entire pressure vessel 1 moved from location to location by being tipped and then pulled to a new position using the handles 21 while the wheels 13 on the wheel base 9 rotate about the axle 15. Additionally, the handles 21 protrude above the valve assembly 7 thereby protecting the valve assembly 7 from being knocked and damaged.
As will be described in detail the lid 17 is attached to the protective jacket 3 using a retaining ring 19 which prevents the lid 17 from being removed accidentally but permits the lid 17 to be dismantled when the contents of the inner pressure vessel 5 has been exhausted enabling the inner pressure vessel 5 to be removed from the protective jacket 3 and replaced or refilled.
The assembly of the pressure vessel 1 of
Initially as is shown in
Once the base 23 has been inserted into the interior of the protective jacket 3, the pressure vessel 5 is then inserted into the protective jacket 3. In this embodiment the circumference of the pressure vessel 5 is slightly smaller than the interior circumference of the protective jacket 3. When the inner pressure vessel 5 is inserted into the protective jacket 3 the walls of the protective jacket 3 hold the inner pressure vessel 5 in a fixed orientation with the end of the inner pressure vessel 5 resting upon the indented surface of the base 23.
Once the inner pressure vessel 5 has been inserted into the protective jacket 3, a spacer 25 is placed on the surface of the inner pressure vessel 3 at the open end of the jacket 3. This spacer 25 comprises a disc of protective material similar to that of the base 23. In a similar way to the base 23, the spacer 25 acts to protect inner pressure vessel 5 should the lid 17 be forced against the inner pressure vessel 3. A hole 27 is provided in the centre of the spacer 25 through which a portion 29 of the inner pressure vessel 5 for attachment to the valve assembly 7 protrudes.
Having inserted the inner pressure vessel 5 into the protective jacket 3 the lid 17 is then constructed and inserted (
The upper surface 33 is substantially semi circular in shape with a semi circular notch 37 being provided in the centre of the surface 33. These notches 37 are such that when the two parts of the lid 17 are fixed together, the notches 37 define a hole which provides access to the portion 29 of the inner pressure vessel 5 for attaching the valve assembly 7 to the inner pressure vessel 5.
The handles 21 extend away from the upper surfaces 33 of the handle sections 31 and provide means for gripping the lid 17.
The perimeter walls 35 of the handle sections 31 extend along the curved edges of the handle sections 31 on the opposite side of the upper surface 33 to the handles 21. At either end of the perimeter walls 35 are a male 39 and a female 41 latch portions. When the two handle sections 31 are pushed together this causes the male latch portion 39 on one of the handle sections 31 to enter the female 41 latch portion provided on the other handle section 31 and vice versa. When this is done, this latches the two handle sections 31 together.
The configuration of the two handle sections 31 when latched together is shown in
For additional security, in this embodiment, once the two handle sections 31 have been latched together, the two handle sections 31 are retained in place by passing pins 43 though holes 45 provided in the male and female latch portions 39,41.
A series of rhombozoidal lugs 47 are provided which protrude from the outer surface of the perimeter walls 35. These lugs 47 are arranged in pairs on the outer surface of the perimeter walls 35 and act to divide the perimeter wall 35 into a central circumferential channel 49 and a series of axial channels 51. The rhombozoidal lugs 47 are shaped so that the width of the circumferential channel 49 varies with the width of the channel being narrowest adjacent one edge of each pair of lugs 47 widening to a greatest extent adjacent the adjacent the opposing edge.
In this embodiment the arrangement of the rhombozoidal lugs 47 is such that when the two handle sections 31 are fixed together twelve axial channels 51 are defined equally spaced around the exterior of the lid 17 with each of the channels 51 having the same dimensions. In each of these axial channels 51 except for the axial channels 51 immediately beneath the handles 21 there is provided a detent 53. The detents 53 are such that they can be depressed so as to lie flat against the surface of the axial channels 51 but in the absence of a depressing force the detents 53 protrude beyond the perimeter wall 35 into the axial channels 51 where they are provided. As will be explained later these detents 53 interact with depressions on the inside of the retaining ring 19 to prevent the retaining ring 19 from being withdrawn by a user without the use of a special tool.
Referring to
The interaction of the lugs 49 on the lid 17 with the projections 57 extending into the interior of the protective jacket 3 adjacent the open end of the protective jacket 3 will now be described with reference to
As can be seen in
At this point the projections 57 on the interior of the protective jacket 3 lie at the intersections of the circumferential channel 49 with the axial channels 51 on the exterior of the perimeter wall 35 of the lid 17.
The external appearance of the lid 17 and the top of the protective jacket 3 once the end of the lid 17 has been inserted into the open end of the protective jacket 3 is illustrated in
When in this position the lid 17 can be removed from the open end of the protective jacket 3 by pulling the lid 17 away from the jacket 3 because the projections 57 on the interior of protective jacket 3 lie within the axial channels 51 on the exterior of the lid 17.
However, the lid 17 can be fixed in position by rotating (
Additionally, in this embodiment two pairs of lugs 47 are connected by a rib 60 which extends across the circumferential channel 49. These ribs 60 are provided on opposite sides of the perimeter wall 35 of the lid 17 spaced 180° apart and connect the lugs 49 either side of the channel 49 where the channel 49 is narrowest. These ribs 60 act as a further stop preventing the lid 17 from being rotated other than in a single direction when in the position of
If the lid is rotated about the axis of symmetry of the protective jacket 3, this causes the relative positions of the lugs 47 and projections 57 to become arranged as in
In the position shown in
Returning to
Having attached the required covers 61 and/or monitoring equipment 63, the configuration of the pressure vessel 1 is then fixed by placing (
The configuration of the retaining ring 19 is such that it can fit over the lid 17 with the portions 73 of the flange 71 of greater extent lying inside the arches formed by the handles 21. In this position the flange extensions 73 extend over the edge of any cover 61 or monitoring equipment 63 inserted in the apertures 65 provided in the lid 17. Thus in this way the flange extension 73 acts to prevent the covers 61 or monitoring equipment 63 from being removed.
When the retaining ring 19 is placed over the lid 17, as is illustrated in
In this embodiment in order to prevent a user removing the retaining ring 19 once it has been inserted, recesses 75 are provided on the interior of the circular band 67 above each of the tabs 69 except the tabs 69 extending from the portions of the circular band 67 where the flange extension are provided 73. As the tabs 69 pass over the detents 51, the detents 51 on the exterior of the lid 17 are caused to be depressed. When the tabs 69 of the retaining ring 19 are fully inserted into the axial channels 51 on the exterior of the lid 17, the recesses 75 are positioned opposite the detents 53 on the exterior of the lid 19. This releases the detents 53 which enter the recesses 75 locking the retaining ring 19 in place. With the retaining ring 19 locked in place, as it is not possible to remove the retaining ring 19 it is not possible to rotate the lid 17 relative to the protective jacket 3 and hence the lid 17 cannot be removed from the protective jacket 3.
Should removal of the lid 17 be desired for example in order to refill or replace the inner pressure vessel 5, a tool can be inserted into the gap between the retaining ring 19 and the exterior of the lid 17 where the detents 53 are present. Inserting a tool into the gap between the retaining ring 19 and the exterior of the lid 17 would then depress the detents 53 removing the detents 53 from the recesses 75 in the retaining ring 19. This would then permit the retaining ring 19 to be removed.
In order for the retaining ring 17 to be removed in this embodiment all the detents 53 would need to be simultaneously depressed. This can be achieved by depressing the detents 53 using a pair of curved tools corresponding to the curve of the exterior of the lid 17 adjacent the detents 53. Requiring that removal is dependent upon the simultaneous depression of multiple detents 53 acts to ensure that removal can only be effected using a suitable tool and hence accidental removal by a user in the absence of such a tool is prevented.
The configuration of the pressure vessel 1 with the retaining ring 19 attached is illustrated in
Having attached the retaining ring 19 to the pressure vessel 1, the pressure vessel 1 is then (
A slot 77 for receiving the axle 15 is provided at the closed end of the main body 11 with the slot 77 being offset from the centre of the main body 11. The side walls of the main body 11 are indented adjacent the slot 77 so as to define two wheel arches 79. A pair of strengthening ribs 81 are provided with the interior of the cavity defined by the walls of the main body 11. These ribs 81 extend across the interior the main body 11 and to a height slightly below the top edge of the walls of the main body 11 act to increase the rigidity of the main body 11.
A pair of claw latches 85 are provided on opposite sides of the main body 11 of the wheel base 9. The claw latches 85 are arranged to engage with a ridge near the base of the protective jacket 3 just above the narrowed portion 76 of the protective jacket 3 when the enclosed end of the protective jacket 3 is inserted into the open end of the main body 11 of the wheel base 9.
In this embodiment to assist with the positioning of the protective jacket 3 on the wheel base 9, the a pair of indentations 87 are provide on the exterior of the protective jacket 3 adjacent the closed end of the protective jacket 3 and a corresponding pair of indentations 89 are provided in the walls of the main body 11 of the wheel base 9. When the indentations 87 at the base of the protective jacket 87 are aligned with the indentations 89 in the walls of the main body 11 of the wheel base 9 the narrowed portion 76 of the protective jacket 3 is able to enter into the open end of the wheel base 9 until the base of the protective jacket 3 comes to rest upon the ribs 81 on the interior of the wheel base 9. When mounted on the wheel base 9 in this fashion the ridge on the exterior of the protective jacket 3 is caused to be located in a position immediately above the claw latches 85 and the protective jacket 3 can be secured to the wheel base 9 by engaging the latches 85 to the ridge at the base of the protective jacket 3.
Having mounted the pressure vessel 1 to the wheel base 9 a valve assembly 7 is then (
The completed pressure vessel 1 can then be transported from place to place by pulling on the handle 21 closest to the axle 15 of the wheel base 9 causing the pressure vessel 1 to rotate about the axle 15 and lift the portion of the wheel base 9 remote from the wheels 13 off the ground. The pressure vessel 1 can then be pulled to a new location whilst as the wheels 15 rotate before being placed upright again as shown in
Although in the above embodiment the lid 17 has been described as being formed from two separable sections 31, it will be appreciated that in some embodiments the lid 17 could be an integrally formed unit. It will also be appreciated that in other embodiments the specific details of the retaining ring 19, the lugs 47 on the exterior of the lid 17 and the protections 57 on the interior of the protective jacket 3 could be modified.
Thus for example it would be appreciated that whereas in the above described embodiment a lid 17 is described as having twelve axial channels and the retaining ring 19 is described as having twelve tabs 69 in other embodiments greater or lesser numbers of channels 51 and tabs 69 may be provided.
It will also be appreciated that whereas in the above described embodiment the projections 57 are described as being prevented from passing though the narrowest portions of the circumferential channel 49 defined by the lugs 47 on the exterior of the lid 17, with some of the lugs 49 being connected by ribs 60, in other embodiments other means could be provided to limit the possible extent and direction of rotation of a lid 17. Thus for example either a circumferential channel 49 of variable width or one or more ribs 60 alone could be provided on the exterior of the lid 17 to limit the extent the lid 17 could be rotated after being inserted into a protective jacket 3.
In addition it will also be appreciated that whereas in the above embodiment channels 49, 51, have been described as being provided on the exterior of a lid 17 which are arranged to receive projections 57 extending from the interior of a protective jacket 3, in other embodiments these arrangements could be reversed. That is to say a circumferential channel intersected by a number of axial channels could be provided on the interior of a protective jacket 3 where the channels are arranged to receive an arrangement of projections on the exterior of a lid.
Although in the above embodiment the projections 57 on the interior of a protective jacket 3 are described as being spaced from the edge of a channel 55 at the open end of the jacket 3, it will be appreciated that in some embodiments the projections 57 may be provided immediately adjacent the channel walls.
Further although in the above embodiment projections 57 have been described as being provided extending inward into the interior of the cavity defined by the walls of the protective jacket 3, in other embodiments the projections 57 could be provided on the exterior of the jacket 3 with a complementary arrangement of lugs 47 being provided on the interior of the perimeter wall 35 of the lid 17.
Number | Date | Country | Kind |
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1015655.2 | Sep 2010 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2011/001351 | 9/20/2010 | WO | 00 | 6/10/2013 |