GB2351719A

GB2351719A - Foldable frame for a conveyor system

Info

Publication number: GB2351719A
Application number: GB0016099A
Authority: GB
Inventors: Neill Suitor; Daniel James Mccusker
Original assignee: Powerscreen International Distribution Ltd
Current assignee: Powerscreen International Distribution Ltd
Priority date: 1999-07-03
Filing date: 2000-07-03
Publication date: 2001-01-10
Anticipated expiration: 2020-07-03
Also published as: GB2351719B; GB9915554D0; CA2313266A1; GB0016099D0

Abstract

A frame for a conveyor system, for example when used with screening units, comprises a first frame section 1, a second frame section 2 movably connected to the first frame section 1 and a third frame section 3 movably connected to the second frame section 2, first and second support members 4, 5 each movably connected at a first end thereof to the first frame section 1 and at a second end thereof to the third frame section 3, first operating means 6 connected between the first frame section 1 and the second frame section 2, and second operating means 7 connected between the first frame section 1 and the third frame section 3. The operating means 6, 7 act to move the second and third frame sections 2, 3 between an operative position wherein they lie substantially in line with each other and the first frame section (see Figure 2), to an inoperative position wherein the second and third frame sections 2, 3 are folded with respect to the first frame section 1. The first operating means 6 acts to pivot the second frame section 2 relative to the first frame section 1 about a first pivot axis, and the second operating means 7 acts to pivot the third frame section 3 relative to the second frame section 2 about a second pivot axis. When the frame is placed in the inoperative position, it is suitably positioned for storage and transportation.

Description

2351719 FOLDABLE FRAME FOR A CONVEYOR SYSTEM The invention relates to

foldable frames for conveyor systems, and particularly to foldable frames for conveyor systems of screening units.

Screening units are used in many applications for the processing of various materials, such as sand, gravel, stone, soil and aggregate material. Such units comprise a screening device, and one or more conveyor systems on frames to carry the various types or grades of screened material to individual stockpiles. It is desirable that these screening units be movable from place to place within a worksite, and, indeed, from site to site. To achieve this one or more of the conveyor systems, particularly any side conveyor systems, are usually placed in a folded position prior to transport of the unit. If the unit is to be moved to a different site, it is important that the conveyor systems fold as close to the unit as possible, to meet the restrictions imposed on the width of vehicles travelling on public highways. Even if a unit is to remain in the same place within a site, it is desirable that the conveyor systems be placed in a folded position, to avoid inadvertent damage to them. Foldable conveyor systems and foldable frames for such systems have been developed, but many of these have experienced problems, for example in the ease of folding, or the strength of the frame, etc.

According to a first aspect of the present invention there is provided a frame for a conveyor system comprising a first frame section, a second frame section movably connected to the first frame section and a third frame section movably connected to the second frame section, first and second support members each movably connected at a first end thereof to the first frame section and at a second end thereof to the third frame 2 section, first operating means connected between the first frame section and the second frame section, and second operating means connected between the first frame section and the third frame section, the operating means acting to move the second and third frame sections betwe en an operative position wherein they lie substantially in line with each other and the first frame section, to an inoperative position wherein the second and third frame sections are folded with respect to the first frame section, the first operating means acting to pivot the second frame section relative to the first frame section about a first pivot axis, and the second operating means acting to pivot the third frame section relative to the second frame section about a second pivot axis.

The arrangement is most preferably such that when the frame (and associated conveyor system) is placed in the inoperative position, the frame is suitably positioned for storage and transportation.

The first frame section may be connected to the second frame section via one or more coaxial pivot joints. The or each pivot joint may comprise a pivot plate attached to the first frame section, a pivot plate attached to the second frame section, and a pivot pin connecting the plates and defining the first pivot axis about which the second frame section pivots relative to the first frame section. The first and second frame sections may each be ladder-like in construction, each comprising first and second substantially parallel elongate members spaced apart by one or more rungs. The or each rung may be provided with a carrying member, for carrying a conveyor belt. A pivot joint is preferably provided between the first elongate member of the first frame section and the first elongate member of the second frame section, and between the second elongate member of the first frame section and the second elongate member of the second frame section. The pivot pins of such pivot joints are aligned, such that 3 the second frame section moves relative to the first frame section about a single pivot axis.

The second frame section may be connected to the third frame section via one or more pivot joints. The or each pivot joint may comprise two pivot plates attached to the second frame section and a pivot pin connected to the plates and the third frame section, and about which the third frame section pivots relative to the second frame section. The pivot plates may be attached to a rung of the second frame section. When one pivot joint is provided, the plates may be attached to a rung in an approximately central position thereof. The third frame section may comprise a single elongate member. A first end thereof may be attached to a pivot pin of a pivot joint, and a second end thereof may be provided with a fork-like structure for supporting a conveyor belt. The third frame section may be provided with one or more carrying members for carrying a conveyor belt.

As the first and second frame sections and the second and third frame sections each move relative to each other about only a single pivot axis, i.e. they pivot in one plane only, the pivot joints by which the frame sections are connected need not be complicated. For example, it is not necessary to provide universal type pivot joints. The first pivot axis about which the second frame section pivots with respect to the first frame section, and the second pivot axis about which the third frame section pivots with respect to the second frame section are preferably substantially perpendicular to each other. This allows the second and third frame sections to lie snug against a screening unit to which the frame may be attached.

The first support member may comprise a first leg. This may be attached 4 to the first and third frame sections via pivot joints. The length of the first leg may change during movement of the frame between operative and inoperative positions, e.g. it may become shorter and/or longer, using, for example, a sliding mechanism. The second support member may comprise a second leg. This may be attached to the first and third frame sections via pivot joints. The length of the second leg preferably varies throughout movement of the frame between operative and inoperative positions. The second leg may comprise a first member connected to the first frame section, and a second member connected to the third frame section. At least a portion of the first member is preferably received and slides within the second member, thereby decreasing and increasing the length of the leg. For example the first and second members may be constituted by a pair of telescoping box sections. The support members act to support the third frame section when in its operative position, thereby increasing the overall strength of the frame.

The first frame section may be provided with a connector element which may protrude from the first frame section at an angle of approximately 66 degrees. An end of the first operating means may be attached to the connector element. The second frame section may be provided with a connector element, to which an end of the first operating means may be attached. The second operating means may be directly connected between the first and third frame sections, or may be indirectly connected between the two. For example, the second operating means may be connected to the second support member, which, in turn, is connected to the first and third frame sections. A first end of the second operating means may be attached to the first member of the second leg, and a second end of the second operating means may be attached to the second member of the second leg. The second operating means may cause the second member to slide towards and away from the first member.

The first and second operating means may each comprise a hydraulic ram. The hydraulic rams preferably operate simultaneously. They may be connected to the same hydraulic valve to achieve this.

The frame may be fixedly attached to a screening unit preferably by the first frame section. When the frame is in its operative position, the first, second and third frame sections preferably extend away from the screening unit in an upward direction: for example they may project out at right angles to the screening unit and be upwardly inclined at an angle of approximately 20-30 degrees to the horizontal. Preferably, the frame sections are upwardly inclined at an angle of approximately 24 degrees to the horizontal. The connector element of the first frame section may then take up a substantially vertical position. The frame is preferably attached to a side portion of the screening unit, and supports a side conveyor belt. The conveyor belt may be 80Omm wide. When folded into the inoperative position, the second and third frame sections of the frame preferably lie at least substantially parallel to the side of the unit, and in close proximity thereto.

According to a second aspect of the present invention there is provided a screening unit comprising one or more frames according to the first aspect of the invention, for supporting one or more conveyor systems.

An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a frame according to the present invention shown in the inoperative position, and 6 Figure 2 is a perspective view of the frame of Figure 1, shown in the operative position.

The frame comprises a first frame section 1, a second frame section 2 connected to the first frame section, and a third frame section 3 connected to the second frame section. A first support member 4 and a second support member 5 are each connected between the first frame section and the third frame section. A first operating means 6 is connected between the first frame section and the second frame section, and a second operating means 7 is connected to the second support member 5.

The first frame section comprises first and second elongate members 8 and 9 respectively. The elongate members are spaced apart and fixed substantially parallel to each other by first and second rungs 10 and 11 respectively (Figure 2). The rungs are fixed to the elongate members as by welding. A connector element 12 is attached to the first frame section. The connector element comprises a first arm 13 attached at one end thereof to the elongate member 8 and a second arm 14 attached at one end thereof to the elongate member 9. The arms are joined at their opposite ends by a rung 15. The arms form an angle of approximately 66 degrees with the elongate members. The elongate members are provided with flanges 16,17 for attachment thereof to a screening unit.

The second frame section 2 comprises first and second elongate members 18 and 19 respectively. The elongate members are spaced apart and fixed substantially parallel to each other by rungs 20, 21 and 22. The rungs are fixed to the elongate members as by welding. The rungs 20,21 each have a carrying member 23 attached thereto, for carrying a conveyor belt (not shown).

7 The second frame section is connected to the first frame section by a first pivot joint 24 and a second pivot joint 25. The first pivot joint comprises a first pivot plate 26 attached to the elongate member 8 of the first frame section, a second pivot plate 27 attached to the elongate member 18 of the second frame section, and a pivot pin 28 connecting the plates together and about which the elongate member 18 pivots relative to the elongate member 8. The second pivot joint comprises a first pivot plate 29 attached to the elongate member 9 of the first frame section, a second pivot plate 30 attached to the elongate member 19 of the second frame section and a pivot pin 31 connecting the plates together and about which the elongate member 19 pivots relative to the elongate member 9. The pivot pins 28,31 lie parallel to and in line with each other, and the elongate members 18,19 therefore pivot about the same, single first pivot axis defined by these pivot pins.

The third frame section 3 comprises an elongate member 32. Carrying members 33 are attached at intervals along the elongate member, for supporting a conveyor belt (not shown). The elongate member has a forklike structure 34 attached to one end. This has first and second tines 35 which are provided with end slots 35a for supporting axle pins of a roller (not shown) which serves to support and guide the outboard end of the conveyor belt. The elongate member has a connector element in the form of a cross-tree 36 attached thereto.

The third frame section is connected to the second frame section by a pivot joint 37. The pivot joint comprises first and second pivot plates 38,39 attached to the rung 22 of the second frame section, and a pivot pin 40 connected to the two plates and to an end of the elongate member 32 of the third frame section. The pin provides a pivot line about which the elongate member 32 pivots relative to the second frame section. The 8 pivot line lies substantially perpendicular to the pivot line of the pivot joints 24,25. The third frame section therefore pivots relative to the second frame section substantially at right angles to the direction of pivot of the second frame section relative to the first frame section.

The first support member 4 comprises a first leg which is of box section and which is attached via a pivot joint 41 to the rung 15 of the first frame section, and via a pivot joint 42 to the cross-tree 36 of the third frame section. The length of this leg can change, e.g. it can be telescopically extended by up to about 70mm, in order to accommodate any variations in the distance between its end pivots 41, 42 during folding movement of the frame between the operative position and the inoperative position. The second support member 5 comprises a second leg which is also of box section and whose length varies as the frame is moved between operative and inoperative positions. This leg comprises a first member 43 attached via a pivot joint 44 to the rung 15 of the first frame section, and a second member 45 attached via a pivot joint 46 to the structure 36 of the third frame section. The first member telescopes within the second member, thereby decreasing and increasing the length of the leg.

The first operating means 6 comprises a hydraulic ram 48. The housing 49 of the ram is attached via a pivot joint 50 to the rung 15 of the first frame section. The piston 51 of the ram is attached via a pivot joint 52 to a portion 53 of the second frame section. The ram is attached to a hydraulic valve (not shown), and from there to a hydraulic fluid reservoir (also not shown). Fluid from the reservoir activates the ram, causing the piston to move into and out of the housing thus causing the second frame section to pivot about the pivot joints 24,25. The second operating means also comprises a hydraulic ram 54. The housing 55 of the ram is attached via a joint 56 to the first member 43 of the second leg. The piston 57 of 9 the ram is attached via a joint 58 to the second member 45 of the second leg. This ram is also attached to the hydraulic valve, and from there to the hydraulic fluid reservoir. Fluid from the reservoir activates the ram, causing the piston to move into and out of the housing thus driving telescopic movement of the second leg and causing pivotal movement of the third frame section about the pivot 37.

The frame is foldable to and from an inoperative position (Figure 1), to an operative position (Figure 2). In the inoperative position, the second and third frame sections 2,3 are folded along the side of a screening unit to which the frame may be attached for use. The pivot axes about which the second and third frame sections pivot are substantially perpendicular to each other, allowing the frame sections to lie in their stored positions as shown in Figure 1. In that inoperative position, the elongate member 32 and each of the tines 35 of the third frame section 3 lie along and substantially parallel to the side of the screening unit, thus reducing the overall width of the folded frame. The tines 35 which support the conveyor belt end roller lie vertically above one another so that the outer reach of a conveyor belt may be held snugly against the body of such a screening unit: the second frame section 2 is generally vertical so that the middle reach of such conveyor belt is held snugly against the side of the screening unit.

Thus the conveyor belt may be nested in against the body of the screening unit on which it is mounted so that the frame in its inoperative position is stored in a position in which it projects sideways from the remainder of the screening unit to only a small extent, if at all, and the unit to which the frame is attached can be transported with the frame in this position.

This allows a favourable compromise to be reached as between the size of the basic screening unit (and thus its total throughput capacity) and its maximum width dimension (including side conveyors) when those side conveyors are in inoperative, storage position. This is particularly valuable when it is desired to move such a screening unit along a public road.

To unfold the sections 2,3, the ram 48 is activated to draw the piston 51 into the housing 49. This causes the second frame section 2 to pivot about the pivot joints 24,25, lowering it into a position substantially in line with the first frame section 1. At the same time, the ram 54 is activated to push the piston 57 out of the housing 55. This causes the second member 45 of the second leg to slide away from the first member 43, and the length of this leg increases. This in turn causes the third frame section 3 to pivot about the pivot joint 37, bringing the third frame section 3 substantially into line with the second frame section 2. Thus the frame takes up its operative position as shown in Figure 2, and a conveyor belt can be supported by and travel along the frame sections. Material screened by the unit can then be carried by the conveyor belt, from the screening device of the unit to a stockpile therefor. The legs support the third frame section, and therethrough the second frame section, in their operative positions, and the majority of the weight of these sections is carried by the legs. The frame sections and the legs together form a tripod-like structure, and the overall strength of the frame for the conveyor is high.

Claims

A frame for a conveyor system comprising a first frame section, a second frame section movably connected to the first frame section and a third frame section movably connected to the second frame section, first and second support members each movably connected at a first end thereof to the first frame section and at a second end thereof to the third frame section, first operating means connected between the first frame section and the second frame section, and second operating means connected between the first frame section and the third frame section, the operating means acting to move the second and third frame sections between an operative position wherein they lie substantially in line with each other and the first frame section, to an inoperative position wherein the second and third frame sections are folded with respect to the first frame section, the first operating means acting to pivot the second frame section relative to the first frame section about a first pivot axis, and the second operating means acting to pivot the third frame section relative to the second frame section about a second pivot axis.
2. A frame according to claim 1 in which, when the frame is placed in the inoperative position, it is suitably positioned for storage and transportation.
3. A frame according to claim 1 or claim 2 in which the first frame section is connected to the second frame section via one or more coaxial pivot joints.
4. A frame according to claim 3 in which the or each pivot joint comprises a pivot plate attached to the first frame section, a pivot plate 12 attached to the second frame section, and a pivot pin connecting the plates and defining the first pivot axis about which the second frame section pivots relative to the first frame section.
5. A frame according to any preceding claim in which the first and second frame sections are each ladder-like in construction, each comprising first and second substantially parallel elongate members spaced apart by one or more rungs.
6. A frame according to claim 5 in which the or each rung is provided with a carrying member, for carrying a conveyor belt.
7. A frame according to claim 5 or claim 6 as dependent from claim 3 or claim 4 in which a pivot joint is provided between the first elongate member of the first frame section and the first elongate member of the second frame section, and between the second elongate member of the first frame section and the second elongate member of the second frame section.
8. A frame according to any preceding claim in which the second frame section is connected to the third frame section via one or more pivot joints.
9. A frame according to claim 8 in which the or each pivot joint comprises two pivot plates attached to the second frame section and a pivot pin connected to the plates and the third frame section, and about which the third frame section pivots relative to the second frame section.
10. A frame according to claim 9 as dependent from claim 4 or claim 5 in which the pivot plates are attached to a rung of the second frame section.
11. A frame according to claim 10 in which one pivot joint is provided and the plates are attached to a rung in an approximately central position 5 thereof.
12. A frame according to any preceding claim in which the third frame section comprises a single elongate member.
13. A frame according to claim 12 in which a first end of the elongate member is attached to a pivot pin of a pivot joint, and a second end of the elongate member is provided with a fork-like structure for supporting a conveyor belt.
14. A frame according to any preceding claim in which the third frame section is provided with one or more carrying members for carrying a conveyor belt.
15. A frame according to any preceding claim in.which the first pivot axis about which the second frame section pivots with respect to the first frame section, and the second pivot axis about which the third frame section pivots with respect to the second frame section are substantially perpendicular to each other.
16. A frame according to any preceding claim in which the first support member comprises a first leg.
17. A frame according to claim 16 in which the first leg is attached to the first and third frame sections via pivot joints.

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18. A frame according to claim 16 or claim 17 in which the length of the first leg changes during movement of the frame between operative and inoperative positions.
19. A frame according to claim 18 in which the first leg becomes shorter and/or longer using a sliding mechanism, during movement of the frame between operative and inoperative positions.
20. A frame according to any preceding claim in which the second support member comprises a second leg.
21. A frame according to claim 20 in which the second leg is attached to the first and third frame sections via pivot joints.
22. A frame according to claim 20 or claim 21 in which the length of the second leg varies throughout movement of the frame between operative and inoperative positions,
23. A frame according to any of claims 20 to 22. in which the second leg comprises a first member connected to the first frame section, and a second member connected to the third frame section.
24. A frame according to claim 23 as dependent from claim 22 in which at least a portion of the first member is received and slides within the second member, thereby decreasing and increasing the length of the leg.
25. A frame according to claim 24 in which the first and second members are constituted by a pair of telescoping box sections.

is
26. A frame according to any preceding claim in which the support members act to support the third frame section when in its operative position, thereby increasing the overall strength of the frame.
27. A frame according to any preceding claim in which the first frame section is provided with a connector element.
28. A frame according to claim 27 in which the connector element protrudes from the first frame section at an angle of approximately 66 10 degrees.
29. A frame according to claim 27 or claim 28 in which an end of the first operating means is attached to the connector element.
30. A frame according to any preceding claim in which the second frame section is provided with a connector element.
31. A frame according to claim 30 in which an end of the first operating means is attached to the connector element.
32. A frame according to any preceding claim in which the second operating means is directly connected between the first and third frame sections.
33. A frame according to any of claims 1 to 31 in which the second operating means is indirectly connected between the first and third frame sections.
34. A frame according to claim 33 in which the second operating 30 means is connected to the second support member, which, in turn, is 16 connected to the first and third frame sections.
35. A frame according to claim 34 as dependent from any of claims 23 to 25 in which a first end of the second operating means is attached to the first member of the second leg, and a second end of the second operating means is attached to the second member of the second leg.
36. A frame according to claim 35 in which the second operating means causes the second member to slide towards and away from the first 10 member.
37. A frame according to any preceding claim in which the first and second operating means each comprise a hydraulic ram.
38. A frame according to claim 37 in which the hydraulic rams operate simultaneously.
39. A frame according to claim 38 in which the hydraulic rams are connected to the same hydraulic valve to achieve simultaneous operation.
40. A frame according to any preceding claim which is fixedly attached to a screening unit.
41. A frame according to claim 40 in which the first frame section is 25 fixedly attached to a screening unit.
42. A frame according to claim 40 or claim 41 in which, when the frame is in its operative position, the first, second and third frame sections extend away from the screening unit in an upward direction.

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43. A frame according to claim 42 in which the first, second and third frame sections project out at right angles to the screening unit and are upwardly inclined at an angle of approximately 20-30 degrees to the horizontal.
44. A frame according to claim 43 in which the frame sections are upwardly inclined at an angle of approximately 24 degrees to the horizontal.
45. A frame according to claim 44 as dependent from any of claims 27 to 29 in which the connector element of the first frame section takes up a substantially vertical position.
46. A frame according to any of claims 40 to 45 in which the frame is attached to a side portion of the screening unit, and supports a side conveyor belt.
47. A frame according to claim 46 in which, when folded into the inoperative position, the second and third frame sections of the frame preferably lie at least substantially parallel to the side of the unit, and in close proximity thereto.
48. A screening unit comprising one or more frames according to any of claims 1 to 47, for supporting one or more conveyor systems.
49. A frame substantially as described herein with reference to the accompanying drawings.