SPECIFICATION

CROSS-REFERENCE TO RELATED APPLICATIONS This PCT application claims the benefit under 35 U.S.C. §119(e) of Application Serial No. 62/936,866 filed on November 18, 2019 entitled SECONDARY BELT CLEANER WITH MODULAR, TORSIONAL TENSIONED ARM AND REPLACEABLE BLADE TIPS and whose entire disclosure is 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 thatwhen 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 3C-3C 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; and

Fig. 5B is a side view functional diagram of the longer (LA) blade arm. 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 of the 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.

F ig. 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 26A and 26B; these brackets 26A/26B 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 28A releasably secured (e.g., using a fastener such as a screw, rivet, etc.) to a blade support 28B. The blade support 28B 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 of the 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 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 28A 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 28A coverage overlaps and that there is no gap in between the blade tips 28A. 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 30A and the longer (LA) blade arm 30B, 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 30A 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 28A are aligned, as shown most clearly in Fig. 3C.

In operation, the torsion spring 36 provides a bias to maintain the blade tip 28A 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 28A, 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 28B (e.g., by removing fasteners (not shown) from the apertures shown in Figs. 4A-4B) and to replace it with another new blade tip 28A; all other components of the blade device 22 are unaffected. This allows for a quick onsite rebuild.

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.