Patent Publication Number: US-2022227431-A1

Title: Vehicle body element connecting joint

Description:
TECHNICAL FIELD 
     The invention relates to a vehicle body element connecting joint for connecting a first body element to a second body element of a vehicle module, during assembly of multiple connected body elements to form a vehicle module. 
     BACKGROUND OF THE INVENTION 
     In the production of passenger transport vehicles or commercial vehicles in general there is a desire to produce several versions of such vehicle based on the same basic layout. The different versions can have different lengths, passenger capacity and/or load-carrying capacity. Typical examples of such vehicles are buses of an original single-unit structure based on chassis units of trucks. However, the principle is also applicable to trucks, for instance when assembling different sizes of drivers cabs or load carrying compartments. 
     U.S. Pat. No. 4,469,369 shows examples of module elements used for the assembly of a city motor bus or similar vehicle. In this case, a module comprising a transverse window section of the body open at the end portions is assembled end to end with adjacent modules comprising front and rear modules to form a complete vehicle. Such design makes it possible to assemble bodies of different lengths in the same assembly jig and to widely apply automatic welding. 
     EP0818373 shows an alternative method of assembling module elements, wherein welding can be replaced by a joint comprising locking wedges and fasteners for clamping facing edges of two modules together. In a vehicle assembled from such module elements, the parts and assemblies of the vehicle body can be assembled and subsequently replaced if necessary. 
     A problem with the above solutions is that the connecting joints used for connecting body elements can often be difficult to assemble. In addition, the assembled connecting joints may create undesired local force concentrations and/or may be unable to keep the body elements tightly clamped together over time. 
     The object of the invention is to provide an improved connecting joint, in particular a corner joint, for joining vehicle body elements of different types or versions that solves the above problems and facilitates the assembly of such body elements. 
     INVENTION 
     The above problems have been solved by a connecting joint as claimed in the appended claims. 
     In the subsequent text, the term “vehicle module” is intended to describe an individual vehicle module that can be connected to at least one other vehicle module. Two or more vehicle modules are assembled to make a complete vehicle. In the case of a passenger transport vehicle, such as a bus, vehicle modules can comprise a front driver&#39;s cab module, a rear drive module, and one or more intermediate passenger compartment modules having window and/or doors. Each vehicle module comprises a number of vehicle body elements, such as an upper element, a lower element and two side elements connectable to corresponding body elements on an adjacent vehicle module. These elements will be referred to as “body elements”. When assembled, body elements in the form of a roof, a floor and two side walls will form a vehicle module. 
     A body element connecting joint can be used for connecting one or more body elements to form a vehicle module. The invention relates to one such connecting joint between adjacent body elements. In the subsequent text, the body element connecting joint described to is a generic joint suitable for use in any one of the upper elements, lower elements and side elements to be joined. The connecting joint is preferably a corner joint, wherein two adjacent elements will be arranged at or approximately at right angles to each other. 
     In the subsequent text, body element connecting joint is described in connection with a body module suitable for passenger vehicles, such as buses. The reason for this is to maintain a consistent set of reference terms for accurately describing the form and function of the body element connecting joint. However, the use of the body element connecting joint is not limited for use in buses or as a joint only arranged in the longitudinal direction of a vehicle. Alternative uses for the body element connecting joint track-bound vehicles, such as trams and trolley cars or load carrying vehicles such as trucks. In the latter case, a load carrying compartment could be designed using the inventive body element connecting joint in any longitudinal, transverse and vertical corner to build a box-shaped load compartment. 
     The assembled body elements can be arranged to form a portion of a side wall section, a roof or ceiling section and/or a floor section. Consequently, the assembled body elements will have an inner surface, an outer surface and a pair of facing side edges. Each side edge is provided with elongate connecting profiles, wherein connected profiles have facing surfaces adjacent the connecting joint and remote surfaces adjacent the respective body module edges. Side surfaces on the profiles are substantially parallel to the inner and/or outer surfaces of the body element to which it is joined. The connected profiles have a longitudinal extension parallel with the longitudinal extension of their respective adjacent body element and the main longitudinal direction of the vehicle. Similarly, the connected profiles have a transverse extension at right angles to their longitudinal extension and in the plane of their respective adjacent body element. 
     The above terminology and the description of the relative locations of components in a connecting joint between two body elements will be adhered to in the text below. 
     According to a preferred embodiment, the invention relates to a vehicle body element connecting joint for connecting a first body element to a second body element, which connecting joint comprises first and second elongate profiles arranged along adjacent edges of the first and second body elements, respectively. The connecting joint comprises a first projection protruding from the first elongate profile parallel to a side surface of the first elongate profile and extending towards a free end of the first elongate profile, a first recess arranged in a side surface of the second elongate profile and arranged parallel to an edge of the second elongate profile, wherein the first projection is inserted into the first recess. 
     The connecting joint further comprises a first dovetail section protruding from the first elongate profile and arranged along the free end of the first elongate profiles and a second dovetail section protruding from the second elongate profile and extending parallel to and out of the free end of the second elongate profile. At least one fastening strip having a profile arranged to contact the first dovetail section and the second dovetail section is provided to clamp the first and second elongate profiles to each other along their adjacent free ends, and at least one fastener is arranged to be inserted through the fastening strip in order to press it towards the first dovetail section and the second dovetail section in order to achieve a clamping force when the joint is tightened by means of the fastener. 
     The inventive connecting joint comprises elongate profiles arranged along facing edges of the first and second body elements, respectively. The profiles are provided with shaped sections commonly referred to as “dovetails”, which sections have their widest cross-sectional dimension facing into the joint. A dovetail joint is also referred to as a swallow-tail joint or a fantail joint. The adjacent profiles are clamped together by locking wedges arranged parallel to the profiles, matching the shape of the dovetail sections. The body modules will inherently have an inner surface and an outer surface, whereby the locking wedges will be arranged along the dovetail sections of said profiles on opposite sides of the inner and outer surfaces of the respective body modules. The locking wedges are connected by fastening means extending between facing profiles on said edges of the first and second body elements. The fastening means can be any suitable type of fastener, such as a screw. The fasteners connecting the locking wedges are arranged at right angles to the facing contact surfaces between the first and second elongated profiles. 
     According to one example, the connecting joint comprises a first profile arranged along a side edge of the first body module along a surface remote from the connecting joint and a second profile arranged parallel to and in form-fitting contact with the first profile along facing side surfaces; wherein the assembled first and second profiles forming a single, common first dovetail section along a surface facing the connecting joint. In order to achieve this, the first and second profiles are assembled side-by-side and have form-fitting sections facing into the joint which sections are interlocking and shaped to form a single dovetail after assembly of the first and second profiles. 
     According to one example, the first and second elongated profiles of the connecting joint are joined along facing contact surfaces, wherein a first contact surface extends parallel to the side surface along the first elongate profile and a second contact surface comprises an end surface along the second elongate profile facing the first elongate profile. In this example, the first projection and the first recess are separated from the first and second dovetail sections, respectively, by the facing contact surfaces between the first and second elongated profiles. The first projection and the first recess are located on the opposite side of a plane coinciding with the assembled contact surfaces relative to the first and second dovetail sections. 
     According to a further example, the first projection of the first elongate profile and the first recess of the second elongate profile comprise complementary beveled surfaces arranged to force the first and second elongated profiles together when the joint is tightened with the fastener. The fastener is arranged to be threaded into a corresponding threaded recess in the end surface of the second elongate profile through the fastening strip in order to press the fastening strip towards the first and second dovetail sections. The number of fasteners used and the spacing between adjacent fasteners is dependent on factors such the length of the profiles making up the connecting joint and the required strength of the connecting joint. 
     According to a further example, the fastener is a tapping screw arranged to be threaded into a longitudinal slot along the end surface of the second elongate profile. In this way, there is no need for exactly positioned threaded recesses in the end surface of the second elongate profile. The number of fasteners is determined by a predetermined number of holes provided for fasteners through the fastening strip. The longitudinal slot parallel to the edge along the end surface of the second elongate profile allows fasteners to be located at any position. Fasteners are inserted through the holes in the fastening strip and will create their own threads as they are screwed into the slot to clamp the fastening strip in position. 
     According to the invention, the contacting portions of the first and second elongated profiles allows the elongated profiles to form a corner joint, along which corner the first and second body elements are connected to form a vehicle module. Additional corner joints can be used along two or more longitudinal corners of the vehicle module in order to connect at least three of the body elements making up a vehicle module. 
     According to a further example, the fastening strip and the at least one fastener are covered by an elongated cover profile hooked into a recess in the first elongated profile and snapped over a side edge of the fastening strip. The cover profile can have a substantially L-shaped cross-section. Along a first free end the cover profile can be provided with a curved attachment section, which is inserted into a similarly curved, form-fitting slot in the outer side surface of and adjacent the free end of the first elongate profile. Both the curved slot and the curved attachment section preferably have a part-circular cross-section. Along a second free end the cover profile can be provided with a hook-shaped locking section. When the curved attachment section is inserted in the curved slot, the cover profile can be rotated about a pivot axis created by the part-circular shape of the curved slot. In a final step, the cover profile is fixed into position by snapping the locking section over a longitudinal edge of fastening strip remote from the free end of the first elongate profile. 
     The invention is not limited to the above examples describing the cover. For instance, the locking section can be snapped into a longitudinal recess in the outer side surface of the second elongate profile. Alternatively, the locking section can be snapped over a longitudinal projection extending along the outer side surface of the second elongate profile. Further, at the first free end the cover profile can be provided with an attachment section having alternatively shaped cross-sections, suitable for insertion into a similarly shaped, form-fitting slot in the outer side surface of and adjacent the free end of the first elongate profile. Consequently, the attachment section can have a cross-section that is curved, L-shaped, V-shaped, as long as it is suitable for hooking into or otherwise cooperating with a corresponding slot or groove in the outer side surface of the first elongate profile. 
     The substantially L-shaped cover profile can be an optional component provided to protect the connecting joint from physical damage as well as from dirt and humid conditions. This is an advantage when the body elements and the connecting joint form an integral part of the visible outer skin of a body module. 
     The invention further relates to a vehicle comprises vehicle body modules assembled by means of connecting joints according to the above description. 
     In the production of passenger transport vehicles or commercial vehicles in general there is a desire to produce several versions of such vehicle based on the same basic layout. The different versions can have different lengths, passenger capacity and/or load-carrying capacity. Typical examples of such vehicles are buses of an original single-unit structure based on chassis units of trucks. However, the principle is also applicable to trucks, for instance when assembling different sizes of drivers cabs or load carrying compartments. The connecting joint according to the invention is particularly advantageous for such applications. A connecting joint according to the invention can be used for exchangeable body elements, which allows the same connecting joint to be applied to any number of body element and/or body module combinations. 
     In the above-mentioned text, the first and second profiles are provided with individual dovetail sections and with individual mating wedge sections. This arrangement allows a single fastener strip to be used, which reduces material cost weight and time for assembly. The invention provides a modular system that eliminates the need for manufacturing special profiles for each joint. Wall panels, floor panels and roof panels comprising standard elongate profiles can thereby be assembled and form part of the body module without requiring any modifications. The inventive body element connecting joint can therefore be used in any longitudinal, transverse and vertical corner to build anything from body modules for buses to box-shaped load compartments for trucks. A further advantage is that the connecting joint that has a transverse dimension allowing fasteners to be pre-loaded. Such a pre-load acting on the compressed joint components provides external tension loads with a path through the joint other than through the fastener, thus reducing the fatigue loading on the fastener. Pre-loading also improves the durability of the fastener under repeated loading, which is a common loading case in vehicles. 
    
    
     
       FIGURES 
       In the following text, the invention will be described in detail with reference to the attached drawings. These schematic drawings are used for illustration only and do not in any way limit the scope of the invention. In the drawings: 
         FIG. 1  shows a schematic vehicle comprising body elements with connecting joints according to the invention; 
         FIG. 2  shows a schematic perspective view of body elements assembled using connecting joints according to the invention; 
         FIG. 3  shows a perspective view of a cross-section through a connecting joint according to the invention; 
         FIG. 4  shows a cross-section through a connecting joint according to the invention; 
         FIGS. 5-8  show an assembly process for a connecting joint according to the invention; and 
         FIGS. 9-10  show the assembly process for an optional cover profile for a connecting joint according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a schematically illustrated vehicle  100  comprising body elements to be assembled using connecting joints according to the invention. The vehicle  100  in this example will comprise a front vehicle module  101 , such as a driver&#39;s cab module, a rear vehicle module  102 , such as a drive module comprising a propulsion unit, and an intermediate vehicle module  103 , such as a passenger module having windows and doors, to form a complete vehicle  100 . 
     At least the intermediate vehicle module  103  can be assembled from body elements making up roof, floor and side elements. In the intermediate vehicle module  103  shown in  FIG. 1 , connecting joints  111 ,  112  according to the invention are used to assemble adjacent body elements in the longitudinal direction of the vehicle. Further, adjacent side edges of body elements on the front and rear vehicle modules  101 ,  102  can be provided with such connecting joints in both the longitudinal and the transverse direction of the vehicle, as will be described below. 
       FIG. 2  shows a schematic perspective view of body elements making up a body module, which body elements are assembled using connecting joints according to the invention. In this example, a body module  105  is made up of multiple body elements  121 ,  122 ,  123 ,  124  in the form of two facing side elements  121 ,  123 , a floor element  122  and a roof element  124 . Adjacent body elements are joined by connecting joint  111 ,  112 ,  113 ,  114  along each corner of the body module  105  in the longitudinal direction of the body module. 
       FIG. 3  shows a perspective view of a cross-section through a connecting joint according to the invention. The figure shows a side element  121  and a floor element  122  (indicated in dashed lines) as shown in  FIG. 2 , which body elements  121 ,  122  are assembled by a connecting joint  111 . The connecting joint  111  comprises first elongate profile  131  attached along an adjacent edge of the first body element  121  and a second elongate profile  132  attached along an adjacent edge of the second body element  122 . The first and second elongate profiles  131 ,  132  are connected by means of form-fitting mating surfaces and a pair of dovetail sections on the respective first and second elongate profiles, which arrangement will be described in further detail below. The first and second elongate profiles  131 ,  132  are clamped together by a fastening strip  133  having a profile arranged to contact the dovetail sections, which fastening strip  133  is attached by means of fasteners  134  (one shown) extending into holes or a recess in the second elongate profile  132  and arranged to press the fastening strip  133  towards the dovetail sections. The fastening strip  133  and any fasteners  134  can be enclosed by an optional cover profile  135  extending along the first and second elongate profiles  131 ,  132 . When the body elements  121 ,  122  and the connecting joint  111  form an integral part of the outer skin of a body module, then the substantially L-shaped cover profile  135  can be provided to protect the connecting joint  111  from physical damage as well as from dirt and humid conditions. If the body elements  121 ,  122  and the connecting joint  111  are instead covered by an outer protective skin, then the cover profile  135  can be dispensed with. 
       FIG. 4  shows a cross-section through the connecting joint  111  in  FIG. 3 . The figure shows the assembled connecting joint  111  comprising a first elongate profile  131  attached to a second elongate profile  132 . The side element  121  and the floor element  122  are indicated in dashed lines, and the transverse extensions of these body elements  121 ,  122  are indicated by dash-dotted lines X and Y, respectively. As defined above, the transverse extension of the respective body element is at right angles to their longitudinal extension in the longitudinal direction of the vehicle. The transverse extension of the respective elongate profile is at right angles to their longitudinal extension and in the plane of their respective adjacent body element. The connecting joint  111  forms a corner joint, wherein the side element  121  and the first elongate profile  131  have an outer side surface  126 , facing away from the second elongate profile  132 , and an inner side surface  126  facing the second elongate profile  132 . Similarly, the floor element  122  and the second elongate profile  132  have an outer side surface  127 , facing away from the first elongate profile  131 , and an inner side surface  128  facing the first elongate profile  131 . 
     As indicated above, the first and second elongate profiles  131 ,  132  are connected by means of form-fitting mating surfaces. The form-fitting surfaces comprise a first projection  141  protruding from the first elongate profile  131  and a first recess  142  arranged in a side surface of the second elongate profile  132 . The form-fitting surfaces on the first projection  141  and the first recess  142  comprise complementary beveled surfaces. The first projection  141  protrudes from the first elongate profile  131  remote from its free end and extends parallel to a side surface  125 ,  126  of the first elongate profile  131  towards the free end of the first elongate profile  131 , The free end of the first elongate profile faces away from the first body element  121  to which the first elongate profile is attached. The first recess  142  is arranged in the inner side surface  128  of the second elongate profile  132  and arranged parallel to the free end of the second elongate profile. The free end of the second elongate profile faces away from the second body element  122  to which the second elongate profile is attached. During assembly, the first projection  141  is inserted into the first recess  142 , as will be described in further detail below. 
     The first and second elongate profiles  131 ,  132  are further connected by means of a pair of dovetail sections on the respective first and second elongate profiles  131 ,  132 . The first and second elongate profiles  131 ,  132  are clamped together by a fastening strip  133  attached by parallel fasteners  134  (one shown) extending into the second elongate profile  132 . A first dovetail section  143  protrudes from the first elongate profiles  131  and is arranged along the end surface at the free end of the first elongate profile  131 . The first dovetail section  143  has an angled first contact surface (see  FIG. 5 ) arranged to face the first elongate profile  131 . The first contact surface is located in a plane arranged to intersect a plane through the axes of the fasteners  134  at an acute angle remote from the second elongate profile  132 . A second dovetail section  144  protrudes from the second elongate profile  132  and extends parallel to and out of the free end along an edge of the second elongate profile  132 . The second dovetail section  144  has an angled second contact surface (see  FIG. 5 ) arranged to face away from the first elongate profile  131 . The second contact surface is located in a plane arranged to intersect a plane through the axes of the fasteners  134  at an acute angle remote from the second elongate profile  132 . 
     The first and second elongated profiles  131 ,  132  are joined along facing contact surfaces  145 ,  146 , respectively, wherein a first contact surface  145  extends parallel to the side surface  126  along the first elongate profile  131  and a second contact surface  146  comprises an end surface along the second elongate profile  132 , which end surface faces the first elongate profile  131 . In this example, the first contact surface  145  is parallel to and recessed a predetermined distance into the side surface  126  of the first elongate profile  131 . This arrangement provides a step along the side surface of the first elongate profile  131  in which step the free end of the second elongate profile  132 . The recessed distance into the side surface  126  of the first elongate profile  131  is selected to allow contact between the complementary beveled surfaces on the first projection  141  and the first recess  142 . The width of the recessed contact surface  145 , measured in the transverse extension Y away from the free end of the first elongate profile  131 , is less than the thickness of the second elongate profile  132  but greater than the width of the second contact surface  146 , measured parallel to said second contact surface  146 . In the example shown in  FIG. 4 , the first projection  141  and the first recess  142  are separated from the first and second dovetail sections  143 ,  144 , respectively, by the facing contact surfaces  145 ,  146  between the first and second elongated profiles  131 ,  132 . Further, the first projection  141  and the first recess  142  are located on the opposite side of a plane coinciding with the assembled contact surfaces  145 ,  146  relative to the first and second dovetail sections  143 ,  144 . This plane is located parallel to the transverse extension Y of the first elongate profile  131 . In addition, the fasteners clamping the first and second elongated profiles  131 ,  132  together are arranged with their axes at right angles to the facing contact surfaces  145 ,  146  between the profiles. 
     The fastening strip  133  has a cross-sectional profile arranged to contact the angled first and second contact surfaces of the first dovetail section and the second dovetail section, respectively. Matching angled contact surfaces on the fastening strip  133  causes the first and second elongate profiles to be clamped to each other along their adjacent ends under the action of the fasteners  134 . The fastening strip  133  is attached by means of fasteners  134  extending into the second elongate profile  132  in the direction of its transverse extension X, at right angles to the transverse extension Y of the first elongate profile  131 . Under the action of the fasteners  134 , the first and second elongate profiles  131 ,  132  are clamped together by the fastening strip  133  contacting the dovetail sections, which fasteners  134  extend into holes or a recess  136  in the second elongate profile  132  as they are tightened. According to a preferred embodiment, the fasteners are self-threading, or tapping screws which are fastened into a longitudinal recess or slot in the end surface of the second elongate profile. Alternatively, tapping or threaded screws can be fastened into pre-drilled holes. At the same time the angled contact surfaces on the fastening strip  133  are arranged to be pressed towards the angled contact surfaces on the dovetail sections, drawing the dovetail sections together and causing the complementary beveled surfaces on the first projection  141  and the first recess  142  to be forced together to create an interlocking connection joint  111 . The example in  FIG. 4  also shows the optional cover profile  135  enclosing the fastening strip  133  and the fasteners  134 . 
       FIGS. 5-8  show an assembly process for a connecting joint according to the invention. For reasons of clarity, the body elements are not shown in these figures. Most of the reference numbers used to indicate component parts in the subsequent figures have been defined in connection with the description of  FIGS. 3 and 4 . 
       FIG. 5  shows an exploded view of the first and second elongate profiles  131 ,  132 , prior to assembly.  FIG. 5  indicates the first projection  141  and the first recess  142  and their complementary beveled surfaces. A first beveled surface on the first projection  141  faces away from the second contact surface  146  at the free end of the second elongate profile  132  and is arranged at an angle α relative to the adjacent first contact surface  145  on the first elongate profile  131 . Similarly, a second beveled surface on the first recess  142  faces away from the first contact surface  145  in the recessed side surface of the first elongate profile  131  and is arranged at an angle α relative to the adjacent second contact surface  146  on the second elongate profile  132 . Both complementary beveled surfaces are arranged at the same angle α in order to facilitate force distribution and to avoid point or line contact between the projection and the recess. 
     The example in  FIG. 5  shows an advantageous design for the first contact surface  145  and the corresponding second contact surface  146 . Along its lower edge, the first contact surface  145  can be provided with a raised, third contact surface  147 . In this way, the first and second elongate profiles  131 ,  132  are in contact at the upper portions of the first and second contact surfaces  145 ,  146 , adjacent the first and second projections  141 ,  142 , and at the lower portions of the first and second contact surfaces  145 ,  146 , along the third contact surface  147 . This design is advantageous in view of the manufacturing tolerances of the extruded first and second elongate profiles  131 ,  132 . The third contact surface  147  creates a gap between the upper and lower portions of the first and second contact surfaces  145 ,  146 . This gap can take up minor variations in surface quality between the first and second contact surfaces and ensures correct assembly of the first and second elongate profiles  131 ,  132 . 
       FIG. 5  further indicates the angled first contact surface of the first dovetail section  143 , which contact surface faces the first elongate profile  131 . The first contact surface of the first dovetail section  143  is located in a plane arranged to intersect a plane through the axes of the fasteners  134  at an acute angle β remote from the second elongate profile  132 . The second dovetail section  144  has an angled second contact surface arranged to face away from the first elongate profile  131 . The second contact surface is located in a plane arranged to intersect a plane through the axes of the fasteners  134  at an acute angle β remote from the second elongate profile  132 . The fastening strip  133  is arranged to be clamped to the contact surfaces of the first and second dovetail sections  143 ,  144  of the first and second elongate profiles  131 ,  132 . Consequently, the fastening strip  133  is provided with matching angled contact surfaces at the same angle β relative to a plane through the axes of the fasteners  134 . The contact surfaces for the dovetail sections and the fastening strip are arranged at the same angle β in order to facilitate force distribution and to avoid point or line contact between the projection and the recess. 
       FIG. 6  shows a first step of the assembly process for the first and second elongate profiles  131 ,  132  and their attached body elements (not shown). During assembly, the free end of the first elongate profiles  131  is initially angled away from the free end of the second elongate profile  132 . The first projection  141  of the first elongate profile  131  is then inserted into the first recess  142  of the second elongate profile  132 . The first projection  141  and the first recess  142  are then hooked together by angling free end of the first elongate profiles  131  into contact with the second elongate profile  132 , as indicated by the arrow A 1 . 
       FIG. 7  shows a second step of the assembly process, wherein the fastening strip  133  is placed in contact with the first and second dovetail sections  143 ,  144 , as indicated by the arrow A 2 . Subsequently, the fasteners  134  are positioned in through holes (not shown) in the fastening strip  133  prior to tightening, as indicated by the arrow A 3 . At this time the first projection  141  and the first recess  142  are in position relative to each other, but not necessarily in contact. 
       FIG. 8  shows a third step of the assembly process, wherein fasteners  134  in the form of tapping screws are fastened into a longitudinal recess or slot  136  in the end surface of the second elongate profile  132 , as indicated by the arrow A 4 . Tightening of the fasteners  134  causes the fastening strip  133  to be pressed towards the angled contact surfaces on the dovetail sections  143 ,  144 , whereby the dovetail sections are drawn together. The first elongate profile  131  will then be displaced along the second contact surface  146  causing the complementary beveled surfaces on the first projection  141  and the first recess  142  to be forced together to create an interlocking connection joint  111 . 
       FIGS. 9-10  show the assembly process for an optional cover profile  135  for a connecting joint according to the invention. As shown in  FIG. 9 , the fastening strip  133  and any fasteners  134  can be enclosed by an optional cover profile  135  extending along the first and second elongate profiles  131 ,  132 . The cover profile  135  has a substantially L-shaped cross-section. Along a first free end the cover profile  135  is provided with a curved attachment section  137 , which is inserted into a similarly curved slot  138  in the outer side surface  125  adjacent the free end of the first elongate profile  131 , as indicated in  FIG. 9 . Along a second free end the cover profile  135  is provided with a hook-shaped locking section  139 . When the curved attachment section  137  has been inserted in the curved slot  138 , the cover profile  135  is rotated about a pivot axis created by the curved slot  138  as indicated by the arrow A 6 . In a final step, the cover profile  135  is fixed into position by snapping the locking section  139  over an edge of fastening strip  133  remote from the free end of the first elongate profile  131  as shown in  FIG. 10 . The substantially L-shaped cover profile  135  can be provided to protect the connecting joint  111  from physical damage as well as from dirt and humid conditions. This is an advantage when the body elements  121 ,  122  and the connecting joint  111  form an integral part of the outer skin of a body module. 
     The invention should not be deemed to be limited to the embodiments described above, but rather a number of further variants and modifications are conceivable within the scope of the following patent claims.