US3046875A

US3046875A - Presses working sheet material

Info

Publication number: US3046875A
Application number: US839229A
Authority: US
Inventors: Bobst Henri
Original assignee: Bobst And Son S A
Current assignee: Bobst And Son S A
Priority date: 1958-09-19
Filing date: 1959-09-10
Publication date: 1962-07-31
Anticipated expiration: 1979-07-31

Description

July 31, 1962 H. BoBsT 3,046,875

PREssEs WORKING SHEET MATERIAL Filed Sept. lO, 1959 2 Sheets-Sheet 1 5b w y@ l E t .l

Y &\\\\\\ \\m\\\\\ 21:0 zslse 2:8 2400 'A 1 l lao 24o 50o :zo o' 3o so |20 July 31, 1962 H. BoBsT 3,046,875

PREssEs WORKING SHEET MATERIAL Filed sept. 1o, 1959 2 sheets-sheet 2 United States ifatent Claims priority, application Switzerland Sept. 19, 1958 7 Claims. (Cl. 1013) The present invention relates to presses for 'working material such as, for instance, paper and cardboard sheets, and more particularly to presses for submitting said sheets to embossing operations.

Such Ypresses generally allow embossing from the very moment they are capable of providing the high pressures lrequired by this kind of work. However, the exerted pressure is not the sole factor which is important when quality embossing is desired, the time for which the pressure is applied playing a large part in determining quality. For this reason, the working rate should, for example, be lowered when passing from cutting operations which are fast to embossing operations. In a press cutting, for instance, 4000 sheets per hour, it is not uncommon to be compelled to slow down the speed to 600 cycles/ hour for embossing.

In order to increase production, a press according to the invention comprises at least two possible working rates, the speed of one of them is a fraction of the other, and means are provided making it possible to change automatically from one to the other in the course of each working cycle, so that the slowest rate is employed during at least part of the active period of each cycle and the fastest rate at other times.

During the active period of each cycle is effected the setting under pressure of the tools, the conveyingnof sheets from registering and take-in stations to processing and waste or deposit stations.

'I'he attached drawing shows an embodiment of the 4invention given by way of example. In the drawing:

FIG. 1 is a longitudinalcross-section of a press of the type under consideration, showing the main elements necessary for a better understanding of the invention.

FIG. 2 is a longitudinal cross-section of the driving members making it possible to transmit to said press the contemplated running rates.

FIG. 3 is a diagram explaining the running of the press when ettecting embossing.

FIG. 4, finally, is a schematic electrical diagram of the control means for the press to govern the driving members of FIG. 2.

The press represented in FIG. 1 comprises a pair of frames, one of which is seen at 1, these frames supporting an upper xed plate 2 and a support 3 for the driving mechanism of a movable lower plate 4.

Plate 4 goes up and down successively once during each Working cycle of the press, and is driven by toggle levers 5, operated by connecting rods 6 which are coupled to main shaft 7 by eccentrics. A motor (not shown) drives a ywheel 3, and shaft 9 and worm 10. Worm 10 meshes with a cogwheel 11 keyed on the main shaft 7 to drive the latter. On either side of the press is an endless chain 12, these chains being connected by conveying gripping bars 13 and impelled by an intermittent translatory motion.

` To a small plate 14 are fed the paper or cardboard sheets to be worked. These sheets are registered by lknown means (not shown) and are seized by the gripping bar 4located immediately under the chain wheels 15, then conveyed one by one between the plates 2 and 4. Then, under the action of the toggledevers, the plates, bearing appropriate tools and `counter-tools, are applied one lagainst the lother and perform the desired cutting or emire 2. bossing operation, or perhaps these two operations at one and the same time.

Said operations are repeated each operating cycle, corresponding to one revolution of the main shaft 7.

In the press described above, the running speed is uniform and will be, for instance, 4000 cycles/hour for rule cutting which should be reduced to 600 cycles/hour 'for embossing operations. These speeds can be obtained, for instance, by means of an appropriate speed changing device by varying the motor speed.

As already stated above, there results from the applicationof these two working speeds a very low output which may be, for instance, nearly seven times inferior to the possible maximum output of the press.

Now, the reduced speed required by they embossing operations serves `only to increase the duration ofV setting the plates under pressure and it is not necessary to reduce in the same ratio the conveying speed of the sheets. Y

In the case of the press described, the setting under pressure of the plates is substantially achieved in 60 of rotation of the main shaft 7, and hence during `one sixth of each cycle, of which five sixths are otherwise employed. Therefore, the ideal would be to make it possible for the main shaft to perform during each cycle a rotation of 300 at 4000 r.p.h., followed by `a rotation of 60 at 600 r.ph. Thus, the maximum theoretical output of the press would be obtained which would amount to a production of 3433 worked sheets an hour.

However, it is mechanically ditncult to realize this ideal case because of the stresses involved and of the masses in motion. K

Nevertheless, it is possible to try to come close to it, for instance according to the example which will follow, where the press is arranged so as to be in a position, in the course `of each cycle, to work at two successively different rates, one of which is four times faster than the other, it being understood that other'ratios comprised between three and seven still present some sufciently practical interest.

T he slowest rate in the following will be at `60() operations per hour, as indicated above in the given 4case of embossing, -the fastest will be at 2400 cyclesper hour and the obtained working average will be ysubstantially 1800 cycles per hour, corresponding to'an output of nearly half of the possible maximum output of 4G00 cycles/hour. i A

To come to this result, a speed changing mechanism with two translation ratios such as shown in cross-section in FIG. 2 will be placed yon the shaft 9 between the iiywheel 2 and the worm 10. g

The flywheel 8, turning idle on the shaft 9 is integral with a toothed wheel 16 and a disk 17 of a magnetic coupling, whose other disk 16 is keyed on the shaft 9.

The toothed wheel 16 meshes with wheel 19 xe'd to wheel A20 engaging wheel 21 located on the shaft 9 and turning idle on this latter. 'I'he number of teeth of the cogwheels are such that there be between the wheel 16 integral with the ywheel 8 and the wheel 21, a step down ratio of vfour to one.

Finally, the toothed wheel 21 is tixed to disk 22 of a magnetic coupling, the other disk 23 of which is keyed to the lshaft 9.

Elements

24 and 25 lschematically represent the excitation coil operating on the magnetic coupling elements 17-18 and 22-23 with a View of setting them into action.

It is evident that a coupling of elements 17-18 will join ywheel 8 directly as with the shaft 9'and to impart *the speed of the iiywheel to this shaft. A coupling of elements 22--23` joins Vthetlywheel -8 to the shaft 9 through the gears 16-'19-20-2L and will cause the shaft'speed them.

`300" of rotation and the coupling 22-23 during the remaining 60.

Practically, this is rimpossible due to the shocks toV which 'the'.descri'bed* mechanism would be submitted by passing so suddenly from one speed rate to the other.

The diagram of the FIG. 3 shows a practical working kexample of the presses of FIG. 1 equipped with the gear- 'changing system of FIG. 2.

The abscissas correspond to a press working cycle, i.e.

Y to a rotation of 360 of the main shaft 7, or of any other Vshaft performing Ya one turn working cycle. The ordilnates correspond to the speed of the shaft.

. The centre abscissas is zero, which is supposed to occupy theV middle of the period of setting under pressure of the plates which`v period extends therefore from 330 to 30, with a corresponding working speed of 600 cycles/ hour. The corresponding part of the diagram is hatched. .The coupling 17--1'8 being assumed to have been actuated and the shaft 7 turning normally at 2400 r.p.h. is the case at the 180 indication, which is the beginning of the curve shown.

' At 210, Ithe coupling 17-18 is disengaged, the press position of a

member

33 or 34. These commutators opering circuit of coil 25 by

elements

36, 37 and 38 is opened.

It has 'been seen that the coil k25 operates the coupling 22-23, on which depends the slowV running Vrate of 600 r.p.h., given by way of example. Y

The shaft continues to turn, and the cam Y27 thus ultimately causes the switch 29 to open after having'covered an angle of 67. .This is the point C of the curve of FIG.

3, i.e. of declutching of the slow running rate. The openr- Y ing ofthe switch 29 causes the armature 34 to fall and to open the circuit of the coil 2S.

The cam 26 turns jointly with the cam 27 and after having covered an angle of 92 4from the illustrated starting position, it will cause the switch 2S to be closed, while -29 is still open. Y Y The excitation of the coil 31 resulting therefrom causes the armature 33 to be raised. The lower bar of armature 33 breaks a

circuit including elements

39, 40, 34, 41, 24 and 42. The coil 24, -being excited, sets the coupling 17-18 into action, i.e. the fast running rate of the press Y corresponding to point D of the curve of FIG. 3.

:182 of rotation of vthe cam 26, thefast running willbe 'continuing however to work by virtue of the acquired inertia. However, the ywheel 8 no longer ntervenes, for it now turns freely on the shaft 9, at the uniform speed which is imparted to it by the motor. This occurs at point A of the curve.

The speed of the elements in motion decreases, but before it drops to 600 r.p.h., at point B corresponding yto 296, the disks 22-23 are engaged. This operation corresponds -to setting the press at Vthe rate of 600 cycles/ hour. VThe coupling will rst exert a slight braking on Y the system, Ibut lshortly before the time position corresponding to 330, the desired rate of 600 r.p.h. will have been achieved. By applying motive power, it will be maintained up to point C, loca-ted at 3 beyond zero or the upper dead position of the movable plate. At this point, the coupling 2'2-23 is disengaged and. the press is again left to itself. This will maintain the acquired reduced speed sincethe dead point being overrun, the pressure `operating on the lower plate and Iwhich will Ibe for instance of -several hundred tons, will tend to protract the motion of the toggle levers and members which drive F Shortly beforev the end of the setting under pressure, at

point'D located at 28, the coupling 17-18 is set again into action; that is to say the press will be driven at 2400 cycles/hour.y V'In this case al-so, .there will be Ia slight sliding between

elements

17 and 18 with, however, a rapid acceleration up to about 80, where the high rate will be restored and maintained up to point A, or 210. The operations already described then start again andrrepeat as long as desired.Y

-It is evident that the clutching and declutching angles of the two couplings such as indicated above-are not limitative, other angles being likely to provide excellent results. f Y

The diagram of FIG. 4 gives an example of coupling control for the main shaft 7 and an arrow indicates its position which connectsit to the conductor 45, there re- The closing period Vof the switch 28, extending over maintained until it reaches that point corresponding to A on the curve of FIG. 3. Y

At that moment, the fast speed driving, i.e. 2400 r.p.h., is interrupted and the two switches 2S and 29 remain open during still 86 until they reachv the illustrated starting position, i.e. the re-clutching of the slow running rate.-

Therefore, the passage at the desired moment, 'om

one running rate to the other and inversely, takes placeautomatically in the course of each working cycle of the press in relation with the rotation of its main shaft 7.

However, this is possible only in the represented position of FIG. 4 of thecommutator 43, allowing the feeding of the switches 28 and 29.V

IIn its two other positions, it disconnects theseswitchesV and sets the described contrivance'out of gear.

' In its median position, it is seen that the coil V31 is excited through the conductor 44, thus raising its armature so as to makeV the commutator 33 occupy the feeding position of the fast running coupling coil 24. This feeding is possible owing to the Afact that the commutator 34 occupies at that moment its resting position inverse Y to that represented in the drawing. The press is therefore in a state of fast running.

If now the commutator 43 is brought into its third suits the setting under voltage of the coil 46 via line 47, the armature 48 breaking the feeding circuit of the coil 49 operating a brake (not shown).

The press equipped with the change-gear of FIG. 2 gov- Y erned by a circuit such as that of FIG. 4 will be able to work selectively as a normal press or as a Special pressk at two successive running rates or may be immobilized in any desired position, thisl by the simple control of the switch 43. Y

What is claimed is: j f

l. Apparatus comprising a sheet embossing press i11- Ycluding at least one reciprocable member, a conveyor system for conveying sheets to saidV press, and means for driving said system and press at different speeds; said Vmeans comprising a shaft coupled to said member and system to drive the same, and a control for said shaft comprising means operatively coupled to said shaft to rotate the same at one speed before said reciprocating member is brought to its range of operative positions and 5 at the other speed before the reciprocating member leaves the range of operative positions.

2. In combination with a sheet embossing press includ- Iing at least one reciprocable member and a conveyor system yfor conveying sheets to said press, means for driving said system and press at diierent speeds and comprising a shaft, said reciprocable member having a range of 'operative positions corresponding to a determinable angle of rotational movement of said shaft, -a flywheel freely rotatable on said shaft, means to drive said flywheel, clutch discs concentric with and .freely rotatable on said shaft, one of said discs being Xed to said flywheel and the other being separate therefrom, two further clutch discs concentric with and keyed to said shaft, said frnther Adiscs being operatively disposed with respect to and adapted for respectively engaging the iirst said discs in pairs, control means operatively associated with said discs to control engagement of the same, and a gear train coupling said other of the first said discs to said flywheel whereby the speed of said shaft is controllable in accordance with the selective engagement of said vfurther discs by the first said discs; said control means being operatively "coupled to said shaft to engage one of the pairs of `discs at a time, said control means engagingthe pair of discs associated with the gear train before said reciprocating member is brought to its range `of operative positions and the other pair of discs jbeing actuated before the reciprocating member leaves the range of operative positions.

3. A device comprising a sheet embossing apparatus including at least one reciprocable member, a conveyor system lfor conveying sheets to said press, and means for driving said system and lapparatus at different speeds whereby embossing and conveying Voperations are etliciently effected; said means comprising a shaft coupled to said member and system, a ilywheel freely rotatable on said shaft, means to Ydrive said ywheel, magnetic discs concentric with and freely rotatable on said shaft, one of said discs being fixed to said flywheel and the other being separate therefrom, two further magnetic discs concentric with and keyed to said shaft, said further discs being operatively Vdisposed with respect to and adapted for respectively engaging the first said discs, inductance coils adjacent said discs to control a magnetic engagement of the same, a gear train coupling said other of the first `said discs to Said iywheel whereby the speed of said shaft is controllable in accordance with the selective cngagement of said further discs by the first said discs, and a control for said coils; said control comprising a power source, iirst and second relays each including -a relay coil, an armature and rst and second sets of contacts, the first sets of contacts being connected in electrical series between said power source and one of the rst said coils, the second sets of contacts being connected in electrical series between said power source and the other of the first said coils, first and second switches connecting the relay coils to the power source, and first and second cam means coupled to said shaft and adapted to operate said switches whereby the iirst said coils are effectively -connected to said power source, said cam means being operatively disposed on said shaft to actuate one of the first said coils at a time with an interruption between actuation of these coils, said cam means actuating the coil associated with the gear train -before said reciprocating member is brought to a range of operative positions corresponding to a determinable angle of rotation of said shaft and the other coil being actuated before the reciprocating member leaves said range of operative positions.

4. A sheet embossing press comprising iirst and second movable sections, and means for driving said sections at different speeds; said means comprising a drive operatively coupled to and adapted for driving said iirst section, means operatively coupled to and adapted for driving said second section, a main shaft coupled to said drive and second said means to drive the same, said second section having a range of operative positions correspondspacers s ing to a determinable angle of rotational movement of said main shaft, a further shaft coupled to said main shaft, a iiywheel freely rotatable` on said further shaft,`

means to drive said flywheel, clutch sections on said further shaft, one of said clutch 'sections being lixed to said tllywheel and the other being separate therefrom, two further clutch sections keyed -to said further shaft, said further clutch sections being operatively disposed with respect to and adapted for respectively engaging the 'rst said clutch sections, control means adjacent said clutch sections to control engagement of the same in pair, a gear train coupling said other of the iirst said clutch sections to said iiywheel whereby the speed of said shafts is controllable in accordance with the selective engagement of said clutch sections; said control means comprising means operatively coupled to said main shaft to engage one of the pairs of clutch sections at a time with an interruption between engagement of these pairs, the clutch 'section pair associated with the gear train being engaged before said lreciprocating member is brought to its range of operative positions and the other clutch section pair being `engaged before the reciprocating member leaves the range of operative positions.

5. In an apparatus comprising a sheet embossing press including at least one reciprocable member 4and a 'corrveyor system for conveying sheets to said press; means for driving said system and press at diiferent speeds, said means comprising a conveyor `system drive operatively coupled to and adapted for driving said conveyor system, a linkage means operatively coupled to and ladapted for Vdriving said reciprocable" member, a main shaft coupled to said drive and linkage means'to drive the same, said reciprocable member having a range of operative positions corresponding to a determinable angle of rotational movement of Ysaid main shaft, a further shaft, means coupling said shafts, a iy'wheel freely r0- tatable on said further shaft, means -to drive said ilywheel, discs rotatable on said further shaft, one of said discs being fixed to said flywheel and the other being separate therefrom, two further discs keyed to said further shaft, said further discs being operatively disposed with respect to and adapted for respectively engaging the first said discs in pairs, means adjacent said discs to control engagement of the same, a gear train coupling said other of the first said discs to said flywheel whereby the speed of said shafts is controllable inaccordance with the selective engagement of said further discs and the rst said discs, and a control for the means controlling engagement of Vthe discs; said control comprising means operatively coupled to said main shaft to engage one of the pairs of said discs at a time with an interruption between sequential engagements, the pair of discs associated with the gear train being engaged before said reciprocating member is brought to its range of operative positions and the other pair of discs being engaged before the reciprocating member leaves the range of operative positions.

6. Apparatusvcomprisiug a sheet embossing press including at least one reciprocable member, a conveyor system for conveying sheets to said press, and means for driving said system and press at different speeds whereby embossing and conveying operations are efficiently effected; said means comprising a conveyor system drive operatively coupled to and adapted for driving said conveyor system, a toggle linkage means operatively coupled to and adapted for driving said reciprocable member, a main shaft coupled to said drive and linkage means to drive the same, said reciprocable member having -a range of operative positions corresponding to a determinable angle of rotational movement of said main shaft, a further shaft, -a worm and gear combination coupling said shafts, a ywheel freely rotatable on said further shaft, means to drive said ily-Wheel, magnetic discs concentric with and freely rotatable on said l:further shaft, one of said discs being fixed to said flywheel and the other being Y 7 Y separate therefrom', twofurther magnetic discs concentric with and keyed to said further shaft, said further discs `being operatively disposed with respectptorand vadapted for respectively engaging the first said discs, inductance y'coils adjacent said discs to control a magnetic engagement of the same, a gear train coupling said other of the first said discs to said Vflywheel whereby the speed of said shafts is controllable in accordance with the selective engagement of said `further discs by the first said discs, and a control forsaid coils; said control comprising iirst and second power sources, first and second relays each including a relay coil, an armature and first and second sets of contacts, the rst sets of contacts being connected in electrical series between said first power source and one of thelirst said coils, the second `sets of kcontacts being connected' in electrical series betweenrsaid rst power sourceandy the other of the rst said coils, vrst and second switchesgconnecting the relay coils to the second power source, and iirst and second cam means on said main shaft and adapted to operate said switches whereby Vthe grst said coils are effectively connected tov said Vfirst tacts, the first sets of contacts beingconnected in elec# e power source, said cam means being operativelydisposed on said main shaft to actuate one of the Yfrst'said coils for conveying` sheetsfto said press; means for driving said system land press at different speeds whereby embossing Aand conveying operations are ethciently effected; lsaid means comprisingV a conveyor system drive operatively coupled to and adapted for driving said conveyor system,

a toggle linkage means operatively coupled to,r and adapted for driving `said reciprocable member, a Vmain shaft coupled to said drive and linkage means tordrive the same, said reciprocable member having a range of operative positions corresponding to a determinable angle of rotational movement of saidrmain shaft, arfurther shaft, a

worm and gear combinationv coupling saidfshafts, a flywheel freely rotatable on said further shaft, means to drive said ywheel, magnetic discs concentric withand freely rotatable on said further shaft, one ofk said discs being fixed to said dlywheel and the other being separate therefrom, Vtwo further magnetic discs concentricrwith and keyed .to said further shaft,"s aid further fdiscs ybeing operatively disposed with respectto and adapted 'for respectively .engaging the first said discs, inductance .coils adjacent "said discs to control a magnetic engagement of the same, a gear train coupling said other of the =rst said discs to said flywheel whereby. the speed offsaidshafts is controllable in accordance with the selectiveengagement of said further discs by the flrstsaid Ydiscs,1and'a control Y for said coils; said control comprising irst and` second power sources, rst and second relays each including a relay coil, an armature and irst andsecond sets of contrical seriesVV between said first power source and oneY of the iirst said coils, the second sets of contacts being connectedlin electrical series between said first power source andY thef'other of the instfsaidy coils, rst and second switchsadapted lfor connecting the relay coils to the second power source, -and first' and second cam Vmeans on said main shaft Y'and adaptedV to Voperate said switches wherebyV the rst said coils are effectively connected to said first power' source, said cam means beingopera tively disposed on Ysaid shaft to actuate one of the lirst saidv coils at a time with an interruption between actation of these coils, the coil associated with the gear train being actuated before Vsaid reciprocating member is brought to its range of operative positions and the other coil being actuated lbefore the reciprocating member leaves therrange of operative positions;v and a selector switch connected to said second power source and said .first Vand second switches Yand adapted to ldisconnect one ofthe latter said switches from the secondpower source.

V2,856,044 Koenig et al Oct. 14, 1958 Danly et a1. Dec. 17, 1957 Y