US2284430A - Sheet feeding mechanism - Google Patents

Description

May 26, 1942. I ,1. F. JIROUSEK 0 SHEET FEEDING MECHANISM I Filed Nov. so. 1940 -s Sheets-Sheet 1 INVENTOR.

JOSEPH EJIROUSEK ATTORNEYS May 26, 1942. J. F. JIROUSEK SHEET FEEDING- MECHANISM Filed Nov. 30,1940 sheets-shed 2 Iii 28 29 I "7! T /.s I 5% Fla-L5! i 59 i HEP? $15M 60 1 g 59 3 56 El g i9 59 T 5 i 57 57 i 6| 57 66 51 mm 56 58 e5 e3 8 58 64 vi l 58 5 64 v 2' 65a 8 v JOSEPH EJIROUSEK 631 i 72F-IE 6 Q 1 y ATTORNEYS.

May 26, 1942; J. F. JIROUSEK SHEET FEEDING MECHANISM Fil ed Nov. 30; 1940 3 Sheets-Sheet 3 INVENTOR. JOSEPH EJIRO USEK BY l ATTORNEYS- sna'a'r FEEDING rmsM doseph r. .i'ironsek, Cleveland, Ohio, assignor a- The Chandler. a Price (.lonipany, Cleveland, Gino, a corporation of Ohio Application November 30, 1e40, serial No. 367,993

12 line. (Cl. 271-12) This invention relates, as indicated, to feedin mec for printing presses, and especially presses of the lithographic or offset type. This invention isalso concerned with a new and improved method of feeding sheets whereby such sheets may be forwarded in lapped relation.

This application is a continuation in part of Fig. 5 is a sectional view along the line 5-5 on Fig. 4. showing one of such air blast means;

Fig. 6 is an elevational view of the rearroller of the sheet conveyor illustrating the position of theair blast means at the forward edge of the stack;

my co-pending application Serial No. 299,308,

filed October-13, 1939, to which'reference may be had for those details of construction with which the present invention is not primarily concerned.

The primary object of this invention is to provide a sheet feeding mechanism adapted to separate and advance a large number of sheets in a short space of time without the necessity of overly rapid 'movement of such sheets en route from the stack to the impression cylinder.

Another object is to provide such mechanism whith is simple in construction and maybe ad- .iusted for eficient use without the exercise of unusual shill.

A further object of this invention is to provide 9 a method of separating sheets in a stack which will be rapid and positive in action.

, lated ends, said invention, then, consists of the means hereinafter fully described and particular- 1;? pointed out in the claims, the annexed drawhide and the following description setting forth in detail certainmeans and one mode of carrying out the invention, such disclosed means and mode illustrating, however, but one of various ways in which the principle of the invention may he used.

in said annexed drawings:

Fig. l is a fragmentary top plan view of the feeding mechanism of this invention;

g. 2 is a sectional view of the cam mechanism operating the sheetpicker means, -taken along the line 22 on Fig. 3;

Fig. 3 is a side elevational view of such operating mechanism taken along the line 3-3 on Fig. 4 is a rear elevational view of the sheet with attendant air blast and Fig. 7 isja sectional view through such air blast means taken along the line on Fig. 5;

Fig. .8 shows one of the hold-down means at the rear edgeof the stack and is takenalong the line 8-8 on Fig. 4;

Fig, 9 is a sectional side elevational view of the sheet feeding mechanism of this invention showing the path of movement of the sheet from stack to impression cylinder;

Fig. 10 is a somewhat diagrammatic illustration of the sheets in process of being conveyed, showing their underlapping relationship;

Fig. 11 isa somewhat diagrammatic sectional view showing a sucker tip seizing the top-most sheet of the stack;

- Fig. 12 is a view similar to Fig. 11, showing the position of such sucker mechanism immediately atfer vacuum has been applied thereto; and

Fig. 13 shows the further path of movement of the sucker tip.

Referring now more particularly to saidannexed drawings, the sheet feeding mechanism of this invention comprises sheet picker means adjustably mounted on the frame I of the press and sheet conveying means for transporting the sheets to the impression cylinder-2.

The sheet picker assembly is constituted as follows: Attached solidly to the framel of the press and on either side of the feed table which supports a. stack 3 are racks such as i on which.

move pinions such as 5. At each end of pinion shaft 6 and supported on sleeves embracing said racks are end members such as l which carry cross shafts 8, 9 and It therebetween. Shafts 9 and III are hollow, shaft 9 being adapted to carry compressed air and shaft it being connected to a vacuum line. Shaft 8 is rotatably mounted in bushings in end members 'lwith a bevelled gear ii at one end. Engaging said gear is another bevelled gear I3 slidably keyed to shaft it by means of a groove is in said shaft. Gear is may be fixedly positioned on such shaft by means of a set screw which effectively prevents movement of such pinions on'such racks in a direction toward said impression cylinder. Movement in the other direction is prevented by a sleeve ll about shaft M which is bolted to the end member i. By means of bevelled gears i8 and i9 power is v derived from. the cross drive shaft 29 when the thereto.

2 pin 2| is in engagement with the slot 22 in gear l9. Conventional clutch means controlled by lever handle 23 isvemployed to effect such an engagement and disengagement.

Slidably positioned on shaft 8 isthe sheet picker means of this invention. Such means comprises a rectangular block 24 mounted on shaft Band reciprocable within a U-shaped member 25. The upper portions of the arms of such U-shaped member are bridged by a plate 26 carrying a cam roller 21 which rides on cam 28 and thus supports such U-shaped member 25. A coil spring 29 keeps ,roller 21 and cam 28 in close engagement. Piercing the upper ends of such u-shaped member and sildably mounted therein is a rod 39. A member 3| is pivotally attached to the lower portion of such U-shaped member and connected to a stud 32 on rod 30 by means of the link 33. A roller 34 is mounted on said member 3| in position to engage cam 35, which, upon rotation, thusacts to reciprocate rod 30.

A coil spring 36 is compressedbetween terminal stop 31 and bracket 38 attached to such U-shaped member and serves to maintain 'roller 34 in constant engagement with cam 35. A crescent-shaped arm 39, attached to block 24 by two pins 40 and 4!, embraces shaft 9 and thus prevent pivotal movement of the whole'picker assembly about shaft 8. It will now be seen that rotation of shaft 8, with consequent rotation of cams 28 and 35, will result in both vertical and horizontal reciprocation of rod 30 and the sheet picker means carried thereby, as more particularly described below.

tical tubes 46 and 48'are carried forwardly in such brackets and communicate by horizontal extensions 41 and 41' with vertically disposed suction tubes such as '48. A tubular piston or plunger 49 is fitted within the lower portion of tube 48 with a pin- 50 serving as a, stop in slot to limit the degree of reciprocation permitted A coil spring 52 in the upper portion of tube 48 tends to urge such plunger downwardly to the degree permitted by such stop. A rubber sucker tip 53 is provided on the lower end of such plunger which protrudes from tube 48. Suction lines 54 and 54' are also provided,

sheet being handled should render such desirable. As best shown in Figs. 4, 8 and 9, hold down means are provided to bear at spaced in-' tervals on the upper surface of the stack adjacent the rear edge thereof. Brackets 55 and 58 are mounted on shaft l8 and carry laterally extending rods 58 and 58. Adjacent the ends of such last-named rods are small vertically disposed rods 51 'to which the hold-downs proper may be clamped. Such hold-downs comprise wire spring members 58 set in blocks 59 adaptedv to be adjustably positioned on such vertical rods 51 in order to obtain the desired degree of pres-' sure on the rear edge of stack 3 (see Fig. 8).

Also carried in such brackets 55 and 55' are rods 60 and-80 carrying arms 6i and 6! at their respective ends. Clamping members 62 and 62' are pivotally mounted on such arms with springs 63 and 63' tending to hold such clamps in engagement with stops B4 and 64'. Air blast tubes 65 and 65 are carried in such clamps and are connected by rubber tubing such as 66 with hollow shaft 9 to which air pressure isadapted to be intermittently applied. The position of such rubber tubes is shown in Fig. 4 by means of dash lines to avoid obscuring other portions of the drawings.

Air blast means is also provided adjacent the forward edge of the stack, such means being best illustrated in Figs. 1, 6 and 7. The hollow tube 61 is adjustably held in clamp 68 mounted on cross rod 69. The upper end of such tube is closed and a vertcal slit I9 is provided toward the forward edge of the stack. Conveyor roller ii is cut away except for a core portion so that it may not undulyblock the air blast. Rubber tubing I2, connected to the lower end of tube 81, communicates with an air pressure source adapted to provide intermittent blasts of air thereto.

Conveyor means is provided for forwarding the 4 shaft l4. Tension in saidbelts is maintained by means of a belt tightener ll. Hold-down means comprising rollers 18, rollers 19, brushes and freely rotatable balls 8|, are adapted to rest on the sheets as they are forwarded in underlapping succession to the impression cylinder. Rods 82 further serve to keep the sheets in position. A

" resiliently mounted roller 83 is adapted to be intermittently raised and lowered by action of a cam 84 mounted on shaft 20. Such movement of this roller is timed so that the roller may be raised when the forward edge of a sheet is in' process of being presented to the conveyor.

The operation of the device of the present invention may be now understood by referring to Figs. 9 to 13 inclusive. The air blasts both at the forward and rear edges of the stack come on causing several of the uppermostsheets of the stack to becomeseparated from each other and partially floated. The rear edges of such sheets are, however, retained beneath hold-downs i8 and, after forwarding of the sheets has been commenced, the forward edge of the topmost sheet of the stack will be held beneath the rear portion of the next preceding overlapping sheet' in process of being forwarded. As shaft 8 revolves, the cam mechanism above described causes the sheet picker mechanism to descend and suckers 53 to' contact the rear portion of the topmost sheet, as shown in Fig. 2. Suction is then applied to such sucker tips causing the same to seize the sheet, and plunger 49 is then at once abruptly retracted in tube 48 by action of the vacuum resulting when the sucker orifice is closed by the sheet, as shown in Fig. 12, elevating the body of such topmost sheet considerably above the subiacent sheets. As shaft 8 continues to tum, the cam mechanism causes the sucker tips to rise to the position illustrated in dash line in Fig. 13. At this point the air blasts are turned off and rotation of cam 28 causes the picker mechanism to be advanced,

withdrawing the rear edge of the topmost sheet portion of the next suceeedingsheet on the stack,

preventing displacement of the same. The suction is then turned off, permitting the suckers to'release the sheet and the sheet picking mechanism returns to position to repeat the cycle. The, sheets will preferably be forwarded in underlapping relationship, as illustrated diagram matically in Fig. 10, it being noted that the sheets are forwarded at such intervals that portions of three successive sheets are desirably superimposed. -It will of course be. understood that the relationship of one sheet to the next may be modified as desired by proper timing of the sheet picker and conveyor mechanism.

From the foregoing it will be readily seen that the sheet feeding mechanism of this invention is relatively simple both in construction and operation, and when once properly adjusted requires very little further attention. The stack of sheets is of course elevated in the usual manner; as sheets are removed from the top thereof; in order that the'upper level of the stack maybe substantially even. with, or a trifle below, the sheet forwarding conveyor. Also, with certain types of sheets, the rear air blasts may not be required, although generally desirable. Other modes of applying the principle-of. my invention. may be employed instead of the one explained, change being made as -regards the seize, elevate and advance the top-most sheet'of aistack, and air-blast means positioned to direct=blasts of air against the forward and rear edges of such stack operative during the elevation of such sheet.

2.1n sheet feeding mechanism for printing presses and the like, suction means operative to seize and abruptly elevate the top-most of a stack, hold-down means at the rear edge of such stack, means for advancing said suction means and thus such sheet, and air-blast means positioned to direct blasts of air against the forward and rear edges of such stack operative during the elevation of such sheet.

3. In sheet feeding mechanism for printing.

presses and the like adapted to feed sheets in lapped relation, hold-down means operative to bear on the rear edge of a stack of sheets, air- .blast means positioned to direct blasts of air against the forward and rear edges of such stack and'operative to separate the ton-most sheet from the next subjacent sheet of the stack,'and suction means operative to seize, abruptly elevate, and advance such sheet.

4.121 sheet feeding mechanism for printing presses and the like, suction means adapted to seize and abruptly elevate a sheet comprising a aaeasso vertically disposed cylinder, a tubular piston therein having its lower end protruding therefrom, means limiting the degree of reciprocation permitted to said piston, resilient means within said cylnder tending to force said piston downwardly, a sucker tip on such protruding end, and a vacuum line connecting with sai cylinder.

5. In sheet feeding mechanism for printing presses and the like, means for initially separating the top-most sheet of a stack from its next subjacent sheet comprising a hold-down adapted to bear on the rear edge of such stack. and air-blast means disposed in position to direct blasts against the rear and forward edges of such stack and adapted to be operated while the forward edge of such top-most sheet is still overlaid by the preceding sheet in process of being forwarded.

6.v The method of feeding sheets to a printing press or the like which comprises blowing against the rear and forward edges of a stack to separate the top-most sheet from the next subjacent sheet of such stack, abruptly elevating the rear portion of such sheet by suction means, and advancing such sheet while the forward edge of such sheet is still overlaid by the preceding sheet in process of being forwarded.

'7. The method of feeding sheets to a printing press or the like which comprises blowing at the rear and forward edges of a stack to initially separate the top-most sheet from the next subjacentsheet of such stack, the forward edge of such top-most sheet being still overlaid by the preceding sheet in process of being forwarded and the rear. edge of such top-most sheetbeing confined by hold-down means, abruptly elevating the rear portion of such top-most sheet by sucs tion means, discontinuing such blowing, and advancing such sheet by action of such suction means in underlapped relationship to such next preceding sheet. a

8. The method of feeding sheets to a printing press or the like which comprises blowing at the forward edge of a stack to initially separate the top-most sheet from the next subjacent sheet of such stack, the forward edge of such topmost sheet being still overlaid by the preceding sheet in process of being forwarded and the rear edge of such top-most sheet being confined by hold-down means, abruptly elevating the rear portion of such top-most sheet by suction means, discontinuing such blowing, and advancing such sheet by action of such suction means in underlapped relationship to such next preceding sheet.

9. In a method of feeding sheets from a stack to a printing pressor the like, the steps comprising blowing the forward edge of such stack,

holding down the rear edge of the topmost sheet of such stack whereby the rear portion of such topmost sheet may be upwardly bulged, seizing such .bulged portion with suction means, and abruptly elevating such means.

10. The method of feeding sheets from a stack to a printing press or the like which comprises blowing the forward edge of. such stack, holding down the rear edge of the topmost sheet of such stack whereby the rear portion of such topmost sheet may be upwardly bulged, seizing such. bulged portion with suction means, elevating such means whereby to elevate the rear portion of such sheet, and advancing such sheet while the forwardedge thereof is still overlaid by the next preceding sheet in process of being forworded.

11. The method of feeding sheets from a stack to a printing press or the like which comprises blowing the forward edge of such stack, holding down the rear edge of the topmost sheet of such stack whereby the rear portion of such topmost sheet may be upwardly bulged, seizing such bulged portion with suction means, abruptly elevating such means whereby to ensure separation of the rear portion of such sheet from the next subjacent sheet, and advancing such sheet while the forward edge thereof is still overlaid by the next preceding sheet in process of being forwarded.

' JOSEPH F. JIROUSEK.

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