US2725229A - Sheet feeding apparatus - Google Patents

Description

Nov. 29, 1955 A. P. BATTEY SHEET FEEDING APPARATUS 2 Sheets-Sheetl Filed Sept. 22, 1951 lll INVENT R aw? ATTORNEY N 1955 A. P. BATTEY 2,725,229

SHEET FEEDING APPARATUS Filed Sept. 22, 1951 2 Sheets-Sheet2 mvsw TOR flepuxzwaaza a? A TT RNEK United States Patent SHEET FEEDING APPARATUS Alfred l'ierssene Battey, Barwick-in-Elmet, England, assignor to R. Hoe & Co. Inc., New York, N. Y., a corporation of New York Application September 22, 1951, Serial No. 247,793

4 Claims. (Cl. 271-56) This invention relates to sheet feeding apparatus of the kind employing pneumatic suckers which are given movement in constantly recurring cycles and to which in different parts of the cycles vacuum is supplied in automatic timing to cause the sucker to take charge of a sheet and to move it, the vacuum then being cut off to free the sheet when the sucker returns to take another sheet. Such apparatus is commonly employed to take sheets one at a time from a pile and to advance them towards a machine, such as a printing machine which is to operate on the sheets.

Such apparatus provides a manually operated control (hereinafter referred to as a hand device) by which the feed of sheets can be interrupted or recommenced at will. Such hand device usually operates a valve to render the vacuum supply to the sucker effective or ineffective,

the supply when rendered ineifective making it impossible for the sucker to hold a sheet to itself. The device may in addition operate a clutch or similar mechanism to render part or the whole of the machine inoperative. For example it might stop the conveyor bands which carry the sheets towards the machine on which they are to beoperated on. the control of a vacuum alone will be referred to. Obviously such a hand device can be operated at any time in the operating cycle of the sucker. Thus vacuum could be cut off at a time when the sucker has charge of a sheet and this would result in the sheet being released at an improper time in its advancing movement with consequent derangement in essential sheet sequence in the feed. Conversely the operator could operate the hand device to open the vacuum line when the sucker is not properly located to take a sheet and this again would cause disturbance in the sheet sequence.

The main object of this invention is to provide an arrangement which while incorporating a hand device to discontinue and recommence the feed of sheets will permit that control to be effective only during a safe period in the operating cycle of a sucker, i. e. when suction is not applied to the sucker.

According to the present invention the hand device, instead of operating direct on the vacuum control valve, operates through a timing component which is actuated in step with the vacuum and non-vacuum periods in the operating cycle of the sucker. this component operating to render the hand device effective only during the non-vacuum periods. Thus in effect the hand device pre-sets the control valve (to make the vacuum supply effective or ineffective) for operation at a proper time in the cycle as governed by the timing component.

The invention is illustrated in one form of construction in the accompanying drawings in which Figure 1 is a side elevation of a sheet feeding installation, and Figures 2, 3 and 4 are detail views to a larger scale of the essential parts of the invention, Figure 2 being a sectional side elevation, Figure 3 a sectional plan view and Figure 4 a local elevation.

Referring firstly to Figure 1 there is employed a board 1 which supports a pile 2 of sheets, the board being sup.-

For convenience in the following description ported by chains 3 or by other flexible supports. The chains depend from a shaft 4 which is supported by a frame 5 and which is operated at intervals to maintain the top of the pile 2 within the reach of pneumatic suckers (of which only one is indicated at 6) disposed over the rear end of the top sheet of the pile. Disposed behind the rear end of the pile are nozzles 8 to which air under pressure is supplied. Over the forward end of the top sheet of the pile 2 are forwarding pneumatic suckers (of which only one is indicated at 9). The suckers 6 and 9 are raised and lowered pneumatically by ram and cylinder arangements 11 and the arrangement 11 of the suckers 9 is rocked to and fro so as in their forward movement to deliver the leading end of the top sheet to the nip of forwarding rollers 10.

Such an installation is in common use and for the purpose of understanding the present invention it is believed sufiicient to describe briefly a typical operating cycle. The suckers 6 are lowered to the top sheet of the pile 2 and vacuum is applied to them to cause that sheet to adhere to the suckers as they are raised at which time the nozzles 8 deliver jets of air under pressure to assist in the separation of the top sheet. The suckers 9 are lowered at this time and vacuum is applied to them to cause the front end of the top and now separated top sheet to adhere to 3 them and then the suckers 9 are swung forward to deliver the front end of the sheet to the rollers 10. When the suckers 9 are in charge of the sheet, vacuum is cut off from the suckers 6 to release the sheet and these suckers 6 then commence the next operating cycle to take the freshly exposed top sheet of the pile. The suckers 9 having delivered the sheet to the rollers It) the vacuum applied to them is cut off and the suckers 9 swing back to commence another operating cycle.

It is obvious that in each cycle the pneumatic suckers 6 and 9 both have vacuum and non-vacuum periods. It is usual in such installations to provide a hand device which operates a valve by which vacuum is cut off from the operating parts of the installation. This hand device can of course be operated at any time. Thus it could be operated at a time when the suckers 9 have only partly advanced the sheet with the result that the cessation of vacuum would cause the sheet to be freed from control so that when the hand device is again operated to resume the feed of sheets the freed sheet would not be disposed to be taken by the suckers 9 from which it had been freed. Again the operator might discontinue the supply of vacuum to the suckers 6 when they are rising and taking with them a sheet which will thus pass down out of control and in the wrong position to be again taken when vacuum is re-established. Such conditions obviously operate against the maintenance of the steady sheet feed which is essential and it is the purpose of the mechanism now to be described to prevent such disadvantages while at the same time giving the operator control of the apparatus.

In the particular arrangement shown in the drawings the hand device is constituted by a lever 12 which is secured on a spindle 13. The vacuum on off control is constituted by an on-off cock or a vacuum control valve having a spindle 14 (Figure 2).

Now, instead of connecting the hand lever 12 directly to the spindle 14, the spindle 14 is arranged to be operated by a cam 15 which rotates in phase with the operating cycle of the machine and hence in phase with the vacuum and non-vacuum period of the suckers 6 and 9. The cam has an operating surface 16 (Figures 2 and 3) engaged by a roller or cam follower 17 on an arm 18 pivoted at 19 which is loaded by a spring 20 holding the roller 17 against the cam 15. This operating surface 16 is set angularly on the cam so as to pass under the roller 17 during the nonvacuum period.

To the free end of the arm 18 is pivoted at 21, a push rod 22 which is embraced between blocks 23, 24 on a rod 25 mounted in a block 26 which is pivotally mounted onan arm 27 secured to the spindle 13.

With the parts so far described, the continuous rotation of the cam 15 will cause the arm 18 to oscillate and the push rod 22 to rise and fall. The rising movement of the push rod 22 will be in step with the non-vacuum periods of the installation since the operating cam 15 itself is in phase with those periods.

The rising movement of the push-rod 22 is utilized to etfect operation of the spindle 14 to open and to close the vacuum supply to the suckers 6 and 9 and this operation of the push-rod is rendered effective under the control of the hand lever 12. As the rising movement of the push rod 22 is in phase with the non-vacuum period of the suckers 6 and 9 it follows that the operation of the hand lever 12 is effective only in the non-vacuum period, i. e. at a time when the suckers are not lifting or otherwise controlling a sheet. In other words, the actuation of the hand lever merely pro-sets the vacuum control spindle 14 for actuation during a safe period.

This is eifected by providing two arms 23, 29 forming abutment supports which are mounted to rock on a common pivot 36. The arm or abutment support 23 carries an abutment in the form of a pin 31 and this arm is connected by a rod 32 to a lug 33 on a sleeve 34 secured to the spindle 14. The arm or abutment support 29 similarly carries another abutment in the form of a pin 35 and this arm is connected by a rod 36 to a lug 37 on the sleeve 34. It will be assumed that with the parts in the position shown, the hand lever 12 is in the setting corresponding to the vacuum or position. The mechanism has already been operated and the operating part 16 of the cam 15 has caused the pins 31 and 35 to be displaced to the position shown and the spindle 14 to be correspondingly turned to the vacuum olf position.

When now it is desired to open the vacuum supply, the hand lever 12 is moved in a clockwise direction and this causes through the rod 25, the push-rod 22 to swing on its pivot 21 from a position of alignment with the abutment pin 35 toward one of alignment with the abutment pin 31. When now the push-rod 22 is next caused to rise by the operating surface 16 of the cam 15, its upper end will engage and then move upwardly the pin 31. This movement of the pin 31 will cause the arm 28 to rock about its pivot 30 and at the same time it will through the rod 32 rock the spindle 14' to reestablish the vacuum supply to the suckers 6 and 9.

The movement of the spindle 14 will be transmitted back, through the rod 36, to the arm 29 which will be rocked to re-set its abutment pin 35 in a position in which it is within the reach of the push-rod 22 when it is again moved by the hand-lever 12. Until that time however, the push rod 22 will move up and down idly in register with the abutment pin 31 which it has just displaced and out of register with the pin 35.

Thus while the operator has control of the sheet feeding operation and is able to operate the hand lever 12 at any time the resulting control effect is effective only during the non-vacuum period as governed by the cam 15 so that change cannot be made in such a way as will derange the proper sheet sequence.

The hand lever 12 is biased by an over-centre spring 39 which biases the hand lever, once it has been moved to wards a position of change, to the appropriate extreme position. Thus when the lever is moved to effect a change, the push-rod 22 will be pressed against and ride by the pin 31 or 35 which is about to be displaced and when the end of the push-rod falls clear of that pin it will be sprung by the action of the spring 39 into position in alignment with the pin to displace it when the push-rod is moved upwardly by the cam.

What I claim is:

1. In a controller for a sheet feeding apparatus used with a rotary printing machine and employing pneumatic suckers for separating sheets from a pile and supporting them as they are carried toward the machine, and including a vacuum supply controlled in timed relation with the machine, to apply suction to the suckers while a sheet is being lifted and held, and periodically interrupted to destroy the suction when the sheet is to be released, the combination therewith of a valve in the vacuum supply operable for starting and for stopping the feeding of sheets while the machine is running, a timing device operated in synchronism with the machine, a pair of abutment supports connected to the valve and each having an abutment, a push rod reciprocated by the timing member and movable into position to engage the abutment on one of the abutment supports for closing the valve and alternatively movable into position to engage the abutment on the other abutment support for opening the valve, and a hand lever connected to the push rod and operable to eifect its engagement with either abutment and thereby to start, and alternatively to stop the feeding of sheets during the operation of the machine.

2. A controller as claimed in claim 1 in which the abutment supports are each pivotally mounted and connected to the valve by a rod.

3. A controller as claimed in claim 1 in which the timing mechanism comprises a rotating cam and the push rod is connected to a pivotally supported arm having a roller engaging the cam.

4. A controller as claimed in claim 1 in which the hand lever is provided with an overcenter spring, thereby biasing the push rod toward one of the said abutments to open the valve and alternatively toward the other abutment to close the valve.

References ited in the file of this patent UNITED STATES PATENTS 1,665,723 Tremper Apr. 10, 1928 2,320,100 Rupp May 25, 1943 2,622,524 Friel Dec. 23, 1952

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