Fall arrester and emergency retrieval apparatus and anchor apparatus therefor

A fall arrester and emergency retrieval apparatus comprising:

• a. speed sensitive drum means rotatable about a central axis of rotation in a first direction and a second direction, said drum means being biased in said second direction to prevent slack in associated line means, said drum means being adapted to gradually brakingly halt rotation in said first direction at a predetermined rotational speed and being adapted to lock in a non-rotating position subsequent to said braking so long as an externally applied torque in said first direction of rotation is applied to said drum means and being adapted to unlock and allow rotation when said externally applied torque in said first direction is removed;
• b. line means operably attached at a first end thereof to said drum means for being windingly retracted and unwindingly extended therefrom, said line means being operably attachable at a second end thereof to a worker's safety harness;
• c. housing means for rotatably mounting said drum means therein, said housing means being operably attachable to a fixed support structure;
• d. gear means selectively positionable in a first operating mode in disengaged relationship with said drum means and a second operating mode in engagement with said drum means for turning said drum means in said second drum means direction of rotation and for being turned by said drum means during rotation of said drum means in said first drum means direction of rotation;
• said gear means comprising a pinion gear operably mounted on said shaft means and a drum gear operably mounted on said drum means, said pinion gear being selectively positively engageable and disengageable with said drum gear;
• said pinion gear being rotatably fixed relative said shaft means and being axially movable along said shaft means between a first position in engaged relationship with said drum gear and a second position in disengaged relationship with said drum gear;
• said pinion gear being biased toward said first position in engaged relationship with said drum gear;
• said pinion gear being retainable in said second position by a radially displaceable detent plate;
• wherein stop means are provided for stopping the axial displacement of said pinion gear by said biasing means at said first position in engaging contact with said drum gear;
• said stop means comprising a radially extending flange portion of said drum means;
• e. shaft means, having a longitudinal shaft axis, operably associated with said gear means for turning and being turned by said gear means in a first shaft rotation direction associated with said first direction of rotation of said drum means and a second shaft rotation direction associated with said second direction of rotation of said drum means;
• said longitudinal axis of said shaft means being positioned in parallel alignment with said central axis of rotation of said drum means and wherein said shaft means is rotatably mounted in said housing means;
• said shaft means comprising an elongate shaft member having a first end and a second end, said shaft member being received through opposite openings in opposite first and second walls of said housing means said first end of said shaft members being received within a sleeve affixed to said second housing wall, said shaft member having an annular shaft bearing fixedly mounted thereon at a position proximate said second end and located axially outwardly of said first housing wall, said annular shaft bearing being rotatably supported within a bearing housing fixedly attached to said housing means whereby said shaft member is rotatable about said shaft axis and is radially and axially fixed relative said housing means;
• f. drive means operably associated with said shaft means for turning said shaft means in said second direction associated with said second direction of rotation of said drum means and for selectively tightening and loosening a clutch means;
• g. clutch means operably associated with said shaft means and said drive means for selectively causing rotational engagement and disengagement of said drive means with said shaft means wherein rotation of said drive means in said first direction causes adjustable clutching disengagement of said drive means and said shaft means allowing rotation of said shaft means in said first direction in response to a load on said line means, and wherein rotation of said shaft means in said first direction with said drive means in an immobilized position produces clutchingly engagement of said shaft means and said drive means whereby rotation of said shaft means is brakingly halted, and wherein initial rotation of said drive means in said second direction causes adjustable clutching engagement of said drive means and said shaft means and wherein rotation of said drive means in said second direction subsequent to said clutching engagement causes rotation of said shaft means in said shaft means second direction;
• wherein said clutch means comprises:
• said radially extending plate means being integrally formed with an axially extending sleeve adapted to threadingly accept a nut means thereabout;
• ratchet gear means, said ratchet gear means being engaged for clutching engagement with said plate means mounted in annular relationship with said shaft means at a position axially outward of said plate means in rotationally and axially displaceable relationship with said shaft means and said plate means, by pawl means for preventing rotation of said ratchet gear means in said first shaft direction of rotation;
• radially extending plate means for resisting an axial load, mounted in rotationally and axially fixed relationship with said shaft means in annular relationship therewith;
• wherein said pawl means comprises a first pawl and a second pawl adapted to engage said ratchet wheel in alternating sequence, each pawl being arcuately deflectable about an associated axis of rotation between a first inwardly positioned orientation in engagement with said ratchet gear means and a second outwardly deflected orientation in disengaged relationship with said ratchet gear means, each of said pawls being biased in said first inwardly oriented position in engagement with said ratchet gear means, said second pawl being operably associated with said detent means for actuating said gear means, said second pawl being mounted in rotatably fixed relationship on a second pawl shaft having a central shaft axis of rotation and said detent means being mounted in rotatably fixed relationship on said second pawl shaft, whereby an arcuate deflection of said second pawl about said second pawl shaft axis of rotation produces a simultaneous and corresponding arcuate deflection of said detent means, whereby said detent means is deflectable to actuate said gear means from said first operating mode to said second operating mode in engagement with said drum means by rotation of said drive means in said shaft second direction of rotation;
• axial load applying means for applying and removing a selectable axial load against said ratchet gear means for variably adjustably moving said ratchet gear means into and out of engagement with said plate means, said axial load applying means comprises threaded nut means for axial displacement relative said shaft means by screwing rotation of said nut means about said shaft means axis, said threaded nut means being operatively attached to said drive means and screwingly rotatable thereby;
• first clutch pad means positioned between said nut means and said ratchet gear means and second clutch pad means positioned between said ratchet gear means and said radially extending plate means for transmitting friction and absorbing shocks;
• h. whereby said fall arrester and retrieval apparatus is stablely mountable on said tripod means and is operational in a first state, wherein said gear means is disengaged from said drum means, for arresting the fall of a worker attached to said line means, and
• whereby said fall arrester and retrieval apparatus is operational in a second state, wherein said gear means is engaged with said drum means, for raising or lowering a worker to a selected position subsequent to a fall by rotation of said drive means in said second direction to wind in the line means to raise the worker and by rotation of said drive means in said second direction to remove the torque load on said cable drum to release the locking mechanism of said cable drum and to subsequently permit lowering of the worker by rotation of said drive means in said first direction to cause said clutch means to adjustably disengage said drive means and said shaft means to allow controlled descent of the worker by controlled rotation of said drum means in said first direction.

A method of retrieving a person suspended from a cable which is windingly attached to a fall arrester of the type having a clutch-brake cable drum of the type designed to freely rotate in a cable winding direction and designed to permit rotation in a cable unwinding direction up to a predetermined rotational speed in a first mode of operation;

• and designed to clutchingly halt the unwinding of the cable from the drum after said predetermined rotational speed is exceeded in a second mode of operation;
• and designed to be locked to prevent further rotation of the drum in the cable unwinding direction subsequent to said halting of cable unwinding, so long as an external cable unwinding load is applied to the cable, in a third mode of operation;
• and designed to return from said third mode of operation to said first mode of operation when said cable unwinding load is removed;
• the method comprising the steps of:
• a. positively engaging the cable drum with rotatable gears when the drum is in the locked condition of said third mode of operation;
• b. clutchingly engaging the rotatable gears by rotation of a rotatable drive designed to clutchingly engage the rotatable gears when rotated in a second direction and designed to clutchingly disengage the gears when rotated in a first direction;
• c. rotating the drive means in the second direction subsequent to engaging the gears to retractably wind the cable to raise the person attached thereto to a predetermined position and to return said clutch-brake cable drum to said first mode of operation.

A fall arrester and retrieval apparatus comprising:

• a. speed sensitive drum means rotatable about a central axis of rotation in a first direction associated with line means extension and a second direction associated with line means retraction, said drum means being biased in said second direction by a biasing torque to prevent slack in associated line means;
• said drum means being substantially free rotating in said second direction except for said biasing torque;
• and said drum means being substantially free rotating in said first direction except for said biasing torque, up to a predetermined speed in a drum means free-rotating state;
• said drum means being adapted to gradually brakingly halt rotation in said first direction at said predetermined rotational speed in a drum means braking state;
• and said drum means being adapted to lock in a non-rotating position subsequent to said braking so long as an externally applied torque in said first direction of rotation is applied to said drum means and so long as said externally applied torque does not exceed a predetermined override value in a drum means locking state;
• and said drum means being adapted to unlock and return to said free rotating state when said externally applied torque in said first direction is removed;
• b. line means operably attached at a first end thereof to said drum means for being windingly retracted and unwindingly extended therefrom, said line means being operably attachable at a second end thereof to a worker's safety harness;
• c. housing means for rotatably mounting said drum means therein, said housing means being operably attachable to an anchorage;
• d. gear means selectively positionable in a disengaged operating mode in disengaged relationship with said drum means and an engaged operating mode in engagement with said drum means for turning and being turned by said drum means when in said engaged operating mode;
• e. shaft means, having a longitudinal shaft axis, operably associated with said gear means for turning and being turned by said gear means during said engaged operating mode in a first shaft rotation direction associated with said first direction of rotation of said drum means associated with line means extension and a second shaft rotation direction associated with said second direction of rotation of said drum means associated with line means retraction;
• f. drive means operably associated with said shaft means for turning said shaft means and for selectively tightening and loosening a clutch means, said drive means being rotatable in a first drive means direction associated with line means extension and a second drive means direction associated with line means retraction;
• g. clutch means operably associated with said shaft means and said drive means for use during said gear means engaged operating mode for selectively causing rotational engagement and disengagement of said drive means with said shaft means wherein rotation of said drive means in said first drive means direction associated with line means extension causes adjustable clutching disengagement of said drive means and said shaft means allowing rotation of said shaft means in said first shaft means direction associated with line means extension in response to a load on said line means when said drum means is in said free rotating state, and wherein rotation of said drive means in said first drive means direction subsequent to engagement with a drive means stop cause overriding rotation of said drum means when said drum means is in said locked state and wherein rotation of said shaft means in said first shaft means direction with said drive means in an immobilized position produces clutching engagement of said shaft means and said drive means whereby rotation of said shaft means is brakingly halted, and wherein initial rotation of said drive means in said second drive means direction associated with line means retraction causes adjustable clutching engagement of said drive means and said shaft means and wherein rotation of said drive means in said second drive means direction subsequent to said clutching engagement causes rotation of said shaft means in said shaft means second direction associated with line means retraction;
• h. whereby said fall arrester and retrieval apparatus is operational in a fall arrester state associated with said gear means disengaged operating mode, for arresting the fall of a worker attached to said line means, and
• whereby said fall arrester and retrieval apparatus is operational in an emergency retrieval state associated with said gear means engaged operating mode, for raising or lowering a worker to a selected position subsequent to a fall by rotation of said drive means in said second drive means direction to retract the line means to raise the worker and by rotation of said drive means in said second drive means direction to remove the torque load on said drum means to release the locking mechanism of said drum means and to subsequently permit lowering of the worker by rotation of said drive means in said first drive means direction to cause said clutch means to adjustably disengage said drive means and said shaft means to allow controlled descent of the worker by controlled rotation of said drum means in said first drum means direction and by rotation of said drive means in said first drive means direction subsequent to engagement with a drive means stop to thereby override said drum means resistance to rotation in said locked state to cause lowering of a worker.

A cargo handling apparatus comprising:

• a. speed sensitive drum means rotatable about a central axis of rotation in a first direction associated with line means extension and a second direction associated with line means retraction, said drum means being biased in said second direction by a biasing torque to prevent slack in associated line means;
• said drum means being substantially free rotating in said second direction except for said biasing torque;
• and said drum means being substantially free rotating in said first direction except for said biasing torque, up to a predetermined speed in a drum means free-rotating state;
• said drum means being adapted to gradually brakingly halt rotation in said first direction at said predetermined rotational speed in a drum means braking state;
• and said drum means being adapted to lock in a non-rotating position subsequent to said braking so long as an externally applied torque in said first direction of rotation is applied to said drum means and so long as said externally applied torque does not exceed a predetermined override value in a drum means locking state;
• and said drum means being adapted to unlock and return to said free rotating state when said externally applied torque in said first direction is removed;
• b. line means operably attached at a first end thereof to said drum means for being windingly retracted and unwindingly extended therefrom, said line means being operably attachable at a second end thereof to a cargo payload;
• c. housing means for rotatably mounting said drum means therein, said housing means being operably attachable to an anchorage;
• d. gear means in engagement with said drum means for turning and being turned by said drum means when in said engaged operating mode;
• e. shaft means, having a longitudinal shaft axis, operably associated with said gear means for turning and being turned by said gear means in a first shaft rotation direction associated with said first direction of rotation of said drum means associated with line means extension and a second shaft rotation direction associated with said second direction of rotation of said drum means associated with line means retraction;
• f. drive means operably associated with said shaft means for turning said shaft means and for selectively tightening and loosening a clutch means, said drive means being rotatable in a first drive means direction associated with line means extension and a second drive means direction associated with line means retraction;
• g. clutch means operably associated with said shaft means and said drive means for selectively causing rotational engagement and disengagement of said drive means with said shaft means wherein rotation of said drive means in said first drive means direction associated with line means extension causes adjustable clutching disengagement of said drive means and said shaft means allowing rotation of said shaft means in said first shaft means direction associated with line means extension in response to a load on said line means when said drum means is in said free rotating state, and wherein rotation of said drive means in said first drive means direction subsequent to engagement with a drive means stop cause overriding rotation of said drum means when said drum means is in said locked state and wherein rotation of said shaft means in said first shaft means direction with said drive means in an immobilized position produces clutching engagement of said shaft means and said drive means whereby rotation of said shaft means is brakingly halted, and wherein initial rotation of said drive means in said second drive means direction associated with line means retraction causes adjustable clutching engagement of said drive means and said shaft means and wherein rotation of said drive means in said second drive means direction subsequent to said clutching engagement causes rotation of said shaft means in said shaft means second direction associated with line means retraction;
• h. whereby said cargo handling apparatus is operational for raising or lowering a cargo payload to a selected position when said drum means is in said locked state by rotation of said drive means in said second drive means direction to retract the line means to raise the cargo payload, and by initial rotation of said drive means in said second drive means direction to remove the torque load on said drum means to release the locking mechanism of said drum means and to subsequently permit lowering of the cargo payload by rotation of said drive means in said first drive means direction to cause said clutch means to adjustably disengage said drive means and said shaft means to allow controlled descent of the cargo payload by controlled rotation of said drum means in said first drum means direction and by rotation of said drive means in said first drive means direction subsequent to engagement with a drive means stop to thereby override said drum means resistance to rotation in said locked state to cause lowering of the cargo payload.