A SYSTEM FOR THE PRODUCTION OF RUBBER TUBES

Abstract: A system for the production of rubber tubes on elongate horizontal cores (14) comprises two pairs of drive heads (5) mounted on structures (1) capable of displacement upwardly and downwardly with respect to corresponding fixed bases (3). Between the drive heads (5) there is positioned a bed (2) of predetermined length carrying, with the interposition of suitable cushioning means (20,21) intermediate stands (1) for supporting the cores (14). Adjacent the said bed (2), on either side, there is a respective ground bar (22) positioned substantially at floor level for supporting and guiding carriages (23) which are movable parallel to the bed (2).

Description: The present invention relates to a system for the production of rubber tubes, provided with constructional characteristics able to permit a perfect alignment of the cores on which the tubes are made with respect to the rotary drive heads, regardless of the diameter of the cores. Known systems for the production of rubber tubing in predetermined lengths substantially comprise a pair of rotary heads to which the ends of the cores are fixed, the cores being constituted by round bars, and supported along their length by a plurality of stands having a fixed adjustment and mounted on a suitable supporting structure or bed. In such known systems, given the length of the cores and the fixed height of the axes of rotation of the drive heads of the capstans, a correct operating process can only be obtained by utilising cores the radius of which is equal to the distance between the axis of the said drive heads and the support surface of the stands. Obviously, small differences from this theoretical radius can be admitted without causing excessive working inconveniences; but differences greater than a certain limit, can cause an unwanted flexure of the end portions of the cores and, therefore, the risk of oscillation phenomena thereof. If such oscillations happen it is essential to reduce, proportionately, the speed of rotation of the drive heads, with a corresponding reduction in the working capacity of the system. Moreover, in current systems for the production of rubber tunes, the carraiges which normally lie adjacent the beds, and which are utilised in applying the cladding and/or for the insertion of reinforcing strips, fabrics, metal wires and the like, onto tubes being produced, are usually carried by a pair of rollers slidable along U-shaped guides fixed at the side of the supports of the beds themselves. This type of fixing, however, is not able to eliminate the possibility of transverse oscillations of the carriages, with consequent detrimental effect on the proper operation of the process. The present invention seeks therefore, to overcome disadvantages of the prior art systems by providing an installation for the production of rubber tubes, which allows for the possibility of a continuous adjustment of the height of the axes of rotation of the rotary heads driven by the capstans. According to the present invention, there is provided a system for the production of rubber tubes comprising two horizontally extending cores on which the tubes are formed, characterised by the fact that it includes two pairs of drive heads mounted on capstan structures capable of adjustment upwardly or downwardly with respect to corresponding fixed bases a bed of pre­ determined length extending between the drive heads and carrying, with the interposition of cushioning means, stands for supporting the cores along their length and, adjacent the bed, there being a guide bar positioned substantially at floor level for supporting carriages which in use of the system cooperate with the said drive heads. One advantage of the present invention is that it provides a system for the production of rubber tubes, in which unwanted transverse oscillations of the carriages moving along the two sides of the bed are minimised. Another advantage of the present invention is that it provides a system for the production of rubber tubes, in which there are provided means which prevent or at least reduce vibration of the stands which support the core from being transmitted onto the bed. One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic plan view of the bed of a system for producing rubber tubes and the drive heads positioned at the two ends thereof; Figure 2 is a schematic end view of one of the carriages adjacent the bed, and one of the capstan structures supporting the drive heads; Figure 3 is a perspective view illustrating the coupling between one end of a core and a drive head; Figure 4 is a longitudinal section showing the female attachment coupling for connecting a drive shaft of a drive head; Figure 5 is a side view of the male part of the attachment coupling, which is securely fixed to the ends of the said core; Figure 6 is a perspective view showing one of the stands for the support of the cores; Figure 7 is a side view of the stand shown in Figure 6; and Figure 8 is a transverse section of the carriage guide bar adjacent the bed. With reference now to the drawings, the illustrated system for the production of rubber tubes comprises two pairs of counterposed capstans, generally indicated with the reference numeral 1, between which is interposed a bed 2 the structure of which is formed substantially according to known constructional criteria. These capstans 1 are each constituted by a fixed base 3 incorporating mechanical means for raising and lowering a movable structure 4 coupled thereto and carrying a pair of drive heads 5. The said mechanical means may be formed, for example, by vertical threaded spindles engaged by corresponding nuts put into rotation jointly via a chain by means of a geared motor unit, or by other functionally equivalent mechanisms. The drive shaft of each said drive head carries a terminal flange to which is connected a flange 6 of a female coupling unit 7 within which is fitted a female attachment 8 firmly fixed thereto by the engagement of steel balls 10 in circumferentially spaced sockets 11, the balls 10 being housed in radial seats in the tubular body of the coupling unit 7 and being locked in position by an axially movable locking ring 9. The said female attachment 8 has a cylindrical seat 12 having differ­ entiated sections open radially to the exterior through slot 13. The end of each core 14, in its turn, carries a male attachment 15 the free end 16 of which is shaped in such a way as to form, substantially, an eccentric disc. In practice the connection between the core 14 and the associated drive head is formed by inserting the end poart of the core, which carries the aforesaid male attachment 15, laterally into the interior of the slot 13 formed in the female attachment. In this way the two attachments, by the effect of the particular form and the axial tension normally caused by the drive heads, by means of appropriate pneumatic cylinders, are securely locked together thereby transmitting rotary drive from the motor to the core. The said male and female attachments can of course be utilised for cores of any diameter. The transverse distance between the axis of the drive heads 5 and the support surfaces of the stands 17 mounted at regular intervals on the bed 2 for the support of the cores themselves, can be adjusted at will at least within certain limits by operating, to raise or to lower the capstan by acting on the movable structure 4. The said stands are each provided with a set of three rollers 18 having horizontal axes, which are mounted on a supporting structure 19 rigidly connected to the bed 2 with the interposition of a disc 20 of anti-vibrating material, and of a rubber block 21. By this arrangement the vibrations and shocks generated in operation of the system are transmitted only to the stands, thereby saving the bed from oscillations and therefore allowing these to be made using lighter structural elements that are utilised for the production of beds for systems of conventional type. At the foot of the bed 2 there is disposed, on each side, a tempered and ground bar 22 for the guidance of carriages 23 normally cooperating with the capstans 1 for the production of tubes. This bar is mounted on a support 23 resting on an anti-vibrating plate 24 which, with the interposition of a neoprene or like disc 25 is supported by a base plate 26 also of anti-vibrating material. This ground bar guides the said carriages, which roll on a pair of rubber wheels 27, in such a way that these translate parallel to the bed without subjecting it to even the smallest transverse oscill­ ation.

Claims: 1. A system for the production of rubber tubes comprising two horizontally extending cores (14) on which the tubes are formed characterised by the fact that it includes two pairs of drive heads (5), mounted on capstan structures (1) capable of adjustment upwardly or downwardly with respect to corresponding fixed bases (4), a bed (2) of predetermined length extending between the drive heads (5) and carrying, with the interposition of cushioning means (19,20,21) stands for supporting the cores (2) along their length, and adjacent the bed, there being a ground bar (22) positioned substantially at floor level for supporting carriages which in use of the system cooperate with the said drive heads (5). 2. A system for the production of rubber tubes according to Claim 1, including two pairs of counter­ posed capstans (1) between which there is interposed a bed having a structure known per se, characterised in that these capstans (1) are constituted by a fixed base (3) having mechanical means (3) for raising or lowering a movable structure (1) coupled thereto and carrying a pair of drive heads (5). 3. A system for the production of rubber tubes according to Claim 1 or Claim 2 characterised in that the drive shaft of each said drive head carries a terminal flange (6) to which is connected a coupling unit (7) to which is connected a female attachment (8) which is securely fixed thereto by axial movement of a connecting ring (9) capable of locking steel balls (10) within corresponding concave seats formed circum­ ferentially in the attachment itself. 4. A system for the production of rubber tubes according to Claim 3, characterised in that the said female attachment (8) is provided with a coaxial inner cylindrical seat (12) having a section (13) open radially to the exterior via a slot; and in that the terminal part of the aforesaid cores (14), in turn, carry a male attachment (16) the free end of which is shaped in such a way as to form an eccentric disc. 5. A system for the production of rubber tubes according to any preceding Claim, characterised in that the said stands (15) substantially comprise a set of three rollers (18) having horizontal axes, mounted on a supporting structure rigidly connected to the aforesaid bed (2) with the interposition of a disc (20) of anti-vibrating material and a rubber block (21). 6. A system for the production of rubber tubes according to any preceding Claim, characterised in that at the foot of the said bed (2), on each side thereof there is disposed a tempered and ground guide bar (22) for supporting carriages (23) which are movable along the bed, each said bar (22) being mounted on a support carried on a vibration-absorbing plate (24) which, with the interposition of a neoprene disc (25) or the like is supported by a base plate (26) also of vibration-­ absorbing material.

Inventors: COLBACHINI, GIUSEPPE ALDINIO
Applicants: I.V.G. COLBACHINI S.P.A.
Application year: 1986
Main classification: B29C53
IPC codes: B29C70, B29D23, B29C31, B29K21