TECHNICAL FIELD

The present invention relates to conveyor systems and speci fically to a support structure for supporting a conveyor belt , such as an impact bed or impact cradle for supporting a conveyor belt in a loading zone of a conveyor system to absorb and dampen the impact force of falling aggregate . The invention also relates to a resilient wear member, such as an impact bar or a glide bar, for being releasably fixed to a frame of an impact bed or cradle or other support structure .

BACKGROUND OF THE INVENTION

Conveyor systems are commonly used in various fields of technology . In general , conveyors are used as continuous transport systems for moving resources or goods from one point to another . In mining or aggregate operations , belt conveyor systems are most- f requently used for transportation of bulk material , such as rock, crushed ore or the like . Typically, such belt conveyors comprise a frame and a conveyor belt arranged to move relative to the frame , usually supported by rollers driven for rotation .

The bulk material or aggregate to be transported by the conveyor are loaded onto the belt at a so-called loading point or loading zone . Traditionally, loading zones of conveyors include successive rollers mounted in parallel which received the feed . However, these known configurations cause belt sagging at each interstice between the rollers . Also , there is a risk that the impact of falling material causes damage to the conveyor system and in particular to the conveyor belt in the area of the loading zone . Although the impact varies in accordance with parameters like drop height , the type of material and fragment si ze , no conveyor remains unaf fected . Constant wear and tear would crush the belt , break the rollers , crack the frame , and thereby signi ficantly increase the overall costs .

To prevent such damage to the conveyor system, a so-called " impact bed" - equally known as " impact cradle" - has been used in the loading zone to support the conveyor belt from below . The impact cradle typically comprises a frame made out of a strong steel mounting that is tough enough to withstand high impact forces , and a number of impact bars from a resilient , shock absorbing material such as rubber to support the conveyor belt and absorb impact energy acting on the conveyor belt . The use of impact bars reduces sagging and protects the belt from damage .

The impact bars of impact cradles known in the prior art typically consist of a base body made of a specially designed rubber compound for absorbing the impact energy, and a surface component from plastic material to face a surface of the conveyor belt . For example , high-density polyethylene ( PE ) is used for the wear layer, which lowers friction and gives a good wear li fe . The high-density PE is vulcani zed onto the rubber base body . Via a reinforced aluminum profile vulcani zed into the rubber base body and a matching screw connector ( e . g . a T-bolt ) , the impact bar is mounted to the frame of the impact cradle .

Since the impact bars are subj ect to the forces and impacts resulting from the aggregate being loaded and from the conveyor belt being in sliding contact with the impact bar, the impact bars and speci fically the plastic components thereof wear away over time , and the impact bars need to be replaced once the plastic components are worn .

Figure 7 illustrates a conventional impact cradle 100 for use in a loading zone of a conveyor system . The impact cradle 100 includes a frame 120 which has a series of individual frame elements spaced from one another in the travelling direction of a conveyor belt (not shown here ) . The frame elements would in turn be supported to a basic structure of the conveyor system . In the present embodiment , each frame element includes two U-beams 126 bolted together and a cradle element 124 fixed to the U-beams 126 . Each cradle element 124 is made up from an essentially planar central portion 128 and inclined side portions 127 , also known as wings .

A number of resilient impact bars 110 extend generally perpendicular to the U-beams 126 and cradle elements 124 and in the travelling direction of the conveyor belt . The impact bars 110 are configured to absorb and dampen the impact force of falling aggregate . Impact bars of this type are e . g . known as "Trellex Impact Bars" . The impact bars 110 are mounted to the frame 120 , speci fically to the cradle elements 124 thereof , by means of respective screwed connections 150 comprising T-bolts and nuts . The T-bolts 150 have bolt heads in engagement with aluminum profiles 115 of the impact bars 110 and bolt shafts extending through corresponding openings in the cradle elements 124 of the frame 120 and being secured by the nuts . In this prior art example , the impact bars extend along the series of five cradle elements 124 and U-beams 126 , and screwed connections 150 are provided between each impact bar 110 and each of the five cradle elements 124 across which it extends .

Each impact bar 110 comprises a wear layer 113 made from a plastic material , a base body 114 from e . g . rubber which is configured to absorb impact energy acting on the conveyor belt , and an aluminum profile 115. The plastic layer 113 , the base body 114 and the aluminum profile 115 are vulcani zed or pressed together in such a manner that they are inseparably connected to each other .

WO 2014 / 03985 Al and US 2002 / 011400 Al illustrate comparable impact cradles .

An alternative way to releasably attach impact bars to a supporting structure is known from US 2008 / 0006514 Al . The impact bed disclosed in this patent application comprises a plurality of polymeric bars , with a smooth upper surface and a plurality of lugs dimensioned and spaced to fit into a plurality of T-shape apertures in a supporting structure . The apertures and lugs are designed to interlock with one another such that no special tools are needed to remove the bars form the top plate when the bars become worn out . A maintenance person need only strike the bars with the heel of his hand in an upstream direction relative to the conveyor belt until the lugs are again aligned with the head portion of the T-shaped aperture . This then allows the bar to be li fted free from the arcuate panels of the impact bed frame and replaced with another .

According to US 2008 / 0006514 Al , each of the bars comprises a top layer from an ultrahigh molecular weight (UHMW) polymer, such as polyurethane or polyethylene , adhered to a cushioning layer 48 either by cold-bonding with a suitable adhesive or, alternatively, vulcani zing the two layers in a hot press .

Still other variants of impact cradles use di f ferent types of resilient bars in the bottom section as compared to one or both of the wing sections of the cradle : while impact bars as described above are used in the bottom section, wider and thinner bars designated glide bars are used at one or both of the wings . The glide bars have a top layer of the same quality as the impact bars , and are used on the troughed sides when transporting light material . Simi lar glide bars are also known for use upstream or downstream of the impact cradle to support the edges of the travelling conveyor belt , thereby e . g . preventing sag between conveyor rollers . Glide bars of this type are e . g . known as "Trellex Glide Bars" .

SUMMARY OF THE INVENTION

An obj ect underlying the present invention is to provide a conveyor belt support structure , as well as a wear member for being releasably fixed to a frame of the support structure , to increase the ef ficiency and productivity of a conveyor system . To achieve this obj ect , the present invention provides a wear member for supporting a conveyor belt in a conveyor system according to the independent claim 1 . The wear member comprises a base body configured to be attached to a frame of the conveyor system, and a surface component configured to face a rear side of a conveyor belt of the conveyor system . According to the invention, the surface component of the wear member is releasably attached to the base body thereof .

The releasable attachment of the surface component to the base body results in a modular configuration of the wear member which in turn makes it possible to replace an individual component of the wear member without replacing the entire wear member . In other words , only worn or damaged parts of the wear member - such as the surface component - may be replaced while the remaining components of the wear member - e . g . the base body - may be reused . This leads to a more ef ficient , e . g . in terms of costs , as well as to a more sustainable usage of the wear member .

Additionally, the modular design of the wear member makes it possible to detach the surface component from the base body without even releasing the wear member from the frame of the conveyor system . The time needed to replace the surface component is considerably reduced thereby, which leads to a reduction of downtime of the conveyor system and, thus , to an increase in productivity of the system .

The modular design of the wear member is also advantageous in terms of recycling . That is , the single components of the wear member can be recycled separately and in accordance with the requirements of the speci fic materials used for the components of the wear member .

Moreover, the stock si ze of wear members for replacing worn or damaged wear members can be reduced since replacement surface components can be stored separately, and the number of entire wear members in store can be reduced . While the wear member of the invention may be used in various locations of a conveyor system, one speci fic location for the wear member is in a loading zone of the conveyor system . In the loading zone , the wear member can be provided in the form of an impact member for use in an impact bed or cradle for supporting a conveyor belt in the loading zone of the conveyor system to absorb and dampen the impact force of falling aggregate . The impact member acts to absorb the impact energy acting on the conveyor belt , speci fically during the process of loading the conveyor belt .

Alternative possible locations for a wear member of this invention are upstream and downstream of a loading zone or generally speaking between impact regions . At these locations , the wear members may be provided as glide members or glide bars , e . g . designed speci fically for the trough-shaped sides on the conveyor belt . Glide members support the edges of the belt and prevent sagging between conveyor rollers , giving an even surface to seal against . Glide members may have a surface of ultra high molecular weight polyethylene , which has low friction and good wear resistance . Glide members can be installed in many di f ferent ways , either in combination with impact bars on an impact cradle in the loading zone , or in lighter-weight applications on a formed plate that replaces edge rollers . A third option is a special support where the angle , width and height are all adj ustable .

Turning now to the configuration of the wear members or bars , the base body thereof may be formed of an elastic material , such as a rubber compound or polyurethane . In the case of e . g . ain impact member, the base body may be made from a shock absorbing material such as a rubber compound or else any other resilient , shock absorbing material which is configured to absorb impact energy acting on the conveyor belt .

In general terms , the material of the surface component may be di f ferent from the material of the base body . The surface component may be formed of a plastic material providing for a reduced friction and improved wear li fe , such as high-grade polyethylene . The surface component thereby allows the conveyor belt to smoothly move along the outer surface thereof and also constitutes a protective member for the base body . During operation, an outer surface of the surface component faces or is in contact with a rear surface of the conveyor belt .

The surface component partially or entirely covers the base body at the side facing the conveyor belt . The thickness of the surface component may be less than the thickness of the base body . The surface component may have the form of a wear layer with a thickness signi ficantly smaller than the thickness of the base body . The thickness of the surface component in the present context is defined as the extension of the surface component in a direction perpendicular to the outer surface of the surface component facing the base body .

The wear member can, but must not necessarily have the shape of a bar . That is , the wear member may be an elongated or beam-shaped element or may e . g . be substantially plateshaped along a longitudinal axis .

The cross-section of the base body perpendicular to a longitudinal extension thereof may be substantially square or rectangular . The thickness of the base body may be greater than the thickness of the surface component . The thickness of the base body in the present context is defined as the extension of the base body in a direction perpendicular to the outer surface of the base body facing the surface component .

Turning now to the releasable connection of the surface component to the base body, the base body has a supporting surface , the surface component has an attachment surface facing the supporting surface , and the opposing surfaces are configured to make the surfaces adhere to one another upon pressing the surface component against the base body in a direction perpendicular to the opposing surfaces . This allows for a quick and easy attachment and detachment of the surface component to the base body, possibly without the need of any tools to attach and/or to detach the surface component .

In embodiments , the base body has a supporting surface , the surface component has an attachment surface facing the supporting surface , and the supporting surface of the base body has adhering means provided thereon or therein and configured to attach to the opposing attachment surface of the surface component , and/or the attachment surface of the surface component has adhering means provided thereon or therein and configured to attach to the opposing supporting surface of the base body . In a variant , the attachment surface of the surface component and the supporting surface of the base body both have respective adhering means provided thereon or therein, and the adhering means of the surface component and the base body are configured to releasably attach to one another to releasably attach the surface component to the base body .

One practical example to establish the releasable connection between the surface component is by means of a touch fastener, in particular a hook-and-loop fastener or a dual-lock fastener .

In the case of a hook-and-loop fastener, also known as Velcro® fastener or Velcro®, the attachment surface of the surface component would compri se the hook layer of the fastener and the attachment surface of the base body would comprise the loop layer, or vice versa .

In an alternative , the attachment surface of one of the surface component and the base body may comprise a series or array of protrusions , and the attachment surface of the other one of the surface component or the base body may comprise a series or array of matching recesses . The protrusions and recesses are configured to engage with one another by means of a frictional engagement and form- fit so as to releasably attach the surface component to the base body . This principle is known from interlocking toy bricks such as Lego® bricks .

In another alternative , the attachment surfaces of both the surface component and the base body may each comprise a series or array of protrusions , and the respective protrusions may be configured to engage with one another so as to releasably attach the surface component to the base body . The protrusions on the surface component and on the base body may or may not have identical shapes .

In further embodiments , the surface component i s releasably attached to the base body by means of one or more magnetic elements , one or more suction cups , and/or a releasable adhesive disposed on the surface component and/or the base body .

A suction cup attaches to a surface by means of a vacuum created in a cavity between the suction cup and the surface . A magnetic element attaches to another magnetic surface by means of magnetic forces . A releasable adhesive could be provided on one or both of the facing attachment surfaces of the surface component and the base body .

While the wear member of the invention may be used in various locations of a conveyor system, the wear member may for example be an impact member or impact bar, e . g . for use in an impact bed or impact cradle for supporting the conveyor belt in a loading zone of a conveyor system; or a glide member or glide bar, e . g . for supporting an edge portion of the conveyor belt .

The invention further provides a support structure for supporting a conveyor belt in a conveyor system as recited in claim 11 . The support structure comprises a frame and at least one wear member releasably attached to the frame , wherein the frame has a supporting surface , and the wear member has an attachment surface facing the supporting surface . According to the invention, the supporting surface of the frame and the attachment surface of the wear member are configured to make the surfaces adhere to one another upon pressing the wear member against the frame in a direction perpendicular to the opposing surfaces .

The connection of the wear member to the frame thus relies on an adherence of the opposing surfaces of the wear member and frame when the wear member is pressed towards the frame . This allows for a time-ef ficient replacement of the wear member which in turn reduces downtime of the conveyor system and, thus , increases productivity . Furthermore , the connection between the wear member and the frame is advantageous as it can be established and released without any tools .

An aluminum rail for fixing the wear member to the frame can be dispensed with . This further facilitates recycling of used wear members , and also achieves a reduction in height and weight of the wear member .

Some optional features of the claimed support structure are set forth in the claims dependent on claim 11 .

As to the releasable connection between the wear member and the frame , this connection can in general terms be constituted much in the same manner as the above described releasable connection between the surface component and the base body of the wear member . Similar as the adhering means for releasably attaching the surface component to the base body, the adhering means for releasably attaching the wear member to the frame may comprise a touch fastener, in particular a hook-and-loop fastener or a dual-lock fastener ; or one or more magnetic elements , one or more suction cups , and/or a releasable adhesive disposed on the surface component and/or the base body . Finally, the support structure of the invention may be located in di f ferent sections of a conveyor system . For example , the support structure may be , or may include , an impact bed or cradle for supporting a conveyor belt in a loading zone of a conveyor system. The impact bed or cradle is provided to absorb and dampen the impact force of falling aggregate .

BRIEF DESCRIPTION OF THE DRAWINGS

The above , as well as additional obj ects , features and advantages of the present invention will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings , where the same reference numerals will be used for similar elements , wherein :

Figure la is a perspective view of an impact cradle as one embodiment of a support structure according to the present invention,

Figure lb is a front view of an impact cradle as one embodiment of a support structure according to the present invention,

Figure 1c is a side view of a conveyor loading station comprising two impact cradles according to Figure lb,

Figure 2 is a perspective view of an impact bar as one embodiment of a wear member according to the present invention,

Figure 3 is a detailed view of an impact bar releasably connected to a frame of an impact cradle according to the present invention,

Figure 4 is a perspective view of an impact bar according to the present invention, Figure 5 illustrates an impact cradle according to the invention comprising impact bars as well as glide bars ,

Figure 6a is a front view of a support structure comprising glide bars according to the present invention,

Figure 6b illustrates a conveyor system comprising an impact cradle comprising impact bars as well as a support structure comprising glide bars , and

Figure 7 illustrates an impact cradle according to the prior art .

DETAILED DESCRIPTION

Support structures of the inventi on

Figure la illustrates an impact cradle 1 as a first embodiment of a support structure according to the present invention . Impact cradles are also known as impact beds , and both expressions are used synonymously in this application .

The impact cradle 1 is similar to the aforementioned impact cradle 100 in Figure 7 as far as the basic configuration of a frame 20 thereof is concerned, which by and large corresponds to the frame 120 of the conventional cradle 100 in that it comprises a series of frame elements each comprising two U-beams 26 bolted together and a cradle element 24 , the cradle element 24 in turn comprising an essentially planar central portion 28 and upwardly inclined side portions , or wings , 27 . Other configurations of cradle elements can be used as they are known in the art, e . g . cradle elements having one continuous curved shape rather than the straight hori zontal central and inclined side portions .

The impact cradle 1 of the invention further comprises a series of resilient impact members in the form of impact bars 10 configured to absorb and dampen impact forces in the loading zone , where soil , rocks , gravel and other aggregate material drops onto a conveyor belt (not shown here ) . The impact bars 10 extend generally perpendicular to the U-beams 26 and cradle elements 24 and in the travelling direction of the conveyor belt . The impact bars 10 thereby constitute what is known as an impact bed having a trough configuration for the conveyor belt which would run along the exposed surfaces of the impact bars , generally indicated 25 . The impact bars 10 each include a first end 11 , a second end 12 and a longitudinal extension L between said first end 11 and said second end 12 .

In the impact cradle 1 of the invention, the impact bars 10 are attached to the frame 20 by means of a releasable connection generally indicated at 40 in the drawings , which relies on opposing surfaces of the impact bars 10 and frame 20 adhering to one another in a manner that will be described in more detail below .

Figure lb is a front view of an impact cradle similar to the one of Figure la, though with a di f ferent number of impact bars 10 (nine impact bars in this case ) . Also shown here is a conveyor belt 50 being supported in a troughing configuration by the cradle elements 24 of the impact cradle 1 and their upwardly inclined side walls 27 , or wings .

Figure 1c is a side view of a loading station comprising two impact cradles 1 according to Figure lb arranged in series , with conveyor idle rollers placed upstream of , between and downstream of the impact cradles as seen in the travelling direction of the conveyor belt which would be the hori zontal direction in the drawing .

While the impact cradles 1 of Figure la as well as Figures lb and 1c use a single kind of impact bars 10 , an impact cradle of the invention may also use resilient bars with di f ferent shapes or configurations . For example , di f ferent types of resilient bars may be used in the bottom section as compared to the wing sections of the cradle : while impact bars as described above are used in the bottom section and one of the upwardly inclined wings , wider and thinner bars designated glide bars are used at the other one of the wings . The glide bars have a top layer of the same quality as the impact bars , and are used on the troughed sides when transporting light material . Figure 5 illustrates a corresponding embodiment with impact bars 10 in the bottom section and wider and thinner glide bars 15 at one of the wing sections 27 of the cradle . Glide bars could as well be used at both of the wing sections 27 of the cradle .

Also , while the Figures j ust described relate to impact cradles , the invention is not restricted to impact cradles or loading zones , but encompasses support structures in general terms for supporting a conveyor belt in a conveyor system . Figure 6a illustrates a front view of an embodiment of a support structure according to the present invention comprising wear members in the form of glide bars 15 for supporting the edges of the moving conveyor belt 50 and to prevent sagging . Figure 6b shows a conveyor system comprising a support structure comprising an impact cradles with impact bars 10 as well as with said glide bars 15 arranged downstream of the impact cradle in a conveying direction of the conveyor belt .

Shape and configura ti on of the wear members

Turning now to the configuration of the wear members as such, the wear members are not limited to any speci fic shape . While the following explanations are presented exemplarily for the impact bars 10 , the explanations equally apply to other embodiments of wear members , including the glide bars 15 .

In the embodiments illustrated in Figures la and lb, the wear members , in this case impact bars 10 , have an elongated or beam-like shape along the longitudinal extension L thereof . It is also possible for the wear members 10 to have a platelike , such as a square or rectangular shape . The wear members 10 have cross-sections perpendicular to the longitudinal extension L that are rectangular in the illustrated embodiment . The cross-sectional shapes may also be substantially square , circular or oval . In the case of circular or oval cross sections , it is preferred, however , that the cross-sectional shapes comprise at least one flattened segment in the area facing the rear side of the conveyor belt 50 .

The shape of the cross-sections of the wear members 10 may be substantially constant along the length L . The wear members

10 may have a substantially constant thickness or height along the longitudinal extension L . In the region of the first end

11 and/or the second end 12 , the wear members 10 may have a slight chamfer as shown in Figure la which reduces the thickness .

Figure 2 is a detailed view of an end 12 of an impact bar 10 of the impact cradle of Figure 1 . The impact bar 10 comprises a base body 14 and a surface component 13 which in this case has the shape of a wear layer 13 . The base body 14 may be formed from a shock absorbing material such as a rubber composition, whereas the wear layer 13 may be formed of plastic material such as polyethylene ( PE ) . The exposed surface of the wear layer 13 faces or is in contact with the conveyor belt , particularly with a rear surface of the conveyor belt , and the low frictional coef ficient of the wear layer material allows for the conveyor belt 50 to smoothly move over the impact bars . The plastic material of the wear layer 13 may also provide for an improved wear li fe of the overall system : The wear layer 13 may use material with a slightly lower wear resistance than the belt . In this way wear can be confined to the wear layer 13 thus extending the working li fe of the signi ficantly more expensive belt .

While the base body 14 is made from one solid piece in this embodiment , it could in principle have the form of a laminate made up from two or more layers of di f ferent materials , such as a relatively rigid base layer to be attached to the frame 20 and a more resilient layer at the interface to the wear layer 13 . The wear layer 13 in this embodiment has the shape of a flat and thin layer . Its extension along the length L is signi ficantly greater than its thickness . The thickness of the wear layer 13 is also less than the thickness of the base body 14 .

At tachment of the wear members to the frame

In support structures 1 according to the present invention, the wear members 10 , 15 are releasably attached to the frame 20 in a way that will now be exemplarily described with respect to the aforementioned Figures la- lc and 2 as well as Figure 3 which is a detailed partial view of the impact cradle of Figure la, showing impact bars 10 and their releasable connections 40 to the frame 20 . While the following explanations are again presented exemplarily for the impact bars 10 , the explanations equally apply to other embodiments of wear members , including the glide bars 15 .

The releasable connection 40 between each impact bar 10 and the frame 20 is formed by making an attachment surface 18 of the impact bar 10 , speci fically of the base body 14 thereof , adhere to an opposing supporting surface 21 of the frame 20 . The attachment surface 18 is at the side of the impact bar 10 opposite the wear layer 13 . The attachment surface 18 of the impact bar 10 and the supporting surface 21 of the frame have a configuration that makes these surfaces 18 , 21 adhere to one another upon pressing the impact member against the frame in a direction perpendicular to the opposing surfaces , to thereby form the releasable connection 40 between the frame 20 and the impact bar 10 .

In this embodiment , the releasable connection 40 is a hook and loop connection, wherein a hook layer 41 of the hook and loop connection is provided on the attachment surface 18 of the impact bar 10 whereas a loop layer thereof is provided on the supporting surface 21 of the frame 20 . The hook layer 41 comprises a plurality of hook-shaped protrusions 42 configured to engage with loop-shaped elements on the complementary supporting surface 21 of the frame 20 .

This solution provides a simple but still reliable connection of the impact bar 10 to the frame 20 . Since the impact bar 10 and frame 20 adhere to one another upon pressing the impact member against the frame , the impact bar 10 can be quickly mounted to the frame 20 and also quickly detached therefrom without the need of e . g . loosening a plurality of screwed connections . Thereby, downtime of the conveyor system can be reduced in case a worn or damaged impact bar 10 needs to be replaced . Thus , the productivity of the overall process can also be increased .

The hook and loop connection also negates the need for an aluminum profile 115 as used with prior art impact bars 100 ( see Figure 7 ) . Without said aluminum profile , the thickness of the impact bar 10 and thereby also its weight can be reduced, so that the handling of the impact bar 10 is improved . Also , the manufacturing of the impact bar 10 is simpli fied and, thus , more cost ef ficient .

I f hook-and-loop is used to bond two rigid surfaces such as the attachment surface 18 and supporting surface 21 in the present embodiment , the bond is particularly strong because any force pulling the pieces apart is spread evenly across all hooks . Also , any force pushing the pieces together is disproportionately applied to engaging more hooks and loops . Vibration can cause rigid pieces to improve their bond .

The hook and loop fasteners used in the present context are preferably ones with an industrial quality . That is , the hook and loop fasteners are configured to withstand environmental impacts . Examples available on the market include METAKLETT , a multiply mountable and dismountable metallic hook and loop fastener that can be applied in environments where synthetic materials lose their practicality . The metallic hook and loop layers of this system would be fastened preferably by welding or riveting to the opposing surfaces to be j oined . For other industrial grade hook and loop options made of plastic, a strong adhesive , e . g . a pressure sensitive adhesive , or vulcani zation could also be used to bond each layer to its substrate .

In the illustrated embodiment , the hook layer 41 is formed substantially along the entire length L of the impact bar 10 . The hook layer 41 could also extend only intermittently along the length L of the impact bar 10 , speci fically it could be restricted to the areas in which the impact bar 10 is supported by the frame 20 . The hook layer 41 does also not need to cover the whole width of the surface 18 of the impact bar 10 . The hook layer 41 may further be arranged in one or multiple , e . g . two , three or four, lines along the length L .

While a hook and loop connection 40 with hook-shaped protrusions 42 and complementary loops is used in the embodiment , other types of touch fasteners could be used to adhere the impact bars to the frame 20 , including touch fasteners which have identical protrusions on both surfaces to be connected . Such protrusions may have heads with e . g . semispherical or mushroom-shaped heads . Heavy-duty variants such as "Dual Lock" or "Duotec" feature mushroom-shaped stems on each face of the fastener, providing an audible snap when the two faces mate .

Alternative embodiments include other configurations to make the attachment surface 18 of the bar 10 adhere to the supporting surface 21 of the frame 20 . In general terms , corresponding elements or structures may be formed on or bonded to or into the attachment surface 18 and/or the supporting surface 21 .

For example , one or more suction cups could be supported on the attachment surface 18 of the bar 10 and arrange so as to adhere to the supporting surface 21 of the frame 20 , or vice versa . Suction cups attach to a surface by means of a vacuum formed in a cavity created in between the suction cup and the surface to which the suction cup adheres . In another exemplary embodiment , a magnetic element could be provided on or in the attachment surface 18 to adhere to the supporting surface 21 , or vice versa .

In a further example , one or more protrusions on the attachment surface 18 could cooperate with matching recesses in the supporting surface 21 , or vice versa . The protrusions could be generally cylindrical , square or rectangular . The surfaces 18 , 21 would then adhere to one another by a frictional engagement and form fit between the protrusions and recesses . This concept is based on the principle of interlocking toy bricks .

Depending on the speci fic configuration of the releasable connection 40 used, the impact bar 10 may releasably adhere to the frame 20 upon application of a force above a predefined threshold in a direction perpendicular to the opposing surfaces 18 , 21 of the bar 10 and frame 20 . For example , protrusions on one component and recesses on the other component could be configured to engage with one another upon application of a speci fic force perpendicular to the opposing surfaces .

In any event , the impact bar 10 may be released from the frame 20 by separating the bar 10 from the frame in a direction substantially perpendicular to the j oined surfaces of the bar 10 and frame 20 . In contrast , forces acting substantially in parallel with the j oined surfaces are not prone to release the bar 10 from the frame 20 . This avoids an unintentional loosening of the impact bar 10 from the frame 20 by forces trans ferred to the bars 10 from the moving conveyor belt 50 since such forces act in parallel to the j oined surfaces . In other words , the shear strength of a corresponding connection, e . g . hook and loop connection, at 0 ° to the j oined surfaces signi ficantly exceeds the pull-out strength thereof at 90 ° to the j oined surfaces . Rel easabl e connecti on of the surface component to the base body

In the wear members 10 , 15 according to the present invention, the wear layer 13 is releasably attached to the base body 14 . This will now be exemplarily described in detail with reference to Figure 4 in which the releasable connection 30 between the two components is illustrated in more detail . While the following explanations are presented exemplarily for an impact bar 10 , the explanations equally apply to other embodiments of wear members , including the glide bars 15 .

An attachment surface 16 of the wear layer 13 faces a supporting surface 17 of the base body 14 . The attachment surface 16 of the wear layer 13 is opposite the surface of the wear layer 13 that is arranged to face the conveyor belt 50 . The supporting surface 17 of the base body 14 is opposite the attachment surface 18 of the base body 14 that is attached to the frame 20 .

The releasable connection 30 between the wear layer 13 and the base body 14 of the impact bar 10 allows separation of the single components , e . g . when components of the impact bar 10 are worn or damaged . It is , thus , possible that only the worn or damaged components are replaced while the remaining components can be reused . This al lows a more ef ficient usage , e . g . in terms of costs , of the impact bars 10 and, in addition, a more sustainable usage of materials .

Moreover, due to the releasable connection 30 between the wear layer 13 and the base body 14 it is possible to detach the wear layer 13 without detaching the entire impact bar 10 from the frame 20 . Advantageously, a replacement of worn or damaged components can be , therefore , done more quickly whereby the downtime of the conveyor belt system can be reduced and, thus , the productivity of the overall system can be increased . Additionally, the stock si ze of impact bars 10 necessary for replacing worn or damaged impact bars 10 can be reduced . That is , only a number of wear l iners and/or base bodies may be stored . As the case may be , only the worn or damaged part can be replaced without replacing the entire impact bar 10 .

Similar as the releasable connection 40 between the bar 10 and the frame 20 , the releasable connection 30 between the wear layer 13 and the base body 14 of the bar 10 relies on the j oined surfaces of the two components being configured to adhere to one another upon contact . In the speci fic embodiment illustrated in Figure 4 , the base body 14 carries the hook layer 31 of a hook and loop fastener, and the wear layer 13 carries the loop layer (not visible from this perspective ) of the hook and loop fastener . The hook layer 31 comprises an array of hook-shaped protrusions 32 .

This releasable connection of the wear layer 13 to the base body 14 allows for a time ef ficient exchange of a worn wear layer 13 against a new one without replacing the entire impact bar 10 .

In the illustrated embodiment , the hook layer and the loop layer extend along the entire length and width of the bar 10 to securely j oin the wear layer 13 to the base body 14 . One could also think of providing the hook and the loop layers only intermittently along the bar 10 though, with portions thereof being spaced apart along the length and/or the width of the bar 10 .

The invention is not restricted to the embodiments described above but may be varied within the scope of the appended claims .

For example , the impact cradle 1 of Figure la comprises seven impact bars 10 and five frame elements (U-beams 26 and cradle elements 24 ) , and the impact cradle 1 of Figures lb and 1c comprises nine impact bars 10 and four frame elements . The impact cradle 1 may, however, also comprise more or less impact bars 10 depending on e . g . the width of the conveyor belt , and more or less frame elements .

REFERENCE S IGNS

1 impact cradle

10 impact bar

11 first end 12 second end

13 surface component or layer 14 base body

15 glide bar

16 attachment surface of the wear layer

17 supporting surface of the base body

18 attachment surface of the base body

20 frame

21 supporting surface of the frame

24 cradle element

25 exposed surface of impact bars

26 U-beams

27 inclined portions of cradle elements

28 planar portions of cradle elements

30 releasable connection

31 hook layer

32 protrusions

40 releasable connection

41 hook layer

42 protrusions

50 conveyor belt

100 (prior art ) impact cradle

110 (prior art ) impact bar

113 (prior art ) wear layer

114 (prior art ) base body

115 (prior art ) aluminum profile

120 (prior art ) frame

124 (prior art ) cradle element

126 (prior art ) U-beams

127 (prior art ) inclined portions of cradle elements

128 (prior art ) planar portions of cradle elements

150 (prior art ) screwed connection L longitudinal extension of the bar