SYSTEM FOR MANUFACTURING SHAFTS FOR THE HELICAL ELEMENTS IN DEHYDRATING SCREW PRESSES

Abstract: A system using longitudinal forms (1) with, ideally a square section provided in advance on one or two corners with a bevel (2) to form a wall (3) adjacent to the subsequent form. The assembling condition can be obtained by operating with inside (4) and outside (5) welds. By means of a turning operation, two parts (6 and 7) are then removed, thus obtaining the tubular shape. The sys­ tem, to form cylindrical shafts, consists in modules with a constant section, and modules with a progressively changing section for coni­ cal shafts, whereas longitudinal square section (3) and rectangu­ lar section (9) modules are required to obtain shafts with drain­ ing channels (20). These rectangular section modules are provided with bevels (10 and 11) on the inside corners to form walls adjacent to the ones of the other interposed modules, and are assembled by means of welds (12, 13, 14 and 15). The shapes (16) are then positioned on the square section modules (8) and are connected to hollow bent sectors (17) of a perforated sheet by welds (18 and 19). The drainage casing thus formed shows a system of channels (20) with an end discharge completed with shapes (21).

Description: The invention refers to a new conception proceeding for manufacturing the shafts of the helical elements to be used in special deshydrating presses. These presses are used to deshydrate fibrous materials containing liquids, such us foragers, and also in the manufacturing treatment of the sugar beet, of fish and meats. These presses are foreseen with a longitudinal filtering cage in which the product to treat is at first charged and presses, in a subsequent phase, by means of one or more helical elements, and while the deshydated residue is discharged at the cage end, the liquid comes out steadily from the outer cage as well as from draining canales built-in the helical elements. In order to avoid a considerable reduction of the helical element, limited size draining canals were initially foreseen. A futher proceeding foresees the draining shaft by means of composition, on a central tubular part which will form the shaft of the helical element, of a peg system in radial disposition holding a drilled cage. This proceeding allows an efficient draining effect, but it weakens the resistance of the shaft which supports the system of pegs and, therefore, of the helical helement. A present proceeding for manufacturing either cylindrical or conical shafts is the calendering one which carries out half-part shaping with subsequent welding. A third known system foresees to, manufacture the shaft from an initial flat shape which is forged around a core to subsequently extract. DE-C-681 109 discloses a shaft as defined in the pre-characterizing portion of the appended claim 1, in which various longitudinal elements of quadrilangular cross-section are mutually joined at their respective longitudinal edges in order to form the shaft. In comparison with all these known proceedings, the invention system enables to manufacture the shaft simply by means of composition of longitudinal forms to assemble through welding lines and either by using or not finishing operations. In this way, a general operational simplification is allowed by previously arranging the forms to use as a store and by forming the parts as a shaft by means of adjustment, if required, their arrangement in composition and by fixing the components according to essential welding lines. Substantially, the system foresees the essential use of a form 1 having an ideally square section, with a chamfer 2 on a corner to obtain by milling, in order to form the adherence wall 3 to the subsequent composition form. The assembling condition is obtained by working with inside 4 and outside 5 welding wires. By means of turning, parts 6 and 7 are then removed, thus obtaining the tubular form of the shaft. The system thus allows to use the same models for carrying out shafts with different thickness and diameters. In a version, the direct manufacturing of shafts with chamfers 2, 5 and 6 is foreseen to allow shafts with constant size and by manufacturing without adjusting operations. To manufacture cylindrical shafts, the system uses longitudinal models with constant section, and londitudinal models with progressively changing section for obtaining conical shafts with changing section. To form shafts with draining canals, on the contrary, essential longitudinal modules with square section 8 and rectangular section 9 are used; these last ones with hollows 10 and 11 on the inside corners to form the walls adhering to the ones of the other interposed form. The forming of the above whole can be obtained by assembling the components by means of the welding wires 12, 13, 14 and 15. In order to form the outer filtering cage, shapes 16 are positioned on the modules 8 and are blended with the bent sectors 17 in drilled plate by assembling the parts by means of the welding wires 18 and 19. The shaft with filgering cage thus obtained shows the system of draining canals 20 for the end discharge completed with shapes 21 fitted inside with modules 8. Execution forms of two shafts, one of which without grooves and the other with filtering cage, both carried out according to the system foreseen by the present invention, are illustrated in the drawings of tables 1 and 2. With reference to these tables in table 1 the components and the execution system of an elementary shaft are illustrated. Fig. 1 is the perspective view respectively of a longitudinal modular component 22, of parallelopiped type, apt to compose cylindrical shafts, and of another component 23 for composing conical shafts. Fig. 2 shows the square section of a longitudinal modular component and subsequently the same section from which part 2 has been removed by means of milling. Fig. 3 is a view of the operative sector to show the assembled condition carried out between two components 1 which have been connected on wall 3, with execution of the inside 4 and outside 5 welding wires execution. The subsequent operation phase, which leads to the completion of the operation by turning and removing parts 5 and 6, can be noted in a particular of fig. 4. Fig. 5 is the view of a shaft transversal section obtained by means of a longitudinal form 1. In table 2, the components and the execution system are illustrated to obtain a shaft with filtering cage and radial scheme drain canals. With reference to this last one, fig. 6 is the perspective view of the used components: the type 8 and 9 longitudinal forms, shape 16, one sector 17 in drilled plate and a canalization shape 21. Fig. 7 is the view in transversal section of the component 8 form which parts 10 and 11 have been removed by means of milling. Fig. 8 is the view of a sectors of the above shaft to show the location of the parts and the welding lines through which the operation of the shaft inside is integral which supports the drilled cage consisting of forms 16 and 17. Fig. 9 is the view in transversal section of a shaft with draining canals carried out according to the present invention. In the realizations, the shape and number of the modular structures to use in the system and in carrying out each shaft may anyhow be different. The modular components, as well as those forming the filtering cage may be carried out in different ways too and in any possibile materials and, if required, they may be replaced with other equivalent elements for the use finalities.

Claims: System for manufacturing shafts for the helical elements in dehydrating screw presses, comprising a plurality of longitudinal modules (8,9,22,23) having an initial substantially quadrilangular cross-section which are mutually connected along their longitudinal borders by means of welding wires (4,5,12,13,14,15) to thereby form said shaft, characterized in that said modules comprise a milled chamfer (2,10) at one corner so as to form an adherence wall (3) which abuts against an adjacent module, said welding wires being provided above and below said adherence wall. System according to claim 1, characterized in that said longitudinal modules (22,23) are provided with further corner chamfers (6,7) for forming a final shaft in tubular form. System according to any one of claims 1 and 2, characterized in that said longitudinal modules (22) have a constant cross-section for forming cylindrical shafts. System according to any one of claims 1 and 2, characterized in that said longitudinal modules (23) have a progressively variable cross-section for forming conical shafts. System according to claim 1, characterized in that said longitudinal modules comprise square section longitudinal modules (8) alternated with rectangular section longitudinal modules (9) which are provided with two of said milled chamfers (10,11) for forming said adherence walls which abut against said square section longitudinal modules (8) which project above the plane of arrangement of said rectangular section longitudinal modules (9), the system further comprising drilled plate filter sectors (17) interconnected between profiled elements (16) connected to the tops of said square section longitudinal modules (8) to form an outer cylindrical shape of the shaft, and canalization profiled elements (21) also interconnected between said profiled elements but lying above said rectangular section longitudinal modules (9) to there by form shafts with draining canals (20).

Inventors: BABBINI, LIONELLO
Applicants: FRATELLI BABBINI & C. SAS
Application year: 1988
Main classification: B30B9
IPC codes: B30B9