Vent assembly

Abstract

A vent assembly, suitable for marine use including, for example, venting an enclosure, such as an engine compartment, on a boat. The vent assembly has substantially the external appearance of a cast or machined, one piece, stainless steel vent, at a cost very little more than a molded plastics vent. A molded plastics vent has a head perforated by a pattern of ventilating slots separated by flanking strips. A decorative, corrosion-resistant, sheet metal cover shell lies tight against the front side of the molded plastics vent and has a pattern of slots and strips mapping substantially on the pattern of slots and strips of the molded plastics vent. Snap-fit fasteners fix the cover shell on the vent so that the cover shell slots are a substantially flush continuation of the vent slots, so as to provide the decorative appearance of a solid metal vent at substantially lower cost and without compromising or through flow capability.

1 . A vent assembly, suitable for mounting in a hole in a wall of an enclosure, to vent such enclosure, and comprising; 
 a molded plastics vent having a radially extending head, said head having a radially outward facing edge and having a continuous peripheral edge portion inboard of said edge, said head being perforated by a pattern of elongate ventilating slots extending axially therethrough and laterally to said peripheral edge portion, ones of said slots having end walls at said peripheral end portion, said slots being separated by flanking strips defining sidewalls of said slots, said head having front and back sides separated by said radially outward facing edge and through which said slots open, said molded plastics vent having a generally tubular base extending substantially coaxially from said head back side at said peripheral edge portion, said base being spaced inboard of said radially facing edge by a coaxial, radially extending, rear facing, enclosure wall abutting, annular lip and having a coaxial throughpassage communicating with said slots;    a radially extending, decorative, corrosion resistant, sheet metal cover shell lying tight against said front side of said vent head, said shell having a continuous peripheral edge portion mapping on said head peripheral edge portion and a pattern of slots mapping on said pattern of vent head slots in shape, size and relative location, said cover shell slots being separated by strips substantially mapping on said vent head strips in shape, size and relative location, an edge of a given cover shell slot being a substantially flush, forward continuation of the adjacent edge of the corresponding vent head slot to minimize disruption of airflow through the vent assembly, said cover shell including resiliently bendable, cantilevered tabs angled substantially rearwardly from ends of ones of said shell slots and extending into adjacent vent head slot ends, a given said tab having a leg extending along and adjacent the opposed vent head slot end wall, a heel protruding from the free end of said leg beyond said vent head slot end and snugly behind said vent head peripheral edge portion and locking said cover shell on the front face of said vent head, a foot extending rearward from the radially outboard end of said heel, and a toe angled rearward and radially inward from the free end of said foot, said toe having a cover shell installing position bearing cammingly on the front of said vent head peripheral edge portion to assist snap-fit installation of said tab in its said vent head slot, said cover shell being contoured three dimensionally in a shallow, cup-like shape having a front wall incorporating said slots and strips and a peripheral wall covering said radially outward facing edge of said vent head to give the outside appearance of a solid metal vent, said peripheral wall having an enclosure wall approaching, free, peripheral edge rearwardly approaching the plane of said vent head annular lip.    
   
   
       2 . The apparatus of  claim 1  in which the axial thickness of said head strips and cover strips is approximately in the range of ratios 1/20 to 1/80.  
   
   
       3 . The apparatus of  claim 1  in which said cover is a stainless steel stamping.  
   
   
       4 . The apparatus of  claim 2  in which said front side of said vent head is convexly rounded and said cover shell is correspondingly convexly rounded and lies tight against said front side of said vent head.  
   
   
       5 . The apparatus of  claim 4  in which said head slots extend substantially parallel and widthwise of said head, said shell slots extending correspondingly parallel and widthwise of said head.  
   
   
       6 . The apparatus of  claim 1  in which said cover shell has at least one cross strap extending across at least one of said shell slots and between flanking strips, said strap connecting and minimizing deflection of said flanking shell strips.  
   
   
       7 . The apparatus of  claim 6  in which the width of said strap is at most substantially the width of a said flanking shell strip to minimize interference with flow through said head.  
   
   
       8 . The apparatus of  claim 1  in which the thickness of said cover shell is in the range 0.2 mm to 1.0 mm.  
   
   
       9 . The apparatus of  claim 8  in which the thickness of said cover shell is about 0.5 mm.  
   
   
       10 . The apparatus of  claim 1  in which said cover shall is of type 316 stainless steel sheet.  
   
   
       11 . A vent assembly, suitable for marine use and the like, for covering a vent opening while permitting air flow therethrough, and comprising: 
 a vent comprising a radially extending head perforated by a pattern of ventilating holes extending axially therethrough, said holes being separated by flanking portions defining side walls of said holes, said head having front and back sides through which said holes axially extend, said head having a radially outwardly facing edge and a peripheral edge portion inboard of said edge;    a radially extending, decorative, corrosion-resistant, cover shell of substantially rigid sheet stock, said cover shell lying tight against the front of said vent head, said shell having a peripheral edge portion mapping said head peripheral edge portion and a pattern of holes mapping on said pattern of vent head holes in shape, size and relative location, said cover shell holes being separated by flanking portions substantially mapping on said vent head portions in shape, size and relative location, an edge of a given cover shell hole being a substantially flush, forward continuation of the adjacent edge of the corresponding vent head hole to minimize disruption of air flow through the vent assembly, said cover shell being fixed on said vent head, said cover shell forwardly and sidewardly covering said vent head.    
   
   
       12 . The apparatus of  claim 11  in which said cover shell has a rear facing peripheral edge and said vent head has a rear facing surface substantially flush with said cover shell rear facing edge, the latter two being adapted to substantially abut an environmental surface having a vent hole to be covered by the vent assembly.  
   
   
       13 . The apparatus of  claim 11  in which said vent is a molded plastics mass and said cover shell comprises a sheet metal stamping perforated by said holes, said sheet metal stamping including integral rearward extending fastener elements in snap-fit engagement with said mass.  
   
   
       14 . The apparatus of  claim 13  in which said fastener elements are tabs bent rearward from the peripheral portion of the sheet metal at edges of said holes, said tabs being elongate leaf spring-like elements, a given said tab comprising an elongate rearward extending leg received at the edge of a corresponding vent head hole, said leg extending rearward through said corresponding vent head hole and having a heel engaging a rearward surface of said vent head at said corresponding vent head hole end to positively hold said cover shell tight against the front of said vent head in a positive yet resiliently releasable manner.  
   
   
       15 . The apparatus of  claim 11  in which said vent head has a substantially dome shaped front portion, said cover shell being three-dimensionally shaped to conform to said dome shape, said cover shell continuously abutting and covering said vent head forwardly and sidewardly.  
   
   
       16 . The apparatus of  claim 11  in which at least ones of said vent head and corresponding cover shell holes are elongate slots.  
   
   
       17 . The apparatus of  claim 16  in which said cover shell slots are mutually parallel.