GB2127373A

GB2127373A - Drag chain conveyor and chain link therefore

Info

Publication number: GB2127373A
Application number: GB08323911A
Authority: GB
Inventors: Thomas G Krulick
Original assignee: Fuller Co
Current assignee: Fuller Co
Priority date: 1982-09-17
Filing date: 1983-09-07
Publication date: 1984-04-11
Also published as: FR2533285B1; GB2127373B; ES278156Y; ES8406355A1; FR2533285A1; ZA836360B; ES278156U; CA1227156A; ES525655A0; MX156398A; AU1811883A; GB8323911D0; IN162252B; AU560688B2

Abstract

A drag chain conveyor is capable of being reversible so that material can be fed to the centre and conveyed in either direction of travel. The chain link (30) is in the general shape of a cross with one member (33) of the cross acting as the material pusher and the other member (32) being in the direction of travel of the chain (25) and serving as the chain link. The member (32) has a lug (35) at one end and a U-shaped enlargement (39) at the other end with the lug (35) of the link (30) pivotally connected to the enlargement (39) of an adjacent link (30) to form the chain (25). When the conveyor is driven in one direction, a drive sprocket engages one face e.g. 48 of the link (30), and when the conveyor is driven in the other direction, a drive sprocket at the other end of the conveyor engages the other face 49 of the link. <IMAGE>

Description

SPECIFICATION Drag chain conveyor and chain link therefore The present invention relates to drag chain conveyors of the type used to handle hot and cold bulk materials such as cement clinker, burnt lime, coal, cement dust, ores, sand, and gravel. More particularly, the invention relates to a modified T-link chain link and a drag chain conveyor utilising that chain link design which is capable of being reversible in its direction of travel.

Conveyors of the type to which the present invention relates have been known for may years for conveying bulk materials. Such conveyors utilise an endless chain moving around spaced apart sprockets with one sprocket serving as the drive sprocket and the other as an idler sprocket. The conveying portion of the chain may move through a trough. The trough may be in the bottom of a hopper or other place where material is continuously supplied to the trough along the length thereof, and as the chain moves along the trough, material is pulled towards an outlet. An alternative arrangement is to have a specific feed point for material into the trough and a defined material outlet. Generally, the drive is located at the head section or outlet of the conveyor and pulls material towards the outlet while the tail section or idler section is near the inlet for the conveyor.

The conveyor chain itself is made up of a plurality of links which may be in the form of a U-shape or they may be a T-shape or several variations thereof. The present invention relates to a modified T-shaped or cross-shaped chain link and the conveyor chain made up from a plurality of such links.

One of the important features of a drag chain conveyor is the fit of the chain into the sprocket to insure long life of the operating parts and smooth operation of the conveyor. It is, therefore, important to coordinate the design of the chain link and the design of the drive and idler sprockets. It is also important to have interchangeable parts so the drive sprocket should be made up of substantially identical parts as the idler sprocket.

There are some instances where it would be desirable to have a drag chain conveyor which is capable of being reversible, i.e., driven in either direction along the length of the conveyor. Such an application could be in a mining or minerals processing situation where material may come from a central source with the process flow requiring material be conveyed to alternative use points with a single conveyor. In this instance there might be a central feed point to a drag chain conveyor with alternative parallel outlets at opposite ends of the conveyor so that if the conveyor is operated in one direction, material is conveyed to one of the use points, while if the conveyor is operated in the other direction, material is conveyed to the other use point.

It is, therefore, an object of the present invention to provide a drag chain conveyor capable of conveying bulk materials which includes an improved chain link and sprocket design, and to provide an improved form of chain link.

According to the present invention there is provided a chain link adapted to be connected to other similar chain links to form a conveyor chain for conveying material, said chain link comprising a generally cross-shaped member having a first member and a second member perpendicular to the first member; said first member having a lug at one end an enlargement at its other end; the lug at one end being adapted to be connected to the enlargement on an adjacent, similar chain link of a conveyor chain; said enlargement having a pair of projections, each extending outwardly from said enlargement on opposite sides of the first member; each projection having a pair of faces on opposite sides thereof, each adapted to be selectively engaged by a drive sprocket of a conveyor chain.

Further according to the present invention there is provided a chain link conveyor for conveying material comprising: a plurality of substantially identical links pivotally connected to each other to form an endless conveyor chain; a pair of sprocket means, each located at one end of the conveyor and operatively connected to said chain; one of said sprocket means being a drive sprocket means and the other of said sprocket means being an idler sprocket means; each sprocket means includes a shaft and a sprocket wheel mounted on said shaft;; each of said links including a cross-shaped member having a first member extending in the direction of travel of the conveyor chain, a second member transverse to the first member for conveying material, said first member having a lug at one end and an enlargement at its other end with the lug of one link being pivotally connected to the enlargement of the adjacent link to thereby form the endless chain; said enlargement at said other end of the first member of each of said links having a pair of projections each extending outwardly on opposite sides of said enlargement and each having a pair of faces on opposite sides thereof;; one face of the projection being adapted to be selectively engaged by teeth on the sprocket wheel at one end of the conveyor and the other face of the projection being adapted to be selectively engaged by teeth on the sprocket wheels at the other end of the conveyor.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a conveyor according to the present invention with parts broken away for clarity; Figure 2 is a perspective view of the chain of the Fig. 1 conveyor illustrating individual links of the chain each according to the present invention; Figure 3 is a view of a sprocket and chain when the chain is moving in one direction of travel; Figure 4 is a view similar to Fig. 3 showing a chain and sprocket when the chain is moving in the opposite direction of travel; Figure 5 is a plan view of a conveyor and chain taken on the line 5-5 of Fig. 3; and Figure 6 is an elevation view of a conveyor similar to Fig. 1 showing an inlet and alternative outlets with the conveyor itself shown in phantom.

Referring to Figs. 1 and 6 there is shown a conveyor generally indicated at 1 which may include a housing 2 including a trough 3 and a cover 4. The conveyor may have an inlet 5 for material to be conveyed and outlets 6 and 7 at opposite ends thereof. Since the conveyor is designed to be operated in either direction of travel and since one should pull on a chain rather than attempt to push that chain, two drive means 10 and 11 are used with each being capable of serving as the drive sprocket means or the idler sprocket means.

Each drive means includes a motor means 15, a clutch, diagrammatically illustrated at 16, a speed reducer 14, a drive chain 17, a drive sprocket 18, and a driven sprocket 1 8a.

The drive means also includes a sprocket means 1 9 including a shaft 20 fixed to the driven sprocket 1 8a and suitably mounted in bearings (not shown) on opposite sides of the conveyor, and as illustrated in Fig. 1, a pair of spaced apart sprocket wheels 21 and 22 fixed by means of keys 1 3 to the drive shaft 20.

Alternatively, a single sprocket wheel with longitudinally spaced apart teeth could be used.

One of the drive means serves as the drive sprocket and the other serves as the idler sprocket means, depending upon which direction of travel the conveyor is moving. When one of the drive means 10 or 11 is acting as the drive sprocket, its clutch is engaged so that the motor rotates and drives the sprocket wheels 21 and 22 and chain conveyor through chain 17, sprockets 1 8 and 1 8a, and shaft 20. At the same time, the clutch means 1 6 of the other drive means 10 or 11 is disengaged and the motor 1 5 is shut off so that the sprocket wheels 21 and 22 serve as idler sprockets.

Referring to Figs. 2 to 5, the conveyor chain is generally indicated at 25 and is made up of a plurality of chain links, each generally indicated at 30. The chain links 30 are substantially identical to each other and are pivotally connected to each other at 26 by means of suitable pins 27 to thereby define an endless chain.

The present invention utilises a chain link generally known in the art as a T-link. Each of the links includes a cross-shaped member or a modified T-link generally indicated at 31 having a first member 32 which extends in the direction of travel of the conveyor and a second member 33 which is transverse to the first member 32 and serves to convey material along the trough 3 from the inlet 5 to either outlet 6 or 7 depending upon the direction of travel of the chain or in an open type conveyor from material dropping into the trough from along its length.

The first member 32 includes a lug 35 at one end having a hole 36 therethrough and an arcuate leading surface 37. The first member 32 also includes a U-shaped enlargement 38 at its other end. The U-shaped enlargement includes a base 39 and a pair of legs 40, each having a projection 41 thereon which extends outwardly therefrom, parallel to the second member 33. Each of the projections 41 has a hole 42 therethrough aligned with the hole in the other projection.

The U-shaped enlargement at one end of one of the lengths 30 is dimensioned to receive the lug 35 of the adjacent link 30.

The pin means 27 extends through the openings 42 of projection 41 and the opening 36 of the lug 35 of the adjacent link to thereby pivotally connect two adjacent links together at 26. This linkage is clearly shown in Figs. 2 and 5 and the pivotal connection is apparent from Figs. 3 and 4. The rounded or arcuate leading surface 37 of lug 35 facilitates the pivotal movement of one link 30 relative to its adjacent connected links.

Each projection 41 on the enlargement 38 includes a pair of faces 48 and 49 each of which is adapted to be selectively engaged by a tooth on the drive or idler sprockets as will become apparent. The faces 48 and 49 as well as the top surface 50 of each projection is rounded or arcuate in configuration and has its axis coextensive with the centreline of the hole 42 through enlargement 38. The bottom surface 51 of the projection as well as the entire link 30 is substantially flat. These flat surfaces provide a large wearing surface which will result in a longer chain life. This is particularly true in the area of the lug 35 and U-shaped enlargement 38.

Both side surfaces 52 and 53 of the material conveying or second member 33 are concave and serve as material pusher surfaces depending on the direction of travel. Both the bottom and top surfaces 54 and 55 respectively of member 33 are flat. The flat bottom surfaces of the link 30 also enables the con veyor chain to move freely in its trough 3 and thereby convey most of the material within that trough.

The drive and idler sprockets means are substantially identical to each other. Each includes a pair of spaced apart sprocket wheels 21 and 22. Each sprocket wheel is asymmetrical in configuration in that both flanks of the teeth 60 on the sprocket wheel are not identical. The trailing flank 61 in the direction of rotation of the sprocket and a portion of the root of the wheel 21 or 22 is relieved. A symmetrical tooth 60a is illustrated in Fig. 3 wherein the relieved portion of a tooth 60 is shown by dotted lines 60b. Referring to Figs.

3 and 4, it will be seen that the chain 25 is pulled or driven by the generated or leading flank 62 of tooth 60. The radius 63 at the intersection of generated flank 62 and the root 64 of the sprocket wheel is dimensional so that it substantially matches the curvature of the faces 48, 49 and 50 of enlargements 38 and projections 41. In this manner, the sprocket tooth drives the chain on a circular arc having its center concentric with the center line of the pin hole 42, 36 connecting the individual links 30 of the chain 25. As illustrated in Figs. 3 and 4, the chain link 30 pivots around the centerline of the pin 27 from the point 70 of the initial engagement with the tooth 60 and sprocket wheel until the point 71 of disengagement of the chain link 30 from the sprocket wheel.This pivotal movement ensures greater life for not only the chain links 30 but also for the sprocket wheels 21 and 22.

The trailing flank 61 is relieved at 60b by an amount sufficient to permit a chain link 30 to lie substantially flat against the root 64 of the sprocket wheel 21 or 22 to thereby allow for proper chain engagement and disengagement. The sprocket wheel and chain must be designed so that the back end of the sprocket tooth 60 clears the front face of each chain flight. To this end, the link 30 and the circumferential distance between the teeth 60 are dimensioned so that the distance between the second member 33 and the enlargement 38 on the first member 32 fits between adjacent teeth 60 on the wheel 21 or 22. The leading edge or side surface 78 of legs 40 of the U-shaped enlargement 38 of each link serves to position the link 30 on the sprocket wheel in one direction of movement of the chain.The lug 35 has a side surface 79 which serves aid in the positioning of the link 30 on the sprocket wheel in the other direction of movement.

When the chain is being driven in one direction of travel, one of the faces 48 or 49 of projections 41 will be engaged by the teeth of the drive sprocket wheel and the other face 48 or 49 will be engaged by the teeth of the idler sprocket wheel. In the other direction of rotation, the opposite will occur. For example, referring to Figs. 3 and 5, when the chain is driven to the left as shown in the drawings, faces 49 of projections 41 are engaged by the leading flank 62 of teeth 60 on drive sprock ets 21a and 22a.

At the same time the faces 48 of links 30 at the other end of the conveyor engage trailing flank of the teeth 60 of the idler sprocket wheels 21 b and 22b to rotate that idler sprocket means. Referring to Figs. 3 and 5, when the chain 25 is driven in the opposite direction or to the right as shown in the drawings, faces 48 of projections 41 are engaged by the leading flank 62 of teeth 60 on what is in this direction the drive sprocket wheels 21b and 22b. At the same time the faces 49 of link 30 at the other end of the conveyor engage the teeth 60 of what is now idler sprocket wheels 21a and 22a to rotate that idler sprocket means.Thus, one of the faces 48 or 49 of the projection 41 is adapted to be selectively engaged by the teeth on the sprocket wheel at one end of the conveyor and the other face 48 or 49 of the projection 41 is adapted to be selectively engaged by the teeth on the sprocket wheel at the other end of the conveyor.

The sprocket wheels 21 and 22 on one sprocket means 1 9 at one end of the conveyor are a mirror image of the sprocket wheels at the other end of the conveyor. This ensures that the generated flank 62 of the wheel engages the link 30 in both directions of travel. As a result, in appearance, the leading flank of the idler sprocket is relieved as at 60b and the trailing edge of the drive sprocket is releived as at 60b. In manufacture, the wheels are identical, but in assembly, the wheels are mounted on the shaft 20 in opposite ways to produce the mirror image. This results in a reversible conveyor which is made up of similar drive and idler sprockets thereby saving production costs.

As shown Fig. 5, in the preferred embodiment, the sprocket wheels 21b and 22b are set closer together than the sprocket wheels 21a and 22a. In this way, the tooth 60 engages surface 48 adjacent side surface 79 of lug 35 and the side surface 79 acts as a guide for the sprocket wheels. This is similar to the manner in which the side surfaces 78 act as guides for sprocket wheels 21a and 21b.

While Figs. 1 and 6 show a drag chain conveyor with a cover and a specific inlet, it is to be understood that the present invention is equally applicable to open conveyor applications such as in the bottom of a hopper. It should also be understood that while the invention has been described for reversibility, the chain link and sprocket are equally applicable to unidirectional applications.

From the foregoing it should be apparent that objects of this invention have been carried out. It is intended that the foregoing be merely a description of a preferred embodiment and that the invention be limited solely by that which is within the scope of the appended claims.

Claims

1. A chain link adapted to be connected to other similar chain links to form a conveyor chain for conveying material, said chain link comprising a generally cross-shaped member having a first member and a second member perpendicular to the first member; said first member having a lug at one end and an enlargement at its other end; the lug at one end being adapted to be connnected to the enlargement on an adjacent, similar chain link of a conveyor chain; said enlargement having a pair of projections, each extending outwardly from said enlargement on opposite sides of the first member; each projection having a pair of faces on opposite sides thereof, each adapted to be selectively engaged by a drive sprocket of a conveyor chain.

2. A chain link according to claim 1, wherein said enlargement is U-shaped and the lug is dimensioned to fit between the legs formed by the U-shaped enlargement of an adjacent, similar chain link.

3. A chain link according to claim 2, wherein one of said projections extends outwardly from each leg of the U-shaped enlargement of the first member, parallel to the second member.

4. A chain link according to claim 3, wherein said lug and each of said projections has a hole therethrough adapted to receive a pin for pivotally joining the lug of a chain link to the U-shaped enlargement of an adjacent chain link.

5. A chain link according to claim 4, wherein each projection has an arcuate upper surface and a flat, bottom surface, said arcuate upper surface extending to its side to form the pair of faces on opposite sides thereof.

6. A chain link according to any preceding claim, wherein the second member has a concave material pusher face on each side thereof and substantially flat top and bottom surfaces.

7. A chain link conveyor for conveying material comprising: a plurality of substantially identical links pivotally connected to each other to form an endless conveyor chain; a pair of sprocket means, each located at one end of the conveyor and operatively connected to said chain; one of said sprocket means being a drive sprocket means and the other of said sprocket means being an idler sprocket means; each sprocket means includes a shaft and a sprocket wheel mounted on said shaft; each of said links including a cross-shaped member having a first member extending in the direction of travel of the conveyor chain, a second member transverse to the first member for conveying material, said first member having a lug at one end and an enlargement at its other end with the lug of one link being pivotally connected to the enlargement of the adjacent link to thereby form the endless chain;; said enlargement at said other end of the first member of each of said links having a pair of projections each extending outwardly on opposite sides of said enlargement and each having a pair of faces on opposite sides thereof; one face of the projection being adapted to be selectively engaged by teeth on the sprocket wheel at one end of the conveyor and the other face of the projection being adapted to be selectively engaged by teeth on the sprocket wheels at the other end of the conveyor.

8. A chain link conveyor according to claim 7, wherein each of said sprocket means includes drive means connected to said shaft including motor means and clutch means between said motor means and said shaft; one of said drive means being adapted to selectively drive its associated sprocket wheel in one direction and the other of said drive means being adapted to selectively drive its associated sprocket wheel in the other direction whereby when the clutch means of one drive means is engaged to permit its associated motor means to positively drive its associated sprocket wheel, the other clutch means is disengaged so that its associated sprocket wheel acts as an idler for the conveyor to thereby permit the conveyor to be reversible and convey material in either direction of travel.

9. A chain link conveyor according to claim 7, wherein said conveyor further includes at least one inlet for material to be conveyed and at least one outlet for material, and each sprocket means includes a pair of spaced apart wheels mounted on said shaft.

10. A chain link conveyor according to claim 7, wherein each of said sprocket wheels has a plurality of circumferentially spaced apart teeth and the trailing flank of each tooth of the drive sprocket means is relieved to provide an asymmetrical sprocket.

11. A chain link conveyor according to claim 10, wherein the leading flank of each tooth of the idler sprocket means is relieved to provide an asymmetrical sprocket.

1 2. A chain link conveyor according to claim 10, wherein the enlargement at the other end of the first member of the chain link is U-shaped and the leg at said one end is dimensioned to fit between the legs of the adjacent link; said lug and said enlargement having holes therethrough for receiving pin means for pivotally connecting adjacent links.

1 3. A chain link conveyor according to claim 12, wherein one of said projections extends outwardly from each leg of the Ushaped enlargement of the first member of the link parallel to the second member of the chain link, and each projection has an arcuate surface defining the pair of faces and having its axis coextensive with the center-line of the hole through the enlargement, said chain link being adapted to pivot about said axis when it is in engagement with the leading flank of each tooth of the drive sprocket means.

14. A chain link conveyor according to claim 13, wherein each sprocket means includes a pair of spaced apart sprocket wheels or said shaft and one of the sprocket wheels of each spocket means is adapted to engage one of the faces of each projection.

1 5. A chain link conveyor according to claim 14, wherein the second member of each link has a concave material pusher face on each side thereof.

16. A chain link conveyor according to claim 10, wherein each of the chain links is dimensioned so that the distance between the second member and the enlargement on the first member fits between adjacent teeth of the sprocket wheel.

1 7. A chain link conveyor according to claim 16, wherein each of the trailing flank of the teeth on the sprocket wheel is relieved by an amount sufficient to permit a chain link to be substantially flat against the root of the sprocket wheel.

18. A chain link as claimed in claim 1, and substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.

1 9. A claim link conveyor as claimed in claim 7, and substantially as hereinbefore described with reference to Figs. 1-6 of the accompanying drawings.