US2151890A - Press for cutting cardboard - Google Patents

Description

H. BOBST March 28, 1939.

PRESS FORJGUTTING CARDBOARD Filed Nov. 9, 1957 2 Sheets-Sheet 1 INVENTORI 76 5 75 HENRI BOBST 3%m%9 ATTORN EMS H BOBST March 28, 1939;

CARDBOARD PRESS FOR CUTTING 2 Sheets-Sheet 2 Filed Nov. 9, 1937 INVENTOR- HENRI! 505st. J

' Z ATTORNEYS lit Patented Mar. 28, 1939 UNl'lD STATES- ATENT OFFICE Application November 9, 1937, Serial No. 173,548 In Switzerland November 18, 1936 .4 Claims.

This invention relates to a press, serving especially for the cutting of cardboard worked in a continuous Web.

The press according to the invention is characterized by a fly wheel which maintains a speed of rotation which is substantially constant and by a device which makes it possible to give the press two different working speeds constituting a fast and a slow rate of working.

The press will, in preference, be provided with means to prevent the press from stopping in the neighbourhood of its dead centre, where it furnishes its productive effort, said means remaining inactive when the press is working idle.

The accompanying drawings show two embodiments of the press according to the invention and given by way'of example.

Fig. l is a side view of the first embodiment, which is driven electro-mechanically and which comprises means to prevent the press from stopping, when it is furnishing its productive eifort.

Fig. 2 is a corresponding plan view.

Fig. 3 shows the diagram of the connections of this first embodiment.

In the embodiment shown in Figs. 1 to 3, a motor l drives the press of which the head 2 guided by a frame 3 effects an alternative vertical movement, and cuts by means of a steel punch a web of cardboard 4, which advances intermittently from a reserve, which it is assumed is situated on the left hand of the drawing, then said web after it has been punched is cut by cutters 5 and eventually passed to a printing group which would be'situated on the right hand, but is not shown on the drawings.

The head 2 of the press is actuated by means of belts 6, of a two speed clutch, which will be described more in detail hereinunder, of a shaft 7, of a pinion 8, of a toothed wheel 9, of a shaft l0 carrying the eccentrics II and the connecting rods l2. Whenever the eccentrics II pass their lower dead centre, i. e. the inverse position to that shown, the head 2 is lowered and cuts off that part of the web of cardboard 4 under same.

It is however possible to prevent the punching operation from taking place by acting on the lever l3, which is connected to an eccentric l4 controlling a connecting rod l5 which is itself connected to a lever l6, and this makes it possible to modify the position of an eccentric ll turning in the head of the connecting rod 12 which same connects to the head 2; a similar eccentric is situated on the other side of the press and is made integral with the first eccentric 56 by means of the shaft Hi. In fact, by bringing the lever 13 into the position l3 shown in dot and dash line, the connecting rod I5 is caused to rise and the lever I6 is caused to rotate counter-clockwise in respect'to the drawings, and the corresponding rotation of the shaft l8 and of its eccentrics cause the head 2 to rise slightly in relation to the connecting rod I2, which can'no longer apply the steel punch against the corresponding platen of the press, upon which the web of cardboard lies.

As for the two speed clutch, it is constructed as follows:

A fly Wheel l9 which is driven directly by the motor rotates freely round a sleeve 20, which is connected to the shaft 1 by means of the key 2!.

The fly wheel as it rotates drives the planet wheels 22, 23 which are formed like toothed pinions and which are integral with eachother, the planet wheels 22 being however smaller in diameter than the planet wheels 23. The planet wheels 22 catch in a corresponding gear of the sleeve 20, whereas'the planet wheels 23 catch in another gear of a drum 24 of a cheek brake, the cheeks of which are designated by the reference numeral 25. Frictional members 26 are mounted in slots of drum 24 being free to slide radially in these slots and capable of connecting the drum with the fly wheel by their application against an inside surface 21 of the latter, a cone 28controlled by a fork 29 being provided for this purpose.

It can easily be seen that in the position shown of the different members, that is to say when the brake 24 is not braked and when the cone 28 is taken out of said drum, the press cannot be driven. In 'fact, in this case, the rotation of the flywheel causes the rolling of the planet wheels 22 overthe gear, of thesleeve 2U,'Whl0h as it is connected to the press, offers a resistance which forces the planet wheels 22 to rotate. As the planet wheels then rotate at the same speed but act on the gear of the drum 24 which is of smaller diameter than the sleeve 20, the result is a relatively slow movement of the drum and in a direction which is contrary tothat of the rotation of the wheel.

If now by acting on the cheeks 25, the drum is immobilized, the slow movement given previously to the latter will have to be transmitted to the sleeve 20 and in a contrary direction, that is to say in the same direction as the rotation of the fly wheel. In fact, at this moment, it is the planet wheels 23 that are obliged to roll over the gear of the drum and the'gear of the sleeve 20 that will have to move because of the difference in diameter of the planet Wheels 23 and 22. The press will therefore work, but at a relatively reduced speed, although the fly wheel l9 maintains its speed, which is given it by the motor, approximately constant.

If, finally, instead of acting on the cheeks 25 and instead of braking the drum, the cone 28 is driven in the latter, so as to connect the drum and fly wheel with each other by reason of the clutching effect thus produced, it will be seen that the shaft 1 will have to rotate at the speed of the fly wheel, since it will no longer be possible for the planet wheels 23 to roll over the gear of the drum and consequently to have an absolute rigidity in the system of transmission just described. This operation corresponds to the rapid working of the press, since the fly wheel maintains substantially the speed given it by the motor,

It is clear that the arrangement described is complete, only when a locking has been provided between the brake of the drum and the cone of the clutch to prevent the machine from being jammed or a piece from being broken by the simultaneous operation of these two members, which have the effect of causing simultaneously the slow and rapid rates of working.

In the press shown, another improvement is provided, which comprises at the same time the above locking.

The slow rate of working of the press is in deed particularly useful for efiecting regulating operations, that is to say, for causing the members of the latter to advance but a short distance at the time. This, for instance, is necessary when the press is worked with a printing group that must be subjected to minute regulation. There is, however, a drawback which must at all events be avoided when regulating, and that is the jam- 'ming of the press in the neighbourhood of its dead centre, where it furnishes its productive effort for, when jammed in such a position, it is extremely difficult to set it going again and in any case impossible to do so with the sole force furnished by the motor.

In order to prevent this accident, electro-mechanical means are provided which oppose any stopping of the press, that is to say any unclutching of the latter, when its head 2 is in the neighbourhood of its punching position, but these electro-mechanical means remain inactive, when the lever I3 is brought into its position 13', and the press is not working.

The means in question are constituted as follows:

To actuate the brake of the drum 24 by means of the lever 30, use is made of an electro-magnet 3|. To cause the clutching of the drum 24 by means of the cone 28 and of the fork 29, use is made of a lever 32 which acts on a bar 33 and. by means of the lever 34 on the rod 35, the bar 33 carrying a contact 36 which closes an electric circuit in the position shown of these members. Finally, a contact 3'! is provided which is raised and lowered at the same time as the head 2 and which can likewise close a circuit at its lower dead centre, when the press is working, that is to say when the lever l3 occupies the position shown in full-line. In the other position, the contact 3'! is raised with the connecting rod [5 and can no longer meet the contacts 38 by means of which it closes the circuit.

If the diagram of Fig. 3 is now consulted, in which are found again part of the elements just described, it will be seen that from a source of energy shown by the terminals 39, the electric circuit passes through the lead 4!] and the electromagnet 3| to start the slow working, and then passes through the contact 36 in order to join a lead 41 from which the circuit can be closed on the lead 42, either by said contact and contacts 31, 38, or by one of the switches 43, 44, 45 which are all branched in parallel,

These switches are nothing else but control buttons which are placed at different points on the press and the object of which is to make it possible, while regulating and from said points, to start the slow rate of working. In fact, in the position shown of the different parts of this diagram, it is only necessary to close one of these switches in order to energize the electromagnet 3|, to cause the drum 24 to brake and to obtain the slow rate of working of the press. This is, however, only possible, if the contact 36 closes the circuit, that is to say if the lever 32 L occupies the position which is shown in Figs, 1 and 2 which corresponds to the removal of the cone 28 and the non-clutching of the drum 24 with the fly wheel l9. In the clutching position of the lever 32, the circuit of the electro-magnet can no longer be closed, so that the accident previously described, resulting from a simultaneous starting in slow and fast speeds cannot arise.

It is finally to be remarked that the contact 31 and the contact 33 are also capable of closing the circuit of the electro-magnet and of causing the slow rate of working. This arises, when the lever I3 is in the working position of the press and whenever the head of the latter is lowered, that is to say working. In fact, whenever the head of the press passes through its lower dead centre, the contact 31 reaches the contact 38 and closes the circuit (as much as the contact 36 is closed), so that even if at this moment it were necessary to release the switches 43, 44 or 45 which are worked for the regulation, the press would continue to work slowly, until it had left this dangerous dead centre. This effect of the contact 3'! does not of course occur in the position l3 of the lever 13. In this position, there is besides no dangerous pressure to be overcome, since the press is working idle.

In short, the operation of the press described is extremely simple, on the one hand, motor and fly wheel maintain substantially a constant speed, whatever the operations executed. Then for normal rapid work, the press is clutched by means of the lever 32, whereas when it is being regulated, it can be caused to rotate slowly and at a rate just fast enough for the regulating operations, by actuating any of the switches which are placed anywhere on the press, and thus any jamming due to faulty operation is automatically avoided.

It is clear that the contacts 31, 38 act, even if the fast speed is unclutched by means of the lever 32 at the precise moment, when the press could be jammed. In this position and at this moment, the press is automatically put into and said clutch means and connecting the same tov said press, mechanical means for clutching the fast speed of the clutch means to said shaft means for driving said press and electro-magnetic means for clutching the slow speed of said clutch means to said shaft, said electro-magnetic means comprising an electrical circuit having at least one switch placed at any desired point for causing or interrupting at will the slow speed and another switch controlled by movement of the mechanical clutch means so that the circuit is open when the fast speed is thrown into clutch and closed when thrown out of clutch. I

2. A press serving especially for the cutting of cardboard worked in a, continuous web, comprising a movable press head cooperating with a support for cutting said cardboard and having a flywheel, means for rotating said flywheel at a substantially constant speed, a two speed clutch means placed between said flywheel and said press, a shaft for axially supporting said flywheel and said clutch means and connecting the same to said press, mechanical means for clutching the fast speed of the clutch means to said shaft for driving said press, and electro-magnetic means for clutching the slow speed of said clutch means to said shaft, said electro-magnetic means comprising an electrical circuit having at least one switch placed at any desired point for causing or interrupting at will the slow speed and another switch controlled by movement of the mechanical clutching means so that the circuit is open when the fast speed is thrown into clutch and closed when thrown out of clutch, said electro-magnetic circuit also including an additional switch mpans connected to said press head for operating said additional switch when said press is in the neighborhood of dead center so that the clutch is thrown in slow speed during the time when the press is passing dead center.

3. A press serving especially for the cutting of cardboard worked in a continuous web comprising a movable press head cooperating with a support for cutting said cardboard and having a flywheel, means for rotating said flywheel at a substantially constant speed, a two speed clutch means placed between said flywheel and said press, a shaft for axially supporting said flywheel and said clutch means and connecting the same to said press, and means for preventing the press from stopping in the neighborhood of dead center, said flywheel carrying two groups of planet wheels with pinions of one of said groups rolling on a gear which is integral with the drum of a brake, means for mechanically connecting said brake to said flywheel and electrical means for applying said brake.

4. A press, serving especially for the cuttin of cardboard worked in a continuous web, com- HENRI BOBST.

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