US 12,403,953 B2
Steering systems, steering and speed coordination systems, and associated vehicles
Axel Schaedler, Olmsted Falls, OH (US); Hans Hauser, Strongsville, OH (US); Rick Ruebusch, El Paso, TX (US); and Ian David Cornwell, Lancashire (GB)
Assigned to MTD PRODUCTS INC, Valley City, OH (US)
Filed by MTD Products Inc, Valley City, OH (US)
Filed on Sep. 21, 2020, as Appl. No. 17/027,584.
Application 13/081,482 is a division of application No. 11/490,881, filed on Jul. 21, 2006, granted, now 7,992,659, issued on Aug. 9, 2011.
Application 17/027,584 is a continuation of application No. 14/664,457, filed on Mar. 20, 2015, granted, now 10,780,917.
Application 14/664,457 is a continuation of application No. 13/081,482, filed on Apr. 6, 2011, granted, now 9,409,596, issued on Aug. 9, 2016.
Claims priority of provisional application 60/731,593, filed on Oct. 28, 2005.
Claims priority of provisional application 60/710,231, filed on Aug. 22, 2005.
Claims priority of provisional application 60/701,716, filed on Jul. 22, 2005.
Prior Publication US 2021/0146996 A1, May 20, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. B62D 7/09 (2006.01); B62D 3/02 (2006.01); B62D 7/08 (2006.01); B62D 9/00 (2006.01); B62D 11/00 (2006.01); B62D 11/24 (2006.01); B60W 10/10 (2012.01); B60W 10/20 (2006.01); B60W 30/045 (2012.01)
CPC B62D 7/09 (2013.01) [B62D 3/02 (2013.01); B62D 7/08 (2013.01); B62D 9/00 (2013.01); B62D 11/006 (2013.01); B62D 11/24 (2013.01); B60W 10/10 (2013.01); B60W 10/20 (2013.01); B60W 30/045 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A vehicle comprising:
a chassis;
a left front steerable, non-driving wheel coupled to the chassis and capable of turning more than 90 degrees left;
a right front steerable, non-driving wheel coupled to the chassis and capable of turning more than 90 degrees right;
left and right rear drivable wheels coupled to left and right hydrostatic drive units;
a steering wheel that can receive a steering input from an operator of the vehicle;
a steering assembly coupling the steering wheel to the left front and right front steerable, non-driving wheels such that they will follow substantially-true Ackermann steering in response to turning the steering wheel to cause a zero radius turn, the steering assembly including:
a first gear pair for turning the right front steerable, non-driving wheel, the first gear pair comprising:
a first wheel gear having a first wheel gear pivot axis and a first wheel gear pitch line that changes in distance from the first wheel gear pivot axis; and
a first steering gear engaged with the first wheel gear, the first steering gear having a first steering gear pivot axis and a first steering gear pitch line that changes in distance from the first steering gear pivot axis;
a second gear pair for turning the left front steerable, non-driving wheel, the second gear pair comprising:
a second wheel gear having a second wheel gear pivot axis and a second wheel gear pitch line that changes in distance from the second wheel gear pivot axis; and
a second steering gear engaged with the second wheel gear, the second steering gear having a second steering gear pivot axis and a second steering gear pitch line that changes in distance from the second steering gear pivot axis;
a speed pedal that can receive a speed input from an operator of the vehicle;
first and second speed cams oriented parallel to each other and coupled to the speed pedal, the first speed cam including a first curved slot and the second speed cam including a second curved slot, the first and second curved slots having the same shape, where movement of the speed pedal causes the first and second speed cams to rotate in the same direction and by the same amount about an axis extending through each of the first and second curved slots;
a first follower that rides in the first curved slot and that will move in response to steering wheel movement to a right-hand turn from a straight-ahead position; and
a second follower that rides in the second curved slot and that will move in response to steering wheel movement to a left-hand turn from a straight-ahead position;
where the left and right hydrostatic drive units are capable of driving the left and right rear drivable wheels at different speeds and in different directions; movement of the steering wheel without a speed input from the speed pedal does not cause rotation of the left and right rear drivable wheels; and the same one of the left and right rear drivable wheels will rotate faster than the other of the left and right rear drivable wheels in both forward and reverse for a turned position of the steering wheel.