Method and apparatus for a minimally aggressive vehicle stopping system

A vehicle stopping system including a vehicle capture net disposed between a pair of towers, each tower including a stanchion comprising:

• a shaft;
• a pair of spaced apart spools coupled to the shaft;
• a corresponding pair of straps having one end coupled to one of the pair of spools and the other end coupled to one side of the net, each strap being wound on one of the spools;
• braking means coupled to the shaft and operatively connected to the spools for providing a restraining force of increasing magnitude on the straps as the straps are unwound from the spools, where the braking means comprises a mechanical brake providing a braking force proportional to the degree of compression of the mechanical brake, having two braking surfaces in frictional relationship with each other and where the degree of compression is the magnitude of displacement of one braking surface relative to the other braking surface;
• and
• means for rewinding the straps onto the spools, where the spools are rotationally fixed to the shaft, where the means for rewinding the straps onto the spools comprises a single electric motor and clutch assembly coupled to the shaft, and where the braking means includes a threaded rod directly coupled to the motor and clutch assembly, the rod being coupled to the shaft by a block and axial slot combination which permits a degree of axial movement of the block, so that when the rod is selectively held rotationally fixed by the motor and clutch assembly, unwinding of the spools rotates the shaft and axially activates the braking means.

A method of stopping a vehicle comprising:

• deploying a vehicle capture net having each of its opposing sides connected to a pair of straps each of which is wound on a corresponding spool;
• permitting the vehicle to collide with the capture net and to unwind the straps from corresponding spools;
• and
• providing a restraining force on the spools of increasing magnitude as the straps are unwound from the spools
• where providing a restraining force of increasing magnitude on the straps as the straps are unwound from the spools comprises providing mechanical friction braking to generate restraining force in which the brake pressure is proportional to the length of the straps unwound from the spools,
• where providing mechanical friction braking to generate restraining force in which the brake pressure is proportional to the length of the straps unwound from the spools comprises generating an axial displacement of two friction disk brake surfaces toward each other as a function of the length of the straps unwound from the spools.

A method of stopping a vehicle comprising:

• deploying a vehicle capture net having each of its opposing sides connected to a pair of straps each of which is wound on a corresponding spool;
• permitting the vehicle to collide with the capture net and to unwind the straps from corresponding spools;
• and
• providing a restraining force on the straps of increasing magnitude as the straps are unwound from the spools by providing mechanical friction braking to generate the restraining force in which the brake pressure is proportional to the length of the straps unwound from the spools by in turn generating an axial displacement of two friction disk brake surfaces toward each other as a function of the length of the straps unwound from the spools;
• and
• where generating an axial displacement of two friction disk brake surfaces toward each other as a function of the length of the straps unwound from the spools comprises axially advancing at least one of the spools on a threaded portion of a shaft wherein at least one of the two friction disk brake surfaces is coupled to the spool.

A vehicle stopping system including a vehicle capture net disposed between a pair of towers, each tower including a stanchion comprising:

• a shaft;
• a pair of spaced apart spools coupled to the shaft;
• a corresponding pair of straps having one end coupled to one of the pair of spools and the other end coupled to one side of the net, each strap being wound on one of the spools;
• and
• braking means coupled to the shaft and operatively connected to the spools for generating a restraining force applied to the spools of increasing magnitude at a substantially uniform rate to the spools throughout substantially the entire unwinding range as the straps are unwound from the spools.

A vehicle stopping system including a vehicle capture net disposed between a pair of towers for restraining a vehicle, each tower including a stanchion comprising:

• a shaft;
• a pair of spaced apart spools coupled to the shaft;
• a corresponding pair of straps having one end coupled to one of the pair of spools and the other end coupled to one side of the net, each strap being wound on one of the spools;
• and
• braking means coupled to the shaft and operatively connected to the spools for providing a restraining force of increasing magnitude on the straps as the straps are unwound from the spools, where the braking means comprises a mechanical brake providing a braking force proportional to the degree of compression of the mechanical brake, having two braking surfaces in frictional relationship with each other and where the degree of compression is the magnitude of displacement of one braking surface relative to the other braking surface,
• where the magnitude of displacement of one braking surface relative to the other braking surface comprises the screw advance of the spools on the shaft toward the brake as caused by the unwinding of the straps from the spools
• where the shaft and spools are provided with and engaged with each other by a threaded screw having a thread design capable of sustaining a side loading force applied to the screw and arising from the capture of the vehicle in the capture net the without causing the screw to bind or gall.