Web-tension device for printing-presses
US 558426 A
Description (OCR text may contain errors)
W. SCOTT. WEB TENSION DEVICE FOR PRINTING PRESSES.
Patented Apr. 14, 1896.
WWW ZZ, A
NGTUN UNITED STATES PATENT OFFICE.
VALTER SCOTT, OF PLAINFIELD, NEIV JERSEY.
WEB-TENSION DEVICE FOR PRINTING-PRESSES.
SPECIFICATION forming part of Letters Patent No. 558,426, dated April 14, 1896. Application filed March 6, 1894. Renewed January 24, 1896. erial No. 576,743. (No model.)
To all whom it may concern.-
Be it known that I, \VALTER SCOTT, a citizen of the United States, residing at Plainfield, in the county of Union and State of New Jersey, have invented an Improvement in lVeb-Tensions for Printing-Presses, of which the following is a specification.
In web-tensions for printing-presses difficulty has heretofore been experienced in maintaining the proper tension upon the paper as it is drawn off from the roll and such roll diminishes in diameter. It has heretofore been usual to wind the paper upon an iron tube and when the roll is brought to the press an axis or shaft is passed through the iron tube, and the axis is supported in suitable bearings and provided with a frictionwheel at one end, and a clamp and screw applies to the wheel a friction for preventing the paper unwinding too fast and for insuring the proper delivery of the paper into the:
press. The workman sometimes applies too much friction and the paper is injured, or too little friction and the web becomes loose between the roll and the impression-cylinder.
In my present improvements I make use of a cross-shaft and arms carrying a laterallymoving roll, around which the web passes, and by its tension the roll is moved bodily, and connected with this shaft are devices that receive motion from the lateral movement of the roll, so as to apply more friction if the web is too loose or less friction if the web becomes too tight, and I combine with the before-described devices an indicator by which the workman can readily see whether the adjusting-screw that applies friction to the axis of the paper-roll needs to be regulated or not.
In the drawings, Figure 1 is a diagram illustratin g the present improvement, wherein the lateral movement of the roll applies more or less friction through intervening levers. Fig. 2 is a diagram illustrating the motion as communicated to the friction device by gearing and a screw, as well as by the leverage action. Fig. 3 illustrates a modification in the clamp applied to the wheel upon the axis of the roll. The roll of paper A is of any usual size or character, and the shaft or axis B passes through the center of the roll and is supported in bearings, as usual, and upon such shaft B is a friction-wheel 0, having clamping-segments D D, the segment D being pivoted at 2 upon the frame or bearing for the roll-shaft, and the screw 3 serves to connect the upper ends of the segments D D and to regulate the friction of these segments upon the wheel 0, and the lower end of the segment D is movable, so as to automatically increase or lessen the clamping action of the segments D D upon the Wheel 0, as hereinafter described.
The web of paper A passes from the roll A either over the rolls E F, as seen' in Fig. 1, or under such rolls, as seen in Fig. 2, and the roll G is between the rolls E and F, the paper passing around the same in the form of a loop or bend, and from the roll F the web of paper passes to the impression-cylinder II of the press, preferably over an intermediate roll I, and this roll G is mounted upon arms K and a cross-shaft L, so that such roll G may be :moved laterally accordingto the tension upon the paper, and I usually provide an indexarm Mat one end of the cross-shaft L and a scale Nby which the lateral movement of the roll G will be more easily indicated outside the frame of the printing-machine, and usually a spring 0 is applied to give motion to the arms K and cross rock-shaft L and by moving the roll G laterally apply to the web of paper any-desired tension.
If the tension of the web increases, the roll G will move toward the rolls E F. If the tension on the Web lessens, the roll G will be moved laterally away from the rolls E F.
I avail myself of the movement which the roll G receives to apply more or less friction by the clamping-segments D D to the roll of paper. In Fig. 1 I have shown a lever P connected by a rod Q to one of the arms K on the shaft L, and on this lever P is an eccentric with a rod S that :extends to the lower end of the clamping-segment D, and it is advantageous to adjust the pivotal connection at between the rod Q and the lever P, so as to vary the leverage and pressure applied through the levers to the clamping-segments D and thereby proportion the parts so that as the tension upon the web A may lessen and the roll G de scend the segment D will be pressed toward the friction-wheel C to increase the friction, or the reverse.
In Fig. 2 the same parts before described are represented, but the roll G is shown as above the rolls E F, and the connecting-rod Q extends to the slotted lever P, upon the hub of which lever is a bevel-pinion 5, connecting with a similar pinion 6 upon a nut T, surrounding the screw S, which is connected at its other end to the lower portion of the clamping-segment D. Hence, when the tension upon the web A may lessen and the roll G rise the lever-arm and rod Q, acting upon the slotted lever P and bevel-pinion, turn the nut T and through the screw S apply more friction to the wheel 0, and when the tension of the web increases and the roll G is drawn down the reverse movement takes place and the friction of the clamping-segments D D upon the wheel 0 is lessened. By these means I am enabled to adjust the friction applied to the roll of paper automatically, so that the risk of injury to the web is reduced to a minimum and the tension is maintained nearly uniform as the web decreases in diameter; and I remark that in cases where the attendant observes by the index-arm that the tension upon the web is too great or too little, the screw 3 allows for an adjustment by hand so as to obtain the benefit of human oversight in the supply of the Web to whatever extent may be desired.
In Fig. 3 I have represented clamping-segments D upon the ends of levers D which levers are acted upon by a screw S connected with the bevel-pinion 6 before mentioned, such screw S passing through nuts at the ends of the levers D such nuts and the screw-threads being right and left handed, so as to act uniformly in either increasing or lessening the friction applied to the wheel C.
I do not limit myself to any specific character of friction device applied to the axis or shaft of the roll of paper, as the present improvement is available with any friction device capable of being lessened or increased.
It will be apparent that it is not necessary for the roll G to revolve, and hence a bar may be used as its equivalent, and according to the weight of the roll or bar and the direction in which it acts springs may or may not be employed, as the weight of the roll or bar may be suificient for the intended purpose.
I do not limit my invention to use with a web of paper passing from a roll into a printing-press, as the present invention may be applied to a roll of paper from which the web is drawn off for printing or otherwise.
I claim as my invention- 1. The combination with the paper -roll shaft and its friction-wheel, of friction mechanism applied to such wheel, rolls around which the web of paper passes, a laterallymoving roll acting upon and moved by the said web, a cross-shaft and arms carrying said roll, a visual indicator receiving its motion from the said cross-shaft, a spring for acting on the cross-shaft, arms and laterallymoving roll, and a connecting-rod and adjustable pivotal connection for varying the action of the laterally-moving roll on the friction mechanism, substantially as specified.
2. The combination with the paper roll shaft and its friction-wheel, of friction mech anism applied to such wheel, rolls around which the web of paper passes, a laterallymoving roll acting upon the web and moved by the web, a cross-shaft and arms carrying the said roll, a visual indicator receiving its motion from the said cross-shaft, automatic mechanism acted upon by the cross-shaft for regulating the frictional detention upon the roll automatically and ahand-actuated mechanism for also varying the friction and regulatin g the tension upon the web of paper, substantially as set forth.
3. The combination with the paper roll shaft and its friction-wheel, of friction mechanism applied to such Wheel, rolls around which the web of paper passes, a laterallymoving roll acting upon and moved by the said web, a cross-shaft and arms carrying said roll, a visual indicator receiving its motion from the said cross-shaft, and a connecting-rod and adjustable pivotal connection for varying the action of the laterally-moving roll on the friction mechanism, substantially as specified.
Signed by me this 26th day of February, 1894.
GEO. T. PINCKNEY, A. M. OLIVER.