Patent Publication Number: US-2022227588-A1

Title: Secondary belt cleaner with modular, torsional tensioned arm and replaceable blade tips

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Continuation-in-Part application claims the benefit under 35 U.S.C. § 120 of application Ser. Ser. No. 17/084,909 filed on Oct. 30, 2020 which in turn claims the benefit under 35 U.S.C. § 119(e) of Application Ser. No. 62/936,866 filed on Nov. 18, 2019, and all of which are entitled SECONDARY BELT CLEANER WITH MODULAR, TORSIONAL TENSIONED ARM AND REPLACEABLE BLADE TIPS and all of whose entire disclosures are incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a blade of a conveyor belt scraper that contacts the conveyor belt surface, and more particularly, to a belt cleaner that cleans the surface on the return side of a conveyor belt after the conveyor belt payload has been discharged. 
     Cleaning devices that are installed to clean the return side of a conveyor belt are referred to as “secondary belt cleaners.” These cleaning devices typically comprise a torsionally-tensioned cleaning arm to permit relief for any large material that gets between the cleaning element and the return side of the conveyor belt. In many of these cleaning devices, a rubber or urethane tensioning element is used with the cleaning arm. Moreover, the cleaning element portion of the cleaning arm is molded into the cleaning arm. 
     However, rubber or urethane tensioning elements (or other “ROSTA” (viz., rubber suspension, oscillating and tensioning) style components) in these conventional secondary belt cleaners are susceptible to performance changes as the temperature rises and falls. Another drawback of these conventional secondary belt cleaners is that when the cleaning element becomes worn, the entire cleaning device requires replacement thereby greatly increasing the rebuild costs. 
     Thus, there remains a need for a secondary belt cleaner that is greatly insensitive to temperature changes and which permits only a cleaner blade portion to be replaced when the blade portion becomes worn. 
     All references cited herein are incorporated herein by reference in their entireties. 
     BRIEF SUMMARY OF THE INVENTION 
     A secondary belt cleaning system for cleaning the return side surface of an endless conveyor belt is disclosed. The secondary belt cleaning system comprises: a plurality of blade devices mounted to a support shaft having mounting brackets at each end of the support shaft in order to configure the plurality of blade devices to be transversely positioned against the return side surface of the conveyor belt; each one of the plurality of blade devices comprising a torsion spring (e.g., stainless steel torsion spring) to rotatably bias a replaceable blade tip (e.g., a carbide blade tip) against the return surface of the conveyor belt. 
     A method of cleaning the surface of the return side of an endless conveyor belt is disclosed. The method comprises: providing a plurality of blade devices mounted to a support shaft having mounting brackets at each end of the support shaft in order to configure the plurality of blade devices to be transversely positioned against the return side surface of the conveyor belt; and rotatably biasing a replaceable blade tip (e.g., a carbide blade tip) of each one of the plurality of blade devices against the return side surface of the conveyor belt by pretensioning a respective torsion spring (e.g., stainless steel torsion spring) within respective blade devices. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
       Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a partial side view of a conveyor belt system showing the secondary belt cleaner system of the present invention installed thereat; 
         FIG. 2  is an isometric view of the secondary belt cleaner system of  FIG. 1 ; 
         FIG. 3A  is a top plan view of the secondary belt cleaner system of  FIG. 1 ; 
         FIG. 3B  a back plan view of the secondary belt cleaner system of  FIG. 1 ; 
         FIG. 3C  is a side view of the secondary belt cleaner system taken along line  3 C- 3 C of  FIG. 3B ; 
         FIG. 4A  is an exploded front view of the blade device of the secondary belt cleaner system of the present invention; 
         FIG. 4B  is an exploded isometric view of the blade device of the secondary belt cleaner of the present invention; 
         FIG. 5A  is a side view functional diagram of the shorter (SA) blade arm; 
         FIG. 5B  is a side view functional diagram of the longer (LA) blade arm; and 
         FIG. 6  is similar to  FIG. 1  but in addition shows the location of a primary belt cleaning system (PBCS) that is not coupled to the secondary belt cleaning system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the figures, wherein like reference numerals represent like parts throughout the several views, exemplary embodiments of the present disclosure will be described in detail. 
     Throughout this description, various components may be identified having specific values, these values are provided as exemplary embodiments and should not be limiting of various concepts ofthe present invention as many comparable sizes and/or values may be implemented. 
     As shown in  FIG. 1 , the secondary belt cleaner system  20  is positioned underneath the return side  14  of the conveyor belt  10 , in a position that is transverse to the conveyor belt motion, and wherein the head portion of a plurality of blade devices  22  are in contact with the outer surface  16  of the return side  14  of the conveyor belt  10  as a head pulley  12  moves the conveyor belt  10  in the direction indicated by arrow  18 . 
       FIG. 2  is an isometric view of the secondary belt cleaner system  20  showing the plurality of blade devices  22  mounted to a support shaft  24  whose ends are releasably secured in respective mounting brackets  26 A and  26 B; these brackets  26 A/ 26 B permit the system  20  to be mounted to the conveyor belt system (not shown) in the orientation shown in  FIG. 1 .  FIGS. 3A-3C  provide different views of the secondary belt cleaner system  20 . 
     As shown in  FIGS. 4A-4B , each blade device  22  includes a head portion  28  that comprises a replaceable blade tip  28 A releasably secured (e.g., using a fastener such as a screw, rivet, etc.) to a blade support  28 B. The blade support  28 B is integrated on one end of a blade arm  30  while the other end of the blade arm  30  is coupled to a rotatable shaft  32 . The other end of the shaft  32  is positioned inside a hollow cylindrical housing  34  wherein a torsion spring  36  connects with the other end ofthe shaft  32 . A bushing  38  (e.g., ultra-high molecular weight polyethylene, etc.), concentrically located on the shaft  32 , closes off one side of the housing  34  while an end cap  40 , coupled to one end of the torsion spring  36 , closes off the other side of the housing  34 . The housing  34  is fixedly secured on the support shaft  24  via housing strut  42 . As such, the head portion  28  is thus rotatably biased  2   0  against the surface  16  of the return side  14  of the conveyor belt  10  when the system  20  is installed thereat. The replaceable blade tip  28 A may comprise a carbide material and the torsion spring  36  may comprise stainless steel. 
     It should be noted from  FIGS. 2 and 3A  that the head portions  28  of the blade devices  22  are staggered, i.e., they do not form a single line from one end of the support shaft  24  to the other. This is to ensure that the blade tip  28 A coverage overlaps and that there is no gap in between the blade tips  28 A. This achieved by using different blade arm  30  lengths for alternate blade devices  22 ; see  FIGS. 5A and 5B  which are side view functional diagrams of the shorter (SA) blade arm  30 A and the longer (LA) blade arm  30 B, respectively. However, in order to ensure that each blade tip  28 A is in contact with the surface  16  of the return side  14  of the conveyor belt  10 , the torsion spring  36  for particular blade devices  22  are pretensioned differently. By way of example only, the shorter blade arm  30 A is pretensioned to 10° with respect to a longitudinal axis of the rotatable shaft  32  while the longer blade arm  30  is pretensioned to 15° with respect to a longitudinal axis of the rotatable shaft  32 . As such, the tops of the blade tips  28 A are aligned, as shown most clearly in  FIG. 3C . In operation, the torsion spring  36  provides a bias to maintain the blade tip  28 A against the surface  16  of the return side  14  of the conveyor belt  10 . Should any large object adhering to the surface  16  be encountered by the tip  28 A, the blade arm  30  will pivot in the direction of the conveyor motion  18  ( FIG. 1 ) to provide relief thereto. Moreover, because the torsion spring  36  comprises stainless steel, it is largely insensitive to temperature changes. Furthermore, if the blade tip  28 A becomes worn, it is only necessary to remove the blade tip  28  from the blade support  28 B (e.g., by removing fasteners (not shown) from the apertures shown in  FIGS. 4A-4B ) and to replace it with another new blade tip  28 A; all other components of the blade device  22  are unaffected. This allows for a quick onsite rebuild. 
       FIG. 6  is similar to  FIG. 1  but now also shows a primary belt cleaner system PBCS used in conjunction with the secondary belt cleaning system  20  of the present invention. The PBCS cleans the payload delivery side of the conveyor belt  10 , whereas the secondary belt cleaning system  20  cleans the return side  14  of the conveyor belt  10 . As shown in  FIG. 6 , there is no coupling between the PBCS and the secondary belt cleaner system  20  of the present invention. Since there is no coupling of these two systems together, to replace any of the blade tips  28 A of the secondary belt cleaner system  20  does not require the use of any load plates or other mechanisms for displacing both the PBCS and the secondary belt cleaner system  20  just in order to replace any of the blade tips  28 A. As such, there is no need to displace any portion of the PBCS to replace any of the blade tips  28 A. 
     In contrast, in U.S. Pat. No. 8,776,990 (Felton, et al.), because the belt cleaner assembly  140  and the secondary belt cleaner assembly  150  are coupled together, applying forces to load plates  164  and  180  are required for displacing both the belt cleaner assembly  140  and the secondary belt cleaner assembly  150  away from the conveyor belt  32  in order to replace any of the blades in the secondary belt cleaner assembly  150 . 
     As such, the invention of the present application provides a more easy to use system for replacing any of the secondary cleaning system blade tips  28 A. 
     While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.