Helicopter landing securing device

Claim 1

A trap device suitable for rapidly securing a probe once that probe is properly positioned relative to the trap device, the trap device comprising: a. a housing; b. an opening in the housing suitable for the reception of the probe; c. a first arresting beam extending across the opening; d. a second arresting beam extending across the opening parallel to the first arresting beam; e. firing means mechanically connected to the two arresting beams and arranged when operated to move the two arresting beams towards one another across the opening to engage and trap the probe when positioned in the opening; f. catch means arranged to lock the two arresting beams together in the engaged position; g. stop means arranged to hold the two arresting beams in the engaged position against movement across the opening; h. a stop, forming part of the stop means, disposed between the two beams and movable by the beams as the beams travel towards one another to engage a probe lying anywhere in the opening; i. a flexible connector such as a cable or chain extending transversely of the two arresting beams; j. a first pulley or chain sprocket; k. a second pulley or chain sprocket spaced apart from the first pulley or chain sprocket, the flexible connector being wrapped around the two spaced-apart pulleys or chain sprockets; l. the stop being connected to the flexible connector; m. readily releasable holding means arranged when activated to hold the stop against further movement, and thus to hold the arresting beams and the trapped probe against further movement; n. the readily releasable holding means being arranged to act on at least one of those pulleys or sprockets to hold the cable or chain and thus the stop and beams against displacement; o. a first rotatable member forming part of readily releasable holding means and provided with a first circular set of teeth; p. a second member forming part of the readily releasable holding means, held against rotation with the first member, and formed with a second circular set of teeth complementary with the first set of teeth; and q. hydraulic piston means arranged to control the engagement and the disengagement of the first set of teeth with the second set of teeth; whereby the second set of teeth can be made effective to anchor the rotatable member, the cable or chain, the stop and thE two beams.