SELF-PROPELLED MULTIPART MACHINERY FOR PREPARING IN-SITU AND SPREADING OUT COLD BITUMINOUS OR CEMENTITIOUS MIX

Abstract: The machinery comprises means (1, 3) for gathering the material (2) to be mixed; means (4) for transferring the collected material (2) into an accumu­ lation hopper (8) including weighing means (9); means (6) for cleaning and subjecting to suction the roadbed (7) on which the new layer is to be spread out; means (10) for transferring said material from the hopper (8) to a screen (11); a device (12) for crushing the material rejected by said screen (11); at least one reservoir (5, 14) for the binding material; a mixer (13) and a device (16) for spreading out the new layer.

Description: This invention relates to a self-propelled, multi-part machinery for preparing in situ and spreading out a cold bituminous or cementitious mix. More particularly, this invention relates to a machinery of the type mentioned above which is provided with all necessary devices for making a road paving by a cold process, including the cleaning of the roadbed which is to be spread as well as screening and crushing devices for the previous paving and weight metering devices for the additives to be employed, so that the whole preparation and spreading out cycle of a bituminous or cementitious mix is made possible. It is well known that the technical problem met with in the making of damaged road pavings consists in the recovery of the paving itself. This is convenient both because of the obvious savings of inert materials and of the bitumen already contained in the paving, and because of the obvious power savings stemming from the complete absence of transportation and hot working operations, and in addition also because of the ecological aspects as such recovery is absolutely free from evolution of smokes due to the particular cold working technique employed for the material in question. At present no machinery among those employed at the present time allows the roadbed on which the new paving is to be spread out to cleaned automatically and simultaneously together with the screening and breaking or crushing of the previous paving, as well as the weight metering of the additives, in order to obtain a predetermined granulometric plot. In EP-A-0237424 it is described a self-propelled multipart machinery for preparing in situ and spreading out a cold bituminous or cementitious mix by which cold working operations are performed, said operations allowing a complete preparation and spreading out cycle to be carried out in situ. Accordingly, the Patentee suggests the realization of a machinery capable of working by exploiting all advantages that are proper of the cold working and that allows all operations connected with the realization of a complete cycle to be carried out, including the operations of cleaning the roadbed automatically, continuously, on the working site. It is thus a specific object of the present invention to provide a self-propelled, multipart machinery for preparing in situ and spreading out a cold bituminous or cementitious mix, said machinery comprising means for gathering the inert material to be mixed from the roadbed; means for cleaning the roadbed on which the new layer is to be spread, and for exerting a sucking action on such plane; means for transferring the collected material into hopper means which are provided with weighing means for the material itself; means for transferring said material from said hopper means into a screen; means for crushing the material rejected by said screen; a mixer that is fed by said screen and/or by said crushing means; at least a reservoir for the binding material with means for distributing the binding material itself onto the inert material at the point corresponding to said mixer; and a device for spreading the material coming from the mixer itself onto the roadbed previously arranged, according to predetermined values of width and thickness. More particularly, said means for gathering the inert material to be mixed from the road plane can be made up of conveyor blades and of a cylindrical collecting rotor including blade arms, and said means for transferring the material towards hopper means can be made up of a conveyor belt. The hopper means are provided with an extracting-weighing belt and they unload the inert material onto a vibrating conveyor belt that transfers said material onto said screen, which preferably is of the vibrating type. Further according to the present invention the mixer is of the type including a double shaft with spraying bars. Two reservoirs for the binding material are preferably provided, the first one of them being at the point corresponding to said means for transferring the material to said hopper means, while the second one is arranged above said mixer. The second reservoir is provided with a pump body for distributing the binding material, the throughput being adjustable and controlled by the weighing device of the hopper means. The device for spreading out the material so prepared is preferably made up of a vibratory screed bench. Moreover, the machinery according to the present invention can also be provided with a general control board for the production cycle as well as with adjusting and control devices. This invention will be disclosed in the following just for illustrative and not for limitative purposes with particular reference to the preferred embodiment of the same as illustrated in the enclosed figure which shows a schematic side view of the machinery according to the present invention. The self-propelled machinery shown in the figure comprises conveyor blades 1 by means of which the material 2 to be mixed is collected. The material 2 is conveyed towards the collection rotor 3 which is provided with blade arms serving the purpose of conveying and lifting the material up to the conveyor belt 4. The reference numeral 5 points out a stockage reservoir for the binding material. The cleaning and sucking device 6 for cleaning the roadbed 7 on which the new paving is to be spread out is arranged below said reservoir 5. An accumulating hopper 8 comprising the extracting-weighing belt 9 is arranged at the end of the conveyor belt 4. Moreover, a vibratory conveyor belt 10 is also provided which conveys the material onto a vibrating screen 11 endowed with a system for selecting the materials according to a previously determined curve. A crushing device 12 serves the purpose of reducing the sizes of the material rejected by the vibratory screen 11. A two-shaft mixer 13 is provided below said vibratory screen 11 and below said device 12, said mixer being provided with means for spraying and introducing the binding material coming from the reservoir 5 or from a second reservoir 14 for stocking the binding material, said reservoir being provided with a metering pump for distributing the binding material itself. The reference numeral 15 points out a metering bar which sprays the binding material drawn from the reservoir 5 or from the reservoir 14 into the space between the old paving plane and the new layer. The operation of spreading out the new layer according to predetermined values of width and thickness is carried out by means of the vibratory screed bench 16. Moreover, the machinery according to the invention is also provided with the control board 17 and with wheels 18. After the already existing roadbed has been broken down to the desired depth, it is lifted by means of the blades 2 and the rotor 3 and then carried by means of the conveyor belt 4 up to the hopper 8. The plane to which the new layer is to be applied is simultaneously cleaned and subjected to sucking through the device 6. After the material has accumulated in the hopper 8, it is weighed and transferred by means of the conveyor belt 10 to the vibratory screen 11 for undergoing selection on the basis of its granulometry. The material having the required grain sizes is conveyed directly to the mixer 13, whereas the material whose granulometry is higher than that previously determined is conveyed to the crushing device 12 and then to the mixer 13. Fresh binding material is introduced into the mixer 13 simultaneously with the arrival of said material into the same, the binding material being introduced by means of a double diffusion-device (not shown) which is controlled by an adjustable flowrate pump automatically controlled by the weighing device 9. The product is mixed and prepared within said mixer 13 and then it is spread out, after finishing and regenerating, by means of the bench 16, according to values of width and thickness determined on the basis of some specific requirements.

Claims: A self-propelled multipart machinery for preparing in situ and spreading out a cold bituminous or cementitious mix, said machinery comprising means (1,3) for gathering the inert material (2) to be mixed from the roadway (7); means (6) for cleaning and subjecting to suction the roadbed (7) on which the new layer is to be spread out; means (4) for transferring the material collected (2) into hopper means (8) which are provided with means (9) for weighing the material itself; means (10) for transferring said material from said hopper means (8) into a screen (11); means (12) for crushing the material rejected by said screen (11); a mixer (13) which is fed by said screen (11) and/or by said crushing means (13); at least one reservoir (5, 14) for the binding material, said reservoir being provided with means for distributing the binding material itself onto the inert material at the point corresponding to said mixer; and a device (16) for spreading out the material coming from the mixer (13) onto the previously prepared roadbed, according to predetermined values of width and thickness. A machinery according to claim 1, wherein said means (1, 3) for gathering the inert material (2) to be mixed from the roadway (7) are made up of conveyor blades (1) and of a cylindrical collecting rotor (3) including blade arms. A machinery according to claims 1 or 2, wherein said means (4) for transferring the material (2) towards said hopper means (8) are made up of a conveyor belt (4). A machinery according to any one of the preceding claims, wherein said hopper means (8) are provided with an extracting-weighing belt (9). A machinery according to any one of the preceding claims, wherein said means for transferring the material from said hopper means (8) to said screen (11) are made up of a vibratory conveyor belt (10). A machinery according to any one of the preceding claims, wherein said screen (11) is a vibratory screen. A machinery according to any one of the preceding claims, wherein said mixer (13) is a double-shaft mixer with spraying bars. A machinery according to any one of the preceding claims, wherein two reservoirs (5, 14) are provided for the binding material, the first one (5) of said reservoirs is arranged at the points corresponding to said means (4) for transferring the material to said hopper means (8), whereas the second reservoir (14) is arranged above said mixer (13). A machinery according to claim 8, wherein said second reservoir (14) is provided with a pump-body for distributing said binding material with adjustable flow-rate controlled by said weighing device of said hopper means. A machinery according to any one of the preceding claims, wherein said device (16) for spreading out the material so prepared is made up of a vibratory screed bench. A machinery according to any one of the preceding claims, wherein a general control board (17) provided with adjustment and control devices, is provided for the whole production cycle. A machinery according to any one of the preceding claims, wherein at least one metering bar (15) is provided that distributes the binding material contained within said reservoirs (5, 14) onto the already prepared roadbed, said bar being arranged upstream said mixer (13).

Inventors: MARGUTTI, SERGIO
Applicants: TODINI COSTRUZIONI GENERALI S.P.A.
Application year: 1989
Main classification: E01C23
IPC codes: E01C23, E01C19