Patent Publication Number: US-10765895-B2

Title: Fall protection device and safety belt base thereof

Description:
BACKGROUND OF THE INVENTION 
     Technical Field 
     The invention relates generally to a fall protection device, and more particularly to a fall protection device with strong structure and durable feature and its safety belt base. 
     Description of Related Art 
     Generally, those who work at an elevated work site, such as roof, factory, elevator, shipyard, aerospace base and construction site, and etc., will equip with safety parts such as a fall protection device (i.e. a fall arrest device). The fall protection device usually mates with a safety belt and it is adapted with the safety belt, wherein an end of the safety belt is attached to a user. Thereby, as long as the user accidentally falls from the elevated work site, the fall protection device could provide a quick-lock action or slow down the speed of the unwinding safety belt. It ensures the user&#39;s safety by preventing the user from keeping falling or slowing down the user&#39;s falling speed. 
     Taiwan patent number 1574715 discloses a fall protection device, wherein a safety belt  200  is wound around a rolling drum  40 . When the safety belt  200  is pulled out from the rolling drum  40  by the user who falls accidentally, the pulling force destroys the structure of a ring  46  and a sleeve  44  of the rolling drum  40 . For example, the ring  46  may be broken or be separated from the sleeve  44  due to being unendurable to the suddenly strong pulling force. As a result, the fall protection device may lose the function of braking. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the above, the objective of the present invention is to provide a fall protection device and its safety belt base, wherein the safety belt base for wrapping a safety belt has a special structural design to reinforce its structure. 
     To achieve the above object of the present invention, the present invention provides a fall protection device adapted to be connected to a safety belt, wherein the fall protection device includes a frame, a shaft, and a safety belt base. The frame has a receiving place. The shaft is disposed on the frame. The safety belt base is fitted around the shaft and is located in the receiving place. The safety belt base includes a first portion and a second portion, wherein the first portion has a ring. The second portion has a sleeve and a reinforcement portion, wherein the sleeve is surrounded by the ring and is adapted to be connected to the safety belt. The reinforcement portion is embedded within the ring. 
     To achieve the above object of the present invention, the present invention provides a safety belt base. The safety belt base is adapted to be disposed in a fall protection device and includes a first portion and a second portion, wherein the first portion has a ring and is adapted to be wrapped by a safety belt. The second portion has a sleeve and a reinforcement portion connected to the sleeve, wherein the sleeve is surrounded by the ring and is adapted to be connected to the safety belt. The reinforcement portion is embedded within the ring. 
     With the reinforcement portion buried within the sleeve of the safety belt base, the first portion and the second portion could be firmly fixed together and could not break apart easily. 
    
    
     
       BRIEF DESCRIPTION OF THE A PLURALITY OF VIEWS OF THE DRAWINGS 
       The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which 
         FIG. 1  is a perspective view of the fall protection device of an embodiment according to the present invention; 
         FIG. 2  is an exploded view of the fall protection device according to the embodiment shown in  FIG. 1   
         FIG. 3  is an exploded view of the fall protection device according to the embodiment shown in  FIG. 1 ; 
         FIG. 4  is a perspective view of the safety belt base of the fall protection device according to the embodiment shown in  FIG. 1 , disclosing the reinforcement portion is embedded within the ring; 
         FIG. 5  is a perspective view of the second portion of the fall protection device according to the embodiment shown in  FIG. 1 ; 
         FIG. 6  is a schematic diagram, showing the breaking parts is forced to spin out to be abutted against the blocking portions respectively; 
         FIG. 7  is a side view, disclosing the relationship among the decelerating member, the safety belt base, and the safety belt. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A fall protection device  100  according to an embodiment of the present invention is shown in  FIG. 1  to  FIG. 7 , wherein the fall protection device  100  is adapted to be connected to a safety belt  200  and includes a frame  10 , a shaft  20 , and a safety belt base  30 . In the current embodiment, the fall protection device  100  further includes a decelerating member  40 , a braking plate  50 , a braking assembly  60 , a spiral spring  70 , a lateral cover  80 , and a housing  90 . 
     The frame  10  includes a frame body  12  and a hanging ring  14  which is engaged with a top of the frame body  12 . The frame body  12  forms a receiving place. The frame body  12  has two side plates  121 ,  122  which face each other. Two perforations  123 ,  124  are respectively and correspondingly disposed on the side plates  121 ,  122 . Moreover, one of the side plates (i.e., the side plate  121 ) has a blocking portion  125 . Preferably, in the current embodiment, the side plate  121  has two blocking portions  125 . The hanging ring  14  is adapted to be connected to or be fixed on a stable support as a pivot. The support could be a cable or a post, etc. However, the support is not limited to the examples given above. 
     The shaft  20  is disposed on the frame  10 . In the current embodiment, two ends of the shaft  20  penetrate through the perforations  123 ,  124  of the side plates  121 ,  122  respectively. 
     The safety belt base  30  fits around the shaft  20  and is located in the receiving place. The safety belt base  30  has a first portion  32  and a second portion  34 . As shown in  FIG. 4  and  FIG. 5 , the first portion  32  has a ring  322 , and the second portion  32  has a sleeve  342  and a reinforcement portion connected to the sleeve  342 . The sleeve  342  is surrounded by the ring  322  and is adapted to be connected to the safety belt  200 . The reinforcement portion is embedded within the ring  322 . In the current embodiment, the reinforcement portion includes a plurality of pillars  344 . The pillars  344  are set at intervals within the ring  322 . Moreover, the first portion  32  further includes a first base plate  324 , wherein a side of the first base plate  324  is connected to the ring  322 ; the second portion  34  further includes a second base plate  346 , wherein a side of the second base plate  346  is connected to the sleeve  342  and the plurality of pillars  344  of the reinforcement portion. The second base plate  346  is embedded in the first base plate  324 . Referring to  FIG. 7 , in the current embodiment, the ring  322  has an opening gap  323 , wherein an end of the safety belt  200  is connected to or is mounted between the ring  322  and the sleeve  342 , and the rest part of the safety belt  200  passes through the opening gap  323  and is wound around an outer peripheral surface of the ring  322 . 
     In an embodiment, the first portion  32  is made of plastic material, and the second portion  34  is made of metal material. For example, in the current embodiment, the second portion  34  is made of steel, and the first portion  32  is made of engineering plastics. The method for manufacturing the safety belt base  30  could be a secondary covering buried injection molding, a metal-plastic hybrid injection molding, or etc. However, such method is not limited to the examples given above. For instance, the second portion  34  is fixed in a mold at first, and then the first portion  32  of the first base plate  324  and the ring  322  is formed by an injection molding, wherein the first base plate  324  and the ring  322  cover the second base plate  346  and the reinforcement portion of the second portion  34  respectively. With such design, both the reinforcement portion (such as the plurality of pillars  344 ) and the second base plate  346  support and reinforce a framework of the first portion  32 . Therefore, the first portion  32  could be firmly engaged with the second portion  34  and could not be disengaged easily. 
     The decelerating member  40  has a perforation  42  and is fitted around the shaft  20  via the perforation  42  to be located in the sleeve  342 . An outer peripheral surface of the decelerating member  40  has a plurality of friction surfaces  41  being in contact with an inner peripheral surface  340  of the sleeve  342 . For instance, the plurality of friction surfaces  41  and the inner peripheral surface  340  are tight fit. Moreover, the decelerating member  40  further provides with a plurality of positioning holes  44 . 
     The braking plate  50  has a central hole  52  which is adapted to connect to an end of the shaft  20 . In the current embodiment, the central hole  52  is square in shape, and the end of the shaft  20  has a positioning portion  22 , so that the positioning portion  22  is wedged in the central hole  52 . Furthermore, the braking plate  50  further has a plurality of positioning holes  54 . In an embodiment, a plurality of positioning members (such as a bolt) could be threaded through the positioning holes  54  of the braking plate  50  to be fixed in the positioning holes  44  of the decelerating member  40 , so that the braking plate  50  could move synchronously with the decelerating member  40 . 
     The braking assembly  60  includes a braking part  62  and a restoring spring  64 , wherein the braking part  62  is pivotally disposed on the braking plate  50 . An end of the restoring spring  64  is connected to an end of the braking part  62 , while another end of the restoring spring  64  is connected to the braking plate  50 . The restoring spring  64  provides an elastic force to urge the braking part  62  to normally stay at a restoring position, so that the braking part  62  isn&#39;t in contact with the frame  10 . In the current embodiment, there are two sets of braking assembles  62  disposed on the braking plate  50 . 
     The spiral spring  70  is disposed inside of the lateral cover  80 , and an end  72  of the spiral spring  70  is connected to the shaft  20 . For instance, in the current embodiment, the end  72  of the spiral spring  70  is connected to a groove  24  of the shaft  20 , while another end  74  of the spiral spring  70  is engaged with the lateral cover  80 . Both of the spiral spring  70  and the lateral cover  80  are connected to a side of the side plate (i.e., the side plate  122 ) which is oriented a direction away from the side plate  121 . 
     The housing  90  is adapted to receive the frame  10 , the shaft  20 , the safety belt base  30 , the decelerating member  40 , the braking plate  50 , the braking assembly  60 , and etc. The housing  90 , in the current embodiment, includes a first half portion  92  and a second half portion  94  which could be engaged with the first half portion  92 . 
     With the aforementioned design, a first operating condition is defined when the user is in a safe condition (i.e., before the falling happens). For instance, the user walks on a place as a platform or a pallet as usual. Under the first operating condition, the braking assembly  60  is at the restoring position without being in contact with the blocking portion  125  of the frame  10 . At this time, the braking plate  50  and the decelerating member  40  rotate coaxially along with the safety belt base  30  (i.e., both of the braking plate  50  and the decelerating member  40  rotate along with the safety belt base at the same time). When the safety belt  200  is pulled and unwrapped, for example, when the safety belt is pulled due to the user moves away from the fall protection device  100 , the spiral spring  70  is stretched with the pulled safety belt  200  to provide a recovering force or an elastic force for recovering to its rolling form. While when the user approaches the fall protection device  100 , a force which pulls the safety belt  200  becomes weak and is weaker than the elastic force of the spiral spring  70 , so that the spiral spring  70  recovers to its rolling form and wraps or rolls the safety belt  200  back to the safety belt base  30 . 
     A condition when the safety belt  200  is pulled out rapidly is defined as a second operating condition. As shown in  FIG. 6 , under the second operating condition, the braking part  62  would be spun out by a torque or a centrifugal force which overcomes the elastic force of the restoring spring  64 , so that the braking part  62  is abutted against the blocking portion  125 , and braking plate  50  is then fixed. The decelerating member  40  fixed on the braking plate  50  is also fixed to be prevented from rotating. Referring to  FIG. 7 , pulling the safety belt  200  rotates the safety belt base  30  continuously. Since the inner peripheral surface  340  of the second portion  34  is conjugated with the friction surfaces  41  of the decelerating member  40 , when the safety belt base  30  rotates relatively to the decelerating member  40 , the friction surfaces  41  of the decelerating member  40  rubs the inner peripheral surface  340  to generate a rolling friction, thereby to slow down or limit the rotational speed of the safety belt base  30  and to further slowing down the unwound speed of the safety belt  200  and the falling speed of the user who is attached by the safety belt  200 . 
     With the design of the first portion  32  and the second portion  34  of the safety belt base  30  of the present invention, the reinforcement portion of the second portion  34  is buried within the ring  322  of the first portion  32 . Therefore, the second portion  34  and the first portion  32  could be engaged tightly. When the safety belt  200  bears a strong pulling force, the first portion  32  and the second portion  34  could be still firmly engaged and could be not breaking apart easily. 
     It must be pointed out that the embodiments described above are only some embodiments of the present invention. All equivalent structures which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.