AU604869B2 - Vehicle loading/unloading apparatus - Google Patents

Description

I- -F- V 4 sa r COMMOUWEALT'H OF AUSTRALIA The Patents Act 1952-1909 Name of Applicant: THE SOUTH EAST ELECTRICITY BOARD 150 Charlotte Street Brisbane, Queensland, Q U E 1 1 1 AND Address of Applicant: Aotual Inventors: Addreca for Servico: 4000 Kenneth John Dun Keith Geoffrey Batton CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: I' 14 VEHICLE LOADING/UNLOADING APPARATUS The following statement is a full description of the invention including the best method of performing it known to us: *1 0 THZS INV1EMTX01 rolator, generally toe appanIiLwA suitable for mounting on a trailer or truck, for loading and4 unloading objects on the trailer or t~ruck. In particular, the invention is directed to a self-loading cable trailer, Cables, such as electrical power or telephone cables, crane wire etc., are normally wound on large drums, and the weight of a fully wound drum can be of the order oIf six tonnes or more. Such cable drums must therefore ba handled by mechanical means as they are obviously too heavy to be handled manually. The principal handling operationo are the loading of the cable drum onto the trailer or truck on which it is to be transported, (ii) the unloading of the cable drum at the installation or storage site and (iii) the rotatable mounting of the drum in an elevated position to enable the cable to be unwound therefrom.

*4 To date, cable drums have beer loaded/unloaded by 4*440various means, such as external crane, or by using winches to

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drag the drums along ramps. Such known methods of loading or unloading are laborious however. Furthermore, extra care has to be takern when unloading the drums to ensure that the drums do not career or roll unchecked down the ramps. As the drums are deposited on their cylindrical sides, they have a propensity to roll if rested on a surface which is not level, Furthermore, due to their huge mass and inertia when moving, any,uncontrolled motion of the cable drums is both dangerous and difficult to stop.

There are known mechanical devi~ce,. for' facil.itatingJ the loading and unloading of cable drums onto and from trailers or trucks. Ono such loading/unloading mechanism comprises a pair of parallel spaced-apart arms each pivotallXy mounted at~ a resp~ective end thereof to a trailer or truck and pivotable about a common axis. The arms are rigidly connected and pivot in unison. To load the cable drum, the arms are first lowered to enable their free ends to be coupled directly to the drum shaft; the arms are then pivoted back, e.g. hydraulically, to lift the cable drum and place it upon the trailer or truck, It has been f ound that such prior art loading/unloading mjchanism has several significant disadvantages. First, it is difficult to align the free ends 1.114 of the loading arms with the shaft ends protruding on each side of the cable drum, particularly when reversing the trailer or truck towards the cable drum. Secondly, alignment is made more difficult if the cable drum is inclined or if the shaft of the cable drum is otherwise not in the same plane as a line joining the free ends of the loading arms.

In such cases, it is not possible to couple both shaft ends onto the loading arms simultaneously. Thirdly, the prior art loading mechanism requires at least two operators; one operator reversing the trailer or truck while the other operator lowers the loading arms into position.

It is an object of the present invention to provide A U 0

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4 an improved loading/unloading mechanism which overcomes or substantially ameliorates the abovestated problems or disadvantages of the prior art, or at least provides tht4 public with a useful choice.

In one broad form, the invention provider, a transport vehicle having apparatus for loading or unloading an object on the vehicle, the apparatus comprising a pair of spaced-apart, independently operable, lifting arms pivotabl(, about a common axis and located adjacent to a loading side of the vehicle, means for pivoting the arms between a firsL disposition whereat the object is mounted on the vehicle and a second disposition whereat the object is dismounted, and a pair of connection members for coupling to the object, each connection member being connected to a free end of a respective one of the lifting arms by a respectivo substantially inextensible, flexible line member.

In the preferred embodiment, the loading apparatur is designed for use with a cable drum, and in use, the connection members are coupled to respective ends of a shaft ,'2fl passing through central bores in the sides of the cable drum.

C7 The independent lifting arms provide greater flexibility of operation for the loading apparatus of this invention; for example, by independently operating the arms, drums which are inclined can be set upright before lifting.

The independent arms can be used to turn drums from their sides to their edges and vice versa. Furthermore, by ,'r independently operating the arms, the drums can be unloaded onto sloping surfaces and even laid gently onto their axial end faces. When loading, the independently pivotable arms are able to accurately align the shaft on drum support means on the vehicle, The independent operation of the lifting arms is achieved by pivoting each arm about its own pivot pin, with no rigid mechanical tie between the arms. Each arm is preferably driven from a separate hydraulic pump in its own hydraulic circuit. However, the arms could be driven from a single hydraulic pump using a flow divider. A fully independent hydraulic system for each arm is preferred since it is difficult to compensate for mismatched loads with a single load dividing or splitting device.

i 5 Each flexible line member is typically a chain, cable, steel rope or other flexible connecting device of sufficient tensile strength to support the weight of the object to be lifted. The use of flexible members between the connection members and the free ends of the lifting arms i ,2 allows for even greater tolerances in the positioning of the vehicle relative to the drum prior to loading, and in the arm position relative to the drum when preparing to lift. As a result, the loading and unloading operation can be carried out by a single operator. The vehicle is first reversed close to the drum and roughly aligned with it. After stopping the trailer or vehicle in that position, the 6 operator can then lower the lifting arms such that the free ends are as close as possible to the ends of the shaft through the cable drum. The connection members on the endo of the chains can then be affixed to respective ends of the shaft. The flexibility of the chains allows for misalignment between the arms and the drum, and inclined drum shafts. The lifting arms are then swung up and back over the vehicle to deposit the cable drum in a suitable drum support. The arms can be pivoted in any suitable manner, e.gj. hydraulically, mechanically or electrically.

in the preferred embodiment, the handling apparatu., is mounted on a trailer. However, it will be apparent to those skilled in the art that the handling apparatus may be(, *mounted on a truck or similar vehicle. Retractable or L6 pivotable support legs are suitably provided on the vehicle for levelling the vehicle, and to prevent abnormal weight distribution on the vehicle during loading and unloading operations.

Preferably a closed frame chassis it; used for the trailer, thereby permitting lighter, commercially produced 0- Xsections to be used in the construction of the trailerL chassis. The trailer can use standard commercially mass produced suspension and braking systems, thus enabling costs to be contained.

In the preferred embodiment, the connection members at the ends of the chains include sealed bearings which can

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z__ ra(r~ II1I~ be slidably mounted onto respective ends of the drum shaft and looked into position by a locking pin. The connection members are removed from the shaft simply by reversing the procedure. unlike prior art bearings which have open jaws, the bearing located in each connection member of the preferred embodiment is closed to prevent contamination of the bearing by foreign material. Yet, the bearing housing is totally removable from the shaft as a complete unit. The bearings also permit the rotation of the drum using reduced torque.

Conventionally, a solid steel rod is used as the drum shaft. Such shafts can weight of the order of 50 Kg and are therefore cumbersome to handle. Moreover, such heavy shafts are awkward to thread through the two holes on either **4J 5 side of the cable drum since the moment created by the weight of the bar must be counter-balanced at the outer end of the ~bar while the inner end is prodded against the opposite side of the drum to locate the opposite centre hole. Such disadvantages of the prior art are overcome by the preferred S 0 embodiment of the invention which uses a hollow shaft. The shaft is manufactured from a hollow rod with end caps machined to provide a lead for easy insertion through the l centre holes on each side of the cable drum. By using a hollow shaft, the mass of the shaft is reduced to less than half of a conventional solid shaft. Furthermore, by using a hollow shaft with machined leads, the shaft is easier to C 4i'

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i 8 manoeuvre through the centre hole in the opposite side of the drum.

In order that the invention may be more fully understood and put into effect, a preferred embodiment thereof will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a side elevational view of the preferred embodiment of invention; Fig. 2 is a plan view of the embodiment of Fig. 1; Fig. 3 is an end; elevational view of the loading apparatus of the embodiment of Fig. 1; Fig. 4 is a half sectional elevation of the shaft and bearing assembly of a connection member of Fig. 1; Fig. 5 is an end view of a lifting arm of the s o* 1 4, preferred embodiment; Fig. 6 is a side elevation view of the lifting arm j of Fig. Fig. 7 is a half section of the pivotal mounting of the arm of Fig. I 0 Fig. 8 is an end view of the drum support mounting of the preferred embodiment; j t Fig. 9 is a side elevational view of a drum support j of Fig. 8; and Fig. 10 is an end elevational view of the drum support of Fig. 9.

As shown in the drawings, the loading/unloading 1>O 4, C I- 7 apparatus of the preferred embodiment is specially designed for the loading and unloading of cable drums. The apparatus is fitted on a trailer to form a self-loading cable trailer.

(The term "self-loading" is intended to mean that the trailer includes means thereon for loading/unloading the cable drums, rather than external means such as cranes.) The trailer comprises a chassis 10 which is supported on leaf springs 13 mounted on a pair of axles having ground engaging wheels 12 at respective ends thereof.

The use of a standard suspension system, as well as a standard braking system, enables the construction costs of the trailer to be contained. Furthermore, a box section or closed frame chassis 10 is used, thus permitting lighter, ocor. e commercially produced section to be used in the construction of the trailer chassis.

0oo The loading apparatus comprises a pair of spaced 0000 0 lifting arms 20, 21 each being pivotally mounted at one end thereof on respective horizontal axles 22 having a common axis. The lifting arms 20, 21 are pivotally mounted at the loading end of the trailer, and are independently pivotable between an upper disposition or orientation whereat the drum is loaded on the trailer and a lower disposition "B" whereat the drum is unloaded on the ground (Fig. The arms 20, 21 are moved between these two dispositions by hydraulic cylinders 23. However, any other suitable means o can be provided to operate the arms 20, 21.

Yr,- 7 Flexible lines, such as chains 24, 25 are attached to the free ends of respective arms 20, 21. At their other ends, the chains 24, 25 are attached to respective connection members 26, 27 as illustrated in Fig. 3. In use, the connection members 26, 27 are connected to respective ends of a shaft 28 passing through the cable drum Connection member 26 and shaft 28 are illustrated in more detail in Fig. 4, connection member 27 being a mirror image of connection member 26. The connection member 26 comprises a sleeve 40 which can be slidably mounted onto the end of shaft 28. Sleeve 40 acts as a bearing carrier for bearing housing 41, the gap 42 between the sleeve 40 and housing 41 being filled with a lubricant via grease nipple 43. The housing 41 has attached thereto an arm 44 which is connectable to chain 24. The bearing is sealed such that even when removed from the shaft 28, the bearing assembly is i free from contamination by dirt etc.

After sliding the bearing assembly onto the end of shaft 28, it is locked in position by inserting locking pin i 20 45. The locking pin 45 not only locks the bearing assembly onto the end of the shaft 28, but also fixes the bearing li carrier 40 relative to the shaft. The bearing housing 41 however, is free to rotate about the shaft 28.

As can be seen in Fig. 4, the shaft 28 is of hollow tubular construction to reduce weight. The ends 46 of the shaft are also machined to facilitate the insertion of the shaft in the central bores of the cable drum. A plate 49 with attached pipe clamp 47 is slidably mounted on each end of the shaft 28 between the cable drum and connection member, Once the shaft has been centrally located in the cable drum, plates 49 are placed against the outer drum faces and clamped in that position by tightening nut 48 on the associated pipe clamps 47. The shaft 28 is then fixed relative to the cable drum.

Arm 20 is illustrated in more detail in Figs. 5 to 7, arm 21 being a mirror image of arm 20, The arm comprises upper and lower portions 20', 20, the upper portion being angled at 7' to the lower portion. Attached to the upper portion 20' is a flange or bracket 42 to which chain 24 is connected. The bracket 42 is angled at 8' to the vertical o'o 1* and 15' to upper portion 20', Another flange or bracket 41 S44 is fixed approximately 'midway along the bottom portion 20 of "4 1 the arm, the bracket 41 being connected to a respective hydraulic cylinder 23. The arm 20 is pivotally mounted as illustrated in Fig. 7. The pivotal mounting comprises a sleeve 29 welded to the bottom end of the arm and mounted on \A a pair of spherical plain bearings 50 spaced apart on shaft 43.

When mounted on the trailer, the cable drum is held by support means illustrated in Fig. 8. The support means comprises a pair of upright arms 31, 32 mounted on the S' chassis 10 of the trailer frame. The top operative portion -1

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12 of arm 31 is shown in more detail in Figs. 9 and 10, the corresponding portion of arm 32 being a mirror image. The arm 31 comprises an upright box section 55 having a right angle bend at the top thereof. Two upwardly extending flanges 56, 57 are welded to the top of the box section and are spaced apart by the length of the bent end portion, The outer flange 56 has an angled wing portion 51 directed generally toward the loading end of the trailer but flared outwardly. The wing portion 51 guides and locates the corresponding connection member 26 as the drum is being loaded onto the support means. The inner flange 57 has a Ushaped cutout 52 upon which the respective connection member 26 is mounted when the cable drum is loaded. Lever latches o 53 (Fig. 1) are pivotally mounted in more 54 and serve to lock the connection members 26, 27 onto the support arms 31, 32 for transportation.

The support means holds the drum in an elevated position on the trailer yet the drum is free to rotate so that the cable can be unwound from it.

Legs 58 are pivotally mounted on chassis 10 and are used to level the trailer during loading and unloading operations. The legs 58 are raised and lowered by hydraulic jcylinders 59 which are housed in cylinder mounts at the loading end of the trailer.

The operation of the trailer will now be described.

When unloading a cable drum, the trailer is positioned 6-iSP FaBI~ C 13 adjacent the location at which the drum is required.

Retaining levers 53 are opened to unlock the connection members 26, 27 from the support means. The support legs 58 are then lowed to ground level. The legs 58 can be lowered by any suitable means, e.g. hydraulically or manually.

Hydraulic cylinders 23 are then operated to rotate the arms 21 first to lift the connection members 26, 27 clear of the support means and then to lower the cable drum onto the ground. The arms may be operated independently to place the drum on inclined ground. The arms 20, 21 are lowered further to slacken the chains 24, 25 to p-rmit the connection members to be removed from the drum shaft 28. The connection members are disconnected from the shaft simply by removing the 4,#6 locking pins 45 and sliding the bearing assemblies off the °-415 respective ends of the shaft. The shaft can then be removed *4 from the cable drum, if desired. If the shaft is removed from the cable drum, the connection members preferably are reconnected to the shaft and the arms swung back to the loaded position (as shown in Fig. The retaining levers 53 are closed to lock the connection members during transportation. The support leges 58 are then raised and the trailer is ready for transport to another location.

When loading a cable drum, the trailer is first reversed generally ir line with the drum. A shaft is inserted through the drum, if not already present. The 4 4- support legs 58 are lowered to ground level to stabilise the 1-1 trailer during the loading operation. Tho arms 20, 21 are then swung back so that their free ends are olse to the respective ends of the shaft 28 through the cable drum. Tho locking pins 45 are removed from the bearing assemblies in the connection members to enable the bearing assemblies to be slid onto respective ends of the shaft, and then reinserted to lock the bearing assemblies in position. The arms 20, 21 are then swung back over the trailer to load the drum onto the support means. The retaining levers 53 are closed to lock the shaft/connection member assembly in that position during transportation. The support legs 58 are then raised to place the trailer in a condition for transport.

The drum can be wound or unwound either when it iu mounted on the support means, or when it is suspended above *I the ground by the lifting arms 20, 21.

The arms 20, 21 can be operated independently to S manoeuvre the drum onto 'its side, or onto an inclined surface, or to pick up a drum which is on its side or otherwise inclined.

The foregoing describes only one embodiment of the S\ present invention, and the modifications which are obvious to those skilled in the art may be made thereto without departing from the scope of the invention as defined in the following claims.

i now

Claims (9)

1. A transport vehicle having apparatus for loading or. unloading an object on the vehic3.eo the apparatus comprising a pair of spaced-apart, independently operable, lifting arms pivotable about a common axis and located adjacent to a loading side of the vehicle, means for pivoting the arms between a first disposition whereat the object is mounted on the vehicle and a second disposition whereat the object 4,.r mounted, and a pair of connection members for coupling to the object, each connection member being connected to a free end of a respective one of the lifting arms by a respective, substantially inextensible, flexible line member.

2. A transport vehicle as claimed in Claim 1, wherein each flexible line mernber is a chain, cable or rope.

3. A transport vehicle as claimed in Claims 1 or 2, wherein each connection member includes a bearing such that the connection member may be rotatably coupled to the object.

4. A transport vehicle as claimed in claim 3, wherein each bearing is located in a sealed housing in its respective connection member. A transport vehicle as claimed in any preceding claim, wherein the object is a cable drum, and the connection members are rotatably coupled to respective ends of a shaft passing through the cable drum.

6. A transport vehicle as claimed in claim 5, further comprising means for locking the connection m~embers in 2 position onto respective ends of the shaft'.

7. A transport vehicle aG claimed in Claim whovo:C"z1 the shaft is of hollow construction.

8. A transport vehicle as claimed in any preceding claim, further comprising retractable or pivotable support legs for stabilizing the vehicle.

9. A transport vehicle as claimed in any preceding claim, wherein the transport vehicle is a trailer, or truck, the apparatus being mounted on the trailer or truck such that the loading side is at the rear of the trailer or truck. A transport vehicle as claimed in any preceding claim, further comprising support means for rotatably mounting the object in an elevated position on said vehicle.

411. A transport vehicle as claimed in Claim 10 wherein the support means comprises a pair of -paced-apart upright supports each having a holder portion near its top for receiving a respective connection member and support~ng samo in an elevated position. IM: 12. A transport vehicle as claimed in Claim 11 further comprising means for locking each connection member in position in its respective holder portion. 13. A transport vehicle as claimed in Claim 11 wherein each upright support includes at least one flange member for guiding the respective connection member into its holder portion. Apparatus suitable for loading or unloading an object on a transport vehicle, the apparatus comprising a pair of spaced-apart, independently operable, lifting armr pivotable about a common axis and located in use adjacent to a loading side of the vehicle, means for pivoting the arms between a first disposition whereat the object is mounted on said vehicle and a second disposition whereat the object is dismounted, and a pair of connection members for coupling to the object, each connection member being connected to a free end of a respective one of the lifting arms by a respective substantially inextensible, flexible line member. A cable trailer comprising a pair of spaced-apart independently operable lifting arms pivotable in use in *9' ps respective vertical planes about a common horizontal axis located adjacent the loading side of the trailer, means for pivoting the arms between loading and unloading positions, and a pair of connection members for rotatable coupling to respective ends of a shaft of a cable drum, each connection member being connected to the free end of a respective lifting arm by a substantially inextensible, flexible line member. 16. A cable trailer substantially as hereinbefore described with reference to the accompanying drawings. DATED this twenty-fourth day of July 1990 THE SOUTH EAST QUEENSLAND ELECTRICITY BOARD By their Patent Attorneys CULLEN CO.