GB2389086A - Liquid transportation tank - Google Patents

Abstract

A liquid transportation tank 10 for motor vehicles comprises a sealed rigid plastic tank 10 having at least one baffle plate (14 see fig 2) and an integrally formed connection member (40 see fig 3) for connecting the tank 10 directly to a motor vehicle. An aperture (18 see fig 2) extends through the baffle (14), which is integrally formed with or welded to opposing walls 16 of the tank 10. The tank 10 is provided with a top panel 30 and a bottom panel (28 see fig 2). The plastic material is preferably high density polyethylene and the wall thickness may be 6-16 mm. The walls 16,24 are typically extrusion welded along seams 12. The tank 10 may be used for transporting a cleaning fluid and elongate cleaning tools 60 which may be supported on integral seating features 56 provided in a welded support frame 50.

Description

Liquid Transportation Tank The present invention is directed to a

transportation tank for motor vehicles and, more particularly, to a transportation tam; to allow the safe movement of liquids.

The invention is also directed towards a cleaning system, notably for windows and building exteriors, employing the use of such a liquid transportation tank.

With the considerable increase in commercial buildings, especially large scale 10 office blocks, the traditional methods of cleaning the windows and facias of these buildings has become more demanding whereby traditional window cleaning techniques on their own, are unable to cope with the volume demand now encountered. 1' The majority of modern office buildings have a significant proportion of their wall area covered by windows, fascias and cladding which require constant cleaning.

Traditional methods of using a ladder to access non-ground floor windows is no longer convenient due to such buildings having more than two storeys, whereby a ladder would be impracticable for higher storey windows, and, since many 70 buildings employ large areas of glass, they would be unable to support the weight of a ladder. Thus it has been commonplace to employ other means to allow the window cleaner to access the windows to be cleaned, such as the use of extendable platforms (commonly known as 'cherry pickers"), traditional scaffolding or roof mounted cradles which may be supported by a mechanism on

ret the roof of the building and generally moved along both vertically and horizontally to allow an operator in the cradle to access the windows. All these techniques employ means of allowing the window cleaner immediate and adjacent access to the windows to be cleaned so that he is able to use traditional handheld window cleaning tools. However, there are considerable drawbacks with these types of window cleaning operations for office buildings and, notably, the use of a cradle is a very expensive piece of equipment and also it is very time consuming in its use having to be consistently reset and adjusted along the face of the buildings to allow the operator access to those windows to be cleaned. Similarly, 10 the use of an extendable platform is both expensive in outlay on the original equipment and also time consuming in consistently requiring the operator to reposition both the vehicle and the platform to the appropriate window. The use of traditional scaffolding is probably the least preferred of the above options since it involves the construction of a temporary structure to allow the window cleaner 1 access to those areas to be cleaned and they need to be taken down and reconstructed when the operator wishes to move to another area to be cleaned.

Thus these traditional methods of cleaning office block windows are considered to be both time consuming and expensive.

20 An alternative window cleaning procedure has therefore been established allowing the window cleaner to operatively clean windows and fascias whilst remaining remote from the windows themselves, by mounting the actual cleaning tools and brushes on the end of elongate tubular poles of varying length, with the hollow

l t: l:l a:::.

poles containing appropriate pipes conveying both water and detergent to the cleaning head or brush. These pole systems allow the operator or window cleaner to remain on the ground whilst using the poles to extend the cleaning head to the generally inaccessible windows to be cleaned, the user also having access to appropriate fluid control valves further having remote with the thereby allowing remote control of both the water and detergent being applied to the cleaning head as it used to clean the windows at the end of the pole. Such pole systems are generally applicable up to heights of 25m from ground level. Generally, such pole systems can be operated by a single person for pole lengths of up to 14m whereby 10 heights between 14m and 25m generally require additional support by a second operator from the roof of the building being cleaned. An example of such a pole cleaning system is that sold by the Tucker Manufacturing Co. Inc. of the United States under the Trademark TUCKER POLE SYSTEMS.

1: Whilst such pole cleaning systems have proved to be extremely effective and flexible in allowing a single operator to clean a large area from the ground, it has also been determined, that since a squeegee is not used to remove water following cleaning and washing, that in areas of hard water, the system can leave hard water stains on the window once the water has dried. Since water is necessary to 90 constantly rinse and remove the detergent during the cleaning operation, it has been determined that this problem can be overcome by using softened or de ionised water of up to 99.9% purity. Since such de-ionised water is not available through nominal mains systems, the window cleaner is thus obligated to provide

, 4 À 1

À his own source of de-ionised water, necessitating the use of a liquid transportation tank mounted in his vehicle, such tanks being required to carry between 40(] and 100 1itres to carry out an adequate cleaning operation.

5 The transportation of liquids by motor vehicles is known to have inherent problems due to the lack of stability of such liquids and the resultant constant shifting of the centre of gravity of the liquid mass resulting from the centrifrugal forces acting thereon which result from motion of the vehicle. Any fluid contained in a tank mounted thereon tends to be unstable wherein several hundred 10 1itres of water. if not properly restrained, can result in significant variation of the centre of gravity of such a large load which can, in extreme circumstances cause the driver to lose control of the vehicle and can in fact cause the vehicle to become unstable and possibly tip over. For this reason, it has previously been commonplace to custom build the payload area of such vehicle (normally vans, 1' small trucks or trailers) to be provided with rigid metal frameworks bolted to the sub-frame of the vehicle which are then used to support fibreglass tanks, constructed in-situ within the van itself. Due to the materials used to construct such transportations tanks, considerable weight is employed within the tank itself limiting the volume of water that can be contained by the tank due to the overall 20 weight limitations of the vehicle. Also the materials used and the inherent nature of the frame design tend to be very bulky limiting the space that can be adequately utilised to store water. In addition, the customization of such vehicles is both time

l r consuming and expensive due to the individual nature in design and construction of each vehicle.

It is therefore an object of the present invention to provide a liquid transportation 5 tank which alleviates the aforementioned problems and to further provide a cleaning system utilising such a tank.

According to the present invention there is provided a liquid transportation tank for motor vehicles, comprising a sealed, rigid, plastics tank having at least one 10 internal baffle plate integrally formed with and extending between opposed inner wall surfaces of the container, the at least one baffle plate having an aperture therethrough, whereby the tank further comprises an integrally formed connection member for connecting the tank directly to a motor vehicle. Preferably, the connection member will comprise at least one flange member which extends from 1: a lower surface of the tank and thus provides a connection to allow the tank to be bolted or otherwise connected to the floor of the vehicle in which it sits.

It is preferred that the tank will be constructed of high density polyethylene usually between 6mm and 16mm, and ideally 12mm thick. The tank is normally 20 rectangular and will comprise extrusion welded sheets of polythene to provide a strong rigid structure with watertight seals.

, t ,, I

,, 1 ,,,,, . À À

The tank wiJI preferably be provided with external fixing elements mounted on and secured to an external surface of the tank for the mounting of external buckets or fixtures used for securing accessories to the tank. When used in conjunction with pole cleaning systems, such accessories can include a pump, a 5 hose reel, a de-ionisation chamber and various tools used in such systems.

Usually, a plastics fixing plate will be bonded to an external surface of the tank so as to be formed substantially integral therewith (either by welding or adhesive bonding) whereby this fixing plate will usually have mounted therein fixing 10 elements having externally projecting portions for engagement by and mounting of the external fixtures. These fixing elements are subsequently secured between the fixing plate and the tank to be restrained from displacement relative thereto.

In this manner, the fixing elements themselves do not pass through the walls of the tank nor are embedded or otherwise connected directly to such walls in a manner 1: which could damage and/or create a potential point of weakness in such walls.

The transportation tank may further comprise a resealable inlet valve to allow water or other liquids to be poured into the tank and will usually comprise at least one outlet valve to allow the liquid to be removed.

2(1 A further feature of such tank is that it may be provided with an integrally mounted support frame for supporting elongate members thereon, which support frame usually comprising at least two remote support walls each having at least

( l t e t 4 1 I l one slot formed therein to provide a seat for the elongate member extending therebetween. These support walls may, advantageously, be castellated to present a plurality of slots therein.

5 Further, according to the present invention, there is also provided a modular cleaning system, preferably for pole cleaning systems, which will comprise a transportation tank according to the present invention, together with a plurality of cleaning tools and accessories, each of which is intended for fluid engagement with the tank, wherein the plurality of cleaning tools and accessories are 10 selectively engageable with the tank so as to be releasably stored thereon. Thus a compact modular cleanin,, system is provided, based upon the design of the plastics transportation tank. This provides for a system which may be easily installed within a motor vehicle and, due to its modular design, provides a compact modular system having a carefully controlled centre of gravity.

The present invention further provides a novel method of construction of such liquid transportation tanks.

A preferred embodiment of the present invention will now be described, by way 20 of example only, with reference to the accompanying illustrative drawings in which;

'.:: ' ':

( ' e t d Figure I is a perspective view at a basic liquid transportation tank according to the present invention; and Figure is a front elevation of the transportation tank of Figure 1; and s Figure 3 is a side elevation of the transportation tank of Figure 1; and Figure 4 is a rear elevation of the transportation tank of Figure 1; and 10 Figure is a plan view from above of the transportation tank of Figure 1; and Figure 6 is an opposite side view of the transportation tank of Figure 1; and Figure 7 is a cross sectional view along the lines VI-VI of the transportation tank 15 of Figure 6.

Conventional liquid transportation tanks for motor vehicles may comprise metal welded tanks which are welded or bolted onto the sub-frame of the vehicle itself and have welded strengthening ribs around the exterior periphery of the tank for (I rigidity. Altematively, it is also known to utilise fibre glass tanks supported within a rigid metal support frame, the support frame again being welded or bolted to the sub-frame of the motor vehicle and substantially enclosing the fibre glass material of the tank to both strengthen the tank and prevent it from moving. The

d fibre glass mate Tat on its own does not have sufficient strength to support such large volumes of liquid, particularly when subject to centrifugal forces. However, one of the major drawbacks of such existing tanks is the inherent weight associated with the use of metal either to form the tank itself or to form the rigid support frame. Additionally, such tanks also tend to be bulky due to the support frames disposed around the external periphery of such tanks, both of which drawbacks serve to reduce the overall capacity that can be transported in mid range size vehicles (such as vans, trucks or trailers) commonly used by window cleaners. It is appreciated that such mid size vehicles have a maximum load capacity which limits the weight and, hence, volume of liquid they are able to carry. If considerable weight is also utilised within the tank itself this obviously reduces the volume of water that can safely be carried by that vehicle.

Specifically, liquid transportation tanks of this type are necessary for use with pole cleaning systems (as previously discussed). It is well understood for the use of pole type window cleaning systems also require a high volume of equipment, including the poles and extension pieces, a pump or pumps to pump both the water 70 and detergents through the poles, a plurality of different working heads for performing different jobs at different angular orientations, together with hose reels and the flexible hoses for conveying both liquid and detergent from the operator's vehicle to the cleaning tool head. Again, vehicle space will be of a premium to

,,, t ... .. À À - À

(, , d,,, contain all the required equipment together with a suitable volume tank to allow the operator sufficient water in order to undertake the cleaning operation. Also, whilst the tanks are used to transport softened or de-ionised water obtained from a fixed source, it is often desirable to provide the tanks with an additional de-ioniser 5 tank through which the water is passed prior to being pumped to the cleaning head All of which additional equipment is both heavy and bulky, requiring appropriate storage within the cleaners vehicle.

Referring now to Figure 1, a liquid transportation tank (10) according to the 10 present invention is schematically illustrated. This tank is formed of 19mm thickness high density polyethylene sheet material which is extrusion welded along its seams (12) to form a substantially rectangular container. Extrusion welding, whereby a molten polymer is generated inside a welding tool and pumped into the weld joint as the tool is moved along the weld, is commonly used lS for the welding of seams in plastics and composite materials to provide very strong joints when either used to form a butt-weld or a right angle joint, whereby a melted polymer is injected between the adjacent sheet materials. Since extrusion welding of thermoplastic and polyethylene materials is well known and its benefits and advantages are well understood by those skilled in the art of plastics 70 material it will not be described herein further save to confirm that a tank formed by such extrusion welding will have very strong watertight joints. In addition, the use of 12mm high density polyethylene provides a very strong, rigid material.

l l , À À À 1

Referring now to Figures and Figure 6, the interior of this rectangular tank (to) comprises a plurality. (in this embodiment two), baffle plates (14) extending between two longitudinally opposed sidewalls (16) of the container. The baffle plates (14) are shown in dotted lines in these figures, indicative that they are internal. Each baffle plate (14) is again formed of 12mm high density -

polyethylene and comprises a substantially central aperture (18) extending therethrough and, at each of its corners, secondary smaller triangular apertures (hi)) disposed between the baffle plate (14) and the interior comers of the tank (IO). As seen in Figure 6, these two baffle plates (14) divide the tank into three 10 similar sized chambers (27).

The two opposed end walls (74) of the tank (10) are further provided with vertical strengthening ribs (26) illustrated again in Figures 6 and Figure 4 (in hashed lines) which are utilised to provide additional rigidity to these end walls (24). Both the 15 baffle plates (14) and the support plates (26) are also extrusion welded onto the respective sidewalls (22) or end walls (24) of the tank using conventional extrusion welding techniques so as to be effectively integral therewith. In particular, the baffle plates (14) are extrusion moulded onto the two sidewalls (16) and also the bottom panel (28) and top panel (30) of the tank (10), so as to be 20 rigidly attached to the tank about its entire periphery.

In order to achieve appropriate extrusion welding of the baffle plates internally of such a rectangular sealed transportation tank (10), a unique manufacturing method

l l is employed whereby the rectangular tank (10) is firstly formed by extrusion welding the four sidewalls (16) (ad) onto the bottom plate (28) and then extrusion welding the top plate (30) onto this extrusion welded box. Subsequently, the two end faces (24) are removed to provide an open ended rectangular tube at which stage the baffle plates are inserted into their correct positions extending between -

the sidewalls (16). The first baffle plate is then welded, from either side, to provide a strong welded engagement to both the sidewalls (16) and also the bottom (28) and top (30) plates respectively. The second baffle plate is then inserted and its outwardly facing edges are welded using extrusion welding.

The manufacturer is then able to access the "interior" side of the second baffle (14) plate through the circular aperture (18) in the first baffle plate.

If more than two baffle plates are employed, then this procedure is again repeated 15 for the consecutive baffle plates by gaining access to interior directed surfaces through the apertures of the adjacent baffle plates. This allows the baffle plates to be welded about their complete periphery, and on either side, to adjacent walls of the tank, thereby providing a very strong joint.

90 Strengthening ribs (26) are then extrusion welded onto each of the end walls (24) in the positions shown in Figure 7. These end walls (24) are then again extrusion welded to the two side walls (16) and bottom (28) and top (30) plates to again form a rectangular, solid, watertight transportation tank (10).

i::':':; ; r; ; The baffle plates are primarily used to restrict displacement of water or other liquid contained in the tank (10) during transportation and serve to arrest and slow fluid flow between adjacent chambers (I?) in a conventional manner. However, 5 the baffle plates also serve to provide additional rigidity and strength to the tank ( IO). Due to the large volumes of liquid or water to be held by such tanks (ideally, tank capacities will range from about 700 litres to 1600 litres with average tank sizes of 600-800 litres) a considerable pressure will be exerted on the tank when full. This pressure will significantly increase if centrifugal forces are exerted on 10 the liquid during transportation. Thus the baffle plates (14) not only help reduce displacement of the liquid but, due to their rigid attachment to the walls of the tank, also serve to help distribute the pressure over a larger surface area and, through the creation of separate chambers, helps reduce the exerted pressure on the walls in each chamber (22). The ribs (26) provide additional strength to the 1: end walls to prevent the walls buckling under high pressure, as is conventional.

Since this transportation tank (10) is intended for use in motor vehicles, it is provided with additional flange surfaces (40), as best seen in Figure S. which again are extrusion welded to both the end faces (24) and the bottom plate (28) of 30 the tank (10). In this particular embodiment, the flange plates (40) are provided with appropriate bolt holes (42) which allow the tank (10) to be bolted to the floor of an appropriate vehicle. Alternatively, the flanges (40) may be provided with other fixing means for securing the tank (10) to the floor or these flanges could be

t.:' 41;; (; ' d; À; #e formed around the entire periphery of the tank to provide additional stability if required. These flanges could also be welded or otherwise bonded (e.g. adhesively) to the underside of the bottom surface (28) so as to extend at different orientations around the lower periphery of the tank to allow connection in a 5 plurality of different positions. Preferably, appropriate fixings will be mounted to the vehicle floor to receive an appropriate bolt which will extend through the bolt holes (42). If required, washers or metal sleeves could also be inserted through the bolt holes (42) to provide additional strength when securing the tank to the vehicle floor to reduce the possibility of the bolts shearing through the flanges.

Although not shown in Figure 1 for clarity, the tank (10) is provided with a plurality of valve members (44) extending through the respective walls (24 and 16) of the tank (10) and comprise, in this embodiment, conventional female screw threaded connectors for co-operating engagement with conventional male 15 connectors. These female connectors (44) are again extrusion welded onto both the interior and exterior surfaces of the talk (10) to provide a watertight seal thereabouts. Alternative types of valve are equally applicable to the current invention. which valves are shown here illustratively to establish fluid communication between the water transportation tank (10) and exterior fittings 20 and connectors. With reference to Figure 5, the tank (10) is also provided with a main inlet aperture (46) formed in the upper plate (30) of the tank (10) and will again comprise a large diameter aperture extending through this top sheet (30) for receiving a screw threaded tube, again extrusion welded onto the high density

l: 81 'd' I' ( l polyethylene material and for receipt of a complimentary screw threaded plug in releasable sealing engagement therewith. As is conventional, this plug (not shown) can be removed by appropriate rotation to allow the user to fill the tank when appropriate.

A further beneficial feature of this current invention comprises the mounting of a castellated support frame (SO) on the upper surface of the tank (10). This support frame (50) comprises two upright and longitudinally extending support walls (52) which are again extrusion welded onto the upper surface of the tank (10) and, at 10 the longitudinally opposed ends of these parallel support walls (52) are disposed two transversely extending castellated wall members (54) formed with a plurality (here three) of 'U' shaped slots (56). These end walls (54) are again both extrusion welded onto the upper surface of the tank (10) and also to the sidewalls (52) to form a substantially upstanding rectangular frame (SO). Each of the 'U' IS shaped slot members (56) is longitudinally aligned with a second 'U' shaped slot (6) in the longitudinally opposed wall (54) to form two seat members for receipt and support of the elongate poles (60) (Figure 1) which are commonly employed in pole cleaning systems, thereby providing appropriate storage for such elongate pole members (60) when being transported by the users vehicle. As shown in 20 Figures 1 and 2, the end walls (54) can optionally be provided with apertures (64) adjacent to the 'U' shaped slots (56) to allow the user to connect fastenings to this wall (54) in order to tie the poles into the appropriate stored position if so required.

c::.:: Ad. This rectangular frame (50) also provides an additional storage area on top of the tam; since its walls (59, 54) form an appropriate enclosed space with the upper surface of the tank (10).

This particular transportation tank (10) is specifically intended for use with a pole cleaning system which is operated by a cleaner who remains remote from the window itself. The procedure for cleaning the windows differs significantly from conventional window cleanin: wherein, conventionally, the cleaner will clean the 10 windows with appropriate hand tools and subsequently remove both the water and detergent by use of a squeegee member. Pole cleaning systems operate differently by allowing the operator to use brush and other cleaning tools on the end of a pole to clean the windows from a distance. The poles are also used to provide, by means of internal pipes, both water and detergent to the cleaning head to allow an is appropriate operation to clean the windows. Once the cleaning operation has been achieved water is then directed onto the window to remove all detergent.

However, in hard water areas, the water, when dried can leave streaks on the window. To alleviate this potential downside, it has been determined that 0 softened, de-ionised water avoids this problem and thus is used as the rinse means.

For this reason that pole type cleaning systems require water transportation tanks to provide such de-ionised water as opposed to simply utilising conventional mains water. However. mains water can, optionally, still be provided for the

cleaning operation, with the de-ionised water simply used for the rinsing operation upon provision of the appropriate pipes within the poles to provide both water types. Due to the need to transfer the water from the tank to the cleaning head, pole systems also require a pump (not shown) to force the water from the tank (10) to the appropriate height (up to 25m) in order to direct water and detergent to its required elevation. This pump member can be quite heavy, as will be the appropriate hose reels carrying the flexible hoses (used for transporting water 10 from the tank to the head) and the hose that will be carried on such reels. Often, two reels will be required, one hose for water and one hose for detergent.

Additionally, in one preferred pole type cleaning system, not only is deionised water used in the tank but a final purification means, employing a large local de ionisation tank may also be employed on-site to further soften the water used 1: during the rinse operation.

Subsequently, a large volume of heavy cleaning equipment is required for pole cleaning systems as well as the water transportation tank.

90 It is well understood that the water transportation tank, when mounted to a vehicle significantly affects the stability of the vehicle in operation, particularly when fully laden. For this reason, great care is taken in positioning the tank (10) in the vehicle so that its centre of gravity is substantially central to the vehicle itself so as

to minimise the impact that the water transportation tank will have on the vehicle's centre of gravity.

However, since the additional equipment for this type of pole cleaning system also 5 comprises significant weight, it is also beneficial for these products to be stored in the vehicle as close to the original centre of gravity of the vehicle to again minimise their impact on the vehicle's stability when driven. For this reason, such accessories are also required to be mounted as close as possible to the centre of gravity of the water tank (10). This has necessitated the mounting of such tools to directly onto the transportation tank (10) itself. Due to the relatively high weight of such products as the pump, hose reels and de- ionisation tank and the specific plastics material used to form the tank (10), it is not practical to secure such accessories to the tank (10) using conventional fixing techniques.

1: Since the material used is 12mm high density polyethylene, if fixing brackets were to be screwed directly into the polyethylene material there would be insufficient depth to receive sufficient screw threaded connectors to ensure appropriate support strength without either puncturing the tank itself or creating an area of weakness which could rupture under the pressure of the water contained within 20 the tank, and the weight exerted on such screw threaded connectors.

Alternatively, if bolt members were to be passed through the wall of the tank then, due to the high loads they would be expected to bear, such boltmembers could not be maintained within a sealing fit within any aperture extending through the tank

, 1

::' d:d li':: : I:::

material. In particular, even if a sealant was provided about the bolt member aperture, it is likely that due to the shifting loads incurred during transportation, the bolt would likely result in failure of the seal thereabouts, creating both an area of weakness and a potential area of water loss from the tank which could prove 5 catastrophic. As such, fixing elements are required which do not reduce the integrity of this specific tank design.

Therefore, this problem has been addressed by the use of fixing plate members (70) an example of which is shown particularly in Figure 6 and, in cross section in 10 Figure 7. Fixing plates (70) comprise additional sheets of high density polyethylene, the same material used to form the tank itself. Referring now to Figure 7, an inwardly directly surface of these fixing plates (70) are preformed with a circular recess (79) which receives a metal washer (74) and a conventional hexagonal headed fixing bolt (ideally M6) (76). The recesses (72) are circular is such that the hexagonal bolt head (78)is then driven under force into this hole (74) to form a substantially rigid engagement therewith. The depth of the recess (77) corresponds to the depth of the washer (72) and bolt head (78) so that an outer surface of the bolt head is maintained flush with the inner surface of the plate (70) when mounted therein. The inner surface, and hence the bolt head (78) 90 are then placed in abutment with the outer surface of one of the walls (16) of the tani; and this mounting plate (70) is then again extrusion welded (87) onto the exterior surface of the tank (10) in a conventional manner. Due to the relatively large surface area, and hence periphery, of the fixing plates (70) a relatively long

.:':': ':' '. I45 dld:e JO weld joint (82) is formed between the fixing plate (70) and the tank (10) and the length of such weld joint (82) serves to distribute any force exerted on that plate (when an article is fixed thereto by engagement with the bolt members (76)) over a large area, thereby providing a rigid fixture to the tank (10) with an appropriate arrangement of externally projecting fixing bolts (76) as required to secure an appropriate article thereto.

It is equally possible that instead of the bolt head being secured in the recess (72) of the fixing element (70), a hexagonal nut could be secured therein. Thus, when 10 the plate (70) is fixed to the tank, this nut is restrained from displacement and capable of receiving a screw threaded bolt passed into the fixing element (70) to allow a fixing bracket to be secured thereto.

By providing for securement of the accessories directly to the tank (10) walls, 15 allows them to be secured more closely to the centre of gravity and, hence, improving stability for transportation of the this type of cleaning system.

It will be appreciated that, as an alternative to extrusion welding these fixing plates (70) to the exterior surface of the tank (10), they can, alternatively, be 20 bonded thereto by use of an appropriate structural plastic adhesive, an example of which is sold under the Trademark ScotchWeld _ which is a two-part acrylic based adhesive utilised specifically for bonding polyethylene materials. One of the additional advantages of using such an adhesive is that where extrusion

a: 's-:. eel l..

( c t c l l l welding can only be undertaken about the periphery of the fixing plate (70), the adhesive effects a bond between the fixing plates (70) and the tank (10) over the entire surface area of the plate (70) providing further distribution of any load born by this fixing plate (70).

One of the advantages of the tank design disclosed herein is the high degree of flexibility in customization of the basic tank design. In particular, due to the ease of adding valve members (44) it is possible to customise operation and design of the tank. One beneficial feature allows the simple attachment of a water level 10 monitor. Although not shown herein, such a water level monitor will usually comprise an elongate tube for substantially vertical attachment to one of the valve members (44) and will have an elongate window therein for an observer to monitor the water level within this tube which will, as is standard, reflect the water volume within the tank (10) itself. A coloured flotation element could also l: be positioned within this tube to float on the water level therein to provide a clearer illustration of the water level of the tan};.

This particular transportation tank (lo) provides for significant advantages over those tanks of the prior art. Firstly, due to the inherent strength of the tank

90 according to the present design, it removes the need for a support frame which provides a significant advantage in installation of such tanks into conventional trucks and vans by allowing the tank (10) to be manufactured remote from the vehicle and simply lifted therein and bolted to the subframe in a conventional

::e.:' l'':: t' ( t,,, __ manner. This allows mass production of such transportation tank since they no longer have to be customised to each vehicle and built in situ with an appropriate support frame. Additionally, the overall mass of the transportation tank according to the present invention is significantly reduced when compared to existing transportation tanks, thus increasing the volume of liquid that may be transported within existing vehicles before exceeding their load bearing capacity. Further, by removing the need for a large support frame, the actual volume of space required by the tam; is also significantly reduced thus providing for a more efficient use of the load space of the users vehicle which again provides the ability to utilise a 10 larger tank and hence larger capacity while still maintaining sufficient space for t he appropriate tooling and accessories. Also, by providing the fixing plate (70) directly onto the tank itself this provides for a more uniform weight distribution of the entire window cleaning system and apparatus, since additional heavy articles are maintained as close as possible to the main centre of gravity of the 1: vehicle and the water transportation tank. This, in itself, allows the transportation tank described herein to form the basis of a modular water cleaning system to which the appropriate apparatus can be directly attached prior to its installation in an end vehicle, providing for considerable ease of manufacture and installation as compared to the need to custom build existing water tanks directly into the vehicle 30 itself. Since the tank (10) is formed as a standard unit, substantially as shown in Figure I, it further provides the basis for forming a modular pole cleaning system to

d À. À À -. À À

À À À. which various pole cleaning accessories and attachments are readily mounted to provide a single unit for installation in the users vehicle. This has particular benefit when considering the wide variety of vehicles to receive such pole cleaning systems whereby the ease ot the formation of the apertures for receiving S the appropriate valves and also the placement of various fixing elements (70) allows the basic tank unit to readily adapted for vehicles of different design (ie. for example where doors and access points are required at different positions around the load bearing space of such vehicles. Therefore, the manufacturers are able to manufacture a single base unit whereby the attachments, fixings and valves are 10 then selectively positioned as appropriate for the vehicle use.

Whilst the preferred design of tank (10) described herein comprises an extrusion welded rectangular tank, alternative designs and manufacturing techniques are equally applicable. For examples the tank itself could be rotationally moulded, 15 with wedge shape inserts employed and Downing the wedge shaped integral baffle plates. Altematively, rotational moulding could be employed for the main tubular body with baffle plates and end walls being subsequently attached so as to be integral therewith (usually, but not exclusively be extrusion welding).

It is also envisaged that other forms of thermoplastics welding can be employed to 20 form appropriate joints, such as ultrasonic welding.

Further, alternative tank designs are equally applicable such as cylindrical tanks.

However, internal baffle plates will still be required

Claims (1)

1. Claims

   1. A liquid transportation tank for motor vehicles, comprising a sealed Agid plastics container having at least one internal baffle plate integrally formed 5 with and extending between opposed inner side walls of said container, said at least one baffle plate having an aperture tnerethrough, whereby said tank further composes an integrally formed connection member for connecting the tank directly to a motor vehicle.

   10 2. A transportation tank as claimed in claim 1 wherein said connection member composes at least one flange member extending from a lower surface of said tank. 3. A transportation tank as claimed in either of the preceding claims constructed 15 of high density polyethylene between 6 and 16 mm thick.

   4. A transportation tank as claimed in claim 3 wherein said tank is rectangular and comprises extrusion welded sheets of polyethylene.

   20 5 A transportation tank as claimed in any one of the preceding claims comprising external fixing elements mounted on and secured to an external surface of said tank.

   ( 6. A transportation tank as claimed in claim 5 comprising at least one plastics fixing plate bonded on an external surface thereof so as to be integral with said tank.

   5 7. A transportation tank as claimed in claim 6 wherein said fixing plate has mounted therein fixing elements having externally projecting portions for engagement by and mounting of external fixtures.

   8. A transportation tank as claimed in claim 7 wherein said fixing elements are 10 secured between said fixing plate and said tank and restrained from displacement relative thereto.

   9. A transportation tank as claimed in any one of the preceding claims having a resealable inlet valve.

   10. A transportation tank as claimed in any one of the preceding claims having at least one outlet valve.

   11. A transportation tank as claimed in any one of the preceding claims 20 comprising an integrally mounted support frame for supporting elongate members, said support frame comprising at least two remote support walls each having at least one slot formed therein to provide a seat for said elongate member extending therebetween.

   f 12. A transportation tank as claimed in claim 11 wherein each of said remote support walls are castellated to present a plurality of slots therein.

   5 13. A modular cleaning system comprising a transportation tank as claimed in any one of the preceding claims and a plurality of cleaning tools and accessories, each for fluid engagement with said tank, wherein said plurality of cleaning tools and accessories are selectively engageable with said tank so as to be releasably stored thereon.

   14. A transportation tank herein before described with reference to the accompanying drawings.

   15. A modular cleaning system comprising a transportation tank substantially as 15 herein before described with reference to the accompanying drawings.