Patent Description:
Pumping apparatuses are known, which comprise a containing compartment, inside which there is concrete in a more or less liquid form, and a pumping unit intended to pump the concrete toward a distribution pipe.

The pumping unit normally comprises two pumping cylinders, respectively a first and a second, each having an internal chamber inside which a respective pumping piston slides.

Usually, the two pumping pistons are hydraulically driven by an oil-dynamic system which, in turn, is driven by an endothermic motor, under the control of a control unit.

In particular, the action of the two pumping pistons is synchronized by the control unit so that while a first piston sucks in the concrete present in the containing compartment, making it enter the chamber of the first pumping cylinder, a second piston thrusts the concrete present in the chamber of the second cylinder into the distribution pipe. This guarantees a continuous delivery at the distribution point.

In order to guarantee the correct operation of the two pumping pistons, inside the containing compartment there is an exchange valve, known to persons of skill in the art by the term "S" valve.

This valve has the function of guaranteeing the alternate connection between the two pistons and the containing compartment. The synchronism of the pumping pistons and the exchange valve can be obtained hydraulically or electrically.

<CIT> discloses a pumping apparatus for pumping concrete or similar material according to the preamble of independent claims <NUM> and <NUM>.

One disadvantage of known apparatuses is that, since the two pistons are driven and synchronized by means of an oil-dynamic system, it may happen that they are not perfectly synchronized with each other. This can lead to a loss of performance of the apparatus itself, as well as possible malfunctions.

Another disadvantage is that the construction layout of known apparatuses is rather complex and, in the event of malfunctions, it can be complicated to intervene on the operating components of the pumping apparatus.

There is therefore a need to perfect a pumping apparatus that can overcome at least one of the disadvantages of the state of the art.

In particular, one purpose of the present invention is to provide a pumping apparatus in which the synchronization of the two pumping pistons is precise and not subject to possible asynchrony.

Another purpose of the present invention is to provide a pumping apparatus that is compact and has a simplified construction layout with respect to the state of the art.

Another purpose of the present invention is to provide a pumping apparatus that is highly efficient and has high operating performance.

In accordance with the above purposes, and to solve the above technical problem in a new and original way, also obtaining considerable advantages compared to the state of the prior art, a pumping apparatus according to the present invention, for pumping concrete or similar material, comprises at least one pumping unit having a first pumping cylinder and a second pumping cylinder, a first pumping piston and a second pumping piston both mobile with a respectively alternating motion inside respective chambers present in the first cylinder and in the second cylinder respectively, and a motor for driving the first and second piston with an alternating motion.

The pumping apparatus also comprises movement means each having respective threaded rods which are driven in rotation by the motor with a respectively opposite and alternating sense of rotation, and on which respective bushing elements, which are integral with the first piston and the second piston respectively, are mobile, being screwed and unscrewed in relation to the sense of rotation in order to generate the alternating motion of the first and second piston with respect to the first and second cylinder.

In accordance with another aspect of the present invention, the movement means comprise, or consist of, a first ball screw and a second ball screw.

The first and second pistons are mobile along respective axes of sliding and are provided with respective terminal ends.

In accordance with another aspect of the present invention, the threaded rods are disposed coaxial to the axes of sliding of the first and second piston, and the bushing elements are associated with the respective lower ends of the first and second piston.

In accordance with the present invention, the motor is operatively connected to a transmission member which is associated with both of the threaded rods, and which is configured to split the motion generated by the motor, making the threaded rods rotate simultaneously with the respectively opposite sense of rotation, in order to synchronize the movement of the bushing elements and, therefore, the alternating motion of the first and second piston.

In accordance with another aspect of the present invention, the motor is an electric motor, and it is capable of inverting its drive sense in a cyclical manner and substantially continuously so that the transmission member reverses the senses of rotation of the threaded rods.

In accordance with another aspect of the present invention, the pumping apparatus also comprises a converter connected to the motor, an electric accumulator and a connection device, wherein the electric accumulator and the connection device are connected to the converter so as to supply powering and/or driving electrical energy to the motor, for a completely electric operation of the first and second piston.

In accordance with another aspect of the present invention, the connection device is configured both to connect the electric accumulator to a source of electrical energy, when the energy level of the latter is low, and also to supply driving electrical energy to the motor.

The pumping unit is configured to pump a certain quantity of material from a containing compartment to a distribution pipe by means of an exchange valve.

In accordance with another aspect of the present invention, the first or second piston, in relation to the sense of rotation of the respective threaded rod, is configured to alternatively assume a suction condition, or step, and a thrust condition.

In the suction condition, the piston, by retracting, is able to suck the material from the containing compartment, making it enter inside the chamber of the respective cylinder.

In the thrust condition, the piston, by advancing, is able to thrust the material already present in the chamber of the respective cylinder into the distribution pipe.

Furthermore, the alternating connection of the first and second piston with the distribution pipe is determined by the exchange valve.

In accordance with another aspect of the present invention, one or more oil-dynamic pumps can be associated with the transmission member, which have the function of selectively driving one or more auxiliary services of the pumping unit, which comprise the drive of the exchange valve, the drive of mixing means present in the containing compartment and the drive of a cleaning device for cleaning the containing compartment.

In accordance with a variant of the invention, the exchange valve is associated with an electric drive device, or a drive device of another type.

The present invention also concerns a method for pumping concrete, or similar material, which uses the pumping unit as above, which has a first pumping cylinder and a second pumping cylinder, a first pumping piston and a second pumping piston, both mobile in the respective cylinder, and a drive motor. The method comprises a main drive step in which the motor drives the first and second piston with alternating motion in order to move them inside respective chambers present in the first cylinder and in the second cylinder, respectively.

In the drive step, the motor drives movement means, each having respective threaded rods which are driven in rotation by the motor with a respectively opposite and alternating sense of rotation, and on which respective bushing elements, which are integral with the first piston and the second piston respectively, are screwed and unscrewed in relation to the sense of rotation, in order to generate the alternating motion of the first and second piston with respect to the first and second cylinder.

In accordance with the present invention, in the drive step a transmission member, connected to the motor and associated with the threaded rods, splits the motion generated by the motor simultaneously making the threaded rods rotate, with a respectively opposite sense of rotation, in order to synchronize the movement of the bushing elements and, therefore, the alternating motion of the first and second piston.

In accordance with the present invention, in the drive step it is provided that the first and second piston reciprocally alternate between a suction step, in which, by retracting, they suck the material from a containing compartment making it enter into the chamber of the respective cylinder, and a thrust step, in which, by advancing, they thrust the material already present in the chamber of the respective cylinder into a distribution pipe.

In accordance with another aspect of the present invention, the method comprises another drive step in which the motor, by means of the transmission member, drives one or more oil-dynamic pumps in order to selectively drive one or more auxiliary services of the pumping unit.

In accordance with another aspect of the present invention, the method comprises a recharging step in which, since the motor is an electric motor powered and/or driven, by means of a converter, by an electric accumulator, if the latter has a low charge level and such that it does not allow to power and/or drive the motor itself, the electric accumulator is connected to an external source of electrical energy by means of a connection device, which is also connected to the converter, so as to be recharged.

We must clarify that in the present description the sole function of the phraseology and terminology used, as well as the figures in the attached drawings also as described, is to better illustrate and explain the present invention, their function being to provide a non-limiting example of the invention itself, the scope of protection being defined by the claims.

With reference to <FIG>, a pumping apparatus <NUM> according to the present invention is suitable and usable to pump and distribute building material, intended here as concrete but not limited thereto, used to make residential constructions or components.

Advantageously, the pumping apparatus <NUM> can be installed, or mounted, on a mobile operating machine <NUM>, such as a truck-mounted pump, a truck mixer pump, or similar operating machines.

The pumping apparatus <NUM> essentially comprises a pumping unit <NUM> to pump the concrete from a containing compartment <NUM>, which is associated, in the example representation of <FIG>, at the rear part with the pumping unit <NUM> and into which the concrete to be pumped is introduced, to a distribution pipe <NUM> in order to distribute and convey the concrete toward a determinate destination zone. The distribution pipe <NUM> is associated at the rear part with the containing compartment <NUM> and can be supported by an articulated arm, of a known type and not shown in the drawings.

Briefly, the containing compartment <NUM> is substantially of a known type and it can have the shape of a hopper into which the concrete is introduced, in a more or less liquid form, by means of another mobile operating machine <NUM>, for example a truck mixer. Inside the containing compartment <NUM>, the concrete is mixed by suitable mixing means, not shown in the drawings, which have the function of maintaining a correct fluidity of the concrete, thus preventing it from solidifying.

Furthermore, in the lower part of the containing compartment <NUM> there is an exchange valve <NUM>, also known by the term "S valve", which allows to correctly pump the concrete from the containing compartment <NUM> to the distribution pipe <NUM>, as will be described in detail below.

The pumping unit <NUM> comprises a pair of cylindrical tubular elements, respectively a first pumping cylinder <NUM> and a second pumping cylinder <NUM>, which are disposed side by side, parallel to each other and operatively connected to the exchange valve <NUM> and, therefore, to the containing compartment <NUM>.

The two pumping cylinders <NUM> and <NUM> comprise respective chambers <NUM>, <NUM> inside which a respective pumping piston <NUM>, <NUM> can slide along a corresponding axis of sliding X1, X2. Specifically, a first pumping piston <NUM> is able to slide, along the first axis of sliding X1, inside the chamber <NUM> of the first cylinder <NUM>, and a second pumping piston <NUM> is able to slide, along the second axis of sliding X2, inside the chamber <NUM> of the second cylinder <NUM>.

As shown in <FIG> and from <NUM> to <NUM>, both the first piston <NUM> and also the second piston <NUM> each comprise a cylindrical tubular body 23a, 23b with which there is associated a head, or initial, portion 24a, 24b which is configured to come in contact with the concrete. Furthermore, each tubular body 23a, 23b comprises a lower end 25a, 25b.

The two pistons <NUM> and <NUM> have a continuous alternating motion, or operation, and they are each configured to alternately pass from a suction condition, or step, to a thrust condition, or step (figs. from <NUM> to <NUM>). Specifically, while one of the two pistons <NUM> or <NUM> is in the suction condition, in which by retracting it is able to suck the concrete from the containing compartment <NUM>, making it enter into the chamber <NUM> or <NUM> of the respective cylinder <NUM> or <NUM>, the other piston <NUM> or <NUM> is in the thrust condition, in which by advancing it is able to thrust the concrete already present in the chamber <NUM> or <NUM> of the respective cylinder <NUM> or <NUM> into the distribution pipe <NUM>.

It should be noted that each piston <NUM>, <NUM>, at least in correspondence with the respective head portion 24a, 24b, can be provided with suitable sealing means, not shown in the drawings, to prevent the concrete from escaping from the chamber <NUM>, <NUM> of the respective cylinder <NUM>, <NUM> in an uncontrolled manner.

In the continuous alternating motion, the exchange valve <NUM> is configured to allow the selective and alternating connection between the piston <NUM> or <NUM> which is in the thrust condition and the distribution pipe <NUM>.

In particular, the pumping apparatus <NUM> comprises a motor <NUM> (<FIG> and from <NUM> to <NUM>) which is provided to drive the first and second piston <NUM> and <NUM> with the alternating motion described above.

In accordance with one aspect of the present invention, the pumping apparatus <NUM> also comprises movement means <NUM> and <NUM>, each having respective threaded rods 29a and 29b which are driven in rotation by the motor <NUM> with a respectively opposite and alternating sense of rotation, and on which respective bushing elements 30a and 30b, which are integral with the first piston <NUM> and with the second piston <NUM> respectively, are mobile, being screwed and unscrewed in relation to the sense of rotation, so as to generate the continuous alternating motion.

In particular, the threaded rods 29a and 29b are disposed coaxial to the first axis of sliding X1 and to the second axis of sliding X2 respectively, and the bushing elements 30a and 30b are rigidly constrained to a respective terminal end 25a, 25b of the first and second piston <NUM> and <NUM>.

In accordance with one aspect of the present invention, the movement means comprise, or consist of, a first ball screw <NUM> and a second ball screw <NUM>. In this case, the bushing elements 30a, 30b are internally threaded and can perform the function of a "nut screw", known to the people of skill in the art.

It should be noted that, since the tubular body 23a and 23b is integral with the corresponding bushing element 30a, 30b, the term "nut screw" can also be understood to mean the combination of the tubular body 23a, 23b with the respective bushing element 30a, 30b.

Specifically, between the threading of the threaded rods 29a and 29b and that of the bushing elements 30a and 30b there is a plurality of balls or suitable elements, not shown in the drawings, which have the function of transforming the rotary motion of each threaded rod 29a, 29b into a translational motion for the bushing element 30a, 30b.

Therefore, in relation to the sense of rotation of the threaded rod 29a, 29b, the bushing element 30a, 30b is able to advance, or alternatively retract, along the respective axis of sliding X1, X2. Each piston <NUM>, <NUM> can therefore pass from a retracted position, in which it is almost entirely outside the chamber <NUM>, <NUM> of the respective cylinder <NUM>, <NUM>, to an advanced position, in which it is substantially inside the chamber <NUM>, <NUM> of the respective cylinder <NUM>, <NUM>, and vice versa (figs. from <NUM> to <NUM>).

In accordance with another aspect of the present invention, as shown in the attached drawings, the motor <NUM> is operatively connected to a transmission member <NUM> of the mechanical type, which is associated with the threaded rods 29a and 29b and which is configured at least to split the motion generated by the motor <NUM>, simultaneously making the threaded rods 29a and 29b rotate, with a respectively opposite sense of rotation, in such a way as to synchronize the alternating motion of the first and second piston <NUM>, <NUM>. In particular, one of the two senses of rotation is concordant with the sense of drive, or of rotation, of the electric motor <NUM>, while the other is discordant.

By way of example, the threaded rod 29a of the first ball screw <NUM> is made to rotate clockwise in order to make the respective bushing element 30a and therefore also the first piston <NUM> advance along the respective axis of rotation X1, thus determining the thrust condition described above, while the threaded rod 29b of the second ball screw <NUM> is made to rotate counterclockwise in order to make the respective bushing element 30b and therefore also the second piston <NUM> retract along the respective axis of rotation X2, thus determining the suction condition described above (figs. from <NUM> to <NUM>).

In accordance with another aspect of the present invention, the motor <NUM> is an electric motor, and is capable of reversing its sense of drive in a cyclical manner and substantially continuously, so that the transmission member <NUM> reverses the senses of rotation of the threaded rods 29a, 29b so as to cause the two pistons <NUM> and <NUM> to cyclically pass from the suction condition to the thrust condition, and vice versa.

As shown in <FIG>, each threaded rod 29a, 29b is provided with a first pair of start-of-travel bearings <NUM>, disposed in correspondence with the initial part of the respective threaded rod 29a, 29b, and with a second pair of end-of-travel bearings <NUM>, disposed in correspondence with the terminal part of the respective threaded rod 29a, 29b.

In accordance with possible embodiments of the present invention, a hollow connection member <NUM>, disposed transversely to the axes of sliding X1 and X2, is associated in correspondence with respective inlet zones ZI of the two cylinders <NUM> and <NUM>. The connection member <NUM> defines a piston-cylinder connection interface and has the function of supporting the movement of the two pistons <NUM> and <NUM>, in particular of the two tubular bodies 23a and 23b.

Specifically, the connection member <NUM> comprises: a first wall <NUM> facing toward the motor <NUM> and provided with special apertures for the passage of the first and second cylinder <NUM> and <NUM>; a second wall <NUM> facing toward the containing compartment <NUM> and provided with suitable apertures in which the two cylinders <NUM> and <NUM> are attached; and an upper wall <NUM> provided with an access door <NUM> for possible maintenance operations, for example to replace the head portion 24a and 24b. Furthermore, sealing elements <NUM> are disposed in correspondence with the apertures of the first wall <NUM> to guarantee a hermetic seal of the connection member <NUM>.

Preferably, in order to protect the ball screws <NUM> and <NUM>, respective tubular protection members 41a and 41b can be disposed externally thereto, which are associated on one side with the transmission member <NUM> and on the other with the connection member <NUM>.

In accordance with one aspect of the present invention, the pumping apparatus <NUM> also comprises a converter <NUM> (<FIG>, <FIG>) connected to the electric motor <NUM>, an electric accumulator <NUM> and a connection device <NUM> both connected to the converter <NUM> so as to supply powering and/or driving electrical energy to the motor <NUM>, for a completely electric operation of the first and second piston <NUM>, <NUM>.

In particular, the electric accumulator <NUM> comprises one or more electric batteries to electrically drive the motor <NUM>, and the connection device <NUM> for a connection to an external source of electrical energy, for example a normal electrical network.

In particular, the connection device <NUM> is configured both to connect the electric accumulator <NUM> to the source of electrical energy when the energy level of the latter is low, and also to supply powering and/or driving electrical energy to the motor <NUM> itself. In this regard, the presence of the converter <NUM> has the function of an inverter and allows to guarantee a correct management of the direct DC and/or alternating AC electrical energy and a correct electrical operation of the motor <NUM>.

According to other embodiments of the present invention, not shown in the drawings, the electric accumulator <NUM> can be connected to a power take-off of the endothermic motor that drives the mobile operating machine <NUM>; in this case, it is provided that the operative connection between the power take-off and the electric accumulator <NUM> occurs by means of an electric generator associated with the converter <NUM>.

The pumping apparatus <NUM> has the advantage that the pumping of concrete and, therefore, the drive of the pistons <NUM> and <NUM> occurs without the use of an oil-dynamic system; moreover, thanks to the use of the movement means <NUM> and <NUM> and of the transmission member <NUM>, the movements of the first and second pistons <NUM> and <NUM> are not independent from each other, but they are synchronized with each other in a mechanical manner. This allows to have an optimized and highly performing alternating motion of the two pistons <NUM> and <NUM>.

In accordance with possible embodiments of the present invention, shown in <FIG>, the transmission member <NUM> can also be used with a coupler function for keying other drive elements, or components, configured to drive one or more auxiliary systems of the pumping apparatus <NUM>. Specifically, it is possible to key, in a rear part of the transmission member <NUM>, one or more oil-dynamic pumps <NUM> capable of driving the auxiliary systems of the pumping unit <NUM>.

As shown in the embodiment of <FIG>, provided by way of example only, there are several oil-dynamic pumps <NUM>, respectively:.

In order to maintain a simpler construction layout and configuration of the pumping apparatus <NUM>, as shown, by way of example, in the embodiment of <FIG>, it is possible to provide a single oil-dynamic pump <NUM> with which there is associated a distribution member <NUM> configured to manage the oil-dynamic flows toward the auxiliary services, defined by the correct drive of the exchange valve <NUM>, of the mixing means and of the cleaning device <NUM>.

The construction layout of the pumping apparatus <NUM> is therefore very compact and allows to optimize the efficiency of the pumping unit <NUM>, since the use of oil-dynamic pumps <NUM> is limited to the auxiliary services only.

Within the scope of the invention, it is understood that the exchange valve <NUM> can be associated with an electric drive device, or a drive device of another type, not shown in the drawings.

The operating method of the pumping apparatus <NUM> comprises the following steps.

In a main drive step (figs. from <NUM> to <NUM>) the motor <NUM> is powered by means of the electric accumulator <NUM>, or possibly by means of the connection device <NUM>, when the electric accumulator <NUM> has a low energy level, and by means of the transmission member <NUM> it drives the movement means, which in the example provided here consist of the first and second ball screw <NUM>, <NUM>. Therefore, the threaded rods 29a, 29b rotate with a respectively opposite sense of rotation, consequently moving the bushing elements 30a, 30b so that while one of them is screwed, the other is unscrewed, generating the forward and backward alternating motion of the two pistons <NUM> and <NUM> described above.

In particular, in the main drive step it is provided that the two pistons <NUM> and <NUM> alternate reciprocally between the suction step and the thrust step, as previously defined.

The method comprises a secondary drive step, in which the motor <NUM>, by means of the transmission member <NUM>, drives one or more oil-dynamic pumps <NUM> in order to selectively drive the one or more auxiliary services of the pumping unit <NUM>.

Furthermore, the method also comprises a recharging step in which, if the electric accumulator <NUM> has a low charge level and such that it does not allow to power and/or drive the motor <NUM>, the same electric accumulator <NUM> is connected to an external source of electrical energy by means of the converter <NUM> and the connection device <NUM>, so as to be recharged.

It should be noted that both during the main and secondary drive steps, and also during the recharging step, the converter <NUM> manages the conversion of the direct DC and/or alternating AC electrical energy in relation to the specific operating needs of the apparatus <NUM>.

It is clear that modifications and/or additions of parts may be made to the pumping apparatus <NUM> and to its operating method as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve other equivalent forms of pumping apparatuses, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claim 1:
Pumping apparatus (<NUM>) for pumping concrete, or similar material, comprising at least one pumping unit (<NUM>) having a first pumping cylinder (<NUM>) and a second pumping cylinder (<NUM>), a first pumping piston (<NUM>) and a second pumping piston (<NUM>) both mobile with a respectively alternating motion inside respective chambers (<NUM>, <NUM>) present in said first cylinder (<NUM>) and in said second cylinder (<NUM>) respectively, a motor (<NUM>) being provided to drive said first and second piston (<NUM>, <NUM>) with alternating motion, wherein said pumping apparatus also comprises movement means (<NUM>, <NUM>) each having respective threaded rods (29a, 29b) which are driven in rotation by said motor (<NUM>) with a respectively opposite and alternating sense of rotation, and on which respective bushing elements (30a, 30b), which are integral with said first piston (<NUM>) and said second piston (<NUM>) respectively, are mobile, being screwed and unscrewed in relation to said sense of rotation, in order to generate said alternating motion of said first and second piston (<NUM>, <NUM>) with respect to said first and second cylinder (<NUM>, <NUM>), characterized in that said motor (<NUM>) is operatively connected to a transmission member (<NUM>) which is associated with said threaded rods (29a, 29b) and which is configured to split the motion generated by said motor (<NUM>), making said threaded rods (29a, 29b) rotate simultaneously with said respectively opposite sense of rotation, in order to synchronize the movement of said bushing elements (30a, 30b) and, therefore, said alternating motion of said first and second piston (<NUM>, <NUM>).