Concrete form unit
US 2341993 A
Description (OCR text may contain errors)
1 l w. A. JENNINGS 2,341,993
7 CONCRETE FORM UNIT Filed Nov. 25, 1940 a Sheets- -sheet 2 a L rllllllllk IIIWW/ I .N M 9 w INVENTOR.
w. A. JENNINGS CONCRETE FORM UNIT 7 Filed Nov. 25, 1940 3 Sheets-Sheet 3 ATIIORNEYS.
Patented Feb. 15, 1944 UNITED STATES PATENT OFFICE CONCRETE FORM UNIT William Allen Jennings, Des Moines, Iowa Application November 25, 1940, Serial No. 367,082
Claims. (01. 25-131) My invention relates to that class of forms used for making concrete structures in which there is employed a number of units detachably connected to define the surface boundaries of the structure when the concrete is poured.
Another object is to provide an improved type of construction for a form unit which is particularly useful in making units of odd sizes or irregular shapes.
Another object is to provide a form unit which when used in conjunction with well-known clamping means will fit tightly at the joints ad.- jacent the surface of the concrete, and thus avoid formation of upstanding ribs or fins in the surface of the concrete structure.
A further object of my invention is to provide a type of form unit with punched flanges, in which the perforations punched in the flanges are arranged symmetrically about a center line of the plate.
Still a further object is to provide another type of form unit with perforations uniformly spaced longitudinally of th flange, in which the distance from a corner of the unit to the center of the first perforation is the same as the center to center distance of the uniformly spaced perforations.
Another object is to provide form units each having a row of perforations extendin longitudinally along a flange of the unit, in which the distance from the centers of the perforations in the row to the surface of the unit which bounds the concrete structure is uniform, so that units so constructed may be connected in adjacent relation by centering means extending through the holes in adjacent flanges on units placed edge to edge.
With these and other objects in view my invention consists'in the construction, arrangement and combination of the various parts of my device whereby the objects contemplated are attained, and in the method of making such a device, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, in which:
Figure 1 is an elevational view of a fragmentary portion of a punched flange strip used in making my units.
Figure 2 is an exploded perspective View of a form unit showing the elements which enter into the assembly.
Figure 3 is similar to Figure 2, being a perspective view of the finished assembly.
Figure 4 is an enlarged fragmentary horizontal sectional view taken'on the line 4-4 of Figure 3.
Figure 5 is a view similar to Figure 4 showing a modified form of flange construction. c
Figure 6 is an exploded perspective view ofa form unit in which the perforations are arranged somewhat differently from those in Figure 2.
Figure '7 is a perspective view showing the relation in which units made according to my invention are assembled.
Figure 8 is a perspective view of portions of adjacent units, showin one stage in the procedure of connecting them by a clamp.
Figure 9 is a sectional view showing the rela tion of the flanges in Figure 8.
Figure 10 is a view similar to Figure .8, showing another stage in the procedure of connecting the units.
Figure 11 is a sectional view correspondin to Figure 9, showing the relation of the flanges in Figure 10.
Figure 12 is a view corresponding to Figure 9, showing a modified form of a flange construction.
Figure 13 is a view corresponding to Figure 11, showing the modified form of flange construction.
Figure 14 is a view corresponding to Figure 9, showing a second modified form of flange construction.
Figure 15 is a view corresponding to Figure 11, showing the second modified form of flange construction.
Figure 16 is an elevational View of portions of the adjacent edges of two units made according to one form of my invention, showing one form of corner construction.
Figure 17 is a view corresponding to Figure 16, but showing another form of corner construction.
In the accompanyin drawings I have used the reference numeral 20 to designate generally what I refer to in this application as a base plate, which is cut from sheet metal, usually sheet iron,
. to the desired shape and size.
'24 and 25.
The numeral 22 designates a flange member, which according to the method of my invention is preferably formed from a punched strip of metal, as illustrated particularly in Figure 1. This strip is provided with row of perforations As indicated in Figure 1, the holes 24 and 26 are uniformly spaced apartlongitudinally of the flange strip 22, the standard unit of spacing being indicated by the reference character A.
- The perforations 2B are uniformly spaced from the adjacent edge of the flange strip22,v- In Figures 2 and 3 it will be seen how portions of the "or odd shaped form units.
strip 22, cut to the proper length, are applied to the base plate 20 by welding or other suitable means, to form a flange which is seen in detail in the sectional view of Figure 4. The spacing of the holes 26 from the edge of the flange strip is determined by the fact that according to my invention all perforations 26 in a set of form units should. be the same distance from the surface 28 of the base plate 2!] (Figure 4) which contacts and forms the boundary of the concrete struc ture. Th thickness of the plate 29 may be different in different units, inasmuch as the requirements of strength and rigidity make it advisable to use heavier material in larger units. Consequently the distance B (in Figure 1) from the center line of the holes 26 to the adjacent edge of the strip 22 is dependent upon the thickness of the plate 20 with which the particular strip is to be used, and the dimension B is made such that when added to the dimension C (the thickne'ss of plate 29) it will give a distance D which is uniform for all units. The holes 24 are similarly formed in the strip 22 at a distance E from the edge determined by the thickness C of the plate 29 with which the strip 22 is to be used, and such that E plus C for all units in the set will be a uniform value F.
All the perforations 24 and 26 are of the same size, and preferably of circular shape. Therefore when two units made as described are placed with their flanges adjacent, (see Figure 8) insertion of the tapered pin 30 of a clamp 32 through any pair of adjacent holes in the flanges will bring the surfaces 28 of the respective base plates 20 into accurate alignment.
Rectangular units can be made in various sizes, having dimensions which are multiples of the dii'nension A, the unit of longitudinal spacing of the holes. With the uniformly spaced holes, it will be apparent that many combinations of units may be connected together, using the clamps 32, to make up a panel of practically any dimensions which may be required in a particular construction job.
\ For maximum interchangeability it is desirable that the units be constructed with lengths and widths which are integral multiples of the dimension A. The flanges for such a unit are preferably out to length through the transverse center line of a pair of holes 24 and 26. When the flanges so made are attached to the plate, the unit will have on all sides perforated flanges in which the first pair of holes at each corner is spaced from the corner of the unit by a distan'c'e A. Standard units so formed can be used to ether in innumerable combinations, since they may be arranged and combined in any way desired.
Forms somewhat similar to those above described, but with the flanges bent up integrally from the base plate, have been in use, but their economical manufacture required the use of tools and jigs which were conveniently adaptable only for making form units of the standard integral unit sizes. The manufacture of odd-size or irregularly shaped form units with integral flanges was either impossible or commercially impracticable.
In many concrete structures, however, special conditions give rise to requirements for special My method of assembly, as above described, is admirably adapted to meet such requirements.
It is only necessary to cut the base plate to shape, out side pieces to length from the punched flange-strip, and weld the side pieces onto the base plate to form flanges. The flange strip, as pointed out previously, has its holes spaced transversely to allow for base plates of a given thickness. If various thicknesses are used for plates of different sizes, it is necessary to have a stock of flange strip for each thickness to be used. The economy and simplicity which this procedure makes possible contributes greatly to the ease and convenience of building concrete structures with metal form units. Special architectural or ornamental featurees can be provided for at minimum additional cost.
Many of such odd shaped or such special forms will have dimensions which are not integral multiples of the standard spacing unit A. It is therefore desirable to arrange the perforations in the flanges in some consistent manner such that the maximum convenience and utility in the use of the special form units can be achieved. In Figure 3 is illustrated one type of construction for the flanges which I have found satisfactory. It involves selecting one corner of the unit as a reference point, preferably a right angle corner such as 44 in Figure 3. From this corner along the two adjacent sides the perforations follow the standard unit spacing, coming "out at the corners 46 and 48 in whatever manner may be determined by the lengths of the intervening sides. An odd shaped unit formed as described can always be fitted into a standard panel assembly along the two sides described. In some cases, 'oval holes (elongated lengthwise of the flanges) can be employed on odd sides, so that adjacent panels with standard punchings can be fitted flush with either end of the odd side.
A second form of construction for the flange perforations is illustrated in Figure 6. According to this modification the flange is cut in such a manner that its perforations are symmetrical about the transverse center line of the flange. Where the length of theflan'ge is not an integral multiple of the perforation spaces, this will ordinarily mean that the distance from the corner of the unit to the first perforation is not a standard unit. However, a rectangular form unit such as that shown in Figure '6, when the perforations are symmetrically arranged as described, has the advantage that it may be turned end for end interchangeably, and hence it does not have to be examined "carefully to see which way it will fit when it is being put in place.
In concrete forms employing units of the general kind here involved, the joints between units give rise to numerous problems. The units often receive hard use in the field, so that they become slightly bent or distorted. Also, even units in first class condition may deflect slightly under the stresses resulting when the concrete is poured, particularly when vibration or other impact'ing methods are used. If distortions resulting from such causes are sufficient to bring about separation of the adjacent edges of base plates 29 in an assembly of form units, the concrete will run into the spaces between the units, making ribs or fins in the surface of the concrete structure which remainafter the form units are removed. The ribs can be chiseled or ground off by abrasive wheels, but this operation obviously involves additional expense, and is not entirely satisfactory because the lines in the cement are What run out into the crack between the units, whereas the coarser aggregates, being unable to pass into the narrow space, are retained. When the rib is chipped or ground away, the
strip of coarser structure is exposed, and does not match the rest of the concrete surface.
It will be appreciated, therefore, that 'form units which fit tightly at the edges under all practical conditions of use, are highly desirable.-
The construction which I have devised for attaining the desired result is illustrated in Fig-; ures 7-17. It consists principally in arranging the flanges 22 on the base plate 20 in such a Way that the free edges 34 of the flanges are spaced inwardly from the plane passing through the edge of the base plate and perpendicular to the base plate. With such a construction, when two units are placed in adjacent relation, with their base plates lying in the same plane, the free edges of the flanges will normally be somewhat spaced apart, as seen in Figures 9, 12 and 14. These three figures illustrate three various forms of construction which embody my invention. In Figure 9 the flange 22 is attached perpendicularly to the base plate 20, but is inset slightly from the edge of the base plate. In Figum 12 the flange 22 is attached to the base plate flush with the edge of the latter, but is inclined inwardly somewhat as may be seen in the figure. Figure 14 shows a modified construction in which the flange 22a is formed integrally with the base plate 20 by folding the sheet of metal from which the base plate is made. A reverse fold in the flange gives it additional strength. As in the Figure 12 form, the flange is inclined in- Wardly.
In all three of the forms illustrated it will be appreciated that when the jaws 36 of the clamp 32 are pressed down over the free edges of the adjacent flanges, the flanges will be pulled together. The successive stages of this operation are illustrated in perspective in Figures 8 and 10, and in sectional views in Figures 11, 13 and 15. Obviously the important result of the clamping is that the base plates 20 are drawn tightly together along the line 38. A very firm, secure fit is thus obtained, and with form units constructed as in Figures 9 and 12 the formation of ribs or ridges at the joints is practically eliminated.
With the integrally formed flange of Figure 14, a slight rib will appear in the concrete, because the units must necessarily have slightly rounded corners at 38. However, the heel or base of the flanges at 38 will be held in tight fitting relation so that there will be no seepage of the fines in the concrete mixture. Such a rib as does result with this type of unit can therefore be ground ofi without exposing a strip of coarser aggregate.
Form units incorporating the inset flange of my invention can be made up in several ways, each having certain advantages. In Figure 7 I illustrate one form, in which a flange is inset from the edge of the base plate, as shown in section in Figure 9. Thi'sinset at the attached edge of the flange is continued throughout its length.
In Figure 16 I show a form which would appear in-section like Figure 12 or like Figure 14. It consists of a flange which is attached to the base plate flush with the edge thereof. The flanges at their ends 40 (i. e., at the corners of the form unit) are perpendicular to the base plate. Intermediate the corners, as at 42, the flanges are inclined inwardly, so that when the units are placed in adjacent relation the flanges are spaced apart at their free edges, in the manner indicated in Figures 12 and 14. The advantage of this type of construction is that the tight fitting feature of my invention is obtained by the inclined intermediate portions of the flange, whereas the square corners help to retain adjacent panels in a straight line when they are clamped together without requiring exceptionally sturdy auxiliary lining means.
Figure 1'7 shows a modified form in which the flanges are attached at the base plate substantially flush with the edges thereof. The flanges are inclined throughout their length. This type of construction has the advantage of simplicity I for units of various sizes.
and economy in manufacture. Units of any size can be made conveniently by affixin a standard strip to the base plate according to the method above set out, without any special jigs or fixtures Obviously, however, since the cornersof the units are not square, a. panel assembly consisting of a number of units clamped together must be retained in a straight line by auxiliary alignment means such as a wood or metal beam clamped to the various units. The same would also be true of the type of construction illustrated in Figure 7.
The various modified forms shownin Figures 7, 16 and 17 all have the common feature that the free edge of the flange, at points intermediate'the ends thereof, is inset from the plane passing through the edge of the base plate and perpendicular to it. Thus in all these forms, when the clamp jaws are applied, the flange edges are sprung together, and a positive tight fit at the heel of the flange, adjacent the base plate, is achieved.
Some changes may be made in the details of procedure involved in the practice of my method, and in the construction and arrangement of the parts of the devices which I have described, without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any variant modes of procedure and any modified forms of structure or use of mechanical equivalents which may reasonably be included within their scope.
1. A concrete form panel consisting of a base plate, upstanding flanges around the periphery of said base plate, and a row of perforations extending longitudinally along said flanges, said perforations being uniformly spaced from the plane of the surface of said base piate opposite said flanges, and said flanges being so shaped that the outer edges thereof, at points intermediate the corners of the panel, are inset from the respective planes perpendicular to the base plate through the edge of the base plate, whereas the ends of said flanges, at the comers of the panel lie in said respective planes.
2. A concrete form unit comprising a flat base plate and a flange on said base plate having a plurality of perforations therein, said flange being perpendicular at its ends to said base plate, and being inclined inwardly relative to said base plate at points intermediate its ends.
3. The combination of a pair of form units each comprising a base plate and a flange along one edge thereof, said flange at its ends lying in the plane perpendicular to the base plate through the edge thereof, the free edge of the flange, at points intermediate the ends of the flange, being normally inset from the plane perpendicular to the base plate through the edge thereof, said units being positioned with their flanges in adjacent relation and with their base plates in substantially the same plane, and clamp means embracing said adjacent flanges intermediate their ends and tending to draw the free edges of said flanges together.
4. The combination of a pair of form units each comprising a base plate, a flange along one edge thereof, and a row of perforations formed in said flange, uniformly spaced longitudinally thereof and uniformly spaced from the outer surface of said base plate, said flange at its ends lying in the plane perpendicular to the base plate through the edge thereof, the free edge of the flange, at points intermediate the ends of the flange, being normally inset from the plane perpendicular to the base plate through the edge thereof, said units being positioned with their flanges in adjacent relation, aligning means extending through adjacent perforations in said adjacently positioned flanges, and clamp means embracing said adjacent flanges intermediate their ends and tending to draw the free edges of said flanges together. 7
5. A concrete form unit comprising a base plate having a plurality of substantially straight edges, and an upstanding flange along one of said edges, the free edge of said flange, at points intermediate the ends of the flange, being normally inset from the plane perpendicular to the base plate through the edge thereof, and the ends of said flange lying in said plane.
WILLIAM ALLEN JENNINGS.