AU702343B3 - Improvements to earth working tools - Google Patents

Description

SUMMARY OF THE INVENTION This invention relates to improvements to earth working tools and in particular to an improved method and means for securing a replaceable digging point to the shank of an earth working tool.

BACKGROUND ART Earth working tools of many different designs are currently available ranging from tools having shanks which are rigidly fixed to a supporting frame, to stump jump tools in which the shank is mounted so as to lift upwardly on striking an obstruction in the ground to enable the tool to pass the obstruction without damage thereto. Many tools also are provided with replaceable earth working points. These points allow the tools to be used in different applications by simply removing one point and replacing it with another point. Worn points can also be removed and replaced when required. One difficulty encountered particularly although not exclusively with stump jump ploughs using replaceable points is that the point can often become detached from the shank necessitating stopping the earth working operation and reattaching or replacing the point. A number of different arrangements have been employed to enable the point to be secured to the tool shank. Whilst these arrangements generally serve to overcome the problem of easy detachment, they have some disadvantages. Thus where for example bolts or similar fasteners are used, their removal becomes difficult because the threads become worn or damaged in use. Use of bolts or other similar fasteners also requires the use of specialised tools.

SUMMARY OF THE INVENTION 0 *lo The present invention aims to overcome or alleviate one or more of 25 the disadvantages of known earth working tools as described above or at least provide an alternative to the known tools. Other objects and advantages of the invention will become apparent from the following description.

The present invention thus provides a replaceable point for an earth working tool of the type including a tool shank having a lower end portion, said point having a front end and a rear end and a hollow socket in said rear end for receiving said shank lower end portion, aligned openings in opposite sides of said point for receiving elongated retaining means for retaining said point to said shank end portion, and recess means on opposite sides of said point and extending rearwardly from said openings for receiving opposite deformed ends of said retaining means.

Opposite ends of the retaining means projecting through the openings on opposite sides of the point are suitably deformed by being bent or turned over to ensure that they are retained to the point to prevent detachment of the point from the tool shank. Suitably the retaining means is formed of a ductile material. A particularly suitable retaining means comprises an elongated relatively stiff wire.

The recess means are suitably in the form of slots to receive the ends of the retaining means.

Raised abutment means may be provided on opposite sides of the point adjacent to the openings to define the slots. The abutment means may be in the form of a raised lands. The lands may be of generally U-shaped form to extend around O the leading side of the openings in the point and also rearwardly therefrom relative to the normal direction of movement of the tool. The leading ends of the lands may be of tapered configuration so as to deflect soil in use to opposite sides of the retaining means. The rearwardly extending arms of the U-shaped lands define therebetween the slots for receiving the turned over ends of the retaining means.

The end portion of the tool shank suitably includes means for cooperation with the retaining means whereby to ensure that the point can be retained to the end portion of the shank. In one form, such means may comprise an opening or slot in the end portion of the shank which is aligned in use with the openings in the point to receive the retaining means. The opening or slot may suitably be formed in a lug on the upper side of the shank end portion. The shank 25 end portion may additionally include an apertured lug on the lower side thereof whereby the removable point may be inverted and re-engaged with the end portion of the tool shank so that again the openings in the point can be aligned with the aperture in the normally lower lug to receive retaining means as before.

As an alternative to the apertured lugs, the tool shank end portion may include an abutment which in the engaged position of the point is located forwardly of the retaining means passed through the point openings so as to cooperate therewith j- o prevent point detachment. The abutment may be in the form of a lug located on the upper side of the shank end portion. A similar abutment or lug may be provided on the lower side of the shank end portion to enable the point to be inverted as described above.

The point suitably also includes, relative to its normal attitude, a guard on the underside thereof which is positioned in use forwardly of the lug on the underside of the shank end portion to protect the lug during movement of the point through the earth. The guard also serves to protect the lug on the upper side of the shank end portion when the point is inverted in attitude.

In a further aspect, the present invention provides an earth working tool assembly including a tool shank having an end portion, a replaceable point as described above and retaining means extending through said openings and cooperating with said end portion of said shank for retaining said point to said shank •end portion, deformed ends of said retaining means being received substantially :Wove" within said recess means on opposite sides of said point.

BRIEF DESCRIPTION OF THE DRAWINGS "In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein Fig. 1 illustrates an end portion of a tool shank and a replaceable tool point prior to interconnection; Fig. 2 illustrates the tool point located over the end of the tool shank; Fig. 3 illustrates the manner in which a retaining pin interconnects the tool point and tool shank; 3- Fig. 4 is a sectional view along line A-A of Fig. 3; 4. 25 Fig. 5 illustrates the point in an inverted attitude applied to the tool end; and Fig. 6 is a partly cut away view showing an alternative form of shank engaged with the point.

DETAILED DESCRIPTION OF THE EMBODIMENT Referring to the drawings and firstly to Fig. 1, there is illustrated the lower portion of the shank 10 of an earth working tool and a replaceable point 11 for mounting on the shank 10. The shank 10 which is normally supported in an upright attitude has at its lower end a forwardly directed tapered end or foot 12 which includes on its top and bottom sides, lugs 13 and 14, each of which is provided with an aperture 15 and 16 respectively therethrough. The point 11 tapers to its front end and includes in its rear end a hollow tapered socket 17 (see Fig. 4) for receiving the complementary shaped end 12 of the shank 10. The socket 17 includes an upper channel 18 for receiving the lug 13 (or 14) whilst the underside of the point 11 includes a longitudinally e 1 C C p.

3 extending slot 19 to receive the lug 14 in the normal digging attitude of the point 11.

Aligned apertures 20 are provided in opposite sides of the point 11 to intersect the channel 18 and socket 17. Partially surrounding each aperture 20 on the opposite sides of the point 11 is an abutment 21 in the form of a raised land which is of a generally U-shaped configuration with the trailing arms 22 thereof defining therebetween a slot or recess 23 extending rearwardly from the aperture The leading end of the abutment 21 is tapered as at 24. The point 11 is retained to the end 12 of the shank 11 by an elongated retaining wire or pin 25. The slot 23 has a depth at least the same as or greater than the thickness of a retaining pin or wire 25 for a purpose which will hereinafter become apparent. The underside of the point 11 is provided with a lug 26 which is aligned longitudinally with the slot 19.

The lug 26 has a thickness which is at least the same as or greater than the thickness of the lug 14.

For assembly purposes, the end 12 of the shank 10 is forced into the hollow socket 17 of the point 11 to the position of Fig. 2. In this position, the opening 15 in the lug 13 is aligned with the openings 20 in the point 11. A length of wire 25, of a diameter less than the diameter of the openings 20, is passed through one opening 20, through the opening 15 in the lug 13 and through the other opening 20 to project on opposite sides of the point 11 as shown in dotted outline.

20 Opposite projecting ends 27 of the wire 25 may then be bent over as shown in dotted outline in Fig. 3, for example by hand or by use of an impact tool, until the turned over ends 27 lie in the slots 23 on opposite sides of the point 11.

Alternatively, the ends 27 of the wire 25 may be partly bent over to the position of Fig. 3 to retain the point 11 to the tool shank 12 with if necessary any excess length of wire being severed. Using the point 11 in earth will then urge the projecting ends 27 of the wire 25 rearwardly until they lie within the slots 23.

It will be seen in this position and as more clearly shown in Fig. 4 0°o0 that the ends 27 of the wire are located behind the abutment 21 and substantially a within, and not projecting outwardly, or to any substantial extent outwardly, of the 30 slots 23, or laterally of the point 11, this occurring because the diameter of the wire 25 is the same or less than the depth of the slot 23. On the underside of the point 11, the lug 14 on the tool end 12 is located rearwardly of and aligned with the lug 26 of the point 11.

In use in ploughing, the shank 10 is suitably supported in a known manner from a tool bar or the like with the point 11 extending in a forward direction relative to the direction of ploughing and located normally in, or substantially in the ground. As the point 11 travels through the ground, the ends 27 of the wire 25, being located within or substantially within the slots or recesses 23 will be shielded from direct contact with the earth. If the wire 25 has not been fully bent over so that its ends are located within the slots or recesses 23, the force of the earth on the ends 27 as the point travels through the ground will urge the ends 27 rearwardly until they self locate within the slots or recesses 23. As the ends 27 are thus located within the slots or recesses 23, they will be subject to little wear. Thus the tendency of the wire 25 to break is minimised reducing substantially the chances of the point 11 becoming detached from the shank end 12. Further as the ends 27 of the wire 25 are substantially protected from damage, the wire 25 may be relatively simply removed by either severing an end 27 or bending an end 27 out of a slot S° 15 or recess 23 to allow the wire 25 to pass outwardly through the aligned openings 20 and 15. In movement through the ground also, the lug 26 on the underside of the point 11 will protect the lug 14 on the point 11 against damage guiding the passing earth to 0 opposite sides of the lug 14.

The configuration of shank end 12 and point 11 also allow the point 11 to be inverted into the position of Fig. 5 and engaged with the tool end 12 in a similar manner to that described previously with the apertures 20 in this configuration being aligned with the opening 16 in the lug 14. In this case however, the retaining wire 25 is passed through the openings 20 and opening 16 in the lug 14 to retain the point 11 to the 3 tool end 12. Further, the lug 26 is located adjacent to and forwardly of the lug 13 to protect the lug 13 from damage as the point 11 travels through the earth.

In the above described embodiments, the end 12 of the tool shank 10 is provided with apertured lugs 13 and 14 to receive the retaining pin or wire 25. The lugs 13 however may be in the form of unapertured lugs or raised abutments 28 as for example shown in Fig. 6. In this embodiment and in the normal position of the point 11, the upper 3 0 lug 28 is located forwardly of the aligned apertures 20 such that when the retaining pin wire 25 is passed through the apertures 20, the wire acts as a stop in preventing withdrawal of the shank end 12 from the point 11. Of course as before, ends 28 of the wire 25 are deformed by being bent downwardly to locate within the slots 23. The point 11 may also be inverted to engage the end 12 of the shank 11 in the same manner as described with reference to Fig. 6.

It will be apparent that the arrangement described allows for simple attachment of a digging point to a shank of an earth working tool by means of easily available wire or similar retaining means. This is allowable because the ends of the 9 4 s.

4 wire are protected from damage from the soil being located in the recesses on opposite sides of the point. Therefore breakage or wear is minimised. Wire is also is readily available in the field and therefore inexpensive. Of course other forms of retaining means other than wire may be used such as a purpose formed pin or other elongated member.

It will further be appreciated that whilst the slots 23 in the described embodiment are formed by raised lands on the side of the point 11, they may also simply be formed in a side face of the point 11.

Whilst the above has been given by way of illustrative embodiment of the invention, all such modifications and variations 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 defined in the appended claims.

S* 0 3

1. A replaceable point for an earth working tool of the type including a tool shank having a lower end portion, said point having a front end and a rear end and a hollow socket in said rear end for receiving said shank lower end portion, aligned openings in opposite sides of said point for receiving elongated retaining means for retaining said point to said shank end portion, and recess means on opposite sides of said point and extending rearwardly from said openings for receiving opposite deformed ends of said retaining means.

2. A replaceable point according to Claim 1 wherein said recess means are defined between the arms of generally U-shaped lands on opposite sides of said point.

O S 3. An earth working tool assembly including a tool shank having a lower 15 end portion and a replaceable point as defined in Claim 1 or Claim 2, said point being retained to said tool shank by retaining means extending through said openings :o and cooperating with said end portion of said shank for retaining said point to said shank end portion, deformed ends of said retaining means being received in said recess means on opposite sides of said point.

Dated this third day of December 1998 ALLAN JAMES YEOMANS By My Patent Attorney S John R. G. Gardner o