EP0259241A2

EP0259241A2 - Taping apparatus

Info

Publication number: EP0259241A2
Application number: EP87630140A
Authority: EP
Inventors: George Allan West; Richard J. Pederson
Original assignee: Bemis Co Inc
Current assignee: Amcor Flexibles North America Inc
Priority date: 1986-09-03
Filing date: 1987-08-11
Publication date: 1988-03-09
Also published as: DE259241T1; EP0259241A3; JPS6366063A

Abstract

Apparatus for applying a length of pressure-sensitive adhesive tape (T) from a supply roll (27) to a case (1) being fed forward to seal the case (1), in which the tape (T) is adhered to the case and pulled from the roll by the forward movement of the case, the tape being pressed against the case, the apparatus having a knife (37) operable to cut the tape to length, and being provided with a mechanism (103) operable in association with the knife (37) for controlling the tension on the tape (T) when it is cut for repeatability of the length of cut, without the necessity for adjustment of the drag (101) on the drag (101) on the supply roll (27) on account of decrease in its diameter during operation, or generally from one supply roll to the next.

Description

This invention relates to taping apparatus, and more particularly to apparatus for applying tape, and especially pressure-sensitive adhesive tape, from a roll of the tape to cases as the cases are fed forward for being taped to seal them.
The taping apparatus of this invention is in the same general field as the taping apparatus disclosed in U.S. patents 3,954,550 and 4,039,367, for example, and in the specific aspect in which it is herein illustrated involves an improvement upon the apparatus disclosed in the copending coassigned U.S. patent application of Robert C. James and Richard J. Pederson, Serial No. 876,848, filed June 20, l986, entitled Easy-Open Case Taping, which is incorporated herein by reference.
The apparatus disclosed in the said James and Pederson application is operable to apply a length of pressure-sensitive tape unwound and cut from a supply roll to a case having a closure (e.g. a top) comprising two folded-over flaps having adjoining edges, the tape being unwound from the supply roll by the engagement of the leading end of a case being fed forward with the adhesive face of the tape and the pressing of the tape against the case, the tape being adhered to the margins of the flaps along the adjoining edges to seal the case. An integral end portion of the tape is folded back on the adhesive face of the tape and adhered to the tape to form a tab which is unadhered to the case for being grasped and pulled to peel the tape away from the case. The apparatus comprises a first roller for pressing the tape including the folded-back portion against the leading end of the case as the case moves forward and then pressing the tape against the flaps, a knife for severing the tape to provide a length thereof sufficient to extend down on the trailing end of the case, and a second roller for pressing the tape down on the trailing end of the case.
While said apparatus has been generally satisfactory in operation, difficulty has been observed in certain instances in obtaining repeatability of the cut-off length, this being somewhat critical in that, after a cut, there must be a sufficient length of tape extending down in front of the first presser roller to provide for formation of a tab of appropriate length. Stating this another way, it is somewhat critical that the location of the end of the tape, after each cut, be repeatable. Inherent in this is that the length of tape which is cut off on each cycle of operation be repeatable.
It has been observed that the length of tape cut off by the knife of the apparatus (prior to the present improvement) may be affected by such factors as the diameter of the supply roll at the time of the cut, the retardation of unwinding of the supply roll and (with the tape being a pressure-sensitive adhesive tape) the amount of pull required to unwind the tape from the roll (noting that each successive convolution of the tape tends to adhere to the preceding convolution). While it is possible more or less to obtain repeatability by adjustment of the resistance to rotation of the supply roll, it is necessary that such adjustment be made from time to time during operation in view of the decrease in supply roll diameter, and from roll to roll in view of the variation in the pull required to unwind the tape, and even non-uniformity of pull from the beginning to the end of a given roll. And it is generally undesirable to require adjustment of the apparatus by an operator during the unwinding of a roll, or from roll-to-roll.
While developed primarily as an improvement for the tab-forming apparatus of said James and Pederson application, it is to be understood that the invention is also applicable to taping apparatus of that general nature without the tab-forming feature, where repeatability of cut-off length may be desired.
Accordingly, among the several objects of this invention may be noted the provision of taping apparatus of the class described which, in an effective yet simple manner, provides generally for repeatability in the location of the cut end of the tape, after each tape, and without requiring adjustment by the operator.
In general, apparatus of this invention functions to apply a length of tape supplied from a roll thereof to a case being fed forward in a predetermined path, having means for holding the roll, first presser means against which the leading end of the tape extending from the roll is engageable by the leading end of a case being fed forward for adherence of the tape to the case and resultant pulling of the tape from the roll and pressing of the tape against the case as the case is fed forward, and second presser means downstream from the first for completing the pressing of the tape against the case after passage of the trailing end of the case past the first. The tape extends in a reach from the first presser means downstream to the case following the passage of the trailing end of the case past the first presser means. A knife is operable to cut said reach of the tape and thereby cut off said length of tape for application to the case from the supply of tape issuing from said roll. The knife is mounted for movement between a retracted position permitting passage of a case and an advanced position for cutting said reach of the tape, and is movable from its retracted position to its advanced position for the cutting of said reach on passage of the trailing end of the case past the knife. The tape extends in a path from the supply roll to the first presser means for adherence of the leading end of the tape to the case and then around the first presser means into said reach. A drag for the tape is provided between the supply roll and the first presser means for tensioning the tape as it is pulled forward through this said path by a case, and means is provided between the supply roll and said drag operable to tension the tape between the supply roll and the drag as the tape is pulled forward by a case with the knife in its retracted position, and to relieve tension on the tape between the supply roll and the drag as the knife moves from its retracted to its advanced position to cut the tape.
Other objects and features will be in part apparent and in part pointed out hereinafter.

Brief Description of the Drawings

Fig. l is a perspective of a case with a tape having the above-described easy-open feature applied thereto;
Fig. 2 is a side elevation of Fig. l;
Fig. 3 is an end elevation of Fig. 2 as viewed from the left of Fig. 2;
Fig. 4 is a plan of Fig. 2 with the tape partly broken away;
Fig. 5 is an enlarged vertical longitudinal section on line 5--5 of Fig. 4;
Fig. 6 is an enlarged vertical transverse section on line 6--6 of Fig. 4;
Fig. 7 is a vertical longitudinal section of the head of taping apparatus having incorporated therein means for providing the tape with said easy-open feature and with the improvement of this invention; and
Fig. 8 is a vertical transverse section generally on line 8--8 of Fig. 7.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Detailed Description

Referring to the drawings, there is generally indicated at l a case (or carton) made of paperboard or the like, e.g. corrugated box board, having a top 3, bottom 5, sides each designated 7 and ends each designated 9. The top 3 is illustrated as a top closure such as is conventionally formed, after the case has been packed, by folding two end flaps each designated ll over from the top of the case ends 9 on top of product packed in the case, and then folding over two side flaps each designated l3 from the top of the case sides 7 on top of the end flaps. The side flaps l3, when completely folded over, are generally coplanar and have adjoining parallel edges each designated l5 which may be generally in abutting relation or closely adjacent relation. The flaps l3 are secured together along said edges l5 by a strip of tape l7, more particularly a strip of pressure-sensitive tape of a type conventionally used for taping cases, having pressure-sensitive adhesive on one face A thereof by means of which the strip of tape is adhered to the margins of the flaps l3 along said edges l5. The strip of tape extends throughout the length of the top 3 of the case, and has portions l9 extending down on the outside of the ends 9 of the case for some distance. The bottom closure 5 generally also comprises end flaps and side flaps, like the top closure, these flaps being secured in suitable manner. They may be taped, like the top closure.
For providing an easy-open feature, the tape has at least at one end thereof, i.e. at the lower end of one of the downwardly extending portions l9, an integral end portion 2l folded over on a line 23 extending across the tape from one side thereof to the other and generally at right angles to the side edges of the tape, with the adhesive on said folded-over end portion 2l on the inside of said end portion 2l and with said end portion 2l flattened and adhered by the adhesive to the tape to form a tab indicated at 25 at said one end of the tape which is unadhered to the end of the case and thus free of the end of the case for being grasped and pulled to peel the tape throughout its length away from the flaps l3 of the case.
The tab 25 for grasping the tape and peeling it away from the case is formed during the operation of applying the tape to the case as illustrated in Fig. 7. As shown therein, basically, a continuous length of tape T having the adhesive A on said one face thereof is fed forward (down) from a supply, more particularly a roll 27 of the tape, and applied to a case l as the case is fed forward (toward the left as viewed in Fig. 7) endwise along a horizontal path by a case conveyor 29, the tape being adhered by the said adhesive first to a portion of the leading end 9 and then to the margins of the flaps l3 along the edges l5 of the flaps. The continuous length of tape is severed to supply the strip l7 of sufficient length to provide for end portions l9 of the tape extending down on the ends 9 of the case. Before the application of the tape to the case, the integral end portion 2l of the tape is bent up and the bent up end portion 2l is adhered by the adhesive on the tape to the tape to form the tab 25. The tape T is guided to extend down from the supply roll 27 with the tape at its lower end extending down into the path of a case l being fed forward in the stated horizontal path by the conveyor 29, and with the adhesive face A of the tape facing the oncoming leading end 9 of the case.
The conveyor 29 is operable to feed a case l to be taped forward under a taping head indicated generally at 3l. The taping head, which is suitably fixed in position above the conveyor at a taping station along the length of the conveyor, applies pressure-sensitive adhesive tape issuing from the tape supply roll 27, which is suitably mounted above the head, to the case as the case is fed forward under the head. The head comprises a frame including a pair of side plates each designated 33. A first presser means comprising a roller 35 is provided for pressing the tape against the leading end of a case l and then down on the top 3 of the case over the length of the case as the case is fed forward on the conveyor 29 under the taping head 3l. At 37 is indicated a knife for cutting the tape. A second presser means comprising a roller 39 is provided for continuing the pressing of the tape, down on the top of the case over the length of the tape, and, after the tape has been cut by the knife, against the trailing end 9 of the case. Roller 35 is mounted at one end, constituting the lower end, of a two-sided lever 4l pivoted for swinging movement on a horizontal transverse axis at 43 between the side plates 33. The roller 35 is free-rolling on a pin 45 extending horizontally between the sides 47 of lever 4l at its said lower end. Roller 39 is mounted at one end, constituting the lower end, of a two-sided lever 49 pivoted for swinging movement on a horizontal transverse axis at 5l between the plates 33 downstream (in relation to the travel of a case l) from lever 4l and roller 35. The roller 39 is free-rolling on a pin 53 extending horizontally between the sides 55 of lever 49 at its lower end.
The levers 4l and 49 are interconnected by a link 57 for conjoint movement, and are biased by a spring 59 connected to lever 49 to swing down to the lowered retracted position in which each of the rollers 35 and 39 is illustrated in solid lines in Fig. 7 wherein they are below the plates 33 and in the path of a case l being fed forward on the conveyor. The first roller 35 is adapted to swing up with lever 4l in clockwise direction as viewed in Fig. 7 from its lowered position, and, acting through the link 57, thereupon swings the lever 49 carrying roller 39 in the opposite direction, i.e. counterclockwise, raising the roller 39 out of the path of the case. On such upswing of the levers 4l, 49 and rollers 35, 39, spring 59 is tensioned and biases the levers to swing back down. The tape T is trained to extend from the supply roll 27 down through the head frame passing around a guide roll 6l extending between the side plates 33, and thence around guide rolls 63 and 65 extending between the sides 47 of lever 4l to have a lower end reach indicated at 67 in Fig. 7 extending downwardly and rearwardly at the front (the upstream side) of the first presser roller 35 between the latter and the oncoming leading end 9 of a case l being fed forward on conveyor 29 toward roller 35.
The knife 37 is carried by a two-sided lever 69 pivoted for swinging movement at 43, the two sides of lever 69 being on the outside of sides 47 of lever 4l and inside side plates 33. The lever 69 is biased to swing down by a spring 7l to the position shown in solid lines in Fig. 7 wherein the knife is below the plates 33, and is adapted to be swung up against the spring bias by a case l fed forward on conveyor 29, the spring snapping the lever back down when the case passes out of engagement with the lever, for severing of the tape by the knife.
The taping head 3l is provided with means generally designated 73 for folding up integral end portion 2l of the stated lower end reach 67 of the tape for the formation of the tab 25. As shown in Fig. 7, this means comprises a pocket-forming member 75, formed from a piece of sheet metal, generally in the shape of a J (as viewed from one side) having a straight leg 77, an arcuate foot 79 shaped in accordance with the presser roller 35, and a toe portion on the foot comprising an outwardly extending relatively narrow web 8l and a flange or lip 83 extending up from the web at its outer edge. This pocket-forming member 75 has its straight leg 77 pivoted for swinging movement on a horizontal transverse axis at 85 between the sides 47 of the lever 4l above the roller 35, and is biased by a spring 87 to swing to the position in which it is illustrated in solid lines in Fig. 7 wherein its leg 77 engages the back (the downstream side) of the roller 35, with the curved foot 79 extending around the bottom of the roller 35, and with the web 8l and flange 83 at the front (the upstream side) of the roller 39 forming an upwardly facing recess or pocket 89 at the front of the roller, the back of this pocket being defined by the roller itself, and the bottom of the pocket being defined by the web 8l, and the front of the pocket being defined by the flange 83 as best shown in Fig. 7. The stated lower end reach 67 of the tape T is shown in phantom in Fig. 7 extending down over the front of the roller 35 and thence over the pocket, prior to being forced into the pocket as will appear.
The tape folding means 73 further comprises means for forcing the tape into the pocket 89 and thereby initiating the folding thereof to form the tab, this means comprising a nozzle 9l for delivering a blast of air on the portion of the tape which extends over the pocket to blow that portion into the pocket, thereby forming a loop L of the tape in the pocket with the front side of the loop (the side away from the roller 35) constituting the stated end portion 2l of said end reach 67 of the tape bent up on the inside of the flange and extending up beyond the flange for a relatively short distance, the other side of the loop extending up on the front of the roller 35. Delivery of the air blast via the nozzle is under control of a control valve 93 which in turn is under control of the presser roll mechanism by means of engagement of the lever 49 at its upper end with an actuator 95 for the valve 93. This controls the supply of air under pressure from a source (not shown) to a valve 97 which, on delivery of control air thereto from valve 93, acts to deliver a shot of air from the source of air to the nozzle 9l via a line 99, the arrangement being such that on actuation of the valve 93 by the lever 49 as it returns to its home position of Fig. 7, a blast of air is delivered through the nozzle.
The taping head 3l as thus far described is generally the same as that described in the aforesaid copending coassigned U.S. patent application of Robert C. James and Richard J. Pederson, Serial No. 876,848, and, apart from the tab-forming feature, is generally the same as that of a case taping machine which has been on the market by Bemis Company, Inc. of Minneapolis, Minnesota, under the name BEMISTAPER. In accordance with this invention, the apparatus (the taping head) is provided with a drag l0l for the tape T between the supply roll 27 and the first presser roller 35 (more particularly between the supply roll and the guide roll 6l) for tensioning the tape as it is pulled forward by a case through its path from the supply roll to the first presser roller and around the first presser roller into the reach R of the tape which extends from the first presser roller downstream to the case following the passage of the trailing end of the case past the first presser roller. Further, the apparatus is provided with means indicated generally at l03 between the supply roll 27 and the drag l0l operable to tension the tape between the supply roll and the drag as the tape is pulled forward by a case and to relieve tension on the tape between the supply roll and the drag as the knife 37 moves from its retracted to its advanced position to cut the tape, thereby in effect to isolate the tape downstream from the drag from the supply roll during the cutting of the reach R of the tape by the knife.
The drag l0l comprises a roller l05 around which the tape travels in its path between the supply roll and the first presser roller 35, and means indicated generally at l07 in Fig. 8 for braking the roller l05. The latter is rotatable on a shaft l09 mounted on the side plate 33 by means of a bolt lll extending transversely of the tape head from one side wall 33 of the tape head and the braking means l07 comprises a brake disk ll3 biased by a spring ll5 reacting from a nut ll7 threaded on the freeend of the threaded bolt lll against a shoulder ll9 in the roller at the inner end of a counterbore l2l in the roller. The disk ll3 is held against rotation, while being axially engageable against said shoulder, by a pin l23 extending from the bushing through an opening l25 in the disk. The roller l05 imposes a substantially constant drag on the tape for substantially constant tape tension downstream from the roller l05.
The means l03 which acts to tension the tape between the supply roll 27 and the drag roller l05 as the tape is pulled forward by a case and to relieve tension on the tape between the supply roll and the drag roller on operation of the knife 37 comprises a first guide l27 constituted by an idler guide roller carried by the tape head somewhat above and to the right of the drag roller l05 as viewed in Fig. 7, and a second guide l29 also constituted by an idler guide roller carried by an extension as indicated at l3l of the knife lever 69 and offset to the right as viewed in Fig. 7 from the plane P of the axes of the idler roller l27 and the drag roller l05. The tape issuing from the supply roll 27 is trained around the roller l27, around the roller l29 on the knife lever 69, and thence around the drag roller l05 on its way to the roller 6l, thereby forming a loop l33 in the tape between the supply roll and the drag roller. The roller l29 is movable with the knife lever 69 from a first position (in which it is illustrated in phantom in Fig. 7) spaced the distance Dl from the plane P of the axes of the idler roller l27 and the drag roller l05 and a second position (in which it is illustrated in solid lines in Fig. 7) spaced a lesser distance D2 from said plane on the cutting movement of the knife 35 from its retracted position (in which it is shown in phantom in Fig. 7) to its advanced position (in which it appears in solid lines in Fig. 7), and is movable back to its first position on movement of the knife back to its retracted position. The said first position of roller l29 may be referred to as the loop-pulling position of the roller and the second may be referred to as the loop-releasing position.
The supply roll 27 is mounted on a core l3l carried on a bushing l33 rotatable on a shaft l35 extending from one of the side walls 33 of the tape head. Braking means for the supply roll is shown to comprise a brake plunger l37 (made of nylon, for example) slidable in a hole l39 in the bushing and biased toward engagement of its inner end with the shaft l35 by a spring l4l reacting from a set screw l43 threaded in a tapped hole l45 in the core.
At the start of each application of tape to a case l, the presser rollers 35 and 39 and the knife 37 are all down in the lowered position in which they are shown in solid lines in Fig. 7. Tape T from the supply roll 27 of tape extends from the supply roll around rollers l27, l29 and l05 and thence around guide rolls 6l, 63 and 65 with the lower end reach 67 of the tape extending in front of the roller 35, the adhesive side A of the tape facing away from the roller 35, toward the leading end 9 of a case l to be fed forward on the conveyor 29, the end of the tape having been formed as a result of the previous taping application into the loop L in the pocket 89. The roller l29 is in its loop-releasing position shown in solid lines in Fig. 7.
The case l to be taped is fed forward on the conveyor 29 from the right of the first presser roller as viewed in Fig. 7 toward the first presser roller 35. As the case is fed forward, its leading end 9 substantially simultaneously engages both the exposed portion of the tape 2l and the top of the upturned flange 83 on the top of the arcuate foot 79 of the pocket-forming member 75, and swings the member 75 clockwise on its pivot 85 against the return bias of spring 87 so that the flange 83 is swung away from in front of the upwardly extending end portion 2l of the lower end reach 67 of the tape. On continued movement of the case l, the leading end 9 of the case engages the bent-up end portion 2l and then presses it against part of the tape immediately adjacent portion 2l, thereby to squeeze together portion 2l and said adjacent part of the tape so that they become securely adhered together by the adhesive on the tape and form the tab 25 with the outside (the non-adhesive side) of portion 2l included in the tab facing the leading end of the case.
On further forward progression of the case l, the leading end 9 of the case, engaging the outside of the upwardly folded end portion 2l of the tape and the adhesive side of the lower end reach 67 of the tape above end portion 2l where the adhesive is exposed, pushes against the roller 35 so that the lower end reach of the tape is securely adhered to the leading end of the case. The lever 4l carrying the roller 35 is swung up (clockwise) against the bias of spring 59, the roller 35 riding up the leading end of the case, and then riding on the tape on top of the case to press the tape down on top of the flaps l3.
On upward swing of the lever 4l carrying roller 35, lever 49 carrying roller 39 is swung up (counterclockwise) against the bias of spring 59 by the link 57 to raised position (as shown in phantom in Fig. 7) to clear the way for the travel of the case past the roller 39. Also, as the leading end 9 of the case moves on past the roller 35, it engages the lower ends of the sides of the knife lever 69 and swings this lever up against the bias of spring 7l to the raised position in which the lever is shown in phantom in Fig. 7, the lever being held up in the raised position by engagement with the top of the case. This results in movement of the roller l29 to the loop-pulling position in which it is shown in phantom in Fig. 7 for tensioning of the tape between the supply roll 27 and the drag roller l05. Then, when the case passes by the lower end of the lever 69, the lever 69 is snapped down by the spring 7l for the knife 37 to sever the tape with the length of the strip l7 of tape so severed from the continuous strip T of tape such as to provide for trailing end portion l9 of the tape to extend down on the trailing end of the case. As the knife lever 69 swings down, roller l29 moves to the loop-releasing position in which it is shown in solid lines in Fig. 7 to relieve tension on the tape between the supply roll 27 and the drag roller 35.
Both rollers 35 and 39 remain up until the trailing end 9 of the case clears the roller 39. The lever 49 then swings down (clockwise) under the bias of the spring 59, and presses the trailing end or tail of the cut-off strip l7 of the tape against the trailing end of the case, rolling down on the tape on the trailing end of the case. As the lever 49 swings down, lever 4l swings down to return the roller 35 to its home position in which it is illustrated in solid lines in Fig. 9 and l0.
As the case l moves forward with the tape T adhered thereto, it acts to pull the tape T from the supply roll 27, and just before the case passes by the lower end of the knife lever 69, there is a short horizontal reach of tape extending from the bottom of roller 35 to the trailing end of the case and over the top of the case. The pocket-forming member 75 is held back in a retracted position relative to the roller 35 against the bias of spring 87 by this reach engaging the flange 83. When the tape is cut, and the lever 4l and roller 35 return to home position, the pocket-forming member 75 is returned by the spring 87 to the pocket-forming position in which it appears in solid lines at the lower right of Fig. 7, and the lower end reach 67 of tape is reestablished extending over the pocket 89 as shown in phantom in Fig. 7. At the end of the return, lever 49 activates valve 93 and so that a blast of air is delivered through nozzle 9l to tuck the tape into the pocket 89 to form the loop L, and thus the end of the tape is prepared for taping the next case.
With relief of tension on the tape between the supply roll 27 and the drag roller l05 each time the tape is cut by the knife, the tension on the tape between the drag roller and the case is generally constant for each cut, being determined at the time of cut by the drag of the drag roller on the tape as the tape is pulled forward by the case, the drag imposed by the drag roller being relatively constant. The release of the loop l33 on the cutting of the tape in effect isolates the tape downstream from the drag roller l05 from the supply roll 27 during the cutting of the tape. The net result is that the tension in the reach of tape being cut is relatively unaffected by the diameter of the supply roll at the time of the cut, the braking of the supply roll and the amount of pull required to unwind the tape from the roll, and thus the location of the end of the tape after each cut is repeatable, and the length of tape cut off on each cycle is repeatable, since each cut is made under substantially the same conditions.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. Apparatus for applying a length of tape supplied from a roll thereof to a case being fed forward in a predetermined path comprising:

means for holding the roll;

first presser means against which the leading end of the tape extending from the roll is engageable by the leading end of a case being fed forward for adherence of the tape to the case and resultant pulling of the tape from the roll and pressing of the tape against the case as the case is fed forward;

second presser means downstream from the first for completing the pressing of the tape against the case after passage of the trailing end of the case past the first;

the tape extending in a reach from the first presser means downstream to the case following the passage of the trailing end of the case past the first presser means;

a knife operable to cut said reach of the tape and thereby cut off said length of tape for application to the case from the supply of tape issuing from said roll;

means mounting the knife for movement between a retracted position permitting passage of a case and an advanced position for cutting said reach of the tape;

said knife being movable from its retracted position to its advanced position for the cutting of said reach on passage of the trailing end of the case past the knife;

the tape extending in a path from the supply roll to the first presser means for adherence of the leading end of the tape to the case and then around the first presser means into said reach;

said apparatus being characterized in having a drag for the tape between the supply roll and the first presser means for tensioning the tape as it is pulled forward through this said path by a case; and

means between the supply roll and said drag operable to tension the tape between the supply roll and the drag as the tape is pulled forward by a case with the knife in its retracted position and to relieve tension on the tape between the supply roll and the drag as the knife moves from its retracted to its advanced position to cut the tape.

2. Apparatus as set forth in claim l wherein the means between the supply roll and said drag comprises a guide around which the tape travels in a loop in its path between the supply roll and the drag, said guide being movable from a loop-pulling position for tensioning the tape between the supply roll and the drag and a loop-releasing position for relieving tension on the tape between the supply roll and the drag on movement of the knife from its retracted to its advanced position for cutting the tape, and movable back to its loop-pulling position on movement of the knife to its retracted position.

3. Apparatus as set forth in claim 2 wherein the means mounting the knife for movement between its said retracted and advanced positions comprises a lever pivoted for swinging movement on an axis extending transversely with respect to the path of the tape, said apparatus including spring means biasing the lever to swing the knife from its retracted to its advanced position, the lever being held in a retracted position wherein the knife is in its retracted position by a case being fed forward, and being released to swing the knife to its advanced position on passage of the trailing end of the case past the lever, and said guide comprising a roller carried by the lever and movable with the lever between said loop-pulling and loop-releasing positions.

4. Apparatus as set forth in claim l wherein said drag comprises a roller around which the tape travels in its path between the supply roll and the first presser means, and means for braking said drag roller.

5. Apparatus as set forth in claim 4 wherein the means between the supply roll and said drag roller comprises a guide around which the tape travels in a loop in its path between the supply roll and the drag roller, said guide being movable from a loop-pulling position for tensioning the tape between the supply roll and the drag roller and a loop-releasing position for relieving tension on the tape between the supply roll and the drag roller on movement of the knife from its retracted to its advanced position for cutting the tape, and movable back to its loop-pulling position on movement of the knife to its retracted position.

6. Apparatus as set forth in claim 5 wherein the means mounting the knife for movement between its said retracted and advanced positions comprises a lever pivoted for swinging movement on an axis extending transversely with respect to the path of the tape, said apparatus including spring means biasing the lever to swing the knife from its retracted to its advanced position, the lever being held in a retracted position wherein the knife is in its retracted position by a case being fed forward, and being released to swing the knife to its advanced position on passage of the trailing end of the case past the lever, and said guide comprising a roller carried by the lever and movable with the lever between said loop-pulling and loop-releasing positions.

7. Apparatus for taping a case having a top, bottom, sides and ends, the top comprising two folded-over flaps having adjoining edges, the tape having adhesive on one face thereof and being supplied from a roll thereof to case as the case is fed forward endwise in a predetermined path, comprising:

means for holding the roll;

first presser means against which the leading end of the tape extending from the roll is engageable by the leading end of a case being fed forward for adherence of the tape to the case and resultant pulling of the tape from the roll and pressing of the tape against the case as the case is fed forward;

means associated with said first pressing means for folding back an integral end portion of the tape on said face of the tape and adhering said end portion to the tape to form a tab which is unadhered to the leading end of the case for being grasped and pulled to peel the tape away from the case;

second presser means downstream from the first for completing the pressing of the tape against the case after passage of the trailing end of the case past the first;

the tape extending in a reach from the first presser means downstream to the case following the passage of the trailing end of the case past the first presser means;

a knife operable to cut said reach of the tape and thereby cut off said length of tape for application to the case from the supply of tape issuing from said roll;

means mounting the knife for movement between a retracted position permitting passage of a case and an advanced position for cutting said reach of the tape;

said knife being movable from its retracted position to its advanced position for the cutting of said reach on passage of the trailing end of the case past the knife;

the tape extending in a path from the supply roll to the first presser means for adherence of the leading end of the tape to the case and then around the first presser means into said reach;

said apparatus being characterized in having a drag for the tape between the supply roll and the first presser means for tensioning the tape as it is pulled forward through this said path by a case; and

means between the supply roll and said drag operable to tension the tape between the supply roll and the drag as the tape is pulled forward by a case with the knife in its retracted position and to relieve tension on the tape between the supply roll and the drag as the knife moves from its retracted to its advanced position to cut the tape.

8. Apparatus as set forth in claim 7 wherein wherein the means between the supply roll and said drag comprises a guide around which the tape travels in a loop in its path between the supply roll and the drag, said guide being movable from a loop-pulling position for tensioning the tape between the supply roll and the drag and a loop-releasing position for relieving tension on the tape between the supply roll and the drag on movement of the knife from its retracted to its advanced position for cutting the tape, and movable back to its loop-pulling position on movement of the knife to its retracted position.

9. Apparatus as set forth in claim 8 wherein the means mounting the knife for movement between its said retracted and advanced positions comprises a lever pivoted for swinging movement on an axis extending transversely with respect to the path of the tape, said apparatus including spring means biasing the lever to swing the knife from its retracted to its advanced position, the lever being held in a retracted position wherein the knife is in its retracted position by a case being fed forward, and being released to swing the knife to its advanced position on passage of the trailing end of the case past the lever, and said guide comprising a roller carried by the lever and movable with the lever between said loop-pulling and loop-releasing positions.

l0. Apparatus as set forth in claim 7 wherein said drag comprises a roller around which the tape travels in its path between the supply roll and the first presser means, and means for braking said drag roller.