US3463441A - Forms for concrete rib ceilings - Google Patents

Description

g 1969 A. BASALLA ET AL 3,463,441

FORMS FOR CONCRETE RIB CEYILINGS Filed Jan. 23, 1967 2 Sheets-Sheet 1 Aug. 26, 1969 A. BASALLA ET AL FORMS FOR CONCRETE RIB CEILINGS 2 Sheets-Sheet 2 Filed Jan. 23, 1967 United States Patent M 3,463,441 FORMS FOR CONCRETE RIB CEILINGS Alfred Basalla, Bad Soden, Taunus, and Hans Ungemach, Frankfurt am Main, Germany, assignors to Willy Kaiser, Frankfurt am Main, Germany, a company of Germany Filed Jan. 23, 1967, Ser. No. 610,953 Claims priority, application Germany, Jan. 22, 1966,

B 8 ,49 Int. Cl. E04g 11/40; B28b 7/28 US. Cl. 249-28 12 Claims ABSTRACT OF THE DISCLOSURE The invention relates to forms for concrete vault-shape ceilings which have transverse ribs.

Forms of this type which consist of steel sheets, pressed board, gypsum, asbestos or similar materials, are laid at determined intervals either on form planks or between light weight steel girders. Depending upon the design, they can be reused or can remain in the ceiling as a dead form. The length of ribs to be formed vary in different ceilings. Therefore, the form sections must always be adjusted to the length required. This is achieved, for example by making form bodies in the lengths required in each particular instance but this involves a great deal of labor and expense. Much more often the form body is made of constant length. The differences as to rib length are balanced out through differences in overlapping of the ends of the form sections. However, this is possible only with forms of small wall thickness. With thick form bodies, such overlapping is either not possible at all depending upon the steepness of the lateral walls, or is subject to the objection that cavities develop between the form bed and the rib form, through which concrete can flow.

This invention makes it possible for form bodies of brittle material and form bodies with thick walls, regardless of the steepness of the lateral walls, to achieve an overlapping of the form ends without developing cavities through which concrete can flow.

The form body in accordance with the invention is characterized by the fact that at least one vault section running, for example in a direction perpendicular to the longitudinal axis of the body, is offset or staggered to the extent of the material thickness toward the outside or toward the inside of the form.

With such a design, the forms can be laid in overlapping manner, the overlapping point being completely tight. The staggered vault section can be designed in such a manner that its interior contour corresponds to the outer contour, or its outer contour corresponds the interior contour, of a nonstaggered vault section. With such construction, it is possible to achieve a locking effect between neighboring form bodies. This means that after the overlapping has been effected, the form bodies can no longer move in axial direction. Alternatively, if the contour of the vault section located on the outside is made larger than that of the contour located on the inside, then there is a possibility of a shifting of the forms relative to one another without hereby impairing the tight- 3,463,441 Patented Aug. 26, 1969 ness of the joint. Thus the total length of form bodies joined together tightly can be varied continuously by a specific value.

The invention is illustrated by way of example in the accompanying drawings in which:

FIG. 1 is a cross section, transverse to the longitudinal axis, of a form resting on two girders;

FIG. 2 is a longitudinal section taken approximately on the line IIII in FIG. 1;

FIG. 3 is a longitudinal section of a form body with which an axial shifting is possible;

FIG. 4 is a longitudinal section of a form similar to that of FIG. 3, but with greater possibility of axial shifting.

In FIGS. 1 and 2 there is shown a form body 1 which rests on a form plank 2 of a light-weight steel girder 3. The form is made of suitable material of substantial thickness, for example plywood or pressboard. The position of the form in a horizontal direction is determined by a girder base 4. The form body has ribs 5 projecting toward the interior of the form, which serve to stiffen the structure. The lateral walls 6 of the form are slightly inclined. Ribs 5 can, if desired, be continued into lateral walls 6 (not shown). As can be seen particularly in FIG. 2, the central or intermediate parts between the ribs and corresponding portions of the lateral walls do not have the same height. Thus, every second intermediate part 7 is staggered or offset toward the inside of the form to the extent of material thickness S. The interior contour of the nonstaggered parts 8 correspond to the outer contour of the staggered parts 7. Intermediate part 7 then fits tightly into a nonstaggered part 8 (see FIG. 2). Tight connecting points can be established between neighboring form bodies of the same type. This is not only possible at the end of the form bodies but also intermediate the ends since high and low central sections follow alternately. Hence it is only necessary to cut the form body between a higher and a lower central part in such a manner that the lower connecting wall of the rib located in between, is eliminated (see FIG. 2). Then, at the end of the form body, a higher central part remains. A central part staggered toward the interior of a further form body, can be tightly inserted therein. With this design, the two form bodies can no longer be mutually shifted after the two form bodies have been united. The form bodies can be closed at the end by end walls 9', which are shown provided with an edge ledge 10 projecting toward the outside and having a width corresponding to half the rib width of the girder to be designed between two form bodies.

In the example shown in FIG. 3, the ribs have a greater width than in the example according to FIG. 2. The central parts located between the ribs have different heights and different widths. The central parts 11 between ribs, which are staggered or offset to the extent of the material thickness S toward the inside, are only approximately half as wide as the nonstaggered central parts 12. The form is provided with a terminal Wall 13 adjacent a lower central part 11. During the assembling of form bodies designed in such a manner, the form is cut adjacent the sloping edge of a long central part 12 which fits over the short central part 11 of an adjacent form body. By reason of the staggering of central part 11, there is obtained an overlapping joint without lifting either of the form bodies. The form sections are thus assembled in longitudinal alignment with one another. Since the nonstaggered central parts 12 are longer than the staggered central parts 11, the form bodies can be shifted toward each other even after assembly. The amount of shifting depends upon the length of the interior contour of the higher central part 12. By virtue of such shifting, the total length of the assembled form body can be changed in a continuous and simple manner, whereby tolerance in construction or length of the form bodies can be balanced out.

With the example according to FIG. 3, the terminal wall 13 is not sloping but projects downwardly to the extent of a thickness D beyond the lower edges of the lateral walls. The thickness D corresponds to the thickness of the form ledge 2. In this manner a tight sealing end of the front wall is obtained in the event that the form body is put onto the form ledge.

In the example according to FIG. 4, ribs are arranged in such a manner that two ribs are combined to form a pair 14, with a middle piece 15 which is lower to the extent of the material thickness S than the middle piece 16 arranged between two rib pairs. With this construction the shifting permitted between adjacent forms is greater than with the embodiment according to FIG. 3. If the form body is cut off within the area of the middle piece 16 adjacent the sloping flank of the following rib,

then the length of two assembled form bodies can be changed by an amount V. If the cut is made at point 17, then the two form bodies can be further pushed together.

End walls 13 are sloping and shoulders 18 are provided least two sections disposed longitudinally of one another 7 and formed of material of substantial wall thickness, each of said sections having opposite longitudinally extending lateral Wall portions and a top wall portion extending between said lateral walls and having transverse corrugations forming downwardly projecting ribs extending approximately perpendicular to the longitudinal extent of said form section and plane intermediate portions between said ribs, selected ones of said intermediate portion being offset relative to other of said intermediate portions to the extent of the wall thickness of said form section, said form sections being assembled in longitudinal alignment with one another, with a said ofiset portion of one section overlapping a cooperating non-offset portion of the other said section to form a concrete-tight joint between said sections said non-otfset intermediate portions of successive sections lying in a common plane.

2. A form according to claim 1, in which every other One of said intermediate portions is offset downwardly toward the inside of the form.

3. A form according to claim 1, in which said offset portions have a width in a direction longitudinal of said form not greater than half the width of the non-offset portions.

4. A form according to claim 1, in which said form is provided with an end wall extending between said lateral walls.

5. A form according to claim 4, in which said form is supported by form planks and in which end wall extends below said lateral walls a distance equal to the thickness of the form planks by which said form is supported.

6. A form according to claim 4, in which said end wall has at its lower edge an outwardly extending flange having a width equal to half the width of a girder for said ceiling.

7. A form according to claim 4, in which said end wall is inclined and is provided at its upper portion with an inwardly projecting shoulder, whereby a plurality of forms can be nested for storing or transport.

8. A form according to claim 1, in which the outside contour of the terminal offset portion and adjacent rib wall of one section corresponds to the inside contour of the cooperating non-offset portion and adjacent rib walls of the other said section, whereby said sections are interlocked against longitudinal movement when assembled.

9. A form according to claim 1, in which the terminal offset portion of one section is of lesser longitudinal extent than the cooperating non-offset portion of the other said sections, whereby said sections are slidable relatively to one another in a longitudinal direction when assembled.

It). A form according to claim 1, in which the ribs are arranged in pairs with the intermediate portion between the two ribs of a pair offset relative to the portions between pairs of ribs by an amount equal to the wall thickness of the form.

11. A form body of vaulted shape for concrete ribbed ceilings, comprising longitudinally extending lateral wall portions and a top wall portion extending between said lateral wall portions and having vault sections extending transversely of said top wall portion substantially at right angles to the longitudinal axis of said form body, selected said vault sections being offset relative to other said vault sections toward the inside of said form body by the wall thickness of the material of. said form body and having a width in a direction longitudinal of said form body not greater than half the width of the non-offset vault sections.

12. A form body of vaulted shape for concrete rib ceilings, said form body being formed of material of substantial wall thickness and comprising longitudinally extending lateral wall portions and a top wall portion extending between said lateral wall portions and having transverse corrugations forming transverse ribs projecting toward the inside of the form body and intermediate vault sections between said ribs, selected said vault sections being offset relative to other said vault sections to the extent of the wall thickness of the material, whereby a plurality of said form bodies are assembled longitudinally of one another with a said offset vault section of one form body overlapping a said non-offset vault section of another form body to form a concrete-tight joint between said form bodies and with said non-oiiset vault sections of successive form bodies in longitudinal alignment with one another.

References Cited UNITED STATES PATENTS 1,999,783 4/1935 Riesbol 249-157X I. SPENCER OVERHOLSER, Primary Examiner DE WALDEN W. I ONES, Assistant Examiner US. Cl. X.R.

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