Patent GB-698481-A (GB)
Title: Improvements in web-renewing mechanism for printing and other machines
Inventor: BENNETT THOMAS RICHARD
IPC: B65H19/16
Filed: 1949-05-17
Abstract: 698,481. Feeding webs. HOE & CO., Ltd., R. May 17, 1950 [May 17, 1949], No. 13174/49. Class 100(i) In a web-renewing mechanism of the kind in which web-renewal is effected without stopping the web-using machine, a single belt or a set of parallel belts is adapted to engage a web roll by its periphery, the belt or belts being driven at two speeds by a variable speed drive, one an accelerating speed for accelerating a replacement roll from rest and the other a tensioning speed to tension a web passing from a roll in use, the variable speed gear being under the automatic control of the renewing mechanism, such that the variable speed gear is set at the accelerating speed when the mechanism is set to effect web-renewal and at the tensioning speed when the mechanism has effected webrenewal. A support 1, Fig. 1, rotatable by a motor and through gearing 5 carries three web rolls each rotatable from a loading position 6 into a running position 7 and a replacement position 8. A roll 9, in the running position 7, is engaged by endless belts 10 passing over pulleys 11, 12 and 13 and driven at a speed slightly below the speed at which the web W is drawn on by the machine being supplied. The tension of the web may be varied by varying the wrap of the belts 10 about the roll 9 by controlling the position of arms 14 carrying the pulley 11 by an electric motor 15 controlled by a roller 16 movable in response to changes in tension. The belts 10 are driven by the pulley 13 through a variable speed drive 29 by a shaft 27. The variable speed drive, Fig. 4, comprises a shaft 31 carrying gear wheels 32, 33 in mesh with gear wheels 34, 35 loose on a secondary shaft 36 to provide two different gear ratios. The opposing faces of the gear wheels 34, 35 are formed with teeth 37, 38 for engagement with either teeth 40, or 41 of a clutch 39 movable axially of the shaft 36 by a fork 43. The fork 43 sets the drive to accelerating speed by the movement of brush and knife arms 19 and 20 from their inoperative positions to their operative positions. The fork 43 is connected by a swivel block to an operating rod 46 pivoted to a pivoted arm 47. The arm 47 has a cam follower 49 engaging a cam 50 on a shaft 51 rocked when the arms 19, 20 are rocked. The arms 19, 20 and arm 25 are U-shaped; the two latter arms are secured at each end to a shaft 22, while the arm 19 is loose onshafts 22, but is normally latched to the arms 20. To ensure that the shafts 22 move together they are connected through gears 54 to the shaft 51. The arms 19 carry a deflecting brush 23, the arms 20 a sheath 24 for the severing knife, and arms 25 a bar 26 to engage the web in the expiring position and deflect it against the periphery of the replacement roll to which adhesive has been previously applied. Thus, the expiring web W is pressed against the replacement roll by the brush 23 and caused to adhere thereto. The knife in the sheath 24 is then released to sever the expiring web, and the arms 19, 20 and 25 are then raised to their inoperative position, thus setting the drive to tensioning speed; alternatively, the drive may be set to tensioning speed by an electromagnet controlled by a switch operated by the actuation of the severing knife. Specification 672,695, [Group XXXV], is referred to.