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Publication numberUS2252626 A
Publication typeGrant
Publication dateAug 12, 1941
Filing dateJun 26, 1940
Priority dateJun 26, 1940
Publication numberUS 2252626 A, US 2252626A, US-A-2252626, US2252626 A, US2252626A
InventorsGoldbeck Caspar C
Original AssigneeGoldbeck Caspar C
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Safety attachment for punch presses
US 2252626 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Aug. 12, 1941. c. c. GOLDBECK SAFETY ATTACHMENT FOR PUNCH PRESSES Filed June 26, 1940 0. a sauna);

IQIHIIIIHHII Patented Aug. 12, 1941 sAFETYAT'rAoHMENnmR Punch ,7 i. if "-PRESJSES,

Caspar of. Gbldbeck,"Cam'den, N. J. ApplicationJuneZfi, 1940,. Serial No. 342,570

"5 Claims. (CL-21 92 127) This invention relates to punching -machines or presses and more=particularly to a safety attachment by means of which the operation of the punch or press maybe stopped-when the dies become-clogged withmateriaL.

At the presentitime :in the operation of: punches or presses for forming ends of cans,-cons-iderable difficulty is experiencedin-theiaccumulation of punched out material which sticks; in the. moviable :die ,and causes considerable damage :noit ionly to the dies *but 'to "the press qorwm'achine proper. Various safety idevices Eh'ave rloieen' iapplied tothe punches or presses byrmeans'ofwhieh the operating "lever may be shifted .to .stop the machine and While attempts havevheretofore been made to provide a safety 'means :to stop themachine when punchedout'ends accumulate inthe dies, such safety means have-been-of'such a delicate nature that thevibrat-ion of the :punch "or press has a tendency to renderthe safety idevices ineffective. It therefore, an-obj'ect-of this invention to provide 'asafetvmeansnof an automatic character which :is operatively con- 'nected tothe-starting and stopping lever of the machine through the solenoid.leveroperatorat present forming part of" the machine and which is so constructed as to immediately :;stop" the operation of the machine zafter'not'imore than "two ends are accumulated in the dies.

Another object of this invention is to provide a safety attachment of this kindwhich is connected to the flexible end-engaging member-which is mounted on the movable die and which-flexible member is adapted to strikeithe ends-'as=they are ireleased from-the dies so as 'to'foroe-itheends'to lie flat on the chutezleading from"the dies,zthe chute having a means associated with thezflexible end engaging member "for closing a circuit tolthe solenoid leveroperator whenan endis-rnot 'discharged from the dies.

A further object of thiszinventi'on is to-provide a safety means of this kind 'which 'isrsimple'in construction and may be mountedon the present parts of a punch or press and'which'is not-readily afiected by vibrations of the press or punchiout which-will be positive in its-operation so thatithe dies and the-press or punch apparatus will 'not be damaged "by accumulationo'f ends in one or the other of the dies asis at presentthe case.

To the foregoing objects and to others which may hereinafter appear, the invention consists 0f the novel construction, -combination rand aarrangementof parts as will be more specifically referred to and illustrated in theaccompanying -in se'ction {and-partly diagrammatic of the "dies of a can end, punch or -press apparatus having a safety attachment constructed according to this invention connected therewith.

Figure 2 is a plan View of thestationary die and "the discharge chute showing themanner of mounting a portion of the safety attachment in the chute.

-;Fi-gure 3%is'a' -bottom plan'of the flexible end engaging membermemoved from the press and having a portion-of the safety attachment .rnounted thereon; and I Figurei isa fragmentaryiview ininverted-plan 'of the stripper .Withthe flexible *flapper attached thereto.

Referring to the :drawing; *the numeral l0 "designates generally-a plunger or-die head'which has mounted thereon a'rnovable die member II. The die member H onits under face is formed with :an annular outer cutting edge 42 and 'an annulariend- -forming channel !3. The under or 'lower -face-of the die member ll =may also be "formed with'additional grooves M depending only 'up'on' the'shape *of' the end which it is desired to *forrn by 'thedie structure. A substantially stationary or lower die l5is disposed in confrontingrelationto themovabl'e diemember l l and is :formed withcomplementary ribs and grooves Iii .andd'l-which areadapted to confront the grooves i3 and M andany additional grooves orprojection'swhich are formed 1 in the upper ormovable -die member H. Anz annular cutter'ia is disposed below the movable die! i and is positioned "about the lower-die member ii. The cutter I8'is stationary and is secured-to the lower portion H) of "the press; A strip positioning or holding ring eZU'isinterpOsed between'the-cutter if! and the -'lo'w'erdie member f5 and is adapted to'engage the un'de'r"su-rface' of the strip T-2-l aout if of which the can endsare to-be punched.

A cylindrical or annular end stripper 22 is islidably-disposed about the movable die -=m.ember 4i, being provided at .its upper :edge with an .annular flange .23rformed with openings =24. A plurality of stripper guide rods .or =bc-ltsZ5 are secured to. the head iii and -.-loosely engage through the openings 24 in thewflange .23. A spring "261s positioned about .each'bolt or guide "drawing, wherein =is shown an embodiment :of red-25 and at one end bears againsttheunderside of head l and at the other end engages against the upper face of the flange 23 so as to constantly urge the stripper 24 to a stripping or operative position with the lower edge of the stripper 22 below the lower cutting edge |2 or the die The structure hereinbefore described is conventional in presses or punches and is here disclosed as one type of punch or press with which the hereinafter described safety attachment may be combined. A chute 21 is disposed on the rear side of the press being positioned with the upper edge thereof adjacent the cutter I8 and the chute 21 as shown in Figure 1 is disposed in a downwardly and rearwardly inclined position so as guide the punched material into a suitable receptacle or other conveying means. The chute 21 comprises an inclined bottom wall 28 and upstanding side flanges 29. At the present time when the ends punched out by the two dies H and I fall onto the upper surface of the chute 21, these ends are forced to assume a flat position with respect to the chute 21 by means of a flexible member 39. This flexible member 30 is formed of leather or other suitable flexible material and one end of the flapper or end engaging member 30 is fixed relative to the flange 23 of the stripper 22 as shown in Figure 4 so that the flapper 3!! will be disposed in a position overlying the chute 21 and in a position extending lengthwise of the chute 21.

At the present time the press or punch structure is started and stopped by means of an operating lever 3| which is positioned at one side of the machine and also associated with the operating lever 3| is a solenoid structure 32. This solenoid structure 32 is at present connected to various portions of the press or punch so as to shift the lever 3| to a stopping position in the event undesirable conditions exist in the several parts of the machine. The solenoid 3| is connected to a suitable source of electric current supply and is normally inactive, being rendered active upon operation of one or more of the several safety devices connected therewith.

In order to provide a means whereby the solenoid 32 may be rendered active when the die member H is operating and when one or more of the ends cut from the supply strip 2| stick in the recesses of the die II, I have provided a switch structure including a flexible metal strip This strip 33 is formed with a downwardly arched or arcuate portion 34 and a straight portion 35 which is secured as by a bolt 35 to the under side of the flapper or flexible member 30. The opposite end 31 of the switch member 33 is free and slidably engages the under face of the flexible member 3|] adjacent the free end thereof. The bolt 36 not only constitutes a means for holding the flexible member 33 on the flexible strip 3!] but also constitutes a terminal by means of which a conductor 38 may be connected to the switch member 33. The conductor 38 may be connected to a portion of the press or machine to form a ground which ground is connected as This contact member 40 is connected by means of a conductor 4| to the electric current supply source which is connected to the solenoid 32 so that when the switch member 33 engages at contact 40 a circuit will be completed to the solenoid 32. As shown in Figure l, the contact member 40 is positioned slightly below the upper surface of the bottom wall 28 of the chute 21 so that when an end lies flat on the upper surface of the bottom wall 28 and the flexible member 3|) is flexed downwardly, the electric circuit to the solenoid 32 will not be completed through the end engaging over the slot 39.

However, in the event one or more of the can ends should stick in the die H, the flapper or flexible member 30 will flex downwardly toward the chute 21 and due to the fact that there is no end moving downwardly and rearwardly from the dies II and I5, the switch member 33 will project through the slot 39 and contact with the contact member 40 and thus close the electric circuit to the solenoid 32 and effect movement of the operating lever 3| to a stopping position.

In the normal operation of the punch or press, the head II] with the die I is moved in the'direction of the lower substantially stationary die l5 and the supply sheet 2| is shifted by well known means relative to the dies II and I5. The die H is adapted to cut off an end 2| and this end is formed of a suitable configuration depending upon the configuration of the confronting faces of the two dies II and I5.

At the present time considerable difiiculty is experienced by reason of the fact that the ends 2P accumulate in the upper die II and these accumulated ends cause considerable damage to result both to the die II and to the entire press or punch apparatus. After the machine has been in operation the reciprocation of the head It! is suflicient to cause the flexible member 39 to be flexed downwardly and strike the bottom wall 23 of the chute 21 for the purpose of causing the cut ends to lie flat on the chute 21 and slide downwardly into a receptacle or conveyor at the lower end of the chute.

In the event one or more of the ends should stick in the die H or otherwise not be discharged onto the chute 21, the flexible member 3!] will nevertheless be flexed downwardly toward the chute 21. In the absence of an end which may be engaged by the flexible member 3!], the switch member 33 will engage within the slot 33 and contact with the stationary contact 40 so as to thereby close the electric circuit to the solenoid 32.

losing of the circuit to the solenoid 32 will effect movement of the operating lever 3| to a stopping position.

With an attachment of this kind the press or punch will be automatically stopped when not more than two ends have accumulated in the die member H and these ends may then be removed from the die II and machine operated in the usual manner. The accumulation of two ends in the die II will not be sufficient to cause any material damage to result to the dies II and |5 or to the machine proper so that an attachment of this kind will provide an effective means for preventing damage to the machine in the event the ends are not discharged into the chute 21 in the normal manner. This switch device may be mounted on the present parts of a positioning machine or press, it only being necessary to form an opening 39 in the chute 21 so that the contact member 49 may be attached to the underside of the chute 21 within the opening 39. The switch member 33 may be secured to the flapper or end engaging member 30 and connected to the present lever operating solenoid which now forms a part of a machine. A device of this kind has been placed in actual operation and has been found to be more efficient than devices heretofore available particularly in view of the fact that this device is not affected by vibrations of the machine so that the device will not get out of order by such vibrations. In addition the safety attachment is of an exceedingly simple character embodying a small number of parts so that the safety device will not materially increase the cost of the punching machine or press.

It will be understood that when the starter lever 3| is initially shifted to start up the machine or press, the solenoid 32 is disconnected from the electric supply source by means of a cut-01f switch 42 which is connected to one side of the supply source. When the press begins to run and the punched material moves through the machine the solenoid is connected to the electric supply source by means of the manually operated switch 42 so that if the material does not move regularly from the dies, the circuit closer 33 will contact the stationary switch member 40 and energize the solenoid 32 and effect movement of the operating lever 3| to a machine stopping position.

What I claim is:

1. A safety attachment for a punching machine having a movable die, a stationary die and a discharge chute for the formed article, said attachment comprising a flexible member adapted to be operatively connected at one end with said movable die, a switch member carried by said flexible member, and a contact below the upper surface of the chute in a position for engagement with said switch member when the chute is free of a formed article.

2. In combination a punching machine comprising a movable die, a stationary die, a discharge chute extending downwardly and rearwardly from said stationary die for guiding a formed article, a starting and stopping lever for causing actuation of said movable die, a solenoid connected to said lever and adapted upon energization thereof to shift said lever to a stopping position, a switch member movable with said movable die and connected to one ide of said solenoid and a contact fixed relative to said chute in a position for engagement with switch member to thereby close a circuit to said solenoid when the chute is free of a formed article,

3. In combination a punching machine comprising a stationary die, a movable die, a discharge chute inclined downwardly from said stationary die for guiding the punched material away from said dies, said chute having an opening therein, a flexible member fixed at one end relative to said movable die and adapted upon downward movement of said movable die to flex toward said opening in said chute, a rockable operating lever for causing actuation of said movable die, a solenoid connected to said lever for shifting said lever to a stopping position, a contact disposed in said opening of said chute and positioned below the upper face of the chute bottom, a switch member carried by said flexible member in a position to engage said contact when an article punched out by said dies sticks within one of said dies, said switch member being connected to said solenoid to thereby close a circuit to the latter for shifting the lever to a stopping position upon the sticking of the article.

4. In a punching machine having a stationary die, a movable die, a starting and stopping lever, a lever shifting solenoid for shifting said lever to a stopping position, a discharge chute for the formed article and a flexible article striking member, carried by said movable die for flatwise positioning the article in the chute; a safety attachment for energizing said solenoid upon failure of the article to slide downwardly of said chute, including a circuit making and breaking means connected to said solenoid and carried partly by said flexible member and partly arranged below said chute.

5. In a punching machine having a starting and stopping lever, a solenoid connected to said lever for shifting said lever to a stopping position, a pair of material punching dies and a discharge chute leading from said dies; a safety attachment for energizing said solenoid when an article fails to move over said chute, said attachment including a stationary switch part fixed relative to said chute, a movable switch part correlated with said stationary part, said movable part being connected with said solenoid, and means swing-ably mounting said movable part for movement with one of said dies.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2584855 *Jun 26, 1948Feb 5, 1952Post Machinery CoBox blank folding machine
US2829477 *Mar 25, 1954Apr 8, 1958Rca CorpAutomatic racking apparatus
US5628220 *Apr 14, 1995May 13, 1997Wilhelm Schafer Maschinenbau Gmbh & Co.High-pressure bulge-forming system for tubular workpieces
DE1170893B *Sep 30, 1960May 27, 1964Metallwaren & Maschf P SchwarzVorrichtung zur UEberwachung des Auswurfes einzelner bearbeiteter Werkstuecke
DE4414706A1 *Apr 15, 1994Oct 19, 1995Schaefer Maschbau WilhelmVorrichtung zum Herstellen eines Hohlkörpers aus einem metallischen Rohrabschnitt nach dem Innenhochdruck-Umformverfahren
U.S. Classification192/127
International ClassificationG05G15/00
Cooperative ClassificationG05G15/002
European ClassificationG05G15/00A