Inflator and remote sensor with through bulkhead initiator

Safety apparatus for protecting the driver of a vehicle during a collision, said vehicle having a steering wheel and an elongated steering shaft on which said steering wheel is mounted, a portion at least of the outer surface of shaft being cylindrical, said apparatus comprising an inflatable air bag that is expandable from a first condition to a second condition in which said air bag is adapted to restrain movement of the driver during a collision, comprising,

• an inflator for inflating said inflatable air bag, said inflator being fixedly attached to said inflatable air bag and, mounted on said steering wheel for rotation therewith,
• sensor means for detecting the occurrence of a collision, said sensor means being fixedly mounted on the vehicle and operative under predetermined conditions of deceleration of the vehicle to produce a shock wave,
• first and second pyrotechnic transmission lines each of which has a first end and a second end for transmitting the sensor produced shock wave to said inflator for initiating operation thereof and thereby inflation of said air bag, the first end of said first transmission line being connected to said sensor and the first end of said second transmission line connected to said inflator,
• means for coupling the second ends of said first and second transmission lines to allow said inflator to turn with the steering wheel comprising a ring positioned in surrounding relationship with the shaft of said vehicle, said ring having an outer periphery and an inner cylindrical surface, said inner cylindrical surface mating with the outer cylindrical surface of said shaft, being in sliding relationship therewith, said ring having a radial plenum formed therein and having a hole formed therein that extends radially from the outer periphery thereof to said radial plenum,
• first means for fixedly connecting the second end of said first transmission line in the radial hole in said ring,
• the end of said shaft adjacent the steering wheel having a first hole and a second hole formed therein, said first hole extending from said end of said shaft internally of and axially along a substantial portion of the length thereof, said second hole extending radially of said shaft to the outer surface of said shaft from the inner end of said first hole and providing communication with said radial plenum formed in said ring,
• said second transmission line being positioned in said first hole in said shaft with the second end thereof positioned adjacent the second hole in said shaft and the first end thereof positioned adjacent said end of said shaft whereby said second transmission line is entirely enclosed within the first hole in said shaft and is protected from influences external of said shaft that may cause damage thereto, and
• second means for fixedly connecting the first end of said second transmission line to said inflator to ignite it responsively to a shock wave produced by the said sensor responsively to the onset of a collision.

An assembly for coupling an ignitive reaction to the inflator of a vehicle safety apparatus from a remotely located and relatively stationary sensor responsive to the onset of a collision, comprising:

• first and second transmission lines each comprising a hollow tube having a reactive substance coating the inner surface thereof, which coating is operative to support and propagate a gaseous percussion wave throughout the length of the tube,
• an elongated shaft having an end and an outer cylindrical surface over a portion at least of the length thereof and having a first hole and a second hole formed therein, the first hole having a first end and a second end and extending from the first end internally of and axially from the end of said shaft along a substantial portion of the length thereof, the second hole extending radially of said shaft from the second end of the first hole to the outer surface of said shaft, said second one of said transmission lines being positioned in the first hole of said shaft and extending from said end thereof for the full length of the first hole, whereby said second one of said transmission lines is entirely enclosed within the first hole,
• a ring positioned in surrounding relationship with said shaft, said ring having an outer periphery and an inner cylindrical surface, said inner cylindrical surface mating with the outer cylindrical surface of said shaft, being in a rotative sliding relationship therewith, said ring having a radial plenum formed therein and being positioned on said shaft such that said radial plenum is in communication with the radial hole in said shaft as said ring and shaft are rotated relatively to each other, said ring having a hole therein that extends radially from the outer periphery thereof to said radial plenum, and
• means for fixedly connecting and end of said first one of said transmission lines in the radial hole of said ring for communication with the radial plenum therein and thereby the radial hole in said shaft.