Patent Publication Number: US-10316530-B2

Title: Jaw assembly for a demolition tool

Description:
CLAIM FOR PRIORITY 
     This application is a U.S. National Phase entry under 35 U.S.C. § 371 from PCT International Application No. PCT/EP2013/061659, filed Jun. 6, 2013, which claims benefit of priority of European Patent Application No. 12171213.7, filed Jun. 7, 2012, all of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     This disclosure relates to the field of demolition tools for crushing and/or cutting material and more particularly to the field of replaceable working parts for demolition tools. 
     BACKGROUND 
     A demolition tool for crushing and/or cutting material is generally known. Typically, the demolition tool may comprise a jaw assembly having a lower jaw and an upper jaw. The upper and lower jaws may be pivotally connected. The upper and lower jaws may be moveable relative to each other. Blades may be provided on both the upper jaw and the lower jaw. The work material may be crushed or cut by closing the upper jaw and the lower jaw under hydraulic pressure. 
     The demolition tool may comprise a frame that connects the jaw set to a jib of a machine. 
     The demolition tool may have a jaw assembly that is suitable for crushing concrete. The jaw assembly may be adapted for crushing or cutting other materials, for example for cutting scrap iron and/or iron sections. The abrasive nature or hardness of some of these materials may cause the relatively rapid wear of the surfaces that engage the materials. 
     The demolition tool may be provided with replaceable working parts that have wear surfaces. The working part may be connected directly to the jaw assembly by conventional techniques. The working part may be provided on the upper and/or the lower jaw. The working part may be retained by fasteners. 
     The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of the prior art system. 
     BRIEF SUMMARY OF THE INVENTION 
     In a first aspect, the present disclosure describes a jaw assembly for a demolition tool, the jaw assembly having a first jaw and a second jaw and comprising: a support portion centrally disposed on the second jaw, the support portion having a first contact surface and an aperture disposed on the first contact surface; a work plate removably mounted on the support portion, the work plate comprising: a plate member having a first plate portion, the plate member being in abutting contact with the support portion; at least one tooth member extending from the first plate portion; and a boss extending from the first plate portion in a direction opposite to the at least one tooth member on the first plate portion, the boss being engaged to the aperture, a pair of seating portions disposed on the second jaw laterally on opposite sides of the support portion, each seating portion having a slot; and at least one work module removably mounted in each seating portion, the at least one work module comprising: a base; at least one tooth extending from the base; and a mounting element extending from the base in a direction opposite to the at least one tooth and engaging the seating portion. 
     In a second aspect, the present disclosure describes a work plate for removable mounting to a jaw assembly of a demolition tool, the work plate comprising: a plate member configured for abutting contact with a support portion disposed on a second jaw of the jaw assembly, the plate member having a first plate portion; at least one tooth member extending from the first plate portion; and a boss for engagement with an aperture disposed on a first contact surface of the support portion, the boss extending from the first plate portion in a direction opposite to the at least one tooth member on the first plate portion. 
     In a third aspect, the present disclosure describes a modular system for removable mounting of replaceable parts to a jaw assembly of a demolition tool, the modular system comprising: a work module having: a base; at least one tooth extending from the base; and a mounting element extending from the base in a direction opposite to the at least one tooth and engaging an at least one seating portion disposed on a second jaw of the jaw assembly; a work plate having: a plate member configured for abutting contact with a support portion disposed on a second jaw of the jaw assembly, the plate member having a first plate portion; at least one tooth member extending from the first plate portion; and a boss for engagement with an aperture disposed on a first contact surface of the support portion, the boss extending from the first plate portion in a direction opposite to the at least one tooth member on the first plate portion, such that when the work module and the work plate are assembled on the second jaw the bases extend over the plate member to retain the work plate on the second jaw. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and advantages of the present disclosure will be more fully understood from the following description of various embodiments, when read together with the accompanying drawings, in which: 
         FIG. 1  is an isometric view of a jaw assembly according to the present disclosure; 
         FIG. 2  is an isometric view of the upper jaw of the jaw assembly of  FIG. 1 ; 
         FIG. 3  is an isometric view from above of a first replaceable wear part according to the present disclosure; 
         FIG. 4  is an isometric view from below of the first replaceable wear part of  FIG. 3 ; 
         FIG. 5  is an isometric view from above of a second replaceable wear part according to the present disclosure; 
         FIG. 6  is an isometric view from below of the second replaceable wear part of  FIG. 5 ; 
         FIG. 7  is an isometric view of the lower jaw of the jaw assembly with the first replaceable wear parts mounted thereon according to the present disclosure; 
         FIG. 8  is a cross-section view through the lower jaw of the jaw assembly with the first and second replaceable wear parts mounted thereon according to the present disclosure; 
         FIG. 9  is an isometric view from above of a third replaceable wear part according to the present disclosure; 
         FIG. 10  is an isometric view from below of the third replaceable wear part of  FIG. 9 ; 
         FIG. 11  is an isometric view of a fourth replaceable wear part according to the present disclosure; 
         FIG. 12  is an isometric view of the upper jaw of the jaw assembly with the third and fourth replaceable wear parts mounted thereon according to the present disclosure; 
         FIG. 13  is a side view of the upper jaw of the jaw assembly with the third and fourth replaceable wear parts mounted thereon according to the present disclosure; and 
         FIG. 14  is an isometric view of the jaw assembly with the first, second, third and fourth replaceable wear parts mounted thereon according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure generally relates to replaceable wear parts for a jaw set of a demolition tool. 
       FIG. 1  illustrates a jaw assembly  10  having a first jaw  12  and a second jaw  14 . First jaw  12  and second jaw  14  may be elongated. The first jaw  12  and a second jaw  14  may be connected for mutual relative movement. The first jaw  12  and a second jaw  14  may be connected through a pivot connection at respective ends. First jaw  12  and second jaw  14  may have opposed faces onto which replaceable wear parts may be mounted. 
     In an embodiment, the first jaw  12  may be the upper jaw and the second jaw  14  may be the lower jaw. 
     The second jaw  14  may have a first arm  13  and a second arm  15 . Arms  13 ,  15  may be substantially T-shaped. Arms  13 ,  15  may have respective ends connected through the pivot connection. Opposite the ends connected through the pivot connection arms  13 ,  15  may be provided with a further connection point. Extending from the portion having the connections, first arm  13  and second arm  15  may have a mounting portion  17  configured for the mounting of the replaceable wear parts. The second jaw  14  may have a seating portion  24  and a support portion  74  for the mounting of the replaceable wear parts. 
     At least one seating portion  24  may be disposed on the second jaw  14 . The seating portion  24  may be positioned at an end of the arm  13 ,  15  opposite the end connected through the pivot connection. The seating portion  24  may be elongated. Seating portion  24  may be hollow with a side which is formed as a slot  26 . The slot  26  may be elongated and may be parallel to the longitudinal axis of the mounting portion  17 . 
     The seating portion  24  may comprise a ledge  36  which surrounds the slot  26 . The seating portion  24  may comprise holes  34  extending through opposite walls of the seating portion  24 . The holes  34  may detachably accommodate bolts for the mounting of the replaceable wear parts. 
     In an embodiment, two seating portions  24  may be disposed on the second jaw  14 . The seating portions  24  may be disposed at the ends of the arm  13 ,  15  opposite the ends connected through the pivot connection. The seating portions  24  may be positioned laterally on opposite sides of the second jaw  14 . A seating portion  24  may be connected to the first arm  13  and seating portion  24  may be connected to the second arm  15 . The seating portions  24  may be substantially parallel to each other. 
     The support portion  74  may be centrally disposed on the second jaw  14 . The support portion  74  may be positioned between the arms  13 ,  15 . The support portion  74  may be positioned between a pair of seating portions  24 . 
     The support portion  74  may have a first contact surface  76  and a second contact surface  78 . The first contact surface  76  may be inclined relative to the second contact surface  78 . A curved surface  77  may connect the first contact surface  76  and the second contact surface  78 . 
     The first contact surface  76  may lie on a first plane and the ledges  36  that surround the slots  26  of the pair of seating portions  24  may lie on a second plane. The first plane may be substantially parallel to the second plane. The first contact surface  76  may be spaced from the ledges  36  such that the second plane is superposed on the first plane. 
     The support portion  74  may have an aperture  80 . The aperture  80  may be disposed on the first contact surface  76 . Aperture  80  may be spaced equidistant from each seating portion  24 . The aperture  80  may have any suitable shape. In an embodiment, the aperture  80  may be circular. In an embodiment, the aperture  80  may be elongated with circular ends. 
       FIGS. 3 and 4  illustrate a replaceable wear part which is a work module  16  that may be removably mounted to the jaw assembly  10  of a demolition tool. The work module  16  may be removably mounted to the second jaw  14 . The work module  16  may be removably mounted in the seating portion  24 . 
     The first work module  16  may comprise a base  28 . The base  28  may have a dimension to fit on the ledge  36  of the seating portion  24 . The base  28  may have a dimension to fit on the ledge  36  of the seating portion  24 . The base  28  may be rectangular in shape. 
     The base  28  may have a dimension such that the perimeter of the base  28  extends beyond the seating portion  24 . The base  28  may have a dimension such that the perimeter of the base  28  extends over the first contact surface  76 . 
     The work module  16  may have at least one tooth  30 . The tooth  30  may extend from the base  28 . The work module  16  may have a mounting element  32 . The mounting element  32  may extend from the base  28  in a direction opposite to the tooth  30 . The mounting element  32  may be configured for engaging the at least one seating portion  24 . The mounting element  32  may have a mounting hole  31 . With the work module  16  positioned at the seating portion  24  the mounting hole  31  may be aligned to the hole  34  disposed on the seating portion  24 . 
     The work module  16  may have a plurality of teeth  30 . The teeth may be mutually spaced along a longitudinal direction along the base  28 . The plurality of teeth  30  may extend laterally across the base  28 . The teeth  30  may be mutually substantially parallel. With the work module  16  positioned at the seating portion  24  the longitudinal axes of the teeth  30  may be normal to the longitudinal axis of the slot  26 . 
     Each tooth  30  may have slanted sides and may have a pyramidal shape. The slanted sides of each tooth may be angularly spaced. Each tooth  30  may have a truncated apex  42 . 
     The work module  16  may further comprise a positioning element  38 . The positioning element  38  may be interposed between the base  28  and the mounting element  32 . The positioning element  38  may be dimensioned to be provided within the perimeter of the base  28 . The perimeter of the positioning element  38  may be disposed on the base  28  and within the perimeter of the base  28 . In an embodiment, positioning element  38  may have corners thereof cut-away. 
     The work module  16  may further comprising a shoulder  40  provided between the perimeter of the positioning element  38  and the perimeter of the base element  28 . The shoulder  40  may encircle the positioning element  38 . The shoulder  40  may be configured to abut and rest on the ledge  36 . The shoulder  40  may extend beyond the seating portion  24 . The shoulder  40  may extend beyond the ledge  36 . The shoulder  40  may extend over the first contact surface  76 . The base  28  may have a dimension such that the shoulder  40  may extend beyond the ledge  36  and over the first contact surface  76 . 
     With reference to  FIG. 7 , two work modules  16  may be removably mounted to at least one seating portion  24 . The work modules  16  may be positioned end to end such that their respective longitudinal axes are coaxial. The bases  28  of the work modules  16  may be supported on the ledge  36 . A tooth  30  on each work module  16  may extend laterally across the respective bases  28 . The tooth  30  on one work module  16  may be substantially parallel to the tooth on the adjacent work module  16 . 
       FIGS. 5 and 6  illustrate a replaceable wear part which is a work plate  18  that may be removably mounted to the jaw assembly  10  of a demolition tool. The work plate  18  may be removably mounted to the second jaw  14 . 
     The work plate  18  may comprise a plate member  82  to abut and rest on the support portion  74 . The plate member  82  may have a first plate portion  84  and a second plate portion  86 . First plate portion  84  may be inclined relative to second plate portion  86 . A curved plate portion  85  may connect first plate portion  84  to second plate portion  86 . First plate portion  84  and second plate portion  86  may be supported by first contact surface  76  and second contact surface  78  respectively. The curved plate portion  85  may be supported by the curved surface  77 . 
     The work plate  18  may comprise at least one tooth member  88  extending from the first plate portion  84 . The work plate  18  may comprise a plurality of tooth members  88  extending from the first plate portion  84  and the second plate portion  86 . The tooth members  88  may be mutually spaced along a longitudinal direction along the plate member  82 . A tooth member  88  may extend from the first plate portion  84  to the second plate portion  86 . Each tooth  30  may have slanted sides and a substantially pyramidal shape. Each tooth member  88  may have a truncated apex  92 . 
     The work plate  18  may comprise a boss  90  extending from the first plate portion  84  in a direction opposite to the at least one tooth member  88 . The boss  90  may engage to the aperture  80 . The boss  90  may have a shape and a dimension to fit into the aperture  80 . The boss  90  may be circular. 
     The plate member  82  may have a cut portion  81  extending along the side edges thereof. The cut portion  81  may be positioned on the surface comprising the boss  90 . 
     A modular system for removable mounting of replaceable parts to a jaw assembly  10  of a demolition tool may be composed of the work module  16  and the work plate  18 . The work module  16  may have a base  28 ; at least one tooth  30  extending from the base  28 ; and a mounting element  32  extending from the base  28  in a direction opposite to the at least one tooth  30  and engaging an at least one seating portion  24  disposed on a second jaw  14  of the jaw assembly  10 . The work plate  18  may have a plate member  82  configured for abutting contact with a support portion  74  disposed on a second jaw  14  of the jaw assembly  10 , the plate member  82  having mutually inclined first plate portion  84  and second plate portion  86 ; at least one tooth member  88  extending from the first plate portion  84 ; and a boss  90  for engagement with an aperture  80  disposed on a first contact surface  76  of the support portion  74 , the boss  90  extending from the first plate portion  84  in a direction opposite to the at least one tooth member  88  on the first plate portion  84 . When the work module  16  and the work plate  18  are assembled on the second jaw  14  the bases  28  may extend over the plate member  82  to retain the work plate  18  on the second jaw  14 . 
     With reference to  FIG. 8 , bases  28  may extend over the plate member  82 . Bases  28  may extend past the ledges  36  away from the slot  26 . The shoulders  40  may extend over the plate member  82 . The bases  38  of each work module  16  may extend over opposite sides of the plate member  82 . The shoulders  40  of each work module  16  may extend over opposite sides of the plate member  82 . 
     The edges of the bases  28  may act as cantilevers extending over the plate member  82 . The base  28  of a work module  16  may extend over a side of the plate member  82 . The base  28  of a second work module  16 , located in the opposite seating portion  24  may extend over the opposite side of the plate member  82 . Vertical movement of the plate member  82  relative to the first contact surface  76  may be prevented by the edges of the bases  28  of the work modules  16 . 
     In an embodiment, the work module  16  may be mounted to the side of the seating portion  24  adjacent the first contact surface  76 . Bases  28  may be supported at the side of the seating portion  24  adjacent the first contact surface  76 . 
     The mounting of the modular system may involve mounting the work plate  18  onto the support portion and subsequently mounting at least one work module  16  at each seating portion  24 . The work modules  16  may hold the work plate  18  so as to prevent any movement in a direction away from the first plane. The work modules  16  may hold the work plate  18  so as to prevent any movement in a direction away from first contact surface  76 . The boss  90  may fit in the aperture  80  and prevent any movement of the plate member  82  in a direction substantially parallel to the first plane. The boss  90  may fit in the aperture  80  and prevent any movement of the plate member  82  in a direction substantially parallel to first contact surface  76 . 
     The work plate  18  may be lowered onto the support portion  74  till the first plate portion  84  and the second plate portion  86  may abut the first contact surface  76  and second contact surface  78  respectively and the boss  90  may fit into the aperture  80 . 
     The work modules  16  may then be inserted into the slot  26  till the shoulders  40  abut the ledges  36 . The positioning elements  38  may fit within the inner walls of the seating portions  24 . A pin may be inserted through the holes  34  and through the mounting holes  31 . The pin may be held in the holes by spring retainers. In an embodiment, a bolt may be inserted through the holes  34  and through the mounting holes  31 . 
     With reference to  FIG. 1 , the first jaw  12  may have a first plate  7  and a second plate  8  which have respective ends connected through the pivot connection. At the opposite ends of first plate  7  and second plate  8 , a front plate  9  may be connected to both plates  7 ,  8 . The first plate  7  and a second plate  8  may each have an active edge  11  configured for the mounting of the replaceable wear parts. 
     In an embodiment, the first jaw  12  may be composed of a single body that is provided with an active edge. 
     With reference to  FIG. 2 , the active edge  11  may have at least one first coupling portion  44 . The first coupling portion  44  may comprise an intermediate contact member  46  and a pair of side contact members  48  laterally extending from opposite sides of the intermediate contact member  46 . 
     The intermediate contact member  46  may be an extension from the active edge  11 . Intermediate contact member  46  may have width which corresponds to the width of the active edge  11 . 
     The intermediate contact member  46  may have a contact surface  64 . Contact surface  64  may be spaced from the active edge  11 . Contact surface  64  may be substantially v-shaped with end portions being spaced further from the active edge  11  than a center portion. 
     In an embodiment, the end portions may have an abutment surface  94  which is parallel to the active edge  11 . 
     Side contact members  48  may protrude from the plates  7 ,  8  in a direction that is parallel to the active edge  11 . Each side contact members  48  may present an abutment surface  94  which is adjacent to the sides of the intermediate contact member  46 . Abutment surface  94  may be normal to the sides of the intermediate contact member  46 . The contact surface  64  may be spaced from the abutment surface  94 . Contact surface  64  and abutment surface  94  may face the same direction. A slot  95  may be provided in each side contact member  48 . Slot  95  may extend from the abutment surface  94  in a direction away from the contact surface  64 . Slot  95  may be located in the center of the abutment surface  94 . 
     Slot  95  may overcome dimension variations. First protrusion  50  and second protrusion  52  may be formed as plates and welded to opposite sides of the intermediate contact member  46 . First protrusion  50  and second protrusions  52  may be welded with a fixed distance to the bore  100  and normal to active edge  11 . The slot  95  may enable mounting of first protrusion  50  and second protrusions  52  may be welded without requiring them to be individually attached to the intermediate contact member  46 . 
     The abutment surface  94  may be substantially arcuate shaped. Abutment surface  94  may be formed such that the center is adjacent to the center portion of the contact surface  64 . The respective ends of the abutment surface  94  and the contact surface  64  may be nonadjacent. 
     Each side contact member  48  may comprise a first protrusion  50  spaced from a second protrusion  52 . The first protrusion  50  and second protrusion  52  may be located at opposite ends of the abutment surface  94 . Each first protrusion  50  and second protrusion  52  may define the limits of the side contact members  48 . First protrusion  50  and second protrusion  52  may be remote from the ends of the contact surface  64 . First protrusion  50  and second protrusion  52  may extend from the abutment surface  94  to the contact surface  64 . 
     In an embodiment, the free ends of each first protrusion  50  and second protrusion  52  may be in-line with active edge  11 . 
     The first protrusions  50  may have a first engagement surface  96  which faces the second engagement face  98  of the second protrusions  52 . The first engagement surface  96  and second engagement surface  98  may comprise curves. The first engagement surface  96  and the second engagement surface  98  may each have a convex curve and a concave curve. The concave curves may be proximate to the abutment surface  94 . The convex curves may be distal to the abutment surface  94 . 
     The first engagement surface  96  and the second engagement surface  98  may transit from convex curve to the concave curve from the free end to the abutment surface  94 . The degree of change from the convex curve to the concave curve is greater for the first engagement surface  96  relative to the degree of change from the convex curve to the concave curve for the second engagement surface  98 . The inflection of the convex curve to the concave curve on the first engagement surface  96  is greater relative to the inflection of the convex curve to the concave curve of the second engagement surface  98 . 
     The convex curve of the first engagement surface  96  has a higher curvature relative to the curvature of the convex curve of the second engagement surface  98 . 
     In an embodiment, convex and concave curves of first engagement surface  96  and second engagement surface  98  may have cross-sections defined by circular arcs. 
     The active edge  11  of each plate  7 ,  8  may have a plurality of first coupling portions  44 . The first coupling portions  44  may be mutually aligned longitudinally. The first coupling portions  44  may mutually spaced apart. 
     A first coupling portion  44  may be positioned adjacent to the front plate  9 . A first coupling portion  44  may be positioned adjacent to the ends of plate  7 ,  8  connected through the pivot connection. The side contact members  48  of the first coupling portion  44  adjacent to the front plate  9  may be mirror symmetrical with the side contact members  48  of the first coupling portion  44  adjacent to the pivot connection. 
     With reference to  FIG. 2 , the active edge  11  may have at least one second coupling portion  68 . The second coupling portion  68  may be adjacent to the at least one first coupling portion  44 . The second coupling portion  68  may be contiguous with the at least one first coupling portion  44 . 
     The second coupling portion  68  may comprise of through bore  100 . The bore  100  may extend through the plate  7 ,  8 . Bore  100  may be adapted to accommodate bolts for fixing a replaceable wear part. Bore  100  may be located on the plate  7 ,  8  spaced from the active edge  11 . Bore  100  may be provided transverse to the longitudinal axis of the plate  7 ,  8 . At a side of each plate  7 ,  8  bore  100  may open onto an opening  102 . The opening  102  may receive the spring retainers. The pin may be held in the bore  100  by spring retainers. In an embodiment, opening  102  may receive the head of a bolt which is inserted into the bore  100 . 
     The active edge  11  of each plate  7 ,  8  may have a plurality of second coupling portions  68 . The second coupling portions  68  may be mutually aligned longitudinally. The second coupling portions  68  may mutually spaced apart. 
     The second coupling portions  68  may be interspersed between the first coupling portions  44 . The first coupling portions  44  and the second coupling portions  68  may be mutually aligned longitudinally on the active edge  11 . The second coupling portions  68  may be bordered by the side contact members  48  of alternate first coupling portions  44 .  FIGS. 9 and 10  illustrate a replaceable wear part which is a wear plate  20  that may be removably mounted to the jaw assembly  10  of a demolition tool. The wear plate  20  may comprise a body element  54  that is configured to saddle the first coupling portion  44 . The body element  54  may be substantially u-shaped. 
     Body element  54  may have a central panel  104  connected to a pair of side panels  106 . Central panel  104  may be normal to the side panels  106 . The central panel  104  may have a notch orientated transverse to the longitudinal axis of the central panel  104 . With the wear plate  20  mounted to the first coupling portion  44 , the central panel  104  may rest on the contact surface  64 . The central panel  104  may have a contact face  66  which is complementarily shaped to the contact surface  64 . The contact face  66  may be substantially v-shaped to fit into the contact surface. The center protrusion of the contact face  66  may fit into the center depression of the contact surface  64 . The complementarily shaped contact surfaces  64 ,  66  may limit the axial movement of the wear plate  20  on the first coupling portion  44 . 
     Each side panels  106  may have an abutment edge  108  located opposite the edge connected to the central panel  104 . The abutment edges  108  may be shaped to fit onto the abutment surface  94  of the side contact member  48 . 
     A pair of first engagement elements  56  may extend from an end of the body element  54  for engaging to first protrusions  50  provided on the at least one first coupling portion  44 . First engagement elements  56  may extend in a direction substantially away from the central panel  104 . The pair of first engagement elements  56  may be spaced apart on the body element  54 . The pair of first engagement elements  56  may be mutually substantially parallel. The pair of first engagement elements  56  may be mirror symmetrical. First engagement elements  56  may be disposed on the side panels  106  and on the central panel  104 . 
     Each first engagement element  56  may comprise a pair of bifurcate fingers  60 ,  62 . First fingers  60  may be angularly spaced relative to second fingers  62 . First fingers  60  may have an angular spacing of 10° to 50° relative to second fingers  62 . Preferably, first fingers  60  may have an angular spacing of 15° to 35° relative to second fingers  62 . Preferably, first fingers  60  may have an angular spacing of 20° to 40° relative to second fingers  62 . Preferably, first fingers  60  may have an angular spacing of 25° to 45° relative to second fingers  62 . Preferably, first fingers  60  may have an angular spacing of 30° relative to second fingers  62 . 
     With an angular spacing of 30° the wear plate  20  may be retained in engagement to first protrusions  50  and to prevent the fingers  60 ,  62  from becoming to long and small which may increase the risk of breaking. With an angle of more than 50° the wear plate  20  may not be retained in engagement to first protrusions  50 . A first groove  110  may be formed between each pair of bifurcate fingers  60 ,  62 . First grooves  110  may have cross-sections defined by circular arcs. The circular arcs may be opposite the respective openings. First grooves  110  may receive first protrusions  50 . First grooves  110  may have dimensions and shapes to accommodate the first protrusions  50 . 
     Each first finger  60  may be provided on the side panel  106 . First finger  60  may be inclined relative to central panel  106 . The longitudinal axis of first finger  60  may be inclined relative to the longitudinal axis of central panel  104 . The longitudinal axis of first finger  60  may be inclined relative to the longitudinal axis of second finger  62 . The side of first finger  60  opposite the side bordering the first groove  110  may form the side of the abutment edge  108 . 
     Each second finger  62  may be disposed at the connection of side panel  106  and central panel  104 . Second finger  62  may partially extend from side panel  106  and may partially extend from central panel  104 . The longitudinal axis of second finger  62  may be parallel to the longitudinal axis of central panel  104 . 
     The sides of second fingers  62  opposite the sides bordering the first grooves  110  may be planar with a surface of the central panel  104 . A first retainment zone  114  may be formed by a surface at the end portion of the central panel  104  and the side of second finger  62  which are mutually planar. The first retainment zone  114  may be bordered by the notch. 
     A pair of second engagement elements  58  may extend from an end of the body element  54  for engaging to second protrusions  52  provided on the at least one first coupling portion  44 . Second engagement elements  58  may extend in a direction substantially away from the central panel  104 . Second engagement elements  58  may extend in a direction opposite to the direction of extension of the first engagement elements  56 . The pair of second engagement elements  58  may be spaced apart on the body element  54 . The pair of second engagement elements  58  may be mutually substantially parallel. The pair of second engagement elements  58  may be mirror symmetrical. Second engagement elements  58  may be disposed on the side panels  106  and on the central panel  104 . 
     Each second engagement element  58  may comprise a pair of bifurcate branches  63 ,  65 . First branches  63  may be angularly spaced relative to second branches  65 . First branches  63  may have an angular spacing of 10° to 50° relative to second branches  65 . Preferably, first branches  63  may have an angular spacing of 15° to 35° relative to second branches  65 . Preferably, first branches  63  may have an angular spacing of 20° to 40° relative to second branches  65 . Preferably, first branches  63  may have an angular spacing of 25° to 45° relative to second branches  65 . Preferably, first branches  63  may have an angular spacing of 30° relative to second branches  65 . 
     With an angular spacing of 30° the wear plate  20  may be retained in engagement to second protrusions  52  and to prevent the branches  63 ,  65  from becoming to long and small which may increase the risk of breaking. With an angle of more than 50° the wear plate  20  may not be retained in engagement to second protrusions  52 . 
     The bifurcate fingers  60 ,  62  may have the same angular spacing as the bifurcate branches  63 ,  65 . In an embodiment, the bifurcate fingers  60 ,  62  may have a smaller angular spacing than the bifurcate branches  63 ,  65 . 
     A second groove  112  may be formed between each pair of bifurcate branches  63 ,  65 . Second grooves  112  may have cross-sections defined by circular arcs. The circular arcs may be opposite the respective openings. Second grooves  112  may receive second protrusions  52 . Second grooves  112  may have dimensions and shapes to accommodate the second protrusions  52 . 
     Second grooves  112  may have the same dimension as first grooves  110 . Second grooves  112  may have the same diameter as first grooves  110 . In an embodiment, second grooves  112  may have a greater dimension relative to first grooves  110 . Second grooves  112  may have a diameter that is greater relative to the diameter of first grooves  110 . 
     Each first branch  63  may be provided on the side panel  106 . First branch  63  may be inclined relative to central panel  106 . The longitudinal axis of first branch  63  may be inclined relative to the longitudinal axis of central panel  106 . The longitudinal axis of first branch  63  may be inclined relative to the longitudinal axis of second finger  65 . The side of first branch  63  opposite the side bordering the may form the first groove  110  may form the side of the abutment edge  108 . 
     Each second branch  65  may be disposed at the connection of side panel  106  and central panel  104 . Second branch  65  may partially extend from side panel  106  and may partially extend from central panel  104 . The longitudinal axis of second branch  65  may be parallel to the longitudinal axis of central panel  106 . 
     The sides of second branches  65  opposite the sides bordering the first grooves  110  may be planar with a surface of the central panel  104 . A second retainment zone  116  may be formed by a surface at the end portion of the central panel  104  and the side of second branch  65  which are mutually planar. The second retainment zone  116  may be bordered by the notch. Second retainment zone  116  may be formed opposite the first retainment zone  114 . 
       FIG. 12  illustrates the wear plate  20  mounted on the first coupling portion  44 . First engagement elements  56  and second engagement elements  58  may extend along the side of the intermediate contact member  46 . The first retainment zone  114  may be planar with an abutment surface  94  of the intermediate contact member  46 . The second retainment zone  116  may be planar with an abutment surface  94  of the intermediate contact member  46 . 
       FIG. 11  illustrates a replaceable wear part which is an active module  22  that may be removably mounted to the jaw assembly  10  of a demolition tool. The active module  22  may comprise a body member  70  that is configured to be mountable to the at least one second coupling portion  68 . Body member  70  may be substantially U-shaped to straddle the intermediate contact member  46 . Legs  118  may extend from the body member  70 . Legs  118  may extend longitudinally from the body member  70 . Legs  118  may be provided with through bores  120  for receiving pins for coupling to the second coupling portion  68 . 
     Active module  22  may have at least one brace  72  disposed on the body member  70 . Brace  72  may protrude laterally from the body member  70 . Brace  72  may be disposed on the member  70  spaced away from the legs  118 . Brace  70  may have a substantially triangular shape. Brace  70  may have a triangular cross-section. 
     In an embodiment, brace  70  may be a planar extension. Brace  70  may have a rectangular cross-section. 
     Brace  72  may have a retainment face  122  which faces the direction of extension of legs  118 . Retainment face  122  may be planar. Retainment face  122  may have a dimension such that with the active module  22  mounted at the second coupling portion  68  the brace  72  may extend over the wear plate  20 . Brace  72  may extend over the second engagement elements  58 . Brace  72  may extend over the first engagement elements  56 . 
     With reference to  FIG. 12 , brace  72  may extend over the second engagement elements  58 . Brace  72  may extend over the first engagement elements  56 . Retainment face  122  may contact the abutment surface  94  and the first retainment zone  114 . Retainment face  122  may contact the abutment surface  94  and the second retainment zone  116 . 
     The retainment face  112  may engage the second engagement elements  58  to retain the wear plate  20  on the first jaw  12 . The retainment face  112  may engage the second retainment zone  116  to retain the wear plate  20  on the first jaw  12 . The retainment face  112  may engage the first engagement elements  56  to retain the wear plate  20  on the first jaw  12 . The retainment face  112  may engage the first retainment zone  114  to retain the wear plate  20  on the first jaw  12 . 
     In an embodiment, a pair of braces  72  may be provided on opposite sides of the body member  70 . The braces  72  may extend from the body member  70  in opposite directions. The braces  72  may be configured to extend over the first engagement elements  56  and the second engagement elements  58  of alternate wear plates  20 . The braces  72  may be configured to extend over the second engagement elements  58  of alternate wear plates  20 . 
     A modular system for removable mounting of replaceable parts to a jaw assembly  10  of a demolition tool may be composed of the wear plate  20  and the active module  22 . The wear plate  20  may comprise a body element  54  configured to saddle an at least one first coupling portion  44  disposed on a first jaw  12  of the jaw assembly  10 ; a pair of spaced apart first engagement elements  56  extending from an end of the body element  54  for engaging to first protrusions  50  provided on the at least one first coupling portion  44 ; and a pair of spaced apart second engagement elements  58  extending longitudinally from an opposite end of the body element  54  for engaging to the second protrusions  52  provided on the at least one first coupling portion  44 . The active module  22  may comprise a body member  70  configured to be mountable to the at least one second coupling portion  68  disposed on a first jaw  12  adjacent to the at least one first coupling portion  44 ; at least one brace  72  disposed on a side of the body member  70  and configured to extend over the second engagement elements  58 . When the wear plate  20  and the active module  22  are assembled on the first jaw  24  a brace  72  may extend over the second engagement elements  58  to retain the wear plate  20  on the first jaw  12 . 
     In an embodiment, a pair of braces  72  may be disposed on opposite sides of the body member  70 . The braces  72  may be configured to extend over the first engagement elements  56  and the second engagement elements  58  of alternate wear plates  20 . The braces  72  may be configured to extend over the second engagement elements  58  of alternate wear plates  20 . 
     The mounting of the modular system may involve mounting the wear plate  20  onto the first coupling portion  44  and subsequently mounting at least one active module  22  at second coupling portion  68 . 
     The wear plate  20  may be mounted on the first coupling portion  44 . Wear plate  20  may be positioned such that the first engagement elements  56  may be pointed towards the firsts protrusions  50 . Wear plate  20  is moved towards first coupling portion  44  and the first engagement elements  56  contact with the first protrusions  50 . The first fingers  60  may contact the concave curves of the first engagement surfaces  96 . The convex curves of first engagement surfaces  96  may fit into the first grooves  110 . The second fingers  62  may engage the free ends of the first protrusions  50 . Side panels  106  may contact the sides of the intermediate contact member  46 . 
     Once, the first engagement elements  56  are engaged with the firsts protrusions  50 , the wear plate  20  may be rotated onto the first coupling portion  44  along the line A as illustrated in  FIG. 13 . Line A may be concentric with the convex curve of first engagement surfaces  96 . Wear plate  20  may be rotated away from the first coupling portion  44  along the line A as illustrated in  FIG. 13  when being removed therefrom. 
     The convex curves may rotate in the first grooves  110  relative to the side contact members  48 . The first fingers  60  may rotate in concave curves of the first engagement surfaces  96  side contact members  48 . Side panels  106  may slide against the sides of the intermediate contact member  46 . 
     As wear plate  20  rotates about the convex curves of the first engagement surfaces  96  of the first protrusion  50  the second engagement elements  58  move into contact with the second engagement surfaces  98  of the second protrusions  52 . The first branches  63  may slide past the convex curves of the second engagement surfaces  98  to contact the concave curves thereof. The second branches  65  may move into contact the free ends of the second protrusions  52 . The second branches  65  may contact and rest on the convex curves of the second engagement surfaces  98 . The abutment edges  108  of the side panels  106  move into contact with the respective abutment surfaces  94  of the side contact members  48 . The contact face  66  of the wear plate  20  may fit into the contact surface  64  of the intermediate contact member  46 . 
     After, the wear plate  20  is mounted at the first coupling portion  44 , the active module  22  is moved into the second coupling portion  68 . The body member  70  straddles the active edge  11  and the legs  118  are positioned such that the bores  120  are aligned with the bores  100 . Bolts may be inserted through bores  120  and bores  100  so as to hold the active module  22  at the second coupling portion  68 . With the active module  22  mounted at least one brace  72  may be disposed on a side of the body member  70  and may extend over the second engagement elements  58 . 
       FIG. 14  illustrates a jaw assembly  10  having mounted thereon the replaceable wear parts represented by the work module  16 , the work plate  18 , the wear plates  20  and the active modules  22 . 
     The skilled person would appreciate that foregoing embodiments may be modified or combined to obtain the jaw assembly  10  and the replaceable wear parts  16 ,  18 ,  20 ,  22  of the present disclosure. 
     INDUSTRIAL APPLICABILITY 
     This disclosure describes a jaw assembly  10  and replaceable wear parts. The replaceable wear parts may be mounted to the jaw assembly  10  of a demolition tool such as multiprocessors, pulverizers, crushers and other demolition tools that may have a jawset or grapple tine which have closing movements. The replaceable wear parts may be mounted to the corresponding support portions of the jaw assembly  10 . The replaceable wear parts may shield the jaw assembly  10  from wear during demolition operations such as crushing or cutting of materials. The replaceable wear parts may be made of materials suitable for the crushing or cutting operations. 
     The replaceable wear parts may be easily and efficiently mounted on and dismounted from jaw assembly. Once the replaceable wear parts are spent due to operation of the demolition tool, the modules may be easily replaced with a substitute replaceable modules. 
     The replaceable wear parts  18 ,  20  may be removably mounted on the jaw assembly  10  without the use of bolts or pins. 
     Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein. 
     Where technical features mentioned in any claim are followed by references signs, the reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, neither the reference signs nor their absence have any limiting effect on the technical features as described above or on the scope of any claim elements. 
     One skilled in the art will realise the disclosure may be embodied in other specific forms without departing from the disclosure or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the disclosure described herein. Scope of the invention is thus indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalence of the claims are therefore intended to be embraced therein. 
     The disclosures in European Patent Application No. 12171213.7 from which this application claims priority are incorporated herein by reference.