Conveyors: power-driven – Conveyor section – Endless conveyor
Reexamination Certificate
1999-04-26
2001-03-06
Ellis, Christopher P. (Department: 3651)
Conveyors: power-driven
Conveyor section
Endless conveyor
C198S851000
Reexamination Certificate
active
06196380
ABSTRACT:
The present invention refers to an apron-conveyor chain comprising chain links interconnected at hinge points, said hinge points being provided with at least one sleeve and one bolt, and further comprising transport plates arranged on at least one side of said chain links and provided with a flat transport surface, said transport plates forming an apron conveyor in common and being each firmly connected to a bolt included in a hinge point.
Such apron-conveyor chains comprise long chain links, each bolt being connected to a transport plate at a hinge point. For fastening the bolts to the transport plate as stably as possible, the connecting head of the bolt has a diameter which is larger than that of the rest of the bolt. This connecting head is then pressed into a complementary connecting hole of the transport plate. In most cases, the bolt is releasably secured to the chain links with the aid of releasable fastening means, e.g. cotter pins or retainer rings. There are also variants in the case of which the bolt is not a component part of the hinge itself, but is passed through a hollow pin of the outer chain link so that the transport plates can be exchanged without dismounting the chain links. Furthermore, variants are known in the case of which the lower surface of the transport plate is provided with a small guide pin which is guided in an opening of the associated outer or inner link plate so that the transport plate is prevented from rotating excessively about the main fastening bolt. One disadvantage of the hitherto known apronconveyor chains is to be seen in the fact that great efforts are necessary for arranging the transport plates such that an apron conveyor is formed which is as flat as possible. This necessitates separate alignment processes and exacting manufacturing tolerances. Even small displacements of the transport plates relative to one another or even small angular inaccuracies—because said transport plates are orientated at an oblique angle relative to one another—can result in undesired vibrations and, consequently, disadvantageous effects when objects arranged on the transport surface of the transport plates are conveyed. Since such apronconveyor chains can also be used for conveying objects whose height exceeds their width and length, respectively, said vibrations can cause an excessive amount of unpleasant noise and they may even cause said objects to turn over.
It is therefore the object of the present invention to provide an apron-conveyor chain of the type cited at the start, which provides, in a structurally simple manner, an apron conveyor which is as precise as possible.
According to the present invention, this object is achieved by the feature that each transport plate is firmly connected to two neighbouring bolts of two neighbouring hinge points. The inventor perceived that a main problem of hitherto used apron-conveyor chains is that the connection of the support plate to a single fastening bolt results in undesired manufacturing inaccuracies. Due to the use of two neighbouring bolts for attaching a transport plate, the number of fastening points doubles and, consequently, the possibility of aligning the plate with respect to a fastening point doubles as well. The transport plate is also supported more effectively against forces acting thereon because it is not only provided with a single central support, as has been the case in the prior art. In addition, the second bolt also prevents a rotation of the transport plate about the first fastening point so that a to-and-fro motion of the transport plate, which normally occurs in the prior art, is not caused by the vibration of the chain. The present arrangement is comparatively rigid and therefore subject to little vibration. As has already been mentioned hereinbefore, another main advantage is, however, that, due to the double fastening by means of the two bolts, the individual transport plates can be aligned with respect to one another more simply and more effectively when they are being produced.
One embodiment can be so conceived that inner chain links and outer chain links are alternately connected to one another, that the inner chain links comprise two inner link plates which are arranged in parallel and two sleeves by means of which said inner link plates are connected, and that the outer chain links comprise two outer link plates which are arranged in parallel and two bolts by means of which said outer link plates are connected, one sleeve of the inner chain link and one bolt of the outer chain link being included in a respective hinge point, and that the length of a transport plate is longer than the length of a chain link. Up to now, long chain links, whose length exceeds that of the transport plates, have always been used for apron-conveyor chains. The reason for this was that the transport plates were always secured to a single bolt. Due to the fastening to two neighbouring bolts of an outer chain link, commercially available flat link articulated chains can be used whose pitch is smaller than the hitherto usual pitch of apron-conveyor chains. This will also reduce the polygon effect, and this will in turn contribute to a quiter running of the chain.
The transport plate can be firmly connected to the two bolts of an outer chain link. This will reduce the number of parts and a compact structural design of the chain will be achieved.
Up to now, it has been common practice that the transport plates of apron-conveyor chains are arranged parallel to an outer link plate of the chain. Due to the fact that the transport plate is now firmly connected to the two bolts of an outer chain link, it is also possible to dispense with an outer link plate at this point completely and to replace said outer link plate by the transport plate. This will save an enormous number of components, whereby the chain according to the present invention can be produced at a very reasonable price.
According to a preferred embodiment, the transport plates can be provided with two holes, an end portion of a bolt being pressed into each of said two holes. This is a connection which can be produced in a simple and precise manner and which offers sufficient alignment possibilities. Such a connection technology proved to be superior to e.g. welding, since alignment errors may occur in the case of this known connection technology.
Bolts for apron-conveyor chains which have been used up to now and which were pressed into the transport plates always had a specially shaped connection head so that the highest possible degree of alignment accuracy could be achieved. Since the alignment is substantially improved due to the fastening at two points, such a structural design is no longer necessary. One variant is therefore so conceived that the bolts have the shape of a cylinder with a uniform diameter. Hence, conventional chain hinge bolts can be used, which do not have any enlarged areas used for pressing in. Only on the opposite side of the transport plate, the outer link plate can still be fastened by riveting the bolt, whereby the diameter of said bolt can be slightly enlarged in the end portion thereof. Such a connection technique can, however, not be applied on the side of the transport plate because the bolt should not project beyond the transport surface. According to a further embodiment, the end portions of the bolts are therefore implemented in such a way that they do not project beyond the transport surface of the transport plates.
One embodiment is so conceived that one end face of the transport plate is provided with a projection having a semicircular edge region which is arranged symmetrically with regard to the centre line of the transport plate and which has a radius that corresponds essentially to half the centre-to-centre distance of the bolts. In addition, the present invention can be so conceived that the other end face of the transport plate is provided with a semicircular recess which is arranged symmetrically with regard to the centre line of the transport plate and in which the semicircular edge region of
Grabmann Peter
Teuber Toralf
Armstrong, Westerman Hattori, McLeland & Naughton
Ellis Christopher P.
Joh. Winklhofer & Sohne GmbH & Co. KG
Sharma Rashmi
LandOfFree
Apron-conveyor chain does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apron-conveyor chain, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apron-conveyor chain will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2447551