US2547828A - Braking system for intermittent feed apparatus - Google Patents

Description

April 3, 1951 v F. K. MAussNEsT BRAKING SYSTEM Foa INTERMITTENT FEED APPARATUS I Filed Dec.v 18, 1947 Patented Apr. 3, 1951 UNITED STATES PATENTOFFICE lBEARING SYSTEM FOR` INTERMIIITENT f FEED APPARATUS Frederick KMMaussnesn Qens village, ,Y.,

assigner to Hedwig Mangt, Queens village, N. Y. Application-December 1s, 1947, serial No. 792,503

(o1. itil-2.4)'

, `11 Claims.

The present invention relates generally to anA improved braking system for rolls orvshafts in machine tools, and more particularly to itsalpplcation to automatic feeding mechanisms for punch presses and other forms of metal working and metal forming machines, which will intermittently feed the material betweenlthe punch and die of the machine in timed relation to its Stroker v The primary object of the invention is to `provide one single continuous braking system 4for two or more rotating rollsor shafts. v I

Another object is to provide,Y the intermittently revolving shafts of automatic roll feeds for punch presses, and other metal working machines with this improved continuous braking system to eliminate over-travel and to obtain extreme accuracy in feeding length.

A still further object of the invention is to provide one central adjusting point forthe single continuous brake system tomateria'lly impreve the accuracy of feed in intermittentlyactuated mechanisms of this type and Ato simplify at the same time theladjustment of the braking system for diiferent'feeding lengths, thus combining optimum feeding accuracy with mini-mum effort for adjustment.V I Y i Other objects and advantages which inake this particular automatic feeding vmechanism cheaper to manufacture and particularly 'rapid and efe' fective in its manner of operation will becne apparent during the coursey of the following description of the accompanying drawings 'where-- 1n:

.Figure i is a front elevation oran automatic roll feed embodying the invention and showL ing a portion thereof broken away to illustrate the height adjustment between the upper Aandv lower rolls. v Y Figure l2 is an end view of the" mechanism shown in Figure I.. 4

Figure 3 is an enlarged partial vertical crssjsectional view taken on line 3--3 of Figurevl and shows in greater detail the vbrake arrangement for upper and lower feed rolls' as well asifor the drive shaft.

Figure 4 illustrates in diagrammatic `form the brake arrangement for the feed rolls and drive 'shaftofthe automatic roll feedshown in Figures l, 25 andn3. v l i Figure 5 depicts eliag1"afrnrrlatically` a 'similar braking system for upper and lower feed rolls and drive shaft when theA operating direction"`v is reversed as compared with Figure' 4l4 Figure srsiicws dieramsmtieeuyftnefnewftype of braking system as employed in connecti'n withan automaticfeed such as 'shown in Figures 1 to 3, when only the upper and lower feed r'lls are` provided. with, this new brake. l Figure 7 illustrates diagrammatically a siniilar braking system for tlieulzper and lower ieed rolls as shown in Figure 6.', but fr reversed oper- 'ating directio'nl I Figure shows diag-'rammatioally a mdication of the lnew continuous braking system snilar to that shown in Figure 4, hwever, with an additional intermediate shaft.

While the present inlention may he applied to any mechanism or machine employing rblls 6r shafts which require brakes for ahsrbi'ng the inertia of their masses, I have chosen to illustrate the application of this new and improved con; tinuous braking system in connection with automatic roll .feed such as is used for presses andsiniilar nietl'wrkiig ria'chine's. u

In the drawings,l wherein I" the purpose f illustrating the invention, likegreifernc char;

acters will' be employed to designate like parts throughout, reference character II illilstiates part of a bolster or piatrrm of a runen press (Figs. 1lantl"2)`. actuatefrrn: the crankshaft "of the press, at the end of'which an adjustable crank (not shfwi is prvidedwhich is capable of varying the thi''w of connecting rod l2 for changing the length feed; Atts lower end the connecting rbd yI2 is pivo'tallyconnected as at `14 to a one-way clutch I3 of conventional and well-known de; sign; its upper end is'similarly connectedto the aforementioned adjustable crank on the crankshaft of the press (not shown). One-way clutch I3 is keyed to one end of drive shaft I4 and vis adapted to rotate this drive shaft I4 in a clockiwise directionr Shaft I4 is vjeurnaled in bearings I 6 and Il of roll vfeed base I5 and carries brake drum I8 adjacent to one-way clutch" I3. Gear I9 is keyed' to the other end of shaft I Said feed base I5 may be fastened to bed H by any suitable means (het shown) Gear 20, keyed to one end of lower feed roll 2|, is infrnesl with gear I9.l The lower roll 2l is journaled i the 1eft and right hand housings 2-2 and rslrespectively, and a brake drum 24 is vfast to its ether end. H0uSi`ngsf2-2 and 23 are seildto bas I5 by machine screws 15, ningelpins su enacting with straps 8| secured by screws 82 as shownf Upper left andl rightA nana yadjustable been ingv blocks 25 andfz. suitably guided in'respeetive housings 22 and"23 as shownt carry the upper feed-ll roll 21 inlbeaingsf 28 and 29pv respectively.

The automatic rll feed. is usilally Gear 36 is keyed to the right hand end of roll 21 and brake drum 3| is fast to its left hand end which terminates in a square 32 for the purpose of rotating the roll feed by hand if desired by means of a wrench, or suitable crank. The gears I9, 20, and 30 are in mesh with each other, and the brake drums I8, 24, and 3| are located in the same vertical plane. Upper and lower feed rolls 21 and 2| are shown as being of the same diameter. Gears 30 and 20 have therefore thev same number of teeth to rotate these rolls 21 and 2| in unison. A continuous brake band 33 is slung or wrapped around brake drums 3|, 24, and I8 in a double S or sinuous shape. The lower end of brake band 33 may be suitably fastened in a slot of a pin 34 threaded or otherwise attached to base I of the roll feed. The other end of said brake band is spring-loaded by means of bracket 35 threaded into, or otherwise fastened to, the left hand housing 22. A pin 36 is slidably mounted in this bracket and fastened by means of an angle 31, or other suitable means, to brake band 33. The lower portion of pin 36 is threaded and carries nut 39 with spring seat 40. A spring 38 is placed in compression between said bracket 35 and spring seat 40 to keep brake linings 4|, 42, and 43 in contact with brake-drums 3|, 24, and I8, respectively. The brakes on all three shafts (I4, 2|, 21) may be simultaneously tensioned by spring 38 whose pressure may be varied by means of nut 39.

To keep their momentum to a minimum, it is general practice to make the feedrolls 2| and 21 of hollow construction as shown in Figure 3. The feed length of a roll feed must be capable of adjustment to take care of the variety of work done on a punch press. As is well known, this is accomplished by varying the throw of the previously mentioned adjustable crank on the crankshaft of the press. Thus, the throw of connecting rod I2 is similarly varied. The resulting change in the angle of oscillation of one-way clutch I3 turns feed rolls 2| and 21 through corresponding kangles which determine directly the 'feedinglength of the roll feed for each revolution Vof thepress shaft.A Consequentlyjthe magnitudev of the .momentum of the revolving masses to be braked to an absolute standstill during each .press cycle varies with the feed length. With my new and improved braking system, a centralized ,adjustment for all revolvingl shafts is provided so that the setting of the brakes to obtain maximum accuracy is simple and foolproof, inasmuch as the operator has to manipulate one single spring (38) only which automatically regulates the tension on all brakes until the desired feeding accuracy has been obtained.

Various thicknesses of material have to be fed to punch presses by mechanisms of Vthis type. Therefore, the upper feed roll 21, mounted in upper housings 25 and 26 is adapted to be raised and "lowered by means of sleeves 44 and 45 which are threaded in upper housings 25 and 26 respectively, and rest on top of their respective lower 4 to prevent rods 46 from turning as shown in Figure 1. Rods 46 are threaded at their upper ends to receive nuts 46ZL and lock-nuts 49. Further lock-nuts 50 coact with threaded sleeves 44 and 45. To adjust the upper roll 21 for a different thickness of material, lock-nuts 50 are loosened and threaded sleeves 44 and 45 adjusted in relation to lower housings 22 and 23 until the desired opening between upper and lower feeding rolls 21 and 2| is obtained. Then lock-nuts 5|) are tightened. If the spring load on upper roll 21 is to be changed, the compression of springs 48 may be varied by loosening or tightening nuts and lock-nuts 48a and 49, respectively.

A bracket or'plate 5I may be fastened across the two lower housings 22 and 23 by means of screws 52 or the like. Plate 5| may have a transverse slot 53 in which two guide rolls 54 for guiding the work material may be mounted as shown in Figure 1. Guide rolls 54 are usually transversely adjustable in slot 53 to accommodate strips of different widths.

For lifting the upper feed roll 21, a hand-lifter 55 may be used to facilitate inserting a new strip between the upper and lower feeding rolls. Handlifter 55 consists of twin cam-type levers 56 and 51 interconnected by handle or cross-bar 58 and housings 22 and 23, as clearly shown in Figures 1 and 2. Rods 46 extend through upper bearing blocksv 25 and 26 and bores 11gof housings 22 and 23. Larger bores 19, concentric with bores 11, are arranged at the bottom of the lower- housings 22 and 23 to accommodate springs 48. kThese springs 48 are-compressed between the tops. of bores 19 and heads 41 of rods 46 which preferably may b e provided with projections 13 extending into vertical recesses 18 offho'usings 22 and 23 concentrically and rotatably mounted on the journals of roll 21. The actuating elements of levers 56' and 51 may be circles, such as designated by reference character 62. They may be provided at their lower ends with flat portions 59 (Fig. 1), resting on shoulders 60 and 6I of lower housings 22 and 23, respectively, when hand-lifter 55 is in inoperative position. By rotating handlifter 55 suiciently in a counter-clockwise direction as viewed in Fig. l, the upper roll 21 is lifted against the springs 48 onto the circular part 62 of levers 56 and 51, thereby increasing the opening accordingly between upper and lower feed rolls 21 and 2| to release the grip of the rolls on the stock.

An automatic lifter 63 may also be provided to lift the upper roll 21 at the end of each feeding stroke in synchronism with the reciprocating ram 64 of the punch press. To synchronize the automatic lift with the work to be done, a block 65 is usually adjustably fastened to ram 64 of the punch press in a manner well known in the art. The automatic lifter 63 is substantially the same functionally as hand-lifter 55. It may also comprise twin cam-levers 66 and 61, whose arms 68 and 69 are interconnected by cross-bar 10 carrying an element 1| which is actuated by block 65 in timed relation with the press cycle. Camlevers 66 and 61 may also lbe concentrically and rotatably mounted on the journals of roll 21, adjacent to similar elements 56 and 51 of the handlifter 55. Circular in shape, levers 66 and 61 also possess flats resting on the shoulders 60 and `6| of lower housings 22 and 23. Thus, when ram 64 descends, block 65 will contact element 1| and thereby slightly lift the upper roll 21 so that the stock gripped between upper and lower feed rolls 21 and 2| is momentarily freed therebyallowing pilot pins or other mechanisms in the die or punch ltolocate the work material accurately and Ito insure its correct location with respect to the rolls at the beginning of the next feeding stroke. Strings 48- will causev upper roll 21 to grip the stock again as soon as ascending block 65 re- :leasesto the automatic lifter element 1|, vbecause the stroke of the latter is usually so adjusted that itonlyufciently rotates the automatlclfter fama-'see 63 to Vfree the work material, but Ynot `to lift upper .roll 21 onto the circular parts of ycams 66 vand '6l Figures 1 to 3 show a single rollffeed to pull the material from right to lef-t through the dies. Figure 4A shows the double \S brake arrangement in diagrammatic form, as welll asthe directions of rotation of the Aindividual'meinters of this par- 'ticular roll feed. It therefore needs no further explanation. v

Figure 5 depicts a similar double S brake system for feeding stock from left to right. In order to simplify the description, identical parts have received identical reference characters, however, with the subscript a. i

Figure 6 illustrates a single S brake as may be employed for the automatic roll feed as shown in Figures 1 to 3, if the one-way clutch should be mounted directly on lower feed roll 2i as is frequently done in practice when only short feeds are required. :Corresponding parts have received corresponding numerals, however, with the subscript 19.

Figure 7 shows a single S brake for the upper and lower feed rolls similar to that of Figure 6 except that the feeding direction is from leftJ to right. Corresponding parts have received corresponding numerals, however, with the 'subscript Hc.

Figure 8 depicts a feed from right to left and is, therefore, similar to Figure 4. Corresponding parts have received corresponding numerals, however, with the subscript df To demonstrate that this continuous braking system may be used for any number of rotating shafts or rolls,

an intermediate drive shaft is indicated by a brake drum l2. In a roll feed, this intermediate shaft may berequired in order to increase the ratio of gearing between the actuating medium, such as one-way clutch (i3)` and thel feed rolls (2|, 2l). In this case also, all four brakes may be simultaneously adjusted with the advantages pointed out previously. K

While I have chosen todepict a singleroll feed unit for pulling the material from right to left, such" feeds mayfalso be arranged in double fashion, namely, that one feed unit is mounted on the left hand end of the 4presstable (il) as shown, and a similar unit on the right end of the press table. The two roll feed units, arranged in tandem between the dies, areV substantially alike, but their one-way clutches are usually interconnected by means of a rod and linkages in order to transmit .the oscillating movement of .one-way clutch I3 to the corresponding one-way clutch of the second unit as is well known in the art.

In Fig. 4., for instance, brake drum 3|, because of its clockwise rotation, tends tov push brake lining 4l with brake strap 33 in clockwise direction, namely,in the same direction as the pull of spring 38. rl."he end of lining fil adjacent to bracket 31 will be termed the trailing end, and the other end of said lining the leading end. These terms are chosen to designate the ends of the brake linings with respect to the directions of rotation of the brake drums. Using this terminology and following the sinuous path of strap 33, the leading end of lining 43 is next. to pin 34, and its trailing end is followed by the leading end of lining 42, whose trailing end in turn is followed by the leading end of lining 4i. The'friction between all the brake drums and linings therefore exerts a uni-directional now of forces on the strap 3? `in the direction of the pull of spring 38. Successive brake drums along the slnuous path ofthe strap are shown to' revolve in respective opposite directions. Similar forcefand rotational conditions are-shown in Figs. 5, 6, 7, and 8. i It should also be noted that in all the brake systems shown in Figs. 4 to 8 inclusive, the braking means or brake linings envelop the peripheries of at least two braking surfaces more than degrees, thus still further increasing the `effectiveness of the brake system on account of the large wrapping angles made possible by the single S and multiple S configurations. In Figs; 4 and 5, for instance, the upper and lower rolls with their brake drums 3|, 24 and 3la, 24a,

respectively, are located in one plane, and the drive shafts with brake drums I8 and 18a, respecf tively, are located in a different plane. The brake bands 33 and 3M envelop the respective brake drums in successive connected S configurations and the angle of wrap of each of these brakes is more than 180 degrees. These connected S configurations may also be called connected double S congurations.

In all figures, the brakes have been shown in the preferred form, arranged so that the direction of rotation of the masses supplements the spring action, i. e. that the tangential forces at the rim of the brake drum assist the spring 38 in tightening the brakes. However, if desirable, any of the pivot points 34 and spring brackets 35 may be interchanged with the possible disadvantage, however, that the moments of the revolving masses will not tend to increase the tension of the brake band and, consequently, more powerful springs may have to be employed. Instead of having one fixed point (3Q), a second spring similarly arranged as spring 38 may be substituted. The tightening of either spring will still result Vin controlling the braking pressure on all brakes.

While the several shafts of an automatic roll feed such as shown in Figures l to 3 are driven by a continuous gear train to accomplish the desired function of the roll feed, this condition is clearly not essential to the proper action of the new centralized braking system as disclosed, and itmay be advantageously applied in other devices regardless of the relative directions of rotation of adjoining brake drums and shafts.

The brake band proper (33), or element for carrying the brake lining has been shown as one uninterrupted piece, but may be assembled from several separate parts, hinged together or other- -wise suitably connected to form a continuous chain which acts as a unit when tension is exerted on it and which is adapted to transmit said tension to the brake lining of each individual brake of the system, The brake band could also be dispensed with altogether by using only a 'brake lining without a brake band. Moulded brake lining or woven lining reinforced with metal wires may be adapted to circumect the brake drums or braking surfaces in the proposed sinuous path.

In contrast to brake` systems employed heretofore which were neither block brakes nor band brakes, the new brake systemmay be employed as a pure form of band brake and results in maximum braking effort asa direct function of the spring tension. The S type brake makes it feasible to obtain an even and simultaneous braking haction for the upper and lower feed rolls, controlled from a single point. The preferred embodiments shown demonstrate the further advantage that the full braking effect is instantly available-without time-delay, because of the proposed particular sinuous path of the braking means. V

As applied to automatic roll feeds, the thickness of the work material or stock has no influence on the improved braking action. The effectiveness of brakes employed heretofore has been dependent to a great extent upon the wear of the brake lining and frequent readjustments to compensate for wear were required. It is obvious that with the new S type braking system, the wear of the brake linings has no direct influence upon the braking action. The new brake arrangement is equally effective for roll feeds working from left to right or vice-versa.

In roll feeds or other mechanisms requiring a separate drive shaft (Figs. 4 and 5) or additional intermediate shafts (Fig. 8), the new and improved braking system may be applied as a double S system, or any multiple thereof. The band brake and linings might also be described as being wrapped around the brake drums in successive reversed semi-circles, or in a sinuous path. All existing moments of the revolving masses can therefore be braked from one single central point with the result that the feeding accuracy of an automatic roll feed, for instance, may be adapted quickly and easily to any operative requirements which is of utmost importance when the roll feed is employed for high speed precision work. Despite all the advantages gained, a number of members, such as brake blocks, screws, pins, bolts, springs, etc. have been eliminated.

The type of drive for actuating the feed is usually selected according to particular requirements. While I have shown the well known oneway or over-running clutch mechanisms (i3) for illustrative purposes, any other suitable mechanism may be employed such as a ratchet and pawl, a rack and pinion drive, etc.

In view of the broad scope of the invention, the terms employed herein are to be considered as descriptive rather than in a limiting sense, except for such possible limitations as may be required by the state of the prior art.

What I claim is: r

l. A braking systemvfor an automatic feed for intermittently feeding a strip of material; cornprising relatively movable upper and lower feed rolls, a drive shaft, means for operatively interconnecting and intermittently rotating said rolls and drive shaft, brake drums on said rolls and said drive shaft, braking means acting substantially as a single unit for contacting each of said brake drums along more than 180 degrees of their peripheries in successive substantially reversed semi-circles in such a manner that the forces exerted by said brake drums on said braking means are uni-directional along said braking means, and adjustable tensioning means near the end of said braking means for simultaneously regulating the braking action on both said rolls and said drive shaft.

2. A braking system for an automatic feed for intermittently feeding a strip of material, comprising a pair of coacting and relatively movable feed rolls, means' for intermittently actuating said feed rolls in respective opposite directions, a brake drum mounted on each of said feed rolls, braking means adapted to be wrapped around both said brake drums in successive substantially reversed semi-circles, the forces exerted by said brake drums on said braking means being unidirectional along said braking means, and adjustable tensioning means near one end of said braking means for regulating the brakeload on both said brake drums simultaneously.

3. In mechanisms comprising a plurality of rotatable members, braking surfaces on said members, braking means adapted to circumflect said braking surfaces in a sinuous path, means for rotating successive members along the sinuous path of said braking means in respective opposite directions in combination with means for displacing at least one of said members relative to the other members, whereby uni-directional braking forces will be exerted by said braking surfaces on said braking means.

4. In mechanisms comprising a plurality of rotatable members, means for moving at least one of said members with respect to the other members, braking surfaces on said members, braking means adapted to circumflect said braking surfaces in a continuous sinuous path, means for intermittently rotating successive members along said sinuous path including their braking surfaces in respective opposite directions whereby uni-directional forces will be exerted by said braking surfaces on said braking means, and adjustable tensioning means near one end of said braking means for simul.aneously regulating the braking action on all said members.

5. A braking system for feed mechanisms for intermittently feeding a strip of material comprising a pair of relatively movable coacting feed rolls, means for intermittently rotating said feed rolls in respective opposite directions including means for intermittently displacing one'of said feed rolls with respect to the other one, a brake drum associated with each of said feed rolls. a

.brake strap wrapped around said brake drums in single S configuration, means for maintaining one end of said brake strap in relatively fixed position, tensioning means acting on the other end of said brake strap, said brake strap being wrapped around said brake drums in such a manner that the tangential forces exerted by both said brake drums assist said tensioning means in tightening said brake strap. Y

6. A braking system for feed mechanisms for intermittently feeding a strip of material. comprising a lower feed roll, an upper feed roll coacting therewith and relatively movable thereto, means for operatively interconnecting and inter-'- mittently revolving said rolls in relative opposite directions, braking surfaces on said rolls, a brake band adapted to be wrapped around more than 180 degrees of the peripheries of each of said braking surfaces in an uninterrupted sinuous path, tensioning means acting on one end of said brake band for regulating the braking force exerted by said brake band on both said braking surfaces.

7. In a brake mechanism of the character described, relatively movable upper and lower feed rolls adapted to be rotated intermittently in respective opposite directions, a brake strap in,- cluding brake lining spaced therealong for enveloping more than 180 degrees of the circumference of each of said rolls in single S configuration, said brake strap being disposed with respect to said rolls so that uni-directional braking forces will be exerted by said rolls on said brake strap, means for maintaining one end of said brake strap in xed position, and adjustable tensioning means acting on the other end of said brake strap and adapted to exert a pull in the same direction as said uni-directional braking forces for imposing a desired braking load on both said rolls.

8. In automatic feed mechanisms of the character described, aseries of rotatable members, means for intermittently displacing one of said members withy respect to the other members, braking surfaces on said members, brake lining means acting as a single unit for enveloping said members in successive connected S congurations, said brake lining means being adapted to contact at least two of said members along more than 189 degrees of their respective peripheries,

cans for maintaining one end of said brake lining means in relatively xed position, and adjustable tensioning means acting on the other end of said brake lining means for regulating the braking action on all said members simultaneously.

9. In intermittent feed mechanisms of the character described, a plurality of rotatable members spaced in close proximity, at least one of said members being movable with respect to the other members, a brake band wrapped around successive members and adapted to envelop more than 180 degrees of the peripheries of at least two of said rotatable members, means for maintaining one end of said brake band in substantially fixed position, and yieldable tensioning means connected to the other end of said brake band and adapted to vary the brake load on all said members simultaneously.

10. In mechanisms of the character described, a series of three rotatable members, two members of said series being disposed in one plane l0 taining one end of said braking means in xed position, and yieldable tensioning means acting on the other end of said braking means for regulating the brake load on al1 three members simultaneously.

11'. In an automatic feed for intermittently feeding a strip of material, a lower feed roll, an upper feed roll coacting therewith, a driveshaft, means for operatively interconnecting and intermittently rotating said driveshaft and said rolls, resilient means for pressing said rolls towards each other to grip said strip, means for intermittently moving said upper feed roll with respeci; to said lower feed roll, a brake drum for each of said feed rolls and for said drive shaft,

REFEREN CES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 345,468 Wilmott July 13, 1886 554,587 Evans Feb. 11, 1896 1,669,832 Marcalus et al May 15, 1928 1,671,527 Jones May 29, 1928 1,740,844 Strout Dec. 24, 1929 1,880,368 Sundqust Oct. 4, 1932 1,991,716 Wood Feb. 19, 1935 2,168,284 Crane et al Aug. 1, 1939 2,336,751 Sandberg Dec. 14, 1943 2,469,915 Capstai May 10, 1949

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