US3309078A

US3309078A - Continuous sheet feeding device having registering means

Info

Publication number: US3309078A
Application number: US379605A
Authority: US
Inventors: Nash Elmer Dale
Original assignee: Harris Intertype Corp
Current assignee: Harris Graphics Corp
Priority date: 1964-07-01
Filing date: 1964-07-01
Publication date: 1967-03-14
Anticipated expiration: 1984-03-14
Also published as: DE1561146A1; JPS495283B1; GB1103294A; DE6610272U; DE1561146C3; DE1561146B2; GB1103293A

Description

E. D. NASH 3,309,078

CONTINUOUS SHEET FEEDING DEVICE HAVING REGISTERING MEANS March 14, 1967 4 Sheets-Sheet l Filed July 1, 1964 0 w E fimnwmwmm W E0 T J 2 26; m H w M .Emzw oz 1 N 4 51 255m wnSwmEw QM E .L 18 965 M ,5 :65 E J W ATTORNEYS E. D. NASH March 14, 1967 CONTINUOUS SHEET FEEDING DEVICE HAVING REGISTERING MEANS Filed July 1, 1964 4 Sheets-Sheet 2 INVENTORv E. DALE NASH ATTORNEYS March 14-, 1967 E. D. NASH 3,309,078

CONTINUOUS SHEET FEEDING DEVICE HAVING REGISTERING MEANS Filed July 1, 1964 v 4 Sheets-Sheet 5 INVENTOR.

ATTORNEYS E. D. NASH arch 14, 1967 CONTINUOUS SHEET FEEDING DEVICE HAVING REGISTERING MEANS 4 Sheets-Sheet 4 Filed July 1, 1964 INVENTOR.

E. DALE NASH W WVfl BY zzw ATTORNEYS United States Patent Ofiice 3,309,078 Patented Mar. 14, 1967 3 309,078 CONTINUOUS snnn'r FEEDING DEVICE HAVING REGISTERING MEANS Elmer Dale Nash, Dayton, Ohio, assignor to Harris-intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed July 1, 1964, Ser. No. 379,605 Claims. (Cl. 271I2) This invention relates to sheetfeeding devices for printing presses or other sheet handling machines, particularly such devices arranged to stream feed individual sheets to a sheet-fed rotary printing press.

The present invention comprises novel combinations of elements which enable the stream feeding of sheets from a stack thereof in underlapped relation, under register of each sheet, and subsequent feeding of these registered sheets, one sheet at a time, to a high speed printing press. The features of the invention are particularly useful in providing adequate time for alignment and registry of the individual sheets such that a sheet-fed press can be operated at a continuous relatively high speed. Another advantage of the present invention is derived from the manner in which the individual sheets, although stream fed, are positively handled for registering purposes and to minimize double feeding of sheets which can lead to jamming, delays, and possible damage to the press.

Accordingly, the present invention has for its principal object the provision of a novel sheet-feeding device, in which the individual sheets are fed to an alignment or registering position with the leading edge of each sheet underlying the trailing edge of the preceding sheet, and wherein the leading edge of each sheet is positively restrained during acceleration of the receding sheet as it is pulled away from the stream into the press.

Another object of the invention is to provide such a sheet feeding device which includes a novel construction and arrangement for initiating the acceleration of each sheet from the stream at the proper time to advance the sheet into the sheet handling mechanism of the press.

A further object of the invention is to provide a novel vacuum operated sheet advancing mechanism for use with sheet feeding devices whereby individual registered sheets can be accelerated while maintaining registration into a sheet handling mechanism.

An additional object of the invention is to provide a novel stream feeding device for printing presses in which each sheet, although fed in lapped relation, is positively controlled from the time that it leaves the supply stack or pile until the sheet is under the control of the mechanism of the press.

Another object of the invention is to provide such a stream feeding device which eliminates the need for guiding elements which tend to press upon the individual moving sheets, thereby avoiding any tendency for sheets being fed, which have been printed on one side, from streaking or soiling due to contact with pressing or rubbing elements.

Another object of the invention is to provide a feeding device for accelerating individual sheets into sheet handling mechanism from a stationary registering position, wherein the registration of the sheets is maintained through a vacuum gripping device during acceleration, without relative movement between the sheet and the device, and wherein the vacuum grip is released, and friction between such device and the sheet is minimized by providing air under pressure to the vacuum gripping device as it releases control of the sheet.

A further object of the invention is to eliminate, in an under-register stream feeding arrangement, the need for auxiliary mechanism sometimes used to capture and control the leading edge of each sheet as it approaches the front register stops.

An additional object of the invention is to provide a sheet accelerating device as previously mentioned, incorporating a stationary vacuum box with a relatively Wide opening presented to the underside of sheets at the registering position, together with movable perforate belts or the like mounted to extend over the opening in the vacuum 'box forming a moving seal between the box and a substantially wide area of the sheet, together with a drive for producing an accelerating movement of the belts appropriate for accelerating the sheets once they are registered.

Another object of the invention is to provide such a sheet accelerating arrangement wherein the belts are caused to repeat their motion such that the same part of the belt always contacts a like portion of the sheet, to control any ofisetting of ink or the like, which might accidentally be deposited on the belts from a printed underside of the sheets, to Within the same printed areas of the registered sheets.

Another object of the invention is to provide a vacuum gripping and accelerating device which operates against a relatively large area of the sheets, and thus is capable of accurate control of the sheets with relatively low pressure, reducing the tendency to press the sheets against the belts and thus reducing the tendency to offset any incompletely dried ink on the undersurface of the sheets.

A further object of the invention is to provide in such an accelerating mechanism for proper tracking of the movable perforate belts such that their accelerating motion is maintained straight with respect to the feed path, thereby avoiding any tendency to shift the registered sheets sideways during acceleration, which would result in loss of side registration.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings:

FIG. 1 is a general perspective view, partly schematic, illustrating the overall arrangement of a sheet feeding device in accordance with the invention;

FIG. 2 is a diagrammatic view, partly in section and partly in side elevation, of the device shown in FIG. 1;

FIG. 3 is an enlarged detail view showing certain parts of the device at the time a leading edge of a sheet is ap- 'proaching the register stops and hooks of the device;

FIG. 4 is a detail view similar to FIG. 3, showing the leading edge of a sheet under control of the hooks, and with the sheet transport mechanism having released the leading edge of the sheet;

FIG. 5 is a view showing the manner in which the accelerating mechanism of the device operates to advance the sheet into the grippers of a printing press;

FIG. 6 is a detail view on an enlarged scale, with some parts shown schematically, and some parts shown in section, illustrating the interior construction of the sheet accelerating mechanism and associated parts;

FIG. 7 is a broken plan view of a portion of the device shown in FIG. 6, illustrating the cooperative arrangement of one perforated friction feeding belt, the vacuum-air box, and the co-operating parts for controlling motion of the belt;

FIG. 8 is a detail view of a portion of the driving mechanism for the feeding belts;

FIG. 9 is a schematic view showing the relationship of the parts illustrated in FIGS. 6 and 8;

FIG. 10 is a view similar to FIG. 6, on approximately the same scale, showing a modified form of sheet accelerating mechanism;

3 FIG. 11 is a detail view of .a drive'mechanism used with the mechanism shown in FIG. and

FIG. 12 is a timing diagram. Referring to the drawings, which illustrate preferred embodiments of the invention, and particularly with reference to FIGS. 1 and 2, a cylinder of a printing press is shown at 16, mounted to be driven in rotation by a shaft 12. This cylinder includes grippers 15 carried on a supporting shaft 16,.and as is well known, these grippers are controlled by suitable mechanism to engage the leading edge of a sheet. Beneath or between the grippers, as may be desired, there are suitable gage pins '18 against which the leading edge of a sheet is engaged just prior to clamping thereof by the grippers 15, in order to obtain accurate final register of the sheet.

The sheets are supplied to the cylinder 10 over a supporting "table 2t) which may be made up of severalsectio-ns as shown, and guide fingers 22'-are supported to extend'over a portion of the table adjacent the cylinder to assist in guiding the sheets.

numeral 25; This mechanism. may be of any suitable construction, for example the type shown in U.S. Patent No. 2,857,160, although the deviceshown is not in exactly the same configuration as shown in said patent.

Thesheets to be printed are supplied from a stack or pile 23 which is carried on a suitable support'means 30,.

incorporating the usual construction for lifting the pile as it is, depleted to maintain thetop level of the pile convenient to the separator and sheet feed initiating device, parts of which are shown schematically in FIG. 2.

Basically, this device includes one or more suckers 31 mounted to swing with a reciprocating arm 32.. These are arranged to lift a part "of the tail of the uppermost sheet on thepile, and the tube 33 is arranged to direct a stream of air underneath. thethus separate-d top sheet, after which the suckers swing forward in known manner to advance the top sheet with its leading edge moving toward .the table 20.

C-ooperating'with the table is a novel transport conveyor in the form of a pair of endless chains 35, extend-,

ing

aroundsprockets

36 and 37 which are mounted beneath the. front and rear of the table 20 suchthat the chains extend almost thefull length of the table.. The.

sprockets are continuously driven at constant speed, and in timed relation to rotation of cylinder 10, during oper: ation of the sheet feeding apparatus.

The chains contain cooperating pairs of transport grippers, details of which are shown in FIGS. 3 and .4. 'The grippers are indicated by the general reference numeral. 38, and they include a lower pad member or the like 40 formed on certain ones of the links of chains 35, to-

gether with cooperating upper gripper fingerrnembers 42 formed on the preceding links. When these links pass around the

sprockets

36 and 37,.

themembers

40 and 42 are opened as shown in FIG. 4, but when these links pass along the level flights of the chain, the; parts 40. and 42 come together as shown in-FIG. 3 to grip an edge of a sheet S, as shown in FIG. 3.

Thus, as a sheet is moved forward by the separator mechanism it is guided over the turned edge 20a. of table 20 toward the transport grippers 38 which come around the sprocket 36,-beneath this portion of the table, andv the leading edge of each sheet is pushed into the space between the

separated members

40 and 42 and is gripped,

thereby as these .parts come together and thegrippers 38 .proceed down the table 23. force is provided by tension in the chain.

The present invention is particularly directed to sheet feeding devices of the stream type, in which the sheets are fed'in what might be termed an underlapped stream. In other words, the tail or trailing edge of each sheet lies over the leading edge of each succeeding sheet, and thus successive transport grippers 38 are spaced apart on the Intermediate the table 20; there is a plate 24 which forms a part of a conventional side register mechanism indicated by the general reference 1 The gripper holding 38 maintain control of the sheets during the stream feeding thereof over the major length of the table 20,, and as these grippers pass around the sprockets 37 they open and release the leading edge of the sheet at that time.

As this release occurs, the leading edge of the sheet S is engaged by a plurality of hook-like stops 45 which are mounted to swing through slots 46 formed in the front section of the table 20. The timed swinging actionof these hookstops can be obtained by any known mechanism for lifting and lowering the stops into and out of the path of a sheet moving over the table.20.1 It should be understood also that the hook-like projections 48 may be provided on the top of only some of the stops 45, or t the actual stop members may be mounted on different arms from the arms carrying the hooks, ina manner such as shown for examplein the U.S.patent to Kist, No;

The functions required are that the stops 45 engage.

the leading edge of each sheet at. a plurality of locations after the sheet is releasedby the transportgrippers, and thus actto align or register the leading edge of the sheet transversely of the .table. like portions 48 function also to hold down the leading edge of the. sheet and prevent it from following the overlying trailing. edge of the preceding sheet as that sheet is being pulled ahead. by the press cylinder. 10. Thus,

the hooks prevent the leading edge of a sheet from cling- I ing to the trailing edge ,of the preceding sheet for any reason and assure that only a single sheet is fed at a time- Therefore, the transport grippers to the. press cylinder.

. do not release the leading edge of. a sheet until after it is under the hook projections48n With theleading edgeof the :sheet engaged by the stops 45, the side register mechanism 25 nextrfunctions to move the sheet laterally against a predetermined stop cleared the1stops 45, the. grippers 15 on-the-cylinder 10 will shortly be presented at the front edge oftable 20.- to receive the next sheet,'and at this time the stops 45.

including the. hook portions 48 are moved away from the leading edge of the sheet ,(FIG. 5) to freethe sheet. I

S for'advancing movement, it being desired to accelerate the sheet and advance its leading edge against the gage pins 18, after which the gripper-s15 will clamp the leading edge to the-cylinder.- Control of the sheet then is assumed by the cylinder 10 to drawthe sheet from the feed mechanism.

An important feature of the present invention is the device provided for thus advancing the registered sheet. It consists of a box-like member 50 extending through a suitable aperture in the table 20, between the side'register support plate 24 and thestop members. 45. The. member 50' has openings 52 which face upward, between chains 35 .and between these chains and the;side edges,

of table 20. These openings 52face toward the .underside-of each sheet as it passes along the table, and each opening is closed olf at its side edges,

The openings 52are covered-by perforated belts 55 1 which may take different forms in accordance with the invention. One suitable form shown in FIGS. 2, 6

and 7 consists of a strip of synthetic material, preferably having a relatively high coefficient of friction at its surface presented to the sheets.' This'belt has a relatively large number of perforations or holes 55', in offset orstaggered relation as shown in FIG. 7.

The belt-55 is fastened at one end 56 to a smalldrum or roller 60, and it passes from this roller to a guide'roller On the other hand, the hook- 61, these being located at opposite rear and front edges of the box member as shown in FIG. 6. The other end 62 of belt is fastened to a take-up roller 65 which is mounted generally below the main roller 60. Roller is driven from a shaft 63, and this shaft carries a drive gear 86 and a driven gear 72, the latter being in turn driven through idler 73 by a main drive gear 75. The main drive gear is mounted on a common shaft with a pinion 76, and this pinion is in mesh with a sector 78 carried on the end of a pivotally mounted arm 89. The arm is oscillated by means of a roller 82 which follows cam 83, and the cam is driven from the press cylinder 10, as indicated by the segment of the cylinder shaft 12 shown in FIG. 6.

A drive gear 86 meshes with an idler 85, and this idler in turn drives a gear 79 which, as shown in FIGS. 8 and 9, is mounted on shaft 38, but is free to rotate on this shaft. Next to the gear 7t there is a collar 9% fixed to rotate with shaft 88 by the key 91, and a lug, such as a stud, 92 extends from the side of collar 96 into a pocket 95 formed in the gear 76. The lug 92 is pressed to one end of the pocket by a spring as. This arrangement provides a form of breather mechanism which permits limited relative rotation between the collar 91 and the gear 70 to compensate for wrap overlap of belt 55 onto roller 65. The roller is in turn driven from the gear through spring 96 to collar fixed by key 91 to shaft 88.

The reason for this arrangement is that, due to space limitations in the construction shown, the speed of the belt 55 could tend to change somewhat as it builds up or overlaps on the roller 65. The construction allows the speed of the roller 65 to change due to any pull exerted from the belt 55, while still maintaining the gear drive to both rollers, as shown in FIG. 6.

It is desirable that the belt or belts 55 track properly at all times, that is, that they move in a straight line with respect to the direction of motion of the conveyor chains 35 and the direction of rotation of the cylinder 10. As shown in FIG. 1, the belts extend through suitable openings in the surface of table or apron 20. By forming a slight taper on the roller 61, it is possible to cause the belts to tend to move to slide against one edge of the opening in the table 26, and thus each assures proper tracking. If necessary, a suitable flange guide (not shown) can be added to one side of the belts for this purpose. This arrangement prevents any tendency of the belts to move partially crosswise of the table when carrying the sheets forward, thereby assuring that side register is maintained.

The interior of the box member 56 is connected through a conduit such as a flexible hose 1% (FIGS. 2 and 6) to a three-way valve 102 which is shown schematically in FIG. 2. This valve is arranged to connect the hose 100 alternatively with sources of vacuum and air under pressure, as indicated schematically in FIG. 2. Valve 102 can occupy a third position wherein both the vacuum and air sources are cut off from the hose 100. Movement of valve 100 is provided by suitable operating linkage (not shown) timed to the operation of the sheet feeding mechanism as shown by the timing diagram in FIG. 12.

This drive mechanism provides a means for causing the drive roller 66 and 65 to rotate with a motion that stops and starts, and follows a predetermined cycle of acceleration and deceleration, resulting in a similar linear motion of each belt 55. When the transport grippers 38 are carrying a sheet up to the stops 45, these stops are raised as shown in FIG. 3, the vacuum supply to the box member 5%} is cut oif, and the pressure air supply is on, as indicated in FIGS. 3 and 12. As the transport gripper 3 moves around sprocket 37, and thus releases the leading edge of the sheet S, this edge engages the stop 45 and extends under the hook portion 48. In the meantime the previous sheet is being pulled 6 away by the cylinder 18, and the hook portions 4-8 assure separation of the sheets.

At an apropriate time, the stops 45 and hooks 48 are withdrawn or lowered, and the drive mechanism shown in FIG. 1 causes the perforated belts 55 to move. The air is cut off and vacuum is supplied to conduit 100 prior to the stops being withdrawn, and thus the sheet is drawn to the belt 55 and held firmly thereto. The relatively large area of the sheet which is thus exposed to the negative pressure or vacuum, enables this device to use a lower vacuum, reducing the tendency to offset any incompletely dried ink onto the underside of the belts.

Belt 55 carries the sheet S forward on the table 20 advancing it toward the cylinder 10. By reason of the negative pressure continuously exposed to the underside of the sheet S through the holes in the belts 55, the belts have a secure grip on the sheet across a substantial area, and their linear speeds are the same. Hence, during advancing movement caused by belts 55 there is no relative movement between the belts and the sheet. This advancing movement is greater than the surface speed of cylinder 1t} and continues until a short while after the leading edge of sheet S engages the gage pins 18 and the grippers 15 close, as shown in FIG. 5.

At this time, the vacuum supply is disconnected from conduit Tilt and the pressure air is immediately connected to it, and air under pressure passes through the box member 50 and through the holes in belt 55, providing an effective air breathing between the sheet and the belt 55, and quickly releasing the sheet from the vacuum grip. Therefore, the fact that the upper surface of the belt has a desirably high coetlicient of friction does not impede the advance of the sheet once it is being pulled from the table 29 by the press cylinder, since a thin film-like flow of air exists between the belt and sheet at this time. Once the leading edge of the next sheet is carried over the belt 55, this succeeding sheet provides a buffer between the tail of the preceding sheet and the belt 55, and the air supply thus can be cut off if desired although it is possible to continue the pressure air supply until just before the transport grippers release the succeeding sheet coming to the register position.

The mechanism shown in FIGS. 10 and 11 is another form ofconstruction for the sheet accelerating mechanism. The same reference numerals have been applied to like parts, including the box member 50 and its supply hose 100. Here, the belts 105 are continuous members having perforations of the same nature as shown in FIG. 7 on the belt 55. The belt members 1% are, passed over guide rollers 107 and 168 at the front and rear of the box member 50, around a driving roller 110, and past a tension control roller 112. The roller 112 is adjustably mounted, with its ends being guided by the slot 113 in the support bracket 114, and thus the rollers can be moved vertically to adjust the tension in the belts 105.

The drive to the belts is provided by a number of cross pins 115 fastened in the driving roller 110 and cooperating with certain ones of the perforations in the belt to function in the same manner as a sprocket-chain drive. At one end of roller 110 there is a driving gear 117 which meshes with a transfer gear 118, and the transfer gear is of sufficient width, as shown in FIG. 11, to mesh also with the input gear 119. This gear is driven through a one-way clutch 120 from a shaft 122, which is comparable to the shaft 68 (FIG. 6). The shaft 122 is in turn driven by mechanism actuated by the press cylinder, such as shown in FIG. 6.

The operation of this accelerating mechanism is essentially the same as previously described, with the exception that the motion of the belts 105 may be uni-directional, or reversible, dependent upon whether clutch 120 is used. With the one-way clutch 120, reverse rotation of shaft 122 does not result in any movement of the belts 105. The pin drive, of course, assures proper tracking of the 7 belts, although'it may be desirable to include the aforementioned taper in the rollers Hi7 and Mid in addition, to avoid loss of tracking if the holes in the belt should wear slightly. I

It will be appreciated that other arrangements of these accelerating belts can be provided. For example, integral toothed portions can be formed on these belts, as in tim' ing belts, which may mesh directly with suitable drive gears, in place of the pin-type drive shown in FIG. 10. Also, if space limitations permit, the take-up roller 65 as shown in FIG. 6 can be made larger, such thatthe belt 55 never overlaps on this roller, thereby eliminating the need for the construction shown in FIGS. 8 and 9.

While the forms of apparatus herein described constitute preferred-embodiments of the invention, it is to be understood that this invention is not limited to these precise forms of apparatus and that changes may be made therein'without departing from the scope of the invention which is defined in the appended claims.

What is claimed is: I

1 Sheet handling apparatus for feeding and registering sheets in underlapped relation such thatthe leading edge of each sheet underlies the trailing portion of the preceding sheet, comprising a support for a supply stack of sheets, mechanism for operating on the sheets individually, means forming a feed path between said support and said operating mechanism, separating apparatus operativeon the stack to' move a leading edge portion of a single sheet toward said path, a sheet conveyor movable beneath said path from said support toward said operatingmechanism, grippers on said conveyor spaced apart along said path by a distance less than the maximum sheet length capacity of the operating mechanism, retractable stops mounted to extend in a raised position from beneath and across said path to intercept the leading edge of sheets carried by said grippers, hook members movable with said stopssand engageable in said raised position overthe leading edge of each sheetvupstream from the end of said, conveyor to separate it from the overlying trailing portion of the preceding sheet, advancing mechanism for carrying sheets positioned by said retractable stops to said operating mechanism, and controls operative on said retractable stops to withdraw said stops and hook members beneath said path permitting said advancing mechanism to move the freed sheet to the operating mechanism and to return said stops to normal position after the leading edge of the freed sheet has been carried past said'stops and before the leading edge of the succeeding sheet reaches the, normal raised position of said stops to assure that the leading edge of the succeeding sheet held by said grippers is engaged under said hook members whilethe trailing portion of the; preceding sheet is advanced into the operating mechanism.

2. Sheet handling apparatus comprising, means forming a supply source of sheets, mechanism for operating on the sheets individually, means defining asheet path between said supply means and said operating mechanism, a plurality of movable sheet-retaining members arranged across said path to engage the leading edge of a sheet moving toward said operating mechanism and to retain the sheet for registration, sheet conveying means operative to move sheets from said supply means to said retaining members, means operative to withdraw said sheet-retaining members from said path to permit passageof the sheettosaid operating mechanism, raccelerating mechanism operating intimed relation to said operating mechanism to move the; registered sheets to said operating mechanism while maintaining registration;

said accelerating mechanism including means defining a vacuum chamber-located beneath saidpath. adjacent and upstream of said retaining members and having an opening facing upward,tat least one'perforate belt member mounted across said opening to support the sheets, means for selectively connecting said chamber to a source of vacuum in timed relation to movement of said retaining members to cause the underside of registered sheets to be gripped by said beltimember, and means for moving said beltvmember over said chamber toward said operating mechanism with an accelerating motion while said chamber is connected to the vacuum source to carry the registered sheets to the operating mechanism while maintaining registration of the sheets. a

3. Sheet vhandling apparatus as defined in claim 1 including accelerating mechanism incorporated in said advancing mechanism and operating in timed relation to the mechanism for operating on individualsheets to accelerate each sheet from a rest condition to the speed of said operating mechanism when said hook portions are withdrawn.

4.'Sheet handling apparatus as defined in claim 1, including control means incorporated in said means for connecting saidchamber to a vacuum source and opera-t sheets in underlapping stream. fashion and said sheet-e retaining members are mounted beneath said sheetpath,

at least some of said sheet-retaining membersincluding,

hook portions operating to engage over the leading edge of a sheet and to assist in preventing theengaged sheet from clinging to the overlapping portions of the preced ing sheet, and wherein said sheet-retainingmembers are withdrawn below the sheet path after the vacuum source is connected to said chamber to assure thata sheet is registered at the time it is gripped by said belt member.

6. Sheet handling mechanism as defined in claim'4,

wherein said belt member is anendless belt, and means for guiding a portion of saidrbelt over said opening in said vacuum chamber.

7. Sheet handling mechanism as defined in claim 4,

wherein mounting means are provided for said belt member including a first drive roller on one side of said vacuum chamber and a second drive roller, opposite ends of said belt member being connected to respective ones I of said drive rollers; means guiding said belt over the opening in said vacuum chamberandfromone tovthe otherof said rollers, and wherein said means for moving said belt member is connected .to, rotate said rollers in a direction to pull said belt memben over, said vacuum- -chamber with an accelerating motion toward the operating mechanism and to move said belt member in return:

in the opposite direction after a sheet is fed to the operating mechanism.

8. Sheet handling mechanism as defined in claim 7 including means timed to apply air under pressure to said vacuum chamber to form'a layer of air between the upper surface of the belt and adjacent parts of a sheet and thus to avoid moving a sheet by the belt during its return motion and to avoid resistance to movement of a sheet with respect to the belt.

9.i Sheet handling apparatus comprising means forming a supply source of sheets, mechanism for operating on the sheets individually, means defining a sheet path between said supply means and said operating mechanism, a plurality of movable sheet-retaining members arranged across said path to engage the leading edge of a sheet moving toward said operating mechanism and to retain thesheet for registration, sheet conveying means extending from said supply means vto said retaining members and operative to convey sheets in stream fashion from said supply means to said retaining members, means operative to withdraw and sheet-retaining members from said path to permit passage of the sheet to said operating mechanism, accelerating mechanism operating in timed relation to said operating mechanism to move the registered sheets to said operating mechanism while maintaining registration, said accelerating mechanism including means defining a vacuum chamber located beneath said sheet conveying means adjacent said retaining members and having an opening facing upward, at least one perforate belt member mounted across said opening to support the sheets, means for selectively connecting said chamber to a source of vacuum in timed relation to movement of said retaining members to cause the underside of registered sheets to be gripped by said belt memher, and means for moving said belt member over said chamber toward said operating mechanism with an accelerating motion while said chamber is connected to the vacuum source to carry the registered sheets to the operating mechanism while maintaining registration of the sheets.

10. Sheet handling apparatus comprising means forming a supply source of sheets, mechanism for operating on the sheets individually, means defining a sheet path between said supply means and said operating mechanism, a plurality of sheet-retaining members arranged across said path including hook portions extending above said path and facing toward said support to engage over the leading edge of a sheet moving toward said operating mechanism and to retain the sheet for registration, an endless sheet feeding conveyor extending from said supply means to said retaining members, said conveyor having grippers operative to grip the leading edge portion of individual sheets and to release such leading edge portion under said hook portions, said grippers being spaced along said conveyor by a distance less than the minimum sheet length capacity of the apparatus to convey the sheets with the leading edge beneath a trailing portion of the preceding sheet, means operative to withdraw said sheet-retaining members below said path to release said hook portions from the sheet and to permit passage of the sheet to said operating mechanism, a perforated belt member extending below said sheet feed conveyor adjacent said retaining members to engage a substantial area of the leading edge portion of a retained sheet, means for selectively drawing air downwardly through said belt member to hold a sheet against said belt member, and means connected to advance said belt member while a sheet is held thereto toward said operating mechanism in timed relation to withdrawal of said retaining members.

References Cited by the Examiner UNITED STATES PATENTS 2,221,500 11/1940 Upham 2715O 2,466,862 4/1949 Peyrebrune et al. 27110 2,848,226 8/1958 Buttner et al. 271-12 FOREIGN PATENTS 569,729 2/ 1933 Germany. 709,606 8/ 1941 Germany. 938,209 10/ 1963 Great Britain.

References Cited by the Applicant UNITED STATES PATENTS 2,227,370 12/ 1940 Seybold. 2,642,282 6/ 1953 Backhouse. 2,756,049 7/ 1956 Stolz. 3,190,664 6/1965 Schwebel. 3,206,194 9/ 1965 Barthel.

M. HENSON WOOD, JR., Primary Examiner.

R. B. REEVES, Examiner.

A. N. KNOWLES, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,309 ,078 March 14 1967 Elmer Dale Nash It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8 line 15 for the claim reference numeral "1" read 9 Signed and sealed this 8th day of April 1969.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

Claims

9. SHEET HANDLING APPARATUS COMPRISING MEANS FORMING A SUPPLY SOURCE OF SHEETS, MECHANISM FOR OPERATING ON THE SHEETS INDIVIDUALLY, MEANS DEFINING A SHEET PATH BETWEEN SAID SUPPLY MEANS AND SAID OPERATING MECHANISM, A PLURALITY OF MOVABLE SHEET-RETAINING MEMBERS ARRANGED ACROSS SAID PATH TO ENGAGE THE LEADING EDGE OF A SHEET MOVING TOWARD SAID OPERATING MECHANISM AND TO RETAIN THE SHEET FOR REGISTRATION, SHEET CONVEYING MEANS EXTENDING FROM SAID SUPPLY MEANS TO SAID RETAINING MEMBERS AND OPERATIVE TO CONVEY SHEETS IN STREAM FASHION FROM SAID SUPPLY MEANS TO SAID RETAINING MEMBERS, MEANS OPERATIVE TO WITHDRAW AND SHEET-RETAINING MEMBERS FROM SAID PATH TO PERMIT PASSAGE OF THE SHEET TO SAID OPERATING MECHANISM, ACCELERATING MECHANISM OPERATING IN TIMED RELATION TO SAID OPERATING MECHANISM TO MOVE THE REGISTERED SHEETS TO SAID OPERATING MECHANISM WHILE MAINTAINING REGISTRATION, SAID ACCELERATION MECHANISM INCLUDING MEANS DEFINING A VACCUM CHAMBER LOCATED BENEATH SAID SHEET CONVEYING MEANS ADJACENT SAID RETAINING MEMBERS AND HAVING AN OPENING FACING UPWARD, AT LEAST ONE PERFORATE BELT MEMBER MOUNTED ACROSS SAID OPENING TO SUPPORT THE SHEETS, MEANS FOR SELECTIVELY CONNECTING SAID CHAMBER TO A SOURCE OF VACUUM IN TIMED RELATION TO MOVEMENT OF SAID RETAINING MEMBERS TO CAUSE THE UNDERSIDE OF REGISTERED SHEETS TO BE GRIPPED BY SAID BELT MEMBER, AND MEANS FOR MOVING SAID BELT MEMBER OVER SAID CHAMBER TOWARD SAID OPERATING MECHANISM WITH AN ACCELERATING MOTION WHILE SAID CHAMBER IS CONNECTED TO THE VACUUM SOURCE TO CARRY THE REGISTERED SHEETS TO THE OPERATING MECHANISM WHILE MAINTAINING REGISTRATION OF THE SHEETS.