US2141052A - Adhesive applicator - Google Patents

Description

Dec. 20, 1938. c. S,.STEPHANO,

ADHES I VE APPLI CATOR Filed May 11, 1937 INVENTOR v Consiiznizne 8. Slephurzo d ATTORNEYS ZUifnesses Patented Dec. 20, 1938 UNITED STATES ADHESIVE APPLICATOR Constantine s. Stephano, Elkins Park, Pa.

Application May 11,

3 Claims.

This invention relates to improvements in ad-' hesive applicators and has particular relation to improved mechanism for aiding in securing uniform distribution of the desired amount of adhe-" sive over the surface to which it is to be applied. My invention is particularly adapted for use in association with adhesive applicators in continuous rod cigarette making machines, although it is to be understood that it may be used in other in associations. In continuous rod cigarette making machines the tobacco particles are fed on to a moving strip of cigarette paper and then passed under a rod-forming tongue which shapes and compresses the particles of tobacco into a cylinthe conventional cigarette. As the particles are thus formed into a rod the cigarette paper is partially wrapped around the rod, and shortly after the rod emerges from the end of the tongue paste is applied to one edge of the cigarette paper which is then wrapped about the rod until it overlaps the other edge of the paper, forming a complete paper-encased rod. The rod is passed through a suitable dryer causing the paste to adhere and is then cut into short sections of the proper length to form cigarettes.

A frequent cause of difiiculty in the making of continuous rod cigarettes is the application of an insufiicient amount of paste to the paper by the paste wheel. At the present time an insufficient amount of paste is revealed only by'the breaking of the cigarette rod or the opening of the cigarette rod or the cigarette in the catcher belt of the machine, or by an inspection of the cigarettes if the inspector happens to be present at the time the defect occurs. The result is that frequently the defect is not discovered until it has existed for some time and often a considerable number of cigarettes of insuflicient strength have been 40 placed in packages. The mechanical stresses associated with the removal of the cigarettes from the packages or the moistening of the cigarettes at the time of smoking, causes the cigarettes with insufficient adhesive to open.

It is an object of the invention to overcome the dimculties occasioned by the application of insufllcient adhesive as outlinedabove and to provide an improved device whereby the application of the desired amount of adhesive can be readily obtained.

A further object is the provision of an improved signalingdevice of the above character which will indicate automatically and instantaneously when an insumcient amount of adhesive has been applied to the cigarette paper, but which will be drical rod of slightly smaller circumference than 1937, Serial No. 141,988

unaffected by variations in the moisture content of the paper itself.

My invention contemplates the utilization of the differences in resistance to an electric current between the plain cigarette paper and cigarette paper to which an adhesive has been applied, and also the differences in resistance between cigarette paper to which varying amounts of adhesive have been applied to control an .electrical circuit through the medium of an electric valve, such as an electronic tube.

For a fuller understanding of the invention reference should be had to the accompanying drawing which shows a plan view of the adhesiveapplying mechanism of a conventional continuous rod cigarette making machine, and also a diagrammatic representation of the electrical circuits and the connections to the adhesive applicator.

My invention is particularly adapted for use with the adhesive applicator of a continuous rod cigarette making machine and for this reason is' illustrated in this association. However, it is to be understood that my invention may be used in association with different types of adhesive applicators.

In the drawing the numeral I indicates a paste wheel applying a layer of paste 2 to the surface of the cigarette paper 3 adjacent one lateral edge thereof. For the purpose of clarity the cigarette paper and the layer of paste are shown in exaggerated form. The paste wheel i is of a conventional type employed in continuous rod cigarette machines, the paste being applied to the periphery at the point 4 and the paste wheel revolving in the direction of the arrow so that the adhesive from the periphery of the wheel is applied to the. surface of the paper as shown. A scraper 5 preferably engages the periphery of the wheel beyond the point of contact with the cigarette paper so as to removethe excess dried paste therefrom.

In the usual type of cigarette rod making machine the paste wheel engages the surface of the paper adjacent one lateral edge thereof after the continuous rod has been almost completely formed, the rod being fed beyond the wheel and the lateral edge with the adhesive applied thereto being folded around the rod until it overlaps the otheredge of the paper and is adhesively held in position. In the accompanying drawing the paper is being fedtowards the left so that the portion to the right of the paste wheel has no adhesive applied thereto, whereas the portion to a casein content and when applied to the paper the moisture penetrates therethrough and the resistance of the paper at that point to an electrical current is reduced, or stated in another' way, the conductivity of the paper moistened with the paste is increased. As the amount of paste applied to the paper is increased the resistance is further reduced, and, likewise, as the amount of paste is reduced the resistance is increased, the amount of paste and the resistance being in a general way inversely proportional. In car.- rying out my invention I take advantage of this variation in the resistance to control the operation of an electrical circuit through the medium of an electronic tube.

I have found, however, that the moisture content of the paper which may be affected by the humidity of the air or the moisture content of the tobacco, also affects the resistance of the paper, and I provide means whereby the circuit will not be responsive to variations in resistance occasioned by variations in the moisture content of the paper itself. Thus I provide a suitable source of current, such as the battery 8, and connect the negative side thereof by means of leads I to a contact 8 which engages the under surface of the cigarette paper at the point 3 a short distance prior to-the point of contact with the paste wheel I. The positive side of the battery 6 is connected by lea'ds l8 and H to contact l2 which engages the under surface of the cigarette paper at the point H a similar distance beyond the point of contact with the paste wheel I. The paste wheel engages the opposite surface of the paper .at the point [5 midway between the contacts 8 and I2.

The dry cigarette paper offers considerable resistance to the passage of an electrical current. If no paste is applied to the surface of the paper 3 by the paste wheel I, the voltage drop between the contact 8 and the point 15 where the paste wheel engages the paper will be the same as the voltage drop between the contact l2 and the point I5. Howevenif paste is applied to the paper by the paste wheel I the voltage drop between the contact i2 and the point 15 will be less than the voltage drop between the contact 8 and the point [5, and as the amount of paste is increased the voltage drop from the contact H to the point I5 becomes proportionately smaller.

Due to. the arrangement of the two contacts 8 and I2 in engagement with the under surface of the paper before and after it engages the paste wheel, the resistance offered by'the paper itself, even though the moisture content thereof should vary, does not affect the relative potential of the point I5. The only factor affecting the relative potential of the point I5 is the amount of paste applied to the paper by the paste wheel I. Thus if more paste is applied to the paper the point 5r becomes relatively more positive. If

-less paste is applied it becomes relatively less positive or more negative. This variation in the relative potential of the point I 5 is taken advantage ofto control an electrical circuit and for this purpose I provide a brush IS in engagement with the side of the paste wheel i and connected by means of a lead I! to the grid ll! of a three element electronic tube l8. The paste wheel I is formed of electrically conducting ma.-

the left of the wheel'has the layer of adhesive terial and engages the surface of the paper at the point i5 and thus the grid 18 receives its potential or bias from the point I5 of the paper.

The plate and filament of the electronic tube, indicated at 20 and 2!, are connected so as to control the flow of current in an electrical circuit. The filament 21 is lighted by being connected through leads 22 and 23 to the secondary winding 24 of a transformer 25, while the primary winding 26 of the transformer is connected by leads 2! and 28 to a suitable source of alternating current. The positive side of the battery 6 is connected to the filament 21 by means of leads 29, 38 and 3|, which connects at the central point of the winding 24 and thus has connection with the filament,

Disposed in the plate circuit of the electronic tube 18 is a sensitive relay 32,.one end of the winding being connected by a lead 33 to the plate 28 and theother end of the winding being connected by leads 34 and 35 to lead 28 which is connected to one side of the source of current supply. The circuit of relay 32 preferably has a fuse 36 disposed therein as indicated. The plate circuit thus includes leads 21, 28, 38, and 3|, winding 24, leads 22 and 23, filament 2i, plate 20, lead 33; coil of relay 32, and leads 34, 35, and'28.

It will be seen that the greater the amount of paste applied to the cigarette paper, the more positive will be the bias of grid is, due to the decreased resistance of the paper to which the adhesive is applied, with the result that a greater amount of current will flow in the plate circuit of the tube. On the other hand, as the amount of paste applied to the paper decreasesthe positive bias of the grid l9 likewise decreases, with the result that a smaller amount of current flows through the plate circuit.

The sensitive relay 32 includes a movable contact '31 having an adjustable tension spring 38 tact 39 is connected by leads 44, 38 and 28 to the lead 21 connected to one side of the course of current supply. The other side of the source of current supply is connected by leads 28, 35

and to the electrode 46 of the neon tube.

The tension of spring 39 is adjusted by means of the thumb screw 40 so that when the predetermined minimum amount of paste desired or a greater amount is being applied to the paper, sufficient current will fiow through the plate circuit of tube l8 so that the relay 32 holds the switch in open position. When the amount of pasteapplied to the surface of the paper drops below the predetermined minimum amount desired, the current flowing through the plate circuit decreases to such an extent that the spring 38 overcomes the force exerted by the relay, closing the switch to the position indicated in the drawing, and causing the operation of neon tube 43, thus clearly indicating to the operator that insufficient paste is being applied to the paper.

,In using my improved adhesive applicator the spring 38 is first adjusted to the desired tension so as to enable the operator to determine when the quantity of adhesive being applied to the cigarette paper falls below the desired predetermined minimum level, and the cigarette machine is then placed in operation. As long as the desired amount oi adhesive is being applied to the paper, the potential; of the point l5 of the cigarette paper will be 'relatively'more positive with the result that the grid IE! will have a relatively positive bias causing av suflicient amount of current to flow through the plate circuit of electronic tube l8 to operate the relay 32 and open fixed contact 31. Neon lamp 43 accordinglywill not operate as long as sufficient adhesive is being applied to the paper.

When the amount of adhesive being applied to the paper falls below the'desired amount, however, the potential of the point IS on the paper becomes relatively less positive with the result that the bias of grid l9 becomes less positive reducing the flow of current in the plate circuit of the electronic tube l8. The tension of spring 38 is then suflicient to overcome the pull of relay 32 with the result that the circuit of neon tube 43 is closed, causing the tube to light and thereby indicating to the operator that insuflicient adhesive is being applied to the cigarette paper. The operator can then investigate and determine what is causing the application of an insuflicient amount of adhesive and take the necessary steps to correct the dimculty.

It will be seen that where it is desired to increase or decrease the predeterminedminimum amount of paste to be applied to the paper, the tension of spring 38 should be increased or decreased to cause the operation of the signal 43 at the proper time.

It will thus be seen that I have provided an improved adhesive applicator which is especially adapted for use in association with continuous rod cigarette making machines, and which facilimum level. The circuit arrangements will be similar to those illustrated with the exception that the relay controlling the signal will be.

caused to close the circuit when the flow of current in the plate circuit of the electronic tube rises above a predetermined level.

It should also be understood that instead of employing a signal in the form ofv a neon. tube 43,

other types of signals may be employed, or that instead of employing a signal the circuit may be connected directly to the adhesive feed so as to vary the flow of adhesive.

While my improved device is especially adapted ,for use in association with continuous rod cigarette making machines, it may also be used in association with other similar adhesive applicators.

I claim:

1. In an adhesive applicator for applying adhesive toa-moving strip of paper, an adhesive applying member disposed in the path of movement of the paper, a pair of contacts connected to the two poles of a source of electric current and positioned in the path of movement of the paper before and after the adhesive applying member, an electric circuit, and means electrically coupling said circuit to said source and to a point in the path of movement of the paper intermediate the two contacts so that the circuit is controlled by variations in resistance of the adhesive coated paper relative to the uncoated paper.

2. In an adhesive applicator for applying an adhesive to a moving strip of paper, an adhesive applying member formed of conducting material positioned in the path of movement of the strip of paper, a pair of contacts connected to the two poles of a source of'electric current and positioned in the path of movement of the paper before and after the adhesive applying member, an electric circuit, and means electrically coupling said circuit to said source and to the said adhesive applying member so that the circuit is controlled by variations in resistance of the adhesive coated paper relative to the uncoated paper. 3. In an adhesive applicator for applying ad hesive to a moving strip of paper, an adhesive applying member formed of conducting material and positioned in the path of movement of the paper on one side thereof, a pair of contacts connected to the two poles of a source of electric current and positioned in the path of movement of the paper before and after the adhesive applying member and on the opposite side of the paper therefrom, an electric circuit and means electrically connecting said circuit to said source and to the the adhesive applying member so that the circuit is controlled by variations in resistance of the adhesive coated paper relative to the uncoated paper.

CONSTANTINE S. STEPHANO.

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