Web splicing, unwinding and forwarding apparatus

Claim 2

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality of idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for maintaining substantially constant dancer loading only throughout a lower range of dancer elevation and means for increasing dancer loading in a predetermined manner with respect to dancer elevations above said lower range.

Claim 3

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality oF idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for maintaining substantially constant dancer loading only throughout a lower range of dancer elevation and means for increasing dancer loading in a predetermined manner with respect to dancer elevations above said lower range, said means for increasing said dancer loading comprising a spring, and spring engaging means for adding spring force to said dancer loading as a direct function of dancer displacement above said lower range.

Claim 4

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality oF idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for maintaining substantially constant dancer loading only throughout a lower range of dancer elevation and means for increasing dancer loading in a predetermined manner with respect to dancer elevations above said lower range, said means for increasing said dancer loading comprising a spring, and spring engaging means for adding spring force to said dancer loading as a direct function of dancer displacement above said lower range.

Claim 5

The improved web splicing, unwinding and forwarding apparatus of Claim 2 wherein said spring is a tension spring having one end secured to said frame, and said spring engaging means comprises a rod and yoke assembly intermediate the other end of said spring and said dancer.

Claim 6

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality of idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for increasing, in a predetermined manner, brake loading above its normal dancer-elevation-dependent value during periods said dancer is descending at a rate equal to or greater than a predetermined rate, said apparatus further comprising means for maintaining substantially constant dancer loading only throughout a lower portion of said range of dancer elevations, and means for increasing dancer loading in a predetermined manner as a function of dancer elevation above said lower portion of said range of dancer elevations.

Claim 7

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality of idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for increasing, in a predetermined manner, brake loading above its normal dancer-elevation-dependent value during periods said dancer is descending at a rate equal to or greater than a predetermined rate, said apparatus further comprising means for maintaining substantially constant dancer loading only throughout a lower portion of said range of dancer elevations, and means for increasing dancer loading in a predetermined manner as a function of dancer elevation above said lower portion of said range of dancer elevations.

Claim 8

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality of idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for increasing, in a predetermined manner, brake loading above its normal dancer-elevation-dependent value during periods said dancer is descending at a rate equal to or greater than a predetermined rate, said means for increasing brake loaDing comprising rate sensing and signaling means for sensing whenever said rate equals or exceeds said predetermined value and for providing an output signal during such periods, and means responsive to said signal for increasing said braking.

Claim 9

An improved web splicing, unwinding and forwarding apparatus for unwinding web from a succession of supply rolls and forwarding web uninterruptedly to downstream apparatus at substantially constant velocity under substantially constant tension, said apparatus including a frame, splicing means, web forwarding means, unwinding means including means for revolvingly mounting a plurality of said rolls for unwinding them and braking means for applying a controllable braking force to retard said unwinding, web accumulator means intermediate said forwarding means and said splicing means, said accumulator means including a vertically moveable underslung web loading dancer assembly and a plurality of idler rollers defining a looped path of variable length for said web, the length of said path being inversely related to the displacement of said dancer assembly above the lower end of its range of travel, and means for normally controlling said braking force as a dependent function of dancer elevation to maintain substantially constant web tension, the improvement comprising means for increasing, in a predetermined manner, brake loading above its normal dancer-elevation-dependent value during periods said dancer is descending at a rate equal to or greater than a predetermined rate, said means for increasing brake loaDing comprising rate sensing and signaling means for sensing whenever said rate equals or exceeds said predetermined value and for providing an output signal during such periods, and means responsive to said signal for increasing said braking.

Claim 10

The improved web splicing, unwinding and forwarding apparatus of claim 5 wherein said braking means are pneumatically operated and said means for increasing said braking force comprises an electrically operated valve and means for operating it to bypass the normal source of dancer-position-dependent regulated pressure supplied to said braking means.

Claim 11

The improved web splicing, unwinding and forwarding apparatus of claim 4 wherein said means for increasing said dancer loading comprises a spring, and spring engaging means for adding spring force to said dancer loading as a direct function of dancer displacement above said lower range.