WINDOW STAYS

Abstract: A window stay comprises a track (2) which defines a channel (4) in which a guide portion (5) of a slider (6) is longitudinally movable. One end of each of a pair of links (8, 10), is pivotally mounted to the slider (6). The other end of the link (8) is pivotally mounted to one end (12) of a bar (14) which is secured to a side of an openable window vent. A strut (18) is pivotally mounted at one end to the base portion of the track offset from the channel (4) and at the other end to an intermediate point of the bar (14). The other end of the link (10) is pivotally connected to an intermediate point on the strut (18). In the closed position of the stay the bar (14) overlies the strut (18) alongside the channel (4) so that the links (8, 10), bar (14) and strut (18) may be made relatively thicker than in designs where the bar overlies the track channel and, therefore, provide a more rigid construction which can support windows of a greater weight.

Description: The present invention relates to window stays and, more particularly, to friction window stays of the four bar linkage type. A four bar friction linkage window stay is described in U.S. Patent Specification No. 2784459. This type of stay comprises a slider which is movable along an elongate track which is fixed to the window frame. Two links each have one end pivotally mounted to the slider. The other end of one link is pivotally connected to a bar which is fixed to the frame of the openable window vent. A strut is pivotally mounted to the track and is also pivotally connected to the other end of the other link and to an intermediate point on the bar. In the closed position of the window the bar overlies the track with the links and strut inbetween the track and the bar. The end of the track is normally provided with a cap member into which the end of the bar seats in a closed position. Such window stays may be mounted to the window frame at either side of the window, in which case the window vent will pivot open about its top edge. The window vent is held in a desired open position by the friction between the slider and the track. Such stays may also be used for side opening windows. In this case the stays are mounted to the upper and lower edge of the window frame. With such a mounting the stay fixed to the lower window frame member carries a considerable load when the window is open. Since the depth of the stay in the closed position must be accommodated in a recess formed in the frame of the openable window vent in order that a good fit may be maintained between the window vent and the frame in the closed position, a limit is effectively imposed on the overall depth of the closed stay. However, if the links are made relatively thin to keep down the depth of the stay they lack the necessary rigidity for carrying the weight of a side opening window. The present invention is directed to solving the technical problem of providing a window stay of the above-mentioned type which is capable of providing the required rigidity to support large pivoting windows, and, particularly such windows which are side opening, without increasing the overall depth of the closed stay. The present invention accordingly provides a window stay comprising an elongate track defining a channel, a slider having a guide portion disposed in and movable along the track channel, first and second links each having one end pivotally mounted to said slider, a bar for mounting to the frame of an openable window vent, the other end of the first link being pivotally mounted adjacent one end of said bar, a retaining cap member mounted to the track, said one end of the bar being shaped to be retained by said cap member, and a strut having one end pivotally mounted to the other end of said track, the other end of said strut being pivotally mounted to an intermediate point on the bar, and the other end of said second link being pivotally mounted to an intermediate point on said strut, characterised in that in the closed position of the stay the bar lies parallel to and to one side of the track channel with its one end retained by said cap member at a position offset to one side of said track channel. Such a window stay can be provided with links, struts and bars which are relatively thicker than those of the prior art for a given overall depth of the stay, since, in the closed position, the bar lies offset to one side of the track channel which may have the same overall depth as the combined depth of the bar, a link and the strut. This allows the stay to have a greater rigidity. In one embodiment the track comprises a relatively thin base portion carrying two longitudinally extending, parallel upstanding portions each having an inturned edge overlapping the base portion, one upstanding portion being defined along a longitudinal edge of the base portion and the other upstanding portion being defined spaced from the other longitudinal edge, the two upstanding portions defining an upwardly open channel with the inturned edges facing one another. This construction of the track allows easy assembly of the stay and convenient fixing to the window frame. The portion of the slider which projects laterally from the guide portion must overlie the upper edge of the channel. However, this portion may be made relatively thin so that it does not substantially add to the overall depth of the stay. In an alternative embodiment, the track comprises a relatively thin base portion, an upstanding edge portion along one longitudinal edge of the base portion which carries an upper portion overlying the base portion, which portion terminates in a downwardly projecting lip extending parallel to and inwardly of the other longitudinal edge of said base portion, in order to define a laterally-open track channel for receiving the guide portion of the slider, the base portion to one side of the channel pivotally mounting said one end of the strut and carrying the cap member. This construction provides a channel which is closed on three sides and therefore provides a larger friction surface for engagement with the slider than in the alternative arrangement. A further advantage of both embodiments of the track is that the base portion to one side of the channel can provide additional support for the links if required so as to provide better rigidity of the strut in the open position and therefore enable its use with much larger windows than hitherto possible with prior art stays. In order to limit the pivoting motion of the window, a preferred embodiment of the stay is provided with a stop projecting from the base portion to one side of the channel, said stop engaging with a projecting edge of the slider at the limit of pivoting motion, said stop engaging and supporting said second link in the closed position of the stay. In this way the stay is maintained rigid in its closed position as opposed to prior art structures in which, in the closed position, this link would be unsupported yet spaced from the base of the channel making up the track. Another technical problem associated with prior art designs of this type of window stay is that it is difficult to secure the window vent at its pivoting edge when the vent is closed. It is relatively easy for an intruder to force the window by wrenching the end of the bar from its engagement with the cap member, even when the opposite edge of the window vent is locked to the frame. In the embodiment in which the cap member includes an upstanding projection instead of a recess, extra resistance to forcing is provided by the use of a metal upstanding projection which effectively locks the edge of the bar in the closed position. Alternatively, the cap member may be provided with a locking member on its side remote from the track, said locking member engaging in the closed position of the stay with the edge of said one end of the bar. Preferably a cut-out is formed in the edge of the end of the bar to receive the locking member. The engagement of the cut-out with the locking member, which can be more rigid than the remainder of the cap member, prevents the end of the bar from being wrenched out of the cap member. Two embodiments of a window stay in accordance with the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: Figure 1 is a plan view of a first embodiment of the window stay in a partially open position; Figure 2 is a plan view of the stay of Figure 1 in a closed position; Figure 3 is a side view of the stay of Figures 1 and 2; Figure 4 is a perspective exploded view of the slider used in the stay of Figure 1; Figure 5 is a perspective view of the end cap used in the stay of Figure 1; Figure 6 is a plan view of a second embodiment of the window stay in a partially open position; Figure 7 is a plan view of the slider for use in the window stay of Figure 4; Figure 8 is a section on line IIX-IIX in Figure 6; Figure 9 is a transverse section through a modified embodiment of the cap member; and Figure 10 is a transverse section through another modified embodiment of the cap member. The window stay illustrated in Figure 1 is one of a pair. The other window stay of the pair is a mirror image of the stay illustrated, otherwise it is identical in all respects. Therefore, only one stay of the pair will be described. The stay comprises a track 2 which defines an upwardly-­ open channel 4 in which a guide portion 5 of a slider 6 can be moved longitudinally of the track. First and second links 8, 10, each have one end pivotally connected to the slider 6. The other end of the first link 8 is pivotally connected close to one end 12 of a bar 14 which is provided with fixing points 16 for securing it to the base of a recess in a side of an openable window vent. The bar 14 is also pivotally connected at an intermediate point to one end of a strut 18 which has its other end pivotally connected to the track 2 via a support pad 19. The second link 10 has its end remote from the slider 6 pivotally connected to an intermediate point on the strut 18. The strut 18 and the bar 14 are stepped at portions 20 and 22 respectively so that when the slider 6 is moved to its uppermost (relative to Figure 1) position, the bar 14 can be closed up to the track 2 so that its end 12 is received and retained by a cap member 26 fitted at the end of the base plate 2. In this closed position the bar 14 overlies the strut 18 and the links 8 and 10 to one side of the channel 4 as best seen in Figure 3. The track 2 is an elongate member made of metal, preferably aluminium. The track 2 comprises a flat, relatively thin (for example 1.5 to 2 mm) base portion 28 which lies against the frame of the window. The base portion has two upstanding portions 29 and 31 each with a laterally inturned edge overlapping the base portion. The inturned edges face one another to define the upwardly open channel 4. Upstanding portion 29 is formed along one longitudinal edge of the base portion and the other upstanding portion 31 is spaced intermediate the longitudinal edges of the base portion so as to leave a part of the base portion laterally offset to one side of the channel 4. The channel 4 receives the guide portion 5 of the slider 6 which is illustrated in more detail in Figure 4. The track 2 is fixed to the window frame by means of countersunk screws which pass through elongate fitting holes 58, 60 in the base portion of the track channel. The mounting holes 58, 60 are disposed beyond the limits of movement of the slider within the channel. An additional mounting hole 61 may be provided at the end of the track 2 in the base portion to one side of the channel. The guide portion 5 of the slider is sized to be received within the channel 4 and is preferably made of glass reinforced plastics material, e.g. nylon. The guide portion 5 is secured by means of three screws or pins to an upper slider plate 102 which is preferably made of austenitic stainless steel. The slider plate is relatively thin and extends across the entire width of the track as shown in Figures 1 and 2. A slider support pad 104 is also secured to the slider plate 102 by means of two screws passing through the holes 106, 108 in the slider plate and support pad respectively. The support pad lies between the portion of the track laterally offset from the channel and the slider plate. It has a downwardly turned edge 110 which co-operates with the longitudinal free edge of the track. The central portion 112 of the support pad 104 is of greater depth than the remainder so that, when secured to the slider plate 102, two slots 46, 47 are formed between the slider support pad and the slider plate in which the ends of the links 8 and 10 can be respectively received. Bores 114, 116 are formed in the slider plate through which pivot pins are mounted to secure the ends of the links 8 and 10. The edges of the central portion 112 defining the ends of the slots 46, 47 are curved so as to support the links in their pivoting motion. A cut out 40 is provided in both the slider plate and the slider support pad to accommodate the head of a fixing screw 16′ used in fixing the bar 14 to the frame of the openable window vent in the closed position of the stay as illustrated in Figure 3. The slider support pad 104 together with the slider plate form a mounting portion of the slider. The end cap 26 is shown in more detail in Figure 5. The end cap may be a glass reinforced plastics, preferably nylon, member or a stainless steel pressing. The end cap is secured to the track by means of a tongue 120 which is sized to be a tight fit in the channel of the track. The tongue 120 is formed with an elongate hole through which a mounting screw passes. The elongate hole 122 aligns with an elongate hole 58 in the base portion of the track so that a single mounting screw passing through the holes in the tongue and the base of the track secures the track to the window frame. The cap member 26 defines an upstanding edge 64 which is aligned with the outer edge of the upstanding portion 31 so that, in the closed position of the stay as shown in Figure 2 the inner edge of the end 12 of the bar 14 lies against this upstanding edge 64. The retaining edge 64 prevents the bar being opened out from the track in the wrong direction, i.e. to the left as shown in the drawings. Such incorrect opening is also resisted by the edge 31 of the channel. An upstanding projection 124 is mounted in the corner of the cap member to one side of the channel so that as the tapered end 12 of the bar 14 is brought into its closed position, the inclined edge slides behind the upstanding projection 124 as the tip slides along the edge 64. When the bar is in its fully closed position the projection 124 engages against the inclined edge of the end 12 and retains the bar in the closed position until the window is pivoted open again. The upstanding projection is, in this embodiment, eccentric head of a pin made of austenitic stainless steel. The head is eccentric so that the position of the upstanding projection can be adjusted by rotation of the pin so that the projection abuts against the inclined edge of the end 12 in the closed position of the stay but does not interfere with the smooth closing action. By abutting against the inclined edge of the end 12, the upstanding projection 124 also serves as a locking member preventing forcing of the bar transversely away from the track as in an attempted break in. The portion of the end cap carrying the upstanding projection 124 is also provided with a tongue 126 which overlies the end of the base portion of the track laterally offset from the channel to provide a support for the upper end of the link 8 in the closed position of the stay as clearly shown in Figure 3. The second embodiment of the window stay illustrated in Figures 6 to 8 is essentially similar to the embodiment described above except for the construction of the track, the details of the mounting of the links 8, 10 to the slider 6, and the design of the end 12 of the strut and the cap member 26. The basic construction of the second embodiment will therefore not be described in detail. The same reference numerals have been used for the same features in the drawings of both embodiments. The track 2 is an elongate metal plate with a cross section as illustrated in Figure 8. The track 2 comprises a flat, relatively thin base portion 28 which lies against the frame of the window. The base portion has one free edge 30 which is slightly upturned to provide a support for the motion of the links 8 and 10. The other longitudinal edge 32 of the base portion is an upstanding edge portion which carries an upper portion 34 parallel to the base portion 28. The free edge of the upper portion 34 terminates in a downwardly projecting lip 36 which extends parallel to and inwardly of the edge 30 of the base portion 28. The upstanding edge portion 32, the upper portion 34, the part of the base portion 28 beneath the upper portion 34, and the depending edge portion 36 together define the channel 4 which is of rectangular cross section with a longitudinally extending open slot 38 between the edge portion 36 and the base portion 28. This channel 4 receives the guide portion 5 of the slider 6. In this embodiment, the slider 6 is made of plastics material and comprises a thin flat plate 41 which carries a rectangular block 42 which is surmounted by a top plate 44 so as to define at either side of the block 42 two slots 46, 47 having upper and lower portions defined by the top plate 44 and the base plate 41. The block 42 and adjacent parts of the plates 41, 44 define the guide portion 5. The ends of the links 8, 10 are received in the slots 46, 47 and are pivotally mounted to the slider by means of a rivet or other pin which passes across the slot and is secured to the top plate 44 and base plate 41. The cross-section of the guide portion 5 is sized to be received in the rectangular cross-section of the channel 4 with a part of the plate 41 projecting through the slot 38. It will be appreciated that the slider may be formed as a one-piece moulding. As shown in Figure 8, a grub screw 48 is received in a transverse bore which extends through the guide portion 5 of the slider 6 to a recess 50 defined in the bottom of the guide portion. The recess 50 receives a pad 52 which is engaged by the end of the grub screw 48. The screw 48 can be tightened so as to press the pad 52 into relatively tight engagement with the surface of the base portion 28 of the channel. As the pad is forced into tight engagement with the base portion the top of the guide portion will frictionally engage the inside wall of the upper portion 34 of the channel. The grub screw 48 can be suitably adjusted in order to maintain the correct degree of friction between the slider and the track so that once moved to a selected position along the track the slider stays there. However, the friction must not be such as to require undue force to move the slider along the track to open or close the window. This friction adjusting device can also be incorporated into the guide portion of the slider of the first embodiment. Adjustment holes 54, 56 are provided in the upper portion 34 of the track so that the grub screw 48 in the guide portion 5 of the slider 6 can be adjusted to provide the required friction. The access opening 54 is positioned so that it overlies the grub screw 48 when the slider is at one limit of its motion in which the stay is in the closed position. This adjustment opening can be used for factory pre-setting the friction. It will be appreciated that this opening will be inaccessible once the stay is fitted to a window as in the closed position the window vent will be closed over this opening. The access opening 56 is positioned so that the grub screw can be adjusted with the window open. Conveniently, the access opening 60 overlies the grub screw 48 when the slider is at its other limit of motion with the window in the fully opened position. This position is defined by the engagement of the mounting portion 39 or projecting plate 41 of the slider with an upstanding stop 62 defined in the track 2. The upstanding stop 62 has a height such that it does not obstruct the pivoting motion of the second link 10 but supports the link 10 when the stay is in its closed position. The track 2 is fixed to the window frame by means of countersunk screws which pass through fitting holes 58, 60 in both the upper and base portions 34, 28 of the channel. Therefore the screws perform the functions of securing the base plate to the window and also preventing the channel being forced open. The mounting holes 58, 60 are disposed beyond the limits of movement of the slider within the channel. An additional mounting hole 61 may be provided at the end of the track 2 in the base portion to one side of the channel. The end of the track 2 is provided with an end cap 26 in which the recess 24 for the end of the bar is defined. In the embodiment of Figures 1 to 5 the cap member is rectangular in plan so that the stay can be mounted close up to the corner of the window frame. In this second embodiment the cap member 26′ is triangular in plan with the recess 24′ defined by upstanding cam surfaces 66 and 68 and upstanding retaining edge 70. The cam surface 66 is aligned with the depending edge portion 36 of the channel. At its upper end the cam surface 66 adjoins the cam surface 68 which is inclined at 135° to the surface 66. The surface 68 is set at right angles to the upstanding retaining edge 70, which extends at 45° to the longitudinal direction of the base plate 2. A metal locking pin 72 is positioned close to the lower end of the retaining edge 70 and a corresponding cut-out 74 is formed in the edge of the end 12 of the bar 14. The retaining edge 64 prevents the bar being opened out from the track in the wrong direction, i.e. to the left as shown in the drawings. Such incorrect opening is also resisted by the edge 31 of the channel. In Figure 9 an alternative embodiment of the cap member 26″ is illustrated. This cap member defines a closed recess 24 in which part of the cam surface 63 is replaced by a roller 76 which is rotatably mounted by means of a transverse pin 78. The inclined edge of the end 12 of the bar 14 engages with the periphery of the roller 76 as it enters the recess 24 defined in the cap member 26″. In Figure 10 a further alternative embodiment of the cap member 26‴ is illustrated. In this embodiment the cam surface or projection is replaces by a pivotable pawl 80 which is mounted in the cap member 26‴ by means of a transverse pivot pin 82. The pawl 80 has a first arm 84 against which the end 12 of the bar 14 engages as it is brought into the cap member 26‴. The engagement of the bar 14 with the arm 84 causes the pawl to pivot to the position shown in chain line in Figure 10. In this position the second arm 86 acts on the inclined edge of the end 12 of the bar 14 so as to resist forced opening of the stay. In use, the track 2 of either embodiment of the stay is secured to a window frame with the cap member 26 fitted close to the corner of the frame adjacent to the intended pivoting edge of the window. The base portion 28 can be seated in a slight recess in the frame if required. The recess must not be so deep as to obstruct the pivoting motion of the links 8, 10. A corresponding track of a mirror-image stay will be fitted to the opposite side of the window frame. The stays may be fixed to vertical or horizontal edges of the window frame in dependence on whether the window is to be top opening or side opening respectively. The bars 14 are secured to recesses formed in the sides of the window vent by means of fixing screws passing through the fixing slots 16. The end 12 of the bar 14 is offset from the main plane of the bar 14 by the step 22 so that it is placed slightly spaced from the base of the recess in the frame of the openable window vent. When the window stays are fitted the friction between the slider and the track is adjusted by use of the grub screw 48. The required friction will vary in dependence on the type and weight of window to which the stay is secured and whether the pivoting axis of the window is horizontal or vertical. Pivoting the window relative to the frame causes the slider 6 to move along its track 4. As the window is opened, the slider 6 moves downwardly (as illustrated in Figure 1 or 6) until its support pad 104 or projecting plate 40 engages the stop 62. In the first embodiment, as the window is closed the slider 6 moves upwardly as shown in Figure 1 with the tip engaging edge 64 until the inclined edge of the end 12 engages behind the projection 124. In the second embodiment, as the window is closed the slider 6 moves upwardly as shown in Figure 6 until the pointed tip of the end 12 comes into engagement with the cam surface 66 of the cap 26′. The tip engages with this surface because of the offset between the pivoting points of the links 8 and 10 and the pivoting point of the strut 18. The tip of the bar moves up the surface 66 until it reaches the junction between the surface 66 and 68 where it follows the surface 68 until it finally becomes seated at the junction between the cam surface 68 and the retaining edge 70. Due to the described motion the inclined surface of the end 12 passes behind the locking pin 72 which is received in the cut-out 74 as the bar 14 moves into its final closed position as the tip moves along the cam surface 68. The engagement of the pin 72 in the cut-out 74 provides a considerable degree of resistance to forcing of the stay. The operation of the embodiment of Figure 9 is similar to the operation of the first embodiment, except that in this case the inclined edge of the end 12 of the bar 14 engages with the periphery of the roller 76 as it moves into recess 24. In the embodiment of Figure 10, the end 12 of the bar 14 engages the inner surface of the arm 84 of the pawl and causes it to pivot round to the chain line position as shown in Figure 10 as the stay reaches its closed position. In order that the stay may be suitable for supporting relatively large side opening windows, the depth of the links 8, 10, bar 14 and strut 18 may be relatively large since the overall depth of the closed stay is determined by the combined depth of three of these members together with the thickness of the base portion 28 of the track 2, which, since it does not serve any structural purpose can be relatively thin. In the second embodiment, if the edge 30 is not required for supporting the pivoting motion of the links 8, 10, that portion of the base portion 28 of the track 2 which extends to the right (as shown in Figure 1) of the channel 4 can be removed between the two ends so that only sufficient is provided at one end 26 for carrying the cap member 26′ and at the other end for supporting the pivoting mounting of the strut 18. In such an embodiment the stop 62, if required, would need to be provided by for example a screw directly mounted into the window frame.

Claims: 1. A window stay comprising an elongate track (2) defining a channel (4), a slider (6) having a guide portion (5) disposed in and movable along the track channel (4), first and second links (8, 10) each having one end pivotally mounted to said slider (6), a bar (14) for mounting to the frame of an openable window vent, the other end of the first link (8) being pivotally mounted adjacent one end (12) of said bar (14), a retaining cap member (26) mounted to the track (2), said one end (12) of the bar (14) being shaped to be retained by said cap member (26), and a strut (18) having one end pivotally mounted to the other end of said track (2), the other end of said strut (18) being pivotally mounted to an intermediate point on the bar (14), and the other end of said second link (10) being pivotally mounted to an intermediate point on said strut (18), characterised in that in the closed position of the stay the bar (14) lies parallel to and to one side of the track channel (4) with its one end retained by said cap member (26) at a position offset to one side of said track channel (4). 2. A window stay according to claim 1, characterised in that the links (8, 10) are pivotally mounted to a portion (104) of the slider (6) which projects laterally from the guide portion (5) outside the channel (4), and said one end of the strut (18) is mounted to the track laterally offset from said channel such that the mountings of the links (8, 10) to the slider (6) and the strut (18) to the track (4) lie substantially on a common longitudinal axis. 3. A window stay according to claim 1, characterised i that the links (8, 10) are pivotally mounted to the guide portion (5) and the strut (18) is pivotally mounted offset from the channel (4). 4. A window stay according to any one of the preceding claims, characterised in that the track comprises a relatively thin base portion (28) carrying two longitudinally extending, parallel upstanding portions (29, 31) each having an inturned edge overlapping the base portion (28), one upstanding portion (29) being defined along a longitudinal edge of the base portion and the other upstanding portion (31) being defined spaced from the other longitudinal edge, the two upstanding portions defining an upwardly open channel (4) with the inturned edges facing one another. 5. A window stay according to any one of claims 1 to 4, characterised in that the track comprises a relatively thin base portion (28), an upstanding edge portion (32) along one longitudinal edge of the base portion which carries an upper portion overlying the base portion (34), which portion terminates in a downwardly projecting lip (36) extending parallel to and inwardly of the other longitudinal edge (32) of said base portion, in order to define a laterally-open track channel (4) for receiving the guide portion (5) of the slider, the base portion to one side of the channel pivotally mounting said one end of the strut and carrying the cap member. 6. A window stay according to claim 5, characterised in that the fastening means for securing the track to the window frame preferable pass through both the upper portion (34) and the base portion (28). 7. A window stay according to any one of the preceding claims, characterised in that it further comprises a stop (62) projecting from the base portion to one side of the channel, said stop engaging with a projecting edge (40, 104) of the slider (6) at the limit of pivoting motion, said stop engaging and supporting said second link (10) in the closed position of the stay. 8. A window stay according to any one of the preceding claims, characterised in that the retaining cap member (26, 26″) defines an upstanding surface (64) adjacent an outer edge of the track channel (4) against which said one end (12) of the bar (14) abuts in the closed position of the stay, the cap member further carrying an upstanding projection (124) laterally offset from said channel which engages against an edge of said one end of the bar in the closed position of the stay to retain the bar in the closed position. 9. A window stay according to claim 8, characterised in that the projection (124) comprises an eccentrically-­ headed screw member so that rotation of said screw member adjusts the retaining position of the bar (14) in the closed position of the stay. 10. A window stay according to any one of claims 1 to 7, characterised in that the cap member (26, 26″) defines a recess (24) laterally offset from said channel (4), which recess (24) is defined by at least one cam surface (63; 66, 68, 72) which guides said one end (12) of the bar (14) as the stay is brought into its closed position. 11. A window stay according to claim 10, characterised in that the cap member (26, 26″) is provided with a locking member (124, 72, 73) on its side remote from the track, said locking member (124, 72, 73) engaging in the closed position of the stay with the edge of said one end (12) of the bar (14). 12. A window according to claim 11, characterised in that a cut-out (74) is formed in the edge of the end (12) of the bar (14) to receive the locking member (72).

Inventors: CHAPMAN, COLIN WILLIAM
Applicants: CEGO LIMITED
Application year: 1986
Main classification: E05D15
IPC codes: E05D15