US20140246441A1

US20140246441A1 - Collapsible fluid containment berms with rotating support brackets

Info

Publication number: US20140246441A1
Application number: US14/193,954
Authority: US
Inventors: Robert J. Starr; Matthew A. Romito; Mark S. Woytowich; Dane R. Jackson
Original assignee: New Pig Corp
Current assignee: New Pig Corp
Priority date: 2013-03-01
Filing date: 2014-02-28
Publication date: 2014-09-04
Also published as: WO2014134549A1

Abstract

Collapsible fluid containment berms with collapsible sidewalls are disclosed. Support brackets including sidewall support arms may be rotated from lowered positions in which the sidewall is collapsed to raised positions in which the sidewall is generally vertical. The sidewall support arms may be contained in a pocket formed between inner and outer sidewall panels. The support brackets may include bottom legs connected to the rotatable sidewall support arms. The bottom legs may extend generally horizontally outwardly and/or inwardly from the sidewall, and may be contained in sleeves attached to a floor and/or an external skirt of the containment berm. A control strap connected to the sidewall support arms may be used to move the arms between their collapsed positions and their raised positions. A flexible control strap may be pulled to rotate the sidewall support arms around an axis such that the sidewall support arms slide within the sidewall pocket.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/771,299 filed Mar. 1, 2013, which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to containment berms, and more particularly relates to containment berms having collapsible sidewalls that can be raised and lowered.

BACKGROUND INFORMATION

Portable collapsible liquid containment berms are used to prevent hazardous fluids from entering the environment from the spillage of the fluids during, for example, the loading and unloading of storage containers and transport vehicles, wash-down of equipment and vehicles, and repair/maintenance of equipment and vehicles.
Typically one or more sides of the containment berm can be lowered and laid flat so that the equipment or vehicle can easily enter the containment area. Once the equipment or vehicle is inside, the sidewall(s) are then extended to prevent fluids from escaping. Any leaked, spilt or wash-down fluid is retained within the containment berm and can be pumped out for proper disposal. Once the containment berm is emptied, the sidewall(s) can be lowered to remove the equipment, storage containers or vehicle.
These devices are typically made with a flexible barrier material, such as a rubberized fabric, reinforced PVC or a heavy weight film, and are folded or rolled-up for easy storage and transport. During use, the collection berm must be unfolded/unrolled and the sides extended to a generally vertical position to achieve its fluid retaining capability. To maintain the sidewalls in this generally vertical position, a number of sidewall braces have been employed, for example, as disclosed in U.S. Pat. Nos. 5,316,175; 5,762,233; 6,092,686; and 6,880,720. Since each side brace must be individually manipulated by hand to extend or to lower the sidewalls, the operators must bend over and work their way down the sidewall(s) that need to be raised or lowered.

SUMMARY OF THE INVENTION

An aspect of the present invention is to provide a containment berm comprising: a floor; at least one collapsible sidewall connected to the floor; and at least one sidewall support bracket comprising a rotatable sidewall support arm structured and arranged to support the sidewall in a raised position, wherein the sidewall support arm is rotatable around an axis substantially perpendicular to a plane of the raised sidewall.
Another aspect of the present invention is to provide a containment berm comprising: a floor; a collapsible sidewall connected to the floor; and multiple sidewall support brackets comprising sidewall support arms structured and arranged to support the sidewall in a raised position, wherein each sidewall support arm is rotatable around an axis substantially perpendicular to a plane of the raised sidewall.
A further aspect of the present invention is to provide a containment berm comprising: a floor; at least one collapsible sidewall; multiple support brackets comprising rotatable sidewall support arms structured and arranged to support the sidewall in a raised position; and a control strap connected to upper ends of the sidewall support arms structured and arranged to force the sidewall support arms into raised positions when an end of the control strap is pulled.
Another aspect of the present invention is to provide a containment berm comprising: a floor; at least one collapsible sidewall connected to the floor comprising an inner sidewall panel, an outer sidewall panel, and a pocket located therebetween; multiple support brackets comprising sidewall support arms at least partially positioned in the pocket; and a control strap at least partially positioned in the pocket and connected to the sidewall support arms structured and arranged to force the sidewall support arms into raised positions when an end of the control strap is pulled.
These and other aspects of the present invention will be more apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a collapsible containment berm in accordance with an embodiment of the present invention.

FIG. 2 is an isometric view illustrating features of a collapsible containment berm in accordance with an embodiment of the present invention.

FIG. 3 is a top view illustrating features of a collapsible containment berm in accordance with an embodiment of the present invention.

FIG. 4 is a side view illustrating features of the collapsible containment berm of FIG. 3.

FIG. 5 is an enlarged side view of a portion of the collapsible containment berm shown in FIG. 4.

FIG. 6 is a partially cutaway side view of a sidewall and a rotatable sidewall support arm for a collapsible containment berm in accordance with an embodiment of the present invention.

FIGS. 7 and 8 are cross-sectional views of the sidewall and sidewall support arm of FIG. 6. In FIG. 7, the sidewall support arm is in an upper raised position, while in FIG. 8 the sidewall support arm is in a lowered collapsed position.

FIG. 9 is an isometric view illustrating a control strap connected to multiple sidewall support arms in accordance with an embodiment of the present invention.

FIG. 10 is a side view of a portion of a collapsible containment berm including a strap retainer in accordance with an embodiment of the present invention.

FIG. 11 is a bottom view of a floor of a collapsible containment berm with four outer sidewall panels arranged for attachment thereto.

FIG. 12 is an enlarged view of a portion of FIG. 11.

FIG. 13 is a side view of a portion of a collapsible containment berm in accordance with an embodiment of the present invention.

FIG. 14 is a side view of another portion of the collapsible containment berm of FIGS. 13.

FIG. 15 is an isometric view of a portion of a collapsible containment berm including sidewall support brackets having horizontally outwardly extending bottom legs in accordance with an embodiment of the present invention.

FIG. 16 is an isometric view of the sidewall portion of a collapsible containment berm as shown in FIG. 15, with the support brackets rotated and the sidewall in a collapsed position.

FIG. 17 is an isometric view of a portion of a collapsible containment berm including generally T-shaped support brackets including bottom legs extending generally horizontally inwardly and outwardly from the sidewall.

FIG. 18 is an isometric view of a portion of a collapsible containment berm illustrating the use of two control straps for raising and lowering separate sets of sidewall support arms in separate sections of a sidewall in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention provide portable collapsible fluid containment berms that eliminate the need to individually manipulate each sidewall support brace or bracket during raising or lowering of the flexible sidewalls. The support brackets for each sidewall comprise arms that are rotatable from a lowered position in which the sidewall is collapsed to a raised position in which the sidewall is generally vertical. The rotatable sidewall support arms of the brackets may be contained in pockets or sleeves on the sidewall and/or between adjacent sidewall layers in embodiments in which the sidewalls comprise two separate sheets of material. The sidewall pockets may be at least as high and wide as the as the length of each sidewall support arm.
In certain embodiments, the support brackets also include bottom legs connected to the rotatable sidewall support arms. The bottom legs may extend generally horizontally outwardly and/or inwardly from the sidewall, and may be contained in close-fitted hinge pockets or sleeves on a bottom or top surface of the floor of the berm and/or an external apron or skirt of the berm. The bottom legs can rotate in the hinge pockets or sleeves, with the rotational axis being generally perpendicular to the sidewall orientation when the sidewall is in its raised position.
In certain embodiments, a series of sidewall support arms may be joined together at or near their top ends with a control strap such as a cable, cord, rod or the like. The control strap may extend externally from the sidewall of the berm, e.g., from the first and last support brackets in a series, and a loop or handle may be attached to the free ends of the strap. The control strap may be used to change the orientation of the sidewall support arms within the sidewall pockets. For example, pulling on a flexible control strap rotates the sidewall support arms around an axis such that the sidewall support arms slide within the sidewall pocket(s). When the sidewall is to be collapsed, the sidewall support arms are moved from their generally vertical positions to their generally horizontal positions. When the sidewall is to be raised, the flexible control strap may be pulled in the opposite direction to rotate and slide the sidewall support arms in the sidewall pocket(s) from their generally horizontal collapsed positions to their generally vertical raised positions.
FIGS. 1-8 illustrate features of collapsible containment berms 10 in accordance with embodiments of the present invention. The containment berm 10 includes a liquid impermeable floor 12 that is generally horizontal and sidewalls 20 that are generally vertical when they are in their raised positions. The floor 12 and sidewalls 20 may be made of any suitable liquid impermeable materials known in the art, such as rubberized fabric, reinforced PVC sheets and the like. Multiple support brackets 30 are provided in or adjacent to the sidewalls 20. Each support bracket 30 includes a rotatable sidewall support arm 32. In certain embodiments, each support bracket 30 also includes a horizontal bottom leg 34.
One or more of the sidewalls 20 may include an inner sidewall panel 22 and an outer sidewall panel 24 forming a continuous or discontinuous pocket 23 therebetween. For purposes of illustration, FIGS. 2-5 show the outer sidewall panels 24 in horizontal positions prior to their securement to the inner sidewall panels 22 to form the pockets 23. As more fully described below, the rotatable sidewall support arm 32 of each bracket 30 can move inside the pocket 23 between the inner and outer sidewall panels 22 and 24 to thereby raise the sidewall 20 or allow the sidewall 20 to collapse.
As shown most clearly in FIGS. 6-8, the sidewall support arm 32 of each bracket 30 may rotate in the direction R around an axis of rotation A to move the sidewall support arm 32 between a generally horizontal collapsed position shown in phantom in FIG. 6 to a generally vertical position shown in solid lines in FIG. 6. As the sidewall support arm 32 rotates, it moves within the pocket 23 between the inner and outer sidewall panels 22 and 24 of the sidewall 20. As shown in FIGS. 6-8, and described in further detail below, the inner and outer sidewall panels 22 and 24 may be connected together by a lower weld 26 and an upper weld 27. Although the inner and outer sidewall panels 22 and 24 are shown as continuous panels in the figures, it is to be understood that one of the panels may alternatively be provided as a discontinuous sheet of material, e.g., individual pockets for each sidewall support arm 32 may be attached to the opposing panel by welding, adhesives, mechanical fasteners or the like.
FIGS. 7 and 8 are cross-sectional views showing a sidewall 20 in a raised position (FIG. 7) and a collapsed position (FIG. 8). In the raised position shown in FIG. 7, the sidewall support arm 32 is in a generally vertical orientation within the pocket 23 between the inner and outer sidewall panels 22 and 24. The sidewall support arm 32 includes a hole 36 near its upper end for receiving a control strap 40, as more fully described below.
In the collapsed position shown in FIG. 8, the sidewall support arm 32 has been rotated around the axis A from the generally vertical position shown in FIG. 7 to a generally horizontal position. In the generally horizontal position shown in FIG. 8, the sidewall support arm 32 rests at or near the bottom of the pocket 23 between the inner and outer sidewall panels 22 and 24. The sidewall 20 is thus no longer supported by the sidewall support arm 32, and it may collapse under its own weight to a lower position such as the generally horizontal position shown in FIG. 8.
As shown in FIGS. 6-8, the sidewall support arm 32 rotates around the axis A, which may be substantially perpendicular to the plane of the sidewall 20 when the sidewall 20 is in its raised position. In the embodiment shown, the axis A of rotation is generally horizontal and lies within a plane that is substantially parallel with the plane of the floor 12. As further shown in FIGS. 6-8, when the sidewall support arm 32 rotates between its collapsed and raised positions, it travels in a plane that is substantially parallel with the plane of the sidewall 20 when the sidewall 20 is in its raised position.
In certain embodiments, each sidewall support bracket 30 may also include a bottom leg 34 that may be generally horizontal. For example, the sidewall support arm 32 and bottom leg 34 may have a fixed orientation in relation to each other, such as a generally L-shaped or T-shaped configuration, as more fully described below. The sidewall support arm 32 and bottom leg 34 may be integrally formed from the same piece of material, e.g., by bending a rod, bar or tube of metal or plastic material, or by molding plastic material to the desired shape. Alternatively, separate sidewall support arm 32 and bottom leg 34 pieces may be fastened together by any suitable means such as welding, mechanical fasteners, adhesives and the like. The cross sections of the bottom legs 34 may be generally round to allow for easy pivoting with a hinge sleeve or pocket 16, but other cross-sectional shapes such as squares and hexagons, will work as long as they can pivot in the hinge sleeve 16. The cross sections of the sidewall support arms 32 may be the same or different from the cross sections of the bottom legs 34. For example, the sidewall support arms 32 and bottom legs 34 may both have round cross sections. Alternatively, the sidewall support arms 32 may have flattened cross sections such as rectangular, oval, elliptical or the like. The sidewall support arms 32 and bottom legs 34 may have typical diameters or widths of from 0.2 to 1 inch or more, for example, from 0.25 to 0.5 or 0.75 inch.
The bottom leg 34 of the support bracket 30 is aligned with the axis of rotation A in embodiments shown in the figures. As shown in FIGS. 1-8, the bottom leg 34 may be located under the floor 12 and may be secured to the underside of the floor 12 by means of hinge sleeves 16 having openings 17 of sufficient size to receive the bottom leg 34 and allow it to rotate within the sleeve openings 17. The hinge sleeves 16 may be attached to the floor 12 by any suitable means such as welding, adhesives, mechanical fasteners and the like. While the bottom leg 34 is positioned underneath the floor 12 in certain embodiments shown in the figures, it is to be understood that the bottom leg 34 may alternatively be positioned above the floor 12, or between separate layers of the floor if a multiple-layer floor is used.
As shown in FIGS. 13 and 14, the collapsible berm 10 may optionally include an external skirt 14, which may be secured to the ground by optional grommets 15.
In certain embodiments such as shown in FIGS. 15 and 16, the bottom legs 34 may extend outwardly, e.g., above the external skirt 14.
In certain embodiments, the bottom leg 34 may be generally T-shaped as shown in FIG. 17, in which case a portion of the bottom leg may extend inwardly from the sidewall 20 and a portion of the bottom leg may extend outwardly from the sidewall 20.
In certain embodiments, the bracket 30 does not require a rotatable bottom leg 34, in which case the rotatable sidewall support arm 32 may be pivotally attached to any suitable support structure that allows the sidewall support arm 32 to rotate between its collapsed and raised positions, while providing sufficient bracing support for the sidewall 20. For example, the support brackets may be formed of two separate pieces that are pivotally joined to each other, e.g., a substantially horizontal stationary floor member to which a rotatable sidewall support arm is attached. Since the bottom portion of a pivoting two-piece design may not need to rotate within a hinge pocket, the bottom horizontal leg can be a significantly different shape, such as a plate, than the rotatable sidewall support arm 32. In certain embodiments, the bottom hinge pocket 16 may be eliminated and the bottom leg 34 of the support bracket 30 may be joined directly to the floor and/or external skirt of the containment berm.
As shown in FIGS. 2-5 and 9-14, a control strap 40 may engage multiple sidewall support arms 32 to allow the support arms 32 to be moved between their collapsed and raised positions without the necessity of individually moving each support arm 32. In the embodiments shown, the control strap 40 passes through a hole, such as a drilled hole, grommet, ring or loop, that is located at an upper end of the sidewall support 32, i.e., the hole is located at least halfway up the vertical length of the sidewall support arm 32 at or near the upper end of each support arm 32. As used herein, the term “strap” means any suitable type of strap, cord, wire, string, rope, rod or the like that may be pulled or pushed to raise and lower the sidewall support arms 32. For example, a coated or uncoated flexible wire cable may be used to form a control strap 40. In the embodiment shown, the control strap 40 includes ends 41 and 42 that may be optionally be formed into handles, loops or any other configuration suitable for hand gripping or gripping with a tool. In certain embodiments, one handle 41 may comprise the raising end of the control strap 40, while the other handle 42 may comprise the collapsing end of the control strap 40. As shown most clearly in FIGS. 5, 9, 13 and 14, crimps 44 may be provided on the control strap 40 on opposite sides of a sidewall support arm 32. The opposing crimps 44 may be spaced apart from each other a sufficient distance to allow a limited amount of travel of the control strap 40 in relation to the sidewall support arm 32. As used herein, the term “crimps” means any crimp, sleeve, washer, deformation or the like that engages the sidewall support arm 32 to enable the control strap 40 to move the sidewall support arm 32 between its collapsed and raised positions.
As shown in FIG. 14, a stop member 28 may be used to prevent the brackets from overshooting their vertical raised positions when the sidewall 20 is being raised. The stop member 28 may be formed by any suitable means such as joining together a small section of the opposing inner and outer sidewall panels 22 and 24 adjacent to the vertical position of at least one of the sidewall support arms 32. In certain embodiments, the stop member 28 may be located next to the last support bracket 30 on the collapsing strap end 42. Alternatively, a free end of the control strap 40 may be fastened to limit travel of the sidewall support arms 32 to their vertical positions when the opposite end of the control strap 40 is pulled.
One method to string the sidewall support arms 32 together is run a control strap 40 in the form of a vinyl coated cable through the hole 36 in the upper portion of each arm 32, and then to place cable crimps 44 in the form of sleeves onto the cable on both sides of each arm 32 to lock it in position. To ensure that the arms 32 lay flat when collapsed, the crimps 44 may be located a slight distance away (e.g., about 1 inch) from the arm 32 to enable the cable to bend out of the way. This results in some cable play, which is not an issue. If the crimps 44 are placed too close to the arm 32, the cable may not be able to bend until it is clear of the crimps, thus keeping the arms 32 from lying flat.
As shown in FIG. 10, a retainer 29 may be used to secure the free ends 41 and 42 of the control strap 40 when not being used, which may remove a tripping hazard.
As illustrated in FIGS. 11 and 12, the sidewalls 20 of the containment berm 10 may be fabricated by laying strips of the outer sidewall panels 24 onto the underside or bottom of the floor 12. As shown most clearly in FIG. 12, the bottom edge of each outer sidewall panel may be attached to the periphery of the floor 12 by thermally or sonically welding 26 (hatched areas) or any other suitable means such as adhesives or fasteners. The regions of the floor 12 outside of the welded areas 26 become the inner sidewall panels 22. The top edges of the inner and outer sidewall panels 22 and 24 may be left unsealed until the control strap 40 mechanism is installed. Then the top edges of the inner and outer panels 22 and 24 may be bonded together, e.g., by the weld 27, to form the pocket 23.
FIG. 18 illustrates a containment berm including two sections 20 a and 20 b of the sidewall 20 that may be raised and collapsed using two control straps 40 a and 40 b. One section 20 a of the sidewall 20 includes a first set of rotatable sidewall support arms 32 a, while the other section 20 b of the sidewall 20 includes a second set of rotatable sidewall support arms 32 b. In this embodiment, the force necessary to pull each of the control straps 40 a and 40 b is reduced in comparison with the force required to pull a single control strap. This embodiment may be particularly useful where the sidewall 20 is relatively long. In the embodiment shown in FIG. 18, the collapsing ends 42 a and 42 b of the control straps 40 a and 40 b are located in a central region of the sidewall 20, and the raising ends 41 a and 41 b are located near the ends of the sidewall 20. The first set of sidewall support arms 32 a rotate in one direction R_awhen they are collapsed, and the second set of sidewall support arms 32 b rotate in the opposite direction R_bwhen they are collapsed. Alternatively, the directions of rotation during collapsing of the arms may be the same, or they may be switched from the directions shown in FIG. 18. Stop members 28 a and 28 b prevent the sidewall support arms 32 a and 32 b from rotating past their vertical orientations when they are raised.
Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.

Claims

What is claimed is:

1. A containment berm comprising:

a floor;

at least one collapsible sidewall connected to the floor; and

at least one sidewall support bracket comprising a rotatable sidewall support arm structured and arranged to support the sidewall in a raised position, wherein the sidewall support arm is rotatable around an axis substantially perpendicular to a plane of the raised sidewall.

2. The containment berm of claim 1, wherein the sidewall support arm travels in a plane substantially parallel with the plane of the raised sidewall.

3. The containment berm of claim 1, wherein the sidewall comprises a pocket, and the support arm is movable in the pocket when it rotates around the axis of rotation.

4. The containment berm of claim 3, wherein the sidewall comprises an inner sidewall panel and an outer sidewall panel, and the pocket is located between the inner and outer sidewall panels.

5. The containment berm of claim 4, wherein the inner and outer sidewall panels are substantially coextensive with each other.

6. The containment berm of claim 1, wherein the sidewall support bracket further comprises a bottom leg connected to the sidewall support arm.

7. The containment berm of claim 6, wherein the bottom leg and sidewall support arm are generally L-shaped.

8. The containment berm of claim 6, wherein the bottom leg and sidewall support arm are generally T-shaped.

9. The containment berm of claim 6, wherein the bottom leg is connected to the floor.

10. The containment berm of claim 9, wherein the bottom leg is rotatably mounted on the floor by a hinge sleeve attached to the floor and having sleeve opening receiving at least a portion of the bottom leg.

11. The containment berm of claim 10, wherein the hinge sleeve is fastened to a bottom surface of the floor.

12. The containment berm of claim 6, wherein the bottom leg is rotatably mounted on an external skirt extending outwardly from the sidewall in a generally horizontal direction.

13. The containment berm of claim 1, further comprising a control strap connected to the sidewall support arm structured and arranged to force the sidewall support arm into a raised position when an end of the control strap is pulled.

14. The containment berm of claim 13, wherein the control strap is structured and arranged to force the sidewall support arm into a collapsed position when an opposite end of the control strap is pulled.

15. The containment berm of claim 1, wherein the sidewall comprises a stop member structured and arranged to prevent the sidewall support arm from rotating substantially past a generally vertical raised position when the sidewall support arm is rotated from a generally horizontal lower position to the raised position.

16. The containment berm of claim 15, wherein the stop member comprises a welded portion between an inner sidewall panel and an outer sidewall panel of the sidewall.

17. A containment berm comprising:

a floor;

a collapsible sidewall connected to the floor; and

multiple sidewall support brackets comprising sidewall support arms structured and arranged to support the sidewall in a raised position, wherein each sidewall support arm is rotatable around an axis substantially perpendicular to a plane of the raised sidewall.

18. The containment berm of claim 17, wherein each sidewall support arm travels in a plane substantially parallel with the plane of the raised sidewall.

19. The containment berm of claim 17, wherein the sidewall support arms travel in at least one pocket formed in the sidewall.

20. The containment berm of claim 19, wherein the sidewall comprises an inner sidewall panel and an outer sidewall panel, and the at least one pocket is located between the inner and outer sidewall panels.

21. The containment berm of claim 17, wherein each sidewall support bracket further comprises a bottom leg connected to the sidewall support arm.

22. The containment berm of claim 17, further comprising a control strap connected to the sidewall support arms structured and arranged to force the sidewall support arms into raised positions when an end of the control strap is pulled.

23. The containment berm of claim 22, wherein the control strap is structured and arranged to force the sidewall support arms into collapsed positions when an opposite end of the control strap is pulled.

24. A containment berm comprising:

a floor;

at least one collapsible sidewall;

multiple support brackets comprising rotatable sidewall support arms structured and arranged to support the sidewall in a raised position; and

a control strap connected to upper ends of the sidewall support arms structured and arranged to force the sidewall support arms into raised positions when an end of the control strap is pulled.

25. The containment berm of claim 24, wherein the control strap passes through a hole in each of the sidewall support arms.

26. The containment berm of claim 25, wherein the strap can slide a limited distance in each of the holes.

27. The containment berm of claim 24, further comprising at least one crimp on the control strap structured and arranged to contact at least one of the sidewall support arms.

28. The containment berm of claim 24, further comprising opposing crimps on the control strap located on opposite sides of one of the sidewall support arms, wherein one of the crimps contacts the sidewall support arm when the strap is pulled to rotate the sidewall support arm into its raised position, and the other crimp contacts the sidewall support arm when the strap is pulled to rotate the sidewall support arm into a lower collapsed position.

29. The containment berm of claim 24, wherein the sidewall support arm is rotatable around an axis substantially perpendicular to a plane of the raised sidewall.

30. A containment berm comprising:

a floor;

at least one collapsible sidewall connected to the floor comprising an inner sidewall panel, an outer sidewall panel, and a pocket located therebetween;

multiple support brackets comprising sidewall support arms at least partially positioned in the pocket; and

a control strap at least partially positioned in the pocket and connected to the sidewall support arms structured and arranged to force the sidewall support arms into raised positions when an end of the control strap is pulled.