EP1002950A2

EP1002950A2 - Single-cylinder pump particularly for pumping mortar and similar materials

Info

Publication number: EP1002950A2
Application number: EP99122043A
Authority: EP
Inventors: Fabio Campeol; Livio Campeol; Adriano Nardi
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-11-18
Filing date: 1999-11-15
Publication date: 2000-05-24
Also published as: ITTV980152A1; IT1303379B1; EP1002950A3

Abstract

A single-cylinder pump (1), particularly for pumping mortar and similar materials from a hopper or tank. The pump comprises a lower intake chamber (3) provided with a first gravity valve (8), the intake chamber (3) is connected to the delivery of a piston (12) with dual compensating action and to a second gravity valve (9) for feeding the mortar to an upper delivery chamber (6). The dual-action piston (12) is also provided with a transit chamber (17) which is connected to an outlet (18) for the pressurized material and to a duct (19) for connection to the upper delivery chamber (16). A single-cylinder pump is thus obtained which allows to have a sufficiently constant output flow of material at high pressure.

Description

The present invention relates to a single-cylinder pump, of the type that can be used in machines adapted to pump mortar and similar materials.
The field of building currently uses machines designed to pump mortars and similar materials, usually by means of a single-cylinder pump with single-action piston.
These conventional pumps substantially suffer the drawback of considerable discontinuity in the flow of mortar sent to adapted pipes for delivering the mortar for example at a wall to be plastered. As a partial solution to this drawback it is known to apply to the conventional pumps compensation devices, known as plenum chambers, or elastic mortar feed hoses.
Also these two solutions are not ideal, since compensation devices are not presently accepted by EU standards and elastic hoses suffer the considerable drawback that they cannot exceed a given pressure, thus restricting their field of application.
The aim of the present invention is to solve the noted technical problems, eliminating the drawbacks of the cited prior art, by providing a pump which can be used in machines for pumping mortar and similar materials which allows to deliver a constant flow of material.
Within the scope of this aim, an important object of the present invention is to provide a pump which does not have to use plenum chambers or elastic hoses.
Another important object of the present invention is to provide a pump which associates with the preceding characteristics that of allowing to obtain a flow of material which has higher pressures for an equal power usage with respect to conventional pumps.
Another object of the present invention is to provide a pump which is structurally simple and has low manufacturing costs.
This aim, these objects and others which will become apparent hereinafter are achieved by a single-cylinder pump, particularly for pumping mortar and similar materials from a hopper or tank, characterized in that it comprises a lower intake chamber provided with a first gravity valve which is connected to the delivery of a dual compensating action piston and a second gravity valve for feeding the mortar to an upper delivery chamber, said piston being provided with a transit chamber which is connected to an outlet and to a duct for connection to said upper delivery chamber.
Further characteristics and advantages of the present invention will become apparent from the following detailed description of a particular but not exclusive embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
Figure 1 is a side view of the pump according to the present invention;
Figure 2 is a sectional view of the pump, taken along a median plane thereof;
Figure 3 is a sectional view of the pump, taken at the duct for connecting the transit chamber to the upper delivery chamber;
Figures 4, 5 and 6 are views, similar to Figures 1, 2 and 3, of a second embodiment of the pump according to the present invention.
With reference to the above figures, the reference numeral 1 designates a single-cylinder pump which is used in particular in machines for pumping mortar and similar materials.
The pump is constituted by a body 2 which is internally provided with a lower intake chamber 3 and is connected, in a downward region, by means of adapted quick couplings, at a first duct 4 which is connected to a hopper or to a tank for conveying mortar and similar materials.
In an upward region, the body 2 is connected, by means of adapted quick couplings, to a second body 5 which internally forms an upper delivery chamber 6 to which a suitable pressure gauge 7 is connected.
The lower intake chamber 3 has, at the connection to the first duct 4, a first gravity valve 8 which is constituted by a ball suitable to temporarily close the opening of the first duct 4.
The lower intake chamber 3 is further connected, at the connection to the second body 5, to a second gravity valve 9 which is again constituted by a ball suitable to temporarily close the access between the lower intake chamber 3 and the upper delivery chamber 6.
The first and second gravity valves 8, 9 are such that they act alternately.
The lower intake chamber 3 is further connected to a suitable second duct 10 which protrudes radially with respect to the first body 2 and inside which a jacket 11 is formed within which there slides a piston with dual compensating action designated by the reference numeral 12.
The piston is therefore constituted by a stem 13 which has, at its tip, a head 14 with which a first annular gasket 15 is associated.
A seat 16 is furthermore formed coaxially to the stem 13, to the rear of the first annular gasket 15, and is connected to a transit chamber 17 which is in turn connected to an outlet 18 and to a duct 19 for connection to the upper delivery chamber 6.
The transit chamber 17 is further connected to a bypass 20 for safety and for recycling the material.
The pump operates as follows: consider first of all the suction of the mortar or similar material from the hopper or tank.
This step occurs during the retracting motion of the piston 12 inside the jacket 11, and this causes the rise of the first gravity valve 8 and the simultaneous closure of the second gravity valve 9.
Through the first duct 4, the mortar or similar material then fills the lower intake chamber 3 and the region of the jacket 11 located in front of the head 14 of the piston.
The motion of the piston then propels the material toward the outlet 18 of the pump, simultaneously filling the seat 16 and the transit chamber 17.
When the piston moves toward the lower intake chamber 3, this in fact causes the closure of the lower gravity valve 8 and the opening of the upper gravity valve 9, consequently filling the upper delivery chamber 6.
The material flows from the latter into the duct 19 and then at the transit chamber 17, also filling the part of the seat 16 that is coaxial to the stem of the piston.
The transit chamber 17 is connected to the outlet 18, at which it is possible to associate suitable couplings for ducts adapted to spray the mortar or similar materials where necessary.
After the filling of the lower intake chamber 3, of the upper delivery chamber 6 and of the transit chamber 17 during the initial step, the actual pumping of the material begins. The pumping occurs in both directions of the motion of the piston, which allows to define the invention as a single-cylinder pump with dual compensating action.
This entails the fact that during the forward thrust of the piston head (toward the lower intake chamber), 50% of the material exits from the transit chamber 17 and flows to the outlet, whereas the remaining 50% fills the seat 16, helping to push the piston head forward, halving the force to be applied.
During the opposite motion of the piston, the material contained in the seat 16 is forced into the transit chamber 17, drawing further material from the lower intake chamber.
A bush 21 is arranged coaxially to the stem 13 of the piston and is adapted to protect the stem.
A second annular gasket 22 cooperates with the bush 21 and is adjacent to the outlet 18 and the bypass 20; its purpose is to prevent the escape of the material and compensate for any play of the bush 21.
A cycle with constant flow-rate is thus obtained which constitutes the characteristic of the piston with dual compensating action.
It has thus been observed that the invention has achieved the intended aim and objects, a pump having been provided which allows to have a sufficiently constant flow of material, thus avoiding the need for conventional compensation devices or for rubber elements which can undergo deformation; moreover, for an equal power level, in such pump the mortar flows out with a pressure in bar which is approximately twice that of conventional pumps which use a single-action piston; accordingly, machines for pumping mortars and similar materials that use said pump extend their operating range both in terms of distance and in terms of height.
Moreover, it has been observed that, though the doubling of the pressure with respect to machines using a conventional pump with a single-action piston, connection to the residential single-phase 220V mains is still possible and equally achieves a considerable useful plastering distance and height.
The invention is of course susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept.
Thus, for example, Figures 4, 5 and 6 illustrate a second embodiment of a single-cylinder pump 101 which is again constituted by a body 102 which is internally provided with a lower intake chamber 103 and is connected in a downward region, by means of adapted quick couplings, at a first duct 104 which is connected to a hopper or to a tank for conveying mortar and similar materials.
In an upward region, the body 102 is connected, by means of adapted quick couplings, to a second body 105 which internally forms an upper delivery chamber 106 which is connected, in an upward region, to a duct 119 for connection to a transit chamber 117.
The transit chamber is connected to a suitable pressure gauge 107.
The upper delivery chamber 106 is further connected to a bypass 120.
This illustrated solution further solves any problems in terms of clogging of the material that might affect the single-cylinder pump because the pumped material, such as mortar and the like, does not have good flow characteristics.
With respect to the preceding solution, the only modification of this solution is the location of the bypass and of the pressure gauge; the function of said bypass, namely to discharge and recycle the material in the initial tank in case of clogging of the ducts applied to the pump, is unchanged.
The arrangement of the bypass in the present solution, therefore in practice at the duct 119, allows to discharge the transit chamber 117, thus obtaining a more linear path of the material and accordingly reducing the possibility of said material to clog.
The displacement of the pressure gauge 107 in the position assumed by the bypass in the preceding solution furthermore causes no change to the transit chamber 117.
This solution, too, therefore achieves the intended aim and objects.
The materials and the dimensions that constitute the individual components of the pump may of course also be the most pertinent according to specific requirements.
The disclosures in Italian Patent Application No. TV98A000152 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A single-cylinder pump, particularly for pumping mortar and similar materials from a hopper or tank, characterized in that it comprises a lower intake chamber provided with a first gravity valve which is connected to the delivery of a dual compensating action piston and a second gravity valve for feeding the mortar to an upper delivery chamber, said piston being provided with a transit chamber which is connected to an outlet and to a duct for connection to said upper delivery chamber.
The pump according to claim 1, characterized in that said body is internally provided with a lower intake chamber and is connected, in a downward region, by means of quick couplings, at a first duct which is connected to a hopper or to a tank for conveying mortar and similar materials.
The pump according to claim 1, characterized in that said body is connected in an upward region, by means of quick couplings, to a second body which internally forms an upper delivery chamber to which a pressure gauge is connected.
The pump according to claim 2, characterized in that said lower intake chamber has, at the connection to said first duct, a first gravity valve which is constituted by a ball adapted to temporarily close said first duct.
The pump according to claims 3 and 4, characterized in that said lower intake chamber is further connected, at the connection to said second body, to a second gravity valve which is constituted by a ball adapted to temporarily close the access between said lower intake chamber and said upper delivery chamber.
The pump according to claims 1 and 5, characterized in that said first and second gravity valves act alternately.
The pump according to claim 1, characterized in that said lower intake chamber is connected to a second duct which protrudes radially with respect to said first body, inside which a jacket is provided in which said dual compensating action piston slides which is constituted by a stem provided, at its tip, with a head with which a first annular gasket is associated.
The pump according to claim 7, characterized in that a seat is formed coaxially to said stem and to the rear of said first annular gasket, said seat being connected to said transit chamber which is in turn connected to said outlet and to said duct for connection to said upper delivery chamber.
The pump according to claim 1, characterized in that said transit chamber is connected to a bypass provided for safety and for recycling the material.
The pump according to claim 1, characterized in that said piston is connected, in a rear region, to said transit chamber which is connected to said outlet and to said duct for connection to said upper delivery chamber.
The pump according to one or more of the preceding claims, characterized in that a bush is arranged coaxially to said stem and is adapted to protect said stem, a second annular gasket cooperating with said bush, said gasket being adjacent to said outlet and to said bypass, preventing the escape of the material and compensating for any plays of said bush.
The pump according to one of the preceding claims, characterized in that said bypass is connected to said connection duct, which is in turn connected to said upper delivery chamber.
The pump according to claim 1, characterized in that a pressure gauge is connected to said transit chamber.