IMPROVEMENTS IN AND RELATING TO A TRAILER ROOF

Abstract: A trailer having a roof consisting of a frame and a cover (10) which is attached to the frame by means of a clip (12) and preferably also by adhesive (14). The clip (12) holds the cover (10) to the frame while the adhesive (14) sets and helps to prevent the cover (10) peeling from the frame. The adhesive (14) acts to restrict shear loads between the cover (10) and the frame.

Description: This invention relates to trailer roofs and particularly to means for attaching a roof cover to a trailer roof frame. EP-A-0021226 relates to a roof frame having a complex clamping strip which clamps the sheet to the frame. The strip is particularly complicated in design and is therefore expensive to manufacture. In known trailer roof assemblies, such as that disclosed in GB-A-1002670 (or LU-A-46236), the roof frame is covered by a sheet of suitable material which is secured to the frame by rivetting. This is a labour intensive operation since a large number of rivets are required to provide a good seal. Sealants and/or adhesives are commonly introduced between the cover sheet and frame to make the joint watertight. A trailer-according to the present invention has a roof construction comprising a frame and a cover supported by the frame, the cover being attached to the frame by a clip means which engages the frame tightly by its own inherent resilience (as it is known e.g. from LU-A-46236) and is characterised in that the clip means is packed with adhesive (14) and then positioned around the outer edges of the cover and the frame. Packing the clip with adhesive before driving it into position on the frame, causes adhesive to extrude over every surface of the joint which increases the joint shear strength and ensures good sealing. When the trailer roof is assembled the clip means are in positive engagement with the roof frame. Preferably adhesive is used between the cover and the frame. The clip serves the dual function of holding the cover to the frame while the adhesive sets and of removing peeling loads to which the adhesive is vulnerable. Shear loads between cover and frame are carried entirely by the adhesive. The roof frame preferably consists of two side cant rails, a front cross-member, a rear cross-member and roof bows. This results in a glued roof joint which is resistant to peeling and which avoids the necessity of having to be clamped in jigs while the adhesive sets, resulting in time saving and consequent reduction of costs. An additional advantage is that the roof according to the invention has a continuous water seal along all the outer edges of the trailer roof. Further, the joint between the roof and trailer body is more resistant to loads in service than conventional roof/body joints. The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a plan view of the roof of a trailer in accordance with the invention. Figure 2 is a cross-section of a part of the trailer roof of Figure 1 taken along lines A-A. Figure 3 is a cross section of a second embodiment of a trailer in accordance with the invention. The trailer roof, shown in Figure 1, has a frame comprising two side cant rails 2, a front cross-member 4, a rear cross-member 6, and roof bows 8 which provide bracing across its width. The frame is covered by a roof covering 10 being a sheet of aluminium, fibreglass or other suitable material. Figure 2 shows, in section, the roof covering 10 secured to the outer edge of the cant rail 2 by a clip l2 of aluminium, spring steel or the like. Layers of adhesive l4 are provided between the cant rail 2 and the covering 10, between the clip 12 and the covering 10, and optionally between the roof bows 8 and the covering 10. In order to attach the covering 10 to the frame, a continuous run of adhesive 14 is placed along the outer edge of the cant rails 2, the front cross-member 4 and the rear cross-member 6. A run of adhesive may also be placed over the roof frame. Clips 12 packed with adhesive, are then positioned around the outer edges of the cant rails 2, front cross-member 4 and rear cross-member 6 with the roof covering 10 partly interposed as shown in Figure 2. The design of the frame and the clip elements illustrated in Figure 2 is such that the inside lower edges of the clips have a detent 16 which rides up a sloping face 18 of the corresponding projection of the cant or end rail and then springs down behind a detent 20 of the rail to form a positive lock, thus preventing the roof covering from lifting and the clip elements from disengaging. The clip also serves to hold the roof covering against the frame whilst the adhesive sets giving a good joint. In the event of adhesive failure in use or the local absence of adhesive due to inefficient placing of the run of adhesive, the clip elements acts as a secondary mechanical restraint against the roof lifting. Since each clip element is formed as a strip of the same length as the appropriate side of the frame to which it is to be attached, a continuous water seal is provided along each of the outer edges of the roof frame. In the modified arrangement shown in Figure 3 the cant rail 2' is of a constant thickness and so cannot form a detent 20 around which one end of the clip 12 can hook. In this arrangement the spring clip is formed in a slightly more closed position with a thicker but smoother inner end 20 which is positioned beneath and tightly engages the upper flange 22 of the cant rail. The roof cover 10 is also firmly held in position by the clip together with the adhesive layer between the cover material and the cant rail and/or inner surface of the clip.

Claims: A trailer having a roof construction comprising a frame and a cover supported by the frame, the cover being attached to the frame by a clip means which engages the frame tightly by its own inherent resilience characterised in that the clip means (12) is packed with adhesive (14) and then positioned around the outer edges of the cover (10) and the frame (12). A trailer as claimed in claim 1 characterised in that the cover is stuck to the frame at least at the outer edges of the frame by means of adhesive with the clip (12) engaging the edge of the frame and the overlapping roof cover (10) to hold the roof cover edge tightly in contact with the edge frame. A trailer as claimed in any one of the preceding claims characterised in that the clip (12) is in the form of a strip extending along the whole length of the outer edges of the roof frame. A trailer as claimed in any one of the preceding claims characterised in that the clip is of U-section with the leg of the U which in use engages beneath a flange of the outer rail of the roof frame, being formed with a detent (16) to engage with a corresponding detent (20) on the edge of the flange of the cant rail firmly to lock the clip (12) in position.

Inventors: DAVIS, ROBERT CLIVE BROWNING
Applicants: YORK TRAILER COMPANY LIMITED
Application year: 1987
Main classification: B62D33
IPC codes: B62D33, B62D27