US2241307A - Tension regulator for paper feed rolls - Google Patents

Description

C. J. KERN May 6, 1941.

TENSION REGULATOR FOR PAPER FEED ROLLS 2 Shets-Sheet 1 Filed April 28, 1939 Fild April 28, 1959 2 Sheets-Sheet 2 the roll.

Patented May 1941 g 2,241,301 TENSION aacm'roa roa PAPER. FEED norms Colts-(1'1. Kern,

Mollie & W! (20.,

Drexei Park, Pa., assignor to The Philadelphia, Pa, :1. corporation of Pennsylvania Application April as, 1939, Serial No. 2mm

This invention relates to automatic brakes for paper feed rolls and, for maintaining a uniform braking resistance to the withdrawal of paper from a roll supplying a press or similar structure to insure proper ten- 1 sion at all times on the sheet withdrawn from- News presses and corresponding structures which require supply rolls of considerable diameter are usually equipped with what is known as a back-stand upon which the roll is mounted and from which it is drawn to the press or the like. Obviously, the tension at which the paper is removed from the roll is important, particu larly in the case of news presses where changes in tension will cause a considerable change in register..

Likewise, obviously, the tension of any fixed diameter brake will vary as the diameter of the roll of paper reduces since the leverage arm represented by the roll radius reduces constantly in ratio to the diameter of the brake. For this reason some means must be provided to compensate for the reduction in diameter of the roll. All such means with which I slderation the fact that such rolls are usually purchased in quantity and stored in such manner that they become flattened at one side.

Important objects of the present invention are the provision of a back-stand including braking mechanism which will compensate for the variation in diameter of the roll and which will not be affected by variations in the shape thereof to any appreciable extent and in which the variation of pressure is determined by a plurality of contact members which are so located that a flattened roll will not affect the braking in the usual manner.

These and other objects I attain by the construction shown in the accompanying drawings wherein, for the purpose of illustration, I have shown a preferred embodiment of my invention and wherein:

Fig. 1 is a side elevation partially broken away and partially diagrammatic illustrating roll tensioning means constructed in accordance with my invention;

Fig. 2 is a plan view thereof and Figures 3 and 4 are detail sectional views through valves employed in controlling the braking action.

Referring now more particularly to the drawlngs, the numeral Ill generally designates one of a pair of bearin s for receiving the roll shaft ii of a paper roll l2. Adjacent the illustrated bearam familiar fail to take into conmore particularly, to a means ing it an outboard bearing I3 is provided, this bearing, together with bearing l0, mounting a shaft l4 which, between the bearings l0 and I3, is equipped with a brake drum it having associated therewith a band brake l5 anchored at one end as at I I and having its opposite end connected'at 18 to the piston IQ of a cylinder 20 hereinafter more particularly to be described. Shaft H at its inner end is equipped with a gear 2! with which a pinion 22 on roll shaft i i meshes.

Mounted between a bracket 23 on bearing iii and a further bearing indicated at 24 and parallelihgroll shaft H a pair or shafts 25 each'havlng thereon an arm provided with a roll-surfaceengaging portion 26 at its free end the arms indicated at 21 and 2-8 extend in opposite directions about the roll engaging the periphery thereof at points which are well spaced circumferentially. These shafts are geared to one another by gears 28 of equal size and one of the shafts has attached thereto a counterweighted arm 30 so arranged that the counterweight constantly serves to urge the roll-engaging elements 26 into engagement with the surface of roll i2. Likewise, one of the shafts has secured thereto a lever 3i by means of which the arms 2'! and 28 may be moved to an open position permittingready insertion of roll l2 andits shaft I One of the gears 29 meshes with a small pinion 32 on a shaft 33, this shaft likewise bearing a sprocket 34 about which a chain 35 is trained, such chain likewise passing over a second sprocket 36. Beneath one run of the sprocket chain a lever 31 is disposed, this lever being pivoted at 38 at a point adjacent one end thereof and at saidend being equipped with an adjustable tensioning means generally designated at 39. The long end or arm of the lever has engaged therewith a weighted roller 40 which is linked at 4| to sprocket chain 35 and it will be obvious that as the sprocket chain is shifted through rota- ;tion of arms 21 and 28 and corresponding rotation of the shafts 2 5 and shaft 33 the effective weight imposed on the long arm of the lever will be .varied due to change in position of the roller 40.

The numeral 42 designates a motor driven pump receiving its supply from a sump indicated at 43. The discharge line 44 leads to a simple four-way valve 45 such as that shown in Figure 4 through which the discharge may be directed by conduit 44a or 44b either to the upper or lower end of cylinder 20. An outlet line 45 from this four-way valve leads to sump 43. The discharge line 44 from the pump is equipped with a by-pass means tending to maintain said 41 having arranged therein a pressure-regulating valve 48 the pressure control of which is varied in accordance with the weighting of the long arm of lever 31. This valve may be of any desired construction, a convenient form being illustrated in Figure 3. In this figure the valve proper, indicated at 48a, is shown as spring seated and as having at the upper end of its stem 48b a. roller 480 to engage the under surface of lever The casing 48d of this valve may conveniently include an arm 48c mounting the pivot for lever 31. The extent of opening of the valve is determined by the pressure exerted through lever 31. This discharge line is likewise further provided with a relief valve indicated at 49.

With a roll l2 newly placed in position, the position of the several parts will be substantially as illustrated injFigure l of the drawings, pump 42 delivering pressure fluid to the upper end of cylinder 20 (seeFigure 4) through valve 45 and conduit 44a. and it will be obvious that as the diameter of the roll reduces roller 40will be shifted along lever '31 to correspondingly vary the pressure exerted by piston IS on the band brake. Due to the fact that two circumferentially spaced contact elements are provided and these elements will always remain equidistant from the axis of roll I2, if the roll be flattened as indicated by dottedlines at l2a, this will not vary theposition of roller 40, thus avoiding the oscillatory action 01 the pressure-applying memher which results when but a single arm is employed; When the roll is to be replaced, valve 45, which is manually actuated, may be shifted to deliver the pressure fluid to the lower end of the cylinder through line 44b and exhaust the fluid from the upper end of the cylinder through line 46. This will release the brake, permitting free running of gear 2| which is, obviously, necessary in installing the new roll and threading the sheet therefrom into the associated machine (not herein shown).

It will also be obvious that the construction illustrated is capable oi' considerable modification without departing from the spirit of my invention.

I claim:

1. Means for controlling the tension of paper drawn from a roll rotating about a fixed axis comprising a brake for the roll and means to vary the tension of the brake in accordance with variation in diameter 01' the roll, said means including a shii'table member shifting of which varies the braking resistance of the brake, a plurality of rollengaging elements adapted to engage the periphery o! the roll at circumferentially spaced points,

elements in engagement with the roll, connections between said elements whereby their roll-engaging portions are maintained at points equidistant from the axis of said roll and a connection between said elements and said shiftable member constructed and arranged to position said member in accordance with the position of said elements.

2. Means for controlling the tension of paper drawn from a roll rotating about a fixed axis comprising a brake for the roll, a plurality of roll engaging elements adapted to engage the periphery oi the roll at circumferentially spaced points, means tending to maintain said elements in engagement with the roll, connections between said elements whereby their roll-engaging portions are maintained at points equidistant from the axis of said roll and a connection between said elements and said brake constructed and arranged to vary the position of said brake in accordance with the spacing of said elements from the axis of the roll.

3. Means for controlling the tension of paper drawn from a roll rotating about a fixed axis comprising a brake for the roll, a plurality of roll-engaging elements adapted to engage the periphery of the roll at circumferentially spaced points, means tending tomaintain said elements in engagement with the roll, connections between said elements whereby their roll-engaging portions are maintained at points equidistant from the axis of said roll, a connection between said elements and said brake constructed and arranged to vary the position of said brake in accordance with the spacing of said elements from the axis of the roll comprising a fluid pressure cylinder having a piston the position of which controls the position of said brake, and means to vary the position of the piston in accordance with the position of said elements.

4. Means for controlling the tension of paper drawn from a roll rotating about a fixed axis comprising a brake for the roll, a plurality of roll-engaging elements adapted to engage the periphery'of the roll at circumferentially spaced points, means tending to maintain said elements in engagement with the roll, connections between said elements whereby their roll-engaging portions are maintained at points equidistant from the axis of said roll and a connection between said elements and said brake constructed .and arranged to vary the position of said brake in accordance with the'spacing of said elements from the axis of the roll comprising a fluid pressure cylinder having a piston the position of which controls the position ofsaid brake, and means to vary the position of the piston in accordance with the position of saidelements, including a pressure regulating valve and means to load said valve in accordance with the position of said elements.

5. Means for controlling the tension of paper drawn from a roll rotating about a fixed axis comprising a brake for the roll, a plurality of rollengaging elements adapted to engage the periphery of the roll at circumferentially spaced points, means tending to maintain said elements in engagement with the roll, connections between said elements whereby their roll-engaging portions are maintained at points equidistant from the axis of said roll and a connection between said elements and said brake constructed and arranged to vary the position of said brake in accordance with thespacing of said elements from the axis of theroll comprising a fluid pressure cylinder having a piston the position of which controls the position of said brake, and means to vary the position of the piston in accordance with the position of said elements including a pressure regulating valve, alever loading said valve and means to vary the lever loading in accordance with the position of said elements.

CONRAD J. KERN.

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