Patent Publication Number: US-2003224889-A1

Title: Idle wheel adjustment assembly

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates to an idle wheel adjustment assembly. More particularly, the present invention relates to an idle wheel adjustment assembly for transmission chains.  
       [0002] U.S. patent application Ser. No. 09/650,209 has been filed by the same inventor on Aug. 29, 2000. U.S. patent application Ser. No. 09/650,209 has disclosed a transmission assembly having idle wheels. However, the idle wheels are useful in one rotating direction only. If the idle wheels are useful clockwise, the idle wheels will be useless counterclockwise. If the idle wheels are useful counterclockwise, the idle wheels will be useless clockwise.  
       SUMMARY OF THE INVENTION  
       [0003] An object of the present invention is to provide an idle wheel adjustment assembly which are useful while rotating clockwise.  
       [0004] Another object of the present invention is to provide an idle wheel adjustment assembly which are useful while rotating counterclockwise.  
       [0005] Accordingly, an idle wheel adjustment assembly comprises a generally L-shaped frame, a coiled spring, an oblong rocking frame, a first shaft pin, a first bearing, a first idle wheel, a second shaft pin, a second bearing, and a second idle wheel. The coiled spring has a first hook end and a second hook end. The generally L-shaped frame has a through hole and an end column. The oblong rocking frame has a main shaft, an upper pillar, an upper circular hole, and a lower round hole. The first bearing is inserted in the first idle wheel. The second bearing is inserted in the second idle wheel. The first shaft pin is inserted through the upper circular hole of the oblong rocking frame and the first bearing. The second shaft pin is inserted through the lower round hole of the oblong rocking frame and the second bearing. The main shaft is inserted through the through hole of the generally L-shaped frame. The first hook end of the coiled spring is connected to the upper pillar of the oblong rocking frame. The second hook end of the coiled spring is connected to the end column of the generally L-shaped frame. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0006]FIG. 1 is a perspective exploded view of a pair of idle wheel adjustment assemblies and a vehicle frame of a preferred embodiment in accordance with the present invention;  
     [0007]FIG. 2 is a partially elevational view of FIG. 1;  
     [0008]FIG. 3 is a partially enlarged view of an idle wheel adjustment assembly of a preferred embodiment in accordance with the present invention;  
     [0009]FIG. 4 is a perspective assembly view of an idle wheel adjustment assembly of a preferred embodiment in accordance with the present invention;  
     [0010]FIG. 5 is a perspective exploded view of an idle wheel adjustment assembly of a preferred embodiment in accordance with the present invention; and  
     [0011]FIG. 6 is a schematic view illustrating an operation of an idle wheel adjustment assembly of a preferred embodiment in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0012] Referring to FIGS.  1  to  6 , a vehicle frame  1  has a transmission shaft  2 , a pair of wheel shafts  3 , a pair of wheels  4 , a pair of main gears  11 , a pair of drive gears  12 , and a pair of transmission chains  10 .  
     [0013] The main gears  11  are disposed on the transmission shaft  2 .  
     [0014] Each wheel shaft  3  is connected to the corresponding wheel  4  and the corresponding drive gear  12 .  
     [0015] Each transmission chain  10  surrounds the corresponding main gear  11  and the corresponding drive gear  12 .  
     [0016] A pair of idle wheel adjustment assemblies are disposed on the vehicle frame  1 .  
     [0017] Each idle wheel adjustment assembly engages with the corresponding transmission chain  10 .  
     [0018] Each idle wheel adjustment assembly comprises a generally L-shaped frame  60 , a coiled spring  70 , an oblong rocking frame  50 , a first shaft pin  22 , a first bearing  21 , a first idle wheel  20 , a first generally C-shaped retainer  40 , a second shaft pin  32 , a second bearing  31 , a second idle wheel  30 , a second generally C-shaped retainer  40   a , and a third generally C-shaped retainer  80 .  
     [0019] The coiled spring  70  has a first hook end  71  and a second hook end  72 .  
     [0020] The generally L-shaped frame  60  has a through hole  61  and an end column  62 .  
     [0021] The oblong rocking frame  50  has a main shaft  53 , an upper pillar  55 , an upper circular hole  51 , and a lower round hole  52 .  
     [0022] The first bearing  21  is inserted in the first idle wheel  20 .  
     [0023] The second bearing  31  is inserted in the second idle wheel  30 .  
     [0024] The first shaft pin  22  is inserted through the upper circular hole  51  of the oblong rocking frame  50  and the first bearing  21 .  
     [0025] The second shaft pin  32  is inserted through the lower round hole  52  of the oblong rocking frame  50  and the second bearing  31 .  
     [0026] The main shaft  53  is inserted through the through hole  61  of the generally L-shaped frame  60 .  
     [0027] The first hook end  71  of the coiled spring  70  is connected to the upper pillar  55  of the oblong rocking frame  50 .  
     [0028] The second hook end  72  of the coiled spring  70  is connected to the end column  62  of the generally L-shaped frame  60 .  
     [0029] The first shaft pin  22  has a first annular groove  23  to receive the first generally C-shaped retainer  40 .  
     [0030] The second shaft pin  32  has a second annular groove  33  to receive the second generally C-shaped retainer  40   a.    
     [0031] The main shaft  53  has an annular recess  54  to receive the third generally C-shaped retainer  80 .  
     [0032] The first idle wheel  20  and the second idle wheel  30  engage with the corresponding transmission chain  10 .  
     [0033] The first idle wheel  20  and the second idle wheel  30  are useful while rotating clockwise.  
     [0034] The first idle wheel  20  and the second idle wheel  30  are useful while rotating counterclockwise.  
     [0035] The invention is not limited to the above embodiment but various modification thereof may be made. Further, various changes in form and detail may be made without departing from the scope of the invention.