US3332345A - Sheet alignment apparatus - Google Patents

Description

July 25, 1967 c. E. SMYTH 3,332,345

SHEET ALIGNMENT APPARATUS Filed May 24, 1965 3 Sheets-Sheet l INVENTOR. @V/mBE/m BY v f 1/ I I r I July 25, 1967 c. E. SMYTH 3,332,345

SHEET ALIGNMENT APPARATUS Filed May 24, 1965 3 Sheets-Sheet 2 July 25, 1967 c. E. SMYTH 3,332,345

SHEET ALIGNMENT APPARATUS Filed May 24, 1965 3 Sheets-Sheet 5 INVENTOR.

0/4/9155 5 (QM 7W United States Patent Illinois Filed May 24, 1965, Ser. No. 458,252 2 Claims. (Cl. 101-409) This invention relates to a new and useful improvement in a sheet alignment apparatus and more particularly to the structure by which sheets are maintained in correct registration as they are subjected to successive impressions made by printing machines and the like.

The structure and method of sheet control to be hereinafter described and claimed is adapted to be associated with a transfer cylinder type press such as is shown in Patents 2,100,852 and 2,577,099. It has been found that sheets, while going through the various units of the printing press, will frequently warp or distort especially at their trailing edges due to the effect of atmospheric and press conditions. This effect is most noticeable on offset presses in which the water used has a tendency to humidity the sheets and expand the trailing edges. The lateral stretch or fan-out of the sheets requires a corrective measure to be taken so that subsequent impressions printed thereon will be in precise registration throughout the entire area of the sheet.

In the past the corrective mechanism included a plurality of guide members for engaging and holding, not only the side edges of the sheet, but also for gripping and distorting through a horizontal plane, the leading edges of the sheets as they pass through the various printing stages.

One of the principal objects of this invention therefore is to provide an improved sheet registering apparatus which is conveniently adjustable to compensate for irregularities in the positioning of the sheet.

Another object of the invention is to provide in a sheet registering mechanism of this character, a means whereby the sheet is adjusted longitudinally as well as angularly transversely to the plane of the sheet whereby its register position can be corrected.

A still further object is to provide a method for effecting sheet control by elevating a portion or portions of the leading edges of the sheet relative to the cylindrical surface of the printing mechanism.

Other objects will appear hereinafter.

This invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

FIG. 1 is a fragmentary perspective view of the improved sheet registering mechanism;

FIG. 2 is a fragmentary front elevational View of the improved sheet registering mechanism;

FIG. 3 is a fragmentary detail front elevational view similar to FIG. 1 but showing certain portions of the mechanism in different operative positions;

FIG. 4 is a fragmentary detail front elevational view similar to FIG. 1 but showing certain portions of the mechanism in different operative positions;

FIG. 5 is a fragmentary detail front elevational view similar to FIG. 1 but showing certain portions of the mechanism in different operative positions;

FIG. 6 is a fragmentary detail sectional view taken on line 66 of FIG. 2;

FIG. 7 is a fragmentary detail sectional view taken on line 7-7 of FIG. 3;

FIG. 8 is a fragmentary detail sectional view showing a modified method of adjusting the gripper pads of the sheet registering mechanism;

FIG. 9 is a fragmentary front elevational view of a modified form of adjustment mechanism for the sheet registering mechanism;

FIG. 10 is a fragmentary detail view showing a modification of the adjustment mechanism for the sheet registering apparatus as shown in FIG. 9;

FIG. 11 is a fragmentary front elevational view of a modified form of adjustment apparatus for the sheet registering mechanism;

FIG. 12 is a fragmentary perspective view of the device shown in FIG. 11;

FIG. 13 is a diagram illustrating the corrected condition of a sheet subject to the operation of my improved sheet registering mechanism; and

FIG. 14 is a similar diagram to FIG. 13 showing the opposite corrective operation of my invention.

The present invention is primarily adapted to be used in a continuous offset printing operation wherein the sheets are continuously fed through a multiple unit press employing a plurality of rotatable cylinders. In the course of travel the sheet is caused to pass between cylinders of the press by means of transfer mechanisms which include a plurality of gripper fingers incorporated in each cylinder that function to receive and hold the leading edge of the sheet as it is transferred through its travels from cylinder to cylinder of the press unit.

The construction and operation of the gripper fingers as well as guide apparatuses employed in offset presses are shown and described in the aforementioned patents as well as in Patents Nos. 2,231,914 and 2,286,032. The specific structure and operation of the grippers and guide mechanisms shown and described in these patents are to be incorporated in association with my invention, but make up no part thereof, and as these structural components and their operation are well known in the art, they will not be shown or described herein except by reference to their functional association with the present invention.

As viewed in FIG. 1, I show an impression cylinder 10 rotatably supported upon a shaft 11. The cylinder 10 has a portion of its peripheral area recessed as at 12 so as to provide a chamber for my improved sheet registering mechanism. Journalled between the end walls 13 and 14 as defined by the recess 12, is a shaft 15. Mounted upon the shaft 15 are a plurality of equally spaced gripper fingers 16. Coiled about the shaft 15 is a spring 17 which includes a portion 18 in engagement with each of the gripper fingers 16 so as to yieldably hold the free ends thereof in facial abutment with the peripheral edge of the cylinder 10.

By a suitable mechanism not shown or described in this application but well known in the art, the shaft 15 is caused to periodically rotate axially so as to raise all of the gripper fingers 16 out of engagement with the peripheral edge of the cylinder 10 during that portion of the printing operation when the sheet is being transferred onto the impression cylinder 10. The leading edge of the sheet is brought into registration with the edge 18 of the recess 12 whereupon the shaft 15 is caused to be rotated in an opposite direction permitting the spring 17 to yieldably force the gripper finger 16 into contact with the leading edge of the sheet so as to securely hold the same onto the impression cylinder 10.

Between the end walls 13 and 14 defined by the recess 12 and adjacent to the edge 18 of such recess 12, is mounted a retaining bar 19. This retaining bar 19 may be releasably connected to the recess wall 20 by means of screws 21 or the like. This retaining bar 19 functions to fixedly maintain a plurality of gripper pads 22 in a predetermined relation with respect to the complementary free ends of the gripper fingers 16. This in a manner and for the purpose hereinafter made apparent.

Formed in the recess wall 20 and in open communication with the peripheral edge 18 of the recess 12 are a plurality of channels 23. Positioned within each of the channels 23 is a rectangularly shaped gripper pad 22. These gripper pads 22 are of a length greater than the length of the channels 23 so that such pads 22 may be moved longitudinally therethrough. The gripper pads 22 have their innermost end 24 resting upon circular cam surfaces 25, formed circumferentially and periodically throughout the length of a rotatable cam rod 26 which extends through suitable bearings 27 provided by the end walls 13 and 14 of the impression cylinder 10 as shown in FIGS. 1 through 5. The cam surfaces 25 are eccentric relative to the axis of the rod 26 and so arranged that starting from opposite ends of the cam rod 26 they consist of sets so that as seen in FIGS. 3 through different sets of gripper pads 22 associated therewith may be vertically adjusted relative to the remaining sets of pads. The cam rod 26 is adapted to be freely rotated axially so as to determined the location of each set of cam surfaces formed therein relative to their associated set of gripper pads.

Referring to FIGS. 5 and 7, it is clearly seen that when one portion of the cam surface 25 is positioned with respect to one of the pads 22, such pad will have its opposite end in flush alignment with the peripheral surface of the cylinder as shown in FIG. 6. In the event the cam rod 26 is rotated to relocate the cam surface 25, the same will eifect the elevation of the free end of the gripper pad 22 relative to the peripheral edge of the cylinder 10 as shown in FIG. 7. Thus by rotation of the cam rod 26, the operator may determine the respective positioning of the gripper pads so that when the leading edge of the sheet is deposited thereon, such leading edge will assume the elevated arcuated plane defined by the gripper pads across the peripheral edge of the cylinder 10.

When the cam rod 26 is rotated to position the gripper pads 22 in the desired position relative thereto, the retaining bar 19 may be fastened upon the wall 20 of the recess 12 and thus rele-asably retain the gripper pads 22 in such positions. Upon release of the retaining bar 19 and rotation of the cam rod 26, those pads 22 which are no longer held in an elevated position by their respective cam surfaces 25 will by the action of the spring 17 upon the gripper fingers 16 force such pads 22 into their retractive position.

As illustrated in FIGS. 13 and 14, the registration of the sheet is achieved by elevating the opposite corners of the leading edge of the sheet S or by elevating the center portion of the leading edge of such sheet. The elevation is achieved by the adjustment of the gripper pads 22 in their respective channels 23 through the cam surfaces of the cam rod 26. In FIG. 13, I illustrate the condition of a sheet subject to the above operation wherein the opposite corners of the leading edge have been elevated thus causing expansion of the sheet throughout its length with the trailing edge being stretched outwardly of the normal longitudinal plane thereof.

In FIG. 14, I show the corrected position of the sheet by elevating the middle portion of the leading edge thus causing the sheet to assume the position shown therein wherein the trailing edge moves inwardly of the normal plane of such sheet.

To achieve the above desired results all that an operator need do is to effect rotation of the cam rod 26. This may be achieved through a manual control or by a suitable control mechanism responsive to the operators instruction.

Referring to FIG. 8, I show a modified method of adjusting the gripper pads. In this form the gripper pad 28 has its bottom edge 29 resting upon the free end of a threaded shaft 30 of an adjusting nut 31. The adjusting nut 31 is adapted to be threaded vertically through a suitable bearing 32 provided by a mounting bracket 33 connected by means of screws 34, or the like, to the recess wall 20. In the modified form, I maintain the use of the retaining bar 19 and thus when the same is sufficiently loosened from its connection to the recess wall 20, the operator may rotate the adjusting screw 21 of each gripper pad 28 so as to raise or lower the same.

Referring to FIG. 9, I show another form of construction embodying my invention. In this form the gripper pads 35 have their lowermost edge 36 adapted to rest upon a support which comprises two sections 37 and 38 pivotally connected together as at 39. Each of the sections 37 and 38 of the support has pivotally connected intermediate their ends pivot links 40 and 41 respectively. The free ends of the sections 37 and 38 as well as the free ends of the links 40 and 41 are adjustably connected, by means of wing bolts 42 and 42' or the like, to a mounting bracket 43 which contains an elongated slot 44 behind which are retained suitable nuts, not shown, into which the wing bolts 42 and 42 are adapted to be securely threaded. By this arrangement, if the sections 37 and 38 and/or the links 40 and 41 have their free ends moved through the slot 44 as shown in FIG. 9, the sections 37 and 38 of the support will likewise pivot, thus causing each of the gripper pads 35 to be adjustably positioned relative to the periphery of the cylinder.

To achieve an even finer adjustment of each of the gripper pads 35, a modification may be made thereto as shown in FIG. 10. In such showing, each of the gripper pads 35 has its bottom edge 36 provided with a threaded bore 45 into which is adjustably threaded a screw 45, the head of which rests upon a portion of the adjustable support (section 37 as shown in FIG. 9). By this arrangement all of the gripper pads 35 may be simultaneously adjusted by the mechanism shown in FIG. 9 and then the individual screws 45 of each gripper pad 35 may be threaded into or out of the bottom edge 36 thereof to further adjust each selected gripper pad.

In FIG. 11, I show another modification of an adjusting means wherein the retaining bar 19 is provided with a plurality of apertures 46 through which the smooth shank 47 of a pinion 48 projects. The tooth end 49 of the pinion 48 engages a rack segment 50 positioned within a slot 51 formed in the body of the pad 52. By this arrangement the retaining bar 19 is loosened and each pinion 48 is rotated so as to raise or lower its associated gripper pad 52 into the desired position relative to the periphery of the cylinder.

Each of the modifications hereinbefore described permits the elevated adjustment of a plurality of gripper pads which cooperate with the gripper fingers 16 to receive and position the leading edge of a sheet upon the impression cylinder 10. As hereinbefore explained, the adjustment of the gripper pads permits an arcuated distortion of the leading edge of the sheet through a vertical plane relative to the periphery of the cylinder 10, thus effecting proper registration of the sheet.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a sheet alignment apparatus including a printing machine having a sheet receiving cylinder comprising (a) a plurality of gripper fingers carried by said cylinder for releasably securing the leading edge of the sheet to be printed, upon the cylinder,

(b) a plurality of gripper pads movably mounted on said cylinder and positioned beneath said gripper fingers and cooperating therewith for releasably securing the leading edge of the sheet onto the cylinder,

(c) a retaining bar carried by said cylinder and extending across each of said gripper pads intermediate their ends for releasably holding said gripper pads on said cylinder with certain free ends thereof positioned relative to the periphery of the cylinder, and

(d) a movable supporting element in contact with the opposite ends of each of said pads and cooperating With said retaining bar for simultaneously radially adjusting said gripper pads individually with the said certain free ends thereof in selected elevated positions relative to the periphery of said cylinder so as to secure the leading edge of the sheet in an arcuated elevated plane relative to the periphery of said cylinder so that the trailing end of the sheet is placed in proper registration for a succesive printing operation.

2. In a sheet alignment apparatus as defined by claim 9 wherein said movable supporting element is a rotatable rod carried by said cylinder and having a plurality of cam surfaces formed circumferentially about said rod with certain of said cam surfaces eccentric with respect to each other and said rod and supporting a gripper pad so that upon axial rotation of said rod different cam surfaces Will support said pads in difierent elevated relation to the periphery of the cylinder.

References Cited UNITED STATES PATENTS 1,303,793 5/1919 Henderson et a1 101-412 2,577,099 12/ 1 Albrecht 101183 FOREIGN PATENTS 507,122 6/ 1939 England.

WILLIAM B. PENN, Primary Examiner. ROBERT E. PULFREY, Examiner. H. DINITZ, Assistant Examiner.

Claims (1)

1. IN A SHEET ALIGNMENT APPARATUS INCLUDING A PRINTING MACHINE HAVING A SHEET RECEIVING CYLINDER COMPRISING (A) A PLURALITY OF GRIPPER FINGERS CARRIED BY SAID CYLINDER FOR RELEASABLY SECURING THE LEADING EDGE OF THE SHEET TO BE PRINTED, UPON THE CYLINDER, (B) A PLURALITY OF GRIPPER PADS MOVABLY MOUNTED ON SAID CYLINDER AND POSITIONED BENEATH SAID GRIPPER FINGERS AND COOPERATING THEREWITH FOR RELEASABLY SECURING THE LEADING EDGE OF THE SHEET ONTO THE CYLINDER, (C) A RETAINING BAR CARRIED BY SAID CYLINDER AND EXTENDING ACROSS EACH OF SAID GRIPPER PADS INTERMEDIATE THEIR ENDS FOR RELEASABLY HOLDING SAID GRIPPER PADS ON SAID CYLINDER WITH CERTAIN FREE ENDS THEREOF POSITIONED RELATIVE TO THE PERIPHERY OF THE CYLINDER, AND (D) A MOVABLE SUPPORTING ELEMENT IN CONTACT WITH THE OPPOSITE ENDS OF EACH OF SAID PADS AND COOPERATING WITH SAID RETAINING BAR FOR SIMULTANEOUSLY RADIALLY ADJUSTING SAID GRIPPER PADS INDIVIDUALLY WITH THE SAID

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