Abstrict A can crusher includes two endless belt assemblies arranged alongside
each other with the mutually facing runs of said belt assemblies
being arranged to define a converging gap therebetween in the direction
of motion of the belt so that a can to be crushed fed into the converging
space is progressively crushed as it moves between the belts. One
of the belt assemblies is pivotally mounted relative to the other
such that the angle of convergence can vary, the conveyance movement
being controlled by, for example, gas-springs.
Claims I claim:
1. A can crusher including two endless belt assemblies arranged
alongside each other with facing runs of said belt assemblies being
arranged to define a converging passage therebetween in a direction
of motion of the belts, one belt assembly being located generally
adjacent the other and one being pivotally mounted relative to the
other whereby an angle of convergence of the passage and a gap between
the belts at its smallest point are variable, biasing means to bias
the facing runs of the endless belt assemblies toward each other,
a pair of facing plates between which the pivotally mounted endless
belt assembly is mounted, the pair of plates being pivotally mounted
about an axis of rotation of a drive roller of the pivotally mounted
belt assembly, and wherein the biasing means biases the pair of
facing plates and the pivotally mounted belt assembly relative to
the other belt assembly.
2. A can crusher as claimed in claim 1 including a second pair
of facing plates between which the other endless belt assembly is
mounted and the biasing means being mounted at one end to a first
plate and at the other to a second plate.
3. A can crusher as claimed in claim 2 in which a casing is provided
between the second pair of plates around an idler end of the second
belt assembly and part of a return run thereof to guide cans to
be crushed around the idler end to the converging passage between
belts of the belt assemblies.
4. A can crusher as claimed in claim 1 in which the biasing means
is a pair of air springs.
5. A can crusher as claimed in claim 1 in which the pivotally
mounted belt assembly is shorter than the other belt assembly.
6. A can crusher as claimed in claim 1 in which said other belt
assembly has an intermediate guide roller arranged alongside a trailing
end guide roller of the pivotally mounted belt assembly to define
a nip at the inner end of the converging passage between the facing
runs of the belt assemblies.
7. A can crusher as claimed in claim 1 in which backing plates
are arranged against the inner faces of said facing runs of each
belt.
8. A can crusher as claimed in claim 1 in which adjustable tensioning
rollers are provided to co-act with a return run of each belt assembly
to tension the belts.
9. A can crusher as claimed in claim 1 in which the biasing means
are adjustable.
10. A can crusher as claimed in claim 1 in which the belts are
operatively connected so as to be driven at the same linear speed.
11. A can crusher including two endless belt assemblies arranged
alongside each other with the facing runs of said belt assemblies
being arranged to define a converging passage therebetween in the
direction of motion of the belts, one belt assembly being located
generally adjacent the other and one being pivotally mounted relative
to the other whereby the angle of convergence of the passage and
the gap between the belts at its smallest point are variable, including
biasing means to bias the facing runs of the endless belt assemblies
towards each other, a first pair of facing plates between which
the first endless belt assembly is mounted, a second pair of facing
plates between which the second endless belt assembly is mounted,
the first pair of plates being pivotally mounted about an axis relative
to the second pair and the biasing means being mounted at one end
to a first plate and at the other to a second plate, and in which
the first endless belt assembly has a drive roller the axis of rotation
of which is incident with the axis about which relative pivotal
movement between the first and second pairs of plates take place.
12. A can crusher as claimed in claim 11 in which the biasing
means is a pair of air springs.
13. A can crusher as claimed in claim 11 in which the first belt
assembly is shorter than the second belt assembly.
14. A can crusher as claimed in claim 11 in which backing plates
are arranged against the inner faces of said facing runs of each
belt.
15. A can crusher as claimed in claim 11 in which adjustable tensioning
rollers are provided to co-act with a return run of each belt assembly
to tension the belts.
16. A can crusher as claimed in claim 11 in which the biasing
means are adjustable.
17. A can crusher as claimed in claim 11 in which the belts are
operatively connected so as to be driven at the same linear speed.
18. A can crusher including two endless belt assemblies arranged
alongside each other with the facing runs of said belt assemblies
being arranged to define a converging passage therebetween in the
direction of motion of the belts, one belt assembly being located
generally adjacent the other and one being pivotally mounted relative
to the other whereby the angle of convergence of the passage and
the gap between the belts at its smallest point are variable, including
biasing means to bias the facing runs of the endless belt assemblies
towards each other, a first pair of facing plates between which
the first endless belt assembly is mounted, a second pair of facing
plates between which the second endless belt assembly is mounted,
the first pair of plates being pivotally mounted about an axis relative
to the second pair and the biasing means being mounted at one end
to a first plate and at the other to a second plate, in which said
second belt assembly has an intermediate guide roller arranged alongside
a trailing end guide roller of the first belt assembly to define
a nip at the inner end of the converging passage between the facing
runs of the belt assemblies.
19. A can crusher including two endless belt assemblies arranged
alongside each other with the facing runs of said belt assemblies
being arranged to define a converging passage therebetween in the
direction of motion of the belts, one belt assembly being located
generally adjacent the other and one being pivotally mounted relative
to the other whereby the angle of convergence of the passage and
the gap between the belts at its smallest point are variable, including
biasing means to bias the facing runs of the endless belt assemblies
towards each other, a first pair of facing plates between which
the first endless belt assembly is mounted, a second pair of facing
plates between which the second endless belt assembly is mounted,
the first pair of plates being pivotally mounted about an axis relative
to the second pair and the biasing means being mounted at one end
to a first plate and at the other to a second plate, in which a
casing is provided between the second pair of plates around an idler
end of the second belt assembly and part of a return run thereof
to guide cans to be crushed around the idler end to the converging
passage between belts of the first and second belt assemblies.
Description BACKGROUND OF THE INVENTION
The present invention concerns improvements in or relating to can
crushers, especially but not exclusively can crushers for drinks
cans.
In view of the vast numbers of drinks cans used every day, it is
important both ecologically and economically that the cans are re-cycled.
This presents a problem in that the empty cans occupy a large volume.
This problem can be overcome to a large extent if the cans are reduced
in size by crushing them at the collection point so that their subsequent
transportation and storage prior to re-cycling can be economically
achieved.
There presently exists a number of can crushers, some of which
are manually operated others of which are mechanically operated
which are intended to crush cans at the collection point or even
in the home. These suffer a number of disadvantages, for example,
they are generally single operation machines, that is, they crush
only one can per operation. Additionally, they have no means for
separating steel cans from other cans. Furthermore, they can readily
be rendered inoperative by feeding "foreign" objects into
them.
There is a need to provide a can crusher which can operate continuously,
that is on a "process" basis, can automatically separate
magnetic crushed cans from other cans, will not be damaged or rendered
inoperative by foreign bodies fed thereto and can operate reliably,
safely and economically.
SUMMARY OF THE INVENTION
According to the present invention there is provided a can crusher
including two endless belt assemblies arranged alongside each other
with the facing runs of said belt assemblies being arranged to define
a converging passage therebetween in the directional motion of the
belts, one belt assembly being located above the other and one being
pivotally mounted relative to the other whereby the angle of convergence
of the passage and the gap between the belts at its smallest point
are variable.
Preferably biasing means are provided to bias the endless belt
assemblies towards the greatest angle of convergence, the biasing
means including two gas springs each of which is mounted on plates
mounting the first and second belt assemblies.
Preferably the first belt assembly is shorter than the second belt
assembly.
Preferably the shorter belt assembly is mounted between two plates
and the second, longer belt assembly is also mounted between two
plates which are located between the plates of the first assembly,
the plates of the first assembly being pivotally mounted about the
axis of the leading guide roller for the belt of the first assembly.
Preferably the leading guide rollers for the first and second belts
are driven by intermeshing gear wheels arranged externally of said
plates, the guide rollers and gear wheels being the same diameter
and having the same number of teeth such that the belts are driven
at the same linear speed.
Preferably the leading and trailing guide rollers for each belt
are toothed and the inner surface of each belt is correspondingly
toothed.
Preferably the second belt assembly has an intermediate guide roller
arranged alongside the trailing guide roller of the shorter, first
belt assembly to define a nip at the inner end of the constricted
space between the facing runs of the belt assemblies.
Preferably backing plates are arranged against the inner faces
of said facing runs of each belt. Said inner faces and said backing
plates may be coated with a material having a relatively low co-efficient
of friction.
Preferably adjustable tensioning rollers are provided to co-act
with the return run of each belt assembly to tension the belts.
Preferably said biasing means includes a gas spring. Two gas springs
may be provided each being mounted at its respective ends on the
plates mounting the first and second belt assemblies.
Preferably said gas springs are adjustable.
Preferably said gear wheels are driven through the intermediary
of a spur gear and gear box by an electric motor.
Preferably can delivery means are provided to convey cans to the
can crusher. This means may include a roller conveyor powered through
appropriate transmission means by said electric motor.
Preferably said roller conveyor is semi-circular and extends between
said can crusher and an inclined plane leading from an entry port
to a casing enclosing the can crusher and the can delivery means.
Preferably means are provided to detect the introduction of a can
to the can delivery means. Said means may comprise a proximity switch.
Preferably said proximity switch is adapted to open means normally
closing the entry port on detection of an object at the entry port.
Preferably the proximity switch operates only when it detects items
made from an electrically conductive material.
Preferably the proximity switch actuates the drive for the can
crusher and can delivery means.
Alternative delivery means may employ the return run of the second
belt assembly to convey cans to the first belt assembly.
Embodiments of the present invention will now be described by way
of example only with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of an assembly comprising a can
crusher and can delivery means, side plates of the can crusher and
other non-essential components having been omitted for clarity;
FIG. 2 shows a view from a direction opposite to that in which
FIG. 1 is taken of the can crusher;
FIG. 3 shows a side elevation of the can crusher.
FIG. 4 shows a perspective view of another embodiment of a can
crusher in which a side plate of the can crusher and other components
have been omitted for clarity; and
FIG. 5 shows a further perspective view of the can crusher taken
from the opposite side, with both plates in position.
DETAILED DESCRIPTION
FIG. 1 shows a can crusher 10 which will be described in greater
detail below, to which cans 12 are fed by a can delivery means or
can conveyor 14. The can conveyor and can crusher are mounted within
a casing (not shown) which has an entry port having a closeable
door, the entry port leading to an inclined plane 16 down which
cans fed through the entry port can slide to a semi circular roller
conveyor 18. The radially arranged rollers 20 of the roller conveyor
are driven by means to be described below and transport cans 12
to the can crusher 10.
The crusher comprises a first conveyor belt assembly having an
endless belt 30 which runs over a driven leading end guide roller
32 and a trailing end idler guide roller 34 mounted respectively
on shafts 3638. The shafts are mounted in bearings 40 supported
in side plates 42 which are generally triangular in shape, that
is the side plates extend upwardly from the line joining the axis
of the shafts 3638. The plates 42 have corresponding slots 44 formed
therein and a tensioning roller 46 is mounted on a shaft which,
in turn, is adjustably mounted between the slots 44 such that the
first conveyor belt can be suitably tensioned.
A support plate 48 is provided below the upper run of the belt
30 and is mounted between the plates 42 by fixing bolts (not shown)
passing through apertures 50 formed through the plates.
A second pair of spaced apart plates 52 are mounted between the
plates 42. The shaft 36 passes through said second plates 52 and
the plates 52 are pivotal, in unison, about said shaft relative
to the plates 42.
A second endless belt 54 is carried by a driven leading guide roller
56 an idling trailing end guide roller 58 and an idling intermediate
guide roller 60 mounted respectively on shafts 626466 supported
by bearings 68 in the plates 52.
A tensioning roller 70 is also mounted between the plates in corresponding
slots 72 whereby its position and consequently the tension it exerts
on the return run of the belt is adjustable.
The lower run of the belt 54 has support plates 7476 placed alongside
its inner surface, the support plates being mounted between the
side plates 52 by bolts (not shown) passing through apertures 78
formed through the plate.
It will be observed particularly from FIG. 1 and 3 that the axes
of the shafts 626466 do not lie in a straight line but the axis
of shaft 66 is displaced away from the line joining the axes of
shafts 6264. In the normal operating position illustrated in the
drawings and particularly in full lines in FIG. 3 of the drawings,
it will be clearly observed that the facing runs of the belts 3054
converge between the leading end rollers 3256 and the trailing
end roller 34 of the first shorter belt and the intermediate roller
60 of the upper longer belt. This provides a converging space terminating
in a nip, into which cans are fed in the direction of arrow C in
FIG. 2 and it will be appreciated that if the belts are driven in
a direction of arrows B, cans will be pulled into the crusher towards
the nip and in so moving will be crushed so that when they pass
between the nip defined by the rollers 3466 they will be flattened.
Means are provided for biasing the upper and lower belt assemblies
towards the normal operative relative position shown in the drawings
with the nip at its minimum dimension. The means comprise a pair
of gas springs 80 each mounted by one end of the upper extension
of the plates 42 and by the other to the rearward extension of the
plates 52.
It will be recalled that the plates 4252 are pivotally mounted
about the axis of shaft 36 so that if an object fed between the
conveyor belts has a resistance to flattening which is greater than
the biasing force exerted by the gas springs, the plates 52 will
pivot relative to the plates 42 to cause the nip between the rollers
3462 to temporarily increase against the biasing action of the
gas springs to allow the item to pass therethrough. This action
will also occur when a can cannot be flattened to the minimum dimension
of the nip, for example, at its upper end.
The apparatus is driven by an electric motor 82 mounted to the
plates 52 and driving, through a worm gear reduction gear box 84
a drive shaft 86 on which is mounted a spur gear 88 which meshes
with a first drive gear 90 fixed to the drive shaft 62 for the leading
guide roller 62 of the conveyor 54 and in turn meshing with a similar
sized and toothed gear wheel 92 fixed to the drive shaft 36 on which
the leading guide roller 32 for the first belt 32 is mounted. It
will be realised therefore that the drive assembly drives the belts
3054 in the same direction at the same speed and does not hinder
the pivotal movement of the plates 52 relative to the plates 42.
The conveyor belt guide rollers 32345658 and 60 are all similarly
toothed and corresponding toothed formations are provided on the
inner faces of each belt such that the belts are positively driven
in the manner of a timing belt.
The outer surface of the belts may be coated with hard-wearing
abrasion resistant material.
It is preferable that the inner faces of at least the support plates,
4874 and 76 are coated with a material having a low co-efficient
of friction such that the belts 3054 can readily slide over them.
Additionally, it is preferable that the plate 76 is magnetic such
that magnetic cans emerging from the nip are held for a greater
time to the downwardly facing surface of the belt 54 then non-magnetic
cans such that non-magnetic cans are collected in a first receptacle
placed close to the nip while magnetic cans are collected in a second
receptacle placed close to the trailing roller 58.
It is preferable that a drive taken from one or other of the shafts
6236 provides the means for rotating the rollers 20 of the can
conveyor 14.
It will be appreciated that if a solid object is fed to the can
crusher, the nip between rollers 3460 will open against the biasing
action of the gas springs 80 to allow it to pass therethrough without
the apparatus stalling. This condition is shown by the chain lines
A in FIG. 3.
It is preferable that the plates 52 are supported by a framework
which also supports the casing enclosing the assembly. The casing
has not been shown on the drawings but it will be appreciated that
it incorporates a gated entry port at the upper end of the inclined
plane 16. The port may be openable through the influence of the
proximity switch arranged at the port and adapted to open an entry
door only when suitable objects are introduced into the port, for
example, electrically conductive objects and not, for example, lumps
of wood or glass bottles. Actuation of the proximity switch can
also be used to start the electric motor driving the apparatus which
can run until a predetermined period after the entry port has closed.
It will be appreciated that the can crusher crushes cans continuously
and not in a step-by-step operation, as a result the apparatus is
unlikely to experience problems encountered by existing apparatus
when a following can enters a crushing assembly designed to crush
a single can and thereby cause the apparatus to stall. A continuous
line of cans can be processed by the present apparatus without the
need to provide a gating assembly to ensure that only a single can
is presented to the crusher at one particular time.
A second embodiment of the can crusher of the present invention
is shown in FIGS. 4 and 5. In this embodiment a powered can delivery
means is not required and one of the conveyor belt assemblies is
used to deliver cans to the crushing zone whilst ensuring that the
crushing zone is spaced from the entry to the crusher by a distance
which is sufficiently great to prevent a person reaching into the
crushing zone by way of the can entry port.
This second embodiment is similar to the first embodiment in that
it comprises two conveyor belt assemblies, the first of these is
an endless belt 130 which runs over a driven leading end guide roller
132 and a trailing end idler roller 134 each mounted in bearings
140 supported in triangular side plates 142. The plates 142 have
corresponding slots (not shown) and a tensioning roller 146 is mounted
on a shaft which is adjustably mounted between the slots such that
the first conveyor belt can be suitably tensioned. A support plate
148 is supported in slot 149 in the side plates 142 below the upper
run of the belt 130.
A second pair of spaced apart rectangular plates 152 are mounted
between the plates 142. The shaft of the roller 132 passes through
the second plates 152 so that the plates 142 pivot in unison about
said shaft relative to the plates 152. The second endless belt 154
is carried by a driven leading guide roller 156 idling trailing
end guide drum 158 idling intermediate guide roller 160 and a tensioning
roller 170 mounted between the plates 152 in corresponding slots
172 whereby its position, and consequently the tension it exerts
in the return run of the belt, is adjustable. The lower run of the
belt 154 has support plates 174176 placed alongside its inner surface,
the plates being mounted between the side plates 152.
It will be observed that the runs of the belt passing over the
support plates 148 and 174 respectively are not parallel but converge
to the normal operating position shown in the drawings and define
a nip between the rollers 134 and 160. It will also be observed,
however, that when a can is fed into the nip in the direction of
arrow C in FIG. 4 it will be crushed and flattened but allowed to
pass through the nip in its flattened condition by pivotal movements
of the plates 142 relative to the plates 152 thereby allowing the
roller 134 to move away from the roller 160 against the action of
a biasing force.
Means are provided for biasing the belt assemblies towards the
normal operative relative protection shown in the drawings. The
means comprise a pair of gas-springs 180 each mounted by one end
to the upper apex of the triangular plates 142 and by the other
to the plates 152. By this method, if a can or other "foreign"
obstacle, for example, a block of wood, is fed to the can crusher,
the crusher will not be damaged as the first conveyor assembly will
pivot away from the second conveyor assembly against the action
of the biasing means 180 allowing the non flattened object to pass
through the nip.
As before, means are provided for separating magnetic material
from non-magnetic material. This is achieved by ensuring that plate
176 is magnetised so that any magnetic material passing through
the nip is held against the outer surface of the second belt assembly
by the magnetic action of the plate 176 until the belt reaches driven
roller 156 at which stage the object falls into an appropriate container
located generally below the roller 156. On the other hand, a non-magnetic
flattened can passing through the nip falls directly off the belt
at the nip into a second container placed therebelow.
As can be seen from FIG. 5 the apparatus is driven by an electric
motor 182 mounted to one of the plates 152 and driving, through
a gearbox 184 a drive pulley 185 which, by means of a drive belt
187 rotates a drive pulley 190 rigidly mounted to the shaft of
the leading end drive roller 132 of the first conveyor belt assembly.
Another output shaft from the gear box 182 drives the drive roller
156 of the second conveyor belt assembly.
A casing 191 is mounted between the side plates 152 and surrounds
part of the upper run of the second belt 154 and the end of that
belt passing round the idler drum 158 so that a can to be crushed
delivered to the top run 192 of the second belt by a delivery chute
194 leading from an entry port 196 in a casing (not shown) for the
crusher is conveyed over the top of the first belt, around its end
and on to the top of the belt 130 of the first conveyor assembly
so that it travels in the direction of the arrow C into the nip
thereby being crushed.
The belts and rollers of the second assembly can be similar to
that of the first assembly, for example, they can be toothed and
have special surface treatments.
Various modifications can be made without departing from the scope
of the present invention, for example, the arrangement of conveyor
belts can be altered, provided that they provide a converging space
in which cans are crushed. The belts could be arranged with their
surfaces vertically, rather than horizontally, as shown in the drawings.
Alternative means can be employed to mount the belts and alternative
biasing means could be employed, for example, coil springs could
replace the gas springs. |