Methods and apparatus for folding vehicle chassis
In exemplary implementations of this invention, a foldable vehicle has a foldable chassis. The wheelbase (and thus the overall footprint) of the vehicle can be reduced when parking, and can be extended when driving on the open road. In exemplary implementations the ability to shorten and lengthen the wheelbase is achieved by using two 4-bar linkages, activated by one or more linear actuators positioned in parallel. The dual 4-bar linkage and linear actuator(s) can provide: (i) the ability to maintain full maneuverability in the vehicle's folded and unfolded state; (ii) a fail-safe static system, and (iii) a rigid but transformable chassis.
1. Apparatus comprising a linkage system and one or more actuators, wherein:
(a) the linkage system is configured to bear and distribute a majority of the weight of a motorized vehicle, which vehicle includes or is operatively connected to wheels configured to roll over a surface external to the vehicle, which wheels include one or more front wheels and one or more back wheels;
(b) the linkage system comprises a first mechanical linkage and a second mechanical linkage;
(c) the first linkage is configured to distribute weight to at least one of the one or more front wheels;
(d) the second linkage is configured to distribute weight to at least one of the one more rear wheels;
(e) the first linkage is operatively connected to the second linkage;
(f) the first and second linkages each, respectively, comprise a planar linkage; and
(g) each of the one or more actuators, respectively, is attached to at least one point in the linkage system and is configured to actuate or to help actuate, directly or indirectly, at least the following motions
(i) changes in shape of the first linkage,
(ii) changes in shape of the second linkage, and
(iii) changes in the wheelbase of the vehicle, which changes in the wheelbase include, at some times, a lengthening motion that substantially increases the wheelbase and, at other times, a shortening motion that substantially reduces the wheelbase;
(h) a first link is included in the first linkage;
(i) a second link is included in the second linkage; and
(j) the first and second links are mirror symmetric with respect to each other.
2. Apparatus comprising a linkage system and one or more actuators, wherein:
(a) the linkage system is configured to bear and distribute a majority of the weight of a motorized vehicle, which vehicle includes or is operatively connected to wheels configured to roll over a surface external to the vehicle, which wheels include one or more front wheels and one or more back wheels;
(b) the linkage system comprises a first mechanical linkage and a second mechanical linkage;
(c) the first linkage is configured to distribute weight to at least one of the one or more front wheels;
(d) the second linkage is configured to distribute weight to at least one of the one more rear wheels;
(e) the first linkage is operatively connected to the second linkage;
(f) a first link is included in the first linkage;
(g) a second link is included in the second linkage;
(h) the first and second links are mirror symmetric with respect to each other; and
(i) each of the one or more actuators, respectively, is attached to at least one point in the linkage system and is configured to actuate or to help actuate, directly or indirectly, at least the following motions
(1) changes in shape of the first linkage,
(2) changes in shape of the second linkage, and
(3) changes in the wheelbase of the vehicle, which changes in the wheelbase include, at some times, a lengthening motion that substantially increases the wheelbase and, at other times, a shortening motion that substantially reduces the wheelbase.
3. The apparatus of claim 2 , wherein the apparatus further comprises the vehicle.
4. The apparatus of claim 3 , wherein:
(a) the apparatus further comprises a set of wheels, which set consists of the one or more front wheels and the one or more back wheels; and
(b) at least one wheel out of the set of wheels is configured for in-wheel steering.
5. The apparatus of claim 2 , wherein the first and second linkages each, respectively, comprise a four-bar linkage.