Patent Publication Number: US-11376631-B2

Title: Mobile screen body and mobile mineral material processing plant with support legs

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national stage application of International Application PCT/FI2019/050349, filed May 6, 2019, which international application was published on Nov. 14, 2019, as International Publication WO 2019/215387 A1 in the English language. The International Application claims priority of Finnish Patent Application No. 20180063 filed May 8, 2018. 
     TECHNICAL FIELD 
     The present invention generally relates to a mobile screen and a mobile mineral material processing plant with support legs. 
     BACKGROUND ART 
     This section illustrates useful background information without admission of any technique described herein representative of the state of the art. 
     A mobile screen for mineral material can be implemented as a trailer to be towed by a truck. To this end, the mobile screen can be pivotably moved between an operating position and transport position in which the screen is compacted in order to meet transport dimensions. 
     The screen can be motorized to shake mineral material down along and through the screen so as to separate fractions of different dimensions. One or more screen decks can be vibrated through a screen frame to which screen meshes are attached. The screen frame itself can be vibrated by a vibrator, such as a motor that rotates an eccentric mass. When resiliently supported e.g. by springs, the screen moves under vibration effect back and forth so that mineral material covering the screen passes through or along the screen towards the front end of the screen for subsequent in-line crushing or conveying for further processing or use. 
     A mobile screen is typically implemented with a two-tier frame system comprising a platform chassis and a screen support frame that carries the screen, a crusher (if provided) and any conveyors. The processing equipment frame is pivoted to the platform frame and moved between the operating and transport positions by hydraulic rams. In order to support the screen more robustly, the platform frame is supported by legs against ground and supports maintain the screen support frame in its correct position above the platform frame e.g. by beams fixed between the platform and screen support equipment frames. 
     Impacts and vibration experienced by the screen support frame are conveyed to the platform frame which thus needs to be very robustly built accordingly. This further increases the total mass of the mobile screen, which may be problematic particularly in terms of transport (mass limits of bridges, fuel consumption). 
     It is an object of the present invention to provide reduce weight and/or increase robustness of a mobile screen. 
     SUMMARY 
     According to a first aspect, there is provided a mobile screen body comprising:
         a platform frame;   a plurality of legs for supporting the platform frame to ground;   a screen support frame supported by the platform frame movably between a transport position in which the screen support frame is adjacent to the platform frame and an operating position in which the screen support frame is elevated from the transport position; and   a plurality of supports having first ends configured to be structurally coupled with the screen support frame and second ends configured to be structurally coupled with respective ones of the plurality of legs, when the screen support frame is in the operating position.       

     The supports may be arranged in pairs that reside outside the platform frame in sideways direction. 
     Structural coupling may be arranged by coupling parts with each other directly or via one or more intermediate parts such that the coupled parts are structurally connected together. 
     The mobile screen body may further comprise lifting equipment for moving the screen support frame between the transport position and the operating position. The lifting equipment may comprise at least one hydraulic ram. The at least one hydraulic ram may be telescopic. 
     The second ends of the legs may be configured to be structurally coupled with respective ones of the plurality of legs, when the screen support frame is in the operating position, so that downward forces experienced by the screen support frame are transmitted to the legs bypassing the platform frame. Downward forces of each support may be directed to respective legs via the second ends of the supports. 
     The first ends of the supports may be pivotably coupled with the screen support frame. The second ends of the supports may be detachably attachable to respective legs in the operating position. The screen support frame may comprise stowing points configured to enable detachably attaching of the second ends of the supports to the stowing points in the transport position. 
     In the operating position, the screen support frame may be pivoted to an upwards inclining angle of greater than 10 degrees. In the operating position, the screen support frame may be pivoted to an upwards inclining angle of less than 20 degrees. 
     The supports may be beams. The first ends of the supports may be shaped as forks configured to extent around plate formed structures of the screen support frame. The second ends of the supports may be shaped as forks configured to extent around plate formed structures of the legs. 
     The plurality of legs may reside under the platform frame. The plurality of legs may be attached to the platform frame. 
     The supports may be arranged in two pairs so that the legs of each pair reside at same distance from the pivot joint. 
     The mobile screen body may further comprise one or more X-beam structures for strengthening at least one of the pairs of the supports when the screen support frame is in the operating position. The X-beams may be configured to increase sideways sturdiness of the screen support frame. 
     The supports may be inclined towards pivot connection between the platform frame and the screen support frame so as robustly support the screen support frame against the pivot joint. 
     The legs may be extendable. The legs may be hydraulically extendable. The legs may be foldable. The platform frame may comprise wheel suspension for a plurality of wheels. The wheel suspension may be retractable and expandable by machine operation for transferring weight of the mobile screen body from the wheels to the legs and back to the wheels so that the legs can be set up for operating position and for the transport position without equipping the legs with actuators. 
     The platform frame may be made of steel plate. 
     The plurality of legs may be made of steel plate. 
     The screen support frame may be made of steel plate. 
     The plurality of supports may be made of steel plate. 
     According to a second aspect, there is provided a mobile mineral material processing plant comprising:
         the screen body of the first aspect; and   a screen attached to the screen support frame.       

     The screen may be attached to the screen support frame via a plurality of spring groups each comprising one or more springs. The first ends of the supports may be configured to be detachably attachable to the screen support frame under a respective spring group. 
     The mobile mineral material processing plant may further comprise a crusher attached to the platform frame. The crusher may be a cone crusher. The crusher may be an impact crusher. The crusher may be a jaw crusher. The mobile mineral material processing plant may further comprise a feed for supplying an oversize fraction of the screen to the crusher. 
     The mobile mineral processing plant may be constructed to be transportable as a semi-trailer. 
     According to a third aspect, there is provided a method in a mobile screen body, comprising:
         supporting by a plurality of legs a platform frame to ground;   supporting the platform frame a screen support frame movably between a transport position in which the screen support frame is adjacent to the platform frame and an operating position in which the screen support frame is elevated from the transport position; and   structurally coupling first ends of a plurality of supports with the screen support frame and second ends of the supports with respective ones of the plurality of legs, when the screen support frame is in the operating position.       

     Different non-binding example aspects and embodiments of the present invention have been illustrated in the foregoing. The embodiments in the foregoing are used merely to explain selected aspects or steps that may be utilized in implementations of the present invention. Some embodiments may be presented only with reference to certain example aspects of the invention. It should be appreciated that corresponding embodiments may apply to other example aspects as well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Some example embodiments of the invention will be described with reference to the accompanying drawings, in which: 
         FIG. 1  shows a side view of a mobile mineral material processing plant according to an embodiment of the invention in an operating position; 
         FIG. 2  shows a perspective view of the mobile mineral material processing plant of  FIG. 1 ; 
         FIG. 3  shows a detail of a leg and a support joint of  FIG. 2 ; and 
         FIG. 4  shows a side view of a mobile mineral material processing plant according to an embodiment of the invention in a transport position. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, like reference signs denote like elements or steps. 
       FIG. 1  shows a side view of a mobile drawing of a mobile mineral material processing plant  100  according to an embodiment of the invention. The plant comprises a mobile screen body that comprises
         a platform frame  110 ;   a plurality of legs  112  for supporting the platform frame  110  to ground (e.g., for sturdy supporting of the mobile screen body when operating any equipment attached to the mobile screen body, such as a screen and/or crusher);   a screen support frame  120  supported by the platform frame  110  movably (e.g., pivotably over a pivot joint  122 ) between a transport position (not shown) in which the screen support frame  120  is adjacent to the platform frame and an operating position (shown in  FIG. 1 ) in which the screen support frame  120  is elevated from the transport position (e.g., pivoted to an upwards inclining angle); and   a plurality of supports  114 ,  114 ′ having first ends  114   a  configured to be structurally coupled with the screen support frame  120  and second ends  114   b  configured to be structurally coupled with respective ones of the plurality of legs  112 , when the screen support frame  120  is in the operating position.   The supports  114 ,  114 ′ can be arranged in pairs that reside outside the platform frame  110  in sideways direction (perpendicularly to the longitudinal direction i.e. the direction of the platform frame  110 ).       

     The supports  114 ,  114 ′ drawn in  FIG. 1  differ only by length. However, as their structure is not quite identical, the shorter ones are depicted with reference sign  114 ′. In some embodiments, there are yet also other differences (for example, in the thickness, form of the first and/or second ends, materials and/or profile) 
     In an embodiment, lifting equipment is provided for moving the screen support frame  120  between the transport position and the operating position. The lifting equipment comprise, for example, at least one hydraulic ram  118 . The at least one hydraulic ram can be telescopic such that the ram can achieve sufficient extension length while not extending obtrusively low in the transport position. 
     The first ends  114   a  of the supports  114 ,  114 ′ are shown to be pivotably coupled with the screen support frame. The second ends  114   b  of the supports  114 ,  114 ′ are in this embodiment detachably attachable to respective legs  112  in the operating position. The screen support frame of  FIG. 1  comprises for ease of transport stowing points  124  configured to enable detachably attaching of the second ends  114   b  of the supports  114  to the stowing points  124  in the transport position. 
     The upwards inclining angle of the screen support frame  120  can be, for example, greater than 10 degrees and/or less than 20 degrees. 
     The supports  114 ,  114 ′ can be beams. The first ends  114   a  of the supports  114 ,  114 ′ are shaped in an embodiment as forks configured to extent around plate formed structures of the screen support frame  120 . The second ends  114   b  of the supports  114 ,  114 ′ can be shaped as forks configured to extent around plate formed structures of the legs  112 . The forks can be integrally formed into the supports or attached, for example, by bolts or welding. The counterpart structures in the screen support frame  120  and/or the legs  112  can be also integrally formed or provided with separate parts. 
     The supports  114 ,  114 ′ can be arranged in two pairs so that the legs ( 112 ) of each pair reside at same distance from the pivot joint ( 122 ). In some embodiments, at least one of the pairs of the supports can be strengthened by use of one or more X-beam structures. The structure is preferably removable. 
     The supports  114 ,  114 ′ can be inclined towards pivot joint  122  so as to robustly support the screen support frame  120  against the pivot joint  122 . This may be particularly useful in that if there is some play in the pivot joint, the screen support frame forms a force that in both positions and throughout moving between the operating and transport positions keeps the pivot joint  122  in the same extreme of the play. 
     In  FIG. 1 , the screen support frame  120  is shown movably supported by the platform frame  110  using a pivot joint. In an alternative embodiment, the screen support frame  120  movably supported by the platform frame  110  using, for example, hydraulic or pneumatic rams, linear motors, and/or wedges. 
     The legs  112  can be made extendable, e.g. hydraulically or by manual action. As an example of manual extending, the legs  112  can be foldable. In order to enable easy use of such manually extendable legs  112 , the platform frame  110  can be equipped with wheel suspension for a plurality of wheels  119  that is retractable and expandable by machine operation for transferring weight of the mobile screen body from the wheels  119  to the legs  112  and back to the wheels  119  so that the legs  112  can be set up for operating position and for the transport position without necessarily equipping the legs  112  with actuators such as hydraulic or pneumatic cylinders or electric actuators. The platform frame  110  can be alternatively equipped with crawler tracks. In an embodiment, the platform frame  110  also comprises a crawler track suspension for one or more crawler tracks, which crawler track suspension is retractable and expandable by machine operation. The platform frame  110  can be equipped with an engine unit to provide self-propelling capability. 
     Various parts of the structures can be made of steel plate, including, for example, partially or entirely any one or more of the following: platform frame  110 ; the legs  112 ; the screen support frame  120 ; and the supports  114 ,  114 ′. 
     In  FIG. 1 , the mobile mineral material processing plant  100  further comprises a screen  130  attached to the screen support frame  120 . 
     The screen  130  can be attached to the screen support frame  120  via a plurality of spring groups  132  each comprising one or more springs  1322 . The first ends  114   a  of the supports  114 ,  114 ′ can be configured to be detachably attachable to the screen support frame  120  under a respective spring group  132 . 
     In an embodiment, the mobile mineral material processing plant  100  further comprises a crusher  140  attached to the platform frame  110 , such as a cone crusher, an impact crusher or a jaw crusher. The mobile mineral material processing plant  100  further comprises in an embodiment a feed  134  such as a channel or conveyor for supplying an oversize fraction of the screen  130  or screening produced by the screen  130  to the crusher  140 . 
     The mobile mineral processing plant  100  is constructed in an embodiment to be transportable as a semi-trailer. 
       FIG. 3  shows a detail of a leg and a support joint of  FIG. 2  for structurally coupling the support  114  of  FIG. 1  with the leg  112 . The support joint  300  comprises a horizontal connecting part  301  that is connected to a top part of the leg  112 . On the upper side of the connecting part  301  a hinge bracket  303  is connected on the connecting part  301 . The hinge bracket preferably comprises two vertical parts at a distance of each other both having an aperture for receiving a locking pin  305  that connects the second end  114   b  of the support via the support joint  300  to the leg  112 . 
     The support joint  300  further comprises a vertical connecting part  302  below the horizontal connecting part  301 , which vertical connecting part is connected to the upper side of the support leg  112 . 
     The support joint  300  further comprises vertical brackets  304  that are connected to the vertical connecting part  302  and to the horizontal connecting part  301 . 
     Parts  301 - 304  are preferably connected together by welding. 
     In an embodiment, the support joint further structurally couples the leg  112  with the platform frame  110 . For example, the platform frame  110  can be constructed using two side beams that are I-beams. An outer surface of the leg  112  and the vertical connecting part  302  can be aligned with an outer edge of a flange of a side beam of the platform frame  110  and the horizontal connecting part  301  can sandwich the outer side of the flange. The horizontal connecting part  302  can be bolted to the leg  112  through the outer side of the flange of the platform frame  110 . The inner side of the flange can be bolted to the leg  112  as well so that the leg  112  is firmly attached to the platform frame  110  on both sides of the web of the side beam. 
     By structurally coupling the support  114  to the leg  112  sandwiching a portion of the flange of the side beam of the platform frame  110 , vertical forces can be directed through the support  114  to the leg  112  without stressing seams of the side beams. Also incurring shear forces to the platform frame  110  may be avoided. 
       FIG. 4  shows a side view of a mobile mineral material processing plant according to an embodiment of the invention in a transport position. 
     Various embodiments have been presented. It should be appreciated that in this document, words comprise, include and contain are each used as open-ended expressions with no intended exclusivity. 
     The screen in question can be also a horizontal screen, wherein the supports  114  and  114 ′ are equal length. The screen support frame can be also without the pivot point  122 . 
     Springs can be metal or rubber springs or torsion bar type elastic members as an example. 
     The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments of the invention a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention. 
     Furthermore, some of the features of the afore-disclosed embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.