GB2032290A - Mobile mixer and readymixed mortar delivery system - Google Patents

Abstract

A mobile truck-mounted mixer for use in the distribution of a readymixed mortar is a self-contained unit (11) mounted on the chassis of a tipper truck (13). A body (14) provides a V-shaped hopper-like tank running lengthwise of the truck and contains a mixing screw which is rotated in one direction to impel the chamber contents against an inclined front end wall of the chamber to effect thorough mixing thereof, and in the opposite direction to impel the mixed contents towards a rear discharge aperture controlled by a valve (17) which discharges into an external adjustable chute (18). A diesel engine is connected to the front end of the mixing screw through a clutch and gearbox with reverse gear. All the engine, clutch and gearbox controls (41) and the engine instrumentation (42) are grouped at the rear of the mixer unit (11) so that they are accessible to an operator standing adjacent the discharge outlet. <IMAGE>

Description

SPECIFICATION Mobile mixer and readymixed mortar delivery system This invention relates to a mobile mixer for mortar and to distribution systems for readymixed mortar.

The distribution of readymixed mortar using mobile truck-mounted mixers is a novel conception.

It enables the ingredients of the mortar to be supplied in the correct proportions at a central mixing plant and delivered to a building site in usable condition with no further mixing by on-site operatives required. A primary object of the invention is to provide a mixer suitable for this purpose.

According to the invention a mixer, especially suitable for mixing a cement-lime mortar (C.L.M.), comprises a body mounted or mountable on a mobile chassis and providing a mixing chamber in which a rotatable mixing screw is so arranged that rotation thereof effects mixing by impelling the chamber contents against one end wall of the chamber.

Preferably the chamber is of trough-like form, comprising aV-shaped hopper-like tankwith the screw running longitudinally along the trough of the V. In preferred embodiments a discharge outlet aperture associated with an external controllable discharge chute is positioned in the opposite end wall so that reversal of the direction of rotation of the screw results in displacement of the mixed contents of the chamber towards the aperture. To assist discharge the screw axis and the bottom of the chamber may be inclined towards said opposite end wall; alternatively a horizontal axis may be employed and the body mounted on a tipper vehicle the tipping action of which is employed to assist discharge.

The body is preferably so constructed that it can readily be lifted on to the body of a tipper vehicle, or be permanently mounted on a truck chassis, and the mixing screw may be driven by a hydraulic motor powered from a power-take-off of the vehicle.

However the mixer may be completely selfcontained in the sense that it has its own prime mover to drive the screw, and this may be found preferable for all mixers, including large mixers of, say, 7 cu m capacity.

Normally the screw will impel the contents against the front wall of the chamber (considering the vehicle-mounted position) during mixing and either the truck-powered hydraulic drive means, or a diesel engine providing a prime mover with associated clutch and gearbox incorporating reverse gear, may conveniently be mounted at the front of the mixer body. In the former case the hydraulic circuit, including the drive means and a reversing-control valve, may have flexible hose connections with make-and-break couplings for connection to the hydraulic supply; in the latter case controls for the clutch and gearbox, and the engine controls and instrumentation, are preferably mounted at the rear of the mixer so as to be readily accessible to an operator standing adjacent the discharge outlet.A water storage tank with a valved discharge into the chamber may be mounted on top of the mixer body.

According to one preferred embodiment a mixer suitable for use in the distribution of readymixed mortar comprises a self-contained unit with a body providing a mixing chamber, a mixing screw rotatably mounted within the chamber and operative to mix the chamber contents by impelling them against an end wall of the chamber, and a prime mover mounted outside the chamber and coupled through a clutch and forward/reverse gearbox to one end of the screw for rotation of the latter. Such a unit of large capacity may be mounted as a permanent fixture on a suitable truck chassis, thereby turning the whole vehicle into a specialised mixer/delivery truck.

A distribution system according to the invention for readymixed mortar, preferably a retarded C.L.M., employs a truck-mounted mixer with a mixing chamber and a rotatable mixing screw as referred to above, and a plurality of stackable site delivery skips.

Thus a readymixed C.L.M. can be transported to a building site by the mobile mixer, and delivered to the various user points on the site in the skips which are filled from the mobile mixer truck.

The delivery skips are preferably fabricated from steel plate with a rectangular plan form and tapering sides for stackability. Apertured lifting lugs, by which the skips can be hoisted and transported around the site, may be fitted at the tops of the skips and positioned centrally at each end thereof. Typical top dimensions for the skips are 1285 mm long by 680 mm wide, for example tapering to 1145 mm by 540 mm at the bottom.

The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, two truck-mounted mobile mixers. In the drawings: Figure 1 illustrates in perspective view one mobile C. L.M. mixer; Figure 2 is a similar view of a larger mobile mixer; Figures 3and 4are respectively plan and side elevation views of the fabricated body of the larger mobile mixer; and Figure 5 illustrates the lateral cross-sectional shape of the fabricated body.

Figure 1 illustrates a mixer 1 mounted on the body 2 of a tipper truck 3 and comprising a fabricated steel body 4 providing a V-shaped hopper-like tank 4a running fore-and-aft of the truck chassis and forming a mixing chamber along which is positioned a rotatable continuous mixing screw (not shown). A discharge tube 5 fixed to the rear end wall of the body 4 supports a rear end bearing 6 for the screw and has a lower discharge aperture controlled by a flap valve 7. This valve discharges into an external adjustable chute 8 which can direct the mix down to ground storage or, alternatively, into a site delivery skip of a distribution system in accordance with the invention.

For mixing of the chamber contents rotation of the mixing screw impels the contents against the front wall 4b of the body 4, this wall being inclined to provide upward defiection within the tank to promote thorough mixing of the mortar. After mixing is complete and for discharge of the mixed mortar, reversal of the screw displaces the mix towards the tube 5 so that a controlled discharge is obtained through the flap valve 7. The screw is powered from the truck engine, a hydraulic motor coupled to the front end of the screw being connected to a hydraulic P.T.O. (power-take-off) of the truck.

The mixer body 4 is designed so that it can readily be lifted on to the body of the truck 3, and detached therefrom to allow the vehicle to be used for other purposes. To this end the body 4 has fabricated box-like and support columns which rest on the vehicle body and lifting eyes for attachment for a lifting sling. The reversible hydraulic motor is mounted on an external mounting at the front end of the body 4 and is permanently connected by piping to a manually-operated reversing-control valve, and flexible supply and return connections of the hydraulic circuit have make-and-break couplings for connection to the hydraulic supply on the vehicle.

The hydraulic power is, for example, obtained by a modification to the gearbox P.T.O. of the vehicle and through this utilising the hydraulic power which would normally be used to raise and lower the tipper body.

A rectangular water tank 9 is mounted on top of the mixer body 4 at the front mixing end thereof, and has a discharge pipe (not shown) leading into the mixing chamber and containing a manuallyoperated control valve. The tank 4a is closed by a top plate with an access aperture closable by a hatch through which the chamber is loaded, a grid of bars below the aperture being fitted as a safety measure to prevent the operator falling into the tank. Operator access to the top aperture is provided by a permanent ladder 10 fixed at the rear or discharge end of the mixer body 4.

The mixer of Figure 1 is typically of about 3.5 cu m capacity, whereas the mixer 11 of Figure 2 is considerably larger, say 7.0 cu m capacity, and is mounted on the body 12 of a correspondingly iarger 3-axle, 24 tonnes, truck 13. The mixer 11 functions in a similar manner to that of Figure 1, a body 14 containing a mixing screw (again not shown) which is reversed to deliver into a discharge tube 15 supporting a rear end bearing 16 of the screw and having a discharge aperture controlled by a flap valve 17 which discharges into a controllable chute 18. The valve 17 pivots at 19 and has an operating lever arm 20 with an end nut 21 engaging an operating screw 22 turned by a handle 23 and journalled in a support bracket 24 on the tube 15.

Thus turning the handle 23 opens or closes the valve 17.

The fabricated body 14 is illustrated in some detail in Figures 3 to 5 which show that it is mounted on a base frame 25 which projects at both front and rear ends of the body 14. The body is of overal V-shaped lateral section and mainly comprises two inclined side plates 26 reinforced by spaced box-section external webs 26a, and end plates 27 and 28 to provide a mixing chamber which is basically of the same general shape as that of Figure 1. The mixing screw as in the Figure 1 embodiment mixes the contents by impelling them against the front end plate 27, and the discharge tube 15 is mounted on the rear end plate 28.The side plates 26 converge downwardly to a bottom trough section having a profile clearly illustrated in Figure 5 and defined by two narrow vertical walls 29 disposed between the side walls 26 and two somewhat wider but still relatively narrow inclined walls 30 parallel to the walls 26, and a horizontal bottom wall 31. The mixing screw runs along this bottom trough section within the mixing chamber.

The body 14 is closed by a top plate 32 with two access hatches 33, shown open in Figure 3. An access ladder 34 is mounted at the rear of the body, and a high level water tank 35 mounted at the front is arranged to supply the mixing chamber via a valved conduit. The mixer 11 is a self-contained unit including its prime mover to drive the mixing screw.

The prime mover is an air-cooled diesel engine 36 (shown diagrammatically in broken lines in Figure 4) with a self-starter and mounted on the forwardly projecting section of the base frame 25 below a rain canopy 37. The engine 36 is connected to the front end of the mixing screw through a clutch 38, a gearbox with reverse gear 39, and a drive coupling 40.

All the engine, clutch and gearbox controls and the instrumentation for monitoring engine performance are grouped at the rear of the truck body as part of the mixing unit. They are mounted on the rearwardly projecting section of the base frame 25, and comprise a row of control levers 41 and an instrument console 42 as shown in Figure 2.

Either of the truck-mounted mixers illustrated can suitably be utilised in a distribution system for readymixed mortar according to the invention.

Broadly speaking such a system comprises a truckmounted mixer with a mixing screw, which operates in the manner described, and a plurality of stackable site delivery skips which can be of any suitable size and shape. In view of this such a skip is not illustrated herein but a typical skip is of elongated rectangular shape in plan view with inclined side walls and inclined end walls providing a tapering cross-section such that the skips are stackable one within the other.

In one specific preferred construction of skip the open top thereof has its periphery reinforced by lengths of steel angle welded externally along the top edges of the side and end walls, and a flat bottom wall of the skip is reinforced by lengths of steel angle welded underneath. The side walls and bottom wall are formed to shape from a single piece of steel plate, separate plates forming the end walls then being welded on. End feet are provided which extend the full width of the bottom and apertured lifting lugs are provided at each end of the skip.

Claims (17)

1. A mixer for a cement-lime mortar or the like, comprising a body mounted or mountable on a mobile chassis and providing a mixing chamber in which a rotatable mixing screw is so arranged that rotation thereof effects mixing by impelling the chamber contents against one end wall of the chamber.

2. A mixer according to claim 1, wherein the chamber is of trough-like form comprising a Vshaped hopper-like tank with the screw running longitudinally along the trough of the V.

3. A mixer according to claim 1 or 2, wherein a discharge outlet aperture associated with an external controllable discharge chute is positioned in the opposite end wall so that reversal of the direction of rotation of the screw results in displacement of the mixed contents of the chamber towards the aperture.

4. A mixer according to claim 3, wherein to assist discharge of the mixed contents the screw axis and the bottom of the chamber are inclined towards said opposite end wall.

5. A mixer according to claim 3, wherein the screw axis and bottom of the chamber are generally horizontal and the body is mounted, or adapted for mounting, on a tipper vehicle the tipping action of which is employed to assist discharge.

6. A mixer according to any one of claims 1 to 5, wherein the body is so constructed that it can readily be lifted on to the body of a tipper vehicle, or is permanently mounted on a vehicle chassis, and the mixer includes hydraulic drive means for the mixing screw comprising a motor adapted to be powered from a power-take-off of the vehicle.

7. A mixer according to claim 6, wherein a hydraulic circuit, including the drive means and a reversing-control valve, has flexible hose connections with make-and-break couplings for connection to a hydraulic power-take-off of the vehicle.

8. A mixer according to any one of claims 1 to 5, wherein the mixer is completely self-contained in the sense that it has its own prime mover to drive the mixing screw.

9. A mixer according to claim 8, wherein the prime mover with associated clutch and gearbox incorporating reverse gear are mounted at the front end of the mixer body, namely the end against which the contents are impelled during mixing, and coupled to the front end of the screw.

10. A mixer according to claims 3 and 9, wherein controls for the clutch and gearbox, and the engine controls and instrumentation, are mounted at the rear of the mixer so as to be accessible to an operator standing adjacent the discharge outlet.

11. A mixer according to any one of the preceding claims, wherein a water storage tank with a valved discharge into the chamber is mounted on top of the body.

12. A mixer suitable for use in the distribution of readymixed mortar comprising a self-contained unit with a body and a mixing screw according to claim 1, wherein the unit includes a prime mover mounted outside the chamber and coupled through a clutch and forward/reverse gearbox to one end of the screw for rotation of the latter.

13. A mixer according to claim 12, wherein the unit is mounted as a permanent fixture on a truck chassis to provide a specialised mixer/delivery truck.

14. A distribution system for readymixed mortar, employing a truck-mounted mixer according to any one of the preceding claims and a plurality of stackable site delivery skips.

15. A distribution system according to claim 14, wherein the delivery skips are fabricated from steel plte with a rectangular plan form and sides which taper from the top to a smaller bottom area.

16. A mixer for a cement-lime mortar, constructed and arranged substantially as herein particularly described with reference to Figure 1, or Figures 2 to 5, of the accompanying drawings.

17. A distribution system for readymixed mortar, employing a truck-mounted mixer and a plurality of stackable site delivery skips, substantially as described.