Gearbox apparatus

A gearbox apparatus, said apparatus comprising:

• a housing which includes:
• a first portion:
• a second portion disposed adjacent to said first portion;
• a first assembly including:
• said first portion which defines a first enclosure and a second enclosure;
• a first gearwheel rotatably disposed within said first enclosure about a first axis of rotation, said first gearwheel defining a plurality of gear teeth;
• a second gearwheel rotatably disposed within said second enclosure about a second axis of rotation such that said plurality of gear teeth intermesh with said second gearwheel;
• a second assembly selectively interchangeable with said first assembly, said second assembly including:
• said first portion;
• a further first gearwheel rotatably disposed within said first enclosure about said first axis of rotation, said first enclosure being of sufficient capacity to selectively accommodate either of said first and further first gearwheels, said further first gearwheel defining a further plurality of gear teeth, said further plurality of gear teeth being different in number from said plurality of gear teeth of said first gearwheel;
• said second gearwheel rotatably disposed within said second enclosure about a further second axis of rotation, said further second axis of rotation of said second gearwheel being spaced from said second axis of rotation of said second gearwheel such that said further plurality of gear teeth of said further first gearwheel intermesh with said second gearwheel;
• a third gearwheel rotatably disposed within said second portion of said housing for rotation about a third axis of rotation, said first, second, further second and third axes of rotation being disposed spaced and parallel relative to each other so that said third gearwheel intermeshes with said second gearwheel for generating a first gear ratio between said first and third gearwheels and when said first assembly is selectively replaced by said second assembly, a second gear ratio is generated between said further first gearwheel and said third gearwheel;
• and
• said first enclosure permitting a selective reception therein of said first gearwheel and said further first gearwheel.

A gearbox apparatus, said apparatus comprising:

• a housing which includes:
• a first portion:
• a second portion disposed adjacent to said first portion;
• a first assembly including:
• said first portion which defines a first enclosure and a second enclosure;
• a first gearwheel rotatably disposed within said first enclosure about a first axis of rotation, said first gearwheel defining a plurality of gear teeth;
• a second gearwheel rotatably disposed within said second enclosure about a second axis of rotation such that said plurality of gear teeth intermesh with said second gearwheel;
• a second assembly selectively interchangeable with said first assembly, said second assembly including:
• said first portion;
• a further first gearwheel rotatably disposed within said first enclosure about said first axis of rotation, said first enclosure being of sufficient capacity to selectively accommodate either of said first and further first gearwheels, said further first gearwheel defining a further plurality of gear teeth, said further plurality of gear teeth being different in number from said plurality of gear teeth of said first gearwheel;
• said second gearwheel rotatably disposed within said second enclosure about a further second axis of rotation, said further second axis of rotation of said second gearwheel being spaced from said second axis of rotation of said second gearwheel such that said further plurality of gear teeth of said further first gearwheel intermesh with said second gearwheel;
• a third gearwheel rotatably disposed within said second portion of said housing for rotation about a third axis of rotation, said first, second, further second and third axes of rotation being disposed spaced and parallel relative to each other so that said third gearwheel intermeshes with said second gearwheel for generating a first gear ratio between said first and third gearwheels and when said first assembly is selectively replaced by said second assembly, a second gear ratio is generated between said further first gearwheel and said third gearwheel;
• said housing being fabricated from metal;
• said first portion being a casting;
• said second portion together with said first portion being a one piece casting;
• said first enclosure permitting a selective reception therein of said first gearwheel and said further first gearwheel;
• said second gearwheel including:
• a support pin having a first and a second end, said pin registering with a first hole defined by said first portion of said housing when said pin is disposed in a first location in which the gearbox is in a first mode of operation for generating said first gear ratio;
• a bearing disposed concentrically about said pin;
• a gear defining a cylindrical cavity for the reception therein of said bearing such that said gear is bearingly supported by said pin for rotation of said gear about said second axis of rotation within said second enclosure;
• said pin registering with a second hole defined by said first portion of said housing when the gearbox is in a second mode of operation for generating said second gear ratio, such that said gear is bearingly supported by said pin for rotation thereof about said further second axis of rotation within said second enclosure, said second hole being spaced from said first hole such that said second axis of rotation is disposed at a first radial distance from said first axis of rotation so that said plurality of gear teeth intermesh with said gear of said second gearwheel when in said first mode of operation and such that said further second axis of rotation is disposed at a second radial distance from said first axis of rotation so that said further plurality of gear teeth intermesh with said gear of said second gearwheel when in said second mode of operation;
• said pin being of cylindrical configuration;
• said first hole being of cylindrical configuration for the removable reception therein of said first end of said pin;
• a further first hole defined by said first portion of said housing, said further first hole being aligned relative to said first hole for the removable reception therein of said second end of said pin such that in said first mode of operation of the gearbox apparatus, said gear is rotatably supported by said pin for rotation thereof about said second axis of rotation, said gear and said bearing being disposed between said first hole and said further first hole;
• said second hole being of cylindrical configuration for the removable reception therein of said first end of said pin;
• a further second hole defined by said first portion of said housing, said further second hole being aligned relative to said second hole for the removable reception therein of said second end of said pin such that in said second mode of operation of the gearbox, said gear is rotatably supported by said pin for rotation thereof about said further second axis of rotation, said gear and said bearing being disposed between said second hole and said further second hole;
• and
• said second axis of rotation and said further second axis of rotation being disposed at a same radial distance from said third axis of rotation such that said gear intermeshes with said third gearwheel when the gearbox is disposed in said first and second modes of operation.