Hand brake

Abstract

Provided is a hand brake, comprising a hand wheel (4), a chain (5), an enclosure (1), a drive shaft assembly (3) which is disposed in the enclosure (1), bull gear (13), and base assembly; the hand wheel (4) is connected to the drive shaft assembly (3), one end of the chain (5) is fixed to the bull gear (13) by means of rivets, and the main shaft of the bull gear (13) is a chain winding shaft (2). The hand brake further comprises a limiting device disposed on the chain winding shaft (2) between the bull gear (13) and the base (22); the limiting device comprises a first bearing (10), a torsion spring (11), a guide plate (9), and a guide plate holder (23). Installing the hand brake not only prevents the problem of the chain interfering with the movable pulley when the hand brake is deployed and thus affecting the performance of the hand brake, but also provides for a better appearance.

Claims

1. A hand brake, comprising a hand wheel (4), a chain (5), an enclosure (1), a drive shaft assembly (3) which is disposed in the enclosure (1), a bull gear (13), and a base assembly (6); wherein the hand wheel (4) is connected to the drive shaft assembly (3), one end of the chain (5) is fixed to the bull gear (13), and a main shaft of the bull gear (13) is a chain winding shaft (2), the base assembly (6) comprises a base (22); wherein the hand brake further comprises a limiting device disposed on the chain winding shaft (2) between the bull gear (13) and the base (22); the limiting device comprises a first bearing (10), a torsion spring holder (12), a torsion spring (11), a guide plate (9), and a guide plate holder (23); the torsion spring (11) is sleeved on outside of the first bearing (10), the torsion spring holder (12) is disposed at a first side of the torsion spring (11) close to the bull gear (13); the guide plate (9) and the guide plate holder (23) are successively disposed at a second side of the torsion spring (11) close to the base (22); a first stopper post (8) is secured to a side of the guide plate (9) facing the torsion spring (11); a second stopper post (26) is secured to a side of the base (22) facing the guide plate holder (23); a third stopper post (7) is secured to a side of the torsion spring holder (12) facing the torsion spring (11); both ends of the torsion spring (11) are curved hooks, the guide plate (9) and the guide plate holder (23) are of an annular structure; an arcuate groove is provided on the guide plate (9) that passes through the guide plate (9), and a hole matching with the second stopper post (26) in size is arranged on the guide plate holder (23), and the second stopper post (26) passes through the guide plate holder (23) via the hole and slides in the arcuate groove.

2. The hand brake according to claim 1, wherein the number of turns of the torsion spring (11) is N, 3≦N≦6; and a wire diameter of the torsion spring (11) is r, 4 mm≦r≦6 mm.

3. The hand brake according to claim 2, wherein a height of the third stopper post (7) is H.sub.3, a height of the second stopper post (26) is H.sub.2, and a height of the first stopper post (8) is H.sub.1, r≦H3≦(N−1)*r, r≦H1≦(N−1)*r, H.sub.2 is greater than a thickness of the guide plate holder (23), no greater than the sum of a thickness of the guide plate (9) and the guide plate holder (23).

4. The hand brake according to claim 2, wherein a first end (11a) of the torsion spring (11) close to the torsion spring holder (23) is clamped with the third stopper post (7), a second end (11b) of the torsion spring (11) close to the guide plate (9) is clamped with the first stopper post (8).

5. The hand brake according to claim 4, wherein a height of the third stopper post (7) is H.sub.3, a height of the second stopper post (26) is H.sub.2, and a height of the first stopper post (8) is H.sub.1, r≦H3≦(N−1) r, r≦H1≦(N−1)*r, H.sub.2 is greater than a thickness of the guide plate holder (23), no greater than the sum of a thickness of the guide plate (9) and the guide plate holder (23).

6. The hand brake according to claim 1, wherein a first end (11a) of the torsion spring (11) close to the torsion spring holder (23) is clamped with the third stopper post (7), a second end (11b) of the torsion spring (11) close to the guide plate (9) is clamped with the first stopper post (8).

7. The hand brake according to claim 1, wherein a width of the groove is not less than a diameter of the second stopper post (26), an arc length of the groove is not greater than 75% of a circumference of a circular arc which the groove belongs to.

8. The hand brake according to claim 1, wherein the drive shaft assembly (3) comprises a drive shaft (16), a pin wheel (17), a clutch (18), a ratchet (19), a pinion (20) and an end part (21) arranged successively; the hand wheel (4) is disposed at a first end close to the drive shaft (16) and secured to the drive shaft (16), and the bull gear (13) is located at end close to the pinion (20) and engaged with the pinion (20).

9. The hand brake according to claim 8, wherein the end part (21) is connected with the drive shaft (16) by an elastic cylindrical pin.

10. The hand brake according to claim 1, wherein the enclosure (1) is provided with a function handle (14), a pawl (27), a pawl pin (28) and a pawl holder (29), the function handle (14) is fixedly connected with the pawl pin (28), and the pawl (27) is restricted on the pawl pin (28) rotatably through the pawl holder (29).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a first schematic diagram of a hand brake in the present invention;

(2) FIG. 2 is a second schematic diagram of a hand brake in the present invention;

(3) FIG. 3 is a first schematic diagram of limiting device of a hand brake in the present invention;

(4) FIG. 4 is an A-A sectional view of FIG. 3;

(5) FIG. 5 is a first schematic diagram of base assembly of a hand brake in the present invention;

(6) FIG. 6 is an A-A sectional view of FIG. 5;

(7) FIG. 7 is a second schematic diagram of base assembly of a hand brake in the present invention;

(8) FIG. 8 is a first schematic diagram of drive shaft assembly of a hand brake in the present invention;

(9) FIG. 9 is a second schematic diagram of drive shaft assembly of a hand brake in the present invention;

(10) FIG. 10 is a schematic diagram of chain state of the prior hand brake under the relief state;

(11) FIG. 11 is a schematic diagram of chain state of a hand brake under the relief state in the present invention;

(12) FIG. 12 is an exploded view of the handle of a hand brake in the present invention.

(13) Of which, 1 enclosure, 2 chain winding shaft, 3 drive shaft assembly, 4 hand wheel, 5 chain, 6 base assembly, 7 third stopper post, 8 second stopper post, 9 guide plate, 10 first bearing, 11 torsion spring, 12 torsion spring holder, 13 bull gear, 14 handle, 15 rivet, 16 drive shaft, 17 pin wheel, 18 clutch, 19 ratchet, 20 pinion, 21 end part, 22 base, 23 guide plate holder, 24 bearing holder, 25 second bearing, 26 second stopper post, 27 pawl, 28 pawl pin, 29 pawl holder, 30 counterweight.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(14) The invention is further described in combination with drawings and embodiments.

Example 1

(15) A hand brake, comprising a hand wheel 4, a chain 5, an enclosure 1, a drive shaft assembly 3 which is disposed in the enclosure 1, a bull gear 13, and a base assembly 6; the hand wheel 4 is connected to the drive shaft assembly 3, one end of the chain 5 is fixed to the bull gear 13 by means of rivets, and the main shaft of the bull gear 13 is a chain winding shaft 2. The drive shaft assembly 3 comprises a drive shaft 16, a pin wheel 17, a clutch 18, a ratchet 19, a pinion 20 and an end part 21 arranged successively; the hand wheel 4 is disposed at the end close to the drive shaft 16 and secured to the drive shaft 16, and the bull gear 13 is located at the end close to the pinion 20 and engaged with the pinion 20. The end part 21 of the hand brake is connected with the drive shaft 16 by elastic cylindrical pins, which can facilitate the overhaul of the drive shaft assembly.

(16) The enclosure 1 is provided with a function handle 14, a pawl 27, a pawl pin 28 and a pawl holder 29, the function handle 14 is fixedly connected with the pawl pin 28, and the pawl 27 is restricted on the pawl pin 28 rotatably, through a pawl holder 29. A counterweight 30 is disposed on the side of pawl pin 28 away from the pawl 27. The pawl 27 is clamped between adjacent gears of ratchet 19, so that the ratchet 19 can rotate clockwise driven by the drive shaft 16, preventing the counterclockwise rotation of the ratchet 19.

(17) The hand brake further comprises a limiting device disposed on the chain winding shaft 2 between the bull gear 13 and the base 22. The limiting device comprises a first bearing 10, a torsion spring 11, a guide plate 9 and a guide plate holder 23. The torsion spring 11 is sleeved on the outside of the first bearing 10, the torsion spring holder 12 is disposed at the side of the torsion spring 11 where close to the bull gear 13, and the guide plate 9 and the guide plate holder 23 are successively disposed at the side of the torsion spring 11 where close to the base 22. A third stopper post 7 is secured on the side of the spring holder 12 facing the torsion spring 11, a first stopper post 8 is secured on the side of the guide plate 9 facing the torsion spring 11, and a second stopper post 26 is secured on the base 22 facing the guide plate holder 23. Curved hooks are provided at both ends of the torsion spring 11, and the guide plate 9 and the guide plate holder 23 are annular structures. The guide plate 9 is provided with an arcuate groove that penetrates the guide plate 9, and the width of the groove is not less than the diameter of the second stopper post 26, and the arc length of the groove is not more than three-quarters of the circumference. Holes matching with the second stopper post 26 are arranged on the guide plate holder 23, and the second stopper post 26, by means of a hole, penetrates the guide plate holder 23 and rotates in the arcuate groove. The base 23 is further provided with second bearing 25, which is disposed on the base 23 through the bearing block 24. Outside of the bearing block 24 is the guide plate holder 23. The guide plate holder is 4 mm in thickness and the guide plate is 6 mm in thickness.

(18) The torsion spring 11 is made of 65Mn; the number of turns of the torsion spring 11 is 4; the wire diameter of the torsion spring 11 is 5 mm. The end 11a of the torsion spring 11 close to the spring holder 23 is clamped with the third stopper post 7, and the end 11b of the torsion spring 11 close to the guide plate 9 is clamped with the first stopper post 8. The height H.sub.3 of the third stopper post 7 is 5 mm, the height H.sub.2 of the second stopper post 26 is 9 mm and height H.sub.1 of the first stopper post 8 is 5 mm.

(19) Since the bull gear of the hand brake after improvement adopts a limiting structure, under the natural state, there is a lateral distance of 47 mm between the center of chain and the center of chain winding shaft. The prior hand brake lacks of the limiting device, and the chain naturally drops under the action of gravity, thus there is no lateral offset between the chain center and the center of the chain winding shaft.

(20) The improved hand brake can guarantee the performance of the hand braking system of the truck after adjusting the position of the mounting location (to avoid interference with the windshield), and the multiplying power of the improved hand brake is consistent with that before improvement. The distance between the drive shaft of the hand brake and the central line of the chain at the end of chain winding shaft is 40 mm greater than that before improvement.

(21) TABLE-US-00001 TABLE 1 Comparison of technical parameters between the present invention and prior hand brake The present Prior No. Technical Parameters invention hand brake 1 Diameter of hand wheel D/mm 400 400 2 Braking ratio γ 27 27 3 Involvement amount of chain L/mm ≦458 ≦458 4 Input torque/N .Math. m 156 156 5 Minimum output chain tension/kN ≧10 ≧10 6 Machine maximum width/mm 524 524 7 Machine maximum height/mm 400 400 8 Machine maximum thickness/mm 270 236 9 Shape and size of mounting hole/mm Lateral 286, Lateral 286, vertical 305 vertical 305 10 Weight/kg 37 34

Example 2

(22) The difference from Example 1 is as follows: The number of turns of the torsion spring 11 is 3; the wire diameter of the torsion spring 11 is 6 mm. The height H.sub.3 of the third stopper post 7 is 10 mm, the height H.sub.2 of the second stopper post 26 is 7 mm and the height H.sub.1 of the first stopper post 8 is 6 mm.

Example 3

(23) The difference from Example 1 is as follows: The number of turns of the torsion spring 11 is 5; the wire diameter of the torsion spring 11 is 4 mm. The height H.sub.3 of the third stopper post 7 is 6 mm, the height H.sub.2 of the second stopper post 26 is 10 mm and the height H.sub.1 of the first stopper post 8 is 14 mm.

Example 4

(24) Different from Example 1, there are six turns of the torsion spring 11, and the wire diameter of the torsion spring 11 is 4 mm. The height H.sub.3 of the third stopper post 7 is 8 mm, the height H.sub.2 of the second stopper post 26 is 8 mm, and the height H.sub.1 of the first stopper post 8 is 8 mm.