US2222168A - Sheet material feeding mechanism - Google Patents

Description

Nov. 19, 1940. I

M. E. BROQKS SHEET MATERIAL FEEDING MECHANISM I Filed July 29, 1956 6 Sheets-Sheet l IN VENT OR RNE Y a n llllllll II I lllllllll NOV. 19, 1940. M, B Q 2,222,168

SHEET MATERIAL FEEDING MECHANISM Filed July 29, 1956 6 Sheets-Sheet 2 IN VENT OR fl/osfs 5 fi/eoors ORNEY Nov. 19, 1940. I M. E. BROOKS ZZZ 2,168

SHEET MATERIAL FEEDING MECHANISM Filed July 29, 1936 6 Sheets-Sheet 5 33 J5 .34- .38 J3 a o 84 85 76 Z5 60 4- i 41 8 m o i.

J9 1 87 m m IN VEN TOR BY 2:055: f. 560 7/55 ATIbENEY Nov. .19, 1940. E BROOK; 2,222,168

SHEET MATERIAL FEEDING MECHANISM Filed July 29, 1936 6 Sheets-Sheet 4 INVENTOR WMOJE: 5 Bio 0K5 NOV. 19, M E BROOKS 2,222,168

SHEET MATERIAL FEEDING MECHANISM Filed July 29, 1936. 6 Sheets-Sheet 5 JHZ r 13.- I INVENTOR A RNE Y Nov. 19, 1940. M. E. BROOKS SHEET MATERIAL FEEDING MECHANISM 6 Sheets-Sheet 6 Filed July 29, 1936 RNEY INVENTOR -fl/asE-b 5200K:

titted Nov. 19, 1940 NITED STATES Aluminum Company of Wm Pittsburgh,

Pa., a corporation oi Pennsylvania I Application July 29, 1936, Serial No. 93,215

4 Claims.

This invention relates to automatic sheet material feeding mechanisms for metal working machines such as shearing machines, and more particularly to mechanism for feeding sheet material into position for shearing.

Shearing machines having a reciprocating gate lrnife and a clamp which feeds successive lengths of sheet material into proper position to be sheared by the knife are well-known in the art.

- However, considerable difficulty is experienced with such machines when it is desired to shear uniform lengths of sheet material, since the run ning clearances between the parts which actuate the feeding clamp frequently accumulate in one direction, causing over-travel or under-travel of the said clampand a consequent variation in the length of the piece fed to the shearing blade. When a high degree of accuracy and uniformity in the dimensions of all the pieces cut is desired, even comparatively small variations in length, resulting from under-travel or over-trave1 of the clamp, may cause much of the material cut to be unfit for the purpose desired. By means of the clamp-actuating mechanism of the type disclosed hereinafter, the possibility of over-travel or under travel of the feed clamp is practically eliminated, and a high degree of uniformity in thelength of the sheets out can be obtained. With shearing machines constructed in accordance with my invention, it is possible to produce sheets having a length tolerance as low as plus or minus /1000 (0.005) of an inch.

One object of the invention is to provide an improved sheet material feeding mechanism for machines which will prevent variations in the length of sheets due to the accumulation of running clearances in the mechanism for actuating the feed clamp.

A further object of the invention is to provide a feeding mechanism having a feed clamp adapted to reciprocate between a fixed stop and an adjustable stop, the clamp being operatively connected with an improved mechanism for imparting reciprocal movement to it.

A further object of the invention is to provide an improved machine for handling sheet material, the machine .having a feed clamp adapted to reciprocate between a fixed stop and an adjustable stop, the feed clamp being provided with mechanism for reciprocating it, and said mechanism including resilient means for absorbing overtravel. I

further object of the invention is to provide an improved apparatus for imparting a Clampv to the association of the mechanism of this invention with a shearing machine and in which:

Fig. '1 is a front elevation of the shearing machine;

Fig. 2 is a top plan of the machine, partly broken away to show the hold-downs, with the feedclamp at the end of its feeding movement;

Fig. 3 is a horizontal sectional view of the machine taken on the line IIIIII of Fig. 1, showing the lower section of the clamp at the end of the feeding movement;

Fig. l is a side elevation of the machine;

Fig. 5 is a fragmentary plan view to an enlarged scale of a portion of the mechanism shown in Fig. 3, showing the end of the lower section of the feed clamp and the resilient means for absorbing over-travel in the clamp-actuating mechanism;

Fig, 6 is a detail side elevation of the end of the lower section of the feed clamp of Fig. 5 and of a portion of the clamp-actuating mechanism, including the resilient means for absorbing over-travel Fig. 7 is a detail sectional view taken on the line VII-VII of Fig. 9;

Fig. 8 is a. fragmentary view to an enlarged scale of a portion of the mechanism shown in Fig. 4, showing the feed clamp at the end of its feeding movement, the fixed stop and the adjustable stop, and the mechanism which controls the operation of the pressure valve of the pressure cylinder which imparts a clamping action to the feed clamp; I

Fig. 9 is a vertical sectional view taken on the line IX-IX of Fig. 8;

Fig. 10 is a vertical section through the knifesupporting cross-head, the feed clamp and the feed table on the line X-X of Fig. 2, showing the feed clamp at the end of its feeding movement, the pneumatic hold-downs pressing the sheet to the feed table, and the shearing knife descending to cut the sheet;

- nected at the top by across bar 3, together with feed table 4 extending between housings I, I,

form the main frame of the shearing machine. Crank shaft is journalled through housings i, I, projecting beyond them at both sides, and supports reciprocable crosshead 6, which carriesknife I (Fig. by means of sleeves 8 mounted on eccentrics on the crankshaft. Feed clamp 9, for feeding successive lengths of sheet material into shearing position, consists of upper and lower members 9a and 9b which extend across said table 4 and are adapted for longitudinal reciprocation. Upper member 9a is also adapted for vertical reciprocation, as will be more fully described hereinafter, and is provided with a rubber gripping surface IIJ (Fig. 10), which perholes 2|,' 2l in said member. '46

mits more even clamping of the sheet material. The forward end of feed table 4 terminates in a seat for a fixed blade [I which cooperates with knife I attached to cross-head 6 to shear the successive lengths of sheet material fed to the blades byfeed clamp 9. T-slot l2 at the other end of the feed table affords means for attaching an extension to the feed table, if desirable, which may include squaring guides. Member 9a of the'feed clamp is provided with spaced extensions l3 which, when the feed clamp is at the end of the feeding movement, project between pneumatic hold-downs |4 located between crosshead 6 and clamp 9 and carried by'cross-beam l5 which is fastened to side members I, I. Member 9b is provided with spaced extensions l6 which coincide with extensions l3'and which, when the feed clamp is at the'end of the feeding movement, project between pads I! located beneath hold-downs l4. The projections l3 and I6 permit effective clamping of sheet material adjacent to the shearing blades, and thus'reduce the amount of scrap.

Member 9a of the feed clamp is in the form of a hollow beam and is U-shaped at each-end to accommodate pressure cylinders l8, 18, as shown in Figs. 7 and 9, which cylinders each have a flanged base l9 resting on member 9b and bolted thereto by bolts '20, 26 (passing through The bolt 20 likewise clamps flanged bar 22 to the under-side of clamp member 9b, said bar having sliding bearing in T-slot 23 of table 4 and cooperating therewith 'to guide clamp 9 during longitudinal re- 36 suitably attached to clamp member 9a, whereby vertical reciprocation of rod 26 results in a corresponding reciprocation of member 9a and a consequent opening and closing of clamp 9. The action of valve 24 in admitting pressure to the pressure cylinder is controlled by disc 3| (Figs. 8 and 9) mounted on crank-shaft 5 and having a cam surface 32, said disc bearing on roller 33 which is rotatable on pin 34 journalled in studs 35, 35 of piston 36. Piston 36 isintegrally connected to rod 31 and is adapted to reciprocate vertically in sleeve 38 attached to housing I. Downward movement is imparted to said piston and rod by the action of cam surface 32on roller 33 during the rotation of disc 3|, and upward movement is produced by coil pring 39 resting on seat 40 in sleeve 39 when pitman.

the pressure of cam surface 32 is released. Rod 31 extends through sleeve 38 and is pivotally connected to coupling 4| which is keyed to shaft 42 between bearings 43 and 44 fastened to side member I, said shaft 42 extending parallel with feed table 4 and being slidably mounted through bearings 45 and 46 integrally attached to plate 25. Located between bearings 45 and 46, and splined to shaft 42 for rotation with it, is sleeve 41 having a lug 48 slidably keyed in a groove in said shaft and having an integral arm 49 pivotally connected to plunger 50 of valve 24. Reciprocation of rod 31 turns shaft 42, which in turn causes plunger 56 to reciprocate, and thus alternately admits and excludes pressure to or from cylinder l8 in a known manner, thus reciprocating piston rod 26 and clamp member 9a, thereby opening and closing the clamp.

Lateral reciprocation of-clamp 9 is produced by rocker arm 5| (Fig. 4) pivotally mounted on housing lfor oscillation about point 52, the oscillatory motion being imparted to said arm by means of pitman 53 which is pivotally connected to the extension 54 of said arm, and eccentric 55 mounted on crank shaft 5 and carrying said tached to rocker arm 5|by coupling 51 which extends through a slot in said rocker arm and is clamped in the desired position by nut 58. By appropriately positioning connecting rod 56 in the slot of the rocker arm, the length of throw 'of said connecting rod may be regulated as desired. The distance said rod moves can thus be predeterminedwith the aid of the graduations on the rocker arm (seeFig. 4). Connecting rod 56 is pivoted to lever 59, which is pivotally mounted at one end to the housing. The other end of lever 59 carries clevis 66 which forms bearings for studs 6| and 62 of sleeve 63, which slidably encircles a portion of rod 64, said rod having boss 65 at one end.v At the end of clamp member 9b is extension 66 having a tongue 61 resting in a slot in the clamp member and held there by pressure cylinder l8. Said extension projects through said boss and is attached thereto by washer 63 and nut 69 the latter being threaded on stud II which forms the end of the extension. Bearing 1| separates extension 66 from boss 65. Sleeve 63 is positioned on rod 64 between collars 12 and 13, which may-be in the form of nuts threaded on said rod. Between the ends of sleeve 63 and collars l2 and I3 are springs I4 and I5. It will be seen that oscillation of, rocker arm 5| by pitman 53 moves connecting rod 56 backward and forward, causing lever 59 to reciprocate rod 64, which in turn reciprocates clamp -9 longitudinally on the feed table.

Lateral movement of the clamp toward the shearing blades I and II is'limited by fixed stop 16' attached to housing and so positioned that it will be'struck by clamp 9' when the clamp is moved forward, while movement of the clamp away from the shearing blades is limited by adjustable stop 11. Stop 11 is slidably mounted in T-slot 19 in the housing by key member 19 integrally'attached to said stop, and is adjustable with respect to fixed stop 16 by means of hand wheel 80 and screw bolt 8|, said screw bolt bein threaded through key member 19 and its reduced end being held in bearing 92, positioned at the end of T-slot 19, by nut 33 threaded on the end of said bolt. The other end of screw bolt 3| is carried by support 94, which also cart es hand-wheel 99, which operates any well- Connecting rod 56 is adjustably ata lrnown type of means (not shown) for rotating said screw bolt, which rotation causes stop 11 to move toward or away from the shearing blades of the machine. Micrometer gauge 85 may be provided on support 84 for enabling accurate positioning of stop ll. Any clearances between stop ll and screw-bolt 8| are always held in the same direction by means of counter-weight ht anchored to said stop by a suitable chain or cable til, passing over wheel 88. The lower edge of T-slot it may be graduated, as shown in Fig. 8, so that by means of these graduations and the micrometer gauge, the distance between fixed stop lit and adjustable stop ll can be accurately 1d determined and set at exactly the length of the cut desired.

I Suitable means for supplying motive power to I the machine are provided, such as electric motor ht, pinions llll and ti and gears iii and M, with clutch t l adapted to engage cooperating clutch mechanism 95 ongear 93, so that the crank shaft and the members mounted thereon may be, caused to rotate whenever the operator sov desires. Clutch Bil may be moved in and out of operative engagement with the cooperating clutch mechanism 95 by any well-known means.

In the operation of the machine, the distance between stops it and ll is first adjusted by hand- .wheel lit so that the clamp can move no further than the length of sheet to be sheared, and connecting rod 56 is adjusted on rocker arm til so that if the stops were not present the sheet would be moved slightly more than the desired sheet length plus the sum of any possible accumuiation of running clearances. The arcuate form and position of rocker arm hi are such as to permit connecting rod 5% to be adjusted to any position along the slot in the rocker arm when clamp ii is against fixed stop it, without ill in any way affecting the position of the clamp.

it will be readily seen that oscillation of rocker arm til by pitrnan E53 moves connecting rod hi5 backward and forward, causing lever hit to recipr ocate rod M, which in turn. reciprocates 4h clamp ll longitudinally on the feed table, be-

tween stops "it and The additional distance travelled by studs iii and after clamp ll has come to rest against either stop it or stop ill will only result in compression of spring i l or 5% spring ltl, depending on the direction of travel of the clamp. Since the above arrangement insures that the feed clamp will always move the sheet a distance exactly equal to the length of sheet to be cut, regardless of any accumulation oz? running clearances which-otherwise would result in under-travel. or over-travel of the clamp, the length of the sheets cut by the shear will always be equal, and will not be subject to variations caused by such accumulations.

Disc til, eccentric tit, eccentrically mounted sleeves t and hold-downs it are so co-ordinated, and arranged to operate in such relation to each other, that the operation of the machine is as follows: Feed clamp member ea is lowered by piston rod it so that the sheet material is gripped between members he and lib, whereupon (ill the clamp moves the sheet material forward until the clamp strikes'the stop it and the spring ll l is compressed, whereupon the hold-downs ill m descend and press the sheet material tightly against the shear table, after which pressure is admitted to cylinder it and piston rod it raises member to so that the feed clamp releases the sheet and starts its backward movement, at m which time knife l falls, shearing off the desired length of sheet material. Clamp continues its backward movement until it strikes stop ll, when spring is compressed to take up the overtravel. Clamp member 9a, is then again lowered into clamping position, after which the holddowns M are released, and the sheet is moved forward again. This cycle is repeated as long as desired. It will be noticed that the action of the feed clamp is so timed with that of the holddowns that the sheet is held at all times by either the clamp or the hold-downs, or both.

Although in the above description and in the accompanying drawings, the invention has been presented as applied to an automatic shearing machine, it of course could be applied to other types of sheet-handling machines as well.

I claim:

1. In a feeding mechanism for handling sheet material, the combination of a rigid stop fixedly attached to the housing or the machine, a rigid stop movably attached to said housing, a feed clamp mounted for reciprocation between said stops, said clamp having a flat gripping surface, a rod attached to said clamp, a coupling slidably mounted between springs on said rod, a lever attached to said coupling and pivotally mounted in the housing of the machine, a connecting rod having one end attached to said lever and "the other end attached to a rocker arm pivotally mounted in the housing of the machine, a pitman pivotally connected at one end to an entension on said roclrer arm and at the other end to an eccentric mounted on the cranlr shaft of the machine, and means for maintaining the feed clamp in positive material clamping relationship during its reciprocation between said stops, said 'means being actuated by the crank shaft in. timed relationship with the rocker arm.

2. In a machine for handling sheet material, a fixed rigid stop and an adjustable rigid stop, means presenting fiat surfaces extending stantially across the machine adapted to engage and feed material a distance corresponding to the distance between the stops, said means ing adapted for adjustment to vary the length of feed when at the position limited by the fixed stop, and means associated in timed relationship with said material engaging and feeding means adapted to insure positive engagement of the material during a feeding operation.

in a material handling mechanism, a plate for supporting one member of a material clamping device, a pressure cylinder secured to said member and having its piston rod secured to a second member superposed the first-anew tioned member, means for imparting reciprocal movement to said clamping device between a fixed stop and an adjustable stop, said clamping device presenting flat surfaces in contact with a width of material during reciprocal movement, resilient means associated with said reciprocal movement imparting means adapted to compensate for over-travel of the reciprocal movement imparting means with respect to the movement of said clamping device between saidstops, a stationary clamping means disposed adjacent said fixed stop, means associated with said cylin der and reciprocal movement imparting means adapted to admit and exhaust pressure from said cylinder to actuate the clamping device into and associated with said adjustable stop adapted to permit accurate setting thereof.

4. In a material handling mechanism, a movable clamping device adapted to engage and advance material, said movable clamping device comprising opposed material engaging members, a' bed plate for supporting said movable clamping device, a pressure cylinder secured to one of said members and having its piston directly secured to the opposed member, said cylinder securing means cooperating with the bed plate and adapted topermit relative sliding movement between the bed plate and movable clamping device, means for imparting reciprocating moveciprocating movement, a plurality of positive spaced stationary material clamping devices adjacent one of said stops, and means incorporated in said movable material clamping device adapted to extend between said spaced stationary clamping devices in the extreme positionof said movable clamping device adjacent said stationary clamping devices. MOSES E. BROOKS.

Images