Rowing machine including a gear shift mechanism

Abstract

Rowing machines are described that permit a rower to adjust the rowing resistance using a gear shift mechanism. The rowing machine includes a handle connected to a chain, which passes, sequentially, over a derailleur and then to the gears of the gear cassette. The gear cassette is coupled to a resistance unit, which may be similar to resistance units used in off wheel bicycle trainers. This configuration of derailleur and gear cassette permit the rower to smoothly select a gear.

I claim: 
     
         1 . A rowing machine comprising:
 a resistance unit including a gear cassette comprising a plurality of gears coupled to a mechanism to resist the rotation of the gear cassette;   a frame adapted for placing on the ground and attached to the resistance unit;   a seat movable along the frame;   a handle;   a chain having a first end attached to the handle and a second end attached to the frame;   a derailleur attached to the frame; and   a gear shifter operably connected to the derailleur,   where the chain extends, sequentially, from the handle, through the derailleur, and engages a gear of the plurality of gears,   such that the engaged gear is selectable using the gear shifter.   
     
     
         2 . The rowing machine of  claim 1 , where the resistance unit is an off-wheel bicycle trainer resistance unit. 
     
     
         3 . The rowing machine of  claim 1 , where the mechanism to resist the rotation of the gears includes a one-way clutch connecting the mechanism to the gear cassette. 
     
     
         4 . The rowing machine of  claim 1 , where the mechanism to resist the rotation of the gears includes a flywheel. 
     
     
         5 . The rowing machine of  claim 1 , where the mechanism to resist the rotation of the gears includes an electromagnet. 
     
     
         6 . The rowing machine of  claim 1 , where the rowing machine includes a return mechanism disposed between the second end of the chain and the frame. 
     
     
         7 . The rowing machine of  claim 6 , where the return mechanism includes an elastic cord. 
     
     
         8 . A rowing machine attachment connectable to a resistance unit, where the resistance unit includes an axle and a gear cassette comprising a plurality of gears coupled to a mechanism to resist the rotation of the gear cassette, said rowing training attachment comprising:
 a frame adapted for placing on the ground and including a fork end adapted to accept the axle of the resistance unit;   a seat movable along the frame;   a handle;   a chain having a first end attached to the handle and a second end attached to the frame;   a derailleur attached to the frame; and   a gear shifter operably connected to the derailleur,   where, when the fork end of the frame is attached to the axle of the resistance unit and where the chain extends, sequentially, from the handle, through the derailleur, and engages a gear of the plurality of gears,   such that the engaged gear is selectable using the gear shifter.   
     
     
         9 . The rowing machine attachment of  claim 8 , where the resistance unit is an off-wheel bicycle trainer resistance unit. 
     
     
         10 . The rowing machine attachment of  claim 8 , where the mechanism to resist the rotation of the gears includes a one-way clutch connecting the mechanism to the gear cassette. 
     
     
         11 . The rowing machine attachment of  claim 8 , where the mechanism to resist the rotation of the gears includes a flywheel. 
     
     
         12 . The rowing machine attachment of  claim 8 , where the mechanism to resist the rotation of the gears includes an electromagnet. 
     
     
         13 . The rowing machine attachment of  claim 8 , where the rowing machine includes a return mechanism disposed between the second end of the chain and the frame. 
     
     
         14 . The rowing machine attachment of  claim 13 , where the return mechanism includes an elastic cord.