IL29599A - Inflatable forms - Google Patents

Inflatable forms

Info

Publication number
IL29599A
IL29599A IL29599A IL2959968A IL29599A IL 29599 A IL29599 A IL 29599A IL 29599 A IL29599 A IL 29599A IL 2959968 A IL2959968 A IL 2959968A IL 29599 A IL29599 A IL 29599A
Authority
IL
Israel
Prior art keywords
base
peripheral
assembly
central
hollow
Prior art date
Application number
IL29599A
Original Assignee
Heifetz H
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Heifetz H filed Critical Heifetz H
Priority to IL29599A priority Critical patent/IL29599A/en
Publication of IL29599A publication Critical patent/IL29599A/en

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Classifications

    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04BGENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/16Structures made from masses, e.g. of concrete, cast or similarly formed in situ with or without making use of additional elements, such as permanent forms, substructures to be coated with load-bearing material
    • E04B1/167Structures made from masses, e.g. of concrete, cast or similarly formed in situ with or without making use of additional elements, such as permanent forms, substructures to be coated with load-bearing material with permanent forms made of particular materials, e.g. layered products
    • E04B1/168Structures made from masses, e.g. of concrete, cast or similarly formed in situ with or without making use of additional elements, such as permanent forms, substructures to be coated with load-bearing material with permanent forms made of particular materials, e.g. layered products flexible
    • E04B1/169Structures made from masses, e.g. of concrete, cast or similarly formed in situ with or without making use of additional elements, such as permanent forms, substructures to be coated with load-bearing material with permanent forms made of particular materials, e.g. layered products flexible inflatable
    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04GSCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G11/00Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs
    • E04G11/04Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs for structures of spherical, spheroid or similar shape, or for cupola structures of circular or polygonal horizontal or vertical section; Inflatable forms
    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04GSCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G11/00Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs
    • E04G11/04Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs for structures of spherical, spheroid or similar shape, or for cupola structures of circular or polygonal horizontal or vertical section; Inflatable forms
    • E04G11/045Inflatable forms
    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04HBUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H15/00Tents or canopies, in general
    • E04H15/20Tents or canopies, in general inflatable, e.g. shaped, strengthened, or supported by fluid pressure
    • EFIXED CONSTRUCTIONS
    • E04BUILDING
    • E04HBUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H15/00Tents or canopies, in general
    • E04H15/20Tents or canopies, in general inflatable, e.g. shaped, strengthened, or supported by fluid pressure
    • E04H15/22Tents or canopies, in general inflatable, e.g. shaped, strengthened, or supported by fluid pressure supported by air pressure inside the tent

Description

29599-3 nian'an m'aan Inflatable forms HAIK HEIFBT2 C: 28018 ! This invention relates to inflatable forms of the kind which have been proposed for use in the construction of shells for use in building, such shells being formed by the casting or gunning of cementitious or plastic materials or the like on the form after the latter hae been inflated. Various proposals have hitherto been made for the use of inflatable forms in building con^ struction. None of these prior proposals, however, have led to a practical economic method of construction and, in consequence, there has been very little exploitation or development of the idea.
It has now been found that the successful use of inflatable molds in building construction depends on satisfying the following conditions: 1. The facility for ready inflation and deflation of the form and its removal from the cast shell for subsequent re-use; 2. The maintenance of a predetermined shape, location and set of dimensions of the inflated form during casting and setting of the shell and the predetermined shaping of any openings therein; and 3. The ability of the form and associated structure to withstand and/or counteract the very substantial elevating forces which act thereon as a consequence of inflation, such forces becoming critical with large forms and tending to raise the form and its foundations from the ground.
None of the prior proposals satisfy in their entirety any of these conditions and certainly fail to satisfy all the conditions.
As far as the first condition is concerned, no practical provision seems to have been made .in accordance with the prior proposal for the designing of the form in such a fashion as to facilitate its ready removal from the cast shell and its subsequent re-use. It will be readily appreciated that an inability to re-use the form would weaken, if not entirely remove, the economic basis for the system. Furthermore, in most of the prior proposals where means are suggested for disassembling and removing the form after use, the form is described as being anchored to a base at discrete anchoring points. In other wewrds, there is a concentration of tension at these specific points consequent upon inflation ©f the form with a consequen increased likelihood of rupture Of the form at these points thereby rendering the form incapable of further use. Alternatively, any form which is designed so as to avoid these dangers would be of entirely uneconomical weight and strength.
In accordance with some of these prior proposals the second condition referred to above was to be satisfied by inflating the form to a very high pressure (pressures of between 2 to 5 lbs per sq inch having been proposed) .. Such proposals have been recognised as impracticable seeing that they involve the provision of forms made of flexible materials capable of withstanding very considerable forces and such materials, even if available, are rohibitivel ex ensive.
In contrast, other proposals have involved inflating the former to a relatively low pressure (pressures of the order of 2 oz. per sq. inch have been proposed in this connection). With such low pressures, howevsr, it has proved to be very difficult if not impossible to control the chape, location and dimensions of the former, these being very susceptible to distortion by the weight of the applied materials and the force of application as well as to external influences such as variations in temperature, winds or the like. In consequence, domes produced under such conditions are subject to disintegration in view of the development of planes of rupture and it ha? in fact been proposed to provide such forms with expensive reinforcing rings designed to support the shell during application and setting.
In one of the prior proposals is the third condition referred to above mentioned, let alone any construction suggested so as to enable the former to meet this condition.
It is an object of the present invention to provide a new and improved inflatable former for the purpose referred to which is capable of use so as to satisfy some or all of the conditions referred to above.
According to one aspect of the present indention there is provided an inflatable former assembly for use in the construction of hollow structures comprising:- a) a base structure having a peripheral portion surrounding a central portion, said central portion comprising structural memb rs coupled to the peripheral portion, b) a hollow, inflatable member having upper and lo;'er sections, c) and means for continuously. securing the peripheries . of said upper and lower sections to said peripheral portion of the base structure whereby upon inflation of said member said upper section bows upwardly to constitute a former surface and said lower section presses downwardly on said central portion of the base structure and any stresses The peripheral portion can oo.¾pri»© a bnuo ring whioh can, if equired, bo anchored to an appropriate foundation.
Alternatively, the ba e rinf;> can bo maintained oomplotoly dotuohod frota any ouch foundation th roby facilitating tho uno of tho -bal oiv or fora ia tho production of prefabricated nhollt* dooi^nod for subsequent trancjport to a aito.
The form is preferably isanufacturod of a material which ia rainiraally extendable. iJeeinti that it ia to all intents and purposes ixnpoaulble to utilise for thia purpose a completely unextendible oateriai, which would still bo within tho realm of eoonooic feaiiibility, steps have to be taken to ensure that tho extension or stretching of the fora material durins inflation should bo entirely predetermined and as unifora as possible.
In view of the faot that It io precl3ely at tho ria region of tho f ora, whoro it io connected to tho baso ring, that stretching ia inhibited It io csHontinl, in order to ensure a uniform deformation of tho aaterittl duri g inflation, to have those rim portlona pre-atrotchod to a de^roe conparable with tho stretching of tho reaainder of tho fora during inflation.
A fora of thia kind in accordance with tho preaont invention ia particularly adapted for UJSQ with pro3aurea of inflation which two not no hl<;h tw> to roiiulr form mutorialii of exceptional otron^th or «o low ni:i to render difficult If not im oii!jiblo tho maintenance of the fona uhapo against tho distorting effect of the weigh of the applied material and against extraneous dlaturbing Influences, ouch aa winds, totoporaturo variations^ or tho like* j Thus, pressures of inflation of the order of 2 -60 gm/cm can suitably be employed, the actual pressure depending, inter alia, on the size (diameter) of the form.
It, will be understood that suitable control means must be provided to ensure that the pressure of inflation is maintained within well-defined limits (e.g. - 1 gm/cm ) during casting and setting of the shell. Similarly, measures have to be taken so as to ensure that the ultimate shape of the inflated form is as predetermined. Such measures are particularly required during the critical setting stage when the materials whilst inelastic are nevertheless still very sensitive to deformation.
The feature of having the form secured to or adapted to be secured to a rigid or rigid izable base ring facilitates the ready removal of the form from the constructed shell after the latter has set whilst the fact that the form is continuously secured at its rim to this base ring ensures the uniform distribution of stress in the form and thereby greatly reduces the danger of rupture of the form which arises when the form is secured at discrete points to a base.
A form provided with a base ring in accordance with the present invention can readily be adapted to withstand the very considerable elevating forces acting on the form and on its base ring when the form is inflated. For this purpose the form, which in this case is integral with a base portion so that the form and the base portion constitute a sealed whole has its base ring associated with 29599-3 - 7 -like anchored there o, the a angement bein^ such that when said cables are tenoionod said rinr* is placed in co:apre3sion» to the transversely directed cables and this downwardly directed force ip transformed into transvorsely directed tensioning forces in the cables which in turn serves to put the base rin^ into compression. Alternatively, the base ring is associated with a plurality of radially directed struts or trusses, aa a result of which the downwardly directed forces are transformed into radially directed compressive forces which nerve to tension the base rin^;. In effect, therefore, the form and its associated base structure (base rin¾ and transverse cables or struts) constitute a closed forcesystest, i.e. all forces developed in the syotea are retained therein and are substantially not transmitted outside the system, β.β. to the ground. By virtue of this arrangement it is possible to provide forms of very considerable dimensions in which the effect of the elevating fo ces on the founations of the form would be otherwise so large as to require either the provision of extresaely heavy foundations or anchoring devices or the excavation of a hemispherical cavity below the foro ίΐοηβ of these solutions are economically feasible* In accordance with a particular embodiment of the present invention the upper and lower balloon sections are located between respective sets of transversely directed tensioning cables, rods or the like anchored to the base structure.
Such an embodiment can be readily employed for the construction of ceilings, roofs, floors or the like on, or for 29599-3 P/2A80* transport to a site. Thus, upon inflation, the upper set of tensioning cables limits the maximum curvature of the former and the concrete or other cemontitious material can be applied to the for er, the upper set of cables becoming embedded therein and serving as reinforcements. On the other hand the lower set of cables serve to take up the downwardly directed forces consequent upon inflation of the former transforming them into tensioning forces which in their turn serve to put the base ring of the former into compression. In the case of this embodiment as in the case of the previous embodiment the entire assembly constitutes a closed force system.
According to a further aspect of the present invention there is provided a method of constructing a hollow structure on a predetermined site, comprising:- a) locating a base structure at said site, said base structure having a peripheral portion surrounding a central portion and said central portion comprising structural members connected to the peripheral portion, b) securing to said peripheral portion of the base structure a peripheral portion of a hollow, inflatable airtight member, c) inflating said ember to cause an upper section of the member to bow upwardly to constitute a former surface and to cause a lower section of the member to press downwardly on said central portion of the base structure any stresses thereby imposed on the central position being transmitted to the peripheral portion of the base structure which is so constructed so as not to dfeform thereunder, d) applying building material to said former surface, e) maintaining the member in inflated condition until said material has set to form a rigid hollow structure, f) deflating said member, g) and finally removing at least said member from the hollow structure. Various embodiments of the present invention will now be described by way of example and with reference to the accompanying drawings in which :- Figure 1 is a schematic sectional view of an inflated former and associated base structure in accordance with the present invention, Figure 2 is a schematic flow diagram of the air supply and control system used for inflating the former, Figure 3 is a perspective view of a portion of the base structure of the forner shown in Figure 1, Figure 4 is a front elevation of a detail of the base structure shown in Figure 3 showing the mode of coupling together with the constituent segments of the base structure, Fig. 5 is a cross-sectional view of the base structure shown in Fig. 3 in a position ready to receive the form rim, Fig. 6 is a similar view to that of Fig. 5 but with the form rim shown firmly clamped in position, Fig. 7 shows, in schematic plan view, a length of anchoring pipe associated with the form rim, Fig. 8 is a perspective view showing the mode of entry and exit of the anchoring pipe through" the base structure, Fig. 9 is a longitudinal sectional view of a form of the kind shown in Fig. 1 with a superimposed smaller form, Fig. 10 is a detail of the view 3hown in Fig. 9 on an enlarged scale, Fig. 11 shows schematically a hemispherical shell formed on a form in accordance with the invention and provided with lifting cables, Fig. 12 is a view, on an enlarged scale, of a detail of the shell as shown in Fig. 11, Figs. 13a and 13b are respective plan and sectional views of the surface of a form reinforced with hexagonal plates, Fig. 14 is a sectioned side elevation of a composite form and associated cable structure, Fig. 15 is a perspective view of the cable structure shown in Fig. 14, Fig. 16 is a perspective view of a portion of the composite form and cable structure shown in Fig. 14 with the use of a composite form and cable structure for con-structing the roof, Fig. 18 is a perspective view of a window form and clamp associated with an inflatable form, Fig. 19 is a longitudinal sectional view of the clamp and form shown in Fig. 18 embedded in concrete, Fig. 20 is a plan view of a portion of a modified and re-usable base structure in accordance with the invention, Fig..21 is a cross-sectional and detailed view of a portion of the base structure shown in Fig. 20 taken along the line XXI-XXI, Fig. 22 is an enlarged plan view of a detail of the base structure shown in Fig. 20, and Figs, 23, 24 and 25 are schematic longitudinal sectional views respectively of three modifications of inflated form and associated re-usable base structure in accordance with the invention facilitating the construction of a substantially "foundation-less" structure.
As seen schematically in Fig. 1 of the drawings, a flexible hemispherical form 1 is. anchored at its rim 2 to a base structure 3· The structure 3 consists of an annular base ring 4 and a transverse cable tensioning structure 5. The latter consists of an inner ring 6 and radially directed tensioning cables 7. Each cable is secured at its inner end to the inner ring 6 and at its outer end to the annular base ring 4. The form 1 is formed integrally vith a flexible base 8 adapted to rest on the transverse cable tensioning structure 5« source of compressed air via a suitable pressure control means is illustrated in detail in Fig. 2 of the drawings.
The form rim 2 is associated with an anchoring pipe illustrated in detail in Figs* 6 and 7 of the drawings and a pressure fluid supply for this anchoring pipe i3 introduced via a supply conduit 10.
As seen schematicall in Fig. 2 of the drawings, the form 1 is supplied with compressed air from a compressor 11. The form 1 is coupled to an automatic control valve 12 via a control conduit 15 which projects into the interior of the form 1 and is capable of sensing the pressure conditions prevailing in the form interior and via an outlet conduit 14. The control valve 12 is regulatable by means of a control mechanism 15 which is provided with an outlet 16. In use, the automatic control valve is set to regulate at a given pressure level by means of the control mechanism 15 and, upon actuation of the compressor 11, the form is inflated, the pressure level in the form being thereafter maintained substantially constant.
Reference will now be made to Figs. 5 to 8 of the drawings for a clear illustration of the base structure of the form and its coupling to the form itself. As can be seen in the drawings, the base structure consists of a base ring 4 comprising a plurality of channel-shaped segments 21 and a plurality of clamping elements 22. The channel-shaped segments 21 are coupled together so as to form a ring by means of coupling elements 23 of U-shaped cross-section which, as can be seen in Fig. 4 of the drawings, are inserted in the adjacent ends of respective pairs of segments, and are bolted thereto. The clamping elements 22 are coupled to the channel-shaped segments 21 by means of clamping bolts 24 , which extend through corresponding apertures formed in the segments 21 , clamping nuts 25 being provided at either end of the bolts 24o Thus in the position shown in Fig. 5 of the drawings , the clamping element 22 is displaced from the channel-shaped segment.21 so as to be ready to receive the form rim, whilst, as shown in Fig. 6 of the drawings, the clamping, elements 22 are clamped tightly against the channel-shaped segments 21 firmly retaining the form rim in position.. Each clamping element 22 has a "question-mark" profile the curved section 26 of which is designed to receive the form rim, whilst the vertical lirnb 27 of which is designed to be clamped against the channel-shaped segment 21» The clamping of the form rim by the clamping elements not only serves to anchor the form to the base structure, but also serves to impart to the form rim a degree of pre-stretching. This pre-stretching is in many instances essential, in order to ensure that the inflated form achieves the predetermined shape.
One set of ends of radially directed tensioning cables 28 extend respectively between adjacent clamping elements 22 through apertures formed in the channel-shaped segments 21 and associated coupling elements 23 and clamping plates 29 to which they are firmly bolted* The other and inner set of ends of the radially directed cables 28 are respectively secured to an inner ring 30.
The lowermost edge or rim of the form 1 and form base 8 is formed integrally with a double walled skirt portion 31 in which is located a flexible anchoring pipe 32 the ends of which extend out through appropriate elongated apertures formed in the channel-shaped segment 21 to be connected to a pressurized water or other fluid source. As clearly seen in Fig. 7 of the drawings, a dummy pipe section 33 is interposed in the clamping element so as to fill the space between the bent over portions of the clamping pipe 32.
The assembly of the form takes place as follows* The form, made of a minimally stretchable material, together with the form base 8 and anchoring pipe 32 as described above, is brought to the site and is spread out thereon. The clamping elements 24 are loosened and, in their loosened position, the rim of the form (including the anchoring pipe 32) is inserted into the curved section 26 of the clamping elements 22 , the two ends of the anchoring pipe emerging through the apertures as shown. With the form rim in position the clamping elements 22 are clamped firmly against the channel-shaped segments 21 by a tightening of the clamping bolts and water, or other fluid under pressure is forced into the anchoring pipe 32 causing it to expand so as to fill the space between the curved section of the clamping elements and the channel-shaped segment and thereby alternative to the use of a fluid filled anchoring pipe a flexible cable made for example of rubber may be employed.
With the form 1 thus anchored to the base ring and with the tensioning cables 28 having been previously given a predetermined degree of slackness by turning the clamping bolts which are distributed around the periphery of the channel-shaped segments 21, the form 1 is inflated to the required working pressure depending on the size 2 of the form (for example 30-60 gm/cm ). The control valve 12 is employed to ensure that the pressure remains substantially constant at the required level during the subsequent application of the cementitious or other material and its setting.
In addition to ensuring that the form is inflated to and maintained at the required pressure it is also necessary to ensure that the form acquires, upon inflation, the required stability and its predetermined shape and for this purpose visual observation means are employedβ Vith the inflation of the form, the downwardly directed forces, acting on the form base and tending to force that base to assume a spherical shape, are transmitted to the tensioning cables 28 and result in the further tensioning of these cables, these tensioning forces being transmitted to the base ring which absorbs these forces. Thus, the form and its associated base structure constitute a closed force system and forces developed in this system as a result of the inflation of the form are substantially maintained within the system and not transmitted out of the system. In other acting on the ground and thereby subjecting any foundations of the form to overwhelming elevating forces. The construction of this closed force system renders it possible to ignore completely the effects of these elevating forces and as a consequence there is no necessity of anchoring the base ring to the ground. This anchoring can take place if desired or can be dispensed with if not required 0 W ith the form anchored and inflated as described above, a layer of quick hardening material such as for example gypsum is applied to the form and when tHis has set to form a shell the form is deflated, the clamping elements loosened, the anchoring pipe emptied of its water and the form removed from the shell via an opening which has been left in the shell for this purpose. There can then be applied to the shell one or more layers of cementitious material. If desired pretensioned reinforced rods can be embedded in the layers of the cementitious material thus applied having been preliminarily anchored to the base ring. In this way a hemispherical dome can be easily and inexpensively constructed on an inflatable form. In the 'example just described this dome is formed on the channel-shaped base ring which sits freely on the ground and the dome can therefore be transported to any suitable site. If desired, however, the base ring can preliminarily be embedded in a concrete foundation, in which case the dome is premanently cast on the predetermined site.
With the casting and setting of the shell the ten-sioning cables and central ring can, if desired, be removed. Alternatively, these tensioning cables which are now in a tensioned state, can be allowed to remain so as to become embedded in a subsequently cast concrete floor thereby providing reinforcement for the floor which is suspended on its base ring,, Figs. 9 and 10 show how a small superstructure can be cast on an auxiliary inflatable form 36 anchored to a dome 37 which has been previously cast on a main inflatable form. Thus, as can be seen in the drawings, and in particular in Fig. 9 thereof, a cylindrical (preferably transparent) base ring 38' is supported by means of a lower flange 39 on the rim of an upper central aperture 40 of the dome 37· This cylindrical "base r ng" 37 surrounds a cylindrical wooden form 41 having a circular wooden lid 42. An auxiliary inflatable hemispherical form 43 is secured at its rim to the cylindrical wooden form 41» the base 44 of the auxiliary form 43 bearing on the upper surface of the wooden lid 42. An auxiliary air inlet p.ipe 45 passes through the "base ring" 38 and the wooden form.42 into the inner space of the auxiliary form 43 and in this wa the auxiliary form 43 can be inflated „ After inflation to the required pressure the cementitious material is cast on the auxiliary form 43 and after it has set the auxiliary form 43 together with the wooden form 42 are removed leaving the auxiliary, dome-like super-structure 35 and the cylindrical transparent fanlight 38.
As indicated above the shell can be prefabricated on a base ring and can then be transported to a site on which it is to be erected. A convenient method of transporting such shells, especially to relatively inaccessible in Pigs, 10 and 11 of the drawings, the shell is provided with lifting cables 47 which are coupled to a single suspension cable 48 designed to be coupled to a helitfpter. Fig. 11 shows clearly how the lifting cables 47 are secured to lugs 49 which are in their turn secured to the base ring.
A particularly advantageous use of such transportable shells is in connection with sealed medical units such as for example field operating theatresβ For this purpose the shells can be prefabricated in the raenner described above from a light-weight material such as, for example, polystyrene reinforced with glass fibres« The shell thus produced is provided with a light-weight flooring (e.g. of polyethylene) which rests on the tensioning cables and which serves to seal the unit which will have been rendered sterile. The unit can be fully equipped with all the necessary medical equipment and can be readily transported by helicopter together with the medical team so that any injured person can be operated on, on the site.
From the description which has just been given it will be realized that the base ring, which constitutes an essential element of the base structure associated with the form, serves a plurality of vital functions among which are the following: 1. A rigid annular structure to which the form can be continuously anchored; 2. An annular structure to which can be anchored be described below, radial struts or trusses) designed to take up the elevating forces which would otherwise act on the foundations of the form and to transform them into compressive or tensioning forces for the ring; 3. A base from which can be secured reinforcing cables to be embedded in the cementitious material forming the dome which is set for a suitable means for securing the dome to a base to which it is to be anchored.
Whilst in the arrangements specifically described above the form is clamped to a rigid base structure, the base ring can convenientl be formed as a rigidizable structure. Thus, under certain circumstances, the metal base ring can be dispensed with and the anchoring pipe can be adapted so as itself to constitute the base ring on the structure, which can in its turn form an anchoring ring for the transversely directed cables.
The form should be constructed of a flexible material of low elasticity. A suitable material is natural or synthetic rubber which can, if required, be suitably reinforced by means, for example, of natural or synthetic fibres. Thus, the. form can be constituted for example of a fabric formed of cotton or nylon fibres the fabric being impregnated and covered with natural or synthetic rubber. The degree of reinforcement and strength of the form is of course determined by the stresses to be imparted to the form as a result of shell. Suitably the form is constructed in the form of segments which are secured together by bonding, welding, sewing or the like so as to constitute the shape required. The segments can be arranged to overlap so as to impart a further degree of reinforcement to the form itself.
In the embodiment schematically illustrated in Figs. 13a and 13b of the drawings, the form is constituted by rigid hexagonal plates 57 which can be formed of a suitable rigid material (e.g. hard rubber) which are bonded onto a flexible base at such a spacing that the entire structure remains flexible but assumes a hemispherical form when inflated.
Reference will now be made to Figs. 14, 15 and 16 of the drawings wherein are illustrated the construction of a composite form and cable structure and its use in the construction of reinforced concrete, roofs or floorse The composite structure comprises a peripheral base ring 61 to which is peripherally^ecured an upper flexible form 62 and an integrally formed lower flexible form base 63. The upper form 62 and lower form base 63 are respectively enclosed between an upper set of form j Γ limiting cables 64 and a lower set of tensioning cables j 65. Both sets of cables are respectively secured at their outer sets of ends to the base ring 61. ! In a similar manner to that described above, the cables of each set are radially disposed and are secured - - at their inner ends to an inner ring 66 and at their outer ends to the base ring 61, Fig. 15 shows clearly the construction of the two sets of cables 64 and 65 with the interposed form and base removed, As can be clearly seen in Pig. 16 of the drawings, the base ring 61 consists of segments 67 of rectangular cross-sectioned shape, which are coupled together (by means not shown) so as to conform to the desired peripheral shape pf the form* Secured to the segments 67» in a manner similar to that described above, is a plurality of clamping elements 68 which are substantially identical in construction with the clamping of the combined rim of the upper form 62 and lower form base 65· The outer ends of the two sets of cables pass through the segments 67 and ,are secured thereto, tensionin of the cables being possible at their inner ends.
In the use the composite form and cable structure is assembled so that the base ring 61 rests on a prepared structure on which the floor or ceiling is to be cast. Thus, as can be seen in Fig. 17 of the drawings, the composite structure is placed on the upper edge of a cylindrical building^ and is U3ed to cast a roof for the building. The form is then inflated, t being ensured that inflation takes place to the desired pressure and this pressure is maintained during casting of the material and subsequent setting. The upper set of cables 64 serve to delimit the degree of inflation of the form and thereby ensure the relative flatness of the form and the structure subsequently to be cast thereon. The lower set of cables 65 on the other hand serve to take up the downwardly directed elevating forces which are created in the form base as a result of its inflation, these forces being converted into tensioning forces of the cables which are in turn transmitted to'the base ring 61. Cementitious material, such as concrete, is cast on the form, the upper form limiting cables becoming embedded in the concrete and serving to reinforce the concrete» If necessar and desired (especially in connection with large structures) the radially directed, form limiting, and concrete reinforc ing cables can be bridged by transverse reinforcing elements in the form of cables, wire mesh or the like0 After the cementitious material, such as concrete has been cast on the form to the required depth, completely embedding the upper set of cables, the material is allowed to set after which the form is deflated and removed, leaving the cast roof or floor in position.
It can be shown theoretically that a structure cast on a composite form and cable structure in accordance With the present invention and as just described, enjoys special strength characteristics over and above structures constructed in a conventional manner. Thus it is possible to use this method for covering very substantial areas, such as sports stadia, swimming pools, shelters or the likee The method is particularly economical as it can be carried out using a very thin layer of concrete and the degree of support for such a structure is also minimum.
Whilst in the examples specifically described above the tensioning cables have always been shown to be disposed radially, embodiments can equally well be conceived where the tensioning cables are disposed in other transverse directions» The provision of a dome-like shell, constructed in accordance with the present invention, with windows can be effected by means of the combined window form and clamp shown in Figs. 18 and 19 of the drawings.
As seen in these drawings, a window 71 already fitted in a rectangular metallic window frame 72 is clamped between a pair of window form-clamp components 73 and 74. The components 73 f 74 are both of inverted U-shape.
The component 74 has an upwardly tilted, substantially horizontal limb 75 and a pair of vertical limbs 76, the outer edges of the limbs 75 and 76 being curved so as to conform with the shape of. the flexible form to which it is to be attached. The component 73 consists of a substantially upwardly tilted horizontal limb 77 which terminates in an upwardly directed flange 78 and substantially vertical limbs 79 whose outer edges slope downwardly towards the flexible form. The two components 74 and 73 are secured to each other and to the metallic window frame 72 by means of straps 80 which are bolted to the adjacent components and the frame by means of bolts 81, these bolts being removable from inside - - The window form-clamp together with the window rests on a precast window sill 82, the latter being supported in the required position against the flexible form by support means (not shown), Cementitious or plastic material is applied to the flexible form and to the window form-clamp so as to adopt the outer contour shown by the broken line 83» When the cementitious or plastic material has set and the flexible form removed, the form-clamp components 73 and 74 (which can be made, for example, of suitable fibre glass material) can be detached by removal of the bolts 81. The component 73 can be removed from the outside of the shell whilst the component 74 can be removed from the inside of the 3hell. Thus, the window 71 and its frame 72 are left firmly set in the wall of the shell within an appropriate window niche. If desired the form-clamp components can be left in position,, Where, however, the form-clamp components are removed they can be re-used on further occasions.
In the embodiment, shown in Figs. 20, 21 and 22 of the drawings, a simplified and modified form of base structure is employed. With this base structure an annular concrete base ring 85 is preliminarily cast and, if desired, is anchored in the ground. Embedded in and projecting upwardly from the concrete ring 85 and equiangularly spaced around the ring 85 are mounting posts 86. The concrete base ring 85, when being cast is provided with through-going bores 07 through which tensioning cables 88 are arranged to pass. As show in the drawings the through-going bore 87 as well as the upper surface of the concrete ring 85 slope slightly upwardly in a direction away frota the centre of the ring. Coupled to the mounting posts 86 is a form clamping structure 89 which consists of a plurality of annular segments 90 and a plurality of clamping elements 91 having the characteristic questionmark profile referred to above. The segments 90 and clamping elements 91 are coupled together and to the mounting posts 86 by means of elongated bolts 92 which pass through the juxtaposed elements and which are provided with tightening nuts 93 and elongated sleeves 94· The end of each tensioning cable 88 which emerges from the base ring 85 is externally threaded and is provided with a nut 94a a steel washer 95 and a flexible washer 96. As seen in Fig. 22 of the drawings, adjacent segments of the clamping mechanism 89 are rigidly coupled together by means of pairs of coupling plates 97 and 98, the coupling plate 98 being formed integrally with an elongated tubular sleeve 99. A coupling bolt 100 extends through the coupling plates 97 and 98. Clamping of the two plates together is effected by means of a nut 101 which, bearing against the end of the sleeve 99» presses- the two coupling plates 97 and 98 together, thereby securing together the two elements 0 and 91 of the clamping structure.
In operation, the rim of an inflatable form is clamped in the clamping structure 89 in a manner as the form rim) and the clamping structure itself is secured to the mounting posts 86 by tightening of the clamping nuts 93· Successive segmental sections of the clamping structure are rigidly secured together by tightening of the clamping nuts 101 on the clamping bolts 100. The tensioning cables 88 are then given a predetermined degree of slackness by turning of the nuts 94a and upon the inflation of the form, the cables 88 are tehsioned by the downwardly directed force on the form base. The cementitious or other suitable material is then applied to the form so as to form a shell 97. When this has set, loosening of the. nut 93 results in the un-clamping of the rim of the flexible form which thereupon can be removed as can the clamping structure 89 and the tensioning cables 88, the resulting concrete shell having been formed on the concrete base ring 85 « Whilst in the embodiments described above the shell is formed on a base ring which can, if desired, be anchored to an appropriate foundation and which serves for anchoring the rim of the inflatable form, there will now be described, with reference to Fig. 23 of the drawings, an embodiment wherein the shell is formed on a base structure which is entirely separate from the base ring, thereby allowing the base ring to be removed together with the inflatable form after the setting of the shell for re-use.
AS seen in Fig. 23 an inflatable form 105 is anchored to a base structure 106, the latter being of the kind of the drawings. The base ring 107 of the base structure 106 is supported on jacks 108 by virtue of which the base ring is raised sufficiently from off the ground 109 to take account of the downward displacement of the tensioning cables 110 and inner ring 111 upon inflation of the form. The base structure 106 is located within a cylindrical wall 112 which can be constructed by conventional means and which, in addition to any preformed apertures for doors etc., is provided with apertures 113 by means of which access can be had to tensioning nuts 114 located on the base ring 107 and by means of which the slackness of the tensioning cables 110 can be adjusted to a required level.
As can be seen from the drawing the wall 112 is sufficiently spaced from the base ring 107 for the vertical wall to be directed substantially tangentially to the inflated form 105 and so that the layer of cementitioua material 115 applied to the form 105 continues initially, substantially continuously from the cylindrical wall 112. In other words the form must "swell" towards the cylindrical wallf This modification renders the process cheaper and faster to carry out seeing that it is possible to retrieve and re-use the base structures of the inflatable form whilst the use of jacks for raising the base structure above the floor facilitates the use of this method with floors which are preformed. The cylindrical wall can be formed by any conventional method such as, for example, Whilst in all the specific embodiments described above there has been described a base structure having a base ring so constructed as to be capable of withstanding the compressive forces arising out of the tensioning of the tensioning cables, the present invention is equally applicable in the case of a base structure having a base ring constructed to be capable of withstanding compressive forces.
Fig3. 24 and 25 of the drawings show schematically such a modification . As seen in Fig. 24 a form 117 having a base 118 i3 anchored to a base structure 119 consisting of a base ring 120 to which are secured the ends of a plurality of radial compression struts 121 whose inner ends are coupled at a central hub 1229 As seen in the drawing, upon inflation of the form 117 the base 118 thereof adopts a convex shape (as opposed to the concave shape adopted by the base in all the previous embodiments) and this base presses down on the compression struts 121 as a result of which these 3truts press against the ring 120 which is in consequence tensioned.
In the embodiment shown in Fig. 25 the struts 121 of the embodiment shown in Fig. 24 are replaced by radial trusses 123 which also serve to convert the downwardly directed forces acting thereon into tensioning forces on ring 120, The ring 120 which is made of metal can easily withstand such tensioning forces and in consequence the forces which would otherwise tend to lift the form are easily overcome without any necessity for anchoring the base structure in the ground.
It will readily be seen that embodiments of the kind shown in Figs. 24 and 25 enjoy the advantage that the base ring can be placed directly on the ground there being no necessity for allowing for the downward displacement of the tensioning cables.
It should be realised that the invention is not only applicable in the case of construction of hemispherical domes or structures with a circular peripheral shape but structures of other shapes can equally well be constructed.
Finally, whilst the invention has been specifically described in connection with the use of an inflatable form, on which, after inflation a cementitious or plastic material is applied and is allowed to set, the invention is equally applicable in the case where the form is used as a basis round which there is constructed, for example, a geodesic construction. Alternatively the invention is applicable in the case wherein the cementitious material is applied to the form prior to its inflation and the form is subsequently inflated and the material is allowed to set„

Claims (24)

CLAIMS:
1. An inflatable former assembly for use in the construction of hollow structures comprising a) a base structure having a peripheral portion surrounding a central portion, said central portion comprising structural members coupled to the peripheral portion, b) a hollow, inflatable member having upper and lower sections, c) and means for continuously securing the peripheries of said upper and lower sections to said peripheral portion of the base structure whereb upon inflation of said member said upper section bows upwardly to constitute a former surface and said lower section presses downwardly on said central portion of the base struoture and any stresses thereby imposed on the central portion are transmitted to the peripheral portion of the base structure which is so constructed as not to deform thereunder.
2. j» An assembly according to Claim 1, wherein the peripheral portion of the base structure comprises a plurality of rigid curved segments and means for coupling said segments together to form a rigid base ring of predetermined shape·
3. An assembly according to Claim 2, wherein a plurality of clamping elements are attached to the segments and are adapted to hold the peripheral portions of the upper and lower sections of the member.
4. An assembly according to any one of Claims 2 or 3, wherein said central portion of the base structure includes a series of cables or rods anchored to the base ring and extending aoross the area enclosed thereby.
5. An assembly according to Claim 4» wherein the cables or rods extend radially between the base ring and a central hub,
6. An assembly according to any one of Claims 2 or 3, wherein said central portion of the base structure includes a plurality of radial struts or trussea with outer ends bearing on the base ring..
7. An assembly according to Claim 6, wherein said radial struts or trusses form a shallow, upwardly bowed dome-shaped structure.
8. S. An assembly according to any one of the preceding Claims, wherein said base structure is collapsible and removable from the inflatable member.
9. An assembly according to any one of the preceding Claims» wherein an annular pocket is formed at the junction between the upper and lower sections of the inflatable member.
10. An assembly according to Claim 9# wherein said pocket contains a pipe for anchoring the member to the peripheral portion of the base structure.
11. An assembly according to Claim 10, wherein the pipe is a flexible hollow tube connected to a source of fluid pressure.
12. An assembly according to Claim 10 or 11, when dependent upon Claim 2, wherein said annular pocket and pipe are held by clamping elements. connected. to the base ring.
13. · An assembly according to any one of the preceding Claims which also includes a plurality of transversely directed members anchored to the peripheral portion of the base structure and located above the upper section of the inflatable membe 29599-3 the arrangement being such that said members serve to limit tho degree of inflation of the upper section and become embedded in the final structure as reinforcing members.
14. A method of constructing a hollow structure on a predetermined site, comprising a) locating a base structure at said site, said base structure having a peripheral portion surrounding a central portion and said central portion comprising structural members connected to the peripheral portion, b) securing to said peripheral portion of the base structure a peripheral portion of a hollow, inflatable airtight member, c) inflating said member to cause an upper section of the member to bow upwardly to constitute a former surface and to. cause a lower section of the member to press downwardly on said central portion of the base structure any stresses thereby imposed on the central position being transmitted to the peripheral portion of the base structure which is so constructed so as not to deform there-under, d) applying building material to said former surface, e) maintaining the member in inflated condition until said material has set to form a rigid hollow structure, f) deflating said member, g) and finally removing at least said member from the hollow structure.
15. A method according to Claim 14, wherein the peripheral portion of the base structure comprises a plurality of rigid curved segments which are coupled together to form a rigid base ring of predetermined shape. ^ " · , , · : "" 29 99 -
16., A method according to Claim 14 or 15» wh§.?e¾¾? ^^ an annular pocket is formed at the junction between the e and lover sections of the hollow member, a flexible hollow tube is inserted into this pocket, the tube containing pocket is anchored to the base ring**by means of longitudinal, curved clamping elements and fluid pressure is applied to the flexible hollow tube.
17. A method according to any one of Claims 14, 15 or 16 wherein a series of cables or rods are positioned across the central portion of the baso structure and are anchored to the base ring, these cables or rods bowing downward slightly being tensioned under the pressure exerted by the lower section of the member when the member is inflated.
18. A mothod according to any one of Claims 14, 15 or 16, wherein a series of radial struts or trusses are inserted in the central area of the base structure with their outer ends bearing on the base ring, said struts or trusses bowing upward to form a shallow dome-shaped structure, downward forces exerted thereon b the lower section of the member being transmitted by said struts or trusses to the base ring.
19. · A method according to any one of Claims 14 to 18, iherein the hollow structxvre is erected without a foundation. 20. A method according to any one of Claims 14 to 19, wherein a plurality of form limiting cables or rods are anchored to the peripheral portio of the base structure and located above the upper section of the meiaber, these cables or rods serving to limit the degree of inflation of the member and remaining embedded in the final structure as reinforcing members.
20. 29599
21. A method according to any one of Claims 14 to 20, \ ^ wherein the inflatable member is inflated to a pressure of
22. about 30 - 60 gm/ ,cifl2.
23. 22 o A method according to any one of Claims 14 to 21, wherein the settable building material applied to the. former ie a light-weight plastics material and at least part of the peripheral portion of the base structure is left in the 24. completed struoture as a reinforcement. 25. A method according to any one of Claims 14 to 22, wherein at least one window form, including a window unit, is removably attached to the inflatable member, whereby after the settable building material haa been applied to the former, the material has set and the member removed, the window unit is permanently fixed in the hollow structure.
24. An inflatable former assembly for use in the construction of hollow structures according to Claim 1 and substantially as hereinbefore described by way of example and with reference to the accompanying drawings. 25« method of constructing a hollow structure on a predetermined site according to Claim 14 and substantially as hereinbefore described by way of example and with reference to the accompanying drawings. - 3 3 - For the Applicants DR RHNHOLD COHN AND * m.
IL29599A 1968-03-07 1968-03-07 Inflatable forms IL29599A (en)

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Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
IL29599A IL29599A (en) 1968-03-07 1968-03-07 Inflatable forms
AT213869A AT303358B (en) 1968-03-07 1969-03-04 Inflatable formwork
SE03030/69A SE357230B (en) 1968-03-07 1969-03-05
DE1911352A DE1911352C3 (en) 1968-03-07 1969-03-06
NO0940/69A NO125902B (en) 1968-03-07 1969-03-06
BR206917/69A BR6906917D0 (en) 1968-03-07 1969-03-06 Improvements in inflatable roofs
FI690682A FI49077C (en) 1968-03-07 1969-03-06 Inflatable mold.
FR6906157A FR2003402A1 (en) 1968-03-07 1969-03-06
NL6903581A NL6903581A (en) 1968-03-07 1969-03-07
US805143A US3643910A (en) 1968-03-07 1969-03-07 Inflatable forms

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IL29599A true IL29599A (en) 1972-02-29

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ID=11044382

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IL29599A IL29599A (en) 1968-03-07 1968-03-07 Inflatable forms

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US (1) US3643910A (en)
AT (1) AT303358B (en)
BR (1) BR6906917D0 (en)
DE (1) DE1911352C3 (en)
FI (1) FI49077C (en)
FR (1) FR2003402A1 (en)
IL (1) IL29599A (en)
NL (1) NL6903581A (en)
NO (1) NO125902B (en)
SE (1) SE357230B (en)

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1393404A (en) * 1971-06-22 1975-05-07 Western William J T Moulding apparatus
US3719341A (en) * 1971-07-26 1973-03-06 Himmel I Inflatable form for concrete building shell
FR2188938B1 (en) * 1972-06-16 1976-04-16 Rabeu Andre
US3985330A (en) * 1973-05-25 1976-10-12 Jan William Dorfman Disposable inner mould for boats
US3832745A (en) * 1973-05-25 1974-09-03 J Dorfman Disposable inner mould for boats and method of manufacture
US3909992A (en) * 1974-03-18 1975-10-07 Us Navy Inflatable ice igloo
US4077177A (en) * 1974-08-09 1978-03-07 Boothroyd Rodney L Curved architectural structure of foam and cement
IL46523A (en) * 1975-01-29 1978-10-31 Heifetz H Building method and equipment for use therewith
AT354056B (en) * 1976-08-09 1979-12-27 Burzler Otmar Ing METHOD OF MANUFACTURING A CORRUGATED COVER
IT1072998B (en) * 1976-10-07 1985-04-13 Binishells Spa Procedure and apparatus for the erection of substantially domed building structures
DE2658971C2 (en) * 1976-12-24 1987-04-30 Hans-Peter 7141 Benningen De Pfisterer
US4452017A (en) * 1981-05-13 1984-06-05 Dyckerhoff & Widmann Aktiengesellschaft Air inflated bubble roof
US4446083A (en) * 1981-08-03 1984-05-01 Nicholls Robert L Air-inflated fabric-reinforced concrete shells
US4659527A (en) * 1983-02-17 1987-04-21 Misawa Homes Company Limited Method of molding a light-weight, cellular concrete panel having a window or ceramic plate embedded therein
US5094044A (en) * 1983-12-09 1992-03-10 Dykmans Maximilliaan J Multi-purpose dome structure and the construction thereof
US4879859A (en) * 1983-12-09 1989-11-14 Dykmans Max J Method and apparatus for constructing circumferentially wrapped prestressed structures utilizing a membrane
US5408793A (en) * 1983-12-09 1995-04-25 Dykmans; Max J. Multi-purpose dome structure and the method of construction thereof
US5675941A (en) * 1983-12-09 1997-10-14 Dykmans; Maximiliaan J. Method and apparatus for constructing prestressed structures utilizing a membrane and floating dome assembly
US5134830A (en) * 1983-12-09 1992-08-04 Dykmans Max J Method and apparatus for constructing circumferentially wrapped prestressed structures utilizing a membrane
US4776145A (en) * 1983-12-09 1988-10-11 Dykmans Max J Multi purpose dome structure and the construction thereof
US4678157A (en) * 1984-08-30 1987-07-07 Robert Fondiller Apparatus for the construction of a low cost structure
US4629592A (en) * 1986-01-22 1986-12-16 Horrall Harrington Method and apparatus utilizing inflatable membrane form for construction of concrete shell building
US4799982A (en) * 1986-03-20 1989-01-24 Charmasson & Holz Method of molding monolithic building structure
IL96825D0 (en) * 1990-12-30 1991-09-16 Pavie Henry Inflatable construction apparatus
WO1995028538A1 (en) * 1992-05-07 1995-10-26 Giles Brian C Method of constructing curvilinear structures
SE501983C2 (en) * 1993-11-01 1995-07-03 H G Tech Ab Method of manufacture of shell-shaped structures
US5564369A (en) * 1994-06-22 1996-10-15 Barber; Todd R. Reef ball
IL115527D0 (en) * 1994-10-07 1996-01-19 Easton David C Method of stabilizing earth for building earthen walls and structures
US6282842B1 (en) 1995-02-06 2001-09-04 Robert R. Simens Inflatable roof support systems
SE504224C2 (en) * 1995-04-20 1996-12-09 Hg Tech Ab Ways to produce a shell-shaped structure with an inflatable mold
AT1030U1 (en) * 1995-12-05 1996-09-25 Stoegner Herbert Dr METHOD AND DEVICE FOR PRODUCING HOLLOW ice bodies
US20050120643A1 (en) * 2003-12-09 2005-06-09 Siedentopf Robert A. Primary-geodesic least surface shapes for predetermined ground plots and functions
GB0501113D0 (en) * 2005-01-20 2005-02-23 Cintec Int Ltd Improvements in and relating to blast protection structures
WO2009078692A1 (en) * 2007-12-14 2009-06-25 Instituto Tecnológico y de Estudios Superiores de Monterrey Construction system and method based on re-usable moulds for a formwork having a special semicurved shape
GB2473017B (en) * 2009-08-27 2014-10-29 Jolyon Eric Emery Inflatable dome structure
US9151577B2 (en) * 2013-07-03 2015-10-06 Rixford Smith Pyramid-sphere bunker system
US9611662B2 (en) * 2014-06-11 2017-04-04 Nicoló Bini Anchoring mechanisms for a Binishell
CN105780797A (en) * 2014-12-26 2016-07-20 深圳市博德维环境技术有限公司 Air film building and foundation thereof

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2335300A (en) * 1941-11-25 1943-11-30 Neff Wallace Building construction
US2948047A (en) * 1955-12-27 1960-08-09 Lawrence F Peeler Method of building structures
US3462521A (en) * 1966-12-12 1969-08-19 Binishells Spa Method for erecting structures
US3478472A (en) * 1967-11-29 1969-11-18 John P Kwake Means for constant pressurization of inflatable and other enclosures

Also Published As

Publication number Publication date
DE1911352B2 (en) 1975-01-09
BR6906917D0 (en) 1973-02-08
AT303358B (en) 1972-11-27
DE1911352A1 (en) 1969-10-09
FI49077B (en) 1974-12-02
US3643910A (en) 1972-02-22
FI49077C (en) 1975-03-10
FR2003402A1 (en) 1969-11-07
NL6903581A (en) 1969-09-09
DE1911352C3 (en) 1975-08-28
SE357230B (en) 1973-06-18
NO125902B (en) 1972-11-20

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