US2668707A

US2668707A - Pneumatic sheet feeding mechanism

Info

Publication number: US2668707A
Application number: US155574A
Authority: US
Inventors: Spiess Georg
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-04-13
Filing date: 1950-04-13
Publication date: 1954-02-09
Anticipated expiration: 1971-02-09

Description

Feb. 9, 1954 G. SPIESS PNEUMATIC SHEET FEEDING MECHANISM 2 Sheets-Sheet 1 Filed April 15, 1950 'NVENTOR.

GEORG Spnsss ATTORNEYS MJWW G. SPIESS PNEUMATIC SHEET FEEDING MECHANISM Feb. 9, 1954 2 Sheets-Sheet 2 Filed April 13, 1950 hvvsm'on.

650m SPIESS.

Patented Feb. 9, 1954 UNITED STATES PATENT OFFICE PNEUMATIC SHEET FEEDING MECHANISM Georg Spiess, Leipzig, Germany Application April 13, 1950, Serial No. 155,574

7 Claims. (01. 271-47) The present invention relates to a mechanism for the feeding of sheets of paper, cardboard, .metal sheets etc. from a pile or web to printing,

:folding or other sheet operating machines whereby the sheets are fed, either singly one after the other or in. an overlapping manner, in the direction of the front register to the operating machine. At the end of this feed mechanism i. e. at the transition to the operating machine there is -:a control mechanism provided for the testing of the feed of the sheet into the operating machine. Ifthis control mechanism reacts, for instance in a case of a sheet not arriving or of any other disturbing reason, an automatic disengagement of the operating machine will result and at the same time the sheet feed mechanism will automatically be stopped entirely. The sheets, lying on the feed table, which has continually running carry- ,in'g. belts, rest therefore in the position which .they. occupy. At. such an event, the so-called ,stopper the sheet lying at the front register stone, which caused the stoppage is removed and Jafterwards the sheet feed mechanism is actuated ,;again. Jolts will occur at such reactuating of the sheet feed mechanism especially in fast running feeding machines and the sheet carrying belts .will slip on their rollers.

Accordingly the sheets lyingon the carrying belts will shift and another stopper may be expected immediately. That is the reason why it is preferred in case of a stopper to remove from the feeding belt all sheets lying on it. This causes not only a longer loss of time and a considerable impairment of production capacity but also mostly results'in the disadvantage that the sheets get dirty or damaged and .become useless.

This is especially disadvantageous in colour-printing work.

Separate devices with special handles to operate them are arranged on these mechanisms for putting the belt driving roller into operation again and for turning on the air current for the nozzles. In starting again, first of all the handle for the control of the air current to the nozzles has to be operated. Next the belt driving roller is actuated by another handle. This latter operation has to be made at an exactly determined moment, and this calls for very special attention machines which eliminates thedisadvantages described above.

According to the present invention the sheet feed mechanism islikewise constructed in such a way that only the belt driving roller is stopped and the air current for the nozzles is cut off when-a stopper has occurred, but the operator has to manipulate one handle only for putting the-sheet feed into operation again and does not have to watch any other movements, and in consequence to the hereby influenced means the feed of the sheets is made exactly registered to the front register stops of the operating machine aswell as the taking oil the next sheet of the pile by the nozzles.

, According to the present invention this will be attained in such a way that all the means of the mechanism for the automatic stopping of the sheet carrying are positively connected to a shaft on which is a handle (cranked handle, handwheel or such like) the operating of which controls the air current for the nozzles as wellas puts the belt driving roller of the sheet feedinto operation again. Thereby the means, provided for the control of the air current to the nozzles and for putting the belt driving roller into operation again, come into force automatically at a determined time during the working rhythm of the mechanism for the exact registering of the feed of the sheets to the front register stops of the operating machine. 7

The sheets-lying on the feed table are suitably held in position by special holding devices during the stopping of the sheet feed so that the sheets cannot bedisplaced when the sheet is taken off which caused the disturbance. There are also holding devices provided above the pile which press on the pile during the time in which the nozzles are working without air so that the top sheets of the pile cannot be displaced by the lost motion of the nozzles. I

In the accompanying drawings the object of the invention is shown. in one example of design, and

it shows:

Fig. l the sheet feed mechanism in a side view.

Fig. 2 a view in direction of the arrow A' of Fig.1. V

Fig. 3 the clutch coupling for connecting and disconnecting of the sheet carrying in connected position.

Fig. 4 the device for making the nozzles to take the sheets oiT the pile exactly in register, the said device being in the position it occupiesv after the sheet carrying has been put into operation again.

Fig. 5 the same device but in turned off position.

carrier nozzles 3. The sheets are then by means I of the said carrier nozzles 3 forwarded to the driven belt roller 4 Which acts in' connection'with i timing rollers. The sheets come from here either in an overlapping manner (as it is shown in Fig.

1) or singly one after the other to the front reg,- ister stops 1 of a sheet operating machine 8 for instance a printing machine, by way of a feed,

consisting of continuously moving conveyor belts 5, and passing a feed table 6-. The speed of the conveyor belts is such as to guarantee that on each occasion when grippers on the pressure cylinder of the printing machine pass the front register stop I of the stacking table l3, a sheet, and only one sheet, is ready to be picked up. A control mechanism 9 is arranged near the front register stops 1, and serves the purpose of testing and controlling the feeding of the sheets to the operating machine. The control mechanism 9 is provided with feeler fingers suspended so that they can swing. In the drawing, Fig. 1, they are represented in the highest position. At approximately the same time as the front sheet l4 reaches the front register stop i, the fingers sink against the table. Normally they contact one sheet. If when swinging downwards, the fingers should, however, fail to contact a sheet at the front register stop I, or if the sheet at the stop 1 should have a piece torn out of it, the feeler fingers come into contact with the table. At the spot where the fingers 9 touch'the table or an extension thereof, there is an insulated contact plate which is in circuit with one branch of a lead forming a circuit through electro-magnet Hi. The other branch of this lead is attached to the finger or fingers 9. If, therefore, one of the feelers 9 comes into contact with the plate when the latter is not covered by a sheet, the circuit will be closed, with corresponding excitation of the electro-magnet IS. The control mechanism 9 will react in case of any irregularity. The effect of this reaction is:

The operating machine 8 will automatically be stopped, so will the sheet carrying devices 4, 5 and at the same time the air current to the nozzles 2, 3 will be cut off. The sheets I 9 to [4 stay in the position they occupy and are pressed by the conveyor rollers l5 which work in connection with the conveyor belts 5, and the nozzles 2, 3' continue their working rhythm without air current I and cannot take any sheets oif the pile I.

Electro-magnet I6 is arranged underneath the sheet feed. The said electro-magnet' It has a f tappet l1 which works against areleasable catch 18 locking a tie rod l9 when sheet feed is regular. The catch i3 is fitted in a bearing at one end at I00 so that it will turn. On its underside at I0! there is a point provided. Against this point IOI abuts a nose I92 fitted on one side. Due to the contact between the nose I92 and the point l9l on the catch l8, the bar I9 is prevented from yielding to the pull of the spring 29. ;If the electro-magnet I6 is excited by the effect of the sheet detector, the tappet H (core of the 4 electro-magnet) moves upwards (shown in Fig. 2). When making this movement, it takes the releasable catch [8 with it, against the end of which lies the free end of the tappet l1, thus drawing the projection IOI on the releasable catch l8 away from the nose on the tie-rod l9. As soon as the projection IOI is separated from the nose I92, the spring 29 comes into action moving the rod, l9 to the right in the direction of the arrow cc in Fig; 2. When thecontrol mechanism 9 reacts the tappet I! will be pressed against the catch l8 and the tie rod [9 will thereby become released. To the tie rod 19 on the one side is connected a cranked connecting rod 2| which acts on a lever 22, the said rod 22-being spring pressed. Part 22 consists of a tube housing a; spiral spring. Both ends of this spring are supported by bolts passing through longitudinal slits in the tube. One of the bolts is connected to one arm of a crank lever 2| and the other bolt with one arm of the crank lever 23. The spring tension is so great that in most cases the movement of crank lever 2i is directly transmitted through the spring to the crank lever 23. If when lever 2| moves there is some hindrance-to the movement of lever 23 (e. g. because thetwo halves of the clutch coupling 24 cannot. immediately be brought into contact), a movement' of lever 2| will first of all cause the spring in the tube to be compressed. The crank lever- 2! can be displaced in the sense that lever 23 does not participate in the movement of lever 2 I. 1 As soon as the obstruction against the freemovement is removed, i. e. when both halves of the coupling 24, for instance,.have come'together in a' manner enablin them to engage correctly, the tension in the spring takes effect and causes a subsequent movement of the lever 23. O-n'the rod 22 is arranged a cranked lever 23 the short arm of which engages a two part clutch coupling 24. The clutch coupling 24 is mounted on a shaft'29 in such a way that the shiftablehalf rotates with the shaft and the other half is freely rotatably mounted on the shaft 29. A spur gear 30 isarranged on the movably connected half 'of the clutch'coupling 24, the said spurgear 39 engaging a spur gear 3| and driving the shaft 34 by means or the spur gears 32, 33. The driving roller 4 is rigidly connected to the shaft 34 and drives the-" conveyor belts 5 of the sheet feed. To the tie rod I9 on the other side is connected a lever'25 rigidly fastened to a shaft 25 which has a worm'gejr 21 which engages a worm gear 28. The worm gear 28 is rigidly connected with a shaft -36 on which a revolving piston is arranged inside of an air valve box 31. Figures 6-8 showthat the revolving piston is formed like a plug; i-. e. 1the piston consists of a cylinder with borings for'registering with each of the

leads

38 and 39,. The revolvin piston can be so set that. the borings come into register with the leads 3,8-and 39. so that air can pass through unhinderedfIf it is turned through theflow of air is stopped in the well-known manner.

The boring in the piston which 'registerswith lead 39 has a branch lead running'i-nto it perpendicularly, thus forming athree-way valve-at this point in the well-known manner. By-designing the piston in this way, it. is possiblewhen lead 39 is cut off-to connect the leads 4:18. and 49 to the suction pump. The revolving pistonc'ontrols in a known way the valves for the compressed-air tube 38, which directs air horizontally against the topmost sheet of thepile Fthrbiigh p i -meansof'the lever system 2|, 22, 23. In this anozzle (not shown) and'for the suction-air tube 39. I Y

"The lever 25 is firmly attached to the shaft 26, to which is firmly keyed the diagonally cut gear 21. A movement of the tie rod |9 causes the shaft 26 to be turned through the lever 25, thus also the worm gear 21, in mesh with worm wheel 28, which also turns. Vice versa, a movement of the hand crank 4|] will again cause the cog wheel 28 to'operate the gear 21, turning the shaft 26, so that the arm 25 fixed to the shaft 26 will displace the tie rod |9.

In case the tie rod I9 is automatically released by the control mechanism 9 then the clutch cou- 24 will become positively disengaged by way'the spur gear'39 will be stopped and so will the belt driving'roller 4. At thesame time the

worm gear pair

21, 28 will be positively actuated by the lever 25. Thereby'the revolving piston will control the valves of the pressure'and suction-

air tubes

38, 39 so that the pressure air nozzle and the nozzles 2, 3 do'not get any air.

Accordingly the sheets III to H, are stopped by stoppage of' the conveyor belts and the nozzles 2,3 cannot take any more sheets off the pile I.

If the sheet |4 having caused the stopper is now removed and the disturbance cleared away then the mechanism can be started again without further consideration and for this there is only one movement necessary according to the present invention. For this purpose a handle 40 is provided (the said handle being a cranked handle, a hand-wheel or such like) fixed on the shaft 36 'with which all the means of the mechanism for stopping 'the sheet carrying are positively connected. By turning the said handle 48 in a counterclockwise direction (Fig. 1) which turning however is possible only at a certain moment (what will be described later on) the revolving piston will be rotated to normal position and in this way'the pressure and suction-air currents of the air .

tubes

38, 39 will be turned on so that the nozzles 2, 3 are fed with air again. Moreover the lever 25 by means of the worm gears 21, 28 and thereby the tie rod' |9 will be moved back so that by means of the lever system 2|, 22', 23 the clutch coupling 24 becomes engaged again and bymeans of gear 39--34 the belt driving roller 4 is set in a turning motion. The clutch coupling 24 is constructed as a one tooth clutch coupling and the lever 22 is equipped with a spring. For

,the engagement of the tooth of the clutch cou- -,.pling, which said tooth is on the shiftable half of ;the clutch coupling, there is'provided a recess "on the other half of the clutch coupling which iscontinuously turning with the shaft 29. This recess is synchronized to the rhythm of the mechanism for an exactly registered feed. After the sheet feed has been put into operation again by "means of the cranked handle 48 the spring of the lever 22 presses against the lever 23 until the short arm of the said lever 23 has securely engaged the tooth of the clutch coupling with the recess. is made at the right moment. At the back'movement of the tie rod l9 the catch l8 has been engaged again with the bolt of the shaft.

In order also to guarantee that the nozzles 2,3 take the next sheet off the pile I in right time and in such a way that the distance from the preceding sheet In is accurate or approximately accurate, an eccentric 4| is provided on the shaft 29 against which a roll 42 rolls up. The roll 42 .118 arranged'on a=doub1e arm swinging lever 43.

This friction guarantees that the start a gliding surface of the segment 45. The segment 45 can be turned again only when the arm 44 has left this gliding surface (see: position in Fig. 5 broken lines) and this is determined-by the rotation of the eccentric 4|. The eccentric 4| has an eccentric boss corresponding with such a position of the working rhythm of the nozzles 2, 3- determined by the shaft 29, in which'the nozzles 2 set down on the pile in order to take off the next sheet. The operator has only to press the cranked handle 40 without having-to pay heed to any movements in order to put the sheet carrying into operation again. The segment 45 prevents a turning of the cranked handle 40 if the right position respectively the'correct moment for starting the mechanism again the belt driving roller, and will effect turning" of the shaft 36 and in turn the control of the air current for the nozzles 2, 3.

It is also desirable to hold the sheets lying on the feeder securely as it has been suggested above. According to the present invention special holding devices 46, 41 can be provided for this purpose on the mechanism either underneath the feed way (as shown in Fig. 1) or above it. The holding devices 46, 41 are for instance devised as air controlled pistons'arranged in an airtight box and being spring-pressed the said pistons acting from underneath against the back of the sheets l2, l3 i. e. sucking the sheets from underneath. For this

purpose air tubes

48, 49 are provided connected with the piston box and leading to the air valve box 31. If the sheet feed is stopped and the pressureand suction-air currents are turned off in the manner described above then according to the present invention the suction tube 39 will be simultaneously connected with the

tubes

48, 49 and thereby the pistons 46, 41 will be moved against the back of the sheets |2, |3. Upon placing the sheet feeder into operation again, the air current will be directed back to the nozzles 2, "3 thereby the air tubes 46, 49 will be turned off again from the air tube 39 and the pistons 46, 41 will release the sheets |2, |3.

According to the present invention there ar furthermore provided holding devices above the pile I. These sheet holding devices are for instance devised as spring-pressed valve pistons 58 which can be connected with the suction tube 39. For this purpose an air tube 5| leading to the air valve box 31 is connected with the cas- When the pressure and suction-air currents have been turned off the suction-air tube 39 will simultaneously be connected with the tube 5| and thereby directed .to the. valve piston 50 or to some mor'ev'alve pistons sothat it moves against the pile ii and presses on .it. By starting the :sheet'xfeed again the'airi current will be .directed back again to the nozzles 2, 3 the airtube 5 vtherefore is again turned off the .suction-air'tube 3-9 and the valve piston :50 is raised from the'pile under the infiuence of its spring.

If the operator wants to stop the sheet carry- .ing for some other-reason there .is yet another, mechanical stopping device :provided .fors'uch cases which acts on the catch I58, consisting for instance of the lever rods 52., 53, 54 the angle lever T53 "of which is with the catch 1 -8 supported by a support 55 arranged on the wall :of the mechanism. The lever 54 is provided with a handle, the catch 18 will be pressed upwards when the said lever handle is pulled, and the tie rod 19 will thereby become released. In :order to put the mechanism into operation again the cranked handle 40 will also be operated in such a case.

'Thepresent invention provides finallya stop- :ping device for such cases when on-ly'the sheets to M lying on the feed table shall be fed -'to the operating machine 8 for instance to finish off the edition. In connection with the tubes :38, 39 for the pressure and suction-air currents there is for this purpose a casing 56 provided with a spring-pressed auxiliary piston 51.. This :said piston 51 is shiftably supported and will be operated by hand By pressing against the piston 51 it will be moved and will close the suction-air current for the nozzles *2, 3. The

piston 57 has to be pressed until the last sheet has been fed to the operating machine. Having done this the "mechanism will be stopped altogether entirely.

What I claim as my invention and desire to secure by Letters Patent of the United States 1. A sheet feeder comprising an endless conveyor for transporting sheets to a machine to be fed, means provided with suction grips for lifting and transferring a top sheet from a pile to the conveyor, a main driving shaft, means for driving the conveyor from the driving shaft including a clutch, a conduit connected :with said suction grips, a valve in said conduit, an actuator for engaging and disengaging said clutch, an actuator for said valve, means interconnecting the clutch and valve actuators, spring means urging the clutch to disengaged position and the valve to closed position, a locking device for retaining the clutch engaged and the valve open against the action of said spring, a sheet detector positioned at the end of said conveyor, means controlled by the sheet detector and operable for releasing the locking device, and a single manually operated control element connected to said actuators for engaging the clutch and open-:

ing said valve and resetting the locking device.

2. A sheet feeder comprising an endless conveyor for transporting sheets to a machine to be fed, means provided with suction grips for lift- 'ingand transferring a top sheet from a pile'to-t the conveyor, a main driving shaft, means for driving the conveyor from the driving shaft including a clutch, a conduit connected with said suction grips, a valve in said conduit, an actuator for engaging and disengaging said clutch,

an actuator for said valve, means interconnecting the clutch and valve actuators, springmeans urging the clutch to disengaged position and the valve to closed position, a locking device for .retaining theclutch engaged and the :valve open against the action of sa-id sprin zazsheetzdetece tor positioned at the end of said conveyor; means controlled .by the sheet detector and operable for releasing the locking device, a single mants ual'ly operated :control element connected to said actuators for. engaging the clutch and opening said valve and resetting the locking device, and means locking the manually operated control elementduring a given period of revolution of the 110 main driving shaft, and .a yieldable member in the means interconnectmgthe clutch and valve actuators.

3. A :sheet feeder comprising an endless conveyorfor. transporting sheets to a machine to be .15 fed,':m'eans provided with suction grips for lifting and transferring a top sheet .from a pile to the SCOIIVBYOI'J'E main driving shaft, means for driving the 'conveyor'from the drivingtshaft including a clutch, a conduit connected with said suction :20 igrips, a valve in said conduit, an actuator for engaging and disengaging said clutch, an 184C111!- zator for. said valve, means interconnecting. the clutch :andvalve actuators, spring means urging the clutch to disengaged position and the valve to closed -position,.a locking device for retaining the clutch engaged and the valve open against the :action 'of said spring,a conveyor table about which the conveyor extends, on. and off feeler fingers carried by the table, movablecontac't .30 plates fitted .in the table opposite the .feeler fingers, an electromagnet, arcircuit for energizing said magnet including said fingers, .plates and electromagnet means actuated by said magnet for releasing the locking device, and :a single manually operated control element connected tosaid actuators for engaging the clutch and opening said valve and resetting the locking device.

I 4. A sheet feeder comprising an endless con-- veyor for transporting sheets to a machine to he -40 fed, means provided with suction grips for lifting and'transferring a top sheet from a pile -to the conveyor, a maindriving shaft, means for driving the conveyor from the driving. shaft including a clutch, a conduit connected withLsaid.suction grips, a valve in said conduit; an actuator fo'r engaging and disengaging said .clutch,-.-an'actu- .ator for said valve, means interconnecting' th'e clutch and'valve actuators-spring means urging the clutchto disengaged position "an'd'the valve to closed position, a locking device for retaining the clutch engaged and the :valve open against the action of said spring, a sheet'detector positioned at the end :of saidconveyor, means controlled by the sheet detector and J operable for releasing-the locking device, and a single manurally operated control element connected to said actuators for engaging the :clutch and'opening said valve and resetting the locking device, a shaft carrying said manually actuated element, a segment on said last mentioned shaft, a lever having aportion movable into the path of travel of said segment for blocking. movement thereof, an ce- "centriczrotated in synchronism with the main- "shaft and'cooperating with said lever to peace, ically shift saidlever into and out ofthe path of -movement of said segment. L i 59A sheet feeder comprising an endless conveyor for transporting sheets to a'machine t'obe fed, means provided with suction grips for lifting and transferring a top-sheet from a pile-to the conveyor, a main driving shaft, means for driving the conveyor from the driving shaft including a clutch, a conduit connected-with said suction grips, a valve in said conduit, an actuator for engaging. and disengaging said unman actuator for said valve, means interconnecting the clutch and valve actuators, spring means urging the clutch to disengaged position and the valve to closed position, a locking device for retaining the clutch engaged and the valve open against the action of said spring, a sheet detector positioned at the end of said conveyor, means controlled by the sheet detector and operable for releasing the locking device, a single manually operated control element connected to said actuators for engaging the clutch and opening said valve and resetting the locking device, suction means for holding the sheets on the conveyor during stoppage of the latter, and means cooperating with said valve for energizing said last mentioned suction means upon stoppage.

6. A sheet feeder comprising an endless con veyor for transporting sheets to a machine to be fed, means provided with suction grips for lifting and transferring a top sheet from a pile to the conveyor, a main driving shaft, means for driving the conveyor from the driving shaft including a clutch, a conduit connected with said suction grips, a valve in said conduit, an actuator for engaging and disengaging said clutch, an actuator for said valve, means interconnecting the clutch and valve actuators, spring means urging the clutch to disengaged position and the valve to closed position, a locking device for retaining the clutch engaged and the valve open against the action of said spring, a sheet detector positioned at the end of said conveyor, means controlled by the sheet detector and operable for releasing the locking device, a single manually operated control element connected to said actuators for engaging the clutch and opening said valve and resetting the locking device, suction actuated means for pressing on the top of the pile of sheets, and means for energizing said last mentioned means upon release of said locking means.

7. A sheet feeder comprising an endless conveyor for transporting sheets to a machine to be fed, means provided with suction grips for lifting and transferring a top sheet from a pile to the conveyor, a main driving shaft, means for driving the conveyor from the driving shaft including a clutch, a conduit connected with said suction grips, a valve in said conduit, an actuator for engaging and disengaging said clutch, an actuator for said valve, means interconnecting the clutch and valve actuators, spring means urging the clutch to disengaged position and the valve to closed osition, a locking device for retaining the clutch engaged and the valve open against the action of said spring, a sheet detector positioned at the end of said conveyor, means controlled by the sheet detector and operable for releasing the locking device, a single manually operated control element connected to said actuators for engaging the clutch and opening said valve and resetting the locking device, and a manually actuated valve for controlling operation of the suction means.

GEORG SPIESS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,652,172 King Dec. 13, 1927 1,741,848 Kelly Dec. 31, 1929 1,956,647 McCoy May 1, 1934