US1420458A - Sheet-feeding machine - Google Patents

Description

H. STEINIVIETZ.

SHEET FEEDING MACHINE.

APPLICATION FILED JUNE 6. 1919.

1 420,458 a Patented June 20, 1922.

I a SHEETS-SHEET 1.

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E. A TTORNE Y5 H. STEINMETZ.

SHEET FEEDING MACHINE.

7 APPLICATION FILED JUNE 6, 1919. 1,420,458., Patented June 20, 1922.

6 SHEETSSHEET 2.

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H STEINIVIETZ.

SHEET FEEDING MACHINE. APPLICATION HLED JUNE 6,1919- 5g, Patented June 20, 1922.

6 SHEETS-SHEET 3- H. STEINMETZ.

SHEET FEEDING MACHINE.

APPLICATION FILED JUNE 6,1919. 1 ,4 fl58v Patented June 20, 1922'.

6 SHEETS-SHEET 4.

%L'; A TTORNE Y5 H. STEINMETZ. SHEET FEEDINQ MACHWE. APPLICATION FILED JUNE 6. 1919:

Patented June 20, 1-922.

6 SHEETS-SHEET 5- LVITNESSES:

H. STEINMETZ.

SHEET FEEDING MACHINE.

-APPL|CATION FILED JUNE 6,1919.

Patented June 20, 1922.

6 SHEETS-SHEET 6.

i 1 MM\ mmmwm uNirED STATES HERMAN STEINMETZ F ROCHESTER, NEW YORK.

SHEET-FEEDING MACHINE.

Specification of Letters Patent. Patented June 20, 1922.

Application filed June 6, 1919. Serial No. 302,227.

- State of New York, have invented certain new and useful Improvements in Sheet- Feeding Machines; and I do-hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of the specification, and to the reference numerals marked thereon.

My present invention relates to feeding devices and more particularly to sheet feeding means and it has for its object to provide a simple, durable and efficient machine of this kind more particularly adapted to feed sheets of relatively heavy material such as tin plate. Further objects of the invention are to provide a machin that will work efliciently at highspeeds but with the same precision at all speeds and to generally im prove the automatic features necessary in such a mechanism. To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: 1

Figure 1 is a front viewr of a sheet feeding machine constructed in accordance with and illustrating one embodiment of my invention;

Figure 2 is a top view;

Figure 3 is an enlarged transverse section taken substantially on the line 3--3 of Figure 1, showing the initial movement of the sheet as it is raised from the pile;

Figure 4 is a similar view showing the presentation of the sheet to the feeding element;

Figure 5 is a similar view showing the sheet fed into the delivery rolls;

Figure 6 is an elevation of the right hand end of the machine;

-Figure 7 is an elevation of the left hand end of the machine:

Figure 8 is an nlarged detail section of the pneumatic lifting device;

Figure 9 is an enlarged detail view in vertical section showing the clutch element for feeding the table with its controlling device in normal position:

Figure-10 is a similar view showing the controlling device in actuated position;

Figures 11 and 12 are enlarged fragmentary detail sections illustrative of the engagement and disengagement of the clutch elements in Figures 9 and 10, respectively; Figure 13 is an enlarged detail section through the lifting device showing it in normal position, and

Figure 14 is a similar view showing the lifting device in actuated position.

Similar reference numerals throughout. the several views indicate the same parts.

The machine shown in the present embodiment of the invention is designed for the particular purpose of feeding tin plate blanks to can making machines, though it will be understood thatthe invention is not limited to this particular application of the principles and mechanisms involved and I will first briefly describe it'in a general wayto give an idea of its functions and the range of its movements. The sheets are arranged in a pile on a table that is automatically fed vertically, step by step, to compensate for I the depletion of the pile, the feeding being under the control of an automatic clutch mechanism that is thrown out the instant the table gets too high. A clamp holds the ad-- vance edges of the sheets against the table but is periodically released at the time that a pneumatic suction cup raises the rear edge of the top sheet and is then kicked laterally to free the sheet from the clamp. At this point. such rear edge is presented to an os-' cillatory feed arm that carries the sheet over the inclined top of the clamp and presents it to delivery rolls that move it rapidly away to the machine in conjunction with which the feeding machine is used. The pneumatio lifter is pneumatically operated both to cause the sheet to adhere thereto and to raise it to the feeding element and the exhauster for creating the air depression is operated and relieved in timed relation to the other elements. I

Referring more particularly to the drawings, 1 indicates the frame of the machine and 2 vertical guide rods at the ends thereof on which slide the brackets 3 of the table 4. Adjacent each guide rod is a vertical feed screw 5 threaded in 1% lug 6 of the bracket and carrying a bevel pinion 7 at its upperend meshing with a bevel gear8 on a shaft 9 extending across the machine above the table and having bearings in extensions 10 of the frame. Fixed to the shaft 9 isthe gether by bolts 15.

beveled friction wheel 11 of a clutch mechanism for communicating intermittent driving impulses to the feed screws 5, which mechanism is shown in detail in Figures 9 to 12. 'Parallel with the shaft 9 is a drive shaft 12 that is also a cam shaft carrying a cam 13 that vibrates a rocking beam 14 mounted-to turn freely on shaft 9 by engagement with a roller 14 on the beam. The latter comprises, in the present instance, two spaced plates shown in Figure 11 that embrace thewheel 11 and are secured to- The roller is held-by gravity on the cam 13. Pivoted on one of the bolts 15 is a friction pawl 16 having a \l-shaped engaging portion 17 normally cooperating with and conforming to the beveled surfaces of the wheel 11. The pivot 15 of the pawl is so arranged with reference to the periphery of'the wheel 11 that when the beam 14 is rocked through an upward movement of the roller 14", the pawl will jam and grip the wheel 11 turning it a corresponding distance and elevating the table 4 "through the vfeed screws 5, proportionately. As the motion ofthe beam is reversed on return movement, the pawl will disengage and ride idly back to another 1s a feedm element 111 the present form of engaging point. This feeding impulse is communicated at each cycle of operation of the machine and the sheet feeding devices hereinafter described and compensates for .the removal of one sheet from the pile indicated at 18 on the table 4. I prefer, however, to provide for a feeding impulse that will advance the table 4 slightly in excess of a distance equal to the thickness of,

one sheet so that a margin of safety will be insured with respect to the sufliciency of the upward progress of the table and I then provide as follows for an automatic slowing up of the feed or an idle movement of the feeding devices, should the table get too high, to restore it to its proper position.

' 24' at its lower end resting on the pile of Spanning-the frame in rear of the shaft 12 and below the shaft 9 and parallel to both is a fixed rod 19 having a bracket 20 secured thereon by a set screw 21. A tubular vertical guide 22 forms a rigid downward exten sion of thisbracket in which is adapted to slide a thrust rod 23 having a ball bearing sheets 18 on the table. The rod is held against the sheets by a spring 25 within the tube 22 and the lower end of the latter is provided with a roller 26 that prevents the tilting or curling of the sheet by the lifting device hereinafter described from raising the thrust rod 23. The upper end of the lat ter is in a position to thrust against a semiannular head 27 embracing the under side of the shaft 9 and carried on an arm 28 fixed at 30 to the friction pawl 16. Thus, when the table gets too high it raises the rod 23, lifts the arm 28 and hence the clutch element 16 and prevents it from locking with the friction wheel 11 to turn the same so that the vibration of the beam 14 is an idle one. As the head 27 is concentric with the shaft 9 it is always in position to be engaged by the thrustrod and the device is so sensitlve j means, it is necessary to place the finger beneath the arm 28 of the friction pawl element of the clutch mechanism and hold it up while the shaft 9 is being directly rotated, but the table may be raised without opposition and in starting the machine, it is so raised to approximately the position of Figure 9, where the thrust rod 23 is just tou'ching the head 27 but not sufficiently to release the ball.

Mounted to vibrate freely on the rod 19 a bell cran lever 31 having a hook shaped engaging portion. 32 (Figure 4) pivoted thereto at 33 and limited in its downward movement under the influence of a spring 34-by a stop pin 35. The said bell crank lever is adapted to swing in a direction across the table 4 under the influence of a cam 36 on the cam and driving shaft 12 and when the engaging portion 32 is hooked over the rear edge of the top sheet of the pile 18, as shown in Figure 4, it will slide it off the pile and insert its advance edge between two deliveryrolls 37 and 38, the latter being, in the present instance, more in the nature of wheels running against the continuous lower roll 37. Bell crank 31 is returned by a spring 39 connecting it with an arm 40 fixed to and extending laterally from the guide tube 22 of the thrust rod 23. The rolls 37 and 38 have bearings in standards 41 on the frame 1 and at the right of the machine, as illustrated in Figures 1 and 2, the

rolls have pinions 42 meshing with each.

feeding element 31, must be withdrawn from a clamping member 51 located at one side of the table 4 and, in the present instance,

65 screwed in at 66.

between the latter and the delivery rolls 3738. This clamp is inclined or tapered to a knife edge so that a sheet once released therefrom will ride over the clamp when the sheet is pushed back toward it and enter between the rolls and the said clamp engages over the advance edges of the pile of sheets 18 and holds them down securely against the table, lateral gages 52 being provided at one side of the table to assist in holding the sheets squarely thereon and to help guide them toward the delivery rolls 3738. The clamp has a shank 53 guided vertically on a bracket 54 secured to a fixed rod 55 connecting the two parts ofthe frame 1. The said shaft 53 has a parallel member 56 to which it is connected by posts 57 'and extending between these two parts are headed pins 58 on which they" are guided for vertical movement, said pins being rigid with the bracket 54 The clamp is normally held in operative position by a spring 59 connected to the rod 55 and to an extension 60 that proceeds forwardly at' right angles from the portion 56 of the same. This extension is provided with a shoulder 61 with which cooperates a cam 62 on drive shaft 44 journaled in the frame 1. Thus, the clamp 51 is momentarily released upon each revolution of the drive shaft 44 and remains raised only long enough for the top sheet to be withdrawn, after which it drops back into engagement immediatelyowing to the abrupt termination of the cam surface 62 conforming to the abruptness of the shoul der 61.

The lifting means that withdraws the top sheet from the clamp 51 and presents its rear edge to the engaging portion 32 of the feeding'member consists of a vacuum cup 63 and connected pneumatic and mechanical mechanism shown in detail in Figures 8, 13

and 14. A-rubberor similar cup is secured to a perforated head 64 by a perforated plug A tubular stem 67 on the head runs through a guide 68 in which it is longitudinally movable, the guide being formed by a lug on a two-piece casing 69 supported by said lug 68 on the yoked end 70 of an arm 71 mounted to vibrate freely on rod 19. The said arm is part of a bell crank lever 72 terminating in a roller that rides against a cam '74 on the cam shaft 12, the roller being held against the cam and the vacuum cup moved in an inward or forward direction by a spring 75 connected to the arm 71 and to a portion of the bracket guide 22 of the plunger 23.

To return to the pneumatics of the liftingcup 63, the two parts of the casing 69 are formed to clamp between them a flexible diaphragm 76 which divides the casing into a lower chamber 77 open to the atmosphere through perforations 78' and an upper vacuum chamber 79 communicating through a flexible pipe connection 80 with an exhauster 80 (Figure 6) the cylinder of which is secured on the right side of the frame 1 by means of a bracket 81, in the present instance. The piston rod 82 of the exha-uster is connected to a crank pin v83 on a wheel 84 fixed to' the adjacent end of the cam shaft 12. When the piston on the upward or exhausting stroke passes a port or ports 85in the cylinder, it acts as a valve to open these ports and restore atmospheric pressure in the cylinder, the connecting pipe 80 and the vacuum chamber 79. The vacuum cup 63 is normally in the lowered position of Figures 8 and 13 to which it is returned by a spring 86 surrounding the tubular stem 67 between the head 64 and the lug 68. v

The complete operation of the machineis as follows:

The arm 28 of the friction pawl 16 is raised and the table quickly lowered by rotating the shaft 9 by means of the crank until the required pile of sheets 18 can be placed on the table 4. The table is then quickly elevated in the same manner until the thrust rod 23 is in the position of Figure 9 and the machine is then set for operation as in Figures 1, 2, 6 and 7. As the exhauster proceeds on its down stroke to displace the air from the cylinder. the cam 74 recedes and allows the spring 75 to pull the arm 71 down and bring the vacuum cup 63 against the top sheet. On the exhausting stroke of the piston, a depression is created in the vacuum chamber 79 which is communicated to the vacuum cup 63, causing the top sheet to adhere thereto and not only this, but the atmospheric pressure in the contiguous chamber 77 will raise the diaphragm 66 as in Figure 14. and lift the stem 67 and cup 63. raising the rear edge of'the sheet acted on. At the same time, the clamp 51 is raised and released by the cam 62, "whereat the vacuum'cup and the sheet still adhering to it is kicked rearwardly or laterally by the cam 74 as in Figures 3 to 4. This presents the rear edge of the sheet thus released from the clamp to the engaging hook 32 of the feeding element 31 which is on the low point of'its cam 36. The friction clutch has meantime given the table 4 an upward impulse and the clamp 51 has immediately snapped back as in Figure 4. About this time. the piston of the eXhauster passes the ports 85 and restores atmospheric pressure in the chamber 79. This releases the sheet from the vacuum cup and also allows the cup to drop and rest lightly on the sheet which is being sustained by the engaging hook 32. The high point of the cam 36 now moves the feed arm 31 forwardly. carrying the sheet over the clamp 51 and into the bite of the rolls 3738 which feed it very. much I by another feed hook iii-J feeding element which is returned by its spring 39 and the low point of the cam 36 to its elevated rearward position, at-the same time that a similar condition in the control of the vacuum cup 63 allows it to drop quickly down upon the uncovered edge portion of the sheet next below and so the cycle is repeated. On the next cycle, the succeeding sheet is raised and in the feed hook 32 before its predecessor has passed through the rolls 3738.

It sometimes happens that burrs on the edges of the blanks will cause the top sheet to pull the next lower sheet rearwardly with it, though such lower sheet does not oin 1n the lifting movement because the vacuum cup does not act upon it and hence it does not get into the feed hook 32, but is left in an overhanging position. On the next cycle, this sheet is raised by the vacuum cup, 1nstead of 'dislod'ging a new sheet from beneath the clamp'5l, and though the sheet cannot enter the feed hook 32, it is nevertheless fed 99 extending rearwardly from the first and which I provide for such contingencies. This second feed hook moves it back into position to be engaged by the first feed hook. I

Of course, the exhauster need not be combined with the machine structure, as shown,

and, any means for creating depression m the chamber 79 can be employed in the general practice of the invention.

I claim as my invention:

1. In a sheet feedingmachine, the combination with a table and a clamp at-one side thereof adapted to hold'the advance edges of a pile of sheets against the table, of a feeding element movable in a direction across the table toward the clamp and a pneumatic suction device adapted to raise the rear edge of the topmost sheet and present it to the feeding element.

7 2. In a sheet feeding machine, the combination witha table and a clamp at one side thereof adapted to hold the advance edges of a pile of sheets against the table,

of a feeding element movable in a direction across the table toward the clamp, a pneumatic suction device adapted to raise-the rear edge of the topmost sheet and ,means for moving said devicelaterally oppositely to the feeding device to remove one edge of the sheet from the clamp and presentthe other to the feeding element.

3. In a sheet feeding device, thercombination with a table and a feeding element movable in a direction across the same, of a pneumatic suction device adapted to raise the topmost sheet on thetable and present it to the feeding element, and a delivering mechanism adapted to receive the sheet from the feeding'element and propel it from the table at an increased speed.

4. In a sheet feeding machine, the comdelivering mechanism beyond the clamp, of

a feeding element movable in a direction across the table toward the delivering mechanism, a pneumatic suction device adapted to means for moving said device laterally oppositely to the feeding .device to remove one edge of the sheet from the clamp and present the other to the feeding element, the delivery mechanism being adapted to propel the sheet at a faster rate than the feeding element,

5. In a sheet feeding machine, the combination with atable anda feeding'element movable in a direction across the same, of a clamp at one side of the table adapted to hold theadvance edges of the sheets thereon, means for momentarily releasing the clamp and means for simultaneously withdrawing the top sheet therefrom and presenting its rear edgeto the feeding device.

6. In a sheet feeding machine, the combination with a table and a feeding element movablein a direction across the same, of a clamp at one side of the table adapted to hold the advance edges of the sheets thereon, means for momentarily releasing the clamp and a pneumatic suction device having a combined upward and lateral movement for Withdrawing the top sheet from the clamp and presenting its rear edge to the feeding device simultaneously with the release of the side thereof, of a spring normally actuating the clamp to engage the advance edges of a pile of sheets and hold them on the table, a feeding element movable in a direction across the table toward the clamp, a cam for momentarily releasing the clamp and means for simultaneously withdrawing thetop sheet therefrom and presenting its rear edge to the feeding element.

8. In a sheet feeding machine, the combination with a table and a clamp at one side thereof, of a spring normally actuating the'clamp to engage the advance edges of a pile of sheets and hold them on the table, a feeding element movable in a direction raise the rear edge of the topmost sheet and across the table towardthe clamp, a cam for momentarily releasing the clamp, a

- pneumatic suction device for raising the rear edge of the top sheet and means operating'in timed relationship to the clamp releasing cam for actuating the suction device laterally to withdraw the advance edge of the sheet from the clamp and present the rear edge to the feeding element.

9. In a, sheet feeding machine, the combination-with a table and a shaft arranged above the same, of an arm on the shaft, a

cam for oscillating the arm'and a feed hook pivoted to the arm to engage the edge of a sheet onthe table and propel it across the latter.

10. In a sheet feeding machine, the combination with a tabletand a shaft arranged above the same, of an arm on the shaft, means for oscillating the arm, a feed hook pivoted to the arm to engage the edge of a sheet on the table and propel it across the latter, and a pneumatic suction device adapted to lift the top sheet and present its edge to the feeding hook.

11. In a sheet feeding machine, the combination with a table and a clamp at one side thereof adapted to engage the edges of a pile of sheets and hold them on the table, of a shaft arranged above the latter, an oscillatory feeding element on the shaft adapted to engage a sheet edgewise and move it in a direction across the table and an oscillatory and vertically movable pneumatic suction device mounted on the shaft to withdraw the top sheet from the clamp and present its opposite edge to the feeding element.

12. In a sheet feeding machine, the combination with a table and a'clamp at one side thereof for engaging the advance edges of a pile of sheets and holding them against the table, of an oscillatory feeding element inounted above the table to move in a direction across the same and having an engaging member adapted to cooperate with the rear edge of a sheet, means for Withdrawing the top sheet from the clamp and lifting it to the said engaging member of the feeding element and a second engaging member on the latter spaced from the first in the direction of movement thereof and adapted to feed the next lower sheet if Withdrawn from the clamp with the top sheet.

13. In a sheet feeding machine, the combination with a table and a feeding element having a movement in a direction across the table and arranged above it, of a pneumatic suction cup adapted to cooperate with the top surface of a sheet on the table, a vacuum chamber with which the cup communicates and having adiaphragm Wall by which the cup is carried, means for creating a depression in the vacuum chamber to cause the sheet to adhere to the cup and to raise the latter and present the sheet to the feeding element through atmospheric pressure on the diaphragm and means acting in timed relation to the feeding element to restore pressure in the vacuum chamber and release the cup and sheet.

14. In a sheet feeding machine, the combination with a table, a clamp at one side thereof adapted to engage the edges of a pile of sheets and hold them on the table, and means for intermittently releasing the clamp, of a pneumatic suction cup adapted to cooperate with the top surface of a sheet on the table, a vacuum chamber with which the cup communicates and having a diaphragm wall by which the cup is carried,

means for creating a depression in the vacuum chamber to cause the sheet to adhere to the cup and to raise the latter through atmospheric pressure on the diaphragm, means for actuating the cup laterally in timed relation to the clamp releasing means to withdraw the sheet from the clamp, and means operating in timed relation to such actuating means to restore pressure in the vacuum chamber and release the cup and sheet.

15. In a sheet feeding machine, the combination with a table and sheet feeding and retaining devices adapted to cooperate with a sheet on the table, of a pneumatic suction cup adapted to cooperate with said sheet to withdraw it from the clamp and present it to the feeding element, a support for the cupembodying a vacuum chamber With which the cup communicates having a diaphragm wall by which the cup is directly carried and means acting in timed relation to the clamp and the feed element to create depression and then restore atmospheric pressure in the vacuum chamber.

16. In a sheet feeding machine, the combination with a table and sheet feeding and retaining devices adapted to cooperate with a sheet on the table, of a pneumatic suction cupadapted to cooperate with said sheet to withdraw it from the clamp and present it to the feeding element, a support for the cup embodying a vacuum chamber with which the cup communicates having a diaphragm wall by which the cup is directly carried and an exhauster acting in timed relation to the clamp and the feed element for creating depression in the vacuum chamber and embodying a cylinder pump provided with a relief valve.

17. In a sheet feeding machine, the combination with a table and a feeding element, of a pneumatic suction cup having a-combined upward and lateral movement for selecting single sheets and presenting them to the feeding element, mechanical means for moving said cup in one direction and pneumatic means for moving it in the other direction.

18. In a sheet feeding machine, the combination with a table, a sheet clamp cooperating therewith and a feeding element, of a pneumatic suction cup for selecting single sheets and presenting them to the feeding element, a stem on the cup, a pivoted guide for the stem, a pneumatically operated diaphragm supporting the stem and by which the cupis raised to present the'sheet to the feeding element and means for oscillating the guide to withdraw the sheet from the clamp.

HERMAN STEINMETZ.

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