# Patent

## Title
Motion damping system designed for reducing obstruction within open spaces

## Abstract

The invention provides for a method, system and apparatus for resisting and restraining potentially destructive movement within a building structure while introducing little or no obstruction with respect to how a building structure is designed and how it is intended to function.

## Background
CROSS REFERENCE TO DOCUMENTS INCLUDING RELATED SUBJECT MATTER
This document is a United States non-provisional utility patent application. This document includes subject matter that is related to subject matter of U.S. Pat. Nos. 5,934,028 and 5,870,863 to Taylor, which are each entitled “Toggle Linkage Seismic Isolation Structure”, and to U.S. Pat. No. 6,438,905 to Constantinou, entitled “Highly Effective Seismic Energy Dissipation Apparatus” and to U.S. Patent to Haskell, which is entitled “Building Damper Apparatus”. The above aforementioned patent documents are herein incorporated by reference in their entirely.
BACKGROUND OF THE INVENTION
Building structures are at risk from damage and destruction from various harmful events, including for example, earthquakes, wind storms and explosions. These harmful events can cause unwanted motion within the building structure leading to damage and/or destruction of the building. The resistance of a building to such harmful events can be reinforced via addition to the building structure of apparatus that is designed to reduce the unwanted and damaging motion within the building structure itself. However, measures to reinforce a building structure can cause interference with respect to how a building structure is designed and how it is intended to function.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE INVENTION
The invention provides for a method, system and apparatus for resisting and restraining potentially destructive movement within a building structure while introducing little or no obstruction with respect to how a building structure is designed and intended to function.



BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention can encompass other equally effective embodiments.
The drawings are not necessarily to scale. The emphasis of the drawings is generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Differences between like parts may cause those parts to be indicated with different numerals. Unlike parts are indicated with different numerals. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which:
FIG. 1A illustrates a building structure including ground level bays (open spaces) that are designed to provide storage (ingress and egress) for road vehicles.
FIG. 1B illustrates a building structure, similar to that of FIG. 2A, that has suffered catastrophic damage from a seismic event.
FIGS. 2A-2G each illustrates various embodiments of prior art apparatus employed to absorb and remove seismic energy within a building structure during a seismic event.
FIGS. 3A-3D illustrate two embodiments of a damping apparatus of the invention including a damper that is cable tethered to anchors located along a perimeter portion of a bay, in order to minimize obstruction within the bay.
FIGS. 4A-4B illustrate an embodiment of a damping apparatus of the invention including actuator rods and rotatable lever arms and a damper located proximate to an upper portion of a bay.
FIGS. 5A-5B illustrate an embodiment of a damping apparatus of the invention including actuator rods and rotatable lever arms attached to a damper located proximate to a side portion of a bay.
FIG. 6A-6B illustrates an embodiment of a damping apparatus of the invention including multiple dampers that are separately attached to actuator rods and a rotatable lever arm.
FIGS. 7A-7D collectively illustrate two embodiments of a damping apparatus of the invention that are each designed to resist relative movement with respect to a series of multiple bays each having locations collectively spanning multiple stories within a building structure.
FIGS. 8A-8B illustrate an embodiment of a damping apparatus of the invention that also spans multiple stories within a building structure and that includes a damper located at a lower elevation than that other apparatus components.
FIGS. 9A-9B collectively illustrate an embodiment of a damping apparatus of the invention that is designed to resist movement across a set of horizontally and vertically adjacent bays collectively spanning multiple stories within a building structure.



DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A illustrates a building structure including ground level bays (open spaces) that are designed to provide storage (ingress and egress) for road vehicles. As shown, there are (5) garage doors that each provide access to a ground level bay for which a road vehicle can be sheltered.
FIG. 1B illustrates a building structure, similar to that of FIG. 2A, that has suffered catastrophic damage from a harmful event. As shown, a lower portion of a building structure has collapsed as a result of this harmful event. The lower portion of the building structure appears to have included ground level bays including at least one garage (ground level bay) for shelter of an automobile. An upper portion of the building structure appears to have collapsed onto an automobile that was located within one of the ground level bays.
FIGS. 2A-2G each illustrate various embodiments of prior art apparatus employed to absorb and remove seismic energy within a building structure during a seismic event.
FIG. 2A is a diagram that illustrates an apparatus designed to resist movement of structural members that are located along a perimeter of a bay 210 within a building structure. This apparatus includes a damper 220a and a rod 222 that are attached in series and that together span between a lower left hand corner and an upper right hand corner of a bay 210 within a building structure.
FIG. 2B illustrates the apparatus 200 of FIG. 2A under relative motion. A deflection angle 226a indicates a rightward motion of an upper beam 212 relative to a lower beam 214 of the bay 210.
The design of this apparatus visually and physically obstructs an otherwise accessible area located within the bay 210. For example, if this bay functioned as an opening to a garage, installation of the apparatus 200 would obstruct and prevent an automobile from passing through the bay 210 to enter or exit the garage. If this bay were a window, the apparatus would at least partially obstruct a view through this window.
FIG. 2C is a photograph of an apparatus like that of FIG. 2A, as it is installed within outdoor ground level bays of a building structure. As shown, the ground level bays are designed to pass visual light and air and are not designed for passage of a large physical object, such as that of an automobile.
FIG. 2D is a diagram that illustrates an apparatus 250 designed to resist movement of structural members that are located along a perimeter of a bay 210 within a building structure. This apparatus includes a damper 220b that is pivot attached to an upper beam 212 and pivot attached to a top portion of a peak shaped structure 224. This peak shaped structure is also referred to as a chevron brace. A bottom portion of the peak shaped structure 224 has a first end 224a and a second end 224b that are each is fixedly attached to a lower left corner and to a lower right corner respectively, of the bay 210.
FIG. 2E illustrates the apparatus 250 of FIG. 2D under relative motion. A deflection angle 226b indicates a rightward motion of an upper beam 212 relative to a lower beam 214 of the bay 210.
FIG. 2F is a photograph of an apparatus like that of FIG. 2D, as it is installed within an indoor bay of a building structure. As shown, the bay is not designed for passage of an automobile.
FIG. 2G is a photograph of an apparatus like that of FIG. 2D, as it is installed within outdoor and near ground level bays of a building structure. As shown, the near ground level bays are designed to pass visual light and air and are not designed for passage of large physical objects, such as automobiles.
FIGS. 3A-3D collectively illustrate two embodiments 300, 350 of a damping apparatus of the invention that each include a damper 320 that is tethered via cables 334a-334b to end anchors 330a-330b, or 330c-330d, that are mounted to structural members that are located along a perimeter portion of a bay 310. The bay 310 is located within a building structure. These damping apparatus embodiments 300, 350 are designed to resist against undesirable movement of these structural members. This damping apparatus 300, 350 is further designed to minimize visual and physical obstruction of the bay 310 that is caused by installation of the damping apparatus itself, while it is disposed within the bay 310. Any obstruction caused by this damping apparatus is substantially less than obstruction caused by many other prior art damping apparatus, such as that shown in FIGS. 2A-2G.
As shown in FIG. 3A, a damper 320 is mounted (fixedly attached) to a structural member, specifically an upper beam 312, that is located along a first side of the perimeter of the bay 310. The damper 320 is designed to provide extension (tensile) resistance to pulling forces of cables 334a-334b, that are each attached to opposite sides of the damper 320. Cable 334a is attached to a first attachment interface (of the damper 320) that is located on a left hand side of the damper 320. The cable 334b is attached to a second attachment interface (of the damper 320) that is located on a right hand side of the damper 320.
Intermediate anchors 332a and 332b are each protrusions that are fixedly attached to and protrude away from a near side of the upper beam 312. The cables 334a and 334b are each arranged to make physical contact with and pass outside of and along a curved surface of each respective intermediate anchor 332a-332b, and to each fixedly attach to the damper 320. Each of the curved surfaces facilitates movement (sliding) of each respective cable 334a-334b while it is pressing against and passing outside of each respective intermediate anchor 332a-332b. An intermediate anchor including a curved surface to make physical contact with an anchor is preferred to reduce friction between the cable and the intermediate anchor, especially while there is movement of the cable while it is pressing against and being restrained by the intermediate anchor.
An intermediate anchor can be of a loop type of design, including an inner curved surface, like that of an inner surface of a donut shaped loop, for example, where the loop portion of this intermediate anchor surrounds the cable (analogous to a cable passing through a hole of a metal donut) to create a barrier to prevent lateral movement of the cable to a location that is outside of the boundary defined by the hole of the loop, but instead allowing movement of the cable so that it can be pulled in either of two opposite directions through the hole of the loop. This hole defined by the loop functions as a receiving portion within this type of intermediate anchor. Alternatively, an intermediate anchor can be of a non-loop (partial loop) design and have an outer exposed surface, such as that of the inner surface of a semi-circle, that projects towards and presses against a cable and restrains the cable from lateral movement away from the confines of the partial loop formed by the inner surface of the semi-circle. This intermediate anchor functions without entirely surrounding and restraining the cable from movement in any lateral direction, but instead allowing movement of the cable so that it can be pulled in either of two opposite directions across the inner surface of the partial loop. The inner surface of this non-loop intermediate anchor design functions as a receiving portion of this type of intermediate anchor.
The cable 334a has a first end that is attached to the first attachment interface on the left hand side of the damper 320 and a second end that is attached to an end anchor 330a. The cable 334b has a first end that is attached to the second attachment interface located on the right hand side of the damper 320 and a second end that is attached to the second end anchor 330b. The end anchor 330a is fixedly attached to a near side of the left column 316, which is a structural member located along a left side of the perimeter of the bay 310. The end anchor 330b is fixedly attached to a near side of the right column 318, which is a structural member located along a right side of the perimeter of the bay 310. As shown, the bay 310 forms a rectangular shape having (4) right angle corners separating each horizontal beam 312-314 and vertical column 316-318.
Cross-section viewing perspective 340 illustrates a cross-sectional side view of the apparatus 300 as installed onto the bay 310. The intermediate anchor 332a is shown protruding away from upper beam 312. The end anchor 330a is shown protruding away from the left column 316.
As shown in FIG. 3B, when under stress, from perhaps a potentially harmful event, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bay 310, and within the bay 310 itself. This relative motion can cause deflection among the beams 312-314 and columns 316-318 of the bay 310.
With the deflection, as shown within FIG. 3B, the upper beam 312 moves slightly towards a right hand direction relative to the lower beam 314, as measured by a deflection angle 326. During this deflection, vertical columns 316-318 slightly tilt in a clockwise direction and an upper portion of each column 316-318 moves towards the right hand direction while attached to the upper beam 312, and a lower portion of each column 316-318 remains attached to the lower beam 314.
FIG. 3C shows a damping apparatus like that of FIG. 3A, except for that intermediate anchors 332c and 332d are each located on a lower side of the upper beam 312. Also, the end anchors 330c and 330d are located on an inner side of the vertical columns 316-318 respectively.
As shown in FIG. 3D, when under stress, relative motion can occur between the earth and the building structure, between the earth and the bay 310, and within the bay 310 itself. This relative motion can cause deflection and/or deformation among the beams 312-314 and columns 316-318 that are located along a perimeter of the bay 310.
With relative motion, as shown within FIG. 3D, the upper beam 312 moves slightly towards a right hand direction relative to the lower beam 314, as measured by a deflection angle 326. During this deflection, vertical columns 316-318 slightly tilt in a clockwise direction where an upper portion of each column 316-318 moves towards the right hand direction while attached to the upper beam 312, and a lower portion of each column 316-318 remains attached to the lower beam 314.
It should be understood that only a small amount of deflection of the bay, as a result of relative motion, can cause catastrophic damage to the bay 310 and to the building structure itself. For example, in typical building structures, as little as a (5) degree deflection angle to a bay, can cause permanent damage and/or to or even collapse of the building structure itself.
In some embodiments, for example, the damper has an extension stroke rating of 2 inches and a maximum extension and/or compression resistance force rating of 10,000 pounds. In other embodiments, the stroke of the damper is 10 inches and its maximum extension and/or compression resistance is 500,000 pounds. Note however that a 500,000 pound rated damper would have a much larger width dimension (perpendicular to a direction of the stroke) than that of the 10,000 pound rated damper.
In some embodiments, the intermediate and end anchors are typically made from a metallic material, for example a steel alloy, and are fastened to respective structural members via a metal band that is designed to wrap around each respective structural member.
In some embodiments, cables 334a-334b are made from one quarter inch diameter metallic material, such as a steel alloy, and can withstand a maximum tensile force of approximately 2.5 tons. In other embodiments, the cables 334a-334b are made from one half inch diameter metallic material, such as a steel allow, and can withstand a maximum tensile force of approximately 20 tons. Some cables having a diameter of 2 inches can withstand a maximum tensile force of 200 tons.
The above described invention is not limited to the arrangement (3) shown in FIGS. 3A-3D. Although the lower beam 314 is shown as having no attached end anchors, in other embodiments, one or both end anchors 430a-430b may be attached to the lower beam 314. In other embodiments, one or both of the intermediate anchors 332a-332b can be mounted onto the left column 316 and right columns respectively.
In other embodiments, the damper 320 can mounted on a structural member other than the upper beam 312. For example, the damper 320 and intermediate anchors 332a-332b can be located on the lower beam 314 while the end anchors 330a-330b, 330c-330d are each located on an upper portion of the left and right columns respectively. Also, in some embodiments, the damper 320 is instead mounted on a column 316, 318 while the intermediate anchors 332a-332b. and optionally the end anchors 330a-330b or 330c-330d are mounted onto a respective beams 312, 314.
In another one half sided (mirrored) embodiment, the damper 320 has one attachment interface, one cable 334a, one intermediate anchor 332a and one end anchor 330a, and consequently, resists motion traveling in only one first direction. As shown, this one half sided embodiment would resist relative motion along a first direction from a left hand to a right hand side of the bay 310.
However, another mirror image of this one half side embodiment, including another damper 320, one other cable 334b, one other intermediate anchor 332b and on other end anchor 330b, is designed to resist motion in a second direction of relative motion that is opposite to the first direction, and is installed into another bay (not shown), that is horizontally adjacent to bay 310 for example. The another bay that is located for example, adjacent to the right hand side of the bay 310 shown in FIGS. 3A-3D. In this arrangement, each side of the damping apparatus 300 is separately and respectively installed into each one of the pair of horizontally adjacent bays and each one side of the apparatus is designed to resist each relative motion from the respective two opposite directions that collectively affects this pair of horizontally adjacent bays. As an example showing the concept of this type of embodiment, sec FIGS. 6A-6B as an example of each mirrored one half side of a damping system 600 that is instead installed into each horizontal half of one bay. Each side of this damping apparatus resists forces in opposite directions. Each side of this damping system can instead be installed into separate and horizontally adjacent bays within a building structure.
FIGS. 4A-4B illustrate an embodiment 400 of a damping apparatus of the invention that includes a damper 420 that is physically attached to a first end of rod 434a and to a first end of a rod 434b. Each rod 434a-434b also has a second end that is each attached to a separate bell crank 432a-432b respectively. Bell crank 432a and 432b are each fixedly attached to and located on an under side of the upper beam 312 of bay 310. Bell crank 432a is also attached to a first end of rod 436a and bell crank 432b is also attached to a first end of rod 436b. Rod 436a has a second end that is fixedly attached to end anchor 430a, which is fixedly attached to an inner surface of the left hand column 316. Rod 436b has a second end that is fixedly attached to end anchor 430b, which is fixedly attached to an inner surface of the right hand column 318.
This damping apparatus embodiment 400 is designed to resist and restrain movement of structural members of the bay 310 of the building structure. The damping apparatus is further designed to reduce visual and physical obstruction of the bay 310 that is caused by the damping apparatus being disposed within the bay 310, as compared to obstruction caused by another prior art damping apparatus, such as that shown in FIGS. 2A-2G.
As shown in FIG. 4A, a damper 420 is swivel mounted and fixedly attached to a structural member, and is here shown to be specifically attached to an upper beam 312, that is located along a first side of the perimeter of the bay 310. The damper 420 is designed to provide at least one of extension (tensile) resistance to pulling forces of the rods 434a-434b and compression resistance to pushing forces of the rods 434a-434b that are each attached to opposite sides of the damper 420. Preferably, the damper 420 provides both extension and compression resistance to pulling and pushing forces of the rods 434a-434b respectively. Rod 434a is attached to a first attachment interface (of the damper 420) that is located on a left hand side of the damper 420. The rod 434b is attached to a second attachment interface (of the damper 420) that is located on a right hand side of the damper 420.
Bell cranks 432a and 432b are fixedly attached to and protrude away from an underside of the upper beam 312. A pushing force from rod 436a causes bell crank 432a to rotate clockwise and to pull rod 434a away from damper 420. A pulling force from rod 436a causes bell crank 432a to rotate counter clockwise and push rod 434a towards damper 420. Likewise, a pushing force from rod 436b causes bell crank 432b to rotate counter clockwise and to pull rod 434b away from damper 420. A pulling force from rod 436b causes bell crank 432b to rotate clockwise and push rod 434a towards damper 420.
As shown in FIG. 4B, when under stress, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bay 310 and between portions of the bay 310 itself. This relative motion can cause deflection among the beams 312-314 and columns 316-318 of the bay 310.
With deflection, as shown within FIG. 4B, the upper beam 312 moves slightly towards a right hand direction relative to the lower beam 314, as measured by a deflection angle 426. During this deflection, vertical columns 316-318 slightly tilt in a clockwise direction and an upper portion of each column 316-318 moves towards the right hand direction while attached to the upper beam 312, and a lower portion of each column 316-318 remains attached to the lower beam 314.
The above described invention is not limited to the arrangement shown in FIGS. 4A-4B. The damper 420 can be located on a different structural member along the perimeter of the bay 310. Although the lower beam 314 is shown as having no attached end anchors, in other embodiments, one or both end anchors 430a-430b may be attached to the lower beam 314. In other embodiments, a bell crank 432a can be mounted onto the left column 316 and/or bell crank 432b can be amounted onto the right column 318.
Also, the dimensions of the bell cranks 432a-432b can be altered. Each bell crank has (lever) arms, the length of which affects an amount of leverage provided by a bell crank 432a-432b to a rod attached to it. The longer a lever arm, the more leverage and length of stroke proved to an attached rod. The shorter a lever arm, the less leverage and length of stroke provided to an attached rod. Each bell crank 432a-432b is sized to accommodate a length of stroke of a damper 420 that is attached to the bell crank 432a-432b via a rod 434a-434b. 
Also note that a rod is required to have a wider dimension to withstand a compression force than is required for it to withstand an extension (tensile) force of the same strength as the aforementioned compression force. In other words, a rod of a particular diameter can withstand a much larger maximum extension (tensile) force without breaking apart than it can withstand a maximum compression force without bending.
As a result, an apparatus that resists destructive motion via resistance to extension (tensile stress), requires non damper hardware, such as metal rods that are thinner (less wide and of shorter diameter) than the rods of an apparatus that is designed to resist motion via resistance to compression. Furthermore, apparatus that is designed to resist destructive motion via resistance to extension (tensile stress), can in some circumstances, substitute one or more rods with a cable as shown in FIGS. 3A-3D, to resist such extension force loads.
FIGS. 5A-5B illustrate an embodiment 500 of a damping apparatus of the invention that includes a damper 520 that is physically attached to a third side 318, specifically the right hand side column 318, of the perimeter of the bay 310. A first end of rod 536a is attached to damper 520. A second end of rod 536a is attached to a bell crank 532a. A first end of rod 536 b is also attached to an opposite side of bell crank 532a. A second end of rod 536b is attached to bell crank 532b. A first end of rod 536c is attached to bell crank 532b. A second end of rod 536c is attached to an end anchor 530. The end anchor 530 is fixedly attached to an inner side of the left hand column 316.
Like prior embodiments of the invention, this damping apparatus embodiment 500 is designed to restrain movement of structural members of the bay 310 of the building structure. The damping apparatus is further designed to reduce visual and physical obstruction of the bay 310 that is caused by the damping apparatus being disposed within the bay 310, as compared to obstruction caused by another prior art damping apparatus, such as that shown in FIGS. 2A-2E.
As shown in FIG. 5A, a damper 520 is fixedly attached to a structural member that is located along a perimeter of the bay 310. This structural member is specifically a right hand side column 318 as shown here, that is located along a third side of the perimeter of the bay 310. The damper 520 is designed to provide compression resistance to pushing forces and designed to provide extension resistance from pulling forces, via its attachment to the rod 536a, which is directly attached to the damper 520. The rod 536a is also attached to rod 536b via bell crank 532a, and rod 536b is also attached to rod 536c via bell crank 532b. Hence, the damper 520 is indirectly attached to rods 536b-536c via bell cranks 532a-532b, and rod 536b is indirectly attached to rod 536c via bell crank 532b. 
Bell cranks 532a and 532b are fixedly attached to and protrude away from an underside of the upper beam 312, as shown here. When rod 536c is under tension, for example during relative movement as described above, a pulling force from rod 536c upon the bell crank 532b causes the bell crank 532b to rotate counter clockwise and to push rod 536b away from bell crank 532b and towards bell crank 532a. A pushing force from rod 536b upon bell crank 532a causes bell crank 532a to rotate counter clockwise and pull rod 536a away from damper 520 and causing an extension force to be applied to the damper 520.
Alternatively, if rod 536c is under compression, for example during some type of relative movement, a pushing force from rod 536c upon the bell crank 532b causes the bell crank 532b to rotate clockwise and to pull rod 536b towards bell crank 532b and away from bell crank 532a. A pulling force from rod 536b upon bell crank 532a causes bell crank 532a to rotate clockwise and push rod 536a towards damper 520 and causing a compression force to be applied to the damper 520.
As shown in FIG. 5B, when under stress, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bay 310 and between portions of the bay 310 itself. This relative motion can cause deflection among the beams 312-314 and columns 316-318 of the bay 310.
With deflection, as shown within FIG. 5B, the upper beam 312 moves slightly towards a right hand direction relative to the lower beam 314, as measured by a deflection angle 526. This deflection causes an extension force to be applied to rod 536c. 
The above described invention is not limited to the arrangement shown in FIGS. 5A-5B. For example, the damper 520 can be mounted onto a structural member other than the right column 318. Accordingly, the other rods 536a-536c can be mounted onto other structural members to implement a working apparatus 500. Like stated in association with the apparatus 400 of FIGS. 4A-4B, the dimensions and design characteristics of the damper 520, of the bell cranks 532a-532b and rods 536a-536c can be altered to suite circumstances of a specific building structure.
FIGS. 6A-6B each illustrate an embodiment 600 of a damping apparatus of the invention that includes a dampers 620a-620b. Damper 620a is physically attached to a first end of rod 634a. Rod 634a has a second end which is attached to bell crank 632a. Bell crank 632a is also attached to a first end of rod 636a. Rod 636a has a second end that is fixedly attached to end anchor 630a which is fixedly attached to an inner surface of the right hand column 318. Likewise, damper 620b is physically attached to a first end of rod 634b. Rod 634b has a second end which is attached to bell crank 632b. Bell crank 632b is also attached to a first end of rod 636a. Rod 636b has a second end that is fixedly attached to end anchor 630b which is fixedly attached to an inner surface of the right hand column 318.
This damping apparatus embodiment 600 is designed to restrain movement of structural members of the bay 310 of the building structure. The damping apparatus 600 is further designed to reduce visual and physical obstruction of the bay 310 that is caused by the damping apparatus 600 being disposed within the bay 310, as compared to obstruction caused by another prior art damping apparatus, such as that shown in FIGS. 2A-2G.
As shown in FIG. 6A, each damper 620a-620b is fixedly attached to a structural member, and specifically attached to an upper beam 312, that is located along a first side of the perimeter of the bay 310. Each damper 620a-620b has one attachment interface and is designed to provide at least one of a high tensile resistance to pulling forces of either of the rods 634a-634b and compression resistance to pushing forces of either of the rods 634a-634b. Rod 634a is attached to a first attachment interface (of the damper 620a) that is located on a left hand side of the damper 620a. The rod 634b is attached to a first attachment interface (of the damper 620b) that is located on a right hand side of the damper 620b. 
Bell cranks 632a and 632b are fixedly attached to and protrude away from an underside of the upper beam 312. A pulling force from rod 636a causes bell crank 632a to rotate counter clockwise and push rod 634a towards damper 620a and causing a compression force to be applied to damper 620a. Conversely, a pushing force from rod 636a causes bell crank 632a to rotate clockwise and to pull rod 634a away from damper 620a, and a pushing force from rod 636b causes bell crank 632b to rotate counter clockwise and pull rod 634a away from damper 620b. 
A pulling force from rod 636b causes bell crank 632b to rotate clockwise and to push rod 634b towards damper 620b and causing a compression force to be applied to damper 620b. A pushing force from rod 636b causes bell crank 632b to rotate counter clockwise and to pull rod 634b away from damper 620b and causing an extension (tensile) force to be applied to damper 620b. 
As shown in FIG. 6B, when under stress, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bay 310 and between portions of the bay 310 itself. This relative motion can cause deflection among the beams 312-314 and columns 316-318 of the bay 310.
With deflection, as shown within FIG. 6B, the upper beam 312 moves slightly towards a right hand direction relative to the lower beam 314, as measured by a deflection angle 626. During this deflection, vertical columns 316-318 slightly tilt in a clockwise direction and an upper portion of each column 316-318 moves towards the right hand direction while attached to the upper beam 312, and a lower portion of each column 316-318 remains attached to the lower beam 314.
During this particular type of deflection, rod 636a applies a pulling force to bell crank 632a and causes bell crank 632a to rotate in a counter clockwise direction and to apply a pushing force to rod 634a, which applies a pushing force to damper 620a, which is resisted by damper 620. Conversely, during this particular deflection, rod 636b applies a pushing force to bell crank 632b and causes bell crank 632b to rotate in a counter clockwise direction and to apply a pulling force to rod 634b, which applies a pulling force to damper 620b, which is resisted by damper 620.
In one embodiment, the extension dampers 620a-620b are designed to resist a high compression force and to resist a relatively low extension force. For this embodiment, the particular relative motion of FIG. 6B would cause damper 620a to provide more resistance than damper 620b, because the damper 620a resistance would be provided from its relatively high compression resistance when activated as a result of this particular type of relative motion.
However, other types of relative motion could yield a different response from this embodiment of the apparatus 600. For example, if the upper beam 312 should move in a leftward direction relative to the lower beam 314, a compressive force would be applied to the damper 620b and an extension force would be applied to the damper 620a. 
In preferred embodiments, the dampers 620a-620b are each designed to provide both a relatively matched compression and extension resistance force. In other embodiments, the dampers 620 are designed to provide a larger extension resistance force than a compression resistance force, or vice versa.
The above described invention is not limited to the arrangement shown in FIGS. 6A-6B. For example, the damper 620 can be mounted onto a structural member other than the upper beam 312. Accordingly, the other rods 634a-634b, 636a-636b, can be mounted onto other structural members to implement a working apparatus 500. Like stated in association with the apparatus 400 of FIGS. 4A-4B, the dimensions and design characteristics of the damper 520, of the bell cranks 532a-532b and rods 536a-536c can be altered to suite circumstances of a specific building structure.
Although the lower beam 314 is shown as having no attached end anchors, in other embodiments, one or both end anchors 430a-430b may be attached to the lower beam 314. In other embodiments, a bell crank 432a can be mounted onto the left column 316 and/or bell crank 432b can be amounted onto the right column 318.
Notice that the apparatus 300 of FIGS. 3A-3D introduces almost no obstruction to the bay 310, except for the upper left and upper right hand corners. Such a small obstruction would permit the bay 310 of FIGS. 3A-3D, if sufficiently large, to provide passage of road vehicles. Any obstruction introduced by the apparatus 400, 500, and 600 of FIGS. 4A-4B, 5A-5B and 6A-6B is also small and confined to be located along an inside portion of the perimeter of the bay 310, and would also enable the bay 310 of FIGS. 4A-4B, FIGS. 5A-5B and FIGS. 6A-6B, if sufficiently large, to also provide passage to road vehicles.
To address visual aesthetics, coverings (not shown), typically made from plastic, rubber and/or leather, can be installed over the apparatus hardware 300, 400, 500 and 600 to create a more desired visual appearance of the installed apparatus within the context of the desired appearance and design of the building structure.
FIGS. 7A-7D collectively illustrate two embodiments 700, 750 of a damping apparatus of the invention that are each designed to resist movement across multiple bays collectively spanning multiple stories within a building structure. Each embodiment 700, 750 includes a damper 720 that is tethered via cables 734a-734b to end anchors 730a-730b, or 730c-730d, that are mounted to structural members that are located along a perimeter portion of multiple bays 710a-710d. The bays 710a-710d are located within a building structure.
Like prior described damping apparatus embodiments, these damping apparatus embodiments 700, 750 are also designed to resist against undesirable movement of the structural members that are located along the perimeter portion of these bays 710a-710d. This damping apparatus 700, 750 is further designed to minimize visual and physical obstruction of the bays 710a-710d that is caused by installation of the damping apparatus itself, while it is disposed within the bays 710a-710d. Any obstruction caused by this damping apparatus is substantially less than obstruction caused by many other prior art damping apparatus, such as that shown in FIGS. 2A-2G.
As shown in FIG. 7A, a damper 720 is mounted (fixedly attached) to a structural member, specifically an upper beam 712a, that is located along a first side of the perimeter of the bay 710a. The damper 720 is designed to provide extension (tensile) resistance to pulling forces of cables 734a-734b, that are each attached to opposite sides of the damper 720. Cable 734a is attached to a first attachment interface (of the damper 720) that is located on a left hand side of the damper 720. The cable 734b is attached to a second attachment interface (of the damper 720) that is located on a right hand side of the damper 720.
Intermediate anchors 732a and 732b are each protrusions that are fixedly attached to and protrude away from an inner side of the upper beam 712a. The cables 734a and 734b are each arranged to make physical contact with and pass outside of and along a curved surface of each respective intermediate anchor 732a-732b, and to each fixedly attach to the damper 720. Each of the curved surfaces facilitates movement (sliding) of each respective cable 734a-734b while it is pressing against and passing outside of each respective intermediate anchor 732a-732b. 
The cable 734a has a first end that is attached to the first attachment interface on the left hand side of the damper 720 and a second end that is attached to an end anchor 730a. The cable 734b has a first end that is attached to the second attachment interface located on the right hand side of the damper 720 and a second end that is attached to the second end anchor 730b. The end anchor 730a is fixedly attached to an inner side of the left column 716, which represents structural members located along a left side of the perimeter of the bays 710a-710d. The end anchor 730b is fixedly attached to an inner side of the right column 718, which represents structural members located along a right side of the perimeter of the 710a-710d. As shown, the bays 710a-710d form a rectangular shape having (4) right angle corners separating each horizontal beams 712a-714d and vertical columns 716-718.
As shown in FIG. 7B, when under stress, from perhaps a potentially harmful event, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bays 710a-710d, and within or between each of the bays 710a-710d. This relative motion can cause deflection among the beams 712a-714d and columns 716-718 of the bays 710a-710d. 
With the deflection, as shown within FIG. 7B, the upper beam 712a moves slightly towards a right hand direction relative to the lower beam 714d, as measured by a deflection angle 726. During this deflection, vertical columns 716-718 slightly tilt in a clockwise direction and an upper portion of each column 716-718 moves towards the right hand direction while attached to the upper beam 712a, and a lower portion of each column 716-718 remains attached to the lower beam 714d. 
FIG. 7C shows a damping apparatus like that of FIG. 7A, except for that end anchors 730a and 730c are each located within different bays 710d and 710c respectively.
As shown in FIG. 7D, when under stress, relative motion can occur between the earth and the building structure, between the earth and the bays 710a-710d, and within and between the bays 710a-710d. This relative motion can cause deflection and/or deformation among the beams 712a-714d and columns 716-718 that are located along a perimeter of the bays 710a-710d. 
With relative motion, as shown within FIG. 7D, the upper beam 712a moves slightly towards a right hand direction relative to the lower beam 714d, as measured by a deflection angle 726. During this deflection, vertical columns 716-718 slightly tilt in a clockwise direction where an upper portion of each column 716-718 moves towards the right hand direction while attached to the upper beam 712a, and at least a lower portion of each column 716-718 remains attached to the lower beam 714d. 
As stated earlier, only a small amount of deflection of the one or more bays, as a result of relative motion, can cause catastrophic damage to one or more of the bays 710a-710d and to the building structure itself. For example, in typical building structures, as little as a (5) degree deflection angle to one or more bays, can cause damage to and/or even collapse of the building structure itself.
As stated earlier, in other embodiments, and as shown in FIGS. 8A-8B, the damper 720 can mounted on a structural member other than the upper beam 712a. For example, the damper 720 and intermediate anchors 732a-732b can be instead mounted on the lower beam 714d while the end anchors 730a-730b, 730c-730d are each located on an upper portion of the left and right columns respectively. Also, in some embodiments, the damper 720 is instead mounted on a column 316, 318 while the intermediate anchors 332a-332b, and optionally the end anchors 330a-330b, or end anchors 330c-330d are mounted onto a respective beam 312, 314.
In another one half sided (mirrored) embodiment, the damper 720 has one attachment interface, one cable 734a, one intermediate anchor 732a and one end anchor 730a, and consequently, resists motion traveling in only one first direction. This one half sided embodiment would resist relative motion along a first direction from a left hand to a right hand side of the bays 710a-710d. 
However, another mirror image of this one half side embodiment, including another damper 720, one other cable 734b, one other intermediate anchor 732b and on other end anchor 730b, is designed to resist motion in a second direction of relative motion that is opposite to the first direction, and is installed into bay (not shown), that is adjacent to the bays 710a-710d for example, a set of bays that are located to the right hand side of the bays 710a-710d shown. In this arrangement, each side of the damping apparatus 700 is separately installed into each bay of the horizontally adjacent pairs of bays and is designed to resist relative motion from two opposite directions that collectively affects this set of bays. See FIGS. 6A-6B as an example of each mirrored one half side of a damping system 600 that is instead being installed into each half of one bay, instead of each being installed into a horizontally adjacent bay.
FIGS. 8A-8B illustrate an embodiment of a damping apparatus of the invention that has a damper of lower elevation than other apparatus components and that spans multiple bays within a building structure. Like other embodiments, this embodiment is designed to resist relative movement with respect to multiple bays within a building structure. This embodiment includes a damper 820 that is tethered via cables 834a-834b to end anchors 830a-830b, that are mounted to structural members that are located along a perimeter portion of multiple bays 810a-810d. As opposed to the embodiments 700, 750, the damper 820 of this embodiment is attached at a lower elevation than that of the end anchors 830a-830b, where elevation is measured as a distance relative to the surface of the earth.
The bays 810a-810d are located within a building structure. Like prior described damping apparatus embodiments, this damping apparatus embodiments 800 is also designed to resist against undesirable movement of the structural members that are located along the perimeter portion of these bays 810a-810d. This damping apparatus 800 is further designed to minimize visual and physical obstruction of the bays 810a-810d that is caused by installation of the damping apparatus itself, while it is disposed within the bays 810a-810d. Any obstruction caused by this damping apparatus is substantially less than obstruction caused by many other prior art damping apparatus, such as that shown in FIGS. 2A-2G.
As shown in FIG. 8A, a damper 820 is mounted (fixedly attached) to a structural member, specifically an upper beam 812a, that is located along a first side of the perimeter of the bay 810a. The damper 820 is designed to provide extension (tensile) resistance to pulling forces of cables 834a-834b, that are each attached to opposite sides of the damper 820. Cable 834a is attached to a first attachment interface (of the damper 820) that is located on a left hand side of the damper 820. The cable 834b is attached to a second attachment interface (of the damper 820) that is located on a right hand side of the damper 820.
Intermediate anchors 832a and 832b are each protrusions that are fixedly attached to and protrude away from a lower side of the upper beam 812d. The cables 834a and 834b are each arranged to make physical contact with and pass outside of and along a curved surface of each respective intermediate anchor 832a-832b, and to each fixedly attach to the damper 820. Each of the curved surfaces facilitates movement (sliding) of each respective cable 834a-834b while it is pressing against and passing outside of each respective intermediate anchor 732a-732b. 
The cable 834a has a first end that is attached to the first attachment interface on the left hand side of the damper 820 and a second end that is attached to an end anchor 830a. The cable 834b has a first end that is attached to the second attachment interface located on the right hand side of the damper 820 and a second end that is attached to the second end anchor 830b. The end anchor 830a is fixedly attached to an inner side of the left column 816, which represents structural members located along a left hand side of the perimeter of the bays 810a-810d. The end anchor 830b is fixedly attached to an inner side of the right column 818, which represents structural members located along a right side of the perimeter of the bays 810a-810d. As shown, the bays 810a-810d form a rectangular shape having (4) right angle corners separating each horizontal beams 812a-812d and 814d and vertical columns 816-818.
As shown in FIG. 8B, when under stress, from perhaps a potentially harmful event, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bays 810a-810d, and within or between each of the bays 810a-810d. This relative motion can cause deflection among the beams 812a-814d and columns 816-818 of the bays 710a-710d. 
With the deflection, as shown within FIG. 8B, the upper beam 812a moves slightly towards a right hand direction relative to the lower beam 814d, as measured by a deflection angle 826. During this deflection, vertical columns 816-818 slightly tilt in a clockwise direction and an upper portion of each column 816-818 moves towards the right hand direction while attached to the upper beam 812a, and a lower portion of each column 816-818 remains attached to the lower beam 814d. 
As with the other embodiments described herein, other types of relative motion can occur along the perimeter of one or more bays. The apparatus described herein resists such relative motion that could deform one or more bays in a manner that would violate the functional or aesthetic design of any one of the bays protected by the apparatus described herein.
Options and variations, such as described in association with FIGS. 3A-3D, 4A-4B. 5A-5B and 6A-6B with respect to apparatus component characteristics, such as damper design and cable characteristics, can also be applied to the embodiments 7A-7D and 8A-8B. Also, embodiments including rods, such in association with FIGS. 4A-4B, 5A-5B and 6A-6B can also be applied to multiple bays as shown in FIGS. 7A-7D and FIGS. 8A-8B.
However, there are some advantages to a tensile force resisting cable based apparatus as compared to that of a compression force resisting rod based apparatus. For example, a diameter of a cable or a rod that is designed to resist 10,000 pounds of a tensile type of force, would be substantially smaller in size than a diameter of a rod that is designed to resist 10,000 pounds of a compression type of force. Hence, in some circumstances, a tensile resisting cable based apparatus can be designed to resist forces of a larger magnitude while being constructed from a smaller amount of force resisting material (steel for example), with respect to its weight and its displacement of volume, as compared to that of a compression force resisting rod based apparatus. As a result, a tensile force resisting apparatus can be designed to cause less overall obstruction within a building structure, especially when it is designed to span multiple bays, as compared to another compression force resisting apparatus that is designed to resist a same amount of force resulting from undesired motion within a building structure.
FIGS. 9A-9B collectively illustrate an embodiment 900 of a damping apparatus of the invention that is designed to resist movement across a set of horizontally and vertically adjacent bays collectively spanning multiple stories within a building structure. This type of embodiment is also referred to as a traverse bay installation. This embodiment 900 includes a damper 920 that is tethered via cables 934a-934b to end anchors 930a-930b, that are mounted to structural members that are located along a perimeter portion of multiple bays 910a-910c. The bays 910a-910c are located within a building structure and form an “L” shape. The bay 910d is also shown and is bounded by columns 918c-918d. In this building structure, column 918a and column 918c are one same column and column 918b and 918d are also one same column. As a result, although the apparatus is collectively attached in (3) bays 910a-910c, the apparatus at least partially protects bay 910d from movement of its columns 918c-918d. As shown here, this set of (4) bays forms a 2×2 matrix of bays that are located to form one contiguous rectangle within one side of the building structure.
In other embodiments, the set of bays can form other various arrangements, including arrangements that span across a corner of a building. In such an arrangement, an intermediate anchor, such as a loop shaped intermediate anchor, re-directs the direction of cable by 90 degrees, between a damper and an end anchor. Preferably, a loop shaped intermediate anchor receives a cable into an aperture to surround the cable and prevent it from moving off and/or away from the intermediate anchor itself. In this type of embodiment, laterally and optionally vertically adjacent bays span across two different sides of a building structure.
Like prior described damping apparatus embodiments, this damping apparatus embodiment 900 is also designed to resist against undesirable movement of the structural members that are located along the perimeter portion of these bays 910a-910d. This damping apparatus 900 is further designed to minimize visual and physical obstruction of the bays 910a-910d that is caused by installation of the damping apparatus itself, while it is disposed within the bays 910a-910d. Any obstruction caused by this damping apparatus is substantially less than obstruction caused by many other prior art damping apparatus, such as that shown in FIGS. 2A-2G.
As shown in FIG. 9A, a damper 920 is mounted (fixedly attached) to a structural member, specifically an upper beam 912a, that is located along a first side of the perimeter of the bay 910a. The damper 920 is designed to provide extension (tensile) resistance to pulling forces of cables 934a-934b, that are each attached to opposite sides of the damper 920. Cable 934a is attached to a first attachment interface (of the damper 920) that is located on a left hand side of the damper 920. The cable 934b is attached to a second attachment interface (of the damper 920) that is located on a right hand side of the damper 920.
Intermediate anchors 932a and 932b are each protrusions that are fixedly attached to and protrude away from an inner side of the upper beam 912a and upper beam 912b respectively. The cables 934a and 934b are each arranged to make physical contact with and pass outside of and along a curved surface of each respective intermediate anchor 932a-932b, and to each fixedly attach to the damper 920. Each of the curved surfaces facilitates movement (sliding) of each respective cable 934a-934b while it is pressing against and passing inside of a loop shaped intermediate anchor, or passing outside of each respective non-loop intermediate anchor 932a-932b. 
The cable 934a has a first end that is attached to the first attachment interface on the left hand side of the damper 920 and a second end that is attached to an end anchor 930a. The cable 934b has a first end that is attached to the second attachment interface located on the right hand side of the damper 920 and a second end that is attached to the second end anchor 930b. The end anchor 930a is fixedly attached to an inner side of the left column 916, which represents structural members located along a left side of the perimeter of the bays 910a, 910c. The end anchor 930b is fixedly attached to an inner side of the right column 918b, which represents structural members located along a right side of the perimeter of the bays 910b, 910d. As shown, the bays 910a-910d form a rectangular shape having (4) right angle corners spanning between each horizontal beams 912a-912b, 914c-914d and vertical columns 916a-916b, 918b-918d. 
As shown in FIG. 9B, when under stress, from perhaps a potentially harmful event, relative motion can occur between the earth and the building structure, between the earth and at least a portion of the bays 910a-910d, and within or between each of the bays 910a-910d. This relative motion can cause deflection among the beams 912a-912b, 914a-914b, 914c-914d and columns 916a-916b, 918a,918c and 918b, 918d of the bays 910a-910d. 
With the deflection, as shown within FIG. 9B, the upper beams 912a-912b move slightly towards a right hand direction relative to the lower beams 914c-914d, as measured by a deflection angles 926a-926c. During this deflection, at least one of the vertical columns 916a-916b, 918a-918c, 918b-918d slightly tilt in a clockwise direction and an upper portion of each column 916a-916b, 918a-918c and 918b-918d move towards the right hand direction while attached to the upper beams 912a-912b, and a lower portion of each column 916b, 918c-918d remains attached to the lower beams 914c-914d. 
In summary, in one aspect, the invention provides an apparatus for resisting potentially destructive movement within a building structure. The apparatus includes a first damper designed for resisting at least one extension force and having one or more attachment interfaces and that is fixedly mounted to a structural member located along a first side of a first bay within a building structure, and the apparatus includes a first cable having a first end that is attached to a first attachment interface of the first damper, and having an intermediate portion that passes through a receiving portion of a first intermediate anchor and having a second end that is attached to a first end anchor; and where the first end anchor is fixedly mounted on a structural member located along a second side of the first bay; and where relative motion between the first side and the second side of the first bay causes an extension force to be applied to the first damper causing resistance to the relative motion.
In some embodiments, the first intermediate anchor is fixedly mounted to a structural member located along the first side of the first bay or along the second side of the first bay. Also, the first end anchor can be mounted outside of a centerline of rotation of the structural member located along a second side of the first bay. Optionally, the first damper has a second attachment interface and where a second cable has a first end that is attached to the second attachment interface of the first damper, and the cable having an intermediate portion that passes through a receiving portion of a second intermediate anchor and having a second end that is attached to a second end anchor. In some embodiments, the second intermediate anchor is fixedly mounted to a structural member located along a third side of the first bay.
In some embodiments, a second damper that is fixedly mounted in a second bay, the second bay being adjacent to the first bay and where the second damper is designed to resist a force that is directed in an opposite direction to that of the at least one extension force for which the first damper is designed to resist.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

## Claims

1. An apparatus for resisting potentially destructive movement within a building structure, comprising:
a damper designed for resisting at least one of an extension force and a compression force, and having one or more attachment interfaces, said damper is fixedly mounted to a structural member located along a first side of a bay within a building structure;
a first rod having a first end that is attached to a first attachment interface of said damper, said first rod having a second end that is attached to a first arm of a first bell crank;
a second rod having a first end that is attached to a second arm of said first bell crank; and said second rod having a second end that is attached to a first end anchor;
wherein said first end anchor is fixedly mounted on a structural member located along a second side of said bay; and
wherein relative motion between said first side and said second side of said bay causes either an extension force or a compression force to be applied to said damper, causing resistance to said relative motion via said damper; and
wherein there is no point location within said structural member, said damper, said first rod, said bell crank or said second rod, that is located as or more proximate to a geometric center point location within said bay, in relation to any one nearest side of said bay; without effect of said relative motion.

2. The apparatus of claim 1 wherein said first bell crank is mounted to a structural member located along at least one of said first side of said bay and said second side of said bay.

3. The apparatus of claim 1 wherein said first end anchor is mounted along an inside surface of said structural member located along said second side of said bay.

4. The apparatus of claim 1 wherein said damper has a second attachment interface and wherein a third rod has a first end that is attached to said second attachment interface of said damper, and said third rod having a second end that is attached to a first arm of a second bell crank; and a fourth rod having a first end that is attached to a second arm of said second bell crank; and said fourth rod having a second end that is attached to a second end anchor; and wherein said second end anchor is fixedly mounted on a structural member located along a third side of said bay.

5. The apparatus of claim 4 wherein at least one of said first end anchor and said second anchor is fixedly mounted to a structural member located along a fourth side of said bay.

6. The apparatus of claim 1 wherein said damper is swivel attached to said structural member of said first side of said bay.

7. An apparatus for resisting potentially destructive movement within a building structure, comprising:
a damper designed for resisting at least one of an extension force and a compression force, and having one or more attachment interfaces, said damper is fixedly mounted to a structural member located along a first side of a bay within a building structure;
a first rod having a first end that is attached to a first attachment interface of said damper, said first rod having a second end that is attached to a first arm of a first bell crank;
a second rod having a first end that is attached to a second arm of said first bell crank; and said second rod having a second end that is attached to a first arm of a second bell crank;
a third rod having a first end that is attached to a second arm of said second bell crank; and said third rod having a second end that is attached to a first end anchor; and
wherein at least one of said first bell crank and said second bell crank is mounted onto a second side of said bay; and
wherein said first end anchor is fixedly mounted on a structural member located along a third side of said bay; and
wherein relative motion between any two of said first side and said second side and said third side of said bay causes either an extension force or a compression force to be applied to said damper, causing resistance to said relative motion from said damper.

8. The apparatus of claim 7 wherein said first bell crank is mounted to a structural member located along said first side of said bay.

9. The apparatus of claim 7 wherein said first bell crank is mounted to a structural member located along said second side of said bay.

10. The apparatus of claim 7 wherein said first end anchor is mounted along an inside surface of said structural member located along said second side of said bay.

11. The apparatus of claim 7 wherein said second bell crank is mounted to a structural member located along said second side of said bay.

12. The apparatus of claim 7 wherein said second bell crank is mounted to a structural member located along said third side of said bay.

13. The apparatus of claim 7 wherein said first end anchor is fixedly mounted to a structural member located along a fourth side of said bay.