A brake winch with a reverse release and a self-locking function, the brake winch comprising:
- a housing having a first side wall and a second side wall in spaced relation, the first side wall and the second side wall defining an accommodating space therebetween, the accommodating space having a rope exporting part formed therein, the second side wall having an auxiliary bracket part on an exterior thereof, the auxiliary bracket part and the second side wall defining an auxiliary accommodating space therebetween, the auxiliary bracket part having a shaft hole therein;
- a rotating disk screwed between the first side wall and the second side wall of said housing, said rotating disk being positioned in the accommodating space, said rotating disk having a rope wound therearound;
- a main shaft screwed between the first side wall and the second side wall of said housing, said main shaft being disposed parallel to one side of said rotating disk, said main shaft having a first end and, a second end, the first end of said main shaft being linked by a gear set to said rotating disk;
- a screw adapter on the second side wall of said housing, said screw adapter having an inner connection end and an external end, wherein the inner connection end forms a sleeve joint part assembled onto the second end of said main shaft so as to rotate synchronously therewith, the external end of said screw adapter having a thread groove;
- a driving screw screwed in the shaft hole of the auxiliary bracket part and axially displaceable therewith, said driving screw and said screw adapter being aligned along a central axis, said driving screw having a driven end and a stud section and a round rod section positioned between the driven end and the stud section, the round rod section and the driven end having a pressure flange and an axially arranged section therebetween, the axially arranged section being screwed into the shaft hole, the stud section facing the thread groove of said screw adapter, the stud section and the thread groove having a screw transmission mode or a release mode therebetween as an axial displacement of said driving screw matches a difference of forward rotation and reverse rotation;
- a clamping plate having a circular shaft hole screwed on the round rod section of said driving screw, said clamping plate having a plurality of unidirectional ratchets arranged in spaced relation therearound;
- a unidirectional chucking piece assembled in the auxiliary accommodating space adjacent to said clamping plate, said unidirectional chucking piece elastically abutting on a corresponding unidirectional ratchet of the plurality of unidirectional ratchets of said clamping plate in a resting state such that said clamping plate only rotates in a single direction and in which a rotation opposite to the single direction is chucked;
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- said pressure flange of said driving screw applying pressure onto said clamping plate and said screw adapter so as to synchronize a movement of said driving screw and said clamping plate and said screw adapter when said driving screw moves toward said screw adapter, wherein said pressure flange has a friction component, the friction component having a first friction plate and a second friction plate, the first friction plate and the second friction plate having said clamping plate sandwiched therebetween, the first friction plate having an exterior facing the external end of said screw adapter, the second friction plate having an exterior assembled with a propping component, wherein said pressure flange is linked to the propping component when said driving screw is displaced toward said screw adapter so as to synchronize the first friction plate and the second friction plate and said clamping plate, wherein said pressure flange and the auxiliary bracket part have an elastic underpropping component, assembled therebetween so as to elastically urge said pressure flange toward said screw adapter in a resting state, wherein said main shaft and said driving screw do not contact each other such as to maintain a neutral state, wherein a length of the shaft hole from the thread groove to the auxiliary bracket part is greater than a length from an end of said driving screw to an outer end of said pressure flange, wherein said unidirectional chucking piece has a rotating support end and a swing latch end coordinated with an elastic piece, the swing latch end coordinated with the elastic piece, the swing latch end elastically abutting the one of the unidirectional ratchets of said plurality of unidirectional ratchets when in the resting state.