WO 2009/105804 PCT/AU2009/000153 FORKLIFT ATTACHMENT & METHOD Field of the Invention The present invention relates to forklifts, and in particular, to the provision of a 5 forklift tine or prong, a pair of which can be used on implements which are not designed to be a forklift as their primary function, and yet still achieve a forklift function. Background Art 10 Forklift trucks are well known and widely used by manufacturers and in warehouses for the storage and transport of goods which are loaded on a pallet. The tines of the forklift are dimensioned to be received in the pallet and this enables the tines to be raised and thereby lift the pallet and its associated contents. 15 Forklift trucks are relatively expensive items and are therefore not purchased by those establishments which do not have a continuing use for forklifts. Instead many establishments which have implements such as tractors sometimes purchase forklift attachments for the tractor. These are of two basic types. One type is an attachment which is connected to the three point hitch of a tractor and includes a hydraulic motor 20 which drives a chain on which the tines are mounted, thereby enabling the tines to be raised and lowered. The other type of attachment is a replacement for a bucket on a front end loader type of attachment and so the hydraulics of the front end loader are utilized to move the tines which replace the bucket. Both of these attachments cost many thousands of dollars. Furthermore, both of these attachments require 25 considerable time and effort to set up prior to use, and detach after use. There are many instances where the cost of such attachments is not warranted for the few occasions on which a forklift function is required to be used, even assuming that the proprietor of the establishment has sufficient funds to make the necessary 30 purchase of these expensive prior art attachments. There are many small farms and similar establishments which have occasional use for a forklift implement of some kind, for example, to unload goods delivered by truck and contained on a pallet, and
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WO 2009/105804 PCT/AU2009/000153 yet the cost of either a forklift truck or one of the abovementioned forklift attachments is not warranted. Prior art searches conducted after the priority date have disclosed various proposals 5 including US Patent 3,325,023 (Coleman) where forklift tines are bolted onto the floor of a conventional (single use) bucket. This has the consequence of possibly undermining the structural integrity of the bucket and thereby permanently damaging the bucket. 10 Furthermore, other arrangements such as US Patent 6,988,866 (Friedland) published under No. US2003/0228210 discloses a relatively heavy tine arrangement which is unable to be lifted by a single person and thus the bucket floor is placed above the tines in order to attach the tines to the bucket. This means that the tines hang under the floor of the bucket and chains or similar locking devices are required to resist the 15 forces applied by the pallet and load. Conversely in the arrangement of US6,287,070 (Perry) the tines are supported above the bucket floor but the arrangement is so massive that a weight distribution arrangement is required to spread the load over substantially all of the left to right and 20 front to rear dimensions of the floor of the bucket. In the light of the front end loader de-rating discussed hereafter in relation to Fig. 15 such a massive arrangement becomes impractical. Other proposals such as US 3,667,633 (Capella) rely upon each tine being spaced 25 apart to a maximum extent to thereby abut a corresponding vertical side wall of the bucket. As a consequence the spacing between the tines is not adjustable. This is acceptable for long pipes, however, any object requiring a tine separation less than the bucket width, cannot be accommodated. For example, a 44 gallon (200 litre) drum or small pallets are unable to be engaged with the tines to be lifted and/or moved. 30 Genesis of the Invention The genesis of the present invention is a desire to enable the proprietors of small farms or similar establishments to avail themselves of an existing implement such as a 2 50551-WO Received 18 September 2009 front end loader equipped tractor, or BOBCAT (Registered Trade Mark) type implement, to enable infrequent tasks, which normally require a forklift, to be carried out without having to purchase, hire or borrow a conventional forklift truck or expensive forklift attachment. Preferably, there is no damage to the existing 5 implement nor is lifting equipment (such as a chain or a sling) required to engage the forklift tine(s) and bucket. Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a forklift 10 attachment for a 4-in-1 bucket equipped implement, said 4-in-1 bucket having a floor with a leading edge and a trailing edge, and a rear wall movable with respect to said floor; said attachment comprising a pair of substantially parallel or slightly splayed tines each being shaped to grasped by said bucket whilst surmounting said floor, each said tine having a toe at its leading end and a heel at its trailing end with the 15 longitudinal extent of each said tine from toe to heel exceeding the distance between said floor edges, each said tine having an anchor means adjacent said heel and being adapted to be clamped between said rear wall and said floor with said tines having a pair of spacer means extending therebetween, being spaced apart in the toe to heel direction and attached thereto to maintain said substantially parallel or slightly 20 splayed configuration of said tines. Preferably each tine is substantially hollow. In accordance with a second aspect of the present invention there is disclosed a 25 forklift tine for attachment to an implement equipped with a 4-in-I type bucket having a floor with a leading and trailing edge, and a rear wall movable with respect to said floor; said tine being adapted to be grasped by said bucket whilst surmounting said floor, said tine having a toe at its leading end and a heel at its trailing end with the longitudinal extent of said tine from toe to heel exceeding the distance between said 30 floor edges, said tine having an anchor means adjacent said heel and adapted to be clamped between said rear wall and floor with said tine surmounting said bucket floor, and said tine having a pair of spaced apart at least one attachment means 3 Amended Sheet
IPEA/AU
50551-WO intermediate said toe and heel to receive a corresponding end of a pair of spaced apart elongated spacer means to set the spacing between a pair of like said tines. Preferably the spacer means are a pair of spaced apart threaded rods and the 5 attachment means is a hole in the side wall of each tine and through which a corresponding end of a corresponding rod passes. In accordance with a third aspect of the present invention there is disclosed a method of releasably attaching a forklift attachment as described above to a 4-in-I type 10 bucket equipped implement, said method comprising the steps of: (i) if necessary, moving the bucket rear wall away from the bucket floor to at least partially open said bucket, (ii) placing said tines on the floor of said bucket with said toes facing forwardly and extending beyond said bucket floor leading edge, 15 (iii) positioning the heels of said tines and their associated anchor means adjacent said bucket floor trailing edge, (iv) adjusting said spacer means to set the tine configuration to a configuration selected from substantially parallel tines and slightly splayed tines, and (v) moving said bucket rear wall relative to said bucket floor to clamp said anchor 20 means therebetween. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with 25 reference to the accompanying drawings in which: Fig. 1 is a plan view of the assembled forklift attachment of a first embodiment, Fig. 2 is a side elevation of the attachment of Fig. 1, Fig. 3 is a longitudinal cross-sectional view through a 4-in-I or jaws bucket 30 which is conventionally fitted to tractors and like implements, Fig. 4 is a similar view to Fig. 3 but showing the attachment of Figs. 1 and 2 fitted to the bucket, Amended Sheet IPEAAkU 4 5O55I-WO Fig. 5 is a plan view of an alternative spacer arrangement for determining the spacing between the forklift tines, Figs. 6 is a side elevation of a forklift attachment of a second embodiment, Fig. 7 is a perspective view of the attachment of Fig. 6 held in a 4-in-one 5 bucket, 4A WO 2009/105804 PCT/AU2009/000153 Fig. 8 is an exploded perspective view of the forklift attachment of Figs. 6 and 7, Fig. 9 is a perspective view showing the forklift attachment of Figs. 6-8 supporting a pallet and load, 5 Fig. 10 is a plan view of a forklift attachment of a third embodiment, Fig. 11 is a perspective view from above of the forklift attachment of Fig. 10, Fig. 12 is a perspective view from below of the forklift attachment of Figs. 10 and 11, Fig. 13 is an exploded perspective view of the forklift attachment of Figs. 10 10 13, Fig. 14 is a perspective view showing the forklift attachment of Figs. 10-13 being used to lift a 44 gallon (200 litre) drum, and Fig. 15 is a diagram illustrating a force analysis. 15 Detailed Description As seen in Figs. 1 and 2, the attachment 1 of the preferred embodiment takes the form of two forklift tines 2 each of which has a toe 3 and a heel 4. The spacing between the forklift tines 2 is set by a pair of parallel spacer rods 6, 7. In the embodiment of Fig. 1, the spacer rods 6, 7 are threaded and eight nuts 8 are utilized to securely hold the 20 tines 2 in the desired illustrated configuration. As best seen in Fig. 2, attached to each of the heels 4 is a corresponding C-shaped bracket 10 which opens towards the toes 3 and is secured, preferably by welding or bolts, to the heel 4. 25 Turning now to Fig. 3, a "4-in-i" or "jaws" or "clam shell" bucket 12 is illustrated having a hinge 13, a rear wall 14, a side wall 15 and a bucket floor 16. The bucket floor 16 and the two side walls 15 together form one part of the bucket and the rear wall 14 forms the second part of the bucket. The first and second parts are moveable 30 relative to each other by an hydraulic system (not illustrated) but conventional. In addition, the floor of the bucket is able to be raised by a "crown" action and lowered by means by "dump" action utilizing the conventional hydraulic controls. 5 WO 2009/105804 PCT/AU2009/000153 Preferably the bucket is self levelling so that as the front end loader hydraulics raise or lower the bucket, so the bucket floor retains its initial inclination (that is, the floor is not tilted from its initial position). 5 In order to fit the attachment 1 of Figs. 1 and 2 to the bucket 12 of Fig. 3, the bucket 12 is firstly at least partially opened, if necessary, and the bucket floor 16 is adjusted, if necessary, so as to be roughly horizontal. Then the attachment 1 is lifted by the operator and placed on the bucket floor 16 with the toes 3 facing forwardly as illustrated in Fig. 4. In this way the tines 2 surmount the bucket floor 16. 10 The attachment I is then slid forwardly by the operator so that the C-shaped brackets 10 envelop the rear edge 17 of the bucket floor 16 as illustrated in Fig. 4. Finally, the bucket 12 is closed by operation of the hydraulic controls thereby clamping the rear wall 14 of the bucket against the brackets 10 so as to drive the tines 2 forwardly and 15 the brackets 10 into engagement with the rear edge 17. This securely anchors the entire attachment 1 and enables the tines 2 to be moved together with the bucket using the hydraulic system (not illustrated) of the front end loader or other implement. One method of construction of the tines 2 is for them to be fabricated from sheet steel 20 so as to form a hollow structure. A pair of holes drilled one through each side wall enables one end of the corresponding spacer rods 6, 7 to be attached to the tines 2. Thus each tine 2 has four such attachment holes. If desired, a length of tube can be welded across the interior of the hollow structure at the attachment hole locations so as to receive the spacer rods 6, 7 (or 26, 27). The C-shaped brackets 10 are in this 25 embodiment fabricated from steel bar bent to shape and welded to the underside of the heels 4. As a consequence of the above described construction, after the initial setup of the attachment 1, (which typically is supplied in knock down form as a multi-part kit), the 30 attachment is then as illustrated in Fig. 1 and needs no further modification or manipulation. On those occasions where forklift tines are required, the attachment 1 can be fitted to the bucket 12 as described above in a few moments, thereby quickly readying the implement for use as a substitute forklift. Similarly, disconnecting the 6 WO 2009/105804 PCT/AU2009/000153 attachment so that the bucket 12 can be used normally also only takes a few moments and simply involves reversing the above described procedures. It will be apparent to those skilled in the art from Fig. 4 that with the toes 3 of the 5 tines 2 inserted into a conventional pallet, raising the bucket 12 brings the tines 2 into contact with the underside of the pallet upper layer and raises the pallet and its contents. This action tends to turn the tines clockwise as seen in Fig. 4 but this motion is resisted in two ways, firstly by means of the rear wall 17 of the bucket 12, and secondly by means of the C-shaped bracket 10 which is unable to rotate since if it 10 were to do so it would abut the bucket floor 16. Furthermore, the rear wall 14 ensures that the attachment 1 does not slip to the left as seen in Fig. 4 and thereby disengage the bracket 10 and the bucket floor 16. In the abovedescribed arrangement the rear wall 14 of the bucket 12 generally hides 15 the tines 2 from the view of the operator of the implement. However, this deficiency can be easily remedied either with a mirror positioned on the forward edge of the ROPS (roll over protection system) roof, or by use of an assistant who by means of hand signals can direct the tines to be tilted upwardly, or tilted downwardly, etc. as required. 20 In most instances the spacing between the tines 2 will accept a wide range of pallets and therefore once the attachment I is assembled, no further manipulation or modification to the attachment 1 is required. However, in some instances the spacing between the tines 2 needs to be adjusted to accommodate different pallet 25 arrangements. In this event, the threaded spacer rods 6, 7 of Fig. I can be replaced by solid rods 26, 27 as illustrated in Fig. 5, each of which is provided with a multiplicity of through apertures 28 intended to receive locking pins or bolts (not illustrated). In Fig. 5 the spacing between the tines 2 illustrated in Fig. 1 is illustrated by dot dash lines. If this is required to be changed, the locking pins are removed from the 30 apertures 28 and the tines 2 slid towards each other along the spacer rods 26, 27 until the position illustrated by dashed lines is reached. Then the locking pins are replaced into the alternative apertures 28 thereby securing the tines 2 in the newly desired position. 7 WO 2009/105804 PCT/AU2009/000153 In Figs. 6-9 a second embodiment is illustrated where the attachment 41 has its tines 20 formed from relatively short (eg 1600mm) slippers (which are hollow tubular prongs intended to slide over, and extend the reach of, conventional solid steel forklift 5 tines). The spacer rods 6 and 7 are as before. However, it will be seen that modified brackets 40 are provided and are welded to the upper surface of the tines 20 (rather than the lower surface of the tines 2 as in the case of the brackets 10 of the first embodiment). This has the advantage of excluding 10 vermin from the hollow interior of the tines 20. It will be seen from Fig. 7 that the engagement of the tines 20 with the bucket 12 is substantially as before. Furthermore, as seen in Fig. 8, the attachment 41 is readily assembled from, and able to be disassembled into a knock down kit or parts. 15 Fig. 9 shows the attachment 41 secured to the bucket 12 of a front end loader 42 and with the tines 20 supporting a pallet 44 which in turn supports a box 45 or similar load. The pallet 44 and box 45 are illustrated in phantom in Fig. 9 so as to not obscure the attachment 41 from view. 20 Turning now to Figs. 10-14, here a third embodiment in the form of attachment 51 is illustrated. The attachment 51 is essentially the same as for Figs. 6-9, however, each of the spacer rods 6, 7 passes through a corresponding short length of pipe 36, 37 each of which is of a predetermined length to set the spacing between the tines 20. Washers 46 assist the pipes 36, 37 to bear against the sides of the tines 20. For 25 example, the tines 20 can be set to enable a 44 gallon (200 litres) drum 55 to be picked up by means of the upper of the two chines 56 conventionally provided on such drums. It is desirable in handling such drums for the toes 3 of the tines 20 to be splayed 30 slightly outwardly and for the heels 4 to be closer together than the toes 3. This enables to toes 3 to pass one to either side of the drum 55 before the sides of the drum come into contact with the interior side edges of the tines 20. This positions the drum preferably about midway between the toes 3 and the front edge 19 of the bucket floor. 8 WO 2009/105804 PCT/AU2009/000153 Then the tines 20 can be raised to engage the upper chine 56. This slightly V-shaped (or slightly non-parallel) configuration of the tines 20 enables the drum to be easily loaded onto, and unloaded from, the tines 20. 5 Preferably this desired spacing of the tines is achieved by making the pipe 36 slightly longer than the pipe 37. In this way not only is the inter-tine spacing set accurately, but the accuracy is quickly repeatable if the attachment needs to be dismantled or re configured for some reason. Alternatively an extra washer can be used in respect of the pipe 36. 10 The anchor arrangement for the tines 20 is provided by a short length of U-shaped steel channel 100 which is preferably welded to the tines 20, but can be bolted thereto. As seen in Fig. 6, since the rear wall 14 of the bucket clamps the base 101 of the channel 100 against the rear edge 17 of the bucket floor 16, the lower side edge 102 of 15 the channel 100 (indicated in dashed lines in Fig. 6) can be removed. Under these circumstances the bracket or channel 100 is L-shaped rather than C-shaped. However, the presence of the lower side edge 102 is a desirable additional safety feature. 20 Turning now to Fig. 15, an analysis of the forces applied to the tines 2, 20 by the load such as the box 45, is as follows (ignoring the mass of the tines and pallet). Mg is the downward force on the pallet and is equal to the mass M of the box 45 on the pallet multiplied by the acceleration g due to gravity. If the pallet was in the 25 bucket of the front end loader, the downwards force on the bucket 12 would be Mg. The forklift tines 2, 20 tend to rotate about the front edge of the bucket floor, so this point can be regarded as the fulcrum of a see-saw. The vertical reaction force RI is the upwards force exerted by the bucket to keep the tines in place. An equal and 30 opposite force is exerted by the tines downwardly on the bucket 12 and forms the load to be supported by the bucket 12. 9 WO 2009/105804 PCT/AU2009/000153 Since the tines 2, 20 do not rotate anti-clockwise, there is a reaction force at the rear edge of the bucket floor which prevents this rotation. This is force R2 and is directed downwardly. 5 Since the fork tines neither rise nor fall, the sum of the vertical downward forces must equal the vertical upward force, therefore RI =Mg+R2 Similarly, since the fork tines do not rotate about the front edge of the bucket floor, 10 the anti-clockwise torque Mg. Dp must equal the clockwise torque R2.Db where Dp is the distance between the front edge of the bucket floor and the centre of the pallet, and Db is the distance between the front and rear edges of the bucket floor. Thus Mg.Dp = R2.Db 15 Or R2 = Mg (Dp / Db) Putting the last equation into the first one gives 20 RI = Mg + Mg (Dp / Db) Or RI = Mg (I + Dp / Db) If these two distances Dp and Db are approximately equal (eg about 500mm) then 25 RI = 2 Mg This means that the effective upwards load supported by the bucket 12 is approximately twice the load which would be supported by the front end loader if the object supported by the pallet was instead placed in the bucket 12. 30 Consequently, the load lifting and carrying capacity of the front end loader 42 needs to be de-rated by approximately 50% and then an allowance made for the weight of the tines and pallet (say 60kg and 10kg, total 70kg). Thus, if the front end loader 10 WO 2009/105804 PCT/AU2009/000153 bucket is rated at 400kg, then the pallet and tines should be rated at %/ (400) - 70 = 130kg. As a consequence of the above de-rating it is very advantageous for the tines 2, 20 and 5 their corresponding spacer arrangements (6, 7, 36, 37) be kept as light as possible in weight. In particular the tines 2, 20 should be hollow and the massive solid tine and massive load distributing arrangements of US Patent 6,287,070 (Perry) should be avoided. 10 Furthermore, because of the above geometrical relationship and front end loader de rating, the front tyres of the front end loader 42 as seen in Fig. 14 are often the weakest link in the overall arrangement. This can be compensated for to some extent by increasing the inflation pressure of the front tyres of the front end loader 42. 15 The attachment can be easily stored in the assembled condition by being lent against the wall of a shed, for example, until the next occasion it is required. This frees the front end loader 42 for other duties and reduces the capital expenditure required to operate the establishment. 20 A significant advantage of the abovedescribed arrangement is that the relatively sophisticated hydraulic system of the front end loader is available during forklift functions. Thus, whereas some forklifts need to reverse down a ramp to prevent the pallet sliding from the tines, with the present invention the 4-in-I bucket can be tilted ("crowned") to raise the toes 3 of the tines 2. Thus the implement can go down a 25 ramp forwardly. Furthermore, the "self-levelling" function of the 4-in-1 bucket can be advantageously used to keep a pallet level during raising and lowering of the pallet. The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the forklift art, can be made thereto without 30 departing from the scope of the present invention. For example, the size of the bight of the C-shaped brackets 10, 40, 100 can be adjustable, or can be varied, to suit different models of bucket 12. The C-shaped brackets can be welded, bolted or otherwise secured to the tines. Also, if desired, a spring can have one end connected 11 WO 2009/105804 PCT/AU2009/000153 to the spacer rod 6 and the other end connected to a hook, which when hooked over the front edge 19 of the bucket stretches the spring, thereby drawing the C-shaped brackets 10, 40, 100 into engagement with the rear edge 17. 5 The term "comprising" (and its grammatical variations) as used herein is used in the inclusive sense of "including" or "having" and not in the exclusive sense of ''consisting only of'. 12