Abstract:
The present invention provides a braking mechanism comprising a brake cable set, a spring, a connector, a pair of brake shoes, a brake band, a base, and a brake drum. The brake cable set makes the connector move downwards upon braking, such that the connector coupled to the pair of brake shoes rotates to contact the brake band and thus cause friction, whereby achieving the object of braking.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a braking mechanism, in particular to a braking mechanism used in a stroller. 
         [0003]    1. Description of Related Art 
         [0004]    Various braking mechanisms have been proposed in the prior art. For instance, U.S. Pat. No. 6,142,264 discloses a brake device including a brake drum and a pair of semicircular brake shoes, wherein the brake drum rotates along with the wheel and the pair of brake shoes are disposed pivotally with respect to the center of the brake drum by a pivot. The pair of brake shoes surround the brake drum respectively. Upon braking, the ends of the pair of brake shoes separating from the pivot are subjected to an external force, the pair of brake shoes thus hoop the brake drum pivotally to cease the rotation of the wheel. Since this conventional brake device employs the brake shoes in pair, a steady braking effect may be achieved no matter the stroller is moving forward or backward. 
         [0005]    However, since the aforementioned brake device is controlled by a pedal or a handle disposed adjacent to the wheel, a user must stamp on the pedal by foot or bend down to pull the handle by hand for braking, which is still inconvenient and hazardous. Therefore, in view of the drawbacks, the present invention provides a braking mechanism controlled by a brake cable set in combination with a hand brake, which involves the advantages of safety, easy manipulation, steady braking effect, and simple structure. 
       SUMMARY OF THE INVENTION  
       [0006]    To achieve the aforementioned objects, the braking mechanism of the present invention comprises a brake cable set, a spring, a connector, a pair of brake shoes, a brake band, a base, and a brake drum. The braking mechanism may further comprises a cover and rivets, wherein the braking mechanism is installed onto a wheel through the brake drum which rotates along with the wheel. The connector is disposed in the base with one end of the connector connecting with one end of the spring. The cable in the brake cable set passes through the connector and the spring. One end of the cable is further secured to the base. The spring is located between the connector and the end of the cable secured to the base. One end of the tube in the brake cable set is connected to the connector, and the tube may slide in the connector. Each one of the pair of brake shoes comprises a slot to connect with the pivots on the connector in one end, wherein the pivots may slide in the slots. The brake band is disposed in the base and embraces the brake drum tightly so that the brake band may rotate along with the brake drum. The outer periphery of the brake band comprises a braking surface, and the inner periphery of the brake band comprises at least one protrusion engaging with at least one recess on the outer periphery of the brake drum. The other end of the pair of brake shoes are disposed symmetrically and pivotally in the base, wherein the pair of brake shoes may rotate pivotally in the base and move toward the brake band and thus contact with the brake band. Each of the pair of brake shoes comprises a braking surface, wherein the braking surfaces of the pair of brake shoes are disposed opposite to the braking surface of the brake band. The cover includes an opening to expose an upper portion of the brake drum. The cover is mounted to the base by rivets. 
         [0007]    Upon braking, the tube in the brake cable set is subjected to a force to move along the cable in a direction toward the brake band, whereby pushing the connector to move in the same direction. The pair of brake shoes are then caused to move toward the brake band and contact with the brake band, and thus generate friction therebetween, so as to achieve the purpose of braking. 
         [0008]    All the braking surfaces of the pair of brake shoes and the brake band employed in the present invention are an arc-shaped even surface. However, in order to improve the friction between the pair of brake shoes and the brake band, all the braking surfaces of the pair of brake shoes and the brake band may be formed in shape of serration, or the braking surface of only one of the pair of brake shoes and the braking surface of the brake band may be formed in shape of serration. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]      FIG. 1  is a schematic view of an embodiment of a braking mechanism according to the present invention; 
           [0010]      FIG. 2  is an exploded view of the braking mechanism of the embodiment; 
           [0011]      FIG. 3  is a schematic view of the braking mechanism of the embodiment after removal of the cover and the brake drum; 
           [0012]      FIG. 4  is a schematic view of the braking mechanism of the embodiment being assembled with a wheel; 
           [0013]      FIGS. 5A and 5B  show the braking mechanism of the embodiment in non-braking status and braking status, wherein the connector and the spring are represented in cross-sectional views; and 
           [0014]      FIGS. 6A and 6B  show another embodiment of the braking mechanism of the present invention in non-braking status and braking status. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The braking mechanism of the present invention will be described in detail with reference to preferred embodiments in conjunction with the accompanying drawings. However, certain known details are omitted hereinafter in order not to obscure the technical features of the present invention. 
         [0016]    First, please refer to  FIGS. 1 and 2 , which are a schematic view and an exploded view of the braking mechanism  1  of the present invention. As shown in the figures, the braking mechanism  1  comprises a brake cable set  10 , a spring  11 , a connector  12 , a pair of brake shoes  13 , a brake band  14 , a base  15 , and a brake drum  16 . Additionally, the braking mechanism  1  may also comprise a cover  17  and rivets  18 . 
         [0017]    The brake cable set  10  includes a cable  100  and a tube  101  that the cable  100  is passed through , wherein the end  100   a  of the cable  100  is in a shape of a lump. The center of the connector  12  comprises a cavity (denoted by the reference numeral “ 122 ” in  FIGS. 5A  and SB), and the rear end  120  of the connector  12  is in tube shape. A pivot  121  is disposed on both of the front and rear sides of the connector  12 . One end of each brake shoes  13  comprises a slot  131 , and a first braking surface  130  which is substantially arc-shaped is disposed on the lateral side of each of the brake shoes  13 . The brake band  14  is in a shape of ring and has an outer periphery where disposed a second braking surface  140  and an inner periphery where extended a plurality of protrusions  141 . Both of the first braking surface  130  and the second braking surface  140  are even. A cable fixing portion  150  and rivet holes  151  are disposed in the base  15 . The brake drum  16  comprises a central through hole  162 , and a plurality of recesses  161  are disposed on the rear of the brake drum  16 . The cover  17  includes an opening  170  and rivet holes  171  matching the rivet holes  151  in the base  15 . 
         [0018]    Further, with reference to  FIG. 3 , it illustrates a part of the braking mechanism  1 . As shown, the connector  12  is disposed in the front of the base  15  with the rear end  120  of the connector  12  coupled to one end of the spring  11  and the other end of the spring  11  abutted against the cable fixing portion  150  of the base  15 . The cable  100  passes through the cavity of the connector  12 , and the rear part of the cable  100  not covered by the tube  101  further passes through the spring  11 . The end  100   a  of the cable  100  is fixed to the cable fixing portion  150  of the base  15 . The end of the tube  101  is disposed in the cavity of the connector  12  so that the tube  101  may slide in the cavity. 
         [0019]    The slots  131  of the brake shoes  13  are coupled to the pivots  121  on the connector  12  respectively, whereby the pair of brake shoes  13  are mounted onto the connector  12  and the pivots  121  may slide in the slots  131 . The pivots  121  of the connector  12  may consist of a rivet. Further, it should be noted that although it is described in this embodiment that a pivot  121  is disposed on both of the front and rear sides of the connector  12 , the connector  12  may only comprises a pivot  121  and the two brake shoes  13  are both coupled to the pivot  121  in another embodiments. The brake band  14  is disposed in the back of the base  15 , wherein the brake band  14  is in ring shape and encircled a rear part of the brake drum  16  tightly. The protrusions  141  of the brake band  14  are engaged with the recesses  161  on the rear of the brake drum  16 . The rear ends of the pair of brake shoes  13  are disposed symmetrically and pivotally on the rivet holes  151  (not shown in this figure), such that the pair of brake shoes  13  are able to rotate pivotally in the base  15 . The braking surfaces  130  of the pair of brake shoes  13  are disposed opposite to the braking surface  140  of the brake band  14 . 
         [0020]    The opening  170  of the cover  17  exposes a front part of the brake drum  16 . The cover  17  is mounted onto the base  15  by inserting the rivets  18  into the rivet holes  151  and  171 . 
         [0021]      FIG. 4  is a schematic view of the braking mechanism  1  of the present invention being assembled with a wheel  2 , wherein the brake drum  16  is coupled to the wheel  2  and the braking mechanism  1  is assembled with the wheel  2  by inserting an axle  20  into the center of the wheel  2  and the central through hole  162  (not shown in this figure) of the brake drum  16 . Although not shown in this figure, according to the foregoing description and the figures, it is realized that the axle  20  also passes through the opening  170  of the cover  17  and the center of the brake band  14 . In this manner, the wheel  2 , the brake drum  16 , and the brake band  14  (not shown in this figure) may rotate around the axle  20  concurrently. 
         [0022]    Next, please refer to  FIGS. 5A and 5B , which illustrate the braking mechanism  1  of the embodiment in non-braking status and braking status respectively, in which the connector  12  and the spring  11  are represented in cross-sectional view. As shown in  FIG. 5A , since no force is applied to the tube  101  in the brake cable set  10  in non-braking status, the spring  11  is relaxed and the braking surfaces  130  of the brake shoes  13  are not in contact with the braking surface  140  of the brake band  14 . Upon braking, as shown in  FIG. 5B , the tube  101  in the brake cable set  10  is subjected to a force to move along the cable  100  in a direction toward the brake band  14  (the direction indicated by the arrow A), whereby pushing the connector  12  to move in the same direction and compressing the spring  11 . Because the pivots  121  of the connector  12  are coupled to the brake shoes  13  at the slots  131 , when the connector  12  is moved, the pivots  121  may slide in the slots  131  and make the pair of brake shoes  13  move toward the brake band  14  in the direction indicated by the arrows B and B′ respectively, whereby leading the braking surfaces  130  of the brake shoes  13  to contact the braking surface  140  of the brake band  14  and generating friction therebetween. Because the brake band  14  rotates along with the brake drum  16  and the wheel, when the braking surface  140  of the brake band  14  is rubbed against by the braking surfaces  130  of the brake shoes  13 , the rotation speed of the wheel is lowered and the purpose of braking is achieved. 
         [0023]    Further, when the force applied to the tube  101  is relieved, since the spring  11  is not compressed by an external force, the spring  11  may push the connector  12  to move in an opposite direction (the direction opposite to that indicated by the arrow A), whereby making the pair of brake shoes  13  pivotal relative to the base  15  and move in the directions opposite to those indicated by the arrows B and B′ respectively, such that the braking surfaces  130  of the brake shoes  13  and the braking surface  140  of the brake band  14  are separate and return to the status illustrated by  FIG. 5A . 
         [0024]      FIGS. 6A and 6B  illustrate another embodiment of the braking mechanism of the present invention. As shown, the structure thereof is similar to that of the aforementioned embodiment, but both of the braking surfaces  130 ′ of the pair of brake shoes  13 ′ and the braking surface  140 ′ of the brake band  14 ′ are formed in shape of serration to increase the friction between. Alternatively, it is also possible to improve the friction between by making one of the braking surfaces  130 ′ of the pair of brake shoes  13 ′ and the braking surface  140 ′ of the brake band  14 ′ serrate. 
         [0025]    Although the present invention is described in some preferred embodiments in conjunction with the accompanying drawings for better understanding, the scope thereof is not limited thereto and various changes or modifications may be provided by those skilled in the art without departing from the spirit and scope of the present invention.