Ventilator

Abstract: A two-part ventilator (1) comprises a housing (2) for securing to a frame (6) to overlie an airpath (7) through the frame (6) and a pivotal flap (3) movable to open and close a ventilation opening (9) in a front face (10) of the housing (2) to control air flow. The housing (2) has integral spring legs (17) arranged to bias the flap (3) to each of the open and closed positions.

Description: This invention concerns improvements in or relating to ventilators for controlling air flow and in particular, though not exclusively, for controlling air flow through an air path formed in a frame of a door or window. Ventilators are known in which a flap is pivotal to open and close a ventilation opening to control air flow through an air path formed in door or window frames. The design and construction of such ventilators is often complex requiring manufacture and assembly of several parts which increases the cost. In use, the ventilator is mounted on the inner face of the frame and an exterior hood is often mounted on the outer face of the frame to prevent water penetration. It is usual to fit a fine mesh or the like within the hood to exclude insects but this reduces the cross-sectional area of the ventilation opening so that the ventilation opening has to be made larger than required to obtain the necessary air flow. DE-A-1250092 and GB-A-2136106-A disclose ventilators in which an elongate flap is mounted for pivotal movement in an elongate housing to open and close a ventilation opening in the housing. In both these ventilators, the flap is biased by springs that are separate from the flap and housing and are assembled with the flap and housing during manufacture. It is an object of the present invention to provide a ventilator of simple construction to facilitate manufacture and assembly. According to the present invention a ventilator comprises an elongate housing defining a ventilation opening, an elongate flap mounted for pivotal movement to open and close the ventilation opening and spring means arranged to bias the flap to each of two end positions in which the ventilation opening is open and closed respectively characterised in that the spring means comprises at least one spring leg having one end integral with the housing and the other end free and unattached for biasing the flap to both end positions. The main advantage of the invention is the simple construction with two parts, the housing and flap, for manufacture and assembly of the ventilator. Preferably, the flap is pivotal about an axis extending on one side edge and the spring leg engages the flap remote from the pivot axis. In a preferred construction, the housing has two spring legs at opposite ends of the flap for biasing the flap to both end positions. Advantageously, the flap has an integral grip portion, preferably centrally located between the ends of the flap, that is accessible externally of the housing for pivoting the flap between the end positions. Preferably, the housing and flap are made of plastics, for example mouldings. The housing preferably has holes at opposite ends for fixing screws, and the holes are preferably closed by flush fitting end caps which may be formed integrally with the housing to conceal the fixing screws. In a preferred application, the housing is adapted to be secured to a structure, preferably face fixed horizontally, to overlie one end of an air path through the structure, and a separate hood may be provided which is adapted to be secured to the structure, preferably face fixed horizontally, to overlie the opposite end of the air path remote from the ventilator. Advantageously, the hood has an integral internal grill, preferably formed by two arrays of apertures angled relative to each other to provide a cross-sectional area equal to that of the ventilation opening. The hood is preferably made of plastics, for example a moulding, and has holes at opposite ends for fixing screws, and the holes are preferably closed by flush fitting end caps which may be formed integrally with the hood to conceal the fixing screws. Other features, benefits and advantages of the invention will be apparent from the following description of exemplary embodiments with reference to the accompanying drawings, wherein:- FIGURE 1 is a perspective view of a ventilator embodying the invention; FIGURE 2 is a rear view of the ventilator shown in Figure 1; FIGURE 3 is a section on the line 3-3 of Figure 2; FIGURE 4 is a section showing the ventilator mounted on the inner face of a window frame with the flap in the open end position and an exterior hood mounted on the outer face of the window frame; FIGURE 5 is a rear view of the hood shown in Figure 4; FIGURE 6 is an enlarged fragmentary perspective view from below and one end of the hood shown in Figures 4 and 5; FIGURE 7 is a sectional view of a modified ventilator with the flap shown in broken lines for clarity; and FIGURE 8 is a rear view of part of the housing shown in Figure 7. Referring first to Figures 1 to 4 of the accompanying drawings, the ventilator 1 comprises an elongate housing 2 and an elongate flap 3 mounted within the housing 2 for pivotal movement between two end positions shown in Figures 3 and 4. The housing 2 and flap 3 each comprise a unitary plastics moulding of a size to provide a desired air flow in the open position of the flap 3 shown in Figure 4. The housing 2 has a planar rear face 4 and a screw hole 5 at each end for surface or face fixing to the inner face of a window frame 6 by means of screws (not shown) to overlie and conceal the marginal edge of an air path 7 extending between the inner and outer faces of the window frame 6. Moulded integrally with the housing 2 are flush fitting end caps (not shown) that are a push-fit in the holes 5 to conceal the fixing screws. The air path 7 may comprise an elongate through slot or a series of through holes that are aligned with an elongate rectangular aperture 8 in the rear face 4 of the housing 2. The housing 2 has a ventilation opening 9 formed in a sloping front face 10 which, in this embodiment, constitutes the upper face of the ventilator 1 so that the incoming air flow is directed upwards to reduce or prevent draughts. This is not essential, however, and the housing 2 may be inverted so that the incoming air flow is directed downwards. The ventilator opening 9 extends on either side of a central rectangular hole 11 through which a handle 12 integral with the flap 3 projects for actuation by the user to move the flap 3 between the end positions shown in Figures 3 and 4. In this embodiment, the ventilation opening 9, is sub-divided into slots 13 of which there are two on each side of the hole 11 by transverse webs 14. The length and number of the slots 13 may be altered to suit the air flow requirements for different sizes of ventilator. The housing 2 has an internal longitudinal ledge 15 on which the flap 3 is mounted along one side edge for pivotal movement between the end positions shown in Figures 3 and 4. The flap 3 has an abutment 16 at each end that extends beyond the ends of the ledge 15 and is engaged by an internal spring leg 17 integral with the housing 2 that biases the flap 3 to each of the end positions shown in Figures 3 and 4 to close and open the ventilation opening 9 respectively. The arrangement of the abutments 16 and spring legs 17 provides an over-centre action so that the flap 3 is positively retained in each end position. As a result, the flap 3 firmly engages the housing 2 in the closed position to prevent draughts and is prevented from accidentally closing when in the open position. With reference now also to Figures 5 and 6, an elongate exterior hood 18 is mounted on the outer face of the window frame 6 to overlie and conceal the marginal edge of the air path through the frame 6. The hood 18 is a unitary plastics moulding of a size and shape to provide the required air flow and the plastics material is chosen to be resistant to weathering. The hood 18 has a planar rear face 19 for surface or face fixing to the frame 6 by means of screws (not shown) received in screw holes 20 at opposed ends of the hood 18 and concealed by flush fitting end caps 21 moulded integrally with the hood 18. The hood 18 has an elongate rectangular opening 22 in the rear face 19 that is aligned with the air path 7 through the frame 6 and an elongate rectangular ventilation opening 23 in the underside. The hood 18 has an integral internal grill 24 formed by two longitudinally extending arrays of narrow slots 25 which prevent entry of insects. One array of slots 25 extends horizontally from the rear face 19 partially across the ventilation opening 23 and the other array of slots 25 extends substantially vertically upwards from the free edge of the horizontal array to the inner face of the top wall 26 of the hood 18. By this arrangement of two arrays of slots 25 angled relative to each other, the cross-sectional area of the slots 25 is made equal to that of the ventilation opening 23 so that air flow is not restricted by the provision of the grill 24. In this way, the hood 18 does not have be made larger than necessary to obtain the required air flow. Referring now to Figures 7 and 8 of the accompanying drawings, a modified slimline version of the ventilator above-described is shown in which like reference numerals in the series 100 are used to indicate corresponding parts. The ventilator 101 has a housing 102 and a flap 103 each comprising a unitary plastics moulding. The housing 102 has a flat front face 110 in which a ventilation opening 109 is formed and a respective integral lug 127 and aligned integral spring leg 117 extending rearwardly from the front face 110 at each end of the opening 109. Each lug 127 seats the lower edge of a respective abutment 116 at each end of the flap 103 and the aligned spring leg 117 is inclined towards the lug 127 to engage the upper edge of the abutment 116. The flap 103 is pivotal about the lower edges of the abutments 116 to open and close the opening 109 by means of an integral handle 112 accessible externally of the housing 102 for user actuation. The flap 103 is biased to and held in each of the closed position shown in outline in Figure 7 and an open position (not shown) by the spring legs 117 which provide an over-centre action as the flap 103 is moved from the closed position to the open position and vice versa. The housing 102 has a peripheral rim providing a planar mounting face 104 and a screw hole (not shown) at each end for surface or face fixing to the inner face of a window frame (not shown) by means of screws (not shown) to overlie and conceal the marginal edge of an air path extending through the frame. The fixing screws are concealed by flush fitting end caps (not shown) moulded integrally with the housing 102. The housing may have one or more integral spring legs for biasing the flap to each end position. The or each spring leg may be provided at any position along the length of the flap. For example, a spring leg at one or both ends of the flap. Additionally or alternatively, one or more spring legs may be provided intermediate the ends of the flap. The handle for manually moving the flap between the end positions may be positioned centrally as described or at any other position along the length of the flap. The ventilation opening may be provided by one or more slots of a size and shape to produce any desired air flow in the open position of the flap. The integral grill of the hood may be slotted as described or any other suitable apertures may be provided. Alternatively, other constructions of hood known to those skilled in the art may be used. The arrays of slots or other apertures may extend substantially normal to each other as described or at any other angle. The ventilator and/or hood may be fitted to doors or windows having an air path formed in a fixed or opening frame constructed from timber, plastics, metal or combinations thereof. Where the frame is of hollow profile a sleeve or liner may be fitted in the air path between the hood and ventilator to prevent airflow within the hollow frame profile where condensation may occur with adverse effects on any fittings concealed within the hollow frame profile, for example espagnolette gearing. Finally, whilst the invention has been described with reference to an air path formed in a frame of a door or window, it will be appreciated that the invention has wider application and may be used in other situations where it is desired to control air flow, for example through a wall.

Claims: A ventilator (1) comprising an elongate housing (2;102) defining a ventilation opening (9;109), an elongate flap (3;103) mounted for pivotal movement to open and close the ventilation opening (9;109) and spring means (17;117) arranged to bias the flap (3;103) to each of two end positions in which the ventilation opening (9;109) is open and closed respectively characterised in that the spring means (17;117) comprises at least one spring leg (17;117) having one end integral with the housing (2;102) and the other end free and unattached for biasing the flap (3;103) to both end positions. A ventilator according to Claim 1 characterised in that the flap (3;103) is pivotal about an axis extending on one side edge, and the spring leg (17;117) engages the flap (3;103) remote from the pivot axis. A ventilator according to Claim 1 or Claim 2 characterised in that the housing (2;102) has two spring legs (17;117) at opposite ends of the flap (3;103) for biasing the flap (3;103) to both end positions. A ventilator according to any one of the preceding Claims characterised in that the flap (3;103) has an integral grip portion (12;112), preferably centrally located between the ends of the flap (3;103), that is accessible externally of the housing (2;102) for pivoting the flap (3;103) between the end positions. A ventilator according to any one of the preceding Claims characterised in that the housing (2;102) and flap (3;103) are made of plastics and are preferably mouldings. A ventilator according to Claim 5 wherein the housing (2;102) has holes (5) at opposite ends for fixing screws, and the holes (5) are preferably closed by flush fitting end caps which may be formed integrally with the housing (2;102) to conceal the fixing screws. A ventilator according to any one of the preceding Claims characterised in that the housing (2;102) is adapted to be secured to a structure (6), preferably face fixed horizontally, to overlie one end of an air path (7) through the structure (6), for example a slot or holes extending between opposite sides of a door or window frame. A ventilator according to Claim 7 characterised in that a separate hood (18) is adapted to be secured to the structure (6), preferably face fixed horizontally, to overlie the opposite end of the air path (7) remote from the ventilator (1). A ventilator according to Claim 8 characterised in that the hood (18) has an integral internal grill (24) preferably formed by two arrays of apertures (25) angled relative to each other to provide a cross-sectional area equal to that of the ventilation opening (23). A ventilator according to Claim 9 characterised in that the hood (18) is made of plastics, preferably a moulding, and has holes (20) at opposite ends for fixing screws, and the holes (20) are preferably closed by flush fitting end caps (21) which may be formed integrally with the hood (18) to conceal the fixing screws.

Inventors: FLETCHER TRACY DAIN, TIPPIN ARTHUR DAVID, FLETCHER, TRACY DAIN, TIPPIN, ARTHUR DAVID
Applicants: HARDWARE & SYSTEMS PATENTS LTD, HARDWARE & SYSTEMS PATENTS LIMITED
Application year: 1993
Main classification: F24F13
IPC codes: F24F13