US3477380A - Electric control circuit and hydraulic system for concrete pumping apparatus - Google Patents

Electric control circuit and hydraulic system for concrete pumping apparatus Download PDF

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Publication number
US3477380A
US3477380A US695464A US3477380DA US3477380A US 3477380 A US3477380 A US 3477380A US 695464 A US695464 A US 695464A US 3477380D A US3477380D A US 3477380DA US 3477380 A US3477380 A US 3477380A
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Prior art keywords
fluid
circuit
valve
pumping
concrete
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US695464A
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English (en)
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Frederic R Johanson
Meredith E Smith Jr
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Jaeger Machine Co
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Jaeger Machine Co
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00—Control of flow
    • G05D7/06—Control of flow characterised by the use of electric means
    • G05D7/0605—Control of flow characterised by the use of electric means specially adapted for solid materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L25/00—Drive, or adjustment during the operation, or distribution or expansion valves by non-mechanical means
    • F01L25/08—Drive, or adjustment during the operation, or distribution or expansion valves by non-mechanical means by electric or magnetic means
    • 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
    • F04B15/023—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 supply of fluid to the pump by gravity through a hopper, e.g. without intake valve
    • 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
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/06—Control using electricity
    • 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
    • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
    • F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
    • F04B9/10—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid
    • F04B9/109—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers
    • F04B9/117—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other
    • F04B9/1172—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other the movement of each pump piston in the two directions being obtained by a double-acting piston liquid motor
    • F04B9/1174—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers the pumping members not being mechanically connected to each other the movement of each pump piston in the two directions being obtained by a double-acting piston liquid motor with fluid-actuated inlet or outlet valve
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S417/00—Pumps
    • Y10S417/90—Slurry pumps, e.g. concrete

Definitions

  • a control system for concrete pumping apparatus and the system includes a hydraulic system which effects the several operations and an electrical control circuit which controls the hydraulic system in the performance of the several operations. Fluid control valves in the hydraulic system control the cyclic operation of each of several independently operable concrete pumping units.
  • the electrical control circuit which includes electromechanical interconnection with the several pumping units provides several modes of operation for a concrete pumping apparatus having two independently operable pumping units with the modes of operation including synchronous operation of both units, independent manual operation of either or both units, or any combination of automatic operation with respect to one pumping unit and manual operation with respect to the other pumping unit.
  • Solid state circuitry is employed in the electrical control circuit to provide an automatic control sequence for automatic synchronous operation as well as independent automatic operation of a particular pumping unit.
  • Manual switching elements are incorporated in the solid state circuitry which are selectively operable to bypass the automatic circuit components and permit manual operation of each or both of the pumping units at any particular point in an operational cycle and for any part of a cycle.
  • Pumping apparatus for handling of fluid concrete comprise in general a reciprocating piston and cylinder unit having valve means selectively positionable for placing the cylinder in communicating relationship with either a concrete supply means or a concrete discharge circuit.
  • Mechanical or fluid power means connected with the respective concrete pump piston and valve means is selectively operable to eifect a cyclic operation of the apparatus in forcefully impelling intermittent charges of fluid concrete through the discharge conduit.
  • a multiplicity of pumping units are provided with two units being the normal number.
  • the several discharge conduits are generally connected to a common discharge conduit thereby providing a combined output. Suitable control systems and mechanisms are incorporated and connected with the apparatus to effect the desired automatic operation in performing cyclic pumping of the fluid concrete from the supply means and through the discharge conduit.
  • the known prior art pumping apparatus generally incorporate either mechanical control systems or electromechanical system that utilize electromechanical relays. Such system have not been found fully reliable in applications such as concrete pumping apparatus which are subjected to severe vibration and other adverse environmental conditions. Also, the known prior art systems are not fully and quickly responsive to improper operating situations such as often occur through jamming of the 3 ,477,380 Patented Nov. 11, 1969 valve means. In such instances, it is necessary to reverse or otherwise provide means for removing the material causing the malfunction.
  • An improved control system includes a hydraulic actuating system and a novel electrical control circuit.
  • the hydraulic actuating system includes hydraulic valve elements which are responsive to the electrical control circuit in effecting the desired operation of the concrete pumping apparatus.
  • the electrical control circuit and hydraulic system also permits manual operation of a pumping unit to cause a flow of concrete in a reverse direction as well as independent operation of either the pumping piston or the concrete control valve element which facilitates removal of materials or movement of materials or obstructions that may cause jamming or stopping of a pumping unit.
  • the electrical control circuit includes solid state switching components and solid state logic or gate circuits to .perform the automatic operations of the apparatus in a novel circuit to thereby eliminate the necessity of electromechanical components such as the conventional relays.
  • the hydraulic system also provides lubricaton of the concrete pumping cylinders with the lubricating being automatically performed in conjunction with the operation of the pumping units. Lubrication advantageously occurs at only one point in the cyclic movement of the pumping piston and which point is immediately prior to the start of a pumping stroke.
  • the present apparatus also includes concrete agitating means in the supply hopper to prevent separation of the fluid concrete with this means being hydraulically operated.
  • the hydraulic system includes control valve means permitting selective control of the agitating means with primary electric control in the electrical control circuit.
  • FIGURE 1 is a diagrammatic illustration of a concrete pump apparatus embodying this invention which includes two independently operable pumping; units and which drawing schematically illustrates a portion of the hydraulic system.
  • FIGURE 1a is a schematic diagram of the fluid control circuit in the hydraulic system for the pumping apparatus with the conduit continuations relative to FIG- URE 1 indicated by the identifying numerals as applied to the respective conduits. i 1
  • FIGURE 2 is a schematic diagram of the electrical control circuit for the apparatus.
  • a concrete pump apparatus embodying the improved control system of this invention is diagrammatically illus-' trated in the several figures of the drawings.
  • the illustrated apparatus is exemplary of the type having two independently operable pumping units generally designated by the numerals 10R and 10L with thesubscripts R and L indicating the unit being located at the right and left or may not include means for self-propulsion.
  • Each pumping unit embodies the same construction and similar numerals are, therefore, applied to the identical components.
  • each pumping unit comprises an elongated concrete pumping cylinder 11 having a pumping piston 12 of a construction suitable for concrete pumping apparatus reciprocal within the cylinder and concrete control valve means 13.
  • the control valve means 13 includes a valve housing 14 in fluid communicating relationship with the pumping cylinder 11 and a valve element 15 movably supported within the housing.
  • the valve housing 14 is also provided with an inlet .orifice 16 and an outlet orifice 17 forming valve seats for the valve element 15 when positioned in association with the respective orifice.
  • a concrete supply hopper 18 Connected with the valve housing 14 in communicating relationship with the inlet orifice 16 is a concrete supply hopper 18.
  • This hopper projects upwardly from the valve housing to facilitate gravity flow of the fluid concrete mix into the pumping cylinder and is of adequate size to hold sufficient concrete for continuous operation of the apparatus and allowing for intermittent charging of the hopper from a suitable source, such as the well-known transit mixer. While each pumping unit 10 is shown as provided with its own independent supply hopper 13, it will be readily apparent that the supply hopper 18 for a combined unit may be of unitary construction thereby facilitating the charging operation.
  • a tapered discharge conduit 19 Connected with the valve housing 14 in communicating relationship with the outlet orifice 17 is a tapered discharge conduit 19 with both discharge conduits conveniently connected to a common discharge duct 20 having a discharge opening 21.
  • Each fluid motor includes a cylinder 25 secured in fixed relationship to a supporting structure and a piston 26 reciprocal within the cylinder.
  • An elongated piston rod 27 connected to the piston 26 also connects at a pinned joint 28 with the pumping piston 12.
  • the cylinder 25 is also preferably connected to the supporting structure by a pivoted or pinned joint 29 to permit the assembly to accommodate structural misalignments that may occur in manufacture or operation. Connection of a conduit at either end of the cylinder 25 to an appropriate source of pressurized fluid will cause displacement of the piston 26 in the desired direction and consequent movement of the pumping piston 12.
  • valve means 13 Operation of the valve means 13 is also controlled by a fluid motor MP3 or MP4 as respectively connected with either the right or left pumping unit 10.
  • Each fluid motor MP3 and MP4 also includes a fluid cylinder 31 and a piston 32 reciprocal within the cylinder 31 and having an elongated piston rod 33 connected thereto.
  • One end of the cylinder 31 is also connected by a pivoted joint 34 to the supporting structure to accommodate the arcuate movement involved in moving the concrete control valve element 15.
  • the free end of the piston rod 33 is connected to the valve element 15 by a lever arm 35 with the valve element and lever arm being rigidly interconnected by a valve shaft 36 rotatably supported by the housing 14.
  • the concrete supply hopper 18 is preferably provided with agitating means, indicated generally at 40, for maintaining proper consistency of the fluid concrete mixture and preventing separation of the aggregate particles as to relative sizes.
  • An agitating means 40 is illustrated diagrammatically in FIGURE la and is seen a comprise a revolving beater assembly 41 mounted for rotation of a shaft 42 extending horizontally through the hopper 18 and drivingly connected to a drive motor MP5.
  • the drive motor 43 in the present embodiment, is a fluid motor of a rotary type having an output shaft connected by a suitable belt or chain and sprocket drive wheels 44 to the shaft 42. Specific constructional details of the agitating means 40, particularly the beater assembly, are not illustrated as such apparatus is well known.
  • a fluid supply means for operation of the several fluid motors is a fluid supply means, indicated generally at 46 in FIGURE 1.
  • three independent fluid pumps PP1, PFZ and PF3 are utilized to supply the hydraulic fluid at the desired pressures.
  • These fluid pumps may be of any suitable type although the type utilized in the present embodiment are of the fixed displacement type.
  • Mechanical power for driving of the three pumps may be provided by any suitable means although in a portable of mobile type apparatus this motive power is supplied by either a single internal combustion engine 47 divingly connected to each of the three pumps by mechanical coupling apparatus (not shown) or a separate engine of appropriate power rating may be provided and connected to each of the several pumps.
  • the engine 47 may also be the same engine that provides propulsion power for the vehicle.
  • a hydraulic fluid reservoir 48 of adequate capacity for the apparatus is connected by a suction conduit 49 to the inlet port of each of the respective pumps PP1, PF2 and PF3.
  • the outlet ports of the respective pumps are connected into the hydraulic circuit by fluid supply conduits 50, 51 and 52.
  • Monitoring of the operation of the apparatus during the pumping operation is facilitated by the hydraulic fluid pressure gauges 53 and 54 which are connected to the outlet ports or supply conduits of the pumps PP1 and PP2.
  • a third fluid pressure gauge 55 is connected by a pilot line 56 into the hydraulic circuit, as will be apparent by reference to FIGURE 1a, to determine the pilot pressure provided for control of the apparatus by the fluid pump PP3.
  • Return fluid conduits from the various elements of the control system are connected to a fluid-return manifold 57 having an outlet port connected by a return conduit 58 to the reservoir 48.
  • a fluid filtering apparatus 59 is connected in this return line.
  • a fourth fluid pressure gauge 60 is provided to further facilitate monitoring of the operation of the apparatus with this gauge being connected by a conduit 61 to the return manifold 57 to detect back pressure that may build up in the system due to the filter condition and thereby indicate when the filter needs cleaning.
  • Four main fluid return conduits 62, 63, 64 and 65 connected with the hydraulic circuit connect to inlet poi-ts of the manifold 57 for return of hydraulic fluid to the reservoir.
  • Control of fluid flow to the several fluid motors of the apparatus is effected through a control valve assembly indicated generally at 66 in FIGURE 1a.
  • This control valve assembly may advantageously be of a manifold-type construction wherein the several valve sub-assemblies re quired for control of operation of the apparatus are of similar interfltting configurations having interconnectable fluid passageways formed in the body of the sub-assemblies with the interconnections being indicated by the rectangular or square blocks.
  • Two interconnecting fluid passageways which extend throughout the manifold assembly include a pilot pressure line 67 which is also connected to the external pilot line 56 and a pilot drain line 68.
  • the pilot drain line 68 is connected at one end to the main return conduit 62 through a relief valve sub-assembly 69 with the opposite end being blocked at 68a.
  • the pilot drain line 68 is also connected to return conduit 62 through relief valve sub-assemblies75, 76 and 77.
  • Other fluid flow controlling valve sub-assemblies incorporated in this manifold structure are indicated at 70, 71, 72, 73, and 74.
  • a relief valve subassembly 75 is provided for protection of valve sub-assembly 71 and associated circuit portions.
  • a single relief valve subassembly 76 is provided for protection of both valve sub-assemblies 72 and 73 and a fourth relief valve sub-assembly 77 is provided for protection of the valve sub-assembly 74 along with protection of respective portions of the hydraulic circuit.
  • Pressurized fluid supply conduits 50, 51, and 52 are connected to respective inlet ports of the respective relief valve sub-assemblies 69, 75 and 76 with fluid return conduit 62 connected to an outlet port of relief sub-assembly 69 and return conduits 63 and 64 connected to ports of respective relief valve subassemblies 75 and 76.
  • the fluid return conduit 65 is connected to an outlet port of the valve sub-assembly 74 and a heat exchanger 78 is preferably interconnected in conduit 65 in order that provision may be made for removing heat generated in the hydraulic fluid in operation of the apparatus.
  • This heat exchanger 78 may be of any well-known construction and include a vented tank 79 containing a quantity of suitable coolant and a heat exchanger coil 80 which is immersed in this coolant. Only a portion of the hydraulic fluid is routed from the valve assembly 66 but the heat removal capability is adequate for the apparatus.
  • All of the valve sub-assemblies 70-74 are of the same general construction and comprise a main valve V2, V4, V6, V8 and V and a pilot valve V1, V3, V5, V7, and V9 in each of the assemblies.
  • Each of the main valves and the pilot valves V1-V10 is a three-position, spring centered, spool-type valve with each main valve being operated by a hydraulic actuator and each pilot valve being actuated by an electric solenoid.
  • valve sub-assemblies 70 and 71 control the operation of the fluid motors MP1 and MP2 and are each supplied hydraulic fluid under pressure by the respective fluid pump PF2 and PPl.
  • Fluid supply conduit 50 is connected to the pressure port P of valve V2 and fluid return conduit 63 is connected to the tank port T of this valve.
  • Fluid supply conduit 51 connects fluid pump JFl with the pressure port P of valve V4 while fluid return conduit 64 connects. the tank port T of this valve with the fluid return manifold 57.
  • Ports A and B of valve V2 are connected to opposite ends of a cylinder 25 of fluid motor MP1 by conduits 86 and 87.
  • ports A and B of valve V4 are connected to opposite ends of cylinder 25 of fluid motor MP2 by fluid conduits 88 and 89.
  • the spools of valve V2 and V4 are of a type which will block fluid flow to or from ports A and B when the spool is in a center position.
  • the piston 26 of the fluid motors MP1 and MP2 will be maintained in the last attained position.
  • port P is connected to port T and fluid flow is unrestricted through the valve and thus reduces the power requirements for the system. Shifting of the valve spool in either direction in accordance with the fluid pressure applied to a respective hydraulic actuator will result in prcssurizing a fluid motor MP1 or MP2 to effect a desired displacement of the piston 26 of that motor.
  • the relief valve components 69a and a Connected to the fluid inlet passageway of the valve subassemblies 70 and 71 interconnecting the respective fluid supply conduits 50 and 51 with a respective pressure port P of the main control valve V2 or V4 are the relief valve components 69a and a. These relief valve components have an outlet port connected with the fluid return conduit 62 and are set to open at a predetermined pressure and permit fluid flow through the valve. In the present embodiment of the apparatus, these relief valve components 69a and 75a are set to open when system pressure reaches or exceeds 2,000 p.s.i. This specificpressure setting is deemed adequate for the present embodiment of the apparatus and could be adjusted as necessary for the apparatus to accommodate any specific situation or for other embodiments of the apparatus. This setting has been found adequate to prevent damage to the apparatus that may result when an obstruction is encountered in the pumping unit by either a pumping piston 12 or the valve element 15.
  • Each pilot valve V1 and V3 is of the electric solenoid actuated type having the solenoids VS1, VS2 and VS3, VS4 thereof connected in the electrical circuit as shown in FIGURE 2.
  • a pressure port P of each valve is connected to the pilot pressure line 67 and a tank port is connected to the pilot drain line 68 through passageways formed in the body of the valve sub-assembly.
  • the A and B ports of each pilot valve V1 or V3 are connected by the illustrated fluid passageways 81, 82, 83 and 84 formed in the respective valve subassemblies to respective hydraulic actuators of the main control valves V2 and V4.
  • each pilot valve V1 and V3 is of a type which, when in a center position, blocks the pressure port P thus preventing loss of pilot pressure and connects the tank port to both ports A and B. With ports A and B thus vented to the pilot drain line 68 at any time the spool is centered around the hy draulic actuators of the main valves V2 and V4 will be vented and thus permit centering of the respective valve spool.
  • Valve sub-assemblies 72 and 73 are constructed in a similar manner and include main valves V6 and V8 controlling the operations of respective fluid motors MP3 and MP4 which actuate the respective concrete control valve elements 15.
  • Fluid pump PP3 is connected by condu1t'52 to an inlet port of the relief valve sub-assembly 76 and thence through internal passageways to a pressure port of valve V6.
  • the tank port T of valve V6 is connected through other internal fluid passageways to the pressure port P of valve V8 while the tank portT of valve V8 is connected by internal passageways through relief valve sub-assembly 77 and valve sub-assembly 74 to the return conduit 65.
  • valve V6 The A and B ports of valve V6 are connected to opposite ends of the cylinder 31 of fluid motor MP3 by conduits 90 and. 91 while ports A and B of valve V8 are similarly connected to the cylinder 31 of fluid motor MP4 by conduits 92 and 93.
  • the spool of each valve V6 and V8 is also of a type which blocks ports A and B in a center position and connects the pressure port P to the tank port T.
  • Relief valve component 76a is also connected to the internal passageway connecting with fluid conduit 52 and has an outlet port connected with return conduit 62. This valve is also set for operation when system pressure reaches or exceeds 2,000 p.s.i. for the same operational reasons as the relief valve 69a and 75a.
  • check valve assembly 95 Interposed in the fluid passageways of valve assemblies 72 and 73 connecting tank port T of valve V6 to pressure port P of valve V8, is a check valve assembly 95.
  • This check valve is arranged to permit flow from valve V6 to V8 although flow is resisted by a sprirrg which biases the valve in a closed position and opens when system pressure exceeds a fluid pressure in the range of 65 to 100 p.s.i. Fluid flow is prevented in a reverse direction through the check valve.
  • This check valve 95 thus assures a system pressure of at least 65 to 100 p.s.i. in the fluid passageways upstream from the valve and a positive fluid pressure for the pilot line 67 for operation of the main control valves V2, V4, V6, V8, and V10.
  • Internal passageway 96 formed in the body of valve subassembly 72 connects the inlet passageway to port P of valve V6 to the pilot pressure line 67 with fluid pump PF3 thus providing the necessary pressurized fluid for the pilot line.
  • pilot valves V5 and V7 Operation of the main control valves V6 and V8 in controlling actuation of the fluid motor MP3 and MP4 is effected by the pilot valves V5 and V7.
  • Both pilot valves V5 and V7 are of a construction similar to V1 and V3 having a pressure port P blocked in the center position and a tank port T which is connected to ports A and B in this center position thus venting the hydraulic actuators of the main valves V6 and V8.
  • Internal passageways 110, 111, 112 and 113 connect the A and B ports of the pilot valves V5 and V7 to the respective hydraulic actuators of the main valves V6 and V8.
  • Each pilot valve is also provided with electric solenoids for actuation thereof with solenoids VS5 and VS6 in the case of valve V5 and solenoids VS7 and VS8 in the case of valve V7 being connected in the electrical circuit as shown in FIGURE 2.
  • Energization of either solenoid of the pilot valve V5 or V7 as the case may be will thus result in actuation of the main control valve V6 and V8 for operation of the associated fluid motor MP3 or MP4 in the desired direction for appropriate movement of the concrete control valve element 15.
  • each valve sub-assembly 72 and 73 is also utilized in supplying lubricating fluid to a respective pumping unit 10R or 10L.
  • This lubricating fluid for convenience of operation and simplification of the apparatus required is prefereably the same hydraulic fluid utilized for operation of the hydraulic systhem.
  • Each pumping piston 12, which is of a conventional construction with the details thereof being shown in other readily available publications, is formed with an annular wiping band 22 of a suitable fluid-absorbing composition, such as felt, and is located on the piston a distance rearwardly of the front face.
  • a lubrication inlet orifice 23 is formed in each cylinder 11 at a point which coincides with the wiping band 22 when the piston 12 is fully displaced to the rear of the cylinder.
  • a quantity of lubricating fluid is preferably injected into the cylinder at this point and will thus lubricate the cylinder walls during the discharge stroke.
  • Each conduit 98 and 99 is in communication with an internal passageway 100, 101 formed in the body of the respective valve sub-assembly and is connected to the B ports of the respective pilot valves V5 and V7
  • energization of the respective electric solenoid VSS or VS7 will result in fluid flow from the pilot pressure line 67 through the internal passageway 100, 111 and 101, 113 to the conduits 98 and 99 and subsequently to the lubrication orifices 23.
  • the hydraulic actuator of the main valves V6 and V8 are also connected to this internal passageway 100 or 101 and will be actuating the respective valve V6 or V8 concurrently with application of lubricating fluid.
  • a fluid flow restrictor valve 102 and 103 is also connected in each conduit 98 and 99 to assure a positive pressure for operation of the hydraulic actuator associated with the valves V6 and V8.
  • These restrictor valves are preferably of the fixed orifice type with the orifice size selected to obtain the desired lubricant flow to the cylinders.
  • a manually operated shut-off valve 104, 105 is also connected in each con duit 98 and 99 .
  • the check valves 106 and 107- are connected to permit free flow to the lubricating orifice 23 but prevent flow of any material in a return direction and into the hydraulic system thus preventing contamination.
  • These check valves and shut-off valves are preferably located in close physical proximity to the exterior surface of the pumping cylinder 11 for most effective operation.
  • the fifth valve sub-assembly 74 controls the operation of the fluid motor MP5 driving the beater assembly 41 of the agitating means 40.
  • This valve sub-assembly includes a main valve V10 having a spool which also blocks both A and B ports when in a centered position and connects the pressure and tank ports, P and T, together for free fluid flow. Ports P and T of this valve are connected by internal passageways formed in the body of the valve sub-assembly 74 to connect respectively with the tank port of valve V8 and the return conduits 65. Thus, with the spool in a centered position, valve V10 does not interfere with operation of either valve V6 or V8.
  • Relief valve component 77a is connected to the internal passageways interconnecting the tank port valve V8 with the pressure port P of valve V10 and has an outlet port connected to the return fluid conduit 62.
  • This relief valve is set at a relatively lower pressure than the other relief valves since it is the last valve in series fluid flow relationship to valve 76 and would not otherwise function.
  • Valve 77 may have a setting of approximately 800 p.s.i. A lower pressure setting is required for this component of the hydraulic circuit as the fluid motor MP5 is of a type requiring a relatively lower operating pressure.
  • Control of valve V10 is effected by a pilot valve V9 which is controlled by electric solenoids VS9 and VS10. These solenoids are also connected in the electrical circuit as shown in FIGURE 2.
  • a pressure port P of valve V9 is connected to the pilot line 67 with the tank port T being connected to the pilot drain line 68 and ports A and B are connected by internal passageway 114 and 115 to the hydraulic actuators of main valve V10. With the spool of thi valve in a center position, the pressure port P is blocked and both ports A and B are connected to the tank port T for venting of the hydraulic actuators of valve V10.
  • Selective energization of the desired solenoid VS9 or VS10 will result in rotation of the fluid motor MFS in the desired direction. Reversal in rotation direction may be obtained by energizing the opposite solenoid.
  • Control over operation of the several component of the hydraulic system and mechanical mechanism is effected by an electronic control circuit illustrated in detail in FIGURE 2.
  • This control circuit is selectively operable to provide either complete automatic operation of both pumping units, permit manual operation of either or both pumping units, or provide a combination manual-automatic control with these operations subsequently explained in further detail.
  • Solid state circuit elements are utilized throughout the control circuit to provide a compact and rugged circuit which is capable of performing the desired operations.
  • a further advantage of solid state circuitry is the relatively low power requirements for operation of the system which is of advantage since the power supply for this control circuit will also normally be provided by the internal combustion engine 47 driving the fluid pumps PFI, PF2 and PF3.
  • the voltage of a typical electrical power source for mobile concrete pumping apparatus is a nominal 12 volts which is adequate for operation of conventional solid state circuit elements.
  • a protective fuse F Included in the input power circuit connected across the terminals 215 and 216 is a protective fuse F and a main power disconnect switch S1.
  • a filtering capacitor C1 Following the switch S1 is a filtering capacitor C1 which removes any undesired ripple or other transient voltage surges that may occur in the power source.
  • the power source is preferably of the direct current type; however, alternating current power sources may be utilized with suitable rectifier circuits connected to the output thereof and preceding the input terminals 215, 216.
  • a first voltage regulating stage comprising a Zener diode CR9 having a breakdown voltage rating of 18 volts which prevents large power source transients from affecting the operation of the apparatus.
  • the cathode terminal of this diode forms a first output terminal 222 for electrical power in the control circuit.
  • a regulated, relatively lower voltage D.C. electrical power output for the circuit is provided by a second voltage regulator stage following CR9 and which comprises the series-connected resistor 217 and Zener diode CR10.
  • This Zener diode CR10 is selected to have a breakdown voltage rating of approximately 5 volts with the cathode terminal of the diode forming the second output terminal 223 of the regulated power supply for the 5 volts.
  • the anodes of each Zener diode CR9 and CR10 are connected to the input terminal 216 which is also seen to be connected with a common ground terminal. Other portions of circuit will also be noted to include a ground terminal connection.
  • the solenoids VS9 and VS10 which operate the pilot valve V9 are selectively connectable to the 12-volt power terminal 222 by a single pole, three-position, manually operated switch S2.
  • a movable contact of this switch is connected to terminal 222 and is positionable in either a center OFF position or in engagement with terminals connected with the respective solenoids VS9 and V810.
  • the opposite ends of these solenoids are connected to a common ground terminal and selective energization of the solenoids will result in operation of the agitator motor MP5 in the desired direction as previously described.
  • Each of the electrical solenoids VSl through VS8 for operation of the respective pilot vales V1, V3, V5 and V7 are connected in circuit with the 12-volt terminal 222 of the power circuit.
  • Controlling the energization of each electrical solenoid VSI through VS8 is a respective power switching transistor Q1 through Q8.
  • These transistors are of the NPN type connected in series with the respective solenoid with the collector terminal being connected to the solenoid and the emiter terminal being connected to a common ground connection.
  • These power switching transistors Q1 through Q8 are connected in a common emitter configuration with the collector-base junction being reverse biased by the 12 volts from the power circuit.
  • a forward, emitter-base junction biasing voltage to the respective power switching transistors Q1 through Q8 is eflected through either the automatic switching circuitry or by respective manual switches. Selection of the desired mode of operation, either automatic, manual or a combination, is accomplished through a selector switch S3 which may be conveniently located on the control console.
  • the remaining four positions provide either concurrent automatic synchronous operation of pumping units in the SYNC position, automatic operation of either the left-hand or right-hand pumping unit in the respectively indicated LI-I. SYNC or R.H. SYNC positions, or manual operation of both pumping units in the MAN position. In either the left or right SYNC position, the opposite pumping unit may be manually operated.
  • the function of either switch is primarily with respect to automatic operation of the apparatus as opening of either switch will prevent operation of the circuit and halt the pumping operation. Closing of either switch will energize the circuit and enable further operation, either automatic or manual.
  • the switch S4 is preferably located on a control box or console located on the pumping apparatus along with the fluid pressure gauges 53, 54, 55 and 60 while switch S9 is connected as indicated by a long, electrical cable. The purpose of the cable is to permit location of the switch S9 at a remote location, such as at the delivery end of the pumping conduit 20 and thus enable the operator to readily observe the concrete pumping operation at the discharge point and control the unit in accordance with the discharge.
  • the selector switch 53 would be positioned with the movable contact of each section SSA and ,SSB in engagement with the terminal identified as MAN.
  • Switch section 53A is thus seen to supply electrical power to manual switches S5 and S6 associated with the right pumping unit while switch section 83B is seen to supply electrical power to manual switches S7 and S8 associated with the left pumping unit.
  • Each manual switch S5 through S8 is a single pole, threeposition switch which is also located in a convenient location, such as the control console.
  • These manual switches S5 through S8 are preferably of the spring-centered type which must be held in either of the other two positions.
  • a current-limiting resistor 218 through 221 is series connected with the movable contact of each manual switch.
  • Each of the manual switches S5 through S8 is provided with the respectively indicated terminals A, B and C with terminal C being a center OFF position. Positioning of switch S5 to engage terminal A will result in application of a positive bias voltage to the base of the transistor Q1 which will forward bias the emitter-base junction and in transistor Q1 switching to an ON or conductive state. The collector voltage will become minimal while the current increases and the transistor will continue operation in the saturation region with both the collectorbase and emitter-base junctions now being forward biased.
  • Positioning of switch S5 in the B position will result in application of a forward bias voltage to the emitterbase junction of power switching transistor Q2 and effect switching of this transistor to an ON or conductive state in a manner similar to that previously described in connection with transistor Q1.
  • electrical solenoid VS2 With transistor Q2 conductive, electrical solenoid VS2 will be energized and shift the spool of pilot valve V1 to connect the pressure port P to port B.
  • the opposite hydraulic actuator of control valve V2 will be pressurized and shift the spool of that valve to connect the pressure port P to port B and apply pressure to the opposite end of fluid motor MP1. This will result in reverse movement of the piston 26 and piston rod 27 and provides the intake stroke for the right pumping unit 10R.
  • Manual control switch S6 operates in the same manner as switch S5; however. S6 controls power switching tran sistors Q6 and Q5. Both of these transistors are connected in circuit with the respective electrical solenoids VSS and VS6 which operate the pilot valve V5. Pilot valve V5 controls operation of control valve V6 which, in turn, controls the operation of fluid motor MP3 having a piston rod 33 mechanically connected with the concrete control valve 15 of the right pumping unit 10R. Placement of switch S6 in position A will result in switching transistor Q5 to a conductive state and thus energizing electrical solenoid VSS while positioning of switch S6 in position B will result in Q6 becoming conductve and energzing solenoid VS6.
  • the manual control switches S7 and S8 associated with that portion of the control circuit effecting operation of the left pumping unit 10L may be operated in a manner substantially as described with respect to the right pumping unit 10R. Selective positioning of switch S7 in either the A or B position will result in conduction through power switching transistors Q3 or Q4 and energization of the respective electrical solenoid VS3 and VS4. These two solenoids operate pilot valve V3 and will effect operation of fluid motor MP2 in a desired direction. Similarly, switch S8, when positioned in either A or B position, will cause transistor Q7 or Q8 to become conductive and energize the respective solenoid VtS7 or VSS. The latter solenoids operate pilot valve V7 and will effect operation of fluid motor MP4 in a desired direction to operate and place the control valve element 15 of the left pum ing unit 10L in the desired position with relation to the inlet and outlet orifices 16 and 17.
  • switches S5 and S8 have been described with maintenance of the switch in either of the desired positions A or B until completion of operation of a respective fluid motor, MP1, MP2, MP3, or MP4, in performing its intended function, it will be seen that the switches may be momentarily held in a desired position and result in operation of the respective fluid motor for only a portion of that cycle.
  • This jogging feature of the circuit is of a particular advantage in assisting the operator of the pumping apparatus to clear the cylinders 11 of obstructions through movement of either the control valve element 15 or the pumping piston 12 or both, if necessary.
  • a further advantage of the manual control switches S5, S6 or S7 and S8, is the independence of operation of either a concrete pumping fluid motor, MP1 or MP2, or a concrete control valve element actuating motor, MP3 or MP4.
  • the pumping piston 12 or the control valve element 15 may be operated in any desired manner which may not correspond with the usual pumping operation.
  • This feature is also of particular importance as it permits operation of the apparatus in obtaining a reverse concrete flow.
  • concrete may be withdrawn from the discharge conduit and returned to the hopper 18.
  • Automatic control of operation of either the right or left pumping unit or both pumping units in synchronized manner is effected through an electronic switching circuit utilizing solid state elements which is placed in an enabled condition upon placement of the selector switch S3 in either the SYNC position or the single, L.H. SYNC or R.H. SYNC positions.
  • This switching circuit is responsive to the position of pumping pistons 12 and the concrete control valve elements 15 with respect to each pumping unit.
  • This condition responsiveness is effected through limit switches which are mechanically interconnected with the components of each of the pumping units.
  • a limit switch LS1 is provided for responding to the position of the pumping piston 12 and a second limit switch LS3 is provided for responding to the position of the concrete control valve element 15.
  • the left pumping unit is provided with similar limit switches LS2 and LS4 which respond, respectively to the pumping piston 12 and the control valve element 15.
  • the trip blocks 226 and 227 will result in actuation of the arm 228 as the piston 12 approaches the end of either an intake or a discharge stroke.
  • block 227 will engage the arm 228 at the end of an intake stroke while the block 226 will engage the arm as the piston 12 reaches the end of a discharge stroke.
  • the blocks 226 and 227 are also positioned on the rod 225 to actuate tthe respective limit switch LS1 or LS2 just prior to reaching the end of a particular cycle in order to compensate for any delay in the electrical circuit or hydraulic system.
  • the actual position to obtain the desired lead time is determined by the speed at which the apparatus is normally designed to operate.
  • the limit switches LS3 and LS4 are operated by movement of the concrete control valve element to either an intake or a discharge position.
  • Each limit switch LS3 and LS4 is also provided with an actuating lever arm 229 and is relatively positioned to the piston rod 33 to engage respective trip blocks 230 or 231 that are secured to the piston rod.
  • trip block 230 will engage arm 229 and block 231 will engage arm 229 when the element 15 closes the inlet orifice 16.
  • the blocks 230 and 231 are also relatively positioned to each other and to thearm 229 to compensate for necessary lead time.
  • the limit switches LS1 through LS4 are schematically illustrated in FIGURE 2 with the two respective terminals designated as A and B. Each terminal designated either A or B of the four respective limit switches is connected to the 5-volt terminal 223 of the power circuit through the current limiting resistors 235 through 242 and the interconnecting electrical conductors. Each movable contact of the respective limit switches is seento be connected to a common ground terminal at 243 and the effect of the movable contact of each limit switch is to effectively ground that theminal when in engagement with that terminal. The effect of the operation of the limit switches is to either permit application of a signal voltage to the electronic switching circuitry or to remove that voltage by grounding the respective terminal.
  • Performing the switching functions for automatic operation of the pumping units are several logic or gating circuits and the description at this point will be limited to the circuitry associated with the right pumping unit 10R and which circuitry includes four logic or gating circuits 200, 201, 202 and 203 and an inverter gate 211.
  • Each of the gates 200 through 203 are of the NAND type which employ conventional well-known circuitry and utilize solid state circuit components. These NAND-gates are of a type requiring simultaneous application of two input signals to obtain an output signal and in this instance the application of a low or essentially zero input signal voltage at each input terminal will result in an output of a relatively high output voltage signal.
  • each gate 200 through 203 is connected to the base of a driver transistor QlA, QZA, Q5A and Q6A which have an emitter terminal that is connected to respective power switching transistor Q1, Q2, Q5 or Q6.
  • the collector of each driver transistor is connected through a resistor 244 through 247 to both the SYNC and R.H. SYNC terminals of section 83A of the selector switch S3.
  • These transistors are also operated in a switching function and the 12 volts will apply a reverse collector-base bias and application of either a zero or negative voltage to the emitter-base junction will maintain the driver transistors in a cut-off or nonconductive state.
  • Application of a forward bias to the emitter-base junction as by the application of the relatively high output voltage signal from the respective NAND-gate 200 through 203, will result in switching the respective driver transistor QlA, Q2A, QSA or Q6A to an ON or conductive state. Switching of the driver transistors QIA, Q2A, QSA or Q6A to a conductive or ON state will have the same effect on the operation of the apparatus as manual operation of the switches S5 and S6.
  • Diodes CR11, CR12, CR15 and CR16 are connected in the circuit as indicated to prevent interaction between circuit elements should the manual switches S5 and S6 be inadvertently actuated when the circuit is in an automatic operational mode and which could result in an out-of-sequence energization of the solenoids V51, V52, V55 and VS6.
  • This NOR gate 208 has two input terminals, one of which terminals is connected to a terminal of limit switch LS2 operated. by the opposite or left pumping unit 10L.
  • the other terminal of NOR-gate 208 is connected to a mid-point terminal of a voltage divider circuit comprising series connected resistors 252 and 253 with resistor 253 connected to a common ground terminal 256 and resistor 252 connected to both the R.H. SYNC and MAN position terminals 0 fsection 53B of the selector switch S3.
  • a voltage signal will thus be applied to the input terminals of NOR-gate 208 at any time limit switch LS2 is not in a position to connect terminal LS2A to ground terminal 243 in the case of simultaneous automatic operation of both pumping units with the selector switch S3 in SYNC position and a voltage signal will be applied at all times the selector switch S3 is in either R.H. SYNC or MAN position.
  • This NOR-gate 208 is of a design to provide a low or zero signal voltage when a high voltage signal is applied to either input terminal.
  • the NOR- gate 208 provides the second low input signal voltage necessary for the NAND-gate 200 to function in providing the high output signal to forward bias the emitter-base junction of driver transistor QlA. Accordingly, in this mode of operation, automatic sequential movement of the pumping piston 12 and concrete control valve element 15 is achieved through the cyclic operation of the limit switches LS1 and LS3.
  • NAND-gate 200 Both inputs to NAND-gate 200 are of a low value in this assumed condition resulting in a high output and forward biasing of the emitter-base junction of transistor QlA with consequent switching of both QlA and Q1 to a conductive or ON state and energization of solenoid VS1. Concurrently, the high output of NAND-gate 200 is applied to the input terminal of the inverter gate 211 resulting in a low output which is subsequently applied to one input terminal of NAND-gate 202.
  • a grounded capacitor C3 is also connected to gate 200 and 211 at their common junction for circuit stability.
  • a low voltage signal is also applied simultaneously to the other input terminal of NAND-gate 202 since limit switch LS3 is in a position connecting terminal LSSA to the ground terminal 243.
  • NAND-gate 202 also provides a high output signal which forward biases the emitter-base junction of driver transistor Q5A resulting in switching of both QSA and Q5 to a conductive or ON state with consequent energization of solenoid VS5.
  • solenoid V55 results in actuation of control valve subassembly 72 to pressurize fluid motor MP3 to cause retraction of piston rod 33 and rotate valve element 15 to a position blocking the inlet orifice 16 as illustrated in FIGURE 1 while energization of solenoid VS1 results in actuation of control valve sub-assembly 70 to pressurize fluid motor MP1 to extend piston rod 27 and move piston 12 in a discharge stroke. Concrete that had previously been drawn into the pumping cylinder 11 will thus be forced out of the cylinder through the outlet orifice 17 into the discharge conduit 19.
  • trip block 226 engages lever arm 228 thereby actuating limit switch LS1 and placing the movable contact in engagement with terminal LSlB. This removes one of the low level inputs to NAND-gate 200 resulting in removal of bias voltage and return of transistors Q1A and Q1 to a non-conductive or OFF state and de-energization of solenoid VSl.
  • both limit switches LS1 and LS3 connect their respective B terminals to the ground terminal 243 and thus provide two simultaneous low level inputs to NAND-gate 203.
  • NAND- gate 203 provides a high level output signal voltage which forward biases the emitter-base junction of driver transistor Q6A with consequent switching of both Q6A and Q6 to a conductive or ON state and energization of solenoid VS6.
  • Energization of solenoid VS6 actuates control valve sub-assembly 72 to pressurize fluid motor MP3 and cause extension of piston rod 33 with rotation of concrete control valve element 15 to an intake position in blocking relationship to the outlet orifice 17 leaving the inlet orifice to open.
  • trip block 230 Concurrently with rotation of valve element 15 to the intake position, trip block 230 will engage lever arm 229 and actuate limit switch LS3 to place the movable contact in engagement with terminal LS3A.
  • One of the low level inputs to NAND-gate 203 is thus removed with consequent de-energization of solenoid VS6.
  • Terminal LS1B was previously connected to the ground terminal at the conclusion of the discharge stroke and thus provided one of the low level inputs to NAND-gate 201.
  • Actuation of limit switch LS3 at conclusion of movement of valve 15 to the intake position in connecting terminal LS3A to the ground provided the other necessary low level input to NAND-gate 201 resulting in a high level output voltage signal which forward biases the emitter-base junction of transistor Q2A.
  • both transistors Q2A and Q2 switched to a conductive or ON state resulting in energization of solenoid VS2.
  • Energization of solenoid VS2 results in actuation of control valve sub-assembly 70 to pressurize fluid motor MP1 to cause retraction of piston rod 27 and movement of piston 12 away from the discharge-inlet end of the cylinder 11 in an intake stroke. Concrete will thus flow from the hopper 18 through the inlet orifice into the cylinder 11 behind the retreating piston 12.
  • trip block 227 engages lever arm 228 actuating limit switch LS1 to place the movable contact in engagement with terminal LSlA and thus removes one of the low level inputs to NAND-gate 201.
  • the output of NAND-gate 201 returns to a low level resulting in return of Q2A and Q2 to a non-conductive or OFF state. This also results in de-energization of solenoid VS2 and deactivation of control valve sub-assembly 70.
  • Both limit switches LS1 and LS3 now connect their respective A terminals to the ground terminal 243 and the circuit will be in proper configuration for initiation of a discharge stroke. This is the point at which this detailed description started in describing an operational cycle and a repeat cycle will be as previously described.
  • Operation of the left pumping unit 10L by itself may be effected by placing the selector switch S3 in a position where the movable contact of each section is in engagement with the respective terminal identified as L.H. SYNC.
  • Circuit components for operation of the left pumping unit are the same as for the right pumping unit previously described and includes the four power switching transistors Q3, Q4, Q7 and Q8 connected in circuit with the respective electric solenoids VS3, VS4, VS7 and VS8 of the pilot valves, the driving transistors Q3A, Q4A, Q7A and Q8A, the NAND-gates 204, 205, 206 and 207, the NOR-gate 209 and the inverter gate 213.
  • Arc eliminating diodes CR3, CR4, CR7 and CR8 are connected across respective electric solenoids, collector resistors 248, 249, 250 and 251 are connected in circuit with the collectors of the driver transistors and resistors 237, 238, 241, 242, 254 and 255 are connected in circuit with the switching gates.
  • a stabilizing capacitor C2 is also connected in this portion of the circuit as are blocking diodes CR13, CR14, CR17 and CR18 which are connected in circuit with the manual switches S7 and S8. Connections are also made to the power circuit at terminals 222 and 223 to obtain 12 and 5 volt DC. power for operation of the circuit components.
  • Both limit switches LS2 and LS4 are operated in the same manner as described in conjunction with limit switches LS1 and LS3 but with operations related to the movement of the piston 12 and concrete control valve element 15 of the left pumping unit. Since the circuit for operation of the left pumping unit is the same as the circuit for the right pumping unit which has been described in detail, a detailed description of an operational cycle is not believed necessary as the operation may be readily understood by reference to the previous detailed description.
  • Simultaneous automatic operation of both the right and left pumping unit is effected by placing the movable contacts of the selector switch S3 in a position engaging the terminals identified as SYNC.
  • Each side of the circuit will operate as previously described and as determined by actuation of the respective limit switches in accordance with movement of the pistons 12 and concrete control valve elements -15.
  • an input voltage signal of a high level is not continuously provided to each NOR-gate 208 or 209 by the manual circuit connections of the opposite left or right side of the circuit as the manual switches S5, S6, S7 and S8 are not connected to the 12-volt cathode terminal 222 of the power circuit as in the previously described situation where one pumping unit may also 'be manually operated.
  • a high level input signal for each NOR-gate 208 and 209 is obtained through interconnection with the limit switch LS2 or LS1, respectively, of the circuit associated with the opposite pumping unit.
  • a second input terminal of each gate is connected to the A terminal of the respective limit switch and will thus receive a high input voltage signal only when the movable contact of that limit switch is in engagement with the opposite or B terminal as would be the case when the pumping piston 12 had completed a discharge stroke.
  • This circuit interconnection maintains thet wo pumping units in an alternating, synchronous mode of operation as the pumping piston 12 of one pumping unit will not be able to begin a pumping or discharge stroke until the opposite pumping piston has completed a discharge stroke and has tripped its respective limit switch, LS1 or LS2, to the B position and will thus be capable of providing such a high level input signal.
  • both pumping units could be at the same position in their respective operational cycles at a particular instant, such as when the limit switches LS1 and LS2 are in the B position at the conclusion of a discharge stroke, and neither NOR-gate 208 or 209 would be providing the necessary low level signal to its respective NAND-gate 200 or 204. This situation would result in complete stopping of operation of both pumping units.
  • an inverter gate 210, 212 is connected in a feedback circuit arrangement with the respective NAND- gates 200, 204 to maintain the second low level input signal normally supplied by the NOR-gates.
  • each pumping unit may be selectively operated as to the pumping piston and the concrete control valve element to facilitate removal of materials that may be jamming the unit and preventing further operation or to effect a reverse pumping action in clearing the discharge conduit.
  • This manual operation may be of the advantageous intermittent jogging action.
  • a concrete pumping unit which includes a concrete pump cylinder and a concrete pumping piston reciprocable in said cylinder, said cylinder provided with a lubrication orifice at a point which coincides with the position of the concrete pumping piston at the completion of an intake stroke and is adapted to utilize the fluid for operation of said fluid circuit means for lubrication of the pump cylinder and pumping piston, valve means in communication with said pump cylinder for controlling concrete flow relative to said cylinder, said valve means including an inlet orifice and an outlet orifice, and a movable valve element selectively positionable to alternatively connect said pump cylinder to either of said orifices, first fluid motor means mechanically coupled with said pumping piston and selectively operable to effect reciprocable movement of said pump piston, second fluid motor means mechanically coupled with said valve element and selectively operable to effect positioning of said valve element, and fluid pump means for supplying pressurized fluid for operation of the concrete pumping apparatus:
  • a control system comprising (A) fluid circuit means interconnecting the fluid pump means with the fluid motor means and including (1) first fluid control valve means provided with electrical actuating means and connected in said fluid circuit means for controlling fluid flow to the first fluid motor means, and (2) second fluid control valve means provided with electrical actuating means and connected in said fluid circuit means for controlling fluid flow to the second fluid motor means, said second fluid control valve means having a fluid outlet port connected with said lubrication orifice through a fluid conduit and which is provided with pressurized fluid when said second fluid control valve means is actuated to operate the second fluid motor means in positioning the movable valve element in closing relationship to the inlet orifice of the valve means :and thereby cause fluid to flow into the pump cylinder through the lubrication orifice, and (B) electrical control circuit means connected in circuit with the electrical actuating means of said fluid control valve means for selectively controlling the operation thereof, said electrical circuit means including (1) input terminals connect-able with a source of electrical power, and (2) circuit switching means for connecting the electrical actuation means
  • said fluid circuit means includes a source of pilot fluid having a minimum fluid pressure
  • said second fluid control valve means includes a control valve connected in circuit with the second fluid motor for controlling operation thereof and provided with fluid actuation means, a pilot valve connected in circuit with said source of pilot fluid and said fluid actuation means for controlling operation of said control valve and provided with said electrical actuating means, said pilot valve having said fluid outlet port connected with said lubrication orifice through said fluid conduit with said fluid actuation means connected to said conduit, said fluid conduit having a fluid flow restrictor interposed therein to maintain pilot pressure upstream of said flow restrictor with said fluid actuation means of said control valve being connected to said fluid conduit upstream of said flow restrictor.
  • valve means in communication with said pump cylinder for controlling concrete flow relative to said cylinder, said valve means including an inlet orifice and an outlet orifice, and a movable valve element selectively positionable to alternatively connect said pump cylinder to either of said orifices,
  • first double-acting fluid motor means mechanically coupled with said pumping piston and selectively operable to effect reciprocable movement of said pump piston
  • second double-acting fluid motor means mechanically coupled with said valve element and selectively operable to effect positioning of said valve element, and fluid pump means for supplying pressurized fluid for operation of the concrete pumping apparatus:
  • a control system comprising (A) fluid circuit means interconnecting the fluid pump means with the fluid motor means and including (1) first fluid control valve means provided with electrical actuating me'ans and connected in said fluid circuit means for controlling fluid flow to the first fluid motor means to selectively effect movement thereof in either direction, said electrical actuating means having two independently energizable electric solenoids for selective operation of said fluid control valve means, and
  • second fluid control valve means provided with electrical actuating means and connected in said fluid circuit means for controlling fluid flow to the second fluid motor means to selectively efi'ect movement thereof in either direction, said electrical actuating means having two independently energizable electric solenoids for selective operation of said fluid control valve means
  • electrical control circuit means connected in circuit with the electrical actuating means of said fluid control valve means for selectively controlling the operation thereof, said electrical circuit means including (1) input terminals connectable with a source of electrical power, and (2) circuit switching means for connecting the electrical actuating means of said fluid control valve means to said input terminals for energization thereof, said circuit switching means including (a) a respective, normally open switching device connected in series with each of said electric solenoids with said switching devices closing in response to an electrical input signal for energization of a respective solenoid, (b) a first circuit portion responsive to the position of the concrete pumping piston and the movable valve element of the valve means and operative to provide a respective electrical input signal for each
  • circuit switching means includes blocking circuit means interconnected between said first and second circuit portions to prevent interaction therebetween resulting from concurrent operation of both of said circuit portions.
  • the fluid pump means includes a first fluid pump connected in said fluid circuit means for supplying fluid under pressure to only said first fluid control valve means and a second fluid pump connected in said fluid circuit means for supplying fluid under pressure to only said second fluid control valve means for independent operation of the first and second fluid motor means.
  • the concrete pumping apparatus of claim 4 having a concrete supply hopper for re'ceiving concrete in fluid form and provided with a discharge opening in communication with the inlet orifice of the valve means and which includes concrete agitating means mounted in the supply hopper and adapted to be rotatably driven for agitation of concrete within the supply hopper, fluid motor driving means connected in said fluid circuit means and mechanically connected with said agitating means and operable to rotate said agitating means in either direction, and agitator fluid control valve means connected in said fluid circuit for controlling fluid flow to said fluid motor driving means, said agitator fluid control valve means being connected in series fluid flow relationship to said second fluid control valve means.
  • the fluid pump means includes a first fluid pump connected in said fluid circuit means for supplying fluid under pressure to only said first fluid control valve means and a second fluid pump connected in said fluid circuit means for supplying fluid under pressure to only said series connected second fluid control valve means and said agitator fluid control valve means.
  • the first circuit portion of said circuit switching means includes (A) a first limit switch responsive to the position of the pumping piston and positionable in either of two positions and connected in circuit with the switching devices for the electric solenoids of said first fluid control valve means for selective energization of the electric solenoids in relation to the position of the pumping piston, and
  • the first circuit portion of said circuit switching means includes (A) a first limit switch having first and second terminals and a movable contact engaging a respective one of said terminals in response to displacement of the pumping piston, said contact engaging said first terminal when the pumping piston is displaced to a position remote to the end of the pump cylinder in communication with the valve means at the completion of an intake stroke and engaging said second terminal when the pumping piston is displaced to a position adjacent to the end of the pump cylinder in communication with the valve means at the completion of a discharge stroke,
  • each of said gating circuits requires; the application of a signal in addition to that provided by the respective limit switch, to form said electrical input signal, a first one of said gating circuits in circuit with said second fluid control valve means for causing the movable valve element to move into closing relationship to the inlet orifice connected to receive such additional signal from said signal forming circuit means, a second one of said gating circuits in circuit with said second fluid control valve means for causing the movable valve element to move into closing relationship to the outlet orifice connected to the second terminal of said first limit switch, and said gating circuit in circuit with said first fluid control valve means connected to said first terminal of said second limit switch thereby providing automatic cyclic operation of the pumping piston and the movable valve element in performing a pumping operation.
  • concrete pumping apparatus having a concrete pumping unit which includes first and second concrete pump cylinders and first and second concrete pumping pistons reciprocable in respective ones of said cylinders,
  • each said valve means including an inlet orifice, an outlet orifice, and a movable valve element selectively positionable to alternatively connect said pump cylinder to either of said orifices,
  • first fluid motor means mechanically coupled with said first pumping piston and selectively operable to effect reciprocable movement of said first pump piston
  • second fluid motor means mechanically coupled with said valve element of said first valve means and selectively operable to effect positioning of said valve element
  • third fluid motor means mechanically coupled with said second pumping piston and selectively operable to efiect reciprocable movement of said second pump piston
  • fourth fluid motor means mechanically coupled with said valve element of said second valve means and selectively operable to effect positioning of said valve element, and fluid pump means for supplying pressurized fluid for operation of the concrete pumping apparatus:
  • a control system comprising (A) fluid circuit means interconnecting the fluid pump means with the fluid motor means and including (l) first, second, third and fourth fluid control valve means provided with respective electrical actuating means and connected in said fluid circuit means for controlling fluid flow to the first, second, third and fourth fluid motor means, respectively, and
  • first circuit switching means for connecting respective electrical actuating means of said first and second fluid control valve means to said input terminals for energization thereof and second circuit switching means for connecting respective electrical actuating means of said third and fourth fluid control valve means to said input terminals for energization thereof
  • said first and second circuit switching means including (a) a first circuit portion responsive to the position of the respective first and second concrete pumping pistons and to the position of the movable valve elements of the respective first and second valve means and operative to energize the electrical actuating means of the respective ones of said fluid control valve means in predetermined sequence for effecting an automatic concrete pumping operation with either of the concrete pump cylinders and pumping pistons,
  • switch means interconnected in circuit with said first and second circuit portions to connect either of said circuit portions to said input terminals to alternatively enable operation of either circuit portion
  • said electrical control circuit means includes respective enabling circuit means interconnected between each of said first circuit portions of said first and second circuit switching means and the second circuit portion of the other of said first and second circuit switching means to enable the one of said first circuit portions when the second circuit portion of the other of said circuit switching means is enabled.
  • first and second circuit switching means each includes respective blocking circuit means interconnected between the first and second circuit portions thereof to prevent interaction therebetween when said first and second circuit portions are concurrently operated.
  • each of said blocking circuit means prevents energization of the electrical actuating means of the respective fluid control valve means through the manually operable switches of said second circuit portion when the respective first circuit portion is enabled.
  • each concrete pump cylinder is provided with a lubrication orifice at a point which coincides with the position of the concrete pumping piston at the completion of an intake stroke and is adapted to utilize the fluid for operation of said fluid circuit means for lubrication of the pump cylinder and pumping piston
  • said fluid circuit means including a fluid conduit connecting with each respective lubrication orifice
  • said second and fourth fluid control valve means each having a fluid outlet port connected with a respective fluid conduit and which is provided with pressurized fluid when the respective control valve means is actuated to operate the second and fourth fluid motor means in positioning a respective movable 24 valve element in closing relationship to the inlet orifice of the valve means and thereby cause fluid to flow into the pump cylinder through the lubrication orifice.
  • each concrete pump cylinder is provided With a lubrication orifice at a point which coincides with the position of the concrete pumping piston at the completion of an intake stroke and is adapted to utilize the fluid for operation of said fluid circuit means for lubrication of the pump cylinder and pumping piston
  • said fluid circuit means includes a source of pilot fluid having a minimum fluid pressure
  • said second and fourth fluid control valve means each includes a control valve connected in circuit with the second and fourth fluid motor means, respectively, for controlling operation thereof and provided with fluid actuation means, a pilot valve connected in circuit with said source of pilot fluid and said fluid actuation means for controlling operation of a respective control valve and provided with said electrical actuating means, each said pilot valve having a fluid outlet port connected with a fluid actuation means for actuating a respective control valve in operating the respective second or fourth fluid motor means in positioning a respective movable valve element in closing relationship to the inlet orifice of the valve means, and a fluid conduit connecting each pilot valve port
  • the fluid pump means includes a first fluid pump connected in said fluid circuit means for supplying fluid under pressure to only said first fluid control valve means, a second fluid pump connected in said fluid circuit for supplying fluid under pressure to only said third fluid control valve means, and a third fluid pump connected in said fluid circuit means for supplying fluid under pressure to said second and fourth fluid control valve means.
  • each fluid motor means is of the double acting type and wherein said first, second, third and fourth fluid control valve means are each selectively operable to effect movement of the respective fluid motor in either direction
  • the electrical actuating means of each fluid control valve means having two independently energizable electric solenoids for selective operation of the respective fluid control valve means
  • said electrical control circircuit means includes a normally open switching device connected in series with each electric solenoid of the electrical actuating means of each fluid control valve means, each switching device closing for energization of a respective solenoid in response to an electrical input signal, the first circuit portion of each of said circuit switching means being connected to the respective switching devices and operative to provide an electrical input signal to each switching device.
  • each of said first circuit portions of said first and second circuit switching means includes (A) a first limit responsive to the position of the respective pumping piston and positionable in either of two positions and connected in circuit with the switching devices for the electric solenoids of each said first and third fluid control valve means, respectively, for selective energization of the electric solenoids in relation to the position of the pumping piston,
  • each of said first circuit portions of said first and second circuit switching means includes (A) a first limit switch having first and second terminals and a movable contact engaging a respective one of said terminals in response to displacement of the respective pumping piston, said contact engagingrsaid first terminal when the pumping piston is displaced to a position remote to the end of the pump cylinder in communication with the valve means at the completion of an intake stroke and engaging said second terminal when the pumping piston is displacedto a position adjacent to the end of the pump cylinder in communication with the valve means at the completion of a discharge stroke,
  • each of said gating circuits requires the application of a signal in addition to that provided by the respective limit switch to form said electrical input signal, a first one of said gating circuits in circuit with each said second and fourth fluid control valve means for causing the respective movable valve element to move into closing relationship to the inlet orifice connected to receive such additional signal from the respective signal forming circuit means, a second one of said gating circuits in circuit with said second and fourth fluid control valve means for causing the respective movable valve element to move into closing relationship to the outlet orifice connected to the second terminal of the respective first limit switch, and said gating circuit in circuit with each said first fluid control valve means connected to said first terminal of said second limit switch thereby providing automatic cyclic operation of the respective pumping piston and the movable valve element in performing a pumping operation.
  • each of said signal forming circuit means comprises a gating circuit requiring the application of a signal in addition to that provided by the respective first limit switch,
  • a first gating circuit for supplying a signal having an output terminal connected to the gating circuit of one of said signal forming circuit means in one of said first circuit portions and having two input terminals, one of said input terminals connected to the first terminal of the first limit switch of the other of said first circuit portions and the other of said input terminals connected to the second circuit portion associated with said other first circuit portion to receive a signal therefrom when said second circuit portion is enabled, said first gating circuit supplying a signal when receiving a signal at either of said input terminals, and
  • a second gating circuit for supplying a signal having an output terminal connected to the gating circuit of one of said signal forming circuit means in the other of said first circuit portions and having two input terminals, one of said input terminals connected to the first terminal of the first limit switch of said one first circuit portion and the other of said input terminals connected to the second circuit portion associated with said one first circuit portion to receive a signal therefrom when said second circuit portion is enabled, said second gating circuit supplying a signal when receiving a signal at either of said input terminals.
  • the concrete pumping apparatus of claim 25 which includes feedback circuit means connected between an 0utput of said gating circuit of each of said signal forming circuit means and interconneted terminals of said gating circuit and a respective gating circuit of said synchronizing circuit means for maintaining the output thereof so long as the respective limit switch contact engages the respective first terminal.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Reciprocating Pumps (AREA)
  • On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
  • Details Of Reciprocating Pumps (AREA)
US695464A 1968-01-03 1968-01-03 Electric control circuit and hydraulic system for concrete pumping apparatus Expired - Lifetime US3477380A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US69546468A 1968-01-03 1968-01-03

Publications (1)

Publication Number Publication Date
US3477380A true US3477380A (en) 1969-11-11

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ID=24793079

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Application Number Title Priority Date Filing Date
US695464A Expired - Lifetime US3477380A (en) 1968-01-03 1968-01-03 Electric control circuit and hydraulic system for concrete pumping apparatus

Country Status (10)

Country Link
US (1) US3477380A (xx)
JP (1) JPS4820489B1 (xx)
BE (1) BE716230A (xx)
CH (1) CH498997A (xx)
DE (1) DE1703283A1 (xx)
ES (1) ES353644A1 (xx)
FR (1) FR1567714A (xx)
GB (1) GB1192657A (xx)
LU (1) LU56224A1 (xx)
NL (1) NL6808242A (xx)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580696A (en) * 1969-04-18 1971-05-25 Friedrich Schwing Concrete pump assembly
US3670787A (en) * 1968-01-03 1972-06-20 Gerhard Hansen Apparatus for filling a chamber
US3773438A (en) * 1971-04-29 1973-11-20 Kelsey Hayes Co Well stimulation apparatus and method
US3976401A (en) * 1975-01-02 1976-08-24 Mountain Donald C Pump for abrasive slurries and the like
US3981622A (en) * 1974-11-20 1976-09-21 Kelsey-Hayes Company Hydraulic intensifier control system
US4512188A (en) * 1982-08-25 1985-04-23 Getty Oil Company Flow rate control and metering means for shear-sensitive liquids
US4512187A (en) * 1981-11-19 1985-04-23 Getty Oil Company Flow rate controller
US5161954A (en) * 1990-02-08 1992-11-10 Thomas Willett & Co. Ltd. De-sludging systems
WO1993004832A1 (en) * 1990-03-05 1993-03-18 Partek Concrete Ltd. Method and apparatus for compacting concrete
WO1994019564A1 (en) * 1993-02-18 1994-09-01 Stewart, Marie, Teresa Pumps for viscous liquids or slurries
WO2015065198A1 (en) * 2013-10-29 2015-05-07 Thermtech Holdings As System for feeding and pumping of less pumpable material in a conduit line
CN110341048A (zh) * 2019-08-09 2019-10-18 上海城建物资有限公司 用于搅拌站生产的外掺料添加储料装置

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0167635B1 (en) * 1984-06-05 1989-09-27 COMPAGNIA ITALIANA FORME ACCIAIO S.p.A. Hydraulic circuit for the control of reciprocating pistons pump
EP1847710B1 (en) * 2006-04-20 2009-06-17 COMPAGNIA ITALIANA FORME ACCIAIO S.p.A. Improved open circuit oleodynamic system to actuate and control a concrete piston pump
JP2021162105A (ja) * 2020-03-31 2021-10-11 ナブテスコ株式会社 流量制御装置、流量制御方法及び流量制御プログラム

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198123A (en) * 1963-07-16 1965-08-03 Case Co J I Pump and valve assembly
US3279382A (en) * 1964-04-14 1966-10-18 Royal Industries Pump
US3279383A (en) * 1965-01-06 1966-10-18 Burnup And Sims Inc Hydraulic powered mobile concrete pump assembly
US3327634A (en) * 1965-08-30 1967-06-27 Whiteman Mfg Company Concrete pumping apparatus
US3380388A (en) * 1966-02-03 1968-04-30 Robert T Sherrod Automatic control system for concrete pump

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198123A (en) * 1963-07-16 1965-08-03 Case Co J I Pump and valve assembly
US3279382A (en) * 1964-04-14 1966-10-18 Royal Industries Pump
US3279383A (en) * 1965-01-06 1966-10-18 Burnup And Sims Inc Hydraulic powered mobile concrete pump assembly
US3327634A (en) * 1965-08-30 1967-06-27 Whiteman Mfg Company Concrete pumping apparatus
US3380388A (en) * 1966-02-03 1968-04-30 Robert T Sherrod Automatic control system for concrete pump

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670787A (en) * 1968-01-03 1972-06-20 Gerhard Hansen Apparatus for filling a chamber
US3580696A (en) * 1969-04-18 1971-05-25 Friedrich Schwing Concrete pump assembly
US3773438A (en) * 1971-04-29 1973-11-20 Kelsey Hayes Co Well stimulation apparatus and method
US3981622A (en) * 1974-11-20 1976-09-21 Kelsey-Hayes Company Hydraulic intensifier control system
US3976401A (en) * 1975-01-02 1976-08-24 Mountain Donald C Pump for abrasive slurries and the like
US4512187A (en) * 1981-11-19 1985-04-23 Getty Oil Company Flow rate controller
US4512188A (en) * 1982-08-25 1985-04-23 Getty Oil Company Flow rate control and metering means for shear-sensitive liquids
US5161954A (en) * 1990-02-08 1992-11-10 Thomas Willett & Co. Ltd. De-sludging systems
WO1993004832A1 (en) * 1990-03-05 1993-03-18 Partek Concrete Ltd. Method and apparatus for compacting concrete
WO1994019564A1 (en) * 1993-02-18 1994-09-01 Stewart, Marie, Teresa Pumps for viscous liquids or slurries
WO2015065198A1 (en) * 2013-10-29 2015-05-07 Thermtech Holdings As System for feeding and pumping of less pumpable material in a conduit line
US10648462B2 (en) 2013-10-29 2020-05-12 Thermtech Holdings As System for feeding and pumping of less pumpable material in a conduit line
CN110341048A (zh) * 2019-08-09 2019-10-18 上海城建物资有限公司 用于搅拌站生产的外掺料添加储料装置

Also Published As

Publication number Publication date
ES353644A1 (es) 1969-10-16
JPS4820489B1 (xx) 1973-06-21
NL6808242A (xx) 1969-07-07
LU56224A1 (xx) 1969-04-22
DE1703283A1 (de) 1972-03-09
FR1567714A (xx) 1969-05-16
CH498997A (fr) 1970-11-15
BE716230A (xx) 1968-12-09
GB1192657A (en) 1970-05-20

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