TAPE APPLICATOR PRESSURE CONTROL

Abstract

A tape head or tape applicator applies low impact to the leading face of the incoming carton and low pressure to the top of the carton and a higher pressure to wipe down the tape onto the rear or trailing face of the case by increasing the tension in the spring driving the wipe down and a high cutting force to the cut-off mechanism for fast response of the cut-off mechanism by increasing the tension in the spring driving the cut-off mechanism.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO MICROFICHE APPENDIX

Not Applicable.

FIELD OF INVENTION

The present invention relates a tape applicator or tape head more particularly to a tape applicator for applying tape to seal a soft case or carton or the like controlled to adjust the pressure applied to the case or carton being sealed as required and at the appropriate times.

BACKGROUND OF THE PRESENT INVENTION

Conventional tape heads as currently used to tape or seal cases or cartons are designed to apply a reasonably strong force on the tape to better ensure a strong bond between the tape and the case or carton. Conventionally most of these cartons are made from corrugated paperboard that is generally a laminate of two opposed surface layers or liners with a corrugated layer sandwiched therebetween and adhered to each liner which generally provides a material of sufficient strength for the intended use. Even when the case or carton is made of such material and is not properly or fully filled care must be exercised to ensure the pressure applied during sealing does not unduly deform the closure flaps being sealed with the by the applied tape. This problem of deforming the case or flaps is exacerbated when the case is made of flimsier material and/or particularly when such a case or carton is not properly filled to provide what is referred to as a soft case or carton of the like.

Distortion of the carton closure flaps a problem which on-line shopping and resulting shipping has magnified significantly generally requires reduction of the pressure applied to the closure flaps of the case or carton during the taping operation. With week cases or cartons the amount of force applied to the leading and/or trailing face (in the direction of movement of the case being sealed) of the carton may also be important to better ensure these faces are not damaged during the taping operation

Signode U.S. Pat. Nos. 9,517,914 and 9,630,796 provide examples of a device specifically designed to try to overcome the problem of damaging the case or carton being sealed and uses a pair of pneumatic actuators one to reduce pressure applied against the top (as opposed to the ends) of the carton or case to which a sealing tape is being applied by the tape application rollers and a second to reduce pressure applied by the cut-off mechanism of a convention tape applicator or tape head. The earlier of these 2 patent relates specifically to reducing the pressure applied to by the wipe down roller and the later to reducing the pressure applied by the cut-off mechanism. As indicated each uses a dedicated actuator to reduce pressure being applied.

US application 2013/174962 uses a sensor to sense the position of a carton to which a sealing tape is being applied and activate an actuator to raise and lower the tape applying and pressing rolls to apply different pressures to the tape and thereby the to the carton.

U.S. Pat. No. 9,061,857 increases the spring tension in stages to reduce the forces applied to the leading face of the case being taped with the increased tension being generated using a bar that presses against the case.

Chinese patent CN102092497 uses an actuator to position the application and pressure roller of the tape applicator. Japanese patent JP4265745 connects a actuator to the trailing or wipe down arm and another actuator connects to the cut-off mechanism each via a lost motion connection

U.S. Pat. No. 5,338,384 uses an actuator to change the pressure applied to the rollers more particularly to increase the pressure to the wipe down roll when wiping the tape onto the trailing face of the carton.

US patent application 2018/022492 also uses an actuator to adjust the pressure applied to the case being sealed to apply less pressure to the top of the case.

It is also known that devices used to apply what are know as L-clips to seal the flaps by applying short lengths of tape to the flaps adjacent the opposed ends of the flaps so there is no tape application over a significant central portion of the flaps using a actuator to direct the tape towards the knife to be cut, see, for example, U.S. Pat. No. 8,176,959 issued May 15, 2012 to Lam or German patent DE3820060 both of which manipulate the push bar connecting the front and back application rollers to move them way from the box or case between the applications of the L-clips. These devices are not designed to reduce pressure on the case or carton rather the applicator roll is moved up to bring the tape towards the knife for cutting.

None of the reference found to-date teach a simplified system of the present invention wherein low impact is applied to the front or leading face of the incoming carton and low pressure against the top of the carton or case and applies high pressure as required for tape cutting and for wiping the tape onto the rear or trailing face of the carton.

BRIEF DESCRIPTION OF THE PRESENT INVENTION

It is an object of the present invention to provide a tape applicator or tape head to softly apply a tape to a soft carton; a carton with under-filled contents or a “Re-shipper” carton (i.e.: a reusable carton with no flap memory) over a significant portion of the length of the case or carton so that the tape application does not significantly distort the closure flaps of the case or carton being sealed by the tape.

The tape head or tape applicator of the present invention is able to apply low impact to the leading face or front of the incoming carton and low pressure to the top of the carton and apply a higher pressure to wipe down the tape onto the rear or trailing face of the case or carton by increasing the tension in the spring driving the wipe down and a high cutting force to the cut-off mechanism for fast response of the cut-off mechanism by increasing the tension in the spring driving the cut-off mechanism. These characteristics of the invention facilitate sealing of underfilled or cartons made of lighter material (less strong than conventional corrugated boxes) and to enable improved operation on such cases or cartons at high speeds.

In effect the present invention applies low impact to the front or leading face of the incoming carton and low pressure against the top of the carton or case and the required pressure to the wipe down and ensure faster action of the cut-off mechanism by adjusting the tension in the applicator and cut-off mechanism springs to apply appropriate forces against the case or carton being sealed at appropriate times.

Broadly the present invention relates to a tape applicator, comprising a frame, a source of tape mounted on said frame, an front applicator assembly including a front applicator to apply a leading end of a tape from said source to a leading face of a carton moving relative to said tape applicator pivotably mounted on said frame on a first pivotal axis, a rear wipe down assembly including a rear wipe down roll to wipe a tape applied to said carton along a trailing face of said carton remote from said leading face pivotably mounted on said frame on a second pivotal axis parallel to said first pivotal axis, a push bar link interconnecting said application roll assembly and said wipe down assembly for movement together to form a tape applicator assembly, a cut-off mechanism mounted on said frame on a third pivotal axis parallel to said first and second pivotal axes and positioned between said first and second axes, a nonlinear helical coil applicator spring connected at one end to said applicator mechanism and a nonlinear helical coil cut-off spring connected at a first end to said cut-off mechanism, a spring pressure adjuster mechanism connected to an opposite end of said applicator spring remote from said one end and to a second end of said cut-off mechanism spring remote from said first end to adjust the extension of said applicator and cut-off mechanism springs, said spring pressure adjuster mechanism including an actuator and a controller controlling the delivery of power to said actuator to have low tension in said applicator spring and said cut-off spring and to increase tensions in the applicator and said cut off springs before said wipe down and cut-off mechanism are activated.

Preferably, said controller comprises sensor means to sense location of said carton to control power to said actuator.

Preferably, said sensor means is a sensor sensing said carton

Preferably, said sensor means includes two sensors in series.

Preferably, spring pressure adjuster mechanism comprises a pressure lever pivotably mounted on said frame on a lever axis and said actuator is connected to said opposite and said second end of said applicator and cut-off mechanism.

Preferably, said opposite and said second end are connected to said pressure lever on the same side of said lever axis.

Preferably, said opposite and said second end are connected to said pressure lever on opposite sides of said lever axis.

Preferably, said spring pressure adjuster mechanism comprises a pressure bar connected to said opposite and said second end and to said actuator.

Preferably, said spring pressure adjuster mechanism comprises two actuators connected one between said frame and said opposite and another between said frame and said second end.

Preferably, said sensor means includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Further features, objects and advantages will be evident from the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings in which;

FIG. 1A is a side elevation with parts omitted to shown the main moving elements of the present invention in their initial position awaiting the arrival of a case or carton to be sealed with actuator in de-actuated position with reduced spring tension to the applicator and the cut-off mechanism.

FIG. 1B is a plan view of the embodiment of the present invention shown in FIG. 1A showing the relative positions various element of the invention.

FIG. 1C is a view similar to FIG. 1A but using a single control valve that controls air flow to and from the actuator in their initial position awaiting the arrival of a case or carton to be sealed with actuator in actuated position with increased tension to the applicator and the cut-off mechanism springs.

FIG. 1D is a view similar to FIG. 1C in advanced position of the case being sealed wherein the control valve stops air flow to de-actuate the actuator and permit air to exhaust from the actuator to reduce tension to the applicator and the cut-off springs.

FIG. 1E illustrates the use of detectors to detect the leading and trailing ends of a case or carton being taped to control spring tension and schematically illustrates the flow through control valves connected in series to the actuator as illustrated in FIG. 1.

FIG. 1F is a schematic illustration of a pair of sensors to signal a control that controls a control valve as illustrated in FIGS. 1C and 1D.

FIG. 2 is a view similar to FIG. 1A with the case or carton to be sealed having the tape applied to the leading end or face thereof with the actuator remaining in the de-actuated position to maintain reduced tension in the applicator and the cut-off mechanism springs.

FIG. 3 is a view similar to FIG. 1A with the case or carton to be sealed having with the tape applied along o the top i.e. to what is normally designated as the major closure flap to seal the top of the case or carton with the actuator remaining in the de-actuated position to maintain reduced tension to the applicator and the cut-off mechanism springs.

FIG. 4 is a view similar to FIG. 1A with the case or carton with the tape applied to the leading end and top thereof and pressure control cam positioned to actuate the actuator and increase pressure to increase the tension in the applicator and cut-off springs.

FIG. 5 is similar to FIG. 4 but showing the tape having been cut and the wipe down completing the application of tape to the trailing face of the case or carton by applying increased tension in the cut-off and applicator springs to complete the cutting and wipe down of the tape.

FIG. 6 shows the wipe-down roll having completed the application or wipe down of tape to the trailing face of the case and the air supply to the control valve turned off.

FIG. 7A is similar to FIG. 1A showing with parts omitted an alternative spring pressure applicator.

FIG. 7B is a plan view of the embodiment of the present invention shown in FIG. 7A showing the relative positions various element of the invention.

FIG. 8A is similar to FIG. 1A showing with parts omitted another alternative spring pressure applicator.

FIG. 8B is a plan view of the embodiment of the present invention shown in FIG. 8A showing the relative positions various element of the invention.

FIG. 8C is a partial view similar to FIG. 8A but showing a solenoid in place of the air cylinder of FIG. 8A.

FIG. 9A is similar to FIG. 1A showing with parts omitted yet another alternative spring pressure applicator.

FIG. 9B is a plan view of the embodiment of the present invention shown in FIG. 9A showing the relative positions various element of the invention.

FIG. 9C wherein pneumatic actuators used in FIG. 9A have been replaced by electrical actuators (normally solenoids).

FIG. 10A shows with parts omitted a tape head employing a lever similar to that illustrated for example in FIGS. 1A and 1C but using a rotary actuator.

FIG. 10B is a plan view of FIG. 10A.

DETAILED DESCRIPTION OF THE INVENTION

The drawings and description show the tape applicator applying tape to the top of a case it could equally well apply tape to the bottom of a case and in that case the tape head 10 would simply be turned upside down. In all the drawing generally only those parts deemed necessary to explain the invention have been included and some of the Figures have been strategically placed relative to a figure directly there above to more clearly illustrate the relative positions of sensors or the like to other parts of the tape applicator embodiment.

The term applicator as used herein is intended to included various devices including solenoids and air cylinders or motors (rotary actuators) or the like. The term controller as used in the claims is intended to include the various control systems described below whether electrical or mechanical to control the delivery of power to the actuator at the appropriate time to accomplish the intent of this invention.

The tape applicator or tape head 10 of the present invention has a frame 12 composed of a pair of opposed sides frame members 12A and 12B (see FIG. 1B) coupled together in fixed parallel relationship by transverse shafts or the like 14 and 16 as well as the transverse shaft 102 mounting the actuator 100 in the FIGS. 1A to 8A embodiments as will be described below. The shaft 14 pivotably mounts as indicated at 19 in FIG. 1B a front application arm 18 to which an adhesive tape 20 having and adhesive side 22 is fed as shown in FIG. 1, for example, from the tape roll 24 rotatably mounted on support arm 26 in the conventional manner. The tape 20 follows a tape path 28 over guide roll 30 and then one-way clutch roll 32 to guide roll 34 and 36 mounted on the arm 18 and onto the application roll 38 mounted on the arm 18 adjacent to a free end 40 thereof i.e. into a position to engage the adhesive side 22 thereof with a carton of case 500 to which the tape 20 is to be applied as it is moved passed the tape head 10.

A push bar connector link 42 extends between the application arm 18 and the wipe down arm or assembly 44 and is pivotably connected to the arm 18 as indicated at 46 and to the wipe down arm 44 as indicated at 48.

The wipe down assembly or arm 44 is pivotably mounted as indicated at 49 in FIG. 1B on shaft 16 and has a biasing branch 50 extending in a first direction from one side of the shaft 16 or mounting 49 and the wipe down roll mounting branch 54 extending in a second direction form a second side of the shaft 16 or mounting 49. The pivotal connection 48 to the push bar link 42 is positioned adjacent to a free end 52 of the biasing branch 50 and a wipe down roll 56 adjacent to a free end 58 of the branch 54. An applicator spring 60 is connected at one end 62 to the biasing arm 50 adjacent to the free end 52 thereof and at its opposite end 64 remote from the one end 62 to a spring pressure adjuster mechanism indicated 66.

The application arm 18 and its application roll 38 coupled to the wipe down arm 44 and its wipe down roll 56 via the pus bar link 42 combine to form the application mechanism or assembly.

Also, pivotably mounted as indicated at 68 on the frame 12 between the wipe down mechanism or arm 44 and the application arm 18 is a cut-off mechanism 70 which has a first arm 72 connected as indicated at 76 adjacent to its free end to a first end of a cut-off spring 74. The second end of the spring 74 remote from the first end is connected to the spring pressure adjuster mechanism 66 as indicated at 78. The spring 74 biases the first arm 72 against a stop 80. A second arm 82 of the cut-off mechanism 70 extends in a second direction from the mounting 68 and terminates in a cut-off control cam element 84 and mounts a cut-off knife 86 adjacent to the cut-off knife cam element 84.

The device as described above with the exception of the spring pressure adjuster mechanism 66 (spring ends connect directly to the frame 12 in the conventional tape heads) is a conventional tape head currently in use in the industry.

In the FIG. 1A embodiment the spring pressure adjustment mechanism 66 is composed of a pressure lever 90 pivotably mounted on the frame 12 as indicated at 92 and which is held against stop 94 by tension in the springs 60 and 74 which will each normally be a nonlinear helical coil spring. These springs 60 and 74 have their opposite end 64 and second end 78 connected as shown at 64 and 78 respectively to the lever 90. The effective radius of the ends 64 and 78 from the pivotal mount 92 determines the relative amount of stretch applied to the springs as the lever 90 is pivoted on mount 92.

Connected to pressure lever 90 as indicated at 96 is the free end of the shaft or piston rod 98 of pneumatic cylinder type actuator 100 which is pivotably mounted to the frame 12 on rod 102 which extends between the frame members 12A and 12B. The shaft or piston rod 98 is connected to the piston 104 of the actuator 100 and moves with the piston 104.

In the FIG. 1A embodiment the air pressure applied to the actuator 100 is delivered from a source 120 to first control valve 122 which is an on-off control valve 122 the operation of which is controlled by the interaction of the cam roller 124 and with the on-off cam 126 mounted on the wipe down 44 in the illustrated arrangement on arm 54 of the wipe down mechanism 44. These cams 124 and 126 cooperate to provide a sensor sensing the position of wipe down 44 which is determined by the position of the case 500 being sealed and operate to open the valve 122 when the wipe down 44 is in elevated position as shown in FIG. 2 and close the valve 122 as shown in FIGS. 1A and 6 i.e. at the appropriate times. In effect the valve 122 is in the off position stopping flow to the control valve 130 until the application roll 38 has moved up (in the illustrated arrangement) the leading face 504 of the case 500 and approaches the top 506 of the case 500 i.e. the rolls 38 and 56 are in elevated position as will be described below. Pressurized air is conducted via line 128 to the control valve 130. The control valve 130 is a normally open (NO) valve that directs air flow to or from the actuator 100 as required as is controlled (as illustrated for example in FIGS. 2 to 6 for this embodiment) a control valve control cam 132 which is pivotably mounted to the frame 12 as indicated at 134 and the movement of the cam 132 on mounting 134 is limited by the pin 136 fixed to the frame 12 and the size of the slot 138 in the cam 132 in which the pin 136 is received. The cam 132 operates as a sensor sensing the when the leading face 504 of the carton 500 being sealed is in a certain relative position to the device 10 in that it engages with the case or carton 500 which, based on the position of the leading face 504 of the carton 500, moves the cam 132 around pivot 134 i.e. based on the sensed position of the leading face 508. This movement of the cam 132 moves cam surface 140 which is part of the cam 130 which engages with the cam roller 142 of control valve 130 to control the operation of the valve 130 i.e. air flow to and from the actuator 100 through line 144 as will be described below.

The springs 60 and 74 are designed to apply only the amount of pressure desired to the leading face 504 and top 506 of the case or carton 500 being taped or sealed.

The operation of the device a using embodiment of FIG. 1A as the example will now be described with reference to FIGS. 1A to 5 inclusive. In FIG. 2 the case or carton 500 moving the direction indicated by the arrow 502 has its leading face 504 with the tape 20 applied thereto and the application roll 38 about to reach the top 506 (obviously if the bottom of the case was being sealed the bottom) of the case. In this position the wipe down 44 has been raised as shown which adds addition tension to the spring 60 thereby increasing the force applied to the leading face 504 as the roll 38 moves up the face 504 until it is adjacent to the corner 510 at the top leading end of the case 500 and the cam action 124 and 126 opens the valve 122 for pressurized air flow to the control valve 130. The control valve 130 under control of the cam 132 i.e. the cam roll 142 is in position on the cam surface 140 where the control valve 130 prevent flow from line 128 to line 144 and the actuator 100 so the shaft 98 thereof remains fully extended so as to not apply additional tension to the springs 60 and 74.

The case 500 continues to progress in the direction of arrow 502 and with the cut-off cam 84, the application roll 38 and the cam 132 on the top 506 of the case 500 (see FIG. 3) both the and the valves 122 and 130 remain in the positions shown in FIG. 2 i.e. valve 122 permitting flow and 130 stopping air flow to the actuator 100 so here is no air flow or power to the actuator 100.

In FIG. 4 the case 500 has progressed to where the cam 132 has cleared the case 500 and the cut-off cam 84 is about to do so. In this position the valve 130 has been opened to permit air flow to the actuator 100 and move the piston 104 and thus the shaft 98 to pull the lever 90 away from the stop 94 and stretch the springs 60 and 74 and increase the tensions therein so they can apply stronger force to speed up the cutting knife 86 movement to facilitate proper cutting of the tape 20 and to the wipe down roll 56 as required to wipe the tape 20 against the trailing face 508 which is moving away from the roll 56 as this is happening.

FIG. 5 shown the final stage of application of tape 20 to the trailing face 508 of the case 500. As shown the valves 122 and 130 are still in position to direct air from source 120 to the actuator 100 but the cam 126 on the wipe down 44 and cam roller 124 controlling valve 122 are about to engage as the roll 56 completes the wipe down operation and return to their positions shown in FIGS. 1A and 6 where there is no flow or power to vale 130.

The embodiment shown in FIGS. 1C and 1D is similar to the device shown in FIG. 1A except that the on-off valve 122 and its related cams etc., have been eliminated and the air supply 120 is directly connected to the input port of control valve 130A. The valve 130A permits flow from a source 120 through the control valve 130A to the actuator 100 at the start of the cycle as the case or carton approaches the application roll 38 the springs 60 and 74 are extended so that added force or pressure is added to the cut off mechanism 70 and the application roll 38 as shown in FIG. 1B. When the cam 132 is engages the leading top corner 510 of the case 500 i.e. in the position shown in FIG. 1C the valve 130A closes and stops flow to the actuator 100 and the springs 60 and 74 pull the piston to extended position and the valve 130A permits air to exhaust from the actuator 100 i.e. the piston 104 and shaft are move to the left in FIG. 1C or 1D (move the lever 90 into abutment with the stop 94) and reduce the tension in the springs 60 and 74 so that the spring pressure applied by spring 60 to application roll 38 at impact of the case striking the roll 138 is low. It must be noted that the cam 138 must be placed so that the springs 60 and 74 have time to move the piston to the left as shown before the roll 38 contacts the leading face 504 of the case 500. The piston 104 remains in this position until the valve 130 is again activated to increase tension in the springs 60 and 74 as will be described below.

In the FIG. 1E the valves 122 and 130 are schematically illustrated as 401 and 402 and are as directly controlled by cams 403 and 405 that directly engage the case 500 and position the valves 401 and 402 as required to operate as above described with respect to FIG. 1A to 6. The cams 403 and 405 are not mounted on the tape head 10 but on the machine on which the head is mounted and as indicated are positioned relative to the head 10 as required to activate the actuator 100 as described above.

FIG. 1F schematically shows the positions of sensors 601 and 611 that provide signals to the control 613 that operates the valve 403 which is equivalent to valve 130A described above and the sensors 601 and 11 to control valve 403 in the same manner the cam 132 is used to control flow the valve 130A as described above.

Turning to the remaining FIG. 7A to which show different embodiment of the invention only the changes will be described the other parts being essentially the same as shown in FIGS. 1A to 6 inclusive.

FIGS. 7A and 7B the lever 90 has been replaced by a lever 90A pivotably mounted on the frame 12 on pivot 92A with the spring 60A and piston or shaft 98 connected to the lever 90A on one side of the pivot 92A and spring 74 on the opposite side obviously at rest i.e. starting position the spring 60A holds the lever 90 against the stop 94A and actuator 100 with its piston 104 and thus shaft 98 in extended position as shown. In this embodiment the pivotal mounting 68A of the cut off mechanism 70A has been reversed i.e. in this embodiment the pivotal mounting is on the opposite side of the knife 86A than in the other embodiments i.e. it is closer to the application arm 18 than to the wipe down 44.

In FIGS. 8A and 8B the lever 90 or 90A has been eliminated and the piston or shaft 98 is connected to a cross bar 200 to which the ends of springs 60B and 74B. In this embodiment the strengths of the springs have to be as required for the specific function they are to perform (obviously this is the case for all embodiments).

FIG. 8C shows essentially the same device as shown in FIGS. 8A and 8B but the pneumatic cylinder 100 has been replaced by the electrical solenoid 650K power to which will be controlled either by a cam equivalent to the cam 132 or detector or switches as illustrated in FIGS. 1E and 1F

FIGS. 9A and 9B shown an embodiment where a separate actuator (equivalent to actuator 100) i.e. actuator 100C and 100D, 100C being used to extend spring 60C and the other spring 74D. In this case the actuators 100C is mounted on a stub shaft 102C extending from frame member 12A and actuator 100D on stub shaft 102D extending from frame member 12B, FIG. 9B is essentially the same as that shown in FIGS. 9A and 9B except the activator 100C and 100D are in the form of solenoids 650 and 651 the power to which is delivered via power line 701 the input to which is controlled by switches 620 and 621 coupled together vial line 700 (see FIG. 9C). In this arrangement the switch 620 must be closed (permit current flow) to permit the switch 621 to activate the solenoids 650 and 651 i.e. witches 620 and 621 operate in a similar manner to the valves 122 and 130.

FIG. 10A illustrates an arrangement similar to FIG. 1A but uses a rotary actuator 800 as the actuator. As illustrated in FIGS. 10A and 10B the rotary actuator 800 drives the shaft 92H to which the lever 90H is connected to turn with the shaft 92H to adjust the tension in the springs 60 and 74 at the appropriate times.

The embodiments of FIGS. 7A through 9A may be used with any of the control systems described above with respect to any of the embodiments described above to apply tension to the springs 60 and 74 and their equivalents.

The controller of the present invention includes the various valves or switches and their cooperating cams. Many systems are available to control the application of pressurized air flow or electrical power to the actuator(s) whether pneumatic or electrical, such as, cams, limit switches, sensors, timers, solenoids, valves and controls.

All of the spring 60 and 74 and their equivalents 60A, 70A. 60B, 74B and 60 C and 74D will be nonlinear helical coil springs.

In summery the actuators 100 whether pneumatic or electrical are controlled in various way to limit pressure applied to the leading to the carton or case while adding additional tension to the springs driving the wipe down 44 and the cut-off mechanism 70 at the appropriate time in the taping operation which tension is released to provide the required power at the appropriate time to ensure the tape is properly cut and the wipe down 44 applies the required pressure to properly apply the tape to the trailing 508 of the case or carton 500 without inflicting significant damage to the case or carton.

Having described the invention, modifications will be evident to those skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims

1. A tape applicator, comprising a frame, a source of tape mounted on said frame, a front applicator assembly including a front applicator to apply a leading end of a tape from said source to a leading face of a carton moving relative to said tape applicator pivotably mounted on said frame on a first pivotal axis, a rear wipe down assembly including a rear wipe down roll to wipe a tape applied to said carton along a trailing face of said carton remote from said leading face pivotably mounted on said frame on a second pivotal axis parallel to said first pivotal axis, a push bar link interconnecting said applicator assembly and said wipe down assembly for movement together to form a tape applicator assembly, a cut-off mechanism mounted on said frame on a third pivotal axis parallel to said first and second pivotal axes and positioned between said first and second axes, a nonlinear helical coil applicator spring connected at one end to said applicator assembly and a nonlinear helical coil cut-off spring connected at a first end to said cut-off mechanism, a spring pressure adjuster mechanism connected directly to an opposite end of said applicator spring remote from said one end and directly to a second end of said cut-off spring remote from said first end to adjust the extension of said applicator and cut-off springs, said spring pressure adjuster mechanism including an actuator and a controller controlling the delivery of power to said actuator to have low tension in said applicator spring and said cut-off spring and to increase tensions in the applicator and said cut off springs before said wipe down and cut-off mechanism are activated.

2. The tape applicator as defined in claim 1 wherein said controller comprises a sensor to sense location of said carton to control power to said actuator.

3. The tape applicator as defined in claim 2 said sensor is a sensor sensing said carton.

4. The tape applicator as defined in claim 3 said sensor includes two sensors in series.

5. The tape applicator as defined in claim 1 wherein, said spring pressure adjuster mechanism comprises a pressure lever pivotably mounted on said frame on a lever axis and said actuator is connected to said opposite and said second end of said applicator and cut-off springs via said pressure lever.

6. The tape applicator as defined in claim 5 wherein said opposite and said second end are connected to said pressure lever on the same side of said lever axis.

7. The tape applicator as defined in claim 5 wherein said opposite and said second end are connected to said pressure lever on opposite sides of said lever axis.

8. The tape applicator as defined in claim 1 wherein said spring pressure adjuster mechanism comprises a pressure bar connected to said opposite and said second end and to said actuator.

9. The tape applicator as defined in claim 1 wherein said spring pressure adjuster mechanism comprises two actuators connected one between said frame and said opposite and another between said frame and said second end.

10. The tape applicator as defined in claim 2 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

11. The tape applicator as defined in claim 3 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

12. The tape applicator as defined in claim 4 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

13. The tape applicator as defined in claim 5 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

14. The tape applicator as defined in claim 6 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

15. The tape applicator as defined in claim 7 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

16. The tape applicator as defined in claim 8 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.

17. The tape applicator as defined in claim 9 wherein said sensor includes a control cam mounted on said frame and positioned to engage said carton and control said activator.