Chart drive system

Claim 2

A chart drive assembly including a frame comprising two end plates secured in spaced opposed relationship by at least one cross member; a supply Roll station on said frame including a pair of pads secured to said frame, a different one of said pads being located adjacent different ones of said end plates and a pair of spring members secured to said frame, a different one of said spring members being spaced from and generally opposed to different ones of said pads, said spring members having a curved section formed therein adapted to generally match the curvature of a cylindrical supply roll and hold said supply roll between said spring members and said pads; a platen secured upon said frame; chart drive means rotatably secured upon said frame between said end plates for selectively advancing paper from a supply roll past a recording station and over said platen; a take-up roll rotatably secured between said end plates proximate said platen for restoring paper from said chart after it passes said recording station; and take-up roll drive means secured to said take-up roll through a slip clutch.

Claim 3

The chart drive assembly of claim 1 wherein said pads are provided with a coating of resilient material having a relatively high coefficient of friction and wherein said spring members are provided with a coating of material having a relatively low coefficient of friction whereby drag is exerted upon the paper as it is dispensed from said roll adjacent said pads.

Claim 4

A chart drive assembly including a frame; supply roll station means secured upon said frame for resiliently gripping a roll of chart paper and providing a predetermined drag on said roll; a platen secured upon said frame; chart drive means secured upon said frame for providing forward tension on said roll to selectively advance paper from said roll past a recording station and over said platen, said drive means including a drive roll rotatably secured upon said frame, said drive roll having three spaced apart sets of gear teeth formed therein, one set of gear teeth being located at the central portion of said drive roll and different ones of the other sets of gear teeth being spaced inwardly from respective ones of the opposite ends of said drive roll; a plurality of idler pulleys rotatably supported upon said frame, an idler pulley being spaced from and aligned with each of said sets of gear teeth formed in said drive roll; a plurality of drive belts, each drive belt being continuously flexible and having teeth formed on the inner surface thereof for engaging respective ones of said idler pulleys and sets of gear teeth formed in said drive roll, each drive belt having chart drive teeth protruding from the outer surface thereof and adapted to engage perforations in the chart paper for driving said paper; power means secured to said drive roll through an overrunning clutch for operating said chart drive means; and a take-up roll rotatably secured upon said frame for taking up paper from said supply roll station after it passes a recording station.

Claim 5

A chart drive assembly including a frame; supply roll station means secured upon said frame for resiliently gripping a roll of chart paper and providing a predetermined drag on said roll; a platen secured upon said frame; chart drive means secured upon said frame for providing forward tension on said roll to selectively advance paper from said roll past a recording station and over said platen, said drive means including a drive roll rotatably secured upon said frame, said drive roll having three spaced apart sets of gear teeth formed therein, one set of gear teeth being located at the central portion of said drive roll and different ones of the other sets of gear teeth being spaced inwardly from respective ones of the opposite ends of said drive roll; a plurality of idler pulleys rotatably supported upon said frame, an idler pulley being spaced from and aligned with each of said sets of gear teeth formed in said drive roll; a plurality of drive belts, each drive belt being continuously flexible and having teeth formed on the inner surface thereof for engaging respective ones of said idler pulleys and sets of gear teeth formed in said drive roll, each drive belt having chart drive teeth protruding from the outer surface thereof and adapted to engage perforations in the chart paper for driving said paper; power means secured to said drive roll through an overrunning clutch for operating said chart drive means; and a take-up roll rotatably secured upon said frame for taking up paper from said supply roll station after it passes a recording station.

Claim 6

The chart drive assembly of claim 3 wherein the projections extending from the outer surface of the centrally located drive belt are adapted to engage, without play in any direction, perforations formed in said paper and said projections extending from the outer surface of the other of said drive belts being adapted to engage perforations formed in said chart paper without play in the direction of drive but allowing lateral movement of the chart paper with respect thereto.