Patent Publication Number: US-2015084367-A1

Title: Glazing System and Methods

Description:
TECHNICAL FIELD 
     The invention relates to the field of glazing systems for service vehicles, such as passenger service vehicles. In particular, but not exclusively, the invention relates to a glazing system, including glazing frames, for passenger service vehicles, as well as other associated apparatus and methods, such as methods of installation and/or repair. 
     In some examples, the invention relates to passenger service vehicles comprising such glazing systems. Those glazing systems may be provided on both single and double-deck vehicles. 
     BACKGROUND 
     Significant innovation and technology development has occurred in recent years in relation to the design of passenger service vehicles. In particular, there has been a continued drive towards providing vehicles that allow for ease of construction, ease of maintenance, ease of cleaning, fuel efficiency, reduced weight and running costs, etc., while at the same time maintaining or improving the safety of those vehicles. 
     The glazing on passenger service vehicles, such as the main glazing provided on either side of a vehicle, is prone to damage, such as by accident or vandalism. The ease and time with which repairs can be made in the event of such damage is an important factor in the commercial operability of such vehicles. Furthermore, the ease and time with which the construction of vehicles can be made is an important factor in the costs of providing such vehicles. 
     One existing type of glazing system comprises fitting a glazing panel to a rubber gasket, which is then mounted to a window frame. Such systems are prone to leaking, are not aesthetically appealing, but are easy to install and repair. An alternative system bonds glazing panels to the vehicle (e.g. using an adhesive at a periphery of the panel, and affixing this to the vehicle). Such systems are less likely to leak, are more aesthetically pleasing, but are difficult to install and/or repair. 
     This background serves only to set a scene to allow a skilled reader to better appreciate the following description. Therefore, none of the above discussion should necessarily be taken as an acknowledgement that that discussion is part of the state of the art or is common general knowledge. One or more aspects/embodiments of the invention may or may not address one or more of the background issues. 
     SUMMARY 
     According to a first aspect of the invention there is provided a glazing system for a passenger service vehicle. 
     The provision of an improved glazing system may allow for one or more of: ease of construction; ease of maintenance and/or repair; ease of cleaning; reduced weight and running costs, etc., and maintaining or improving the safety of those vehicles. 
     The system may comprise a glazing frame. The glazing frame may be configured to attach to a passenger service vehicle. The frame may comprise one or more frame portions, which served to form or define the overall frame when the system is attached to a service vehicle. In other words, the glazing frame may comprise one or more frame portions (e.g. for use with waist rail, cant rail, and/or pillars) such that, when attached to the vehicle, they form an overall glazing frame for use with a glazing panel. In such examples, once assembled, the system may comprise a plurality of defined frames. 
     The/each glazing frame may comprise a glazing mount, which may extend along (e.g. around, such as inwardly around) some or all of the frame. The mount may be configured to associate a glazing panel with the frame. The mount may be configured to prevent a glazing panel from being forced outwardly from the vehicle (e.g. by a passenger). The frame (e.g. the mount) may be formed from an alloy. 
     The system may further comprise a removable retainer configured to engage with the frame, and to retain a glazing panel against the glazing mount. In other words, in use of the vehicle, the glazing panel is retained against the mount by the removable retainer. In some examples, the system is configured such that the removable retainer is configured to directly mount with a glazing panel (e.g. rather than indirectly, via secondary glazing, or a sacrificial interior or glazing). 
     The removable retainer may be configured to engage with a frame retainer. That frame retainer may be provided on the frame itself (e.g. formed integrally with the frame). The removable retainer may be configured to engage between the frame retainer and a glazing panel (e.g. in an interference manner) in order to retain, or urge and retain, a glazing panel against the glazing mount. Some or all of the removable member may be resiliently deformable. 
     The frame retainer may be configured to engage in a complementary manner with a portion of the removable retainer. The frame retainer may be configured as a recess, for example a recess on the frame. The removable retainer may comprise a retaining rib, element, or other such protrusion, specifically configured to locate and engage with the recessed frame retainer. The removable retainer may additionally comprise a locating element, configured to allow for ease of location of the removable retainer with the frame retainer (e.g. for complementary location with a corresponding recess). The locating element may be provided with the rib or protrusion, such that a corresponding recess is provided at the frame retainer. In use, the locating element of the removable retainer may be located with a corresponding recess of the frame retainer. 
     The removable retainer may comprise one or more fins, configured to engage with glazing (e.g. two or more fins). Each fin may be configured to be substantially parallel with each further fin. The removable retainer may comprise two fins configured to engage with a glazing panel (e.g. in an interference manner). 
     The removable retainer may comprise one or more interior fins. The interior fin may be configured to engage with a portion of the frame. Such a configuration may provide a contiguous surface on the inside of the frame. 
     The removable retainer may comprise a removal element, configured to allow a user to remove the retainer from the frame. The removal element may be operable by hand. 
     The removable retainer may comprise a removal pivot. In some examples, the removal pivot may be configured to cooperate with the removal element (and/or the frame) in order to assist with removal of the removable retainer from the frame. Actuation of the removal element may urge the removable retainer from the frame, causing the removal pivot to pivot on the frame (or a portion thereof), and assist with removal of the retainer from the frame (e.g. the removable retainer from the frame retainer, and so from the frame). 
     The removal pivot may additionally or alternatively assist with locating of the removable retainer. The frame may comprise a pivot region for use with the removal pivot. The pivot region may be provided at or with the frame retainer. 
     The removable retainer may be configured as a removable strip. The removable retainer may be configured to extend around some or all of the frame. The removable retainer may be configured to extend along one or more sections of the frame (e.g. top section, a bottom section, and/or a one or more side sections). The glazing system may comprise a plurality of removable retainers (e.g. four per window). 
     The, or each, removable retainer may be configured to engage with the frame, and to urge and retain glazing against a frame seal, which in turn retains glazing against the frame. The seal may be configured to associate glazing with the frame. The seal may be provided at the frame mount. The seal may be configured to be removable/replaceable from the frame. The seal may be configured to extend around some, or all, of the frame or mount. The seal may be compressible. 
     The system may comprise one or more secondary retainers. The or each secondary retainer may additionally be configured to retain glazing against the mount/frame. The secondary retainer may be configured to affix to the frame, and retain glazing against the mount. The secondary retainer may be screwed, bolted, adhered, or the like, to the frame, in order to retain a glazing panel. The secondary retainer may be fully or partially covered, or concealed, by the removable retainer (e.g. covered and concealed from a passenger). The system may comprise a plurality of discrete secondary retainers (e.g. provided at particular intervals on the frame). 
     The system may comprise one or more strips of removable retainer, each covering a plurality of discrete secondary retainers. 
     The system may comprise one or more exterior frame portions. The system may additionally comprise one or more interior frame portions. The glazing frame may be provided by one or more exterior frame portions, together with one or more interior frame portions. 
     The exterior and interior frame portions may be configured to engage with, or mount with, an exterior and an interior of a passenger service vehicle respectively (e.g. via an intended window aperture of the passenger service vehicle). In order words, the formed frame may extend from the exterior of a vehicle to the interior of a vehicle. 
     Each portion may be further configured to operatively engage together so as to retain the frame on the passenger service vehicle (e.g. retained on a waist rail). 
     The frame portions may comprise complementary engagement elements, configured to retain one portion of the frame to the other. The frame portions may comprise complementary recesses and protrusions, configured to engage and retain the frame portions together. A retained exterior frame portion and interior frame portion may provide a frame depth. The engagement elements may be configured to allow for a variable frame depth (e.g. in a ratchet-style arrangement). 
     One of the interior frame portion or exterior frame portion may comprise a plurality of engagement elements, configured to engage with a complementary element on one of the exterior frame portion or interior frame portion. The plurality of engagement elements may be configured so as to provide the variable depth of frame. 
     The engagement elements may be fully or partially concealed by the removable retainer. The removable retainer may be configured to assist retaining the engagement elements together. 
     Alternatively, the glazing system may comprise interior and exterior frame portions that couple with one another via a slip joint, or the like. In such examples, the exterior frame portion may additionally comprise a bonding retainer, such as a grooved recess, configured to permit the exterior frame portion to be held in position during curing or the like of bonding adhesive. The grooved recess may be generally U-shaped, and may comprise an obliquely-formed recess. The recess may be configured for use with removable clips or other retaining means to hold the frame portion in place during bonding. 
     The system (e.g. the interior frame portions) may comprise first and second interior members. The interior members may serve additionally to define the interior of the frame within the vehicle. 
     The first interior frame member may be mountable with the vehicle (e.g. with the waist rail, cant rail, etc.). The first interior member may comprise a grooved slot at which the member can be screwed, or otherwise affixed, to the vehicle (e.g. to the waist rail). 
     The first interior member may comprise retaining clips that interoperate with complementary clips on the second interior member. The second interior member may be removably attachable to the first interior member. When coupled or otherwise attached together, the first and second interior members may provide a contiguous interior profile or surface of the system. The contiguous surface may also be provided additionally by the retaining member, when in situ. 
     The interior frame portion may be configured to hold and retain interior trim or décor with vehicle, when in position. The second interior member of the interior frame portion may be configured, when coupled to the first interior member, to hold and retain interior trim or décor with vehicle. 
     The system may be configured such that, when clipped or otherwise attached to the first interior member, the second interior member forms an interference fit with interior trim so as to assist with retaining that trim in place. The second interior member may be removable from the first interior member to allows the trim to be replaced (e.g. in the event of damage, or refurbishment). 
     The frame may comprise one or more adhesion regions, configured to allow the frame to be adhered to a passenger service vehicle (e.g. adhered to a waist rail, cant rail, pillar, or the like). The adhesion region may be provided with the exterior frame portion, and may be configured to allow the exterior frame portion to be adhered to a vehicle. 
     The system may comprise one or more profiled rails (e.g. waist rails), which may be obliquely profiled, for use with an exterior frame portion. Such profiled rails may allow for a flush overall appearance of the exterior frame and body panelling of the vehicle, in use. The/each profiled rail may be configured such that a region (e.g. a region corresponding to the adhesion region of the frame) is recessed or inward of the exterior of the rail. The system may comprise one or profiled body panels, configured in complementary manner with the profiled rail. 
     In some examples, the interior frame portion may be configured to mount between at least two exterior frame portion (e.g. across the pillar). In such examples, a common interior frame portion may be used with the frames of two glazing panels. 
     The/each frame may comprise a drainage aperture, defined by the frame. The drainage aperture may be configured to allow fluids, such as water, trapped within the frame, to be removed. 
     The frame/each (e.g. the interior and exterior frame portions) may be configured as one or more extrusions. Features provided on the frames (e.g. the frame retainer, frame portions, etc.) may be provided by extrusion. Such a configuration may allow for ease of manufacture. The frame portions may comprise metal, such as aluminium. The frame portions may comprise plastic, such as UPVC. The frame portions may not be self-supporting (e.g. without comprising a glazing panel, or when not attached with a vehicle). In other words, the frame may not be able to support its weight, without have a glazing panel retained with the frame. 
     The removable retainer may be configured as one or more extrusions. The seal may be configured as one or more extrusions. 
     The system may comprise one or more glazing panels, retained with the frames. The system may be configured for use with main glazing of a passenger service vehicle (e.g. along a side of the vehicle). 
     The system may be configured such that the removable retainer mounts to a glazing panel directly (i.e. not onto sacrificial glazing, or the like). 
     According to a second aspect of the invention there is provided a glazing system for a passenger service vehicle, comprising:
         a glazing frame configured to attach to a passenger service vehicle; the glazing frame comprising a glazing mount extending inwardly along some or all of the frame, and configured to associate a glazing panel with the frame; and   a removable retainer configured to engage with the frame, and to retain a glazing panel against the mount.       

     The glazing frame may comprise a plurality of frame portions or sections, each configured to attach to a vehicle. 
     According to a third aspect of the invention there is provided a glazing system comprising one or more exterior frame portions, and one or more interior frame portions, the exterior and interior frame portions configured to engage with an exterior and an interior of a passenger service vehicle respectively, each portion further configured to operatively engage together to as to retain the frame on the passenger service vehicle. 
     Each portion may be configured to operatively engage together to as to retain the frame on a rail, such as a waist or cant rail, of a vehicle. 
     The frame portions may comprise complementary engagement elements, configured to retain one portion of the frame to the other. The frame portions may comprise complementary recesses and protrusions, configured to engage and retain the frame portions together. A retained exterior frame portion and interior frame portion may provide a frame depth. The engagement elements may be configured to allow for a variable frame depth. 
     One of the interior frame portion or exterior frame portion may comprise a plurality of engagement elements, configured to engage with a complementary element on one of the exterior frame portion or interior frame portion. The plurality of engagement elements may be configured so as to provide the variable depth of frame. 
     The interior frame portion may comprise one or more interior frame elements. Each interior frame element may be configured as a clip, or the like. 
     According to a fourth aspect of the invention, there is provided a passenger service vehicle comprising a glazing system according to any of the features of the first, second or third aspects. 
     According to a fifth aspect of the invention, there is provided a method of installing or replacing a glazing panel on a passenger service vehicle, the method comprising:
         removing a removable retainer that is engaged with a glazing frame, the removable retainer configured to retain a glazing panel against a glazing mount extending along some or all of the frame, the mount configured to allow for associating a glazing panel with the frame;   associating a glazing panel with the glazing mount; and   replacing the removable retainer so as to engage the removable retainer with the frame and retain the glazing panel against the mount.       

     The method may comprise replacing the removable retainer so as to engage between a frame retainer of the frame and the glazing panel (e.g. in an interference manner) in order to retain, or urge and retain, the glazing panel against the mount. 
     The method may comprise using a removal element of the removable retainer to remove the retainer from the frame. The removal element may be operable by hand. The method may comprise removing and replacing a plurality of removable retainers (e.g. four). The removable retainers may be configured as strips. 
     The method may comprise associating the glazing panel with a seal, which in turn associates the glazing panel with the mount/frame. The method may comprise removing and/or replacing the seal, and then associating the glazing panel with the frame. 
     The method may comprise removing a secondary retainer to allow for installation or replacement of a glazing panel on a passenger service vehicle, such a secondary retainer configured to additionally retain a glazing panel against the mount. 
     The method may comprise unscrewing, or the like, the secondary retainer from the frame. The method may comprise removing the removable retainer to reveal the one or more secondary retainers, and then removing the secondary retainer(s). The method may comprise associating a glazing panel with the frame, and then screwing, bolting, affixing, or the like, the secondary retainer to the frame in order to retain the frame. The method may then comprise replacing the removable retainer to so as to conceal the secondary retainer, and so retain the glazing. 
     The method may additionally comprise removing an existing glazing panel to be replaced, before associating a replacement glazing panel with the frame. 
     The method may comprise replacing a glazing panel from the interior of the vehicle. 
     According to a sixth aspect of the invention, there is a method of installing a glazing system, comprising:
         positioning an exterior frame portion of a glazing frame at an exterior of a passenger service vehicle,   positioning an interior frame portion of the glazing frame at an interior of the passenger service vehicle,   engaging the exterior frame portion together with the interior frame portion, and retaining the glazing frame on the passenger service vehicle.       

     The method may comprise operatively engaging the exterior frame portion together with the interior frame portion. 
     The method may comprise engage the exterior frame portion together with the interior frame portion so as to provide a contiguous interior surface, extending from the exterior portion to the interior portion. 
     The method may comprise adhering the exterior frame portion to the passenger service vehicle. The method may comprise providing adhesive to the exterior frame portion or the passenger service vehicle, and then operatively engaging the interior frame portion in order to retain the frame on the vehicle. 
     The frame portions may comprise complementary engagement elements, configured to retain one portion of the frame to the other. The frame portions may comprise complementary recesses and protrusions, configured to engage and retain the frame portions together. A retained exterior frame portion and interior frame portion may provide a frame depth. The engagement elements may be configured to allow for a variable frame depth. 
     One of the interior frame portion or exterior frame portion may comprise a plurality of engagement elements, configured to engage with a complementary element on one of the exterior frame portion or interior frame portion. The plurality of engagement elements may be configured so as to provide the variable depth of frame. 
     The exterior frame portion may comprise a glazing panel. 
     The invention includes one or more corresponding aspects, embodiments or features in isolation or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation. For example, features associated with particular recited embodiments relating to the first aspect, may be equally be appropriate as features of embodiments relating the second, third, fourth, fifth or sixth aspects, and vice versa. Furthermore, features associated with particular recited embodiments relating to methods, may be equally appropriate as features of embodiments relating specifically to apparatus, and vice versa. 
     It will be appreciated that one or more embodiments/aspects may be useful with in providing glazing systems for passenger service vehicles. 
     The above summary is intended to be merely exemplary and non-limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       A description is now given, by way of example only, with reference to the accompanying drawings, in which:— 
         FIG. 1  shows a perspective view of a passenger service vehicle, 
         FIG. 2   a  shows a cross-section of an example of a portion of a glazing system, and 
         FIGS. 2   b  and  2   c  show perspective view of the exemplary glazing system, 
         FIGS. 3   a  and  3   b  shows further examples of the glazing system of  FIG. 2 . 
         FIGS. 4   a - 4   f  show an alternative example of portions of a glazing system; and 
         FIG. 5  shows an interior of a vehicle comprising the glazing system of  FIGS. 4   a - 4   f.    
     
    
    
     DESCRIPTION OF SPECIFIC EMBODIMENTS 
       FIG. 1  shows a perspective representation of an exemplary passenger service vehicle  100 , which, by way of example only, is shown as a vehicle  100  having both a lower passenger deck  110  and an upper passenger deck  120 . Such vehicles  100  are commonly referred to as double-deck vehicles  100 . 
     The vehicle  100  comprises main glazing  200  provided along each side of the vehicle, on both the upper and lower decks  110 ,  120 . The main glazing  200  comprises a plurality of glazing panels  210  (e.g. glass panels). During manufacture, these glazing panels must be assembled with the vehicle. In addition, from time to time, these glazing panels  210  require replacement, for example, due to damage. 
       FIG. 2   a  shows a cross-section of a portion of an exemplary glazing system  300  for the passenger service vehicle  100 . The glazing system  300  comprises a glazing frame  310  that is configured to attach to a passenger service vehicle  100 . In this particular example, the glazing frame  310  comprises an exterior frame portion  310   a , and an interior frame portion  310   b . As will be appreciated in light of the following described embodiments, further examples may not use exterior and interior frame portions  310   a ,  310   b , but may be provided as only a single portion, or even only an exterior portion. 
     The exterior and interior frame portions  310   a ,  310   b  are configured to engage with the exterior and interior of the passenger service vehicle  100  respectively, as is shown in  FIGS. 2   b  and  2   c , and as will be described in further detail below. Here, each portion  310   a ,  310   b  of the frame  310  is configured to operatively engage together so as to retain the frame  310  at an intended window aperture of the passenger service vehicle  100 . For example, the frame  310  may be retained on a waist rail, or the like (as is exemplified as  320  in  FIGS. 2   a ,  2   b  and  2   c ). Here, the interior frame portion  310   b  extends with, and engages with, the exterior frame portion  310   a  along the length of the exterior frame portion  310   a . Of course, in further examples, the interior frame portion  310   b  may comprise one or more interior frame portion elements (i.e. discrete elements, such as clips), configured to engage with particular regions of the exterior frame portion  310   a . In other words, while in the example shown the interior frame portion  310   b  could be provided by a single extrusion, configured to extend along the length of the frame  310 , in further examples, the interior frame portion  310   b  may be provided by a plurality of discrete frame portions. In some cases, each of those discrete portions may be spaced from one another along the length of the frame. A single interior frame portion  310   b  may be more aesthetically pleasing, and easier and quicker to assemble, while discrete interior frame portions  301   b  may reduce overall weight and material. 
     Further, when in use, the interior frame portion  310   b  can hold and retain interior trim  410  with vehicle  100 . In some cases, the system  300  may be configured such that, when coupled to or otherwise attached to the exterior frame portion  310   a , the interior frame portion  310   b  forms an interference fit with the interior trim  410  so as to assist with retaining that trim  410  in place. In those, and similar examples, subsequent removal of the interior frame portion may allow replacement of the interior trim. 
     In this particular example, the frame portions  310   a ,  310   b  comprise complementary engagement elements  330   a ,  330   b  that are configured to engage and retain the frame portions  310   a ,  310   b  together. In other examples, as will be explained in more detail below, that need not be the case. However, here, the elements  330   a ,  330   b , as shown in  FIG. 2   a  are provided as recesses  330   b  and a protrusion  330   a  (e.g. in a ratchet-style arrangement). Of course, in alternative embodiments, alternative or additional engagement elements  330   a ,  330   b  may be used. 
     The frame  310 , and in this case the exterior frame portion  310   a , further comprises an adhesion region  342 . The adhesion region  342  is configured to allow the frame  310  to be adhered to the passenger service vehicle  100 . While for the purposes of the following description, the adhesion region  342  is used with adhesive, it will be appreciated that that need not be the case in all examples. For instance, the adhesion region  342  may be configured to mount or otherwise attach the exterior frame portion  310   a  with the vehicle  100 , without using adhesive (e.g. adhere using screws, bolts, or other such fixings). A skilled reader will readily be able to implement those further embodiments accordingly. 
     However, as is shown in  FIG. 2   b , the frame  310  of this example can be adhered (and bonded) to the vehicle  100  using an adhesive  345  (e.g. epoxy, etc.). The frame  310  may, of course, be adhered or otherwise affixed to the vehicle at further locations (e.g. see  347  in  FIG. 2   b , for example). 
     The frame  310  shown in  FIG. 2  also comprises a drainage aperture  317 , which is defined by the frame  310 . The drainage aperture  317  allows fluids, such as water, which may be trapped within the frame  310  (e.g. in use) to be removed. 
     The glazing frame  310  further comprises a glazing mount  340 . The glazing mount extends (e.g. inwardly) along some or all of the frame  310 , and is configured to allow for a glazing panel (shown as  400 ) to be associated with the frame  310 . When assembled, the frame  310  may comprise a glazing mount that extends around the resultant aperture defined by the frame. 
     In this particular example, the system  300  further comprises a seal  350 , positioned at the glazing mount  340 , such that glazing is retained against the seal  350 . Here, the seal  350  has a seal element  355 , configured to allow for ease of locating of the seal  350  with the frame  310 . In this example, the seal  350  is removable/replaceable from the frame  310 . Of course, in some examples, no seal  350  may be provided with the frame  310 . For example, in some embodiments, any replacement glazing panel itself may comprise a seal configured for association with the glazing mount  340 . 
     The frame  310  further comprises a removable retainer  360 , which is configured to engage with the frame  310 , and to retain a glazing panel  400  against the frame (or mount  340 ). In this particular example, the retainer  360  is provided as a removable strip (shown, for example, in  FIGS. 2   b  and  2   c ). In other words, and in a similar manner to the interior frame portion  310   b , the retainer  360  can extend along a length of the frame in a strip-like manner. 
     The removable retainer  360  is configured to engage with a frame retainer  370  provided on the frame  310 , such that, in this example, the removable retainer  360  is engaged between the frame retainer  370  and the glazing panel  400  in an interference manner so as to retain, or urge and retain, the glazing panel  400  against the mount  340 . In this case, the removable retainer  360  can be considered to be resiliently deformable. Of course, in some examples, only those portions that engage with the frame or glazing may be deformable for ease of use, while the remainder of the retainer may be comparably non-deformable. Such a configuration may allow for ease of use. 
     It will be appreciated that the removable retainer is configured such that is able to sufficiently hold and retain a glazing panel against the frame, when the vehicle is in every day use. In the example described, the system is configured such that the removable retainer is configured to directly mount with a glazing panel, which may be a single glazing panel (e.g. rather than indirectly, via secondary glazing, or a sacrificial interior or glazing). 
     As can been seen in  FIG. 2   a , in this example, the frame retainer  370  is essentially provided as a recess, such that a complementary retaining rib or member  362  of the removable retainer  360  locates, and engages, with the recessed frame retainer  370 . Here, the removable retainer  370  additionally comprises a locating element  364 , configured to allow for ease of location of the removable retainer  360  with the frame  310  (e.g. for complementary location with a corresponding recess). In this example, the locating element  364  is provided as a rib or protrusion corresponding to a recess  372  of the frame retainer  370 . 
     In this particular embodiment, the removable retainer  360  comprises two fins  365 , configured to engage (e.g. flexibly engage) with the glazing panel  400 . Both fins  365  are configured to be substantially parallel. Here, the fins  356  provide an interference engagement with glazing  400 , when in use. Providing a plurality of fins allows for a greater retaining force to be applied to the glazing  400 . 
     Here, the removable retainer  360  further comprises a removal element  366 , configured to allow a user to remove the retainer  360  from the frame  310 . The removal element  366  is arranged such that it can operable by hand (e.g. by pulling). In use, and as is shown for example in  FIGS. 2   b  and  2   c , the removal element  366  can, in some cases, conceal, and in some further cases assist with maintaining, the engagement elements  330  of the interior and exterior frame portions  310   a ,  310   b.    
     In this example, the removable retainer  360  further comprises a removal pivot  368 , which pivots upon the frame  310  to assist with removal (as well as placement). Here, the pivot  368  also cooperates with the removal element  366  in order to assist with removal of the removable retainer  360  from the frame  310 . In other words, actuation of the removal element  366  may urge the removable retainer  360  from the frame  310 , causing the removal pivot  368  to pivot on the frame  310 , and assist with removal of the retainer  360  from the frame  310 . 
     The glazing system  300  further comprises one or more secondary retainers  380 , which are additionally configured to retain a glazing panel  400  against the mount  340  (e.g. in addition to the removable retainer  360 ). Here, the frame  310  comprises a plurality of discrete secondary retainers  380 , which are positioned an intervals along the frame  310 , one of which is shown in  FIGS. 2   b  and  2   c . Each secondary retainer  380  is specifically configured to affix to the frame, for example, by screw, bolt or the like, which may, in some cases, require a specialised tool to remove. As such, in many cases, the secondary retainer  380  may be considered not to be removable by hand. As can be seen in  FIG. 2 , the secondary retainer  380  is essentially concealed by the removable retainer  260 , when in use (e.g. concealed from a passenger). 
     Having the secondary retainers  380  concealed from the passengers may help mitigate the risk of a passenger considering, and acting upon, any attempted removal of the window. In addition, have the removable retainer in the manner shown may be easier to clean, and more aesthetically pleasing. However, in further examples, the secondary retainers  380  may be apparent, or may be comprised with the removable retainer  280 . For example, the removable retainer  280  may comprise fixings, such as screws, or the like, to affix the retainer to the frame. In those cases, any secondary retainer (e.g. fixing) may first be removed (e.g. using a special tool), and then the removable retainer may be removed, in the same manner as above. 
     In this particular example, the frame  310  (e.g. the interior and exterior frame portions  310   a ,  310   b ) are provided by extrusions, such as aluminium or plastic extrusions. In some example, the extrusions can be mounted together to provide the overall frame  310 , which can be mounted to the vehicle  100  as is shown in  FIG. 3   a  and  FIG. 3   b , for example. Of course, in other examples, the frame may be assembled on the vehicle in sections (i.e. rather than mounting a portal-style frame to the vehicle  100 ). 
     In this particular case, the frame  310  is configured such that need not be self-supporting (e.g. without comprising a glazing panel  400 ). In other words, the glazing panel  400  may provide the rigidity of the frame  310 . 
     During assembly, manufacture, or repair of the passenger service vehicle  100 , the glazing system  300  of  FIGS. 2 and 3  can be installed by positioning the exterior frame portion  310   a  at the exterior of a passenger service vehicle  100 , and positioning the interior frame portion  310   b  from the interior of vehicle  100 . In some cases, the exterior frame portion  310   a  may be adhered or otherwise affixed to the vehicle  100  (e.g. using the adhesion portion  340 ). In this example, both frame portions  310   a ,  310   b  can be brought together (e.g. across an intended window aperture) to operatively engage, and retain the glazing system on the passenger service vehicle  100 . In some cases, these may operatively engage not to retain fully the frame  310 , but to serve to maintain the frame  310  to the vehicle while any adhesive (e.g.  345 ,  347 ) bonds the frame  310  to the vehicle  100 . Providing a frame  310  in such a manner may obviate the need to provide additional support to the frame  310  as the applied adhesive cures (e.g. using external block to press and hold the frame  310  in position as the adhesive cures). 
     It will also be appreciated that, after the frame  310  has been attached to vehicle  100 , the vehicle  100  effectively provides the structural support for the frame (and glazing panel  400 ). Therefore, the frame  310  may be installed with a glazing panel  400 , such that the glazing panel  400  provides the support for the frame  310  when the frame  310  is not attached to the vehicle  100 , and then subsequently (e.g. if the glazing panel is removed), the structure of the vehicle supports the frame  310 . In such a way, a lighter weight frame  310  can be used, which can reduce manufactures needs, as well as improve the efficiency of any vehicle. 
     Furthermore, it will be appreciated that using the exterior frame portion  310   a  and interior frame portion  310   b  in the manner described, for example, allows for alternative frame depths to be accommodated, as so allow for ease of manufacturing. In other words, a standard frame may be used with different vehicles  100 , whereby a differing thickness of the aperture can be accommodated by using a plurality of engagement elements  330   a ,  330   b , such as a ratchet arrangement. 
     If, during the lifespan of the vehicle  100 , a glazing panel  400  requires installation or replacement, then firstly, the removable retainer  360 —which is engaged with a glazing frame—can be pulled from the frame  310 , for example, using the removal element  360 , and/or pivot  368 , etc. In some embodiments, for example, those using secondary retainers  380 , any existing glazing panel  400  will remain retained against the frame  310  even in the event of accidental removal of the removable retainer  360 . In which case, those secondary retainers  380  can then also be removed in order to remove an existing glazing panel  400 . In some cases, a specialised tool may be required in order to remove those secondary retainers  380 , so as to avoid accidental removal by a passenger. 
     Subsequently, a new glazing panel  400  can be associated with the glazing mount (e.g. via a seal); and the secondary retainers  380  and removable retainer  360  can be replaced so as to engage the removable retainer  360  with the frame and retain the glazing panel against the mount. 
     It will be appreciated that due to the configuration of the described glazing system  300 , any replacement glazing need only be mounted from the inside of the vehicle  100 . As such, after initial manufacture, an operator of the vehicle  100  may be able to readily replace the glazing (e.g. after damage), without the need for specialise platforms, or the like, which may otherwise be required in order to reach the upper heights of the vehicle. In such a manner, using the described glazing system may minimise the time that any vehicle remains out of service. 
     It will further be appreciated that the use of the removable retainer  360 , in the manner disclosed, allows for the glazing to be replaced without necessarily disrupting the interior finish of the vehicle. Therefore, again, an operator of the vehicle can quickly and effectively replace the glazing. 
     In addition to the above benefits, the manner is which the system  300  is configured, particularly with respect to the glazing mount  340 , inhibits the possibility of a glazing panel  400  being forced outwardly of the vehicle by a passenger inside the vehicle (e.g. a disruptive passenger). In such a way, the operational safety of the vehicle  100  can be improved. 
     While in the above described example the glazing system  300  comprises interior and exterior frame portions  310   a ,  310   b  that operatively couple with one another, that need not always be the case. Further, while in the example shown in  FIG. 3 , the frame  310  may be considered to provide a portal-style frame, nevertheless in further embodiments, the frame of the glazing system  300  may be provided from horizontal sections (e.g. cant and waist rail sections), and vertical sections (e.g. pillar sections). Such sections or portions may be provided from different extrusions that, when assembled, serve to form one or more frames for glazing  400 . 
     Consider now the glazing system  600  of  FIGS. 4   a  to  4   f , which is similar to that described in relation to  FIGS. 2 and 3 . These figures show, essentially as a cross-section, a further embodiment of the exemplary glazing system  600  for the passenger service vehicles  100 . Again, the system  600  is shown mounted (albeit without showing adhesive, or the like) with various sections of the passenger service vehicle  100 .  FIGS. 4   a  to  4   c  show the system  600  mounted at a waist rail  605  of the vehicle  100 , while  FIGS. 4   d  and  4   e  show the system mounted at a cant rail  705  of the vehicle. A skilled reader will appreciate that the waist rail  605  and cant rail  705  sections can be considered to be those structural frames of the vehicle  100  that extends along some or all each side of the vehicle  100 . Such rails  605 ,  705  may be provided on both single and double-deck vehicles  100 .  FIG. 4   f  shows a cross section of the system  600  at a one structural pillar  805  (e.g. a pillar that extends between waist and cant rail of the vehicle  100 ). In this example, the pillars  805  can serve to define the apertures at which the windows of the vehicle  100  are provided. 
     Again, the glazing system  600  can be considered to comprise a glazing frame  610 , which serves to support a glazing panel  400 . The frame  610  again can be considered to have interior and exterior frame portions  610   a ,  610   b , that are configured to attach to a passenger service vehicle  100 . However, it will be appreciated that in view of the following description that the glazing system  600  may in some examples comprise only exterior frame portions  610   a . Further, in this example, and as will be explained, the frame  610 , and in particular the interior frame portions,  610   b  are generally formed in horizontal and/or vertical sections which serve to define windows of the vehicle  100 , rather than providing a portal frame, as such (see  FIG. 5 , for example). Nevertheless, those portions or sections can still be considered to provide a glazing frame  610 . 
     With reference to  FIGS. 4   a  to  4   e , the interior frame portion  610   b  associated with the cant and waist rail sections  605 ,  705  of the system  600  comprise first and second interior members  615   a ,  615   b . The interior members  615   a ,  615   b  serve additionally to define the interior of the frame  610  within the vehicle  100 . The first interior frame member  615   a  is formed generally as an “L” shape, and is mountable with the waist rail  605  (or cant rail  705 ) via a grooved slot  625  at which the member  615   a  can be screwed, or otherwise affixed, to that rail  605 ,  705 . Providing such a grooved slot  625  along the length of the first interior member  615   a  allows for ease of manufacture, yet that that member  615   a  can be affixed at appropriate locations on the vehicle  100 . Of course, other means for affixing the first interior member  615   a  may be used. 
     As is shown, the first interior member  615   a  comprises retaining clips  618   a ,  618   b , that interoperate with complementary clips  619   a ,  619   b  on the second interior member  615   b . As such, the second interior member  615   b  can be removably attached to the first interior member  615   a . When coupled together, the first and second interior members  615   a ,  615   b  provide a contiguous interior profile or surface  700  of the system  600 . In such a way, a pleasing aesthetic interior finish of the system  600  can readily be provided. 
     In addition, the second interior member  615   b  is further configured, when coupled to the first interior member  615   a , to hold and retain interior trim or décor  710  with vehicle  100 . In some cases, the system  600  may be configured such that, when clipped or otherwise attached to the first interior member  615   a , the second interior member  615   b  forms an interference fit with the interior trim  710  so as to assist in retaining that trim  710  in position. The second interior member  615   b  can then be removed from the first interior member  615   b  (e.g. by pulling, or levering), which in turn allows the trim  710  to be replaced (e.g. in the event of damage, or refurbishment). In such a way, the trim  710  can be replaced without unduly affecting the system  600 . While in this example, complementary clips  618   a ,  618   b ,  619   a ,  619   b  have been described, it will be appreciated that other means of releasably attaching the first and second interior members  615   a ,  615   b  may be used. In addition, and as is shown in  FIGS. 4   d  and  4   e , the second interior member  615   b  may be configured, when at the cant rail  705 , to form a contiguous interior surface with a roof portion (not shown). 
     In this example, and unlike the example above, each portion  610   a ,  610   b  of the frame  610  engages together via a slip joint  630  (i.e. rather than a ratchet arrangement). In such a way, the system  600  can again accommodate varying dimensions of rail  605 ,  705 . As such, the same glazing system  600  may be used on numerous different vehicles  100 , thus potentially reducing overall manufacturing costs and/or providing ease of manufacture. 
     Here, the exterior frame portion  610   a  comprises an adhesion region  642 , in a similar manner to that described above. The adhesion region  642  again is configured to allow the frame  610  to be adhered to the passenger service vehicle  100  (e.g. the waist rail  605 ). Bonding of the exterior frame portion  610   a  to the waist rail  605  or cant rail  705  can occur at the adhesion region  642 . 
     In this particular example, and as is shown in  FIGS. 4   a ,  4   b  and  4   c , the waist rail  605  is additionally profiled so as to allow for a flush overall appearance of the exterior frame  610   b  and body panelling  715  of the vehicle  100 , in use (flush profile is shown at dashed  800 ). Here, the waist rail  605  is configured such that a region corresponding to the adhesion region  642  (e.g. a complementary region) is recessed, or inward, of the exterior of the waist rail  605 . In such a manner, when assembled, the exterior frame portion  610  can be flush with body panelling  715 . Being able to provide a flush exterior not only improves the aesthetic look of the vehicle  100 , but also improves the ease with which the vehicle can be maintained (e.g. cleaned). 
     In this example of the glazing system  600  shown in  FIGS. 4   a - 4   c , the body panelling  715  is also profiled in a complementary manner with the waist rail  605 . This maintains the overall flush appearance of the exterior frame  610   b  and body panelling, but mitigates or eliminates the possibility of the water entering behind the panelling  715 , as water runs down from the glazing  400 . Of course, in some examples, the panelling  715  at the waist rail  605  may not profiled inwardly, and may be entirely flush with the exterior frame portion  610   a . In those examples, additional bonding agent, or filler, may be provided behind the panelling  715  so as to mitigate water ingress. Further, it will be appreciated that while water may run from the glazing  400  to the body panelling  715  at the waist rail  605  section, nevertheless the same may not be true at the cant rail  705  section (as shown in  FIGS. 4   d  and  4   e ), in which the body panelling  715  need not be profiled in the same manner. 
       FIG. 4   f  shows a cross-section of the system  600  provided at the pillar section  805 . Here, two exterior frame portions  610   a  meet at the pillar  805 . Adhesive, bonding, or filler, can be provided at the adhesion region  642  of each in order to provide a contiguous exterior surface (shown at dashed  801 ). Further, the interior frame portion  610   b  in this example is configured such that it mounts between the two exterior frame portions  610   a , across the pillar  805  (see also  FIG. 5 ). As such, an aesthetically pleasing interior can be provided, and fewer parts are required, hence reducing manufacturing time and costs. 
     In the examples shown in  FIG. 4   a - 4   f , the exterior frame portion  610   a  additionally comprises a generally U-shaped grooved recess  675 , which is provided on an interior side of the frame portion  610   a . The grooved recess  675  extends along some or all of the exterior frame portion  610   b , and is configured to allow the frame portion  610   a  to be maintained with the vehicle  100  during adhering of the frame portion  610   a  to the waist rail  605  (or cant rail  705 , or pillar  805 ). Removable clips or other retaining means can be used with the grooved recess  675  to hold the frame portion  610   a  in place during bonding, or the like. In the example shown, the U-shaped groove  675  comprises an obliquely-formed recess, which assists with any retention. 
     In the same manner as the embodiments described above, the system  600  comprises a glazing mount  640 , which is configured to allow for the glazing panel  400  to be associated with the frame  610 . Again, a seal  650  is provided such that glazing  400  is retained against the seal  650 . The system  600  further comprises a removable retainer  660 , which is configured to engage with the frame  610 , and to retain the glazing panel  400  against the frame (or mount  640 ). 
     As before, the retainer  660  is provided as a removable strip, which in the example shown extends along the length of the frame  610  in a strip-like manner. Here, the removable retainer  660  is configured to engage with a frame retainer  670  in a similar manner to that described above (e.g. fins  665 , removal element  666 , removal pivot  668  etc.). However, additionally, the retainer  660  comprising an interior fin  667 , which forms in interference fit with the interior frame portion  610   b . In such a manner, the contiguous surface  700  of the interior is maintained. Nevertheless, again, the retainer  660  can be removed and re-introduced a similar manner to that described in relation to  FIG. 2 . In some examples, the interior frame portion  610   a  may comprise a complementary groove, or the like, to assist with locating and retaining of the retainer  660 . 
     Again, the glazing system  600  further comprises one or more secondary retainers  680 , which are additionally configured to retain a glazing panel  400  against the mount  640  (e.g. in addition to the removable retainer  660 ). The secondary retainers again are essentially concealed by the removable retainer  660 , when in use (e.g. concealed from a passenger). 
       FIG. 5  shows an example of the glazing system  600  of  FIGS. 4   a - 4   f  at the interior of the vehicle. As can be seen, the interior frame portions  610   b  extend along the length of the vehicle. In some examples, those frame portions may be apportioned so as to allow for ease of replacement. 
     During assembly and manufacture of the passenger service vehicle  100 , the glazing system  600  of  FIGS. 4 and 5  can be installed by positioning the exterior frame portions  610   a  at the exterior of a passenger service vehicle  100 , and mounting thereto. Subsequently, the interior frame portion  610   b  can be positioned in place from the interior of vehicle  100 . After the frame  610  has been attached to vehicle  100 , the vehicle  100  can effectively provide the structural support for the frame (and glazing panel  400 ). In such a way, a lighter weight frame  610  can be used, which can reduce manufactures needs, as well as improve the efficiency of any vehicle. 
     In the same manner as before, a glazing panel  400  can be installed or replaced by firstly removing the removable retainer  660 —which is engaged with a glazing frame. Then, the secondary retainers  680  can be removed. Subsequently, a new glazing panel  400  can be associated with the glazing mount (e.g. via a seal); and the secondary retainers  680  and removable retainer  660  can be replaced so as to engage the removable retainer  660  with the frame and retain the glazing panel against the mount. This replacement can take place from inside the vehicle  100 . As such, there is no requirement to provide external scaffolding or platforms in order to replace the glazing  400  (e.g. on double-deck vehicles). In addition, changes to the interior trim  710  can readily be achieved by removing the second interior member  615   b.    
     Providing such glazing systems  300 ,  600  allows for the quick and easy replacement of glazing panels  400  for passenger service vehicles  100 . Such systems  300 ,  600  provide easy of replacement, similar to a gasket glazing system, with resistance to leaking and improved appearance, similar to an adhesive glazing system. Further, the systems described  300 ,  600  serve to allow for ease of positioning of glazing within the vehicle (e.g. either during manufacture and/or maintenance), as well as allowing for an aesthetically pleasing interior trim to be provided. 
     While the above examples described embodiments in relation to twin decks  110 ,  120 , in further examples, the system  300 ,  600  may be used on single deck vehicles. In addition, while the system  300 ,  600  has been described in relation to the side glazing, or main glazing, of a vehicle  100 , such system may equally be positioned, for example, at the front or rear of the vehicle  100 , or used as a glazing system for other vehicles, such as other service vehicles (e.g. other commercially operated vehicles). A skilled reader will readily be able to implement such further embodiments. 
     It will be appreciated that any of the aforementioned members, frames, surfaces, elements, etc. may have other functions in addition to the mentioned functions, and that these functions may be performed by the same members/frames/surfaces/elements. 
     It will readily be appreciated that any of the features of the system shown in  FIGS. 4 and 5  (e.g. the first and second interior portions  615   a ,  615   b ) may equally be used with any of the features of the system shown in  FIGS. 2 and 3 , and vice versa (e.g. the use of the complementary retainers between exterior and interior portions). The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.