US 2753220 A
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Description (OCR text may contain errors)
July 3. 1956 5% INVENT'OR. E HEW/PER,
2 Sheets-Sheet l KEMPER NING OF TUNNELS M. F. APPARATUS FOR CONTROLLING THE APPLICATION OF CONCRETE IN THE LI Filed March 27, 1953 ATTO/QNE Y.
July 3. 1956 M. F. KEMPER APPARATUS FOR CONTROLLING THE APPLICATION OF CONCRETE IN THE LINING OF TUNNELS 2 Sheets-$heet 2 Filed March 27, 1955 INVENTOR.
40 MAXWELL 1 KEMPEE,
BY W1 flTTopA/Eyhired States Patent ice 2,753,226 Patented July 3, 1956 to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims. 2,753,220 Referring to the drawings:
APPARATUS FKDR CONTROLLING THE APPLI- (CATEUN 8F CUNCRETE IN THE LINING OF TUNNELS Maxwell F. Kemper, Los Angeles, Calif. Application March 27, 1953, Serial No. 344,959
4 Claims. (Cl. 302-52) This invention relates to the lining of tunnels with concrete by means of apparatus for conveying the concrete to the lining forms under the force of compressed air.
Apparatus for this purpose is disclosed in my U. S. Letters Patent Numbers 2,344,703, issued March 21, 1944; 2,534,270, issued December 19, 1950; 2,565,029, issued August 21, 1951, and 2,660,034, issued November 24, 1953, as well as in my pending application Serial No. 344,960, filed March 27, 1953.
As disclosed in the aforesaid patents and applications, mobile vessels or containers, known as placers, are run on rails into a tunnel to provide a supply of concrete ready for use. Each vessel includes a hopper from which the concrete gravitatcs into a pressure chamber having an outlet adapted to be connected with a conduit for conducting the concrete to the place where it is to be poured. Compressed air is introduced into the pressure chamber to force the concrete through the outlet thence through the delivery conduit.
It is an object of the present invention to provide an improved method of controlling the application of compressed air to the pressure chamber of a supply vessel or placer such as described, in a manner which makes possible the desired control of the velocity and rate of flow of a given batch of concrete throughout the entire potu'ing cycle of such a batch.
It is another object of this invention to provide a method such as described which makes it possible to discharge concrete from the delivery conduit in a manner that will cause voids or cavities in the arch of a tunnel bore to be packed with the concrete whereby a more effective lining of the tunnel will be provided.
it is another object of this invention to provide a method such as described which makes it possible to provide the desired constant low velocity flow of the concrete with a low consumption of compressed air while at the same time making available an ample reserve supply of air under high pressure subiect to ready application at the will of the operator.
It is another object of the invention to provide a method such as described which affords a greater nicety of control of the volume and pressure of the air supplied to the carriers than heretofore.
It is an additional object of this invention to provide apparatus for the purpose described which is of simple construction and subject to easy operation to provide the advantages stated herein.
it is a further object of this invention to provide in apparatus such as described a novel relief valve operable to stop the flow through the conduit at will.
This invention possesses many other advantages and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown one form in the drawing accompanying and forming part of the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not Fig. l is a diagrammatic view showing how this invention may be carried out for packing voids or cavities in the arch of a tunnel being lined with concrete;
Fig. 2 is a diagrammatic view, similar to Fig. 1, showing how this invention is carried out for elfecting a constant low velocity flow of concrete in the operation of lining a tunnel with concrete;
Fig. 3 is a vertical sectional view of apparatus embodying the present invention;
Fig. 4 is a horizontal sectional view of the apparatus shown in Fig. 3, with a portion of the apparatus in top plan to show the location of the relief valve; and
Fig. 5 is a fragmentary sectional view of the relief valve, as taken on the line 5-5 of Fig. 4.
The present invention may be carried out, as shown in Figs. 1 and 2, for lining a tunnel 6 with concrete by delivering the concrete from a concrete carrier '7 under air pressure through a conduit 8 into the lining form 9.
As set forth in my aforementioned U. S. Letters Patent Numbers 2,344,703 and 2,534,270, it is important to cause the concrete to fiow at a substantially constant low velocity and to be uniformly discharged without forming wads or slugs separated by air pockets. This low velocity flow assures a proper pouring without causing components of the mass to be segregated as would be likely due to impact of the concrete continuously discharged under high velocity against previously poured concrete.
The present invention constitutes an improvement of the methods practiced with the apparatus shown in Patent Numbers 2,344,703 and 2,534,270, in that it makes possible the desired constant low velocity flow with a lower constunption of compressed air while aifording a nicety of control of the flow of concrete at all times during the pouring of a given batch. Such a low velocity fio-w also provides in reserve a large volume of air at high pressure for instant use at will, to increase the velocity of flow for filling voids in the arch and places not reached under the normal low velocity flow of the concrete. Moreover, the present method makes it possible to prevent the un desirable increase in flow velocity which heretofore tool-c place as the last of the concrete from the carrier was being forced through the conduit. This method also provides for instantaneous stopping of flow through the conduit at will and a resumption of flow at the desired low velocity or desired high velocity as conditions warrant.
Accordingly, the present method provides for introducing compressed air into the carrier at a pressure be low the maximum pressure available from a supply line leading to the carrier, with provision for varying this below-maximum pressure to obtain the desired velocity and rate of flow, subject however to the application of greater pressure up to the maximum when it is desired to appreciably increase the velocity of the flow.
Fig. 1 illustrates how the concrete, when discharged from the conduit under a high velocity flow, will cause a void in the arch to be packed with concrete, whereas Fig. 2 shows how the concrete will flow into the form under a low velocity.
One way in which this method may be carried out is diagrammatically shown in Figs. 1 and 2 wherein a high pressure flow line 10 is represented as leading from a suitable source of compressed air (not shown) to the concrete carrier 7. A valve 11 is provided in this line between the carrier 7 and a pressure gauge 12 also connected in the line. A low pressure line 13 is connected in the main line 10 so as to bypass the valve 11. The flow through the line 13 is controlled by a pressure regulator 14 and a valve 15, the valve 15 being located between the regulator and the carrier 7. A pressure gauge 3 16 is mounted in the line 13 between the regulator 14 and the valve 15.
As it is desired to control the volume of the compressed air entering the carrier, so that a uniform flow of concrete therefrom will be induced without causing segregation of the components of the mass or the formation of air pockets, a valve 17 corresponding to the valve V shown in my U. S. Patents Numbers 2,344,703 and 2,534,270 is provided in the carrier 7 for this purpose.
When the main line valve 11 is closed and the valves and 17 are opened, the main line pressure passes through the pressure regulator 14 which, for example, is adjusted to pass a pressure below the maximum pressure in the main line 10, whereby a pressure is supplied to the carrier to effect a desired constant low velocity flow of the concrete through the conduit 8. Should a variation in the flow velocity be desired, the regulator 14 may be adjusted accordingly. The volume control valve 17 may also be adjusted, whereby a nicety of con trol of the air flow is provided to assure the desired fiow of concrete through the conduit line with a minimum consumption of compressed air. However, for an appreciable increase in flow velocity, the valve 15 is closed and the valves 11 and 17 are opened, whereby maximum pressure may be applied to the carrier with the volume of such air subject to variation by means of the valve 17.
Should it be desired to instantly stop the flow through the conduit, a relief valve 18 on the carrier 7 is opened, thereby releasing the pressure from the carrier and instantly stopping movement of the concrete. Flow will be resumed on closing this valve and the resumption of an adequate air pressure in the carrier.
As shown in Figs. 3 and 4, the carrier 7 is of substantially the same construction as shown in my U. S. Patents Numbers 2,344,703 and 2,534,270, except for the provision of the relief valve 18 and the means for introducing the compressed air at differential pressures as provided in accordance with the present invention.
Accordingly, the carrier 7 provides a sealed hopper 19 adapted to maintain air under pressure. This hopper is provided with a filling opening 20 and a discharge opening 21. A closure means 22 forming the subject matter of my U. S. Letters Patent 2,565,029, issued August 21, 1951, is provided for sealing the opening 20. Concrete will gravitate through the discharge opening 21 into a sectional conduit 23 which forms a pressure chamber 24 beneath the hopper.
Compressed air is introduced into the chamber 24 from the rear end of the conduit 23 through a port 25 located rearwardly of the opening 21. The volume control valve 17 is subject to actuation by a spring loaded operating means 26 normally holding the valve closed and which includes a lever 27 readily accessible on the carrier for operation to open and control the valve. An intake manifold 28 is connected with the chamber 24 and communicates therewith through the port 25, being supplied With air by a pipe 29 leading from an air intake chamber 30 at the forward end of the carrier 7.
A section 31 of the conduit 23 is extended through the air intake chamber 30 and terminates beyond the front Wall 32 of this chamber with its outer end adapted to be telescopically connected with a coupling unit 34. This coupling unit is carried at the intake end of the concrete delivery conduit 8 and serves to detachably couple the conduit section 31 with the concrete delivery conduit 8, as well as to connect the high and low pressure air lines 10 and 13 respectively with the air intake chamber 30. Such a coupling unit is shown in detail in my pending application, Serial No. 344,960, filed March 27, 1953.
The air connection of the lines It and 13 with the intake chamber 30 is effected by means of perforated conical nozzles 36 and 37 projecting from chambers .4 38 and 39 on the coupling unit 34 so as to be extended through openings 40 in the wall 32 of the chamber 30, as shown in Fig. 4. The nozzle 36 is connected with the high pressure line 10 through the chamber 38, while the nozzle 37 is connected with the low pressure line 13 through the chamber 39, as will be apparent with reference to Fig. 4. The high pressure control valve 11 and the low pressure control valve 15 are mounted on the lines 10 and 13 respectively at points adjacent the coupling unit 34 for a convenient operation of such valves, there being handles 42 and 43 for operating these valves.
A flap valve 44 is provided in the conduit 21 and is closed to prevent escape of the concrete when moving the carrier 7 to position for connection with conduit 8. Suitable means 46, including the lever 47, are provided for opening and closing the flap valve 44.
As shown in Figs. 4 and 5, the relief valve 18 is mounted on the top wall 48 of the carrier 7 to one side of the closure means 22, and includes a disk valve member 49 mounted within the carrier for opening and closing a vent opening 50 in the top wall. An annular seat 51 defines the margin of the opening 50 below the top wall 48 and is adapted to be engaged by an annular rubber or similar sealing ring '52 carried by the valve member 49. The valve member 49 is provided with a stem 53 pivoted, as at 54, to one end of an operating lever 55. This lever is fulcrumed as at 56, intermediate its ends, upon the top wall 48 and is of suflicient length to provide a leverage making it possible easily to open the valve member 48 against the air pressure holding the valve seated. The weight of that part of the 'lever between the fulcrum and the free end of the bore is such that the valve is urged against its seat. When the valve member 48 is opened, the activating air pressure in the carrier and conduit is relieved, thereby stopping the flow of concrete through the conduit.
It is important to note that the provision for introducing compressed air at selected differential pressures from a single supply line leading from a source of supply of compressed air, makes possible a more effective control of the rate of delivery of the concrete, in the best possible condition, into the form and a more efficient lining operation. One advantage resulting from this control of the application of compressed air to the carrier is the provision for the desired constant low velocity flow of the concrete to the form while making available an ample supply of compressed air at high pres sure subject to use at will, whereby the rate of flow may be increased for packing voids in the arch of the tunnel bore. The control afforded by the pressure regulator 14 and the valves 11 and 15 associated therewith together with the volume control valve 17 in the carrier, provide for a greater nicety of regulation of the flow of concrete than heretofore, with a consequent increase in the efficiency of the tunnel lining operation.
While not necessary in all instances of packing off voids or cracks in the arch of the tunnel bore, it has been found that a quick and thorough packing of such cracks and voids is obtained by leaving the discharge end of the conduit 8 submerged in previously poured fluent concrete atop the form, as shown in Fig. 1, when subjecting the concrete to a high velocity flow. Likewise, it is desirable, as shown in Fig. 2, to have the discharge end of the conduit submerged in this manner during the normal low velocity flow of the concrete, as it provides for a more even flow and distribution of the concrete within the form and prevents segregation of components of the mass and formation of air pockets.
1. Apparatus for controlling the velocity of how of concrete through a conduit to a lining form in a tunnel to be lined with concrete including: a vessel adapted to contain concrete; said vessel having an outlet adapted to be connected with said conduit; a how line for introducing compressed air into said vessel for efiecting flow of concrete through said outlet and conduit to said form; a valve for controlling the 110w through said line; a second flow line connected with said first mentioned line so as to bypass said valve; a pressure regulator in said second line; and a valve in said second line for controlling flow from said regulator to said vessel.
2. Apparatus for controlling the velocity of fiow of concrete through a conduit to a lining form in a tunnel to be lined with concrete including: a vessel adapted to contain concrete; said vessel having an outlet adapted to be connected with said conduit; a flow line for intro ducing compressed air into said vessel for elfecting flow of concrete through said outlet and conduit to said form; a valve for controlling the flow through said line; a second flow line connected with said first mentioned line so as to by-pass said valve; a pressure regulator in said second line; a valve in said second line for controlling flow from said regulator to said vessel; and a volume control valve for varying the volume of the air applied to said vessel under all pressure available through said first mentioned and second lines.
3. Apparatus for controlling the velocity of flow of concrete through a conduit to a lining form in a tunnel to be lined with concrete including: a vessel adapted to contain concrete; said vessel having an outlet adapted to be connected with said conduit; a flow line for introducing compressed air into said vessel for eifecting flow of concrete through said outlet and conduit to said form;
a valve for controlling the flow through said line; a second flow line connected with said first mentioned line so as to by-pass said valve; a pressure regulator in said second line; a valve in said second line for controlling flow from said regulator to said vessel; and a relief valve operable to release the air from said vessel to stop flow through said conduit.
4. Apparatus for controlling the velocity of flow of concrete through a conduit to a lining form in a tunnel to be lined with concrete including: a vessel adapted to contain concrete; said vessel having an. outlet adapted to be connected with said conduit; a flow line for introducing compressed air into said vessel for elfecting flow of concrete through said outlet and conduit to said form; a valve for controlling the flow through said line; a second flow line connected with said first mentioned line so as to by-pass said valve; a pressure regulator in said second line; a valve in said second line for controlling flow from said regulator to said vessel; a relief valve operable to release the air from said vessel to stop flow through said conduit; and a volume control valve operable adjacent said outlet for varying the volume of air applied to said vessel under all pressures available through said flow lines.
References Cited in the file of this patent UNITED STATES PATENTS 1,185,117 MacMichael May 30, 1916 1,275,912 Harding Aug. 13, 1918 1,589,011 Langworthy June 15, 1926 1,684,370 Schuster Sept. 11, 1928 2,093,970 Longenecker Sept. 21, 1937 2,344,703 Kemper Mar. 21, 1944 2,518,811 Nicholson Aug. 15, 1950 2,534,270 Kemper Dec. 19, 1950 2,565,029 Kemper Aug. 21, 1951 2,684,872 Berg July 27, 1954