Patent Publication Number: US-6212740-B1

Title: Fastening device for safety belt

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a fastening device for a safety belt used in escaping or mountaineering or for seat belt of a car or the like. The fastening device is fitted with the a safety belt to form a fastening loop. The fastening device can be quickly slid along the fastening loop to adjust the size thereof to suit different body dimensions. The fastening device permits a user to quickly fit the fastening loop onto his/her body and can be quickly shifted to tighten the user&#39;s body in an emergency. After being fastened and located, the biting plates of the fastening device bite the belt body to prevent the belt body from loosening so as to ensure safety. 
     FIGS. 1 and 2 show an escaping suspension pulley  10  installed at the porch of a building. The suspension pulley  10  is hung on a safety hook  20  fixed on the wall. Two straps  11  downwardly extend from the suspension pulley  10 . The end of each strap is formed as a fastening loop  12  tied with a substantially B-shaped adjustable fastening buckle  30 . FIGS. 3 and 4 show two existing types of the fastening buckles, wherein in FIG. 3, the fastening buckle is plane, while in FIG. 4, the fastening buckle is curved. The fastening buckle  30  can be slid along the strap for adjusting the size of the fastening loop  12  for tightening the waist section of a user as shown in FIG.  1 . Accordingly, as shown in FIG. 4, the user is suspended and able to slowly move down from the porch for escaping in an emergency. 
     The above conventional fastening buckles  30  are freely movably fitted with the strap, while lacking a securing force. Therefore, when the fastening loop  12  tightens the waist section as shown in FIG.  1 . the fastening buckle  38  tends to slip away to enlarge the fastening loop  12 . At this time, in case the user just raises his/her both hands, the user may come loose from the fastening loop  12  to drop down. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a fastening device for a safety belt. The fastening device is fitted with the safety belt to form a fastening loop. The fastening device can be quickly slid along the fastening loop to adjust the size thereof to suit different body dimensions. The fastening device permits a user to quickly fit the fastening loop onto his/her body and can be quickly shifted to tighten the user&#39;s body in an emergency. 
     It is a further object of the present invention to provide the above fastening device in which after the biting plates of the fastening device are fastened and located, the biting plates bite the belt body to prevent the belt body from loosening so as to ensure safety, 
     The present invention can be best understood through the following description and accompanying drawings, wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a conventional escaping suspension pulley installed at a porch of a building; 
     FIG. 2 shows the usage of the escaping suspension pulley of FIG. 1; 
     FIG. 3 shows a conventional plane adjusting fastening buckle of the safety belt; 
     FIG. 4 shows a conventional curved adjusting fastening buckle of the safety belt; 
     FIG. 5 is a perspective exploded view of the present invention; 
     FIG. 6 is a perspective assembled view of the present invention; 
     FIG. 7 shows the usage of the present invention; 
     FIG. 8 shows that the fastening device of the present invention is smoothly slid along the safety belt body; and 
     FIG. 9 shows that the biting plates of the fastening device of the present invention bite the safety belt body to ensure safety; 
     FIG. 10 is a perspective diagram showing the exploded components of another embodiment of the present invention; 
     FIG. 11 is a perspective diagram showing the operation mode of the embodiment as shown in FIG.  10 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIG.  5 . The present invention includes a first longer U-shaped biting plate  48 , a second shorter U-shaped biting plate  50  and an insertion pin  60 . The first biting plate  40  is formed with two rows of ratchets  41  on a inner side. The second biting plate  50  is formed with two rows of ratchets  51  on an inner side opposite to the ratchets  41  of the first biting plate  40 . Each of the biting plates  40 ,  50  is formed with an arch notch  42 ,  52  at a middle section and two inward bent sections  43 ,  44 ,  53 ,  54  at two ends. Each inward bent section is formed with a pin hole. Referring to FIGS. 6 and 7, the biting plates  40 ,  50  are positioned on two sides of a lower U-shaped suspending section of the safety belt and fitted with each other. The bent sections  43 ,  44  of the first biting plate  40  cover the bent sections  53 ,  54  of the second biting plate  50  in a stacked state. As shown in FIG. 7, the U-shaped suspending section of the safety belt  11  is clamped between the biting plates  40 ,  50  with the pin holes thereof aligned with each other. Then the insertion pin  60  is passed through the pin holes and through the U-shaped suspending section of the safety belt  11 . Then the ends of the insertion pin  60  are enlarged to assemble with the safety belt  11  by riveting. Accordingly, the biting plates  40 ,  50  can be quickly slid along the suspending section of the safety belt  11  to adjust the size of the fastening loop. 
     Please refer to FIGS. 10,  11 , where another embodiment of the present invention is presented wherein the surfaces of the biting plates  40 ,  50  are made slightly curved and the ratchets  41 ,  51  are made in a larger size and in a coarser manner so that the biting plates  40 ,  50  can be in biting engagement with the safety belt  11  in a firmer manner and the control of the safety belt  11  in operation becomes more sensitive. 
     The ratchets  41 ,  51  of the biting plates  40 ,  50  can be sharp ratchets or trapezoid or arch ratchets according to the materials of different safety belts  11  for achieving an optimal biting effect. 
     According to the above arrangement, the fastening device of the present invention is applicable to various kinds of safety belts to quickly form an adjustable fastening loop. Referring to FIGS. 8 and 9, the fastening device can be quickly adjustably slid along the safety belt to form different sizes of fastening loops to meet the requirements of different dimensions of the users. The fastening device permits a user to quickly fit the fastening loop onto his/her body and can be quickly shifted to tighten the user&#39;s body in an emergency. After the biting plates are fastened and located, the biting plates bite the belt body to prevent the belt body from loosening so as to ensure safety. 
     The above embodiments are only some examples of the present invention and the scope of the present invention should not be limited to the examples. Any modification or variation derived from the examples should fall within the scope of the present invention.