US2577084A - Reciprocating strip feeding mechanism - Google Patents

Description

Dec. 4, 1951 E. LAXO' RECIPROCATING STRIP FEEDING MECHANISM '7 Sheets-Sheet 1 Filed June 1, 1948 INVENTOR.

ATTOPA [YF Dec. 4, 1951 7 Sheets-Sheet 2 Filed June 1, 1948 INVENTOR. [0 [4x0 Dec. 4, 1951 LAXO 2,577,084

RECIPROCATING STRIP FEEDING MECHANISM Filed June 1, 1948 7 Sheets-Sheet I5 INVENTOR. [a [4x0 BY wga 5 i Dec. 4, 1951 E. LAXO RECIPROCATING STRIP FEEDING MECHANISM Dec. 4, 1951 E. LAXO RECIPROCATING STRIP FEEDING MECHANISM Filed June 1, 1948 '7 Sheets-Sheet 5 Dec. 4, 1951 E. LAXO 2,577,084

RECIPROCATING STRIP FEEDING MECHANISM Filed June 1, 1948 v 7 Sheets-Sheet 6 I Ilium;

' Q r/w INVENTOR. [blue BY MM W ATTOP/Vf/f Dec. 4, 1951 E LAXO RECIPROCATING STRIP FEEDING MECHANISM Filed June 1, 1948 iii 7 Sheets-Sheet 7 Eatented bee. 4,

RECIPROCATING STRIP FEEDING MECHANISM Ed Laxo, Oakland, Calif., assignor to Atlas Imperial Diesel Engine 00., Oakland, Calif., a corporation of Delaware Application June 1, 1948, Serial No. 30,243

Y 1 Claim. 1

v This invention relates to a feeding mechanism. More particularly, it relates to a mechanism for feeding metal blanks, such as strips of tin plate, to a punch press for punching out the ends of cans. The mechanism is, however, applicable to intermittent feeding of various objects to a second mechanism for cutting, punching, stamping or other operations.

In a punch press of the type used to punch the ends of cans from metal strips, two punches are provided which are staggered or disposed diagonally to one another in relation to the line of travel of the metal strips. The punches operate in unison, punching out two, diagonally spaced ends on each punching stroke. Two parallel rows of staggered holes are thus punched in each strip.

In feeding strips to a punch press of this type, each strip must be advanced from an initial position on a feed table to align one end thereof for the first punching operation, and thereafter it must be advanced by uniform increments equal to the center-to-center distance between adjacent holes or ends punched in each row. The second feeding operation will be hereinafter referred to as the main feed and the first feeding operation as the auxiliary feed.

In feeding mechanisms for the purpose described, high speed, dependable and accurate feeding and compactness are of prime importance. It is important that individual strips be rapidly and synchronously extracfled from a supply of the same. It is also important that the main feed and auxiliary feed be such as to allow uniform, rapid reciprocation of the punches and to insure that a blank is properly aligned for punching on each punching stroke. It is further desirable that, in the event of jamming of the feed table by a strip, the feeding be brought to an immediate halt to prevent damage to costly elements of the apparatus.

Feeding mechanisms as heretofore designed leave much to be desired in these and other respects. Thus, the means in use to extract strips from a stack of the same, and to position each strip on the feed table in proper timed relationship to the feeding movements of the preceding strip, have been unduly complicated, bulky, and of not too rugged construction. Also, the auxiliary feeding means has been of awkward design, being top heavy and resulting in a large degree of vibration.

It is an object of the present invention to provide an improved apparatus for feeding metal strips or the like to a punch press or the like.

It is a further object to provide a feeding apparatus of the character described having improved means of extracting metal strips from a supply of the same and positioning each strip in proper timed relationship on a feed table.

These and other objects of the invention will be apparent from the ensuing description and the appended claim.

One form which the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which: H

Fig. 1 is an end view of the feeding mechanism as viewed from the end farthest from the punches, and showing fragmentarily a part of the punch press frame.

Fig. 2 is a transverse section, being a view in the same direction as in Fig. l, and showing certain details of the feed hopper and feed table.

Fig. 3 is a plan view of the feed hopper taken along the line 33 of Fig. 1.

Fig. 4 is a plan view of the feed table with the feed hopper removed.

Fig. 5 is a section taken along the line 5-5 of Fig. 4, showing details of the suction mechanism used for extracting metal strips from the hopper.

Fig. 6 is another view of the suction mechanism, taken along the line 6-6 of Fig. 5.

Fig. '7 is a sectional view taken along the line i1 of Fig. 6, showing certain details of the suction mechanism.

Fig. 8 is a longitudinal sectional view taken along the line 8-8 of Fig. 1, showing the main and auxiliary feed mechanism.

Fig. 9 is an elevational view, partly broken away, showing the safety device employed to interrupt the feed mechanism in the event of jamming of a strip.

Fig. 10 is an end view, taken along the line ifllfl of Fig.8, and Figs. 11 and 12 are transverse cross-sections taken along the lines H--l l and. l2-l2, respectively, of Fig. 8, all showing details of the feed bar structures.

Fig. 13 is a section taken along the line I3-I3 of Fig. 3, showing certain details of the feed hopper construction.

Fig. 14 is a view elevation taken along the line |4|4 of Fig. 13.

Fig. 15 is an end View, taken along the line ||5 of Fig. 1, showing the adjustable mounting of the feed table.

Fig. 16 is a schematic illustration of the progress of a strip through the feeding mechanism and punch press.

Referring now to the drawings, and more particularly to Figs. 1, 2 and 3, the numeral ID indicates one side of the main frame of a punch press including a punching element (not shown) A feed table is secured to a supporting bracket I2 and is aligned therewith by means of keys E3. The supporting bracket I2 is bolted at I4 to an intermediate bracket |5 which is carried in gibs l6 bolted to side In of the press frame by bolts As shown more clearly in Fig. 14, the feed table is adjustable in either of two mutually perpendicular directions, by loosening bolts M or H and turning screw 5 or 6.

As shown, the feed table II is set at a steep angle, and thereabove is a feed hopper generally designated as 20, which comprises end bars 2| and side bars 22, the latter being adjustably clamped to the end bars at 23 to allow variable spacing of the side bars to accommodate strips of different widths. To accommodate strips of different length, an auxiliary end bar 24 is provided which is adjustably clamped to a side bar at 25, as shown. Adjustably clamped to the side bars 22 are posts 26 and retainers 21, and to the left hand end bar (as viewed in Fig. 3) and auxiliary bar 24 are adjustably clamped combination posts and retainers 26a. Each retainer 21, as shown more clearly in Figs. 13 and 14, is provided with claws 35 pivotally supported at 36 and having serrations or teeth 31 at its lower end. An auxiliary member 35a pivotally supported between the arms of the retainer, as shown, serves to guide and align the strips, and adjustable stop screws 31a position the claws 35 and auxiliary members 35a to properly retain the strips. The claws 35 and auxiliary members 35a serve to retain a stack of strips 38 in the hopper until a suction mechanism hereinafter described operates to extract the lowermost strip from the stack of strips. The members 26a are similarly provided with claws to function as combined posts and retainers.

As shown, the end bars 2| extend both outwardly and inwardly of the hopper frame, and at their inner ends they are hingedly connected at 40 by brackets 39 to supporting brackets 4|, which are bolted to the feed table. The outer ends of the end bars 2| are connected by a handle 42, by means of which the feed hopper may be pivoted about its hinged connection 46. Normally, with the feed hopper 20 in operative position, the end bars 2| rest upon adjustable stops or lugs 43 carried by brackets 44 integral with the feed table. Also, clamped to and depending from the inner side bar 22, is a block 45 provided with a notch 45 and a finger 41 at its lower end for the purpose hereinafter described.

Referring more particularly to Figs. 2 and 5 to 7, the strips 38 are withdrawn one at a time from the bottom of the hopper 20, by a plurality of suction means generally designated as 55, each of which is secured to a shaft 56 extending between and journaled in the upper ends of the feed table at 51 (see Fig. 1). Each suction means 55 comprises a generally L-shaped arm 58 clamped to the shaft 56. Secured to the free end of each arm by a screw 59 and washer 60 are a holder 6| and a rubber suction cup 62. The suction arms" 58 are actuated, and are caused to swing through an arc between the plane of the bottom of the feed hopper and the plane of the feed table, by means (see Fig. 1) comprising a lever 63 clamped to the shaft 56, a connecting rod 64, a bell crank 65 (which is mounted on a stub shaft 36 carried by a bearing block 61 secured to the press frame ID), a second connecting rod 58, and an eccentric 69 secured to the outer end of a shaft Ill extending through and outwardly of the press frame If]. The shaft 16 is rotated, through a suitable driving connection (not shown) by the press crankshaft (not shown). The linkage shown as operatively connecting the eccentric 69 and the lever 63 is employed to clear certain parts of the machine, and the connecting rod 68 is threaded into rod ends H and 12 to allow adjustment of the are through which the arms 58 oscillate.

It will thus be seen that, as the shaft '16 rotates, each of the suction arms 58 will swing upwardly into the position shown in Figs. 1 and 2 adjacent the bottom-most strip in the feed hopper, and will then swing downwardly to deposit the extracted strip at a position on the feed table indicated as A in Fig. 2, openings i3 being provided in the feed table (see Fig. 4) to accommodate the suction arms and cups.

Suction is applied to extract the bottom strip from the hopper, and the suction is broken after the strip has been deposited on the feed table at A, by the following means. With particular reference to Figs. 5 to '7, an arm M carried on the shaft 56 adjacent each suction arm 58 is secured against rotation by a slotted bracket secured to and depending from the feed table II. The angularity of the arm i4 is adjustable by means of a screw 16 and slot 11 formed in the bracket 15. A sealing collar 18 is also carried on the shaft and is secured against rotation but is free to slide axially of the shaft by reason of a pin 19 lying within a socket formed in the sealing collar 18 and in threaded engagement with the left hand bracket 44 (as viewed in Fig. 4). A pair of coil springs 8| received Within sockets 62 and 82a formed in the same members serve to force the collar 18 against a fixed sealing member 83c1amped to the shaft 56. A main suction conduit 84 and branch suction conduits 84a are interconnected by a manifold 85 and aligned passageways 86'-'and 86a formed in the sealing collar I8 and sealing member 83; the main suction conduit leading to any suitable suction means (not shown). It will be seen that, as the shaft 56 and the arms 58 oscillate, the suction passages 86 and 86a will align and disalign periodically, and that merely by turning the fixed sealing member 83 and. clamping it in the desired position, the pulling of a vacuum through these passageways can be made to occur at the proper time in the sequence of operations; i. e., when the suction cup 62 is in contact with the bottom strip 38.

An air passage 81 is formed in each arm 58, communicating the branch conduits 84a with their respective suction cups. Each passage 81 is also drilled completely through at 68, and a suction release valve generally designated as 89 is provided. The valve 89 comprises a body 90 pivotally secured to the arm at 9|, a coil spring 92, a valve stem and head 93 and a roller 94. It will be seen that the spring 62 normally seats the valve head 93 in the open end of the passage 81 (which is appropriately cored out to re ceive the valve head), and that, on the downstroke of the arm 53, thevalve is opened by engagement of the roller 94 with a cam surface 95 formed on the arm 14- as is shown in broken lines in Fig. 5. By adjustment of the ang'ularity of the arm I4, the valve 89 is opened, and the suction is released, at the proper moment; i. e., when the extracted strip 38- has been deposited on the feed table II. Further, by meansof the adjustable link 88' referred to hereinabove (see Fig. 1) in the mechanism actuating the shaft 56 I and suction arms 58*, the latter are caused toswing sufficiently below the plane of the feed table to clear the feed fingers (described here-* inafter) which perform the next feeding operation.

' Referring now more particularly to Figs. 1, 2 and 4, each strip, after being deposited upon the feed table at the position A, is next moved across the feed table to a position indicated as Bin alignment with the punches of the press. This transverse feeding movement is accomplished by means of fingers or inserters Isl], each of which is notched at IEII and is so positioned as to align the apex of the notch with the plane of the feed table. Each inserter I90 is secured to the upper end of a rod I82, which is carried under the feed table in bearing blocks IE3 secured to the feed table supporting framework. Each rod I02 is reciprocated by means comprising a drag link I84 clamped to the lower end of the rod, an operating arm Hi5- secured to the other end of the drag link and clamped at its opposite end to a shaft Hi6. One end of the shaft I96 is journaled in a bearing bracket I08 bolted to the feed table,

and the opposite end of the shaft is journaled in an extension M39 of the feed table supporting framework. The shaft IB i extends through the extension I09 and through and inwardly of the press frame Iii, which is suitably cored out to clear it. Within the press frame, as shown in broken lines in Fig. 1, an arm H6 is clamped to the end of the shaft I86 and is connected by a link III to a second arm H2. The arm H2 is clamped to the hub of a cam follower lever II 3 carried on a shouldered stud II4 secured in the press frame, and the lever H3 carries a roller II5 engaging acam III; secured to the abovementioned shaft Til, the follower II'5 being held in engagement with the cam by means of a coil spring. Ill secured at M8. to the arm II 2 and at I I9 to. the press frame.

The cam H6 is so contoured that the inserters IUIl descend. with a relatively rapid motion, dwell for a short period until the strip is properly started forward as described hereinafter, and then rise to inserting. position with a slower movement. It is further to be noted that both the eccentric 69 actuating the suction arms 58 and the cam IIS actuating the inserters I09, are secured to the same shaft. It is thus possible, merely by rotating either of these elements about the shaft 1t, to change their relative angularity and provide proper and accurate timing of. the strip extracting and insertin movements.

As stated, each strip 38 is moved by the inserters I00 from the position indicated as A in Fig. 2 to the position indicated as B, in which latter position it is in alignment with the punches of the press. strip fiat upon the feed table as it is being advanced toward the press punches, there is provided a guide I25 which is carried by supports I21 pivotally secured at I28 toblock's I29 secured ti) the lowermost edge of the feed table. To

For the purpose of holding each age-tasse- 6. secure the guides in position, and also to effect proper alignment of the feed hopper 20', there are provided keeper blocks I30 adjustably bolted to the guide assembly by means of boltsv I3I passing through ovate slots I32 formed in the keeper blocks. The upper end of each keeper block is tapered to provide an angular corner or edge I33, which is complemental to the abovementioned notch 46 formed in the mating blocks secured to the feed hopper 2B. As shown in Fig. 2, when the feed hopper 29 and the guide assembly I25 are in their normal operative position, the notches in the blocks 45 engage the tapered edges of the keeper blocks I30 and rest thereon. By adjustment of the keeper blocks forwardly or rearwardly, it is possible to compensate for discrepancies in the assembly of other parts of the machine. Also, by reason of the hinged connections 48 and I28, it is possible to lift the hopper 20 and guide I25 clear of the feed table to allow access to the latter for repairs, removing damaged strips, etc. A guide key 250 bolted to and running the length of the feed. table, and engaging a grooved section 25I, is also provided as a bottom support and guide for the strips as they are fed toward the punches.

Referring now more particularly to Fig. 8, to provide feeding movement of the strips 38 longitudinally of the feed table and toward the press punches, there are provided a main feed bar I34 and an auxiliary feed bar I35, which are in alignment and are received within and are reciprocable within a slot I36 formed along the length of the feed table (see Fig. 2).

As shown more clearly in the cross-sectional views of Figs. l0, l1 and 12, the main feed bar I34 is in the form of a channel having a stepped recess I31 and a lateral extension I38, and the auxiliary feed bar I35 is in the. form of a solid bar complemental to the recess I37 of the main feed bar. The auxiliary feed bar I35 lies generally within, and is reciprocable in the recess I31;

Bolted to the auxiliary feed bar I35 are a plurality of blocks I39, and adjustably clamped to the main feed bar, to the right of the auxiliary feed bar, by means of bolts I 4!! and blocks MI,

are a plurality of blocks I42 similar to the blocks I39 bolted to the auxiliary bar. Each of the blocks I39 and I42 is recessed at I43 (see Fig. 8), and hingedly secured at I44 within each recess is a feed finger I45 urged upwardly to extend slightly above the feed table by a coil spring I56. The blocks I42, hence the feed fingers I45, thus secured to the main feed bar are equal in number to the ends to be punched in a single row from a strip 38, and they are spaced apart a distance equal to the center-to-center spacing of the ends thus to be punched. The blocks I 39 and feed fingers I45 bolted to the auxiliary feed bar I35 may be fewer in number and their spacing is such as to feed each strip from its initial position B on the feed table (as deposited by the inserters I00) to a second position in proper alignment for hand strip is shown at its initial position Ben the" feed table, and to the right thereof is shown a second strip 88 in alignment with the punches and from which several ends have been punched and from which two more ends (shown in shading) are about to be punched. As the latter ends are being punched, the left hand strip 36 is fed forwardly by the first auxiliary stroke and then by the second and third auxiliary strokes, at which time it is in position for punching the first end therefrom. From thence forward, the strip is fed forwardly in eight successive increments corresponding to the center-to-center spacing of can ends.

Turning now to the means for actuating the main and auxiliary feed bars, the main feed bar I34 is reciprocated by rotation of a crank disc I55 (see Fig. 1) mounted on one end of the press crankshaft (not shown). A connecting rod I56 is threaded at one end into a rod holder I56a connected eccentrically and adjustably to the crank disc I55 by a ball-and-socket connection I51. The other end of the connecting rod I56 is threaded into a second rod holder I58, which is connected by means of a ball-and-socket connection I59 (more clearly shown in Fig. 8) to an arm I60 of a rocker I6I mounted on a post I62 secured to the feed table supporting framework. the other arm I63 of the rocker ISI is secured at I64 to a sleeve or hollow stem I65 which is keyed to a connecting rod I66 by a safety device generally designated as I61 and described in detail hereinaften. The other end of the connecting rod I66 is threaded into a driving yoke I68. The opposite end of the yoke I68 is pivotally connected at I69 to the man feed bar I8 1.

The auxiliary feed bar I35 is reciprocated by the same rocker I6I which actuates the main feed bar. A lever I86 pivotally supported upon the same post I62 on which the rocker pivots, and overlying the rocker, is connected at its outer end through a connecting rod I8I, a rod holder I82, and a driving yoke I63 to the auxiliary feed-bar I35. As shown more clearly in Figs. and 11, the main and auxiliary driving yokes are pivotally secured to their respective feed bars by means of bearings I84 and I86a and clamps I85 and I85a, respectively.

The lever I86 is actuated by the main driving yoke I68 by means of a connecting rod I86 threaded at one end into a rod holder I8I, which is adjustably connected to the lever I88 by a nut and bolt I88 engaging a longitudinal slot I89 formed in the lever, and threaded at its other end into a second rod holder I96 pivotally secured at I9I to a lug I92 projecting from an integral with the man driving yoke I68. It will thus be seen that, as the main driving yoke I68 and main feed bar I34 are reciprocated, the auxiliary driving yoke I83 and auxiliary feed bar I35 will also be reciprocated in synchronism with the main feed bar, and that the stroke of the auxiliary feed bar can be adjusted relatively to that of the main feed bar by means of the adjustable connection of the rod holder I87 and the slotted lever I88.

As is apparent, the feed strokes of the auxiliary feed bar I35 are longer than the feed strokes of the main feed bar I34. This result is accomplished by the means described for driving the auxiliary feed bar. The latter is driven by the rod I86 connected by the rod end I31 to the lever I80 at I88, and by the rod I8I connected to the lever I86 at a point farther from its fulcrum than the point I88. Thus, as shown by the angles shown in broken lines, the amplitude of reciprocation of the rod I8I, hence of the auxiliary feed 8. bar I35, is greater than the amplitude of the rod I66 and main feed bar I34.

Reverting now to the safety device I6'I serving.

to connect the sleeve I65 and connecting rod I66 oi the main feed bar actuating mechanism, as shown more clearly in Fig. 9, a chamber 260 is provided, which is integral with the sleeve I65, and within the chamber 266 are disposed two blocks 2Ill, each having a wedge-shaped portion 202 normally seated on a complemental wedge 283 formed in the connecting rod I66 and held in engagement therewith by a coil spring 206 maintained under any desired compression by means of an adjusting screw 285. The connection thus formed between the sleeve I65 and rod I66 serves to drive the rod, hence the main and auxiliary.

feed bars, during normal operations, but should a strip become jammed, the blocks 2M will be forced out of engagement with the wedge 263 and further reciprocation of the sleeve I 65 will merely result in the sleeve sliding back and forth without reciprocating the rod I66.

It will thus be seen that a machine has been provided which rapidly extracts strips of metal or the like from a supply of the same, in accurately timed relationship to subsequent steps in the cycle of operation; which accurately and rapidly deposits and orients each strip on a feed table in alignment with press punches; which rapidly and accurately advances each strip to a position for the initial punching operation and thereafter feeds the strip in uniform increments through the press; which provides an automatic safety element to stop the feeding movements in the event of jamming of a strip; and which embodies such desirable features as compactness and ruggedness of design, the mounting of parts in relation to each other so as to minimize vibration, etc.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claim.

Having thus described my invention, what I claim and desire to obtain by Letters Patent is:

A strip feeding device adapted to feed strips to a punch press, comprising a feed table having a groove formed therein and auxiliary feed member adapted to reciprocate and, on one or more feed strokes, to feed a strip along said table and align the leading edge thereof for a first punching operation, a main feed member slidably received in the groove and adapted to reciprocate and, on successive strokes, to align said strip for successive punching operations, said main feed member being channel shaped and slidably receiving within the channel thereof said auxiliary feed member, a first oscillatable member, means for oscillating said oscillating member, a rigid reciprocating element interconnecting said first oscillatable member and said main feed member for reciprocating said main feed member upon oscillation of said first oscillatable member, a second oscillatable member mounted for oscillating movement about the axis of oscillation of said first oscillatable member, a second rigid reciprocating element interconnecting said second oscillatable member and said auxiliary feed member for reciprocating said auxiliary feed member upon oscillation of said second oscillatable member, and a third rigid reciprocating element connected at one end to said first reciprocating element and connected at its opposite end to said second oscillatable member for radial adjustment thereof whereby the length of travel of the auxiliary feed member can be increased or decreased by suitable radial adjustment of said opposite end of said third rigid element along said second oscillatable member.

ED LAXO.

REFERENCES CITED UNITED STATES PATENTS Number Name Date Aufdembrinke Mar. 11; 1873 Leslie Oct. 7, 1879 Jacobus Mar. 4, 1913 Arnold May 27, 1913 Alpern Mar. 20, 1917 Schoendelen Jan. 30, 1923 Jones et a1. Oct. 28, 1930 Milmoe May 26, 1936 Esch Oct. 10, 1939 Cronshaw July 28, 1942 Murch et a1. Dec. 14, 1943 Luthi Mar. 13, 1945

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