US3237595A

US3237595A - Adhesive tape dispensing apparatus

Info

Publication number: US3237595A
Application number: US65525A
Authority: US
Inventors: Charles O Kilham
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1960-10-27
Filing date: 1960-10-27
Publication date: 1966-03-01
Anticipated expiration: 1983-03-01

Description

March 1, 1966 c. o. KILHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27. 1960 5 Sheets-Sheet 1 March 1, 1966 c. o. KlLHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27. 1960 5 Sheets-Sheet 2 March 1, 1966 c. o. KILHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed 001;. 27. 1960 5 Sheets-Sheet 5 March 1, 1966 c. o. KlLHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27. 1960 5 Sheets-Sheet 4 Mam}! 1966 c. o. KILHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27, 1960 5 Sheets-Sheet 5 220? 4 T220 200% & a] 244 I J55 42/6 19% 2,76- 5 W5 Mfor 1 ZZZ JJU Z 2m 5 gay [/5 H 615 2w ia 65 54 well as for dispensing theadhesive coated tape.

, 3,237,595 ADHESIVE TAPE DISPENSING APPARATUS Charles 0."Kilham,'Beverly, Mass., assignor to United -Shoe Machinery Corporation, Boston, Mass., a corporation of'New Jersey Filed Oct. 27, 1960, Ser. No. 65,525 2 Claims. (Cl. 118-42) plied, so that a need arises for avoiding the possibility of an operators burning his fingers from contact with heated parts of themachine, or for avoiding other'difiiculties in handling the tape with its adhesive coating as he attempts to grasp a dispensed length.

Besides the possibility of becoming burned as a length of adhesive tape dispensed by the machine of the type referred to is grasped by the operator, a further difiiculty arises in'handling tape coated with pressure sensitive adhesive, particularly when the tape is cut into lengths as it is dispensed. In attempting to grasp a length of adhesive coated tape having a strong tack, the tape may adhere to'the operators' fingers before he has obtained a firm grasp on it or the position of the tape isdisturbed, so that the operator will be unable to utilize it and afiix it accurately in the manner intended without loss of time in restoring his grasp on it.

To assist the operator in grasping a dispensed length of tape withoutdanger of burning or other difiioulty, according to an object of the present invention, the tape is severed from the supply along its coated surface at a position where there are no exposed heated parts of the machine, so that in case of undesired adhesion of the coating on the tape to the operators fingers in grasping the tape, it is only necessary for the operator towithdraw his handfromthe machine, disengaging the tape from his fingers and thereafter making a new attempt, the adhesive grip of the tape being broken by its connection with the supply until severed by a positive act on the part of the operator. Thus, the' difiiculty of restoring the tape within the. grasp of his fingers is minimized. To these ends a feature ofthe invention resides in apparatus for dispensing a predetermined length of tape by advancing it across a delivery plate with its pressure sensitive coating facing away from the delivery plate and a tape severing knife acting directly against the adhesive coated surface of the tape, in'which apparatus a control member is provided for convenient access by the operator to actuate the knife and the advancing means in sequence, so that the severed length of tape may be freed readily without danger of adhesion from the delivery plate before a new length may be advanced along the delivery plate for a subsequent operation. Such an arrangement is distinguished from that in prior machines of this type, in which each length of tape is both advanced and severed before it is removed. In the use of a machine in which the adhesive coated tape is advanced across the delivery plate with its pressure sensitive coating facing away from the plate, the operator has no difficulty in grasping the tape forapplication' to an article and utilizing the adhesive coating on the tape to assist him in applying it to the article intended. Thus, the tape may be removed from United States Patent 0 Patented Mar. 1, 1966 the delivery plate, first, by pressing a finger lightly against the coating,'then, by actuating the control member to sever the tape on the delivery plate from the supply and, finally, by transferring the severed length to the article to be taped, a new length of tape then being advanced automatically after a predetermined time period without further attention by the operator.

In the preferred form of the machine in the presentinvention, the means for advancing the tape across the delivery'plate is actuated by power including driving mechanism, having .a clutch and means driven from the driving mechanism for holding the clutch in driving engagement while the new length of tape is being projected across the plate and a conveniently located control member causes the knife to be actuated and the clutch to "be engaged in proper time sequence, the knife being actuated by the operator uponmovement of the control member in one direction and the clutch being engaged upon movement of the control member in the opposite direction. In its preferred form, the control member consists of a yieldingly raised treadle connected for actuating the knife by depressing the treadle and for engaging the clutch during release of the treadle.

These and other features of the invention, as hereinafter described and claimed, will be readily apparent to those skilled in the art from a consideration of 'thefollowing detailed specification, taken in connection with the accompanying drawings in which:

FIG. 1 is a view in front elevation with front portions of an enclosing casing broken away and shown in section to illustrate the underlying mechanisms of a machine embodying the features of the present invention;

FIG. 2 is a detail view on a slightly enlarged scale illustrating the manner of handling an adhesively coated tape dispensed by the machine shown in FIG. 1;

FIG. 3 is a plan view of the machine of FIG. 1' with a cover removed from the casing;

FIG. 4 is a detail view in left side elevation of a portion of the casing carrying a set of switches and pilot lights;

FIG. 5 is a detail view on an enlarged scale of a base for an adhesive reservoir with a front plate removed, as employed in the machine;

FIG. 6 is a view in right side elevation of the machine shown in FIG. 1;

' spreading roll in the reservoir base of the machine;

FIG. 8 is a plan view on an enlarged scale of a portion of the tape after having adhesive spread thereon;

FIG. 9 is a fragmentary sectional view of a portion of the adhesive spreading roll;

FIG. 10 is a partially sectional side view looking from the left of the machine shown in FIG. 1 with certain parts broken away and removed for clarity;

FIG. 11 is a plan view, looking along the line XI--XI, of a dispensing roll and a delivery plate shown in FIG. 10;

FIG. 12 is an enlarged detail view in front elevation of the dispensing roll and delivery plate;

FIG. 13 is a further detail and partially-sectional view in end elevation and on enlarged scale of a timing switch employed in the machine; and

FIG. 14 is a wiring diagram of the machine, indicating the manner in which the different parts are connected electrically.

The apparatus illiustratedin the drawings is intended for use in dispensing a predetermined length of tape .coated throughout its length on only one side with a pressure sensitive adhesive and is provided with a delivery plate, across which the coated tape is advanced, with its pressure sensitive side facing away from the plate, so

that it does not adhere to the plate and it is unnecessary in removing the tape from the plate to free the adhesive coating therefrom, thus simplifying the operation of transferring the tape from the plate to an article to be taped. Accordingly, an operator may grasp the tape with a very light force insulficient to cause adhesion to his fingers or in some instances he may press one of his fingers lightly against the tape so that only a partial adhesion occurs. In this way the tape may be transferred along the broken line 1 of FIGS. 1 and 2 without adhesive resistance from the plate to the article to be taped with one finger, or the article itself may be pressed against the coated side and after severing the tape it may be withdrawn with the length of tape to a positon where complete and smooth adhesion to the article may be accomplished without interference or further difliculty. In case of improper initial adhesion of thetape with the operators fingers or with the article, the tape may readily be disengaged from the fingers or article, since the dispensed length is not severed from the supply until the operator so chooses. After the severed length of tape is withdrawn from the delivery plate, a new length is automatically advanced, so as to be ready for transfer and application to a new article.

Rather than utilize a reel of tape precoated with a continuous coating of adhesive, the machine of the present invention is provided with a heated adhesive supply reservoir from which the adhesive is coated directly on the tape as it is being unwound from the reel and advanced to the delivery plate. In this way a fresh coated supply of tape is always on hand and the tape is stripped more readily from the reel without the inconvenience of providing a separating layer between turns on the reel or of avoiding deterioration in the coating from lengthy storage.

Referring more particularly to FIG. 2 of the drawings, it is apparent that if a length of adhesive tape 2 is lightly attached by its continuous coating 3 to an operators index finger 4 it may be applied to an article 6 in the direction of the arrows merely by brushing it across the surface of 1 the article and squeezing it against the article by an operators thumb 8 or the article may be pressed directly against the tape. The tape may then be applied smoothly by wrapping it about the article with a rolling action between the thumb and index finger, the adhesion of the tape with the article having sufficient tenacity when first applied to enable the index finger or the article to be stripped from the tape during the complete application of the tape. Handling the tape by reason of light adhesion to the operators index finger is most conveniently accomplished after the tape is dispensed from the machine and before severance takes place. Whether the advancing and severing are initiated automatically upon removal of the length of tape or manually whenever a new length of tape is required, it is dispensed with its adhesive coating exposed and preferably while the tape is still connected to the supply, so that improper contact of the index finger or the article with the tape may be broken by reason of the connection of the length with the supply, thus assisting a new corrected contact with the tape.

The adhesive coated tape is advanced freely without adhesive restriction across a stationary delivery plate, indicated at 10, mounted in a horizontal position at one side of the machine and extending through an opening 12 (see FIG. 6) in a hinged setback door 14 at the right side of the machine. The door 14 is mounted for swinging movement about a vertical piano hinge 16 secured to a casing 18 at the same side of the machine. The casing 18 surrounds the entire machine and is provided with a top cover plate 20 and a base plate 22. Connected to the base plate 22 beneath the machine are four blocks 24 forming supporting legs for the machine, by means of which the machine may be mounted on a table top 26 while providing ventilation for the heated adhesive reservoir and other operating parts of the machine. To secure the delivery plate to the door 14, the door has 4v made fast to it, by means of screws 26 (FIGS. 6 and 12), an angle piece 28 having a horizontal arm to which the delivery plate is similarly attached by screws 30 (FIG. 3). Thus, the base 22 supports the delivery plate at an accessible position for an operator.

Although the tape 2 is advanced across the delivery plate with its adhesive coating 3 uppermost, it is possible with a metal delivery plate that particles of adhesive or the edges of the tape might adhere to the delivery plate in such manner as to interfere with the uiform advancement of the tape. For this reason the delivery plate 10 is composed of a sheet of adhesion resisting material, such as polytetrafluorethylene (TSF-Fluorocarbon) resins, particularly of the high melting point thermocuring type sold under the trade name of Teflon. It is easy then to grasp the adhesive coated tape by downward pressure against the coating 3 on the tape and to transfer the severed length of tape from the delivery plate to an article to which it is to be applied.

To sever the length of tape advanced across the delivery plate from the supply, according to the present invention the tape is acted upon by a knife 32 in the form of a blade sharpened along a lower straight edge and arranged to engage at right angles with a cutting b ock in the form of a rectangular bar 34 formed of relatively soft material such as aluminum or brass. The bar 34 is arranged transversely of the length of the tape and is set into a separating block 36 having its upper surface and that of the bar 34 mounted substantially at the level of the delivery plate 10 and the periphery of a dispensing roll 38 (see FIG. 12), the cutting block being disposed between the dispensing roll and the delivery plate. The dispensing roll acts to advance the coated tape across the delivery plate and the knife is reciprocated vertically to engage the adhesively coated surface of the tape and sever it with a single impact against the flat surface of the bar 34, as distinguished from a shearing action. In this way there is little opportunity for the adhesive to stick to the knife.

As a further means to prevent the tape severing knife from adhering to the adhesive coat on the tape, the knife is heated to a temperature above that which will liquefy the adhesive, the knife being in contact with the tape for such a brief time and a limited area that no difficulty from deterioration of the adhesive occurs. To heat the knife it is slidingly mounted in a heated guide 40 (FIG. 11) embracing the width of the knife.

The knife guide 40 is composed of heat conducting block formed with a rectangular cross section of a length appreciably greater than the width of the cutting edge on the knife, which is normally maintained in loose engage ment with the guide. Along the forward edge of the knife it is held against the guide by an angular clip 41 secured to the guide by means of a screw 42. Along the rear edge of the knife it is retained against the guide by a block 43 secured to the guide by a screw 44. The guide is mounted on a swinging frame 45 mounted at its lower end on a stud 46 passing through a projecting portion of the frame and through lugs on an upstanding portion of a base projecting horizontally from the adhesive reservoir indicated at 48, in FIGS. 3, 5 and 10 which has a horizontal adhesive storage portion.

To heat the tape severing knife guide 40 at its rearward end is bored to receive an electrical heating cartridge 50 (see FIG. 11) of sufficient capacity to maintain it above a temperature at which the adhesive may adhere thereto. To mount the knife guide its rearward end is made fast to the upper surface of the swinging frame 45 in 'alinement with the path of movement of the knife. The swinging frame 45 not only supports the heating guide for the knife, but it has mounted at its upper portion a shaft 52 to the forward end of which the delivery roll 38 is fixed.

To actuate the tape severing knife 32 with an impact against the tape its upper edge is pinned within a slot u formed in a downwardly projecting extension of an armature 54 (FIG. slidingly mounted within the core of an electromagnet 56. To clear the extension of armature 54 the guide 40 has a semicircular cut away area 57 (FIG. 11) alined with the armature. The electromagnet 56 is secured to *a plate 58 spaced from the upper surface of the swinging frame 45 by a pair of cylindrical metal blocks 60, best shown in FIG. 10. Passing through the plate 58 and the blocks 60 is a pair of screws 62 (FIG. 3) threaded at their lower ends into the upper surface of the swinging frame 45. Also passing through a threaded opening in the plate 58 and the upper portion of the swinging frame 45 is a threaded rod 64 (FIG. 10), the lower end of which engages a threaded opening in the lower portion of the frame 45. The upper portion of the rod 64 carries a nut 66 which assists in preventing rotation of the rod in the plate. By means of the mounting for the electromagnet 56 and the heating guide 40 for the knife 32 the parts are kept in alinement with each other and the knife 32 moves freely through the guide toward and from the cutting bar 34 to sever the adhesive coated tape.

' The swinging frame 45- is maintained in a fixed position relatively to the upwardly projecting portion of the base for the reservoir 48 by the engagement of the lower end of the rod 64 with the base. To retain the swinging frame at the position in which the rod 64 engages the .base of the reservoir, the swinging frame has protruding from its left side a horizontal screw 68 (FIGS. 1 and 10) engaged by the upper end of a tension spring 70, the lower end of which is engaged with a pin 72 secured in the reservoir base.

To enable the dispensing roll 38 to engage the uncoated side of the adhesive tape frictionally with suflicient pressure to cause the tape to be advanced across the delivery plate 10 with certainty, the coated side of the tape is acted upon by a nonadhesive member 74 (FIG. 12). The member 74 also is composed of Teflon (polytetrafluoroethylene) and is pressed yieldingly against the upper surface of the tape carried by the delivery roll. For this purpose the member 74 is formed as a wedge shaped block slotted to receive a laterally bent forward end of a lever 76 so that the member may be raised to the broken line position of FIG. 12 for convenience in rethreading the machine with tape. The lever 76 has a central lug through which passes loosely a fulcrum screw 78 (FIG. 10) having its right end engaged in a boss formed on the swinging frame 45. The rearward end. of the lever 76 has an opening to receive the lower end of a tension spring 80, the upper end of which enters a similar opening in the head of a screw 82 passing through a rearwardly projecting block 84 secured by a screw 86 to the upper surface of the plate 58. By rotating the screw 82 the force of the spring 80 may :be adjusted to press the Teflon member 74 into varying degrees of sliding engagement with the adhesive coated surface of the tape and with sufiicient pressure to cause the tape to engage the dispensing roll frictionally, thus to insure advance of the tape as the roll 38 is rotated.

To insure that the adhesive coated tape will separate from the dispensing roll 38, so that the tape may be advanced properly across the delivery plate, the dispensing roll is grooved about its periphery (FIG. 11) and the block 36 is formed with a plurality of fingers projecting to the left with their upper surfaces at the level of the delivery plate to enter the grooves in the dispensing roll. In this way the arc of engagement of the tape is confined to 90 about the dispensing roll.

The apparatus for applying adhesive to the tape is substantially the same as that disclosed in Patent No. 2,965,066 in which the reservoir 48 is heated to a critical temperature of 350 F. The adhesive employed is a combined polyvinyl ethyl ether mixed with a styrene polymer resin without the use of a solvent. On account of the high viscosity of this adhesive and the relatively high temperature to which it must be heated to use it most efficiently, special precautions are required for preventing the operator of the machine from burning his fingers while handling the dispensed tape. To reduce the likelihood of such difficulties the dispensing roll 38 is mounted in the swinging frame 45 at a substantial distance above the point where the adhesive is applied to the tape, thus enabling the adhesive coated tape to cool appreciably between the point of coating and the location of the delivery plate where the operators fingers may be subjected to the temperature of the tape. Accordingly, the swinging frame 45 has at its lower end a pair of spaced bearings through which passes a horizontal shaft 88 (FIGS. 1 and 10) having fixed to its forward end a tape pressing roll 90, acting to maintain the tape in contact with a spreading roll and at the rearward end of the shaft 88 is a sprocket wheel 92 surrounded by a chain 94 engaging a similar sprocket wheel 96, secured to the rearward end of the shaft 52. The arrangement is such that the dispensing roll 38 turns at the same rate of peripheral speed as the pressing roll and its associated adhesive spreading roll.

As in the apparatus of the prior patent referred to, adhesive is supplied to the tape by the adhesive spreading roll, indicated herein at 98,. which is disposed in an outlet opening (see FIG. 5) at the forward side of the reservoir .base, the tape passing across the outlet opening between the pressing and spreading

rolls

90 and 98 to apply the adhesive to the under side of the tape at the same rate or peripheral speed as that of the dispensing roll. The adhesive spreading roll 98 is secured to the forward end of a horizontal shaft 102 running through the reservoir base, and the shaft 102 has at its rearward end a sprocket wheel 104 surrounding which is a chain 106 for driving the shaft. To insure that the peripheral speeds of both the spreading roll 98 and the pressing roll 90 will be the same the two rolls are connected together by meshing

gears

108 and 110 having the proper number of teeth thereon to produce a ratio equal to the diameters of the respective rolls. As the swinging frame 45 moves about the stud 46 the meshing relation of the

gears

108 and 110 changes slightly without causing their teeth to be disengaged. Thus, a reliable grip is maintained on the tape by the rolls at all times under the influence ofthe spring 70. Preferably, the adjustment of the threaded rod 64 prevents actual engagement of the pressing roll with the adhesive spreading roll when no tape is present between them, so. that no contamination of the pressing roll with cement takes place.

To assist in adjustment of the threaded rod 64 and to provide a convenient handle in moving the swinging frame about its mounting stud 46 while replacing the tape in the machine, the upper end of the threaded rod has secured to it a knob 112. Also, the block member 74 may be lifted separately from engagement with the dispensing roll 38 by rearward movement of the upper end of a pin 114 projecting from the lever 76. By lifting the block member 74 from the roll 38 a new supply of tape may readily be applied to that roll while threading the machine with tape.

The surface of the adhesive spreading roll 98 is knurled with a crosshatch pattern, as best shown in FIGS. 7 and 9, formed by two series of intersecting parallel grooves 116. The grooves 116 are of sufiicient depth to receive appreciable amounts of adhesive from the outlet opening 100 in the base of the adhesive reservoir 48. When the adhesive filled grooves move toward the tape a similar over-all pattern of adhesive will be applied to the tape as in FIG. 8. To regulate the amount of adhesive on the tape, the roll has embracing one side thereof a doctor plate 118 (FIG. 7) slidingly mounted in grooves running transversely of the outlet, the doctor plate 118 being arranged for adjustment toward and from the knurled periphery of the roll. To prevent escape of the adhesive 7 the front end of the reservoir has secured to it a cover plate 119.

To provide a supply of uncoated tape the stud 46 has rotatably mounted at its forward end a flanged spool 120 (FIG. 11) over which the tape passes from a supply reel 122, shown in FIGS. 1 and 3. Since the supply of tape, indicated at 124, supported by the reel 122 is uncoated successive turns on the reel do not adhere one to another and the tape may be withdrawn readily from the reel without requiring any additional nonadhesive strip between successive turns to separate them as is required in the winding when the tape is adhesive coated.

The supply reel 122 is rotatably mounted on a spindle 126 (FIG. 3) having one end secured in an upstanding arm on a bracket 128 and the other end formed with a threaded opening to receive a retaining nut 130. The bracket 128 is fixed to the base 22 of the machine in a position where the reel will be aligned with the guide spool 120.

To enable a predetermined length of adhesive coated tape to be advanced across the delivery plate with uniform results the chain 106 (FIG. for the applying roll 98, is actuated by driving mechanisms including an electric motor, an electro-magnetic clutch, a switch for controlling the clutch, a cam for actuating the switch, a friction wheel for driving the cam and a conical drum driven from the roll driving mechanism and engaged along its conical surface by the friction wheel. The chain 106 passes over a sprocket wheel 132 (FIG. 3) secured to a shaft 134 passing through a bearing in a bracket 136 and having its rearward end keyed to a driven member 138 of the electro-magnetic clutch. The driving member of the clutch is indicated at 140 and is keyed to a collar 142 loosely surrounding the shaft 134. The collar 142 is secured to a driving shaft 144 alined with the shaft 134 and mounted in bearings formed Within a reduction gear 146 mounted on the frame of the electric driving motor, shown at 148. For energizing the electrical clutch an electro-maguetic core 150 having a coil 152 surrounds the shaft 134 and is disposed in magnetic relation to the driving and driven members of the clutch.

To enable the length of tape advanced across the delivery plate 10 to be adjusted according to the requirements of the article being taped, the forward end of the shaft 134 has secured to it the conical drum shown at 154, and is connected to the chain 106 of the roll driving mechanism. The drum 154 is engaged along its conical surface by the friction wheel at 156, secured to the cam, indicated at 158 (FIG. 13), both wheel and cam being rotatable loosely on a pin 160. The pin 160 is secured to a vertical plate 162 carried by a horizontal slide 164 fitting within a guideway 166 made fast to the base 22 by screws 168. The slide 164 is secured in adjusted position along the guideway 166 by a clamp screw 170 passing through a slot in the slide 164 and into threaded engagement with the guideway. The guideway is arranged in parallel relation to the left side surface of the conical drum so that during adjustment the friction wheel is maintained in engagement with the conical surface of the drum. Thus, when the slide 164 is shifted rearwardly the wheel 156 engages surface portions of the drum increasing in diameter and when moved in a forward direction the wheel engages the surface portions of the drum decreasing in diameter.

To actuate the clutch controlling switch the cam 158 is formed with a flat side and is engaged by a follower roll 172 rotatable on a pin 174 passing through angularly bent tabs of an arm 176. The arm 176 is engaged by a tension spring 178 (FIG. 13) stretched between the arm and a screw 180 on the plate 162. The lower end of the arm 176 is rotatable on a screw 182 also secured in the plate 162. When the clutch is energized the cam 158 forces the follower roll 172 outwardly and presses the arm 176 against a plunger of the clutch controlling switch, indicated at 184, mounted on the plate 162. When the The arrangement of the cam 158 and the follower roll 172 is such that when the slide 164 is adjusted along the drum the cam completes its rotation in a shorter or longer time as compared to the rotation of the drum. Consequently, more or less tape will be advanced across the delivery plate according to adjustment of the slide.

As in the machine of the Paulsen patent above referred to, the adhesive reservoir is heated by a pair of resistance cartridges illustrated in FIGS. 1, 5, and 10 at 186 and 188. The

resistance cartridges

186 and 188 are disposed at either side of an adhesive conducting passageway 190 running horizontally between the reservoir 48 and the outlet 100. To heat the reservoir and its base to a working temperature it is desirable to employ resistance cartridges of greater capacity than required to raise the parts to the desired temperature and to utilize thermostats to prevent difliculty from both overheating and underheating. For these purposes the upwardly projecting portion of the reservoir base has passing through it a pair of thermostat cartridges 192 and 194 (FIG. 10). The cartridge 192 isarranged to disconnect the motor 148 from its source of power when the temperature of the reservoir falls below a predetermined minimum and the cartridge 194 is arranged to disconnect the

resistance cartridges

186 and 188 when the temperature of the reservoir rises above a predetermined maximum, as in the apparatus of the Paulsen patent.

To enable proper manual control of the apparatus of the invention there are mounted on the left wall of the casing a motor control switch 196 (see FIGS. 3 and 4), a heat control switch 198, and a double pole line switch 200. On the rear wall of the casing is a knife guide heat and control switch 202. Also, on the left wall of the casing are a reservoir heat pilot light 204 and a minimum temperature pilot light 206.

The knife guide heat and control switch 202 is intended for opening andclosing the circuit to the knife guide heater. The control switch 202 includes in its construction a thermostat 207 (FIG. 14) and a separate adjustable thermostat heating resistance 208 connected to the knife guide heating cartridge 50. The switch 202 is provided with a manual operator having a block acting to open the thermostatic switch regardless of the heat produced by the resistance 208. Connected through a flexible electrical cable 209 to the circuits in the casing is also an independently movable unit in the form of a foot switch 210 arranged for actuation by a treadle member 212 (see FIGS. 1 and 3) hinged within a protecting housing 214 biased yieldingly in a raised position by a tension spring 215 (FIG. 14).

Surrounding the vertical portion of the adhesive reservoir 48 is an insulating box 216 to protect the other apparatus within the casing from exposure to excessive temperatures in the reservoir. Also mounted at the rear of the casing is a separate outlet box 218 having a line connection 220 and a clutch disconnecting switch 222, the operating handle of which projects from the upper surface of the outlet box. The outlet box is mounted on spacers 224 secured to the rearward wall of the casing to protect the outlet box from heat developed in the casing.

The circuit connections for controlling the apparatus are illustrated more particularly in FIG. 14, in which the line connection 220 consists of a source of AC. power and is connected to the circuit through the line switch 200, a left hand conductor 226, the heat control switch 198, the

resistance cartridges

186 and 188, the maximum heat thermostat cartridge 194 and a right hand conductor 228 to the line 220. The pilot light 204 is arranged to be lighted whenever the switch 198 is closed.

To start the motor the switch 196 is closed, the circuit being completed from the conductor 226, through the switch 196, the minimum heat thermostat 192, a relay coil 230 and the right hand conductor 228. If the temperature of the adhesive reservoir has reached the minimum required the thermostat 192 completes the circuit to the relay coil 230 to close

relay contacts

230A and 230B energizing the motor 148. When the temperature of the reservoir reaches a maximum the thermostat cartridge 194 opens the circuit to the resistance cartridges and prevents overheating. If the temperature in the reservoir for any other reason drops below the minimum permissible value the thermostat cartridge 192 opens the circuit to the relay coil 230 and causes the motor to be disconnected.

After threading the machine with the leading end of a tape from the supply reel 122 the treadle 212 is depressed closing the circuit through the switch 210 to energize a relay coil 232. As soon as the coil 232 is energized contacts 232A and 232B are closed. The contacts 232A establish a branch circuit from the switch 210 through a coil 234 of a time delay release relay having normally open contacts NO234A and normally closed contacts NC234B. The arrangement is such that when the coil 234 is energized the contacts NO234A are immediately closed and the contacts NC234B are immediately opened. Upon closing the contacts NO234A a circuit is completed from the left hand conductor 226 to the clutch controlling switch 184, contacts NO234A, the coil of the electromagnet 56 and the right hand conductor 228. When the coil of the electromagnet 56 is energized the knife 32 is projected against the cutting block 34 to sever the measured length of tape from the supply.

The contacts 2328 are closed simultaneously with the contacts 232A and in circuit with the contacts 232B is a third relay coil 236 energized from the left hand conductor 226, through the cam operated contacts 184, contacts NO234A and contacts 232B, to the coil 236 and the conductor 228. Energizing the coil 236 causes contacts 236A to be closed to prepare a circuit through the coil 152 of the magnetic clutch. The circuit for this clutch coil, however, is held open by the contacts NC234B which are opened as a result of energizing the time delay relay coil 234.

The clutch coil 152 is energized by direct current from a filter network and a rectifier 238. The filter network includes

resistors

240, 242, and 246 connected in series between the left and

right conductors

226 and 228. Also connected between the resistors are a pair of filter condensers 248, the common connection for which is to the left hand conductor 226. Because the contacts NC234B are opened at the time that contacts 236A are closed the clutch coil 152 is not energized until after the time delay relay contacts NC234B are closed. This closure of the contacts NC234B takes place at an appreciable time after the tape is severed by the knife 32 in order to permit the operator to remove the tape out of the range of movement of a new length of tape about to be projected across the dispensing plate 10.

To insure that the coil 236 remains energized until the time delay contacts NC234B are restored to their closed position the relay of coil 236 has a second set of contacts 236B connecting the cam operated contacts 184 directly with the coil 236. After the contacts 236B are closed the only way to open the circuit to coil 236 is by disengaging the cam operated contacts 184. This occurs as soon as the clutch coil 152 is energized and the driving connections to the dispensing rolls are started in operation. As soon as this occurs the cam operated switch 184 moves away from its uppermost contact, which connects the coil 236, and into engagement with a lowermost contact, bridging the contacts 236A, thus continuing the energization of the clutch coil 152. The cam switch 184 maintains the bridging lower contact closed until the necessary length of tape has been dispensed. After the tape has been dispensed the switch 184 is returned to its uppermost contact, as in FIG. 14, in preparation for a new operation and the circuit to the clutch coil 152 is broken so that the driving rolls are brought to rest.

The nature and scope of the invention having been indicated and a particular embodiment described, what is claimed is:

1. Apparatus for dispensing a predetermined length of tape coated on only one side with a pressure-sensitive adhesive, said apparatus being provided with a stationary delivery plate across which the tape moves and on which the tape is supported after being dispensed, means for advancing the tape across the delivery plate with its coated side facing away from the plate, a nonadhesive member for engaging the coated side of the tape to press the uncoated side against the advancing means, driving mechanism for the tape advancing means, including a clutch and means driven from the driving mechanism for holding the clutch engaged while the length of tape is being projected across said delivery plate, and a cutting block mounted between the delivery plate and the advancing means at a position substantially level with the delivery plate to engage the uncoated side of the tape, in combination with a straight edged tape severing knife acting with a single impact against a flat surface of the cutting block by first engaging the adhesive coated side of the tape, electromagnetic means for actuating the knife and a control member arranged for convenient access by the operator to cause the electromagnetic knife actuating means to be energized and thereafter to engage the clutch in sequence to project a new length of tape across the delivery plate, the knife being actuated upon movement of the control member by the operator in one direction and the clutch being engaged upon movement of the control member in the opposite direction.

2. Apparatus for dispensing a predetermined length of tape coated on only one side with a continuous coating of pressure-sensitive adhesive, said apparatus being provided with a flat stationary delivery plate across which the tape moves and on which the tape is supported after being dispensed, means comprising a dispensing roll engaging the tape at the uncoated side opposite the adhesive for advancing the tape across the delivery plate with its continuously coated side facing away from the plate, a nonadhesive member comprising a block of Teflon engaging the coated side of the tape to press the uncoated side against the advancing means, a resiliently actuated lever on which the block of Teflon is secured for sliding engagement with the coated side of the tape, a cutting block mounted between the delivery plate and the advancing means at a position substantially level with the delivery plate to engage the uncoated side of the tape, a vertical adhesive supply reservoir formed with a heated base extending laterally beyond the vertical portion of the reservoir, and an adhesive conducting passageway running from the reservoir horizontally through the extension of the base and having an outlet opening at one side of the vertical portion of the reservoir, across which opening in the extension of the base the tape is drawn by the dispensing means to coat the adhesive on the tape, the tape being advanced across the delivery plate with the adhesive side up for enabling the adhesive to cool between the coating outlet and the location of the delivery plate, in combination with a straight-edged tape severing knife acting with a single impact against a flat surface of the cutting block by first engaging the adhesive coated side of the tape.

References Cited by the Examiner UNITED STATES PATENTS 1,384,081 7/1921 Mortimer 118-41 1,810,987 6/1931 Schmitt 83--171 1,987,197 1/1935 Krueger et a1 11841 (Other references on following page) 8 1 1 UNITED STATES PATENTS Heckrnan 11841 Anderson 83203 McCain 83922 Krueger 226-96 Von Stoeser 83203 Faulkner et a1 118-44 Hernpel 83203 Cefaly 83658 Labine et a1 11841 Eger et a1 11842 X Paulsen 118407 Possis et a1 83-922 1 2 FOREIGN PATENTS 292,685

1/1916 Germany.

5 OTHER REFERENCES Rudner: Fluorocarbons, 1958, page 13 relied on. Copy in Scientific Library. Reinhold Publishing Corp., New York.

10 MORRIS KAPLAN, Primary Examiner.

CARL W. TOMLIN, J. B. SPENCER, RICHARD'D.

, NEVIUS, CHARLES A. WILLMUTH, Examiners.

Claims

1. APPARATUS FOR DISPENSING A PREDETERMINED LENGTH OF TAPE COATED ON ONLY ONE SIDE WITH A PRESSURE-SENSITIVE ADHESIVE, SAID APPARATUS BEING PROVIDED WITH A STATIONARY DELIVERY PLATE ACROSS WHICH THE TAPE MOVES AND ON WHICH THE TAPE IS SUPPORTED AFTER BEING DISPENSED, MEANS FOR ADVANCING THE TAPE ACROSS THE DELIVERY PLATE WITH ITS COATED SIDE FACING AWAY FROM THE PLATE, A NONADHESIVE MEMBER FOR ENGAGING THE COATED SIDE OF THE TAPE TO PRESS THE UNCOATED SIDE AGAINST THE ADVANCING MEANS, DRIVING MECHANISM FOR THE TAPE ADVANCING MEANS, INCLUDING A CLUTCH AND MEANS DRIVEN FROM THE DRIVING MECHANISM FOR HOLDING THE CLUTCH ENGAGED WHILE THE LENGTH OF TAPE IS BEING PROJECTED ACROSS SAID DELIVERY PLATE, AND A CUTTING BLOCK MOUNTED BETWEEN THE DELIVERY PLATE AND THE ADVANCING MEANS AT A POSITION SUBSTANTIALLY LEVEL WITH THE DELIVERY PLATE TO ENGAGE THE UNCOATED SIDE OF THE TAPE, IN COMBINATION WITH A STRAIGHT EDGED TAPE SEVERING KNIFE ACTING WITH A SINGLE IMPACT AGAINST A FLAT SURFACE OF THE CUTTING