US2841392A - Control for sheet feeder - Google Patents

Description

July 1, 1958 R. K. NORTON 2,841,392

CONTROL FOR SHEET FEEDER Filed 001;. 20, 1955 2 Sheets-Sheet l INVENTOR.

ROBERT K. NORTON BY I ATTORNEYS July 1, 1958 R. K. NORTON CONTROL FOR SHEET FEEDER 2 Sheets-Sheet 2 Filed Oct. 20, 1955 III FIG.3

INVENTOR ROBERT K. NORTON BY I '4 ATTOR Y5 CONTRGL FOR SHEET FEEDER Robert K. Norton, Twinsburg, Ohio, assignor to Harris- Intertype Corporation, a corporation of Delaware Application Qctober 20, 1955, Serial No. 541,779

6 Claims. (Cl. 27127) This invention relates to improvements in controls for sheet feeders, more particularly controls fol-interrupting suction to sheet gripping and forwarding means in a sheet feeder. The invention provides means for interrupting suction instantaneously when a press with which the feeder is used -has impression thrown off automatically because a sheet about to enter the press is disarranged, or because there is an absence of a sheet at the front stops at a time when a sheet should be ready to enter the press.

It is difficult to stop suction to the sheet gripping and forwarding means instantaneously by merely opening the suction line to atmosphere, and this is true particularly Where a Vacuum wheel feeder is employed inasmuch as some residual suction tends to remain in the suction passages of the wheel that have passed the point of connection with the suctionline. Means for cutting off suction in a positive manner have been proposed, but in general they have been cumbersome and costly. The present invention in which suction is utilized for cutting oif the vacuum to a vacuum wheel is a departure from the prior art, is effective, and is of relatively low cost.

One of the objects of the invention therefore is the provision of a valve in the suction line for cutting off suction to the sheet gripping and forwarding means, which valve is operated pneumatically through a suction connection fr the suction line.

Another object is the provision of control means for the pneumatic operation of the valve that is adapted to be set in motion by sheet detecting means of conventional character.

Other objects and features of novelty will appear as 1 proceed with the description of that embodiment of the invention w. "ch, for the purposes of the present application I have illustrated in the accompanying drawing, which Fig. l is a side elevational view in schematic form and n of a pile feeder embodying the inr being in normal operating condition.

Fig. 2 is a tragnrental elevational view with the parts in position to cut off suction to the sheet gripping and forwarding means.

Fig. 3 is a fragmental sectional view illustrating the mounting of the vacuum wheel and the means for driving the same, and

Fig. 4 is a fragmental plan view of the same.

Referring now to Fig. l of the drawing, represents a pile of sheets from the top of which sheets are to be fed off one after another into the bight of pull-0ut rolls 11 and 32 an; onto the upper run of endless tapes 13 and over a feed board 14 to front stops 15. From this position the sheets are taken for entry into a printing press, not shown, or other sheet handling machine.

In the case illustrated herein individual sheets are gripped near their forward edges by a vacuum wheel 16 and forwarded. The invention is applicable however to feeders in which other types of suction feeding means are retested July l, was

ice

utilized. As shown in the drawing the vacuum wheel 16 has its periphery slightly below the bottom of a plate 17 that is supported a short distance above the top of the pile. The wheel 16 is driven continuously while the feeder is running, even when the feeding of sheets is discontinued as will be pointed out later. The wheel has sucker months 55 in a portion of its periphery, these months havin connection with side ports 18 which register one after another with a fixed ported fitting 19 as the wheel turns clockwise. The fitting 19 bears closely against the side of the wheel, and from it extends a suction line 2%}. The opposite end of suction line 2%? its into a perforation 21 formed in one side wall of a valve cylinder 22 within which a spool shaped piston 23 is mounted to slide. This piston is biased by a coil spring 2% toward its down position illustrated in Fig. 2, the spring bearing at one end against an end wall attached to the cylinder and at its opposite end against a recessed wall in one end portion of the piston. Motion in the downward direction is limited by a stop 26.

In the cylinder wall opposite perforation 21 there is another perforation 27, these two perforations providing a passage through the cylinder when the constricted part of the spool shaped piston is in the intermediate position illustrated in Fig. l. A second tubular conductor 2. 3 is attached to the cylinder in communication with the perforation 2'7 and leads to a suction pump 28 or other suction source. The two conductors 2d and 213 will be referred to hereinafter as constituting a suction line between the suction source and the vacuum wheel or other sheet gripping and forwarding means.

Above the perforation 27 and near the upperend of cylinder 22 there is third perforation 39 with which a conductor 31 is connected. Conductor 31 ext through a smooth surfaced plate 32 forming part or the frame of a printing press served by the feeder. The conductor 5i terminates in an atmosphere port 33 in the frame. in the normal operation of the feeder port 35 is covered by a shutter plate 34 which is ca .ied by a shutter operating arm 35 pivoted at 36' to the frame and provided with a knob or handle 37 for manual operation.

Operating arm 35 is biased toward port opening position by a coil spring its movement in response to the spring 'ction is limited by a stop 39 on the frame and an ustabie spring backed pin 4 on the arm. A era pro} non 4i integral with the arm carries a pin .2. which will be referred to hereinafter as a follower since it cooperates with a cam surface 43 on a trigger 4 that is pivotally mounted at 45 on the frame. A coil spring urges the trigger against a stop pin 57 that is mounted on the frame and is adjustable in much the some manner as the pin 4%.

in the normal operation of the feeder the lower arm of the trigger presents an abutment 48 against which the follower i2 bears, latching the shutter arm 35 in the Fig. 1 position against the pull of spring The trigger however may be tilted toward the left, or counterclockwise, to a slight extent suflicient to release follower as when spring 38 will act instantly to throw arm 35 to the Fig. 2 position, uncovering the atmosphere port 33.

The two horizontal perforations 2'7 and 30 in the cyinder housing are connected by a vertical passage 5% so that the conductor 31 is in constant communication with the conductor 2%). The conductor 20 is also in constant communication through passage 5%) with the chamber Si in the upper end of the cylinder. The passage and the perforation therefore constitute a suction connection between the suction source and the valve capable of exerting an upward pull on the piston, and this suction passage is in constant communication with the normally closed atmosphere port 33.

'tion 'line to the vacuum wheeli' is open.

suction efiective in the chamber 51 of the cylinder holds the piston 23 in the position of Fig. l, the suction which is. effective on the full area of the. piston 'beingstr'ong enough t'o'overcorne the pressure of the spring .24. This places the constricted part of :the piston in line'wit-h the passage through perforations Q27 and 21 so thatthe suc- Now should there be a misfeed of sheets, a conventionalsheetdetecting means, not shown, would set in bperation' h sin, not shown, to tilt trigger counterclockwise rel anng the shutter arm 35'wh'ichwould then swing about its pivot due to the action of spring 38 until it assumed the position of Fig. 2, thereby opening atmosphere port 3 3.

The suction in chamber 5 1 would thus be reduced markedly'and spring 24 would'depress the piston 23 to the Fig. 2 position where it would block completely tl e suction passage through'the valve and stop. suction to the vacuum wheel, thereby interrupting promptly the feed of the top sheet. of the pile. The vacuum wheel continues 'to rotate, but the top sheets. of the pile are not disturbed 1 since the suction was positively shut off.

Now as soon as the operator shall have rearranged the 'sheetor sheets on the feed board to correctitie' in feed condition he may grasp the handle 37iand pull it downward, causing the shutter plate'34 to close'the atmosphere port 33 to establish suction in the top of the cylinder and thereby raise the piston to rthe valve. open position of Fig. 1. At the'same time follower iZivill run upon the cam surface 43 to tilt the trigger counterclockwise until its abutment 48 can swing down owing to the action of spring 45 to latch the shutter arm in the operative 'posi- 'tion of Fig. l.

The pivot 36 may conveniently be operatively'connectedwith the impression throwolf mechanism of the press with which the feeder is used, this mechanism being;

set in motion by the tripping of the trigger 413 to throw 'impression'ofi Also when operation of the feeder is to be resumed the operator in manually'swinging the shutter arm down to operative position to start the feed will also start the mechanism for throwing on impression in thepress, V V, Having thus described my'invention, I claim:

'1. in apilefeeder', suction means for gripping and forwarding the top sheet ofthe; pile, a suction source, a

suction line'from said'source to said suction means, a

valve'in said'suction'line, a normally closed atmosphere port, said valve comprising a chamberopen to said source and said port, springjmeans in said chamber biasing said valve to closed position, the suction in said chamber functioning. in'opposition to said "spring 11621118 for over coming the; action of-said spring means and maintaining the valve open, meansfor opening said normally closed port, and trigger meansjadapted to be actuated by sheet detecting means for setting in motion said port opening means, whereupon saidspring ;means acts" to close said means adapted to overcome theflaction of said spring 'rneans andrnaintaln the valve open,said connection having an atmosphere port, a shutter for closing said'port biased toward port opening position, and a trigger for iholding said shutter in port closing position, said trigger being, adapted to 'be actuatedby sheet detecting mechanism for. releasing said shutter to uncover said port,

where-upon said spring means acts to close said valve and interrupt sheet feed. 7 s

. 3. A pile feeder as defined in claim 2, comprising a pivoted mounting for said shutter, a cam surface on said' trigger and a, cooperating follower on said shutter, .said

j shifting said trigger 'tonormal position in whic'h'it trigger norm-ally contacting said follower to hold said shutter in ,port closing position, said trigger when tilted releasing said follower and. permitting said shutter to swing 'to port open position, whereby said shutter'may be valve comprises a cylinder with a closed end and'a spool shaped piston .slida'ble in the cylinder, said cylinder hav-' ing a transverse passage therethrough forsaid suctionline when the constricted part of the spool shaped piston is in an intermediate position in the cylinder, one end por:

tion of the piston being adapted to block said passagd' said spring 'means being adapted to shift said piston-to bring said end portion .into passage blocking position,

and said suction connection being open to'the closed end of the cylinder for acting upon the piston in opposition to the force of said spring means. 7

5. In a pile feeder, a continuously turning rotary vacu um' wheel sheet gripping and forwarding device close above the top of the pile, a suction source, a suction line from'said source to a ported fitting adjacent the wheel, said wheel comprising a series of ports arranged to register one after another withsaid ported fitting as the wheel turns, a sheet gripping suction mouth in the periphery y of said wheel connected with each of said ports, a valve in said suction line, spring means biasing said valve to closed position, a suctionconnection from said source to said valve functioning in opposition to said spring means adapted to overcome the action of said spring means, said connection having a normally closed atmosphere port,.means for opening'said port, and trigger means adapted to be actuated .by sheetdetectingnieans for setting in motion said opening means for said atmosphere port, whereupon said spring means acts ,to'close' -tion gripping means takes t'h'e top sheet of a pile and forsaid valve and interrupttsheet feeding.

6. In a sheet feeder for'a printing press wherein sucwards 'it to said'p'ress, suction creating means, means communicating suction from said creating to said gri ping means, valve means intermediate said creatingand said gripping means, said valve means comprising a cyl inder and a 'piston reciprocable therein, springmeans urging said piston in .one direction to shut oifsuction from said suction creating means to said gripping means, a suction connection from said suction creating means to said valve means cooperating with said piston to urge, said piston in opposition to said spring means into valve open position and means operable upon the absence of References Cited in the file of thispatent UNITED STATES PATENTS 7 Dexter Nov. 20;, 1928 Bailey Q July 7(1953

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