US2816435A

US2816435A - Head frame for structural column

Info

Publication number: US2816435A
Application number: US456912A
Authority: US
Inventors: Donahue John Stanley; George E Strehan
Original assignee: Lally Column Co
Current assignee: Lally Column Co
Priority date: 1954-09-20
Filing date: 1954-09-20
Publication date: 1957-12-17
Anticipated expiration: 1974-12-17

Description

Dec. 17, 1957 J. s. DONAHUE ETAL HEAD FRAME FOR STRUCTURAL COLUMN 2 Sheets-Sheet 1 Filed Sept. 20, 1954 x J F Dec. 17, 1957 J. 5. DONAHUE ET AL 2,816,435

HEAID FRAME FOR STRUCTURAL COLUMN Filed Sept. 20, 1954 2 Sheets-Sheet 2 F195. 4 64 1/ ad i EA 2 a United States Patent Office 2,816,435 Patented Dec. 117,, 1957 HEAD FRAME FOR STRUCTURAL COLUMN John Stanley Donahue, 'Chesmut Hill, Mass, and George E. Strehan, Leonia, N. J., assignors to Lally Column Cu., Cambridge, Mass, a corporation of Massachusetts Application September .20, 1954, Serial No. 456,912

Claims. (CI. 72-15) This invention relates to building columns of the concrate-filled steel pipe type, and pertains more particularly to frames for transmitting the shear and bending movement of ;a floor or roof to the shaft of the column.

The principal object of this invention is to provide a compact and inexpensive head frame which can be'readily assembled .on a column of the concrete-filled :steel \pipe type, which has members extending .sidewise from the top of the column for connection to floor and roof structures, which is sufliciently strong and rigid to transmit relatively high bending and shear loads, and which permits mounting of a second column on top in the usual manner. Another object of importance is to provide a frame which, while having the necessary load carrying capacity, is sufficiently shallow to be completely enclosed in the floor or roof structure which the column supports so as to eliminate projections in the ceiling around the column. The frame here described is especially suitable for embedding in floors of the reinforced concrete slab type which are poured in place, but may also be connected to other conventional floor supporting structures made, for example, of steel or wooden beams.

The frame consists in general of a short piece of cylindrical pipe of smaller diameter than the casing of the column to be used, and a number of beams projecting radially and welded to the pipe. The beams are preferably I-beams and have their top and bottom flanges coped to clear the outside of the column, the webs being received in slots in the column. The short pipe, and adjoining portions of the webs of the beams, are all embedded in the concrete, or similar material, with which the column is filled. The flanges of the beams preferably butt against the outside of the column casing and are welded thereto.

Recommended embodiments of the invention are illustrated in the accompanying drawings, but it will be understood that the structural details and arrangement of elements herein shown and described may be varied to suit particular conditions without departing from the essence of this invention as defined in the appended claims.

In the drawings,

Fig. 1 is a vertical cross-section of a column head on which a frame constructed according to the invention has been installed, showing the frame embedded in a typical reinforced concrete slab floor;

Fig. 2 is a cross-section taken along line 22 of Fig. 1;

Fig. 3 is a cross-section taken along line 33 of Fig. 1;

Fig. 4 is a cross-section taken along line 44 of Fig. 1; and

Fig. 5 is an exploded view of the frame and column head prior to their assembly.

As shown in the drawings, the column 10, of generally conventional construction, consists of a cylindrical steel casing 11 enclosing a core 12 of concrete or other plastic material of high compression strength. Around the head of the column four radial slots 13 are cut in the casing. The four

arms

14, 15, 16, and 17 of the head frame are received in these slots. The arms are in the form of I- beams, with their top and bottom flanges coped to leave web extensions 14a, 15a, 16a, 17a which project through the .slotsin thecasing. The ends of these extension butt against a short piece of cylindrical pipe 18, of smaller diameter than the column casing, and are welded to the pipe by fillet welds along either side, as best seen in Fig. .5. A .pair of dowels .19 and 2.0 are "setcrosswise in the lower partof the pipe.

When the frame is-assembledionthe-head of the column, pipe 18iis mounted concentrically inside the upper part-of casing 11, the web extensions rest in the slots 13, and the

arms

14, 15, 16 and 17 extend radially from the head of .the column- The ends of the top and bottom flanges :of the arms, where they abut the outside of the :casing are butt welded to the casing. Preferably. also, the webs of the beams are welded to the casing along either side of therslots, the welds filling any 'clearancespace in thesloits,

so that the continuity of the slotted region of the casing.

is substantially restored. The head frame is assembled in this manner to the casing before the concrete core is poured, so that the pipe and "web extensions will be embedded and anchored .in the core of the finished column. The

dowels

19 and 20 provide additional anchorage.

The column and frame are prefabricated and assembled together in the factory and shipped out ready for use. This head frame lends itself especially well to reinforced concrete construction where the floor slab, indicated by the numeral 22 in Fig. 1, is poured in place around the arms. As the latter are completely embedded in the floor slab, the ceiling 23 is flat right up to the column. This type of structure has excellent fire resistance because of the fact that the load carrying arms are completely encased in concrete. The frame is also adapted to steel or wood construction, the floor beams being bolted or otherwise connected to the top flanges or webs of the arms in any convenient manner.

If a second column is to be mounted above the head frame, anchor bolts 24 of conventional type are embedded in the core of the lower column. These bolts are disposed around the pipe 18 in the spaces between the arms, and the bent-in lower ends 25 of the bolts extend under the bottom of the pipe. It will be noted that the

dowels

19 and 20 are aligned with the arms so as to leave clear space around the pipe for insertion of the anchor bolts. A head plate 26 is attached to the upper ends of the anchor bolts, and the upper column, indicated by the dotted outline 27, is mounted on the head plate in the usual manner. The head plate is disposed diagonally with respect to the arms and the corners of the plate overlapping the arms are bolted to their top flanges by pairs of bolts 28.

The arms of the frame may be made from standard I-beams, or from other beams of generally similar section shape, such as wide flange beams, or H-beams. It is understood that the size of the beams and the length of the arms may be varied to suit the load conditions for which the head frame is intended. The frame is here shown as having four arms, but it is apparent that more or fewer arms may be secured to a central pipe and mounted in a similar manner.

What is claimed is:

1. A head frame and column assembly comprising: a column having a hollow cylindrical casing and a plastic core; four vertical slots disposed apart around the upper end of said casing; a tubular post of smaller diameter than the casing embedded in the core in the upper end of the column; four beams projecting radially from said casing in line with said slots, said beams having top and bottom flanges connected by upright webs, and the flanges being coped to leave web portions projecting through said slots and connected to said post; anchor bolts mounted in the column in the spaces between said web portions around said post; and a square head plate mountedon the top of the column with its corner regions overlying said beams, the head plate being connected to said anchor bolts, and also being connected, at its corner regions, to the top flanges of the beams.

2. A head frame and column assembly comprising: a column having a hollow casing and a plastic core; vertical slots disposed in spaced relationship around the upper end of the casing; a hollow post enclosed in the upper end of the casing and embedded in the core; a number of beams projecting radially in spaced relationship from said casing, said beams having top and bottom flanges connected by upright webs, and the flanges being coped to leave web portions projecting through said slots and connected to said post; anchor bolts mounted in the column in the spaces between said web portions around said post; and a head plate mounted on the top of the column and having regions overlying said beams, the head plate being connected to said anchor bolts, and also, in said regions, to the top flanges of the beams.

' 3. A head frame and column assembly comprising: a column having a hollow casing and a plastic core; vertical slots disposed in spaced relationship around the upper end of the casing; a hollow post enclosed in the upper end of the casing and embedded in the core; a number of beams projecting radially in spaced relationship from said casing, said beams having upright web portions exregion of the slots being welded to the casing by welds closing the slots.

5. A head frame and column assembly as described in claim 3, said post having dowels projecting radially from its lower end, the dowels being likewise embedded in the core.

References Cited in the file of this patent UNITED STATES PATENTS 835,718 Thorn Nov. 13, 1906 869,869 Lally Oct. 29, 1907 969,097 Ford Aug. 30, 1910 1,185,207 Lally May 30, 1916 1,190,002 Picuri July 4, 1916 1,472,600 Lally Oct. 30, 1923 2,176,007 Heanue Oct. 10, 1939