US172974A - Improvement in printing-presses - Google Patents

Description

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c. B. cTTnELL,

` PRINTING-PRESS. No.17iZ,974. Patented Feb.1,1a7.e.

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C. B. COTTRELL.

v.'IFRINTINW3-PRESS. I No.172,974. Patented Feb.1, 1876.

UNITED STATES PATENT @Ferca GALVER'I B, COTTRELL, OFA WESTERLY, RHODE ISLAND.

IMPROVEMENT IN lPRINTING-PRESSES.

Specification forming part of Letters Patent No. 172,974, dated February 1, 1876; application filed November 27, 1875.

To all whom it may concern Be it known that I, GALvERT B. Go'r'rRELL, of Westerly, Washington county, in the'State- 'ot Rhode Island', have invented certain new and useful Improvements in Printing-Presses; and I do hereby declare that thefollowing'isl a full and exact description thereof, reference being had to the accompanying drawings, andI to the letters of reference marked thereon.

In drum-cylinder presses as heretofore con.

` structed there is a great deal of backlash in the gearing, resulting from thetendency of the drum or impression-cylinder to maintain a uniform and greater velocity than the bed is permitted to travel with at and near each end of the stroke of the latter;l and this lbacklash not only induces to greater-strain and wear and tear of the machine, but renders the Work imperfect. In cut-Work the imperfecw tion is most damaging, the overlays being permitted tostrike over. l

1t will be obvious to those familiarwith the construction and operation of printing-presses that the retardation of the bed (by any of the usual appliances employed to check the velocity and take upY the momentum) at the end of each stroke of the hitter tends to shift the working sides of the teeth of the gearing, and thus occasions more or less strain vand a great amount of backlash in the gears, which must necessarily induce to considera-ble jar and shock, and permit considerable striking over,

all of which is most destructive of the machine and detrimental to perfection of Work.

I propose to overcome all this striking over and imperfection of' work, as Well as the evil consequences to the mechanism of the principle of construction heretofore employed in such presses, by the adopt-ion in,"or use in connec` tion with, such machines of some means for re-k tarding the velocity of the drum or impressioncylinder at the same time that, and about to the same extent as, the bed is retarded, (at

each end of its stroke,) andthns harmonizing the velocity of the drum4 to theirregular velocity of the bed, and keep the gears working always on the same sides of the teeth; and to this end and object my invention consists ini the use, in combination with the drum, of a means for checking or retarding its velocity at the right times and to the proper extent to make it run with about the same variable velocity as the bed, and thus avoid all backlash and any strain or jar in the working of the machine, and to keep the vgears workingfalways on one side ot' the tooth. i In carrying out this `principle of construction 'it has been deemed most advisable to so devise the machine that the device for effecti ing theretardation of the drum shall not be brought into operation or effect when-the machine is not running'at its usualiworking velocity, as then the turning of they drum by hand-power, asis often necessary, will not be rendered any more difficult than heretofore.

To accomplish this end is a furthervobject of my invention, which further consists 1n coinbining the drum-retarding device or mechanism with the governor, or some ruiming part of the machine, in sach fa manner that said Adevice or mechanism will be set and held in an operative condition only when the machine.

has the motive power applied or is running at its usual working velocity. My invention further consists. in certai vhereiHatter-described improvements in the delivery-mechanism of the press. Y l

Ioenable those skilled in the art to make and use my invention, I will proceed to more fully describe the construction and operation of a printing-press involving .my several iinprovements, referring by letters to the accompanying drawings forming part of this specification, and in which- Figure 1 is a side elevation; Fig. 2, a back view; andFig. 3, avertical longitudinal sec- B the proper motions, and whichk also,'t'hrough the medium of a pinion, I, intermediate gear. J, and gear-wheel- K, impartsto the drum C the necessary rotatory motion. On the main shaft E is a gear, L, that engages with an in` termediate gear, M, which drives the spur-pinion N of the governor O. The griper-wheels P, for taking the printed sheet away from the drum', are arranged on a shaft, Q, mounted in the upper part of the main frame, as shown, and the iiy R, for delivering the sheets, is arranged, as seen, so as to take the sheets as they pass out between the wheels P and rollers S.

The liy is operated in any usual manner, and the drum C is provided with the usual griper-tingers, for carrying the sheet round while receiving the impression.

The griper wheels P make each three revolutions to one turn ot' the drum C 5 but the cated with reference to the circumference of the drum and the throw of the bed B that they will come successively into contact with a brake-block, c2, justabout at the times the bed is being checked up and reversing its `direction of motion, (at each stroke ofthe bed,) and this brake-block c2 is mounted or formed on the upper end of a bar, d2, which is jointed to another bar, e2, forming a sort of knucklejoint, as illustrated. Extending from this joint is a pitman or rod, f2, that is connected to the governor, so that when the press is running at its usual speed the brake-block will be drawn up to the position shown at Fig. 3 in full lines, causing the projecting portions a2 b2 of the drum to come into frictional contact with said brake just about the times the bed is being checked up, and so that when the press is not running full speed, the said brakeblocks will drop down into disuse, as shown i by the dotted lines at Fig. 2.

It will be understood that by the means shown and just described the velocity of the drum C is checked up at the sa me time that the throw of the bed is checked, (ateach end of the strolie,) and that, therefore, the irregular speed of the bed is made to harmonize with a similar'irregular velocity of the drum, and' that thus all backlash, and the consequent striking over, and all strain, concussion, and wear and tear on the machine, which would otherwise result from the natural tendency of the rotatory drum to keep traveling fast while the bed is slowed up suddenly, are overcomeV or avoided; and it will be seen that by combining the brake mechanism with the govsuch a manner that the said mechanism will be automatically thrown into use or disuse, as the machine is either run by the usual motive power, or is only put in motion by hand,the unnecessary hinderance to the turning ot' the drum by hand, which would occur were the brake device arranged to always take effect, is avoided.

The general operation of the main parts of the press will, otl course, be understood without particular explanations here.

It will be understood that, so far as the first part of my invention is concerned, any suitable mechanical appliance for checking up the drum, or taking up some of its momentum at the time the bed is (necessarily) being checked, so as to keep the teethvot' the driving-gears always working on the same side, and so prevent all backlash, strain, and jar, will answer, and that this part of' my invention is not limited by the particular devices shown, nor restricted to the described mode of carrying it out, in which the bringing into use of the drum-checking device is eiectedautomatically, and only when the press has the usual motive power applied.

O1' course one part or feature of my invention Vmay be used with more or less advantage without the other features; and it will be understood that, in regard to the tirst part of my invention, the retardation or retarding of the cylinder is most import-aut at such times as the priutingoperation is being performed.

. Having so fully explained the construction and operation ot' a machine embracing my several improvements in the form I have so far practiced that any one skilled in the art can make and use printing-presses involving my invention, `what I claim as new, and `desire to secure by Letters Patent, isy 1. In combination with the druln or impression cylinder, means for intermittently checking the speed of said cylinder or retarding its velocity', substantially as and for the purposes described.

2. The combination of a brake device or other suitable means for intermittently checking or retarding the velocity of the rotatory drum with the governor, or some other movement ot' the machine, in' such manner that the said drum-checking device will be brought into an operative condition only when the ma'- chine is running at its full or working-speed, as hereinbet'ore set forth.

In testimony whereof I have hereunto set my hand and seal this 18th day of November, 1875.

OALVERT B. COTTRELL. [L. s,] In presence of- J N. MGINTIRE,` JACOB FELBEL".

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