Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
  • E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
  • E04G21/02—Conveying or working-up concrete or similar masses able to be heaped or cast
  • E04G21/04—Devices for both conveying and distributing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B15/00—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts
  • F04B15/02—Pumps adapted to handle specific fluids, e.g. by selection of specific materials for pumps or pump parts the fluids being viscous or non-homogeneous

Definitions

• the present invention relates to a self regulating apparatus for pumping concrete and thick pasty mass.
• the present application relates to a concrete pump which uses a simple static hydraulics WITHOUT USING A CONVENTIONAL HYDRAULIC PUMP and using a mechanical drive so as to drastically bring down the capital and operation cost apart from simplifying the pumping operation.
• a concrete pump is an apparatus which is used to pump concrete over a distance which includes horizontal & vertical displacement of concrete.
• the concrete pump has to be a positive displacement pump. Therefore its suction and delivery ports should be closed to each other to avoid loss of pressure and slurry.
• the earlier pumps used rotary valves, followed by simple ball valves, etc. The major issue with these valves was that they could not effectively seal the delivery side from the suction side because of the nature of the material under pumping and the size of the aggregates. Let us consider a single piston reciprocating pump.
• the basic requirement is that the piston should move forward and reverse, with sufficient force enough to displace & suck the column of concrete.
• the reversing piston should create low pressure and should suck the concrete from the open suction port.
• the delivery port should be open and suction port should be completely closed and the pumping cylinder should be filled with concrete.
• the said invention overcomes the following short-comings of the J.C.Kooyman Concrete pump : Multiplication of force & increase or decrease in the stroke length : Since the J.C.Kooyman Pump was driven mechanically where in the mechanical drive was directly given to the reciprocating piston, the reciprocating force was constant & could not be multiplied. However the present invention overcomes this short-coming. Operation of the gate valves at a variable distance from the prime mover without vibrations: The J.C.Kooyman Pump was provided with rotary gate valves which were mechanically operated by mechanical tie rods having adjustments, which had severe limitation in terms of smooth operation and distance & direction of opeartion of the gate valves from the prime mover.
• This invention overcomes this short-coming thereby allowing the gate valves to be placed any-where as they are operated through hydraulic hoses. Reversal of direction & stopping of the pumping action without using a clutch: This feature was not possible with the J.C.Kooyman pump unless the pump used a mechanical gearbox having a reverse gear & a mechanical clutch. The reversal of direction helps greatly in clearing the choking of the concrete pipeline which is a must feature of all the modern concrete pumps. This invention overcomes this short-coming as well by using a three position directional control valve.
• the J.C.Kooyman pump has been cited as the closest prior art because it provided a mechanical drive to the concrete pump. However all the presently available concrete pumps are driven by a conventional hydraulic pump.
• US patent no. 3682575 dated 08/08/72 is related to the arrangement of pumping cylinders and outlet shape & design of valve bodies and is not related to the drive system. Similarly the US patent no. 3877847 is also related to pumping cylinders & gate valve design.
• Another US patent no. 3647325 describes a concrete pump having an arrangement of a common hopper & pair of pumping cylinders irrespective of the source of fluid pressure.
• US patent no. US 2549851 dated 24/6/1946 describes a concrete pump which uses a conventional oil hydraulic pump.
• US patent no. 3712762 dated 23/1/1973 describes a very different method of pumping.
• US patent 3663129 describes a method to provide constant flow of concrete & arrangement of valves mounted in the hopper & is not related to the drive system.
• Another US patent 8439657 dated 14/5/2013 describes a concrete pump provided with a system which enables complete removal of residual concrete from the pump & is not related to the basic drive system of the pump.
• the US patent no. 5344290A describes a concrete pump which again uses a conventional hydraulic pump for providing fluid pressure.
• Another European patent no. EP 1847710B1 dated 15/7/2009 describes "Improved open circuit oleodynamic system to actuate &control a hydraulic piston pump "which also use a conventional hydraulic pump.
• Another European patent No. EP 0167635B1 dated 27/1989 also describes " Hydraulic circuit for the control of reciprocating piston pump” which relates to various types of control hydraulic circuits, however all of them use a conventional hydraulic pump.
• Another European patent no. EP 1906012A1 describes a pumping apparatus which also uses a conventional hydraulic reversing pump.
• An Important object of the present invention is to provide a uniquely designed self regulating self timed concrete pump which - a) works on simple basic fundamentals of hydraulics without using a costly conventional hydraulic pump which is widely used in currently available reciprocating concrete pumps as mentioned above. b) has its own in-built system to achieve the forward & reverse strokes without a separate hydraulic circuit. c) has its own in-built system to achieve controlled & adjustable operation of the delivery & suction ports. d) can increase or decrease the number of strokes simply by changing the rpm. e) has a very low initial cost when compared to the conventionally available concrete pumps having conventional hydraulic pumps. f) is easy to manufacture, service and operate.
• gj is aoie to nanaie tne normally usea reaay-mix concrete or siuage h) is mechanically driven but having a variable reciprocating force and variable stroke length depending upon the requirement. i) could be made in various capacities as per the requirements of the end user simply by using components which are available of the shelf. j) can be operated & maintained even by a lay man. k). is compact and can be made in stationary, trolley or trailer mounted or truck-mounted.
• Another object of the present addition is to provide a user friendiy apparatus for placement of concrete which is highly cost effective both in terms of capital & operational cost.
• a "Hydraulicaliy operated but mechanicaiiy driven & mechanicaiiy reversed impie Concrete Pump” which typically consists off the following components: a. A prime mover which can be an electric motor or a diesel engine, coupled with a suitable capacity reduction gearbox. b. A heavy duty steel fabricated off-centre drive from the said reduction gearbox, converts the rotary movement into longitudinal to and fro movement of a high pressure heavy duty double acting hydraulic cylinder, hereinafter called the main cylinder, which is fixed at one end and reciprocates to and fro due to the mechanical linkage. c. A minimum one, separate high pressure hydraulic cylinder, hereinafter called the drive cylinder is operated by the oil displaced from the main cylinder.
• the difference in cross section areas of pistons between the main cylinder and the drive cylinder result in multiplication or division of the force and increase or reduction in stroke length of the drive cylinder.
• the drive cylinder in turn operates a minimum one concrete pumping cylinder having a rubber Piston moving inside.
• a simple Directional control valve to operate or stop the strokes of the drive cylinder i.
• j. A suitable capacity water tank between the pumping cylinder and the receiving cylinder meant for wash out & lubrication of the rubber piston in each stroke.
• k. Set of flow control valves in the slide gate lines & cross safety relief valves and anti-cavitations valves on both high pressure & low pressure sides.
• m. A tapered pipe at the end of the delivery valve to accommodate the widely available pipeline dia.
• n. Mechanical stabilizers attached to the trolley, o.
• p. A cabled remote having simple functions on it, for the operation of the pump in case of solenoid operated directional control valve.
• q. An optional small air-compressor for cleaning the delivery line after pumping operation is over.
• a suitable capacity pressure accumulator to accommodate the differential volume of oil especially when the pump is operated in NEUTRAL. The capacity of the accumulator depends upon the head end & rod end differential volumes.
• Novelty of the Invention The apparatus is adopted with following novel features which are radically different & never used in any of the prior arts available.
• a. Elimination of conventional hydraulic Pump Almost all the modern concrete pumps available today use hydraulic pumps. However this invention completely eliminates the use of conventional hydraulic pump and makes the machine a very simple apparatus. The hydraulic oil is circulated in a closed loop & does not even require a hydraulic tank when the volume calculations are precisely made.
• b. Use of simple double acting hydraulic cylinder as a source of hydraulic power The invention uses a double acting hydraulic cylinder as a source of fluid power replacing a conventional hydraulic pump.
• a prime mover either an internal combustion engine or an electric motor(1) coupled to a suitable capacity high ratio reduction gearbox (2) with a off-center drive (3) to the Main Cylinder (4) which is connected to the Drive cylinder (5) with the help of hydraulic hoses A & B.
• the Driving cylinder operates the rubber piston (6) in the pumping cylinder (7).
• the pumping cylinder is provided with a slide gate valve system (8) which is operated by a hydraulic cylinders (10) and (11).
• the prime mover (1) starts & imparts rotary motion to the reduction gearbox (2) the off -centre drive (3) causes the main cylinder (4) piston to move to and fro.
• the main cylinder piston (4A) moves to the right, it causes displacement of the oil through the hose (A) to the receiving cylinder (5). Because of this displacement, the receiving cylinder piston is forced forward. Which is the forward working stroke. .
• the output rpm of the reduction gearbox represents the no. of forward strokes in a minute. It is possible to have a multi-geared reduction gearbox wherein the no. of strokes can be changed depending upon the mix and distance. Alternatively the number of working strokes can be simply changed by changing the rpm of the prime mover.
• the hose A Since the hose A is pressurized because of the displacement, it also provides pressure to operate the slide gate valves system (8).
• the displaced oil starts closing the slide gate valve on the suction side at the same time it starts opening the slide gate valve on the delivery side.
• the piston 5A of the said Drive cylinder is pushed forward which in turn pushes the rubber piston (6) forward in the pumping cylinder (7).
• the off -centre point (3) comes diagonally opposite, the forward stroke of the drive cylinder is completed and the reverse stroke starts when the off-center point (3) moves further.
• the difference in cross section areas of the pistons (4A) and (5A) determines multiplication or division of the force and also the increase & decrease in the stroke length of the drive cylinder.
• Individual flow control valves are used to fine tune the working of the slide gate valve, which are not shown in the diagram.
• the said hydraulic cylinders used are alternatively provided with piston having piston rings to have better sealing at high pressure.
• the above mechanism can be used alternatively with a variety of gate-valve designs like S tube or ball valves, etc to control the gate valve operations.
• Figure 1 illustrates the said "PRIOR ART NO. 1" in accordance with the present addition as described in this patent application;
• Figure 2 illustrates the said "PRIOR ART NO.2" in accordance with the present addition
• Figure 3 illustrates a very common hydraulic circuit currently used for concrete pumps called the "PRIOR ART NO. 3"
• Figure 4 & 5 illustrates the said "Working Diagram" in accordance with the present invention
• the said invention uses a normal double acting hydraulic cylinder which replaces a conventionally available hydraulic pump which reduces the cost of the equipment as various types of double acting cylinders are available off the shelf in various sizes at comparatively very low capital costs compared to the conventional hydraulic pump.
• the invention thus reduces the cost of capital investment for the end user by a huge margin.
• the invention enables the manufacturer to make the pumps in various sizes & capacities by using the same or different power input & cylinder combinations.
• the use of heavy duty high ratio reduction gearbox means a very high input torque which operates the main cylinder. Which in turn enables use of heavy duty hydraulic cylinders having huge oil displacements per minute.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Mechanical Engineering (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)

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Citations (14)

• 2014
  • 2014-02-11 IN IN3871MU2013 patent/IN2013MU03871A/en unknown
  • 2014-02-11 WO PCT/IN2014/000088 patent/WO2015087337A1/en not_active Ceased

Patent Citations (14)

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