US2386961A

US2386961A - Apparatus for molding tubular concrete bodies

Info

Publication number: US2386961A
Application number: US519804A
Authority: US
Inventors: Thomas A E Lake
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-01-26
Filing date: 1944-01-26
Publication date: 1945-10-16
Anticipated expiration: 1962-10-16

Description

s. LAKE 2,386,961 APPARATUS FOR MOLDING TUBULAR CONCRETE BODIES Oct. 16, 1945.

Filed Jan. 26, 1944 2 Sheets-Sheet 1 75 Vacuum- Pressure Oct. 16, 1945.

APPARATUS s. LAKE FOR MOLDING TUBULAR CONCRETE BODIES Filed Jan. 26,. 1944 2 Sheets-Sheet 2 on the line 2-2 of Fig. l,

Patented Oct. 16, 1945 UNITED STATES PATENT OFFICE APPARATUS FOR MOLDING TUBULAR CONCRETE BODIES Simon Lake, Milford, Conn; Thomas A. E. Lake administrator of said Simon Lake, deceased Application January 26, 1944, Serial No. 519,804 c 'ZClaims. (.o1.25-30) This invention relates to the molding of con-.

crete, and it has special reference to the moldin of tubular objects such as concrete pipes, particularly those which, in service, may be subjected to high internal pressures and to the action of fluids and liquids, such as gases and petroleum products which normally cannot e fectively be confined within walls of concrete due to the permeable nature of such walls.

One object of the inventionis to provide for the rapid and uniform molding of tubular concrete bodies (pipe sections) in such a manner as to subject the concrete mix, during molding, to pressure adequate to thoroughly compact it, at the same time exhausting. from it all air and excess moisture, thus ensuring a uniform texture free of the blow holes and voids which ordinarily result in the permeability of concrete bodies molded in accordance with the usual methods. v

Another objectis to provide for impregnation and/or coating of the molded bodies with-poresealing or other compounds or agents tending to increase the impermeability of their walls and/or adapting them for use in the handling of substances to which concrete is normally per-. meable, such as corrosive liquids and .gases.

In the accompanying drawings illustrating the invention, in the several figuresof which like parts are similarly designated,

flanged casting 6,

Fig. 1 is an axial, sectionalelevation, taken: on the line l-l of Fig. 2, showing .one form of apparatus in accordance withthe invention, N

Fig. 2 is a partial sectional elevation taken Fig. 3 is a view similar to Fig. 1, but showing a modified embodiment of apparatus in accordance with the invention, .and'

Fig. 4 is a partial sectiOnalelevation taken on the line 4-4 of Fig. 3.

As shown in Figs. 1 and 2, preferably made in a vertical flask A, formed in halves and bolted together, with a strip of packing, not shown, between their flanged joints. The flask is bolted to a platen B, set into a concrete floor slab C, which has a well D, formed below it to receive the reciprocative hollow core E, which, in operation of the apparatus, forms the inner wall surface of-the pipe. This reciprocating core is made of a tube, closed at its lower end as shown at I, and a hydraulic cylinder F is secured at.2 in the. reciprocating core, this cylinder having a fixedpis ton G shown near the top of the cylinder.- A piston rod 3' extends from the piston down through a st lf n vb x 4 at the lower end of the cylinder and out through another stuffing'box 5 at the lower head I of the reciprocating core, where it is secured in a secured to the floor 1 of the The piston rod 3 is provided with two passageways. One of these passageways 8 admits toor discharges from the space 9 above the piston G water or other pressure fluid through pipe l0, and the other passageway ll terminates at a port l2 below the piston andis connected with a pipe [3 which permits water or other pressure fluid to be admitted to or expelled from the space 14 underthe piston. The pipes Ill and I3 are shown as provided with two-way valves l5 and I6, respectively, wherebypressure fluid flow to andfrom the spaces 9 and Hi may be controlled.

When fluid-under space. 9 by opening valve 15 on pipe Ill and valve 56 is adjusted to permit the fluid of flow out from space l4v under the'piston, the pressure space 9 will cause thereeiprocating coreE to.

topofcore E and. extension core E is secured to the cone l'l by .a spider. l8 carried by the cone a short distance above the upper end of core E, thus leaving an annular space through which concrete may flow from the interior of the core extension E into the space between this extension and the walls of flask A, A heavy piston l9 having a cup leather 20 or. other packing is provided to bear upon a batch of concrete mix H dumped into theinterior of the core extension E and form an air tight seal when a vacuum is produced below the cup leather, and the reciprocating core extension E passes up through a stufling box 2| formedon the bolted cover 22 which closes theupper end of the mold s ace between the core and the inner walls of the flask A in which space the concrete forming the pipe is compressed with great force, all as will be explained later. A pipe 23 leads to a vacuum tank, not shown, and a ring of porous material 214, which is permeable to air and steam but acts as a dam for the concrete, is placed in the top of the mold space.

ressure is. admitted into- Steam may be admitted to the space 25 beit is necessary to fill all the pores near the inner tween the core E and cylinder F by way of pipe surface of the pipe wall with a sealing compound, 26 and flexible hose 21, for a purpose hereinafter which may be composed of any suitable plastic to appearing. suit the special purpose for which the pipe is to It is well known that concrete, as usually cast, be used. It has been found that an asphaltum is quite porous. This porosity may be reduced by compound is very satisfactory where the pipe is tamping or by vibration, which causes the air to be used as a water main. In accordance with bubbles liquid, and lighter cement particles to the invention this compound may. be. employed rise to ,the top of the mass in the form of in the follow ng mannerzjThe asphaltum is mixed laitance, which should be removed to get a strong, with a small amount of dead oil and a quantity uniform, concrete product, i oft powdered pumice or slaked lime, to make a It is also of importance in obtaining such a compound which will melt at about 175 F. The product have the casting of the same continuous; ogre E 'E" and the inner surface of the mold A, from start to finish, for, if any stoppageof theare-painted with a layer of this compound which flow of the plastic concreteainto the moldoccurs lfi quiqkly hardens into an enamel-like coating and a film of laitance will rise tothe topl of the-layer, :hblds litslplace on the core and mold until the thus forming a thin stratum of eak c ncrete pipe is cast. When the core is raised to its top Which might act as a parting place.' position, with the steam turned on, a rapid de- In the production of castings according to the hydration o e o c Occurs. but as long as invention as will now be d scrib d a m h there is some moisture in the concrete mass the sounderair and gas tight pipe can -be manu-- ph t cc'ompound will not melt. However, as factured of concrete than has heretofore been S0011 asrthe Concrete is y, t am w l ap d obtained, and with'or Without metal reinforcing raise theytemperatul'e sufficiently 13118 inthe WanS*theI eOf, a:$ de i d, compound and-it willbe absorbed into the inner {The various parts of the apparatus having been 5 a d u e sur aces cf the casting and leave anassembled over the well er: pit, as shown, with nular Spaces b e c i and the ,Walls metal reinforcement in place in the mold space, the Core E vlizdditional c m ou d if desired a batch H of properly mixed concrete, may 110W be forced intdthsespaces at high sufiicient to make the walls tithe ipe, is dumped perature until h a omp etel filled under into the interior of the core extension E and the m any P 655111 W h l be dQSPfi he am piston I9 set in place on top-of the batch. The is now turned o an as $0 sthe o o d valve on pipe 23 isnow opened to the vacuum a q d h y nd heic r s d tank, which drawsa partial vacuum in the space its o m Size} (1116 min th r is hi between-the core E" and fias k'fA :and throughout r %l" "an enam i u fifl V r fI r h r sis the batch of concrete inthe-core; Atthe same i e iaisa @nquit l' heins o 0f time a pressurefluid,preferably water,.jis admitl Q I P i t i SQ F 'i mS an f t y'fi ted into thespace a and the reciprocatingpore insulation; ndrita e n el c r s orr s beginsitsjupward travel: Atmospheric pressure, from st met l n er bme t i such due to the" vacuum now formed beneathpiston |9 is embodied in "the" pipe as castfIf the pipe is to forces the concrete downward, andxthrough the 49 9 used r conveying, gas, Volatileioils, acidu" medium- 0f the'cone H it passes annularly cut-. 1011s qu d ,'d fiercnt kinds of; known tand availwardly into the mold space between the core b P t k fi h P013 and E glll'gandthe Wallsoftheflask A; An'electric ex m j inn n ac h ne-- o vibrator; not" shown; attached to the flask A at T insja paratus i l st t d in. Figs. -3' e fa prepriete point; vibrates the plastic mass embodies i eda ted to the inthe'mold'space' and permits anyair bubbles or casting 9 h n ty .of hell and gases that i ht ha b trapped in the batch spigot'drain pipe,- and also @amodified means for ofconcrete to'rise and beidelivered through pipe molffimpidly forcing the 60110119136 into the mold 2 3into'the'vacuumttanlzf 4' space'between the continuous core E and flash Therisingspeedofi'the reciprocating core is 50 In this m d form the core is-provided' so regulated as to permit the'iconcreteto flow into with a r t l rfl;carrying a series of the im'qld' paceatany desired rate; and it should involute Shaped b -This b 1 eno gh t p t fo a bubbles to tributor is preferably made of wearresistant be drawn .ofi 'soas to filcrirl a -dense wall. This chilled Steel or iron as the ,involute shaped den ity Will bestill further increased as the lower blades act as cams to pushlthe abrasive concrete Dart'E or theeererisee tme to the fact that it. is radiellyrbutwardly u h Openings so formed I slightly lar-eer in diameter [than the extension E circumfiirehtially of P a E21 of the core and acts to compress" the already cast Therqlstnblfltor "1 1S earned by a head W section of the pipewall radiallyoutwardly. ls'pmvlded Wlfih ring me 32 on the Inner As 'the 'ere startsonf its upward stroke steam O r ced l depending flange and With-these maybe 'ad itt' 'd'i tg the-space through com teeth a pinion 34 meshes, as shown. The pinion,

dfit. Lat/1Tb e-heat 6f the steam transmittd 34 is fixed on one end of ashortshaft 35 having. through'thejwalllof the core E to the concrete in 2 1 1 SDacecausesgthe water in the concrete 5 2 -3 5 mi -fi i Weldeg to 232 5 3 1??? as itis molded to evaporate and theimoisture thus ng pen quare Gr p e is a abearing in'the fixed septum 36, and the othere rttttrtairzzetare earths tank wrap-idly asformed' bevel gears 4l. 42 .throughthe drive shaft 43,

whfilll h flo fi 93161165 h D bf its gtrrok the whioh may be driven by any appropriate type of heat pf thesteam causes the core E to expand, mitmnsmiss'ion' V 7, Still urther compressing and increasing the -thtth 3i revolves freely on a bearin fl n de, lS1,ty-.'0,f the molded, concrete. The steam heathyrdtb'th d fjh hydraulicebylinder F1,

ingshould be continued. riuntil'all' evaporation which reciprocatesupon the pi st0n ..G., in the ceases; .1 :(To .1 I Ml: same mannerfl'as alreadydescribed in relation to To make an absolutely li'quid and gas tight pipe "Fig '1, to ra shn d low t '8 E2;

This modified apparatus is operated as follows: With the core E in its lowered position, as shown, a batch of ready mixed concrete, sumcient in quantity to make the pipe, is dumped into the interior of the core on top of the distributor 28. The vacuum operated piston is is now set in position upon the batch and a partial vacuum created through pipe 23 within the mold space. This starts a pull on the plastic concrete of the batch to draw it into the mold space and at the same time starts to pull on the piston I9 to exert pressure on top of the batch of concrete, thus forcing the concrete radially through the series of ports 30. Vibrators now being applied to the walls of the flask, the concrete settles in the mold space and the core is started to move upward as previously described in relation to Fig. l. The downward pressure on piston 19 combined with the upward movement of the core is sufiicient to fill the mold space provided the concrete is fairly wet and free flowing, but if the concrete mixture is what is termed a dry mix, with little water content, it may require greater power to force the concrete through the ports 30 and around the metal reinforcing means, if such are used. This is accomplished by rotation of the distributor 28, the involute vanes 29 of which will force the concrete through the ports and pack it tightly in the mold space.

If steam is now admitted through pipe 21 into the steam space 25' in the core, the moisture in the cast concrete will quickly be evaporated and drawn off into the vacuum tank, so that, as previously described, an inner lining of a more impervious compound may be forced in to thoroughly fill all pores of the concrete pipe nearest the heated core walls. This operation is provided for in the modified form of apparatus by means of a pipe M through which grout or other desired compound may be forced up into the annular perforated pipe 45 and from there outwardly through numerous small mating orifices 46 in the core wall.

Various changes and modifications are considered to be within the principle of the invention and the scope of the following claims.

What I claim is:

1. Apparatus for molding tubular concrete bodies, including a flask, a tubular core of a length substantially twice that of the flask and reciprocative axially of said flask and serving therewith to provide a tubular mold space, the interior of substantially one-half the length of said tubular core serving as a receptacle for receiving a batch of concrete mix adequate to form the said tubular body, and means for reciprocating said core, said core being provided substantially midway of its length with means for ejecting the concrete of said batch radially outwardly to fill the mold space progressively from the bottom upwardly as the core moves upon its upward reciprocation, the length of said core providing for its contact with the concrete in the mold space throughout the entire molding operation.

2. Apparatus as claimed in claim 1, in which there are provided means for subjecting the mold space to suction and means for subjecting said batch of concrete mix to atmospheric pressure.

3. Apparatus as claimed in claim 1, in which said core is provided with a piston furnishing a substantially hermetic seal above the batch of concrete mix, and the mold space is connected with suction-producing means.

4. Apparatus as claimed in claim 1, in which a portion of the core below said radially ejecting means is of greater diameter than the portion above said means, whereby as the core moves upon its upward molding reciprocation its portion of greater diameter will radially compress the concrete progressively deposited in the mold space.

5. Apparatus as claimed in claim 1, in which the portion of the core below said radially ejecting means is connected with a source of heating fluid, whereby, as the mold is progressively filled the concrete therein may be dehydrated by the application of heat through said core.

6. Apparatus as claimed in claim 1, in which a rotary distributor having a plurality of offstanding impeller vanes is provided as a part of said radially ejecting means.

7. Apparatus for molding tubular concrete bodies, including a flask, and a tubular core of a length substantially twice that of the flask and arranged axially of said flask and serving therewith to provide a tubular mold, the interior of said core throughout substantially one-half of its length serving as a receptacle for receiving a batch of concrete mix adequate to form the said tubular body, and means for causing relative axial reciprocation between said flask and core, said core being provided substantially midway of its length with means thus located adjacent to one end of the mold space at one limit of such reciprocation for ejecting the concrete of said batch radially outwardly to fill the mold space progressively from said end longitudinally as such reciprocation progresses.

SIMON LAKE.