An attachment

Abstract

A side shift assembly 76 for mounting to a working arm of a working machine has a fixed carriage 78, a moveable carriage 80 and a side shift mechanism. The fixed carriage includes a first mounting mec

Description

FIELD 5 The present teachings relate to an attachment for mounting to a working machine. In addition the present teachings relate to a side shift assembly. BACKGROUND Numerous attachments are known for mounting to working machines such as telehandlers 10 and loaders. It is sometimes desirable to provide a side shift mechanism on an attachment to reduce the need for the working machine to be repositioned laterally if an operator of the working machine has not positioned the attachment in relation to a load to be lifted or deposited, for example if pallet forks are misaligned with pockets in a pallet. 15 In addition, side shift mechanisms can be used to enable one item to laterally abut another item before it is deposited in a particular location by undertaking a simply forward drive of the working machine followed by a side-shift operation. LO CXI However, side shift mechanisms can be quite expensive. It can therefore be uneconomic 20 for a working machine operator to buy an attachment with a side shift function if it is not regularly used, and also if it can only be mounted onto one model or type of working machine with a particular mounting interface. CXI In addition, side shift mechanisms can be bulky, in particular fore-aft. As such they can 25 adversely impact the manoeuvrability of a working machine when attached, and also limit the payload of the attachment as the attachment may extend further forward and therefore generate a greater tipping moment (as well as being heavier in any event). Even if a side shift mechanism is not present, problems also arise with attachment 30 manufacturers in relation to designing an attachment to fit a range of working machines that may be supplied with differing mounting interfaces. This problem may also arise with a particular operator if they have two or more machines with different mounting interfaces. They may be restricted to using an attachment with only one of those machines. 35 Further, a known, relatively specialist attachment, is a bale grab. Despite being specialist, different operators have different preferred configurations and may desirably use one grab to move bales of differing shapes and dimensions. It can therefore be uneconomic to design multiple versions of grab to meet various operators' needs as sales volumes can be quite small. The present teachings seek to overcome, or at least mitigate, the problems of the prior 5 art. SUMMARY An aspect of present invention provides to a side shift assembly according to claim 1. 10 Optional features of this aspect is provided by the dependent claims. 15 CXI 20 CXI According to a first aspect of the present teachings, there is provided a side shift assembly for mounting to a working arm of a working machine, the side shift assembly comprising: a fixed carriage comprising a first mounting mechanism for mounting the side shift assembly to a working arm of a working machine; a moveable carriage slidably attached to the fixed carriage, the moveable carriage comprising a second mounting mechanism for releasably securing the carriage to an attachment; and a side shift mechanism coupled to the fixed carriage and the moveable carriage, the side shift mechanism comprising an actuator configured to translate the moveable carriage laterally relative to the fixed carriage. The second mounting mechanism may comprise a plurality of mechanical fixture points arranged so as to define a fixture interface. The fixture interface may be complimentary to a corresponding arrangement of mechanical fixture points of a plurality of different attachments. 25 Advantageously, the side shift assembly is versatile and flexible and can be attached to different attachments with a complementary fixture interface as required. In this way, operators can purchase a single side shift mechanism for use with two or more attachments. This reduces costs for the operator. It may also save cost for the attachment manufacturer since a different bespoke side shift mechanism does not need to be 30 developed for each attachment. The side shift assembly provides a flexible option of adapting a working machine to suit different applications, allowing operators to customise the equipment based on their specific needs. In this way, optimal performance and efficient handling of different 35 materials can be achieved. The first mounting mechanism may comprise a quick-release mechanism enabling the mounting of the first mounting mechanism to a working machine without the use of tools. Advantageously, the quick-release mechanism enables the attachment to which the side shift is mounted to be fitted and removed conveniently from the working machine. 5 The first mounting mechanism may comprise two side members located proximate a respective lateral end of the fixed carriage, each side member defining one part of a hook type interface at an upper end, for engaging a corresponding other part of the hook type interface on a working arm of a working machine. 10 Advantageously, the use of a hook provides a quick and efficient means to secure the side shift assembly to a working machine. In this way, an operator can quickly connect or disconnect the side shift assembly to the working machine as required, improving the efficiency of implementing the side shift functionality. 15 Each side member may further comprise an aperture extending through a lower end, each aperture configured for receiving a locking pin so as to secure the side shift assembly relative to a working arm of a working machine when the hooks are engaged with a CM connecting member of the working arm. ^*20 Advantageously, the provision of the aperture for receipt of a locking pin increases the stability of the connection between the side shift assembly and working machine during "1” use, thereby facilitating improved control and accuracy when manoeuvring loads with the ^M working arm. Moreover, the arrangement improves the safety of the assembly, reducing the risk of the assembly shifting or sliding unexpectedly while the machine is carrying 25 loads. The moveable carriage may comprise a plate having a plurality of holes extending therethrough, said holes arranged so as to define an interface complimentary to a corresponding structure on a plurality of different attachments. 30 The plate may be arranged on a plane substantially parallel to a plane on which the side shift moves. Advantageously this may minimise the thickness of the side shift mechanism, which in 35 turn may reduce the amount an attachment extends forward of the working machine, thus aiding manoeuvrability and also maximising the load the attachment may carry by reducing the tipping moment generated by the attachment and any load it carries. 21 07 25 The side shift assembly may further comprise a sliding mechanism having at least one slide block coupled to one of the moveable carriage and fixed carriage slidably mounted on the other of the moveable carriage and fixed carriage such that the moveable carriage moves laterally over the fixed carriage. 5 Advantageously, the sliding mechanism has been found to provide additional support to the side shift assembly, and acts as a guide to promote the accurate movement of the moveable carriage relative to the fixed carriage. In this way, the sliding mechanism promotes a smooth and consistent lateral movement of the moveable carriage, thereby 10 improving the stability of movement of the attachment. The sliding mechanism may further comprise a first support member positioned between the slide block and the part of the fixed or moveable carriage the slide block is sliding relative thereto, wherein the support member is formed from low friction material such as 15 a polymeric material. Advantageously, the support member further enhances the support and promotes smooth relative movement of the slider and thus the moveable carriage 20 This enables the support member to reduce frictional resistance between the slider and the fixed carriage, reducing wear to the carriage. In this way, the support member contributes to the efficient and durable operation of the side shift assembly. A suitable low friction polymeric material includes polyamides. 25 The slide block may be removably mounted to the fixed or moveable carriage. Advantageously, this enables different fixed carriages to be fitted to the moveable carriage, e.g. with a different quick release interface. 30 The side shift assembly may further comprise a second support member mounted between the fixed carriage and the moveable carriage on an opposing side to the first support member. 35 The support member may be formed from a low friction material such as a polymeric material. Advantageously, the support member promotes smooth relative movement of the two carriages. Moreover, the support member can reduce frictional resistance between the two carriages, reducing wear. In this way, the support member contributes to the efficient and durable operation of the side shift assembly. According to a second aspect of the present teachings, there is provided an attachment for mounting to an arm of a working machine, the attachment comprising the side shift assembly of the first aspect. 10 According to a third aspect of the present teachings, there is provided a grab attachment for engaging and manipulating bales of straw and the like, the grab attachment comprising: a frame configured to be secured to a vehicle (e.g. to a working arm of a working machine), the frame defining a horizontal axis and a vertical axis; a grab mechanism removably mounted to the frame, the grab mechanism comprising: at 15 least one arm configured to be pivotable along a clamping arc relative to the frame, the or each arm comprising at least one gripping element for engaging a bale of straw; and an actuation system operatively coupled to the or each arm, the actuation system CXI configured to move the or each arm along the clamping arc; wherein the frame comprises a standard structure for at least two configurations of grab mechanism and wherein the ^^*20 grab attachment may be selectively assembled in one of the first configuration or second configuration by providing a first grab mount on the frame in a first grab mount location "1” and a first actuation system mount on the frame in a first actuation system mount location. CXI Advantageously this allows standardised frame parts to be used for at least two models of 25 grab. The first configuration may be a side grab configuration in which at least one arm is pivotable about a generally vertical axis. 30 The second configuration may be a top grab configuration in which at least one arm is pivotable about a generally horizontal axis. A second grab mount may be further provided on the frame in a second grab mount location for assembling the grab mechanism in the second configuration. 35 A second actuation system mount may be further provided on the frame in a second actuation system mount location for assembling the grab mechanism in the second configuration. Advantageously, this enables multiple grab attachment types to be manufactured from a minimum number of base parts, saving cost for the manufacturer. In addition, the grab attachment may be able to be assembled in different configurations by an operator depending on the operator requirements, meaning the operator can simply switch between the different configurations without having to obtain a different attachment. The grab attachment can be provided as a single unit capable of meeting the requirements of various operations for different bale shapes and sizes. The actuation system may comprise an actuator, such as a linear actuator, and the same actuator may be used for the first configuration and the second configuration. Advantageously this may further save costs. The frame may be a first frame and the grab mechanism may be a first grab mechanism, and the grab attachment may further comprise: a second frame horizontally spaced apart from the first frame, the second frame configured to be secured to said vehicle and defining a horizontal axis that is substantially coaxial with the horizontal axis of the first frame, and a vertical axis offset from the vertical axis of the first frame; and a second grab mechanism removably mounted to the frame. The second grab mechanism may comprise: at least one arm configured to be pivotable along a clamping arc relative to the second frame, the or each arm may comprise at least one gripping element for engaging a bale of straw or the like; and an actuation system operatively coupled to the or each arm. The actuation system may be configured to move the or each arm along the clamping arc. The second frame may comprise a standard structure for at least two configurations of grab mechanism. The grab attachment may be selectively assembled in one of the first configuration or second configuration by providing a first grab mount on the second frame in a first grab mount location and a first actuation system mount on the second frame in a first actuation system mount location. Advantageously, the capacity of the grab is improved. The attachment can therefore accommodate a broader range of applications, e.g. applications that require the lifting and alignment of multiple bales of straw or the like. As such, the versatility of the attachment is improved. Moreover, the attachment can lift more loads in a single operation. In this way, the efficiency and productivity of the attachment is increased, as more load can be lifted in a single operation. The or each frame may comprise a bottom fork mounting structure for releasably mounting a fork proximate a lower extent of the frame. 5 The bottom fork mounting structure may comprise an adjustable positioning mechanism configured so that the arm can be mounted in a plurality of discrete angular positions relative to the frame. The adjustable positioning mechanism may comprise a hydraulic actuator configured to 10 move the arm relative to the lower region of the frame between said plurality of discrete angular positions. The adjustable positioning mechanism may comprise a plurality of pin and abutment positions to select the plurality of discrete angular positions. 15 The grab attachment may further comprise a fixture plate mounted to the frame, the fixture plate configured to mechanically mount at least two different fixture interfaces for CM different working machine headstocks. ^*20 According to a fourth aspect of the present teachings, there is provided an attachment for mounting to a working arm of a working machine, the attachment comprising a linkage "1” mechanism for substantially synchronised pivotable movement of two moveable arms of ^M the attachment in opposing directions, the linkage mechanism comprising: a linear actuator coupled directly or indirectly to the linkage mechanism; and a linkage comprising 25 a first linkage member configured to be moveably coupled to a first of said two moveable arms, and a second linkage member configured to be moveably coupled to a second of the moveable arms; wherein the actuator comprises a hydraulic cylinder configured to move linearly so as to move the linkage mechanism; wherein the first linkage member and the second linkage member are coupled via a central linkage mechanism, said central 30 linkage mechanism configured to reverse motion of the first linkage member so as to induce movement in the second linkage member in a direction opposite to that of the first linkage mechanism such that the second arm moves in an opposite direction to the first arm. 35 Advantageously, the linkage mechanism facilitates the use of a single hydraulic cylinder to provide generally synchronised motion to two arms. The cost of the linkage mechanism is reduced compared to mechanisms of the prior art where each arm has an associated cylinder, as only one cylinder is required. Linkage mechanisms of the prior art can have reduced synchronicity in situations where one arm meets with more resistance than the other. In contrast, the linkage mechanism as set forth has been found to obtain better synchronicity between the two moveable arms. In this way, the two arms are more efficient at grabbing, providing a grabbing attachment with improved stability and enhanced manoeuvrability. The linear actuator may be coupled to the first of said moveable arms. The central linkage mechanism may be pivotable about a central pivot point, and wherein the first and second linkage members may be pivotably connected to the central linkage mechanism at opposing sides of the central pivot point. Advantageously, the provision of the central linkage mechanism facilitates the efficient translation of motion of one arm to the other in an opposite direction via the linkage members. Specifically, movement of the first arm induces movement of the first linkage member in a first direction. The movement of the first linkage member causes a pivotal movement of the central linkage mechanism about the central pivot point, which in turn induces movement of the second linkage member in a direction opposite to that of the first linkage member. The movement of the second linkage member thus induces a movement in the second arm. In this way, the two arms can move in a substantially coordinated manner in opposite directions, allowing for more effective engagement of the arms with a load. The central linkage mechanism may comprise an upper plate and a lower plate. The first and second linkage members may be pivotably connected to both the upper and lower plates such that the linkage members are positioned between the upper and lower plates. Advantageously, the linkage members are supported on an upper and lower side by the upper and lower plates of the central linkage mechanism. In this way, the rigidity of the linkage is improved, meaning the linkage mechanism has improved precision and stability. The first linkage member may be configured to be pivotably coupled at a first end to the first moveable arm and at a second end to the central linkage mechanism. The second linkage member may be configured to pivotably coupled at a first end to the second moveable arm and at a second end to the central linkage mechanism. The actuator may be a linear actuator, e.g. a hydraulic actuator. 21 07 25 Advantageously, a linear actuator can effectively induce a pivotal movement in one of the arms, in a precise and smooth way. 5 Advantageously, a hydraulic actuator can effectively induce a pivotal movement in one of the arms, in a precise and smooth way. According to fifth aspect of the present teachings, there is provided an attachment for a 10 working machine, the attachment comprising a work implement coupled to a fixture plate, the fixture plate configured to mechanically mount at least two different fixture interfaces for different working machine arms or headstocks. Advantageously, the fixture plate provides for an attachment that is versatile and flexible, 15 capable of operating with numerous different types of working machine. In this way, the fixture plate acts as an adaptor to facilitate the interchangeability of different machines (i.e. machines with different fixture interfaces) and attachments. Operators can therefore continue to use the same attachment with different types of working machines, i.e. it is not required to obtain new attachments for use with different working machines. In this 20 way, cost and efficiency savings can be obtained, as separate dedicated attachments for different working machines are not required. The fixture plate may comprise at least one mounting formation, the mounting formation configured be complimentary to one of the at least two different fixture interfaces for 25 different working machine headstocks. The mounting formations may be arranged so as to be laterally spaced apart on the fixture plate. 30 The mounting formations may be arranged so as to be vertically spaced apart on the fixture plate. At least one of the mounting formations may comprise a plurality of apertures extending through the fixture plate. 35 At least one of the mounting formations may comprise an arrangement of projections or protrusions extending from the fixture plate. The fixture plate may be configured so as to removeably mount at least two different fixture interfaces for different working machine headstocks. BRIEF DESCRIPTION OF DRAWINGS Embodiments will now be described by way of example only with reference to the accompanying figures, in which: Figures 1A and IB are side views of an attachment according to an embodiment of the present teachings mounted on a working machine, without and with bales mounted on the attachment respectively; Figures 2 and 3 are perspective views of a rear and front of the attachment of Figure 1A in a grabbing position; Figure 4 is a rear perspective view similar to Figure 2, but in a retracted position; Figure 5 is a view perspective view of an actuation mechanism according to an embodiment of the present teachings; Figure 6 is a close-up view of part of the actuation mechanism of Figure 5 Figure 7 is a view of a lower fork to be mounted to the attachment of Figure 1A Figures 8, 9 and 10 are side views of the attachment with the fork in a float, storage, and transport position respectively; Figures 11 and 12 are perspective and side views of another embodiment of the attachment in a retracted position; Figure 13 is a side view of the attachment of Figures 11 and 12 in a grabbing position; Figures 14 and 15 are views of the attachment of Figure 2 but showing a fixture plate with nothing mounted thereon and with a fixture interface mounted thereon respectively; Figure 16 is a perspective view of a side shift assembly according to another embodiment of the present teachings; and Figure 17 shows the side shift assembly mounted onto the fixture plate of the attachment of Figure 14. DETAILED DESCRIPTION In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments and the teachings. However, those skilled in the art will understand that: the present teachings may be practiced without these specific details or with known equivalents of these specific details; that the present teachings are not limited to the described embodiments; and, that the present teachings may be practiced in a variety of alternative embodiments. It will also be appreciated that well known methods, procedures, components, and systems may not have been described in detail. References to vertical and horizontal in the present disclosure should be understood to be in relation to the machine when stood on horizontal ground in a non-working condition. 5 The term axial is generally used in relation to the longitudinal axis of the machine. The term width is generally used in relation to the longitudinal length, that is, transverse to the length. Referring firstly to Figures 1A and IB, an attachment 22 of an embodiment of the teachings is intended to be used with a working machine 10. The working machine may be a load 10 handling machine. In this embodiment, the load handling machine 10 is a telescopic handler (shown schematically). In other embodiments, the load handling machine may be a rotating telescopic handler, a forklift, a skid-steer loader, a compact track loader, a wheel loader, a telescopic wheel loader, or a tractor with a front loader or rear three-point linkage, for example. The working machine includes a machine body 12. 15 A working arm 14 is connected to the body 12. The working arm 14 is connected to the LO body 12 proximate a first, or proximal, end of the working arm 20. In some embodiments, CM the working arm 14 is pivotally connected to the body 12, typically about a transverse horizontal pivotal axis. 020 The working arm 14 may be a telescopic arm, having a first section 16 connected to the £\j body 12, and a second section 18 which is telescopically fitted to the first section 16. In this embodiment, the second section 18 of the working arm 14 is telescopically moveable with respect to the first section 16 such that the working arm 14 can be extended and 25 retracted. Movement of the second section 18 with respect to the first section 16 of the working arm 12 may be achieved by use of an extension actuator 17, for example a double acting hydraulic linear actuator, an electric linear actuator, a telescopic extension ram, multiple extension rams, and / or a chain and pulley system. As will be appreciated, the working arm 14 may include a plurality of sections, for example two, three (as depicted), 30 four or more sections. Each arm section may be telescopically fitted to at least one other section, and an actuator may be provided therebetween. In this embodiment a working machine carriage or headstock 20 is mounted to a second, or distal, end of the working arm 14. An attachment or a working implement, e.g. a load 35 handling implement, 22 is mounted to the headstock 20, and is pivotable about a second generally horizontal transverse axis with respect to the second end of the working arm 14. The working machine 10 is configured to transport loads over the ground, i.e. with a load held by the attachment 22, an operator can move the machine 10 with the load from one location to another. In the illustrated embodiment, the attachment 22 is a grab attachment for engaging and 5 manipulating a load, particularly bales of straw 24 and the like (e.g. bales of hay, silage, cotton, cardboard, plastic etc.). The attachment 22 includes a frame 26 for supporting the load in the attachment and a grabbing mechanism 28 for engaging the load (i.e. for releasably mounting the load to the attachment). 10 15 CXI Figure 1A illustrates the attachment 22 without a load, while Figure IB indicates the attachment 22 engaging and lifting bales of straw 24. Various straw / hay / silage bale types are known, and have differing dimensions and weights For example, a Hesston bale has typical dimensions of 1.2 x 1.2 x 2.5m and a weight of approx. 500-600kg (for straw, more for hay or silage), a % Hesston 1.2 x 0.9 x 2.5m and weight of 400-550kg, a mini Hesston 0.8 x 0.9 x 2.5m and a weight of 240-350kg, a Quadrant 1.2 x 0.7 x 2.5m and weight of 250-400kg, and round bales are around 1.2m in width, 1.2-1.8m in diameter and weigh around 150-300kg. As such, all require mechanised handled. 20 CXI Referring now to Figures 2 to 4, the attachment 22 is illustrated in more detail. Figures 2 and 4 provide a rear-view of the attachment, while Figure 3 provides a front view of the attachment. 25 Although the attachment 22 will be described in relation to engaging and manipulating bales of straw, it should be understood that the attachment 22 is suitable for engaging and manipulating different baled materials in other embodiments. The attachment 22 includes the frame 26. The frame is configured to be secured to a 30 vehicle (e.g. to the working arm 14 of the working machine 10). In Figures 2 and 3, the attachment 22 is shown secured via the frame 26 to the headstock 20 mounted to a working machine 10 (the remainder of the working machine is not shown for clarity). The working machine headstock 20 is not shown in Figure 4. 35 The working machine headstock 20 serves to secure the attachment 22 to the working machine 10. It should be appreciated that any suitable working machine (and thus any corresponding headstock - or sometimes a direct connection to the working arm) may be used with the attachment 22. In the illustrated embodiment, the frame 26 includes two vertical members 26a that are connected by a series of spaced apart horizontal cross-members 26b. The vertical members 26a and horizontal cross-members 26b provide the load-bearing elements of the 5 attachment 22. The frame design of the illustrated embodiment has been found to provide rigidity and stability to the frame 26. It should be appreciated that an alternative frame design may be implemented, e.g. a planar plate, angular members, or multiple vertical members spaced apart and connected 10 via multiple horizontal members. The frame 26 has an engagement side (i.e. a side configured to engage with bales of straw) and a fixture side (i.e. a side configured to be secured to the working machine headstock 20. In exemplary embodiments, the engagement side defines a substantially 15 planar surface for engaging the bales of straw (i.e. which are substantially planar). In this way, multiple bales of straw can be piled and lifted by the attachment 22 in an aligned configuration. LO CM In the illustrated embodiment, the frame 26 defines a vertical axis Y-Y extending through ^^*20 the centre of the frame 26 in the vertical direction. The frame 26 also defines a horizontal axis X-X extending through the centre of the frame 26 in a horizontal transverse direction. 1— The attachment 22 includes a grab mechanism 28. The grab mechanism 28 includes at least one arm 30a, b that is pivotable along a clamping arc relative to the frame 26. In 25 the illustrated embodiment, the grab mechanism 28 includes a first and a second side arm 30a, 30b. Each arm 30a, 30b has a gripping element or elements 34 that can assist the attachment 22 in grasping a bale of straw. In Figure 2, the gripping elements 34 are spikes or tines 30 that are intended to protrude into the bale of straw to provide a robust grip of the bale. In particular, the tines are curved with a radius that is substantially the same as the same arc described by the arms 30. In an alternative embodiment, another gripping element may be used, such as a clamp or 35 a teeth arrangement compressing and gripping an end or side of the bales. The gripping elements 34 are secured to, or proximal to, a distal end of each arm 30a, 30b (i.e. the end of the arm distal to the frame 26). The gripping elements 34 extend in an initially perpendicular direction from the arms 30a, 30b before curving as described above. A plurality of gripping elements 34 are provided along the length of the arms 30a, 30b, spaced apart in the vertical direction. In this way, the gripping elements 34 can engage with multiple bales of straw that are stacked on top of one another, or with bales 5 of straw that are particularly tall. In exemplary embodiments, the gripping elements 34 are evenly spaced apart along the length of a respective arm 30a, 30b. Only one gripping element per arm 30a, 30b may be provided for some applications. The gripping elements 34 are mechanically secured to the arms 30a, 30b in Figure 2, e.g. 10 via an arrangement of bolt holes that are distributed along the length of the arms 30a, 30b. The bolt hole arrangement facilitates the selective removal or addition of gripping elements 34 at varying positions along the length of the arms 30a, 30b. Alternatively, the gripping elements 34 are welded to, or otherwise integrally formed with, the arms 30a, 30b. 15 In this embodiment, the grabbing mechanism 28 is pivotably mounted to the frame 26 via a mounting mechanism 31. LO CM It should be understood that the mounting mechanism may be provided in any suitable ^^*20 form. In this embodiment, mounting mechanism 31 includes fixture points 32 in the form of bores provided on the frame which align with a corresponding aperture in the arms 30a, "1” 30b, each with a pivot pin received therethrough which is arranged substantially parallel to axis Y-Y. 25 In Figure 2, each of the side arms 30a, 30b are mounted to the frame via two vertically spaced fixture points 32 between a proximal end of a respective side arm 30a, 30b and a mount at a side of the respective vertical member 26a, 26b of the frame 26. The fixture points 32 on opposing sides may be connected by cross members. Only one fixture point 32 may be provided between each arm 30a, 30b and the frame 26 in an alternative 30 embodiment. The configuration of Figure 2 to 4 can be seen as a first configuration, or a side grabbing mode. In such a configuration, the arms 30a, 30b are mounted to the frame 26 so as to be pivotable about a vertical axis that is parallel with axis Y-Y. In the side grabbing mode, 35 the clamping arc is defined as an arc that is in the horizontal plane (i.e. the plane on which the horizontal axis lies). It should be appreciated that the side grabbing mode may include only one arm in some embodiments. In other embodiments, multiple arms may be provided at varying positions along the height at opposite sides of the frame 26. 5 The side mounting mechanism facilitates pivotal movement of the side arms 30a, 30b along the clamping arc between an engagement position (i.e. in Figure 2 and Figure 3), and a retracted position (shown in Figure 4). In the retracted position, each arm 30a, 30b is pivoted so as to define a reflex angle between the vertical axis of the frame and a frontfacing side of the arm (i.e. the side that is intended to contact the load). In such a position, 10 the front-facing side of the arms 30a, 30b are furthest apart from one another and the tips of the gripping elements 34 do not project forward of the front face of the frame 26, or only project forward by a nominal amount. 15 CXI The attachment 22 is typically operated so the arms 30a, 30b are in the retracted position when the attachment is approaching a bale of straw 24, such that the arms 30a, 30b define enough clearance therebetween so that the front face of the frame 26 buts up against the bale. The attachment 22 is operated to then penetrate and engage the bale of straw when moved into the engagement position. ^*20 In the engagement position, the arms 30a, 30b have been pivoted toward each other (e.g. in a closing motion from the retracted position). The arms are closed until the gripping "1” elements engage the straw (e.g. by piercing the bales). In the engagement position of ^Xl Figures 2 and 3, an obtuse angle is defined between the vertical axis of the frame and the front-facing side of each arm 30a, 30b. In such a position, the front-facing side of the 25 arms 30a, 30b are closest together. This position may correspond to engaging of a round bale whose width is relatively small compared to the dimensions of the frame 26 and arms 30a, 30b. If gripping relatively large high density bales of say the Hesston or Quadrant type, the gripping elements 34 become fully engaged when the arms 30a, 30b are substantially co-planar with the front face of the frame 26 (as shown in Figures 1A and 30 IB). Once the straw bales have been engaged and moved to a desired position (e.g. via the working machine 10), the arms 30a, 30b can be pivoted (i.e. opened) from the engagement position to the retracted position such that the gripping elements disengage 35 from the bale 24. It should be understood that the angular position of the engagement and retracted positions may be varied based on operational requirements, e.g. straw bales that have smaller dimensions may require an engagement position in which the two arms 30a, 30b are closer together and the retracted position can define a smaller angle relative to the frame. 5 As is best shown in Figure 3, in this embodiment, the mounting mechanism also includes a lower mounting mechanism 36. The lower mounting mechanism 36 is configured for pivotably mounting a fork 96 (Figure 7) at a lower region of the frame 26 (i.e. a region closest to the ground when the attachment is in operation) such that the fork 96 may pivot about an axis parallel to the horizontal axis X-X at the lower region of the frame 26. The 10 attachment 22 is thus operable in a bottom supporting mode when such an arm is fitted. The lower mounting mechanism includes mounts 38 arranged at or proximal to a lowermost end of the frame 26. The mounts 38 are configured such that the lower fork 96 (not shown in Figures 2 and 3) can be mounted thereto so as to form a hinge or a pivot 15 between the frame 26 and said fork. In Figure 3, the mounts are hinge pins 38 extending from the lower region of the vertical CM members 26a, 26b of the frame 26. ^^*20 Although not shown in Figure 3, each hinge pin 38 is configured to be received in a corresponding aperture in a fork. The pins 38 provide a pivot point about which a "1” respective fork 96 can rotate as described in more detail below. CM In exemplary embodiments, an upper region 40 of the frame is adjustable such that its 25 upper extent is of variable height to support various numbers and dimensions of straw bales 24. In the figures, the adjustable height is provided by a telescopic extension 42 fitted to the upper region of the frame. The telescopic extension 42 can be extended or retracted so as 30 to adjust the height of the frame 26 and set by fitting pins in one of an array of spaced apertures on the telescopic extension 42. As shown in the figures, the vertical members 26a of the frame define a substantially hollow interior at the upper region, such that the telescopic extension 42 can slide into the 35 frame 26. In the figures, an actuation system 44 is operatively coupled to the arms 30a, 30b and is configured to move each arm 30a, 30b along the clamping arc. The actuation system 44 of the figures includes a hydraulic actuator 46, but it should be appreciated that the actuator may be in any form, e.g. pneumatic, electric or the like. The actuator 46 is connected to a hydraulic flow path (not shown) for selectively delivering hydraulic fluid under pressure to the actuator 46 from an auxiliary hydraulic service (not shown) of the working machine 10. 10 15 CXI 20 CXI As best shown in Figure 2, the actuation system 44 is in the form of a single, double-acting hydraulic cylinder 46 that can move linearly. The hydraulic cylinder 46 is directly coupled to the first arm 30a, and is indirectly coupled to the second arm 30b. The hydraulic cylinder 46 includes a rod 48 that can extend and retract from / into the cylinder in response to changes in hydraulic pressure in the cylinder 46. The rod 48 is configured to be connected to the first arm 30a via a pivot mechanism such that linear movement of the rod 48 induces a pivotal movement of the first arm 30a (i.e. along the clamping arc). The first arm 30a is coupled to the second arm 30b via a linkage mechanism 50. The linkage mechanism 50 facilitates substantially synchronised pivotal movement of the two arms 30a, 30b in opposing directions (i.e. towards or away from each other between the engagement position and the retracted position along the clamping arc). The linkage mechanism 50 provides an indirect link between the hydraulic cylinder 46 and the second arm 30b, such that a single hydraulic cylinder 46 can actuate motion in both arms 30a, 30b. The linkage mechanism 50 is configured to transfer and reverse motion from the first arm 30a to the second arm 30b in a substantially instantaneous manner such that the two arms move in a co-ordinated motion. 25 The linkage mechanism 50 will now be described in more detail with reference to Figures 5 and 6. Figure 5 provides a view of the linkage mechanism 50 coupled to the first and second side arms 30a, 30b, while Figure 5 provides a view of the linkage mechanism 50 in isolation. The frame 26 is omitted from these figures for clarity. 30 As shown in Figure 5 and 6, the linkage mechanism 50 includes a first linkage member 52, a second linkage member 54 and a central linkage member 56. The first linkage member 52 is pivotably coupled at a first end to the first arm 30a, and pivotably coupled at a second end to the central linkage member 56. The second linkage member 54 is pivotably coupled at a first end to the second arm 30b, and pivotably coupled at a second 35 end to the central linkage member 56. In this way, the first and second linkage members 52, 54 are coupled via the central linkage member 56. The central linkage member 56 includes a central pivot point 58. The central pivot point 58 can be seen as a fixed pivot point about which the central linkage member 56 is pivotable. The central linkage member 56 may be mounted to the frame 26 via the central pivot point 58, such that the central pivot point 58 is a fixed point relative to the other linkage components 52, 54. In Figures 2 to 4, the central pivot point 58 is defined by coupling the central linkage member 56 to a central mounting region at a transverse centre of the frame. As is shown, when the linkage mechanism 50 is fully assembled on the frame 26 (e.g. as shown in Figure 2), the central pivot point 58 has a pivot axis that is parallel with a central vertical axis of the frame (i.e. the vertical axis Y-Y). The linkage members 52, 54, 56 each include at least one mechanical fixture point at the first and at the second end. The central linkage member 56 also includes a central mechanical fixture point that is positioned centrally between the two ends of the central linkage member 56. The central mechanical fixture point defines the central pivot point 58. The mechanical fixture points facilitate the moveable connections between the respective members 52, 54, 56, and between the first and second members 52, 54 and a respective arm 30a, 30b. In operation, the linkage mechanism 50 acts as a reverse motion linkage mechanism. Specifically, the first linkage member 52 translates and pivots in response to movement of the first arm 30a (e.g. via actuation via the rod 48 of the cylinder 46). The movement of the first linkage member 52 causes the rotation of the central pivot member 56 about the central pivot point 58, which in turn causes translational and pivoting movement of the second linkage member 54 in the opposite direction to that of the first linkage member 52. The second linkage member 54 thereby induces motion of the second arm 30b in the opposite direction to the first arm 30a. In this way, the arms 30a, 30b can move substantially simultaneously between an open and closed clamping position. Implementing such a linkage mechanism 50 into the attachment 22 facilitates the use of a single hydraulic actuator 46 to provide generally synchronised motion to two arms 30a, 30b. This is in contrast to known attachments, in which a hydraulic cylinder is provided to actuate both arms (e.g. two hydraulic cylinders for actuating two arms). In this way, the cost of the attachment 22 can be reduced, since only one hydraulic cylinder 46 is required. Moreover, linkage mechanisms of the prior art can have reduced synchronicity in situations where one arm meets with more resistance than the other. In contrast, the linkage mechanism 50 as set forth has been found to obtain better synchronicity between the two moveable arms 30a, 30b. In this way, the two arms are more efficient at grabbing irrespective of the resistance to penetration encountered, providing a grabbing attachment 22 with improved stability. In the illustrated embodiment, the linkage members 52, 54, 56 are provided as elongate rods. The mechanical fixture points are provided as apertures 52a, 54a, 56a extending through the rods at opposite ends of each rod, and through the centre of the central linkage member 56. It should be appreciated that alternative means of connecting the members together can be utilised. Moreover, in some embodiments, multiple apertures may be provided such that the rods and arms can be coupled at different positions along the length of each rod. As shown in Figure 5, the first linkage member is moveably connected to the arm 30a at a first end by aligning the aperture 52a at the first end of the linkage member with a respective fixture point 32 on the arm 30a. In the figure, the aperture 52a of the first linkage member 52 is aligned with an aperture on the first arm 30a and a fixture member (e.g. a bolt, a pin or the like) is received therethrough. The apertures of the arm 30a and the first linkage member vertically align about the vertical pivot axis defined between the arm 30a and the frame 26. The first linkage member 52 can be pivotably connected to the central linkage member by aligning the aperture (not shown) at the second end of the linkage member 52 with a respective aperture 56a of the central linkage member 56. A fixture member (e.g. a bolt, a pin or the like) is then received therethrough. The apertures 52a, 56a of the first linkage member 52 and the central linkage member 56 align so as to define a vertical pivot axis. The second linkage member 54 can be similarly connected to the central linkage member 56. In this way, the first and second linkage members 52, 54 are pivotably connected to the central linkage mechanism 56 at opposing sides of the central pivot point 58. As can be seen best in Figure 6, the three apertures 56a on the central linkage member 56 are equally spaced. Moreover, the first and second linkage members 52, 54 are of equal length. In the illustrated embodiment, the central linkage member 56 includes an upper plate 56b and a lower plate 56c. Each plate 56b, 56c includes a respective arrangement of apertures 56a. The first and second linkage members 52, 54 are pivotably connected to both the upper and lower plates 56b, 56c, such that the linkage members 52, 54 are positioned between the upper and lower plates 56b, 56c. It should be understood that the linkage mechanism 50 set forth is suitable for use with 5 any attachment that requires the substantially synchronised movement of two moveable arms in opposing directions. The linkage mechanism can facilitate such coordinated movement, without the need for two hydraulic cylinders (i.e. one for each arm). In this embodiment the actuator 46 is vertically offset from the linkage members 52, 54, 10 56 so as not to risk fouling on them. This allows the actuator 46 to extend across substantially the full width of the frame 26 to maximise its range of motion, and therefore that of the arms 30a, 30b. In other embodiments the actuator 46 may instead drive one of the first, second or central linkage members 52, 54, 56. 15 In this embodiment the central linkage member 56 is provided with a projection 57 to act as a stop against a corresponding portion of the frame 26, and restrict over-rotation of the arms 30a, 30b. I Referring now to Figures 7 to 10, the attachment 22 of Figures 1 to 4 is shown with the 20 lower fork 96 fitted to the frame 26 via the lower mounting mechanism 36. The fork 96 has a plurality of tines or spikes 35 that project from a cross-member 37 in a direction toward the load to be engaged. In the illustrated embodiment, the tines 35 extend in a generally perpendicular direction from the cross member 37. 25 It should be appreciated that in an alternative embodiment, a plurality of lower forks 96 may be provided, e.g. distributed along the frame 26 in the horizontal or vertical direction. The lower mounting mechanism 36 includes an adjustable positioning mechanism 98 30 configured to set the angular position of the fork 96 relative to the frame 26. Specifically, the adjustable positioning mechanism 98 is configured so that the fork 96 can be mounted in a plurality of discrete angular positions relative to the lower region of the frame 26. In an exemplary embodiment, the adjustable positioning mechanism 98 is capable of 35 moving the lower fork 96 between at least three angular positions relative to the frame 26. The first of these positions is shown in Figure 8, in which the lower fork 96 is positioned with the tines 35 extending forward at right angles to the vertical axis Y-Y under the influence of gravity and is blocked from pivoting lower, but can pivot upwards against gravity. This position may be referred to as the "float" position. The float position is most preferable for engaging a load since the tines 35 project substantially perpendicularly relative to the frame 26 to engage the lower bale. The ability to float is advantageous when depositing bales as it allows the frame 26 to be pivoted forward, whilst withdrawing the grab, so as to maintain the stability of the bales. The second of the discrete angular positions is indicated in Figure 9, which indicates a "stow" or "storage" position. In this position, the attachment 22 has been detached from a working machine 10, and the frame 26 has pivoted relative to the fork 96 such that the angle between the gripping elements 34 and the frame 26 is acute (e.g. approximately 70 degrees). In this way, the attachment 22 is supported on the ground via the tines 35. The tilt or angle between the frame 26 and the tines 35 provides for a more stable resting position of the attachment 22, reducing the likelihood that the attachment 22 will fall and become damaged. Figure 10 shows the third position. This position may be referred to as the "transport" position. As can be seen, the fork 96 has been pivoted up approximately 90 degrees compared with the arm position of Figure 8 in a direction toward the frame 26, such that tines 35 are proximal, and parallel to, the frame 26, where the sharp tips of the gripping elements 34 not projecting forward, to be safer on highways. It should be appreciated that the adjustable positioning mechanism 98 may be capable of pivoting the fork 96 into any number of angular positions relative to the frame 26. In an exemplary embodiment, the adjustable positioning mechanism 98 includes a manual adjustable positioning mechanism, as best seen in Figure 7. As can be seen, the fork 96 includes a plurality of apertures extending through the fork 96 in the horizontal direction. In Figure 7, the fork 96 includes two pairs of plates 102 spaced apart in the horizontal direction. Each plate 102 includes three apertures 100a, 100b, 100c that align horizontally with the apertures 100a, 100b, 100c of the other plates 102. The plates also include a radial abutment surface 104. Each pair of plates 102 is intended to receive a lowermost end of the vertical frame members 26a, 26b. The main apertures 100a receive the hinge pins 38 to pivotably mount the fork 96. In Figure 7, the abutment surfaces 104 contact pins 97 (Figure 8) correspond to the "float" position allowing upward pivoting. As seen in Figure 9, the locating of a pin (not shown) in the lowermost aperture 100b and a bore 99 of the frame members 26a, 26b corresponds to the "storage" or "stow" position. As seen in Figure 10 the locating of a pin (not shown) 5 in the rearmost aperture 100c and the bore 99 corresponds to the "transport" position. In other embodiments, the fork 96 and frame 26 may engage via a different mechanical arrangement, e.g. a detent mechanism. 10 Although not shown, the adjustable positioning mechanism 98 may alternatively, or additionally, include an actuator configured to move the fork 96 relative to the frame 26 between the plurality of discrete angular positions. In this way, an operator can move the arm automatically between positions (e.g. from a cab of the working machine) without having to manually handle the attachment 22. In such an embodiment, the actuator may 15 be hydraulic, electric, or pneumatic. For example, a hydraulic cylinder may be provided that can induce a pivotal movement in the fork 96, and that can lock the arm in a desired position. The actuator may also have a suitable mechanical or hydraulic arrangement to permit a float setting. ^^*20 Referring now to Figures 11 to 13, an attachment 122 according to another embodiment of the present teachings is illustrated. The attachment 122 has some common features "1” with that of the first embodiment, and so only the differences between the attachment of the previous figures will be described here, with reference numerals for similar features including a prefix '1'. 25 The attachment of Figures 11 to 13 includes an upper arm 1106. The upper arm 1106 pivots about a horizontal axis, and includes gripping elements 134 to act as a top grab. In this embodiment the gripping elements 134 are relatively short, straight tines. 30 In the illustrated embodiment, the upper arm 1106 includes three separate regions, a first region 1106a which is pivotably secured to the frame 126, a second region 1106b which is fixed at a distal end of the first region 1106a, and a third region 1106c connected to a distal end of the second region 1106b. The gripping elements 134 are secured to the third region 1106c in the illustrated embodiments. The second region 1106b is fixed to the first 35 region 1106a so as to define a generally perpendicular angle therebetween and the third region 1106c to the second region 1106b to define an obtuse angle. The configuration of the upper arm 1106 of the figures can allow the gripping elements 134 of the upper arm 1106 to engage with a bale of straw at a top thereof rather than the rear or sides of the bale. The attachment also includes a lower fork 96 that is the same as in the first embodiment, but reacts any force generated by the upper arm 1106 when one or more bales 24 are clamped therebetween to hold the bales in place on the attachment 122. The upper arm 1106 can pivot between an engagement position (see Figure 13) and a retracted position (see Figures 11 and 12). In the engagement position, the first region 1106a of the arm 1106 is pivoted so as to be at a substantially perpendicular angle relative to the frame 126. In this position, the gripping elements 134 are configured to engage with a bale. In practise, depending upon the shape and dimensions of the bale(s), the upper arm may achieve its engagement position at an angle between that of Figures 11 and 12 and Figure 13. In the retracted position, the first region 1106a of the arm 1106 is pivoted so as to define a reflex angle relative to the frame 126. In this position, the gripping elements 134 are elevated so as to provide a space for the frame 126 to engage with a stack of bales. The actuation system 144 of the attachment may be similar to that described in relation to Figures 4-6, but without the linkage mechanism 50. A linear actuator 146, e.g. a hydraulic cylinder is provided to induce a pivotal movement of the upper arm 1106. In the illustrated embodiment, the hydraulic cylinder 146 is orientated differently to that of the attachment in the side grab mode. Specifically, in the side grab mode, the hydraulic cylinder 46 is mounted to the frame 26 in a substantially horizontal orientation, with the cylinder 46 engaging with a side arm 30a at a vertical pivot axis at a side of the frame 26. In the top grab mode, the hydraulic cylinder 146 is mounted to the frame 126 in a substantially vertical orientation, with the cylinder 146 engaging with the top arm 1106 to define a horizontal pivot axis about an upper region of the frame 126. In this embodiment, the mounting mechanism 131 includes fixture points 132 arranged parallel to axis X-X. In addition, different brackets are provided for the top grab actuation system 144. Specifically the hydraulic cylinder is pivotably mounted to a pair of spaced plates extending upwardly from a cross-member 126b. The fixture points 32 providing the mounting mechanism 31 and the mount for the actuator 46 the side grabs of the first embodiment are omitted, but otherwise the frame structure 26 and mounting plate 60 (see below) arrangement is similar. The top grab replaces the telescopic extension 42. As such, this requires a selection to be made at the point of manufacture as to whether the attachment is going to be built as a side grab or top grab with some common parts. However once selected a conversion cannot readily be made from one type to the other. 5 In other embodiments (not shown), the frame 126 is configured such that the cylinder 46 / 146 can be simply moved between the vertical configuration and the horizontal configuration, and the relevant arms 30a, 30b / 1106 mounted and connected to the actuator (and linkage 50 if required). In other words, the frame 126 is configured to engage with a cylinder 146 in either orientation and has mounting mechanisms 31, 131 to 10 facilitate both the side grab and the top grab mode, with suitable brackets being provided for each. Although not shown, the attachment 22 and 122 may be configured to facilitate the modular assembly of multiple frames, and therefore multiple grab mechanisms, adjacent 15 to one another, i.e. a multi-frame attachment. In such an embodiment, a second frame can be provided that is horizontally spaced apart from the first frame 26. Each of the first and second frame may be configured with independently actuatable side grabs of the first I embodiment or a top grab and bottom fork of the second embodiment. The second frame may be of a modular form, i.e. to enable arms to be mounted in varying configurations 20 (e.g. side grabbing mode, top grabbing mode). The multi-frame attachment is securable to a vehicle via a mounting mechanism, e.g. the fixture plate 60 described below that is centrally mounted at the midpoint between the two frames for mechanically mounting a fixture interface for a working machine headstock. 25 The multi-frame attachment allows for the capacity of the attachment to be improved, accommodating a broader range of applications, e.g. applications that require the lifting and alignment of multiple loads, particularly in industrial applications rather than agricultural - such as handling bales that may be incinerated at power stations or in the 30 supply chain to power stations, where higher capacity working machines may be used. Referring now to Figure 14, the means of securing the attachment 22 (or 122) to a working machine 10 will now be discussed. Figure 14 is a rear view of the attachment 22, with the headstock 20 and a fixture interface removed. The attachment 22 includes a fixture plate 60. The fixture plate 60 is configured to mechanically mount at least two different fixture interfaces for different working machine headstocks or other mounts. In exemplary embodiments, the fixture plate 60 is configured to mount a plurality of different fixture interfaces for different working machine headstocks. It should be understood that different manufacturers of working machines utilise 5 headstocks 20 with different mounts having different formations and / or dimensions and which may be proprietary to that manufacturer or be in accordance with a suitable interface standard. The fixture plate 60 can improve the versatility and flexibility of the attachment 22 since 10 the attachment 22 can be fixed to numerous different types of working machine. In this way, if an operator chooses to change the type of working machine used, they will not be required to obtain a new attachment 22 that is mountable to the new machine. The fixture plate 60 acts as an adaptor to facilitate the interchangeability of different machines with the same attachment 22. 15 As shown in Figure 14, the fixture plate 60 includes two side members 62, an upper cross member 64a extending between the side members 62 and a lower cross member 64b I extending between the two side members 62. In alternative embodiments, the fixture plate 60 is in the form of a single planar member which may also be directly or indirectly 20 secured to the frame 26. The fixture plate 60 includes at least one mounting formation that is complimentary with at least two fixture interfaces of working machine headstocks 20. 25 In this embodiment, the mounting formation includes a plurality of apertures 66 extending front to rear through the plate 60 in the illustrated embodiment, although it should be appreciated that different mounting formations may be utilised, such as an arrangement of projections or protrusions that extend outwardly from the plate 60. In some embodiments, a combination of both apertures 66 and projections may be included. 30 In the illustrated embodiment, each side member 62 is a plate which includes an arrangement of apertures 66 that are vertically and / or horizontally spaced apart. The apertures 66 are spaced apart so as to compliment the spacing of apertures or members of a fixture interface for a given working machine headstock. By being complimentary, not 35 all apertures / protrusions of the mounting formation may be utilised, provided sufficient apertures / protrusion intersect to provide a secure mechanical fixing. In rare instances entirely different apertures / protrusions are used with one fixture interface compared to those used with another fixture interface. The rear face of each side member 62 may be planar, at least where contacting the 5 corresponding fixture interface. It should be appreciated that the mounting formations may be arranged in any configuration suitable for engaging a fixture interface of at least two different working machine headstocks, e.g. laterally and vertically spaced apart. 10 In some embodiments, all available fixture interfaces mount to the same formations. In other embodiments certain formations may be used with one fixture interface and others used with another fixture interface. This may be necessary where the shape of the fixture interface blocks or obscures certain formations. 15 In an exemplary embodiment, the apertures 66 have a smooth internal profile. The internal profile facilitates a simple means of attaching and detaching a fixture interface I (e.g. via bolts and a complementary nuts). In other embodiments the internal profile may be threaded, and the fixture interface may be mounted via a complementary threaded 20 screw or bolt alone. Either arrangement enables a secure play-free connection to be achieved which may not be accidentally released. The mounting formations may facilitate the removeable mounting of at least two different fixture interfaces for different working machine headstocks. In this way, an operator can 25 simply remove a fixture interface mounted to the fixture plate with standard tools (e.g. spanners / wrenches) and mount a different interface to the fixture plate 60 if a new working machine is used. Whilst the fixture plate 60 is provided on a bale grab attachment in this embodiment, it 30 should be understood that numerous work implements may include the fixture plate 60, for example, a pair of forks (e.g. a pair of laterally spaced forks), a bucket attachment, sweeper attachment etc. In exemplary embodiments, the fixture plate 60 is permanently secured to the attachment 35 22 e.g. via welding to the frame 26 or other structure of the attachment. The term "fixture interfaces" refers to a means of connecting an attachment to a working machine headstock or other part of a working arm of a working machine. In exemplary embodiments, the fixture plate 60 is configured to mechanically mount a fixture plate in the form of hitch pin interface, a quick coupler interface, a quick-release mechanism, mounting brackets, a hook and latch interface, a tractor three-point linkage interface, and the like. 5 In exemplary embodiments, the fixture interface is a quick-release mechanism enabling the mounting of the fixture plate to a working machine without the use of tools. This enables the attachment to be fitted and removed conveniently from the working machine on a regular basis (e.g. potentially multiple times in a working day, if required). 10 Figure 15 illustrates the attachment of Figure 14, with a fixture interface for a working machine mounted thereon. The fixture interface in Figure 15 is a Q-fit fixture interface bracket 68. "Q-fit" is an interface utilised by the present applicant on its telehandler machines. Other known fixture interfaces include Euro hooks, cone and pin type, and 15 numerous manufacturer specific types, by way of example. In this embodiment the fixture interface is provided as two brackets 68, one for mounting CM on each side member 62 of the fixture plate 60. As can be seen, the brackets 68 include an aperture arrangement that aligns with the arrangement of apertures 66 on the fixture ^*20 plate 60. Each bracket 68 can therefore be aligned with the arrangement of apertures 66 and a bolt or screw can be threaded or inserted therethrough to fix the bracket 68 relative "1” to the plate 60. CM An advantage of using a fixture plate which is planar (and typically in a range of 5-12mm 25 thick) is that the fore-aft depth added to the attachment is minimised, which may be beneficial for maintaining manoeuvrability and maximising the load carried by the attachment. Each Q-fit bracket 66 includes a hook 70 at an upper end. Each hook 70 defines a recess 30 72 for engaging a corresponding member (e.g. a bar) on a headstock 20 of a working machine. Each Q-fit bracket 66 includes an aperture 74 extending through a lower end. Each aperture 74 is configured to align with a corresponding attachment on a working machine headstock and a locking pin or bolt is received so as to secure the attachment to the headstock. 35 The Q-fit bracket 66 provides a quick and efficient means of securing the attachment to a headstock of a working machine 10. It should be understood that an alternative fixture interface may be mounted to the fixture plate to facilitate the mounting of the attachment to a different working machine headstock. Figure 17 shows the attachment of Figure 14, with a different fixture interface for a working 5 machine mounted thereon. The fixture interface of Figure 17 is a side shift assembly 76. The side shift assembly 76 will be described in more detail with reference to Figures 14, 16 and 17. 10 Figure 16 is a perspective view of the side shift assembly 76 in isolation. The side shift assembly 76 includes a fixed carriage 78 and a moveable carriage 80 that is slidably attached to the fixed carriage 78. The fixed carriage 78 is intended to be mounted to a working arm 14 of a working machine 10 (e.g. via a headstock 20 of a working machine) via a first mounting mechanism 82. 15 The moveable carriage 80 is configured to mechanically mount to a plurality of different attachments via a second mounting mechanism 84. Specifically, the second mounting mechanism 84 includes a plurality of mechanical fixture points 86. The fixture points 86 are arranged so as to define a fixture interface that is complimentary to a corresponding arrangement of mechanical fixture points of a plurality of different attachments. In this way, the side shift assembly 76 can operate with different attachments, allowing operators to convert a non-side shift attachment to side shift quickly and with standard tools. Moreover, bespoke, dedicated side shift assemblies are not required for different 25 attachments. Instead, the side shift assembly 76 allows for a modular approach, where different attachments can be interchanged as needed without losing the side shift functionality. In this way, equipment costs are reduced. In an exemplary embodiment, the first mounting mechanism includes a quick-release 30 mechanism that enables the mounting of the first mounting mechanism to a working machine (e.g. to a headstock 20 of a working machine) without the use of tools. The quickrelease mechanism enables the attachment to which the side shift is mounted to be fitted and removed conveniently from the working machine. 35 In the illustrated embodiment, the first mounting mechanism 82 is provided as a Q-fit or other quick-release bracket 68 (i.e. substantially the same as that described in relation to Figure 15). Each bracket 68 is mounted proximal a lateral end of the fixed carriage 78. In the illustrated embodiment, the first mounting mechanism 82 is fixedly secured to the side shift mechanism 76 (e.g. welded to the fixed carriage 78). It should be understood that the first mounting mechanism 82 may be removably mounted in an alternative embodiment, to allow various different types of mounting mechanism to be mounted. 5 Including such a mounting mechanism on the side shift assembly 76 allows the assembly to be mounted directly to a headstock of a working machine, without the need for additional, intermediate components. In this way, the efficiency and compactness of implementing the side shift functionality is improved. 10 The moveable carriage 80 is in the form of a plate in this embodiment. In exemplary embodiments, the plate is arranged on a plane substantially parallel to a plane on which the side shift moves. This may minimise the thickness of the side shift mechanism fore-aft, which in turn may reduce the amount an attachment extends forward of the working machine, thus aiding manoeuvrability and also maximising the load the attachment may 15 carry by reducing the tipping moment generated by the attachment and any load it carries. For example, the side shift mechanism may add less than 50mm, e.g. 35mm or less compared to an interface welded directly to an attachment (i.e. without a fixture plate arrangement). 20 As shown in the figures, the moveable carriage 80 includes two vertical members 80a, 80b and two lateral members 80c, 80d that define a central recess 88 therebetween (e.g. a generally square or rectangular plate with an opening in the middle). The plate may have a thickness in a range of 5mm-12mm. The plate includes a plurality of bolt holes or apertures 86 extending therethrough. The apertures 86 are plain, although in other 25 embodiments may be threaded. The apertures 86 are arranged to define an aperture interface that corresponds to an arrangement of apertures or projections of a plurality of different attachments. In the illustrated embodiment, the apertures 86 are arranged so as to be vertically and horizontally spaced along on the vertical members of the plate. 30 In the embodiment of Figure 17, the apertures 86 of the moveable carriage 80 align with the apertures 66 of the fixture plate 60 and a bolt or screw is received therethrough to secure the moveable carriage 80 of the side shift assembly 76 to the fixture plate 60 of the attachment 22 with a suitable nut. It should be understood that the arrangement of apertures 86 on the moveable carriage is suitable for engaging with a plurality of different 35 types of attachment. Returning to Figure 16, the assembly 76 includes a side shift mechanism that is coupled to both of the fixed 78 and moveable carriages 80. The side shift mechanism includes an actuator 90 that is configured to translate the moveable carriage 80 laterally relative to the fixed carriage 78. In the illustrated embodiment, the actuator 90 is a hydraulic actuator. It should be 5 understood that any form of actuator may be used in alternative embodiments, e.g. an electric actuator or a pneumatic actuator. The hydraulic actuator is connected to a hydraulic flow path (not shown) for delivering hydraulic pressure to the actuator e.g. from an auxiliary hydraulic service of the working machine. The actuator 90 is configured to induce linear (e.g. sideways) motion in the moveable carriage 80 relative to the fixed 10 carriage 78 (e.g. via a rod of the actuator being coupled to the moveable carriage so as to move the carriage when the rod extends or retracts). The actuator 90 is positioned in the central recess 88 of the frame, which advantageously avoids adding extra depth or thickness to the assembly 76. 15 CXI 20 CXI The fixed carriage 78 includes an upper and a lower cross member 78a, 78b. The side shift assembly includes at least one slide block 92 coupled to the moveable carriage 80 and slidably mounted on one of the cross members 78a, 78b. In Figure 16, four slide blocks 92 are provided. Two slide blocks 92 are fixed (e.g. via bolts) to each horizontal member 80c, 80d of the moveable carriage 80. Each slide block 92 is horizontally spaced apart from the adjacent slide block 92. Two slide blocks 92 are slidably mounted over each cross member 78a, 78b of the fixed carriage 78. The slide blocks 92 each define a recess or a slot that extends along the length of the slide block 92 and is configured to receive an upper or lower portion of a cross member 78a, 78b therein so as to slide thereover. 25 The recesses or slots are opposed in this embodiment and spaced so as to restrict relative vertical movement between the fixed carriage 78 and moveable carriage 80. The upper and lower portions of the cross members 78a and 78b are, in this embodiment, a relatively thin lip portion that is engaged by the slide blocks 92 to minimise the size 30 thereof. The slide blocks 92 are configured to move with the moveable carriage 80 in response to the actuator 90, and thus slide laterally over a respective cross member 78a, 78b. The slide blocks 92 provide additional support to the assembly 76 by acting as a guide to 35 promote accurate movement of the moveable carriage 80 relative to the fixed carriage 78, promoting a smooth and consistent movement of the carriage 80 and thus the attachment 22. The slide blocks 92 may also act as stops to prevent excess lateral movement (e.g. movement may be limited to 100mm off-centre in either direction). In exemplary embodiments, the slide blocks 92 include a support member 94 positioned within the recess or slot of each slide block 92, so as to provide an interface between the slide block 92 and the cross member 78a, 78b of the fixed carriage 78. The support 5 member 94 may be a lining of the slide block 92 (i.e. integrally formed on the recessed surface of the slide block 92), or a separate member that is positioned and secured in the recess between the slider 92 and a respective cross member 78a, 78b. In this embodiment the support member 94 is provided on both a horizontal and vertical surface of the recess. 10 In another embodiment, the support member 94 is additionally or alternatively secured to a respective cross member 78a, 78b of the fixed carriage, for example, via a clamping mechanism, and the slide block 92 is positioned thereover. The support member 94 further promotes smooth relative movement of the slide block 92 15 and thus the moveable carriage 80 relative to the fixed carriage 78. Although not shown, one or more support members may be provided between the fixed carriage 78 and moveable carriage 80 (i.e. between the cross members 78a, 78b of the fixed carriage 78 and the horizontal members 80c, 80d of the moveable carriage 80). In this way, the support members 94 can define an interface between the fixed carriage 78 and the moveable carriage 80. In exemplary embodiments, the support member 94 is formed from a low friction material. For example, the support member 94 may be formed from a polymeric material. 25 This enables the support member 94 to reduce frictional resistance between the slide block 92 and the fixed carriage 78, or between the fixed carriage 78 and the moveable carriage 80 reducing wear to the carriage(s) 78, 80. In this way, the support member 94 contributes to the efficient and durable operation of the side shift assembly. In exemplary embodiments, the support member 94 is formed from a polyamide. Polyamides exhibit a low coefficient of friction and thus provides a smooth, wear-resistant interface between the sliding mechanism and the fixed carriage. 35 In exemplary embodiments, the slide blocks 92 are removably mounted to the moveable carriage 80 e.g. by suitable fasteners such as cap head bolts or screws. In this way, the slide blocks 92 can be simply removed, and different fixed carriages can be fitted to the moveable carriage 80, e.g. with a different quick release interface. The one or more embodiments are described above by way of example only and it will be appreciated that the variations are possible without departing from the scope of protection afforded by the appended claims. 5 21 07 25

Claims

5 1. A side shift assembly for mounting to a working arm of a working machine, the sideshift assembly comprising:a fixed carriage comprising a first mounting mechanism for mounting the side shift assembly to a working arm of a working machine, the first mounting mechanism comprising a quick-release mechanism enabling the mounting of the first mounting 10 mechanism to a working machine without the use of tools;a moveable carriage slidably attached to the fixed carriage, the moveable carriage comprising a second mounting mechanism for releasably securing the carriage to an attachment; anda side shift mechanism coupled to the fixed carriage and the moveable carriage, 15 the side shift mechanism comprising an actuator configured to translate the moveable carriage laterally relative to the fixed carriage;wherein the second mounting mechanism comprises a plurality of mechanical LO fixture points arranged so as to define a fixture interface, wherein the fixture interface is CM complimentary to a corresponding arrangement of mechanical fixture points of a plurality ^^.20 of different attachments.

2. The side shift assembly of claim 1, wherein the first mounting mechanism C\j comprises two side members located proximate a respective lateral end of the fixed carriage, each side member defining one part of a hook type interface at an upper end, 25 for engaging a corresponding other part of the hook type interface on a working arm of a working machine.

3. The side shift assembly of claim 2, wherein each side member further comprises an aperture extending through a lower end, each aperture configured for receiving a 30 locking pin so as to secure the side shift assembly relative to a working arm of a working machine when the hooks are engaged with a connecting member of the working arm.

4. The side shift assembly of any preceding claim, wherein the moveable carriage comprises a plate having a plurality of holes extending therethrough, said holes arranged35 so as to define an interface complimentary to a corresponding structure on a plurality of different attachments.

5. The side shift assembly of claim 4, wherein the plate is arranged on a plane substantially parallel to a plane on which the side shift moves.

6. The side shift assembly of any preceding claim further comprises a sliding 5 mechanism having at least one slide block coupled to one of the moveable carriage and fixed carriage slidably mounted on the other of the moveable carriage and fixed carriage such that the moveable carriage moves laterally over the fixed carriage.

7. The side shift assembly of claim 6, wherein the sliding mechanism further 10 comprises a first support member positioned between the slide block and the part of the fixed or moveable carriage the slide block is sliding relative thereto, wherein the support member is formed from low friction material such as a polymeric material.

8. The side shift assembly claim 6 or claim 7, wherein the slide block is removably 15 mounted to the fixed or moveable carriage.

9. The side shift assembly of claim 7 or claim 8, further comprising a second support member mounted between the fixed carriage and the moveable carriage on an opposing side to the first support member; optionally, wherein the support member is formed from a low friction material such as a polymeric material.

10. An attachment for mounting to an arm of a working machine, the attachment comprising a side shift assembly of any preceding claim attached thereto.25 11. The attachment of claim 10 being a grab attachment for engaging and manipulatingbales of straw and the like, the grab attachment comprising:a frame configured to be secured to a vehicle (e.g. to a working arm of a working machine), the frame defining a horizontal axis and a vertical axis;a grab mechanism removably mounted to the frame, the grab mechanism30 comprising:at least one arm configured to be pivotable along a clamping arc relative to the frame, the or each arm comprising at least one gripping element for engaging a bale of straw; andan actuation system operatively coupled to the or each arm, the actuation system35 configured to move the or each arm along the clamping arc;wherein the frame comprises a standard structure for at least two configurations of grab mechanism and wherein the grab attachment may be selectively assembled in one of the first configuration or second configuration by providing a first grab mount on theframe in a first grab mount location and a first actuation system mount on the frame in a first actuation system mount location.

12. The attachment of claim 11, wherein the first configuration is a side grab 5 configuration in which at least one arm is pivotable about a generally vertical axis.

13. The attachment of claim 11 or claim 12, wherein the second configuration is a top grab configuration in which at least one arm is pivotable about a generally horizontal axis.10 14. The attachment of any of claims 11 to 13, wherein a second grab mount is furtherprovided on the frame in a second grab mount location for assembling the grab mechanism in the second configuration.

15. The attachment of any of claims 11 to 14, wherein a second actuation system 15 mount is further provided on the frame in a second actuation system mount location for assembling the grab mechanism in the second configuration.I16. The attachment of any one of claims 11 to 15 wherein the actuation system comprises an actuator, such as a linear actuator, and the same actuator may be used for20 the first configuration and the second configuration.

17. The attachment of any of claims 11 to 16, wherein the frame is a first frame and the grab mechanism is a first grab mechanism, and wherein the grab attachment further comprises:25 a second frame horizontally spaced apart from the first frame, the second frameconfigured to be secured to said vehicle and defining a horizontal axis that is substantially coaxial with the horizontal axis of the first frame, and a vertical axis offset from the vertical axis of the first frame; anda second grab mechanism removably mounted to the frame, the second grab30 mechanism comprising:at least one arm configured to be pivotable along a clamping arc relative to the second frame, the or each arm comprising at least one gripping element for engaging a bale of straw; andan actuation system operatively coupled to the or each arm, the actuation system35 configured to move the or each arm along the clamping arc;wherein the second frame comprises a standard structure for at least two configurations of grab mechanism and wherein the grab attachment may be selectively assembled in one of the first configuration or second configuration by providing a first grab21 07 25mount on the second frame in a first grab mount location and a first actuation system mount on the second frame in a first actuation system mount location.

18. The attachment of any of claims 11 to 17, wherein the or each frame comprises a 5 bottom fork mounting structure for releasably mounting a fork proximate a lower extent of the frame.

19. The attachment of claim 18, wherein the bottom fork mounting structure comprises an adjustable positioning mechanism configured so that the arm can be mounted in a 10 plurality of discrete angular positions relative to the frame.

20. The attachment of claim 19, wherein the adjustable positioning mechanism comprises a hydraulic actuator configured to move the arm relative to the lower region of the frame between said plurality of discrete angular positions.1521. The attachment of claim 19 or claim 20, wherein the adjustable positioning mechanism comprises a plurality of pin and abutment positions to select the plurality of discrete angular positions.20 22. The attachment of any of claims 11 to 21 further comprising a fixture plate mountedto the frame, the fixture plate configured to mechanically mount at least two different fixture interfaces for different working machine headstocks.

23. The attachment of claim 22, wherein the fixture plate comprises at least one 25 mounting formation, the mounting formation configured be complimentary to one of the at least two different fixture interfaces for different working machine headstocks.

24. The attachment of claim 23, wherein the mounting formations are arranged so as to be laterally spaced apart on the fixture plate.3025. The attachment of claim 23 or claim 24, wherein the mounting formations are arranged so as to be vertically spaced apart on the fixture plate.

26. The attachment of any of claims 23 to 25, wherein at least one of the mounting 35 formations comprises a plurality of apertures extending through the fixture plate.

27. The attachment of any of claims 25 to 26, wherein at least one of the mounting formations comprises an arrangement of projections or protrusions extending from the fixture plate.21 07 25

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