Flexible duct sleeve

A sleeve assembly (2) for supporting flexible duct (4) includes a frame (6) with first and second frame sections (10a, b). The frame sections are secured together by fastener subassemblies (8). The sleeve assembly accommodates flexible duct in various angular and straight configurations. The frame can comprise various suitable materials and skeletal or solid-exterior construction. The sleeve assembly is adapted for various installations in air distribution systems of heating, ventilating and air conditioning systems.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to ductwork for heating, ventilating and air conditioning (“HVAC”) systems, and in particular to a sleeve for protecting a length of flexible hose from crimping.

2. Description of the Prior Art

Hoses, ducts and conduits in various sizes and configurations are commonly utilized for conveying, routing and directing various substances and objects. In dynamic systems, examples of such substances include air which has been heated or cooled by heating and air conditioning equipment. In the construction industry such systems are commonly referred to as heating, ventilating and air conditioning (HVAC) systems.

Typical HVAC systems include runs of ductwork extending from the heating and air conditioning equipment to additional air handling equipment, or to distribution devices. Additional air handling equipment examples include variable air volume (“VAV”) boxes which are located in plenum spaces in many commercial structures. Heated and cooled air is typically introduced into the occupied spaces of buildings by diffusers which direct the airflow in predetermined distribution patterns for maximizing the comfort of the occupants.

Routing ductwork from the air conditioning and heating equipment to the supply diffusers often involves ducting routes which turn, bend and intersect with various components and with other runs of ductwork. To accommodate such curved, angled, and bent routing, flexible duct is commonly used for the final portions of the duct runs, which terminate at diffusers or other components. Flexible duct also has the advantage of being easily reconfigurable to accommodate changed space configurations and the like. Another advantage of flexible duct is that it is available with insulation to avoid condensation during cooling operation.

However, a disadvantage of flexible duct is that it tends to crimp when bent (FIGS. 5a,6aand7a). For example, 90° turns into diffusers can crimp unprotected flexible ducts. Crimping tends to restrict air flow and lower overall system efficiency. HVAC equipment thus works harder and consumes more power to overcome flow resistance associated with crimped flexible ducts.

A prior art solution to the problem of flexible duct crimping at diffusers and other bending locations is to install metal elbows, as shown inFIG. 7b. However, such additional components involve additional labor and material costs. Also, insulation may be required and further increase the installation costs.

The present invention addresses these disadvantages of prior art flexible duct installations. Heretofore there has not been available a sleeve for flexible duct with the advantages and features of the present invention.

SUMMARY OF THE INVENTION

In the practice of the present invention, a sleeve assembly is provided for flexible ducts. The sleeve assembly includes a frame comprising first and second frame sections selectively secured together by fastener subassemblies. The frame includes first and second ends and a longitudinal axis extending therebetween. The sleeve assembly can subtend an appropriate angle for supporting a-length of flexible duct through a corresponding bend. The frame includes multiple rings formed by ring halves each located in a respective frame section. Each frame section also includes multiple longitudinal members interconnecting respective ribs. The sleeve assembly is adapted for accommodating various applications and installations involving flexible duct, either straight or bent.

OBJECTS AND ADVANTAGES OF THE INVENTION

The principal objects and advantages of the invention include:providing a sleeve assembly for flexible duct;providing such a sleeve assembly which reduces crimping in flexible ducts;providing such a sleeve assembly which enhances air distribution system efficiency;providing such a sleeve assembly which can accommodate various flexible duct bend configurations;providing such a sleeve assembly which can be fabricated from various materials;providing such a sleeve assembly which can eliminate the need for metal elbows in air distribution systems;providing such a sleeve assembly which can be manufactured from various components; andproviding such a sleeve assembly which is economical to manufacture, efficient in operation, capable of a long operating life and particularly well adapted for the proposed uses thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

I. Introduction and Environment

Referring to the drawings in more detail, the reference numeral2generally designates a sleeve assembly for a flexible member, such as a length of flexible duct4. Without limitation on the generality of useful applications of the sleeve assembly2, the flexible duct4received in same can comprise a portion of the ductwork in a heating, ventilation and air conditioning (“HVAC”) system in a building.

The sleeve assembly2generally comprises a skeletal frame6secured together by multiple fastener subassemblies8.

The frame6comprises first (inner) and second (outer) frame sections10a,bwith an inner radius (“IR”) arc12aand an outer radius (“OR”) arc12brespectively. A longitudinal axis14extends between opposite ends16of the frame6in generally parallel relation to the radius arcs12a,b. A passage13follows the longitudinal axis14and receives the flexible duct4. The frame6includes a plurality of annular rings18each comprising a pair of ring halves or ribs18a,bassociated with a respective frame section10a,b. As shown, the frame6extends through an arc of approximately 90° and includes four rings18, two of which are located adjacent to the frame ends16and the remaining two of which are located intermediate same whereby the rings18are spaced at approximately 30° radial intervals forming gores19separated by respective adjacent rings18.

The inner frame section10aincludes an inside radius longitudinal member20aand a pair of side longitudinal members20bwhich extend in generally parallel relation with respect to the longitudinal axis14and interconnect respective ribs18a. The outer radius frame section10bincludes an outer radius longitudinal member22aand a pair of side longitudinal members22b. The rings18adjacent to the frame ends16include loops24mounted thereon in radially-spaced relation for receiving ties26which are adapted for securing the frame sections10a,btogether.

The frame sections10a,bare secured together by the fastener subassemblies8, each of which includes a pair of tabs30mounted on respective side edges11a,bof the frame sections10a,b. Each tab includes an inner leg30a, a connector30band an outer leg30c(FIG.2). As shown inFIG. 2, the tabs30can be located at the connections between the ribs18aand respective longitudinal members20a,band22a,b. With the frame sections10a,bplaced together with their respective side edges11a,badjacent to each, other, the tab connectors30bare located adjacent to each other with the tab outer legs30cprojecting outwardly.

Each fastener subassembly8further includes a respective coupling32with a channel34receiving the tab outer legs30cand a slot36receiving the tab connectors30b. Each coupling32includes an extension38adapted to be grasped by an installer to facilitate mounting same. The sleeve assembly2described thus far can be fabricated of sheet metal stamped and folded into the desired configuration.

IV. Modified Embodiment Sleeve Assemblies

A sleeve assembly102comprising a first modified embodiment of the present invention is shown in FIG.4and can be molded from plastic or some other suitable material. The sleeve assembly102includes a modified fastener subassembly108with a first notched latch member110aintegrally formed with a respective first frame section112band a second notched latch member110bintegrally formed with a second frame section112a.

Still further, the sleeve assembly can have a generally tubular configuration which is fully enclosed throughout its entire length with a solid exterior open only at its ends. Such an enclosed or solid exterior configuration could be formed from molded plastic, stamped sheet metal, etc. Sleeve assemblies can be fabricated with various numbers of “gores”19, which comprise the sections between respective rings. Thus, the frame6disclosed has three gores of approximately 30° each whereby the frame6subtends an angle of approximately 90° (30°×3=90°). However, other angular configurations and other numbers of gores could be employed to meet the requirements of particular installations.

Moreover, various angles, radii and diameters can be utilized. The material comprising the frame can comprise, for example, plastic, fiber glass, sheet metal, wire, carbon fiber, etc.

Still further, sleeve assemblies can be constructed of multiple chains thereof secured together. Thus, straight pieces could be combined with elbows, and various angular configurations could be assembled from smaller, angle components or elbows.

FIG. 5shows a first installation or application of the sleeve assembly2in an HVAC system52including a supply duct54and a round tap56connected to same. The sleeve assembly2secures the end of a length of flexible duct4to the round tap56and supports same through a flexible duct bend5a. The sleeve assembly2can be secured to the flexible duct4and the round tap56by any suitable means, including mounting screws58extending through receivers60formed in the rings18adjacent to the frame section ends16. Ties26can also be utilized for providing annular constriction of the sleeve assembly2on the flexible duct4and the round tap56. The flexible duct4extends from the sleeve assembly2to a diffuser62mounted in a ceiling64.

A prior art configuration is shown inFIG. 5aand illustrates a potential restricted flow choke point66, which is avoided by the use of a sleeve assembly2.

FIG. 6shows an installation of a modified, extended length sleeve assembly202connecting a length of flexible duct4to a variable air volume (“VAV”) box68. The extended length of the sleeve assembly202accommodates the operation of the VAV box68by providing a relatively straight length adjacent to the VAV box68inlet to enable its sensors to perform effectively pursuant to manufacturers' recommendations.

FIG. 6ashows a prior art configuration for connecting a length of flexible duct4to a VAV box68whereby a choke point66can occur. Moreover, with the prior art configuration shown in6a, the necessary uninterrupted straight run from the flexible duct4into the VAV box68is not accommodated.

FIG. 7shows a sleeve assembly2coupling a length of flexible duct4directly to a diffuser62. Prior art construction details for this configuration are shown inFIGS. 7aand7b.FIG. 7ashows the potential choke point66which can form if no special consideration is given to maintaining the shape of the flexible duct4through a 90° turn as it enters a diffuser62.FIG. 7bshows a prior art solution to this problem wherein a galvanized elbow70is connected to the flexible duct4and to the diffuser62.

FIG. 8shows another installation of the sleeve assembly2for supporting a length of flexible duct4at a bend4athereof located intermediate a supply duct54and a diffuser62.

VI. Second Modified Embodiment Flexible Duct Sleeve202

A sleeve assembly202comprising a second modified embodiment of the present invention is shown in FIG.9and generally comprises a frame204with first and second ends206a,bwith respective first and second rings208a,blocated thereat. As with the previously-described embodiments, the rings208a,blie in planes which are generally perpendicular to an arcuate axis subtending an angle of approximately 90 degrees through the sleeve202. However, the angular orientation of the rings208with respect to each other could fall within a range of suitable angular displacements, ranging from acute angles through obtuse angles.

The rings208a,bare connected by a spacer subassembly210comprising a plurality (3 are shown) of medial and first and second side connecting members212a, b, c, respectively. The connecting members212curve through angles of approximately 90 degrees for maintaining proper spacing and orientation of the rings208a,b. The connecting members212can be provided with ribs for greater stiffness. A spacer cross piece214extends between and interconnects the connecting members212a, b, c. The spacer cross piece214is located approximately medially between the first and second rings208a, b.

Each ring208a,bcomprises first and second sections216a,badapted for selective fastening in closed positions whereby the flexible duct is gripped in the passage defined thereby. For this purpose, each ring208a,bincludes a fastener subassembly218each comprising a plurality of teeth220formed in the ring first section216aand a receiver222formed in the ring second section216b, similar to the fastener subassembly8shown in FIG.2. The receiver222includes a pawl adapted for engaging respective teeth220whereby the ring second section216bis captured by the receiver222of the ring first section216a.

The ratchet-type fastener subassembly218shown facilitates quickly and easily tightening the rings208a,bon the flexible duct4without the need for tools or special assembly techniques. Moreover, the fastener subassembly218can be released by springing the pawl with a screwdriver or similar tool.

In operation, the sleeve assembly202operates in a manner similar to the sleeve assemblies2and102described above. Installation tends to be relatively efficient and simple because the rings208a,bcomprise essentially the only movable or adjustable component. The bend4aof the flexible duct4can be controlled by properly placing the rings208a,bwhen they are cinched down. Thus, the installer can control the relative sharpness or curvature of the bend4a.

The sleeve assembly202can be fabricated from any suitable material using any, suitable manufacturing technique. For example, the entire sleeve assembly202can be molded from plastic.

VII. Third Modified Embodiment Sleeve Assembly302

A sleeve assembly302comprising a third modified embodiment of the presentation is shown in FIG.10. The sleeve assembly302utilizes a construction with sheet metal strips comprising the connecting members312a,b,cand the spacer crosspiece314. The rings308a,bcan comprise either sheet metal strips or plastic integrally molded with the spacer subassembly310. The frame304can be secured together by suitable mechanical fasteners316such as spot welds, rivets, screws, etc.

A sleeve assembly402comprising a fourth modified embodiment of the present invention is shown in FIG.11and includes a frame similar to frame304described above with first and second rings408a,b. Each ring408a,bincludes first and second sections416a,b. The first ring section416aincludes a plurality of posts418each adapted to be received in a respective hole420formed in the second section416b. The posts418are adapted for snapping into respective holes420. It will be appreciated that one or more of the post-hole combinations can be releasably engaged.

In operation, the sleeve assembly402is otherwise substantially similar to the sleeve assemblies2,102,202, and302described above.

A sleeve assembly502comprising a fifth modified embodiment of the present invention is shown in FIG.12. The sleeve assembly502generally comprises a frame similar to those described above, except that each first ring section516aincludes sawtooth edges518and each second ring section516bincludes a slot520. The slot520removably receives the end of the first ring section516awhereby the sawtooth edges518engage the other ring section516bwithin the slot520thereof for capturing the ring section516awithin the slot520of the second ring section516b, whereby the rings are secured in predetermined configurations for clamping the flexible duct4.