GB1600467A - Rotary valve element - Google Patents

Description

PATENT SPECIFICATION

Application No 44661/79 ( 22) Filed 15 May 1978 Divided out of No 1600465 Convention Application No 835514 Filed 22 Sept 1977 in United States of America (US) Complete Specification published 14 Oct 1981

INT CL 3 F 16 K 1/22 () 1 600 467 ( 52) Index at acceptance F 2 V El B ( 72) Inventor JOHN HUNTER ( 54) A ROTARY VALVE ELEMENT ( 71) We, THOMSEN EQUIPMENT COMPANY, a corporation organized under the laws of the State of California, U S A, of 130 West Victoria, Gardena, California 90248, U S A, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-

This invention relates to rotary valve elements as used for example in valve assemblies forming part of apparatus for pumping a moist granular building material, for example plaster, concrete or mortar.

The valve element of the present invention is an improvement over that of the pump disclosed in Patent No, 1,068,863 which discloses a mobile pump that has been widely accepted.

It is an object of this invention to provide an improved valve element for use in valve assemblies as above mentioned.

According to this invention a rotary valve element comprises a one-piece blade-like element of rectangular form and having aligned trunnions extending outwardly therefrom, the blade-like element, being provided with a shallow "C" cross sectional concavity intermediate its ends on both sides thereof.

The invention will now be described by' way of example with reference to the drawings, in which:Fig I is a top plan with a portion shown, in section of a pump provided with a valve assembly including a valve element in accordance with the invention:

Fig 2 is a cross-section of a material chamber on plane 2-2 of Fig 1; Fig 3 is a cross-section of the material chamber on plane 3-3 of Fig 2; Figs 4 a and 4 b when aligned as indicated comprise a view, partly in section, through an entire pumping unit as seen from the line 4-4 of Fig I; Fig 5 is a rear elevation of control valves mounted on the pump units, as seen from the line 5-5 of Fig I; Fig 6 is a part section on plane 6-6 of Fig I; Fig 7 is a part section on plane 7-7 of Fig 4 b; and Fig 8 is an exploded view of the principal elements of the material housing seen in Fig 1.

The pump shown is particularly adapted for pumping moist granular building material, for example plaster, concrete or mortar The pump will be described in conjunction with the pumping of concrete.

The concrete pump may be mounted to the rear of the cab of a motor vehicle or truck In such an application the power unit for the motor vehicle is employed as the primary power source for the concrete pump and is therefore provided with a drive member coupled between the power unit for the motor vehicle and the concrete pump The power unit may be any other type of convenient unit when the pump is not mounted on a motor vehicle, such as an electric motor, for example.

The concrete pump generally comprises a pair of pumping units which are mounted on opposite sides of a material or concrete hopper The hopper, as is conventional, is utilized to receive and store the concrete to be pumped and supplied thereto.

The pumping units are connected with a common material or concrete chamber for the pumps and are arranged in communication therewith and with the hopper to allow the pumping units to be directly charged with the concrete to be pumped from the hopper and to be discharged from the pumping units in response to their pumping strokes through a common outlet for the concrete chamber A conduit is normally coupled to the outlet for conveying the concrete to the point of utilization of the concrete The concrete chamber is provided with a single control valve that is adapted to assume two positions and thereby subdivide the chamber into two portions for allowing the alternate charging and discharging of the ( 21) ( 62) ( 31) ( 32) ( 33) ( 44) ( 51) 0 s concrete to occur substantially simultaneously in each portion of the chamber.

The two positions of the single control valve are effective for substantially closing off one of the pumping units from the hopper while allowing the same pumping unit to discharge concrete through the outlet During this same interval, the other pumping unit is substantially closed off from the discharge outlet while being in communication with the hopper through the hopper port The charging of a pumping unit results due to the drawing in of the concrete from the hopper as a result of the suction created by the pumping unit to be charged being retracted from its completed pumping stroke The control valve is positioned by a fluid pressure motor in a position to allow the pumping unit to discharge concrete through the discharge outlet while the other pumping unit is drawing concrete from the hopper.

The pumping units are constructed in the form of fluid pressure pumping units and preferably are hydraulically operated piston-cylinder units whereby the units are charged during their return strokes The pumping units are controlled by a fluid power control circuit, preferably a hydraulic circuit, adapted to control the alternate charging and discharging of the concrete into and out of the pumping units while controlling the position of the control valve.

The above structure and operation is a brief summary of the concrete pump which is disclosed in the prior Patent No 1,068,863 and is mentioned herein as a basis for simplifying the explanation of the present invention.

Now specifically referring to the drawing, the general organization of the concrete pump 10 will be examined in detail The pump 10 generally comprises a pair of pumping units A and B arranged with a concrete chamber housing C having a single valve control element or flapper element F rotatably mounted within the cylindrical concrete chamber CC The concrete to be pumped is charged into the concrete chamber CC by means of the hopper H arranged in communication therewith The sequencing of the pumping units A and B is controlled by means of the hydraulic drive means HDM The hydraulic drive means HDM functions with a pair of mechanically actuated valves shown as the cycle valve CV and the sequence make-up valve S A storage tank ST for storing a lubricating or cooling medium, such as water, for the pumping units A and B is mounted between the units A and B as illustrated in Fig 1.

The pumping units A and B are arranged in a parallel relationship with the concrete chamber housing C The pumping units A and B each comprise reciprocating pistoncylinder assemblies controlled so that their forward or power strokes are utilized for pumping concrete through the housing C 70 and their return, or suction strokes, are utilized to charge concrete into the pumping units The pumping units A and B are both identically constructed and for the purposes of understanding the present invention only 75 one of the units need be examined in detail.

To this end, the pumping unit B is shown in detail in Figs 4 a and 4 b When the structure of Fig 4 a is aligned with the structure of Fig 4 b, the complete assembly of the 80 pumping unit B will be appreciated The pumping unit B comprises a material or concrete cylinder 12 B having a reciprocating piston unit 13 B mounted therein The piston unit 13 B comprises a 85 piston head 13 HB mounted at the end of the shaft 13 MB The concrete cylinder 12 B is closed at one end, the left-hand end as illustrated in Fig 4 B, and sealed by means of an "O" ring 12-OB for enclosing the 90 cylinder The shaft 13 SB is arranged to reciprocate through the closed end of cylinder 12 B The remaining end of the material or concrete cylinder 12 B is arranged in direct communication with the 95 concrete chamber housing C in order to receive the concrete to be pumped in the cylinder 12 B The piston head 13 HB is hydraulically controlled to reciprocate in a sliding relationship with the concrete 100 cylinder 12 B for drawing in the concrete to be pumped from the hopper H through the concrete chamber housing C and then pumping it through the concrete chamber CC through a discharge outlet DO When 105 the piston head 13 HB is being retracted during the suction stroke from the righthand position towards the left end, or closed end, of the cylinder 12 B, the concrete is drawn into the concrete cylinder 12 B in 110 front of the piston head 13 HB During the pumping strokes of the piston head 13 H it travels from its left-hand end position as illustrated in Fig 4 b to the right for pumping the concrete previously drawn into 115 the cylinder 12 B back through the concrete chamber CC and out through the discharge outlet.

From the above description, it should be appreciated that there is a closed volume 120 defined behind the piston head 13 HB when it is spaced from the closed end of the cylinder 12 B The closed volume is employed for receiving a lubricating and or cooling medium behind the piston head 125 13 HB as it reciprocates within the cylinder 12 B, as will be explained more fully hereinafter A push/pull rod assembly 14 B is coupled to the piston head 13 HB and is carried by the piston head The rod 130 1,600,467 1,600,467 assembly 14 B is mounted outside of the pumping unit proper and as illustrated in Figs 4 a and 4 b is mounted on the top of the pumping units A and B The specific coupling of the push/pull rod assemblies 14 A and 14 B to the piston heads 13 HA and 13 HB is best appreciated from examining Fig 4 b A push-pull rod 14 B is mounted in a rod guide tube 15 secured adjacent the lefthand end of the concrete cylinder 12 B as best appreciated from examining Fig 7 The tube 15 mounts an override spring 16 seated between a pair of spaced bushings 16 A, 16 B and surrounding the tube enclosed portion of the push/pull rod 1413; see Fig 4 a The remaining end of the push/pull rod 14 B is connected to a linkage assembly generally identified by the reference numeral 17 B for operating one of the control valves associated with the hydraulic drive means HDM The push/pull rod 14 B for the pumping unit B is specifically coupled to operate a cycle valve CV The push/pull rod 14 A for the pumping unit A is similarly coupled to a linkage 17 A for operating a sequencing make-up oil valve S The hydraulic drive means for the pumping units A and B is diagrammatically represented by a box HDM in Fig 1 and is generally of the same construction as that disclosed in the said prior Patent No 1,068,863 The hydraulic pressure provided by the drive means HDM is alternately applied to the two pumping units A and B so as to alternately power the corresponding piston heads 13 HA and 13 HB The hydraulic pressure is also alternately applied to the opposite ends of a hydraulic cylinder 20 mounted on the concrete chamber housing C for controlling the position of the single control element, or flapper element F, in accordance with the alternate pumping strokes of the pumping units A and B The hydraulic drive means HDM alternately pressurizes the pumping units A and B to cause one of the piston heads 13 HA or 13 HB to move forward on a pumping or concrete discharge stroke, while the closed loop arrangement of the hydraulic circuit will cause the other pumping unit or piston head to move in the return or suction stroke for charging the pumping unit with concrete from the hopper H The cycle of operation is controlled by the two push/pull rods 14 A and 14 B mounted with the pumping units A and B for operating the cycle valve CV and the sequence makeup oil valve S The cycle valve CV when operated is effective for changing the position of the flapper element F and the valving (not shown) for reversing the direction of the pumping units A and B. The push/pull rod 14 A for the pumping unit A actuates the valve S for automatically maintaining a constant volume of oil in the closed hydraulic circuit so as to assure a full stroke of the pistons 13 HA and 13 HB This general type of operation is disclosed in the said prior Patent.

The efficiency of the hydraulic circuit HDM is increased over prior art hydraulic circuits such as disclosed in the said prior Patent by coupling the hydraulic fluid to act against the head side of the hydraulic pistons: see Fig 4 b In the hydraulic circuit disclosed in the prior Patent the hydraulic pressure is developed to act on the rod side of the hydraulic piston, see Fig 3 of the prior Patent, for example The present circuit arrangement results in more efficient operation since there are less hydraulic line losses In addition, certain costs are eliminated by operating with a very low hydraulic pressure on the rod side of the piston, namely, the elimination of the requirement for a high pressure seal between the hydraulic cylinder and the concrete cylinder.

The water tank ST is mounted between the parallel arrangement of the pumping units A and B with the concrete cylinders 12 A and 12 81 The water tank ST is specifically illustrated in Figs I and 6 of the drawings The water tank ST is of a substantially L-shaped configuration and is arranged to be in direct communication with the left-hand end of the concrete cylinders 12 A and 1213, as best appreciated from examining Fig 1, The upstanding section of the L-shaped tank ST is provided with a cover 20 ' The cover 20 ' is secured to the tank by means of a chain 21 fastened between the cover and a fastener, as best appreciated from examining Fig 6 The tank includes means for draining the lubricating medium or water from the tank.

The means for draining the tank ST, as illustrated in Fig 6, is a manually operated stopper 22 in a drain aperture 22 D in the bottom wall of the upstanding portion of the tank ST The stopper 22 includes a handle 22 H of an L-shaped configuration that is accessible through the tank opening when the cover 20 ' is removed to readily allow the water in the tank to be drained through the aperture 22 D It is necessary to have clear water in the cylinders to prevent damage to the pistons 13 HA and 13 HB.

Features of the present invention are the constructions of the single control valve element or flapper element F The concrete housing C is internally constructed and defined to mate with the configuration of the flapper element F so as to minimize any tendency for flow restriction of the material passing through the chamber CC The construction of the concrete chamber CC and the flapper element F is best appreciated from examining Figs 2, 3 and 8.

The concrete housing C has a concrete chamber CC defined therein which houses 1,600,467 the flapper element F The flapper element F is constructed of one-piece of material with coaxial trunnions FT arranged on opposite sides of the rectangular plate-like element functioning as a flapper element.

The lower trunnion FT is rotatably mounted in the concrete housing C so as to mount the flapper or rectangular portion of the element F adjacent the bottom wall of the concrete chamber CC The upper trunnion FT is similarly mounted.

The configuration of the element F for the above-mentioned purposes is produced by the contouring of the lateral faces of the rectangular plate-like element functioning as the flapper element F Within a preselected area of the faces of the flapper element F a concavity is defined for mating with the cylindrical wall surfaces of the concrete chamber CC within the housing C.

As best appreciated from examining Fig 3, the concave portion of the flapper element is in the form of a shallow -C" configuration The contoured face of the flapper element F, when arranged with the adjacent surface of the cylindrical concrete chamber forms a conduit-like opening through the concrete housing for minimizing any tendency for restricting the material or concrete flow through the chamber CC Since the flapper element F is constructed of one piece of material, it is easier to machine and thereby the concentricities can be more easily controlled than when several pieces have to be machined and assembled.

It should also be noted that the flapper element F is provided with corrosive resistant sleeves secured by welding to the trunnions FT The sleeves are identified in Figs 2 and 3 as sleeves FS illustrated in their assembled relationship with the concrete chamber C The sleeves FS are preferably constructed of a chrome-plated material for anti-corrosion purposes In addition, the outer ends of the flapper element F are tapered and provided with a hard facing overlay for the complete lateral extent thereof for providing shearing edges for the flapper element The hard facing overlay is illustrated in Fig 2 and is identified as the respective portions FOV on the opposite ends of the flapper element F.

The flapper element F and the concrete chamber housing C are also provided with wear means for minimizing the wear on the flapper element F and the housing C per se.

The wear means comprises wear plates WP in the form of discs, one of which is mounted on the bottom surface of the cylindrical concrete chamber CC within the housing C A similar wear plate WP is mounted to the top side of the cylindrical chamber as shown in Figs 2 and 3 The concrete housing C is provided with a large cover CC' that is secured to the top thereof by fasteners 22 and is therefore readily removable The large opening provided upon the removal of the cover CC' permits the interior of the housing C to be readily machined for providing a smooth surface.

As a result, the accuracy with which the interior surfaces of the housing C can be defined is closely controlled This permits the wear plate WP to be easily mounted and assembled in the desired relationship on the bottom surface of the concrete chamber CC On prior art structures, machining was so difficult to accomplish that the wear plates were mounted on uneven cast surfaces and had to be shimmed to provide even surfaces The shimming was by means of a putty-like material which required a high degree of skill to accomplish The remaining wear plate WP is advantageously secured to the inside surface of the cover CC'; see Figs 2 & 3 A portion of the upper trunnion FT extends out of the cover CC' to allow it to be coupled to the cylinder 20 for rotating the flapper element F between its two positions The cylinder 20 is shown in Fig 1 mounted on the top surface of the concrete chamber and is readily accessible The concrete chamber CC is also provided with a plurality of wear pins W Pl secured in the housing C at the four locations that the edges of the flapper element F move into sliding engagement with; see Figs 1 and 8.

For the purposes of cleaning out the housing C, a pair of doors CD, one of which is illustrated in Fig 8, permit access to the interior of the housing C on opposite sides of the flapper element F The door CD is secured to the door opening CDO by means of a seal CDS This allows any residual concrete left in the housing C after completion of the pumping operation to be readily cleaned out from both sides of the flapper element F With the removal of the doors CD, a tool may be inserted into the openings CDO to scrape out the concrete residue.

Other features of the apparatus described above are claimed in our co-pending 115 applications Nos 19586/78 and 44660/79 (Serial Nos 1600465 and 1600466).

Claims (4)

WHAT WE CLAIM IS:-

1 A rotary valve element comprising a one-piece blade-like element of rectangular 120 form and having axially-aligned trunnions extending outwardly therefrom, the bladelike element being provided with a shallow "C" cross-sectional concavity intermediate its ends on both sides thereof 125

2 A rotary valve element according to Claim 1 wherein the tips of the rectangular element have a hard face overlay thereon 1,600,467 for the complete extent and shaped for providing shearing edges.

3 A rotary valve element according to Claim 1 or 2, wherein the trunnions have corrosion-resistant sleeves secured thereto and extending outwardly from the rectangular element.

4 A rotary valve element according to Claim 3 wherein the sleeves are chromiumplated.

WITHERS & ROGERS Chartered Patent Agents, 4, Dyer's Buildings, Holborn, London, ECIN 2 JT.

Agents for the Applicant.

Printed for Her Majesty's Stationery Office, by the Courier Press, Leamington Spa, 1981 Published by The Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.