The invention relates to a conveyor provided with a frame and with
an endless drivable transport means, which is fitted with carriers extending transversely
to the direction of movement of the transport means and parallel to each other,
which carriers are pivotally coupled to at least one endless flexible coupling
means, whilst at least some of said carriers support pusher shoes, which are movable
along the respective carriers near discharge places by guide means mounted on
the frame and by control means cooperating with said guide means and being connected
to said pusher shoes, in order to discharge objects which are present on the transport
means transversely to the longitudinal direction of said transport means.
Conveyors of this type are for example known from European Patent
Application 0084905 or Dutch Patent Application 9100562.
It is noted that from US-A-5,191,959 there is known a conveyor of
the above cited type wherein the pusher shoes have been provided with control means
formed by rollers. Said rollers have been mounted on shafts which can be shifted
with respect to the pusher shoes in order to bring the rollers in desired positions
with respect to guide means mounted on the frame of the conveyor.
EP-A-0 314 519 discloses an automatic sorting system comprising moving
members. Each moving member supports a slidable rod which can be shifted in its
longitudinal direction for co-operating with guide means in order to displace the
moving member in a desired way along rods supporting the moving member.
With these known constructions the control means connected to the
pusher shoe are usually made up of pins, rollers or the like secured to the pusher
shoes, which cooperate with guide means, which can be shifted between a first position,
in which the guide means allow the control means to pass without impediment, and
a second position, in which the guide means divert the control means transversely
to the direction of movement of the transport means, in order to effect that the
pusher shoes coupled to the respective control means are moved along the respective
The shifting of the guide means between the one position and the
other takes some time and of course it must be prevented that a control means comes
into contact with the guide means during this shifting of the guide means between
the one position and the other, since this may cause serious damage to the device.
There is a tendency, however, to increase the working speed of conveyors
of this type more and more. The amount of time required for shifting the guide
means constitutes a serious impediment, however, when attempting to increase the
Consequently the object of the invention is to obtain a conveyor
of the above kind, wherein this drawback of the known conveyors can be avoided.
According to the invention this can be achieved in that the control
means is pivotable about a pivot axis with respect to a respective pusher shoe,
between a first position, in which said control means is caught by the guide means,
and a second position, in which the control means is able to move beyond the reach
of said guide means.
The shifting of the control means of successive pusher shoes, which
may be necessary, may take place at a suitable distance from the guide means in
question, so that the control means can be moved at a high speed with respect to
the guide means and that as a result the working speed of the conveyor can be increased
considerably in comparison with the conveyors that have been usual so far.
The invention will be explained in more detail hereafter with reference
to a few possible embodiments of the construction according to the invention diagrammatically
illustrated in the accompanying Figures.
Figure 1 is a diagrammatic sectional view of a carrier and a pusher
shoe supported by said carrier.
Figure 2 diagrammatically shows the mechanism connected to the pusher
shoe, by means of which a control means made up of a wheel is connected to the
Figure 3 is a view corresponding with Figure 2, wherein the mechanism
takes up a different position.
Figure 4 diagrammatically shows means by which the control means
can be moved from the one position to the other.
Figure 5 is a diagrammatic side view of Figure 4.
Figures 6 and 7 diagrammatically show further means for shifting
a control means.
Figures 8 - 10 show further possibilities for movably providing control
Figure 1 diagrammatically shows a cross-sectional view of a carrier
As is also described in the above-mentioned publications, a large
number of carriers are disposed parallel to each other, being interconnected by
at least one endless flexible coupling means, for example one or more chains, so
that the carriers form a conveyor belt, as it were, which can be moved in its longitudinal
direction by driving means, whereby the carriers extend perpendicularly to this
direction of movement according to the arrow A.
As is furthermore described in the aforesaid publications, at least
one pusher shoe 2 is movable along each of the carriers, in order to push objects
present on the carrier(s) from said carriers at desired discharging places. In
order to be able to effect said movement of a pusher shoe 2 with respect to a respective
carrier 1 a control means is coupled to each pusher shoe, said control means for
example being in the shape of a wheel 3 coupled to the pusher shoe, a pin coupled
to the pusher shoe or the like. Such control means may cooperate with guide means,
for example guide rails, which extend at an angle to the direction of movement
according to the arrow A. When a pusher shoe 2 is to be moved along its respective
carrier 1, the control means 3 must for example be moved to the position which
is illustrated in full lines in Figure 1 and which is illustrated diagrammatically
in Figure 3, so that said control means comes into contact with the guide means.
When no movement of the pusher shoe 2 along its carrier 1 is aimed
at, however, the control means must be moved to a position in which the control
means can freely pass the guide means, for example to the position 3' illustrated
in dotted lines in Figure 1 or the position 3' shown in Figure 2, in which the
control means can move over the guide means fixedly provided in the frame of the
In order to enable such a movement of the control means or wheel
3, which is freely rotatable about a vertically extending axis of rotation 4, a
carrying means 5 supporting the wheel 3 is coupled to the respective pusher shoe
2 by means of two coupling rods 6 and 7, which are each pivotally coupled to the
carrying means 5 at one end, by means of pivot pins 8 extending parallel to the
longitudinal direction of the carrier 1, and which are pivotally coupled to the
pusher shoe 2 at the other end, by means of pivot pins 8. A tension spring 10 is
provided between one of the pivot pins 8 and a fixed point 9 on the pusher shoe.
It will be apparent that in this embodiment the wheel 3 can be pivoted
about an imaginary pivot pin extending parallel to a carrier 1, which is located
before the wheel 3, seen in the direction of movement according to arrow A, from
the position shown in Figure 3 to the position shown in Figure 2. In the position
illustrated in Figure 3 the wheel 3 will for example come into contact with guide
means extending transversely to the direction of movement, in order to effect a
movement of the pusher shoe 2 with respect to the carrier 1, whilst in the position
shown in Figure 2 the wheel 3' can freely move to and fro over said guide means.
When said movement from the one position to the other takes place
the tension spring 10 passes the extension of the pivot pin 8 which couples the
arm 6 to the pusher shoe. The spring thereby moves through a so-called dead centre,
as it were, all this in such a manner that both in the position shown in Figure
2 and in the position shown in Figure 3 the spring tends to keep the wheel 3 in
its respective position. Stops (not shown) will be provided, which prevent the
various parts from pivoting any further.
For moving the wheel 3 from the non-operative position shown in Figure
2 to the operative position shown in Figure 3 it will for example be possible to
use the construction diagrammatically illustrated in Figures 4 and 5.
As is diagrammatically indicated in Figures 4 and 5, a strip-shaped
switch piece 11, which forms a slightly curved guide surface, is carried by a support
12, which is secured to the frame 15 (only diagrammatically indicated) of the device,
for example by means of two leaf springs 13 and 14.
The strip-shaped switch means 11 can be moved to and fro by setting
means 16, for example a setting cylinder or lifting magnet, as indicated by means
of the arrow B. In the position illustrated in Figures 4 and 5 said strip-shaped
switch means 11 thereby lies in the path of movement of a pin 17 secured to one
end of the arm 6, which pin projects beyond the arm 6 on either side, so that the
pin 17 is pushed downwards by the switch piece 11, as indicated by means of the
arrow C in Figure 5, thus moving the wheel 3 from the position shown in Figure
2 to the position shown in Figure 3.
Because the pin 17 projects on either side said pin can cooperate
with switch pieces 11 disposed on either side of the path of movement of the wheel
It will be apparent that when no shifting of the wheel 3 from the
position shown in Figure 2 to the position shown in Figure 3 is desired, the switch
means will be withdrawn from the path of movement of the pin 17 by the setting
The shifting back of the wheel 3 from the position shown in Figure
3 to the position shown in Figure 2 may generally take place at a fixed point of
the device. For this purpose a fixedly disposed guide means 18 may be secured to
the frame 15 of the device, as shown in Figure 6. Said guide means 18 thereby has
a curved surface 19, along which the wheel 3 or for example the pin 17 connected
to the wheel can be guided, in order to push back the wheel 3 from the position
shown in Figure 3 to the position shown in Figure 2.
Another possibility is to use a rotating guide means 20, as illustrated
in Figure 7, whose outer circumference is in turn engaged by the wheel 3 or for
example by the pin 17.
Of course variations and/or additions to the above-described embodiment
are conceivable. Thus Figures 8 and 9 for example show an embodiment wherein a
carrying piece 5 of a wheel-shaped control means 3 is coupled to a pusher shoe
2 by means of a pivot pin 21 extending parallel to the longitudinal axis of a carrier
supporting the pusher shoe, said pivot pin 21 in the illustrated embodiment being
located above the control means, which is in its operative position. The wheel
3 can thereby be pivoted through 90° from the operative position illustrated in
full lines in the Figures to the non-operative position illustrated in dotted
lines, in which position the control means can freely pass the guide means without
coming into contact therewith.
As will furthermore be apparent from Figures 8 and 9 the construction
may thereby be such that the wheel 3 can be pivoted from the operative position
to the non-operative position against the direction of movement of the carrier
(Figure 8) or in the direction of movement of the carrier (Figure 9). Furthermore
an embodiment having both possibilities will be conceivable. The wheel 3 can thereby
be pivoted in a similar manner between the various positions.
Figure 10 shows an embodiment wherein the wheel 3 is pivotable with
respect to the pusher shoe 2 about a pivot pin 23 extending parallel to the direction
of movement according to the arrow A. Also in this embodiment a movement in the
one and/or the other direction from the operative position illustrated in full
lines, by pivoting through 90° to the non-operative position can be realized in
a similar manner as in the preceding embodiments.