US2210003A - Adhesive tape dispenser and applier - Google Patents

Description

Aug. 6, 1940.

c. H.'RANDOLPH i ADHESIVE TAPE DISPENSERy ANI)- APPLIER Filed March 13, 1939` ,-E j ;]a v

4 sheets-sheet 1 Aug 6, 1940.# c. H. RANDOLPH 2,210,003

ADHESIVE TAPE DISPENSER AND APPLIER Filed March 13, 1939 4 Sheets-Sheet 2 ugg, 1940 c. H. RANDLPH ADHESIVE TAlE DISPENSER .AND APPLIER Filed Maron 1;, 1959 4 sheets-sheetV s v l m; Im

Aug. 6, 1940 c. H. RANDOLPH ADHESIVE TAPE DISPENSER AND APPLIER Filed March 13, 1959 4 Sheets-Sheet 4 7W. W Z 1 Z M mi@ W G/ ff f 70 M ,M wmf 9. .mid 6 @y A@ ,/w LJ J 7 NW fnv/.JJ 7

Patented Aug. '6, 1940 ADHESIVE TAPE DISPENSER AND APPLIER Chalmers H. Randolph, St. Paul, Minn., assignor to Minnesota Mining & Manufacturing Company, St. Paul, Minn., Aa corporation of Belaware Application March 1 3,

' 1 Claim.

This invention relates to an adhesive tape dispenser and applier adapted to receive a roll of non-drying pressure-sensitive adhesive tape and automatically position successive predetermined unit lengths of the tape ready for application to packages or other articles, and to apply the same to the articles as they are successively moved into position (manually or otherwise) to receive the tape for sealing or other purposes. This machine may be operated continuously or intermittently; and in the embodiment herein described the machine is driven by an. electric motor, having an associated control circuit, which functions auto- .matically at the press .of a button, so that an operator may readily and rapidly apply tape to a succession of articles of the same or different shape. The machine is primarily vintended for use in sealing packages or other articles, although it is not limited thereto, as it may be employed wherever it is desired to apply to an appropriate article a short length of adhesively coated tape as, for example, a label or sticker. The machine is not limited to the dispensing of the non-drying (normally tacky) pressure-sensitive type of tape,

but can be adapted in an obvious way so as to utilize ordinary gummed tape.

As is well known in the adhesive tape art, a pressure-sensitive adhesive tape comprises a thin iiexible backing having a normally tacky and pressure-sensitive adhesive coating. By normally tacky and pressure-sensitive it is meant that under ordinary atmospheric conditions the adhesive is stably in a condition such that it does not need to be activated by heat or solvents or otherwise prepared in order to secure good adherence to surfaces against which the adhesive coating (with its backing) may be pressed when used. Modern tapes of this type are available which' are further characterized by having a unified adhesive coating possessed of such coherence in relation to adhesiveness and so firmly united to its backing thatthe adhesive tape may be stripped from smoothv non-fibrous surfaces (not possessing special chemical amnity for the adhesive), towhich it may` have been temporarily applied, without offsetting of adhesive material. `Hence such an adhesive vcoating may be termed nOn-oITSetting, and this expression designates an important physical or chemico-physical property or characteristic of the adhesive coating.

Such adhesive tapes may havebackings of van ious kinds, including paper, cloth and resin films.

However, I particularly contemplate the use of adhesive tapes having a clear, lustrous, transparent or opaque backing of a film of yregenerated 1939, Serial N0.261,535

(Cl. 21S-33) cellulose (Cellophane"), cellulose acetate, cellulose nitrate, ethyl cellulose, etc. Pressure-sensitive adhesive tapes of this kind are well known and readily available on the market under the trade-mark Scotch. f

The adhesive tape may be transparent so as not to conceal the printing, decoration or contents of packages. The tape backing may be printed or marked, either on the vface or on the side beneath the adhesive coating, for advertisl0 ing, identification or decorative purposes.

An illustrative portable embodiment is shown in the accompanying drawings, wherein:

1 is a side elevation view and Fig. 2 is a plan view, the casing being cut away to show l5 the interior and the wiring being cut out for the sake of clarity; g

Fig. 3 is an elevation view showing the front or operating end;

Fig. 4 is a central vertical section of the tape 20 roll holder, taken on the line 4-4, Fig. 2;

' Fig. 5 is a central vertical section of the tape tensioning device, taken on the line 5-5, Fig. 2;

Fig. 6 is a vertical section showing the friction 'akg on the motor, taken on the line 6 6, 25

Fig. 7 is a transverse vertical section and elevation view of the dispensing reel and driving mechanism, taken on 1 1, Fig. 2;

Fig. 8 is a transverse vertlcalsection of a por- 30 tion of the dispensing reel, taken on 8 8, Fig.

2, and showing the adhesive tape thereon; and

Fig. 9 is a simpliiied circuit diagram showing the operation of the motor control system.

Referring now particularly to Figs. 1 and 2 35 (except when otherwise indicated), the machine .has a rectangular base I0 and a box-like casing II, which is hinged at the back so that it can be swung up'and back to make the mechanism accessible, and is releasably secured to the front 40 of the base by knurled screw I2. The casing has a sloping front I3,'Which theoperator faces, and through which thetape is dispensed, as herein. after described.

Mounted to the rear on one side of the base 45 is 4the adhesive tape roll holder I4, shown carrying a roll of pressure-sensitive adhesive tape I5, which may be withdrawn toward the frontof the ,machine This 'holder (see Fig. 4) has a supf porting pillar I6 carrying a threaded removable 60 axle Il, which yis provided with a wing-nut I8, and with flange I9 and end pin 20 between which liesV rotatable wheel 2|, flanged at one side, upon whichtheroll of` tape is slipped. The tape roll is mounted so that the adhesive side is down Yas the tape is drawn to the front of the machine for dispensing.

In front of the roll holder there is mounted on the base a tape tensioning device 22 (see Fig. 5) comprised of a supporting pillar 23 carrying a removable threaded axle 24, positioned parallel to but above the axle of the roll holder, and provided with a wing-nut 25 and a head stop 26. Journaled on the axle is a polished metal roller 21, which is free to rotate unless frictionally restrained, and leather washers 28 and 29 located at the ends of the roller. By tightening the wingnut, the washers become pressed against the ends of the roller and act as a brake, so that the degree of tensioning can be readily controlled. The adhesive tape passes over the roller in moving toward the front of the machine, and the underlying tacky adhesive layer contacts and grips the surface of the roller for a substantial circumferential distance. Tenslonon the tape moving toward the front of the machine results from the pull required to free the tacky adhesive tape.

from the roller even when the latter can rotate freely, and the tension is increased by restraining rotation of theroller by frictional engagement of the leather washers. It will be evident that when a non-tacky type of adhesive tape is to be dispensed, that suitable tensioning means can readily be substituted. For example, the tape can be drawn between two rubber rollers which yieldably press against it an one or both of which is provided with a friction brake that can be adjusted.

Near the front of the base and axially parallel to, and in alignment with, the tape holder and the tensioning roller, there is located a driven tape dispensing reel 30Iwhich drawn the tape from its roll and places it in position for application. This reel (see for details Figs. '1 and 8) isA comprised of a projecting hub 3l, bored axially, into the slotted central part of which is set a series of radial projecting arms 32. In the embodiment shown, each arm is comprised of a holder 33, formed of a stiif metal strip doubled over upon itself and with the ends inserted in a slot in the hub, so that the holder lies substantially in a plane intersecting, and parallel to, the axis. 'I'he outer end portion of each holder is slotted so as to provide an opening with a projecting ear or guide 34 at each side. Before the ends of the metal holder strip are set in the hub, a blade 35 is inserted, consisting of a metal strip having a serrated or saw-tooth end edge 36, so that the latter projects into and is exposed at the slot in the ouer end of the holder. The blade is of such length that the inner end 'will lie between the holder strips within the hub slot, whereby the blade will-be firmly-positioned. The holder is wider than the tape to be dispensed and the slot in its end. is preferably just a little wider, so that the tape can lie against the prongs of the blade and will be guided by the holder projections at each end of the exposed blade edge.

'I'he reel arms are equally spaced apart and are of such number and length that the straight-line distance from one blade edge to the next will equal the predetermined unit length of tape which it is desired to dispense. As an example, the unit tape length to be dispensed may be 11/2 inches, using 8 radial arms in each of which the serrated blade edge is located approximately 1%, inches from the axis of the reel (i. e., the edge radius is 1% inches). By using a reel having fewer blades, or longer blade lengths, or both, the predetermined tape length will be made greater than this, and

vice versa. As indicated in Fig. 1, the radius of the hub is less than half the edge radius and the reel arms are relatively thin, thus providing a relatively large open sector between adjacent reel arms.

In the open sector between each pair of adjacent radial arms of the reel there is located a resilient tape applying or forming die 31, adapted to press against the underside of the tape during a sealing operation and yieldingly press it about and against the package or other object, the latter being pushed against the tape and down into the die. This operation will be explained in more detail later on. As shown (see particularly Fig. 8), the resilient applying diemay be formed of a piece of sponge rubber, having a width substantially equal to that of the holders, which is cut out centrally to provide a normally ilat bridge portion 38, the surface of which will just touch, or lie just below, a piece of tape stretched between the blades, and to provide side walls 39 which normally lie against the adjacent holders and the inner ends of which may rest against the hub. The lower portions of the side walls may be secured to the holders and hub by means of a coating of rubber cement 40, or other suitable bonding agent. The upper wall portions should preferably be free to bend away from the holders when an object is pressed against the bridge, thereby rendering the die as' a whole more yieldable and resilient in use. Experience has shown that such forming dies of sponge rubber are very effective and have a life permitting of many tens of thousands of sealing operations. They are quite inexpensive and may be readily replaced when occasion requires. It will be evident that equivalent material may be used and that other forms of applying dies or means may be found useful. With the said tape applying dies in position, the peripheral boundary of the reel has an essentially polygonal shape.

The reel is provided with driving axle 4I, which .passes through the hub and is journaled in supporting ,uprights 42 and 43, secured to the base (see particularly Fig. '1). Set screws 44 and 45 are threaded in the hub and permit the reel to be turned about the axle, for adjustment, and be secured thereto. 'Ihe inner end of the axle projects beyond upright 43 and toward the opposite side of the base, and carries gear wheel 46 which is secured by set screw 41. 'I'he reel may be rotated relative to the gear wheel, for purpose of adjustment, by loosening set screws 44 and 45 or 41.

The gear wheel is driven by pinion 50 carried on the end of driving shaft I, which runs transversely toward the opposite side of the base and parallel to the-reel axle. Thisl driving shaft is connected to the gear reduction .drive 52 .(details not shown) which is integrally mounted at the front end of a small universal electric motor 53 (powered by either alternating or direct current) which is mounted on the base with its axis at right angles to said driving shaft and rearwardly thereof. 'I'he motor and reduction drive are arranged so that the driving shaft will cause the dispensing reel to rotate in a direction such that the topmoves toward the rear of the machine.

'I'he driving shaft'carries an eccentric or cam 54 which bears down against one end of follower strap 55, made of -a strip of relatively sti spring metal, the other end of which is fastened to angle 56 on the opposite side of the casing of a small single-pole two-way micro-switch 51 (details not shown) secured to the base (see particularly Figs.

1 and 2). This switch has a movable actuating pin 58 projecting upwardly through the top of its casing, underlying the follower spring strap and located near its end. 'Ihere is a hole in the strap above the pin and a`concentric internally threaded collar 59 fastened to the strap and threaded by an upwardly projecting machine screw 80 having a knurled head 6I and provided with a locknut 62. 'I'he lower end of the screw is thus located just above the switch pin, in adjustable relation, so that the switch pin will be pushed in when the follower strap is pushed down by the driving shaft eccentric or cam. The switch is of a kind readily available on the market and is so constructed that a slight downward (inward) pressing of the actuating pin will open one contact and close the other, and vice versa when the pin is permitted to move up. One contact is open and the other closed in normal position, at the close and start of a cycle of operation, and rotation of the driving shaft causes the first contact to be closed and the other to be opened during most of the intermediate period of rotation of the driving shaft.

The gear ratio between pinion and gearwheel 46 is such that one complete revolution of the driving shaft will turn the tape dispensing reel through that part of a revolution equal to the reciprocal of the number of arms, i. e., will turn the reel to advance the tape one unit. Thus in the illustrative example where there are eight blades, the gear ratio should be 1:8. The motor in this example may have a horsepower rating of 1/80 and with a rated speed of 5000 R. P. M. the intermediate gear reduction unit may have a ratio of 90:1. In order ,to prevent the. driving shaft from ove'rshooting, when the current to the motor is broken at switch 51 to end .a cycle of operation (one rotation of the shaft), and in order to provide for a mechanical regulation of the speed of rotation of the motor, a frictional brake is provided (see particularly Fig. 6). T'he rearward end of the motor shaft projects and carries a iiat wheel 65. One end of strap 56 is secured to the top of pedestal 61, and the strap passes over the periphery of the wheel and down, the free end being bent outward. A screw 68, having a knurled head 89, passes down through a hole in the free end of the strap and is threaded in the pedestal. A coil spring 10 is located between the end of the strap and the head of the screw. By turning the screw, a variation of pressure on the end of the strap is permitted for regulation. The frictional engagement between the strap and wheel exerts the desired braking action on the motor. i

At the rear of the base there is secured a relay 1 I', employed as a part of the motor control system. This is a two-pole-one-way relay which can be actuated by either alternating or direct current, and is normally open, the contacts being closed only when the field coil is energized. As this is a conventional piece of equipment, details of construction are omitted. A bindingpost connector block 12 is mounted on the base behind the motor and adjacent the relay. It is provided with a plurality of binding posts and is located a four-prong socket and detachable plug 13 which is connected by flexible fourwire cable 14 to the manual operating control switch 15 (details indicated diagrammatically in circuit diagram Fig. 9). Within the casing of this switch there are located two single-pole oneway micro-switches, one of which is normally closed and the other normally open. The actuating pins are operated simultaneously by a cross member which is pushed in when the hand button 16 is pressed, the pins springing back when the latter is released. The operating control switch is normally but removably mounted on the sloping front I3 of the dispenser casing, on the side away from the dispensing reel, and is thus conveniently positioned for hand operation. It may be removed and placed on the floor for foot operation. Toggle snap-switches 11 and 18 are conveniently mounted in the flat top part of the casing.` Each is a single-pole make and break switch, 11 being in the power'line circuitand being closed to turn on the current when the dispenser is to be used, and 18 being in the motor control circuit and serving to set the circuit for continuous or' for intermittent operation of the dispenser according to the desire of the operator. The vactual wiring layout of the machine has not been shown as this is sufllciently indicated by the circuit diagram of Fig. 9 and the actual wiring may be done in any convenient way. 'I'he circuit will -be discussed later on in describing the operation of the dispenser.

The sloping front I8 of the casing is provided with a rectangular opening through which the dispenser reel 38 projects to a degree largely exposing the tape applying die (see Figs. 1 and 7) which is in operative position, the flat outer surface of such die making an angle of .roughly 30 to the horizontal and the sloping front of the casing an angle of roughly 45, for example. A at guide table 8| of sheet metal is provided along which the packages or other articles may be pushed into operative engagement with the tape and die. This is slotted to permit passage of the reel and its position and angle may be adjusted to best suit the work at hand. The table is hinged at the forward edge to an underlying movable plate 82, which is slotted out for the reel, and which rests upon the sloping casing. This plate 82 has a pair of longitudinal slots, one on either side. A pair of guide and holding bolts, 83 and 84, pass through the slots near the lower extremities and through the casing.V These are ordinarily adjusted so as to permit of sliding the plate along the casing for positioning the guide table. A pair of wing-nut bolts, 85 and 86,

are positioned through the slots and casing, to-

lward the other ends of the slots, for guiding and clamping purposes. The guide table is adjustably supported at its outer or rear end portion by an angular pivoting arm formed of straps 81, pivoted to bracket 88 secured to the bottom of the table, and straps 89, pivoted to bracket 90 secured tothe rear of plate 82, the other ends of the straps forming an elbow by being pivoted together by wing bolt 9|, which also serves as a locking means (see Fig. 1). The pivoting arm thus permits the table to be swung up or down about its hinged inner edge, and the sliding plate permits the table to be moved up or down the sloping casing front, thus enabling an adjustment to be made to secure the best position for each type of job, and also permitting the table to be movedv out of the way when it is not to be used.

Ilo

Mode of operationl Referring to Figs. 1 and 2, the machine is placed in condition for tape dispensing by placing a roll of adhesive tape upon the holder I4 so that the tacky coated side is down as the tape is drawn to the dispensing reel. The tape is drawn forward so that it passes over the tensioning roller 21 and down under the dispensing reel 30 and up around the latter, being pressed into engagement with the prongs of the serrated blade edges 36. The uncoated side of the tape faces the sponge rubber applying dies, the tacky coated side facing outwardly for engagement with objects to be sealed.

Rotation of the dispensing reel draws the tape from the supply roll and tensioning means, the prongs of the radial blade edges penetrating into the tape (but without breaking it) and providing a positive gripping action. The initial grip is produced because the tape is under tension and hence becomes rmly pressed against the prongs of the blades when engagement occurs.

The position of the reel at the end of a step of rotation is fixed in advance as heretofore described, by turning it relative to gear wheel 46 and then locking, so that at the end of each step there will be a unit length Y of tape, with its underlying applying die, in operative position above the sloping front I3 of the casing (see Fig. 1). The position of guide table 8| is adjusted for the particular package or other article to which the tape is to be applied, and the tape having been threaded around the reel, the operator is ready to start applying the tape.

With the current turned on and switch 18 put in the intermittent position, the operator pressesI button 16 of manual operating-switch 15 and this causes the dispensing reel to rotate or turn one step, and then stop until the button is again pressed. If the button is held in, the reel will stop just the same, and will not start until the button is released and then pressed again. This permits of automatically controlled step by step operation. When switch 18 is turned to the continuous position, the reel will be continuously rotated for as long as button 16 is held pressed in, and if the latter is released when the reel is in an intermediate position it will continue to rotate through the remainder of the step so that it will stop with a unit length of tape in the proper position.

Assuming that intermittent operation is being employed and that a unit length of tape has been brought to operative position, the operator slides the package down the guide table 8| and into the exposed unit length of tape and the underlying resilient die, the package being held so that the tape will be applied in the desired place. As soon as this occurs, the tape will be forced down and rearwardly, owing to the direction of motion of the package and the engagement between tape and package, and a pulling action will take place at the rear end of the length of tape Where the latter engages the prongs of the blade, which will cause the unit length of tape to become severed. As the involved portion of the package moves farther into the yieldable and resilient die, the latter will press the severedpiece of tape against the contour of the package and thus apply the tape to the surface thereof in sealing position. The package is withdrawn with the seal applied in the desired place, and the operator presses the control button to turn the reel one step and bring up the following unit length of tape into ready position.

A skillful operator working on articles that readily lend themselves to this type of sealing operation, can set the switch for continuous operation and hold down the operating control switch button wih his foot (the switch b'eing placed on the floor), so as to cause continuous rotation of the tape dispensing reel, and feed the articles rapidly enough to apply each unit of tape as it comes into position. In order to facilitate such continuous operation, the motor speed may be reduced as .heretofore described.

For certain types of sealing operation it may be most convenient to feed the articles without using the guide table, simply guiding each article into engagement with the tape by use of the hand and arm.

For sealing folded mailing cards, only a short length of tape is necessary for the seal, and a reel can be used having a greater number of radial arms than in the illustrated embodiment, in order to reduce the unit tape length. In such case the bridge portion of the sponge rubber applying die can be made quite thin so that the cards can be more easily forced in for sealing.

It will be evident that this tape dispensing and applying device can be used in combination with a suitable mechanical device for automatically feeding and removing the articles to be sealed.

While the device has been described with particular reference to use in applying normally tacky pand pressure-sensitive tape, it has previously been indicated that the described embodiment can be easily adapted to normally dry or non-tacky tape which requires moistening or solvent activation, as for example the familiar gummed Apaper tape. In such case a suitable device for applying moisture or solvent can be provided which will activate the tape while on the dispensing reel and just shortly before it The circuit diagram of the electric control system is set out schematically in Fig. 9, and as the connections will be readily apparent upon inspection they will not be detailed, although indicated in the following description of mode of operation. It will be recalled that the system works on either alternating or direct current.

Assuming that the cord 12 has been connected to a suitable power source, and that the dispensing reel is stationary and ready to begin a step of rotation, and that switch 18 is in the open position for intermittent" operation of the machine, the closing of the line switch 11 produces the following result: Current flows directly from one side of the power line to one terminal of the eld coil |00 of relay 1| and to one terminal of drive motor 53, and as these connections include no switching elements it will be understood that they are closed at all times. The other terminal of the field coil connects through the normally closed switch unit |0| of operating switch 15, and through the normally closed part |02 of two-way cam switch 51, to the other side of the power line. The relay field coil is thus energized as soon as the operator closes the line switch, although the'motor circuit remains open. 'I he relay immediately closes, thus closing the two one-way switching units thereof, which are normally open. The closing of relay switching unit |03, which is connected across switch |0|, serves to maintain a closed circuit to the relay eld coil when |0| is open.

Now when the operator presses button 16 of operating switch 15, switch unit |0| thereof opens, but as mentioned, this does not break the relay eld coil circuit. At the same time, switch unit |03 thereof becomes closed and this permits current to flow through the now closed switching unit 05 of the relay to the motor, which immediately starts to rotate. Rotation of the motor turns the eccentric or cam 54 causing actuation of two-way cam switch 51 whereby partl |02 opens and part 06 closes. The opening of |02 breaks the circuit to the relay field coil, resulting in the opening of switching units |03 and |05 thereof, and these remain open unitl the eccentric or cam has nearly completed one revolution.` The closing of |06 immediately completes the circuit therethrough to the motor so that the latter continues to operate (even though |05 is now open) until |06 opens at the time when cam switch 51 is released near the yend of one revolution.

It will be evident that the control button 'I6 can be released as soon as the motor has started and the cam switch 51 actuated, since the motor circuit no longer depends upon |04 being closedf Also that even though the control button is held in, or is pressed a second time before the cycle is completed, the motor will stop as soon as the eccentric or cam has nearly completed one revolution, due to the opening of |06, since .the motor circuit through |04 is broken by the open relay switching unit |05, and the relay will not close until |0| is closed (which requires that the control button be in the out or released position).

This completes a step or cycle of operation.

When continuous operation is desired, switch 'I8 is closed, and as this is shunted across switch unit |0| of the control switch, it is nolonger necessary for the control switch to be released (so as to close |'0|) in order to complete the relay eld coil circuit. The relay eld coil will now be energized whenever |02 is in normally closed position, i. e., at the beginning and close of each cycle of operation. The closing of |04 by pressing the control button causes the motor t'o start and it will continue to run through as many cycles as desired by keeping the control button pressed, since the motor circuit will be kept closed either through |04 and |05 (when |06 isv open) or through |06 (when |05 is open) To stop the motor when desired, the control button is released, opening |04, although if |06 is closed at that moment 'the motor will run to the end of the cycle of operation (i. e., until |06 opens due to release of cam switch 5l).

It will be understood that the foregoing description of an embodiment of my invention has been given for purposes of illustration and not limitation, and those skilled in the art will appreciate that various modications can be made.

What I claim is as follows:

In an adhesive tape dispenser and applier of the character described, a driven rotatable tape dispensing reel having a series of equally spaced thin radial arms of equal length, the open sectors between the arms extending at least about halfway from the ends of the arms to the axis of the reel, a pronged blade at the end of each arm adapted to grip adhesive tape and draw it about the reel during rotation thereof and sever tape lying between adjacent blades when an article is pressed against said tape, a tape applying die located between each pair of arms and formed of a resilient and yieldable material of the nature of sponge rubber, comprised of a bridge portion extending between the arm ends so as to lie just below a piece of tape stretched between the pronged blades and integral spacedapart side members normally resting -against the reel arms and terminating at least about halfway from the pronged blades to the axis so as to provide a substantial opening bounded by the bridge and side members, said side members of the die being free to bend inwardly and away from the reel arms when an object is pressed against the bridge portion so as to facilitate the application of tape thereto, and driving means for rotating the reel.

CHALMERS H. RANDOLPH.

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