US2346756A - Paper reel brake - Google Patents

Description

April 18, 1944. w. HOPPE PAPER REEL BRAKE Filed Jan. 10, 1942 INVENTOR Mun/V1701: BY I @v M ATTORNEYS Patented Apr. 18, 1944 rim REEL BRAKE William liioppe, Loneadow;

National Bread Wrapping Machine (30., field. Mass, a corporation of Massachusetts Mass, assignor to Spring- Appiicatlon January 10, 1942, Serial No. 426,271

(Cl. l8883) s'ciaims.

lem of maintaining a. uniform tension is present when the web is uously.

One object of my invention is to provide a braking device which will, as compared with prior art devices, more nearly approach the ideal of applying a. decelerating braking torque which will at all times bring the roll to rest after each feeding operation without overrunning of the roll and without an excessive degree of tension on the web.

A further object is to secure the above desirable result conditions. 7

The invention will now be described with relation to the accompanying drawing, in which Fig. 1 is a side elevation of a vided with the improved brake;

Fig. 2 is a detail thereof, partly in section and with the parts in a position corresponding to a nearly exhausted reel; and

Fig. 3 is a side elevation of a portion of the mechanism.

It may be shown bring a paper reel to rest with a given overrun a brake shoe against the surface of the web reel by a force which proportional to the cube of the radius.

For this purpose the reel in is provided with a friction roll H having a surface of rubber The yoke 42 is pivoted at Hi to a bell crank l5 swinging on a pivot shaft 46. The short arm H of the bell crank is coupled by atension spring 48 with an adjusting screw i9 carried on a stationary arm 20 and held in adjusted position by a lock nut M. The yoke i2 normally swings difiering lengths. sized hole 21 in the bell crank to limit the oscillatory motion of the yoke.

As previously stated, it i desirable to have the decelerating torque exerted into an overserve for all practical purposes. The torque on the bell crank pivot is thus doubly proportional to the reel radius; or, in other words, proportional to the square of this radius. It acts upon 1! the tension on the web is to be varied, or if I reels or diflerlng lengths are to be used, the screw l8 may be turned to change the initial degree of stretching of the spring l8, leavingall the other proportionality factors unchanged. or a fine adjustment may be readily secured by tuming the screw 25.

What I claim is:

i. A brake for a reel of web material including a member irictionally engagin the surface of the material on the reel to exert a drag upon the rotation of the reel, 9. support carrying the member for movement toward and from the axis of the reel of material as the reel diameter varies, and a spring connected at one end to said support and at its other end to a relatively fixed point, the points or connection of the spring being so positioned that the extension of the spring decreases directly and progressively with a decrease in the size or the reel and simultaneously the component or spring tension causing moveiriction block carried ment of the support towards the reel decreases relative to the total force exerted by the spring.

2. A web reel brake comprising a bell crank, a friction block carried by one arm of the bell crank, a rriction roll movably mounted on the bell crank to be pressed thereby against the reel and having a portion engageable with the block,

.a support, and a spring stretched between the support and the second arm of the bell crank, the second arm of the bell crank being positioned on that side or the line joining the bell crank pivot and the support-carried end of the spring remote from the first arm or the bell crank.

3. A web reel brake comprising a bell crank, a by one arm or the bell crank, a friction roll movably mounted on the bell crank to be pressed thereby against the reel and having a portion engageable with the block, a support, a spring stretched between the support and the second arm of the bell crank, the second arm or the bell crank being positioned on that side of the line Joining the bell crank pivot and the support-carried end of the spring remote from the first arm of the bell crank, and an adjustable spring compressible between the first arm of the bell crank and the -friction roll to vary the pressure of the rriction roll against the block.

WILLIAM HOPPE.

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