US2829890A - Receiving mechanism in machines for operating on sheets - Google Patents

Description

N SHEETS April 8, 1 958 J. KURY ETAL RECEIVING MECHANISM IN MACHINES FOR OPERATING 0 Filed MBJ'Oh 30, .1955

2 Sheets-Sheet l April 8, 1958 J. KURY ET AL 2,

RECEIVING MECHANISM IN MACHINES FOR OPERATING 0N SHEETS 2 Sheets-Sheet 2 Filed March 30, 1955 I Fig.2.

\\\\\\\\\\\\\\\\\\\\ y/g/IIIl/IlI/Ill RECEIVING MECHANISM IN MACHINES FOR OPERATING ON SHEETS Josef Kury, Pully, near Lausanne, and Frederic Laufer,

' y, near Lausanne, Switzerland, assignors to J. Bohst & Son S. A., Prilly, near Lausanne, Switzerland, a corporation of Switzerland Application March 30, 1955, Serial No. 498,0Sli Claims priority, application Switzerland April 3, 1954 6 Claims. (Cl. 271-79) bars moved by endless chains.

Known machines of this character comprise three stations, viz. that in which the registered sheets are engaged by the gripper bars, that at which each sheet is operated on, the corresponding bar being stopped, and finally, that at which the treated sheet is ejected on to a pile as a result of the opening of the gripper parts of the bars holding the same. This last-mentioned station is known as the reception station and may as will be seen hereafter, require special expedients and mechanisms.

Figure 1 of the annexed drawing shows schematically a press having gripper bars conveyed by endless chains, the bar in station A gripping a registered sheet, that in station B holding the operated sheet and that in station C having to eject the processed sheet onto the pile represented at P. The sheets in A, B and C are not shown in order not to complicate the drawing.

When the bars are thick, they generally comprise a longitudinal pin which operates. a cam having the function of opening the grippers.

When, however, the bar is light and consequently of small section, and particularly when it is of small thickness (corresponding for example to the height of the chains), other means are necessary.

Moreover bars of this nature and of small inertia, which are generally used in high speed machines, require special means for braking the transported sheets, so as to cause the delivery thereof onto the pile in a properly stretched and flat condition.

An object of the present invention is to provide a receiver mechanism which is such as to provide for the opening of the grippers of bars which meet too small a sectional size to enable a pin to be accommodated therein. Moreover, the said mechanism may advantageously be completed by brake means which are adapted to the high operating speeds which are possible with this mechanism.

The receiver mechanism in accordance with the present invention is so constituted that the sheet conveyor bars thereof comprise grippers which are adapted to be opened by external pressure, this latter being exerted at the receiver station by cam noses disposed in the path of the elements to be operated but being movable and being retracted immediately after the opening of the grippers and the release of the sheet, thus acting during the travel before the immobilisation of the bar.

The accompanying drawing illustrates an embodiment of the present invention, this being given by way of example.

Figure 1 already cited shows schematically a press operating on sheets convyed by means of endless chains and gripper bars and having a sheet-receiving mechanism as hereinafter described; Figure 2 is a section through the shaft of the pair of chain wheels located at the receiver ltation C and serves to illustrate the way in which the cams co-operate with these bars; Figure 3 shows, on a smaller scale the means used to brake and tension the sheets by opposing the natural inertia effect thereof at the instant when they are released for movement.

Considering Figures 1 and 2 they show the shaft 1 supporting the two chain wheels which guide the endless chains which carry the gripper bars.

One of these wheels is partially illustrated at 2, and the second is to be regarded as in front of the plane of the Figure 2) which indicates the path thereof. This chain carries the bar 4, which is here shown as stationary at the receiver station (C in Figure 1).

Distributed over the length of this bar are grippers which are formed by resilient blades 5 to each of which is riveted a small plunger 6 which passes through the bar and terminates in a roller 7. A pressure which lifts the blade, i. e. opens the gripper, can be exerted on the plunger by an elfort applied against this roller (the position illustrated in Figure 2).

The sheets which have previously been treated in the press are carried in the direction of the arrow 8 by the bar as the latter follows the path of the moving chains from B to C.

However, before reaching the position C illustrated, which will be called the receiver position, the rollers 7 of the plungers of the grippers of the bar 4 encounter, in their travel, inclined planes formed by cam noses, such as 9, disposed on a transverse bar 10, to which they are Thus, before the bar is brought to a standstill, the gripper means thereof will open and release the conveyed sheet and the latter will thus be free to drop correctly and flat on the receiving pile P without being obliged to slide away from a stationary gripper.

Since the cam noses 9, however, oppose the free ejection of the released sheets, the transverse bar is supported at each of its ends by a lever 11 which oscillates about a pivot 12 which enables it, in moving to the position 11, to move the cam nose to 9' and out of reach of the sheets.

Thus, after release of each sheet at the moment the bar reaches the position 4, the lever 11 and its opposite oscillate into the position 11 and the cams leave a free passage for the treated sheet.

Since the transverse bar 10 is free to turn about its shaft, a lever 13 with an abutment screw 14 enables the angular position of the cams 9 to be finely adjusted such as, for example, against the action of springs or any other means ensuring the application of the screw 14 against the lever 11.

a It would also be possible to provide a stationary individual adjustment of each cam, but this has not been illustrated to avoid complicating the drawing.

The arrangement described thus enables the sheets to be released during their travel and allows for all the required regulating actions to take place from the instant at which the grippers of the bar open, and from this provides for simultaneity of the opening operations.

The movement of the lever 11 in which-it travels successively to the position 11 and returns to the starting position in response to the displacement of the bars can be obtained by any appropriate mechanical connection which can be readily conceived by one skilled in the art. Figure 1 shows an embodiment of such a connection having a cam 11 driven by a chain connection with the main shaft 24 of the press, the said cam also acting on the parts to be described hereinafter.

Having regard to the fact that the cams which open the grippers exercise, at this instant, a radial centripetal pres sure, i. e. in the direction of least resistance of the bars, these latter at the moment they reach a position tangential with the chain wheels make tangential contact with one or more discs, such as that shown at 15, supported by the shaft 1.

Since the discs 15 rotate with this shaft at the same speed as the toothed wheels 2, they apply a pressure to the bars without any friction between these two parts.

The mechanism described provides for very high operating speeds, and as a result it is of advantage to supplement it by braking means to deal with the inertia of the sheets, as illustrated in Figure 3.

This shows the chain 3 and a bar 4 in the position at which a sheet is operated on,'this sheet being pressed between the tools carried. by a fixed head 16 and a movable platen 17.

Each sheet is successively carried from the operating station of the bar at 4' in the direction of the arrow 8 to the receiving position of Figure 2.

In so doing the sheet, which follows the bar, is guided over the plate 13 and then against the angle piece 19 which forms a small transverse platform and a small brush 2 bearing thereon from above. These two latter parts, which exert a slight friction on the sheet, brake the movement thereof and prevent the fall of the sheet on to the pile P at the receiver being other than vertical, as a result of its inertia, and prevent it being creased so that it remains fiat and appropriately tensioned.

' To this end it is arranged that, at the instant at which it is to drop on to the pile, the sheet is still held at its rear edge between the brush and the angle piece.

This latter is carried by pivots 21 and this enables it to be oscillated and to move into the position 19 at the moment the sheet is dropped. The rear edge of this latter, at this instant, approximately follows the path correspond ing to the arrow 22.

Since the braking effect may not be advantageous if applied over the whole surface of the sheet, in which event impressions therein, particularly gilding, might suffer as a result, and also because the brush 20 might allow the gripper bars only to pass with difficulty without damage thereto, this brush is also mounted on pivots 23 which enables it to pivot into the position 20'. In this position the brush, which preferably extends across the whole width of the sheet, either continuously or in successive tufts, is outside the path of the gripper bars.

Thus, each gripper bar, with its treated sheet, passes with the brush raised into the position 20' and the angle piece 19 likewise in raised position.

At the moment the sheet is close to the receiver position, the brush is lowered into the position at 20 on to the angle piece 19 and brakes the sheet.

Then, when the grippers of the bar release the sheet as a result of the action of the cams 9, the angle piece 19 is lowered to position 19' and the sheet falls on to the receiving pile.

Thereupon the brush returns to position 20 at the same time that the angle piece is lifted to position 19 and a fresh bar and treated sheet pass.

The necessary correlation between the movements of the chains, of the lever 11, of the angle piece 19, and of the brush 20 will be produced by cams, levers and, generally by any suitable means as shown schematically in Figure 1 and do not form part of this invention.

What we claim is:

1. In a sheet processing device including chains for sequentially conveying sheets to and from a sheet operating mechanism and to a sheet releasing station at which the sheets are released in a determinable path and driving means for driving the chains: a gripping and releasing mechanism comprising a gripper bar coupled to the chains, a gripper on said gripper bar normally closed for supporting a sheet for conveyance to the sheet operating mechanism and to the sheet releasing station, first means in the determinable path in which the sheets are released for opening said gripper to release the sheet, and second means for removing said first means from the determinable path upon the releasing of the sheet whereby the sheet is released unimpeded.

2. In a sheet processing device including a processing station and a releasing station whereat each sheet is released in a determinable path, chains for conveying a sheet in a predetermined path extending through the determinable path from the processing station to the releasing station, at least one toothed wheel located at the releasing station for driving the chains, and retarding means between said processing and releasing station for supporting the sheet until the sheet arrives at the releasing station: a gripping and releasing mechanism comprising a gripper bar coupled to the chains, a gripper device on said gripper bar and normally closed to grip the sheet, a cam extending along the predetermined path and in the determinable path, said cam contacting and opening said gripper device with said gripper bar moving into the releasing station, and means for removing said cam from the determinable path upon the releasing of the sheet whereby the determinable path is unimpeded.

3. A gripping and releasing mechanism as claimed in claim 2 wherein said gripper bar defines an aperture; said gripper device comprising a resilient cantilever normally urged against said gripper bar and a projection extending through the aperture and adapted to contact said cam; said cam being provided with an inclined surface for urging said cantilever away from said gripper bar.

4. A gripping and releasing mechanism as claimed in claim 3 wherein said means comprises a pivotable arm supporting said cam, drive means, and a cam coupled to said drive means for cyclically operating saidpivotable arm to remove said cam from the determinable path each time a sheet is released.

5. A gripping and releasing mechanism as claimed in claim 4 comprising adjusting means for adjusting the position of said cam relative to said pivotable arm whereby the position at which the sheets are released is controllable.

6. A gripping and releasing mechanism as claimed in claim 5 comprising a disc coaxial with the toothed wheel for urging said gripper bar against said cam.

References Cited in the file of this patent UNITED STATES PATENTS 1,080,036 White Dec. 2, 1913 1,094,048 Barber Apr. 21, 1914 1,146,916 Barber July 20, 1915 1,226,168 Barber May 15, 1917 1,920,715 Sager Aug. 1, 1933 2,208,978 Harrold July 23, 1940 2,579,540 Bobst Dec. 25, 1951

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