Patent GB-790072-A (GB)
Title: Automatic lap doffing mechanisms for textile lap-winding machines
IPC: D01G27/02
Filed: 1955-07-19
Abstract: 790,072. Lap winding apparatus. STEIN, M. July 19, 1955 [Jan. 19, 1955], No. 20842/55. Class 120(1) Relates to automatic lap 'doffing in lapwinding machines of the kind in which the lap is wound under pressure from the heads of racks which rise and fall to doff a complete roll and feed an empty lap rod after a predetermined length of lap has been wound, the lap carrier rolls being driven from a scutcher through a one-way clutch; the racks are positively reciprocated by a reversible motor drive; the carrier rolls are accelerated during the upward stroke of the racks, to detach the lap, by the motor drive acting through a second one-way clutch acting in the opposite direction to the first; and control means operate in the highest position of the racks to reverse the motor drive. Rack movement. When a predetermined length of lap has been wound, as measured by a counter, a drop lever 1, Fig. 1, is allowed to fall so as to close a switch 4 and depress the brake lever 3 to the released position where it is retained by a pawl 5a. Closure of switch 4 causes an electric motor to drive the racks 7a upwards, an abutment 11 on one rack engaging a lever 11 to lift drop lever 1 to its original position. In the topmost position of the racks, a switch 14 is operated to reverse the motor to positively lower the racks; in the bottom position a switch 15 is operated to stop the motor and an abutment 16 releases pawl 5a to re-engage the brake. The motor may be arranged to give a higher-speed drive during raising of the racks than during lowering; this speed change could be provided by using a pneumatic or hydraulic motor throttled during the lowering operation. Detachment of roll. During roll-formation the driving rollers 17, 18, Fig. 7, are driven, via a one-way clutch, from the scutcher to which the lap-former is attached. During upward movement of the racks, rollers 17, 18 are given a higherspeed over-drive from the rack-raising motor via a ratchet-and-pawl clutch which is oppositely positive to the clutch in the drive from the scutcher, so as to detach the completed roll by breaking the lap. The period of accelerated drive of rollers 17, 18 may be shortened by automatic release of a clutch in the over-drive after the lap has been broken. To prevent double detachment of the lap, a weight roll arranged between the lowest calender roller and the rear carrier roller may be lifted and lowered by the upward and downward rack movements respectively. Doffing of completed roll and feeding new lap rod. As the racks rise the journals 30 of the lap rod 29 in the completed roll 28, Fig. 7, are engaged by pivoted arms 27 on the racks so that the roll 28 slides down arms 27 to a receiving cradle As . the racks rise further arms 27 are fitted to the Fig. 8 position by engagement of the arm ends 27b with fixed abutments 41; the noses 7b of the rack heads 7 force a new lap rod 29a off a rest 33 on to arms 27; as the racks descend, lap rod 29 a  runs down arms 27 to the dotted-line position, arms 27 being retained in a tilted position by pawls 43 which are released when the racks reach the bottom of their travel. In an alternative arangement, Figs. 13-15, lap rod 29a slides down fixed guides 58 into notches 59 in the racks. As the racks reach the bottom of their travel, tongues 61 spring over the journals 30a. The completed roll is discharged, Fig. 15, over tongues 61. and arms 27 which are of fixed inclination. Further alternative aangements are described. Lap rod. For ease of withdrawal from the completed lap, the lap rod is provided with a loose sleeve which is fluted, machined or provided with a suitable cover so as to have a surface with a high coefficient inclination. Further alternative arrange- 120(1)] is referred to.