GB2462687A

GB2462687A - Hinge with drive mechanism

Info

Publication number: GB2462687A
Application number: GB0815439A
Authority: GB
Inventors: David Thomas Rowe
Original assignee: Securistyle Ltd
Current assignee: Securistyle Ltd
Priority date: 2008-08-22
Filing date: 2008-08-22
Publication date: 2010-02-24
Anticipated expiration: 2028-08-22
Also published as: GB2462687B; GB2462687A8; GB0815439D0

Abstract

A hinge, preferably a pair of hinges for a parallel moving window vent, comprises first and second mounts 12, 14, and a cross member 20 which may comprise a pivotal scissor linkage 22, 24, coupled for sliding in tracks 12, 14 by sliding shoes 52. The hinge further comprises a drive mechanism, provided at the cross member 20, having a guide slot 26 and camming component for running in the slot such as a pin or roller for pushing or pulling the mounts apart. The drive mechanism may comprise a rail 56 with the pin for sliding in the slotted guide fixed to the cross member; the parallel rail may be driven for longitudinal movement by a motor. The guide slot may comprise a curved section and a straight section; a latching pin 60 may engage behind protrusion 62 during final movement of the rail during the straight section of the guide slot to provide secure latching of the window. The guide component may be provided as a separate component for fixing to the cross member.

Description

Drive Mechanism for a Hing The present invention relates to a drive mechanism for a hinge, and in particular a drive mechanism for a parallel hinge for a vent, such as a window.

Parallel hinges for vents are well known, and they come in many shapes and sizes. A parallel hinge, for example, is disclosed in W098/42941. It consists of a pair of mounting tracks for mounting to a frame and an opening member of the vent, respectively. A pair of diagonally crossing links -a cross member -are also provided.

They are each pivotally connected to the two tracks, at their respective ends, and to each other in their centres, to form a cross formation. Each track accommodates a shoe, which carries an end of one of the links -one end of each link is pivotally mounted to a respective shoe for forming the pivotal connection, thereby allowing the end to move back and forth along the track during use of the hinge when moving the vent between open and closed positions. The hinge therefore allows the two tracks to move parallel to one another as the vent opens and closes.

Mechanisms for opening and closing vents are also known. The above-mentioned W098/42941 discloses one such mechanism. It involves a motor driven member that is operable on one edge of a vent for moving that edge of the opening member relative to that edge of the frame, and then three parallel hinges, each one fitted to one of the other three edges of the vent. Another mechanism is disclosed in GB2436 122. It consists of a lever operated mechanism that can operate against a shoe of a parallel hinge, such as that disclosed above, via a rack and pinion gear mechanism, for opening or closing a vent.

It would be desirable, however, to provide a further drive mechanism for a hinge that can provide a smooth, preferably motor drivable, operation.

According to the present invention there is provided, in a first aspect, a hinge comprising first and second mounts, a cross member coupled between the first and second mounts, and a drive mechanism for driving apart the first and second mounts, wherein the drive mechanism is provided at the cross member, and the drive mechanism comprises a guide component with a slot therein and a camming component for running along the slot for pushing or pulling the mounts apart.

One advantage of the present invention is that the drive mechanism is formed as part of a hinge. Another advantage is that the shape of the slot can be varied to provide different opening responses to the movements of the camrning component.

Preferably the camming component is mounted to a rail that extends parallel to one of the mounts. If it is a parallel hinge, the rail extends parallel to both mounts.

Preferably each mount is a track having a shoe therein, respective ends of the cross member being pivotally attached to the shoes.

Preferably the slot is curved along part of its length. Preferably the curve has a fixed radius along that length. A suitable shape for the slot, however, would preferably be chosen to allow a constant, desirable, rate of linear, transverse, travel of the second mount away from the first mount in response to a given, constant rate of linear, longitudinal, travel, of the camming component, or the guide component, as imposed by the drive means provided for moving the rail.

In one arrangement, the camming component is mounted onto the cross member and the guide component is mounted to a rail. Preferably, however, the guide component is mounted onto the cross member and the camming component is mounted onto the rail.

Preferably the rail is longitudinally translatable along a mount, much like the mounts of the hinge, whereby the components of the drive mechanism can be relatively displaced for achieving a camming action therebetween. A worm drive for moving them relative to one another might alternatively be provided.

Preferably, the cross member is a pair of diagonally crossing links which are pivotally connected to each mount and to each other.

Preferably the links are pivotally connected near, or at, their centres.

A hinge of the present invention may comprise two or more spaced drive mechanisms, each drive mechanism operating against a separate, spaced, cross member. Preferably two cross members are provided, each cross member comprising a pair of crossing links that are spaced along the mounts.

Preferably the slot has a non-camming straight section, along which the camming component can pass without a consequential movement of the two mounts relative to one another. This non-camming section is at an end of the slot and is for allowing the drive mechanism to accommodate further relative movements between the two elements thereof so that weather-sealing, or locking, of the vent can occur upon closure of the vent. For that additional purpose the rail can comprise an additional cam, such as a conventional locking cam, for engaging onto an appropriate latch that is mounted to the opening member of the vent.

In one embodiment of the invention the first mount is fixed, e.g. by being mounted to a frame of a vent, and the second mount is movable, e.g. by being mounted to an opening member of the vent.

Preferably, the mounts are tracks which each accommodate a shoe. The shoes carry pivots that are connected to respective ends of the links.

In one embodiment of the invention the drive mechanism comprises a gear mechanism for applying a longitudinal driving force to the rail to move the camming component (or the guide component) so as to move the camming component along the slot in the guide component. Preferably the gear mechanism is driven by a motor.

In one embodiment of the invention the camming component is a roller.

Preferably the rail is mounted upon or within a further mount, guide member or track. In use the further mount, guide member or track is to be fixed relative to the first mount.

The rail is then a slide member that slides along the guide member.

Preferably an 80mm longitudinal movement of the rail results in a full travel of the camming component along the curved section of the slot. Preferably that full travel will separate the mounts by between 140mm and 180mm -the radius of the curve can be varied, while maintaining the same length for the arc, for controlling that extent of separation.

According to a second aspect of the present invention there is provided a vent comprising a fixed frame and an opening member attached to the fixed frame by at least two hinges, at least one of the hinges being in accordance with the first aspect of the present invention as defined above, wherein the opening member is moveable between a position closing the vent and an open position, or vice versa, by the drive mechanism.

Preferably, the vent comprises a window.

Preferably the hinges are parallel hinges. Preferably three or four parallel hinges are provided. With parallel hinges, the two mounts remain parallel to one another, both when the hinge is open and when the hinge is closed.

According to a third aspect of the invention there is provided a drive mechanism for a hinge, the drive mechanism comprising a guide component with a slot therein and a camming component for running along the slot, one of the guide component and the camming component being mounted on a rail and the other being for a cross member of a hinge, wherein the slot has a curved portion that diagonally traverses relative to the longitudinal axis of the rail.

Preferably the camining component is a roller.

Preferably the guide component is a separately formed component that is for attachment to either the rail or the cross member. It could, however, be integrally formed into or onto the rail or the cross member.

Preferably the rail is in accordance with the rail described above with reference to the first aspect of the present invention.

Preferably the slot has an end region that extends approximately parallel to the longitudinal axis of the member to which it is mounted, be that the rail or a link of the cross member.

According to a fourth aspect of the present invention there is provided a guide component for a drive mechanism of a hinge, the guide component comprising a first side and an opposing second side, the first side having a slot therein, the slot having a curved portion and a straight end portion that intersects an end of the curved portion at a non-zero angle. The slot is for receiving a camming component of the drive mechanism.

Preferably the second side has a groove, the groove being substantially straight, and extending along the full length of the guide component. The groove is for mounting the guide component onto a bar. However, it might be mounted flat Onto the bar instead, or it might be formed as part of the bar.

Preferably the curved portion of the slot only partially overlies the groove, or, in use, the bar, the straight end portion of the slot is thus displaced transversely relative to the groove or, in use, the bar. Preferably that straight end portion of the slot is approximately parallel to the groove or, in use, the bar.

Preferably the curved portion of the slot has a second end, away from the straight end portion, that overlies and runs approximately parallel to the groove or, in use, the bar.

The second end may be a second straight end portion. If it is a straight end portion, preferably it intersects the curved portion as a tangent, i.e. with a zero-angle.

Preferably the guide component is formed of a fibre reinforced plastic, such as glass reinforced plastic, or some other tough, impact resistant plastic. The guide component may alternatively be formed from metal, such as steel (preferably stainless), brass or aluminium.

The guide component of this fourth aspect of the invention may form a part of the hinge of the first aspect of the present invention. Similarly it may form a part of the vent of the second aspect of the present invention. Similarly it may form a part of the drive mechanism of the third aspect of the present invention. When it is associated with a rail, preferably the transverse displacement of the straight end portion from the groove, or the bar, is a similar distance to the relative transverse displacement of the rail from the fixed mount.

The invention will now be described in further detail, purely by way of an example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a hinge in accordance with a first aspect of the present invention, in a vent-open configuration; Figure 2 is a section through a vent in accordance with a second aspect of the present invention, incorporating therein the hinge of Figure 1, in that vent-open configuration; Figure 3 is a perspective view of the hinge of Figure 1 in a vent-partially-open configuration; Figure 4 is a section through the vent of Figure 2, incorporating therein the hinge of Figure 3 in that vent-partially-open configuration; Figure 5 is a perspective view of the hinge of Figure 1 in a vent-closed configuration; Figure 6 is a section through the vent of Figure 2, incorporating therein the hinge of Figure 5 in that vent-closed configuration; Figure 7 is a further perspective view of the hinge of Figure 1, in a vent-closed configuration, showing, in close-up, a latch arrangement in an unlatched configuration; Figure 8 is a perspective view of the hinge of Figure 1 in a vent-locked configuration; Figure 9 is a further perspective view of the hinge of Figure 1, in a vent-locked configuration, showing, in close-up, the latch arrangement in a latched configuration; Figure 10 is a front view of a guide component in accordance with a fourth aspect of the present invention; Figure 11 is a section B-B through the guide component of Figure 10; Figure 12 is a top view of the guide component of Figure 10; Figure 13 is a rear view of the guide component of Figure 10; and Figure 14 is a right end view of the guide component shown in Figure 13.

Referring to the drawings, and initially to Figure 1, there is illustrated a hinge 10 according to the invention. The hinge 10 is a parallel hinge 10 viewed as a one-point perspective (whereby it appears to taper towards the right). Although, only one such parallel hinge 10 will be described below in relation to a vent, it will be appreciated by those skilled in the art that a fitted vent may comprise a plurality of parallel hinges 10 (parallel hinges are usually mounted to two or more edges of a vent such as a window allow the window to be fitted to a frame in the wall such that the window will open parallel to the wall of a building by displacing directly outwards from the wall -this is for preserving the exterior appearance of the building from a distant viewpoint).

The hinge 10 comprises first and second parallel mounts 12, 14 and at least one cross member 20. Just one cross member 20 is shown. However, at least one other cross member could be located to the right of the illustrated one in Figure 1.

The mounts 12, 14 are a pair of mounting tracks 12, 14 for mounting the hinge 10 to the vent (see the window 16 and frame 18 of Figures 2, 4 and 6). The first track 12 is a fixed track for attaching to the frame 18 of the vent and the second track 14 is a movable track for attaching to an opening member (i.e. the window 16) of the vent.

The cross member 20 comprises a pair of diagonally crossing links 22, 24 that are pivotally connected both to each mount 12, 14 and to each other at a central pivot 27.

The cross member 20 facilitates or supports the opening and closing action of the vent.

A guide component 26 of a drive mechanism is mounted to the first 22 of the crossing links 22, 24. That guide component 26 is better illustrated in Figures 10 to 14.

As shown in Figures 10 to 14, the guide component 26 has a front side 28 and a rear side 30. The front side, shown in Figure 10, has a slot 32 and two fixing holes 34. The holes are countersunk to allow the guide component 26 to be screwed or riveted onto the first crossing ling 22 without the head of the screw or rivet (not shown) standing above the surface of the front side 28. Other methods of attachment, however, would be possible.

For example, it could be integrally formed onto the crossing link 22, or else it might be glued onto it.

The rear side 30 of the guide component, as shown in Figure 13, has a groove 36 along its length, running end to end. The groove 36 has a constant cross section except for a locating peg 38 located centrally between the two fixing holes 34. Like the fixing holes, the peg is optional. However, it facilitates the location of the guide component into the correct position along the first crossing link 22 since the crossing link will have a corresponding hole (not shown) for accommodating the peg -the groove 36 is sized to fit snugly Onto the first crossing link 22 with the locating peg 38 in the hole of that first crossing link 22. It will be readily apparent, however, that the guide component 26 might be fitted to the link without the use of a groove.

The slot 32 in the front side 28 of the guide component 26 has two portions -a curved portion 40 and a straight end portion 42. The straight end portion 42 is a non-camming portion in that it does not contribute towards any opening or closing function of the drive mechanism. To enable it not to contribute in this way, in this embodiment it intersects a first end of the curved portion 40 at an angle of about 40° due to the range of curvature provided for the curved portion 40. However, in order for it not to contribute to any opening or closing function of the drive mechanism it merely needs to run substantially parallel to a rail 56 of the drive mechanism when the hinge 10 is in a closed configuration. For that purpose it runs almost parallel to the crossing link 22 to which the guide component 26 is attached. It does, however, point slightly, perhaps by about 50, towards the pivot 27 of the cross member 20 in order to make it parallel to that rail 56 when the hinge 10 is in a closed configuration (the links 22, 24 will not be parallel to that rail 56 when the hinge 10 is in a closed configuration, as illustrated in Figure 5). The actual angle by which it points towards the pivot 27 will correspond to the angle at which the link 22 lies relative to the rail 56 when the hinge 10 is in that closed configuration.

The length of the straight end portion 42 is preferably longer than 20mm, and in the illustrated example it is about 24mm long. The length of the curved portion 40 is preferably longer than 80mm, and in the illustrated example it is about 85mm long. The width of the slot 32 is about 10mm for accommodating a camming component therein.

The 80mm plus length allows an 80mm longitudinal movement of the rail 56 to results in a full travel of the camming component along the curved section 40 of the slot 32.

Preferably that full travel will separate the mounts by between 140mm and 180nun. The further 20mm plus of travel provided by the straight end portion of the slot then allows the rail to move even further for engaging or locking a latch member 62.

The second end 44 of the curved portion 40 is closed (like the second end 46 of the straight end portion 42).

The second end 44 of the curved portion 40 of the slot 32 overlies the groove 36 on the rear side of the guide component 26. It also will run approximately parallel to the groove 36, or, the longitudinal axis of the link 22. In the illustrated embodiment, however, it is slightly angled away from parallel -the parallel tangential position of the curved portion is instead located at the point of section B-B in Figure 10.

The curve of the curved section 40 has a substantially constant radius between its two ends, whereby the slot 32 only partially overlies the groove 36 -its first end, where it is intersected by the straight end portion 42, does not overlie the groove 36. Instead that end is laterally displaced away from the groove 36. For that purpose a wing 48 extends from a main body 50 of the guide component 26. That wing 48 also accommodates the straight end portion 42 -the straight end portion is thus likewise not overlying the groove 36. Instead it is laterally spaced from the groove 36.

Preferably the guide component is a molded or milled component.

Referring back to Figure 1, the tracks 12, 14 are C-shaped in section and each accommodate a shoe 52 (one shown), which each carries an end of one of the links 22, 24. More particularly, one end of each link 22, 24 is pivotally mounted to a respective shoe 52, thereby allowing the end of the links 22, 24 to move back and forth along the tracks 12, 14 during use of the hinge 10 when moving the vent between open and closed positions. The other end of each link 22, 24 is fixed to a respective other track 12, 14.

As is conventional, each of the shoes 52 may carry a pair of annular rollers 14 (not shown, but see GB2436122) which are fixed thereto. The rollers 14 significantly reduce the amount of friction generated as the shoes 52 move along their respective tracks 12, 14, and as a result the opening and closing of a heavy vent can be made easier.

Running parallel to and transversely spaced relative to the fixed track 12 is a third track 54. The third track 54 is very similar to the first and second tracks 12, 14. In particular it has a similar C-shaped section. However, rather than accommodating a shoe 52, the third track accommodates the rail 56. The rail 56 slidably extends along the track's length.

The rail 56 has extending out of a side thereof the camming component (not shown). The camming component is sized and positioned to fit within the slot 32 of the guide component for a camming engagement therewith. The camming component may be a peg with a bearing on it, such as a roller bearing. Many forms of appropriate camming components, however, are known in industry.

The rail 56 is also provided with a second cam 60 at or towards a free end 64 thereof.

This second cam 60 is for engaging a latch 62 of the opening member or window 16, as shown in Figures 8 and 9.

The other end of the rail 56 is connected to a gear mechanism (not shown) for longitudinal translation of the rail for operation of the drive mechanism. Many possible and suitable gear mechanisms are known in industry for longitudinally moving such a rail. The movement of that gear mechanism may be motorised, or it may be manual.

With the above described hinge and drive assembly, the drive mechanism works as follows for closing a vent: Starting from the open configuration of Figure 1, the camming component (not shown) is located at the second end 44 of the slot 32 in the guide component 26. Further, the two links 22, 24 of the cross member 20 are substantially perpendicular to one another. Yet further the rail's free end 64 is fully extended away from the gear mechanism so as to be well beyond the end of the third track 54.

For closing the vent, the gear mechanism is then driven to puil the rail 56 backwards into the track 56. This moves the camming component along the slot 32 so as to force the link 22 to which the guide component 26 is fixed to rotate towards the fixed mount 12. That in turn forces the cross member 20 to flatten for closing the gap between the two mounts 12, 14. The hinge thus moves towards an intermediate position, as shown in Figure 3.

Due to the radius of the slot 32, the rate of closure of that gap remains constant as the rail 56 continues to be pulled into the third track 54, even though the angle of the link 22 on which the guide component 26 is mounted is changing relative to that rail. That is because the curve keeps the point of the slot 32 that is in contact with the carnming component, at any point in time, at a constant angle relative to the rail 56.

Eventually the two mounts 12, 14 will close together into the position shown in Figure 5.

In that closed configuration, the camming component has traversed the full length of the curved portion 40 of the slot 32, and will thus start to enter the straight end portion 42 of the slot 32. In that configuration, that straight end portion 42 of the slot 32 is also now arranged parallel to the rail 56. Therefore, additional retraction of the rail 56 into the third track 54 will not result in a movement of the two mounts 12, 14 relative to one another -the camming effect of the drive mechanism is therefore, in effect, "disengaged" once a closed position for the vent is achieved.

Subsequent retraction of the rail 56 into the third track 54 will, however, cause the latch mechanism to be engaged as follows: As shown in Figure 7, before the subsequent further retraction of the rail 56, the second cam 60 is laterally displaced relative to a catch 66 of the latch 62. However, upon the subsequent further retraction of the rail 56, e.g. by the 20mm allowed by the straight end portion of the slot 32, the second cam 60 will be moved into a position that can engage that catch 66. Therefore, as shown in Figure 9, the movable mount 14, that is attached to the opening member of the vent (the window 16) can no longer be displaced away from (i.e. downwards in the figure) the fixed mount 12. The vent is thus now latched.

Opening of the vent simply occurs as a reverse of the above described closing procedure.

The present invention has been described above purely by way of example. It should be noted that modifications in detail may be made within the scope of the invention.

Claims

CLAIMS1. A hinge comprising first and second mounts, a cross member coupled between the first and second mounts, and a drive mechanism for driving apart the first and second mounts, wherein the drive mechanism is provided at the cross member, and the drive mechanism comprises a guide component with a slot therein and a camming component for running along the slot for pushing or pulling the mounts apart.
2. The hinge of claim 1, wherein the camming component is mounted to a rail that extends parallel to one of the mounts.
3. The hinge of claim 2, being a parallel hinge, the rail extending parallel to both mounts.
4. The hinge of any one of the preceding claims, wherein each mount is a track having a shoe therein, respective ends of the cross member being pivotally attached to the shoes.
5. The hinge of any one of the preceding claims, wherein the slot is curved along a portion thereof.
6. The hinge of claim 5, wherein the curve has a fixed radius.
7. The hinge of any one of the preceding claims, wherein the camming component is mounted onto the cross member and the guide component is mounted to a rail.
8. The hinge of any one of claims 1 to 6, wherein the guide component is mounted onto the cross member and the camming component is mounted Onto a rail.
9. The hinge of any one of the preceding claims, wherein the rail is longitudinally translatable along a mount, whereby the carnming and guide components of the drive mechanism can be relatively displaced for achieving a camming action therebetween.
10. The hinge of any one of the preceding claims, wherein the cross member is a pair of diagonally crossing links which are pivotally connected to each mount and to each other.
11. The hinge of claim 10, wherein the links are pivotally connected near, or at, their centres.
12. The hinge of any one of the preceding claims, comprising two or more spaced drive mechanisms, each drive mechanism operating against a separate, spaced, cross member.
13. The hinge of any one of the preceding claims, wherein two cross members are provided, each cross member comprising a pair of crossing links that are spaced along the mounts.
14. The hinge of any one of the preceding claims, wherein the slot has a non-camming straight section, along which the camming component can pass without a consequential movement of the two mounts relative to one another.
15. The hinge of any one of the preceding claims, when dependent upon claim 7 or claim 8, wherein the rail comprises an additional cam for engaging onto a latch of an opening member of a vent.
16. The hinge of any one of the preceding claims, wherein the first mount is fixed to a frame of a vent, and the second mount is movable by being mounted to an opening member of the vent.
17. The hinge of any one of the preceding claims, wherein the mounts are tracks which each accommodate a shoe, the shoes carrying pivots that are connected to respective ends of the links.
18. The hinge of any one of the preceding claims, when dependent upon claim 7 or claim 8, wherein the drive mechanism comprises a gear mechanism for applying a longitudinal driving force to the rail to move the camming component relative to the guide component so as to move the cainming component along the slot in the guide component.
19. The hinge of claim 18, wherein the gear mechanism is driven by a motor.
20. The hinge of any one of the preceding claims, wherein the camming component is a roller.
21. The hinge of any one of the preceding claims, wherein the rail is mounted upon or within a further mount or guide member.
22. The hinge of claim 21, wherein, in use, the further mount or guide member is fixed relative to the first mount.
23. The hinge of any one of the preceding claims, when dependent upon claim 7 or claim 8, wherein the rail travels about 100mm, about 80mm of the longitudinal movement of the rail resulting in a full travel of the camming component along the curved section of the slot, and the further about 20 mm of travel causing the camming component to travel along the straight end portion of the slot for allowing the rail to engage or lock a latch member without, at the same time, moving the mounts relative to one another.
24. A vent comprising a fixed frame and an opening member attached to the fixed frame by at least two hinges, at least one of the hinges being a hinge according to any one of the preceding claims, wherein the opening member is moveable between a position closing the vent and an open position, or vice versa, by the drive mechanism.
25. The vent of claim 24, wherein the vent comprises a window.
26. The vent of claim 24 or claim 25, wherein the hinges are parallel hinges and three or four parallel hinges are provided.
27. A drive mechanism for a hinge, the drive mechanism comprising a guide component with a slot therein and a camming component for running along the slot, one of the guide component and the camming component being mounted on a rail and the other being for a cross member of a hinge, wherein the slot has a curved portion that diagonally traverses relative to the longitudinal axis of the rail.
28. The drive mechanism of claim 27, wherein the camming component is a roller.
29. The drive mechanism of claim 27 or claim 28, wherein the guide component is a separately formed component that is for attachment to either the rail or the cross member.
30. A guide component for a drive mechanism of a hinge, the guide component comprising a first side and an opposing second side, the first side having a slot therein, the slot having a curved portion and a straight end portion that intersects an end of the curved portion at a non-zero angle.
31. The guide component of claim 30, wherein the second side has a groove, the groove being substantially straight, and extending along the full length of the guide component.
32. The guide component of claim 31, wherein the curved portion of the slot only partially overlies the groove, the straight end portion of the slot being displaced transversely relative to the groove.
33. The guide component of claim 31 or claim 32, wherein the straight end portion of the slot is approximately parallel to the groove.
34. The guide component of claim 31, claim 32 or claim 33, wherein the curved portion of the slot has a second end, away from the straight end portion, that overlies and runs approximately parallel to the groove.
35. The hinge of any one of claims 1 to 23, wherein the guide component is in accordance with any one of claims 30 to 34.
36. The vent of any one of claims 24 to 26, wherein the guide component is in accordance with any one of claims 30 to 34.
37. The drive mechanism of any one of claims 27 to 29, wherein the guide component is in accordance with any one of claims 30 to 34.
38. A hinge substantially as hereinbefore described with reference to the accompanying drawings.
39. A vent substantially as hereinbefore described with reference to the accompanying drawings.
40. A drive mechanism for a hinge of a vent substantially as hereinbefore described with reference to the accompanying drawings.
41. A guide component substantially as hereinbefore described with reference to the accompanying drawings.