US1400778A - Sheet-feeding device - Google Patents

Description

a. SIPIESS.

SHEET FEEDING DEVICE.

APPLICATION FILED NOV. 10, 1920- v v Patented Dec. 20, 1921.

8-SHEET I.

2 SHEET G. SPIESS.

SHEET FEEDING DEVICE.

APPLICATION FILED NOV. 10, 1920.

2 SHEETS-SH r a s a 12ft mi-er 2,...3 ill SHEET-JFEEDING DEVICE.

Application filed November 10,1920. Serial No. 423,063.

To all whom it may concern:

Be it known that 1, Gross Srniss, a'citizen of the German Republic, andresiding at Leipzig, Germany, have invented certain new and useful Improvements in Sheet- Feeding Devices, of which the following is a specification.

The present invention has reference to certain new and useful improvements in automatic sheet feeding devices and relates more particularly to improvements in sheet feeding attachments of the friction wheel type for printing presses, folding machines, and the like, in which the release or lifting of the friction members from off the sheet pile is effected by the edge of the fed sheet striking an opposed feeler and causing it to co-' operate with a continuously revolving drive gear, by which then, in the prior devices, a releasing mechanism of springs or weights is freed and actuated for in turn by means of a suitable motion transmitting mechanism lifting the friction feed wheels off the pile, Upon the releasing mechanism being thus freed, the parts owing to their high spring tension or weight load respectively will be actuated for disconnection very suddenly, which will cause severe strain on the parts and is apt to lead to serious damage to them.

On resetting the releasing mechanism the powerful springs must be tensioned again or the wei hts must be lifted, as the case may be, all of which seriously interferes with the smooth operation of the machine According to the present invention these defects are eifectively obviated by employing the movement of the lever arm carrying the feeler for positively lifting the friction wheels or rollers, as will now be fully described in connection with the accompanying drawings, in which Figure 1 is a side elevation of the improved sheet feeding attachment in the position of rest; Fig. 2 is a similar View, with the parts in the last stage of the operative movement; Fig. 3 shows a somewhat enlarged fragmentary side elevation of the feeder device in another operative position; Figs. 4:, 5 and 6 represent detail parts.

Fig. 1 shows the table 1 supporting the brushed-out sheet pile l and the feeding friction wheel 2 let down onto the pile. The front edge of the advancing sheet encounters the finder or feeler 3, pivotally secured to the rock lever 7, pivoted at 8'and pushes it along until its upper pawl-shaped por- Specification of Letters Fatent. Patseni'md D643. 2Q, 1921,,

tion at coacts with the peripheral teeth of.

the ratchet wheel 5 (Fig. 6). This ratchet wheel is continuously rotated in counterclockwise direction and, obviously, will now depress the pawl 1 and in so doing the latter will strike the stop pin 6 laterally extending from the double-armrock lever 7, withthe result that also this latter will be corre spondingly actuated, that'is to say is rocked about'its fulcrum pin 8. The upper end of this rock lever presents an irregular roller track composed of the relatively angularly displaced sections 9, 10, 11 and 12. In its position of rest the rock lever 7 is held in the construction shown by way of example by a spring actuated lever 13 whose front roller 1 1 then engages in the depressed track section 12 (Fig. 1), or a rigid stop may be used for this purpose with equal efie'ct.

As soon as the rock lever 7 commences to swmg in clockwise direction the roller 14 will leave the track'depression 12 and will eventually abruptly roll over the rounded apex 11 of the track (Fig. 2), with the result that the coiiperation between the pawl tand the ratchet wheel 5 is somewhat eased. though not as yet completely interrupted The spring tension of lever 13 during this operative movement is neutral as far. as the rock lever 7 is concerned.

Simultaneously the ascendingtrack section 9 (Fig. 3) presses against the roller 19 of the swing lever 15, whose ofiice it is to displace the friction wheel 2, lifts it and thereby causes the shaft 16 and with it the lever arm 17 rigidly secured thereto to be rotated clockwise. The lever 17 cooperates with the one end of a bell crank 18 whose other end supports the friction wheel 2, which, obviously, during the described movement .will be lifted off the sheet stack (Fig. 2) so that now the feed of the sheets is discontinued. The advanced uppermost sheet is then fed through between the timedly cooperating feed rollers 20 and 21 to the printing press, folding machine, well known manner.

The friction wheel 2 is retained in the raised inoperative position as long as the roller 19 remains in contact with the track section 9. r

The problem now is to completely disconnect the pawl a from the ratchet wheel 5 without injury tothe teeth and pawl respectively. ln'prior devices of this kind, which operated with springs or weights, the

or the like, in

complete disengagement between pawl and ratchet wheel was caused abruptly and before the pawl had quite reached the points;

of the ratchet teeth.

According to the present invention I use positive means for preventing the pawl 4t from Skipping over and injuringrthe teeth of the ratchet wheel 5 1n the shape of means 7 for imparting to the rock lever 7, during the disengaging operation, a speeded-up movement. Toward the end of the swing 'movement of the rock lever 7 the roller let suddenly rolls over the apex down the abruptly descending track section 10, when the spring action of lever 13 will just as suddenly swing the rock lever 7 about in cloclr ,wisedirection, with the result that to the During the stated forward feed of a sheet the shaft 25 has kept on in its counterclockwise rotation and the entire releasing mechanism is now about to be returnedinto the initial position and reset for a succeedng operation. The fixed cam 26, which par takes of the rotation of the shaft 25, encoun- 'ters the roller 27, of the rock lever 7 (Fig. 5

and returns the latter until the roller 14 drops into the recess 1520f the roller track. Together with the rock lever the feeler 3 also is carried back into its initial position of rest. Since, in carrying back the several parts no considerable forces, such as tensioning of springs or raising of weights, are to be overcome, this return movement can be accomplished in a relatively short period of time with the result that the parts are returned and reset that much quicker-and the time in which the feeler 3 remains in its operative position is extended, which considerably improves the performance of the machine. The lowering of the friction feed wheels 2 onto the paper stack is inv no wise affected by this return of the releasing mechanlsm.

Prior to the roller. 19 leaving the track section 9 a roller 28 of the lever-15 coacts with the cam 29 fixed on the shaft 25 (Fig. 4) and there is formed between the oblique track section 9 of the receding rock lever 7 and the roller 19 an interspace, the lever 15 being prevented from dropping down further. Thus, even though the releasing mechamsm has assumed again its position of rest, the friction wheel 2 is still raised above the sheet pileand it will be let down only. after the cam 29 has rotated far enough to oppose to the rolls-r28 the reduced portion 29.

1 Inorder to prevent the edge of the fed sheet from striking the feeler 3 after the period of time in which the sheet feed must have ended has elapsed, the friction wheel 2 will be lifted by the cam 29 raising the roller 28 and thus the lever 15 even if at the termination of the friction period a sheet has not advanced far enough to contact with the feeler. V v V /Vhat I claim is V V l 1. in a sheet feeding device of the character set forth, in combination with a table supporting the stack of sheets, friction means for consecutively feeding single sheets from said stack, and a feeler in the path of the advancing sheet and operated by the impact with the front edge thereof, means actuated by said feeler for positively throwing said friction feed means out of operative contactwith the sheet stack, comprising arock lever pivotally supporting at its lower; end the said feeler'and presenting at its upper end an irregular roller.

track, a bell crank lever, a roller-at the free end thereof adapted for actuation bysald irregular track, a second bell crank lever,

said friction feed means journaled in the one end thereof and its other end coacting with the first said bell crank lever, the cohperation of said roller track, and said bell crank lever roller being so timed that the friction feed means are lifted off the stack of sheets when said rocklever is operated by said feeler being tilted by the advancing sheet. p

2. In a sheet-feeding device of the character set forth, in combination with a table supporting the stack of sheets, friction means for consecutively feeding single sheets from said stack, and a feeler in the path of the advancing sheet, means actuated by said feeler for positively throwing said friction feed means out of operative contact vwith the sheet stack, comprising a rock lever pivotally supporting at its lower end the said feeler and presenting at its upper end an irre ular roller track, abell crank lever, a roller at the free end of this bell cranlr lever adapted for actuation by said irregular track, a member journaling said friction feed meansand adapted to be positively operated by said bell crank lever for throwing said friction feed means into and out of cotiperation with the sheet stack in timed-relation to the operation ofsai d feeler, andmeans for retaining said friction feed means in the raised inoperative position for a brief period after the said rock lever has returned into its position of rest,

comprising a second roller on said bell crank emes V lever and a continuously operable cam adapted to coact with said second roller in timed relation to the movement of said rock lever.

3. In a sheet feeding device of the character set forth, the combination with the sheet supporting table, a sheet feeding tfriction roller a double-armed spring-influenced.

fecler in the path of the sheet feed, and means positively coupling said feeler and said friction roller, of a rock lever pivotally supporting at its lower end said feeler and presenting at its upper end an irregular roller track, a continuously rotatable ratchet Wheel adapted to periodically coact with said. l'eeler for actuating said rock lever and means for quickly irictionlessly disconnecting said feeler and. said ratchet Wheel, comprising a spring-actuated roller ended lever operating on said irregular roller track, normally keeping said roclr lever in the inoperative position by engaging in a depression in said. track. and periodically abruptly throwing over said rock lever in-

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