GUIDE FOR CONVEYOR CHAIN
THIS INVENTION relates to chain conveyors.
According to a first aspect of the invention there is provided a conveyor
segment for a chain conveyor including a track and a chain of a magnetisable
material defining a load-bearing surface, that is moveable over the track, the
conveyor segment being a two-part segment comprising a track-defining
portion defining the track over which the chain is moveable, and a magnet-
holding portion holding at least one magnet, the track- defining portion and the
magnet-holding portion being removably secured to one another in an
arrangement wherein the magnetic lines of force of the magnetic field
produced by the magnet extend through the track-defining portion thereby to
attract the chain against the track-defining portion.
The track-defining portion may define a pair of spaced parallel rails on which
the chain is slidably moveable.
The track-defining portion may have a connecting portion extending between
said parallel rails, the track-defining portion having a substantially U-shaped
configuration when viewed in cross-sectional end view.
The magnet-holding portion may define at least one pocket in which the
magnet is located, in use.
The magnet-holding portion may define a number of pockets in an operative
upper side thereof, the pockets being open-topped, with a magnet being
retained in each pocket between the magnet-holding portion and an underside
of the track-defining portion.
The pockets may be disposed equidistant from one another and arranged in a
plane disposed along a centre line of the track-defining portion defined
between said rails thereof.
The magnet-holding portion may define an elongate recess formation that is
disposed operatively below said pockets, in which a strip of a ferromagnetic
material is retained for enhancing the magnetic effect provided by the
magnets, in use.
According to a second aspect of the invention there is provided a magnet-
holding portion for a conveyor segment of a chain conveyor including a track
and a chain of a magnetisable material defining a load-bearing surface, that is
movable over the track, the conveyor segment including a track-defining
portion defining the track over which the chain is movable, the magnet-holding
portion defining at least one pocket in which a magnet can be located, the
magnet-holding portion being removably securable to the track-defining portion
so as to form a two-part conveyor segment wherein the magnetic lines of force
of the magnetic field produced by the magnet extend through the track-
defining portion thereby to attract the chain against the track-defining portion.
The magnet-holding portion may define a number of pockets in a operative
upper side of the magnet-holding portion, the pockets being open-topped, with
the magnets being operatively retained in the pockets between the magnet-
holding portion and an underside of the track-defining portion when the track-
defining portion is secured to the magnet-holding portion, in use.
The magnet-holding portion may define an elongate recess formation that is
disposed operatively below the pockets, in which a strip of a ferromagnetic
material can be retained for enhancing the magnetic effect provided by the
magnets, in use.
According to a third aspect of the invention there is provided a chain conveyor
including a track and a chain of a magnatisable material defining a load-bearing
surface, that is moveable over the track, the chain conveyor including a two-
part conveyor segment comprising a track-defining portion defining the track
over which the chain is moveable, and a magnet-holding portion holding at
least one magnet, the track-defining portion and the magnet-holding portion
being removably secured to one another in an arrangement wherein the
magnetic lines of force of the magnetic field produced the magnet extend
through the track-defining portion thereby to attract the chain against the
track-defining portion.
The track-defining portion of the conveyor segment may define a pair of
spaced parallel rails on which the chain is slidably moveable.
The track-defining portion of the conveyor segment may have a connecting
portion extending between said parallel rails, the track-defining portion having
a substantially U-shaped configuration when viewed in cross-sectional end
view.
The magnet-holding portion of the conveyor segment may define at least one
pocket in which the magnet is located, in use.
The magnet-holding portion of the conveyor segment may define a number of
pockets in an operative upper side thereof, the pockets being open-topped,
with a magnet being retained in each pocket between the magnet-holding
portion and the underside of the track-defining portion.
The pockets defined in the magnet-holding portion of the conveyor segment,
may be disposed equidistant from one another and arranged in a plane
disposed along a centre line of the track-defining portion defined between said
rails thereof.
The magnet-holding portion of the conveyor segment may define an elongate
recess formation that is disposed operatively below said pockets, in which a
strip of ferromagnetic material is retained for enhancing the magnetic effect
provided by the magnets, in use.
Further features of the invention are described hereinafter by way of a non-
limiting example of the invention, with reference to and as illustrated in the
accompanying diagrammatic drawings. In the drawings:
Figure 1 shows a schematic fragmentary top plan view of a chain conveyor in
accordance with a third aspect of the invention;
Figure 2 shows an enlarged schematic sectional end view of the chain
conveyor of Figure 1 , as viewed along section line ll-ll of Figure 1 ;
Figure 3 shows a schematic exploded three-dimensional view of a conveyor
segment for the chain conveyor of Figure 1 , in accordance with a first aspect
of the invention;
Figure 4 shows a schematic top plan view of a track-defining portion of the
conveyor segment of Figure 3;
Figure 5 shows a schematic sectional end view of the track-defining portion
of Figure 4, as viewed along section line V-V of Figure 4;
Figure 6 shows a schematic top plan view of a magnet-holding portion of the
conveyor segment of Figure 3, in accordance with the second aspect of the
invention;
Figure 7 shows a schematic sectional end view of the magnet-holding portion
of Figure 6, as viewed along section line VIII-VIII of Figure 6;
Figure 8 shows a schematic sectional end view of the magnet-holding portion
of Figure 6, as viewed along section line IX-IX of Figure 6; and
Figure 9 shows a schematic sectional end view of the conveyor segment of
Figure 3, sectioned along a section line passing through a pocket of the
magnet-holding portion thereof.
With reference to the drawings, a chain conveyor, in accordance with the third
aspect of the invention, is designated generally by the reference numeral 10.
The chain conveyor 1 0 comprises a track designated generally by the reference
numeral 1 2 and a chain designated generally by the reference numeral 1 4, of
a magnetisable stainless steel that defines a load-bearing surface 1 6 on which
articles to be conveyed can be supported. The chain 14 is moveable over the
track 1 2 and comprises a number of chain sections that are pivotally
connected to one another so as to provide the load-bearing surface 1 6.
The chain conveyor 1 0 includes a number of conveyor segments that are
connected to one another end-to-end so as to define the track which is
continuous and on which the chain 1 6 is slideably movable. The conveyor
segment depicted in the drawings is a bend segment 1 8 and thus defines a
curved track along which the chain is moveable. The bend segment 1 8 is a
two-part segment comprising a plastics track-defining portion 20 and a plastics
magnet-holding portion in the form of a base portion 22, that are removably
secured to one another.
The track-defining portion 20 and the base portion 22 are secured to one
another by means of screws 24. More particularly, the screws 24 extend from
an underside of the base portion 22 into the track-defining portion 20. As
such, the base portion 22 defines through-holes 25 through which the screws
24 can extend and the track-defining portion 20 defines holes 27 that are in
register with the holes of the base portion, the holes of the track-defining
portion 20 including screw-threaded inserts 26 into which the screws 24 can
be screwed.
The track-defining portion 20 defines a pair of spaced parallel rails 28 on which
the chain is slidably movable, in use, and a central connecting piece 30 which
extends between the rails 28. As such, the track-defining portion 20 has a U-
shaped configuration when viewed in cross-sectional end view.
The base portion 22 defines a number of pockets 32 in which permanent
magnets 34 are located. The pockets are centrally defined in an operative
upper side of the base portion 22. The pockets 32 are open-topped and as
such when the track-defining portion 20 is secured to the base portion 22, the
magnets 34 are retained in the pockets between the base portion 22 and an
under side of the track-defining portion 20.
The base portion 22 defines a curved elongate slot 36 that is disposed
operatively below the pockets 32 and in which a strip 38 of magnetisable steel
is retained for enhancing the magnetic effect provided by the magnets 34, in
use.
The base portion 22 defines recess formations 40 at the ends of the slot 36,
in which ends of the strip 38 can be received, for enhancing the location of the
strip 38 in the slot.
Although the conveyor segment may be straight in other embodiments, the
conveyor segment will in most applications be a bend segment where the
tendency of the chain to lift off the track is greatest.
In use, the surfaces of the track of a chain conveyor that is in contact with the
chain is subject to wear. This is particularly the case along inner and upper
portions of the inner rail of a bend segment of a track including a bend . When
the track becomes so worn that it is no longer operational, it becomes
necessary to replace the affected segments of the track at great cost. This
cost is particularly exacerbated where the permanent magnets are formed
integrally with the track, as is the case with many currently available chain
conveyors. These permanent magnets are relatively expensive. However,
because of the cost involved in attempting to remove the magnets, the
magnets are often discarded together with the worn track segments. In
contrast thereto, a worn track-defining portion 20 of the bend segment 1 8 can
merely be removed by unfastening the screws 24 and replacing the affected
portion with a new track-defining portion. This allows for easy maintenance
of worn tracks and furthermore has the advantage that the permanent magnets
are not discarded together with a worn track segment.