US 3168045 A
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Description (OCR text may contain errors)
Feb. 2, 1965 M. SEBASTIAN! 3,
PUMP FOR THICK MATERIALS Filed Sept. 13, '1961 2 Sheets-Sheet 1 l 1/ Fig.2 20-9 INVENTOR! MART/N SEBASTIAN/ A T TORNEY$ Feb. 2, 1965 Filed Sept. 15, 1961 M. SEBA STIANI PUMP FOR THICK MATERIALS 2 Sheets-Sheet 2 IN VENTOR:
MART/N SEBASTIAN/ EWgm Attorneys United States Patent Office 3,168,045 Fatented Feb. 2, 1965 3,168,045 PUMP FOR THICK MATERIALS Martin Sebastiani, Owingerstrasse 1, Uberlingen, Bodensee, Germany Filed Sept. 13, 1961, Ser. No. 137,785 2 Claims. (Cl. 103-44) The invention relates to a pump for thick materials, particularly for use with mortar-conveying and plastering apparatus.
The invention aims at constructing the pump so that it is possible to adjust its throughput from Zero to a maximum by means of a control valve located at the end of the pressure line.
In known pumps for thick material, which are used particularly for conveying mortar, it is not possible to mount a control valve at the end of the pressure line because, when there is one pressure line and the mortar conveying is stopped, the piston pump is overloaded and the pump is damaged either immediately or after a short time in service. Additional electric circuits were previously used to stop the drive motor of the piston pump simultaneously with the stopping of the mortar conveying. The disadvantage of this construction was that it entailed additional capital outlay, for example in electric leads and switches, and also that it could be operated with only one pressure line. This made the pumps uneconomical, for it would be quite feasible to build pumps large enough to enable three or four pressure lines to be operated simultaneously so that the operators could apply the mortar at different floor levels. However, if the drive motor were stopped, supply of mortar to all the other pressure lines would be stopped too, and it would be impossible to work efiiciently with such pumps.
The invention aims at avoiding these disadvantages and constructing the pump so that, even if several pressure lines are used, it is possible to cut off the pressure lines individually or together without thereby damaging the pump or the drive motor.
According to the invention a pump for thick materials, particularly for conveying mortar, and for use with a pressure line having a control valve located at the end thereof, comprises a working piston and a resiliently supported yielding piston arranged in the pump housing to provide an overload safety device.
When the resistance in the pressure lines increases, as may happen for instance if individual outlet valves are shut off, this yielding piston takes up additional capacity and thus prevents the drive motor or the piston pump from being overloaded and damaged.
In a preferred embodiment a diaphragm is mounted in the pump housing and on one side of the diaphragm there is provided a fluid which transfers the pressure from the working piston to the diaphragm and the yielding piston, which may have an adjustable counter pressure applied to it, while on the other side of the diaphragm there is located the inlet and outlet valves and a collecting chamber for the thick material.
In this embodiment, the diaphragm is moved hydraulically, and the overload safety device is mounted on that side of the diaphragm where it does not come into contact with the thick material.
Regarding the construction of the yielding piston, it is desirable to mount a spring in the yielding piston housing which spring applies an adjustable counter force and supports the yielding piston which may conveniently be hollow.
The adjustment of the yielding piston is necessary if the pumping pressure of the thick material pump needs to be adjusted. If, for instance, individual pressure lines convey mortar up three stories, then the yielding piston must respond only to a higher pressure than would be necessary if the conveying height were less. In a further construction with an adjustable counter force, the yielding piston is connected through a pressure line to a compression chamber and the compression chamber is connected through a valve to the atmosphere.
A pressure gauge can be connected to a compression chamber of this type, and the counter force exerted by the compression chamber on the deflectable piston corresponds to the pumping pressure. That is to say, the set pumping pressure can be read straight from the pressure gauge of the compression chamber.
The accompanying drawings illustrate, by way of example, embodiments of the invention and, together with the following description, introduce further preferred features of the invention. In the drawings:
FIG. 1 is a diagram of the pump for thick material with a mortar container and pressure lines,
FIG. 2 shows an embodiment in which a resiliently supported yield piston is mounted opposite the working piston,
FIG. 3 shows diagrammatically the construction of a diaphragm pump and the connection of the yielding piston to a compression chamber.
FIG. 1 shows a piston pump 1 moved by a drive motor 2. The drive motor may be an. electric motor or an internal combustion engine. The defiectable piston has an adjustable counter force applied to it, and a yielding chamber in the form of a cylinder 3 for the yielding piston is shown diagrammatically. The piston pump sucks thick material such as mortar out of the container 4 and conveys it in the direction of the arrow 5 into the pressure lines 6, 7, 8, 9. The pressure lines have control valves or stopcocks 1t), 11, 12, 13. With this embodiment, therefore, four operators can simultaneously distribute mortar at four different places on a wall.
FIG. 2 shows the pump housing 14 of the piston pump 1. A working piston 15 is mounted in the pump housing. The inlet valve 16 and outlet valve 17 open or close according to the pressure conditions prevailing in the working space 18. In the position shown the inlet valve 16 is closing, and, with the outlet valve 17 open, the thick material is delivered from the working space 18 in the direction of the arrow 22 into the outlet lines 19.
A yielding piston 20 is mounted opposite the working or pumping piston 15 and is supported in yielding piston cylinder 3 by means of a spring 21. The bias of the spring can be adjusted by any suitable means.
In FIG. 3 the same reference numerals indicate similar parts. Here the cylinder of housing 3 of the yielding piston 20 is connected by a compressed air line 23 to a compression chamber 24. The compression chamber has a valve 25 opening into the atmosphere, and a pressure gauge 26. The counter force on yielding piston 20 can be adjusted more accurately and simply by the compression chamber 24 than by the spring 21, and the counter force as set can be read from the pressure gauge 26. The counter force increases or decreases according to the amount of air in the compression chamber 24 and how much air is released by opening the valve 25. The air in the compression chamber can, of course, be replaced by other compressible substances. In this embodiment, the piston pump itself operates differently. A diaphragm 27 in the pump housing separates the chamber 18 from the working space defined by a chamber 28 filled with fluid and communicating directly with a cylinder in which the pumping piston 15 slides. The fluid then hydraulically transfers the pressure of the working and pumping piston 15 to the diaphragm 27 and the yield piston 20. As shown diagrammatically, the yielding piston 20 is mounted on a rod 29.
The invention can be applied to all cases where thick materials have to be tapped from several pressure lines and one or all the pressure lines are shut off as required during conveying of the thick materials.
What I claim is: v v
1. In a pump for thick material such as mortar, feeding a pressure line having at least one control valve at its end, the combination comprising: walls defining a sectional casing, a diaphragm separating the two sections and forming first and second chambers, said first chamber communicating with said pressure line, said diaphragm controlling the volume and pressure of said first chamber, said second chamber containing a pressure fluid; a pumping piston displaceably disposed in said second chamber; means for driving said piston; means defining a cylinder communicating with said second chamber; a yielding piston slidably disposed in said cylinder and being subjected to the pressure of said fluid at one side, said yielding piston enlarging and decreasing the effective volume of said second chamber depending upon the pressure therein and corresponding to the displacement of said yielding piston; a compression chamber having compressed air therein communicating with said cylinder on the other side of said yielding piston; and a conduit having a valve therein communicating with said compression chamber and open to the atmosphere so that the quantity of compressed air within said cornpression chamber can be varied, whereby the resilient counter-force acting against said other side of said yielding piston can be selectively adjusted.
2. In a pump for thick material such as claimed in claim 1, and further comprising a pressure gauge on said compression chamber for indicating the counter-force acting against said yielding piston.
References Cited in the file of this patent UNITED STATES PATENTS