Devices using a dolly for reinforcing the loading capacity of tractor vehicles

Claim 1

A device for reinforcing a loading capacity of a tractor vehicle for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle having tractor steering wheels and having a longitudinal axis, said dolly freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, (b) dolly steering wheels secured to said dolly, (c) detecting means associated with said tractor steering wheels for detecting an amount of steering movement of said tractor steering wheels, (d) control means associated with the dolly steering wheels to control a steering movement thereof, and (e) means connecting said detecting means and said control means to automatically provide, for any variation of a steering position of the tractor steering wheels, a variation of a steering position of the dolly steering wheels such that the longitudinal axis of the dolly is subtantially in alignment with the longitudinal axis of the tractor vehicle in straight line travel as well as in curved travel and in forward travel as well as in rearward travel.

Claim 2

A device for reinforcing a loading capacity of a tractor vehicle for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle having tractor steering wheels and having a longitudinal axis, said dolly freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, (b) dolly steering wheels secured to said dolly, (c) detecting means associated with said tractor steering wheels for detecting an amount of steering movement of said tractor steering wheels, (d) control means associated with the dolly steering wheels to control a steering movement thereof, and (e) means connecting said detecting means and said control means to automatically provide, for any variation of a steering position of the tractor steering wheels, a variation of a steering position of the dolly steering wheels such that the longitudinal axis of the dolly is subtantially in alignment with the longitudinal axis of the tractor vehicle in straight line travel as well as in curved travel and in forward travel as well as in rearward travel.

Claim 3

A device for reinforcing a loading capacity of a tractor vehicle for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle having tractor steering wheels and having a longitudinal axis, said dolly freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, (b) dolly steering wheels secured to said dolly, (c) detecting means associated with said tractor steering wheels for detecting an amount of steering movement of said tractor steering wheels, (d) control means associated with the dolly steering wheels to control a steering movement thereof, and (e) means connecting said detecting means and said control means to automatically provide, for any variation of a steering position of the tractor steering wheels, a variation of a steering position of the dolly steering wheels such that the longitudinal axis of the dolly is substantially in alignment of the longitudinal axis of the tractor vehicle in a straight line as well as in a curve and in forward travel as well as in rearward travel, wherein said detecting means comprises a pilot stage which comprises a pilot link freely rotating on a shaft mounted for rotation on a chassis of the dolly and driven in rotation from a transmission connected to a lever of a steering gear of the tractor steering wheels, said pilot link having one end in the form of a fork cooperating with control pushers of an hydraulic valve connected to two chambers of a double-acting actuator, said valve being carried by a power link fixed on said shaft and to which one end of a piston rod of said actuator is coupled, a double link being also fixed on said shaft and being connected at its ends to bars controlling orientation of the dolly steering wheels so that any movement of the pilot link controlled by a steering of the tractor steering wheels causes a parallel movement of the power link.

Claim 4

A device for reinforcing a loading capacity of a tractor vehicle for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle having tractor steering wheels and having a longitudinal axis, said dolly freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, (b) dolly steering wheels secured to said dolly, (c) detecting means associated with said tractor steering wheels for detecting an amount of steering movement of said tractor steering wheels, (d) control means associated with the dolly steering wheels to control a steering movement thereof, and (e) means connecting said detecting means and said control means to automatically provide, for any variation of a steering position of the tractor steering wheels, a variation of a steering position of the dolly steering wheels such that the longitudinal axis of the dolly is substantially in alignment of the longitudinal axis of the tractor vehicle in a straight line as well as in a curve and in forward travel as well as in rearward travel, wherein said detecting means comprises a pilot stage which comprises a pilot link freely rotating on a shaft mounted for rotation on a chassis of the dolly and driven in rotation from a transmission connected to a lever of a steering gear of the tractor steering wheels, said pilot link having one end in the form of a fork cooperating with control pushers of an hydraulic valve connected to two chambers of a double-acting actuator, said valve being carried by a power link fixed on said shaft and to which one end of a piston rod of said actuator is coupled, a double link being also fixed on said shaft and being connected at its ends to bars controlling orientation of the dolly steering wheels so that any movement of the pilot link controlled by a steering of the tractor steering wheels causes a parallel movement of the power link.

Claim 6

A device for reinforcing a loading capacity of a tractor vehicle for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle having tractor steering wheels and having a longitudinal axis, said dolly freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, (b) dolly steering wheels secured to said dolly, (c) detecting means associated with said tractor steering wheels for detecting an amount of steering movement of said tractor steering wheels, (d) control means associated with the dolly steering wheels to control a steering movement thereof, and (e) means connecting said detecting means and said control means to automatically provide, for any variation of a steering position of the tractor steering wheels, a variation of a steering position of the dolly steering wheels such that the longitudinal axis of the dolly is substantially in alignment of the longitudinal axis of the tractor vehicle in a straight line as well as in a curve and in forward travel as well as in rearward travel, wherein said detecting means comprises a pilot stage which comprises an electric operator device connected on the one hand to a potentiometer connected to a steering control of the tractor steering wheels and on the other hand to a potentiometer connected to a power link fixed on a shaft which is fast with a double link connected to bars controlling an orientation of the dolly steering wheels, said operator device receiving electric modulated signals which are images of a degree of orientation of the tractor steering wheels and of the dolly steering wheels and being connected to a servo-valve for delivering thereto a corrective signal controlling supply to a double acting hydraulic actuator acting on the power link for correcting an orientation of the dolly steering wheels as a function of an orientation of the tractor steering wheels.

Claim 7

A device for reinforcing a loading capacity of a tractor vehicle for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle having tractor steering wheels and having a longitudinal axis, said dolly freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, (b) dolly steering wheels secured to said dolly, (c) detecting means associated with said tractor steering wheels for detecting an amount of steering movement of said tractor steering wheels, (d) control means associated with the dolly steering wheels to control a steering movement thereof, and (e) means connecting said detecting means and said control means to automatically provide, for any variation of a steering position of the tractor steering wheels, a variation of a steering position of the dolly steering wheels such that the longitudinal axis of the dolly is substantially in alignment of the longitudinal axis of the tractor vehicle in a straight line as well as in a curve and in forward travel as well as in rearward travel, wherein said detecting means comprises a pilot stage which comprises an electric operator device connected on the one hand to a potentiometer connected to a steering control of the tractor steering wheels and on the other hand to a potentiometer connected to a power link fixed on a shaft which is fast with a double link connected to bars controlling an orientation of the dolly steering wheels, said operator device receiving electric modulated signals which are images of a degree of orientation of the tractor steering wheels and of the dolly steering wheels and being connected to a servo-valve for delivering thereto a corrective signal controlling supply to a double acting hydraulic actuator acting on the power link for correcting an orientation of the dolly steering wheels as a function of an orientation of the tractor steering wheels.

Claim 9

A device for reinforcing a loading capacity of a tractor vehicle having a tractor steering wheel for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, said tractor vehicle having a longitudinal axis, (b) dolly steering wheels having bars controlling a steering thereof, (c) means for automatically controlling the dolly steering wheels, which comprise: (d) a pivoting lever carried by the dolly and co-acting with a fixed coupling element of the tractor vehicle, (e) a double-acting actuator carried by a chassis element of the dolly and having a piston rod, (f) a rotating shaft, a power link fixed on said shaft and connected to a piston rod of said double-acting actuators, (g) a double link also fixed on said rotating shaft and connected to said bars, (h) an hydraulic valve carried by the dolly and selectively controlling supply of two chambers of the actuator, and (i) a linkage connecting said pivoting lever to a control slide of the hydraulic valve, (j) said means acting to maintain the longitudinal axis of the dolly substantially in alignment of the longitudinal axis of the tractor vehicle in a straight line as well as in a curve and in forward travel as well as in rearward travel.

Claim 10

A device for reinforcing a loading capacity of a tractor vehicle having a tractor steering wheel for receiving a transport semi-trailer for transporting heavy loads, which comprises: (a) an intermediate short semi-trailer called a dolly having a longitudinal axis and having a front part coupled to the tractor vehicle freely pivotable about a vertical axis and coupled to the transport semi-trailer in its turn for freely pivoting about a vertical axis, said tractor vehicle having a longitudinal axis, (b) dolly steering wheels having bars controlling a steering thereof, (c) means for automatically controlling the dolly steering wheels, which comprise: (d) a pivoting lever carried by the dolly and co-acting with a fixed coupling element of the tractor vehicle, (e) a double-acting actuator carried by a chassis element of the dolly and having a piston rod, (f) a rotating shaft, a power link fixed on said shaft and connected to a piston rod of said double-acting actuators, (g) a double link also fixed on said rotating shaft and connected to said bars, (h) an hydraulic valve carried by the dolly and selectively controlling supply of two chambers of the actuator, and (i) a linkage connecting said pivoting lever to a control slide of the hydraulic valve, (j) said means acting to maintain the longitudinal axis of the dolly substantially in alignment of the longitudinal axis of the tractor vehicle in a straight line as well as in a curve and in forward travel as well as in rearward travel.