Conveyor and discharge system for sorting items

A conveyor system for sorting items has a conveyor and discharge system consisting of a rotatable belt on a carriage, as well as motor-driven devices at collecting stations to rotate the belt and effect discharge.

BACKGROUND OF THE INVENTION 
The present invention provides a conveyor and discharge system for a system 
for sorting items. 
A known system for sorting items has a carriage with a revolving belt, 
which defines a conveyor plane on which the items to be sorted are put. 
The carriage is arranged to engage a device at a collecting station on a 
fixed path of the carriage to make the belt rotate and discharge the item. 
Such a carriage particularly fit for a system that sorts a great number of 
items by discharging them at a limited number of collecting stations would 
be useful. 
PRIOR ART 
There are other known systems for sorting items that define a plurality of 
conveyor planes moving along a fixed path for discharging the items at 
predetermined points (collecting stations) along the path. Examples of 
such known systems are described, for example, in the following patents or 
applications: U.S. Pat. No. 4,399,904; U.S. patent application Ser. No. 
107,769 of 1979; Italian Pat. Nos. 937,134, 1,055,285, 1,055,845, 
1,055,897, 1,092,781 and 1,122,898; and Italian Application Nos. 49558 
A/74, 23416 A/80 and 21835 A/82. 
Some of the other known systems are for sorting a few items to a great 
number of destinations, as, for instance, in post offices. In the sorting 
systems most recently designed for this, the conveyor consists of a 
plurality of individual, e.g. carriage units. The support for the item 
conveyed by each unit consists of a belt rotatable in either direction 
orthogonal to the direction of conveyance of the unit to discharge the 
item onto one side of the path of the conveyor unit or the other. In some 
of these known apparatuses, the belt is rotated by an electric motor 
mounted on the same unit or carriage as the belt. More specifically, low 
inertia motors controlled by a computer have been recently used to give 
the belt the rotational speed most suited to the nature of the conveyed 
item, the weight thereof, the forward speed of the carriage and of the 
sizes of both the item and the collecting station. Apparatuses of this 
kind are described in my Italian applications Ser. Nos. 25859 A/81, 21834 
A/82, and 22482 A/82. 
Others of the other known systems, e.g. systems for processing luggage in 
airports, are for sorting quite a few items to a limited number of the 
collection stations. Furthermore, in the former systems, the path of the 
carriage conveyor unit from the loading to the discharging i.e., 
collecting stations is predetermined, but in airport luggage processing, a 
special path is provided for the different pieces of luggage, according to 
the destination, time of departure of the flight, and kind of luggage. 
Still furthermore, in view of the great number of the conveyor units 
needed for processing the large amount of luggage, which is such that the 
conveyor units are kept in parking lots until they are sent to the 
discharge stations, there is a need being felt for conveyor units that are 
less expensive and require less maintenance, because they are not fitted 
with their own controls for the item-discharge belts. 
SUMMARY OF THE INVENTION 
To solve these problems, the present invention provides a conveyor and 
discharge system for sorting items, wherein the conveyor plane of a 
carriage consists of rotatable belt actuatable by a motor unit located at 
a discharge station. For this, the carriage has suitable link devices to 
the motor unit for revolving the belt on the carriage. This makes it 
possible to simplify to a great extent the construction of both the 
preferably-plural carriages and motor units and to reduce remarkably both 
the initial cost and the subsequent maintenance cost of the plant, i.e., 
sorting system.

DESCRIPTION OF THE DRAWN EMBODIMENTS 
The conveyor unit according to the invention consists substantially of a 
carriage at 1 provided with freely-rotatable wheels 1a and wheels 1b that 
are driven along guides, rails, or the like 2 to move the carriage in that 
direction. A belt 3 is rotatably mounted on the carriage by a pair of 
rolls 4 and 5. Of these, roll 4 is linked to rotation-driving mechanisms 
that are described hereinafter, whilst roll 5 is just a stretching roll. 
Belt 3 forms the conveyor plane on which are laid the items to be sorted. 
A shaft 6 of roll 4 is keyed to a pinion 7, which engages a corresponding 
pinion 8, which is mounted on one end of a shaft 9 orthogonal to shaft 6. 
Shaft 9 is rotatably held in a bracket 9a pivoted on the carriage for 
limited angular displacements in the direction of arrow A-B (FIG. 3), 
i.e., transversely to the direction the carriage moves. Spring 10 acts 
between the bracket and the carriage so as to make the pinion or toothed 
wheel 8 continually engage a stop 11 on the carriage; thus, any rotation 
of shaft about its own axis is usually avoided. This avoids any movement 
of rotatable belt 3 and an item thereon, due to inertia of the conveyed 
item as the carriage moves along curved stretches of the rail and, 
consequently, rotation of the belt by friction with the item. A wheel or 
roll 12 is mounted on shaft 9 at its opposite lower end. 
At the respective discharge stations (only one being shown) are located 
motor units at 13a (only one being shown) that act on the above-mentioned 
roll 12 and connected devices to control discharge of any item on the belt 
3. These units respectively consist substantially of pairs of belts 13, 
14, at least one of which may be rotated by an elected motor 16. Upstream 
of belts 13 and 14, relative to the movement of the carriage, there is a 
lever 15 centrally pivoted for movement transversely of the belts at its 
opposite ends, in the direction of arrow C-D, by an actuator 15a (FIG. 3) 
of known type connected to one end. Belts 13, 14 are at the same height as 
the wheel 12, the belt 14 being mounted, at one side, on the opposite end 
of lever 15. 
Operation is as follows: the items to be sorted (not shown) are laid on the 
belt 3 of a conveyor unit such as that described above. The conveyor units 
e.g. carriage 1, which may be dragged by an externally-motorized puller 
(not shown) or self propelled, as shown, move along a path passing by the 
various discharge stations. All the devices that make up the apparatus are 
controlled by a central computer (not shown). 
At the moment of loading, each carriage is given a code via proceedings of 
known type, so that the computer is informed every moment of the position 
of each conveyor unit along the path. When each conveyor unit passes 
through a predetermined discharge station, the computer operates the 
actuator 15a thereat to shift the lever 15 until belt 14 interacts with 
the wheel 12, which is thus pushed in the direction of arrow A, thereby 
disengaging the toothed wheel 8 from stop 11. 
At this point, the shaft 9 can freely rotate around its own axis. As the 
carriage proceeds, belt 14 pushes the wheel 12 farther toward belt 13 
until the wheel is seized between the belts 13, 14, and made to rotate by 
motor-rotated belt 13. This rotary motion is transmitted to the motor roll 
4 via shaft 9 and the pair of pinion 7, 8 thus causing belt 3 to rotate 
and the item thereon to be discharged. 
When the carriage is past the discharge station, wheel 12 disengages from 
between belts 13, 14, and spring 10 returns it to the starting position, 
wherein the mutual engagement between pinion 8 and stop 11 keeps belt 3 
clamped. 
Of course, there will be, too, provision for suitable reference means, e.g. 
roller 14a, connected with the parts of belts 13, 14 facing one another, 
to ensure a proper push contact between the belts and the wheel 12 during 
operation. 
The described embodiment is of very simple construction, and turns out to 
be specially convenient for use in those sorting apparatuses comprising 
several conveyor units and few discharge stations. Consequently, both the 
cost and weight of the system tend to diminish considerably, as well as 
the required maintenance. 
Obviously, the size as well as the employed materials may vary in 
accordance with the requirements of use.