Cowling latch system

A latch system for the nacelle of a gas turbine engine having a cowling which extends circumferentially about the nacelle from a first side of a support structure for the engine to a second side of the support structure, the cowling further including at least one door attached by a hinge joint along a portion of the door to the support structure for the engine, which comprises:

• a first cable;
• a coupling which is attached to the first cable and which extends between the cowling and the first side of the support structure for attaching the cowling to the support structure, the coupling being movable in response to a first level of tension in the cable to a locked position which attaches the cowling to the support structure and being movable in response to a second level of tension in the cable to an unlocked position which does not attach the coupling to the support structure;
• and
• a means spaced from the coupling for applying tension to the cable;
• wherein the latch system further includes a second cable which is attached to the second side of the support structure and attached to the means the applying tension to the cable, and wherein the first and second cables each extend about the interior of the cowling and slidably engage the cowling at circumferentially spaced intervals such that applying a tension to the cables causes the coupling to join the cowling to the support structure enabling the cables to exert a constricting force on the interior of the cowling.

A coupling for engaging a support, the coupling being movable between a locked and unlocked position which comprises:

• a pair of jaws which are rotatably attached to each other, each jaw being pivotable about an axis A, and
• a housing extending about the jaws which is movable with respect to the jaws to a first position such that the housing engages each jaw between one end of the jaw and the axis A to exert a rotational force on the jaws which urges the jaws together toward the locked position and movable with respect to the jaws to a second position such that the housing engages each jaw between the other end of the jaw and the axis A to exert a rotational force on the jaws which urges the jaws apart toward the unlocked position.
• a means for moving the jaws with respect to the housing which includes
• a pin extending between the jaws to pivotably attach one jaw to the other and
• a shaft which is attached to the pin and which is adapted to engage a cable having varying levels of tension therein and wherein a spring is trapped between the shaft and the housing to exert a force which opposes a force exerted by the cable such that a force above a certain level exerted by the cable on the shaft causes the cable to move the jaws to the first position and a force below a certain level exerted by the cable on the shaft causes the spring to overcome the force exerted by the cable and to move the jaws to the second position.

A coupling for attaching a tensioned cable to a support which is movable between locked and unlocked positions, the coupling comprising:

• a housing having a wall which extends circumferentially about a passage through the housing and which converges to form an opening which is smaller than the passageway;
• a first jaw and a second jaw which extend through the opening in the housing and into the passageway, each jaw having
• a first end having a hook which extends toward the hook of the other jaw and which is adapted to overlap the hook of the other jaw, and
• a second end having an ear which extends away from the ear of the other jaw;
• a pin extending between the jaws to pivotably attach the first jaw to the second jaw at a location which is between the ear and the hook of each jaw;
• a shaft in the passageway which is slidable with respect to the housing, the shaft having
• a first end which engages the pin,
• a second end which is adapted to engage the cable;
• and,
• a spring trapped between the shaft and the housing for exerting a force on the shaft in a direction which opposes the force exerted by the cable;
• wherein relative movement between the housing and the jaw causes the jaws to move to a first position with respect to the housing such that the wall of the housing engages each jaw between the pin and the hook to exert a rotational force on each jaw which urges the jaws together toward the locked position and wherein relative movement between the housing and the jaws causes the jaws to move to a second position with respect to the housing such that the wall of the housing engages each the ear of each jaw to exert a rotational force which urges the jaws toward the unlocked position.

A linkage system for providing tension to a first cable and a second cable which comprises:

• a support,
• a first bar having a first joint which adapts the bar to pivotably engage the first cable,
• a second bar having a second joint which adapts the bar to pivotably engage the second cable and which is pivotably attached to the first bar at a third joint, and,
• means for limiting pivotable movement of one of said bars about the third joint between the bar and the cable;
• wherein the second bar is bent toward a reference line R extending between the first and second joints such that the position of the third joint joining the two bars is translatable about the first two joints from a first position on one side of the reference line to a second position on the other side of the reference line to cause a tensile force in each cable which resists movement of the bars from the second position to the first position;
• and, wherein each bar is adapted to engage a pin on the associated cable, wherein a pair of brackets at each pin are attached to the support and are spaced apart by a distance less than the length of the pin, and wherein each of the brackets are adapted by a slot to slidably receive the associated pin.