US700119A - Printing-press. - Google Patents

Description

No. 700,119. Pmmu'na l3, l902 E. meams.

PRINTING PRESS.

7 (Application filed July 19, 1 o1.) No Model.) I

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' type and grind the same, this grinding occur- UNITED STATES P TENT OFFICE.

EUGENE HIGGINS, OF BATTLECREEK, MICHIGAN, ASSIGNOR TO THE DUPLEX PRINTING PRESS (30., OF BATTLEOREEK, MICHIGAN.

PRINTING-PRESS.

SPECIFICATION forming part of Letters Patent No. 700,119, dated May 13, 1902.

Application filed July 19, 1901..

To all whom it may concern:

Be it known that I, EUGENE-HIGGINs,of Battlecreek, in the county of Calhoun and State of Michigan, have invented-certain new and useful Improvements in Printing-Presses; and I hereby declare that the following is a full, clear, and exact description thereof, ref erence being had to the accompanying drawings, which form part of this specification.

This invention is an improvement in printing-presses, and has particular reference to stationary-bed movable-cylinder web-printing presses-such as the Well-known Cox duplex press, for exampleits object being'to prevent the cylindergrinding the type or rupturing or cracking the web during impressions; and this objectis attained by the simple means illustrated in the accompanying drawin gs and hereinafter claimed and is applicable to any form of bed-and-cylinder press, requiring no additional parts. It has been ascertained that in this class of presses the cylinder if overpacked has a tendency to move faster on the type and grind the same, or if underpacked has a tendency to lag or drag on the ring frequently in presses where the cylinder and bed are geared together so that the cylinder must rotate at a certain ratio during impressions, the gearing ordinarily being calculated on the basis of having the cylinder packed so that its diameter will exactly correspond with the pitch-line of the cylindergear. When so packed, no injury will result to the type or web; but this theoretical accuracyis seldom attained in making up the cylinder, and as the gearing remains constant any variation in the circumference of the cylinder due to overpacking or underpacking produces the drag on the type above mentioned, and this drag or crawling of the periphery of theimpression-cylinder on the type tends to *shiftthe paper over the type while nipped in impression, resulting frequently in cracking andrupturing the Web.

The principal objects of the bed-and-cylinder gearingin movable-bed presses is to insure that the periphery of the cylinder be moving uniformly with the type when the impression begins and that the proper portion of the cylinder-packing shall always contact Serial No. 68,921. (No model.)

with the type, and in reciprocating-cylinder stationary-bed presses the gearing is employed to assist in slowingdown, st0pping,and

reversing the rotation of the cylinder v'vithbut it is practically possible to reduce the intermediate gear teeth, thus widening the space between'them, so that when the cylinder is on impression it is permitted ac'ertain slight amount of play relativeto the rack sufficient to permit its periphery to move accurately over the type without pulling or dragging thereon, allowing the cylinder to compensate itself for over or under packing, while by gradually mergin g the reduced gearteeth into the full-sized gear-teethnear the ends of the rackor travel of the cylinder the latter will be always started and stopped in exact proper position and time without rattle or jarring.

The invention consists simply in making certain of the teeth in the gearing between cylinder and bed smaller than normal-sized teeth, thus widening the spaces between such teeth, so as to permit the periphery of the cylinder to move slightly faster or slower during impression than it would otherwise do if the teeth of the gearing anddistance between teeth were uniform throughout, the gearing being so formed for the purpose of compensating forimproper packing of the tionary rack E on the frameG -all substdntially as usual. The packing B of the cylinder should correspond withthe pitch-line of gear F, as indicated inFig. 1; but this theoretically and practically important condition is seldom attained, owing to carelessness of the pressmen. Consequently the evil efiectsof overpacking or underpacking the cylinder above pointed out are produced. To prevent this improperpacking of the impressioncylinder damaging the type or rupturing the web, the teeth of the rack E, which would control the cylinder during impression, (indicated between the lines T T on the drawings,) are made much thinner than necessary to maintain perfect mesh, the widened spaces between these thin teeth permitting a certain amount of play of the periphery of the cylinder, so that it is practically left free to rotate by contact with the type while on impression, thus avoiding dragging or lagging on the type or web. Between the pointsT and S at each end of the bed the teeth are gradually increased in thickness, so as to take up without anysudden shock or jar any crawling forward or lagging of the cylinder between the pointsTT during impression due to improper packing of the cylinder. Between the points S and R the teeth are of full size, so that the cylinder is brought to a stop and reversed properly.

When the cylinder engages with the thick teeth of the rack and moves from position A in the direction of the arrow U, it is caused to revolve in the direction of the arrow V, as shown in Fig. 1.

As the cylinder rolls upon the type the gear F engages with the thin teeth of the rack. If the cylinder be overpacked or u nderpacked, it will when on the type tend to move faster or slower than its normal rate. As the spaces between the teeth in this part of the rack are wider than the thickness of the teeth on the gear, the cylinder will be permitted to so revolve, and its tendency to crawl or drag upon the type and the consequent wear is prevented. After the cylinder leaves the type and is free from surface contact therewith the gear again engages with the gradually-thickening teeth at the 0pposite end of the rack, and before reaching the end of its stroke the position of the cylinder is corrected. The same operation takes place during the return stroke of the cylinder.

As the play allowed between the gear F v and rack E by reason of the shape of the teeth of the latter is very limited, the mechanism will be operative in the manner described only to a correspondingly-1imited degree, sufficient, however, to correct the tendency of the cylinder to drag or crawl on the type.

Having thus described my invention, what I therefore claim as new, and desire to secure by Letters Patent thereof, is

1. The combination of a cylinder, its gear, a bed coaeting with the cylinder and a bedrack meshing with said gear, the teeth of the rack being irregular to permit play of the cylinder relatively to the rack while on impression, substantially as described.

The combination of a cylinder and bed, the cylinder-gear, and the bed-rack coaeting with said gear, said rack having its intermediate teeth thinner than its end teeth, and the spaces therehetween correspondingly wider, for the purpose and substantially as described.

8. The combination of a cylinder and bed, the gear on the cylinder and a bed-rack meshing therewith having its teeth opposite the type-forms on the bed reduced in thickness, and the spaces therebetweenincreased to permit play of the cylinder relatively to the gear while on impression, the teeth of the rack beyond the forms increasing to full size to correct any lost motion or accelerated movement of the cylinder during impression, substantially as and for the purpose set forth.

In testimony that I claim the foregoing as my own I aflix my signature in presence of two witnesses.

EUGENE HIGGINS. In presence of RICHARD L. STOUT, F. W. DUNNING.

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