US2144398A

US2144398A - Face-up delivery device for a printing press

Info

Publication number: US2144398A
Application number: US200531A
Authority: US
Inventors: Leopold A Bakke
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-04-06
Filing date: 1938-04-06
Publication date: 1939-01-17
Anticipated expiration: 1956-01-17

Description

Jan. 17, 1939. 1.. A. BAKKE FACE-UP DELIVERY DEVICE FOR A PRINTING PRESS Filed April 6, 193a 55heets-Shet 1 Jan. 17, 1939. 1.. A. BAKKE FACE-UP DELIVERY DEVICE FOR A PRINTING PRESS Filed April 6, 1938 s Sheets-Sheet 2 jidewr Z egaazddfiafek. @m W, flaw/aim A Jan. 17, 1939. L. A. BAKKE FACE-UP DELIVERY DEVICE FOR A PRINTING PRESS Filed April 6, 1958 3 Sheets-Sheet 3 w Z m M mwdm u mi m Em. n "mm Wmm m il J. DW WW m k\ @ZMX/M m Patented Jan. 17, 1939 UNITED STATES FACE-UP DELIVERY DEVICE FOR A PRINTING PRESS Leopold A. Bakke, Ghicago,'Ill. Application April 6, 1938, Serial No. 200,531

5 Claims.

This invention relates to an attachment for a printing press, and more particularly to mechanism for grasping the front end of a sheet after a printing operation and causing the sheet to be inverted before it is released from the machine so as to avoid damage or smearing to the printed face.

The device is of particular utility'in connection with high grade printing work such as the making of decalcomam'a transfers and in colored printing where a sheet may be subjected to several printing operations in different machines.

The invention has been illustrated as applied to a commercial flat bed press but it will be understood that it is applicable to presses of other types such as rotary presses and the like.

In practicing the invention it has been found desirable to have the gripper-jaws, which grip the front end of the sheet, move in a curved path which will keep the front end portion of the sheet in smooth condition without applying tension to an extent that would cause slippage between the sheet and the delivery cylinder. I

The invention is illustrated in a preferred embodiment in the accompanying drawings, in

which:

Figure 1 is a broken side elevationalview of the device mounted on the frame of a flat bed press; Fig. 2 is an enlarged fragmentary elevational view showing how the gripper-jaws engage the front edge of a sheet on the delivery cylinder of the press, taken as indicated at line 2 of Fig. 4; Fig. 3 is a fragmentary end elevational view of the device showing the jaws gripping the front edge of the sheet and holding it in elevated position; and Fig. 4 is a transverse sectional view, takeri as indicated at line 4 of Fig. 1.

In the embodiment illustrated, A designates the main frame of a printing press having a reciprocating fiat bed A, an impression cylinder A and a delivery cylinder A B; endless conveyor belts for receiving the printed sheets; and C, a face-up delivery device which is driven by the printing press in timed relation thereto.

As printing presses of the type illustrated are well-known in the art, it is not necessary to describe that portion of the machine in detail, but as is well understood, the bed A reciprocates beneath the impression roll A through the action of a gear 5 which engages a fixed rack 6 and a moving rack 1. Power is applied from a drive shaft 8 which is geared to a crank shaft 9 provided with a fixed crank I0 which forces the gear 5 back and forth by means of a pitman I I.

The impression cylinder A a segmental gear l2 which is adapted to be driven from a rack l3 provided on the reciprocating bed A. The gear l2 has a cut-out portion so that the cylinder does not move while the rack l3 makes the return movement to the right, as viewed in Fig. 1. Mechanism (not shown) is provided for turning the impression cylinder A at the beginning of the forward stroke, sufficiently for the gear I2 to engage the rack 13 and be rotated clockwise to print the next sheet. Thus, it will be understood that the impression cylinder turns in but one direction, and its movement is intermittent.

The delivery cylinder A is geared to the cylinder A so as to make two revolutions for each revolution of the impression cylinder. The delivery cylinder A is covered with a surface [4 which is usually kept moist so that contact with the freshly printed face of a printed sheet l5 will not cause injury to the sheet.

The conveyors B are usually in the form of endless narrow belts which fit into grooves on the delivery roll A and are reefed about a sheave 16' provided at some convenient delivery place.

The sheet l5, which is to be printed, may be introduced over the top of the machine I! and has its front-edge portion engaged by a gripper l8, provided on the impression cylinder A and be carried around and impressed against the bed A; As the front end of the strip reaches the delivery cylinder A the gripper I8 is automatically released and the end of the strip engaged by a gripper l9 provided on the delivery cylinder. The latter gripper brings the sheet around the delivery roll to a position where its front end may be engaged by the mechanism C which will now be described in detail. The rotation of the cylinders A and A is stopped at this point while the bed A is making its return stroke.

The face-up delivery mechanism has a pair of arcuate guide-ways 20 provided on opposite sides of the main frame of the machine. A cross-head or slide-block 2| is confined in a slot thus formed. The upper ends of the guide-ways are connected by a cross-bar 22 and each of the cross-heads is provided with suitable anti-friction rollers (not shown) to facilitate movement. It may be noted that a small presser roller 23 is journalled on the frame A and presses the sheet I 5 lightly against the delivery cylinder A The point of contact 24 is used as the focus point for the arc of curvature of the ways 20.

The cross-heads 2| are connected together for parallel movement by a fixed cross-bar 25 upon which a series of gripper-jaws 26 are adjustably fixed. A pivot shaft 21 is j ournalled in the crossmounted on the frame, as indicated at 34, and.

has its right end, as viewed in Figs. 1 and 3', urged downwardly against a fixedistud 35"by a tension spring 36. As will be readily understood, when the cross-head 2| is raised, the trigger member 33 will permit an arm of the rock member 29 to pass, by overcoming the tension'in the On the downward stroke, however, the trigger member will positively engage the arm spring 36.

29 and continued downward movement of the cross-headwillcause the lower gripping-jaws 28 to .be flipped to open position. While in this open position the timing of -the device with respect to the printing machine will bring the lower open jaw under the front edge-of 'thesheet l5 which will then be automatically released by the grippers L9, and as downward travel of the cross-head continues, the other end of the rock member 29 will engage the fixed stop 31 on the frame and this will cause the jaws 28 to be flipped back to closed position so as to grip the front edge of,

the sheet l5. While the cylinders A a and A remain stationary, the cross-head 2| will move upwardly to the position shown in Fig. 3. When rotation of the cylinder A is resumed, the sheet will'be doubled back under the device C, starting as indicated by the dotted lines in Fig. 3, and continued movement will cause the printed sheet to be completelyinverted and the unprinted-i face will be brought into contact with the conveyors B. The cross-heads are then-lowered automati cally. and the jaws opened to free the printed sheet and permit it to be conveyed away with its freshly'printed face-up.

In order to drive the face-up delivery mechanism in promr timed relation to the printing mechanism, the device is driven from a cam 38 provided onthe crank shaft 9, described above. A ro'ck member 39 is-pivotally mounted on-the frame, as indicated at 40, and has a roller 4| which rides on the cam 38. The opposite end of the rock member is pivotally linked, as indicated at 42, to a pitman 23 which makes an adjustable pivotal connection, as indicated at 44, with a crank 45 provided on a gear shaft 46. The shaft 46 is geared to a rock-shaft 41 extending across the machine andhaving at each end crank arms 48,'whose ends are linked to the cross-heads 2| by means of pitmans 49. Thus, it will be understood that when the shaft 9 is rotated to operate the reciprocating bed, the cam 39 will serve to raise and lower the cross-heads 2| and the gripping-jaws carried thereby.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of thepriorart.

I claim:

1. In a sheet printing machine having a delivery roll over which a sheet is fed with the printed face in contact with said roll; endless conveyor belts passing around said roll beneath the "sheet; and means for lifting the front edge of said sheet away from the roll while the remainder of the sheet is fed out and inverted so 'thatthe. unprinted face of the sheet is brought gripper jaws adapted to engage the front end of the sheet when released by the second-mentioned gripper, means-for lifting said jaws away from the delivery roll before the rear portion sheet is being fed out so that-when feeding is resumed the sheet will be curled back, and inverted, and means for opening said gripper-jaws when the sheet rests on said conveyors.

3'. A device as specified in claim 2, in which a presser rolleris provided to press the sheet lightly against, the delivery cylinder, and the jaws aremoved by the lifting means in an are described about the point of contact between the presser roller anddelivery cylinder.

4. A device as specified in claim 2, in which gearyand cam means-is provided for driving the delivery cylinder and face-up delivery device in timedrelation so that the jaws are moved upwardly away from the delivery roll while rotation vof the delivery roll is stopped.

5. A- device as specified in claim 2, in which gear and cam means is provided for driving the delivery'cylinder and face-up delivery device in timed relation so: that the jaws are moved upwardly away from the delivery roll while rotation of the deliver roll is stopped, and guidemeans is provided todirect the movement of the jaws in a curved path which will keep the front end portion of the sheet smooth without sliding any of the printedsheet against the face of the delivery roll.

' LEOPOLD A. BAKKE.