Patent PT-76088-A (PT)
IPC: A21C3/02
Filed: 1983-01-12
Abstract: 1. Motorised drive mechanism having a variable speed and which is reversible, i.e. with reversal of the direction of movement, for the conveyors of a rolling mill for dough, of the type comprising two super-imposed rolls (1, 2) of adjustable spacing, a first conveyor (4) comprising an endless belt (5) situated on one side of the rolls (1, 2) and a second conveyor (8) comprising an endless belt (9) situated on the opposite side and also comprising said reversible motorised drive mechanism connected to the two rolls (1, 2) as well as to the drive rollers (6, 10) of the two conveyors (4, 8), this drive mechanism comprising a reversible speed-reduction unit (12), which drives the rolls (1, 2) and also, in order to obtain a reduction in the speed of whichever of the conveyors is used as a conveyor for supplying dough to the rolls (1, 2), double speed variation means (43, 53) with an input shaft (41) itself also driven by the speed-reduction unit (12) with a first output shaft (46) connected to the drive roller (6) of the first conveyor (4) and with a second output shaft (57) connected to the drive roller (10) of the second conveyor (8), means (68) being provided for acting on the two speed variation means (43, 53), the latter being of the type comprising a belt (44, 55) passsing over a drive pulley (42, 54) and over a receiving pulley (45, 56) whereof at least one comprises cheeks of variable spacing, the drive pulleys (42, 54) of the two variation means comprising a belt (43, 53) being driven at the same speed by the input shaft (41) in turn driven by the speed-reduction unit (12), the receiving pulley (45) of one of the variation means (43) being mounted on the first output shaft (46) which is connected to the drive roller (6) of the first conveyor (4) and the receiving pulley (56) of the other variation means (53) being mounted on the second output shaft (57) which is connected to the drive roller (10) for the second conveyor (8), characterised in that provided for the control of the double speed variation means comprising belts (43, 53) is a single and common sliding member (68), which can be moved manually and comprises a first inclined ramp (72) cooperating with a push-rod (75) making it possible to modify the spacing of the cheeks of the receiving pulley (45) of the first variation means comprising a belt (43) and a second inclined ramp (73) cooperating with a push rod (77) making it possible to modify the spacing of the cheeks of the receiving pulley (56) of the second variation means comprising a belt (53), the relative position of the two inclined ramps (72, 73) being such that when one of the ramps (72 or 73) cooperates with the corresponding push rod (75 or 77) in order to bring nearer together the cheeks of the receiving pulley (45 or 56) of one of the variation means comprising a belt (43 or 53), the push rod (75 or 77) associated with the receiving pulley (45 or 56) of the other variation means comprising a belt (43 or 53) is released and allows the cheeks of this latter pulley to move into a predetermined relative position, keeping the speed of the conveyor (4 or 8) driven by the intermediary of this other variation means constant, the ends of the sliding control member (68) being provided in order to cooperate with two electrical contacts (70, 71) connected to a reversing contact-maker controlling the electrical supply and the direction of operation of the speed-reducer unit (12).