Patent Publication Number: US-2010107360-A1

Title: Caster assembly

Description:
FIELD OF INVENTION 
     The present invention relates to a caster assembly that is attached to and can be steered relative to a vehicle and, more particularly, to a caster assembly including a braking unit for stopping the rolling thereof and a restraining unit for stopping the steering thereof. 
     BACKGROUND OF INVENTION 
     Referring to  FIG. 1 , a conventional caster assembly  10  includes a caster  11 , a fork  12  for supporting the caster  11  rotationally and a braking unit for stopping the rolling of the caster  11 . The braking unit includes a brake  15  and a pedal  17 . The fork  12  includes two prongs  13 . The brake  15  includes a pedal-connecting portion transversely extended from a caster-contacting portion  154 . Two tabs  151  and  153  are formed on a side of the pedal-connecting portion of the brake  15 . A slot  152  is defined in the pedal-connecting portion of the brake  15 . A middle portion of the pedal  17  is formed as a cam  171 . An axle  18  is inserted through the cam  171 , the slot  152 , the prongs  13  and the caster  11 . A nut  181  is engaged with a threaded portion formed at each end of the axle  18 . When an end of the pedal  17  is trodden, the cam  171  is in contact with the tab  153  so that the caster-contacting portion  154  is in contact with the caster  11 . Hence, the rolling of the caster  11  is stopped. When another end of the pedal  17  is trodden, the cam  171  is in contact with the tab  151  so that the caster-contacting portion  154  is removed from the caster  11 . Hence, the rolling of the caster  11  is allowed. 
     In use, the fork  12  is non-rotationally attached to a vehicle such as a skate board and trolley. Therefore, the vehicle equipped with the caster assembly  10  cannot be steered. 
     To overcome the above-mentioned problem, there is a second conventional caster assembly including a fork that can rotationally be attached to a vehicle. The second conventional caster assembly enables the vehicle to be steered when it is encountered with a slope. The automatic steering of the second conventional caster assembly might release the braking of the second conventional caster assembly in the worst case. 
     The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art. 
     SUMMARY OF INVENTION 
     It is the primary objective of the present invention to provide a caster assembly including a braking unit for stopping the rolling thereof and a restraining unit for stopping the steering thereof. 
     To achieve the foregoing objective, the caster assembly includes a caster, a fork for supporting the caster and a connecting unit for rotationally connecting the fork to a vehicle. The fork includes a slot defined therein. The connecting unit includes recesses defined therein. The braking unit includes a brake and a pedal. The brake is connected to the fork and formed with a caster-contacting portion inserted through the slot, a pedal-connecting portion transversely extended from the caster-contacting portion, an upper tab formed on the pedal-connecting portion and a lower tab formed on the pedal-connecting portion. The pedal is located next to the brake and changeable between a releasing position and a braking position. In the releasing position, the pedal is in contact with the upper tab so that the caster-contacting portion of the brake is away from the caster. In the braking position, the pedal is in contact with the lower tab so that the caster-contacting portion of the brake is in contact with the caster. The restraining unit includes a brake-engaging element and a latch. The brake-engaging element is engaged with the brake so that the brake-engaging element can be pivoted between a releasing position corresponding to the releasing position of the pedal and a restraining position corresponding to the braking position of the pedal. The latch is connected to the brake-engaging element so that the latch is inserted in one of the apertures of the disc in the restraining position and that the latch is removed from the apertures of the disc in the releasing position. 
     Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will be described via the detailed illustration of the preferred embodiment versus the prior art referring to the drawings. 
         FIG. 1  is a perspective view of a conventional caster assembly. 
         FIG. 2  is a perspective view of a caster assembly according to the preferred embodiment of the present invention. 
         FIG. 3  is an exploded view of the caster assembly shown in  FIG. 2 . 
         FIG. 4  is another perspective view of the caster assembly shown in  FIG. 2 . 
         FIG. 5  is a side view of the caster assembly shown in  FIG. 4 . 
         FIG. 6  is a side view of the caster assembly in another position than shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring to  FIGS. 2 to 4 , a caster assembly  100  includes a caser  40 , a fork  30  for supporting the caster  40 , a connecting unit  20  for rotationally connecting the fork  30  to a vehicle such as a skate board and trolley, a braking unit  50  for stopping the rolling thereof and a restraining unit  60  for stopping the steering thereof according to the preferred embodiment of the present invention. The caster  40  includes an aperture  42  defined therein. A bearing  43  is disposed in the aperture  42 . An axle  41  is inserted through the bearing  43 . Two annular covers  44  are attached to the caster  40  for protecting the bearing  43 . 
     The fork  30  includes two prongs  32  transversely extended from a middle portion  31 . An aperture  311  is defined in the middle portion  31  of the fork  30 . Two apertures  321  and  322  are defined in each of the prongs  32 . A slot  323  is defined in one of the prongs  32 . 
     The connecting unit  20  includes a plate  21 , a disc  23  and a bearing  22 . The plate  21  is non-rotationally attached to the vehicle. The plate  21  is formed with a rivet  211  at the center. Recesses  231  are evenly defined in the disc  23 . The bearing  22  includes two groups of balls. The first group of balls is located between the plate  21  and the middle portion  31  of the fork  30 . The second group of balls is located between the disc  23  and the middle portion  31  of the fork  30 . Therefore, the fork  30  is rotationally attached to the vehicle with the connecting unit  20 . Inserted through the aperture  311 , the rivet  211  is non-rotationally connected to the disc  23 . Hence, the disc  23  is non-rotational relative to the plate  21 . 
     The braking unit  50  includes a brake  52  and a pedal  51 . The brake  52  includes a pedal-connecting portion  521  transversely extended from a caster-contacting portion  522 . The caster-contacting portion  522  of the brake  52  is inserted through the slot  323 . Two tabs  524  and  525  are formed on the pedal-connecting portion  521  of the brake  52 . A slot  523  is defined in the pedal-connecting portion  521  of the brake  52 . The axle  41  is inserted through the pedal  51  and the slot  523  of the brake  52 . A tongue  526  is transversely extended from the pedal-connecting portion  521  of the brake  52 . 
     The restraining unit  60  includes a brake-engaging element  61  and a latch  62 . The brake-engaging element  61  includes two wings  612  extended from a middle portion  611 . An aperture  615  is defined in each of the wings  612 . A cutout  616  is defined in one of the wings  612 . The latch  62  is connected to the middle portion  611  of the brake-engaging element  61 . A pin  63  is inserted through the apertures  321  and  615 . The tongue  526  of the brake  52  is disposed in the cutout  616  of the brake-engaging element  61 . 
     Referring to  FIG. 5 , an end of the pedal  51  is trodden so that a middle portion of the pedal  51  is in contact with the tab  524  and that the caster-contacting portion  522  of the brake  52  is away from the caster  40 . Hence, the rolling of the caster  40  is allowed. The latch  62  is not inserted in any of the recesses  231  of the disc  23  so that the steering of the vehicle is allowed. 
     Referring to  FIG. 6 , another end of the pedal  51  is trodden so that the pedal  51  is in contact with the tab  525  and that the caster-contacting portion  522  of the brake  52  is in contact with the caster  40 . Hence, the rolling of the caster  40  is stopped. The brake-engaging element  61  is pivoted with the brake  52 . The latch  62  is inserted in one of the recesses  231  of the disc  23  so that the steering of the vehicle is avoided. 
     Advantageously, the rolling of the caster  40  and the steering of the vehicle can be allowed simultaneously so that the vehicle can be driven easily. On the other hand, the rolling of the caster  40  and the steering of the vehicle can be avoided simultaneously so that the vehicle can be parked firmly. 
     The present invention has been described via the detailed illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.