US2248567A - Sheet registering mechanism - Google Patents

Description

July 1941. L H. c Ross K 2,248,567

SHET REGISTERING MECHAISM Filed Aug. 14, 1940 2 Sheets-Sheet l July 8, i941.

y L H. cRoss SHEET REGISTERING MECHANISM Filed Aug 14, 1940 2- Sheets-Sheet 2 INVENTOR [Qa/mrdf. 005.5'

AT RNEY Patented July 8, 1941 oFFicE 12 Claims.

My invention relates to sheet-registering mechanism used in conjunction with sheet-feeding and delivery means for bringing sheets in individual sequence to the cylinder of a printing press. More particularly, the invention relates to such registering mechanism which employs pull-grippers adapted to positively grip the sheet and positively advance it for engagement with stationary drop-guides forming part of suoli registering mechanism, said grippers being adapted to frictionally draw away from the sheet after such engagement. This type of mechanism is clearly distinguished from mechanism adapted to impositively engage and push the sheet into engagement with the drop-guides and adapted to also push upon the sheet during the registry period following its initial engagement with the drop-guides.

An important aspect of my invention is the provision of means cooperative with the pullgrippers to slow down the sheet prior to its engagement with the drop-guides of the registering means and the provision of means causing continual advancement of the sheet under positive control during said operations.

Some prior mechanisms continually push the sheet during the slow-down as well as during the registering period of its advancement. This causes buckling which mitigates accurate registry and causes scuflng of the surface of the sheet. Other prior machines impositively retard the sheet in the slow-down period. This also causes buckling, and further, permits the sheet to rebound, tending to crimp the front edge and otherwise destroy accuracy of registry. Still other prior devices require that the sheet be brought to rest prior to engagement of registering grippers, causing a reduction in efliciency.

Some of these prior mechanisms have their slow-down means combined with their means for delivering and transferring the sheet to relatively stationary jaws of independent pull-grippers. This type suffers inaccuracy on account of the wide variation in arrival of the sheets to an anticipated point between the said jaws at the time of transfer of -control of the sheet from the delivery means to the registering means. This variation in arrival of the sheets is due to a number and variety of causes well understood in the art. In such mechanisms, sheets arriving on schedule are not free of buckling and impact which are inherently associated with impositive control and transfer.

Impacts also occur during transfer of feed control from one set of positively gripping feed means to another set of positively gripping feed means operating at a wide difference of advancing speeds.

Other objections of the prior device are their inability to take care of a relatively wide range oi variations between sheets far ahead or far behind their normally anticipated arrival on schedule.

One of the main objectives of my invention is to overcome the objections to prior devices adapted for registering of sheets and to increase the range of acceptance for registry, of oncoming sheets which are far ahead or behind schedule. Another object is to provide a highly eicient device which supplements the pull-grippers with slow-down characteristics for engagement with front edge of a controlled advancing sheet for controlled ietardment to registry mechanism to secure uniformly accurate front edge registry. Other Objectives are to provide means in my contemplated mechanism for engaging a sheet while traveling at high speed without causing impact or inertia reactions in the sheet, and thereafter, to electuate a gradual deceleration thereof, prior to registry, to a speed where it is brought into contact with the stationary drop-guides for registry, without impact or rebound. A further object is to provide an equal period of slow-down action on all sheets regardless of their schedule of arrival within the wide limits of the mechanism.

Other objects and advantages are contemplated, some will be specically pointed out and yet others will become apparent in the following specification having reference to the accompanying drawings showing preferred embodiments of my invention, in which:

Fig. 1 is a fragmentary semi-schematic sectional view of the forward end of a conventional sheet conveying mechanism of the type known in the art as a cross feeder, embodying the invention, with the parts thereof in an initial operating position at the 'beginning of the forward stroke in the cycle of operation.

Fig. 2 is a fragmentary View similar to Fig. 1 showing certain parts in an advanced operating position.

Fig. 3 is a View similar to Fig. 2 showing the parts in a still further advanced operating position.

Fig. 4 is a view similar to Fig. 3 showing the parts in an operating position at the completion of the forward stroke.

Fig. 5 is a fragmentary section taken substantially on the line 5-5 of Fig. 1.

Fig. 6 is a view taken substantially on the line 6 of Fig. 2.

Fig. 7 is a fragmentary view of a modied form of gripper in the position at the beginning of the registry of an early sheet.

Fig. 8 is a sectional view taken on the line S--S of Fig. 7.

Referring to Fig. l a conveyor mechanism comprising feed-board I9 is suitabiy supported by the machine in any well known manner, not shown, so that its forward end overlies a cylinder I2 of a printing press. Conveyor slats Hl are supported on the feed board, the forward edge tapering off. A pair of frame members I6 are adapted to provide bearings i S for a rock shaft 2o. One of said frames is positioned on each side of. the conveyor strips and supported upon the feed board. Bearings 2?: on these end frames are provided to rotatably support a cam shaft 24 on which is carried a cam 25 having cam surfaces A, B, and C, comprising respectively an accelerating, decelerating, and substantially constant slow speed zones of the operation of the registry gripper jaws to be later described. These zones relate to the effect these cam surfaces have upon the motion of the sheet gripping jaws in their forward stroke.

Secured to the shaft 2U is a rocker arm 28 having a follower 36 urged against the cam 26 by spring 2T. iluso secured tothe rock shaft 2d is an arm 32` connected by link 34 to an extension of an arm 36. Two of such arms 36 are employed, only one being shown and `lese are pivotally supported as at 38 in extensions 43 secured to stationary arms d2'. Only one of this described assembly is shown and described in detail. This arm 42 is adjustably secured to the frame I6 by means of a pin 4d and a pin-and-slot arrangement 5G and 52. This arm is xedly adjustable by means of set screws 48 in the pin 5t) cooperablewithin the slot 52 embracing the pinand the. screws.

Pivoted. as at 5S. is extensible arm 5B having a laterally projecting. pin. Gil. at its forward end. This arm. is providedzwith a. pin and slot adjustment E2 to enable it. to be lengthened or shortened for the purpose to be more fully described later. The :11311.58 is pivotally secured as at to a boss 5E. A pin 6o at the free end of this arm is adaptedv to rest upon the upper edge of a` blade '64. This blade is` pivotally secured asat 66 to the free end of the arm 35 and is adapted to shuttle back and forth as motivated in response to the surfaces A, B, and C, etc., of the cam 26'. Pivotally secured as at 68 tothe shuttle blade 54. is a blade 'l0k having a hook i2 adapted to rest on the pin 66, the said hook forming a rearwardly open slot i4 adapted to permit the blade l to become disengaged from the pin 50 so that its nger T8: can engage a sheet of paper S under it. The sheet is thus clamped between the jaw l'and'und'er a jaw 'I8 secured at its forward end to the shuttle blade 64. The free end of this under jaw 18 is rearwardly directed. Inraised positionv of the blade 'l the jaws 16 and 'i8 form a mouth for the reception of the forward edge of an oncoming sheet.

The tip 80. of the shuttle blade 64 is widened laterally and its bottom surface is curved fore and aft as at 82 so that it is well adapted-to rest and ride along the upper surface of a tongue B4 extending forwardly from under the feed board lil projecting over the upper surfaceof' the cylinder, and terminating under andslightly forward of the drop-guides Sii. Thedrop-guides may be of such conventional type as are supported in a rocker arm S8, and adapted to be raised and lowered in phased relationship with the cam 26, all of which motions are cyclically timed to the operation of the cylinder. The drop-guides may be provided with the usual slot to form a fork through which the tip 8i) and the jaws It and i8 may pass.

Projecting forward from the upper surface of the feed board l, and underlying each of the blade assemblies is a channeled strip 8D, see g. 5, having a groove or recess 92 therein, of such width as to receive the end of the shuttle blade 64 including its jaw 18. The depth of said recess 2` is preferably such as to receive the projecting end of the jaw le completely below the surfaces 84 to prevent its interfering with the front edge of an oncoming sheet.

Rotatably secured to the extension arm 4D is a pin H50 through which a rod 02 is adapted to slide. The lower end of this rod is pivotally secured as. at loll to the shuttle blade 6d. The upper end is' threaded to receive lock nuts ISB. The purpose ofv this will-ber more fully described later.

eferring to Fig. l, it is to be observed that upon rotation of the cam 26 in the direction shown by the arrow, the arms 3 2 and 35 will be swung clockwise, thus bringing the blades forward as illustrated in Fig. 2. During the rotation of the cam under the effect of its surface A, the blades 54 and l are rapidly accelerated from their rearmost position. At the end of the effect of the zone A of the cam, the instant which corresponds to advancement of the pivot pin 55 to the point E, the arm 35 has reached its maximum rotative speed and, coincidently, the maximum speed of the forward motion of the blades. At this time the hook T2 becomes disengaged from the pin S0 permitting the jaw 'l to come into Contact with the sheet, which, under normal operation and schedule, is-positioned with its forward edge substantially midway between the contactable surfaces of the lingers i5 and 73.

From this point on and during actuation of the zone B of the cam, the blades are decelerated to a point where the pivot 66 reaches the position F, a positionshown inY Fig; 3. This period of deceleration is relatively long as compared to impact devices. This substantially long period of deceleration prevents buckling of the sheet due to. gradual reduction of the momentum of the sheet. From this point on the sheet is advanced at asubstantially constant and low speed, much s lower than the speed at which the sheet was initially fed to the gripping fingers` or the speed at which the sheet is clamped between the fingers.

It will be observed in- Fig. 3 that at the time the blades have completed their deceleration, the front edges of the gripping; surfaces of the jaws have reached the rear face of the drop-guides 95 and areA ready for-sheet registry, even for an early sheet if such happens to be the case. As will be seen; the front` edges of the sheet, under moreA normal schedule conditions, is arranged to be no further forward than the middle .of the gripping surfaces.v of.' the jaws. Under conditions of' receiving a. tardy sheet however, little of the front: edge of the sheet will be grasped by the gripping jaws by the rear portions of their vgrippirigsurfaces. In an actual embodiment ofr the character illustrated, I have found that this mechanism is conveniently operable with a stroke of a little over three inches ofthe blades, employing about, one inch of said stroke for acceleration, one half an inch for deceleration, leaving one and one half inches for the registering motion of the blades. This last portion of the forward stroke provides ample motion at slow speed for the accurate registration of sheets which are as much as threequarters of an inch early or three quarters of an inch tardy in their arrival between the jaws at the instant of their closing. This is considered a relatively long range of operability on mistimed sheets.

During the last portion of the forward stroke when the follower 38 is operating along the surfaces C of the cam and the blades are moving between the points F and G at a substantially constant slow speed, the jaws are in frictional engagement with the sheet and are continually moving forward during withdrawal from the sheet upon registry and no rebound occurs. The last portion of the forward motion of the blades is changed by the engagement of the nut IGS with the pin E09, thereby causing the forward end of the blades to rise, but only after the trailing end of. the jaw 'I8 has passed the indexing face of the drop-guides 86 with which the sheet came into contact. This final lift of the tip of the blades consumes very little of the final forward motion. In the raised position of the blades as illustrated in Fig. 4, the sheet is seized by the cylindergrippers and, as is well known, carried into the press.

It will be further noted that as the tip 8U of the blade Eli advances to the left, the angle of the blade G becomes more horizontal, thereby causing the rearmost portion of the spring finger 'it to recede further down into the recess 92, and it is obvious therefore, that in the highest position of the tail end of the finger 1S it is below the lower most surface of an oncoming sheet, that a tardy oncoming sheet cannot be intercepted by the trailedge of the fingers 18. It will also be seen that in order to accurately adjust the point at which the contacting finger cf the blades cooperate to grip the sheets, the pin B may be adjustably positioned in the direction of movement of the blades by means of the pin-andslot connection 62. The pin 60 however, is free to follow the vertical variations of the arcuation of the blade Si inasmuch as the arm 58 is freely pivoted at 5t. In other words, the two blades are held apart during their forward accelerating motion regardless of minor vertical articulation inasmuch as the pin 6i) supports the hook blade and is in turn supported on the upper edge of the other blade, the dips of which it can freely follow.

Under certain conditions of operation with certain types of sheets, the sheet-engaging surfaces need not be kept apart until after the entry of the sheet between them, such sheets may be pushed between yieldably opposing frictional surfaces.

Referring to Figs. 7 an'd 8, it will be seen that such sheet-gripping surfaces of the sheet retarding and pulling means may be provided by the under surface 'ita of a reciprocatory blade 64a and an opposing upper surface 78a of a spring arm 'lh normally urged toward the surface 16a for frictional engagement of the sheet pushed between these surfaces by the sheet delivery means not shown. This occurs during the initial fraction of the forward stroke of the blade. After this period of engagement of the sheet between the gripping surfaces, the continued forward motion of the blade 64a is retarded, thus slowing down the sheet. The said engagement of the sheet and the subsequent slowing down all occur within substantially the same cam zones A and B and cyclic relationships as previously described.

Following the slow-down period, the sheet' S is slowly advanced until its edge comes into engagement with first one and then the other of the two relatively stationary drop-guides, whereafter, the sheet-engaging surfaces are slowly withdrawn from the engagement therewith by their continued forward movement after the sheet has been arrested in registry by the drop-guides. The pressure of the frictional sheet-engaging surfaces may be adjustedby means of the screws lSc so that any momentum of the Sheet is overcome after the feeding influence of the delivery mechanism ceases. Such adjustment permits entry of the sheet between the surfaces of the grippers without buckling. After such engagement, the front edge of the sheet is brought into contact with the drop-guides. This pressure is relatively slight so as not to crimp the sheet in its withdrawal from the grippers during registry. In this modification as well as in the former, the portion of the registering edge which engages the drop-guides is protected against crimping by being confined and reinforced by the said frictional surfaces.

Having thus described my invention in its principal aspects with reference to the specic embodiments thereof, it is understood that similar organizations and arrangements are adapted to other typesV of machines involving merely such changes as to enable adaptation of the principles of this invention to the particulars of such machines. Other variations may be made without departing from the spirit of the invention as defined in the claims appended.

I claim:

l. In sheet registering mechanism of the character described, the combination including means for positively advancing a sheet forward for a predetermined period, reciprocatory jaws disposed on opposite sides of the path of said advancing sheet, gripping surfaces on said jaws adapted to engage the forward portion of said sheet on opposite sides thereof, means on one of said jaws for urging said surfaces into frictional engagement with said sheet on respective sides thereof, means for advancing said jaws forwardly in open position with one jaw on either side of said advancing sheet and for engagement thereof while in motion without retarding the speed of the sheet at the instant of engagement, and means for retarding the motion of said jaws after said engagement of the sheet by said gripping surfaces.

2. In sheet registering mechanism of the character described, the combination including means for positively advancing a sheet forward for a predetermined period, reciprocatory jaws disposed on opposite sides of the path of said advancing sheet, gripping surfaces on said jaws adapted to engage the forward portion of said sheet on opposite sides thereof, means on one of said jaws for urging said surfaces into-frictional engagement with said sheet on respective sides thereof, means to accelerate said jaws not faster than the speed of the sheet in the initial fraction of their forward stroke into cooperative relationship with said advancing sheet for engagement thereof while in motion, and means for decelerating said jaws in a succeeding fraction of said forward motion of said jaws.

3. Insheet registering mechanism of the character described, ther combination including means for positively advancing a sheet forward for a predetermined period, reciprocatory jaws disposed on opposite sides of the path of said advancing sheet, gripping surfaces on said jaws adapted to engage the forward portion of said sheet on opposite sides thereof, means on one of said jaws for urging said surfaces into frictional engagement with said sheet onrespective sides thereof, means to accelerate said jaws not faster than the speed of the sheet in the initial fraction of their forward stroke into cooperative relationship with said advancing sheet' for engagement thereof while in motion, and

means to retard said jaws in a succeeding fractionV of their forward stroke and after said engagement of the sheet.

4. In sheet registering mechanism of the character described, the combination including means for positively advancing a sheet forward for a predetermined period, reciprocatory jaws disposed on opposite sides of the path of said advancing sheet, gripping surfaces on said jaws adapted to engage the forward portion of said sheet on opposite sides thereof, means on one of said jaws for urging said surfaces into frictional engagement with said sheet on respective sides thereof, and means prescribing the forward motion of said jaws to comprise an initial accelerating fraction for bringing said jaws into cooperative relationship with said advancing sheet for engagement therewith, an intermediate decelerating fraction after said engagement, and a final relatively slow constant speed motion adapted for registry and disengagement of the jaws from said sheet.

5. In a sheet registering mechanism of the character described, the combination of means adapted for reciprocatory motion in unison with moving successive sheets, the forward stroke being in the same direction as the direction of travel of the sheets, said forward. stroke including an initial accelerating fraction, means prescribing said fractions in timed relation to the leading portion of each oncoming sheet, opposing surface on said reciprocatory means adapted to engage the forward portion of a passing sheet on opposite faces thereof, means yieldably urging said surfaces into engagement, means for holding said surfaces apart during the accelerating fraction of said stroke, means for deceleratng the forward motion of said'reciprocatory means, and means for disabling said holding means at a predetermined period at the end of said accelerating fraction of the forward stroke.

6.. In a sheet registering,mechanism `of the character described, the combination of means adapted for reciprocatory motion in unison with moving successive sheets, the forward stroke being in the same direction as the direction of travel of the sheets, said forward stroke including an initial accelerating fraction, means prescribing saidmotions of said fractions in timed relation to the leading portion of each oncoming sheet, opposing surfaces on said reciprocatory means adapted to engage the forward portion of a passing sheet on opposite faces thereof, means yieldably urging said surfaces into engagement, means for holding said surfaces apart during the accelerating fraction of said motion, means for decelerating the forward stroke of said reciprocatory means, and means for disabling said'holding means at a predetermined instant in its forward stroke, said instant being'related to the speed of the travel of the sheet.

7. In a sheet registering mechanism of the character described, the combination of means adapted for reciprocating motion in unison with moving successive sheet-s, the forward strokes thereof being' in the direction of travel of the sheets, opposing surfaces on said means adapted to4 frictionally engage opposite sides of the leading portion of each oncoming sheet, means yieldably'urgingf said surfaces into engagement with said sheet, means for holding said surfaces apart during a predetermined fraction of the forward motion of said reciprocatory means, and means allowing the said surfaces to move toward engagement of a sheet in motion during another predetermined fraction of their forward motion and for engaging said sheet when the speed of said surfaces is substantially equal to the speed of the moving sheet.

8. In a sheet registering mechanism of the character described, the combination of means adapted for reciprocatory motion in unison with moving successive sheets, the forward strokes thereof being in the direction of travel of the sheets, opposing surfaces on said means adapted to frictionally' engage opposite sides of the leading portion of an oncoming sheet while in motion, means yeldably urging said surfaces into engagement, and means for holding said surfaces apart during an initial fraction of said forward stroke of` said reciprocatory means, and allowing said surfaces to engage a sheet in motion during a succeeding instant of their forward stroke without retarding the speed of the sheet at the said instant of engagement.

9. In. a sheet registering mechanism of the character described, the combination of means adapted'for reciprocatory motion in unison with moving successive sheets, the forward strokes thereof being in the direction of travel of the sheets, opposing surfaces on said means adapted to frictionally engage on opposite sides the leading. portion of a moving sheet, means yieldably urgingV said surfaces into engagement with said sheet during its travel, means for holding said surfaces apart during an initial fraction of said forward stroke of said reciprocatory means, and means disabling said holding means during the remaining fraction of the said forward stroke of said reciprocatory means for engagement with said sheetat an instant when the speed of the said surfaces is equal to the speed of said moving sheet.

10. In a sheet registering mechanism of the character described, the combination of means adapted'for reciprocationmotion in unison with moving successive sheets, the forward strokes thereof being in the direction of travel of the sheets, opposing surfaces on said means adapted to move in unison and frictionally engage opposite sides of the forward portion of an oncoming` sheet, means yieldably urging said surfaces into engagement during said forward stroke, means f'or holding said surfaces apart during the initial fraction of the forward stroke of said reciprocatory means, means for accelerating the motion of said opposing surfaces during said initial fraction, means for decelerating the motion ofv saidureciprocatory means during a succeeding fraction' of said forward stroke, and means disabling said holding means during the motion of said reciprocatory means in a period between said'accelerating and'decelerating fractions of the forward stroke.

11. In av sh'eet registering mechanism of the character described, the combination of means adaptedfor reciprocatory motion in unison with movingsuccessive'sheets, the forward stroke being in the same direction as the direction of travel of the sheets, said forward stroke including an initial accelerating fraction, means prescribing said motions in timed relation to the leading portion of each oncoming sheet, opposing surfaces on said reciprocatory means adapted to engage the forward portion of an oncoming sheet on opposite faces thereof, means yieldably urging said surfaces into engagement while moving, means for holding said surfaces apart during the accelerating fraction of said motion, means for decelerating the forward stroke of said reciprocatory means, and means for disabling said holding means at a predetermined instant in its forward stroke, said instant being when the speed of the surfaces is substantially the speed of travel of the sheet.

12. In a sheet registering mechanism of the `character described, the combination including LEONARD H. CROSS.

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