MXPA00002703A - Conveyor belt cleaner and tensioner assembly - Google Patents

Abstract

A conveyor belt cleaner and tensioner assembly (30) adapted to be attached to a cross shaft (32), includes a mounting base (50) adapted to be mounted to the cross shaft (32) and an arm member (100) having a first end and a second end. The first end of the arm member is pivotally attached to the mounting base (50) for pivotal movement about a pivot axis (84). A scraper blade (102) is attached to the second end of the arm member (100). A gas spring tensioner (46) has a first end pivotally attached to the mounting base (50) and a second end pivotally attached the arm member (100). The tensioner includes a housing and a ram having a first end located within the housing and a second end located externally of the housing. The ram is extendable and retractable with respect to the housing to thereby pivot the arm member (100) and the scraper blade (102) about the pivot axis (84) The scraper blade includes a metal scraping tip having an elastomeric wear-in tip.

Description

TENSIONING AND CLEANING STRUCTURE BAND CONVEYOR Related Requests This application claims the benefit of the provisional US patent application. No. 60 / 125,167 filed March 19, 1999. BACKGROUND OF THE INVENTION The present invention is directed to a tensioning and belt conveyor cleaning structure, which includes a conveyor belt cleaner having a scraper blade that provides a constant cleaning angle. with a conveyor belt and that is resiliently derived in cleaning coupling with the conveyor belt by a tensioning mechanism. Conveyor belts handle various types of bulk materials such as sand, coal, grain and minerals. Conveyor belt cleaners remove transported material that continues to adhere to the rotating conveyor belt after the rest of the transported material has been discharged. A scraper blade of a conveyor belt cleaner can be oriented with respect to the conveyor belt surface at an obtuse or negative angle, which is referred to as a "peel" angle, or the scraper blade can be oriented at an acute or positive angle with respect to the conveyor belt which is referred to as a "scraping" angle. It has been found that the scraper blades used in connection with the conveyor belts, handle certain continuous bulk materials such as ore or minerals, clean the conveyor belt more efficiently when the scraper blades are oriented at a negative angle or detachment with respect to the conveyor belt, instead of at a scraping or positive angle. Conveyor belt cleaners having scraper blades disposed at a detachment angle tend to vibrate or rattle against the belt, which reduces the efficiency of the conveyor belt cleaner and can cause damage to the conveyor belt and belt cleaner. Another problem with scraper blades of scraper blade release angle, is that scraper blades must be precisely aligned with the belt to avoid damage to the belt, and it is difficult to achieve the desired blade contact with scraper blade during the installation of a cleaner of conveyor belt. Damage to the band usually results when a corner of a scraper blade engages the conveyor belt instead of the entire contact area of the scraper blade.

A problem encountered both by the peel angle and the scraper angle in the belt cleaner is the tendency of the conveyor belt cleaner or that the belt is damaged when the conveyor belt reverses the direction or momentarily "recedes". The conveyor belt reversal or reversal frequently occurs when the conveyor belt passes through a normal shutdown sequence. The band subsequently recoils from a few centimeters to a few tens of centimeters as the tension in the band relaxes. This recoil movement tends to trap the scraper blade, forcing the blade backwards and bending the arm on which the scraper blade is mounted, or otherwise causing the scraper blade to oscillate out of alignment. Occasionally, the scraper blades do not swing back to their original cleaning position when the conveyor belt is re-initialized, or the damage is so severe to the arm that the belt cleaner does not work anymore. Even worse is the potential to damage the belt when it resumes forward movement if the scraper blade engages in a position where only one corner of the scraper blade is in engagement against the belt. The preferred detachment angle or scraping angle with which a scraper blade engages the conveyor belt, varies depending on the type or grade of materials being transported. Conveyor belt cleaners are typically designed to operate optimally at a scraping angle or single shed angle and are not adjusted to provide changes in shedding angle or scraping angle, to allow changes in the type or degree of material transported. Conveyor belt cleaners have also required the use of external tensioners that include an elastomeric torsional member or rubber, which is twisted to store a rotational bypass force that pivots the scraper blades in coupled engagement with the conveyor belt. These external tensioners contribute cost to the conveyor belt cleaner, and if the external tensioner fails, all the scraper blades of the conveyor belt cleaner will fail or fall out of and out of cleaning attachment with the conveyor belt. External tensioners also often require re-tensioning during the lifetime of the scraper blades, since they provide a non-linear output force over their entire operating range. COMPENDIUM OF THE INVENTION A tensioning and cleaning structure of conveyor belt, adapted to be connected to a transversal arrow. A tensioning and belt conveyor cleaning structure includes a mounting base adapted to be mounted on the transverse shaft, and an arm member having a first end and a second end. The first end of the arm member is pivotally connected to the mounting base and thus to the transverse arrow for pivotal movement with respect to a first pivot axis. A scraper blade is connected to the second end of the arm member. A tensioning mechanism includes a first end, pivotally connected to the mounting base and a second end pivotally connected to the arm member. The tensioning mechanism of preference is a tensioner with a gas-operated damper, which includes a housing having a cavity and a ram having a first end located within the housing and a second end located externally of the housing. The ram is extendable and retractable with respect to the housing, so as to pivot the arm member and the scraper blade with respect to the mounting base about the pivot axis. The scraper blade is removably connected to the second end of the arm member and is pivotal with respect to the arm member with respect to a second pivot axis, which is generally perpendicular to the first pivot axis. The scraper blade includes an arc-shaped inner surface and an arc-shaped outer surface, each of which is formed by a respective radius extending from the first pivot shaft. BRIEF DESCRIPTION OF THE DRAWING FIGURES Figure 1 is a side elevational view of a scraper blade embodiment and the gas operated damper tensioner assembly of the present invention shown with a new scraper blade. Figure 2 is a side elevational view of the tensioner structure with gas driven damper and conveyor belt cleaner of Figure 1, shown with a worn scraper blade. Figure 3 is a top plan view of the conveyor belt cleaner of the gas driven damper tensioner structure and conveyor belt cleaner. Figure 4 is a side elevation view of the conveyor belt cleaner taken on line 4-4 of Figure 3. Figure 5 is a top plan view of a mounting member of the conveyor belt cleaner. Figure 6 is a side elevation view taken on line 6-6 of Figure 5. Figure 7 is a top plan view of the arm member of the conveyor belt cleaner.

Figure 8 is a side elevational view of the arm and blade member of the conveyor belt cleaner. Figure 9 is a front elevational view of the scraper blade of the conveyor belt cleaner. Figure 10 is a side elevational view taken on line 10-10 of Figure 9. Figure 11 is a partial cross-sectional view of the gas-operated shock absorber tensioner. Figure 12A is a side elevational view of a modified embodiment of a scraper blade shown at a first release angle with respect to the conveyor belt. Figure 12B is a side elevational view of the scraper blade of Figure 11, which is illustrated at a second detachment angle with respect to the conveyor belt. Figure 13 is a side elevation view of the scraper blade of Figure 11, which is illustrated at a scraping angle with respect to the conveyor belt. Figure 14 is an enlarged partial cross-sectional view of the scraping tip of the modified scraper blade embodiment. Figure 14A is an enlarged partial cross-sectional view of a modified scraping tip.

Figure 15 is a perspective view of the conveyor belt cleaner of a modified embodiment of a gas-actuated shock absorber tension structure and conveyor belt cleaner. Figure 16 is a front elevational view of the modified embodiment of the gas-operated cushion tensioner and conveyor belt cleaner tensioning structure, including a conveyor belt cleaner as illustrated in Figure 15. Figure 17 is a view in FIG. Lateral elevation of the tensioning structure with gas-operated shock absorber and conveyor belt cleaner. Figure 18 is a side elevational view of the tensioner structure with gas driven damper and conveyor belt cleaner illustrated with a new scraper blade. Figure 19 is a side elevational view of the tensioner structure with a gas driven damper and conveyor belt cleaner shown with a worn scraper blade. Figure 20 is a schematic diagram illustrating how the cleaning angle of the scraper blade in the present invention is determined. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES One embodiment of the belt tensioner and belt cleaning structure of the present invention is illustrated in Figures 1 to 10 and identified with the reference number 30. As illustrated in Figures 1 and 2, The tensioning and cleaning structure of conveyor belt 30 is connected to and supported by an elongated cross shaft 32. The transverse shaft 32 is a tubular member such as a circular pipe, which includes a generally circular longitudinal bore 34 extending between the ends of the shaft. transverse arrow 32. The transverse arrow 32 and the perforation 34 include a longitudinal central axis 36. The transverse arrow 32 is preferably mounted at each end with a respective stationary structure such as a conveyor channel. The transverse arrow 32 is mounted on a stationary structure such that the transverse arrow 32 can be selectively rotated about the central axis 36 and can be selectively locked in place to prevent rotation with respect to the central axis 36. Alternatively, the transverse arrow 32 can be mounted for be linearly adjustable. The belt tensioner and belt cleaning structure 30 is illustrated in Figures 1 and 2 in engagement with a moving conveyor belt 38 having an outer surface 40. The belt 38 illustrated in Figures 1 and 2 moves in a left direction on the right as indicated by the arrow or pointed end of the conveyor belt 38. The tensioner and belt conveyor cleaning structure 30 can be employed as a secondary cleaner as illustrated in Figures 1 and 2, wherein the conveyor belt tensioning and cleaning structure 30 engages the return stroke of the conveyor belt 38, or the belt tensioner and cleaning structure 30 can be used as a primary conveyor belt cleaner, wherein the tensioning and cleaning structure of conveyor belt 30 couples the conveyor belt 38 to the main pulley of the conveyor. The belt tensioner and cleaning structure 30 includes a conveyor belt cleaner 44 and a conveyor belt tensioner-cleaner 46. The conveyor belt cleaner 44, as illustrated in Figures 3 and 4, includes a mounting base 50 that comprises an upper mounting member 52 and a lower mounting member 54. As best illustrated in Figures 5 and 6, the upper mounting member 52 includes a semicircular sleeve in general 56, having a first generally planar end wall 58 and a second generally planar spaced end wall 60. The first and second end walls 58 and 60 extend generally parallel to each other and are located in a common plane 62. The sleeve 56 includes a generally semicircular outer surface 64 and an inner surface generally semicircular 66, each of which extends from the first end wall 58 to the second end wall 60. The sleeve 56 it includes a first side wall 68 and a second spaced and generally parallel side wall 70. A central axis 72 is located in the plane 62 halfway between and generally parallel to the end walls 58 and 60. The outer surface 64 and the surface interior 66, each are formed with respect to a respective radius of the central axis 72. A pair of spaced apart and generally parallel perforations 74 extend from the first end wall 58 through the outer surface 64, in a direction generally perpendicular to the first end wall 58 and plane 62. A second pair of spaced apart and generally parallel perforations 76 extend through second end wall 60 and outer surface 64 in a direction generally parallel to second end wall 60 and plane 62. The perforations 74 and perforations 76 are located in a generally rectangular configuration with respect to each other. The mounting member 52 also includes a mounting lug 80A and a spaced and generally parallel mounting lug 80B. Each mounting lug 80A and 80B includes a first end that connects to the outer surface 64 of the sleeve 56 and an outer second that includes a generally circular opening 82. The mounting lug 80A is connected to the outer surface 64 adjacent to the first side wall 68 and the mounting lug 80B is connected to the outer surface 64 adjacent the second side wall 70. The opening 82 of the mounting lug 80A and the opening 82 of the mounting lug 80B are located concentrically to a pivot axis 84. As illustrated in Figure 6, the pivot shaft 84 is generally parallel to the central axis 72 and is located at an approximate angle of 67.5 ° to the plane 62 as measured relative to the central axis 72. The lower mounting member 54 of the mounting base 50 is constructed substantially identical to the upper mounting member 52. As illustrated in FIG. 4, the lower mounting member 54 includes a generally semicircular groove 86 and a cover r of mounting lugs 88A and 88B which are connected to the sleeve 86. Each mounting lug 88A and 88B includes a circular opening 90. Each opening 90 is concentrically located with respect to a pivot axis 92, which is generally parallel to the central axis 72. The pivot shaft 92 is located at an approximate angle of 67.5 ° to the plane 62 as measured relative to the central axis 62. As best illustrated in Figures 1 and 2, the upper mounting member 52 and the lower mounting member 54 they are placed around the cross arrow 32, such that the inner surface 36 of the mounting members 52 and 54 engage the outer surface of the transverse arrow 32. The end walls 58 and 60 of the respective mounting members 52 and 54 are spaced slightly apart from each other. Fasteners extend through the perforations 74 and 76 in the upper mounting member 52 and through the perforations 74 and 76 in the lower mounting member 54. The fasteners tighten and hold the upper mounting member 52 and the mounting member lower 54 to the transverse arrow 32, such that the mounting base 50 is held stationary to the transverse arrow 32 for joint rotation with the transverse arrow 32. The mounting base 50 does not rotate with respect to the transverse arrow 32. As is illustrated in Figure 1, the upper mounting member 52 is connected to the lower mounting member 54, such that the openings 82 in the mounting lugs 80A and 80B and a pivot shaft 84 are located at an angle of approximately 135 ° with respect to the openings 90 of the mounting lugs 88A and 88B and the pivot shaft 92 as measured with respect to the axis 36. The conveyor belt cleaner 44 also includes an arm and blade structure 98 as is illustrated in Figure 8, which has an arm member 100 and a scraper blade 102 that is pivotally connected to the arm member 100. As best illustrated in Figures 7 and 8, the arm member 100 includes an elongated arrow 104. having a longitudinal central axis 106. The arrow 104 comprises a tubular member having a longitudinal bore 105. The outer end of the arrow 104 includes a threaded bore 107 located concentrically on the axis 106. A bracket 108 is connected at the outer end of arrow 104 and extends radially outwardly from arrow 104. Clamp 108 includes a tab 109 projecting outward, beyond the outer end of arrow 104 in a direction parallel to axis 106. Clamp 108 also includes a threaded bore 110 which is in communication with the threaded bore 107 and which is generally perpendicular to the axis 106. A threaded adjusting screw is located in the per 110. A tubular sleeve 112 is connected transversely to the second end of the arrow 104. The tubular sleeve 112 includes a generally circular perforation 114 having a central longitudinal axis 116. A stop arrow member 118 is connected to the tubular sleeve 112 and it extends outwardly from the tubular sleeve 112 concentrically on the shaft 106 to an outer end 120. The stop member 118 is connected to the tubular sleeve 112 on a side diametrically opposite the arrow 104. The stop member 118 may include a screw of adjustment or other adjustment mechanism for the space between the stop member 118 and the sleeve 112, to allow different mounting positions and blade configurations. A pair of spaced apart and generally parallel mounting lugs 122A and 122B are connected to the arrow 104. Each mounting lug 122A and 122B includes an opening 124. The openings 124 of the mounting lugs 12A and 122B are concentrically located on an axis. pivot 126. Pivot shaft 126 is generally parallel to shaft 116. As illustrated in Figures 3 and 4, arm member 100 is pivotally connected to mounting base 50 for pivotal movement relative to pivot axis 84. The tubular sleeve 112 of the arm member 100 is located between the mounting lugs 80A and 80B of the upper mounting member 52, such that the bore 114 is aligned with the openings 82 and such that the shaft 116 is generally coaxial with the shaft. pivot 84. A generally cylindrical pin 128 extends through the openings 82 in the mounting lugs 80A and 80B, through the bore 114 of the sleeve 102 for pivotally connecting the arm member 10. 0 to the mounting base 50 for selective pivotal movement with respect to the pivot axis 84 and the coaxial shaft 116. The pin 128 is preferably made of a metal like bronze. The arm member 100 is preferably made of a metal such as steel. The blade scraper 102 in the structure of the arm and reels 98, as best illustrated in Figures 9 and 10 are generally formed with a curved plate. The scraper blade 102 includes a mounting base 130 having an opening 132 adapted to align with the threaded bore 107 at the end of the arrow 104 of the arm member 100. The mounting base 130 also includes an open-ended slot 131 in the bottom end of the mounting base 130. The slot 131 includes opposite side walls 133A and 133B, which are arranged at an angle such as 15 ° to each other. The slot 131 is adapted to receive the tongue 109 from the bracket 108 of the arm 100.

The scraper blade 102 includes a scraping tip 134 connected to the mounting base 130. The scraping tip 134 includes a wear-resistant scraping element 135, which can be formed from tungsten carbide, a ceramic material or the like. The scraper blade 102 includes a generally concave inner surface 136 that is configured to generally conform to an arc of a circle. The inner surface 136 extends from the upper end of the scraping tip 134 to the bottom end of the mounting base 130. The scraper blade 102 also includes a generally convex outer surface 138 which is generally adapted to an arc of a circle. The outer surface 138 is generally spaced equidistant from the inner surface 136. Both of the inner surface 136 and the outer surface 138 are formed as an arc of a circle wherein each circle has the same center point with the center point located on the axes coaxial 84 and 116. The inner surface 136 and the outer surface 138 each are formed by a respective radius extending from the coaxial axes 84 and 116. In a configuration of the scraper blade 102, the inner surfaces 136 are formed as an arc of a circle having a radius of about 245.4 millimeters and the outer surface 138 being formed as an arc of a circle having a radius of about 257.9 millimeters, wherein each radius originates from the same center point on the pivot axis 84. scraping point 134 includes a generally planar end wall 140 extending from the outer surface 138 of scraping element 135. The former edge The scraper element 135 forms a generally linear scraping edge 142 on the upper end of the inner surface 136. The end wall 140 is located at an angle of approximately 135 ° with respect to a plane 144 extending through the scraping edge 142 and the bottom edge of inner surface 136 as measured with respect to scraping edge 142. Scraper blade 102 includes a first side wall 146 and a second, generally parallel, spaced side wall 148. Mounting base 130 of the scraper blade 102 includes a generally planar and circular recess 149, located at each end of the opening 132, respectively formed on the inner surface 136 and the outer surface 138. A bushing 150 having a circular opening 151 is located in the opening 132 As best illustrated in Figure 8, the scraper blade 102 connects removably and pivotally to the outer end of the arrow 104 of the arm member 100 by a clamp. or 150 such as a bolt, which extends through the opening 132 and the opening 151 in the bushing 150, such that the scraper blade 102 can pivot or oscillate with respect to the axis 106 and with respect to the rod of the fastener 150 with respect to to the arm member 100. The adjustment screw in the bore 110 is clamped against the rod of the fastener 150 to prevent the fastener 150 from rotating with respect to the axis 106. The scraper blade 102 can oscillate approximately 7.5 ° with respect to the axis 106 in either direction from a neutral position where the tongue 109 is located within the slot 131 halfway between the side walls 133A and 133B for a total of 15 ° of movement. The scraper blade 102 can pivot or oscillate about the axis 106 until the side wall 133A or 133B engages the tongue 109. The scraper blade 102 can thus oscillate about the axis 106 within limits to align with the surface 40 of the web. 38 and to adjust to changes in the configuration of the band 38. The scraper blade 102 is preferably mounted on the arm member 100, such that the respective circles or radii that are formed from the inner surface 136 and the outer surface 138 have a common center point located on the pivot shaft 84. The inner surface 136 and the outer surface 138 therefore both will maintain a constant angle of cleaning engagement with the outer surface 40 of the conveyor belt 38, as the tip scraping 134 of scraper blade 102 wears due to its engagement with the rotating band. The scraper blade 102 can be made of a metal, such as T-l steel or tungsten carbide, a ceramic material or an elastomeric material such as urethane. 150 rotates about the axis 106. The scraper blade 102 may oscillate approximately 7.5 ° to the axis 106 in either direction from a neutral position where the tongue 109 is located within the slot 131 halfway between the side walls 133A and 133B for a total of 15 ° of movement. The scraper blade 102 can pivot or oscillate about the axis 106 until the side wall 133A or 133B engages the tongue 109. The scraper blade 102 can thus oscillate about the axis 106 within limits to align with the surface 40 of the web. 38 and to adjust to changes in the configuration of the band 38. The scraper blade 102 is preferably mounted on the arm member 100, such that the respective circles or radii that are formed from the inner surface 136 and the outer surface 138 have a common center point located on the pivot shaft 84. The inner surface 136 and the outer surface 138 therefore both will maintain a constant angle of cleaning engagement with the outer surface 40 of the conveyor belt 38, as the tip scraping 134 of scraper blade 102 wears due to its engagement with the rotating band. The scraper blade 102 can be made of a metal, such as T-l steel or tungsten carbide, a ceramic material or an elastomeric material such as urethane.

The conveyor belt tensioner-tensioner 46 as illustrated in Figure 11 includes a generally cylindrical housing 156 having an elongate generally cylindrical cavity therein formed. A mounting lug 158 having a formed opening is connected to a first end of the housing 556. An elongate cylindrical generally ram 160 has a first end located within the housing cavity 156 and a second end projecting outwardly from the housing. the housing 156. The first end of the ram 160 slidably engages the wall of the cavity and includes a valve. A mounting lug 162 including a generally circular opening is connected to the second end of the ram 160. The ram 160 includes a central longitudinal axis 164. The central axes of the openings in the mounting lugs 158 and 162 are generally parallel to each other. yes and extend through the central axis 164. The ram 160 is slidable with respect to the housing 156 on the central axis 164, such that the ram 160 extends selectively, wherein the mounting lug 162 moves away from the housing 156 and in such a way that the ram 160 is selectively retractable, wherein the mounting lug 162 moves closer to the housing 156.

The mounting lug 158 of the housing 156 is pivotally connected to the mounting lugs 122A and 122B of the arm member 100 by a generally cylindrical pin 170. The pin 170 extends through the openings 124 in the mounting lugs 122A and 122B and the opening in the mounting lug 158. The tensioner 46 is thus pivotally movable with respect to the arm structure and blade 98 relative to the pivot shaft 126. The mounting lug 162 of the ram 160 is pivotally connected to the lugs of assembly 88A and 88B of the lower mounting member 54 by a generally cylindrical pin 172. The pin 172 extends through the openings 90 in the mounting lugs 88A and 88B and the opening in the mounting lug 162. The tensioner 46 this way is pivotally movable relative to the mounting base 50 with respect to the pivot axis 84. The pins 170 and 172 are preferably made from metal such as brass. As best illustrated in Figures 1 and 2, the pivot axes 84, 92 and 126 are generally parallel to each other and are located in a generally triangular position with respect to each other. A preferred conveyor belt tensioner-cleaner 46 is a linear hydro-pneumatic actuator commonly referred to as a gas-operated damper tensioner as illustrated in Figure 11, which has an approximately linear relationship between the position of the ram 170 and the force output. A tensioner with a preferred gas-operated damper is manufactured by AVM under model No. AHP 6240. A gas-actuated damper-damper provides an almost constant linear force output between a first fully retracted position of the ram 160 and a second fully extended position. of the ram 160. The approximately constant amount of force that is provided by the gas-operated tensioner-damper 46, in combination with the configuration of the scraper blade 102 and the manner in which the scraper blade 102 is connected to the arm member 100 for pivotal movement with respect to the pivot axis 84, allows the scraper blade 102 to engage the conveyor belt 38 with an approximately constant cleaning pressure between the scraper blade 102 and the outer surface 40 of the conveyor belt 38 over the wear life of the scraper blade 102. The tensioner 46 may alternatively comprise an electromagnetic actuator or a Sorte mechanical constant force, which provides a force of output generally constant over its operating range. The gas-operated tensioner-damper 46 includes a compressed gas 166, such as nitrogen and liquid 168, such as a hydraulic oil, located within the housing cavity 156. The liquid 168 functions to dampen the movement of the ram 160. The movement damped of the ram 160 with respect to the housing 156, reduces the vibration or rattling of the scraper blade 102 against the conveyor belt 38 that the scraper blades oriented at a detachment angle of another shape are generally tending to generate. As the gas-operated tensioner-damper 46 dampens the tendency of the scraper blade 102 to vibrate, the scraper blade 102 can be used over a wide range of different release angles. The scraper blade 102 can therefore be used at an optimum cleaning angle for a particular set of conditions as determined by variables such as belt speed, belt condition and the type of material transported. The ram 160 in the gas-actuated tensioner-damper 46 has a reaction constant that is significantly greater than that of the elastomeric or rubber torsion springs, which have typically been used to tension secondary conveyor belt cleaners. The conveyor belt cleaner 44 is therefore much less likely to be adversely affected by the recoil of the conveyor belt than conveyor belt cleaners stressed by the torsion springs. As illustrated in Figures 1 and 2, the scraper blade 102 is oriented at a negative detachment angle of 45 ° with respect to the conveyor belt 38. In applications where web recoil is a problem, the preferred cleaning angle It is a scraping angle. In operation, the transverse arrow 32 is mounted in a desired position with respect to the conveyor belt 38 in order to place the scraper blade 102 at a desired cleaning angle with respect to the web 38. The upper mounting member 52 and the member of the lower mounting 54 are then placed around the transverse arrow 32 and fastened together so that the mounting members 52 t 54 are securely fixed to the transverse arrow 32. Alternatively, the mounting lugs 80A and 80B and the mounting lugs 88A and 88B can be connected directly to the cross shaft 32 by welding or the like if desired. The transverse arrow 32 is rotated about the axis 36 to engage the scraper blade 102 against the band 38. Continuous rotation of the transverse arrow 32 compresses the ram 160 of the tensioner with gas-operated damper 46 into the housing 156, such that the ram 160 derives scraper blade 102 in engagement with strip 38. In alternate form, the transverse arrow 32 is linearly adjusted to compress the ram 160. The transverse arrow 32 is then locked in place, such that the transverse arrow 32 does not rotate about the axis 36 after the initial desired compression of the gas-operated shock absorber 46. The tensioner with gas-operated shock absorber 46 is typically compressed until approximately 10 millimeters from the ram 160 are shown. As illustrated in Figure 1, the conveyor belt cleaner 44 includes a new scraper blade 102. The gas-operated damper tensioner 46 exerts a resilient branch force against the arm member 100 and attempts to pivot the arm structure and blade 98 in a counterclockwise direction, as shown in Figure 1 with respect to pivot shaft 84. Gas-operated tensioner-damper 46 in this manner resiliently derives scraping edge 142 from scraper blade 102, in engagement with the conveyor belt 38, with a desired amount of force. As the scraping tip 134 of the scraper blade 102 wears due to its engagement with the rotating belt 38, the gas-operated tensioner-damper 46 will pivot the scraper blade 102 relative to the pivot shaft 84 in continuous shunt engagement with the conveyor belt 38 The gas-operated tensioner-damper 46 will bypass the scraper blade 102 in continuous engagement with the conveyor belt, with approximately the same amount of force over the useful life of the scraper blade 102, since the interior surface 136 and the outer surface 138 of the scraping tip 134 are equally spaced apart from each other, such that the scraping tip 134 has a relatively constant thickness and width, the magnitude of the pressure with which the scraping tip 134 engages the conveyor belt 38, will also remain approximately constant on the wear life of the scraper blade 102. As best illustrated in exaggerated scale in the Figure 2, once the scraping tip 134 of the scraper blade 102 has worn to the point where the scraper blade 102 requires replacement, the stop arrow member 118 of the arm member 100 engages the outer surface of the mounting member 52 to prevent the arm member 100 and the scraper blade 102 from pivoting further in the counterclockwise direction as illustrated in Figure 2 with respect to the pivot shaft 84. The stop arrow member 118 in this manner prevents that the arm member 100 and the holder 150 are pivoted in engagement with the conveyor belt 38. Once the scraper blade 102 wears completely as illustrated in exaggerated scale in Figure 2, the cross shaft 32 can be rotated about the axis 36 for pivoting the conveyor belt cleaner 44 and the scraper blade 102 away from the conveyor belt 38. The holder 150 can then be removed to allow removal and replacement of the scraped blade 102. The pivot shaft 84 with respect to which the scraper blade 102 pivots can be placed in various different positions with respect to the outer surface 40 of the conveyor belt 38 as desired, in order to provide a desired cleaning angle between the blade. scraper 102 and outer surface 40 of web 38. Scraper blade 102 can be used at a release angle or at a scraping angle as desired. The arcuate configuration of the scraper blade 102 and its orientation relative to the pivot axis 84 with respect to which the scraper blade 102 pivots provide a constant cleaning angle between the scraper blade 102 and the conveyor belt 38 no matter how far the cleaner is mounted. of conveyor belt 44 of the conveyor belt 38. When the pivot shaft 84 is located vertically higher than the point where the central axis 106 intersects the inner surface 138 of the scraper blade 102, the scraper blade 102 is placed at a scraping angle positive with respect to the conveyor belt 38. When the pivot shaft 84 is located vertically lower than the point of intersection between the pivot shaft 106 and the inner surface 136 of the scraper blade 102, the scraper blade 102 is positioned at a negative release angle with with respect to the conveyor belt 38. Figure 20 schematically illustrates how the belt tensioning and cleaning structure The conveyor 30 can be selectively positioned with respect to the outer surface 40 of the conveyor belt cleaner 38 to position the scraper blade 102 at the desired cleaning angle with respect to the belt 38. As illustrated in FIG. 20, the inner surface 136 and the scraping edge 142 of the scraper blade 102 is located at a radius A from the pivot shaft 84. The inner surface 136 is formed as an arc of a circle having a radius A. The cleaning angle of the scraper blade 102 with respect to the surface 40 of the conveyor belt 38, is the angle D between the surface 40 of the conveyor belt 38 and a plane 176 extending through the intersection of the scraping edge 142 and the surface 40 and which is tangent to the inner surface 136. The angle E as illustrated in Figure 24 is equal to the cleaning angle D. The angle E is between a radius F extending between the pivot axis 84 through the intersection of the edge of the scraping 142 and the surface 40 of the conveyor belt 38 and a line G extending through the pivot axis 84 which is generally perpendicular to the surface 40. The radius A is equal in length to the radius F. Since the length of the radius A is known by a particular belt tensioner and cleaning structure 30, the distance B in which the pivot shaft 84 must be positioned from the surface 40 of the conveyor belt 38 to obtain the desired angle E, which corresponds to the desired cleaning angle. D can be determined through trigonometric equations such as cosine of E = B divided by F. The distance C can also be determined through trigonometric equations such as sine E = C divided by F. As an example, if the distance B equals the distance C, the angle E and the angle D are both equal to 45 °. A plurality of tensioning structures with gas-operated shock absorber and conveyor belt cleaner 30 can be connected to the transverse shaft 32 adjacent to each other. Since each conveyor belt cleaner 44 has its own conveyor belt tensioner-cleaner 46, the failure of a tensioner 46 will not affect the cleaning ability of the remaining conveyor belt cleaner 44, which is mounted on the transverse shaft 32. modified embodiment of scraper blade 102 is illustrated in Figures 12A-14A, as indicated by reference numeral 180. Scraper blade 180 includes a concave inner surface 182 and a convex outer surface 184 that are configured in the same manner as interior and exterior surfaces 136 and 138 of the scraper blade 102. Scraper blade 180 includes a blade base 186 extending from a first end 188 to a second end 190. The base 186 is preferably made from metal such as steel soft or stainless steel, but can be made from an elastomeric material such as urethane. One or more wear resistant scraping elements 192 are connected to the base 186 at the first end 188. The scraping elements 192 form a portion of the inner surface 182. The scraping elements 192 can be made from wear resistant material. such as tungsten carbide or ceramic materials. The scraping elements 192 extend over the base 186 from a first end 194 to a second end 196. The scraping elements 192 extend across the entire width of the scraper blade 180. A wear tip 200 is connected to the first end. 194 to the scraping elements 192 and the first end 188 to the base 186. The wear tip 200 includes a scraping edge 202. The wear tip 200 also includes a first leg 204 extending down from the first end 194 of the scraping elements 192 on the inner surface 182. The wear tip 200 also includes a second leg 206 extending downwardly on the outer surface 184 of the base 186. The wear tip 200 thus circumscribes the first end 194 of the scraping elements 192 and the first end 188 of the base 186. The wear tip 200, preferably is formed from a material that is considerably less resistant to wear than the material that forms the scraping elements. A preferred material is an elastomeric material such as urethane having a durometer such as 70 Shore D. The urethane material is bonded to the metal scraping elements 192 and the metal base 186. The wear tip 200 can alternatively be made from a metallic material such as bronze or lead, silver alloys, copper, tin, lead or low abrasion materials such as adhesives or charged epoxies. The alloys can be applied as solder. Figure 12A shows the scraping blade 180 positioned at a negative cleaning angle of 30 ° with respect to the conveyor belt 38. Figure 12B illustrates the scraper blade 180 located at a negative cleaning angle of 45 ° with respect to the web. conveyor 38. Figure 13 illustrates the scraper blade 180 positioned at a positive cleaning angle of 2.7 ° with respect to the conveyor belt 38. The scraper blade 180 can be used at various other positive or negative cleaning angles, as desired. The wear tip 200 of the scraper blade 180 allows the scraper blade 180 to be installed at any cleaning angle and allows the scraping tip to be worn out before the wear resistant scraping elements 192 engage the conveyor belt 38. The tip of wear 200, thus eliminating the potential damage that is sometimes caused to the conveyor belts 38 when only a portion of a new scraper blade is coupled by the conveyor belt, instead of the entire width of the scraper blade. The wear tip 200 of the scraper blade 180 eliminates this problem since the wear tip 200 will not damage the band 38 if the scraper blade 180 is initially misaligned with respect to the band. Figure 14A shows a modified embodiment of the scraper blade 180 'where the first end 194' on the scraping element 192 is formed in a semi-circular structure as opposed to a planar shape as illustrated in Figure 14. The semi-form curved circular of the first end 194 'is a wear tip 200' that will prevent damage to the band when the first end 194 'initially couples the band, regardless of the angle of attack of the scraper blade 180.

A modified embodiment of the conveyor belt tensioning and cleaning structure 30 is illustrated in Figures 15 to 19, as the conveyor belt tensioning and cleaning structure 220. The conveyor belt tensioning and cleaning structure 220 is adapted to be removably mounted to the arrow transverse 32. The conveyor belt tensioner and cleaning structure 220 includes a conveyor belt cleaner 222, a pair of mounting bases 224A and 224B and a conveyor belt tensioner-cleaner 226. The tensioner 226 is constructed essentially identical to the tensioner 46 and it preferably comprises a gas-actuated shock absorber tensioner. The mounting bases 224A and 224B each include a first semi-circular mounting sleeve in general 230 and a second generally semi-circular mounting sleeve 232. The second mounting sleeve 232 includes an outwardly extending lug 234 having an opening generally circular 236. The second mounting sleeve 232 is removably connected to the first mounting sleeve 230 by a plurality of fasteners 238 in the same manner that the mounting members 52 and 54 are removably connected to each other. The mounting bases 224A and 224B are stationary fastened to the transverse arrow 32 such that the mounting bases 224A and 224B do not rotate with respect to the transverse arrow 32. The conveyor belt cleaner 222 includes a mounting base 244, a arm member 246 and a scraper blade 248. The mounting base 244 includes a first generally semicircular mounting sleeve 250 and a second generally semi-circular mounting sleeve 252. The first and second mounting sleeves 250 and 252 are connected to each other around of the transverse arrow 32 by fasteners in the same manner as the mounting sleeves 230 and 232. However, the mounting base 244 formed by the connected mounting sleeves 250 and 252 is rotatable with respect to the transverse arrow 32. arm member 246 has a generally inverted U-shape with opposite side walls. The arm member 246 includes a mounting plate 256 at a first end and is connected at a second end to the second mounting sleeve 252. The scraper blade 248 is removably connected to the mounting plate 256 at a first end of the arm member. 246 by one or more fasteners 238. Scraper blade 248 is formed similar to blade scraper 102. Scraper blade 248 is connected to arm 246 and mounting base 244 such that the center or origin of the radius that forms an inner surface arc 260 of the scraper blade 248, and the common center or origin of the radius forming the arcuate outer surface 232 of the scraper blade 248 are located on the shaft 36. The arm member 246 and scraper blade 248 are pivotal relative to the central shaft 36 The tensioner 226 is located partially within the U-shaped arm member 246 between the side walls. The tensioner 226 is pivotally connected to the lugs 234 of the mounting arms 224A and 224B by a pin 266, and the opposite end of the tensioner 226 is pivotally connected to the arm member 246 as a pin 268. The base of the mounting 244 of the wiper conveyor belt 222 is located adjacent to and between the bases of assembly 224A "and B. Figure 18 shows the tensioning and cleaning structure of conveyor belt 220 connected to cross shaft 32 with a new scraper blade 248 in clean coupling with the conveyor belt. 38. As shown in Figure 19, as the scraper blade 248 wears, the ram of the gas-operated tensioner-damper 226 extends from the tensioner housing 226 and pivots the arm member 246 and scraper blade 248 about the shaft. 36, to maintain the scraper blade 248 in bypass coupling with the outer surface 40 of the conveyor belt 38.

Various characteristics of the invention have been shown and described particularly in connection with the illustrated embodiments of the invention, however it will be understood that these particular assemblies merely illustrate and that the invention should be given its complete interpretation within the terms of the attached claims.

Claims (27)

1. CLAIMS 1.- A tensioning and cleaning structure of conveyor belt adapted to be connected to a transversal arrow, the tensioning and cleaning structure of conveyor belt is characterized in that it includes: a mounting base adapted to be mounted on the transversal arrow; an arm member having a first end and a second end, the first end of the arm member is pivotally connected to the transverse arrow for pivotal movement with respect to the pivot axis; a scraper blade is connected to the second end of the arm member; and a bypass mechanism having a first end pivotally connected to the mounting base and a second end pivotally connected to the arm member; whereby the bypass member is adapted to pivot the arm member and the scraper blade with respect to the mounting base.
2. 2. The tensioning and cleaning structure of conveyor belt according to claim 1, characterized in that the mechanism the bypass mechanism a housing having a cavity and a ram having a first end located in the cavity and a second end located closely to the housing, the ram is extendable and retractable with respect to the housing.
3. 3. - The tensioning and cleaning structure of conveyor belt in accordance with the claim 1, characterized in that the scraper blade is removably connected to the second end of the arm member by a fastener.
4. 4.- The tensioning and cleaning structure of conveyor belt in accordance with the claim 3, characterized in that the scraper blade includes an opening having a central axis, the fastener extends through the opening, such that the scraper blade is pivotally connected to the first end of the arm member for pivotal movement with respect to the central axis of the opening with respect to the arm member.
5. 5.- The tensioning and cleaning structure of conveyor belt in accordance with the claim 4, characterized in that the scraper blade includes a slot and a first end of the arm member includes a tab located in the slot, the tab prevents a pivotal movement of the scraper blade with respect to the member beyond a predetermined limit.
6. 6. The tensioning and cleaning structure of conveyor belt according to claim 1, characterized in that the scraper blade includes an interior surface in the form of a generally arc.
7. 7. - The tensioning and cleaning structure of conveyor belt in accordance with the claim 6, characterized in that the scraper blade includes an outer surface in the generally arc shape.
8. 8. - The tensioning and cleaning structure of conveyor belt in accordance with the claim 7, characterized in that the inner surface and the outer surface of the scraper blade are formed by respective spokes extending from the pivot axis with respect to which the arm member pivots.
9. 9. The tensioning and cleaning structure of conveyor belt according to claim 1, characterized in that the mounting base includes a first lug that extends outwardly, the first end of the arm member is pivotally connected to the first lug.
10. 10. The tensioning and cleaning structure of conveyor belt according to claim 9, characterized in that the first end of the arm member includes a sleeve member, the sleeve member is pivotally connected to the first pin.
11. 11. The conveyor belt tensioning and cleaning structure according to claim 9, characterized in that the arm member includes a first stop member that extends outward from the first end of the arm member, the stop member is adapted for coupling the mounting base after the arm member has pivoted in a first pivotal direction relative to the pivot axis to a predetermined position to prevent further pivotal movement of the arm member in a first pivotal direction.
12. 12. The tensioning and cleaning structure of conveyor belt according to claim 1, characterized in that the arm member includes a lug located between the first end and the second end of the arm member, the second end of the tensioning mechanism is pivotally connected to the lug of the arm member.
13. 13. The conveyor belt tensioning and cleaning structure according to claim 9, characterized in that the mounting base includes a second lug that extends outwardly, the first end of the tensioning mechanism is pivotally connected to the second lug.
14. 14. The tensioning and cleaning structure of conveyor belt according to claim 1, characterized in that the first end of the arm member includes a base member, the base member is adapted to extend around the transverse arrow, in such a way that that the base member is pivotally connected to the transverse arrow.
15. 15. The conveyor belt tensioning and cleaning structure according to claim 1, characterized in that the mounting base includes an upper mounting member and a lower mounting member, each mounting member includes a generally semi-circular sleeve adapted to be located partially around the transverse arrow and a lug extending outwardly from the sleeve.
16. 16.- The tensioning and cleaning structure of conveyor belt in accordance with the claim 1, characterized in that the bypass mechanism comprises a gas-operated shock absorber tensioner.
17. 17.- The tensioning and cleaning structure of conveyor belt in accordance with the claim 2, characterized in that the bypass mechanism includes a compressed gas and a liquid located in the housing cavity.
18. 18. A scraper blade for a conveyor belt cleaner, characterized in that it includes: a mounting base; and a scraping tip connected to the mounting base, the scraping tip includes an outer end having a wear tip.
19. 19. - The scraper blade according to claim 18, characterized in that the scraping tip includes a generally arcuate inner surface and an outer surface in a generally arched shape, the inner surface is equally spaced generally from the outer surface.
20. 20. The scraper blade according to claim 18, characterized in that it includes a wear-resistant scraping element at the outer end of the scraping tip.
21. 21. The scraper blade according to claim 20, characterized in that the wear tip comprises a curved scraping end that is formed in the scraping element.
22. 22. The scraper blade according to claim 18, characterized in that the wear tip is connected to and substantially circumscribes the outer end of the scraping tip.
23. 23. The scraper blade according to claim 22, characterized in that the wear tip includes a first leg and a second leg, the first and second legs are arranged on opposite sides of the scraping tip.
24. 24. - The scraper blade according to claim 22, characterized in that the wear tip is formed of a material selected from the group consisting of elastomers, lead, bronze, silver, copper, tin or epoxides.
25. 25. The scraper blade according to claim 18, characterized in that the mounting base includes an opening having a central axis with respect to which the scraper blade is adapted to pivot and a slot that is adapted to limit the pivotal movement of the blade. Scraper
26. 26.- A scraper blade for a conveyor belt cleaner, characterized in that it includes: a mounting base; a scraping tip connected to the mounting base, the scraping tip includes an outer end having a scraping edge, the scraping tip is formed from a metal material; and a wear tip connected to the outer end of the scraping tip, the wear tip substantially circumscribes the outer end and the scraping edge of the scraping tip, the scraping tip is formed from a material that is relatively smooth in comparison with the metal material from which the scraping tip is formed.
27. 27. The scraper blade according to claim 26, characterized in that the tip of • wear is formed from a material selected from the group consisting of elastomers, lead, bronze, silver, copper, tin or epoxies.