GB2170768A

GB2170768A - A self propelled carriage

Info

Publication number: GB2170768A
Application number: GB08602728A
Authority: GB
Inventors: Francesco Canziani
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-02-13
Filing date: 1986-02-04
Publication date: 1986-08-13
Also published as: ATA24786A; KR860006392A; BR8600565A; ES8701081A1; CA1288393C; FR2577183B1; NZ215133A; DK167570B1; DE3603964A1; DK67486A; AU5346486A; AT394703B; MX160187A; NL8600232A; SE8600598D0; ES551898A0; DK67486D0; CN1004799B; ZA86640B; CN86101244A

Abstract

A self propelled carriage for a conveying and sorting machine has a frame (5) running along a monorail (2) on idle sheels (7), and provided with an independent motor (14) actuating spaced driving wheels (20) that engage the monorail (2) therebetween. Resilient basing means, such as a spring, link the motor (14) to the frame (5) to keep the adhesion between the driving wheels (20) and the monorail (2) constant. <IMAGE>

Description

SPECIFICATION A self propelled carriage This invention relates to a self propelled carriage suitable, particularly but not exclusively, for a sorting machine, wherein items to be sorted are placed, after codifying operations, on carriages or conveying surfaces that move along a fixed path, from which the items arethen automatically discharged when passing respective collecting zones.

According to one aspect of the present invention there is provided a self propelled carriage, including a frame having idle wheels by means of which it is supported for movement along a fixed path provided by a monorail, a motor unit hingedly connected to the frame, which motor unit has an electric motor for rotatably driving at least one pair of spaced opposed driving wheels which in operation of the carriage engage the monorail therebetween, and means for pivotally urging the motor unit relative to the frame to keep the driving wheels, in operation of the device, pressed against the monorail.

According to another aspect of the present invention there is provided a self propelled carriage for a sorting machine, including a frame having idle wheels by means of which it is supported for movement along a path provided by a monorail, a unit having an electric motor and transmission gears, which unit is hingedly connected to the frame for rotatably driving a pair of spaced driving wheels which in operation of the carriage engage the mono-rail from opposite sides thereof, resilient biassing means for pivotally urging the motor/ transmission unit relative to the frame to keep the driving wheels operatively pressed against the rail, and means for discharging items carried bythe carriage at either side of the path.

Such a carriage has its own drive motor unit and preferably further motor means, independent of the first unit, for controlling the discharge of carried items. The carriage is meant to move along a path provided by a mono-rail, and is equipped with hinged coupling means for connection to similar carriages.

Selecting and sorting apparatus are known wherein items to be carried are laid on carriages or transport surfaces connected to one another and moved along a fixed path by chains or similar systems. Discharge of the items, controlled by cams, rails or the like arranged along the path, takes place either by tilting of the conveyor surface or by actuation of a pusher element that runs along the surface on which the time has been laid.

These known apparatus, however, involve constructional complications and require, whenever changes to the path need to be made, very expensive modifications and the shut-down of the plant or machine for a long time.

Carriages are also known wherein the conveyor surface is a revolving belt actuated by a motor that moves along with the carriage, so that mechanical means arranged along the path need not be used to effect the discharge.

Recently a plant equipped with self propelled carriages has been proposed, as described in Italian Patent Application No. 22264 A/84 (UK Patent Application 8518856) by the present Applicant wherein some at least of the carriages are provided with independent drive motors, which allows a reduction in numbers of driven carriages used, considerable simplification of the entire structure, and more flexible use of the plant. The carriage of the present invention is suitable for use with such a plant.

Such a carriage is simpler to construct than previous ones (particularly regarding the propelling means) and more practical (particularly maintainance and repair being simpler).

Furthermore, unlike other known carriages, requiring guide-rails and separate rails on which the drive wheels act, the carriage according to the invention has only one simple mono-rail for both functions.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a longitudinal section through a carriage according to the invention, Figure 2 is a cross section of the carriage taken on the line I-I of Figure 1, Figure 3 is a partially sectioned cross-sectional view taken in the direction of the arrow A in Figure 1 of a carriage according to the invention, and Figure 4 is the partially sectioned plan view of a carriage according to the invention, seen from above.

A self propelled carriage (see Figure 1) of the invention includes a support structure 1,that runs along a monorail 2, a motor unit 3 and a conveying and discharging unit indicated generally at 4.

The support structure 1 comprises a frame 5 supported on the upper edge 6 of the monorail 2 by a pair of idle wheels (front and rear) 7, and a pair of uprights 8, set one at each side of the monorail, on which are mounted pairs of idle wheels 9 which are rotatable about substantially vertical axes. The idle wheels 9 run against side walls of the monorail 2 itself to prevent sideways movement of the carriage.

At the lower part of the uprights 8 are idle wheels 10 rotatable about horizontal axes, that run in contact with the underside of a pair of flanges 11 of the monorail 2.

The carriage that moves in the direction of arrow V of Figure 1 can therefore run along the monorail 2 by means of the wheels 7. The idle wheels 9 keep the front part of the carriage exactly positioned on the monorail, while the positioning of the rear part is effected by driving wheels, as will be hereinafter described.

To the frame 5 is fixed a substantially vertical shaft 12 on which is pivoted a mounting member 13 of an electric motor 14.

To a shaft of the motor 14 is keyed a pinion 15, which engages a crown wheel 16 secured to a toothed wheel 17 which, in turn, engages and imparts rotary motion to a similar wheel 18. Wheels 17 and 18 are keyed to substantially vertical shafts 19 mounted on the member 13 via bearings. At the lower end of the shafts 19 are secured a pair of spaced, opposed driving wheels 20 engaging the monorail 2 from opposite sides thereof. Motor 14 rotates the driving wheels 20, moreover, keep the front part of the carriage properly positioned on the monorail 2 itself.

With a view to allowing, when necessary, the coupling together of a number of carriages (one thereof drawing the others), frame 5 has a pair of pivot members 21, to which are secured dragging bars or couplings, besides one or more shock absorbers, not shown in the drawings.

The carriage also includes, resilient biassing means such as a spring 25 or the like, linking motor 14 to frame 5, and exerting a tractive force tending to rotate the motor unit anti-clockwise, as shown by arrow C in Figure 4. This is for keeping the adhesion between the driving wheels 20 and the mono-rail 2 constant. In particular, when the carriage has to run along very curved stretches of the path, the spring 25 holds the motor unit (as well as the driving wheels) in such a position that the wheels 20 are pressed against the rail 2.

At the upper part of the carriage are means for conveying and discharging items to be sorted. Such means may consist either of tiltable plates (that can be actuated mechanically or, preferably, each by an electric motor mounted on the relevant carriage) or, as illustrated in the drawings, of a rotatable belt 24 mounted on a pair of rollers 22 parallel to the direction of movement of the carriage and mounted in their turn on the frame of the carriage.

The rollers 22 of the rotating belt 24 are actuated by a motor 23 preferably of the permanent magnet direct current type, as its acceleration characteristics allow the same to be controlled very quickly. Among other things, it is possible to adapt the speed of such a motor almost instantaneously to the sizes of the discharge stations, and to make said speed fit at any time to the plant requirements.

Either motor 23, 14 is fed with electric current, by sliding contacts 26, from feed rods set along the path and not shown in the drawings. In operation, the carriage is driven by the motor 14 along the monorail 2.

The items to be sorted, after codifying, are each placed upon a carriage. As the carriages pass before the collecting areas, a central control unit of known kind sends electric current signals to the feed rods to which motor 23 is linked, causing the selected carriage belt 24to be set in motion and, while rotating, discharge the selected item at one side or the other of the path. The particular shape and arrangement of the parts of the carriage affords several advantages over the know apparatus.

First of all, the structure of the monorail is very simple and inexpensive, and the carriages can be mounted thereupon in a very quick and easy way.

As each carriage has its own independent drive motor, it is possible to vary at will the capacity of the whole plant, by increasing or decreasing the number of carriages, according to requirements. Such a carriage can even move along twisted and/or sloping paths, and the plant can be fitted without problems to existing sorting rooms.

In plants such as the one herein described, the amperage (tension) ofthe employed current should be very low, for safety reasons. This, however, does not permit full exploitation of the characteristics of permanent magnet motors.

Thus for better exploitation of the acceleration characteristics of such motors without detriment to the operators' safety, in carriages according to the invention motors 23 are fed with impulses the voltage of which is higher than the nominal one, but which has a duration of only a few milliseconds.

In fact these motors have, at starting up, a considerably pick-up of very short duration. It is thus possible to use motors intended for 48 volt. working and to feed current to them, whenever belts 24 should be rotated to make them discharge the conveyed items, with voltage impulses of around 60-70 volts, for few milliseconds' duration.

Thus, the characteristics of the motor are exploited to the utmost while the operations are carried out in safety, without the need to resort to more powerful (and therefore heavier and more costly) motors. The discharge operations take a shorter time, and it is therefore possible eitherto increase the forward speed of the carriages or to employ, for the discharge, containers with a mouth of smaller size.

Of course the sizes, as well as the materials used, can vary as a function of the requirements of use.

Claims

1. Aself-propelled carriage, including a frame having idle wheels by means of which it is supported for movement along a fixed path provided by a monorail, a motor unit hingedly connected to the frame, which motor unit has an electric motor for rotatably driving at least one pair of spaced opposed driving wheels which in operation of the carriage engage the monorail therebetween, and means for pivotally urging the motor unit relative to the frame to keep the driving wheels, in operation of the device, pressed against the monorail.

2. A self propelled carriage for a sorting machine, including a frame having idle wheels by means of which it is supported for movement along a path provided by a monorail, a unit having an electric motor and transmission gears, which unit is hingedly connected to the frame for rotatably driving a pair of spaced driving wheels which in operation of the carriage engage the monorail from opposite sides thereof, resilient biassing means for pivotally urging the motor/transmission unit relative to the frame to keep the driving wheels operatively pressed againstthe rail and meansfordischarging items carried by the carriage at either side of the path.

3. A carriage according to claim 2, wherein the means for discharge of carried items includes a tiltable plate.

4. A carriage according to claim 2, wherein the means for discharging carried items includes of a revolvable belt.

5. A carriage according to claim 1, wherein the motor unit for propelling the carriage includes the electric motor which is operative to drive a pair of toothed wheels each keyed on respective substan tiallyvertical shafts, to the lower end of which shafts are fixedly secured the driving wheels that act on the monorail from opposite sides thereof.

6. A carriage according to claim 4, including a further motor for actuating the revolvable belt, which further motor is a permanent magnet direct current motor fed, to effect discharge of carried items, by a current impulse having a voltage higher than the nominal one, and a duration of a few milliseconds.

7. A self propelled carriage, substantially as hereinbefore described with reference to the accompanying drawings.

8. A sorting machine or plant including a self propelled carriage according to any one of claims 1 to 7, and a monorail.