IE20010352A1 - Unit for motorized beds of parallel rollers for conveying manufactured articles with at least two alternate speeds - Google Patents

Abstract

A unit for motorizing beds of parallel rollers for conveying manufactured articles with at least two alternate speeds, comprising a transmission chain or belt which is mechanically connected to the rollers and to two independent motors, a first one of said motors having a high nominal rotation rate, and a second one of said motors having a low nominal rotation rate, both motors being coupled in output to a respective reduction unit, said reduction units being connected one another by respective half-shafts at the output and merging in an interposed common freewheel device, at least the half-shaft at the output of said reduction unit coupled to said first motor being adapted to motorize a common transmission sprocket which is engaged in said chain. <Figure 2>

Description

.MOTORIZING BEDS OF PARALLEL ROLLERS FOR ,, ... « | NUFACTURED ARTICLES WITH AT LEAST TWO RNATE SPEEDS The present invention relates to a unit for motorizing beds of parallel rollers for conveying manufactured articles with at least two alternate speeds.

Beds of motorized rollers, known as roller conveyors, have long been manufactured and used; the rollers are supported on a base frame so as to be parallel and horizontal and constitute a sort of moving conveyor belt for introducing or removing manufactured items in or from processing machines.

This is the case, for example, of roller beds used in the ceramics industry to feed and unload the kilns inside which the ceramic tiles are fired or the tile drying units.

Due to production cycle requirements, e.g. in order to pack more densely or, conversely, to space the rows of tiles one another, it is necessary that the rollers of the beds be motorized so that they rotate synchronously with at least two speeds which must be significantly different from each other; in particular, one speed must be very low and the other one must be much higher.

The required difference between the absolute values of these speeds is significantly greater (one must be at least twice the other) than achievable by using a single conventional motor drive coupled with a so-called inverter.

For this reason, the roller motorization is currently entrusted to two motors being connected to the rollers of the roller conveyors, each motor having its own nominal speed characteristic; the motors are connected to the rollers by means of a toothed transmission belt or chain being closed in a loop around respective sprockets which are located at the output of two specific reduction units, one for each motor, OPEN TO PUBLIC INSPECTION ? UNDER SECTION > RULE 23 k JNtfcfc ’ 4 ^> $ Of ...I freewheel-type devices being interposed.

Pinions are further keyed on the ends of the rollers and are also engaged by the chain, from which they receive their rotary motion.

Substantially, in operation the motor that turns at low speed is always engaged and, by means of its reduction unit and sprocket, transmits the lowspeed motion to the rollers of the roller conveyor; during this step, the second fast motor is disconnected from the chain by its own freewheel device, which disengages the reduction unit of the motor from the rotation.

When the higher speed is required, the second motor is activated and overrides, in terms of its rotation speed, the slow motor, which in this second condition is bypassed and rendered practically ineffective by means of its own freewheel device. The second motor thus transmits high-speed motion to the rollers by means of its sprocket at the output of its own reduction unit.

When the high-speed motion condition ceases, the second fast motor is deactivated and the transmission returns to the condition in which the slow motor is engaged.

This prior art provides a substantially satisfactory performance, but with significantly high costs caused by the need to have, for each one of these roller conveyors, two specific motors and as many reduction units, freewheel devices, transmission pulleys and controls for activating and deactivating the motors.

Moreover, this conventional motor drive is affected by significant dimensions, indeed due to the necessary duplication of all its components; these dimensions often do not fit the space available along production lines.

Accordingly, the motors and the respective reduction units must be arranged in some cases on opposite sides of the roller conveyors, resorting to at least one transverse shaft to transmit motion to one of the pulleys, which must in any case lie on the same side, since there is a single chain for transmitting motion to the rollers.

The aim of the present invention is to eliminate the above-noted drawbacks of the prior art, by providing a unit for motorizing beds of parallel rollers for conveying manufactured articles with at least two alternate speeds, said unit allowing to eliminate the currently required duplication of transmission pulleys and freewheel devices and accordingly drastically containing the overall dimensions and production costs of roller conveyors.

This aim is achieved by the present unit for motorizing beds of parallel rollers for conveying manufactured articles with at least two alternate speeds, comprising a transmission chain or belt which is mechanically connected to said rollers and to two independent motors, a first one of said motors having a high nominal rotation rate, i.e. being a first fast motor, and a second one of said motors having a low nominal rotation rate, i.e. being a second slow motor, both motors being coupled in output to a respective reduction unit, characterized in that said reduction units are connected one another by respective half-shafts at the output and merge in an interposed common freewheel device, at least the half-shaft at the output of said reduction unit coupled to said first fast motor being adapted to motorize a common transmission sprocket which is engaged in said chain.

Further characteristics and advantages of the present invention will become better apparent from the detailed description of a preferred but not exclusive embodiment of a unit for motorizing beds of parallel rollers for conveying manufactured articles with at least two alternate speeds, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is an exemplifying diagram of a motorization unit for beds with parallel rollers according to the prior art; Figure 2 is a constructive diagram of the motorization unit for beds with parallel rollers according to the present invention.

With reference to the figures, the reference numeral 1 generally IE 0 10 3 5 2 designates a unit for motorizing beds of parallel rollers 2 for conveying manufactured articles 3, ceramic tiles in the specific case, with at least two alternate speeds. Figure 1, although illustrating a conventional motorization unit, is used to illustrate the belt and the rollers which are the same as those used in the present invention.

The unit 1 comprises a transmission chain or toothed belt 4 which is mechanically connected to the rollers 2, e.g. by mounting respective sprockets on the ends of the rollers, and to two independent motors: a first motor 5 having a high nominal rotation rate, i.e. more concisely, a first fast motor, and a second motor 6 having a low nominal rotation rate, i.e. more concisely, a second slow motor.

Both motors 5 and 6 are coupled at their output to a respective reduction unit, designated by the reference numerals 7 and 8 respectively; in turn, the reduction units are connected one another by respective half-shafts 9 and 10 at the output, which merge in an interposed common freewheel device 11.

The half-shaft 9 at the output of the reduction unit 7 coupled to the first fast motor 5 drives a common transmission sprocket 12 which engages the chain 4.

The half-shafts 9 and 10 are supported so as to be coaxial, and in the preferred embodiment of the invention the half-shaft 10 forms a cup-shaped receptacle 13 inside which said common freewheel device 11 is accommodated so as to rotate rigidly with the permanently engaged component thereof.

Correspondingly, the half-shaft 9 protrudes into the cup-shaped receptacle 13 in order to rotationally engage the unidirectional idle component of the common freewheel device 11.

The half-shaft 9 further engages a transmission gear 14 which is part of the reduction unit 7 and is keyed onto the shaft 15 that supports the common transmission sprocket 12: the shaft 15 is preferably arranged at right angles to the half-shaft 9. ΙΕΟ 103 5 2 The operation of the invention is as follows: the second slow motor 6 keeps the common sprocket 12 turning constantly and at low speed, transmitting thereto the rotary motion by way of the coupling between the half-shafts 9 and 10 provided by means of the constantly-engaged part of the freewheel device 11.

The sprocket 12, engaged with the chain 4, in turn transmits the slow motion to the rollers 2.

During this step, the first fast motor 5 is kept deactivated and the freewheel device 11, or more precisely the constantly-engaged part thereof, turns the elements of the fast motor in a passive mode.

When shifting to the higher speed is required, the first fast motor 5 is energized: the half-shaft 9 transmits the fast motion to the common sprocket 12 by means of the transmission gear 14; simultaneously, the freewheel device 11, which rotates rigidly with the receptacle 13 formed by the halfshaft 10, excludes the action of the second slow motor 6, allowing the rotation of the half-shaft 9 with respect to the half-shaft 10.

The fast motion is thus transmitted to the rollers 2 by means of the chain 4 in which the common sprocket 12 engages.

When the fast motion condition ceases, the unit 1 reconfigures itself dynamically as stated above, i.e. the first fast motor 5 is de-energized and the second slow motor 6 resumes, by being constantly engaged, the slow transmission of the rotary motion to the common sprocket 12 and accordingly to the rollers 2.

In practice it has been observed that the described invention achieves the intended aim and objects.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

All the details may further be replaced with other technically equivalent ones.

In practice, the materials used, as well as the shapes and the dimensions, ΙΕΟ 103 5 2 may be any according to requirements without thereby abandoning the scope of the protection of the appended claims.

Claims (10)

1. A unit for motorizing beds of parallel rollers for conveying manufactured articles with at least two alternate speeds, comprising a transmission chain or belt which is mechanically connected to said rollers and to two independent motors, a first one of said motors having a high nominal rotation rate, and a second one of said motors having a low nominal rotation rate, both motors being coupled in output to a respective reduction unit, characterized in that said reduction units are connected one another by respective half-shafts at the output and merge in an interposed common freewheel device, at least the half-shaft at the output of said reduction unit coupled to said first motor being adapted to motorize a common transmission sprocket which is engaged in said chain.

2. The unit according to claim 1, characterized in that said half-shafts are supported so as to be coaxial.

3. The unit according to claims 1 and 2, characterized in that the end of said half-shaft at the output of said reduction unit coupled to said second motor forms a cup-shaped receptacle inside which said common freewheel device is accommodated so as to rotate rigidly therewith.

4. The unit according to claims 1 and 2, characterized in that the end of said half-shaft at the output of said first motor forms a receptacle inside which said common freewheel device is accommodated so that it can be rotationally disconnected.

5. The unit according to the preceding claims, characterized in that said half-shaft at the output of said reduction unit coupled to said first motor protrudes into said cup-shaped receptacle for disconnectable rotary engagement with said common freewheel device.

6. The unit according to the preceding claims, characterized in that said half-shaft at the output of said reduction unit coupled to said second motor protrudes into said cup-shaped receptacle for rigid rotary engagement with said common freewheel device.

7. The unit according to the preceding claims, characterized in that said half-shaft at the output of said reduction unit coupled to said first motor engages a transmission gear which is keyed onto the shaft that supports said common transmission sprocket. 5

8. The unit according to claim 7, characterized in that said transmission gear is an integral part of said reduction unit coupled to said first motor.

9. The unit according to claim 7, characterized in that said supporting shaft is arranged at right angles to said half-shaft.

10. The unit according to the preceding claims, characterized in that the io rotation rate of one of said first and second motors is at least twice the rotation rate of the other.