Pivot Hood Assembly

Abstract

A pivot hood assembly (12) comprises a pair of identical hood pieces (14, 16) comprising a shell (20, 22) and a supporting frame assembly (24, 26). Each hood piece is attachable to a ventilation shaft (18) by an attachment framework (32) to which the hood pieces are pivotably attached. The hood pieces pivot between a closed position where inner edges (52) of each hood piece contact each other, and an open position where the inner edges (52) are spaced from each other to form an opening where the ventilation shaft is accessible.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. application Ser. No. 60/593,304 filed Jan. 5, 2005, and U.S. application Ser. No. 60/593,384 filed Jan. 10, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to hood assemblies for roof-mounted ventilation shafts. In one embodiment, the invention relates to a pivoting hood assembly. In another embodiment, the invention relates to a two-piece pivoting hood assembly.

2. Description of the Related Art

Ventilation shafts are ubiquitous for providing fresh air to the interior of large commercial and industrial buildings, and for exhausting air from the interior of such buildings. Ventilation shafts are typically mounted to extend vertically upwardly through the roof of the building, and may be several feet in width in order to provide sufficient airflow. A motorized fan assembly is frequently installed in the ventilation shaft to increase the flow of air through the shaft. These ventilation shafts are typically provided with a hood extending over the shaft to prevent the influx of precipitation, debris, animals, and the like.

Ventilation shaft hoods are typically adapted to be removed from the ventilation shaft to provide access to the shaft for cleaning, maintenance, removal of obstructions, and the like, particularly with a motorized fan assembly installed in the shaft. However, ventilation shaft hoods are typically very large due to the size of the ventilation shaft, heavy, and unwieldy, making them difficult to remove from the ventilation shaft. Hoods have been adapted to be pivoted about an axis extending along one edge of the ventilation shaft. However, such hoods typically require more than one person to lift and pivot the hood away from the ventilation shaft.

Other hoods are fabricated as two identical mating pieces which can be moved away from the ventilation shaft by sliding the hood pieces horizontally along a track assembly. However, the track assembly is a complex mechanism, involving significant cost in its fabrication. Nevertheless, it can be difficult to move the hood pieces if the track assembly becomes misaligned, corroded or otherwise encrusted with debris.

Ventilation shaft hoods are typically fabricated off-site and must be delivered to the site where they are to be installed. Due to their size and weight, transportation must typically be done on a large semi tractor-trailer, which can be costly.

SUMMARY OF THE INVENTION

According to the invention, a pivot hood assembly for a ventilation shaft, comprises a pair of hood pieces, each hood piece having a shell with an inner edge, and a supporting frame assembly; and an attachment framework adapted to be securely fixed to a ventilation shaft. Each hood piece is pivotably mounted to the attachment framework for movement between a closed position where the inner edges contact each other and an open position where the inner edges are spaced from each other to form an opening. In this way, when the attachment framework is fixed to a ventilation shaft and the hood pieces are pivoted to the closed position, the pivot hood assembly is configured to control the flow of air entering or exiting the ventilation shaft, and when the hood pieces are pivoted to the open position, the ventilation shaft is accessible through the opening.

Preferably, each hood piece is pivotably mounted to the attachment framework at a balanced pivot point wherein little force is required to urge the hood piece to pivot. Also, each pivot hood preferably has at least one closure device to secure the inner edges to each other when the hood pieces are in the closed position.

In one aspect of the invention, the pivot hoods are cooperatively linked so that movement of one pivot hood will also move the other pivot hood. At least one motor can be used to move the pivot hoods between the open and closed positions.

Typically, the pivot hood assembly can have an air filter in each pivot hood and/or a screen in each pivot hood. Preferably, the pivot hood assembly is mounted to a ventilation shaft with the attachment framework attached to the ventilation shaft at an upper end thereof so that when the pivot hoods are in the closed position, each pivot hood has a portion extending below the ventilation shaft end.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a hooded ventilation system according to the invention comprising a pivot hood assembly mounted to a ventilation shaft.

FIG. 2 is a perspective view of the pivot hood assembly illustrated in FIG. 1 comprising a pair of pivot hoods pivotally attached to the ventilation shaft.

FIG. 3 is an exploded view of the hooded ventilation system illustrated in FIG. 1.

FIG. 4 is a perspective view from the underside of a pivot hood illustrated in FIG. 2.

FIG. 5 is a sectional view of the pivot hood assembly illustrated in FIG. 2 taken along view line 5-5.

FIG. 6 is a side elevational view of the hooded ventilation system illustrated in FIG. 1 showing the pivot hoods in a closed configuration.

FIG. 7 is a side elevational view of the hooded ventilation system illustrated in FIG. 1 showing the pivot hoods in an open configuration.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

With reference to the Figures, and specifically to FIG. 1, a hooded ventilation system 10 according to the invention is illustrated comprising a pivot hood assembly 12 operably attached to a well-known ventilation shaft 18. The ventilation shaft 18 can be provided with a motorized fan assembly (not shown) installed in the interior of the ventilation shaft 18 to facilitate the movement of air through the ventilation shaft 18.

The pivot hood assembly 12 comprises a pair of identical hoods 14, 16. Each hood 14, 16 comprises a generally rectilinear shell 20, 22, respectively, supported by a rectilinear frame assembly 24, 26, respectively, to form a unitary hood structure. The hoods 14, 16 are attached to the ventilation shaft 18 through a pair of parallel attachment members 28, 30, thereby forming an attachment framework 32.

Referring now to FIGS. 2-4, the shell 20 of the hood 14 comprises a planar top wall 40, and a pair of planar, parallel side walls 42, 44 depending orthogonally therefrom along a lateral edge thereof. A planar inclined wall 46 inclines downwardly from the top wall 40, and connects the side walls 42, 44. A planar outer wall 48 extends downwardly from the inclined wall 46, orthogonal to the top wall 40 and connecting the side walls 42, 44. The top wall 40 and side walls 42, 44 terminate in and define a rectilinear inner edge 52. The shell 20 defines an airflow chamber 50. The top wall 40, side walls 42, 44, inclined wall 46, and outer wall 48 are interconnected in a suitable manner, such as by welding. The walls 40-48 are fabricated of a suitable material of sufficient strength and durability for the purposes described herein, such as aluminum or steel.

The shell 22 of the hood 16 comprises a planar top wall 60, and a pair of planar, parallel side walls 62, 64 depending orthogonally therefrom along a lateral edge thereof. A planar inclined wall 66 inclines downwardly from the top wall 60, and connects the side walls 62, 64. A planar outer wall 68 extends downwardly from the inclined wall 66, orthogonal to the top wall 60 and connecting the side walls 62, 64. The top wall 60 and side walls 62, 64 terminate in and define a rectilinear inner edge 72. The shell 22 defines an airflow chamber 70. The top wall 60, side walls 62, 64, inclined wall 66, and outer wall 68 are interconnected in a suitable manner, such as by welding. The walls 60-68 are fabricated of a suitable material of sufficient strength and durability for the purposes described herein, such as aluminum or steel.

Referring also to FIG. 5, the frame assembly 24 comprises a parallel array of equal length members, including a pair of outer longitudinal frame member 80, 86, and a pair of inner longitudinal frame members 82, 84. The outer longitudinal frame member 80 extends along a lower edge of the side wall 42. The outer longitudinal frame member 86 extends along a lower edge of the side wall 44. The members 80-86 are joined orthogonally along one end by an outer lateral frame member 92 extending along a lower edge of the outer wall 48. An intermediate lateral frame member 90 and an inner lateral frame member 88 extend orthogonally between the inner longitudinal frame members 82, 84. An end lateral frame member 94 extends between the outer longitudinal frame member 80 and the inner longitudinal frame member 82 opposite the outer lateral frame member 92, and an end lateral frame member 96 extends between the outer longitudinal frame member 86 and the inner longitudinal frame member 84 opposite the outer lateral frame member 92.

The outer longitudinal frame member 80, inner longitudinal frame member 82, the end lateral frame member 94 and the outer lateral frame member 92 comprise a rectilinear frame defining a lateral opening 98. Similarly, the outer longitudinal frame member 86, inner longitudinal frame member 84, the end lateral frame member 96 and the outer lateral frame member 92 comprise a rectilinear frame defining a lateral opening 100. The inner lateral frame member 88, the inner longitudinal frame members 82, 84, and the outer lateral frame member 92 comprise a rectilinear frame defining an end opening 102. The inner longitudinal frame members 82, 84 and the inner lateral frame member 88 are adapted to closely abut the perimeter of the ventilation shaft 18.

The frame assembly 26 comprises a parallel array of equal length members, including a pair of outer longitudinal frame members 110, 116, and a pair of inner longitudinal frame members 112, 114. The outer longitudinal frame member 110 extends along a lower edge of the sidewall 62. The outer longitudinal frame member 116 extends along a lower edge of the sidewall 64. The members 110-116 are joined orthogonally along one end by an outer lateral frame member 122 extending along a lower edge of the outer wall 68. An intermediate lateral frame member 120 and an inner lateral frame member 118 extend orthogonally between the inner longitudinal frame members 112, 114. An end lateral frame member 124 extends between the outer longitudinal frame member 110 and the inner longitudinal frame member 112 opposite the outer lateral frame member 122, and an end lateral frame member 126 extends between the outer longitudinal frame member 116 and the inner longitudinal frame member 114 opposite the outer lateral frame member 122.

The outer longitudinal frame member 110, inner longitudinal frame member 112, the end lateral frame member 124 and the outer lateral frame member 122 comprise a rectilinear frame defining a lateral opening 128. Similarly, the outer longitudinal frame member 116, inner longitudinal frame member 114, the end lateral frame member 126 and the outer lateral frame member 122 comprise a rectilinear frame defining a lateral opening 130. The inner lateral frame member 118, the inner longitudinal frame members 112, 114, and the outer lateral frame member 122 comprise a rectilinear frame defining an end opening 132. The inner longitudinal frame members 112, 114 and the inner lateral frame member 118 are adapted to closely abut the perimeter of the ventilation shaft 18.

The attachment members 28, 30 are elongated members adapted to be attached along an upper edge of the ventilation shaft 18 and to extend laterally beyond the edges of the ventilation shaft 18. The attachment members 28, 30 can comprise solid or hollow metal bars, such as steel bars or square tubing, having suitable strength and rigidity for the purposes described herein. Each end of the members 28, 30 is adapted to form a pivot connection for pivotably connecting a pivot hood 14, 16 thereto. As illustrated in FIGS. 2 and 5, the attachment member 28 is joined at a first end to the inner longitudinal frame member 84 through a pivot connection 144, and at a second end to the inner longitudinal frame member 114 through a pivot connection 146. Similarly, the attachment member 30 is joined at a first end to the inner longitudinal frame member 82 through a pivot connection 140, and at a second end to the inner longitudinal frame member 112 through a pivot connection 142. The pivot connections enable the pivot hoods 12, 14 to pivot upwardly and outwardly away from the ventilation shaft 18. The position of the pivot connections is selected so that the hoods 12, 14 are balanced to enable a person to readily lift and lower the hoods 12, 14.

The attachment members 28, 30 are attached to the ventilation shaft 18, as illustrated in FIG. 2, through suitable fasteners extending through the attachment members 28, 30 into the walls of the ventilation shaft 18. Preferably, the attachment members 28, 30 are attached to the ventilation shaft 18 at an upper portion thereof adjacent the ventilation shaft opening so that, when the pivot hood assembly 12 is in a closed configuration, the bottom of the pivot hood assembly 12 will extend somewhat below the end of the ventilation shaft 18.

FIG. 6 illustrates the hooded ventilation system 10 with the pivot hood assembly 12 in a closed configuration. In the closed position, the inner edges 52, 72 will be brought into contact with each other. The pivot hoods 14, 16 can be provided with suitable closure devices, such as toggle latches (not shown), to maintain the pivot hoods 14, 16 in the closed configuration. Air can flow to or from the ventilation shaft 18 through the lateral openings 98, 100, 128, 130 and the end openings 102, 132 along the perimeter of the pivot hood assembly 12 and the ventilation shaft 18. FIG. 7 illustrates the hooded ventilation system 10 with the pivot hood assembly 12 in an open configuration. In this configuration, the pivot hoods 14, 16 have been pivoted upwardly and outwardly away from each other, thereby enabling ready access to the ventilation shaft 18.

If the pivot hood assembly 12 is used with an air inlet shaft, conventional air filters can be installed in the pivot hoods 14, 16 to filter the air entering the ventilation shaft 18. The filters (not shown) can be single use, fiber-type filters, electrostatic precipitation filters, and the like. The filters would be installed in the frame assemblies 24, 26 in the lateral openings 98, 100, 128, 130 and the end openings 102, 132 to completely intercept air entering the pivot hoods 14, 16. If the pivot hood assembly 12 is used with an air exhaust shaft, conventional air filters can be eliminated. However, screening elements (not shown) can be inserted in the lateral openings 98, 100, 128, 130 and the end openings 102, 132 to prevent the intrusion of animals into the pivot assembly 12 and the ventilation shaft 18. With both the air filters and screening elements, the frame assemblies 24, 26 can be adapted with suitable members and retainers for supporting and a retaining the air filters and screening elements in the lateral openings 98, 100, 128, 130 and the end openings 102, 132.

The pivot hood assembly 12 has been described herein as a manually operable assembly, i.e. the pivot hoods 14, 16 are opened and closed manually. However, in an alternate embodiment, a motorized lift mechanism can be employed to raise and lower the pivot hoods 14, 16. It is anticipated that the lift mechanism would comprise a generally conventional motor, preferably electrically-powered, gearing, structural members, and the like, in a configuration recognizable to a person of ordinary skill in the art as suitable for raising and lowering the pivot hoods 14, 16.

In a further embodiment, the pivot hoods 14, 16 can be cooperatively linked so that the raising or lowering of one pivot hood will raise or lower the other pivot hood. A suitable linkage connecting the two pivot hoods would be utilized to facilitate the coordinated movement of both pivot hoods.

The pivot hood assembly described herein comprising two identical, mating pivot hoods enables a single person to pivot the pivot hood assembly away from a ventilation shaft in order to gain access to the shaft. Complete unobstructed access to the interior of the ventilation shaft is enabled by the use of the two pivot hoods which can be separated and positioned at opposite ends of the shaft, thereby facilitating access to a motorized fan assembly installed in the shaft. The installation of the pivot hood assembly to the ventilation shaft is also facilitated because of the ability to separately mount the two pivot hoods, each of which weighs significantly less than a conventional hood assembly. Finally, transportation of the pivot hood assembly is facilitated by the ability to ship the hood assembly in two parts rather than as a single unit having twice the weight and size as each pivot hood.

While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is b y way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.

Claims

1. A pivot hood assembly (12) for a ventilation shaft (18), comprising:

a pair of hood pieces (14, 16), each hood piece comprising a shell (20, 22) having an inner edge (52), and a supporting frame assembly (24, 26); and

an attachment framework (32) adapted to be securely fixed to the ventilation shaft (18), each hood piece (14, 16) being pivotably mounted to the attachment framework (32) for movement between a closed position where the inner edges (52) contact each other and an open position where the inner edges (52) are spaced from each other to form an opening;

whereby when the attachment framework (32) is fixed to the ventilation shaft (18) and the hood pieces (14, 16) are pivoted to the closed position, the pivot hood assembly (12) is configured to control the flow of air entering or exiting the ventilation shaft (18), and when the hood pieces (14, 16) are pivoted to the open position, the ventilation shaft (18) is accessible through the opening.

2. The pivot hood assembly (12) of claim 1 wherein each hood piece (14, 16) is pivotably mounted to the attachment framework (32) at a balanced pivot point wherein little force is required to urge the hood piece to pivot.

3. The pivot hood assembly (12) of claims 1 or 2 further comprising at least one closure device to secure the inner edges (52) to each other when the hood pieces (14, 16) are in the closed position.

4. The pivot hood assembly (12) of any of claims 1-3 wherein the hood pieces (14, 16) are cooperatively linked so that movement of one hood piece will also move the other hood piece.

5. The pivot hood assembly (12) of any of claims 1-4 further comprising at least one motor to move the pivot hoods between the open and closed positions.

6. The pivot hood assembly (12) of any of claims 1-5 further comprising an air filter in each pivot hood.

7. The pivot hood assembly (12) of any of claims 1-6 further comprising a screen in each pivot hood.

8. The pivot hood assembly (12) of any of claims 1-7 mounted to the ventilation shaft (18) with the attachment framework (32) attached to the ventilation shaft at an upper end thereof so that when the hood pieces (14, 16) are in the closed position, the pivot hood assembly (12) has a portion extending below the ventilation shaft end.