US2268242A - Rapid punch press - Google Patents

Description

Dec. 30, 1941. Z1P.CANDEE ETAL 2,268,242

RAPID PUNCH PRESS Fi-led Jan. 18, 1959 I 4 Sheets-Sheet l lNVENTOR Zenas Candee. George WJac/mpan BY ATTORNEY De c. 30, 1941. -z. CANDEE ETAL 2,263,242

I RAPID PUNCH PRESS Filed Jan. 18, 1959 4 Sheets-Sheet 2 28 [Ng EgTOR nas Indeeq eorg e 77%.

I ATTOVRNEY Dec. 30; 1941.

2. P. CANDEE ET AL RAPID PUNCH PRESS 'Filed Jan. 18, lss

4 Sheets-Sheet 4 INVENTOR ZenasP. Candee.

' Georpvemkcltman.

Jaw?

ATTORNEY Patented Dec. 30, 1941 'ulgurso STATES PATENT OFFICE RAPID PUNCH PRESS Zcnas P. Candee and George W. J ackman, Waterbury, Conn., assignors to The Waterbury Farrel Foundry & Machine Company, Waterbury, Conn., a corporation of Connecticut Application January 18, 1939, Serial No. 251,583 11 Claims. (Cl. 164-89) This invention relates to press machinery, and more particularly to an improved rapid punch press in which a strip of stock is continuously fed into the press by a roll feed which has a reciprocating motion to cause the stock to have zero velocity during the punching operation.

In the conventional typeof roll feeding mechanisms in which the roll housings are stationary, the rolls are inoperative during one portion of the press cycle, and operative to feed the stock to the dies during another portion of said press cycle. With such machines it is necessary to accelerate the feed rolls from zero velocity to maximum velocity, and again reduce the speed to zero during each cycle of the press. Due to the inertia of the rolls and their driving means, the rolls are diflicult to .startJand stop, and have a tendency to over-travel at the end of their operative action. To offset this inertia and overtravel tendency, strong starting. mechanism and brakes are required, with their attendant disadvantages. The intermittent starting and stopping of the rotating parts seriously affects the accuracy of feeding the stock. This is especially true in high speed punch presses having a rapidly reciprocating punch requiring relatively high velocity of stock feeding. When it is attempted to operate presses at high speed with comparatively long feeds, it has been found that the bad effects from the feed roll inertia increase as the square of the speed and a maximum feeding velocity is eventually reached which cannot be exceeded without loss of accuracy of, feed.

By means of the present invention, the above and other disadvantages have been overcome and a rapid punch press has been produced in which the stock feeding rolls are continuously rotatedeliminating the need of starting and stopping mechanisms, and making it possible to obtain faster feeding and operation of the punch press. One object is to provide a mechanism of the above nature having cooperating continuously rotating stock feed rolls mounted in housings which are adapted to oscillate back and forth in the path of ,the stock feed. ,Another object is to provide a rapid punch press of the above nature in which the feed rolls are released from the stock during the punching operation, and in whichcmeans are provided for raising and lowering the rolls together with their driving mechanism to compensate for different thicknesses of the stock and the level on which it is being fed. V

A furtherobject of this invention is to provide an improved stock feeding mechanism of the above nature which will be relatively inexpensive to manufacture, simple in construction, readily manipulated, compact, and very efficient and durable in use.

With these and other objects in view, which will appear as the description proceeds, there have been illustrated in the accompanying drawings two forms in which the principles and features of this invention may be conveniently embodied in practice.

In the drawings:

Fig. 1 is a front elevational view of a punch press embodying the invention.

Fig. 2 is a side elevational view of the same.

Fig. 3 is an enlarged sectional view ofthe same, the section being taken on the line 3-3 of Fig. 1.

Fig. 4 is an enlarged sectional view of the same, the section being taken on the line 4-4 of Fig. 2. p

Fig. 5 is a front view of a modified form of the invention inwhich the feed roll supports are reciprocated in a straight line instead of oscillated in the path of the stock being fed.

Fig. 6 is a chart showing the graphs of the relative motions of certain of the operative parts of the machine.

Referring now to the drawings wherein like reference characters denote corresponding parts throughout the several views, the numeral l0 designates the frame of a punch press of standard construction, including a rotatable crank shaft H, a flywheel l2 secured on one end of the crank shaft H, and a belt l3 drivingly connecting a pulley l5 mounted on the shaft of a variable speed motor I4 to the flywheel l2. The crankshaft H is adapted to vertically reciprocate a punch IS with respect to a die l1 having an opening Ila therethrough and whichis secured on a die plate l8 for causing said die and punch to sever products from a strip of stock l9 located therebetween.

The strip of stock I9 is fed through the press in the direction of the arrows 20 shown in Figs. 2, 3 and 5 by means of two pairs of cooperating continuously rotatingfeed rolls, one pair consisting of the rolls 2| and 22 being located in front of the press, and the other pair consisting of the rolls 23 and 24 being located at the rear The gears 28 and 39 are adapted to mesh with j by the numeral 49.

anism 40 includes a pulley 4| which is drivingly idler gears 32 which in turn are in mesh with pinion gears 33.

Each of the gears 33 is connected through a shaft 34 to a pulley 35, which is drivingly connected by means of a belt (36 or 31) to a common pulley 38 which in turn is drivingly connected, as by a belt 38a, to a pulley 39 forming part of a variable speed mechanism, generally indicated The variable speed mechconnected by a belt 42 to a pulley 43 mounted on one end of the crank-shaft ll. By means of .the above construction, it will'be seenthat the front rolls 2! and 22 andth'erear rolls 2l3and 24 will be continuously rotated while-the press is in operation by means of the variable speed motor I4. It will also be seen that. the speed of said rolls may be varied by manuallyadjusting the variable speed mechanism 49 by means of a hand wheel 44 secured to a threaded stud 45, which is connected by a link 46 to an opcrating arm 41 of the Variable speed mechanism 49. For a full description of a variable speed mechanism of a similar type, reference should be made to Patent No. 1,662,660,, issued to H. C. Clay, MarchlB, 1928, and assignedto the Reeves Pulley Company of Columbus, Indiana.

Oscillating roll supports The upper feed rolls 2! and 23 are journaled in spaced-apart uprights 48 and 49, forming an integral part of an oscillating bracket 59, and the lower feed rolls 22 and 24 are jou'rnaled in spaced apart uprights| and 52 (Fig. 4) forming part of a bracket 53, which is arranged to slide up and down within the bracket 50. The uprights 5| and 52 of the sliding bracket 53 are disposed in vertical guideways 54 and 55 formed in the uprights 48 and 49, respectively.

In order to constantly urge each slidable-bracket 53 upwardly, provision is made of a pair of compression springs 56, each reacting between tension adjusting screw plugsbl threaded into a horizontal partition 58 of the bracket 59, and the base 59 of said bracket 53, whereby the strip of stock l9 will be firmly gripped betweenthe pairs of rolls. I)

Each of the oscillating brackets 59 (see Figs. 1 and l) is pivoted to a fixed bracket 69, which is secured to the machine frame it by horizontal threaded studs BI and nuts .62. The studs EH pass through vertically elongated holes 53 formed in the bracket 69 and screw threaded into the adjacent portion of the frame it]. Both of the brackets 60 are adjustable vertically by means of a screw 64 having an upper head which engages a shoulder 65 on the bracket 60 and. screwthreads into the table top 65 of the press frame it], said brackets 60 being clamped in any desired adjusted position by tightening the nuts 62 on the studs 6|.

The pivotal joint between the oscillating bracket 59 and the fixed bracket 60 is constituted partly by a horizontal pin 6'! extending through and rotatable in an upright 68 extending upwardly from the bracket 60, said pin 6] also extending through and being fixed to a pair of spaced lugs 69 and ill depending fromthe oscillating bracket 58. Theremainderof the pivotal joint comprises an elongated horizontal sleeve H passing through and fixed to an upright 12 extending upwardly from the bracket 69, and also passing through a pair. of spaced- apart lugs 13 and 14 depending from the bracket 5i1 and freely rotatable on the sleeve II. It will be understood that the pulleys 35 also rotate about the same axis as that of the bracket 5!].

Feed roll oscillating mechanism Both of the front and rear oscillating brackets 50 are adapted to be rocked with respect to the fixed brackets by means of an eccentric crank pin 15 mounted in an extension 16 of the crank shaft II. The eccentricity of the pin 15 is adapted to be adjusted by means of a screw H. A downwardly extending link 18 connects the crank pin 15 to a horizontal arm d9 of a common bell crank lever pivoted to the frame In at 8|. The other vertical arm 82 of the bell crank 80 is connected to the front oscillating bracket 59 by a link 83, and to the rear oscillating bracket 5.9 by a link 84, whereby both brack Roll releasing mechanism In order to release the rolls 2|, 22 and 23, 24 from gripping engagement with the strip of stock 9 during the punching operation, provision is made of a pair of vertical studs 86 which are extended upwardly through suitable apertures in each of the oscillating brackets 50 and the sliding brackets 53 (see Figs. 3 and 4), said studs 36 having lock nuts 81 threaded on their upper ends to engage said brackets 53. By means of this construction, the depression of the studs 83 will cause the brackets 53 to slide downwardly along the vertical guideways 54 and 55 to separate the lower rolls 22 and 24 from the upper roll-s 2| and 23. The lower end of each releasing stud 88 is rotatably mounted on a short eccentric shaft end 88 extending from a rock shaft 89 journaled in the sleeve H. As clearly shown in Figs. 2 and 3, the shaft 89 of the front oscillating bracket 59 has a bell crank lever 93 secured thereto, one arm 9| of said lever being connected by a cross bar 92 to an arm 53 secured to the rock shaft 89 of the rear oscillating bracket 50, whereby both front and rear rock shafts 89 will be rocked in unison.

An upwardly extending rod 94 is connected at its lower end to the other arm 95 of the bell crank, lever 90. The upper end of said rod 94 is connected to the outer arm 93 of a rocking lever. 91 pivoted to the frame l9 adjacent the with, The cam, I00 is provided with a raised camming lug. lill, and said cam is timed to cause said lug to effect the release of the stock is from the grip of both pairs of rolls during the punching operation.

Modification This is accom- As in the first form previously described, the bell cranklever 80 is rocked byzthe eccentric pin I of the crankshaft throughtthe depending link 18 connected to thearm "I9 (see Figs. 1 and 2).I

Operation In operation, when the motor III is started, the crank-shaft I I will be rotated and the punch I6 reciprocated' to act upona strip of stock I9 passed between it and thedie I'I. The two pairs of cooperating feed rolls 2|, 22 and 23, 24 are also caused to continuouslyrotate at the desired constant speed to pass the stock I9 through I the press During each revolution of the crank-shaft II, I

the punch IE will be reciprocatedto act in co- I operation with the die II upon the stock I9 disposed therebetween. I I

I Since it is obviously necessary that the metal stock must be standing still while the punch engages it and locks theymetal, punch and die together momentarily, the feed roll housings are givenan oscillating motion in the first form of the invention (and Ia sliding motion inthe second form) timed to produce a short period of dwell in the resultant motion of the strip stock at the time the actual punching takes place. This is accomplished by causing the oscillating feed roll housing when it is traveling in the opposite direction from the metal stock to move at practically the same speed as said stock, so as to compensate for the forward speed thereof Mathematically, the back and forth I motion of the feed roll housings will be equal to the amount of the advance of the stock divided by fpi (3.1416). In other words, the speed of I the feed rollhousing is intermittently brought to zero once each cycle to cancel out the speed of the continuous advance of the metal stock produced by the constant rotation of the feed rolls. The feed rolls will also be preferably separated once each cycle to release their grip upon the metalf stock to make possible the use of stockcentering pilots.I This is accomplished by the action of the cam I00, the lug' I01 of which engages the roller 99 on the lever 91 to cause the rod 94 to move up and down icr rocking the bell crank lever 90 and pulling downwardly upon the sliding brackets 53 to move the lower rolls 22 and 24 away from the upper rolls 2| and23 respectively. I I

During the remainder of the cycle the stock I9 will be fed along to dispose it in position for th'e next stroke of thepunch. The amount of movement required of the stock I9 during each cycle between strokes of the punch will, of course, be dependent upon the size and shape of the article being punched. I

The operation of the invention may be further explained by reference to the motion ch'art shown in Fig. 6, wherein the upper graph IIII represents the reciprocating movement of the punch I6 during one cycle of the press, or revolution of the crank-shaft I I. The next graph III represents a straight line showing the constant peripheral speed of rotation of the stock feeding rolls 2|, 22 and 23, 24 during the same cycle.

Thethird graph I I I2 representsthe movements of *thevoscillating feed roll supporting brackets 50. The graph I I3Irepresents the composite or resultant actual movement or feed of the stock produced by combining the graphs III and ,I I2, and shows the actual motion of the stockIrelative to the centerof the stationary die. The bottom graph II4 represents the cycle of motion of the feed roll release'camI I00 for separating the lower rolls 22 and 24 from the upper rolls 2| and23. I I

It will be clear from the above that the stock I9 willIbe advanced through the press during the major portion of its cycle when the punch I6 is not engaging the stock, and that the stock I will dwell at zero velocity when the punch is in engagement with said stock.

One advantage of this invention is that the feeding movement of the stock I9 will be much smoother than in previous presses, due to the great reduction of inertia effects in the moving parts of the roll feed mechanism.

A further advantage is that due to the continuous rotation of the rolls 2|, 22 and 23, 24, no expensive start and stop mechanism therefor is necessaryv ith its attendant inaccuracy of feeding and limitation on the maximum speed of i the punch press. I

Although it is considered preferable to oscil late the feed rolls in a swinging ,movement by pivoting the brackets 50 to the stationary frame, I e

the feed rolls may be mounted in sliding supports as shown in Fig. 5. In both cases, however, the maximum oscillating or sliding movement of the feed rolls may be variedby adjusting the eccentricity of the crank-pin I5 by means of the screw 11. Also the speed of rotation of the feed rolls may be varied by adjustment of the variable speed mechanism 40, and the roll brackets 50 or I03 may be raised and lowered with respect to the punch anddie by means of the adjusting screws 64. I

While there has been disclosed in this specification, two forms in which the invention may be c'onvenientlyembodied in practice, it is to be understood that these forms are shown for the purpose of illustration only, and that the inven- I tion is not to be limited to the specific disclosures, butmay be modified and embodiedin varmodifications and embodiments coming within I the scope of the following claims,

Having I thus fully described the invention, what is claimed as new and for which itis de sired to obtain Letters Patent is:

1. In a punch press having a die and a Irecip-I rocating punch cooperating with said die, mechanism to feed a strip of stock between said punch and die while the latter are separated including a pair of continuously rotating feed rolls for gripping said stock, a support for said feed rolls, means to move said support backwardly away from said punch and die to produce a dwell in the forward travel of said stock during the punching operation, and automatic means to separate said rolls to release the stock from gripping action thereby just prior to and during said punching operation. e

2. In a stock feeding mechanism for a punch press or the like, a pair or cooperating constantly rotated stock gripping and feeding rolls, a slid- I ing support for said rolls, means to reciprocate place; and cam operated means to separate said feed rolls to 'rel'ea'setheystock gripped thereby during the punching operation.

3. Ina punch and die press, arfram'e, avertically adjustable supp'or-t carried by said frame,

an oscillating bracketlpivoted to said support, a verticall sliding bracket mounted in said. oscillating bracket, said ibrackets carrying cooperating stock feeding rolls, means to cause said oscillating bracket to move rearwardly at such a speed as to produce adwell in the resultant forward motionof said stock duringthe punching operation, and means" to also move said sliding bracket downwardly to release said 'ro'lls' from said stock during said 'punching operation.

4. In a punch and die-press, a frame, an oscillating bracket pivotally mounted in said frame, a spring pressed bracket slidably mounted within said oscillating bracket, said brackets carrying cooperating stockfeeding rolls, means to cause said oscillating bracket to move said rolls in an opposite direction with respect to the movement of said stock at such a speed as toproduce a-dwell in the resultant forward motion of said stock during the punching operation, avertical stud connected to said slidable bracket and depending therefrom, and cam-operated means to depress said stud andslidable bracket to release said rolls from said stock during the punching operation. I

,5. In a punchiand die press, a frame, an oscillating bracket pivotally -mounted in said frame, a spring pressed bracket slidably mounted within said oscillating bracket, said brackets carrying cooperating stock feeding rolls, means to cause said oscillating bracket to move said rolls rear wardly with respect to the forward movement of said stock at such a speed as to produce a dwell in the resultant forward motion of said stock during the punching operation, a vertical stud adjustably connected to said slidable bracket and depending therefrom, and cam-operated means to depress said stud and slidable' bracket to release said rolls from said stock during the punching operation.

6. In a punch press having a' die and a reciprocating punch cooperating with said die, mechanism to feed a strip of stock between said punch and die while the latter areseparated including a pair ofcontinu'ously rotating feed rolls for gripping said stock, a support for said feed as to permit the punching operation to take feed roll forv cooperating with said upper feed rolls, means to move said. reciprocating brackets back and forth inuni'son for producing a dwell? in the forward travel ofsaid stock during'the operation of the punch and die located therebetween, and means operated. in unison to .move said slidable brackets downwardly to release the stock from gripping action just prior to and during said punching operation.

8. In a punch and *diepress, a frame, an oscillating bracket pivotallyrmounted in said frame, a spring pressed bracket slidably mounted within said oscillating bracket, said brackets carrying cooperating stock feeding rolls, crank-operated means to cause said oscillating bracket to move rearwardly with respect to said stock at such aspeed as to produce a fdwell in the resultant forward motion-0f said stock during the punching operation, a vertical stud connected to said-slidable bracket and depending therefrom, andcamoperated means to depress said stud and slidable bracket to release said rolls from said stock :dur-

rolls, means to move said support backwardly away from said punch and die to produce a dwell in the forward travel of said stockduring the punching operation, means to separate said rolls to release the stock from gripping action continuously rotating upper feed roll in the upper part thereof, spring-pressed brackets slidably mounted in each of said reciprocating brackets and each-carrying'a continuously operatedflower 7 ing the'pu-nch-ing operation.

9. Ina press having a die anda reciprocating punch cooperating with said die, mechanism to feed a strip of stock betweensaid punch anddie, while the latter are separated including aframe, two reciprocating brackets located at opposite sides of said punch and die, each carrying a continuously rotating upper feed roll in the-upper part thereof, adjustable brackets slidably mounted in each of said reciprocating brackets and each carryinga continuously operated lower feed roll for cooperating with said upper feed rolls, means to move said reciprocating brackets back and forth in unison for. producing a dwell in the forward travelof said stock during the operation of the punch and die locatedtherebetween, and means operated in unison to move said slidable brackets downwardly to release the stock from gripping action just prior to and during said punching operation. a

' 10. In a punch and die press, mechanism to feed a strip of stock between the punch and die while the latter are separated, including a pair speed of rotation of said feedfrolls, a support for said feed rolls, adjustable means to move said support backwardly and forwardly from said punch and die variable amounts to compensate for the speed of rotation of said feed rolls, whereby a zero velocity or dwell'willresult in the forward travel of said stock'during-rthe punching operation, and means to automatically separate said rolls from said stock during the punching operation;

11. In a punch and die press, means to feed a strip of stock between the punchand die while they are separated, including a pair of continuously rotating rolls for gripping and feeding said stock, adjustable meansto vary the speed of rotation of said feed rolls, a support for said feed VZENAS P. CANDEE. 'GEORGE JACKMAN.

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