US1071343A - Paper-feeding mechanism. - Google Patents

Description

Patented Aug. 26, 1913.

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A. U. PRATT PAPER FEEDING MECHANISM.

APPLICATION FILED NOV. 7, 1910.

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ALPHONSO QGMSTOCK PRATT, 01-3 MONTCLAIR, JERSEY, ASSIGNOE TD THE FULLER MANUFACTURING COMPANY, OF NEW HAVEN, CONNECTICUT, A CORPORATION 013 CONNECTICUT.

PAPER-FEEDING MECHANISM.

Specification of Letters Patent.

Patented Aug" ac, f il T 0 all whom it may concern:

Be it known that I, ALrHoNso COMSTOCK Pna'rr, a citizen of the United States, residing at Montclair, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Paper-Feeding Mechanism, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to improvements in paper feeding mechanism.

Considerable difficulty has been experienced in operating feeding mechanisms in connection with high speed printing machines for a reason that the forwarding .devices which transfer the sheet from the pile to the front stops or other registering de vices necessarily run at such high speeds that the sheet is liable to strike 'the front stops with such force as to interfere with its register. It has been proposed to overcome this difliculty by the use of what are known in the feeding art as slow-downs These slow-down devices are intended to take control of the sheet before it reaches the front stops and slow its speed down to such an extent that the impact of the sheet against the front stops will not be suflicient to interfere with its registration. In certain forms of these slow-down constructions a roll is employed which runs at a constant speed which is considerably slower than the speed of the forwarding devices, the mechanism also including various forms of devices, such, for instance, as a pair of drop rolls, one operating on each margin of the sheet, to enable the slow moving roll to take control of the sheet. These drop rolls, or similar devices, are actuated in such time that the slow moving roll takes control of the sheet after the greater portion ofit has passed beyond the slow-moving roll. This slow-down mechanism, after slowing the sheet. releases it when the head of the sheet is some little distance from the front stops and the shccl is then taken control of by the forwarding mechanism and carried against the front stops. This form of slouw lou 'n incchanism has not proved satisfactory for various reasons. if for instance, the sheet happens to be fed from the pile so that one ofthe. forward corners is traveling very slightly in advance of the other corner and goes into the slow-down in this condition, 1

it will be obvious that one part of the rear edge of the sheet will pass out of the slow down mechanism before the other part has passed out. T he result of this is that when the forwarding mechanism, which is running mrch more rapidly than the slow-down roll, again takes control of the sheet, it is liable to carry one side of it onward considerably in advance of the other, and, therefore, multiply the feeding error. Certain other diificulties arose in connection with this form of slow-down which it is not necessary to enumerate.

In an attempt to overcome the objections to the form of slow-down mechanism just .described, it was proposed to employ a slowdown mechanism comprising a roll extending across and under the sheet pathway with which cooperated a plurality of fixed nipping idler rolls, the under roll and the cooperating rolls nipping and forward ing the sheet. In this form of construct-ion it is obvious that the slow-down rolls must, at the time they take control of the sheet, be driven at the speed at which the sheet is moving, that is, at the speed of the sheet forwarding devices, and that they must not act to slow-down the sheet until the greater portion of the sheet has passed through the slow-down rolls, because it is essential, on account of the speed at which the printing machine is running, that the sheet travel at a high speed between the pile and the front stops. The result of this is that the slowing down of the sheet must take place in a very short period of time, because otherwise sheets could not be fed rapidly enough to the machine. In this form of slow-down mechanism, therefore, it was proposed to drive the roll from what may be termed two sets of driving mechanism, one running at a high speed and the other at a slow speed, and to transfer the control of the roll from the high speed driving mechanism to the low speed driving mechanism at the time it was desired to effect the slowing down of the sheet. This sudden transfer of the control of the slow-down rolls from a driving mechanism running at a high speed to one running at a low speed causes considerable shocks and wear to the operating mecha nism. and, further, an appreciable length of time is required for transferring the control of the rolls from one driving mechanism to the other, which amount of time is not contit) tilii stant. In other Words, under certain conditions of the mechanism, the shift from one driving mechanism to the other may take a longer or shorter period of time than under other conditions. The result of this is that the slow-down mechanism is uncertain in its action and may release the sheet at varying times, or, in other words, at varying distances from the front stops. The sheets, however, are taken from the front stops by grippers or other sheet taking mechanism on the cylinder of the printing machine which cylinder runs at a constant speed. The sheets should arrive at the front stops at the time the grippers are in a predetermined'relation to the stops, that is, at the time the grippers are at such a distance from the stops that the time they consume in reaching the stops will be sufficient to permit the proper manipulation of the sheet to bring it into register. In feeding high speed printing machines, the time allowed to effect the register of the sheet is very short. If, therefore, the slow-down mechanism is uncertain in its action and releases the sheet at varying times, there is liability that in some cases the sheet may not reach the front stops in time to enable registration to be efiected before the grippers come into position to take the sheet, or may pass the front stops before they are dropped.

It is one of the objects of this invention to produce an improved paper feeding mechanism in which the sheet is forwarded by devices which act positively and certainly, in which the sheet is at all times under proper control, and in which the defects in the feeding action due to uncertainty in operation of the forwarding devices are avoided.

A further object of the invention is to produce an improved slow-down for paper feeding machines embodying suitable sheet controlling devices, these devices being operated in such a way that they are certain and positive in their action.

lVith these and other objects not specifically referred to in view the invention consists in certain constructions, and in certain parts, improvements and combinations as will be hereinafter fully described and then specifically pointed out.

Referring to the accompanying drawings:Figure 1 illustrates in side elevation so much of a feeding mechanism constructed in accordance with the invention as is necessary to an understanding thereof. Fig. 2 is a plan view of a part of the construction illustrated in Fig. 1. Fig. 3 is a detail view illustrating more particularly in sectional elevation the driving mechanism for a certain slow-down mechanism which may be employed in carrying invention into effect. Fig. i is a detail front elevation of the construction illustrated in Fig. 3. Fig. 5 is a section on the line 55 of Fig. l. Fig.

Fig.

' construction.

The cylinder of the printing machine is diagrammatically illustrated at 5, and the front registering devices at 6. In the particular machine shown, the sheet forwarding devices include tapes 7 running over the usual rolls, one of which is indicated at 8. The pile from which the sheets are successively detached is indicated at 9, and the pusher mechanism for detaching the sheets at 10. The pusher mechanism and the tapes are driven from a main shaft 11 which is or may be geared up to the driving mechanism of the printing machine, the movement of this shaft being transmitted to the various agencies driven by it by a train of gears 11. The parts so far described are well-known in the art, and any other suitable known mechanism for effecting the same purpose may be substituted for them in whole or in part.

Constructions embodying the invention will include sheet forwarding devices. by which the sheet is positively and certainly controlled in its passage from the pile to the registering devices. While the particular construction by which the invention is carried into effect may be varied within wide limits, in the construction selected to illustrate the invention the sheet forwarding devices comprise, in addition to the tapes 7, a shaft, as 12, this shaft being provided with collars 13, the shaft and the collars being conveniently termed a roll. The shaft 12 is mounted in brackets 14 mounted on the side frames 1. When this roll is employed in carrying the invention into efiect, suitable devices will be used in connection therewith for holding the sheet thereagainst. In the particular machine illustrated, these de vices comprise two idler rolls 15 mounted on arms 16 extending from a cross-bar 17, these idler rolls being so arranged that the sheet advanced from the pile by the tapes 7 will, as they reach the rolls, be nipped between them and the roll consisting of the shaft 12 and collars 13. It will beunderstood that in the construction illustrated this shaft 12 is located beneath the upper run of the tapes and the idler rolls are located above the u pper run of the tapes.

in constructions embodying the invention sheets will be advanced at a variable speed, and in constructions embodying the invention in what is considered the best form, this varial'ile speed will be a constantly varying speed. In the construct-ion illustrated for carrying the invention into effect, the shaft 12 is provided with a pinion 18 meshing with a gear 19 loose on a stud 20 supported at one end in a bearing 21 formed on the bracket 14. This stud 20 supports a miter gear in mesh with a miter 23 mounted on a shaft 24.- supported at one end in a bracket 25' mounted on the stud 20, and at the other end in a bracket 26 carried on a driving shaft 27 operated from the train of gears 11 before referred to, this shaft making one turn for each revolution of the printing machine cylinder. The stud 20 has fast thereon a pinion 28 illustrated as secured thereto by a key 29. The hub of the gear 22 has fast thereto an arm 30 on which is mounted a pinion 31 supported by'a screw stud 32. This pinion meshes with the gear 28 and carries a stud 33 on which is mounted a roll 34 engaging in a slot 35 in the gear 19. It is, of course, apparent that as the gear 22 is rotated, the arm 30 will be rotated and will carry the pinion 31 with it, this pinion not only having a rotary movement about the stud 21 but also rotating on its own axis. The in and roll construction 33, 34 forms a cranli for driving the gear 19 and as the position of this crank pin shifts in the slot 35 as the gear 31 rotates and travels, it follows that the gear 19 will be driven at a speed which is not only variable but which is constantly varying, and that this gear 19 actiig as a driver will drive the shaft 12 at the same speeds that the driver itself has.

The construction is so arranged that at the time a sheet enters between the rolls 13 and 15, the rolls will be moving at the speed of the carrying tapes 7 and will act to forward the sheet at the speed the sheet had when it entered between them. As the head of the sheet approaches the front guides, however, the rolls are slowed down, so that at the time the sheet emerges from between them it is moving at such a speed that its impact against the front guides willnot be sufficient to interfere with its proper registration. It will be observed that the sheet is advanced continuously and at a constantly varying speed, and, furthermore, since these sheet forwarding devices are-in continuous "engagement with the driving mechanism,

there are no sudden shocks or strains put upon the operating parts. It will also be observed that the rolls operate with absolute certainty, there being no error possible, such as is liable to result where a shift has to be made from one driving mechanism to another.

(barges and variations may be made in the construction by which the invention claimed is carried into effect. The invention is not, therefore, to be confined to the particular construct-ion hereinbefore described and illustrated in the accompanying drawings.

What is claimed is 1. In a paper feeding mechanism,the combination with sheet forwarding devices running at a constant-speed, of a slow down mechanism operating to control the movement of the sheets forwarded by the forwarding devices, said mechanism including devices whereby the slow down mechanism is operated at a speed which varies con stantly with respect to the speed of the forwarding devices.

2. In a paper feeding mechanism, the combination with a set of constantly running sheet carrying tapes, of a slow down roll located in the tape path, and intermediate the ends thereof, means cooperating with the roll to hold the sheets thereagainst, and means for driving the roll at a speed which varies constantly with respect to the speed of the forwarding devices.

3. In a paper feeding mechanism,the combination with a set of constantly running sheet carrying tapes, of a slow down roll located in the tape path and intermediate the ends thereof, and a driving mechanism operating at a speed which varies constantly with respect to the speed of the forwarding devices; with which driving mechanism the roll is continuously engaged.

4. In a paper feeding mechanism, the combination with sheet forwarding devices running at a constant speed, of a slow down roll, means for holding the sheets thereagainst, a driving gear with which the roll is continuously connected, and means including a crank movement operating at varying distances from the center of the gear for driving the gear at a speed varying constantly with respect to the speed of the forwarding devices.

5. In a paper feeding mechanism, the coin bination with a set of constantly running sheet forwarding tapes, of a slow down roll arranged in the tape path and intermediate its ends, means for holding the paper thereagainst, a driving gear with which the roll is continuously connected, a second gear, means for giving the second gear a rotating and traveling movement, and a slotand pin connection between the gears.

In testimony whereof, I have hereunto set my hand, in the presence of two subscribing witnesses.

ALPHONSO COMSTOCK PRATT.

Vitnesses:

J AMES Q. RICE, A. WHITE.

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