AU2013100862A4 - A Jack - Google Patents

Abstract

The present invention provides a jack (11) for assisting in the removal of a roller (13) from a roller frame of a conveyor. The jack comprises a handle (15) which supports a spreader device (17). The spreader device (17) is adapted to move between a contracted position, whereby the spreader device can be positioned relative to the roller to be removed, and an expanded condition, whereby at least one end of the roller is spaced away from the roller frame.

Description

A Jack TECHNICAL FIELD 10001] The present invention relates to a jack to assist in removing conveyor rollers. In particular, the present invention relates to a portable jack to assist in accessing 5 conveyor rollers. BACKGROUND ART [0002] The following discussion of the background art is intended to facilitate an understanding of the present Invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general 10 knowledge as at the priority date of the application. [0003] Conveyors are used in many industries to convey material from one location to another for various purposes. Most conveyors employ a conveyor belt that moves over rotatable rollers (or idlers). The rotatable rollers are supported beneath the conveyor belt. The conveyor belt moves over the rotatable rollers, with the underside of the 15 conveyor belt contacting the rollers. The upper side of the Conveyor belt carries the material being conveyed. [0004] By way of example, in the mining industry such conveyors may be used to carry ore or other material around a site, from site to site, as well as to loading bays and on to ships, trains, trucks and/or other suitable transportation. 20 [0005] The rollers are supported in roller frames mounted beneath the conveyor belt. Each roller frame typically supports multiple rollers. These rollers, in turn, support the load of the material conveyed on the conveyor belt. For example, the belts in iron ore mining industries carry very large loads, up to 10,000 tonnes per hour; therefore these rollers are under constant heavy load. 25 [0006] Conveyors also have return rollers which support the conveyor belt on its return journey, [0007] Over time rollers fail for multiple different reasons. In some instances the bearings seize, the roller disintegrates, or can even explodes due to the pressure and heat generated by the roller. Whilst rollers are systematically checked and changed out, roller failure is difficult to predict. As such, rollers can fail whilst in service. These failures can cause hundreds of thousands of dollars worth of damage, as well as loss of production due to the downtime required to effect repairs and/or replacement of broken rollers. 5 [0008] The mining companies typically have full time maintenance crews to maintain the integrity of the conveyors, with some crews repairing the belts and cleaning the scrapers on the belts whilst other crews constantly change out damaged rollers. [0009] Currently, the roller frames which support the rollers are largely formed from a series of channels, referred to in the industry as "RSJ", and are of rigid construction. 10 They are built to carry three or four rollers of differing length and diameter depending on the conveyor belt size and the amount of material required to be carried on the conveyor -belt. The roller frames are attached to stringers which run the full length of the conveyor, and are themselves supported on support frames. [0010] If a roller is damaged during operation of the conveyor it needs to be replaced 15 before it damages the belt. To change a damaged roller 'a four man crew is typically used. Before.the change out can occur the conveyor belt must be cleared of all ore or any other material being carried on the conveyor belt. The time taken to do this depends on the length of the conveyor but can be between 20 - 90 minutes. Once cleared the crew then use a car jack attached to a makeshift extendable pipe. This is 20 supported on the stringer to push the conveyor belt away from the rollers. Once the belt is pushed away the roller requiring change out is accessible. With this technique the belt can only be pushed away from the roller a sufficient distant to access only one roller. As a result the process needs to be repeated for each roller, and will need to be executed on the other side of the conveyor belt for rollers on that side. 25 [0011]Once the damaged roller has been changed, the conveyor the belt is recharged with ore. This could take a similar period of time to get the ore flowing as it was to clear the belt. Typically the time it takes to actually replace the damaged roller is one hour. Whilst roller change out is scheduled accordingly to maintenance schedules, there are still three to five roller change outs required per week which are unscheduled. This 30 represents a significant down time, even more so if the belt has not been damaged by' the failed roller.

-3 [0012] Due to the environment in which many conveyors operate, the rollers tend to be quite large and tend to jam in the roller frames. This is worse in environments in which the conveyor moves heavy loads which push the roller downwardly in their support frame, and where the environment is not clean, as is usually the case in the mining 5 industry [0013] To remove the rollers from the roller frame the maintenance crew typically use a sledgehammer and/or jimmy bars to hit the roller to loosen or remove it from the roller frame. If the belt has not been or cannot be moved sufficiently clear of the roller then removal of the roller becomes more difficult. 10 [0014] Typically the maintenance crew are required to sit between the return belt and the raised belt in order to access and be able to lift the roller to be changed. [0015]Another difficulty with roller change out is the roller location. In some instances operators are required to get underneath the conveyor or be lifted to a conveyor in order to change a roller. This makes it more difficult to loosen a jammed roller. 15 [0016] It is extremely difficult and very unsafe to change rollers under the current practice. Not only does the conveyor experience significant downtime, but the labour intensive process requires a large team. The practice is also quite dangerous in light of the loads and type of machinery which is being repaired. SUMMARY OF INVENTION 20 [0017] It is an object of this invention to provide a jack which may used to assist in the removal of rollers from a conveyor in a safer manner. [0018] The present invention provides a jack for assisting in the removal of a roller from a roller frame of a conveyor, the jack comprises a handle which supports a spreader device, the spreader device being adapted to move between a contracted position, 25 whereby the spreader device can be positioned relative to the roller to be removed, and an expanded condition, whereby at least one end of the roller is spaced away from the roller frame. [0019] Once the spreader device is returned to the contracted position it can be removed. This will allow the roller to return to its position in the roller frame. However, -4 as the roller is no longer jammed an operator can easily remove the roller without requiring sledge hammers and jimmy bars to loosen it from the roller frame. [0020] The handle may be of sufficient length to allow an operator to position the spreader device relative to any roller of the roller frame from.the side of the conveyor. 5 [0021] The handle may be rotatably connected to a first end of a body portion of the spreader device. [00221 The spreader device may have an engagement portion adapted to engage a roller. The engagement portion may be suitably thin such that when in the contracted position the engagement portion may be fitted between the roller to be removed, and a 10 rigid support. The engagement portion may be at a second end of the spreader device remote from -the handle. (0023] In one aspect of the invention the rigid support is part of the roller frame. [0024] In another aspect of the invention the rigid support is removably fitted to the roller frame. Such a removable support will be required for those roller frames in which there 15 is no framework directly below the roller. [0025] The spreader device may comprise a first jaw and a second jaw rotatably movable with respect to each other. The first jaw and second jaw may be rotatably secured to the body portion at respective first jaw ends thereof. [0026] The first jaw and second jaw may provide the engagement portion at a second 20 jaw end remote from the first jaw end. [0027] In one aspect of the invention the second end of the first jaw and the second end of the second jaw are adjacent each other when the spreader device is in the contracted position. With this configuration the combined thickness of the second end of each jaw must be equal to or smaller than the distance between the roller and the rigid support. 25 .[0028] In another aspect of the invention the second end of the first jaw and the second end of the second jaw lie in substantially the same plane when the spreader device is in the contracted position. With this configuration the second end of each jaw is able to be equal or smaller to the distance between the roller and the rigid support. Thus the force which may be exerted, upon the roller can- be increased significantly than that 30 arrangement whereby the jaws are adjacent each other.

[00291 In one aspect of the invention the spreader device is activated to move between the contracted position and the expanded position by a. hydraulic system. The spreader device and source of hydraulic fluid may be connected by a hose which runs 5 through the handle. [0030] In another aspect of the invention the spreader device is activated to move between the contracted position and the expanded position by a pneumatic system. The spreader device and source of compressed air may be connected by a hose which runs through the handle. 10 [0031] The spreader device may also comprise a ram, whereupon activation, at- least one jaw moves, causing the spreader device to move between the contracted position and the expanded condition. Preferably both jaws move upon activation of the ram. [0032] The jaws may be caused to move between the contracted position and the expanded condition. 15 [0033] Each jaw may have a link rotatably mounted between the jaws first end and second end, the link being connected to the ram such'that the ram acts on each link to move the respective jaw. The jaw may b6 double hinged to allow it to open to a wider opening. [0034] The present invention further provides a jack for removing a roller from its 20 support position in a conveyor belt system, the jack comprising: a jaw which is movable between a closed position and an open position; a ram for moving the jaw between said positions; wherein the jaw is positioned between a roller and a fixed surface, as the jaw moves to its open position the roller is caused to move away from its support 25 position so as to be removed from the conveyor system. [0035] The jack may comprise a spreading member which causes the jaw to move between positions. [0036) The ram may act on the spreading member.

-6 [0037] The jaw may be double hinged to allow it to open to a wider opening. [0038] The jaw may have a narrow front portion to allow it to be inserted in narrow spaces. BRIEF DESCRIPTION OF THE DRAWINGS 5 [0039] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention, It should not be understood as a restriction on the broad summary, disclosure or description of the invention as. set out above. . The description will be made- with reference to the 10 accompanying drawings in which: Figure 1 is a perspective view of a jack according to a first embodiment whereby a spreader device is in the contracted position; Figure 2 is a view of the spreader device of figure 1 but in an expanded position; Figure 3 is a plan view of the spreader device of figure 1 in the contracted 15 position; Figure 4 is a side view of figure 3; Figure 5 is a view similar to figure 4 but with the spreader device in an expanded position; Figure 6 is a perspective view 'of a jack according to a second embodiment 20 whereby a spreader device is in the contracted position; Figure 7 is a view of the spreader device of figure 6 but in-an expanded position; Figure 8 is a plan view of the spreader device of figure 6 in the contracted position; Figure 9 is a side view of figure 8; 25 Figure 10 is a view similar to figure 9 but with the spreader device in an expanded position.

-. 7 [0040) In the drawings like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention. DESCRIPTION OF EMBODIMENTS 5 [0041] Referring to figures 1 to 5, the invention according to the first embodiment is in the form of a jack 11 for loosening rollers 13. When the jack 11 is in a contracted position, as shown in figure 1, it can be placed between a roller 13 of a roller frame, and a rigid support 14. When in position the jack 11 is activated such that it moves to an expanded position, as shown in figure 2, As the jack 11 moves to the second position it 10 forces the roller away from the roller frame for easy removal. This negates the need to. force the roller out of the roller frame with sledge hammers or jimmy bars, [0042] The jack 11 comprises a handle 17 rotatably secured to a first end 19 of a body portion 21 of a spreader device 17. The handle 15 incorporates a hose 23 for reasons which will be described below. 15 [0043]The spreader device 17 has an engagement portion 35 at a second end 20 remote from the first end 19 of the spreader device. [0044] The spreader device 17 comprises a first jaw 25 and a second jaw 27, both of which are rotatably secured to the body portion 21 adjacent the first end 19. When in. the contracted position a second jaw end 29 of the first jaw 25 and a second jaw end 29 20 of the second jaw 27 provide the engagement portion 35. In this embodiment the second jaw end 29 of each jaw 25, 27 are configured to be adjacent each other when the spreader device is in the contracted position. [0045] Each jaw has a link 31 rotatably secured thereto at a position between the first jaw end 28 and the second jaw end 29. Each link 31 is also rotatably secured to a 25 hydraulic ram 33 which is housed in the body portion 21. [0046] In operation the hose 23 is connected to a hydraulic pump. The engagement portion 35 is then positioned between the roller 13 to be removed, and the rigid support 14. The hydraulic pump may then be activated such that hydraulic fluid is pumped into the hydraulic ram 33.

[0047] As fluid enters the hydraulic ram 33, the ram 33 extends outwardly and the links 33 move apart. As this occurs the second jaw ends 29 of each jaw 25, 27 move apart to exert a force upon the roller 13. The force is applied until such time as the roller 13 is loosened from the roller frame. 5 [0048] To return the spreader device 17 to its contracted position the hydraulic pump is reversed, causing the ram 33 to retract, bringing the jaws 25, 27 together. [0049] To assist in portability, the handle 15 and spreader device 17 may be made from carbon fibre, [0050]A second embodiment of a jack 111 according to the present invention. is 10 illustrated in figures 6 to 10. For convenience, features of the jack 111 that are similar or correspond to features of the jack 11 .of the first embodiment have been referenced with the same reference numerals. [0051] The configuration and operation of the jack 111 is largely identical to that of the jack 11 of the first embodiment, The only difference between the two embodiments is 15 the configuration of the second jaw end 129 of each jaw 125, 127. In this embodiment each second jaw end 129 is adapted to lie in the same plane when the spreader device 17 is in the contracted position. This enables the.-second jaw end 129 to be thicker than that in the first embodiment. [0052] Modifications and variations such as would be apparent to the skilled addressee 20 are considered to fall within the scope of the present invention. [0053] Reference to positional descriptions, such as lower and upper, are to be taken in context of the embodiments depicted in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term but rather as would be.understood by the skilled addressee. 25 Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers

Claims (26)

1. A jack for assisting in the removal of a roller from a roller frame of a conveyor, the jack comprises a handle which supports a spreader device, the spreader device being adapted to move between a contracted position, whereby the 5 spreader device can be positioned relative to the roller to be removed, and an expanded condition, whereby at least one end of the roller is spaced away from the roller frame.

2. The jack according to claim 1 wherein the handle is of sufficient length to allow an operator to position the spreader device relative to any roller of the roller 10 frame from the side of the conveyor.

3. The jack according to claim I or 2 wherein the handle is rotatably connected to a first end of a body portion of the spreader device.

4. The jack according to any one of the .preceding claims wherein the spreader device has an engagement portion adapted to engage a roller. 15

5. The jack according to claim 4 wherein the engagement portion is suitably thin such that when in the contracted. position the engagement portion is fitted between the roller to be removed, and a rigid support.

6. The jack according to claim 4 or 5 wherein the engagement portion is at a second end of the spreader device remote from the handle. 20

7. The jack according to claim 5 or 6 wherein the rigid' support is part of the roller frame.

8. The jack according to claim 5 or 6 wherein the rigid support is removably fitted to the roller frame.

9. The jack according to any one of the preceding claims comprising a first jaw and 25 a second jaw rotatably movable with respect to each other.

10.The jack according to claim 9 wherein the first jaw and second jaw are rotatably secured to the body portion at respective first jaw ends thereof.

11.The jack according to claim 10 wherein the first jaw and second jaw provide the engagement portion at a second jaw end remote from the first jaw end. -10

12. The jack according to claim 11 wherein the second end of the first jaw and the second end of the second jaw are adjacent each other when the spreader device is in the contracted position.

13.The jack according to claim 11 wherein the second end of the first jaw and the 5 second end of the second jaw lie in substantially the same plane when the spreader device is in the contracted position.

14.The jack according to any one of the preceding claims wherein the spreader device is activated to move between the contracted position and the expanded position by a hydraulic system. 10

15.The jack according to claim 14 wherein the spreader device and source of hydraulic fluid is connected by a hose which runs through the handle.

16. The jack according to any one of claims 1 to 13 wherein the spreader device is activated to move between the contracted position and the expanded position by a pneumatic system. 15

17.The jack according to ckaim 16 wherein the spreader device and source of compressed air is connected by a hose which runs through the handle.

18.The jack according to any one of claims 9 to 17 wherein the spreader device also comprises a ram, whereupon activation, at least one jaw moves, causing the spreader device to move between the contracted position and the expanded 20 condition.

19.The jack according to claim 18 wherein both jaws move upon activation of the ram.

20.The jack according to claims 18 or 19 wherein each jaw has a link rotatably mounted between the jaws first end and second end, the link being connected to 25 the ram such that the ram acts on each link to move the respective jaw.

21.The jack according to any one of claims 9 to 20 wherein each jaw is double hinged to allow it to open wider.

22.A jack for removing a roller from Its support position in a conveyor belt system, the jack comprising: - 11 a jaw which is movable between a closed position and an open position; a ram for moving the jaw between said positions; wherein the jaw is positioned between a roller and a fixed surface, as the jaw moves to its open position the roller is caused to move away from its support 5 position so as to allow removal from the conveyor system.

23. The jack according to claim 22 wherein the jack comprises a spreading member which causes the jaw to move between positions.

24.The jack according to claim 23 wherein the ram acts upon the spreading member. 10

25.The jack according to claim 22, 23 or 24 wherein the jaw is double hinged to allow it to open wider.

26. The jack according to claim 22, 23, 24 or 25 wherein the jaw has a narrow front portion to allow it to be inserted in'narrow spaces. 15