US1780348A

US1780348A - Sheet-registering mechanism for printing machines

Info

Publication number: US1780348A
Application number: US319812A
Authority: US
Inventors: William K Eckhard
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1928-11-16
Filing date: 1928-11-16
Publication date: 1930-11-04
Anticipated expiration: 1947-11-04

Description

W. K. ECKHARD Nov. 4,1930;

SHEET REGISTERING MECHANISM FOR PRINTING MACHINES Filed Nov. 16, 1928 2 Sheets-Sheet l INVENTQR fM f G td-L Nov. 4, 1930. w ECKHARD 4 I Q 1,780,348

SHEET REGISTERING MECHANISM FOR PRINTING MACHINES Filed Nov. 16, 1928 2 Sheets-Sheet 2 Patented Nov. 4, 1930 UNITED STATES PATENT, OFFICE WILLIAM K. ECKHARD, OF DUNELLEN, NEW JERSEY, ASSIGNOR TO R. HOE & 00., INC., OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK SHEET-REGISTERING MECHANISM FOR PRINTING MACHINES Application filed November 16, 1928. Serial No. 319,812.

10 width of sheets which are of the same nominal dimensions, itis customary to arrange one of the guides so that. it forms a positive positioning means, while the other guide is arranged with a spring so that it bears against 5 the sheet with a yielding pressure Thus even though the dimensionsof the sheets vary to some extent, the printing is registered to the side that is engaged by the rigid guide.

Such guides will operate satisfactorily 20 when the side edges of the sheet-s are perfectly straight and are square with the front edge, but if they are not straightand square,

' they may not pass the guides freely and the interference resulting may affect the register 26 of the printing.

In the registering mechanism disclosed herein the side guides are so arranged that a they properly position the sheet and then recede so there is no interference with the sheet as it moves past the guides.

An object of the invention is to provide a side registering mechanism for machines used for printingon tin and similar materials, which will accurately position the sheet with reference to the printing cylinders, and which can be used with sheets which are not accurate as to shape or dimensions;

It is also an object of the invention to provide a sheet registering mechanism of gen erally improved construction, whereby the device will be simple, durable and inexpensive in construction, as well as convenient, ractical, serviceable and efiicient inits use. With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood'that various changes in the precise embodiment of the invention herein disclosed may .be made within the scope of what is claimed without departing from the spirit of the invention.

In the accompanying drawings, Figure 1 is a side View partly in section of a portionof a printing machine showing the side registering mechanism and the means for operating it.

Figure 2 shows the registering mechanism as Viewed from above.

Figure 3 shows the registering mechanism as viewed in the direction of arrow 3 of Figure 2. a

Figure 4 is a detail sectional view of one of the side guides taken on the line 44 of Figure 2 as viewed in the direction of the arrow; and

Figure 5 is a detail sectional view of one side of the guides taken on the line 5-5 of Figure v3 as viewed in the direction of the arrow.

Referring to the drawings, 11 and 12 indicate the side frames of the printing machine and 13 a cross bar on which the supports 1% and 15 are slidably mounted. The

side guide blocks

16 and 17 are secured tothese supports by means of the

screws

18 and 19. The side guide blocks, support rollers 20 and 21 which engage the. edge of the sheet, and.

shields

22 and 23 which guide it as will be hereinafter explained. i

The relation ofthe registering mechanism to the printing cylinders is shown in Figure 1 wherein 24 indicates the blanket cylinder of an oifset press such as is commonly used for this class of work, while 25 indicates the impression cylinder. Grippers 26, are operated by an arm 27 carrying a roller 28 in engagement With a cam 29, secured to the frame 11, and serve to hold the sheet while it is being printed.

Gears not shown on the drawing are provided to drive the cylinder 24 at a peripheral speed uniform with that of the cylinder 25, the latter being driven through the gear 3!) from the gear 31 secured to the shaft 32 which is connected to a suitable source of power.

Screws

33 and 33 may be carried by suitable members secured to the shaft 32 at each side of the frame, and serve to secure the

cams

34 and 34 in the desired relation to the shaft 32.

Slots

35 and 35 allow the cams to be turned through a limited arc and in practice the cams are secured at one or the other of their extreme positions. When the cam 34 is set in the forward position, as shown in Figure 1, the cam 34: will usuallybe set in the rearward position as indicated by the dotted line, and vice versa.

The stud 36 securedto the frame 11 serves as a pivot for the bell crank lever 37, one arm of which carries the roller 38 in engagement with the cam 34: while the other arm is connected by link 39 with one arm of bell crank lever i0. A spring 11 serves to bias the lever 37 downward and hold the rolier 38 in engagement with the cam 34. The lever 40 is pivoted at 42 on the bracket 48, secured to the frame 11, and connected by link 4% with the collar 45.

Collar 45 is provided with a thumb screw 46 by means of which it maybe locked to the support 14 in the correct position to suit the width of sheet being printed. A second collar 47 has a thumb screw 48 for looking it to the support 14 and also an adjusting screw 45) which serves as a means of obtaining a line adjustment-of the collar 45 on the support 1 1, the method of operation being to lock the collar 47 on the support, loosen the collar 45, turn adjusting nut t9, moving collar 4-5 and locking it when the required adjustment is obtained.

The mechanism for reciprocating the support 14; is duplicated on the opposite side of the machine for operating the support 15 and the same reference numbers primed have been used on the drawings.

From the foregoing description it will be understood that rotation of the shaft 32 will result in reciprocating the

side guide blocks

16 and 17, toward and away from the center of the machine, and that by properly posi 'tioning the cams 34 and 34: they may be moved in unison or either may be moved in advance of the other.

The guide block 16 is slotted and a slide 50 is fitted to the slot widthwise but made somewhat shorted than the block. Thus when the slide 50 is secured to the support 1& it holds the guide block 16 in position but allows it a limited longitudinal motion. The bottom of a hole in the slide 50 furnishes an abutment for the spring 51 which forces the guide block toward the center of the machine as far as the slot will permit. The side guide as a whole is thus yieldingly supported with reference to the support 14.

Bushings and 55 are secured to the frames 11 and 12 respectively and serve as bearings in which the supports '14 and 15 slide.

The side guides are mounted in alignment with a feed table 52 over which the sheet 53 passes to the printingcylinders, be

ing forwarded thereto at the proper time by the pusher 54.

In practise, the operation of the side guides is so timed that they will engage the sheet be fore it reaches the printing cylinders, and release it immediately after it reaches the cylinders and the grippers close on it. The

shields

22 and 28 serve to guide the edges of the sheet into engagement with the rollers 20 and 21. The roller 21 being positively positibned, the edge of the sheet which engages it will be accurately registered, but as the roller 20 is spring supported, it will yield when it engages the edge of the sheet and it is thus possible to feed sheets that are not accurate as to width, and still. maintain proper register.

The operation of the side guides is so timed that the roller 20 engages the sheet slightly in advance of the roller 21. They are then both in engagement with the sheet for a short period when it is accurately positioned as to side register. After it is taken by the grippers on the cylinder, the support carrying the roller 20 recedes and immediately thereafter the roller 21 is withdrawn leaving the sheet entirely free on both side edges.

In registering mechanism heretofore used the side guide remained in position while the sheet was moved past it. If the sheet was wider at the back than at the front, or if the edge was convexly curved, there was a tendency to move the sheet underv the grippers as it was drawn past the guide. This difliculty has been overcome by the invention disclosed herein.

lVhen both sides of. the sheets are to be printed it is usually necessary that the printing on both sides be in register with each other. To provide for this the side guides are made interchangeable. One side of the sheet would be printed with the side guides anounted as shown'in the drawings, but when the sheets are turned over to be printed on the other side, the guides would .be interchanged, the block 17 and the parts which it carries being mounted .on the support 14:, while the block 16 and the parts which it carries, together with the slide 50 would be mounted on the support 15. The printing would thus .beregistered to the same edge of the sheet for both printings.-

It would be noted that the arrangement whereby separate mechanism is provided to operate each of the side guide supports,

allows either tozbe set so as to operate later than the others This setting is conveniently accomplished by turning the

cams

34 and 34 through the arc permitted by the

slots

35 and 35, the cam which operates the yielding guide being set in the advanced position while the cam which operates the rigid guide is set in the retarded position. What I claim is :7 v 1.. In combination with a machine having printing cylinders, a sheet registering mechanism of the class described, having two side guides arranged to reciprocate into and out of engagement with the side edges of a sheet being forwarded to the .printing cylinders, and separate mechanisms for operating each guide independently of the other, whereby the guide on either side may be made to con tinue in engagement with the sheet after the guide on the other side has been moved out of engagement with it.

2. In a machine having printing cylinders, and sheet registering mechanism of the class described, guides between which a sheet is forwarded, said guides being so arranged that one guide bears against the sheet on one side edge with a positive pressure and an other guide bears against the sheet on the opposite side edge with a yielding pressure, mechanism for,operating the first mentioned guide in a timed relation with the printing cylinders, mechanism for operating the second mentioned guide in a timed relation to the printing cylinders that is advanced relatively to the timed relation of the first mentioned guide, means for transposing the guides, and means for reversing the sequence of their operation.

3. In a sheet registering mechanism of the class described, a side guide yieldingly mounted on a support which moves it into engagement with the side edge of a sheet being forwarded, and a side guide rigidly mounted on a support which moves it into engagement with the opposite side edge of the sheet; said supports being operated by separate adjustable mechanisms whereby the operation of one may be timed to eitherprecede or follow the operation of the other and the said guides being interchangeable with each other whereby either guide may be mounted on either support.

4. In a sheet registering mechanism of the class described, a cam secured to a driven shaft, a guide for engaging the side edge of a sheet, a roller in engagement with the cam, connections between the roller and the guide whereby the guide is moved to engage and disengage the sheet, a second cam secured to the driven shaft, a second guide for engaging the opposite edge of the sheet, a second roller in engagement with the second cam, connections between the second roller and the second guide, whereby the second guide is moved to engage and disengage the sheet, and means for moving the cams with relation to the shaft so that either guide may be caused to remain in engagement with the sheet after the other guide has been moved out of engagement.

5. In a sheet registering mechanism of the class described, a side guide which is moved to and away from one edge of the sheet, a second side guide which is moved to and away from the opposite edge of thesheet and which