US2400447A - Web-registering device - Google Patents

Description

y 1946- F. H. WELLS ETAL 2,400,447

- I WEB-REGISTERING DEVICE Filed April 25, 1 940 2 Sheets-Sheet /Z1 ne fig 5 19 1 4 W B I i l I C "INVENTOIRIS F7f%11.5&l{5?00i BY E / ATTORNEY May 14, 1946. FqH'. WELLS ET AL WEB-REGISTERING DEVICE Filed April 25, 1940 2 Shets-Sheet 2 INVENTORSI- f'fl/Vlls & 1200? TTORNEY Patented May 14, 1946 WEB-REGISTERING DEVICli Franklin H. Wells, Hackensack, N. J and John J. Root, Hastings on Hudson, N. Y., assignors to American Machine & Foundry Company, a corporation of New Jersey Application April 25, 1940, Serial No. 331,582

6 Claims.

This invention relates to web-registering devices, and an object of the invention is to control wrapping or packaging machines by controlling (Cl. 271e-2.6)

the feeding of the web of wrapping material,

which is provided with recurrent printed indicia or patterns, to stop the web in predetermined position for the wrapper severing operation. To this end there may be employed the capacity effect of electrically conductive spots spaced along the web to produce a current in a high frequency electrical circuit andthis current, after proper amplification, is used to control the feeding of the web to bring the recurring indicia or patterns in registry with the cutter and thereby to control the feeding and the cutting of the web relative to the printing thereon.

The electric capacitance or permittance between two plates in a high-frequency circuit depends upon the dielectric or insulating properties of the material or materials present in the space between the plates. Thus, if a web of insulating material, such as Cellophane, paper or waxed paper, having recurrent index spots M- of high dielectric constantsuch as bronze or other metallic particles dispersed in a non-conductive medium or of comparatively high conductivity, such as India ink, is moved through such a space, the capacitance of the circuit changes markedly every time one of the spots passes by. The resuiting current impulse, amplified by well known means, may be made to energize an electro- Fig. illustrates a modified form of the relative arrangement-of the plates and the traveling web;

and

Fig. 6 is adiagram of a different circuit for registering the recurring spots or marks on the web.

The plates, A, B, may be arranged in opposition as in Fig, 1, in which case a web of material having electrically conductive spots or areas having a dielectric capacity different from the web may be registered; or they may be arranged in alignment as in Fig. 2; or upon the periphery of a drum D, Fig. 3. The distances d between the plates in Figs. 2 and 3 are made less than the length or width of the marks M, so that when the mark M bridges plates A and B it forms two condensers Ca, and Cb, one with each plate, which condensers are connected in series by the mark itself. Thus this device is made much more sensitive.

In Fig. 3, the drum D is made of insulating material and with the plates A and B is enclosed within a cylinder 0 formed of Bakelite or other suitable material revolving on the shaft of drum D. The web W rests on cylinder 0 and guide rollerF' as the-same is drawn thereover by the feed roller F which is driven by a chain J through a magnetic clutch K. The driving member. of

the latter is slidably mounted on the shaft of roller F and controlled by an electro-magnet E which is energized to disengage the driving memcurrent impulse causes the electromagnet E to feed roller F, L indicates the power lines, and M is one of the recurring electrically conductive marks on the web W. PI and S2 are the primaries of transformers T and '1 whose secondaries are indicated at Sl and P2; P3 is the primary of a power transformer I connected to the lines L and having secondaries S3, S3" and 83"; QI, Q2

' are grounded cables leading to the plates; Rl-Rl 0 are resistors; Swl is a" line switch; SW2 is a reset switch; Tl may be a kc. intermediate frequency transformer; T2 maybe a 1'75 kc. osciliating transformer; T4 is a power choke coil; VI is a 6S.J.7 detector tube; V2 i a, 2051 grid glow tube; V3 is a 5T4 power rectifier tube; V4 is a 6J5 oscillatory tube; and V5 is a 6J5 C-bias rectifier tube; and VC1, VCz and VC; are variable condensers.

The condensers and resistors used may be of the following magnitudes, by way of example:

(2) A detector tube detects the A. 0. potential picked up through detector plates A, B and ink mark M, the detector circuit in this case being formed by vacuum tube VI and transformer TI (3) An amplifier circuit using a grid glow tube amplifies the impulse from the detector circuit.

This tube is designated at V2 and is connected tov the electromagnet E to actuate the. clutch K which operates and stops the webfeed.

C1 microfarad .0001 C2 do .0001 C3 do .0005 C4 do .00025 05 do .01 C6 (10---- .0005 C7 do .01 C8 do .05 C9 do .01 C10 do .05 C11 d0 .05 C12 do .03 C13 do .1 C14 do .01 C15 do .01 C16 do 8 C17 do 8 R1 ohms 25,000 R2 d0 150,000 R3 do 10,000 R4 do 100,000 R5 do 2,000,000 R6 d0 25,000 R7 do 50,000 R3 d0 250,000 R9 d 1,000,000 R10 d0. 1,000,000

(4) Vacuum tubes VI and V2 require an opposing negative C-bias for their operation, this C-bias being furnished by tube V5. Part of the voltage generated by tube V4 is rectified by tube V5 and applied to the respective circuits.

(5) Transformer T3, choke coil T4 and rectifier tube V3 furnish the direct current necessary for,

the operation or the complete unit.

Tracing the complete circuit shown in Fig. 4, the operation of the various units is as follows:

The oscillating circuit transformer T2 and tube V4 generate a potential having an A. C. frequency with a range of approximately 10-175 kilocycles. This A. C. potential is applied in two ways: It is fed through condenser C3 to resistor R8. Rectifier tube V5 rectifies the potential across R8 and applies a D. C. voltage across adjustable poten- R9 applies a negative C-bias to tube V2, properly filtered by condensers CI I, CH! and C1. The tap on potentiometer Rl0 applies a negative D. C.

voltage to the grid of tube VI, properly filtered by coupling through mark M to cause a current impulse in plate B, and on through cable Q2 and condenser C I to the primary PI of the intermediate tuned transformer TI. Condensers CI and C2 are in the circuit to diminish the parallel capacity effects of cables QI and Q2. This same current impulse induces a current in the secondary SI of transformer TI and is applied to the grid of tube VI, and it will be understood that the variablecondensers VCl, VC2 and V03, are adjusted to create resonant conditions of the oscillating, detector and amplifying circuits. Tube VI has a resistor R2 in its. cathode circuit and a resistor R4 in its plate circuit. Tube VI in normal operation is biased almost to current cut-ofif by potentiometer RIO, and no voltage is developed across resistors R2 and R4. Now, when the current impulse conducted through the mark M is imposed on the grid of tube VI, only the positive half of the cycle of induced current impulse causes current to flow in the cathode and plate circuits of tube VI, thereby causing one D. C. voltage to develop across resistor R2, filtered by condenser C5, and one D. C. and A. C. potential to develop across resistor R4 which is not filtered.

These two voltage components trip the lock-in circuit in .tube V2 in the following manner: Tube VI being a combined D. C. and pulsating current amplifier, the positive voltage component across resistor R2 is fed in series through potentiometer R9, which normally biases tubeV2 to cut-01f, and

is applied through grid resistor R5 to the grid of tube V2, and at the same time the pulsating current potential across R4 isapplied through condenser C6 across resistor R5 and to the grid of tube V2. Now, tube .V2 is a gaseous tube, and gaseous tubes have a lock-in characteristic when operated on D. C. When a small potential is applied to the grid of tube V2, the gas ionizes and causes this tube to pass current, thereby energizing the electro-magnet E of the clutch K. It will be understood that instead of the lock-in circuit a relay may be used, connected to tube VI for energization of the electromagnet K.

Tube V2 is not capable of returning to normal operating condition until switch Sw2 is opened and closed again. For this purpose a rotary cam may have a suitable cam track engaging a cam follower Y on the switch SW2 and operating in each cycle of operations to momentarily open switch SW2 and then close the same whereby the electromagnet E is deenergized and the circuit tiometers R9 and RIO. The tap on potentiometer reset for operation on the next spot on the web.

Condenser CI 2 charges up in.an opposite polarity when tube V2 fires, thereby assisting deionization of tube V2 when the switch SW2 is used to reset the operation condition of the circuit.

Resistor R1 in conjunction with condenser CIB acts as a line voltage surge stabilizer, wherefore fast line voltage surges will not trip the circuit. Condensers CH and CIS prevent any A. C. voltage from leaking into the line from the oscillator. I

In the arrangement of the plates shown in Fig. 5, the plates A, B are placed in alignment with each other and a grounded plate C is disposed in the gap between plates A and B to reduce primary P and secondary S are adjusted to be at or near a critical condition by adjusting the gap therebetween or otherwise so that the spot or mark M affects the coupling between primary P and secondary S and sets up an impulse, which after amplification, energizes a relay Re which actuates electro-magnet E to disengage the magnetic clutch (not shown) through which is driven the feed roller F engaging the web W. The currents for the relay Re and for the filament of tube V are supplied by batteries BI and B2. The spots M may be formed with conductive ink or ink containing magnetic material, such as iron powder.- Moreover spots or areas having dielectric properties different from the remainder of the web may be used to vary the coupling between primary P and secondary S sufficiently to energize the electromagnet E.

While the invention has been exemplied as stopping thefeeding of the web in a predetermined registered position it will .be understood that it may serve to control the feeding to'obtain the desired registration, and is not limited to web-registering devices. I

spots successively, a device controlled bysaid circuit for terminating the feeding action of said means when said plates are capacitatively counet connected to said lock-in circuit and adapted to be energized by said lock-in circuit and stop said feeding means when a spot on said web establishes a capacitative coupling of said plates,

and a switch for breaking the lock-incircuit material, flat condenser plates spaced from and extending into the proximity of said web, a high frequency alternating current electric circuit connected to one of said plates, a detector circuit connected tothe other of said plates and adapted to detect an electrical impulse created by capacitative coupling of said plates established by each of said spots successively, and a device controlled by said detector circuit for interrupting the feeding action of said means to stop successive spots on said web in predetermined registered position, said plates being disposed on the same side of the web and out of contact with means.

5.'In a web-registering device, the combination with means for feeding a web of material pled by one of said spots, to stop successive spots in predetermined registeredposition, and means for incapacitating said device and reinstating the operation or the web feeding means to advance the next spot on the web into position to capacitatively couple said condenser plates.

2. In a web-registering device, the combination with means for feeding a web of material having recurrent spots having a dielectric capachaving recurrent printed spots containing electrically conductive material of a pair of condenser plates spaced from and extending into the proximity of said web, a high frequency alternating current electric circuit adapted to be affected by capacitive coupling through each of said spots successively, and a device responsive to variations in the current how in said circuit due to capacitative coupling of one of said spots with said plates for interrupting the feeding action of said means to stop successive spots on said web in predetermined registered position, each to be affected by capacitivecoupling through each of said spots successively, and an electromagnetic device controlled by said circuit for interrupting the feeding action 'of said means to stop successive spots on said web in predetermined registered position, a drum carrying said plates, 5

which are disposed on said drum, and a rotating cylinder formed of insulating material and en-' closing said drum. i

3. In a web-registering device, the combination with means for feeding a web of material having recurrent spots of material having adielectric capacity different from the web, of condenser plates spaced from and extending into of said condenser plates being disposed out of contact with said web and spaced from and aligned with.each other, each of said pair-of condenser plates being connected to said circuit, and a grounded third plate disposed between said pair of plates and unconnected to said circuit.

6. The combination with means for feeding materialv having' electrically conductive indicia thereon, of a pair of condenser electrodes spaced from each other and extending into the proximity of and out of contact with the material advanced by said means, an oscillator circuit connected to one of said condenser electrodes and adaptedqto impress high frequency alternating current thereon, a detector circuit connected to the other of said electrodes, and electrical control device connected to said detector circuit and adapted to be operated when an increased c011:- pling of said electrodes is produced .by the proximity of electrically conductive indicia on said materiaLsaid electrodes being disposed on the same side of said material, and a grounded member interposed between said electrodes andunconnected to said oscillator and detector circuits, to minimize the coupling of saidelectrodes and therebv increase their sensitivity.

FRANKLIN H. WELLS. JQHN J. ROOT,

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