WO2019000032A1

WO2019000032A1 - Method and tooling to facilitate maintenance of a machine

Info

Publication number: WO2019000032A1
Application number: PCT/AU2018/050648
Authority: WO
Inventors: Alex Cooper
Original assignee: NRW Holdings
Priority date: 2017-06-27
Filing date: 2018-06-26
Publication date: 2019-01-03

Abstract

A method of facilitating maintenance or service of a machine (10) such as a front-end loader having a boom (12) and an implement (14) such as a bucket. The bucket is pivotally coupled to the boom (12) and to one or more links (18a, 18b). A cylinder (20) is pivotally connected at one end to a support structure (22) on the machine (10) and coupled at an opposite end to one of the links (18a, 18b). The method involves locating mechanical devices (30, 32, 34) between the cylinder (20) and the boom (12), and between the one or more links (18a, 18b) and the boom (12). The mechanical devices (30, 32, 34) are arranged to prevent uncontrolled movement of the cylinder (20) and the one or more links (18a, 18b) relative to the boom (12).

Description

METHOD AND TOOLING TO FACILITATE MAINTENANCE OF A MACHINE

TECHNICAL FIELD

A method and tooling are disclosed to facilitate the maintenance of a machine having one or more hydraulic or pneumatic cylinders for operating or positioning an implement. The method and tooling may for example be applicable to a machine in the form of a tractor such as a front end loader (FEL) for maintenance of a hydraulic cylinder used for tilting a bucket connected to a boom by one or more links.

BACKGROUND ART

Many machines use hydraulic, pneumatic, or hydro pneumatic cylinders (hereinafter referred to in general as "cylinder" in the singular or "cylinders" in the plural) to move and manipulate implements such as buckets, rippers, press plates etc. The implements are typically pivotally connected to a boom enabling the implement to tilt about a tilt axis. One or more links or linkages (hereafter referred to in general as "link" in the singular or "links" in the plural) are also pivotally connected to the implement and the boom. At least one cylinder is connected between the links and a support structure of the machine. For example, a front end loader may be configured so that a barrel of a cylinder is pivotally connected at its blind end to the support structure while a free end of an associated piston rod is attached to one or more links. Respective pivot pins attach of the cylinder to the support structure and the links. For the purpose of maintenance and/or service it is necessary from time to time to remove at least the pivot pin connected to the links. The hydraulic cylinder is very heavy, often in excess of 1 000 kg, and for safety reasons is supported by a crane or other similar lifting device during removal of the pivot pin. This requires the expertise and associated cost of a rigger.

The above description of the background art is not intended to limit the application of the method and tooling disclosed herein.

SUMMARY OF THE DISCLOSURE

In one aspect there is disclosed a method of facilitating maintenance or service of a machine having a boom and an implement, where the implement is pivotally coupled to the boom and to one or more links, and a cylinder is pivotally coupled at one end to a support structure on the machine and pivotally coupled at an opposite end to one of the links, the method comprising : locating a plurality of mechanical devices between: the cylinder and the boom; and, between the one or more links and the boom, wherein the mechanical devices are arranged to prevent uncontrolled movement of the cylinder and the one or more links relative to the boom. I n this way and assuming that the implement is resting on the ground or another support and there is no stored energy, the cylinder and the links are restrained from uncontrolled and thus an expected movement during maintenance or service associated with the cylinder. ln one embodiment locating the mechanical devices comprises:

coupling a first mechanical arrangement between the cylinder and the boom to prevent pivoting of the cylinder about the one end toward the boom; and

mechanically restraining the one or more links against uncontrolled motion.

In one embodiment coupling the first mechanical arrangement comprises locating the first mechanical arrangement between the cylinder and the boom and subsequently adjusting the length of the first mechanical arrangement to contact the cylinder and the boom.

In one embodiment coupling first mechanical arrangement comprises mechanically attaching first mechanical arrangement to one of the boom and the cylinder and adjusting the length of the first mechanical arrangement to contact the other of the boom and the cylinder. In one embodiment mechanically restraining the one or more links comprises coupling a second mechanical arrangement between the boom and a first set of one or more links.

In one embodiment the method comprises locating the second mechanical arrangement between the boom and the first set of one or more links and subsequently adjusting the length of the second mechanical arrangement to contact the boom and the first set of one or more links.

In one embodiment the method comprises mechanically attaching second mechanical arrangement to one of the boom and the first set of one or more links and adjusting the length of the second mechanical arrangement to contact the other of the boom and first set of one or links.

In one embodiment mechanically restraining the one or more links comprises coupling a third mechanical arrangement between a second set of one or more links and the boom.

In one embodiment coupling the third mechanical arrangement comprises mechanically attaching respective attachment members to the boom and the second set of one or more links and connecting opposite ends of a binder to the members. In a second aspect there is disclosed a tooling system for facilitating maintenance or service of a machine having a boom and an implement which is pivotally coupled to the boom and to one or more links and a cylinder pivotally connected at one end to the support structure on the machine and coupled at an opposite end to one of the links, the system comprising: a first mechanical arrangement having a length adjustable first strut arranged for coupling at one end to the boom; and

a first cradle arranged for coupling to an opposite end of the first strut and configured to seat the cylinder. In one embodiment the tooling system comprises a second mechanical arrangement having a length adjustable second strut arranged for coupling at one end to the boom; and a second cradle arranged for coupling to an opposite end of the second strut and configured to engage a first set of one or more of the links. ln one embodiment the tooling system comprises a third mechanical arrangement comprising one or more binders arranged to connect between the second set of the one or more links and the boom.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the method and tooling as set forth in the Summary, specific embodiments will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a photograph of a machine in the form of a wheel loader in relation to which embodiments of the disclosed method and tooling may be used, the wheel loader having implement in the form of a bucket pivotally connected to an end of the boom, a number of links pivotally connected between the bucket and the boom and a hydraulic cylinder for tilting the bucket;

Figure 2 is a schematic representation embodiment of the disclosed method and tooling as applied to of a portion of the wheel loader of configuration similar to that of Figure 1 ;

Figure 3a is an isometric view of an embodiment of a first strut of the disclosed tooling; Figure 3b is a front view of the strut shown in Fig 3a; Figure 4a is an isometric view of a mount may be utilised in the disclosed tooling; Figure 4b is a side view of the amount shown in Figure 4a;

Figure 5a is an isometric view of one form of cradle may be utilised in the disclosed tooling;

Figure 5b is a side view of the cradle shown in Figure 5a; Figure 6a is an isometric view of a second strut of the disclosed tooling; Figure 6b is a front view of the strut shown in Figure 6a;

Figure 7a is an isometric view of a base plate incorporated in the tooling; Figure 7b is a first section view of the base plate shown Figure 7a;

Figure 7c is a second section view of the base plate shown Figure 7a;

Figure 8a is an isometric view of a second form of cradle that may be utilised in the disclosed tooling;

Figure 8b is a front view of the cradle shown in Figure 8a; Figure 9 is a photographic representation of a pair of binders which may be utilised in the disclosed tooling ;

Figure 10a is an isometric view of one possible form of a binder block which may be utilised in the disclosed tooling;

Figure 10b is an isometric view of another possible form of a binder block which may be utilised in the disclosed tooling; Figure 1 1 a is photographic representation of the first strut in use between the cylinder of the front end loader shown in Figure 1 ;

Figure 1 1 b is a photographic representation of the second strut in use between the boom and a set of links of the of the front end loader shown in Figure 1 ;

Figure 1 1 c is a photographic representation of the binders in use between another set of links and the boom of the of the front end loader shown in Figure 1 ; and

Figure 1 1 d photographic representation of the disclosed method and tooling applied to the front wheel loader shown in Figure 1

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Figure 1 shows a machine in the form of a front wheel loader (FEL)10 in relation to which embodiments of disclosed method tooling may be used . The FEL 1 0 has a boom 12 which can be used to raise and lower and implement which in this instance is in the form of a bucket 14. The bucket 14 is pivotally connected to one end of the boom 12 to enable it to tilt about a tilt axis 16. Links 18a and 18b (hereafter for it in general as "links 18") also connect the bucket 14 to the boom 12. The links 18a are connected at one end to the bucket 14 and at opposite end to the links 18b. The links 18b are pivotal connected at their opposite ends to the boom 12. A cylinder 20, in this instance being a hydraulic tilt cylinder, is pivotally coupled at one end to a support structure 22 of the FEL 1 0 and at opposite end to the links 18. More specifically a barrel 24 of the tilt cylinder 20 is pivotally coupled to the support structure 22 while a free end of a piston rod 26 of the tilt cylinder 20 is pivotally coupled by a pivot pin 28 to the links 18.

Embodiments of the disclosed method involved restraining the tilt cylinder 20 and the links 18 from uncontrolled movement while at least the pin 28 is removed . In broad terms this involves locating mechanical devices between the cylinder and the boom 12; and, between the one or more links 18 and the boom 12 thereby preventing uncontrolled movement of the cylinder 20 and the one or more links 18 relative to the boom 12.

With particular reference to Figure 2 the mechanical devices include: · a first mechanical arrangement 30 which is located between the cylinder 20 and the boom 12;

• a second mechanical arrangement 32 located between the links 18a and the boom 12; and • a third mechanical arrangement 34 located between the links 18b and the boom 12.

Each of the mechanical arrangements 30, 32 and 34 is adjustable to enable them to be located in their respective positions. Mechanical arrangements 30 and 32 can then be adjusted in length to contact the boom 12 and the cylinder 20; and the boom12 and the links 18a, respectively. In doing so the mechanical arrangements 30 and 32 are under respective compressive loads. The mechanical arrangement 34 is also adjustable in length after being located between, and connected to, the boom 12 and the links 18b. The length adjustment of the mechanical arrangement 34 involves a shortening of its length placing it in tension.

The first mechanical arrangement 30 comprises a length adjustable strut 40 (Fig 3b), a mount 42 (Figs 4a, 4b) and a cylinder cradle 44 (Figs 5a, 5b). Strut 40 is in the general form of a screw jack having an outer tubular body 46 and an inner threaded stem 48. A screw ring 50 threads onto the stem 48 and rests on top of the body 46. The overall length of the strut 40 can be adjusted by turning the screw ring 50 in one direction to extend the stem 48 from the body 46, and in an opposite direction to retract the stem 48 into the body 46.

The mount 42 has two plates 52 and 54 which are in a generally face-to-face relationship and spaced by an intervening post 56. The post 56 is configured so that the plates 52 and 54 are in this instance angled relative to each other rather than being parallel. A number of holes 58 are formed in the plate 54. When in use the plate 52 of the mount 42 is welded onto the boom 12. A lower end of the body 46 of the strut 40 can then be bolted onto the plate 54 through the holes 58. The post 56 angles the plates 52 and 54 relative to each other so that when secured to the mount 42 a central axis of the strut 40 is substantially perpendicular to the longitudinal axis of the cylinder 20.

The cradle 44 has a curved plate 60 of the radius substantially equal to an outer radius of the cylinder barrel 24. The curved plate 60 is supported on a web 62 and an underlying base plate 64. The base plate 64 is provided with a plurality of holes 66. The holes 66 facilitate bolting of the cradle 44 to the stem 48 of the strut 40.

With particular reference to Figures 6a-8b, the second mechanical arrangement 32 comprises a length adjustable strut 70, a base plate 80, and a link cradle 90. The strut 70 is in the same form as a strut 40 only differing in overall length and the inclusion of handles 72. Strut 70 is in the general form of a screw jack having an outer tubular body 74 and an inner threaded stem 76. A screw ring 78 rests on top of the body 74. The overall length of the strut 70 can be adjusted by turning the screw ring 78 in opposite directions in order to retract the stem 76 into the body 74 or extend the stem 76 from the body 74. Base plate 80 is in the form of a rectangular plate which is bent along opposite longitudinal edges so as to have a channel like profile. Short rectangular plates 82 are welded on the inside of the base plate 80 at opposite ends. A hole 84 at each end of the base plate 80 passes through the respective plates 82. Four mounting holes 86 are also formed through the base plate 80 to facilitate attaching the strut 70. Respective nuts 88 are welded to the inside of the plate 80 in alignment with respect to holes 86 for threadingly engaging bolts used to attach the strut 72 the base plate 80. The cradle 90 has a transverse beam 92 mounted on a plate 94. The beam 92 is formed with opposite end blocks 96 that extend upwardly from an upper surface 98 of the beam 92. Locating posts 100 are attached to and extend from the upper surface 98. When the mechanical arrangement 32 is in use the links 18a lie between respective adjacent end blocks 96 and posts 100.

Figure 9 illustrates two of the third mechanical arrangements 34. Each mechanical arrangement 34 includes a binder 108. Each binder 108 comprises a central internally threaded sleeve 1 10 and respective bolts 1 12 threadingly engaged at each end of the sleeve 1 10. Each bolt 1 12 terminates in an eye 1 14. A ratchet 1 16 with a handle 118 is attached to the sleeve 1 10. The eyes 1 14 enable the binders 108 to be connected between the links 18b and the boom 12. This is facilitated by the use of various binder blocks or binder buttons which are welded to the boom 12 and links 18b. One form of binder block 120 is shown in Figure 10a and comprises a block of material 122 formed with a through hole 124. Bearings 126 are attached to the block 122 on opposite sides of the hole 124 on one face of the block 120. The binder block 120 shown in Figure 10a is for use on a left-hand side of the boom 12. A mirror image binder block (not shown) is provided for use on the right-hand side of the boom 12. A binder button 128 shown in Figure 10b. The binder button 128 formed with a through hole 130 and bearings 132 on opposite sides on one face of the button 128. The button 128 is attached on the inside of each of the links 18b.

With particular reference to Figures 1 and 1 1 a-1 1 d a method of facilitating maintenance of the FEL 10 and in particular replacing the tilt cylinder 20 can be summarised as comprising the following steps:

• The FEL 10 is isolated, tagged out, has wheel chocks installed and is parked on flat ground with the bucket 14 flat on the ground.

• The plate 52 of the mount 42 is welded on the boom 12 in alignment with the cylinder 20 (Fig 1 1 a).

• The base plate 80 is fixed to the boom 12 at a location between the bucket 14 and the links 18b (Fig 11 b). · Binder blocks 120 are welded on opposite sides of the boom 12 and binder buttons 128 are welded on the inside of the links 18b (Fig 1 1 c).

• The strut 40 (Fig 1 1 a) which forms part of the first mechanical arrangement 30 is

bolted to the mount 42 with its stem 48 screwed in so that the strut 40 has a minimal length.

• The cradle 44 (Fig 1 1 a) is bolted to the stem 48 and the screw ring 50 is now turned to extend the stem 48 outwardly so that the cradle 44 contacts the barrel 24 of the cylinder 20. • The strut 70 (Fig 1 1 b) of the second mechanical arrangement 32 is now attached to the base plate 80 with the stem 76 screwed in so that the straight 70 has a minimal length. · The cradle 90 is bolted to the stem 76 and the screw ring 78 turned to the cradle 90 contacts the overlying links 18a. As shown in Figure 1 1 b each link 1 8a is located between an end stop 96 and a post 1 00 of the cradle 90.

• The length of the binders 108 (Fig 1 1 c) of the third mechanical arrangement 34 was adjusted by appropriate screwing of the rods 1 12 so that the respective eyes 1 14 can register with the holes 124 and 1 30 of the binder blocks 120 and binder buttons 128 respectively.

• Respective bolts are now used to bolt the eyes 1 14 to the binder blocks 120 and binder buttons 128.

• The binders 108 are tensioned using the ratchet 1 10.

As result of implementation of the above method the cylinder 20 and the links 18 are now restrained from uncontrolled movement. Service or maintenance of the cylinder 20 can commence by removing the pin 28. Removal of the pin 28 allows the piston rod to be retracted into the cylinder barrel 24 without the possibility of the tilt cylinder 20 pivoting toward the boom 12 about the connection to the support structure 22. The links 18b are unable to pivot in either direction about the connection to the boom 12 due to the operation of the third mechanical arrangement 34/binders 108. The links 1 8a are restrained from pivoting/falling toward the boom 12 about the connection to the bucket 14 due to the second mechanical arrangement 32. This removes a significant safety hazard should a worker have part of the body located between the boom 12 and the links 1 8a. Each of the first second and third mechanical arrangements 30, 32 and 34 may be considered as constituting tooling or a tooling system for facilitating the maintenance or service of a machine such as the described FEL 10.

The tooling holds the various mechanical structures in place and allows for the controlled movement of the cylinder only while disassembling the FEL with the support of overhead crane / crane. This can be performed by a single person eliminating the need to have support equipment and requiring multiple people. Embodiments of tooling eliminate uncontrolled movement reducing / eliminating the risk of harm to a worker. Embodiments of the tooling also reduce the machine down time due to simplifying the disassembly/assembly process as recommended. The tooling allows the repairs to be task/ area specific and not having to remove the whole assembly as recommended in the manufacturers or service manuals. Whilst a specific embodiment has been described, it should be appreciated that the method and tooling system may be embodied in many other forms. For example, the method may be applied to different forms of machines other than a tractor or the FEL 1 0 in particular machines having a different arrangement or number of links 18 and cylinders 20. In that event the tooling system may include only one or two of the mechanical arrangements 30, 32 and 34, or indeed a plurality of any one of the mechanical arrangements 30, 32 and 34. Also, the specific configuration of various components of the tooling system and mechanical arrangements may differ depending on the geometry and configuration of the machine to which they are applied . For example, the angle of the plates 52 and 54 of the mount 42 is determined by the geometry of the machine so that the strut 40 when mounted on the mounting plate 42 has a longitudinal axis which is substantially perpendicular to the axis of the cylinder 20 when the bucket 14 is on the ground . This angle can change for machines of different size or consideration. Similarly, the specific configuration of the cradles 60 and 90 is dependent on that of the cylinder 20 and the links 18a. Embodiments of the disclosed method and tooling system may be applied to machines other than a front-end loader, and in relation to cylinders other than a hydraulic tilt cylinder, such as a pneumatic cylinder or a hydro-pneumatic cylinder.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" and variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features of the container as disclosed herein .

Claims

A method of facilitating maintenance or service of a machine having a boom and an implement where the implement is pivotally coupled to the boom and to one or more links, and a cylinder is pivotally connected at one end to a support structure on the machine and coupled at an opposite end to one of the links, the method comprising: locating mechanical devices between the cylinder and the boom, and between the one or more links and the boom wherein the mechanical devices are arranged to prevent uncontrolled movement of the cylinder and the one or more links relative to the boom.

The method according to claim 1 wherein locating the mechanical devices comprises: coupling a first mechanical arrangement between the cylinder and the boom to prevent pivoting of the cylinder about the one end toward the boom; and

mechanically restraining the one or more links against uncontrolled motion.

The method according to claim 2 wherein coupling the first mechanical arrangement comprises locating the first mechanical arrangement between the cylinder and the boom and subsequently adjusting the length of the first mechanical arrangement to contact the cylinder and the boom.

The method according to claim 3 wherein coupling first mechanical arrangement comprises mechanically attaching first mechanical arrangement to one of the boom and the cylinder and adjusting the length of the first mechanical arrangement to contact the other of the boom and the cylinder.

The method according to any one of claims 2-4 wherein mechanically restraining the one or more links comprises coupling a second mechanical arrangement between the boom and a first set of one or more links.

The method according to claim 5 comprising locating the second mechanical arrangement between the boom and the first set of one or more links and

subsequently adjusting the length of the second mechanical arrangement to contact the boom and the first set of one or more links.

The method according to claim 6 comprising mechanically attaching second mechanical arrangement to one of the boom and the first set of one or more links and adjusting the length of the second mechanical arrangement to contact the other of the boom and first set of one or links.

The method according to any one of claims 5-7 wherein mechanically restraining the one or more links comprises coupling a third mechanical arrangement between a second set of one or more links and the boom.

The method according to claim 8 wherein coupling the third mechanical arrangement comprises mechanically attaching respective attachment members to the boom and the second set of one or more links and connecting opposite ends of a binder to the members.

10. A tooling system for facilitating maintenance or service of a machine having a boom and an implement which is pivotally coupled to the boom and to one or more links and a cylinder pivotally connected at one end to the support structure on the machine and coupled at an opposite end to one of the links, the system comprising: a first mechanical arrangement having a length adjustable first strut arranged for coupling at one end to the boom; and a first cradle arranged for coupling to an opposite end of the first strut and configured to seat the cylinder.

1 1 . The tooling system according to claim 10 comprising a second mechanical

arrangement having a length adjustable second strut arranged for coupling at one end to the boom; and a second cradle arranged for coupling to an opposite end of the second strut and configured to engage a first set of one or more of the links.

12. The tooling system according to claim 1 1 comprising a third mechanical arrangement comprising one or more binders arranged to connect between the second set of the one or more links and the boom.