A hinge suitable for use in a roof window assembly

Abstract: The invention provides a hinge (10) suitable for use in a roof window assembly (40) having a frame (42) and a movable sash (44) connected to each other by a pair of hinges (10) according to the invention. Each hinge (10) includes a first hinge element (12) connectable to the frame (42) and a second hinge element (14) connectable to the sash (44). A pair of linkages (20,22), each pivotally connected to both hinge elements (10) is so arranged as to allow rotational movement of the sash (44) through angles exceeding 90 °.

Description: FIELD OF THE INVENTION This invention relates to a hinge. More particularly, the invention relates to a hinge for use in a window assembly. BACKGROUND TO THE INVENTION The use of roof windows in the roofs of buildings for providing natural illumination in attics or in upstairs living quarters in domestic dwellings and other buildings is well-known. A roof window assembly within the meaning of the present invention generally comprises a frame which is connectable to a surrounding roof structure. The connection between the frame and roof structure is suitably sealed in order to prevent intrusion of moisture from the roof into the space beneath the roof. A movable sash comprising a window pane is supported with clearance within the frame, usually by way of pivotal connection. Any clearance space allowed between the frame and sash for movement of the sash must be covered by suitable means for preventing any intrusion of moisture through this space, at least when the window assembly is in its closed condition. This may be achieved in known fashion by way of complementary flange formations connected to and arranged along the periphery of either the sash or the frame, or both, whereby a substantially weather-proof overlap between the frame and sash is achieved. The flange formations may either form an integral part of the sash and/or frame, as the case may be. Alternatively, sheet metal flashing may be connected to the sash and/or frame in order to overlie the clearance space between the sash and frame. Rotation of the sash in relation to the frame is usually limited, however, to approximately 90°, by reason of the interference of the flange formations or flashing with adjacent portions of the window assembly. This limitation is overcome at least partially in a roof window assembly known to the applicant in which externally mounted pivotal connections are provided between the frame and sash. Each connection is located adjacent to an overlapping joint between a portion of flashing secured to the sash and a further complementary portion of flashing secured to the frame. This arrangement allows the sash to be rotated through an angle in excess of 90° about its pivotal axis while allowing the flashing of the frame when the assembly is in its closed condition. This assembly has the disadvantage, however, of leaving the pivotal connection exposed to the prevailing weather conditions, leading to their eventual deterioration. In yet a further roof window assembly known to the applicant the pivotal connections provided between the sash and frame, are displaceable along tracks whereby the sash is outwardly displaceable in relation to the frame in order to provide sufficient clearance between the flashing of the sash and frame for rotation of the sash through angles in excess of 90°. The track portions and the components co-operating with these must be manufactured and fitted with relatively close mechanical tolerances, which makes this type assembly comparatively expensive. The desired degree of rotation required for a roof window may be obtained in some instances by using a composite hinge having a stationary and a movable hinge element co-operating with two or more pivotally connected linkages. US Patent 2 355 542 (Loftin), for example, discloses a composite hinge having a stationary hinge element connected to a wooden trunk and a movable hinge element connected to the lid of the trunk. Each hinge element comprises a pair of similar plates accommodating a pair of straight linkages between them in co-planar relationship with each other. Each linkage is pivotally connected to the stationary and to the movable hinge element, thereby allowing the lid to rotate through an angle of approximately 90°. The hinge disclosed in the Loftin patent is however unsuitable for roof assemblies because it does not allow the stationary and movable hinge elements to overlap with each other. This is a particular requirement for roof windows, where the hinges must be sufficiently compact to fit with minimum clearance between the sashes and the associated window frames. Furthermore the hinge elements should not protrude beyond or interfere with any flashing attached to the frame and sash. It is particularly desirable that the opening action of any composite hinge for use in a roof window assembly commences along a substantially linear path before rotation of the sash occurs. This allows any flashing connected to the sash to move freely in and out of overlapping relationship with any flashing connected to its associated frame without inhibiting rotation of the sash. Dutch Patent NL-A-8105219 (Kuin Beheer BV), which corresponds to the preamble of claim 1, discloses a hinge for use in roof window assemblies where, in order to obtain the required degree of compactness, the linkages connecting the stationary and movable hinge elements with each other are specifically shaped to allow the linkages to cross over each other as the window sash is displaced from its fully closed towards its fully opened condition, and vice versa. This has the disadvantage that relatively wide recesses in the sash and window frame are required to accommodate the hinge mechanism. Furthermore the manufacture of the linkages requires several steps in order to form the linkages with sufficient accuracy to ensure unobstructed movement when the hinge is fully assembled. It is an object of this invention to provide a hinge for use in a roof window assembly of the kind described above having relatively few components while allowing unimpeded rotation of the sash through an angle of at least 90°. It is a prefered embodiment of this invention to provide a roof window assembly having flashing for providing a weather-proof seal between its frame and sash, in which a portion of the flashing secured to the sash is allowed to pass with clearance underneath a portion of the flashing secured to the frame whenever the roof window assembly is brought towards its closed condition. SUMMARY OF THE INVENTION According to the invention there is provided a hinge for use in a roof assembly having a movable sash which fits into a stationary frame, the hinge including: a first substantially planar hinge element connectable to the frame; a second substantially planar hinge element connectable to the sash and arranged in a plane spaced from, and extending in parallel juxtaposition to, the first hinge element; a first linkage connected to the first and second hinge elements, at two pivot points; a second linkage connected to the first and second hinge elements at two further pivot points; wherein the spacing between the two pivot points of the first hinge element is larger than the spacing between the two pivot points of the second hinge element; the pivot points being so located in relationship to each other that, in use, a reference axis passing through the pivot points of the second hinge element passes through an angle of at least 90° and approaching 170° in relation to its initial fully closed orientation when the hinge is displaced from its fully closed to its fully opened condition; characterised in that the linkages are arranged in co-planar relationship with each other, and the distance between the pivotal connections of the second linkage is less than the distance between the pivotal connections of the first hinge element. The first and second hinge elements are preferably in the form of flat plates, and more particularly flat metal plates. In preferred embodiments of the invention the linkages, also preferably formed from flat metal plates, are arranged between the first and second hinge elements. The pivotal connections between the hinge elements and linkages may be formed by pins extending perpendicularly to, and passing through, circular holes defined by the hinge elements and linkages. The linkages may be so shaped as to define edges whereby the linkages are permitted to abut against each other, the fully opened and fully closed conditions of the hinge being defined by respective orientations of the linkages in relation to each other, in which the edges of the linkages bear against each other. The invention extends to a roof window assembly which includes a frame mounted in a surrounding structure, and a window sash fitting into the frame with clearance and connected to the frame along two of its opposing edges by way of a pair of hinges as set forth above. The roof window assembly may further include flashing secured to the frame and flashing secured to the sash which overlies the clearance space between the frame and sash when the window assembly is in its fully closed condition, characterised by a further portion of flashing arranged along and connected to the outer periphery of the frame, the flashing portions connected to the frame and the flashing connected to the sash overlapping the peripheral flashing when the window assembly is in its closed condition. The hinge elements and linkages are preferably so arranged that, in use, the flashing connected to the sash is allowed to pass freely underneath the flashing connected to the frame when the window assembly is brought into its fully closed condition. The frame may be provided with recesses in the region of overlap between the portions of flashing connected the sash and frame in order to allow the flashing connected to the sash to pass freely underneath the flashing. DESCRIPTION OF THE DRAWINGS The invention is described below by way of example with reference to the accompanying diagrammatic drawings in which Figure 1a shows a side elevation of a hinge according to the invention in its fully closed condition; Figure 1b shows a side elevation of an improved hinge similar to that of Figure 1a; Figure 2 shows an upper plan view of the hinge of Figure 1a in its fully closed condition; Figure 3 shows an upper plan view of the hinge of Figure 2 in a partially opened condition; Figure 4 shows an upper plan view of the hinge of Figure 3 in its fully opened condition; Figure 5 shows a perspective view of a window assembly according to the invention in its fully closed condition, incorporating a pair of hinges of the type shown in Figure 1a; Figure 6 shows an exploded view of the circled portion of the window assembly of Figure 5 on an enlarged scale; Figure 7 shows a perspective view of the window assembly of Figure 5 in a partially opened condition; Figure 8 shows the window assembly of Figure 5 in its fully opened condition; and Figure 9 shows a perspective view of an improved window assembly similar to that of Figure 5 in its fully opened condition. DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION In the accompanying drawings reference numeral 10 denotes generally a hinge according to the invention. The hinge 10 includes pressed metal plates 12 and 14, spaced apart from each other and arranged parallel in juxtaposition to each other, constituting first and second hinge elements respectively. The plate 12 has a pair of circular holes 16 and the plate 14 has a pair of circular holes 18. The holes 16 and 18 all have the same diameter. The spacing between the holes 16 is larger than that between the holes 18, as appears from Figures 2, 3 and 4. When the hinge 10 is in its fully closed condition (Figure 2) one of the holes 16 is substantially in alignment with the holes 18 while the other hole 16 is located approximately adjacent to the hole 18 closest to the first-mentioned hole 16. Linkages 20 and 22 formed of metal plate are arranged between the plates 12 and 14 as appears from Figure 2. The linkages 20 and 22 have circular holes matching the holes 16 and 18 allowing pivot points A,B,C,D between the plates 12 and 14 to be formed by pivot pins 24 passing perpendicularly through the plates and linkages. Annular plastic spacers 26, held captive by the pivot pins 24 are arranged between the plates 12, 14 and the linkages 20 and 22 as shown in Figure 1a in order to permit unobstructed movement of the plates and linkages in relation to each other. The plates 12 and 14 are provided with drilled holes 28 for mounting the hinge 10 to a stationary member and to a movable member respectively, as will appear from the further discussion below. The hinge 10′ shown in Figure 1b is substantially similar in structure to the hinge shown in Figure 1a. The spacers 26′ are preferably of a nylon, however, in order to maintain a desired degree of friction between the plates 12′ and 14′ in relation to each other. This feature has the advantage that roof window assemblies incorporating hinges 10′ are restrained from being open or shut at random by light gusts of wind. The pivot pins 24′ of the hinge 10′ have flattened heads which are recessed within their adjacent plates 12′ and 14′, as the case may be. Lubricated washers 29′ are further-provided at the opposing ends of these pivot pins in order to minimise wear on the pins and plates 12′ and 14′ in the regions of relative movement between these components. The distance between the points A and C in the linkage 22 defined by the pins 24 is less than the distance between the points A and D defined by the holes 16 in the plate 12. As appears more fully from Figures 3 and 4, the arrangement of the points A,B,C and D described above allows the linkages 20 and 22 to move in co-planar relationship with each other without mutual obstruction when the plate 14 is displaced from its closed condition (Figure 2) to a fully opened condition (Figure 4). In a preferred application of the invention shown in Figure 5 a pair of hinges of the type described above is used in a roof window assembly denoted generally by reference numeral 40. The assembly 40 comprises a stationary rectangular timber frame 42 which is connectable to a roof structure (not shown). A moveable window sash 44 comprising a window pane 46 supported in a rectangular timber frame 48 fits with clearance into a frame 42. Figure 6 illustrates the method whereby the frame 42 is connected to an adjacent portion of the sash 44 by way of a hinge 10. The metal plate 12 is secured to the left hand member of the frame 42 by means of wood screws (not shown) passing through the drilled holes 28 and screwed into the timber of the frame. The plate 14 is secured in similar fashion to a corresponding portion of the frame 48 ensuring that the sash fits into the frame 42 with sufficient clearance to allow free movement of the sash. The hinge 10 is fitted in its assembled state, the drilled holes 28 being readily accessible during fitting by suitable rotation of the sash 44 in relation to the frame 42. A further hinge (not shown) having the same components as the hinge 10 shown in Figure 6 is fitted between the right hand members of the frames 42 and 48 shown in Figure 5. The further hinge is mirror-inverted in relation to the arrangement of Figure 6. The plates 12 of the two hinges will accordingly face each other from within the frame 42 while the plates 14 are located in corresponding positions on the frame 48 to allow it to fit with clearance into the frame 42. In order to render the roof window assembly weatherproof it is provided with metal flashing generally denoted by reference numeral 50 extending across the spaces between the outer periphery of the frame 48 and the inner edges of the frame 42 when the assembly 40 is in its closed condition. A first stationary portion 52 of metal flashing is connected to the frame 42 and a movable portion 54 is connected to the sash 44 as appears from Figure 5. It is an important embodiment of this invention that the leading edges 56 of the movable portion 54 of the flashing pass underneath the stationary portion 52 in order to provide a suitable overlap between these portions. The manner in which this overlap is achieved is best understood by reference to Figures 2, 3 and 4. The closed condition of the window assembly 40 corresponds to the closed condition of the hinge 10 as shown in Figure 2. The centres of the holes 18 of the plate 14 are aligned along the line 30. As the window sash 44 is moved to its partially opened condition (Figure 7) the plate 14 of each hinge is displaced to a position approximately as shown in Figure 3. It is evident that this displacement involves a composite movement having a linear and a rotational component. The pivot points B and C centred at holes 18 are displaced both axially and laterally in relation to the line 30; the plate 14 furthermore undergoes rotation through an angle 32 formed between the line 30 and the corresponding line 34 which passes through the points B and C after displacement of the plate. It is apparent from Figure 3 that the pivot point C associated with the lever arm 22 follows an arcuate path adjacent to the reference line 30 when the hinge 10 is displaced from its fully closed towards its open position. It is further evident that the portion of the plate 14 adjacent to this point C initially moves away from the reference line 30 as a result of the rotational movement imparted to this plate by the joint action of the linkages 20 and 22. The leading edges 56 of the moveable flashing 54 are located in close proximity to the above mentioned portion of each plate 14 in the window assembly 40 (Figure 8). These leading edges accordingly have to be initially displaced away from the stationary portion 52 of the flashing 50 as the hinges, and hence the sash 44 moves from the fully closed towards the fully open condition. Similarly, when the motion of the sash 44 is reversed, the leading edges 56 will not snag the stationary portion 52 of the flashing 50. The side members of the frame 42 each have cut-away portions 58, one of which is illustrated in Figure 6. The leading edges 56 of the movable flashing 54 are accordingly permitted to move without obstruction past the frame members 42 while the sash 44 undergoes rotational displacement. The sash 44 is provided with a handle 60 visible in Figures 5, 6 and 7 which is drawn downwardly in order to open the sash. The sash ultimately reaches its fully open condition, illustrated in Figure 8, when the handle is at its lowest point and facing outwardly from the roof structure to which the assembly 40 is connected. The fully open condition of the sash shown in Figure 8 corresponds with the fully open condition of the hinge shown in Figure 4. During transition from the fully closed to the fully open condition the plate 14 and hence the sash 44 undergo a rotation approaching 170° illustrated by the angle 36 which is formed between the lines 30 and 38 shown in Figure 4. As appears from Figure 8 the outwardly facing surface of the window pane 48 is readily accessible for cleaning from within the building to which the frame is connected. The linkages 20 and 22 are designed to have edges which bear against each other when the hinge 10 is either in its fully open or in its closed condition. More particularly, the edges 62 and 64 provided on the linkages 20 and 22 respectively at the regions shown in Figure 3 bear against each other when the hinge 10 is in its fully open position shown in Figure 4. Similarly edges 66 and 68 on the linkages 20 and 22 respectively bear against each other when the hinge 10 is in its fully closed position (Figure 1). In an alternative roof window assembly 40′ shown in Figure 9, which is structurally similar to the assembly 40 described above, the flashing comprises four portions 51′,53′,53′ and 54′. A first portion 51′ is fitted flush with the outer periphery of the frame 42′ and has inwardly stepped portions extending adjacent to the outer edges of the frame. Two lateral portions of flashing 53′ in the shape of inverted channels are arranged along the vertical members of the frame 42′, overlapping the first flashing portion 51′ along its inwardly stepped portions. The flashing 53′ is supported by brackets (not shown) connected to the frame 42′ in order to provide a clearance space between the frame 42′ and the flashing 53′, thereby permitting movement of the leading edges of a flashing 54′, connected to the sash 44′, past the flashing 53′. The flashing 54′ corresponds substantially to the flashing portion 54 in Figures 5, 7 and 8. A hood 55′ completes the flashing on the frame 42′, and is arranged along the upper cross-member of the frame in overlapping relationship with both the flashing portions 51′ and 53′. The flashing portion 51′ allows a weatherproof joint to be formed between the frame 42′ and its surrounding support structure (not shown). The hood 55′ serves to avoid moisture ingress through the clearance space formed between the upper adjacent edges of the frame 42′ and the sash 44′ when the assembly 40′ is in its closed condition. The flashing 54′ is provided with lateral skirting extending with clearance along the outer edges of the sash 44′. This skirting overlaps the inwardly stepped portions of the flashing 51′ when the window assembly 40′ is in its closed condition thereby rendering the entire assembly substantially weatherproof in this condition. The side members of the frame 42′ are generally narrower than the corresponding members of the frame 42, and accordingly do not require any cutaway portions corresponding to the cutaway portions 58 of the assembly 40 (Figure 8). The applicant envisages that the hinges and roof window assemblies described above lend themselves to the numerous adaptations and modifications without departing from the essential elements of the invention set out in more general terms in the preceding description of the invention and the accompanying claims. The scope of the invention should accordingly not be construed as being limited to the description of the preferred embodiments set out above.

Claims: A hinge (10) for use in a roof window assembly having a movable sash (44) which fits into a stationary frame (42), the hinge including a first substantially planar hinge element (12) connectable to the frame (42); a second substantially planar hinge element (14) connectable to the sash (44) and arranged in a plane spaced from, and extending in parallel juxtaposition to, the first hinge element (12); a first linkage (20) connected to the first and second hinge elements, at two pivot points (B,D); a second linkage (22) connected to the first and second hinge elements at two further pivot points (A,C); wherein the spacing between the two pivot points (A,D) of the first hinge element (12) is larger than the spacing between the two pivot points (B,C) of the second hinge element (14); the pivot points (A,B,C,D) being so located in relationship to each other that, in use, a reference axis passing through the pivot points (B,C) of the second hinge element (14) passes through an angle of at least 90° and approaching 170° in relation to its initial fully closed orientation when the hinge is displaced from its fully closed to its fully opened condition characterised in that the linkages (20, 22) are arranged in co-planar relationship with each other, and the distance between the pivotal connections (A,C) of the second linkage (22) is less than the distance between the pivotal connections (A,D) of the first hinge element (12). A hinge according to claim 1 characterised in that the linkages (20, 22) are shaped to define edges whereby the fully closed and fully opened conditions of the sash are respectively determined by two different orientations of the linkages in relation to each other, in each of which the edges of the linkages bear against each other. A roof window assembly which includes a frame (42) mounted in a surrounding structure, and a window sash (44) fitting into the frame with clearance and connected to the frame along two of its opposing edges by means of a pair of hinges (10) according to claim 1. A roof window assembly according to claim 3 which further includes flashing (53′, 55′) secured to the frame and flashing (54′) secured to the sash which overlies the clearance space between the frame and sash when the window assembly is in its fully closed condition, the roof window assembly having a further portion of flashing (51′) arranged along and connected to the outer periphery of the frame, the flashing portions (53′, 55′) connected to the frame and the flashing (54′) connected to the sash overlapping the peripheral flashing (51′) when the window assembly is in its closed condition.

Inventors: SANDELL ANTHONY CHARLES, SANDELL, ANTHONY CHARLES
Applicants: SANDELL ANTHONY CHARLES, SANDELL, ANTHONY CHARLES
Application year: 1991
Main classification: E05D7
IPC codes: E05D7