U.S. patent number 3,909,993 [Application Number 05/359,892] was granted by the patent office on 1975-10-07 for arch supported membrane structure.
This patent grant is currently assigned to Tension Structures Co., Jon Vredevoogd. Invention is credited to Carl F. Huddle.
United States Patent |
3,909,993 |
Huddle |
October 7, 1975 |
Arch supported membrane structure
Abstract
A pre-stressed arch supported membrane structure, a method of
assembly and erection and a means of tensioning a membrane of
double curvature supported by and attached to upright arches. By
moving the ends of flat resilient arch structural members closer
together, pre-stressed arches are formed by "bowing." Assembly and
erection consists of attaching flat arch member ends to base beams,
one fixed and one movable; attaching membranes to these flat
members when reclined on the ground, operatively attaching
transverse or inclined arch members to their respective structural
members; moving the non-fixed base beam towards the fixed base beam
thus causing the arches to be formed as the structure rises to its
erected position. Preliminary tensioning of the membrane can take
place when the transverse or inclined arches are attached to the
arch members in their reclined position. Final membrane tensioning
adjustments at the crown and at the base by moving the arches
horizontally then anchoring the structure to the base, safely
securing the base beams and arch ends completes the erection of the
main structure. An alternate method of erection is provided by
elimination of the base beams by fastening the arches directly to
the base. The support arches are bowed after being attached to the
transverse or inclined arches and then attached to the base by
means of an adjustable fastener. Lightweight end closures or doors
may be assembled and partially attached before erection to
eliminate or decrease above ground assembly.
Inventors: |
Huddle; Carl F. (Pleasant
Ridge, MI) |
Assignee: |
Vredevoogd; Jon (Mason, MI)
Tension Structures Co. (Pleasant Ridge, MI)
|
Family
ID: |
27000669 |
Appl.
No.: |
05/359,892 |
Filed: |
May 14, 1973 |
Current U.S.
Class: |
52/63; D25/21;
52/82; 52/222; 135/905; 135/124; 135/156; D21/834; 52/86; 135/117;
135/906 |
Current CPC
Class: |
E04H
15/425 (20130101); E04H 15/10 (20130101); E04B
1/3205 (20130101); Y10S 135/906 (20130101); E04B
2001/3217 (20130101); Y10S 135/905 (20130101); E04B
2001/3252 (20130101) |
Current International
Class: |
E04H
15/00 (20060101); E04H 15/34 (20060101); E04B
1/32 (20060101); E04H 15/10 (20060101); E04H
15/42 (20060101); E04B 001/32 (); E04B
001/347 () |
Field of
Search: |
;52/86,87,80,88,63,82,222,223R ;135/1R,4R |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Popular Mechanics, "Mushroom" Roof Supports Itself, p. 163, Oct.
1949..
|
Primary Examiner: Purser; Ernest R.
Assistant Examiner: Braun; Leslie A.
Claims
I claim:
1. A tensioned membrane shelter comprised of a multiplicity of
upright arches with curved bights, consecutively spaced apart in
parallel relationship and mounted on the ground or other base that
includes at least one shallow resilient transverse arch with each
end attached to an upright support arch and extending between them
in perpendicular relationship as it bridges at least one
intermediate upright support arch to form a structural frame in
space; a flexible but structural membrane operatively attached to
and extending between said upright support arches that is concavely
curved inwardly between the bights of said upright arches to form a
roof of double curvature that is tensioned longitudinally and
transversely between said upright arches; the arrangement being
such that the shallow transverse arch is bowed to urge apart the
upright support arches attached to its ends to maintain tension in
said membrane and to stabilize the structure.
2. The structure described in claim 1 wherein the upright support
arches are pre-stressed by bowing straight structural arch members,
by moving the opposite ends of each arch closer together.
3. The structure described in claim 2 that includes in addition, a
tension member that extends between the opposite ends of said
upright support arches to maintain their pre-stressed erected
state.
4. The structure described in claim 1 wherein the ends of said
upright support arches on at least one side of the structure are
operatively attached to a base beam which is secured to said
base.
5. The structure described in claim 1 wherein the ends of said
upright support arches are so attached to said base or to a base
beam to provide for adjustment horizontally.
6. The structure described in claim 1 wherein said structural frame
includes at least one upright support arch and one arch inclined
outwardly from the center of the structure with their apexes
aligned and operatively attached to each other near their crowns
and their ends attached to said base.
7. The structure described in claim 6 wherein said inclined arch is
adjustable horizontally on said base; the arrangement being such
that said membrane can be variably tensioned by moving said
inclined arch then securing it to the base to maintain said
membrane in tension.
8. The structure described in claim 1 wherein said shallow
transverse arch is more resilient under compression and bowing in a
plane perpendicular with the top surface of the upright support
arches where it is attached than in any other plane.
9. The structure described in claim 1 wherein said shallow
transverse arch is adjustable in length to vary the membrane
tension between said upright support arches to which it is
attached.
10. The structure described in claim 1 wherein the lower part of
the fexible roof membrane between the upright arches is attached
to: (a) the base, (b) the base beam, (c) the lower part of said
upright support arches.
11. The structure described in claim 1 with the addition of a
safety tension member that is attached to and extends between: (a)
the ends of said shallow transverse arc, (b) the upright arches to
which the shallow transverse arch is attached.
12. The structure described in claim 1 wherein said shallow
transverse arch is operatively attached to at least one
intermediate upright support arch, which it bridges, to maintain
alignment of said shallow transverse arch and maintain tension in
said roof membrane.
13. The structure described in claim 12 wherein the operative
attachment between the shallow transverse arch and the intermediate
upright support arch is adjustable in length to vary the tension in
the roof membrane.
14. The structure described in claim 13 wherein at least one
shallow transverse arch is adjustable in length and is adjustably
attached to at least one intermediate upright support arch which it
bridges.
15. The structure described in claim 12 wherein said shallow
transverse arch is operatively attached to at least one
intermediate upright support arch by (a) at least one resilient
means.
Description
BACKGROUND OF INVENTION
This structure is a combination of my patented inclined and
vertical arch structure but includes a new method of tensioning the
membranes between the arches and a new method of erection by which
very large structures can be assembled on the ground or base, then
erected and adjustments made to properly tension the membranes.
A double arch section in the structure can be used, similar to the
construction in my patent application, Ser. No. 49,811, June 25,
1970, for a "Pavilion With Intermediate Arch", to provide an area
to mount ventilation or other equipment and to also provide
additional structural strength to support overhead cranes, winches
or other such tools for aircraft or other maintenance.
These large shelters should have dependable, continuous membrane
fastener means for quick efficient assembly on the ground and to
prevent point stresses in the membranes as described in another of
my recent patent applications.
SUMMARY OF INVENTION
The principal object of this invention is to provide large arch
supported, highly tensioned double curvature membrane structures
that have clear spans with open ends, closed ends, or full opening
doors and are economical in cost and occupy a minimum of space in
addition to their sheltered area.
The second object of this invention is to provide curved arch
membrane supports that can be formed by "bowing," at the erection
site, from straight or flat structural members that are
sufficiently resilent to be bent to the arch shape desired and
still have the structural rigidity necessary to construct a
dependable, rugged structure that can safely withstand adverse
weather conditions and reasonable shock loads, if necessary.
Another object of this invention is to provide a method to erect
tensioned membrane structures by assembling the structural flat
arch members, used to form arches, to their base beams, attaching
the tailored membranes to these flat structural members, fastening
the membrane tensioning members to their respective structural
members, attaching the end closures, if any, and then erecting the
shelter by drawing the base beams toward each other to form the
structural curved arches.
Another object of this invention is to provide a method of
tensioning the membrane between the support arches by using
inclined arches to force the support arches apart in their crown
area.
Still another object of this invention is to provide a method of
tensioning the membrane(s) between the support arches by using
fairly flat transverse arches between two, or by spaning a
multiplicity of, support arches, to force apart the membrane
support arches.
A further object of this invention is to provide small and large
lightweight shelters that can be moved in their erected state,
weather conditions being favorable, or can be dismantled by
reversing the erection procedure and reassembled in another
location.
Another object of this invention is to provide a closer spaced,
multiple arch section in the structure to support equipment above
and below the roof.
A still further object of this invention is to provide a structual
end arch frame for the shelter to which a full opening door can be
attached and folded within the shelter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a structure using inclined arches
to tension the membranes between the arches.
FIG. 2 is a perspective view of a structure using transverse arches
around and above the structure to tension the membranes between the
arches.
FIGS. 3, 4 and 5 illustrates the erection procedure for a structure
having its membranes tensioned by an inclined arch.
FIGS. 6, 7, 8, 9 and 10 illustrates the erection steps for a
structure that has its membranes tensioned by overhead transverse
arches.
FIG. 11 is a perspective cutaway view of a shelter with overhead
transverse arches under the roof of the structure that tensions the
membranes between the arches.
FIG. 12 is a perspective view of a structure having vertical and
inclined arches with two vertical arches near the center of the
structure to carry extra external or internal loads.
FIG. 13 is a side view of the above structure indicating that a
multiple vertical arch section can be placed at other locations in
the structure.
FIG. 14 illustrates the assembly of typical equipment such as
cranes and hoists that can be supported by the multiple vertical
equipment module.
It is desired to point out that due to the application of these
structures from very small to very large shelters the illustrations
above do not show all the combinations of arch arrangements that
can result from this basic idea. As an example, support arches can
be placed closer together or wider apart. Inclined arches can have
different inclinations and can be located inside as well as outside
of the structure. The same goes for transverse arches. The base
beams can be omitted in some structures as the support arches can
be attached directly to a base and each support and inclined arch
can be individually bowed to the desired shape. All arches can also
have cross-ties to alter their shape for appearance or for better
structural support.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 the shelter illustrated has vertical end arches 1 and one
intermediate center arch 2. In between these arches are membranes 3
having a double curvature that are attached to and supported by the
vertical arches 1 & 2.
The inclined arches 4 are used to force apart the end arches 2
above the base by compression members 5. The membranes 3 can be
operatively attached to the inclined arches 4 to form a truss
effect between the end arch 1 and the inclined arch 4, the
compression members 5, and the tensioned membrane 6. All arches are
adjustable horizontally 7 on their bases to properly tension the
membranes near the base.
In some cases, it may be best not to attach the membrane 3 to the
inclined arch 4. This depends upon weather conditions, size of the
structure, etc. In such cases, the inclined arch 4 may have a
non-uniform cross-section to resist bending in critical areas.
Inclined arches 4 attached to the crowns of the exterior support
arches 1 and adjustably attached to the base can force the support
arches apart by moving the feet of the inclined arch 4 toward the
support arch 1. The latter support arch 1 can be moved to tension
the lower part of the membrane and align the structure.
In FIG. 2 the shelter is supported by a series of vertical curved
arches 8 that support a membrane 9 which is attached to the arches
8 that are forced apart by the transverse arches 10. The transverse
arches 10 are stabilized between the exterior arches by members 11
which can be shortened to increase the tension in the membranes 9
between the arches 8. All the arches can be adjustably attached to
the base 13 to properly tension the membranes between the arches 8
along the base and to align the shelter.
This is a method similar to the use of inclined arches except that
a series of transverse arches can be used to tension the membrane
9. The stabilizing members 11 are adjustable and can be resilent.
The transverse arches are also adjustable in length.
In FIG. 3 a plan view of one shelter with inclined arches is shown
before erection. Here all the arch members 1, 2 & 4 are laid
flat on the base (before bowing) to attach the vertical arch
members 1 & 2 and the inclined arch members 4 to the base beams
13. These vertical arch members 1 are positioned closer together to
permit easy attachment of membranes 3 & 6, in this position,
before erection. The inclined arches 4 are curved on the flat base,
in the same plane as the vertical arch members 1 & 2, attached
to the apex of arch members 1 and the base beams 13.
In FIG. 4 one base beam 13a is anchored in its final position
before the bowing operation to erect the structure or the vertical
arch members 1 & 2 can be individually bowed (fix one arch end
to the base) after the assembly operation, if desired. The base
beams 13 are then drawn closer together (FIG. 4) by winches 14 or
other means.
For small shelters of this type, base beams 13 can be manually
pulled together by brute force or pushed together by manpower, a
vehicle, etc.
In shelters of all sizes, the vertical curved arches 1 & 2 and
the inclined arches 4 are formed from the flat arch members to
support and tension the membranes 3 respectively, by moving the
base beams 13 to which the arches are attached closer together
which causes the structure to rise. This operation is continued
(FIG. 5) until the shelter reaches its erected position. The final
adjustments in alignment and tensioning of the membranes are then
made by moving the arches horizontally in their attachment to the
base beam. Anchoring of the structure is completed to be sure the
shelter will not lift or blow away. Tie cables 14a, steel rods or
other tension members can be used between the base beams 13 to make
sure the arch ends do not separate under the constant pressure of
the bent arch members. Safety cables 15 can also be used to prevent
collapse of the structure in case of membrane 3 failure.
In FIG. 6 the shelter in FIG. 2 is shown in its reclined assembly
position. The base beams 13 are placed at the ends of the flat arch
members 8 which are positioned for easy attachment of the membrane
9 and then attached to the base beams 13.
In FIG. 7, the membrane tensioning arch members 10a in their
reclined flat shape are placed over the arches. The stabilizers 11
are connected to the members 10a but need not be at their final
length. The ends 16 of transverse arch members are then moved
closer to each other causing the flat member 10a to rise and form a
rather flat arch 10, which is then attached to the exterior arches
(FIG. 8) (or between each two arches if shorter rather flat arches
are preferred.) This causes the membranes 9 to be tensioned to a
selected value. In shelters where a long arch 10 is used between
several arches 8, or between exterior arches, the tension in the
membrane 9 can be adjusted by changing the length of the arch 10
and/or stabilizers 11 that attaches the arch 10 to the intermediate
arches 8. Safety cables 17 can be installed between the vertical
arches 8 to prevent collapse of the structure in case of membrane 9
failure.
In the erection of this structure it seems best to provide guys 18
to guide the structure upward when the base beams 13 are drawn
together by winches 14 or moved towards each other by any other
method or force. As the structure rises sufficiently (FIG. 9) to
put enough curvature in the arch members 8, the guys 18 can be
disconnected as the shelter becomes more and more stable as it
reaches its final position (FIG. 10).
The base ends of the arches 8 are then adjustable on the base beam
13 to properly tension the membranes 9 at the base 12. Some
adjustments may be necessary to align the shelter to its design
position.
In FIG. 11 the transverse arches 19 that tension the membrane 9 are
shown inside the shelter and under the arches 8. This design offers
a cleaner appearance for the exterior but some obstructions to the
interior space. Crossing safety cables 21 between adjacent arches
can be used on the interior but will again possibly interfere with
interior occupancy. Safety cables from arch apex to arch apex in
the interior will cause movement of the arches 8 with membrane
failure as they must follow the membrane 9 sag line when
installed.
In FIG. 12 an end enclosure 22 has an uneven surface to obtain
membrane curvature in more than one direction. When this is
designed with convex curvatures 23 of more than 5% between outward
points to inward points or valleys, and the membrane tensioned by
pushing out on the exterior projections, the enclosure can
withstand severe wind loads. These wind loads will be transferred
to the arch frame of the shelter which is prevented from racking by
the tensioned membrane 9 between the arches 8.
In FIG. 13 a section of the structure is shown that has two closer
spaced arches 24 to obtain greater structural strength to support
utilities, ventilators, skylights, cranes, winches or other
equipment. This multiple arch section may be located anywhere in
the structure. More than one of these sections can also be used.
When closely spaced arches 24 are used, the space between them 25
can be bridged or covered by fairly thin sheets of plywood, metal,
composite material, etc. that can be installed before or after
erection. In FIG. 14 thin sheets of such material 26 is easily bent
to the curve of the arches and attached to the arches. These sheets
can be made stiff enough by reinforcing 27, if necessary, to
support exterior equipment 28 and some interior fixtures for
lighting 29, sprinklers, etc. The two arches can be structurally
bridged 30 to support winches 31, monorail devices or bridge cranes
for maintenance and/or repair work on equipment below that is
sheltered in the structure. This feature is similar to the one
shown in my application Ser. No. 49,811, dated June 25, 1970
entitled, "Pavilion With Intermediate Arch and Method of Assembling
and Erecting It.
* * * * *