GB2124172A - Chain conveyor - Google Patents

Abstract

In a chain conveyor, having at least one rotatary endless chain (1), individual chain links (2) of the endless chain carry flanging lugs (3) for fixing conveying elements (9). The flanging lugs (3) are in each case fixed by welding to one straight leg (6) of the particular chain link (2). The weld is located outside the nose regions (4, 5) of the chain link, in such a way that the contact face (10) of the lug lies in a plane which is at right angles to the plane of the straight leg (6) of the link. The lug may be offset from the centre of the link. <IMAGE>

Description

SPECIFICATION Chain conveyor The invention relates to a chain conveyor, having at least one rotatory endless chain, to which conveying elements are fixed which are held by flanging lugs which are fixed in each case, outside the nose regions, to a straight leg of the closed chain link of the particular endless chain and to which the conveying elements are joined by means of bolts.

A chain conveyor of the above kind, designed as a scraper conveyor, is known, wherein the scrapers are held in each case between two flanging lugs which form part of a driving bracket with projections forming the flanging lugs.

For several reasons, the known scraper conveyor is not fully satisfactory. The first reason is that the thickness of the scrapers must be matched precisely to the spacing of the bracket lugs. In practice, it is usually impossible to meet this requirement, because of the tolerances arising during manufacture. The consequence is that undesired distortions occur even when the scrapers are bolted on. A further disadvantage is the comparatively complicated shape of the known driving brackets. Moreover, the flanging lugs merge at the brackets into zones in which the stress conditions are unfavourable. As experience has shown, the driving brackets are indeed the first to break, not least due to the dynamic stresses occurring during the rotation of the endless chains. In other words, they form the weak point of the entire chain conveyor.

It is the object of the invention to provide a chain conveyor of the type under consideration, which is of simpler construction and in which, in spite of using it with one flanging lug, acceptable stress conditions in the link leg carrying the flanging lug are ensured.

According to the invention, this object is achieved when in each case one flanging lug is welded to a leg in such a way that the contact face for the conveying element to be fixed to the flanging lug lies in a plane which extends transversely to the longitudinal axis of the chain link carrying the flanging lug and through the centres of the chain link legs and which intersects the latter at right angles.

The chain conveyor according to the invention has the advantage that, in the region of the fixing of the conveying element, components are used which have a high strength and simple structure. Since no twin lugs are used, distortions are avoided and, since the contact faces for the conveying element to be fixed to the particular flanging lug lie in a plane which extends transversely to the longitudinal axis of the chain link carrying the flanging lug and through the centres of the chain link legs and which intersects the latter at right angles, favourable stress conditions are obtained in the link legs which carry the flanging lug.

Finally, it is advantageous to provide the fianging lugs with a point of weakness. In the case of a blockage of the chain conveyor, causing an overload, the flanging lug breaks in the region of the point of weakness. The chain itself and the remaining parts of the conveyor are thus protected from damage.

Afterwards, a new lug can be welded to the stub of the flanging lug which has broken off, without impairing the characteristics of the chain. After the indicated repair, the chain conveyor is again fully operable.

Due to the circumstance that the flanging lug is arranged on a normal chain link which corresponds to the other links of the chain with respect to the shape of the link, pitch, link tolerance, strength and hardening, smooth running of the endless chains over the chain wheels of the particular chain conveyor is ensured. After endless chains have been drawn in and closed as well as tensioned, the conveying elements can be interchanged, without the need for slackening and opening of the endless chains. In other words, fitting the chain conveyor with replacement conveying elements can be carried out in a much simpler and quicker way than in the case of chain conveyors having connection components formed by chain brackets.

In the text which follows, the invention is explained in more detail by reference to the attached drawing in which: Figure 1 shows a plan view of the fixing point for conveying elements of the chain conveyor; Figure 2 shows a section along the line ll-ll in Fig. 1; Figure 3 shows the position of a flanging lug when an endless chain runs around a toothed chain wheel; Figure 4 shows a section through the toothed chain wheel according to Fig. 3; Figure 5 shows the position of a flanging lug when an endless chain runs around a grooved chain wheel; Figure 6 shows a section through the grooved chain wheel according to Fig. 5; Figure 7 shows a plan view of an endless chain with a flanging lug having a point of weakness;; Figure 8 shows a section along the line VIII-VIII in Fig. 7, and Figure 9 shows a plan view of a part of a chain conveyor with a single endless chain.

In Fig. 1, an endless chain of a chain conveyor designed as a scraper conveyor is generally marked 1. The endless chain has chain links 2 to which the flanging lugs 3 are welded. The junction between the particular flanging lug and the chain link 2 is located outside the nose regions 4 and 5 of the chain link, that is to say the flanging lug is welded to one of the straight legs of the chain link. A conveying element 9 is joined to the flanging lug 3 by means of bolts 8.

In Fig. 2, it will be seen that the contact face 10 for the conveying element 9 to be fixed to the particular flanging lug 3 lies in a plane which extends transversely to the longitudinal axis of the chain link carrying the flanging lug 3 and through the centres of the chain link legs 6 and 7 and which intersects the latter at right angles. The flanging lugs 3 should here be arranged on the chain link leg 6 with an offset from the centre thereof in the direction opposite to the conveying direction indicated by the arrow 11.

Figs. 3 and 4 show the position of a flanging lug 3 when an endless chain 1 runs around a toothed chain wheel 1 2. Figs. 5 and 6, by contrast, show the position of a flanging lug when passing over a grooved chain wheel 13.

Figs. 7 and 8 largely correspond to Figs. 1 and 2. In this case, a flanging lug 14 with a point of weakness 1 5 is shown.

Fig. 9 shows a plan view of a part of a chain conveyor with a single endless chain, wherein every third horizontal chain link 2 is provided with two flanging lugs 14 which each have a point of weakness 1 5. The flanging lugs 14 are joined by welding to the legs 6 and 7 of the particular chain link 2.

The design according to the invention, when used in connection with scraper conveyors, enables scrapers of different thickness to be used. Due to the off-centre arrangement of the flanging lugs and the fitting of the conveying elements at a point which is off-set from the centre of the chain link legs in the direction opposite to that of conveying, the stresses introduced by the chain traction into the link leg carrying the particular flanging lug are influenced in a positive way.

Claims (6)

1. A chain conveyor having at least one rotary endless chain to which conveying elements are fixed, the conveying elements being held by flanging lugs which are fixed in each case, outside the nose regions, to a straight leg of a closed chain link of the particular endless chain and to which the conveying elements are joined by means of bolts, in which, in each case, one flanging lug is welded to a leg in such a way that the contact face for the conveying element to be fixed to the flanging lug lies in a plane which extends transversely to the longitudinal axis of the chain link carrying the flanging lug and through the centres of the chain link legs and which intersects the latter at right angles.

2. A chain conveyor according to claim 1, in which the flanging lugs are arranged on the chain link legs with an offset from the centre thereof in the direction opposite to that of the conveying direction.

3. A chain conveyor according to claim 1 or claim 2, in which the flanging lugs are each provided with a point of weakness.

4. A chain conveyor according to any one of claims 1-3, in which the conveying elements are formed by scrapers.

5. A chain conveyor according to any one of claims 1-4, in which, in each case, one flanging lug is fixed to each leg of a closed chain link.

6. A chain conveyor substantially as described herein with reference to the accompanying drawings.