Lever type braking device

1. A braking device ( 1 ) comprising:

a left lever ( 2 ) journaled in a left bracket ( 3 ) for swinging motion about a first axis ( 4 ),

a right lever ( 5 ) journaled in a right bracket ( 6 ) for swinging motion about a second axis ( 7 ) in parallel with the first axis, the axes dividing each lever in a shorter lever length ( 2 ″; 5 ″) and a longer lever length ( 2 ′; 5 ′),

left and right brake pads ( 8 ; 10 ) respectively, pivotally journaled in the shorter lengths of the left and right levers,

an actuation means ( 19 ) engaging the longer lengths of the levers and operable for swinging the levers in contra-rotating directions about their respective axes ( 4 ; 7 ), the actuation means controlling the movements of the brake pads between braking and idle positions as well as generating a clamping force applied by the brake pads in braking,

wherein the actuation means are a screw jack ( 19 ) comprising an electric motor ( 20 ) and an angle gear ( 21 ) driving a jack screw ( 22 ) which is coupled between the levers ( 2 ; 5 ), and

a load sensor ( 29 ) directly situated on or attached coupled to the right one lever ( 5 ) controls, via a power regulating means ( 25 ), the force applied in braking mode, and a position sensor ( 31 ) directly situated on or attached to the left lever ( 2 ) determines the left lever's positions in idling mode.

2. The braking device of claim 1 , wherein adjustable pivot limiting ( 35 ; 36 ) means on the brackets ( 3 ; 6 ) are adjusted to provide the levers ( 2 ; 5 ) freedom of movement in the idle position.

3. The braking device of claim 2 , wherein an elastic member is connected between a lever ( 2 ; 5 ) and its associated bracket ( 3 ; 6 ) and effective for preventing spontaneous swinging of the levers in the idle position.

4. The braking device of claim 1 , wherein the brake pads ( 8 ; 10 ) are pivotally supported in mutually opposing side faces ( 2 i ; 5 i ) of the left ( 2 ) and right ( 5 ) levers, and in the idle position maintained in parallel relation by a tensioning spring ( 17 ; 18 ) and an adjustable pivot limiter ( 14 ; 15 ) respectively.

5. The braking device of claim 1 , wherein the angle gear ( 21 ) comprises a worm screw ( 27 ) and a geared nut ( 28 ) wherein threads are designed to provide self-locking engagement such that return of the brake pads from braking position to idle position is achievable only by reversing the rotational direction of the electric motor ( 20 ).

6. The braking device of claim 5 , wherein the angle gear ( 21 ) has a gear ratio in the range of 5:1-50:1.

7. The braking device of claim 1 , wherein the relation in lengths between the longer lever length ( 2 ′; 5 ′) and the shorter lever length ( 2 ″; 5 ″) provides a lever ratio in the range of 2:1-6:1.

8. The braking device of claim 1 , wherein a cross-sectional area is gradually and continuously reducing towards the end of the longer lever length of at least one of the left and right levers.

9. The braking device of claim 1 , wherein the left and right brackets ( 3 ; 6 ) are supported on left and right sides respectively of a stand ( 37 ), further comprising a positive lock- and release mechanism ( 100 ) arranged on the stand and operable for arresting a rotary shaft by engagement with a brake disc or flange ( 39 ) affixed to the rotary shaft.

10. The braking device of claim 9 , wherein the lock-and release mechanism ( 100 ) comprises an extendable/retractable plunger which is electrically actuated in extension and retraction by means of an electric motor ( 102 ) and a linear drive ( 103 ).

11. The braking device of claim 1 , wherein the left and right brackets ( 3 ; 6 ) are supported on left and right sides respectively of a stand ( 37 ), and

further comprising a shaft turning mechanism ( 200 ) arranged on the stand and operable for turning a rotary shaft by engagement with a brake disc or flange ( 39 ) affixed to the rotary shaft.

12. The braking device of claim 11 , wherein the shaft turning mechanism ( 200 ) comprises a gear wheel ( 201 ) arranged rotatable with its toothed periphery engageable with a toothed periphery ( 41 ) of the brake disc or flange ( 39 ) affixed to the rotary shaft.

13. The braking device of claim 12 , wherein the gear wheel ( 201 ) is electrically rotatable by an electric motor ( 204 ) and a bevel gear drive ( 205 ).

14. The braking device of claim 1 , further comprising a rotary shaft having a brake disc or flange ( 39 ) affixed thereto, wherein the brake disc or flange comprises a toothed periphery ( 41 ).

15. The braking device of claim 1 , further comprising a rotary shaft having a brake disc or flange ( 39 ) affixed thereto, wherein the brake disc or flange comprises a number of through holes ( 42 ) that are located on a circle radially inside of the periphery of the brake disc or flange.

16. The braking device of claim 2 , wherein the elastic member is a tensioning spring.

17. The braking device of claim 7 , wherein the lever ratio is in the range of 3:1-5:1.

18. The braking device of claim 8 , wherein a thickness dimension (w) of at least one of the left and right levers, is gradually and continuously reducing towards the end of the longer lever length of the respective lever.

19. A braking device ( 1 ) comprising:

a left lever ( 2 ) journaled in a left bracket ( 3 ) for swinging motion about a first axis ( 4 ),

a right lever ( 5 ) journaled in a right bracket ( 6 ) for swinging motion about a second axis ( 7 ) in parallel with the first axis, the axes dividing each lever in a shorter lever length ( 2 ″; 5 ″) and a longer lever length ( 2 ′; 5 ′),

left and right brake pads ( 8 ; 10 ) respectively, pivotally journaled in the shorter lengths of the left and right levers,

an actuation means ( 19 ) engaging the longer lengths of the levers and operable for swinging the levers in contra-rotating directions about their respective axes ( 4 ; 7 ), the actuation means controlling the movements of the brake pads between braking and idle positions as well as generating a clamping force applied by the brake pads in braking,

wherein the actuation means are a screw jack ( 19 ) comprising an electric motor ( 20 ) and an angle gear ( 21 ) driving a jack screw ( 22 ) which is coupled between the levers ( 2 ; 5 ),

a load sensor ( 29 ) is coupled to the right lever ( 5 ) and controls, via a power regulating means ( 25 ), the force applied in braking mode,

a position sensor ( 31 ) is coupled to the left lever ( 2 ) and determines the left lever's positions in idling mode, and

said load and position sensors ( 29 , 31 ) are mounted on opposite ends of said jack screw ( 22 ).

20. A braking device ( 1 ) comprising:

a left lever ( 2 ) journaled in a left bracket ( 3 ) for swinging motion about a first axis ( 4 ),

a right lever ( 5 ) journaled in a right bracket ( 6 ) for swinging motion about a second axis ( 7 ) in parallel with the first axis, the axes dividing each lever in a shorter lever length ( 2 ″; 5 ″) and a longer lever length ( 2 ′; 5 ′),

left and right brake pads ( 8 ; 10 ) respectively, pivotally journaled in the shorter lengths of the left and right levers,

an actuation means ( 19 ) engaging the longer lengths of the levers and operable for swinging the levers in contra-rotating directions about their respective axes ( 4 ; 7 ), the actuation means controlling the movements of the brake pads between braking and idle positions as well as generating a clamping force applied by the brake pads in braking,

wherein the actuation means are a screw jack ( 19 ) comprising an electric motor ( 20 ) and an angle gear ( 21 ) driving a jack screw ( 22 ) which is coupled between the levers ( 2 ; 5 ),

a load sensor ( 29 ) is coupled to the right lever ( 5 ) and controls, via a power regulating means ( 25 ), the force applied in braking mode,

a position sensor ( 31 ) is coupled to the left lever ( 2 ) and determines the left lever's positions in idling mode, and

additionally comprising a sensor seat ( 30 ) supported on an end region of the longer length ( 5 ′) of the right lever ( 5 ) and in which the load sensor ( 29 ) is fixedly received, and

a housing ( 33 ) coupled to an outwardly facing side of the longer length ( 2 ′) of the left lever ( 2 ) and in which the position sensor ( 31 ) is arranged to detect position of a tip ( 32 ) of the jack screw ( 22 ) which extends through an opening in the longer length ( 2 ′) of the left lever ( 2 ) and into the housing ( 33 ).