Abstract:
A digging point assembly for use in earthworking which comprises a main body which includes a socket member defining a hollow socket for engagement with a leading tip of a tyne and first and second replaceable wear parts which are mounted to the main body to protect the leading end and top of the socket member which are normally exposed to wear in movement through soil, the first wear part being maintained in an operative position at the leading end of the socket by the tyne and cooperating with the second wear part to maintain the second wear part in operative position protecting the top of the socket member. The digging point assembly may also include a third replaceable wear part at the leading end of the body part which is held in position by cooperation with the first replaceable wear part.

Description:
Cross-Reference to Related Application 
     This application hereby claims the priority of Australian Provisional Patent Application No. 2009902090, filed May 12, 2009, which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     This invention relates to a digging point assembly and in particular to a digging point assembly for used in agricultural applications for working of the soil. The digging point assembly of the invention is particularly suited for use in subsoiling or deep-working operations but may be used in any other ploughing operations. 
     BACKGROUND ART 
     Subsoiling ploughing operations involve the use of earth working or ploughing equipment usually at depths which are greater than depths at which any previous cultivation on a particular parcel of land has occurred. As a result, tynes of the above equipment used in such an environment are subject to considerable wear at their leading ends and accordingly replaceable wear resistant digging points or tools are commonly used at the leading ends of the tynes. Points or tools of this type increase the effective life of the tyne by protecting the leading end of the tyne to which they are attached. Known points or tools have a shape which allows for considerable wear whilst maintaining a reasonable cutting edge even when worn. 
     To increase their operating life, replaceable points have been made of an increased size and weight. The extra mass of material in the points however tends to round off in use and decreases the digging ability of the implement. 
     Replaceable digging points or tools which are used are also subject to wear not only at their tips but also in other exposed regions of the point or tool. Accordingly digging points or tools which are known also normally have to be replaced regularly. Thus where the digging point has worn to a stage where damage to the tyne is imminent, the point must be discarded to avoid any wear or damage to the tyne. In certain soil types or where subsoiling operations are undertaken, this occurs regularly which adds to costs as the whole point or tool has to be removed from the tyne and replaced. 
     It would be desirable to provide an improved digging point assembly which overcomes or alleviates one or more of the disadvantages of the above described prior art or which at least provides an effective alternative to the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention provides in a preferred aspect although not necessarily the broadest aspect, a digging point assembly comprising a main body adapted to be mounted to a tyne of an earth working implement, and 
     at least two sub-parts, each said sub-part comprising a replaceable wear part adapted to protect different parts of said main body exposed in use to wear in movement of said digging point assembly through soil, and wherein a first said sub-part is adapted in its operative position to cooperate directly or indirectly with a second said sub-part to maintain the second sub-part in its operative position. 
     Preferably the first sub-part is retained in its operative position by cooperation with the tyne when the main body is operatively engaged with the tyne. When the first sub-part is retained in operative position by the tyne, the first sub-part is suitably prevented from detachment from the main body and the first sub-part in its operative position prevents detachment of the second sub-part from the main body. 
     Preferably a retaining pin is provided, the retaining pin being adapted to cooperate with the second sub-part to prevent detachment thereof. Preferably the retaining pin is associated with and held in position by the first sub-part. 
     Preferably the main body includes a central longitudinally extending socket member defining a socket adapted for engagement by the tip of a tyne. Preferably the socket is of a forwardly tapering configuration and is open on the normal trailing side of the main body and a tip or foot of the tyne is of a corresponding tapering configuration such that it may be inserted into, to mate with the socket. 
     Preferably both sub-parts are exposed directly to the soil as the digging point assembly is advanced through the soil such that portions of the main body of the digging point assembly beneath or behind the sub-parts are protected from direct contact with the soil and therefore will not be exposed to excessive wear. Typically the first sub-part protects a leading end of the socket member and the second sub-part protects an upper side of the socket member. 
     Preferably the first sub-part includes a tongue adapted to extend into a leading end of the socket which is open and the leading end of the tyne tip or foot in its operative position is adapted to be located adjacent to or abut the tongue to prevent detachment or substantial movement of the first sub-part away from its operative position. 
     Any suitable means may be provided for connecting the tyne tip or foot to the digging point assembly. Such means may comprise a connection arrangement between the tip and digging point assembly on the underside of the digging point assembly and tip. For this purpose, the underside of the point assembly may be provided with a connector engagement means for engagement with a bolt or stud which extends to the underside of the tip for connection thereto. Alternatively of additionally, the tip or foot and main body of the digging point assembly may be provided with corresponding openings which may be aligned to receive a retaining pin or wire therethrough. 
     Preferably the main body includes a central splitter fin which extends longitudinally of and forwardly of the socket member and a transverse opening is provided in the main body between the fin and socket member. The first sub-part is suitably adapted to be located in the opening and suitably includes flanges adapted to be located on opposite sides of the fin. The first sub-part further may include a recess or channel between the flanges adapted to accommodate the retaining pin. 
     In one form the recess or channel has an open side to receive the retaining pin, the open side of the recess or channel being closed when the first sub-part is located in its operative position with the flanges on opposite sides of the fin to capture the retaining pin in the recess or channel in an operative position. Preferably the retaining pin in its operative position includes a portion extending above the first sub-part. 
     Preferably the second sub-part includes a pair of arms adapted to be located on or adjacent to shoulders on the upper side of the socket member and on opposite sides of the central fin which suitably extends centrally along the socket member. The arms of the second sub-part thus protect the shoulders of the socket member from direct contact with the soil and therefore prevent wear in the shoulders. Preferably the second sub-part includes a transverse cross arm adapted to extend through the transverse opening in the main body, the cross arm being adapted to be located adjacent to and rewarwardly of the extending portion of the retaining pin, the latter acting as a stop to prevent or restrict forward movement and detachment of the second sub-part when in its operative position. The second sub-part is suitably of an elongated U-shaped configuration with the pairs of arms of the second sub-part comprising the respective legs of the U and being joined at one end by the transverse cross arm. 
     Preferably the main body includes locating means for locating the second sub-part. Preferably in the operative position, the retaining pin prevents detachment of the second sub-part from the locating means. In one form the locating means may comprise stops or recesses for receipt of hooks on the arms of the second sub-part. In another form, the locating means may comprise means to receive and capture the free ends of the arms of the second sub-part. 
     The first and second sub-parts suitably are of a width to protect at least the sides and leading end of the socket member of the main body. 
     In a further embodiment, the digging point assembly includes a third sub-part which comprises a replaceable leading end or shroud part adapted to protect the leading end of the body. Preferably the third sub-part is adapted to be retained in position by cooperation with the first sub-part. Preferably the first sub-part includes a stop member adapted in its operative position to act as a stop to prevent detachment of the third sub-part from said body. Preferably the third sub-part includes a headed member and the stop member is adapted to cooperate with the headed member. The headed member may comprise a tongue terminating in a head and the first sub-part may include a pair of stop members adapted to be located on opposite sides of the tongue for cooperation with the head. Suitably the tongue is provided on the lower side of the third sub-part to extend beneath the first sub-part to enable cooperation with the stop members. 
     Preferably the third sub-part includes a head defining a socket and the leading end of the body is complementary to the socket so as to be receivable therein. Preferably the third sub-part further includes opposite side aims or fins which extend from the head and which when the third sub-part part is engaged with the body comprise extensions of the side fins of the body. 
     The sub-parts may be formed of any suitable material which may comprise a suitable wear resistant material such as tungsten carbide steel or alternatively the sub-parts as with the main body of the digging point assembly may be formed of steel. 
     In another aspect, the present invention provides a digging point assembly comprising a main body adapted to be mounted to a tyne of an earth working implement, said main body having a longitudinal axis and a leading end and a trailing end, said main body including a socket member extending along said longitudinal axis, said socket member defining a hollow socket open at least at the trailing end of said main body for receiving a leading tip of said tyne, first and second replaceable wear parts mounted to said main body to protect different parts of said main body normally exposed to wear in movement of said main body through earth or soil, and wherein when said body is mounted to a said tyne, said first wear part is maintained in an operative position by said tyne and cooperates directly or indirectly with said second wear part to maintain said second wear part in operative position and prevent its detachment from said main body. 
     The socket is suitable open at the leading end of said socket member and the first wear part is mounted to the main body to extend transversely thereof to protect the leading end of the socket member. Preferably the first wear part includes a rearwardly extending tongue which extends into the open leading end of the socket and the tip of the tyne cooperates with the tongue to prevent detachment of the first wear part from the body. 
     Preferably the main body includes a transverse opening and a longitudinally extending fin and the first wear part including spaced flanges and is received in the opening such that respective flanges are arranged on opposite sides of the fin. The first wear part also suitably includes a recess or channel between the flanges which accommodates a retaining pin, said recess or channel being closed on one side by the fin to capture the retaining pin in the recess or channel. The retaining pin suitably cooperates with a leading end of the second wear part to prevent detachment thereof. Preferably the retaining pin has a portion extending above the first wear part to act as a stop to the second wear part. 
     The socket member includes a pair of shoulders on its top side on opposite sides of the central fin and wherein the second wear part includes a pair of side arms located and seating on the shoulders. The second wear part suitably is of a U-shaped configuration and includes a cross arm joining the side arms, the cross arm extending through the opening in the main body and being located adjacent the extending portion of the retaining pin, the extending portion of the pin acting as a stop to the cross arm to prevent detachment of the second wear part from its operative position. Suitably means are proved for capturing trailing ends of the arms when the second wear part is in its operative position and the retaining pin prevents disengagement of the ends of the arms from the capturing means. 
     The digging point assembly may also include a third replaceable wear part located at a leading end of the main body for protecting the leading end of the body. Preferably the first wear part cooperates with the third wear part to maintain the third part in its operative position. 
     The third wear part may include a socket and the leading end of the main body includes engagement means complementary to the socket for receipt therein. The main body may also include opposite side fins and the third part may include opposite side arms or fins which in the operative position of said third part comprise extensions of the fins of the body. 
     Suitably, the first wear part includes a stop member which acts as a stop to prevent detachment of the third wear part from the body. The third part may include a headed member on its lower side and the stop member is adapted to cooperate with the headed member. The headed member may comprise a tongue terminating in an enlarged head and the first wear part may include a pair of spaced stop members adapted to be located on opposite sides of the tongue for cooperation with the head. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To enable the invention to be more fully understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein: 
         FIGS. 1 and 2  are views from above and below respectively of a digging point assembly according to a first embodiment of the invention; 
         FIGS. 3 ,  4  and  5  are top, side and bottom views of the digging point assembly of  FIGS. 1 and 2 ; 
         FIG. 6  illustrates a first replaceable wear part of the digging point assembly; 
         FIG. 7  is a longitudinal cross sectional view, the first replaceable wear part with associated retaining pin; 
         FIG. 8  is a front view of the first replaceable wear part in the direction A of  FIG. 6 ; 
         FIG. 9  is an isometric view of a second replaceable wear part of the digging point assembly; 
         FIG. 10  illustrates the main body of the digging point assembly with the wear parts removed; 
         FIG. 11  illustrate the manner in which the parts of the digging point assembly are assembled; 
         FIG. 12  illustrates the digging point assembly mounted to a tyne; 
         FIGS. 13 and 14  are views from above and below respectively of a digging point assembly according to a second embodiment of the invention; 
         FIGS. 15 and 16  are views from above and below respectively of the digging point assembly of  FIGS. 13 and 14  with the leading replaceable end portion detached; 
         FIG. 17  is an exploded view of the digging point assembly of  FIGS. 13 and 14 ; 
         FIG. 18  is an enlarged view of a wear part similar to that of  FIG. 6  modified for use in the embodiment of  FIGS. 13 and 14 ; and 
         FIG. 19  is a longitudinal sectional view of the digging point assembly of  FIGS. 13 and 14  and showing its association with the tip of a tyne (shown in dotted outline). 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings and firstly to  FIGS. 1 to 5 , there is illustrated a digging point assembly  10  according to an embodiment of the invention, the point assembly  10  comprising a main point body  11  having a longitudinal axis X-X and which, in use, is connected to the working end or tip of a tyne of agricultural implement, the main body  11  carrying a pair of replaceable sub-parts comprising wear parts  12  and  13  whose purpose will become apparent further below. The main body  11  includes a blade-like base  14  having a leading end provided in this case with a transversely extending recess  15  adapted to receive a hardened tip or strip  16  (shown in dotted outline in  FIG. 4 ) of complementary shape to the recess  15 , the tip  16  typically being formed of tungsten carbide and being secured in position by soldering. The base  14  of the main body  11  additionally includes opposite rearwardly extending side fins  17  arranged symmetrically relative to the axis X-X. The base  14  additionally may include on its underside, connector engagement means  18  for use in positively connecting the main body  10  to a tyne in a similar manner to that described in my U.S. Pat. No. 6,401,834. 
     Arranged centrally of the base  14  of main body  11  relative to the fins  17  and extending longitudinally along the axis X-X thereof is a socket member  19  (shown also in  FIGS. 6 and 7 ) which defines a hollow socket  20  which opens to the rear of the base  14  at end  21 , the socket member  19  and socket  20  tapering from the end  21  towards the leading end of the main body  11  for receipt of the tip of a tyne which is of a complementary or mating tapering shape. The socket  20  is provided with upper and lower channel portions  22  and  23  for receipt of upper and lower lugs on a tip of a tyne. 
     The main body  11  additionally includes an upright central splitter fin  24  extending longitudinally along the axis X-X which is aligned with the socket member  19  and which extends along and forwardly of the socket member  19 . The fin  24  is inclined downwardly at its leading end  25  to meet the base  14 . The edge of the leading end  25  is formed with longitudinally extending recesses  26  to receive wear members  27  (shown in dotted outline in  FIG. 4 ) similar to the tip  16  to protect the leading end  25  of the fin  24  against wear. 
     A transverse opening  28  is formed in the main body  11  at the leading end of the socket member  19  (see also  FIG. 10 ) between the socket member  19  and fin  24  and the socket  20  opens at its leading end  29  to the opening  28 . A further opening  30  is provided in the base of the main body  11  which communicates with the opening  28  as shown in  FIGS. 2 ,  5  and  10  to allow for the insertion of the wear parts  12  and  13 , the opening  30  being of slightly greater width than the width of the wear parts  12  and  13 . 
     Downwardly inclined shoulders  31  (see  FIG. 10 ) are formed at the top side of the socket member  19  on opposite sides of the central fin  24  and a locator  32  for the second wear part  13  is provided at the trailing end of each shoulder  31 . The locators  32  define circular openings  33  into which ends of the second wear part  13  project in use as described further below. Slots  34  are also proved in the shoulders  27  forwardly of the locators  32 . 
     The first wear part  12  shown also in  FIGS. 6 to 8  is designed to protect the leading end and sides of the socket member  19  against wear and for this purpose, the wear part  12  has a width W which is at least the width of the socket member  19 . The wear part  12  includes a bifurcated leading end  35  which is defined by a central channel or recess  36  which splits the leading end  35  of the part  12  into two spaced flanges  37 . The channel  36  is of a stepped configuration comprising an outermost part  38  which is of a width substantially the same as the width of the central fin  24  adjacent the opening  28  such that it is capable of receiving portion of the fin  24  as described below. The channel  36  also includes an innermost part  39  which is adapted to receive a retaining pin  40  (shown in  FIGS. 6 and 7  and in dotted outline in  FIG. 8 ), the retaining pin  40  having a diameter slightly less than the width of the channel part  39  but being of a greater length than the channel part  39 . The channel part  39  is also closed by an end wall  41  which closes the normal lower end of the channel part  34  whilst the operative upper end of the channel part  39  remains open so that the pin  40  can project or extend above the channel part  39  as shown in  FIG. 7  when the opposite end of the pin  40  abuts the wall  41 . A releasing hole  42  extends transversely from the channel part  49  to the outer surface of the wear part  12  to facilitate removal of the pin  40  by insertion of an appropriate pin or tool therein. 
     The leading outer end of the wear part  12  includes at its lower end a stepped recessed portion  43  (provided in each flange  37 ) adapted to seat on the base  14  of the main body  11  on opposite sides of the central fin  24 . Transversely aligned arcuate recesses  44  are provided in each flange  37  adjacent to and above the recessed portion  43 , the recesses  44  in use being adapted to be aligned with a transverse aperture  45  in the fin  24  of the main body  11  (see  FIG. 1 ). The first wear part  12  also includes on its rear side a rearwardly directed tongue  46  of a width slightly less than the width of the socket  20  and which is adapted to extend into the leading open end  29  of the socket  20 . The flanges  37  are concavely curved in their top surfaces to join or merge into the tongue  46 . 
     The second wear part  13  shown in  FIG. 9  is of an elongated U-shaped configuration having a pair of opposite side arms  48  and a connecting transverse arm  49  at one end thereof adapted to be located in the opening  28  through the main body  11 , the side arms  48  being spaced apart a distance slightly greater than the width of the central fin  24 . The arms  48  are adapted to lie along the shoulders  31  on the top side of the socket member  19  on opposite sides of the central fin  24  and extend into the circular openings  33  in the end locators  32  to be captured therein. For this purposes, the arms  48  are provided with spigots  50  at their free ends which are complementary to the openings  33  and which extend beyond stops  51  adjacent the free ends. The arms  48  are additionally provided on their lower sides adjacent the stops  51  with respective rearwardly directed hooks  52  for receipt in and engagement with the slots  34 . 
     The socket member  19  of the main body  11  is provided with a transverse opening  53  through which a retaining wire or pin may be passed and passed through a corresponding transverse opening in the tip of the tyne to positively retain the digging point  10  assembly to the tyne tip. 
     For assembly purposes, the U-shaped wear part  13  is twisted and passed into the opening  30  from the underside of the main body  11  and then twisted back such that the respective arms  48  thereof can locate on opposite sides of the central fin  24 . The respective arms  48  are then positioned to lie along the shoulders  31  on the top of the socket member  19  on opposite sides of the fin  24  with the spigots  50  extending into the openings  33  in the end locators  32  as illustrated in  FIG. 11  with the hooks  52  being received and hooked into the slots  34  to hold the wear part  13  in position. In this position the transverse arm  49  extends transversely through the opening  28 . 
     The other wear part  12  is then passed into the opening  30  again from the underside of the main body  11  so that the respective flanges  37  thereof locate on opposite sides of the central fin  24  adjacent the opening  28  and the tongue  46  extends into the leading open end  29  of the socket  20 . For this purpose the tongue  46  is initially inserted into the end  29  of the socket  20  and the opposite end of the wear part  12  pivoted upwardly in the direction B of  FIG. 11 . Prior to pivoting the wear part  12  however, the retaining pin  40  is inserted from below in the direction C into the innermost part  39  of the channel  36  so that it projects beyond the channel  36  and abuts the end wall  41  as in  FIG. 7 . Subsequent pivoting of the wear part  12  upwardly in the direction B will move the wear part  12  towards the position of  FIGS. 1 ,  2  and  4 . The wear part  12  is positioned such that the stepped recessed portions  43  seat on the top surface of the base  14  and the wear part  12  it can then slide forwardly on the base  14  to the position of  FIGS. 1 ,  2  and  4  in which the innermost part  39  of the recess  36  is closed by the fin  24  and the pin  40  is captured in the channel part  39 . In this position, the upper end of the pin  40  is located forwardly of the connecting arm  49  of the second wear part  13  and acts as a stop against the arm  49  to prevent the wear part  13  moving forwardly and detaching from the locators  32  and unlatching of the hooks  52 . 
     As shown in  FIG. 12 , the point assembly  10  is used with a tyne  54  having a tapering tip  55  which is of a substantially complementary shape to the socket  20 . The tip  55  as shown in dotted outline in  FIG. 12  is inserted into the rear end  21  of the socket  20  and when the tip  55  is in its fully mated position in the socket  20 , the leading end  56  thereof is located adjacent to or in abutment with the trailing end of the tongue  46  of the wear part  12  which extends into the end  29  of the socket  20 . This prevents the wear part  12  being moved rearwardly from its position of  FIGS. 1 ,  2  and  4  in which the pin  40  prevents detachment or movement of the second wear part  13 . The tip  55  may be retained in position by a bolt or stud/nut connection as show in dotted outline between the aforementioned connector engagement means  18  on the underside of the point assembly  10  and a channel  56  on the underside of the tip  55 . Tightening the bolt or nut will urge the point assembly  10  firmly into engagement with the tip  55  of the tyne  54 . Alternatively the tip  55  which may have at least an apertured lug  57  may be secured relative to the point assembly  10  by means of a transverse wire  58  passed through the transverse opening  53  and lug  57  which is aligned with the opening  53 . 
     The wear part  12  being of the same or greater width of the socket member  19  acts to protect the sides and leading end of the socket member  19  from wear when in use in soil by deflecting soil around and past the socket member  19  and the second wear part  13  protects the top shoulders  31  of the socket member  19  and also the sides of the socket member  19  by also deflecting soil away from the shoulders  31 . The wear strips or members  16  and  27  applied to the tip  15  of the digging point assembly  10  and the recesses  26  also protect leading edges of the digging point assembly  10 . Typically the wear resistant parts  12  and  13  are formed of tungsten carbide or other wear resistant materials and may be readily replaced when they have excessively worn however it is usually not necessary to replace the main body  11  as it has been protected. The wear strips or members  16  and  27  applied to the tip  15  or recesses  26  are usually attached by silver soldering and therefore can also be readily replaced. 
     For detachment of the two wear parts  12  and  13 , the tip  55  of the tyne  54  is required to be at least partly retracted from the socket  20  by release of the pin or wire  58  or loosening of the bolting connection via the connector  18 . This will permit rearward movement of the wear part  12  and detachment of the pin  50 . The wear part  12  can then be withdrawn through the opening  30  and thereafter the wear part  13  can be moved forwardly and detached. These parts  12  and  13  may then be replaced with new parts. 
     Further protection for the sides of the socket member  19  can be provided by a wire or rod  59  passed through the openings  45  which also locates in the recesses  44  in the wear part  12  and which can be bent along the sides of the wear part  12  and socket member  19  as shown in dotted outline in  FIG. 12 . The retaining wire or rod  59  passed through opening  53  and lug  57  may also be bent back on either side to further protect the sides of the socket member  19 . 
     The main body  11  of the digging point assembly  10  may be of various designs and configurations as may be the wear parts  12  and  13 . The socket  20  defined by the socket member  19  is designed to mate with the tip  55  of the tyne  54  and therefore may be of various cross sectional forms to suit the tip  55 . The main body  11  may be varied in design to omit the slots  34  in which case the wear part  13  will be held in position by engagement with the locators  32 . Alternatively the arms  48  may include opposing lugs on their inner sides which may locate in corresponding recesses in opposite side of the fin  24  or in an opening in the fin  24 . 
     Referring now to  FIGS. 13 to 17 , there is illustrated a digging point assembly  60  according to a further embodiment of the invention which is similar to the embodiment of  FIGS. 1 to 5  however in this case the main point body  61  is truncated at its leading end and is adapted to cooperate with a leading shroud-like wear part  62  which envelopes the leading end of the body  61 . The wear part  62  includes a leading socket member  63  which is provided with a rearwardly open socket  64  and the body  61  includes a forwardly extending stepped tongue  65  which is complementary to and adapted to be received in the socket  64 . The main point body  61  is otherwise similar to the main point body  11  of the assembly  10  including a socket  66  for engagement by the tip of a tyne or the like, a central upstanding fin  67 , opposite side fins  68  (which in this case are also truncated), a transverse opening  69  at the forward end of the socket  66  which opens through further opening  70  to the underside of the body  61 . The main point body  61  is also adapted to carry a pair of replaceable wear parts  71  and  73  similar to the wear parts  12  and  13 . The body  61  additionally includes a pair of side rails  73  between the leading ends of the fins  68  and tongue  65 . 
     The leading wear part  62  additionally includes a pair of side fins or arms  74  which extend rearwardly from the socket member  63  and which in the assembled position of the digging point assembly  60  serve as extensions to the side fins  68 . The fins  74  are shaped on their underside to mate with and slide along the rails  73 . The leading end of the wear part  62  further includes upper and lower transversely extending recesses  75  and  76  adapted to receive hardened tips or strips  77  (see  FIGS. 13 and 14 ) of complementary shape to the recesses  75  and  76 . As is apparent, the recess  76  leads the recess  75  and is stepped downwardly therefrom. The tips or strips  77  are typically formed of tungsten carbide and are secured in position by soldering. 
     The wear part  62  additionally includes on its underside and centrally relative to the fins  74  a rearwardly extending tongue  78  which extends rearwardly from the socket member  63  and terminates in an enlarged head  79 . 
     As shown in the exploded view of  FIG. 17 , the digging point assembly  60  also includes a retaining pin  80  similar to but longer than the pin  40  shown in  FIG. 7 . 
     The wear part  71  as shown in  FIG. 18  is as stated above similar to the wear part  12  and is designed to protect the leading end and sides of the socket  66  of the body  61  and is bifurcated at its leading end to form two flanges  81  which are adapted to be located on either side of the central fin  67  and which further form therebetween a central channel or recess  82  which is complementary in cross section to the retaining pin  80 . In this case the channel or recess  82  is open at each end. Further the flanges  81  differ from the flanges  35  of the wear part  12  in that they are extended on their operative lower side beyond the channel or recess  82  to form two transversely spaced fingers or stops  83  which can extend into the opening  70  as described further below. 
     As with the wear part  12 , the wear part  75  includes on its rear side a rearwardly directed tongue  84  of a width slightly less than the width of the socket  66  such that it can extend into the leading end thereof. 
     The wear part  72  is of substantially the same construction as the wear part  13  of the digging point assembly  10  being of a generally elongated U-shaped configuration defined by a pair of spaced side arms  85  joined at one end by a transverse cross arm  86 . 
     For assembly purposes, the U-shaped wear part  72  is initially located in position on the upper side of the socket  66  in the same manner as described with the wear part  13  such that the transverse arm  85  extends through the transverse opening  69 . 
     The wear part  71  is also assembled with the body  61  in the same manner as described with the wear part  12  of the digging point assembly  10  and so that the tongue  84  extends into the leading end of socket  66  as indicated in  FIG. 19 . The retaining pin  80  is then inserted through the opening  70  on the underside of the body  61  into the channel  82  to extend above the wear part  71  as shown in  FIG. 19  it which position the upper end of the pin  80  is located forwardly of the transverse arm  86  of the wear part  72 . Further in this position the two fingers  83  are located above the lower side of the main body  61 . 
     The leading wear part  62  is then slid longitudinally onto the leading end of the body  61 . In this position, the tongue  78  is located centrally relative to the opening  70  such that when the wear part  71  is lowered, the fingers  83  are located on opposite sides of the tongue  78  and defined stops to the enlarged head  79  of the tongue  78  as best seen in  FIG. 14 . In this position, the wear part  71  prevents detachment of the leading wear part  62  from the body  61 . Further in this position, the lower end of the retaining pin  80  abuts the top surface of the tongue  78  and therefore is retained in the position of  FIG. 19 . 
     When the tapering tip  55  of a tyne is inserted into the socket  66  as shown in dotted outline in  FIG. 19 , the leading end thereof is located adjacent to or in abutment with the trailing end of the tongue  84  of the wear part  71 . This prevents the wear part  71  being moved rearwardly and upwardly from its position of  FIG. 19 . In this position, the pin  80  prevents forward movement of the second wear part  72  and it detachment from the body  61  and further the fingers  83  of the wear part  71  prevent detachment of the leading wear part  62 . 
     As above the tip  55  may be retained in position by a bolt or stud/nut connection or by connector engagement means on the underside of the point assembly  60 . Alternatively the tip  55  which may have at least an apertured lug may be secured relative to the point assembly by means of a transverse wire passed through the transverse opening in the body  61  and lug. 
     For disassembly purposes, the tyne tip  55  is withdrawn from the socket  66  which allows the wear part  71  to be raised to retract the stop fingers  83  from opposite sides of the tongue  78  which enables the leading wear part  62  to be detached and thereafter the wear parts  71  and  72  can be removed through the opening  70 . 
     The leading end of the fin  67  may be provided with wear strips (as shown in  FIGS. 15 and 17  and in dotted outline in  FIGS. 15 ) similar to the wear strips  26 . It will also be appreciated that the shape of the various parts of the assembly  60  may be varied from that illustrated and described. 
     It should be noted that reference to the prior art herein is not to be taken as an acknowledgement that such prior art constitutes common general knowledge in the art. 
     The terms “comprising” or “comprises” as used throughout the specification and claims are taken to specify the presence of the stated features, integers and components referred to but not preclude the presence or addition of one or more other feature/s, integer/s, component/s or group thereof. 
     Whilst the above has been given by way of illustrative embodiment of the invention, all such variations and modifications thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein defined in the appended claims.