US269020A - crowell - Google Patents

Description

('Numdel') i I.; of GROWVEILL.

'AIR GUSHIONINGAPPANATUS PUR PRINTING MACHINES. Y1Io-.1269,020. Patented Deo. 12,1882.

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d JQ( irl ieg/331 UNITED STATES PATENT OEEICEi LUTHER o. onowELL, OE BROOKLYN, AssIeNoETO E. HOE a OO., or NEW YORK, n. Y,

AIR-CUSHIONING APPARATUS FOR PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 269,020, dated December 12, 1882.

` Application filed October 7, 188.2.'` (No model.)

To all whom it may concern Be it known that I, LUTHER (J. CROWELL, a citizen of the United States, residing in the city ot' Brooklyn, county of King's,and State of New York, have invented certain new and use ful Improvements in Air-Oushioning Apparatus for Printing-Machines, fullydescribed and represented in the following specification and the accompanying drawings, forming a part of ro the saine;A

L' The present invention relates to that class of printing-machines in which the form is carried upon areciprocating bed and the impression made by a revolving drum or cylinder, and

15 which are known by the general nameof cylinder-presses.

In order to prevent the jarring and strain which would be occasioned by suddenly arresting the hed at the end of its travel in either zo direction,it has been customary to provide this class of machines -With cushioning` devices, which not onlygradually overcome the momen-l tum ofthe bed at the ends of its reciprocation, but also stored up the force of such momentum 4 :e 5 to he utilized in overcoming the inertia of the bed in starting it in the opposite direction. These devices have sometimes consisted of metal springs, but more commonly of air-cushions, which have usually been formed by placing a cylinder, one end of which is closed and the other end of which is adapted to receive a movable piston, at each end of the machine, and so arranging the parts that the bed, as it nears the end of its travel in either direction, will expend its momentum against said pistons and be cushioned by the compression ofthe air in the cylinders. The air thus compressed in the cylinders by the momentum ofthe bed will in expanding act upon the pistons, and so aid in starting the bed in the opposite direction.

In using this class of machines it is often necessary for various purposes-asin adjusting and securing the forni-to move the bed to and fro by hand; but it was found that in large-sized machines this was very diflicult, because of the resistance odered bythe confined air in the cyl` inders. To obviate this difficulty the cylinders have been provided with relief-openings controlled by cocks or valves, so that when the bed was to be moved by hand a passage could 5o be opened for the escape of the air from the cylinders and all resistance to the movement of the bed be removed, and the valves for this purpose have sometimes been caused to operate automatically.

The present invention consists primarily in providing the air cushioning apparatus with relief-openings controlled by valves which operate automatically by reason of their inertia, to allow the air to escape from the cylinders 6o when the bed is moved slowly, as by hand, and to prevent its escape whenV the bed is moved u at such a speed as to make cushioning necesi sary or desirable.

In the accompanying drawings, which show so much of an ordinary cylindenpress as is necessary to illustrate the structure and operation of the present invention, Figure-1 isa longitudinal vertical section of one'of the aircylinders and its piston, showing the inertia- 7o valve in the position it will occupy before the piston enters the cylinder vihen the machine is running at such a speed as to make cushioning necessary. Fig. 2 is a like view, showing the positions the parts will occupy when the '75 bed is at the end of its stroke. Fig. 3 is an end viewot' the piston with the valve-cage removed, and Fig. l is a modification to be hereinafter referred to.

rIhose portions not' the printing mechanism 8o shown are of an ordinary and well-knoWn`con-- struction, and consequently need no specitic description.

The air-cushioning apparatus is also, as to its principal parts, of common form,consisting 8'5 of a pair ot' pistons, l 2, mounted upon the ends of a rod, 3, suspended in a bracket, 4, fixed to the under side of the reciprocating type-bed 5, and a pair of open-mouthed cylinders, 6, (only one of which is shown,) xed to 9o the frame, one at each end of the machine, these parts being so arranged that as the bed nears the end of its stroke in each direction one of the pistons will enter the open end of its cylinder and the momentum of the bed be expended in compressing the volume of air thus conned.

As before stated, it is desirable, when the bed is moved by hand or is otherwise made to travel slowly,that the air should be allowed to escape from the cylinders, so that the pistons will meet with no resistance. complished automatically in the present case `by providing each piston with an escape-passage, 7, the inner end of which is so shaped as to form a scat, 8, for an ordinary 'balli-valve, 9, contained in a cage, 10, which surrounds said seat and extends forward with a slight downward inclination. From this construction and arrangement it results that when the bed is being moved by hand or the machine is otherwise operated slowly the hall-val ves 9 will maintain their normal positions at the inner endsof theircages,as shown at lthe le'tofFig-2, thus leaving the passages 7 open for the escape .of the air from the cylinders. As soon, however, as the machine attains such speed as to make cushioning necessary or desirable, the inertia ofthe valves 9 will cause them to roll up thc inclines ofthe cages and close the openings 7 before the pistons enter the cylinders, as shown in Fig. l, so that the air will be contined and cushioning take place. As soon as one of the pistons has entered its cylinder the pressure ot' the confined air will hold the valve in its seat while the bed comes to rest at the end of its stroke, as shown at the right ot' Fig. 2, and until the pressure of the air has been exerted to aid in starting the bed inthe opposite direction. When the piston has so far withdrawn from the cylinder that the air con- Alined therein has expanded to about its original volume, the inertia of the valve, together with the incline of its cage, will cause it to roll back to its normal position, where it will remain until the bed is again reversed, when it will again move upward and close its passage, and so the operation will continue to be repeated at each reciprocation of the bed as long as the proper speed ismaintained. The speed at which the machine can operate without closing the valves will depend upon the weight ot' the valves and the inclination ot' the cages, and these can be regulated at pleasure. 4

In addition to the functions already specitied, the valves 9 operate, as the pistons are withdrawn, to permit air to enter the cylinders, to compensate for leakage past the pistons, which always occurs to a greateror less extent. This is a function of considerable importance, as, unless some means is provided for supplying this deficiency, a partial vacuum is form-ed in the cylinders, which to some extent retards the forward motion of the bed.

It will be readily understood that the present invention is not limited in its application to cushloning devices in which the parts are aranged as herein shown. The order of the parts may be reversed, the pistons being secured to the frame and the cylinders attached to the' bed of the press and provided with the escape passages and valves.

In Fig. 4 there is illustrated a slight modification in the structure ot' the cage 10.` -This consists in the addition of a light spring, 1l, arranged as shown, and provided with a slight downward bend or projection, 12, by whichv theball-valve, after being carried to its seat by its inertia, is retained there until the suction ofthe air through the passage 7, as the piston is withdrawn, forces it cutot' the seat and back past the said projection. This spring will not usually be found necessary; but in some cases, where the travel of the bed is quite long. it may be found useful.

What I claim is- 1.An air-cushioningapparatus provided with an escape-passage controlled by a valve which vv closes by its inertia, substantially as described.

2. The combination, with the cylinder 6 and piston 2, one ot' which moves and is provided with an escape-passage, ot' a valve, as 9, which is periodically operated by its inertia to close said escape-passage, substantially as described.

3. The combination, with the piston and cylinder, as 2 6, one of which moves and is provided with a'n escape-passage, as 7, ofthe ballvalve 9 and its inclined cage, said cage being so arranged that when theparts attain a given sneed the inertia of said valve will cause it-to close said escape-passage,substantially as described. I

4. The combination, with the piston and cylinder, as 2 6, one of which moves and is provided with an escape-passage, as 7, of a ballvalve, as 9, cage, as 1t), and spring,as 11,sub stantially as described. f

In testimony whereof I have hereunto set my IOO hand in the presence of two subscribing witnesses.

LUTHER C. CROWELL. Witnesses J As. A. HovnY, T. H. PALMER.

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