GB1581547A - Mobile elevator - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO A MOBILE ELEVATOR (71) We, POWERSCREEN (IRELAND) LIMITED, Kilbeggan, County Westmeath, Republic of Ireland, a company organised and existing under the laws of the Republic of Ireland, do hereby declare the invention, fol which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: This invention relates to improvements in or relating to a mobile elevator for increasing the stockpiling capacity thereof, the elevator being of the type having an elongate support structure carrying a roller at each end thereof and around which rollers an endless conveyor belt is arranged, one of said rollers being adapted to be driven so that material fed to the loading end of the eleavtor is carried by said conveyor belt and discharged at the discharge end of the elevator to form a stockpile, an axle assembly having ground-engaging wheels positioned with the axle transversely under said structure at a position between its ends and connected by length-adjustable means to said structure; the elevator being movable by length-adjustment of said means between a transport position in which the structure is substantially parallel to or at a slight inclination relative to the ground on or along which it is stationary or travelling respectively, and a working position in which the elevator is sationary and is in an inclined position with the discharge end thereof being above the loading end whereby the effective ground length of the elevator, namely the distance between verticals through the ends of the elevator, is less than the length of the elevator; the length-adjustment means comprising two pairs of legs, one pair of which is length-adjustable, the two pairs of legs being connected to the axle assembly and diverging from one another to engage the structure.Such elevators will be referred to hereinafter as "elevators of the type aforesaid." The stockpiling capacity of a mobile elevator is determined, firstly by the height of the discharge end off the ground and therefore the angle of elevation and the length of the conveyor, and secondly by the ground distance between a position on the ground of a vertical through the axle of the axle assembly and the position on the ground of a vertical through the outer end of the discharge end, the position of the axle assembly being determined by the requirements for the stability of the elevator.

It is an object of the present invention to obtain a greater stockpiling capacity for a given length of elevator of the type aforesaid.

The present invention is a mobile elevator of the type aforesaid in which the axle assembly is located nearer to the loading end than the discharge end of the elevator, and counterweight means is provided at or adjacent to the loading end to compensate for the weight of the support structure overhanging the axle assembly and to prevent pivoting of the elevator thereabout during use, the location of the axle assembly nearer to the loading end serving to increase the angle of inclination of the sup- port structure thereby to increase the height of the discharge end off the ground and.

consequently, increase the potential size of said stockpile, that is, the stockpiling capacity of the elevator.

Preferably, the counterweight means is a container with ballast therein supported below the structure between the rotary axis and the loading end of the elevator when the loading end is adjacent to the ground.

Alternatively, the counterweight means is a container with ballast therein secured to a stand supporting the loading end off the ground. Further, the counterweight means is, alternatively, provided by the weight of a separate apparatus to which the loading end is attached at a position off the ground.

Preferably also, the loading end is in a plane above the ground.

Preferably also, a platform is provided to support the loading end of the conveyor, said platform and said loading end of the conveyor having mutually complementary swivel members whereby the conveyor can be moved in a horizontal plane relative to said platform about a vertical axis of said members.

Preferably further, the other pair of legs are not length-adjustable and are pivotally connectible to said structure at one of a plurality of selective locations.

An embodiment of the present invention will now be described. by way of example, with reference to the accompanying drawings in which: Fig. 1A is a diagrammatic side view of a mobile elevator according to the present invention, the elevator being in a first position: Fig. 1B is a diagrammatic plan view of the elevator as shown in Fig. 1A Fig. 2A is a side view of the elevator when in a second position and to a larger scale than used in Fig. 1A, one wheel of an axle assembly being omitted for the sake of clarity; Fig. 2B is a plan view of the elevator as shown in Fig. 2A and with both wheels shown; Fig. 3 is a diagrammatic side view of the elevator when in a third position and to a smaller scale than used in Fig. 2A.

Fig. 4 is a side view of a stand used to support the elevator at its loading end when the elevator is in the second position as shown in Fig. 2A, part of the elevator connected to the stand also being shown; and Fig. 5 is a sectional view of mutually complementary swivel members.

Referring to the drawings, a mobile elevator of the type aforesaid has the pair of non length-adjustable legs 10 inclined in the direction of the loading end of the elevator 11 and the pair of length-adjustable legs 12 inclined towards the discharge end of said elevator 11. The length-adjustable legs 12 are telescopic and a longitudinal series of diametrical holes 13 is provided in the lower part of said legs 12 which slides inside the upper part which has two diametrically opposed apertures 9, each of the holes 13 being alignable selectively with the apertures 9, and then the aligned apertures and holes being engageable by a bolt 14. Each bolt 14 is attached to the upper part of the respective leg by a chain 8 or the like. The bottoms of the legs 12 are rooted to the axle 15 and the tops are pivotally connected to the structure 17, said legs 12 being braced together by a tie bar 16.The bottoms and tops of the legs 10 are pivotally connected to the axle 15 and structure 17 respectively. Two pairs of anchorages 18 and 19 are provided on said structure 17 adjacent to the loading end thereof, the anchorages 18 and 19 being spaced apart therealong, and the two anchorages of each pair are located one on each lateral side of said structure 17. The anchorages 18 and 19 are provided for selective pivotal connection of the non length-adjustable legs 10. The tie bar 16 has two positions, an upper and a lower position, in which it can be selectively secured relative to the upper parts of said legs 12, two pairs of lugs, 16A and 16B (Fig. 2B) being provided on the legs 12 for mounting the tie bar 16 in its upper and lower positions respectively.The upper position is for use when the elevator is being used as a conventional elevator as described hereinafter in a first use of the elevator and the lower position for use when the elevator 11 is being used as described hereinafter in a second and third use of the elevator 11. A hydraulic ram 30 is located between the axle 15 and the tie bar 16 and mounted on the axle 15 and the tie bar 16, mid-way thereof, the ram being for length-adjusting the telescopic legs 12. In the fully retracted position of the ram, it is not necessary for the telescopic legs to be bolted together. A power unit 20 including an engine, a hydraulic pump and a reservoir of hydraulic fluid is mounted on a chassis and secured to and between the legs 10 adjacent to the axle 15, the drive roller of the elevator 11 being driven hydraulically from said power unit.

The elevator 11 is articulated for swinging movement in the vertical and horizontal planes, a carrier 21 being transversely disposed under the loading end thereof, said carrier 21 having a horizontal bar 7 from each end of which an arm 22 upstands to be pivotally connected to said structure 17, one arm 22 on each side of said structure 17 thereby providing a transverse axis about which the elevator 11 can move in a vertical plane. A boss 23 upstands from around a hole provided mid-way of the length of said bar 7.

A platform 26 has an aperture centrally therein and through which a headed spindle 27 is journalled with the head 27A located below the platform and abutting the peri Dheral area around the aperture to Drevent further unward movement of said spindle 27 and the shank 27B of the spindle upstand- ing from the platform 26, to be engaged bv said boss 23, thereby providing a vertical axis about which the elevator 11 can move in a horizontal plane. The boss 23 and spindle 27 from mutually complementarv swivel members. The end of the shank 27B remote from the head 27A is provided with a diametrical bore 38 and the boss 23 has two diametrically opposed holes alignable with said bore 38 and through which aligned bore and holes a bolt 39 is passed to secure together said platform 26 and elevator 11.

For conventional use of the elevator i.e. a first working position as shown in Figs.

1A and 1B, the platform 26 is a groundengaging base 28 having peripherally disposed downwardly extending spikes (not shown) for location in the ground thereby to secure the base 28 to the ground and a container 29 is suspended under the structure adjacent to the carrier 21 for receiving ballast. In a second working position, as shown in Figs 2A and 2B, the platform 26 is provided on top of a stand such as a tetrapod 24, tripod or like construction having a container 25 located below said platform 26 and into which weights or like heavy material can be disposed to provide ballast. Alternatively, for a third working position, as shown in Fig. 3, the platform 26 can extend out from a separate piece of apparatus with which the conveyor is in a working relationship, the other apparatus providing the ballasting.

A removable tow bar 40 (Fig. 2B) is provided for mounting at either end of the elevator 11; at the discharge end when the elevator 11 is in the transport position and at the loading end when the elevator 11 is in the working position. The wheels 15A on said axle 15 are pivotally mounted thereon for location of the wheels 15A in one of two positions, namely a first position in which the wheels 15A are in a conventional axle-wheel relationship for movement in a direction at right angles to the longitudinal axis of the axle, and a second position in which the wheels 15A lie in an angular relationship thereto such that the wheels 15A lie on the same arc of a circle whose origin is the vertical axis of the swivel members 23 and 27 and to enable radial movement of the elevator 11 relative to the pivot point or vertical axis.

The support structure 17 is formed by a beam 31 of box-section which in this embodiment is square vertical cross-section and from adjacent to each end of which roller mountings 32 and 33 extend. Each roller mounting comprises two arms, mirror images of each other. Each arm has a minor and a major portion. The minor portions of the arms extend laterally from similar positions on the two opposite side walls of the beam and the major portions of the arms are parallel to each other and to the longitudinal axis of the beam 31 and extend be vond the respective end of the beam 31. Between the outer ends of the major portions of each two arms a roller 34 is mounted, and sliding facilities are provided on one mounting to tighten the roller against the belt thereby to tension the belt.A longitudinal series of low-friction devices 35 for example troughing idlers, is mounted in conventional fashion along the upper face of said beam 31.

Alternatively, the support structure 17 may be fabricated from bars, ties and braces to form a lattice framework in both side and plan elevators, the upper plane of said framework being sheeted over and a longitudinal series of low-friction roller devices, for example, flat bed or troughing idlers, each being mounted transversely on the sheeted surface of the framework along the length thereof, said devices supporting the upper flight of the belt off said sheeted surface and the devices in the form of troughing idlers imparting a concavity to the upper flight of said belt.

A feed boot 36 is mounted at said loading end above the belt but having flexible parts abutting the belt to prevent material fed onto said elevator 11 from downward movement therefrom under gravity.

In use, the elevator 11 is moved to a location in a transport position in which the elevator is inclined towards the discharge end at an angle of five degrees to the ground level with the legs 10 connected to either of the anchorages 18 or 19 and the legs 12 telescoped together, the elevator 11 being secured by two stays 41 to the axle assembly, one stay 41 (Fig. 2A) being provided on each of the two lateral sides of the structure 17, a respective end of each stay 41 being pivoted to said structure for pivotal movement of the stays between an in-use position in which the other end is secured to the axle assembly and an out-of-use position in which the other end is secured to the structure 17.

At the location, the tow bar 40 is removed from the discharge end and the elevator 11 erected into one of three working positions.

For the elevator 11 to be erected into the first working position from a transport position, the tops of the non lengthadjustable legs 10 are attached to the pair of anchorages 18 remote from the loading end of the conveyor and with the loading end secured in position with said groundengaging platform 26 and the container 29 hung under the structure 17 and ballasted with sand, the ram 30 is extended and the telescopic legs 12 are locked together by the respective bolt 14 passing through aligned apertures 9 and hole 13 of each leg when the inclination of the elevator 11 is at the required degree of elevation selectively up to approximately twenty-four angular degrees relative to the ground level.

For the elevator 11 to be erected into the second working position from a trans port position, the tops of the non length adjustable legs 10 are attached to the pair of anchorages 19 nearer to the loading end and the tie bar 16 is moved to the lower position. By these movements, the axle assembly is brought closer to the loading end. The loading end is secured in posi tion with said platform 26 on the tetra pod 24 and the container 25 is filled with ballast. The ram 30 is extended and the telescopic legs 12 are locked together by the respective bolt 14 passing through aligned apertures 9 and hole 13 of each leg, different from those in said first posi tion, when the inclination of the elevator 11 is at the required degree of elevation selectively up to approximately twentyfour angular degrees relative to the ground.

For the elevator 11 to be erected into the third working position from a transport position, the tops of the non length adjustable legs 10 and the tie bar 16 are moved similarly as described in relation to the second position, thereby moving the axle assembly similarly as for said second position. The loading end is secured in position with the platform 26 provided on a separate piece of apparatus. The ram 30 is extended and then the telescopic legs 12 are locked together by the respective bolt 14 passing through aligned apertures 9 and hole 13 of each leg when the inclina tion of the elevator 11 is at the required degree of elevation selectively up to approximately twenty-four angular degrees relative to ground level.

In all three positions, the mobile elevator is for use as a second, third or greater stage in processing discrete material, material being fed onto the loading end of the elevator from the previous stage. The third position of the elevator is used particularly as a second stage in the processing of material, the first stage being the piece of apparatus which is, for example, screening apparatus, dewatering apparatus or a combined screening and dewatering apparatus. Screening apparatus has a conveyor inclined in normal use towards the discharge end which has a screen box with one or more screens. Material to be sizeclassified into grades or fractions is fed into said screen box to pass along or through said screens and be discharged therefrom into stockpiles on the ground surface.With screen apparatus and dewatering apparatus, the screened material is fed from the screening apparatus in or with water to the dewatering apparatus and stockpiles "S" (Fig. IA and 2A) form on the ground surface around the discharge or discharges of said dewatering apparatus.

With increasing cost of equipment, operation and labour costs, the screening apparatus, de watering apparatus and the combined screening and dewatering apparatus have been developed to give a greater through put of material per time period and it can be readily appreciated that in a very short period of time the ground surface area around the discharge(s) will have been stockpiled to capacity necessitating removal and repositioning of either the screening apparatus, dewatering appara tus or the combined screening and dewatering apparatus, or relocating the stockpiles remote from the discharge area. To enable these stockpiles to be formed some distance away, fixed and later swinging boom conveyors have been mounted onto and supported by the screening apparatus or onto the dewatering apparatus.

With still greater throughput, still larger boom conveyors are required. However, the maximum length of boom conveyors that can be mounted on the screening or dewatering apparatus without making the whole assembly unstable has been reached.

Parallel developments to the boom conveyors has been in the use of mobile stockpiling elevators of the type aforesaid, the material from the discharge(s) being fed down through chutes or the like to the feed boxes of such mobile elevators, said boxes being some distance below said discharges.

The mobile elevators of the present invention have the advantage of being used separately or in conjunction with other apparatus to form an integral assembly for, for example, screening, washing, de watering discrete material. The vertical height of the discharge end is hereinafter denoted as "h", said ground distance is hereinafter denoted as "g", and said effective ground length is hereinafter denoted as "1". With the advantages of the ground distance "g" between the axle assembly and the discharge end being greater than heretofore in the first position, the stockpiling capacity is greater than conventional mobile elevators and with the "g" being even greater for the second and third positions, the stockpiling capacity is correspondingly greater. For example, with a mobile elevator of the present invention of length thirty-nine feet and material to be conveyed weighing one hundred pounds per cubic feet (sixteen hundred kilograms per cubic metre), the maximum stockpiling capacity when in the first position is two hundred and seventy-seven tons imperial (two hundred and seventy-three tonnes) when "g"is 5580 millimetres (mum) "h" is 5175 m.m., stockpile "S" is 4715 m.m. in height and the effective ground length "1" is 10280 m.m. The stockpiling capacity of a conventional elevator of the same length in the first position is much less since the "g" is normally 4400 m.m.

-and "h" is normally 4900 m.m. The maximum stockpiling capacity when the elevator of the present invention is in the second or third position with the platform 1360 m.m. off the ground, "g" being 6740 m.m., "h" being 6460 m.m., "S" being 6000 m.m. in height, and "1" being 10280 m.m., the stockpiling capacity is five hundred and fifty-two tons imperial (five hundred and forty-three tonnes) for the same weight of material.

A conventional elevator of the type aforesaid would require to be approximately fifty feet long to be able to match that stockpiling capacity of thirty-nine feet conveyor of the present invention when in the second or third position.

In the first position, the radius of the arc in which the wheels turn is 5000 m.m., and in the second and third positions, the radius is 3900 m.m.

In the third position, the power unit on the mobile conveyor is not necessary since power to drive the roller and operate the ram can be obtained from the separate piece of apparatus.

The roller and hydraulic ram may be electrically driven.

WHAT WE CLAIM IS: - 1. A mobile elevator of the type aforesaid in which the axle assembly is located nearer to the loading end than the discharge end of the elevator, and counterweight means is provided at or adjacent to the loading end to compensate for the weight of the support structure overhanging the axle assembly and to prevent pivoting of the elevator thereabout during use, the location of the axle assembly nearer to the loading end serving to increase the angle of inclination of the support structure thereby to increase the height of the discharge end off the ground and, consequently, increase the potential size of said stockpile, that is, the stockpiling capacity of the elevator.

2. An elevator as claimed in Claim 1, wherein the counterweight means is a container with ballast therein supported below the structure between the rotary axis and the loading end of the elevator when the loading end is adjacent to the ground.

3. An elevator as claimed in Claim 1, wherein the counterweight means is a container with ballast therein secured to a stand supporting the loading end off the ground.

4. An elevator as claimed in Claim 1, wherein the counterweight means is provided by the weight of a separate apparatus to which the loading end is attached at a position off the ground.

5. An elevator as claimed in Claim 1, 3 or 4 wherein the loading end is in a higher plane than the surface on which the wheels of the axle engage.

6. An elevator as claimed in any one of Claims 1, 2, 3 and 5, wherein a platform is provided to support the loading end of the elevator, said platform and said loading end of the elevator having mutually complementary swivel members whereby the elevator can be moved in a horizontal plane relative to said platform about a vertical axis of said members.

7. An elevator as claimed in any one of the preceeding claims, wherein the other pair of legs are not length-adjustable and are connectible to the elevator structure at one of a plurality of selective locations.

8. An elevator substantially as hereinbefore described with reference to Figs.

1A 1B and 5 of the accompanying drawings.

9. An elevator substantially as hereinbefore described with reference to Figs.

2A, 2B, 4 and 5 of the accompanying drawings.

10. An elevator substantially as hereinbefore described with reference to Figs.

3 and 5 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. less since the "g" is normally 4400 m.m. -and "h" is normally 4900 m.m. The maximum stockpiling capacity when the elevator of the present invention is in the second or third position with the platform 1360 m.m. off the ground, "g" being 6740 m.m., "h" being 6460 m.m., "S" being 6000 m.m. in height, and "1" being 10280 m.m., the stockpiling capacity is five hundred and fifty-two tons imperial (five hundred and forty-three tonnes) for the same weight of material. A conventional elevator of the type aforesaid would require to be approximately fifty feet long to be able to match that stockpiling capacity of thirty-nine feet conveyor of the present invention when in the second or third position. In the first position, the radius of the arc in which the wheels turn is 5000 m.m., and in the second and third positions, the radius is 3900 m.m. In the third position, the power unit on the mobile conveyor is not necessary since power to drive the roller and operate the ram can be obtained from the separate piece of apparatus. The roller and hydraulic ram may be electrically driven. WHAT WE CLAIM IS: -

1. A mobile elevator of the type aforesaid in which the axle assembly is located nearer to the loading end than the discharge end of the elevator, and counterweight means is provided at or adjacent to the loading end to compensate for the weight of the support structure overhanging the axle assembly and to prevent pivoting of the elevator thereabout during use, the location of the axle assembly nearer to the loading end serving to increase the angle of inclination of the support structure thereby to increase the height of the discharge end off the ground and, consequently, increase the potential size of said stockpile, that is, the stockpiling capacity of the elevator.

2. An elevator as claimed in Claim 1, wherein the counterweight means is a container with ballast therein supported below the structure between the rotary axis and the loading end of the elevator when the loading end is adjacent to the ground.

3. An elevator as claimed in Claim 1, wherein the counterweight means is a container with ballast therein secured to a stand supporting the loading end off the ground.

4. An elevator as claimed in Claim 1, wherein the counterweight means is provided by the weight of a separate apparatus to which the loading end is attached at a position off the ground.

5. An elevator as claimed in Claim 1, 3 or 4 wherein the loading end is in a higher plane than the surface on which the wheels of the axle engage.

6. An elevator as claimed in any one of Claims 1, 2, 3 and 5, wherein a platform is provided to support the loading end of the elevator, said platform and said loading end of the elevator having mutually complementary swivel members whereby the elevator can be moved in a horizontal plane relative to said platform about a vertical axis of said members.

7. An elevator as claimed in any one of the preceeding claims, wherein the other pair of legs are not length-adjustable and are connectible to the elevator structure at one of a plurality of selective locations.

8. An elevator substantially as hereinbefore described with reference to Figs.

1A 1B and 5 of the accompanying drawings.

9. An elevator substantially as hereinbefore described with reference to Figs.

2A, 2B, 4 and 5 of the accompanying drawings.

10. An elevator substantially as hereinbefore described with reference to Figs.

3 and 5 of the accompanying drawings.