U.S. patent number 3,634,989 [Application Number 05/003,764] was granted by the patent office on 1972-01-18 for modular tower.
Invention is credited to Cyril B. Rogers.
United States Patent |
3,634,989 |
Rogers |
January 18, 1972 |
MODULAR TOWER
Abstract
A prefabricated modular tower structure in which the ends of
each of the legs of one module are joined to the legs of an
adjacent module by an integral angularly disposed connector tube
adapted to receive two bolts.
Inventors: |
Rogers; Cyril B. (Tampa,
FL) |
Family
ID: |
21707470 |
Appl.
No.: |
05/003,764 |
Filed: |
January 19, 1970 |
Current U.S.
Class: |
52/651.09;
52/651.01; 403/306; 52/637; 52/655.1 |
Current CPC
Class: |
E04H
12/10 (20130101); Y10T 403/5741 (20150115) |
Current International
Class: |
E04H
12/10 (20060101); E04H 12/00 (20060101); E04h
012/10 () |
Field of
Search: |
;287/54E,54B,53.5,54C
;52/726,638,637,641,640,645,646,584 ;182/178 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
88,747 |
|
Jul 1958 |
|
NL |
|
384,769 |
|
Dec 1932 |
|
GB |
|
431,576 |
|
1948 |
|
IT |
|
765,287 |
|
1934 |
|
FR |
|
1,263,311 |
|
1961 |
|
FR |
|
1,408,330 |
|
1965 |
|
FR |
|
Primary Examiner: Sutherland; Henry C.
Claims
Now that the invention has been described what I claim is:
1. A skeleton tower comprising a plurality of vertically stacked,
modular sections, each section including a plurality of vertical
legs spaced about the periphery thereof, the vertical legs of one
section being in aligned, end-abutting relation with the legs of
the adjacent section, means connecting the legs together at the
abutting ends, said means comprising a connector tube fixedly
connected to each end of each leg, the tubes at the abutting ends
of the legs forming a pair, the longitudinal axes of the tubes
being in angular relation to the longitudinal axes of the legs, the
pair of connector tubes at the abutting ends of the legs being
aligned with each other, and fastening means traversing said tubes
and clampingly joining the tubes together.
2. The structure of claim 1 wherein said fastening means comprises
nut and bolt combination including a bolt positioned on the
interior of the pairs of connector tubes, and a nut lockingly
engaging one extremity of said bolt so as to be maintained in
frictional engagement with one end of one of said tubes, whereby
said tubes are maintained in locked, aligned engagement with one
another.
3. The joint structure of claim 1 wherein said pairs of connector
tubes have abutting end faces which are angular to a horizontal
plane.
4. The joint structure of claim 1 wherein said pairs of connector
tubes have abutting end faces which are in a horizontal plane.
Description
The invention relates generally to a modular tower structure and
more particularly to a modular tower which utilizes at the ends of
each leg angularly disposed tubes which are bolted together to
fasten the several modules of the tower together.
With the ever increasing use of communication systems, lighting
systems, scaffolds, etc., there is an established need for a
lightweight tower structure which is strong, yet requires minimal
storage and transportation volume and can be rapidly and sturdily
erected. Presently there are two methods of assembling and erecting
towers.
In one method, the tower is completely built in lengthwise sections
of predetermined height in a prefabricating shop and then shipped
to a tower erection site where the sections are assembled, one on
top of another, until a desired tower height is obtained. Typical
patents describing this type tower are: U.S. Pat. Nos. 2,267,638;
2,305,563; 2,462,429; 2,893,521; 3,360,288; 3,156,329; 3,365,853.
The other method is to transport the tower in small basic
components in unassembled condition then, at the job site, assemble
the components into a tower. Typical patents describing this type
are U.S. Pat. Nos. 2,014,784 and 2,060,436.
The particular form which the tower (or scaffold) takes is
generally dictated by its intended use. For instance, towers which
are adapted to carry heavy loads are generally constructed, in the
field, from precut structural steel form. However, towers intended
for supporting lighter loads may be prefabricated in modular units
and these modules assembled at the site of the tower
construction.
In modular construction, it is common practice to join two sections
together by passing bolts, rivets or other similar fastening means
through the tubular legs to join them together. The legs commonly
overlap each other for a short distance. This type of joint is
objectionable in that the holes for the bolt passage usually weaken
the legs, particularly when they are placed in tension. Sometimes
the fasteners are tightened to such an extent that the tubular leg
is flattened. This is particularly true where the tubular leg has a
relatively thin wall. Such deformation causes the leg to assume an
oval or other cross section and this reduces, in at least one
direction, the effective radius of the leg, thus reducing its
strength in column action.
It is therefore an object of this invention to provide a novel
modular structure which maintains the full working strength of its
legs.
Another object is to provide a connector joint for a modular tower
which avoids passing bolts or other fasteners through the tower
legs in a radial direction.
Still another object is to provide a prefabricated modular tower,
the connector joints of which are as sturdy as the legs to the
modular sections.
A further object is to provide a modular tower connector joint
which has a minimum amount of play.
A still further object is to provide a modular tower connector
joint which is easy to assemble whereby the amount of assembly
labor needed is diminished.
Another object is to provide a modular tower structure which may be
assembled at the erection site by simply connecting the modules
with bolts.
Another object is to provide a modular tower structure which,
during assembly, has a self-aligning ability by reason of the
unique connector joint.
Another object is to provide a modular tower structure in which the
modules are easily transportable with minimum use of space.
Another object is to provide a modular tower structure which is
economical to manufacture.
Other objects of the invention will in part be obvious and will in
part appear hereinafter.
The above and other objects not specifically enumerated are
efficiently attained by providing on the ends of each leg of the
tower an angularly disposed connector tube through which a bolt or
other similar fastening means is then passed and tightened. The
connector tube is preferably welded on the end of the tower leg and
so angularly disposed with respect to the leg of the adjacent
module and its connector tube so that the bolt may be easily
slipped through the cavity of both connector tubes.
The invention accordingly comprises the features of construction,
combination of elements, and arrangement of parts which will be
exemplified in the construction hereinafter set forth, and the
scope of the invention will be indicated in the claims.
For a fuller understanding of the nature and objects of the
invention, reference should be had to the following detailed
description in which:
FIG. 1 is a broken front view of an erected modular tower
illustrating the manner in which the connectors of the present
invention operate.
FIG. 2 is a top view of FIG. 1.
FIG. 3 is a cross-sectional view of one connected joint through
line 3--3 of FIG. 2.
FIG. 4 is an exploded cross-sectional view of a second embodiment
of a joint.
Similar reference characters refer to similar parts throughout the
several views of the drawing.
Referring now to FIG. 1, there is shown a prefabricated modular
tower 10. Each section or module 12 may be of any desired length,
usually 8 or 10 feet, so that handling and transporting of the
module is made easier. The tower sets on a suitable base 14,
usually a sound concrete footing of customary design. Its upper end
supports a superstructure 16 which may be adapted to support a
platform, an antenna system, or a light system or any other high
device.
The tower may be supported by a plurality of standard guy wires
(not shown) which may be attached, in any suitable manner, to the
tower at various points and to a suitable anchoring means in the
ground.
Each module 12 has a plurality of vertical legs 18 which may either
be tubular or solid. The module shown in FIG. 1 has three legs in
horizontal cross section through the tower which form an
equilateral triangle (see FIG. 2.). It is also possible to use a
greater number of legs, such as four, five, six, etc. with
appropriate change in the cross-sectional configuration such as a
rectangle, pentagon, hexagon, etc.
Legs 18 are maintained in a rigid, spaced relationship with respect
to each other by a lattice work of truss chords 20 of conventional
construction. Typically, truss chords 20 are formed into a
plurality of W, X or Z shapes which are welded or otherwise
attached to legs 18.
The ends of each leg 18 of each module 12 have a connector tube 22
secured thereto, usually by welding. The tube 22 of the upper
module has the same angular relationship as the mating connector
tube of the lower module (see FIGS. 3 & 4) whereby a bolt 24
may be simply passed therethrough to join the upper and lower
modules together. A nut 26, with or without washers 28 and 30, is
threaded on the bolt until the two connector tubes are tight.
Referring now to FIG. 3, the tubes 22 are shown with abutting end
faces 32 angular to a horizontal plane.
FIG. 4 illustrates the situation where the connector tubes 22 have
abutting end faces 34 which are in a horizontal plane. The
connector tube end face of FIG. 3 is preferred because, in erecting
the modules, one upon the other, the angled end faces tend to
"center" the modules with respect to the one below it. Then by mere
insertion of one bolt 24 in one of the mating connector tubes of
that module, the entire module is stabilized until the other bolts
are inserted in the other connector tubes.
The cavity in the connector tubes 22 and the diameter of bolts 28
may be of any reasonable dimension. Typically, a 3/8-inch bolt is
used with a 13/32-inch inner diameter connector tube. Using high
strain steel for bolts 24, a 3/8-inch bolt has a sufficiently large
root area that it can safely be tightened to develop approximately
12,000 pounds tension. This is normally sufficient to resist normal
wind or other loads on a tower.
It will thus be seen that the objects set forth above, among those
made apparent from the preceding description, are efficiently
attained and, since certain changes may be made in the above
construction without departing from the scope of the invention, it
is intended that all matter contained in the above description or
shown in the accompanying drawing shall be interpreted as
illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended
to cover all of the generic and specific features of the invention
herein described, and all statements of the scope of the invention,
which, as a matter of language, might be said to fall
therebetween.
* * * * *