US1351175A - Printing-press - Google Patents

Description

F. J. LEHR.

PRINTING PRESS.

APPLICATION FILED Aun-L27. 1917.

Patented Aug. 31, 1920.

2 SHEETS-SHEET I.

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F. J. LEHR.

PRINTING PRESS.

APPLICATION FILED Aural?, 19u.

1,351,175. PanIedAug. 31,1920.

2 SHEETS-SHEET 2.

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nutren stares Nr orties.

FRANK J. LEER, OI"` ROCHESTER, NEW YORK, ASSIGNOR TO STECHER LITHOGRAPHIC COMPANY, OF ROCHESTER, NEVJ YORK, A CORPORATION OF NEW YORK.

PRINTING-PRESS.

Application led August 27, 191'?.

To all whom 15 may concern:

Be it known thatl, FRANK J.' Lutin, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Printing- Presses; and I do hereby declare the following to be a full, clear, and exact description of the same, reference heilig had to the accompanying drawings`r forming a part of this specification, and to the reference-nu-y merals thereon.

My invention relates to aprinting press and particularly to a shifting mechanism for the press cylinders and has for its object to automatically effect the sepa lation of the impression and printing, or form, cylinders by the use of electric circuits of relatively high andlow voltage currents in the absence of a sheet from the grippers during the feeding process. Another object of the invention is to effect the closing of a relatively low voltage electric circuit in which is arranged a magnet adapted to effect the closing of a relatively high voltage circuit,

insulated from the press, and serving to operate means for controlling the shifting of one of the press cylinders by the operation of another in absence of a sheet from the grippers thereof. To these and other ends the invention consists in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features beingpointed out inthe claims at the end of the specification.

In the drawings:

Figure l is a. side elevation illustrating one embodiment of the invention with the.

cylinders shown in normal position, and

Fig. 2 is a similar view illustrating` the position of the cylinder shifting mechanism after the electric circuit-s have been closed to effect operation of the same.v Similar reference characters throughout the drawings indicate similar parts.

In printing and lithographie presses it is necessary whena sheet has been missed in the feeding to at once separate the cylinders. lf this were not done an impression would be delivered from the printing surface to the impression cylinder, and the succeeding sheet would thereby have an ims Specification of Letters Patent.

Patented Auu 31, 1920.

serial No. 185,347.

pression in reverse print upon the baclr as well as the regular impression on the face. lt is, therefore, necessary to providemeans for automatically separating the cylinders in cases where sheets are missed in the feeding process. Heretofore in electrical. devices provided for this purpose the trouble experienced has been that'the strength of the current required to perform the necessary operations has been greater than the operator could stand, in cases where the current leaked through the press, the result being that the workmen often become violently shocked while manipulating the machine. lt is to overcome these and other disadvantages of the present day shifting mechanisms that the invention set forth herein is intended to accomplish.

ln the embodiment shown, l represents a portion of the frame of a printing-press upon which the cylinders 2 and 3 are mounted, comprising respectively the impression and plate, or printing cylinders. A plurality of grippers el are mounted on the shaft 5 of the impression cylinder at equal distances apart, the points of the grippers when closed serving to hold the sheets upon the contacts 6 supported by the insulation 7 on the bars S. rlfhe contact 6 is connected with the surface 9 of the cylinder 2 by means of the wire l0, while during rotation of the cylinder said surface engages the contact ll of the frameas shown in Fig. E2, thereby completing the circuit through conductor l2, battery 13, conductor 14, magnet 16 and conductor i7. Thus it will be seen that the gripper et and contact 6 form the means by whic i the absence of the sheets is detected. lf there is no paper between these points when the gripper descends the magnet 16 will be energized to draw the armature 18 away from the insulated point 19, against the action of the spring 20, and into engagement with the contact 2l, thereby closing the main circuit, which is the tripV controlling circuit, through conductors 22 and 23, magnet 2st and conductor 25.

The plate, or operatingl cylinder, 3 is provided with an eccentric bearing 2G, to the arm of which is pivotally connected the downwardly extending rod Q7 arranged to lll@ project loosely through the guide 28 on the press frame l. The rod is held in normal position as shown in Fig. 1, by the compression spring 29 mounted between th'e guide 28 and adjustable stop 30 on the rod. The

rod carries an adjustable collar, or projec-V crank is pivoted upon the lever 34, which is pivotally mounted upon the press frame at 35, said lever being held in normal position by the spring 36 having one end connected with'the rearwardly extending arm 37 and the other with the stop 38 on the frame. The lever is provided with a lug, or proj ection 39, extending into the notch 40 oit' the bell crank constituting stops to limit its'up and down movement. When the cylinder 2 is revolving in the direction `indicated by the arrow the cam 41 will engage the roller 42 of the lever 34 `and depress the latter, and if the paper is between the gripper 4 and contact 6 the arm 32 of the bell crank will escape the projection 31, thus allowinothe rod 27 to remain at normal position. owever, in the absence of a sheet between the gripper 4 andrcontact 6' the low voltage batj tery circuit will serve to effect a closing of be forced down by the lever 34 when the latter is operated bythe cam 4l. This will effect, Vby means of the eccentric bearing 26,

a movement of the printing cylinder 3 in a l direction away from the impression cylinder 2, as indicated by Fig. 2, in which position it will remain as long as the battery circuit is closed.' By this means it will be seen that a relatively high voltage circuit may be used for efectin'g the operation of the cylinder trip mechanism without danger of throwing the current into the press and injuring the operator, while a current of relatively low Vvoltage may be used both for detecting the absence of a sheet from the grippers and i'or automatically closing the high voltage circuit which controls the tripping mechanism.

I claim as my invention:V

Y l. In a printing press, the vcombination of a frame, an impression cylinder rotatively 'mounted therein and adapted to receive a worksheet, a rotatable plate cylinder normally in contact with said impression cylin-V der, a rock arm pivoted to the frame, means actuated by said impression cylinder for rocking said arm, andan electrically controlled bell crank pivoted Vto said rock arm and adapted to separate said cylinders in the absence of a work sheet on the impression cylinder.

2. in a printing press, the combination of a frame, an impression cylinder rotatively mounted therein and adapted'to receive a work sheet, a. plate cylinder coperating with said impression cylinder, a rod connected with said plate cylinder ior'shifting the latter away from the impression cylinder, a projection on said rod, a. bell crank Y having anarmjnormallyout of position to engage said projection but movable toa position to'engage said projection and shift said cylinder, and electric means comprising a circuit adapted to be closed in the labsence ofa sheet from the impression cylinder for moving said bellcrank into position to engage said projection.

3. In a printing press, the combination with impression and plate cylinders adapted to operate upon a work sheet, of automatic means for separating the cylinders in the absence of Va work sheet, said means comprising grippers and complementary contacts on said impression cylinder adapted to engage a work sheet, an electric circuit comprising a relay adapted to operate when the grippers engage saidV complementary contact in the absence of a work sheet, a source of electriccurrent for said circuit of such low tension as to be inappreciable to the human body, a second electric circuit of relatively higher tension actuated by said first circuit and mechanism fory separating the impression and plate lcylinders when said second circuit is energized.

4. In a printing'press thecombination with a frame of impressionanti plate cylins ders, automatic means for separating the cylinders in the absence of a work sheet, said means comprising an eccentric bearing for said plate cylinder, a slidable rod attached thereto for moving the same, a projection on said rod, a lever pivoted to said frame, a cam rotatable with said impression cylinder, a roller onsaid lever for coperation with said cam, a bell crank lever pivoted to one end of the iirst mentioned lever, normally free from coperation withV said projection on said rod, and provided with a notch adjacent the pivot, a projecting lug on said lever in coperation with said notch to limit the pivotal movement of said bell crank lever and an electric magnet fixed relative to said frame and adapted to engage one arm of said bell crank lever when energized, the other arm oit' said bellV crank lever beingadapted to engage the projection on said rod to move the same when said magnet is energized. Y Y

5. V1n `a printing press the combination with a frame of impression and plate cylinders adapted to operate upon a work sheet, Y

ders in the absence of a Work sheet, said means comprising eccentric bearings for said plate cylinder, a slidable rod attached there to for moving the same, a projection on said rod, a lever pivoted to said frame, a cam rotatable on said impression cylinder, a roller on said lever in coperation With said cam aiid an arm pivotally attached ,to Said lever and normally not engaging said projection on said rod, means for moving said 10 arm on the lever.

FRANK J. LEHR.

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