US3247639A

US3247639A - Form supporting girder for use in concrete construction

Info

Publication number: US3247639A
Application number: US323288A
Authority: US
Inventors: Rambelle Robert Dela
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-11-13
Filing date: 1963-11-13
Publication date: 1966-04-26
Anticipated expiration: 1983-04-26
Also published as: GB1037139A

Description

A ril 26, 1966 H. A. DE LA RAMBELJE 3,247,639

FORM SUPPORTING GIRDER FOR USE IN CONCRETE CONSTRUCTION Filed Nov. 13, 1.963 2 Sheets-Sheet 1 NOW BY CHANGE OF mu ROBERT DELA RAMBELL BY 2 ATTORNEYS.

April 1966 H. A. DE LA RAMBELJE 3,247,639

FORM SUPPORTING GIRDER FOR USE IN CONCRETE CONSTRUCTION 2 Sheets-Sheet 2;

Filed Nov. 13, I963 INVENTOR. HENRY A.DE LA RAMBELJE NOW BY CHANGE OF NAME BY ROBERT DELA RAMBELLE 6 TTOR/VEYS United States Patent 3,247,639 FORM SUPPORTHNG GERBER FUR USE IN NRETE CGNSTRIJQTiUN Henry A. de la Ramheije, lilZ-Zd 86th Ave, Richmond Hill, N.Y., now by change of name Rohert Dela Rarnbeiie Filed Nov. 13, 1963, No. 323,288 3 tllainrs. (El. 52-4532) The invention relates to adjustable form supporting girders for concrete construction and more particularly to improvements in girders of the telescopic type.

Girders of the telescopic type in general comprise a cambered box-like section and an I-beam section slidable lengthwise within the cambered box-like section for adjustment of the length of the girder. Locking means are provided for holding an outer end surface of the I-beam section pressed against an inner surface of the cambered box-like section. The cambering of the two sections produces a slight upward arch in the assembled girder as needed to compensate for the deflection produced by the weight of the concrete mix poured on the forms supported by the girders. When the deflection values have been taken into account correctly, the camber of the girder will straighten out under the load so that the ceilings of the poured structure will be level and flat. While it is a relatively simple matter to roll a slight bend into the I- beam section to produce the desired preformed camber therein, it is not so easy to do this where the section to be cambered is in the form of -a box. To camber a box section requires elaborate special machinery in order to prevent buckling and distortion of the walls of the box. In my prior patent, No. 3,054,486, dated September 18, 1962, I described and claimed how to make the box section of a girder from two channel sections, one cambered and the other straight, the two sections being welded together. This simplified cambering by reason of the fact that it is quite easy to camber the upper channel with the use of standard rolling equipment. Also, the resulting box section in such a construction is deeper where the bending momemt is greatest, i.e., toward the center of the section. While my prior patented construction produced a satisfactory girder as demonstrated by widespread successful use in the construction of concrete buildings, I have now discovered how tosecure the same advantages in a girder which is much simpler and easier to manufacture. In particular I have discovered how to produce the eifect of a camber in an extruded box section without bending the section at all, how to form the Lbeam section of such a girder so that it will have improved lateral rigidity, and how to utilize these improved constructions in producing integral end supports and also to provide for a cooperating inlay of polyvinyl chloride or other material of similar characteristics the advantages of which will be described in more detail below.

According to my invention, the box-like section is constructed of a single extruded member having opposed side walls and upper and lower walls extending between the side walls and at least one flange extending lengthwise of the box-like section and projecting upwardly above the upper wall, such upwardly projecting flange being higher toward the center of the box-like section than toward the ends thereof to produce a camber in the uppermost surface of the box-like section without cambering such section as a whole. Because the upwardly projecting flange (or flanges) is higher toward the center of the box-like section than toward the ends thereof, the overall depth of the section toward the center will be greater. The lateral rigidity of the I-beam section is increased by providing at least one upwardly projecting shoulder extending lengthwise of the I-beam. In my preferred construction there is a pair of upwardly projecting shoulders with inwardly projecting lips extending along their top edges, forming a pocket to receive a strip of polyvinyl chloride material, or the like. The provision of the upwardly extending flange (or flanges) on the l-section also serves to so strengthen the upper portion of the I that it can be used to form an integral end support by cutting away portions of the web and lower flanges of the I. These and other features and advantages of my invention will be set forth in more detail in the ensuing description of the best mode contemplated by me for carrying out my invention. 1

FIG. 1 is a side elevational view of a girder constructed.

in accordance with my invention, showing the girder in place and ready for use. The initial camber of the two girder sections has been exaggerated to show it more clearly.

FIG. 2 is a similar view, partly in vertical section, showing the girder deflected under the weight of the poured concrete.

FIG. 3 is a vertical transverse sectional view taken on the line 3-3 of FIG. 1.

FIG. 4 is a detail perspective view of one end of the box section of the girder of FIG. 1.

FIG. 5 is a similar perspective view of one end of the I-beam section of the girder of FIG. 1.

FIG. 6 is a vertical transverse sectional view similar to FIG. 3 showing another embodiment of the invention.

FIG. 7 is a detail side elevational view of one end of the box section of a girder of modified construction.

FIG. 8 is a vertical transverse sectional View of a girder constructed in accordance with a further embodiment of the invention, and

FIG. 9 is a detail side elevational View of the boX section of the girder of FIG. 8.

My adjustable form supporting girder comprises in its general arrangement a cambered box-like section 1 and an I-beam section 2 slidable lengthwise within the boxlike section for adjustment of the length of the girder, and locking means 3 for holding an outer end surface of the I-beam section pressed against an inner surface of the box-like section. The box-like section 1 is constructed of a single extruded member having opposing side walls 4., 4, upper walls 5 and lower walls 6 extending between the side walls and one or more flanges 7 extending lengthwise of the box-like section 1 and projecting upwardly above the upper wall 5. In the preferred construction shown, an upwardly projecting flange 7 is provided along each of the upper corners of the box-like section.

A particular feature of my invention resides in making the upwardly projecting flanges 7 higher toward the center of the box-like section than toward the ends thereof to produce a camber in the uppermost surface of the box section without cambering such section as a whole. Inasmuch as the box section is designed to be extruded it will be understood that the flanges 7 will then be formed initially so as to be of a uniform height throughout the length of the section. Thereafter, the upper edges of the flanges are cut down according to any desired conventional machining process so that the height thereof will be reduced toward the ends of the section. According to the specific embodiment shown in FIG. 1, the end portions :1 of the flanges 7 are machined on a slope while the central portion 11 may be left in its original extruded form. As so constructed the flanges 7 will be of a uniform height throughout the central portion 12 and then slope off on an even inclined plane a toward each end of the section. Thus an arch is formed by the upper surfaces of the portions at and b of flanges 7, such arch being of polygonal configuration which due to the flatness of the arch approximates the are or" a circle. As used herein and in the appended claims theterrn camber refers to the arched upper surfaces of the girder sections and includes arched surfaces of arcuate and polygonal forms. Such surfaces could even be discontinuous, the essential point being that they are higher toward the center of the girder sections than toward the ends thereof, so that when the girder is under load it will afford supports lying approximately in a single plane.

The I-beam section 2 comprises the web 8, upper flanges 9 and lower flanges It). At least one upwardly projecting shoulder 11 extends lengthwise of the I-beam. In the preferred construction shown, a pair of upwardly projecting shoulders 11 is provided, such shoulders extending along the edges of the upper flanges 9 of the I-beam. Shoulders 11 have inwardly projecting lips 12 extending along their top edges. This construction strengthens the I-beam section by providing increased lateral rigidity and also forms a pocket at the top of the I-beam into which is inserted a strip 13 of polyvinyl chloride material, or the like. Such strip 13 is conveniently slid into the end of the pocket where it is held in place by the lips 12 and may be locked against removal by suitable fastenings 14 (FIG. such as a machine screw threaded into one of the flanges 9 of the I. The strip 13 is notched out at its upper corners to receive the lips 12 so that the upper surface of the strip will bear against the under side of upper wall 5 of the box section. By reason of the smooth glassy non-porous surface of the vinyl resin material cement droppings will not readily adhere to it, making it easy to clean. It is contemplated that the girder sections may be extruded from aluminum or other light metal or of plastic resin materials suitably reinforced with fiberglass as desired. Whenever the materials chosen for the extruded sections of the girder are such as to make it advantageous to use the polyvinyl resin-or other insert 13, such insert provides the additional function of a nailing strip so that the usual plywood forms placed on the girders can be conveniently secured in place by nailing down into the strips 13.

In my preferred construction, at least one of the end portions of the box-like section 1 is provided with channelshaped depressions 15 extending along upper side portions thereof, such depressions being provided by laterally extending flanges 16 terminating in upwardly projecting flanges 17. Inwardly extending lips 18 rimming the top edges of depressions 15 extend into notches at the upper corners of inserted strips 19 of polyvinyl chloride material and the like. It is contemplated that the channels 15 will be formed as a part of the box section extrusion. If desired, portions of the channel constructions can be cut away after the extrusion has been cut into the desired lengths. Such cut-away portions are shown by the dotdash lines 20 in FIG. 4. Alternatively, channels 15 may be allowed to remain in place for the full length of the box section, in which case the inserts 19 can also be extended for the full length of the box section.

In the preferred construction shown in FIG. 4, portions of the side walls 4 of the box-like section are cut away leaving projecting end supports 21, 21 comprising U- shaped channels integral with the box-like section. Supports 21 are adapted to rest against the tops of ledgers I. of a supporting framework as shown in FIG. 1. Similarly, portions of the web 8 and lower flanges 18 are cut away at at least one end of the I-beam section, FIG. 5, leaving a projecting end support 22 comprising a U-shaped channel integral with the I-beam section. If desired, the upper edges of the U-shaped supports 21 and 22 may be tapered downwardly and outwardly as at 23,FIG. 4, and 24, FIG. 5.

In the modified form shown in FIGS. 6 and 7, channels 15 are omitted and box section 1, in addition to the top flanges 7', has downwardly extending marginal flanges 25 further strengthening the box section extrusion. In this construction the box section is symmetrical about its transverse horizontal center line. Thus it can be sawed into lengths by a diagonal out line 26, FIG. 7, alternate sections being inverted for use without wasting any of the extrusion. Suitable end supports 27 are welded or otherwise secured to one end of the box section. Such supports are designed for cooperation with a pinch bar 28 inserted between the base of the support and the ledger L for the purpose of wedging the girder away from the ledger by telescoping the two sections of the girder together slightly for removal of the girder when stripping away the forms following setting of the poured concrete.

FIGS. 8 and 9 illustrate another embodiment of the invention in which the box section 1" is extruded in a form in which one of its side walls is comprised of a pair of vertically aligned

sections

29, 30 giving the box-like section the cross-sectional configuration of a rectangular C. The ends of the C are then tied together by suitable fastening means. This may be accomplished, for example, by forming the aligned

sections

27, 28 with inwardly extending terminal flanges 31 apertured to receive bolts 32. As was true of the embodiment of FIGS. 6 and 7, the box section of the form shown-in FIGS. 8 and 9 is symmetrical about its transverse horizontal center line and can be diagonally cut at its ends without wasting any of the material of the original extrusion, alternate sections merely being turned upside down.

The terms and expressions which I have employed are used in a descriptive and not a limiting sense, and I have no intention of excluding equivalents of the invention described and claimed.

I claim:

1. An adjustable cambered form-supporting girder for concrete construction comprising a box-like section and an I-beam section slidable lengthwise within the box-like section for adjustment of the length of the girder, locking means for holding an outer end surface of the I-beam section pressed against an inner surface of the box-like section, said box-like section being constructed of a single extruded member having opposed side walls and upper and lower Walls extending between the side Walls, and at least one flange extending lengthwise of the box-like section and projecting upwardly above said upper wall, said upwardly projecting flange being higher toward the center of the box-like section than toward the ends thereof to produce a camber in the uppermost surface of the boxlike section without cambering such section as a whole.

2. An adjustable form-supporting girder according to claim 1, in which an upwardly projecting flange of the construction defined is provided along each of the upper corners of said box-like section.

3. A cambered box-like section for a form-supporting girder for concrete construction comprising a single extruded member having opposed side walls and upper and lower walls extending between the side walls, and at least one flange extending lengthwise of the box-like section and projecting upwardly above said upper wall, said upwardly projecting flange being higher toward the center of the box-like section than toward the ends thereof to produce a camber in the uppermost surface of the boxlike section without cambering such section as a whole.

References Qited by the Examiner UNITED STATES PATENTS 385,624 7/1888 Hodges 52-376 ,804,673 9/1957 Fex 25-131.5 3,054,486 9/1962 De la Rambelj 52-632 FOREIGN PATENTS 1,218,573 12/1959 France.

FRANK L. ABBOTT, Primary Examiner.

RICHARD W. COOKE, Examiner.

Claims

1. AN ADJUSTABLE CAMBERED FORM-SUPPORTING GIRDER FOR CONCRETE CONSTRUCTION COMPRISING A BOX-LIKE SECTION AND AN I-BEAM SECTION SLIDABLE LENGTHWISE WITHIN THE BOX-LIKE SECTION FOR ADJUSTMENT OF THE LENGTH OF THE GIRDER, LOCKING MEANS FOR HOLDING AN OUTER END SURFACE OF THE I-BEAM SECTION PRESSED AGAINST AN INNER SURFACE OF THE BOX-LIKE SECTION, SAID BOX-LIKE SECTION BEING CONSTRUCTED OF A SINGLE EXTRUDED MEMBER HAVING OPPOSED SIDE WALLS AND UPPER AND LOWER WALLS EXTENDING BETWEEN THE SIDE WALLS, AND AT LEAST ONE FLANGE EXTENDING LENGTHWISE OF THE BOX-LIKE SECTION AND PROJECTING UPWARDLY ABOVE SAID UPPER WALL, SAID UPWARDLY PROJECTING FLANGE BEING HIGHER TOWARD THE CENTER OF THE BOX-LIKE SECTION THAN TOWARD THE ENDS THEREOF TO PRODUCE A CHAMBER IN THE UPPERMOST SURFACE OF THE BOXLIKE SECTION WITHOUT CAMBERING SUCH SECTION AS A WHOLE.