US1996678A - Core for hollow bodies of concrete and the like - Google Patents

Description

April 2, 1935. LEGGAT r AL 1,996,678

CORE FOR HOLLOW BODIES OF CONCRETE AND THE LIKE Filed July 13, 1935 Patented Apr. 2, 1935 5 g 1,996,'6'7& l

- 1 I 396,678 Scone. FOR 11, woweomes F vouchers i Rohertfllzeggat. and. .Johannes comelis Pieter heemhuis li ie ifltiai .Zlhfansvaal, South Africa H Application my 13, leesgjserialno. 680.308. I IrrUnion of South Africa July 28,1932 I, 1 i ftfoaims. (CL-25412.8) The presentinvention. was tea ing 1101:; 1 sniall'relatively to J breadth and he giitgand low bodies" made. of hardened plasticfmaterialt it has 'a vertieal'cavity or preferably two vet'- such. as hollow, concrete jbuildi'ng bl'ocksend tical cavities 3 which are.correspondinglypi con i panels. "siderable. breadtlfand;heightbut'narrQw.The

5 An object or the inventions retains col f formation .ofjs ch cavi i by mownam tn q s lapsible core, which whilst being" rigid use, is presents considerabledifliculties; 2 adapted so to collapse'asslibstantially to di-f "The mouici nowa .compris sthe base minish both its dimensions transverse to the; the/four walls'fij, 5Z5, Whiohfare s'eparably held direction in which it isfto be Withdrawmso that; oeether byimeans citric-bol s. Thewallsafig 10 it can. be, withdrawn without drag on the .lsurjmould.thelhorizontal'edges of the panelandtllelo faces of the cavity. it forms. walls'fifiythe'Verticaledges'thereof. The cores A specific object of the invention is to provide' indicated generally, by f l,1 Y consequently extend a core of this character, which cambe made. between the Walls 5,5]; and parallel'with'the walls,

of considerable dimensions thedirection 5.6). (They, are convenientlysuppdrted in pos which it is to be withdrawn and in one dimention'b'y seating at theirend's intlie apertures 8 15 sion transverse thereto, whilst being of small diin the walls 5, which apertures also determine mensions in the other transverse direction. A the expanded size of the core; The base 4 core or" this kind permits the production of holmoulds one of the fiat faces 9 of the panel. The low concrete building panels of considerable concrete is poured into the open top of the mould height and width and of small thickness. and the second flat facet of the panel is formed 20 Another object is to provide a core which proby screeding the surface of the concrete level I duces an untapered cavity and which permits with the tops of the walls. I the use of a wet concrete mix. Each core 1 comprises the two similar units According to the invention, a core comprises liLlt. Each unit comprises the two similar leaves a unit consisting of apair of hinged leaves adapt- "3, eac having a flat portion and a bent end 25. ed to be spread apart in one direction transverse portion said end portions are ed by to the direction of withdrawal of the core and the hinge l2. 7 thereby define a cavity and to be collapsed about When the core is assembled in its moul the hinge with a movement wholly within the form (Figure III), the two units are arranged opcavity so defined, and comprising also a secposite one 91 and p d Ou SO t at the 30 0nd unit which completes the core surface beedges l3 of the leaves are in contact with one tween the spread-apart edges of said leaves and another and the flat portions of the leaves are which permits the first unit, when collapsed, vto alined with one another. The core thus prebe moved in a second direction transverse to sents a. continuous outer surface which defines the withdrawing movement. Said second .unit the cavity to be produced within the panel.v V v would usually be a hinged pair of leaves like The core is sustained inits expanded form by the first unit, the units being arranged oppothe end'covers l4 and the centralbar [5, 15a. site one another with the edges of their re- The end covers M carry inwardly projecting ribs spective leaves in contact. [6 which hold'the leaves apart and also curved V v 40 In the accompanying drawing the invention is ribs 11 which fit into the curved ends of the units 40 illustrated in a form suitable for curing the thin and so maintain the core at its proper breadth. concrete panels above referred to; Said ribs l6 and 11, being short, are easily in- Figure' I shows the panel; serted into and withdrawn from the leaves; and

Figure II is a perspective view' of the panel they are tapered to facilitate such movements. 7

mould with some parts removed and other parts 'Ihecentral bar I5, l5a, however, extends the 45 displaced, the scale being larger than that of full length of the core and is therefore made col- Figure I. lapsible to facilitate its insertion and withdrawal. I Figure III is a horizontal section on a plane It comprises the two bar members 15 and I501. conindicated by III in Figure I. nected'and maintained parallel with one another 5 Figure IV is similar to Figure III, showing the by the parallel links 18, thus permitting the memcore in process of removal. bers I5; l5a to come together to reduce the effec- The panel 2 is of the kind referred to in; the tive height of the'bar, and to be separated to inspecification of our application for Patent No. crease the effective height of the bar. Each bar. 657 298, filed February 17, 1933. It isof conmember has screw-threaded stem l9 which exsiderable breadth and height; but its width is tends through hole 20 to the adjacent end cover I4 and is there providedWith a nut 2| which bears on the outer face of the cover.

The leaves of the core are provided on theirv inner faces with ribs 22 for positioning the bar- I5, I So. The leaves having been seated in the apertures 8,, the bar I 5. Main its collapsed condition isslid-between .theribs 22. vThe end covers M are slipped over the stems l9, and the nuts 2| are screwed up onto the covers; Thereby the ribs [6, ll of the covers are firmly forced be- '1 tween the leaves and also the bar members l 5, 15a;- are traversed relatively to one another to expand the bar, both operations thus expandingtliecore and holding it rigid against thepressure of'the concrete. I I v 7 When the concrete has been cast and become set, the nuts 2| are removed, the 'en'cl covers l4 withdrawn and the bar l5, I5a is also withdrawn 7 after being collapsed. Theleaves of one core unitare then pressed towards one another as indicated in Figure IV was to detach them from the concrete. As the hinge i2 is almost atthe closed end of the unit, the collapsing movement of all points of the leaves is distinctly'inward away fromjthe concrete face and is therefore readily accomplished without danger of damaging said face. Such movement is least in thearea near to'the drawn from the panel endwise. The second unit is then similarly manipulated and withdrawn.

We claim: 1. The combination of a mould having opposite f walls apertured to form seatings for a core and to determine the expanded size thereof, an open ended core seated in said apertures, end covers for the core having projecting means on their inner faces adapted to enter the core ends and expand them, a bar comprising connected units adapted. to be longitudinally moved relatively to one another and thereby vary the effective width of the' bar, said units having ends projecting through the covers, means on said unit ends for pressing on the outside of the covers to force their projections into the core ends and simultaneously to exert tension on the bar unit ends and thereby expand the bar within the core.

a 2. The combination of a mould having opposite walls apertured to form seatings for a core and to determine the expanded size. thereof, a core seated in'said apertures and comprising two similar units; each unit consisting of a pairof hinged leaves adapted to be spread apart about the hingesin a direction transverse to the mould walls, saidunits being arranged opposite to one v another with the edges of their leavestogether; means adapted to enter the ends of the core and expand the same. and an expansible bar extending between the edges of the leaves to support the latter in their expanded position.

ROBERT LEGGAT. JOHANNES CORNELIS PIETER LEEMHUIS.

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