US2654429A - Knife control for paper-cutting machines - Google Patents

Description

Oct. 6, 1953 w.- c. RUPP KNIFE CONTROL FOR PAPER-CUTTING MACHINES Filed Oct. 27,1949

2 Sheets-Sheet l w i Q a mm mm hm INVENTOR.

WILLIAM C. IZUPP ATTORI/E'Y.

Oct. 6, 1953 w. c. RUPP 2,654,429

KNIFE CONTROL. FOR PAPER-CUTTING MACHINES Filed Oct. 27, 1949 2 Sheets-Sheet 2 INVEN TOR.

WILLIAM C. RUPP SZW W ATTORNEY-5.

Patented Oct. 6, 1953 KNIFE CONTROL FOR PAPER-CUTTING MACHINES William C. Rupp, Parma, Ohio, assignor to The Chandler & Price Company, Cleveland, 01110,

a corporation of Ohio Application October 27, 1949, Serial No. 123,865

7 Claims.

This invention relates as indicated to a knife c tr l for paper cutting machines and, more particularly, to a knife control for power operated paper cutting machines also having a power operated binder clamp adapted firmly to clamp a stack of sheets or the like upon the table of the cutter.

In my co-pending application Serial No. 60,341, filed November 16, 1948, I disclose an improved power operated binder clamp which is much more rapid and efiicient in operation than the common hand clamp means. In my co-pending application Serial No. 112,659, filed August 27, 1949, I disclose certain improved driving mechanism for the reciprocating knife commonly employed in such machines. The present invention relates to novel control means interrelating the operation of the binder clamp with the knife actuating mechanism, and reference may be had to the two foregoing applications for a description of the other features of the machine in which I prefer to incorporate such newly improved control means. It will be understood, however, that such control means may be employed in paper cutting machines generally, including those illustrated and described in Tyler et a1. Patent No. 1,967,600 and Reichart et al. Patent No. 2,305,735.

In such machines a flywheel driven by an electric motor may be connected through a clutch with a crank adapted to reciprocate the knife to cut a stack of sheets or the like. Generally, a bed or table is provided upon which the stack of sheets may be precisely positioned by means of adjustable gauges, and a vertically reciprocable knife is drawn down to make the cut and again elevated by means of such power driven crank. Means will also desirably be provided to prevent accidental actuation of the knife and to insure that the knife will return to fully elevated position after completion of a cut and remain there without repetition of the cycle. It is also highly important that the binder clamp be brought down into firm clamping engagement with the stack upon the table prior to bringing down the knife to cut or trim such stack. It is with such latter aspect that the present invention is concerned.

It is accordingly a primary object of my invention to provide knife control means for paper cutting machines and the like operative to permit operation of such knife only after the material to be cut has been firmly clamped.

A further object of my invention is to provide control means of the type indicated which will 2 be positively actuated and equally effective without adjustment regardless of the thickness of the stack on the table.

Still another object is to provide means effective to prevent manual actuation of the knife drive means until the stack has thus been firmly clamped.

Other objects of this invention will become apparent as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. 1 is a front elevational view of a paper cutting machine embodying my invention;

Fig. 2 is a fragmentary sectional view through the binder clamp of such machine taken along the line 22 on Fig. l; and

Fig. 3 is a front elevational view generally similar to Fig. 1 but illustrating a different embodiment of the invention.

Referring now more particularly to said drawing, my new control means may be incorporated in a paper cutting machine of generally conventional construction comprising a base frame I carrying a bed or table 2 upon which a stack of sheets may be positioned to be out. A back gauge 3 may be adjusted forwardly or rearwardly of table 2 by means of hand wheel 4, the position of such gauge being indicated by a traveling steel tape in window 5 as described in Reichart et al. Patent No. 2,203,547. A knife bar 6 carrying knife I is mounted for generally vertical reciprocation in upper frame 8, a wooden knife stick 9 being inset in the upper surface of the table to avoid possible damage to the knife.

The knife bar 6 and knife 1 are adapted thus to be reciprocated by means of a connecting rod i0, crank II and crankshaft l2 driven through a clutch from a flywheel driven by an electric motor (not shown). Such clutch for engaging and disengaging the fiywheel is adapted to be actuated by a hand lever l3 preferably of the safety type such as that requiring the same to be first moved to the right and then to the left as viewed in Fig. 1 to cause engagement of the clutch to reciprocate the knife bar. When one cycle of operation has been completed, the clutch will be automatically kicked out and the brake ,1

not shown) applied, leaving the knife in elevated position.

Back gauge 3 may be shifted back and forth as desired by means of hand wheel 4 and locked in adjusted position by locking lever I4.

Referring now also to Fig. 2 of the drawing, the binder clamp there illustrated comprises the usual presser foot l5 extending transversely of table 2 and guided for vertical movement in conventional manner by the side frame members. Such presser foot is carried by a vertically extending screw l8 threadedly engaging nut H which is locked against rotation by means of set screw I8. Screw H5 may be driven by a reversible electric torque motor (not shown) through shaft !9 and speed reducing gears and 2!. Gear 2! is adapted to turn freely on'upper end portion of shaft or spindle 22 constituting the upper extension of screw I 6 and rests upon a collar 23 carried by such spindle. Collar 23 in turn normally rests upon the upper surface of bearing 24 and another collar 25 is secured to spindle 22 at a point normally slightly (about inch) below the lower end of such bearing.

' A twin disc friction'clutch of well-known conventional construction is carried by the upper end of spindle 22 for connecting gear 2| in driving connection with such spindle. Such clutch includes a plurality of interleaved driving plates within a casing 25, alternate plates being secured to spindle 22 and gear 2!. Nut 2'5 may be ad:- justed to force steel'baekmp plate 28 against rubber compression member 29 to regulate the friction developed within such clutch. Consequently, the force with which the binder clamp presses down upon the stack of sheets maybe varied as desired. 7

Hand lever is is keyed t rock shaf 353. as llation of which is operative to con l the knife d iv m chan s in crinvent nal ash .1 as a o nits u til such. p eneil slug er a been. re-

t eated A A normally en. l mi swi h i meueted Within. upper sear housin 3.6 with. a en con.- a mended wi rol er 1. adapte t en a e the uppe mar n Qt he ou e er phery of ea F ssuch witch s eqnnecie Q i it with s len id 33 so ha when h switc is cl se t e sql noid w l be en.- e eead to retrac Pl n er. .2 from he. p h of pe mit t e lat r to h ro ked. in a counterclockwise direction as viewed in Fig. 1.

After a stack of sheets has been properly positiqii d on tab 2! a ainst back auge 3.; the operator first moves hand lever [3. to. the. right as viewed in Fig. 1, thereby operating micro-switch 3.8, completing a circuit energizing the electric motor (not. shown) driving shaft I9. The spindle 22 is thereby revolved through the action of gear 2 I; and the clutch means carried by the upper end of such spindle to turn screw 16 to move presser foot 15. downwardly into clamping engagement with such'stack, As above. explained, the degree of pressure imposed upon the stack will depend upon the adjustment of nut 21. When presser iqqt. '5. can lqn rr o n y. c

tinued rotation of screw IE will cause spindle 22 to rise the distance permitted by collar 25, carrying with it gear 2|. Elevation of such gear operates micro-switch 35 to complete the circuit energizing solenoid 33 and retracting plunger 32. Such latter circuit may, if desired, also include electric signal means such as a red lamp or the like to indicate to the operator that the stack has been firmly clamped.

The operator may now move the hand lever to the left as viewed in Fig. l to engage the clutch (not shown) of the knife drive mechanism and disengage the brake (see my above-identified application Serial No.- 60,341). Crankshaft l2 accordingly is turned to reciprocate connecting rod l0 and likewise reciprocate knife bar 6 and knife I to makethe cut. Upon completion of this cycle, lever 13 is automatically rocked in a clockwise direction back into starting position as shown in Fig. l and the knife drive clutch disengaged and the brake reapplied.

' A cam 39 turning with crankshaft l2 is adapted to operate a microeswitch 49 upon return of the knife to its uppermost position, reversing the binder clamp motor to turn screw iii in the op,- posite direction to elevate presser foot l5. When such presser foot is thus elevated, gear 2| is of course permitted tov drop downwith consequent opening of micro-switch 35and de-.-energization of solenoid 33. Solenoid pl n r 32 thereupon again drops down into position between dog 3| nd stop 3 When the binder clamp reaches fully elevated position, it will engage and operate limit. switch A! stopping th binder clamp motor. A n w stac o sheets. new be p aced upon he able and th cycle rep ated.

I wil e app rent fr m the fore oin that. I have p v d dne l knif con rol means render- 1 it miav ible to a uat th knife. til the der c amp s. firmly pres in upon. he. stack of s e to. b cu A additionalymanuauy opera l sw t may be provided if desired, to c s the solenoid operating circ it so that the knife m y t n b broug t for the pu po e o ad stm nt o he ike ithqu at. the same time operating the binder clamp. The binder clamp motor w l b turn d 01 unde such. circuml stances' Not only will engagement of the knife with the stack Prior to clamping of the latter be prevented but also a further safety factor is provided for t e operato o can ot brin down the knife a iden ally Wh l he. arran ing the stack on the table. While the mechanism is simple and inexpensive, it'is neverthele s positive in opera.- tion, the rotation of screw l6 serving first; to lowe h la p, and t e to ele ate the. spindle. laiziqus form f. ar m ans ncludin any suitable. l tch. oc m y e emulated instead of so en id iu'n rnd. While e ctric l c n r i -such. means. is, ef r d it w ll be Q ious that equi en m c n cal dev c s. s ch as ink. an layer m a s b u e a'c ua e uch guard me n in ha i e i in of he i der.- clamp screw. grandpa ea ure of s embodiment o my inv nt on s he rrangeme t where y su h screw ause ri awhen. ilie a k; is firmly clamped and thereby release the means normally preyenting operation of the knife drive. mecha- 1 the words, the. stack clamping ressine is itself utilized to. actuate the knife drive contr l; means.-

Referring nowto, Fi 3. of the drawing, the embodiment of invention there illustrated operates, on the same, general prineipleabove explained. Instead of binder clamp screw 16, however, a double acting fluid pressure pistoncylinder assembly 42 is provided mounted vertically in head frame 8, an extension 43 of such piston engaging and supporting binder clamp presser shoe l5. The usual fluid pressure supply lines 44 and 45 are adapted to conduct such fluid (ordinarily hydraulic, although air pressure may be employed) to the upper and lower ends of said cylinder respectively. A branch line 46 leads to the lower'end of fluid pressure cylinder 41, so that pressure in such line acts to retract plunger 48. Plunger 48 corresponds to armature 32, being interposed between dog 3| and stop- 34, and normally held in extended position by action of compression spring 49. Thus, when fluid pressure is admitted to line 44 and relieved from line 45 by any suitable valving means, then presser shoe [5 will be brought down in clamping engagement upon the stack or table. Pressure is thereupon built up in line 46 sufficient to overbalance spring 49 and retract plunger 48, whereupon lever l'3 may now be shifted to operate the knife drive mechanism. When line 44 is connected to drain and line 45 to pressure the presser foot will be elevated and spring 49 will again be effective to interpose stop plunger 48.

It will be appreciated that control means of the type above described are particularly advantageous where movementof the binder clamp is slower than movement of the knife. When a screw feed for the clamp is employed, the less the pitch, the less the power required to obtain a desired clamping pressure. Similarly, when employing hydraulic means, the slower the piston moves, the lower the capacity of the pump required to supply the fluid under pressure. It is most important that the more rapidly traveling knife should not start its downward movement until the stack has actually been firmly clamped. Provision of an arbitrary time-delay means of well-known type is not a satisfactory solution to the problem under these circumstances since the stack to be cut may be of varying thickness and the time-delay interval allowed would always haveto .be sufficient to permit the clamp-to travel all the way to the table in order to be safe. With my novel arrangement the knife may be actuated promptly just as soon as the stack has been clamped, whatever may be the height of such stack. Furthermore, the knife may be brought down rapidly to obtain desired cutting characteristics without any danger of engaging the stack prematurely prior to proper clamping of the latter. These advantages I achieve by making operation of the knife drive mechanism dependent upon first obtaining clamping pressure on the stack.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a power driven paper cutting machine including a knife, a crankshaft adapted when rotated to reciprocate such knife, and a hand lever adapted to be rocked to actuate such crankshaft and knife; the combination of a binder clamp adapted to clamp a stack of sheets or the like upon the table of such machine prior to actuation of such knife, said binder clamp comprising a vertically disposed spindle, a screw on the lower end of said spindle, a presser foot adapted to bear upon such stack threadedly en-'- gaging said screw for vertical reciprocation when said screw is rotated, a gear supported on the upper portion of said spindle for free rotation relative thereto, a disc-type friction clutch on said spindle interconnecting said gear and spindle in driving connection, a nut threaded on the upper end of said spindle adapted when tightened to increase the frictional resistance of said clutch, whereby the downward thrust of said presser foot upon such stack may be regulated, means operative to drive said gear, a rock shaft adapted to be rocked by such lever to actuate such crankshaft and knife, a dog secured to said shaft for oscillation therewith, a solenoid having an armature adapted when extended to engage said dog to prevent rocking of such lever to actuate such knife, a back-up stop adapted to support said armature against movement by said dog, an electric circuit controlling said solenoid, a normally open limit switch in said circuit located above said gear and adapted to be closed to energize said solenoid to retract said armature to permit rocking of such lever to actuate such knife when continued rotation of said screw afterengagement of said presser foot with such stack operates to elevate said spindle, and means limiting such elevation of said spindle.

2. In a power driven'paper cutting machine including a knife adapted to be reciprocated to make a cut, and a hand lever adapted to be rocked to actuate drive mechanism for reciprocating such knife; a binder clamp adapted to clamp a stack of sheets or the like upon the table of such machine comprising a vertically disposed spindle, a screw on the lower portion of said spindle, a presser foot adapted to bear upon such stack threadedly engaging said screw for vertical reciprocation when said spindle and screw are rotated, a gear carried by the upper portion of said spindle freely rotatable relative thereto, clutch means on such upper portion frictionally interconnecting said gear and spindle in driving connection, means adjustable to vary the degree of friction developed in such clutch thereby to regulate the downward thrust of said presser foot upon such stack, means operative to drive said gear, a back-up stop, means rigid with such lever and rockable therewith, a solenoid having an armature adapted when extended to be interposed between said last-named means and said back-up stop to prevent rocking of such lever to actuate such knife, an electric circuit controlling said solenoid, a normally open switch in said circuit positioned to be operated by lifting of said spindle, and means limiting the distance said spindle may be lifted, whereby, upon engagement of said presser foot with such stack, continued rotation of said screw will operate to lift said spindle to operate said switch to retract such armature, permitting manual operation of such lever to actuate such knife reciprocating mechanism.

3. In a power driven paper cutting machine including a knife adapted to be reciprocated to make a cut, and a hand lever adapted to be rocked to actuate drive mechanism for reciprocating such knife; a binder clamp adapted to clamp a stack of sheets or the like upon the table of such machine comprising a vertically disposed spindle, a screw on the lower portion of said spindle, a presser foot adapted to bear upon such stack threadedly engaging said screw for vertical reciprocation when said spindle and screw are rotated, means operative to drive said spindle,

7 stop means adapted ta prevent reeh ne Q1; eeh lever t aetuate sushi nit dr ve me han sm sel neid operative when energized e trac a d. seep means. n eetrie ircu eohtrelline s d so eneiei. a nermal y o n s it h. said eir ui nesi eaee to. b eaer-e eei by tin f said. spindle, and m ans 11m tin the rii ta e said spind e hus lee. iftedz her ha IJDQIFI. erreasement of said. Pr serfee wi h s i h, s e l; an firm elampine; f. the a t erehy eenr time r tation of said s rew ill o rate t li said sp nd e te Qeera e sa d sw h r c said s in P rmit in anual op r o su h lever: to eetuete siio n e reciprocati g meehanism,

4,. In a po er r v n paper utting ac ne ine u iing a knife adapts/ate be re p o eted to make a cut and a hand lev r ad pted to e rocke tq actuate drive. mechanism for reeiprocating sueh knife; a binder. lamp adap to c mp a stacko h et or he lik up the abl f s machine eqmprising; a vertically dis osed screw, a presser foot adapted in bearupQn sugch stack threadedly engaging said screw for vertical reeiprqcaticn relative thereto when said screw is rctategt; means operative to drive said screw, ele tri ally controlled guard m ans or ally operative to prevent rocking of such lever to actuate such knife drive mechanism, a switch operative when a tuated to releas s gua mitting operati n o su h le r t ctuate, such kn. e r ciprocat ng me anism.

a In a powe d v n ape cuttin ma h e messing kn f d p ed to be operated mak a cgt, and control means adapted to actuate drive mechanism for such knife; a, binder clamp adapted to c amp a ack of s s or he ike comp isin a sc ew, a presser foot adap ed t bear against such stack ree-e rily ng in sai screw for recipro at rel ti e e et hen aid s rew. s ated, ans e rati e to d iv said screw, elec ricall ontr lled guard mea normally eperet ve t9 pr ve t ct ation of such drive mechani m for such lm i a s itc arran ed and disposed. to be ac uated by reciprQ cation Qf said s rew and operat e hen t u aetuated to elease sa d elect a ly contr l ed 8 e i cl. means and means aii ies e said. sc ew ma th s e ree ereesteqi Whereas. upon enga ement o said P esser met w th. sash st'aok a s firm elem irie 'ot the etter th r it iurthe retati n at sa d rew will; serve ta e1 eipreee e the s me e a ua e ioi s teh,

6:- In a sewer ri en sexier s itt ng maeaiee meluiiine a kni e adap ed ibe ope a ed te mess is cut. n manua eoht l m ns fed ra ed te actuate dr v mechan m sueh k ife;- s hih ie olesep adapted to clam a s ack: of, heets he wee eempr ne e serewE a pres es met. aq aiee tebeeraeeinst sueh steels t reede hz enee hse said ser w ie re i e atiori rela ive therete when said e e is re a ned! means o era ive t9 drive said screw guar means no me li ese s ative t pre nt e iuahe r or: su h. eemr l forsuehdriv mean or suc ife, e s means responsi to lif ing o said se ew ehe et e t9 release said shard hsi Wh rehn uses se easement of: seiol. Pr sse "f otwith sash stasis a f r ams ne of th e t r er by isrther rot tion i s id s rew in e same d ee ien wil s rv to li t the am t le se sai ge rs ie-ess- In a, ne er dr e ane se t ng eehihe in udin a kni e ada ted is he dri en s make a out,v a d. dri e mechan m, er srie knife; a binder clam e a tesi e clamp a steak ai sheets o e ike includ n a Press r feet s rew hre d dy n a said' pr sses feet rre i ro atmn Of the ette seie heihs, mount d f mited ax al. shift ng e es} f om sash s ek po c amping eng ement Qi s ze pres r foot with the work witllfconseg rent cessation. qi s ch reei roeatioh seiol Presser et. means med o r ve aid ss wi ree ree te said n e r t a a slower ate then} suehhh e drive m h n s is eriapted to drive sue a and mean eoht oll ne' nitia eh Q me msiit o ush n e resnonsive tosuch axia sh fti of saici sc ew when the WQr h s hus e n cl mped t set up sash kn e drive meehaeism ie eietu,etion,

Beferenees Cited; in the file of this patent UNI E S A' PATENTS

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