This invenLion is described in the following statement:

THIS INVENTION relates to an apparatus for mixing and pumping mortar and particularly to an apparatus which is detachable into two sub-assemblies.

In my earlier Australian patent application 86705/91, the specification of which is incorporated herein by cross-reference, I provided a portable mortar mixer which could mix and pump mortar. The apparatus could pump the mixed mortar through a hose to an applicator which could be held by a bricklayer. The applicator included a valve such that the bricklayer could regulate the amount of mortar flowing out of the applicator. This apparatus was extremely useful and has found great commercial success in that it could mix the mortar, concrete or other substance readily and easily, and then could conveniently convey (or pump) the mixture to the bricklayer. Thus, it was no longer necessary to place the mortar on a mortarboard. This apparatus was entirely portable ^nd incorporated a front wheel, and handles, and could be » -^eled around more or less like a wheelbarrow. This earlier apt ^atus had a mixing tank in which were located rotating p.. ^" 'd which were used to mix the ingredients together, and to he ingredients in a mixed state. The mixing tank had a lov..-r i. tlet which could be opened by a sliding door. At the bottom of the mixing tank was located a pump to pump the mortar through the hose and to the applicator. In front of the mixing tank, and more or less above the wheel was located an engine, and a drive assembly which would power the pump and also rotate the paddles.

While the above arrangement is satisfactory, it has now come to my attention that this earlier apparatus was

relatively heavy in construction. This is because the apparatus included the motor, drive means, pump and mixing tank all in a single apparatus. It was found that this earlier apparatus was quite heavy to allow it to be readily moved to a sand pile, water source, or cement source, all of which could be at a considerable distance from the place where the mortar was to laid. That is, in building sites, the sand used for mixing concrete is usually dumped next to the kerb, and this may be quite a considerable distance from where the mortar has to be used. One way to overcome this, was to not move my earlier apparatus, but instead to bring the sand, water and cement from the respective sources to the apparatus. This was laborious and found to be inefficient and wasteful.

I have now developed a further apparatus where the drive means, and pump are separate from the mixing tank, but where the mixing assembly can be readily coupled thereto. Thus, the mixing assembly is considerably lighter and now can be readily wheeled to the sand pile, etc., for filling. The mixinci assembly can then be wheeled back and coupled to the motor t- -i pump to allow the mortar to be mixed and pumped through t hose to the bricklayer.

1 is an object of the invention to provide an apparatus for mixing and pumping mortar which may overcome the abovementioned disadvantages and/or provide the public with a useful or commercial choice.

In one form, the invention resides in an apparatus for mixing and pumping mortar, the apparatus comprising a base assembly comprising a drive means and a pump - the pump having an inlet and an outlet; and a portable mixing assembly

comprising a mixing tank, mixing means to mix material within the tank, and an outlet to allow the material to pass from the tank, the mixing apparatus being releasably attachable to the base assembly such that the base assembly drives the mixing means when coupled to the mixing assembly, and where the outlet of the mixing tank is in communication with the inlet of the pump.

Thus, with this two-part assembly (i.e., the base assembly and the mixing assembly), all the heavy and bulky components such as the drive means, and pump can form part of the base assembly, and the mixing assembly comprising the mixing tank can be made much lighter and therefore more portable. When coupled together, the drive means can drive the mixing means and the mixing tank can discharge its content into the pump inlet.

The base assembly may comprise a base plate or ^" rame. The base plate or frame may be supported by one or mo'-e wheels, slides or skids to allow the base assembly to be move<- from place-to-place. In practice, it is found that the base at ^mbly needs to be moved only infrequently. he drive means may comprise a motor which may be electixu, diesel, petrol or the like. Typically, a petrol engine is provided. The drive means may be positioned adjacent one end of the base plate or frame. A drive assembly may be provided to allow the drive means to drive the pump, and the mixing means in the mixing tank. The drive assembly may comprise a combination of gears, chains and sprockets and this assembly may be similar to that described in my earlier patent application 86705/91. By having the drive means

separate from the mixing assembly, the drive means can be made larger, stronger and more robust, which allows cheaper components to be used and provides a longer life span.

The pump may comprise any type of pump suitable for pumping mortar or other material to be mixed and pumped. A suitable type of pump includes a positive pressure pump. Suitably, the pump includes a pair of worm drives which are intermeshed, thereby providing a good pumping action. The pump may be positioned on the base plate or frame forward of the drive means and the drive assembly (if provided). Furthermore, it is preferred that the pump is of a low height, such that the mixing assembly can pass over the pump. This arrangement facilitates the positioning of the pump inlet and the outlet of the mixing tank. The pump is suitably driven by the drive means.

The mixing assembly may comprise a mixing tank and the assembly is suitably supported for movement by a forward wheel. Thus, the mixing assembly can be wheeled around much like a wheelbarrow. Handles can be provided extending rearwardly from the mixing tank, again to facilitate wheeling the mi. >g assembly about. Legs may be provided below the miχj... _d tank such that the mixing assembly can adopt a substantially horizontal position when put down. The mixing tank and mixing means may be substantially the same as disclosed in my earlier patent application 86705/91. Thus, the mixing means may comprise paddles or stirrers which can be mounted to a shaft. The shaft may be driven by the drive means. Suitably, the shaft is releasably couplebly to a drive outlet provided on the drive means, or drive assembly, and

this may be achieved by a "dog" clutch.

The mixing tank has a outlet and the outlet is suitably at a lowermost portion of the mixing tank. The outlet may be closed by an openable door. The door may be a sliding door which can be slid open to allow the contents of the mixing tank to pass through the outlet.

Suitably, the inlet of the pump is provided with a hopper arrangement. The upper edge of the hopper arrangement may be located directly beneath the outlet of the mixing tank, when the mixing assembly is coupled to the base assembly. A seal may be provided to seal the hopper to the outlet, and this may be in the form of soft but resilient seal.

The base assembly may include a wheel stop member to position the wheel of the mixing assembly, which in turn can position the outlet of the mixing tank to be adjacent the pump. The wheel stop member is useful as it allows a person to readily position the mixing assembly relative to the base assembly.

An embodiment of the invention will be illustrated with reference to the accompanying figures in which

Figure 1 is a side view of the apparatus according to an embodiment of the invention;

Figure 2 is a plan view of the apparatus of Figure

1. Referring to the drawings, there is disclosed an apparatus for mixing and pumping mortar. The apparatus comprises a base assembly 10 and a portable mixing assembly

11. Base assembly 10 comprises a flat metallic cast base plate 12 having a planar upper support surface 13. One end of

base plate 12 is provided with a pair of wheels 14, while the other end 15 of base plate 12 is provided with a pair of grippable handles 16. This arrangement allows the base assembly 12 to be lifted by the grippable handles 16 and ^ wheeled to a desired place. On top of base plate 12 is positioned a drive means in the form of a petrol engine 17. Engine 17 is located adjacent wheels 14, the reason for this being that it facilitates lifting of base plate 12 by handle 16 due to the weight being located adjacent wheels 14. Petrol 0 engine 17 is of a conventional type and need not be discussed in any further detail. Engine 17 includes a power output 18 which connects to a drive assembly 19. Drive assembly 19 is positioned adjacent engine 17, and again at a forward portion of base plate 12 to facilitate lifting and moving of base 5 assembly 10. Drive assembly 19 comprises a central primary drive shaft 20, an upper secondary drive shaft 21 and a lower secondary drive shaft 22. Drive shaft 20 is coupled to drive shafts 21 and 22 through suitable chains, sprockets, belts and the like. Upper drive shaft 21 has a free end 23 which is 0 provided with a "dog" clutch 24. Lower secondary drive shaft 22 is coupled to pump 25 through a rotatable shaft 26. Pump 25 is positioned on base plate 12 adjacent handles 16. Pump 25 is of an elongate low design to allow the mixing assembly 11 to pass over it. Pump 25 includes an inlet 26 which faces ^,| 5 upwardly, and an outlet 27 which can be connected to a hose and ultimately to an applicator. The hose and applicator can

_* be similar to that described in my earlier patent application 86705/91. Pump 25 is suitably of a twin-worm screw design, an example of which is described in my earlier Australian patent

application PL5106.

The mixing assembly 11 comprises a substantially rectangular box-like mixing tank 27. Mixing tank 27 may include an inlet 28 which can be provided with sieve or mesh- type cover to function as a coarse sieve, or to prevent sticks, leaves and the like from entering into mixing tank 27. The mixing assembly 11 is provided with a pneumatic wheel 29 supported on a forward extension 30, the extension being mounted to the front of mixing tank 27. Handles 31 are provided extending rearwardly of mixing tank 27, and it can be seen that in this arrangement, the mixing assembly 11 looks and functions much like a wheelbarrow. Within mixing tank 27 are provided rotating paddles (not shown) which are similar to that of my earlier patent application, these rotating paddles are mounted to a shaft 32 the shaft being rota ably supported by bearings 33, 34 mounted on each side wall of mixing tank 27, and also by bearings 35 mounted to a forward wall of forward portion 30. Rotatable shaft 32 has a free end which can releasably couple to the "dog" clutch 24. It can be seen that when the mixing assembly 11 is moved into the position shown in Figure 1, the free end of shaft 32 couples with "dog" clutch 34 to allow the paddles to be rotated by engine 17.

Mixing tank 27 is provided with a lower outlet 37 which is closed by a sliding door (not shown). The sliding door can be slid between a closed position where outlet 37 is covered, and an open position. The inlet 26 of pump 25 is coupled to a hopper 38 which is designed and sized to extend to just below outlet 37 of mixing tank 27. A soft rubber or foam seal 39 may be provided to minimise leakage of mortar at

this join. The mixing assembly 11 can be quickly and correctly positioned on base assembly 10 by a wheel stop member 40. Wheel stop member 40 is in the form of an arcuate cradle against which wheel 29 can be pushed. Stop member 40 is positioned, such that when wheel 29 is pushed thereagainst, hopper 38 locates directly below outlet 37 of mixing tank 27.

In use, mixing assembly 11 can be wheeled to a sand pile and sand, water and possibly cement may be added to mixing tank 27 in the correct ratios. The mixing assembly 11 can then be wheeled back to base assembly 10 and pushed over base plate 12 until the wheel 29 of the mixing assembly contacts stop member 40. In this position, shaft 32 also engages with upper secondary drive shaft 23 through the dog clutch 24. This coupling causes shaft 32 to rotate which in turn causes the paddles within mixing tank 27 to rotate to mix the ingredients. When the ingredients have been sufficiently mixed, the sliding door (not shown) can be opened such that the mortar can be pushed (by the mixing paddles) into hopper 38 and thus through pump inlet 26 into pump 25. Pump 25 is driven by lower secondary drive shaft 22 and results in the mortar being passed through the pump and through outlet 27 through a hose (not shown) and to an applicator (not shown). A bricklayer then can control the passage of mortar through the hose by a trigger on the applicator. When the tank contents have been exhausted, the mixing assembly 11 can be removed and refilled. One advantage with hopper 38 is that it provides a further small supply of mortar, even after the mixing assembly 11 has been removed.

It can be seen that this arrangement has the

advantage of making the mixing assembly 11 lightweight while still providing all the benefits of mixing and pumping to the apparatus.

It should be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention.