GB2197285A

GB2197285A - A chain and flight conveyor

Info

Publication number: GB2197285A
Application number: GB08726856A
Authority: GB
Inventors: Aden Michael Gunston
Original assignee: Redler Ltd
Current assignee: Redler Ltd
Priority date: 1986-11-17
Filing date: 1987-11-17
Publication date: 1988-05-18
Anticipated expiration: 2007-11-17
Also published as: GB8726856D0; GB8627480D0; GB2197285B

Abstract

A chain and flight conveyor comprising a single chain of round links (24) and a number of flights (19) secured each to a respective one of the links (24). Each flight (19) has a recess (26, 27) in at least one of its top and bottom edges. The upper recess (26) preferably comprises an arcuate portion (31) separating two step portions (28 and 29) and serving as a seat for the link (24). The lower recess (27) is rectangular. At least one clip (32, 33) is seared to the flight (19), preferably one on either side of the link (24) and each seated in a respective one of the step portions (28 and 29) of the upper recess (26) to locate the flight relative to the link. The clips (32 and 33) may be secured to the flight (19) by crimping. Alternatively the clips may be snap-fitted. <IMAGE>

Description

SPECIFICATION A chain and flight conveyor This invention relates to chain and flight conveyors and to attachment of a flight to a chain.

It has been proposed that a chain of a chain and flight conveyor be round link chain, that is to say the chain comprises a series of links which are formed of a material having a round cross-section.

In the context of use of round link chain in a chain and flight conveyor, there is a requirement for an arrangement by which a flight may be attached to a link of round link chain in a simple inexpensive manner which ensures good location, but yet allows a limited amount of flexibility at the attachment.

According to one aspect of this invention there is provided a chain and flight conveyor having at least one- chain of round link chain comprising a series of links which are formed of a material having a round cross-section, each link having an elongate aperture, and an attachment arrangement by which a generally rectangular flight is attached to a link of the chain, wherein the flight has a recess formed in at least one of its long edges and within which a respective portion of the link is received, the or each link portion begin trapped within the respective recess by a chip which is secured to the flight so as to locate the flight relative to the link.Preferably the clip has laterally projecting portions which coact with portions of the adjacent links that pass through said aperture so as to locate the flight against angular movement relative to the link that is trapped in the recess sufficient to disengage the link portion from the recess.

The flight may be attached to one chain only in which case there would be two such clips, one on either side of the link. Alternatively the flight may be attached to another chain by a similar attachment arrangement at a location spaced along the flight from the first mentioned attachment arrangement.

The or each clip may be secured to the flight by crimping portions of it around the flight. Alternatively the or each clip may be a two part clip which is secured to the flight by assembling the two parts together, around the flight, with a snap fit action.

According to another aspect of this invention, a method of attaching a rectangular flight of a chain and flight conveyor to a link of round link chain, the link having an elongate aperture, comprises inserting the flight, which is recessed in at least one of its long edges, into the aperture of the link by passing one of the end portions of the flight through the aperture until the recess is aligned with the link,and then rotating the flight about its lenath until a nortion of the link is received is secured to the flight adjacent the link portion so that the link portion is trapped in the recess and so that the flight is located relative to the link.Preferably the or each clip has laterally projecting portions which coact with portions of the adjacent links that pass through said aperture so as to locate the flight against angular movement relative to the link that is trapped in its recess, sufficient to disengage the link portion from the recess.

Three forms of chain and flight conveyor in which this invention is embodied will be described now by way of example with reference to the accompanying drawings, of which: Figure 1 is a schematic representation of a typical chain and flight conveyor arrangement; Figure 2 is a transverse cross-section of a chain and flight conveyor which has a single chain, the section being on the line ll-ll in fig.

1; Figure 3 is a view of one flight of a chain and flight conveyor which has a single chain, the flight being shown in elevation and the remainder being sectioned on the line Ill-Ill in Fig. 4; Figure 4 is a section on the IV-IV in Fig. 1; Figures 5 and 6 illustrate the steps of fitting the flight to the link of the chain to which it is attached; Figures 7 and 8 illustrate the steps of fitting a clip to the flight when the flight is fitted to the link as shown in Fig. 6; Figure 9 is a view similar to Fig. 3 of one flight of a chain and flight conveyor which has two chains; Figure 10 is a view similar to Fig. 3 of one flight of a chain and flight conveyor which has a single chain and a different form of clip; the section being on the line X-X in Fig. 11; Figure 17 is a view similar to Fig. 4 on the line Xl-Xl in Fig. 10; and Figure 12 illustrates the steps of fitting the clip to the flight shown in Figs. 10 and 1-1 Fig. 1 shows a typical conveyor arrangement comprising a chain and flight conveyor 10 which is accomodated within a fabricated metal casing 11. The basic casing 11 comprises fabricated, open-ended lengths 12 which are butt-jointed together at their ends, and end plates 13 which close the casing 11 at either end. An inlet 14 is formed in the top of one of the casing lengths 12 near one end of the casing 11, and an outlet 15 is formed in the bottom of another of the casing lengths 12 which is near the other end of the casing 11.

The conveyor 10 comprises at least one endless chain 16 which runs on a spaced pair of sprockets 17 and 18, and which has a number of flights 19 attached to it at spaced intervals so that they extend laterally from it within the casing 11. The sprockets 17 and 18 are journalled within the casing 1 1, one at sprockets is driven by a motor (not shown) which is mounted on the exterior of the casing.

The lower run of the chain 16 extends along the bottom of the casing 11. The chain 16 is driven so that the flights 19 that are attached to the lower run move under the inlet 14, towards the outlet 17 (viz. anticlockwise as shown by the arrows in Fig. 1), carrying with them particulate matter 20 which was inserted into the casing interior through the intlet 14.

Fig. 2 shows the cross-section of a length 12 of the casing 11 for a conveyor 10 having a single endless chain 16. The casing length 12 is formed as a box-section and comprises three sheet metal pieces, viz. a flat top -piece 21 and two angled pieces 22. The two angled pieces 22 are joined together at the centre of the bottom of the casing length 12, through an elongate T-section strip 23 of low-friction plastics material, the stem of T-section strip 23 being sandwiched between the juxtaposed edges of the angled pieces 22 and the arms of the T-section strip 23 projecting laterally to either side of the joint inside the casing 11.

The top of the T-section strip 23 serves as a wear strip for the lower run of the chain 16.

The other end of each angled piece 22 is joined to the respective edge of the flat top piece 21. The top run of the chain 16, which is shown chain-dotted in Fig. 2, runs on another plastic wear strip which is supported within the interior of the casing 11, from the side pieces 21 and 22 and which, together with its supports, is also shown chain-dotted in Fig. 2.

Figs. 3 and 4 show a rectangular flight 19 attached, midway between its ends, to a link 24 of the single chain 16 of the chain flight conveyor 10.

The chain 16 is round link chain. Hence the cross-sectional area of the material of each link is circular as can be seen from Figs. 3 and 4. The aperture 25 of each link is elongate and has semi-circular ends. The radius of each semi-circular end is greater than the radius of the round material of each link as can be seen from Fig. 4.

Opposed recesses 26 and 27 are formed at the middle of the two long sides of the flight 19. The recess 26 comprises two step portions 28 and 29 and an arcuate portion 31 by which the steps portions 28 and 29 are separated. The arcuate portion 31 is semi-circular having a radius which is slightly greater than the radius of the round cross-section of the material of the link 24 which is seated therein as can be seen from Fig. 3. The other recess 27 is rectangular having a depth which is a little less than the diameter of the round cross-section of the material of the link 24 and a length which is substantially the same as that of the recess 26. The portion of the link 24 opposite that portion that is seated in the arcuate recess portion 31 passes through the centre of the recess 27.

Two similar clips 32 and 33 are fitted in the recesses 26 and 27, one on either side of the link 24 so that the link 24 is trapped between the two clips 32 and 33 with its portion seated in the arcuate recess portion 31.

Fig. 3 shows that the clip 32 comprises a central base portion which separates two laterally extending portions 34 and 35 which extend each alongside a respective arcuate end portion of the respective one of the two links of the chain 16 that pass through the aperture 25 of the link 24 at either end. The clip 32 also comprises two arm portions 36 and 37 which extend from the bsse portion between the two links of the chain 16 that pass through the aperture 25, one on either side of the flight portion that separates the two recesses 26 and 27. The end of each arm portion 36, 37 remote from the base portion is hooked, the two hook portions 38 and 39 extending towards one another into the respective stepped portion 28 of the flight 19 in which they are seated.Hence the clip 32 closely surrounds and encompasses the portion of the flight 1 9 that separates the two recesses 26 and 27. The clip 33 similarly closely surrounds and embraces the same portion of the flight 19 on the other side of the link 24, the hooked end portions of the arms of the clip 33 being engaged within the stepped recess portion 29.

Figs. 5 to 8 illustrate assembly of the flight 19 and the link 24.

One end portion of the flight 19 is passed through the aperture 25 between the adjacent two links of the chain 16 that pass through the aperture 25, each long side of the flight 19 being adjacent to a respective one of those two adjacent links of the chain 16. The flight 19 is passed through the aperture 25 until the arcuate recess portion 31 is aligned with the link 24. The flight 19 is then rotated about its longitudinal axis until, as shown in Figs. 3 and 6, the arcuate recess 31 receives a portion of the link 24, the opposite portion of the link 24 passing through the opposed rectangular recess 27. The clips 32 and 33 are then presented to the flight 19, one on either side of the link 24, the arm portions 36 and 37 of the clip diverging from the central base portion (see Fig. 7) so that the hooked end portions 38 and 39 are spaced apart by a distance which is greater than the width of the flight 19 so as to allow the flight 19 to be received between the arm portions 36 and 37. Once the clips have been inserted into the respective rectangular shoulders at either end of the rectangular recess 27, the arms 36 and 37 are crimped into position around the flight 19, as shown in Figs. 4 and 8.

Engagement of the laterally extending portions 34 and 35 of the clips 32 and 33 with the adjacent links of the chain 16 that pass through the aperture 25 of the link 24, locates the flight 19 against significant angular movement about its longitudinal axis, The flight 19 is also located relative to the link 24 by the clips 32 and 33 that are fitted to it, one on either side of, and close to, the link 24. However as none of the parts comprising the links of the chain that pass through each other, the link portions that engage within the respective recess portions and the clips are precise fits, the attachment allows a limited amount of flexibility between all parts of it so that the flight 10 is attached to the chain 12 without being rigidly fixed to it.

In operation of the conveyor 10, the flat bottom surfaces of the clips 32 and 33, and the bottom of the links 24 between them, run on the wear strip 23 (see Fig. 2). Hence the clips 32 and 33 provide a relatively stable supoort for the chain link 24 between them.

Use of a plastic material for the wear strips minimises noise.

Fig. 9 shows that the attachment can be used in a chain and flight conveyor including two chains of round link chain. In this arrangement there are two recesses 41 and 42 in each long side of a rectangular flight 43. The two recesses 41R and 41L in one side of the flight 43 comprise a stepped portion and a semi-circular portion which is juxtaposed to the stepped portion and which receives a portion of the respective link 24R, 24L. The stepped portion of the respective recess 41R, 41L receives the hooked end portions of a respective one of two clips 44 and 45 which are similar to the clips 32 and 33.The portion of each link 24R, 24L opposite that which is received in the respective arcuate recess portion passes through an opposed rectangular recess 42R, 42L along side the base portion of the respective clip 44, 45, the width of the recesses 41R, 42R, 41L 42L being slightly greater that the sum of the width of the respective clips 44, 45 and the diameter of the round links 24R and 24L. Assembly of the clips 44 and 45 to the flight 43 is substantially as has been described above for assembly of the clips 32 and 33 to the flight 19. The casing 11 would be provided with two plastic wear strips, one below each chain.

Figs. 10 to 12 illustrate use of two-part, snap fit, resilient plastic clips 46 and 47 in place of the metal clips 32 and 33 that have to be crimped into position around the flight 19.

Figs. 11 and 12 show the clip 46 comprises a male upper portion 48 and a female lower portion 49, each formed of the resilinet plastic material. The upper portion 48 comprises a -yoke portion 51 and a pair of depending legs 52 and 53 which are spaced apart by a little more than the thickness of the flight 19. Each leg 52, 53 has a detent 54 formed on its side remote from the other leg 52, , the detent 54 being at the upper end of a ramp surface 55 which tapers downwardly to the bottom of the respective leg 52, 53. The lower portion 49 comprises a central base portion which separates two laterally extending portions 56 and 57, the central base portion and the laterally extending portions 56 and 57 being shaped similarly to, and serving the same functions as the corresponding portions of the metal clips 32 and 33.A shallow rectangular recess 58 is formed at the centre- of the upper surface of the central base portion, the width of the recess 58, as seen in Figs. 11 and 12, being substantially the same as the distance between the depending legs 52 and 53. The lower portion 49 also has a pair of upstanding posts 59 and 60. Each post 59, 60 has a detent 61 formed on its side adjacent the other post 59, 60, the detent 61 being at the lower end of a ramp surface 62 which tapers upwardly to the top of the respective post.The distance between the posts 59 and 60 is such that the legs 52 and 53 can be inserted between the posts 59 and 60 but so that the ramp surfaces 55 and 62 would interengage and urge deflection of the respective leg 52, 53 and post 59, 60 until the respective detents 54 and 61 interengage with a snap fit, due to the resilieince of the plastic material from which they are formed, so that the two portions 48 and 49 are locked together.

The flight 19 is inserted into and located within the aperture 25 of a link 24 of round link chain 16 as has been described above with reference to Figs. 5 and 6. The lower female portions 49 are then seated within the recess 27, one on either side of the flight 19, as shown in Fig. 11, the bottom of the flight 19 being seated in the recesses 58. The male upper portions 48 are then snap fitted into the respective female lower portions 49 to form a frame around the flight 19, each upper portion 48 being seated in the respective one of the step portions 28 and 29 of the upper recess 26 of the flight 1 9 when assembly of the clips 46 and 47 is complete.

Claims

1. A chain and flight conveyor having at least one chain of round link chain comprising a series of links which are formed of material having a round cross-section, each link having an elongate aperture, and an attachment arrangement by which a generally rectangular flight is attached to a link of the chain, wherein the flight has a recess formed in at least one of its long edges and within which a respective portion of the link is received, the or each link portion being trapped within the respective recess by a clip which is secured to the flight so as to locate the flight relative to the link.

2. A chain and flight conveyor according to claim 1, wherein the clip has laterally projecting portions which coact with portions of the adjacent links that pass through said aperture so as to locate the flight against angular movement relative to the link that is trapped in the recess, sufficient to disengage the link portion from the recess.

3. A chain and flight conveyor according to claim 1 or claim 2, wherein the flight is attached to one chain only, there being two such clips, one on either side of the link.

4. A chain and flight conveyor according to claim 1 or claim 2, wherein the flight is attached to another chain by a similar attachment arrangement at a location spaced along the flight from the first mentioned attachment arrangement.

5. A chain and flight conveyor according to any one of claims 1 to 4, wherein the recess comprises a juxtaposed shoulder portion and arcuate portion, the latter receiving the link portion and the former affording a seat for the respective clip.

6. A chain and flight conveyor according to claim 5, wherein a rectangular recess is formed in the other long edge of the flight opposite the recess that comprises the juxtaposed shoulder and arcuate portions, the respective clip and link portion passing side by side through the rectangular recess.

7. A chain and flight conveyor according to claim 5 when appended to claim 3, wherein said recess comprises two shoulder portions separated by the arcuate portion, the two shoulder portions providing seats for the respective clips.

8. A chain and flight conveyor according to any one of claims 1 to 7, wherein the or each clip is secured to the flight by portions of it which are crimped around the flight.

9. A chain and flight conveyor according to any one of claims 1 to 7, wherein the or each clip is a two part, snap fit clip.

10. A method of attaching a rectangular flight of a chain and flight conveyor to a link of round chain, the link having an elongate aperture, comprising inserting the flight, which is recessed in at least one of its long edges, into the aperture of the link by passing one of the end portions of the flight through the aperture until the recess is aligned with the link, and then rotating the flight about its length until a portion of the link is received within the recess, whereafter at least one clip is secured to the flight adjacent the link portion so that the link portion is trapped in the recess and so that the flight is located relative to the link.

11. A method according to claim 10, wherein the or each clip has laterally projecting portions which coact with portions of the adjecent links that pass through said aperture so as to locate the flight against angular movement relative to the link that is trapped in its recess, sufficient to disengage the link portion from the recess.

12. A method according to claim 10 or claim 11, wherein, prior to presentation to the flight for securing to the flight, the clip comprises a base portion and a pair of divergent arms each having a hook portion at its end spaced from the base portion, the hook portions extending towards one another and begin spaced apart by a distance which is greater than the width of the flight, the clip being presented to the flight from one of its longitudinal edges until that longitudinal edge is brought into contact with the base portion whereafter the arms are crimped together to embrace the flight and engage their hook portions in the seats afforded by the recess.

13. A method according to claim 10 or claim 11, wherein the clip is a two part, snap fit clip.

14. A chain and flight conveyor including an attachment arrangement by which a flight is attached to a link substantially as described hereinbefore with reference to the accompanying drawings and illustrated in Figs. 1 to 8, or modified as shown in Fig. 9, or modified as shown in Figs. 10 to 12.

15. A method of attaching a flight to a chain and flight conveyor substantially as described hereinbefore with reference to Figs. 1 to 9 to Figs. 10 to 12 of the accompanying drawings.