US2364716A - Protective system for heading machines - Google Patents

Description

12, 4 E'. W. HUEBNER ETAL 2,364,716

PROTECTIVE SYSTEM FOR READING MACHINES Filed Feb. 3, 1945 COMPRESSED 171k LINE I N V EN TORS tf'rnasl' flaenzr BY [010111 15. jdersan I Patented Dec. 12, 1944 2,384,716 PROTECTIVE SYSTEM FOR HEADING MACHINES Ernest W. lluebner and Lowell E. Petersom-Ini dianapolis, 00., ,Inc., Delaware Ind assignors to P. R. Mallory & Indianapolis, Ind. ,--a corporation of Application February. 3, 1943, Serial'No. $74,598

Claims. (Cl. -11) This invention relates to protective systems for machines, particularly for metal heading machines.

An object of the invention is to improve protec: tive systems for machines.

Other objects of 'the invention will be apparent I from the description and claims.

In the drawing: v

Figure 1 is a diagram of the protective circuit together with a diagrammatic illustration of the operating parts of a heading machine with which it is associated; Y 1

Figure 2 illustrates afmodification of part of the machine; and

Figure 3 shows a further modification,

In certain types ofmachines for operating on metal stock, it is of considerable importance .to insure that an appropriate length of raw metal stock be fed into .the machine before each operation. In the making of small parts such as rivets, etc., from metal rod, wire, strip, tubing, special sections and the like, for example, the rod is fed into the machine by feed rollers until it reaches a stop. The end section of the rod isthen cut oil by the machine and carried to aheading po sition where cooperating die members come. together to press the cut-on section of *met'alrod into the'desired shape. U f f If the feeding rollers fail to feed in a suflicient length of metal to the machine, a section whichis too short may be cutoff and carried to the dies. There istheninsufilcient metal to completely fill the stationary die during the coining operation and it is found that the coined piece may not sufficiently fill the die to be held therein by friction when the movable punching die is retracted. If this occurs, thefcrmed piecemay stick to the punching. dieand remain attached to it. When the next rod section is brought between the dies, this will result in an excess-of metal between them and is liable to result in die breakage or damage .to the machine. It, therefore, becomes of considerable importance to insure that the required length of rod stock be measured and cut off for each operation.

The present invention relates to a protective system for stopping the machine whenever an insuflicient length of rod stock is fed to the machine. 7

Referring to Figure 1, the operating parts of the machine necessary for an'understanding of th invention are shown and include'an electric motor I for driving the machine, a shaft 2 driven former secondary winding 2| through relay I9,

thereby and a flywheel 3 on the shaft. The rod stock 4 isfed into the machine by a pair of feed rollers" 5 driven by a one way clutch 6 which in turn is driven by a rocker arm I linked to shaft 2 of the machine. Thus as the arm I oscillates back .and forth it advances the rod 4 during its motion in one direction, the rod remaining stationary during the return motion of the arm.

The rod 4 isfed through an opening in the operating face 8. of the machine until it reaches stop member 9 whereupon a cutter Ill cuts oilthe end section of the rodand an arm ll car ries the cut ofl section to a position between stationary. die 12 and movable die I3, which then come together to coin the rod section into the desired rivet. or other product. Duringnormal operation, the coined rivet remains in the stationary die l2 when the punching die [3 is rear; I I tracted andthe piece is thenejected from die [2 by mechanical plunger l2a or other means such" as compressed air. According to the present invention a brake band it is provided on the outer rim of flywheel.

3 to stop themachine. The brake is'operated-by a lever l5 controlled bycompressed air cylinder i l8 supplied from a compressed air line H under.

control of valve i8,operated by; solenoid 40 Stop member 9 is insulatedfrom the restof, the machine. The protective circuitzcomprises a normally energized protective relay I9 under joint control of a cam operated switch 20 and a :circuit through rod 4 and stop memberfl. The

energizing circuit for relay l9 extends from transthen through normally closed contactsof switch I 20 to ground. A second energizing circuit is pos sible inparallel with switch" via conductor 22,. stop member S and rod 4 to. ground'in the stop member-"l":

machine framewhenever rod 4 is in contact with gizing' circuit for-electridniotor I. The back contacts of relay l9 close anoperating circuit f r valvecontrol-relay flgwhichcontrols the machine." v

With the machine in. the position shown the energizing circuit for relay I! is closed and hence the front contacts of this'relay are closed. To operate the machine, the operator closes starting switch 25 momentarily'to close the energizing clay I! asfrontv-v andflback contacts-th I front contacts being in the holding circuit fora motor control relay ilwhichcontrols the ener- '2 circuit for motor control relay 23 from A. ,C. power line 25. Relay 23, in operating, closes a holding circuit for-itself through its, contacts 21 and thefront contacts of relay 19. It alsocloses circuit for motor I through conhe energizing 'tacts 28 thus starting-the iriac'hinein operation." As shaft2 rotates, rocker arm *1 oscillatesback and forth-advancing rod 4 on each travel inthe direction of the arrow. The arm is adjusted to have a small amount of overtravel so that rod 4 reaches stop 9 shortly before-arm! reaches; "the end of its travel.

The operating arm of switch2llis disposed in the path of travel-ofthe end 29 of-arm -'I which functions-as a camto-mo- .mentarily open switch 20 for a Short interval u during which arm! is at the extreme of its-travel, At this-time, if the feeding mecha'nismis functioning properly, rod 4 will be in contact withstop 9 and thereby provide a parallel holding ,circuit forreIayiQ independent of switch 20. However, shouldrod A fail to be in contact with stop 9 at 3 this time due to failure ofthe feeding mechanism or fo'rany other reason,,the holding circuit for relay 19 will be broken through .both parallel paths andrelay Ill-will release.

Release'of relay 19 closes'theback contacts of. this relay, thereby closing an energizing circuit through valve controlling relay-which thereupon operates closing an energizing circuit for solenoid 40 which operates valve l8 through contacts 30 and a holding circuit for itself through contacts :3l. The solenoid valve immediately op- What is claimed is:

;l. "In a 'machine'fed with conductive rod stock wherein-the end of the rodis fed into said machine and a stop member stops the travel of said rod when a predetermined length of rod has ,en-

tered the.machinewhereuponthe end of saidrod is cut ofl",the combinationwith said machine of a, relay and angenergizing circuit therefor. said energizing circuit having two parallel branches,

one of said branches passing through said rod and stopin series,.a switch in the other of said "branches, and afciam ona cyclically-operating part of 'Jsaid machine 'engageable with said switch to open the same during that part of themachine cycle in which, said rod {is normally against said 'stop before 'being-cut-ofi, and a brake operated responsive tothe release of said relay to stop said machinewhenever said relay circuit is :brokenby said'cam'operated switch (when azparallel holding circuit for-said relay hasnot been established y said rod having I egigled said stop). 2. In a machine fe ith conductive rod stock wherein the endof the rod is Yfed intosaidmachine and a sto'p'member stops the travel'of said erates to supply compressed'air to cylinder 1-6 and tighten the brake band thus applying the brake to stop the machine. The machine stopped almost instantaneously so thatno serious damage can occur.

When relay I9 is released, it also opens'th e holding circuit for relay23 through its front contact thus releasing relay,23 which opens the motor a circuit.

"Whenthe'trouble has been remedied, the brake can be released by momentarily opening brake- =release switch 32to release'relayjfl andrelease the solenoid valve to close the compressed air line and open an exhaust port on the valve, :per-

mittingrelease of the compressed air-incylin'der [6. Switch -25 can then'be momentarily closed to restart the motor.

It is sometimesnecessaryor desirable, to complete the electric circuit independent of the rod or wirebeing fed into the machine. This is the case, for example, when insulatingmaterials, such as Bakelite and other plastics, are being worked upon.

Figures '2 and 3 show arrangements suitable for such cases. InFigure 2 a small contact arm 55' is hinged or pivoted at 5| to-the machine frame and is grounded to it. Thefree end of arm has a contact which is normally 'held'spaced fromstopfmemberi! by a spring 55. Astop pin 52 limits the spacing. When the rod stock in strikes the free end of arm 50'it moves'it'into contact with stop 9 to connect it and conductor-22 to ground. In Figure 3 a plunger- 56 is supported-to slide in-an insulating bushing 59 mounted on a bracket 53 onthe frame. Theend of the plunger is'in contact with thepushbutton -51 of amicroswitch-"'58. When rod 4a depressesthe plunger, the micro-switchis operated to connect ground to conductor 22.

While specific embodiments of the invention have been described,,'itis intended to-cover the inventionbroadly within the spirit and scopelof the appended claims.

rodwhen a predeterminedleng'th 'of rod-has en- .tered'theimachine whereupon theend of said rod is cut off, the combination with said machine of a relay and an energizing circuit thereforrsaid energizing circuit having two .parallel branches,

one of said v branches passing through said rod and stop in series, a switch in the other of said branches, and a cam.on a cyclically operating part of said machine engageablewith said switch to open the sameduring that part of the machine cycle-in whichl said rod-is normallya ainst said stop beforebeing cut off, a'compressed air operated brake for-said machine and a solenoid-operated valve in the air supply line therefor, and

an operating circuit for said valve passing through back contacts of said relay.

3. In 'a-machine fed with conductive rod stock wherein'the'end of theyrod'is fed into s'ai'd rnachine andav stop member stops the travel of said rod when a predetermined length ofrodhas entered the machine whereupon the end of said rod is'cut off, the combination with said machine I of a relay and an energizing circuittherefor, said energizing circuit having .twoparallel branches,

one of said brances passing through said rod and stop in series, a switch in the other of said branches, and a cam on a cyclically operating part of said machine engageable with said switch to openthe same during that'part of the machinecycle in which said rod is normally against said step before being cut off,'a compressed air operated'brake for said machine anda solenoid-operated valve in the air supplyline therefor, and an operating circuit for saidwvalve'passing through back eontacts'oi said relay, an electricmotor the said rod to permit a further section-of rod to-be advanced, a relay and an energizing circuit therefonsaid energizing circuit having twoparallel branches, one of said branches passing through said rod and'stop in series, a switch in the other of said branches, and a cam driven-bysaid motor for openingsaid switch during a portion of each operassure ating cycle in which said rod end is normally in engagement with said stop, a brake for said driving motor and an energizing circuit therefor,

ing said rod and said stop in series therein, the other of said paths including a switch, and a cam driven by said shaft and engaging the operating arm of said switch to open the same for a portion oifi each cycle of operation of said mechanism during which said rod is normally in engagement with said stop, a brake for said power shaft, a brake operating mechanism therefor, and a control circuit for energizing said brake operating mechanism closed by the back contacts of said relay.

relay on release of said ERNEST W. HUEBNER. LOWELL E. PETERSON.

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