US3455213A - Monitoring device for the presence of cellophane tear strips on cellophane packaging apparatus - Google Patents

Description

July 15, 1969 A. SERAGNQLI 3,

MONITORING DEVICE FOR THE PRESENCE OF CELLOPHANE TEAR STRIPS ON CELLOPHANE PACKAGING APPARATUS Filed Feb. 16, 1966 3 Sheets-Sheet 1 MEANS I v INVENTOR. Ariosto Serug noli ATTORNEY FIG.2.

July 15, 1969 A. SERAGNOLI MONITORING DEVICE FOR THE PRESENCE OF CELLOPHANE TEAR STRIPS 0N CELLOPHANE PACKAGING APPARATUS 5 Sheets-Sheet 2 Filed Feb. 16, 1966 FIG INVENTOR. Ariosto S'erugnoli BY ATTORNEY PIC-3.4.

July 15, 1969 A. SERAGNOLI 3,455,213

MONITORING DEVICE FOR THE PRESENCE OF CELLOPHANE TEAR STRIPS ON CELLOPHANE PACKAGING APPARATUS Filed Feb. 16, 1966 FIG.6.

3 Sheets-Sheet 3 36 39 INVENTOR.

ATTORNEY 3,455,213 MONITORING DEVICE FOR THE PRESENCE OF CELLOPHANE TEAR STRIPS N CELLOPHANE PACKAGING APPARATUS Ariosto Seragnoli, Bologna, Italy, assignor to Ditta G. D., Societa in Accomandita Semplice die Enzo Seragnoli ed Ariosto Seragnoli, Bologna, Italy Filed Feb. 16, 1966, Ser. No. 527,860 Claims priority, application Italy, Feb. 17, 1965, 3,718/65 Int. Cl. B31b 1/90 U.S. Cl. 93-1 11 Claims ABSTRACT OF THE DISCLOSURE In a wrapping machine, a drum rotates with tear strips held by suction on its periphery. The drum is part of an electrical circuit; the tear strips are of relatively high resistance. Another part of the electrical circuit is urged toward contact with the drum, but, if the tear strips are correctly in position, their high resistance prevents closure of the circuit. Should an abnormal absence of the tear strips occur, the electrical circuit is closed and an alarm is sounded or the wrapping machine is shut off.

The present invention relates to an apparatus to check for the presence of the tear strip on a wrapping in cellophane wrapping operations.

Tear strips are placed in cellophane wrappings such as for cigarettes to provide easy opening of the wrapped packages. Early and rapid determination of improper placement of these tear strips by the wrapping machine is a critical aspect in cellophane wrapping operations.

An object of this invention is to provide an apparatus to detect a possible imperfection, or defect in the placement of tear strips or the absence thereof in the Wrapping as soon as it occurs.

Another object of the invention is to provide means to give immediate warning of such an occurrence to the operator of the wrapping machine and to stop the machine upon the occurrence thereof.

Yet another object of the invention is to provide the tear strip for a cellophane package with electrical resistance, and the packaging machine with a monitoring device, which instantaneously detects the absence of the electrical resistance strip to provide a warning and stopping of the packaging machine.

Other objects and many advantages of the invention will become apparent to those skilled in the art, after a study of the following detailed description in connection with the accompanying drawings, wherein:

FIG. 1 shows a side view of the device;

FIG. 2 shows a partial view of the device along line 22 of FIG. 1;

FIG. 3 shows a side view of an alternative embodiment of the device of FIG. 1;

FIG. 4 shows a partial view along line 22 of FIG. 1, of a further alternative embodiment of the device;

FIG. 5 shows a side view of a further embodiment of the device;

FIG. 6 shows a view along line 6-6 of the above embodiment of FIG. 5.

Referring in detail to FIG. 1, a reel of cellophane 21, from which a cellophane band 22 is unwound, reaches States Patent 0 3,455,213 Patented July 15, 1969 ice through unwinding compensating roll 23 and idle delay rolls 24 and 25 the moistening roll 26 and then winds around operating drum 27, on which it is joined to tear strips 28 and from which it comes out at 29, provided with tear strips 28 applied to it and is transported by pull means, not shown, toward a wrapping machine. Successive operating elements of the wrapping machine, which cuts the band already provided with the tear strip, wrap the cigarette packages with it.

The moistening of the cellophane band 22 is made by rotating roll 26. Only a longitudinal portion of the surface of the roll is in turn moistened along a suitable circumferential strip by wick 30 which, for instance by capillary action, carries liquid 31 upward. The liquid is a conventional solvent used to glue two cellophane elements together and is contained in container 32.

Tear strip 28 are applied to the band by known means. The tear strips are deposited on a stationary support 33, from which one end of each strip is threaded onto drum 27. The drum has on its periphery at zone 35 on which the end of strip 28 is introduced a large series of holes 34 which are subjected to suction by known means. The strip 28 is drawn by suction, winding thereon.

The suction applied to the rotating holes 34 is limited 'to their position above zone A. The suction ends when the holes reach zone A, and there the tear strip wound on drum 27 is superimposed on the band of wrapping material 22, which is moistened at 2 6 with the adhesive solvent.

As a result of tension pressing the band 22 to drum 27, the strip adheres to the moistened zone of the band and is cemented to it, coming out joined to the band of wrapping material at 29.

In a preferred embodiment, shown in FIG. 2, zone 35 of drum 27, on which strips 28 are wound to be compressed against band 22 is held between two grooves 36, 36', to prevent the moistened zone of band 22 from smearing the drum. For this purpose, zone 35 is made in a width slightly smaller than that of the tear strip 28, so that, during contact with band 22, zone 35 is covered by the strip and cannot be smeared.

A sensitive element 60, placed between support 33 and zone A for superimposition of the band on the strip, gives a warning that the strip is missing. Thus absence of the strip is indicated already in this preparatory phase, most suitable phase for warning since useless unwinding of the further phases, which would occur with defective elements, is avoided.

The element 60 has a pawl 37, journaled at 38, which has a bottom surface with the same radius of curvature as drum 27, and rests on the drum itself pressed by a compressed spring 70.

The covering of drum 27 is electrically conductive and is grounded at 39; the contact surface of the pawl is electrically conductive and is connected by power line 40, to a terminal of transformer 42, which has the other terminal grounded at 39.

On power line 40 and in series with pawl 37 is placed a relay 41, which, when current goes through wire 40, is excited and acts on the switch 41 of the cellophaning machine, otherwise not shown, causing it to stop and at the same time preferably setting off an optical and/or acoustic warning signal. The cellophaning machine is driven by an electric motor controlled by an electromagnetic switch.

The electromagnetic switch remains closed and keeps the cellophane wrapping machine running as long as the self-excitation auxiliary circuit of the winding of the electromagnetic switch is not interrupted. In this case, as shown in FIG. 1, two switches 41' and 41" are actuated by relay 41 the first switch being closed and the second open when relay 41 is not excited and vice versa.

Switch 41 is put in series in the self-excitation circuit of the electromagnetic switch. When current goes through relay 41, switch 41' is opened and the cellophane machine stops. Switch 41" is put in series with an alarm 52, see FIG. 1, fed, for example, by the same transformer 42, which gives a warning signal when current goes through at 37.

The pawl, as long as it rests on the drum surface with the electrically insulated strip interposed, is insulated from the ground. No current flows.

The pawl support surface is developed circumferentially on drum 27 to a length necessary to keep the contact open even when the empty space 53 between one strip and the next passes under the pawl. Thus, the pawl remains raised during the passages of the end of one strip and the beginning of the following strip.

If the strip is missing, the pawl comes in contact with the metal of the drum and closes the circuit of relay 41, causing the cellophaning machine to stop and setting oif the warning signal. The operator can then intervene before rejects occur.

In the alternative embodiment shown in FIG. 3, the sensitive element 60 is made up of a pair of metal contact rollers 43, 43, carried by crosspiece 44 swinging like a balance at the end of shaft 45, journaled at 46 on a fixed base and pulled by a spring or weights, not shown, so as to shove rollers 43, 43 in contact with band 35, FIG. 4 of drum 27.

Rollers 43, 43' are electrically insulated from one another and are electrically connected with power lines 47, 47' which lead to transformer 42 and on which are inserted relays 48, 49 which, when excited, close electric switches 50, 51, put in series in relation to one another on a power line that feeds said relay 41.

Electric contact of one or other roller does not cause the intervention of relay 41, which is excited only when the tear strip is missing under both rollers.

In this way, possible closing by the contact of a roller with the drum, does not cause the machine to stop, which happens only when there is abnormal interruption of the flow of the strips.

The same result can be obtained with only one contact roller, by placing a time-delay relay, which closes only when it is put under current for predetermined period.

In the alternative embodiment shown in FIG. 4, pawl 37 has a width slightly larger than that of zone 35 of drum 27 and is held tight by connector 88 between two plates 54, 54' of electrically insulating material which go slightly down into grooves 36, 36, so as to guide strip 28 on its sides as it passes under pawl 37.

In a further alternative embodiment of FIGS. and '6, the sensitive contact element is made up of a single roller 55, which can turn idle on its pin 57, carried by the swinging arm 58. Ann 58 is fulcrumed at 59 on a base. Roller 55 presses on strip 28 and is electrically connected by line 40 to said relay 41, FIG. 1.

To prevent contact between roller 55 and drum 27 from causing the functioning of relay 41, every time a gap 53 between one strip and the next occurs under roller 55, power line 63 coming, through a rotating contact, not shown, from drum 27 goes to ground 39 by passing through a cyclic switch 160 operated by cam 61 which rotates as one piece with drum 27 and presents slots 62 which, taking away the support from lug 64 of the elastic tongue of switch 160, make the switch open every time a gap 52, FIG. 1, passes under roller 55. In this case it 4 is necessary that at every rotation of drum 27 a complete number of strips be taken and that cam 61 present as many slots 62 as there are strips taken at each rotation of the drum.

It is further provided that the roller 55 has a Width slightly larger than that of zone 35 and is held tight between two electrically insulating disks 56, 56', with a diameter somewhat larger than that of roller 55, which rotate with the roller and go down slightly into grooves 36, 36, and guide strip 28 on its sides.

It should be understood, of course, that the foregoing disclosure relates to only preferred embodiments of the invention and that it is intended to cover all changes and modifications of the examples of the invention therein chosen for the purposes of the disclosure, which-do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

The invention claimed is:

1. In a package Wrapping machine, such as for wrapping cigarette packages, applying prior to the wrapping of packages tear strips to a cellophane band with which the packages are to be wrapped, means to continuously advance said band and said tear strips into a joined integral relationship; said tear strips electrically insulated; means to sense continuously the electric resistance of said insulated tear strips; and means, actuated by said means to sense, to indicate a defectiveness in the electrical resistance of said tear strips.

2. In a wrapping machine as claimed in claim 1, the means to indicate comprising means to interrupt the means to continuously advance said band and said tear strips prior to their joining, whereby waste of unwinding of band and tear strips and of their joining during failure of the tear strip placement and defects in the tear strips are avoided.

3. In a wrapping machine as claimed in claim 2, said package wrapping machine comprising electric start and stop switch means; said means to interrupt comprising circuit means actuating said stop switch means on oc-- currence of a defect.

4. In a wrapping machine as claimed in claim 1, said means to sense comprising a rotatable electrically conductive drum over which said tear strips are advanced for future joining with said band, an electrical circuit means to actuate, upon its being closed, said means to indicate, said electrical circuit means closable by electrical connection of a leg with said drum, said tear strips passing between said leg and said drum, thereby interrupting closing, and contact means to make connection between said leg and said drum, when an insulating tear strip is defective, whereby the electrical circuit means is closed and actuates said means to indicate.

5. In a wrapping machine as claimed in claim 1, said means to indicate comprising automatic signal means for alarm and stopping of the package machine when said means to sense detects an abnormal absence of the electrical resistance of the tear strips.

6. In a Wrapping machine as claimed in claim 4, said contact means being a rubbing pawl having a contact length along said drum of a length preventing closing of said electrical circuit means, except upon occurrence of an abnormal gap between one tearing strip and the next.

7. In a wrapping machine as claimed in claim 4, said contact means comprising a rotating roller and a cyclic switch including and operated by a cam to keep the electrical circuit means open while the normal gap between one tear strip and the next passes under the roller.

8. In a Wrapping machine as claimed in claim 4, said contact means being a rotating wheel, said means to sense further comprising a time-delay relay for closing said circuit means only when contact between said wheel and said drum persists for a predetermined time.

9. In a wrapping machine as claimed in claim 4, said contact means comprising two rollers, each with its own relay-operated switch means to partially close said electrical circuit means in the absence of an interposed portion of said tear strips, said two switches connected in series in the electrical circuit means.

10. In a wrapping machine as claimed in claim 6, a zone (35) on the periphery of said drum, grooves (36, 36) spaced adjacently on each side of said zone (35) said pawl provided with electrically insulating plates flanking the zone (35) and penetrating into the grooves.

11. In a wrapping machine as claimed in claim 7, a zone (35) on the periphery of the drum, and grooves (36, 36) adjacent to the sides of said zone (35), said roller provided with electrically insulating disks fiankin g the zone (35) and penetrating into the grooves.

6 References Cited UNITED STATES PATENTS 2,350,244 5/1944 Malhiot.

2,424,555 7/ 1947 Curtis 8367 X 2,712,800 7/1955 Harris 8363 2,864,285 12/ 1958 Roselius.

3,272,673 9/1966 Focke.

WILLIAM S. LAWSON, Primary Examiner US. Cl. X.R. 537-8; 8367

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