Patent GB-1000345-A (GB)
Title: Improvements in or relating to mechanisms for feeding webs
IPC: B65H20/02
Filed: 1964-07-07
Abstract: 1,000,345. Feeding webs. BROOKHIRST IGRANIC Ltd. July 7, 1964 [Aug. 19, 1963], No. 27940/64. Heading B6B. A web 18a is fed from a web-roll 18, around a tension sensing roller 22 which actuates a switch 5LS, Fig. 9, to control an electromagnetic brake acting on the web-roll spindle, then past a brake member 74a and into a guide comprising two plates 56 and 60 and between a pair of nip rollers 38a, 46a; then past a knife 52 and through a further guide comprising plates 50 and 58 and between a second pair of nip rollers 36a, 44a; and then into a packaging machine. Feed rollers 36a and 38c are driven continuously through chain-and-sprocket gearing by the motor DM of the packaging machine. Idler rollers 44a and 46a are mounted on a pivoted member 4c which operates to bring the idler rollers into contact alternately with their respective drive rollers 36a and 38a. Guide plate 60 is pivoted about its lower end and is spring biased towards the guide 56, but is spaced therefrom. Any jamming of the web between the guide plates 60 and 56 causes the plate 60 to operate a limit switch 4LS, which results in the operation of an alarm, the separation of rollers 38a and 46a, the release of brake 74a and the withdrawal of the web by the tensionsensing roller 22 moving downwards to increase the loop. The driven feed rollers 36a and 38a are mounted on the part 4b, Fig. 2, of the apparatus, which may pivot upwards to allow access and is locked into position by a pair of spring biased levers 26. When in the locking position the levers close switch 6LS in the control circuit, Fig. 9. Attached to the pivoted member 4c are a series of pins 48b, Fig. 5, which protrude through the guide plate 50 when the nip rollers 44a and 36a are engaged. These pins do not interfere with the feed of the web and allow registration of the web when it is threaded into the apparatus. Normal operation (Fig. 9).-To start the packaging machine and the feeding apparatus, a switch PB1 is closed which energizes solenoid M and closes switches M1 to M5. Switch S1 is closed to contact " RUN " together with switch PB3. This energizes solenoid 1CR which closes switches 1CR1, 1CR3 and 1CR5 and opens switches 1CR2 and 1CR4. Passages of the package to be wrapped through the machine operates a switch 1LS to open contacts 1 and close contacts 2. This de-energizes solenoid 2SOL which allows valve member SV2 to be spring returned to its left-hand position and withdraw the knife 52 as air enters the top of cylinder AC2. Withdrawal of the knife 52 closes switch 3LS which energizes solenoid 150L and moves valve member SV1 to the right to pivot member 4c anti-clockwise as air enters the top of cylinder AC1. Movement of member 4c opens switch 2LS 1 and closes switch 2LS2 which energizes, via closed switch 1CR5, solenoid 350L. This moves valve member SV3 to allow air to enter cylinder AC3 and retract the brake member. The web is then fed forward by nip rollers 46a and 38a. When the trailing edge of the package to be wrapped passes the feeler of switch 1LS, the switch opens contacts 2 and closes contacts 1. This results in the de-energization of solenoids 1SOL and 3SOL with the pivoting of member 4c to engage nip rollers 44a and 36a and the application of brake member 74a. Closing of switch 2LS1 energizes solenoid 2SOL which results in the raising of knife 52 to sever the web. The nip rollers then continue to feed the trailing edge of the severed web to the wrapping apparatus.