Apparatus for continuously feeding extrusion and/or rolling machines with viscous material such as rubber and the like coming from discontinuous-cycle machines

Abstract: Apparatus (1) for continuously feeding extrusion and/or rolling machines (20) with viscous material such as rubber and the like coming from discontinuous-cycle machines, comprising a vertical hopper (2), on at least two facing sides (3) of which a conical auger (7) is housed, said auger being arranged inclined with respect to the vertical axis of the machine so as to form a "V" directed towards the inside of the hopper (2), there also being provided means (8) for independently driving said augers (7), means (7f, 3f, 4f) for cooling them and at least one wall (4) of the hopper (2), as well as means (9) for tilting the augers (7) from said inclined working position into a substantially horizontal position where the machine is at a standstill.

Description: The present invention relates to an apparatus for continuously feeding extrusion and/or rolling machines with viscous material such as rubber and the like received from machines operating with a discontinuous-production cycle. In rubber processing technology it is known of the need to supply extrusion and/or rolling machines with the blocks of mixture which emerge from the mixing machines for example of the so-called internal mixer type. It is also known that the rolling and/or extrusion machines operate in accordance with substantially continuous cycles, while the mixers operate with substantially discontinuous cycles. In the art it is also known of machines and apparatus which are specially designed to remove as quickly as possible the block of mixture leaving the internal mixers and feed the material with continuity and at a predetermined throughput to the extrusion and/or rolling machine. Such machines of the known type are based on the use of cylindrical or conical augers which are arranged with a substantially horizontal axis or are slightly inclined with respect to the horizontal, these having certain defects including the fact that said conical augers must be designed so as to be of the so-called "inter-penetrating" type, in order to obtain the necessary thrusting of the block of mixture towards the following extrusion and/or rolling machine. Being of the inter-penetrating type, the augers cannot be independent, but must be perfectly dimensioned and synchronized with one another so as to avoid breakages and/or malfunctions, this requiring the provision of complicated mechanisms which in addition to being costly and reducing the reliability of the machine, also hinder the maintenance and cleaning operations when the machine is at a standstill. A machine of this type in accordance with the preamble of claim 1 is for example known from US-A-4,764,020. The technical problem which is posed therefore is that of providing an apparatus designed to remove in a discontinuous manner a block of viscous material such as rubber and the like leaving a mixer or the like and to feed in a substantially continuous manner extrusion and/or rolling machines, said apparatus being easy and economical to manufacture, not heating the material during feeding, but on the contrary cooling it in the correct manner, and simplifying the maintenance and cleaning operations when the machine is at a standstill. These results are obtained by the present invention, which envisages an apparatus for continuously feeding extrusion and/or rolling machines with viscous material such as rubber and the like coming from discontinuous-cycle machines, which comprises a vertical hopper, on at least two facing sides of which a conical auger is housed, said auger being arranged inclined with respect to the vertical axis of the machine so as to form a "V" directed towards the inside of the hopper, there also being provided means for independently driving said augers, means for cooling them and at least one wall of the hopper, as well as means for tilting the augers from said inclined working position into a substantially horizontal position where the machine is at a standstill. Preferred embodiments of the invention are disclosed in the dependent claims. Further details can be obtained from the following description, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of the apparatus according to the invention; Figure 2 shows a partially sectioned front view of the apparatus according to Figure 1; Figure 3 shows a side view of the apparatus according to Figure 1; Figure 4 shows a section along the plane indicated by IV-IV in Figure 1; Figure 5 shows a partially sectioned front view of the apparatus with the augers in the tilted position; Figure 6 shows a front view of the apparatus with the front wall tilted for removal of the material. As shown in the Figures, the apparatus 1 according to the invention is composed of a hopper 2 consisting of two pairs of vertical and parallel facing uprights 3 forming the longitudinal flanks of the apparatus itself and joined together in the transverse direction by stiffening cross-pieces 3a. In the region of the rear side 1a of the apparatus, the two uprights are connected by a fixed wall 4, while, in the region of the front part 1b of the apparatus, the uprights are connected by a wall 5 rotatable about associated curved guides 5a, integral with the fixed sides 3, designed to allow tilting of the movable wall 5 from the erect working position, in which it is held by bolts 5b, into a position swung downwards (indicated by broken lines in Figure 4) designed to allow access to the inside of the hopper as well as act as a slide for any removal of material. This thus defines a vertical hopper 2 for containing the material to be fed to the extruder or rolling mill and supplied for example from an internal-type mixer either by means of gravity or transported by a belt conveyor (not shown). Each pair of uprights 3 arranged on the same side of the hopper also supports a frame 6 housing a conical auger 7, the axis of which is arranged at a predetermined angle of inclination with respect to the vertical axis of the machine; thus the two augers 7 are arranged in the form of a "V" directed towards the inside of the hopper, which assumes a substantially frusto-conical internal shape with its vertex directed downwards, suitable for promoting collection of the material and feeding thereof to an underlying machine represented, for example, in the figure by a roll-type 21 rolling mill 20. The support frame 6 is closed externally by a curved wall 6d parallel to the conical auger 7, and at the bottom is hingeably mounted on the fixed uprights 3 via pins 6a; the top part instead has seats 6b designed to cooperate with wedge-type cylinders 6c integral with the uprights 3, for locking the frame 6 to the fixed uprights themselves. The frame has moreover a transverse flange 106 provided with an axial opening 106a which has inserted in it a cup member 107 attached to the shaft 7c of the auger 7 by means of intervening bearings 107a, so that the entire auger group is able to be mounted and removed by means of simple translation axially in either direction. As illustrated in Figure 2, said augers 7 have helices with a variable pitch and more precisely with a configuration which is very open and vertical in the top part 7a and more closed and horizontal in the bottom part 7b; as will become more clear below, this configuration facilitates correct feeding of the material to the underlying rolling mill 20. The shaft 7c of each auger 7 is provided with its own driving system consisting for example, in the figures, of a hydraulic motor 8 arranged coaxially with respect to the shaft of the auger 7 and at the front end thereof so as to be able to drive each auger independently of one another. Both the front wall 5 and rear wall 4 of the hopper 2, as well as the conical wall of the frame 6 supporting the auger 7, and the shaft 7c of the auger are provided with internal ducts, 4f, 3f, 5f, 6f, 7f, respectively, through which cooling liquid is recirculated so as to obtain predetermined cooling of the aforementioned parts and hence the mixture which comes into contact with the latter. As can be seen from Figure 5, the frame 6 supporting the augers 7 is connected at the top to the end 9a of a telescopic arm 9, the other end 9b of which is hingeably mounted on the fixed uprights 3 so that it is possible, when required, to tilt the entire auger/motor group from its inclined working position into a position swung downwards and outwards so as to allow easy access to the hopper 2 and/or to the augers 7 themselves for the normal cleaning and/or maintenance operations. Operation of the apparatus according to the invention is as follows: the block of mixture, coming for example from an internal mixer schematically indicated by 30, is fed directly or via a conveyor belt to the hopper 2, into which it falls simply by means of gravity; inside the hopper, the block is subjected to the action of the two conical augers 7, arranged in a V shape, the helix of each of which causes with its top part 7a a first thrusting of the block towards the rear wall 4 and subsequently, with its bottom helical section 7b, a further thrusting movement downwards, i.e. towards the underlying rolling machine 20; it must be emphasized that the vertical configuration of the apparatus facilitates this downward falling movement of the mass owing to the possibility of being able to exploit advantageously the entire force of gravity of the material itself which acts parallel to the thrust component exerted by the augers, and that the substantially frusto-conical shape of the hopper facilitates the collection and regular feeding of the material itself to the underlying rolling machine or the like with which the feeding apparatus will also be synchronized by means of a suitable device. Upon coming into contact with the rear wall 4 of the hopper 2, the mixture also undergoes a predetermined cooling action, retaining its own characteristics and at the same time being made to assume the best condition for subsequent rolling and/or extrusion. Many variations may be introduced as regards realization of the parts which make up the invention, without thereby departing from the protective scope of the present patent as defined in the claims which follow.

Claims: Apparatus (1) for continuously feeding extrusion and/or rolling machines (20) with viscous material such as rubber and the like coming from discontinuous-cycle machines, characterized in that it comprises a vertical hopper (2), on at least two facing sides (3) of which a conical auger (7) is housed, said auger being arranged inclined with respect to the vertical axis of the machine so as to form a "V" directed towards the inside of the hopper (2), there also being provided means (8) for independently driving said augers (7), means (7f, 3f, 4f) for cooling them and at least one wall (4) of the hopper (2), as well as means (9) for tilting the augers (7) from said inclined working position into a substantially horizontal position where the machine is at a standstill. Apparatus according to Claim 1, characterized in that a frame (6) supporting the auger (7) is rotationally connected to each side (3) of said hopper (2). Apparatus according to Claim 1, characterized in that said frame (6) is externally closed by a curved wall parallel to the conical auger (7). Apparatus according to Claim 1, characterized in that said auger (7) is coaxially coupled to a cup member (107) by means of bearings (107a), said cup member being able to be axially inserted and secured to the frame (6). Apparatus according to Claim 1, characterized in that said hopper comprises at least a rear fixed wall (4) and a front wall (5) rotationally secured to the sides (3) via guides (5b). Apparatus according to Claim 1, characterized in that the threading of said auger comprises a top section (7a) which is open and substantially vertical and a bottom section (7b) which is closed and has a limited inclination. Apparatus according to Claim 1, characterized in that the rear walls (4) and the auger support frame (6) are provided with hollow cavities (4f, 6f) for recirculating cooling liquid. Apparatus according to Claim 1, characterized in that said means for tilting the frame (6) supporting the auger (7) consist of a telescopic arm (9), the opposite ends (9a, 9b) of which are respectively attached to the auger support frame (6) and to the fixed sides (3) of the hopper.

Inventors: GHEORGHITA VICTOR, GHEORGHITA, VICTOR
Applicants: POMINI SPA, POMINI S.P.A.
Application year: 1995
Main classification: B29C31
IPC codes: B29C47, B29C43, B29C31, B29B7, B29K21