US2783996A - Feed roll drive and brake mechanism therefor for presses of the punch and blanking type - Google Patents

Description

March 5, 1957 E. w. FORKNER 2,783,996

FEED ROLL DRIVE AND BRAKE MECHANISM THEREFOR FOR PRESSES OF THE PUNCH AND BLANKING TYPE Filed July 27, 1953 2 Sheets-Sheet l A 36 B 7' J 1 .J. I fl 6 I Y J 9 5 --1F I 4 o I Q 1/ I 35 j 43 \34 0 f2 2 INVEN TOR. 'F/XED CENTER Ewa'z W/bRKA/ER 2,783,996 HEREFOR NG TYPE 2 Sheets-Sheet 2 I'll- Ill.

AND BRAKE MECHANISM T FOR PRESSES OF THE PUNCH AND BLANKI Flled July 27, 1953 March 5, 1957 E. w. FORKNER FEED ROLL DRIVE INVENTORQ FORKNER Z/ l 23 E'WELL W. A BY 2 A ys.

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AND BRAKE MECHANISM PRESSES OF THE PUNCH FEED ROLL DRIVE THEREFOR FOR AND BLANKIN G TYPE Application July 27, 1953, Serial No. 370,566 2 Claims. (Cl. 2712.4)

This invention relates to presses of the punch and blanking type, and more particularly to feed roll drives and brake mechanisms therefor.

An object of this invention is to provide a feed roll drive and brake mechanism therefor for intermittently feeding sheet metal stock to punch and blanking presses.

Another object of this invention is to provide a feed roll mechanism of the type set forth in. the preceding object, that is provided with an intermittent drive and a brake for the feed rolls, the brake and drive being so arranged that the brake is released slightly in advance of the beginning of the feed stroke of the drive for the rolls, and is applied slightly after the feed stroke of, said drive has been completed, to thereby positively prevent over-running of the feed rolls but, at the same time, allowing a slight amount of creep of the stock while the die pilots are centering the stock in preparation for the press or punch elements of the die to strike the stock.

Another object of the invention is to provide a feed roll drive, as set forth in the preceding object, in which the brake is applied slightly in advance of the separation of the feed rolls.

A still further object of the invention is to provide a novel arrangement for adjusting the minimum clearance of the feed rolls to accommodate stock of various gauges, without changing the lift of one of the feed rolls when moved to a position Where it is disengaged from the stock.

Other objects of the invention will be apparent to those of ordinary skill in the art to which the invention pertains, from the following description and drawings.

In the drawings:

Figure 1 is a view in side elevation of a press of the punch and blanking type, showing the feed roll drive mechanism, the brake mechanism and the mechanism for separating one feed roll from the other to efiect intermittent feeding of stock in timed relation to the crank shaft of the press, as arranged in accordance with an embodiment of the invention;

Fig. 2 is a partial view in section, taken on line IIII of Fig. 1, illustrating in top plan view the lever which controls the brake, and the lever which separates one feed roll from the other, and the mechanism whereby the minimum gap between the feed rolls may be adjusted;

Fig. 3 is a view in section, taken on line IIIIII of Fig. 1, showing the feed rolls and the mechanism whereby the minimum separation thereof may be adjusted, and the drive therefor;

Figs. 4 and 5 are views in section, taken on lines of Figs. 2 and 1, respectively; and- Fig. 6 is a side view of the feed roll gear drive as seen looking in the direction of arrows VI-VI of Fig. 3.

in Fig. l of the drawings is illustrated a press 1 of the punch and blanking type, having a frame 2 at the front of which vertical reciprocating motion in guideways 4, only one is mounted a punch press ram 3 forfates Patent of which is shown. The ram 3 is connected by a connecting rod 5 to a crank shaft, the center of which is at 6. Outside the frame 2, the crank shaft has mounted thereon cams 7 and 7, and a drive disk or block 8, having an adjustable-length crank 9 and crank pin 10, to which a rack bar 11 is attached. Cams 7 and 7' control stock feed rolls and a brake therefor, as will appear infra. The rack bar 11 is provided at its lower end with rack teeth 12, that mesh with the teeth of a pinion 13, forming part of a one-way clutch 14. The pinion 13 is rotatably mounted on a stub shaft 15, which is a part of a driving element 15' of the one-way clutch 14. On the feed stroke, the driving element 15 is coupled to the driven element 15a of the clutch by clutch rollers 15 of the feed roll 16.

1 As the crank shaft rotates in the direction of arrow 17, the rack bar 11 is reciprocated. On the up or feed stroke of the rack 11, pinion 13 turns in the direction of arrow 18, whereby the driven element 15a is turned in the direction of that arrow. On the return stroke of the rack bar 11, pinion 13 turns in the direction opposite to that of arrow 18. Since the pinion is coupled by means of the one-way clutch to feed roll '16, the driving connection between the pinion and the feed roll is disengaged on the return stroke of the rack bar 11.

Cooperating with the feed roll 16 is another feed roll 20. Feed roll 20 is driven by feed roll 16 through a drive including gears 21 and 22, which are secured to the stub shafts 23 and 24, respectively, of rolls 16 and 20. Roll 20 is supported by rods 25 and 26 from levers 27 and 28. The stub shafts 24 and 24' 27 and 28 are secured to an eccentric, comprising a cylinder 29 that is disposed about a shaft 30. On shaft 30, and within cylinder 29, eccentrics 31 and 32 are keyed to shaft 30. By turning shaft 30, eccentrics 31 and 32 are turned, thereby raising or lowering the cylinder 29. As cylinder 29 is raised or lowered, the levers 27 and 28 and feed roll 20 are likewise raised or lowered. By adjusting cylinder 29 and the eccentrics 31 and 32, the minimum gap 33, between the feed rolls 16 and 20, may be adjusted to accommodate the particular thickness of sheet stock being fed to the press. The sheet stock delivered to the rolls 16 and 20 may be guided by means of guides, not shown, at the rear of the press, to keep the same centered on the feed rolls 16 and 20.

When sheet stock has been fed in the required amount to the press, feed by the rolls must be arrested. Also, the pressure of the rolls 16 and 20 should be relieved in order to allow the stock to feed by creeping slightly, as the punch or pressing operation is that stock.

To effect the release of pressure on the stock, mechanism is provided for raising roll 20 otfthe stock when the feed is to be arrested. As shown in Fig. 1, that mechcounterclockwise, as seen in Fig.

The feed roll 20 will remain in that elevated position until point B of the cam out of engagement with the-stock.

lobe 36 passes out of contact with the cam follower roller The gears 21 and 22 are maintained in driving relation by the gear drive and radius arm arrangement shown in Patented Mar. 5, 1957 of roll 20 operate in windows 0 in the side frame members 2. Levers being performed on Fig. 6. Gear 21, as stated, is the driven gear, and it drives a gear 21a mounted on a fixed shaft 21e secured to a side frame member 2. Gear 21a drives a gear 21!) mounted on a fixed shaft 21d secured-to the side frame member 2. Gear 21b drives gear "22 shaft center of gear 22 and of roll is fixed with relation to the center of shaft 21d by a radius arm 21c coupled to lift rod 26. Thus as the roll 20 and gear 22 are raised and lowered by lift rods 25 and 26, the center for roll 20 and gear 22 rotates about the center of shaft 21:! thereby maintaining a positive drive for roll 16 and roll 2% at all times.

In order to prevent over-travel of the feed rolls 16 and 20 while the feed roll 20 is out of engagement with roll 16, a brake mechanism, controlled by cam 7', is provided that includes a hand brake 38, one end of which is anchored to a bolt 39, secured to a bracket 40 attached t the frame of the press, and the other end of which is connected by a pin 41 to a 'brake rod 42. Band brake 38 works on the driven element 15a of clutch 14. The upper end of the brake rod 42 is connected by a pin 43 to a lever/i4 that is secured to the frame of the machine on a stub shaft 45. Lever 44 has at its free end a cam follower roller 46 that rides on the surface of cam 7, including its lobe 36b.

Cam lobe 36 is active between points A and B, and is so located in relation to the downstroke of the punch press ram 3 that, when point A has traveled to the posi- 'tion where it engages cam follower roller 35, the feed roll 20 will be lifted from the :stock just before'the punch press ram reaches the bottom of its stroke, or just before the die pilots engage and center the stock. Cam lobe 36 remains in engagement with cam follower roller until point B of the lobe passes off theroller. When point B has passed off roller 35, the upper feed roll 20 is loweredinto engagement with the sheet stock being fed to the press. At this point, the upstroke of the rack bar 11 and the feed of stock by rolls 16 and 20., are about to commence.

Cam lobe 36!; extends from points A to B, substantially 180. Point A reaches cam follower roller .46 slightly in advance of the time that pointA of cam lobe 36 reaches cam follower roller 35. Therefore, thebrake band 38 will be applied to stop the feed rolls the moment cam lobe 36 engages cam follower roller 65 to lift roll 20 off the sheet .being fed to the press. Therefore, by ap-' there is no possibility plying the brake in this manner, of over-feeding of the stock to the press. The brake band 38 is applied all the time that cam lobe 36b is in engagement with cam follower roller 46. Therefore, brake will be applied during the entire'return stroke of the rack bar 11, and for a short while after the rack bar 11 has commenced its up or'feed stroke.

in order to assure positive release of the brake when the cam lobe 3612 has passed over follower roller 46, a

tension spring 47 is provided. One end'of that spring is' to the side frame of the ma-- secured to a pin 48, attached chine, and the other is attached to the brake rod 42. The length of the brake rod 42 may be adjusted by means of a threaded connection 49 and a lock nut 56, to thereby adjust the brake band for clearance and working pressure.

As stated supra, the eccentrics 31 and 32, and the cylinder 2), provide the adjustment of minimum gap of feed rolls 16 and 29. The adjustment may be pre-set, as shown in Fig. l, by means of a handle 51 secured to the outer end of shaft 30, and an index ring 52 provided with spaced notches 53 for receiving a spriug-pressed pin S4 at the outer end of handle 51. When handle v51 is in the position shown in Fig. 1, the minimum space or gap between rolls 20 and -16 is at the minimum value. By turning the handle in the direction of arrow 55, the minimum gap may be increased to suit the thickness of stock to .be fed. Adjusting the eccentric does not, however, change the clearance between cam lobe 36 and camfoh lower 35; therefore, the lift of feed roll 20 remains conof roll 29. The

the

' presses having a frame and a crank shaft rotatably supported thereby, for actuating the ram of the press, said feed roll drive comprising a pair of rolls rotatably supported, one above the other, in the path of travel of the stock to be fed to the press, one of said rolls being rotatable but fixed in a vertical plane with respect to the other roll, and the other of said rolls being movable in said vertical plane above the first-mentioned roll, said rolls being gear-connected so as to be positively driven to-' gether, a one-way clutch on the shaft of the fixed roll, "a pinion on said clutch, a rack bar meshing with said pinion, the rack bar being adapted to be driven in timed relation of the crank shaft, to drive said roll through said one-way clutch during the up-stroke of the rack bar means for adjusting said rolls to provide a predetermined minimum: spacing between them, means operating in timed relation with the down stroke of the rack bar for lifting said movable roll vertically while maintaining said rolls in driving relationship, a brake on said fixed roll shaft, and means timed with the upstroke .of said rack bar, to apply said brake and stop the roll at the beginning of, and during, the downstroke of said rack, and to release said brake at approximately thecommencement of the upstroke thereof.

2. A feed roll mechanism for presses of the punchand blanking type, provided with crank shafts, .comprising a pair of gear-connected rolls mounted one above the other, and adapted to intermittently driving said rolls, a lift rod at each end of the upper roll for raising and lowering the same, a

. shaft, an eccentric on the shaft and secured thereto, and

a cylinder on the eccentric, lever arms fast on the cylinder and connected to said lift rods, means for turning said shaft to raise or lower said cylinder and said upper feed roll, means connected to the cylinder .on said .eccentric shaft for turning the cylinder and thereby raising and lowering the relation, said means being adapted to operate in timed relation withthe down and upstrokes, respectively,-of the press crank shaft :to

connected to the cylinder on relation to the crank shaft, a pivotally mounted brake-' actuating lever having a cam follower adapted to engage said second cam, .anda rod connecting the brake-actuating lever and adapted to apply the braking force, said cam followers being so positioned that the cylinder on the eccentric shaft is turned slightly in advance of the brake rod-actuating lever, and the brake-actuating lever is held in braking position for an interval after the eccentric lever is off the first cam,rt-he brake-actuating means being opera.-

tive to release the brake when the eccentric shaft is turning in a direction to lower the upperrolll intoengagement with the stock on the'iixed'roll.

(References on following page) for intermittently feeding sheet feed stock to the press, means for same while maintaining the rolls in driving disengage and engage the stock to be 'fed, said raising and lowering means comprising a first cam adapted to be driven by the crank shaft and a lever said eccentric shaft and having a-cam follower operated by said cam, and means 1 1 for applying a braking force References Cited in the file of this patent UNITED STATES PATENTS 1,030,183 Inman June 18, 1912 1,480,044 Bowers Jan. 8, 1924 1,858,403 Littell May 17, 1932 6 Crane June 25, 1935 Bobst Nov. 18, 1941 Miller Mar. 30, 1943 Scheffey July 4, 1950 Wills Mar. 31 1953

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