WO2012166540A1

WO2012166540A1 - Work machine blade

Info

Publication number: WO2012166540A1
Application number: PCT/US2012/039417
Authority: WO
Inventors: Jamel NECIB
Original assignee: Carterpillar Inc.
Priority date: 2011-05-27
Filing date: 2012-05-24
Publication date: 2012-12-06
Also published as: GB201109127D0; GB2491202A; GB2491202B

Abstract

The present disclosure relates to a blade for a work machine and more particularly a foldable blade for such a machine. The blade comprises a major portion (50), a minor portion (150) and coupling means (81). The major portion includes a major substrate (51) having opposed inside (60) and outside (59) ends, a rear surface (53) and a cutout (87) located at the inside end (60) and extending partway along the substrate towards the outside end (59). The major portion further includes at least one major channel member (65, 67) provided on the rear surface (53) and arranged substantially to overlie the at least one cut-out (87). The minor portion includes a minor substrate (151) having opposed inside (159) and outside (158) ends and a rear surface (152). The minor portion further includes at least one minor member (154, 156) provided on the minor substrate and extending outwardly beyond the inside end (159) so as to define at least one arm (160, 161) arranged to locate within the at least one major channel member (65, 67) of the major portion. The coupling means (81) connect the at least one arm (160, 161) to the at least one major channel member (65, 67) so as to permit relative movement of the minor (150) and major (50) portions between an operational position and a transportation position.

Description

WORK MACHINE BLADE The present disclosure relates to a blade for a work machine and more particularly a foldable blade for such a machine.

Work machines such as tractors and bull dozers are known, particularly in the construction and agricultural industries where they have a wide variety of applications. Typically such machines include a chassis carried on ground engaging tracks or wheels and supporting an operator's cab, an engine and a blade or similar material handling device. Usually the blade is significantly wider than the work machine so that more matter may be handled with each pass of the work machine. This may be particularly advantageous because fewer passes reduces operating costs by saving fuel and time, which is very attractive in such competitive industries.

However, some territories have introduced transportation regulations that prohibit the transportation of work machines fitted with overly large blades. Some of those regulations merely specify that the blade must not extend beyond the width of the work machine while others have specified maximum blade widths, such as three meters, for example. So as to avoid contravening those regulations during transportation, modern machines may be equipped with reconfigurable blades that may be adapted prior to transportation to reduce their effective width. For instance, some of those blades may fold and or pivot so as to avoid extending beyond the width of the work machine. Some of the older, more basic machines, may not be equipped with reconfigurable blades and thus require the blades to be removed prior to transportation and refitted at the destination, which may be a timely exercise.

Many of those folding blades comprise two interconnected portions that may have relatively complex and expensive constructions. It is an object of the present disclosure at least partially to overcome the problems associated with known blades.

According to the present disclosure, there is provided a blade for a work machine comprising:

a major portion including: a major substrate having opposed inside and outside ends, a rear surface and a cut-out located at the inside end and extending partway along the substrate towards the outside end; and at least one major channel member provided on the rear surface and arranged substantially to overlie the at least one cut-out;

a minor portion including: a minor substrate having opposed inside and outside ends and a rear surface; at least one minor member provided on the minor substrate and extending outwardly beyond the inside end so as to define at least one arm arranged to locate within the at least one major channel member of the major portion; and

coupling means connecting the at least one arm to the at least one major channel member so as to permit relative movement of the minor and major portions between an operational position and a transportation position.

By way of example only, one specific embodiment of the present disclosure will now be described in detail, with reference being made to the accompany drawings, in which:

Figure 1 is a side elevation of a front portion of a work machine equipped with a blade;

Figure 2 is a rear perspective view of the assembled blade in its unfolded position;

Figure 3 is a rear perspective view of the assembled blade in its folded position;

Figure 4 is a front view of a major portion of the blade;

Figure 5 is one end view of the major portion of the blade of

Figure 4; Figure 6 is another end view of the major portion of the blade of Figures 4 and 5;

Figure 7 is a perspective view of part of the major portion showing the slide connector in its locked position;

Figure 8 is a perspective view of the slide connector of Figure 7, here shown in its unlocked position;

Figure 9 is a rear perspective view of a minor portion of the blade;

Figure 10 is an end view of the minor portion of Figure 9;

Figure 11 is a plan view of the work machine showing the blade in an operational position;

Figure 12 is a plan view of the work machine showing the blade in a partial transportation position; and

Figure 13 is a plan view of the work machine showing the blade in a full transportation position.

Figure 1 shows a work machine 10 commonly referred to as a track type tractor or bull dozer. The work machine 10 comprises a chassis 11 supporting an operator's cab 12, an engine compartment 13 in front of the operator's cab 12 and a pair of ground engaging tracks 14 driven by the engine and by which the work machine 10 may be propelled. The work machine 10 may also be furnished with a blade 40 mounted in front of the engine

compartment 13 and supported on the chassis 11. Such work machines 10 are known in the field so no further explanation of those is required here, though the blade 40 and its control gear will be described in more detail below.

At the front of the work machine 10 there may be provided a generally U-shaped frame 16 for supporting the blade 40. The frame 16 may comprise a middle portion 17 provided with a support post 18 and first and second limbs 19 extending rearward from the middle portion 17 and having free ends 20 pivoted to opposed sides of the chassis 11 about a common axis X, referred to hereafter as the lift axis X. Each limb 19 may be provided with a lever 23 upstanding partway along its length and a lifting ram 24 may extend between the free end of each lever 23 and a corresponding side of the chassis 11. The lifting rams may be coupled to the respective levers 23 and the sides of the chassis 11 to permit relative pivoting movement of those parts. Furthermore, the lifting rams 24 may be hydraulically controlled in a unified (or independent) manner so as to cause the frame 16, and thus the blade 40, to lower when the lifting rams extend and rise when the lifting rams retract.

The middle portion 17 of the frame 16 may be provided with a support coupling 25 by which the blade 40 may be supported on the frame 16 and allowed to pivot relative thereto. The support coupling 25 may comprise a pivot connector configured for pivoting movement of the blade 40 about an angle axis Y (see Figure 2) lying substantially normal to the lift axis X and the limbs 19 of the frame 16, which may project forward from the work machine 10. In the illustrated embodiment, the support coupling 25 comprises a spherical bearing, also known as a ball joint, and may include a spherical member (not shown) extending forward of the frame 16 for engagement within a socket (not shown) provided towards the bottom of the blade 40.

First and second extendable arms 31, 32, such as hydraulics rams, may be provided to control pivoting movement of the blade 40 about the angle axis Y. The first extendable arm 31 may have one end coupled to the first limb 19 and the other end coupled to a slide connector 100 provided on the blade 40 and the second extendable arm 32 may have one end coupled to the second limb 19 and the other end coupled to a pivot connector 130 provided on the blade 40. The ends of the extendable arms 31, 32 may be coupled to their respective components by part-spherical bearings (not shown), such as ball joints or rose joints to enable considerable articulation between those components.

The support post 18 may be welded, bolted or otherwise rigidly fastened to the middle portion 17 of the frame 16. The support post 18 may be provided with three forward facing projections 27 spaced one above the other and provided with coaxial apertures (not shown) for accommodating a support pin 28. The top of the support post 18 may be provided with a rigid linkage 29 that may connect to the top of the blade 40 and the length of which may be adjusted to vary the pitch of the blade 40.

A tilt actuator 34, such as a hydraulic ram may be configured to control pivoting movement of the blade about a tilt axis Z Fig. 2) lying substantially normal to the lift axis X and the angle axis Y. The tilt actuator may have one end pivotally connected to the support pin 28 and another end pivotally connected to a tilt connector 140 provided on the blade 40. These linkages will be described in more detail below with reference to the various features of the blade.

The blade 40 may be generally rectangular and may comprise a major portion 50 and a minor portion 150 which may be pivotally interconnected to allow the blade 40 to be arranged in an unfolded position (Fig 2) or a folded position (Fig 3).

Referring now to Figures 2 to 6, the major portion 50 may comprise a major substrate in the form of a curved sheet 51 of steel or other suitable material defining the front face 52 and a rear face 53. Top, middle and bottom reinforcement members 54, 55, 56 may be mounted to the rear surface 53 of the curved sheet 51 and which may include a generally rectangular base 54A, 55A, 56A and upper and lower limbs 54B, 54C, 55B, 55C, 56B, 56C extending forward of the base to attach to the rear face 53. The bases 54A, 55 A, 56A may all lie substantially on the same plane and the limbs 54B, 54C, 55B, 55C, 56B, 56C therefore may be of different depths so as to meet the curved rear face 53 of the curved sheet 51. The middle reinforcement member 55 may be disposed approximately midway between the upper and lower edges 57, 58 of the curved sheet 51 and may extend from an outside end 59 of the major portion 50 to an inside end 60 of the major portion 50.

The bottom reinforcement member 56 may be disposed towards the lower edge 58 of the curved sheet 51 and extend from the outside end 59 to a point approximately three-quarters of the way along the rear face 53. The lower limb 56C of this reinforcement member may be angled downwardly from the base 56A so as to define a sloping lower face 44 of the blade 40. The end of the lower reinforcement member 56 lying on the three-quarter line 62 (Fig. 2) may be capped by a lower flange 63 extending rearwardly from the rear face 53 of the curved sheet 51. A bottom channel member 65 having a slightly larger cross- section than the bottom reinforcement member 56 may extend between the other side of the lower flange 63 and the inside end 60 of the curved plate 51.

The top reinforcement member 54 may be disposed near the upper edge 57 of the curved plate 51 and, similar to the bottom reinforcement member 56, it too may extend between the outside end 59 and the three quarter line 62 where it may be capped by an upper flange 66. A top channel member 67 may be aligned with the top reinforcement member 54 and arranged to extend between the inside end 60 of the curved sheet 51 and the upper flange 66. The top reinforcement member 54 may be formed from two sections and a pitch control assembly 69 may be disposed on the rear face 53 of the main portion 50, between those sections. The pitch control assembly 69 may be disposed at a location on the major portion 50 that is substantially midway along the entire blade 40 when in its unfolded position (Fig. 2). Furthermore, the pitch control assembly 69 may include a housing 70 comprising opposed side walls 72 upstanding from the upper limb 55B of the middle reinforcement member 55, a cover 71 supported on the side walls 72 and two brackets 73 extending between the side walls and carrying a connection pin 74. The pin 74 may be adapted to connect to the rigid linkage 29 (Fig. 1) to control the pitch of the blade 40.

The top and bottom channel members 67, 65 may be very similar in that they may have many common features and may both be of a similar size. An opening 76 may be provided on the base 67A, 65 A of each channel member 67, 65 at the end adjacent the respective flange 66, 63 and each opening 76 may be substantially square with dimensions at least as wide as the bases 67A, 65 A. Towards the other end of each base 67A, 65 A, adjacent the inside end 60 of the curved sheet 51 , there may be provided an elongate aperture 77 flanked by upper and lower retaining flanges 78. The upper and lower retaining flanges 78 may be substantially triangular and may include coaxial apertures (not shown) adapted to receive a retaining pin 79.

The upper and lower limbs 67B, 67C, 65B, 65C of the top and bottom channel members 67, 65 may also be provided with coaxial bores (not shown) for receiving a pivot pin 81. The bores may be located at the end of the limbs 67B, 67C, 65B, 65C adjacent the upper and lower flanges 66, 63 such that the pivot pins are accessible through their respective openings 76. Each pivot pin 81 may be generally cylindrical and may have an annular recess (not shown) at one of its ends such that the annular recess of the upper pivot pin 81 may locate just above the upper limb 67B of the top channel member 67 and the annular recess of the lower pivot pin 81 may locate just below the lower limb 65C of the bottom channel member 65. The pivot pins 81 may be provided with a retaining clip 82 that may be fastened to an associated limb 67B, 65C and may locate within the associated annular recess. In the illustrated embodiment, each retaining clip 82 is substantially flat and generally pear shaped, such that the small end includes an aperture for receiving a fastener by which it may be secured to the limb and the large end may be open so that it may locate within the annular recess of the pin 81. The inter-engagement of the large end and the annular recess may prevent relative axial movement of the pivot pin 81 and its respective channel member 67, 65.

The outside end 59 of the major portion 50 may be capped by an outside plate 85 and the inside end 60 of the major portion 50 may be capped by inside plates 86 which may be arranged not to enclose the ends of the top and bottom channel members 67, 65. Furthermore, the curved sheet 51 may include substantially parallel upper and lower cut-outs 87 arranged in registration with respective channels 84 defined by the limbs 67B, 67C, 65B, 65C of the top and bottom channel members 67, 65. The spaces between any two adjacent reinforcement members 54, 55, 56 and channel members 65, 67 may be enclosed by elongate panels 88 lying substantially in the same plane as the bases 54A, 55 A, 56 A, 65 A, 67 A. This way, the bases and the elongate panels 88 may collectively define a rear surface 89 of the major portion 50 to which various connectors 100, 130, 140 may be mounted.

A socket housing 90 of the support coupling 25 may be provided towards the bottom of the rear surface 89 of the major portion 50, directly below the pitch control assembly 69, so as to be located midway along the unfolded blade 40. The housing 90 may comprise a base 91 welded or otherwise secured to the rear surface 89, an annular wall 92 extending rearward form the base 91 to define a cavity (not shown) and an annular cap 93 partially enclosing the cavity. The annular cap may be removably mounted to the cylindrical wall 92 and secured in place by bolts 94 or other suitable fasteners. The cavity and the annular cap 93 may define a socket (not shown) configured to receive a part- spherical member (not shown) provided on the middle portion 17 of the frame 16. The socket and the part-spherical member may define a ball joint for connecting the blade 40 to the work machine 10, the ball joint bearing a large proportion of the blade's weight while permitting relative articulation of the blade 40 and the work machine 10.

Between the top and bottom channel members 67, 65 there may be provided the slide connector 100 for mounting the blade 40 to the first extendable arm 31 extending forward from the frame 16. Referring particularly to Figures 7 and 8, the slide connector 100 may comprise a base 101 secured to the rear surface 89 of the major portion 50 and a pair of slide flanges 102 provided on the base 101, one above the other. Bores (not shown) sharing a common axis may be formed through the slide flanges 102 for receiving a slide pin 103. The slide pin 103 may be similar to the pivot pin 81 noted above insofar as it may include an annular recess (not shown) near its upper end 104 for receiving legs 105 of a retaining clip 106 that may rest on and be fastened to the upper sliding flange 102. Alternatively, the slide flanges 102 and slide pin 103 may be cast or otherwise formed as a single unit or separate parts welded together. The base 101 may also include slide locking means, possibly in the form of a locking slide flange 108 having a bore 109 extending therethrough. The bore 109 may have an axis lying substantially parallel to the axis of the slide pin 103.

The slide connector 100 may also comprise a carrier 110 arranged to slide relative to the base 101 between locked (Fig. 7) and unlocked (Fig. 8) positions and which may be adapted slidably to locate between the upper and lower slide flanges 102. For instance, the carrier 110 may comprise a pair of generally flat members 111 arranged one above the other and spaced apart by extendable arm connection means. The carrier 110 may be machined, cast or otherwise formed as a single unit, or may alternatively comprise an assembly of several components. In the present example, the arm connection means may comprise an extendable arm connection pin 112 arranged to extend through coaxial bores (not shown) defined in the upper and lower members 111. For instance, the extendable arm connection pin 112 may include a central portion and diametrically smaller end portions 113 defining upper and lower shoulders (not shown) against which the upper and lower members 111 may respectively bear to be maintained a set distance apart. The diametrically smaller end portions

113 may each include an annular recess (not shown) for receiving a retaining clip

114 that may be fastened to a respective member 111 in the same manner as those retaining clips described above.

The extendable arm connection pin 112 may be arranged to locate in an eye (not shown) defined on the end 115 of the first extendable arm 31 so as to enable relative pivoting movement between those parts. In the present arrangement, the extendable arm connection pin 112 is furnished with a collar (not shown) having a convex circumferential face so as to define a part-spherical member for connection with a part spherical socket provided in the end 115 of the first extendable arm 31. As such, the slide connector 100 and the first extendable arm 31 may be connected by way of a spherical bearing, such as a ball joint or a rose joint.

At one side of the extendable arm connection pin 112, the members 111 of the carrier 110 may be provided with opposed elongate openings 117 through which the slide pin 103 may locate. In this manner, relative translational movement of the carrier 110 and base 101 may cause the slide pin to move between a locked position (Fig. 7) whereat the slide pin may locate at the right end of the elongate openings 117 and an unlocked position (Fig. 8) whereat the slide pin 103 may be displaced from the right end, and may possibly locate at the left end of the elongate opening 117. At the other side of the extendable arm connection pin 112, the carrier 110 may be provided with locking slide apertures 118, which may align with the locking slide bore 109 in the locking slide flange 108 when the carrier 110 is in its locked position. The carrier 110 may be secured in its locked position by a locking slide pin 119 inserted through the locking slide apertures 118 and locking slide bore 109, and fastened in place by a retaining clip 120.

Referring again to Figure 3, on the other side of the major portion 50 there may be provided a pivot connector 130 for securing the second extendable arm 32 (Fig 1) to the blade 40. This pivot connector 130 may comprise a pivot base 131 welded or otherwise secured to the rear face 89, a pair of pivot flanges 132 extending rearward from the pivot base 131 and a pivot pin 133 extending through apertures (not shown) in those pivot flanges 132. The pivot pin 133 may be located at a similar height to the extendable arm connection pin 112 of the carrier 110 and have an axis substantially parallel to the axis of that extendable arm connection pin 112. Similarly, the pivot pin 133 may be configured to receive a collar (not shown) having a convex circumferential face so as to define a part-spherical member for cooperation with a part-spherical socket (not shown) provided on the second extendable arm 132, so as to form a ball joint or a rose joint.

The pivot base 131 may also be provided with a tilt connector 140 for coupling the blade 40 to the tilt actuator 34 (Fig. 1). The tilt connector 140 may be located above the pivot flanges 132 of the pivot connector 130 and may comprise upper and lower tilt flanges 141 that may define tilt apertures (not shown) for receiving a tilt pin 142 that may be secured in position by a retaining clip (not shown), similar to those described above.

Turning now to the minor portion 150 of the blade 40, best shown in Figures 9 and 10, this may have a similar construction to the major portion 50 described above insofar as it may comprise a curved minor front sheet 151 having a rear surface 152 to which there may be mounted top, middle and bottom laterally spaced channel members 154, 155, 156. Again, those channel members may have bases 154A, 155 A, 156A lying substantially in a common plane and limbs 154B, 154C, 155B, 155C, 156B, 156C of different lengths having ends welded or otherwise secured to the rear surface 152 of the minor front sheet 151. The channel members 154, 155, 156 may be arranged on the rear surface 152 so as to extend between the outside end 158 of the minor portion 150 and the inside end 159 of the minor portion 150.

In the illustrated embodiment, the top and bottom channel members 154, 156 are significantly longer than the middle channel member 155 and may therefore extend beyond the inside end 159 so as to define top and bottom arms 160, 161 that may attach to the major portion 50 of the blade 40. The top and bottom arms 160, 161 may have substantially the same cross-section as the reinforcement members 54, 56 of the major portion 50 and may further include arm pivot apertures 163 at their free ends, those pivot apertures possibly having a common axis possibly extending perpendicular to the length of the arms 160, 161. In this way, the upper and lower arms 160, 161 may locate within the top and bottom channel members 67, 65 such that the arm pivot pins 81 may extend through the pivot apertures 63 in the secondary channel members 67, 65 and the arms 160, 161, so as to allow relative pivoting movement of the minor portion 150 and the major portion 50 about the common axis of the pivot pins 81.

The illustrated arrangement is provided with a lubrication system for improving the lubricity of the arms 160, 161 and the channel members 67, 65. In particular, a tubular member 165 may locate through the pivot aperture 163 in each arm 160,161 and may define a cylindrical bore 166 sized to receive the respective pivot pin 81 extending through an associated channel member 67, 65. Each tubular member 165 may be welded or otherwise fixed to its respective arm 160, 161 and provided with a lubricant port 167, such as a radial drilling through which grease may be delivered to the cylindrical bore 166. Each grease port 167 may be located close to the free end of its arm 160, 161 so as to be easily accessible when the blade 40 is arranged in its folded position and the end of the arm 160, 161 is revealed through the opening 76, as shown in Figures 7 and 8.

The rear face of the base of each arm 160, 161 may be provided with an arm retainer flange 168 provided with an arm retainer bore 169. Each arm retainer flange 168 may be positioned at the end of the arm proximal to the minor portion 150 and may be sized to locate through respective elongate apertures 77 defined in the bases 67A, 65 A of the top and bottom channel members 67, 65, when the blade 40 is in its unfolded position (Fig. 2). The blade may be retained in its unfolded position by locating the retaining pins 79 through the retainer bores 169 so as to inhibit relative movement between the minor and major portions 150, 50.

The ends of the limbs 154B, 154C, 156B, 156C define openings in the front of the arms 160, 161 which may be provided with fascias 170 made of material similar to that of the minor and major curved sheets 151, 51 and sized to form a close fit within the cut-outs 87 when the blade 40 is in its unfolded position. Panels 173 may also be provided between the bases 154A, 155 A, 156A of the top, middle and bottom channel members 154, 155, 156 so as to align with corresponding elongate panels 88 provided on the major portion 50. End caps 174, 175 may be provided to enclose the inside end 159 and outside end 158, respectively. The end cap 174 at the inside end 159 may be angled relative to the rear surface so as to complement the angled inside plate 86 of the inside end 60 of the major portion 50.

Industrial Application

The tilt actuator 34, lifting rams 24, and extendable arms 31, 32 may be connected to a hydraulic circuit (not shown) including a hydraulic pump and various valves. The valves may be electrically or hydraulically controlled by joy sticks, switches or other suitable instrumentation provided in the operator's cab 12. In use, the operator may control the instrumentation to adjust the valves' positions, which in turn may cause the tilt actuator 34, lifting rams 24 or extendable arms 31, 32 to retract or to extend, thereby manipulating the position of the blade 40 according to the requirements of the task being performed. More specifically, the blade 40 may be tilted about the Z axis, angled about the Y axis or lifted and pitched about the X axis.

So as to comply with transportation regulations, the blade 40 shown in Figure 11 may be reconfigured prior to transportation to ensure its outside ends 59, 158 do not extend beyond the width of the ground engaging tracks 14 and thus increase the overall width of the work machine 10. The first step of this reconfiguration process is to arrange the blade 40 in its folded position, as shown in Figures 3 and 12. This may be achieved by first removing the retaining pins 79 from the bores in the arm retaining flanges 168 and the channel member retaining flanges 78. The minor portion 150 may then swing forward of the major portion 50 as the arms 160, 161 pivot about their pivot pins 81 and emerge from their cut-outs 87. This latter process can be effected manually or by titling the blade 40 about the Z axis so as to raise the minor portion and then rapidly angling and tilting the blade 40 about the Y and Z axes so as to cause the minor portion 150 to lower and move forward. The momentum of the minor portion 150 may cause it to swing forward as the tilting and angling movement of the blade 40 is suddenly stopped. The blade 40 may be secured in its folded position by a retaining strut (not shown) arranged for one end to attach to the arm retaining flange 168 on the upper arm 160 and the other end to extend through the elongate aperture 77 in the top secondary channel member and locate between the two retaining flanges 78.

The next step may then be to remove the locking slide pin 119 from the slide connector 100 such that the carrier 110 is secured to the blade 40 solely by the slide pin 103. The first extendable arm may then be retracted and the second extendable arm may be extended so as to cause the blade to pivot counter-clockwise about the Y axis. Once the first extendable arm 31 is fully retracted the blade 40 assumes the position shown in Fig. 12. To complete the reconfiguration process, the second extendable arm may be further extended so as to cause the blade 40 to pivot further about the Y-axis in the counterclockwise direction. As the portion of the blade 40 furnished with the slide connector 100 moves further towards the work machine 10, it urges the carrier 110 and thus the first extendable arm 31 towards the support post 18, thereby causing the slide pin 103 to ride along the elongate aperture 117 as the slide connector 100 moves between its locked and unlocked positions, as shown in Fig. 13.

Although the preferred embodiments of this invention have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.

Claims

1. A blade for a work machine comprising:

2. A blade as claimed in claim 1, wherein the at least one minor member comprises at least one minor channel member having a base and two limbs with free edges mounted to the rear face of the minor substrate.

3. A blade as claimed in claim 1 or claim 2, wherein the at least one arm is generally tubular.

4. A blade as claimed in claim 3 when dependent on claim 2, wherein a front panel is mounted to the free edges of a portion of the at least one minor channel member defining the at least one arm, said front panel being sized to locate within the at least one cut-out when the blade is in its unfolded position.

5. A blade as claimed in any preceding claim, wherein the coupling means include a pivot pin extending through coaxial apertures in the at least one major channel member and in the at least one arm so as to permit relative pivoting movement of the at least one major channel member and the at least one arm about the axis of the pivot pin.

6. A blade as claimed in claim 5, wherein the coupling means include a lubricant reservoir provided on the at least one arm, the apertures in the at least one arm through which the pivot pin locates being defined by openings in the lubricant reservoir.

7. A blade as claimed in claim 6, wherein the lubricant reservoir includes a tubular member extending through the at least one arm near or at the end thereof, the tubular member having a tubular bore defining the openings in the lubricant reservoir.

8. A blade as claimed in claim 6 or claim 7, wherein the lubricant reservoir includes a port through which lubricant may be delivered to the lubricant reservoir.

9. A blade as claimed in claim 8, wherein the port is arranged on the lubricant reservoir so as to be accessible through an open end of the at least one arm.

10. A blade as claimed in any preceding claim, wherein the at least one major channel member includes a base and two limbs extending from the base, each limb having a free edge mounted to the rear face of the major substrate.

11. A blade as claimed in claim 10, wherein an opening is defined in the base of the at least one major channel member and located at or near the end thereof so as to align at least partially with an end of the at least one arm when the blade is in its transportation position.

12. A blade as claimed in any preceding claim, and further comprising upper and lower major channel members and upper and lower minor members, the upper and lower major channel members being spaced laterally apart and the upper and lower minor members defining upper and lower arms arranged at least partially to locate within the upper and lower major channel members.

13. A blade as claimed in claim 12, wherein a major rear panel locates between any two adjacent major channel members so as to define, in combination with the major channel members, a rear surface to which work machine couplings may be mounted.

14. A blade as claimed in any preceding claim, wherein at least one reinforcement member is mounted to the rear face of the major and minor substrate.

15. A blade as claimed in claim 14, wherein the at least one reinforcement member aligns with the at least one major channel member and extends between the outside end of the major substrate and an end of said at least one major channel member.