Cantrail for a Passenger Service Vehicle

Abstract

A cantrail 8 for connecting to a side frame 2, 4 (fig 1), a roof frame 6 (fig 1), and supports 14 of a vehicle comprising; a vertically arranged central web or strut 20, first and second inwardly faci

Description

FIELD OF THE INVENTION This invention relates to a cantrail for a passenger service vehicle, in particular a single deck bus, and to a passenger service vehicle incorporating said cantrails and in particular to an improved cantrail assembly capable of supporting additional roof loads, such as batteries or fuel tanks, mounted on the roof of the vehicle. BACKGROUND OF THE INVENTION A cantrail is a longitudinal structural member which connects a body side frame to a roof frame of a vehicle. In addition to connecting these structures, in a single deck bus, the cantrails help to transfer and dissipate applied loads through the vehicle structure. For example, on a rear engine bus the cantrails are able to transfer some of the cantilever load forwards through the body, putting less reliance on the chassis to be a self-supporting structure. Typical single deck bus structures are not monocoque in design but neither are they ladder frame chassis’ with a body on top. The body and chassis structures are required to work together to support all applied loads. Previously, when it has been required to mount heavy components onto the roof of a passenger service vehicle, in particular a single deck bus, (for example batteries in an electrically powered bus or hydrogen tanks in the case of a hydrogen fuelled bus) additional support frames are often required to be added to the roof structure to carry such components. This typically required heavy steel mounting brackets to be added to the roof structure for direct mounting of the additional support frames to the structure below. Such known support frames and the required mounting brackets typically extend through the roof sheet of the vehicle to connect to the structure beneath, thereby compromising the integrity of the roof sheet and leading to leaks. An object of the present invention is to alleviate these problems by enabling the cantrails of the vehicle to be used to mount such additional support frames and transmit the resulting additional loads to the side frames of the vehicle. SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a cantrail for connecting a body side frame to a roof frame of a public service vehicle, said cantrail comprising a longitudinal metal extrusion having a vertically arranged central web extending from a lower end to an upper end of the cantrail; a first inwardly facing mounting rail being provided on an inner side of said central web at a lower end thereof and a second inwardly facing mounting rail being provided on said inner side of said central web at an upper end thereof; a substantially rectangular first box section portion extending horizontally inwardly from an inner side of said central web at a central region thereof, a third inwardly facing mounting rail being provided on an inner end of said first box section portion; a downwardly extending first inner web extending between said third inwardly facing mounting rail and said first inwardly facing mounting rail, an upwardly extending second inner web extending between said third inwardly facing mounting rail and said second inwardly facing mounting rail, said first and second inner webs defining an inner side of said cantrail; a substantially rectangular second box section portion extending along an outer side of said central web from said central region to said upper end of the vertical web, a downwardly facing mounting rail being provided on a lower side of said second box section portion and an upwardly facing mounting rail being provided on an upper side of said second box section portion. Preferably each of said mounting rails comprises a channel having substantially parallel sides terminating in inner facing lips such that each mounting rail may receive one or more fastening devices therein for securing a second component of the vehicle to the respective mounting rail. In a second aspect of the present invention there is provided a public service vehicle comprising a chassis; a pair of side frames extending upwardly from either side of the chassis, each side frame comprising a plurality of upright side posts mounted to the chassis at lower ends thereof; a roof frame comprising a plurality of transversely extending roof beams; each side frame being coupled together to the roof frame via a respective cantrail, each cantrail comprising a longitudinal metal extrusion having a vertically arranged central web extending from a lower end to an upper end of the cantrail; a first inwardly facing mounting rail being provided on an inner side of said central web at a lower end thereof and a second inwardly facing mounting rail being provided on said inner side of said central web at an upper end thereof; a substantially rectangular first box section portion extending horizontally inwardly from an inner side of said central web at a central region thereof, a third inwardly facing mounting rail being provided on an inner end of said first box section portion; a downwardly extending first inner web extending between said third inwardly facing mounting rail and said first inwardly facing mounting rail, an upwardly extending second inner web extending between said third inwardly facing mounting rail and said second inwardly facing mounting rail, said first and second inner webs defining an inner side of said cantrail; a substantially rectangular second box section portion extending along an outer side of said central web from said central region to said upper end of the vertical web, a downwardly facing mounting rail being provided on a lower side of said second box section portion and an upwardly facing mounting rail being provided on an upper side of said second box section portion, wherein the side posts of each side frame are coupled to the downwardly facing mounting rail of the respective cantrail and the roof beams of the roof frame are coupled to the third inwardly facing mounting rail of each cantrail; one or more support frame being provided above the roof frame, wherein said support frames are coupled to the second inwardly facing mounting rails of the cantrails such that a load carried by the or each support frame is transferred to the side frame via the cantrails. Bracing struts may be provided extending between the cantrails and the roof beams of the roof frame, a lower end of each bracing strut being coupled to the first inwardly facing mounting rail of the respective cantrail. Preferably each side post incorporates mounting rails on either side thereof, mounting brackets being secured to respective mounting rails of the side posts and the downwardly facing mounting rail of the respective cantrail to secure the side posts to the respective cantrail. An inner face of an upper part of each side post of the side frames preferably abuts an outer side of the central web of the respective cantrail beneath the respective downwardly facing mounting rail. Additional frame members may be secured to the outer side of the central web of the respective cantrail adjacent the lower end thereof to extend between the respective side posts and parallel to the respective downwardly facing mounting rail, each additional frame member having further mounting rails on upper and lower sides thereof. Said mounting brackets may be attached to and extend between the downwardly facing mounting rail of the respective cantrail and the mounting rail on the upper side of the adjacent additional frame member. BRIEF DESCRIPTION OF THE DRAWINGS A cantrail, and a passenger service vehicle incorporating same, in accordance with an embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the side and roof structure of a single deck bus incorporating cantrails in accordance with an embodiment of the present invention; Figure 2 is an end view of the structure of Figure 1; Figure 3 is an exploded view of the structure of Figure 1; Figure 4 is an exploded end view of the structure of Figure 1; Figure 5 is a detailed view of the connection between the window pillars and the cantrails of the structure of Figure 1; Figure 6 is an end view of one cantrail of the structure of Figure 1; and Figure 7 is a perspective view of the cantrail of Figure 6.. DETAILED DESCRIPTION OF THE DRAWINGS As illustrated in the drawings, a public service vehicle, in particular a single deck bus and more particularly an electrically powered or hydrogen fuelled bus, incorporating cantrails in accordance with an embodiment of the present invention comprises a chassis (not shown in the drawings), a pair of side frames 2,4 extending upwardly from either side of the chassis and a roof frame 6, each side frame being coupled to the roof frame via a respective cantrail 8. Each side frame 2,4 comprises a plurality of upright side posts 10 mounted to the chassis at lower ends thereof, wherein upper ends of each side post 10 of each side frame 2,4 are coupled to the respective cantrail 8. The roof frame 6 comprises a plurality of transversely extending roof beams 12 coupled to the cantrails 8 at either end thereof to extend between the cantrails 8. A plurality of support frames 14 are mounted above the roof frame 6 for carrying relatively heavy components, such as batteries or hydrogen storage tanks. In the following description and claims the terms “longitudinal”, “inner”, “outer”, “horizontal” and “vertical” refer to the normal orientation of the cantrails when fitted to the vehicle. In a preferred embodiment, and as best shown in Figure 6, each cantrail 8 comprises a longitudinal metal extrusion, preferably an aluminium extrusion, having a vertically arranged central web 20 extending from a lower end to an upper end of the cantrail, a first inwardly facing mounting rail 22 being provided on an inner side of said central web 20 at a lower end thereof and a second inwardly facing mounting rail 24 being provided on said inner side of said central web 20 at an upper end thereof. A substantially rectangular first box section portion 26 extends horizontally inwardly from an inner side of said central web 20 at or adjacent a 6 central region thereof. A third inwardly facing mounting rail 28 is provided on an inner end of said first box section portion 26. A downwardly and outwardly extending first inner web 30 extends between said third inwardly facing mounting rail 28 and said first inwardly facing mounting rail 22 and an upwardly and outwardly extending second inner web 32 extends between said third inwardly facing mounting rail 28 and said second inwardly facing mounting rail 24, said first and second inner webs 30,32 defining an inner side of said cantrail 8. A substantially rectangular second box section portion 34 extends along an outer side of said central web 20 from a position at or adjacent said central region to said upper end of the central web 20, a portion of said central web 20 defining one side wall of said second box section portion 34. A downwardly facing mounting rail 36 is provided on a lower side of said second box section portion 34 and an upwardly facing mounting rail 38 is provided on an upper side of said second box section portion 34. Each mounting rail 22,24,28,36,38 comprises a channel having substantially parallel sides terminating in inner facing lips extending towards one another to define a narrowed opening of the channel, such that each mounting rail may receive one or more fastening devices within the channel thereof for securing a second component of the vehicle to the respective mounting rail. As shown in Figure 5, such fastening devices 40 may comprise a member having a threaded hole for receiving a threaded bolt therein and having a width less than or equal to the narrowed opening of the channel of each mounting rail and a length greater than said width and preferably greater than the width of the channel of each mounting rail, such that a fastening device 40 can be inserted into a channel of a respective mounting rail and then rotated to prevent removal of the fastening device from the channel and lock the device into the channel as a bolt is screwed into the fastening device. Upper ends of the side posts 10 of each side frame 2,4 are coupled to the downwardly facing mounting rail 36 of the respective cantrail 8 and the roof beams 12 of the roof frame 6 are coupled to the third inwardly facing mounting rail 28 of each cantrail 8 using suitable fastening devices, such as the type described above. An inner face of an upper part of each side post 10 of the side frames 2,4 abuts an outer face of the central web 20 of the respective cantrail 8 beneath the respective downwardly facing mounting rail 36 to provide further lateral support to the side posts 10 and cantrails 8. The support frames 14 are preferably coupled to the second inwardly facing mounting rails 24 of the cantrails 8 such that a load carried by the or each support frame 14 is transferred to the side frame 2,4 via the cantrails 8. Bracing struts 42 extend between the cantrails 8 and the roof beams 12 of the roof frame 6, a lower end of each bracing strut 42 being coupled to the first inwardly facing mounting rail 22 of the respective cantrail 8. Each side post 10 incorporates mounting rails 44,46 on either side thereof, mounting brackets 48 being secured to respective mounting rails 44,46 of the side posts 10 and the downwardly facing mounting rail 36 of the respective cantrail 8 to secure the side posts 10 to the respective cantrail 8. Additional frame members 50 are secured to the outer side of the central web 20 of the respective cantrail 8 adjacent the lower end thereof to extend between the respective side posts 10 and parallel to the respective downwardly facing mounting rail 36, each additional frame member 50 having further mounting rails 52,54 on upper and lower sides thereof. The mounting brackets 48 are preferably attached to and extend between the downwardly facing mounting rail 36 of the respective cantrail 8 and the mounting rail 52 on the upper side of the adjacent additional frame member 50 by suitable fastening devices 40 located within the respective mounting rail, as described above. The cantrails in accordance with the present invention transfer loads along the bus body structure as with previous designs. Additionally and advantageously the cantrails provide connection points between the body side frames and the roof frame. The profile of each cantrail is extended above the roof frame with additional mounting rails provided for coupling further components thereto, in particular for mounting support frames to the cantrail for supporting heavy components, such as batteries or hydrogen tanks. The cantrail is also facilitates the mounting of aesthetic cover panels thereon via said upwardly facing mounting rails provided thereon. The elongate mounting rails of the cantrail offer almost limitless mounting points along the roof of the bus. Therefore, a roof mounting frame does not need to bespoke to suit the components being carried. Also, the mass of roof mounted components and their mounting frames is now directly applied to the cantrails, on top of the side frames, providing a direct load path back to the chassis. The roof frame itself is no longer required to directly support heaving components such as batteries or hydrogen tanks. The first inwardly facing mounting rail provided along a lower inside edge of the cantrail facilitates a riveted connection along the upper window rails and provides a facility to include bracing struts for additional support to the roof frame without restrictions on position of the bracing struts, providing greater flexibility for the mounting of internal components to the inner sides of the cantrails. The invention is not limited to the embodiment described herein but can be amended or modified without departing from the scope of the present invention as defined by the following claims.

Claims

1. A cantrail for connecting a body side frame to a roof frame of a public service vehicle, said cantrail comprising a longitudinal metal extrusion having a vertically arranged central web extending from a lower end to an upper end of the cantrail; a first inwardly facing mounting rail being provided on an inner side of said central web at a lower end thereof and a second inwardly facing mounting rail being provided on said inner side of said central web at an upper end thereof; a substantially rectangular first box section portion extending horizontally inwardly from an inner side of said central web at a central region thereof, a third inwardly facing mounting rail being provided on an inner end of said first box section portion; a downwardly extending first inner web extending between said third inwardly facing mounting rail and said first inwardly facing mounting rail, an upwardly extending second inner web extending between said third inwardly facing mounting rail and said second inwardly facing mounting rail, said first and second inner webs defining an inner side of said cantrail; a substantially rectangular second box section portion extending along an outer side of said central web from said central region to said upper end of the vertical web, a downwardly facing mounting rail being provided on a lower side of said second box section portion and an upwardly facing mounting rail being provided on an upper side of said second box section portion.

2. A cantrail as claimed in claim 1, wherein each of said mounting rails comprises a channel having substantially parallel sides terminating in inner facing lips such that each mounting rail may receive one or more fastening devices therein for securing a second component of the vehicle to the respective mounting rail.

3. A public service vehicle comprising a chassis; a pair of side frames extending upwardly from either side of the chassis, each side frame comprising a plurality of upright side posts mounted to the chassis at lower ends thereof; a roof frame comprising a plurality of transversely extending roof beams; each side frame being coupled together to the roof frame via a respective cantrail as claimed in claim 1 or claim 2, wherein the side posts of each side frame are coupled to the downwardly facing mounting rail of the respective cantrail and the roof beams of the roof frame are coupled to the third inwardly facing mounting rail of each cantrail; one or moresupport frame being provided above the roof frame, wherein said support frames are coupled to the second inwardly facing mounting rails of the cantrails such that a load carried by the or each support frame is transferred to the side frame via the cantrails.

4. A vehicle as claimed in claim 3, wherein bracing struts extend between the cantrails and the roof beams of the roof frame, a lower end of each bracing strut being coupled to the first inwardly facing mounting rail of the respective cantrail.

5. A vehicle as claimed in claim 3 or claim 4, wherein each side post incorporates mounting rails on either side thereof, mounting brackets being secured to respective mounting rails of the side posts and the downwardly facing mounting rail of the respective cantrail to secure the side posts to the respective cantrail.

6. A vehicle as claimed in any of claims 3 to 5, wherein an inner face of an upper part of each side post of the side frames abuts an outer side of the central web of the respective cantrail beneath the respective downwardly facing mounting rail.

7. A vehicle as claimed in claim 6, wherein additional frame members are secured to the outer side of the central web of the respective cantrail adjacent the lower end thereof to extend between the respective side posts and parallel to the respective downwardly facing mounting rail, each additional frame member having further mounting rails on upper and lower sides thereof.

8. A vehicle as claimed in claim 7 when dependent upon claim 5, wherein said mounting brackets are attached to and extend between the downwardly facing mounting rail of the respective cantrail and the mounting rail on the upper side of the adjacent additional frame member.

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