WO2024161432A1

WO2024161432A1 - Concrete mixer

Info

Publication number: WO2024161432A1
Application number: PCT/IT2024/050007
Authority: WO
Inventors: Loris Pagotto; Michele Cianciosi
Original assignee: Imer International SpA
Current assignee: Imer International SpA
Priority date: 2023-01-31
Filing date: 2024-01-15
Publication date: 2024-08-08
Anticipated expiration: 2025-07-31
Also published as: EP4658464A1; IT202300001467A1

Abstract

Concrete mixer comprising a load-bearing structure (2), a tank- shaped drum (3) having a predefined volume, a drum-holder arm (4), an electric gearmotor (5) supported by said arm (4) and a push- button panel (6) for controlling the gearmotor (5). The gearmotor (5) comprises an electric motor (50) and a reduction unit (51). The drum (3) has a bottom (3C) and an internal counter bottom (3F), on which an output shaft (51B) of the reduction unit (51) is connected. The internal counter bottom (3F) is delimited by a first surface (3FX) The concrete mixer has a chamber (31) formed on the bottom (3C) below the internal counter bottom (3F) and the reduction unit (51) is housed in said chamber (31), the latter being formed by a structure delimited by a second surface (X31) arranged below the first surface (3FX) delimiting the internal counter bottom (3F).

Description

TITLE

CONCRETE MIXER

DESCRIPTION

The present invention relates to a concrete mixer.

In particular, a concrete mixer in accordance with the present invention is a machine for the preparation of cement mortars and, more generally, mixtures used on construction sites.

It is known that for the preparation of relatively small amounts of mixes and mortars of various kinds on construction sites, concrete mixers are used which essentially consist of a tank-shaped drum of predefined volume in which the mixing of the selected components takes place to form the mortars. The drum is supported by an arm which, in turn, is bound to a load-bearing structure so that it can rotate around a horizontal axis, and is driven into rotation by an electric motor acting on the drum itself through suitable transmission systems.

DE 1852381U describes a concrete mixer comprising a drum equipped with a conical counter-bottom and connected with a drive unit inserted in a housing integral with the structure of a drum-holder arm. This structure implies the need to provide a special drum-holder arm to which the aforementioned housing can be welded and the latter is not part of the drum.

WO 2005/077510A1 describes a concrete mixer comprising a drum with a counter bottom inside which a gearmotor unit is housed. Said gearmotor is housed in the same structure of the drum that defines the counter bottom.

US 1863029A describes a concrete mixer comprising a drum with a counter bottom inside which a gearmotor is housed. Said gearmotor is housed in the same structure of the drum that defines the counter bottom.

DE 202004007078U1 describes a concrete mixer comprising a drum with a counter bottom inside which a gearmotor is housed. Said gearmotor is housed in the same structure of the drum that defines the counter bottom.

US 5190372A describes a concrete mixer comprising a drum with a counter bottom inside which a gearmotor is housed. Said gearmotor is housed in the same structure of the drum that defines the counter bottom.

The main purpose of the present invention is to propose a concrete mixer with a gearmotor positioned on the back of the drum which has peculiar construction characteristics combined with a reduction in costs connected to the configuration of the electric motor.

This result is achieved in accordance with the present invention by adopting the idea of providing a concrete mixer having the features indicated in claim 1. Other features of the present invention are the subject of the dependent claims.

Thanks to the present invention, it is possible to limit the manufacturing costs of the machine, without however compromising the reliability and compactness of the same, maintaining unchanged the methods of operation, management and maintenance to which the operators are accustomed, although positioning the motor unit reducer on the back of the drum.

These and further advantages and characteristics of the present invention will be more and better understood by every person skilled in the art thanks to the following description and the attached drawings, provided by way of example but not to be considered in a limiting sense, in which:

- Fig.l represents a side view of a concrete mixer in accordance with the present invention;

- Fig.2 represents a sectional view of the drive unit of the concrete mixer of Fig.l;

- Fig.3 represents a further sectional view of the drive unit of the concrete mixer of Fig. l.

Reduced to its essential structure and with reference to the attached exemplary drawings, a concrete mixer (1) in accordance with the present invention comprises a load-bearing structure (2), a drum (3) of predefined volume, a drum-holder arm (4) constrained to the load-bearing structure (2) by means of a hinge connection with a horizontal axis (x-x), an electric gearmotor (5) supported by said arm (4) and a push-button panel (6) to control the gearmotor (5). The drum (3) has a bottom (3C) and a lateral surface (3L) with a loading/unloading mouth (30) opposite the bottom (3C). In the attached exemplary drawings, the lateral surface (3L) is cylindrical in a lower part of the drum that includes the bottom (3C) and is frusto- conical in an upper part that includes the loading/unloading mouth (30). The preparation of the cement mixtures or mortars to be used on the construction site takes place inside the drum with known methods.

The drum (3) has, in correspondence of the bottom (3C), an internal counter-bottom (3F) on which a central bushing (3B) is welded which constitutes a power take-off for the rotation of the drum (3) by the motor-reducer (5). In the example shown in the attached drawings, the counter-bottom (3F) is conical and the power take-off (3B) is arranged on the (y-y) axis of the cone defined by the counter-bottom.

In the configuration shown in Fig. l, the load-bearing structure (2) is made up of a frame with a base (20) equipped with wheels (7) and a foot (21) to rest on the ground. The structure (2) has two upper fixed arms (22) on which two corresponding lateral parts (40) of the drum-holder arm (4) are connected by means of hinges that define the aforementioned axis (x-x). In this exemplary configuration, the arm (4) has a section (41) comprised between the lateral parts (40) such that, overall, the arm (4) itself is arch-shaped similarly to the upper part of the loadbearing structure (2). The length of the arms (22) and the lateral parts (40) of the drum-holder arm (4) is such as to allow the positioning of the drum (3) as in Fig. l, i.e. in a vertical position with the respective mouth (30) facing downwards when the concrete mixer is not used. The rotation of the drum-holder arm (4) around the axis (x-x) can be controlled using a lateral handwheel (9). The gearmotor (5) is made up of an electric motor (50) and a reducer (51) with an input onto which the shaft (50A) of the electric motor is engaged and an output formed by a shaft (5 IB) which, in the example shown in the attached drawings, is parallel to the shaft (50A) of the electric motor. The output shaft (5 IB) of the gearmotor (51) is engaged with the power take-off (3B) of the drum (3). Furthermore, in the example shown in the attached drawings, a conical coupling is provided between the output shaft (51) of the gearmotor (5) and the power take-off (3B).

The gearmotor (5) is mounted on a mounting plate (42) formed in a central position on the section (41) of the drum-holder arm (4). Said plate (42) has a plane (420) facing the drum (3) and an annular edge (421). The motor (50) and the reducer (51) are on opposite sides with respect to the plane (420): the reducer (51) is anchored to the side of the plane (420) facing the drum (3) by means of a corresponding flange (52) and the motor (50) is anchored directly to the reducer (51). The shafts (50A) and (51 A) are orthogonal to the plane (420). The motor (50) is partially contained in the space delimited laterally by the annular edge (421) of the plate (42).

Advantageously, between the bottom (3C) and the internal counter-bottom (3F) of the drum (3) there is a chamber (31) in which the reducer (51) is housed. Therefore, the reducer (51) is brought closer to the power take-off (3B), reducing the distance, i.e. the overhang, between the reducer output and the power take-off. Consequently, there is also a notable reduction in the parts resulting outside the arm (3) and this allows the use of even bulkier or heavier, more economical electric motors, without compromising the operation of the machine.

As illustrated in the attached drawings, said chamber (31) is made up of a different structure from that of the counter-bottom (3F). In other words, the chamber (31) is delimited by a respective surface which does not coincide with the internal surface of the counter-bottom (3F). Still in other words, the external surface (X31) of the chamber (31), i.e. the surface of the chamber (31) facing the counter-bottom (3F), is spaced from the internal surface (3FX) of the counter-bottom (3F), so that there is a space between said surfaces (X31, 3FX). Therefore, the reducer (51) is housed in a chamber (31) which is inside the counter-bottom (3F) and is separated from the counter-bottom itself, since it is made up of a structure (for example, a metal sheet) different from the structure of the counter-bottom.

Preferably, said chamber (31) is cup-shaped with an opening for inserting the reduction unit protruding beyond the bottom (3C) of the drum (3). Preferably, said opening is delimited laterally by an annular lip (310) radially oriented towards the outside of the chamber (31). Furthermore, preferably, the aforementioned annular edge (421) extends towards the bottom (3C) of the drum (3) forming a surface with a circular cross section (432) which perimeterally surrounds the lip (310). In this way, a labyrinth structure is formed which prevents the entry of water or solid materials into the chamber (31).

On the motor (50) there is a carter (5C) with ventilation slots (5F).

From the description provided above, it is evident that a concrete mixer according to the present invention is a concrete mixer comprising a load-bearing structure (2), a tank-shaped drum (3) having a predefined volume, a drum-holder arm (4) bound to the load-bearing structure (2) by means of a hinge connection with a horizontal axis (x-x), an electric gearmotor (5) supported by said arm (4) and a push-button panel (6) for controlling the gearmotor (5), wherein

- the gearmotor (5) is formed by an electric motor (50) and a reduction unit (51),

- the drum (3) has a bottom (3C) and a side surface (3L) with a loading/unloading mouth (30) opposite to said bottom (3C),

- the drum (3) has an internal counter bottom (3F) on which an output shaft (51 A) of the reduction unit (51) is connected, the internal counter bottom (3F) being delimited by a first surface (3FX), a chamber (31) is formed on the bottom (3C) below the internal counter bottom (3F),

- the reduction unit (51) is housed in said chamber (31),

- the chamber (31) in which the reduction unit (31) is housed is made up of a structure delimited by a second surface (X31) arranged below the first surface (3FX) delimiting the counter-bottom (3F).

From the description provided above it is also evident that a concrete mixer in accordance with the present invention can have the following additional features even combined with each other: said chamber (31) is cup-shaped and has an insertion opening for the reduction unit projecting beyond the bottom (3C) of the drum (3). said opening is laterally delimited by an annular lip (310) radially oriented towards the outside of the chamber (31). said opening is surrounded by a perimeter sealing ring (432).

- the internal counter bottom of the drum is formed by a conical surface on whose axis (y-y) there is a power take-off (3B) to which the output shaft of the motor-reducer is connected.

- the shaft (50A) of the electric motor and the output shaft (51 A) of the reduction unit (51) are parallel with each other.

In practice, the execution details may however vary with regard to the individual elements described and illustrated, without thereby departing from the scope of the protection offered by this patent in accordance with the attached claims.

Claims

1) Concrete mixer comprising a load-bearing structure (2), a tank-shaped drum (3) having a predefined volume, a drum-holder arm (4) bound to the load-bearing structure (2) by means of a hinge connection with a horizontal axis (x-x), an electric gearmotor (5) supported by said arm (4) and a push-button panel (6) for controlling the gearmotor (5), wherein the gearmotor (5) is formed by an electric motor (50) and a reduction unit (51), the drum (3) has a bottom (3C) and a side surface (3L) with a loading/unloading mouth (30) opposite to said bottom (3C), and the drum (3) has an internal counter bottom (3F) on which an output shaft (51 A) of the reduction unit (51) is connected, the internal counter bottom (3F) being delimited by a first surface (3FX), characterized in that it comprises a chamber (31) formed on the bottom (3C) below the internal counter bottom (3F), in that the reduction unit (51) is housed in said chamber (31) and in that the chamber (31) in which the reduction unit (31) is housed is made up of a structure delimited by a second surface (X31) arranged below the first surface (3FX) delimiting the counter-bottom (3F).

2) Concrete mixer according to claim 1 characterized in that said chamber (31) is cup-shaped and has an insertion opening for the reduction unit projecting beyond the bottom (3C) of the drum (3).

3) Concrete mixer according to claim 2 characterized in that said opening is laterally delimited by an annular lip (310) radially oriented towards the outside of the chamber (31).

4) Concrete mixer according to claim 2 characterized in that said opening is surrounded by a perimetral sealing ring (432).

5) Concrete mixer according to claim 1 characterized in that the internal counter bottom of the drum is formed by a conical surface on whose axis (y-y) there is a power take-off (3B) on which the output shaft of the motor-reducer is connected.

6) Concrete mixer according to claim 1 characterized in that the shaft (50A) of the electric motor and the output shaft (51 A) of the reduction unit (51) are parallel to each other.