Patent GB-541603-A (GB)
Title: Apparatus for effecting continuous movement of strip material
IPC: G03D3/13
Filed: 1940-08-08
Abstract: 541,603. Automatic control systems. KODAK, Ltd. Aug. 8, 1940, No. 12740. Convention date, Oct. 28, 1939. [Class 38 (iv)] [Also in Group XVI]  In apparatus for feeding strips of film, paper, or fabric through a coating, drying or other treating apparatus the web passes in the form of a series of loops between a fixed part of the apparatus and a member floating on the strip to allow of continuous operation of the apparatus while a new strip winding roll is being substituted for a full roll or a new supply roll is being inserted in place of an exhausted roll. The raising of the floating member is effected by a vertically moving elevator member and its descent is effected by gravity. Fig. 1 shows an apparatus for accumulating strip during the changing of the winding roll. The strip S passing from e.g. a drying section of the apparatus, passes over a series of feed-inrollers 51 and then in loop formation over rollers 13 mounted in the fixed frame and rollers 11 carried at each end by a floating member 10 guided for vertical movement in the side frames 3, 4. From the rollers 11, 13 the strip passes over feed-out rollers 51 tension and guide rollers 48, 49 to take the up roll 50. Beneath each floating member 10 is an elevator 9 raised and lowered by screws 14 driven by gearing from an electric motor 18. The feed-in rollers 51 are driven by a motor 41 and the feedout rollers by a motor 54. In the normal running condition the elevators 9 are in lowered position near the bottom of the side frames 3, 4, and the tension of the strip is kept substantially constant by means of a carbon pile rheostat 58 controlling the speed of the motor 54. Increase in tension of the strip raises the member 10 so that through a plunger 61 and lever 60, the rheostat is actuated to reduce the speed of the motor 54. When the tension is consequently reduced, the member 10 falls to break its operative connection with the rheostat and the speed of the motor 54 is again increased. When the roll 50 is full and it is required to connect the strip to a new roll 62, the feed-out rollers 51 are stopped. The continued operation of the feed-in rollers causes the members 10 to fall by gravity until they rest on the elevators 9 which are then in lowered position, the time taken for this movement being sufficient to allow of the attachment of the strip to the roll 62. Upon reaching the lower position the member 10 actuates a switch to start the motor 18 which thereupon drives the screws 14 to raise the elevators 9 and members 10, to the position shown. During this movement the motor 54 is restarted at the upper limit of their travel, the members 10 actuate a second switch to stop the motor 18. The initial threading of the strip about the various feeding and guide rollers is effected by a leader bar and endless belts as described in Specification 534,552, [Group XVI]. These endless belts 29 pass at each side of the apparatus over guide pulleys 30, pairs of guide pulleys 8 on the elevators 9 and pairs of pulleys 5 on the frame 1, guide pulleys 31, driven pulleys 32, further guide pulleys 7 on the elevators 9 and pulleys 6 on the lower fixed frame 2. During the threading operation the elevators 9 are in the raised position shown but when the leader bar has passed beyond the guide pulleys 31, it actuates a switch to drive the motor 18 in the direction to lower the elevators. When these reach their lower position they actuate a switch to stop the motor 18. In a modification the elevators and floating members are made in several short sections independently operable so that one or more may be used according to the amount of strip it is desired to accumulate. When used in connection with the change over of the supply roll, the floating member is normally in its lowest position and to effect the change over the feeding-in rollers are arrested and the floating members are raised by the continued operation of the feed-out rollers.