Claims:WE CLAIM:
1. A pillion frame structure (100) for a vehicle (200), the structure (100) comprising:
a front member (102) oriented vertically to a front-rear direction of the vehicle (200) and adapted to be detachably mounted onto seat rails (202) of a frame member (204);
side members (104a, 104b) oriented vertically to the front-rear direction of the vehicle (200) and extending from ends (102a, 102b) of the front member (102) up to a rear member (106); and
a base member (108) mounted onto bottom surfaces (110) of the front member (102), the side members (104a, 104b) and the rear member (106), wherein the base member (108) along with front member (102), the side members (104a, 104b) and the rear member (106) define a storage area to form a utility compartment (112).

2. The structure (100) as claimed in claim 1, comprises one or more extension portions (114) defined on a front surface (102c) of the front member (102), the one or more extension portions (114) upon engagement with the seat rails (202) are adapted to transfer load acting on the pillion frame structure (100) to the frame member (204).

3. The structure (100) as claimed in claim 2, wherein each of the one or more extension portions (114) comprises:
a mounting portion (114a) adapted to engage with the seat rails (202); and
one or more side skirts (114b) extending from either side of the mounting portion (114a) and adapted to be secured to a bridge member (206) of the frame member (204), each side skirt (114b) defined with a downward extending flange (114c) adapted to abut a rear end of the bridge member (206) for facilitating load transfer to the frame member (204).

4. The structure (100) as claimed in claim 1, wherein top surfaces (116) of the front member (102), the side members (104a, 104b) and the rear member (106) are adapted to receive a seat (208) of the vehicle (200).

5. The structure (100) as claimed in claim 1 comprises a pillion handle (118) surrounding the side members (104a, 104b) and the rear member (106) of the utility compartment (112), the pillion handle (118) defined with mounting provisions (120) on its front portion (118a) for engagement with a bridge member (206).

6. The structure (100) as claimed in claim 1, wherein the rear member (106) is adapted to engage with a rear portion (118b) of the pillion handle (118).

7. The structure (100) as claimed in claim 1, wherein the side members (104a, 104b) are adapted to support a luggage carrier (122).

8. The structure (100) as claimed in claim 1, wherein each of the front member (102), the side members (104a, 104b) and the rear member (106) is made by co-molding of cast steel and polypropylene materials.

9. A frame structure (204) for a saddle-type vehicle (200), the frame structure (204) comprising:
seat rails (202) extending from a head pipe (210);
a pillion frame structure (100) detachably mounted on the seat rails (202), the structure (100) comprising:
a front member (102) oriented vertically to a front-rear direction of the vehicle (200) and adapted to be detachably mounted onto the seat rails (202);
side members (104a, 104b) oriented vertically to the front-rear direction of the vehicle (200) and extending from ends (102a, 102b) of the front member (102) up to a rear member (106); and
a base member (108) mounted onto bottom surfaces (110) of the front member (102), the side members (104a, 104b) and the rear member (106), wherein the base member (108) along with front member (102), the side members (104a, 104b) and the rear member (106) define a storage area to form a utility compartment (112).

10. The frame structure (204) as claimed in claim 9, wherein the pillion frame structure (200) comprises one or more extension portions (114) defined on a front surface (102c) of the front member (102), the one or more extension portions (114) upon engagement with the seat rails (202) are adapted to transfer load acting on the pillion frame structure (100) to the frame member (204).

11. The frame structure (204) as claimed in claim 10, wherein each of the one or more extension portions (114) comprises:
a mounting portion (114a) adapted to engage with the seat rails (202); and
one or more side skirts (114b) extending from either side of the mounting portion (114a) and adapted to be secured to a bridge member (206) of the frame member (204), each side skirt (114b) defined with a downward extending flange (114c) adapted to abut a rear end of the bridge member (206) for facilitating load transfer to the frame member (204).

12. The frame structure (204) as claimed in claim 9, wherein top surfaces (116) of the front member (102), the side members (104a, 104b) and the rear member (106) are adapted to receive a seat (208) of the vehicle (200).

13. The frame structure (204) as claimed in claim 9 comprises a pillion handle (118) surrounding the side members (104a, 104b) and the rear member (106) of the utility compartment (112), the pillion handle (118) defined with mounting provisions (120) on its front portion (118a) for engagement with a bridge member (206).

14. The frame structure (204) as claimed in claim 9, wherein the rear member (106) is adapted to engage with a rear portion (118b) of the pillion handle (118).
15. The frame structure (204) as claimed in claim 9, wherein the side members (104a, 104b) are adapted to support a luggage carrier (122).

16. A saddle-type vehicle (200), comprising:
a frame structure (204) having seat rails (202) extending from a head pipe (210); and
a pillion frame structure (100) detachably mounted on the seat rails (202), the structure (100) comprising:
a front member (102) oriented vertically to a front-rear direction of the vehicle (200) and adapted to be detachably mounted onto the seat rails (202);
side members (104a, 104b) oriented vertically to the front-rear direction of the vehicle (200) and extending from ends (102a, 102b) of the front member (102) up to a rear member (106); and
a base member (108) mounted onto bottom surfaces (110) of the front member (102), the side members (104a, 104b) and the rear member (106), wherein the base member (108) along with front member (102), the side members (104a, 104b) and the rear member (106) define a storage area to form a utility compartment (112).

17. The vehicle (200) as claimed in claim 16, wherein the pillion frame structure (200) comprises one or more extension portions (114) defined on a front surface (102c) of the front member (102), the one or more extension portions (114) upon engagement with the seat rails (202) are adapted to transfer load acting on the pillion frame structure (100) to the frame member (204).

18. The vehicle (200) as claimed in claim 17, wherein each of the one or more extension portions (114) comprises:
a mounting portion (114a) adapted to engage with the seat rails (202); and
one or more side skirts (114b) extending from either side of the mounting portion (114a) and adapted to be secured to a bridge member (206) of the frame member (204), each side skirt (114b) defined with a downward extending flange (114c) adapted to abut a rear end of a bridge member (206) for facilitating load transfer to the frame member (204).

19. The vehicle (200) as claimed in claim 16, wherein top surfaces (116) of the front member (102), the side members (104a, 104b) and the rear member (106) are adapted to receive a seat (208) of the vehicle (200).

20. The vehicle (200) as claimed in claim 16 comprises a pillion handle (118) surrounding the side members (104a, 104b) and the rear member (106) of the utility compartment (112), the pillion handle (118) defined with mounting provisions (120) on its front portion (118a) for engagement with a bridge member (206).

21. The vehicle (200) as claimed in claim 16, wherein the rear member (106) is adapted to engage with a rear portion (118b) of the pillion handle (118).

22. The vehicle (200) as claimed in claim 16, wherein the side members (104a, 104b) are adapted to support a luggage carrier (122).

, Description:FIELD OF THE INVENTION
[001] The present invention relates to a frame structure for a vehicle, particularly to a pillion frame structure for the vehicle.

BACKGROUND OF THE INVENTION
[002] Conventional saddle-type vehicles include a frame structure adapted for supporting vehicle components and a rider. The frame structure is also adapted to include a storage area or a cargo area, for storing items required for the rider.
[003] Typically, the storage area is provided in the fuel tank cover area of the vehicle. However, providing storage area in the fuel tank cover area affects aesthetics of the vehicle. Also, security of the items stored in such a storage area is also compromised, particularly when the vehicle is parked, which is undesirable.
[004] To overcome the above limitations, storage area is alternatively provided in the toolbox area which is disposed adjoining the battery on side of the vehicle or below a split type rider seat or pillion seat in the space between the seat rails and the underneath structures. The storage area in said locations are typically characterized with smaller dimensions, enough to store items such as a wallet or a mobile phone, and securely store these items. However, due to the smaller dimensions of the storage area, items such as a water bottle, a wind sheeter and the like are incapable of being stored therein. Also, the underneath structure include air cleaner that is blocked when items are stored in these areas, resulting in decrease in vehicle performance, which is undesirable.
[005] Additionally, in recent past the saddle-type vehicles are used as multi-purpose vehicles for city-riding conditions and/or for long ride or cruise-ride conditions. As such, the frame structure is required to be modular in order to cater to riding conditions of the vehicle. For instance, in the city-riding conditions, the frame structure is required to include additional storage space for securely store the aforesaid items. On the other hand, the frame structure is required to include additional load carrying features for cruise-ride conditions. Most often, manufacturers tend to come up with two different types of frame structures to meet the requirements of the aforesaid riding conditions. Thus, the modularity of accommodating both the riding conditions is non-existent in the conventional vehicles.
[006] In view of the above, there is a need for a pillion frame structure for the vehicle, which addresses one or more limitations stated above.

SUMMARY OF THE INVENTION
[007] In one aspect, a pillion frame structure for a vehicle is disclosed. The structure includes a front member oriented vertically to a front-rear direction of the vehicle and adapted to be detachably mounted onto seat rails of a frame member. Side members are oriented vertically to the front-rear direction of the vehicle and extend from ends of the front member up to a rear member. A base member is mounted onto bottom surfaces of the front member, the side members and the rear member, wherein the base member along with front member, the side members and the rear member define a storage area to form a utility compartment.
[008] In an embodiment, one or more extension portions are defined on a front surface of the front member. The one or more extension portions upon engagement with the seat rails are adapted to transfer load acting on the pillion frame structure to the frame member. Also, each of the one or more extension portions includes a mounting portion adapted to engage with the seat rails and one or more side skirts extending from either side of the mounting portion. The side skirts are adapted to be secured to a bridge member of the frame member, wherein each side skirt is defined with a downward extending flange adapted to abut a rear end of the bridge member for facilitating load transfer to the frame member.
[009] In an embodiment, top surfaces of the front member, the side members and the rear member are adapted to receive a seat of the vehicle.
[010] In an embodiment, a pillion handle surrounds the side members and the rear member of the utility compartment. The pillion handle is defined with mounting provisions on its front portion for engagement with the bridge member.
[011] In an embodiment, the rear member is adapted to engage with a rear portion of the pillion handle.
[012] In an embodiment, the side members are adapted to support a luggage carrier.
[013] In an embodiment, each of the front member, the side members and the rear member is made by co-molding of cast steel and polypropylene materials.
[014] In another aspect, a frame structure for a saddle-type vehicle is disclosed. The frame structure includes seat rails extending from a head pipe. A pillion frame structure is detachably mounted on the seat rails. The structure includes the front member oriented vertically to a front-rear direction of the vehicle and adapted to be detachably mounted onto the seat rails. The side members are oriented vertically to the front-rear direction of the vehicle and extending from ends of the front member up to the rear member. The base member is mounted onto bottom surfaces of the front member, the side members and the rear member. The base member along with front member, the side members and the rear member define the storage area to form the utility compartment.
[015] In another aspect, a saddle-type vehicle is disclosed. The vehicle includes the frame structure having seat rails extending from a head pipe. The pillion frame structure is detachably mounted on the seat rails. The structure includes the front member oriented vertically to a front-rear direction of the vehicle and adapted to be detachably mounted onto the seat rails. The side members are oriented vertically to the front-rear direction of the vehicle and extending from ends of the front member up to the rear member. The base member is mounted onto bottom surfaces of the front member, the side members and the rear member. The base member along with front member, the side members and the rear member define the storage area to form the utility compartment.

BRIEF DESCRIPTION OF THE DRAWINGS
[016] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 is a schematic view of a saddle-type vehicle, in accordance with an exemplary embodiment of the present invention.
Figure 2 is a perspective view of a frame structure of the vehicle, in accordance with an exemplary embodiment of the present invention.
Figure 3 is a schematic view of the frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 4 is a perspective view of a pillion frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 5a is an enlarged sectional view of frame structure about the plane A-A’, in accordance with an exemplary embodiment of the present invention.
Figure 5b is a sectional view of frame structure about the plane A-A’, indicating the pillion frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 6a is a side view of the pillion frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 6b is a top view of the pillion frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 6c is a bottom view of the pillion frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 7 is a perspective view of the frame structure including a luggage carrier on the pillion frame structure, in accordance with an exemplary embodiment of the present invention.
Figure 8 is an exploded view of the pillion frame structure including the luggage carrier, in accordance with an exemplary embodiment of the present invention.
Figure 9 is an exploded view of the luggage carrier mounted on a pillion handle, in accordance with an exemplary embodiment of the present invention.
Figure 10 is a perspective view of the frame structure including the luggage carrier, in accordance with an exemplary embodiment of the present invention.
Figure 11 is a perspective view of the pillion frame structure including items stored therein, in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[017] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[018] Figure 1 illustrates a schematic view of a saddle-type vehicle 200, in accordance with an embodiment of the present invention. As an example, the saddle-type vehicle 200 is a two-wheeled vehicle. The saddle-type vehicle 200 comprises a prime mover 212 that is adapted to provide motive force for movement of the vehicle 200. In an embodiment, the prime mover 212 is an internal combustion engine, which is preferably a single-cylinder engine. The vehicle 200 comprises a front wheel 214, a rear wheel 216, a frame member 204 (shown in Figure 2), a seat 208 and a fuel tank 218. The frame member includes a head pipe 210, a main tube 238, a down tube 240, and seat rails 202 (shown in Figure 2). The head pipe 210 supports a steering shaft (not shown) and a suspension assembly 220 attached to the steering shaft through a lower bracket (not shown). The suspension assembly 220 supports the front wheel 214, and is adapted to dampen the vibrations generated during vehicle movement.
[019] Further, the upper portion of the front wheel 214 is covered by a front fender 222 mounted to the lower portion of front suspension assembly 220 at the end of the steering shaft. A handlebar 224 is fixed to upper bracket (not shown) and can rotate about the steering shaft for turning the vehicle. A headlight 226, a visor guard (not shown) and instrument cluster 228 is arranged on an upper portion of the head pipe 210. The frame member 204 comprises a down tube (not shown) that may be positioned in front of the prime mover 212 and extends slantingly downward from head pipe 210. The main tube of the frame member 202 is located above the prime mover 212 and extends rearward from head pipe 210.
[020] The fuel tank 218 is mounted on the main tube. Seat rails 202 are joined to main tube (238) and extend rearward to support the seat 208. In the present embodiment, the seat 208 is a split-type seat, including a front seat 208a and a rear seat 208b. A rear swing arm (not shown) is connected to the frame member 204 to swing vertically, and the rear wheel 216 is connected to rear end of the rear swing arm. Generally, the rear swing arm is supported by a mono rear suspension 230 (as illustrated in the present embodiment) or through two suspensions on either side of the vehicle 200. A taillight unit 232 is disposed at the end of the vehicle 200 and at the rear of the seat 208. A pillion handle 118 is also provided to the seat rails 202. The rear wheel 216 arranged below the seat 208 rotates by the motive force of the prime mover 212 transmitted through a chain drive (not shown).
[021] Further, a rear fender 234 is disposed above the rear wheel 216. An exhaust pipe 236 of the vehicle 200 extends vertically downward from the prime mover 212 and then extends below the prime mover 212, longitudinally along length of the vehicle 200 before terminating in a muffler (not shown). The muffler is typically disposed adjoining the rear wheel 216.
[022] Additionally, the frame structure 204 includes a pillion frame structure 100 provided at its rear portion (as shown in Figures 2 and 3). The aspects pertaining to the pillion frame structure 100 are described in description with reference to Figures 4-11.
[023] Figure 4 illustrates a perspective view of the pillion frame structure 100 in accordance with an exemplary embodiment of the present disclosure. The pillion frame structure 100 is detachably mounted onto the rear portion of the frame structure 204 (as shown in Figures 2 and 3).
[024] The pillion frame structure 100 includes a front member 102 oriented vertically to a front-rear direction of the vehicle 200 and adapted to be detachably mounted onto seat rails 202. The front member 102 includes one or more extension portions 114 defined on its front surface 102c for mounting onto the seat rails 202. The one or more extension portions 114 upon engagement with the seat rails 202 are adapted to transfer load acting on the pillion frame structure 100 to the frame member 204.
[025] In the present embodiment, the seal rails 202 include two rail members and accordingly two extension portions 114 are defined on the front surface 102c for engagement. As such, the number of extension portions 114 provided on the front member 102 correspond to the structural configuration of the seat rails 202. In an embodiment, the extension portion 114 is configured with a profile that ensures secure engagement with the seat rails 202. In another embodiment, the extension portion 114 is engaged with the seat rails 202 via conventional mounting techniques such as fastening, clamping, bayonet connection and the like as per design feasibility and requirement.
[026] Further, each of the extension portions 114 includes a mounting portion 114a (for e.g. as shown in Figure 5a) which engages with the seat rails 202. As such, the configuration and dimensions of the mounting portion 114a conform to the configuration of the seat rails 202, for ensuring engagement therebetween. To the sides of the mounting portion 114a one or more side skirts 114b extend. The skirts 114b extend beyond the seat rails 202 and are adapted to engage with a bridge member 206 which supports the seat rails 202 as well as a diagonal tube 242. The skirt 114b is adapted to extend upto a dimension required for engagement with the bridge member 206. Thus, the skirt 114b surrounds (for e.g. as shown in Figures 5a and 5b) the seat rails 202 and is thereafter engaged with the bridge member 206, thereby ensuring secure engagement and transfer of load to the frame member 204. In an embodiment, conventional mounting techniques such as fastening, clamping and the like are employed for engaging the skirt 114b with the bridge member 206.
[027] In the present embodiment, the seat rails 202 include two rails and two diagonal tubes 242 are provided in the frame member 204. As such, two bridge members 206 are provided for each rail and the diagonal tube 242. Therefore, for ease of readability and understanding of the invention, a single reference is made to the bridge member 206 in the description.
[028] Further, each skirt 114b is provided with a downward extending flange 114c, which is adapted to abut a rear end of the bridge member 206. The abutment between the downward extending flange 114c as well as the bridge member 206 further ensures load transfer therebetween. As such, the flange 114c acts as a reinforcement member for engagement between the front member 102 and the seat rails 202.
[029] Further, as shown in Figure 4, side members 104a, 104b extend from ends 102a, 102b of the front member 102. The side members 104a, 104b are oriented vertically to the front-rear direction of the vehicle 200 and extend up to a rear member 106 from the front member 102. The construction of the front member 102, the side members 104a, 104b and the rear member 106 form an enclosed structure. In an embodiment, the side members 104a, 104b extend horizontally from the front member 102. In another embodiment, the side members 104a, 104b extend at an angle (for e.g. as shown in Figure 6a) from the front member 102 to define an inclination to the pillion frame structure 100 from the plane of the seat rails 202. As such, the extension of the side members 104a, 104b from the front member 102 is selected as per configurational requirement of the pillion frame structure 100.
[030] A base member 108 (for e.g. as shown in Figure 6c) is mounted onto bottom surfaces 110 of the front member 102, the side members 104a, 104b and the rear member 106. As such, the base member 108 covers the formed enclosure from the bottom surfaces 110. The base member 108 along with front member 102, the side members 104a, 104b and the rear member 106 define a storage area to form a utility compartment 112. The utility compartment 112 is configured with sufficient storage area to enable storing items 128 such as bottles, wallet (for e.g. as shown in Figure 11) and the like of a rider. Thus, the pillion frame structure 100 provides a storage area, while also ensuring structural rigidity to support load thereon.
[031] Further, top surfaces of the front member 102, the side members 104a, 104b and the rear member 106 are covered by the seat 208, thereby securely storing the contents within the utility compartment 112. The seat 212 includes a latch (not depicted in Figures) which is operable to dismount the seat 208 from the frame member 204, for accessing the utility compartment 112. In an embodiment, the seat 208 including the front seat 208a and the pillion seat 208b, the pillion seat 208b is mounted onto the top surfaces of the front member 102, the side members 104a, 104b and the rear member 106 for enclosing the utility compartment 112. In this embodiment, the latch (not shown) is provided to the pillion seat 208, so that the pillion seat 208 is dismountable for accessing contents in the utility compartment 112. In an embodiment, for mounting the seat on the top surfaces of the side members 104a, 104b include a mounting portion 124 (shown in Figure 6b). On the mounting portion 124, the seat 208 or seat 208b securely engage by conventional techniques such as clamping, bayonet connection and the like, as per design feasibility and requirement. In another embodiment, the seat 208 or the seat 208b is mounted directly onto the side members 104a, 104b, without the requirement of the mounting portion 124.
[032] In an embodiment, the vertical extensions of the front member 102, the side members 104a, 104b and the rear member 106 are identical to the vertical extension of the front member 102. Thus, ensure uniform thickness of the utility compartment 112. Alternatively, the vertical extensions of the front member 102, the side members 104a, 104b and the rear member 106 are selected as per design feasibility and requirement.
[001] In an embodiment, each of the front member 102, the side members 104, the rear member 106 and the base member 108 is a plate-like member made of metallic material. In another embodiment, each of the front member 102, the side members 104, the rear member 106 and the base member 108 is made of non-metallic material. In yet another embodiment, each of the front member 102, the side members 104, the rear member 106 and the base member 108 is made of steel material or polypropylene material or a combination thereof for reducing the weight of the vehicle 200.
[002] In an embodiment, each of the front member 102, the side members 104, the rear member 106 and the base member 108 are configured with thickness based on the structural strength required for the utility compartment 112 to store contents therein and/or for supporting the load acting on the pillion frame structure 100.
[003] Further, the pillion frame structure 100 includes the pillion handle 118 that surrounds the side members 104, the rear member 106 and the base member 108. The pillion handle 118 is provided with mounting provisions 120 on either ends of its front portion 118a for mounting onto the bridge member 206. The pillion handle 118 also acts as a support structure for the utility compartment 112, and thus enables load transfer to the bridge member 206 as well. The pillion handle 118 extends at an angle identical to the side surfaces 104a, 104b for conforming to the configuration of the pillion frame structure 100.
[004] In an embodiment, the rear member 106 abuts or is mounted onto the rear portion 118b, by conventionally known techniques. In another embodiment, the side surfaces 104a, 104b and the rear member 106 includes a rim surface 124, which abuts the pillion handle 118. Such a construction of the rim surface 124 facilitates load transfer to the pillion handle 118, and thereafter to the frame member 204 via the bridge member 206.
[005] In an embodiment, the pillion frame structure 100 including the pillion handle 118, is also configured to support rear fender 234 and the tail lamp 232, as per design feasibility and requirement.
[006] Referring to Figures 7 and 8, the side surfaces 104a, 104b of the pillion frame structure 100 are also capable of receiving a luggage carrier 122, so that luggage or load can be added onto the vehicle 200. The luggage carrier 122 is mounted by conventional mounting techniques onto the side surfaces 104a, 104. Alternatively, ends of the luggage carrier 122 is supported onto the rim surface 124 of the utility compartment 112. In an embodiment, the dimensions of the luggage carrier 122 is selected as per design feasibility and requirement. In the present embodiment, the luggage carrier 122 is defined with a length less than that of the side surfaces 104a, 104b, and thus only covers a portion of the side surfaces 104a, 104b.
[007] In the present embodiment, the seat 208 or seat 208b is removed for enabling mounting of the luggage carrier 122. Such a configuration of the pillion frame structure 100 provides a modular construction, which enables mounting of the luggage carrier 122, thereby enabling use of the vehicle 200 in city driving conditions, as well as in cruise-ride conditions.
[008] Advantageously, the present invention provides the pillion frame structure 100 which is detachably mounted onto the frame structure 204, enabling the rider to customize the vehicle 200 as per requirement. Further, the pillion frame structure 100 is configured with the utility compartment 112, which provides a larger storage area than the conventional vehicles, for storing items 128. Additionally, the pillion frame structure 100 is adapted to be receive the luggage carrier 122, enabling the vehicle 200 to support additional load, thereby enabling use of the vehicle 200 in city conditions or cruise-ride conditions.
[009] In an embodiment, as shown in Figures 9 and 10 the utility compartment 112 is replaced with the luggage carrier 122, wherein the luggage carrier 122 is mounted, by conventional mounting techniques, onto the pillion handle 118. In this embodiment, the pillion handle 118 acts as the pillion frame structure 100.
[010] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.