Transport device

1. A transport device, of a type comprising a screw conveyor ( 5 ), in a casing ( 5 a ) of which a propeller ( 5 b ) rotates, wherein the device comprises an elastic cradle ( 7 ), interposed between the casing ( 5 a ) of the screw and the propeller ( 5 b ), internally of which cradle ( 7 ) the propeller ( 5 b ) of the screw rotates; the cradle ( 7 ) being made of a plastic material, having an arc-of-circle-shaped constant section and being arranged to surround a lower part of the propeller ( 5 b ); characterised in that the cradle ( 7 ) is connected to the casing ( 5 a ) by at least an elastic suspension element ( 8 ), said elastic suspension element ( 8 ) being distinct from said cradle ( 7 ).

2. The device of claim 1 , wherein the cradle ( 7 ) rests on the casing ( 5 a ) of the screw conveyor by means of ribs ( 7 a ) fashioned in a part of the screw conveyor not facing the propeller ( 5 b ), and wherein the elastic suspension element ( 8 ) is arranged at an upper longitudinal edge of the cradle ( 7 ).

3. The device of claim 1 , wherein the cradle ( 7 ) rests on the casing ( 5 a ) of the screw conveyor by means of ribs ( 7 a ) fashioned in a part of the screw conveyor not facing the propeller ( 5 b ), and is connected with the casing by means of the elastic suspension element ( 8 ), arranged at an upper longitudinal edge of the cradle ( 7 ).

4. The device of claim 3 , wherein the cradle ( 7 ) is connected to the casing ( 5 a ) by a pair of elastic suspension elements ( 8 ), each of which comprises a longitudinal flat spring, an end ( 8 a ) of which flat spring is inserted in a channel ( 7 b ) afforded on a longitudinal edge of the cradle ( 7 ), and another end ( 8 b ) of which flat spring is solidly connected to the casing ( 5 a ) of the screw conveyor.

5. The device of claim 3 , wherein the cradle ( 7 ) is connected to the casing ( 5 a ) by an elastic suspension element ( 8 ), which comprises a longitudinal flat spring, an end ( 8 a ) of which flat spring is inserted in a channel ( 7 b ) afforded on the longitudinal edge of the cradle ( 7 ), and another end ( 8 b ) of which flat spring is solidly connected to the casing ( 5 a ) of the screw conveyor.

6. The device of claim 1 , wherein at least a part of the propeller ( 5 b ) is covered with a plastic material.

7. The device of claim 6 , wherein the device comprises inserts ( 9 ), made of plastic material and being shaped as portions of propeller ( 5 b ), which are connected to the propeller ( 5 b ) at a terminal zone thereof, and which continuously cover said terminal zone.

8. The device of claim 1 , wherein the propeller ( 5 b ) of the screw conveyor ( 5 ) is wound on a shaft ( 5 c ) having a prismatic section and is connected to the shaft ( 5 c ) by means of supports ( 5 d ) conformed such as to leave empty spaces ( 5 e ) between the shaft ( 5 c ) and the propeller ( 5 b ).

9. The device of claim 8 , wherein at least a part of the shaft ( 5 c ) and the supports ( 5 d ) are covered in a plastic material.

10. The device of claim 9 , wherein: the covering of part of the shaft and the supports is obtained with modular elements ( 12 ), comprising a metal core covered with a plastic material and provided with a central key ( 12 a ) conformed such as to insert snugly in the shaft ( 5 c ), and exhibiting at least a metal projection ( 12 b ), covered with plastic, conformed such as to realise one or more connecting spokes in the supports ( 5 d ); one or more of the modular elements, which are inserted coaxially on the shaft in contact with one another, being used for covering the portion of the shaft to be covered.

11. The device of claim 1 , wherein the device comprises means of known type for vibrating the cradle ( 7 ) on command.

12. The device of claim 11 , wherein the means for vibrating the cradle ( 7 ) comprise a pump which, on command, introduces fluid between the cradle ( 7 ) and the casing ( 5 a ) of the screw.

13. The device of claim 1 , wherein the screw conveyor ( 5 ) comprises: a loading mouth ( 2 ), through which a fluid comprising a liquid part and a part containing aggregate materials ( 6 ) can be introduced; a first discharge mouth ( 3 ) through which the aggregate materials ( 6 ) conveyed by the propeller ( 5 b ) can exit the device; a second discharge mouth ( 4 ) through which the liquid part of the fluid can exit the device; the elastic cradle ( 7 ), arranged internally of the casing ( 5 a ) of the screw, being arranged between the loading mouth ( 2 ) and the first discharge mouth ( 3 ).