GB2120201A - Tape sealing shallow depth cartons - Google Patents

Abstract

A machine and method for tape sealing shallow depth cartons 10 applies and presses tape 30 against one broad face of a forwardly travelling carton, e.g., the top side with a roller 82 located above the carton, the roller being carried on an arm arrangement 78 operable to maintain the roller 82 in continuous contact with the carton so that it also presses tape against the carton rear wall and at least a portion of the carton bottom side. The roller 82 is mounted on a bracket 90 pivotally connected at 97 to the arm 78 and spring biassed towards said arm. When the roller 82 reaches the bottom of the carton rear wall it moves forwardly at a speed greater than that at which the carton is travelling to press the tape segment 30-5 to the carton bottom. The tape is pressed onto the carton front wall by a roller 70. <IMAGE>

Description

SPECIFICATION Tape sealing shallow depth cartons Various types of machines for tape sealing shipping cartons are known. Generally, such machines apply and wipe down or press a run of sealing tape extending longitudinally of the carton from the front vertical wall thereof, along the top and/or bottom side, and then onto the carton rear wall. The tape run along both the top and bottom sides commonly follows the course of abutment of top side and bottom side infolded carton closure flaps. A machine which seals cartons at both top and bottom sides thereof and with tape applicator means disposed at the top and bottom sides of the carton travel path is, e.g., described in U.S. Patent No. 4,041,675.Such machine is suitable for tape sealing rectangular cartons of a wide range of dimensions particularly with regard to carton depth, i.e. vertical dimension thereof, since the top tape applicator means or assembly is mounted on a vertically adjustable head beam. Where it is desired to tape seal cartons with such type of machine there is limit to which such machine and taping procedure is satisfactory and this relates to tape sealing cartons of relatively shallow vertical dimension. In effecting tape sealing of a carton with known machines and practices, the tape run as noted above extends from the front wall of the carton, along the top and/or bottom sides and onto the carton rear wall. Thus the tape run and effectiveness of secu rement to the carton structure at its beginning and end, i.e. courses on the carton front and rear walls is of paramount importance.If tape securement on the front and rear walls is poor, such condition materialiy jeopardizes the adequacy of the longitudinal tape run at the top and/or bottom sides as a secure closure of the carton to ensure that the carton will remain sealed. Inadequate securement can result from there being insufficient carton front and rear wall vertical dimension to allow for requisite tape anchorage length on such surfaces.

One class of cartons in which the foregoing problems are encountered are one-piece folders and mailers, e.g. book-mailer boxes or cartons, slotted document envelopes, etc. These cartons have very shallow dimension as compared to the longitudinal and transverse dimensions of the carton. A shallow dimension would for example, be one in a range of about 1/2 inch to two inches (1.27 to 5.1 cms). Such shallow cartons could in usual fashion have infolded top and bottom side panels which require sealing, or they could be pre-fabricated as structures having only one pair of broad side closure flaps at either the top or the bottom. One piece folders formed from a flat blank may comprise only a base with two foldable flaps superposing over the base so that the folder depth is essentially only that of a double thickness of the blank stock.Tape sealing of such shallow depth carton, and to ensure proper anchorage of the initial and terminal lengths of the tape run, desirably would follow a course in a wraparound al both the front and rear of the carton and initiating in a segment running rearwardly a distance on one broad face of the carton a distance from the carton front side, running onto the front wall, rearwardly in continuous length along the other broad face, onto the rear wall and then in a terminal tape run segment onto the said one broad face for a distance running forwardly from said rear wall.Known types of tape sealing machines intended for effecting tape sealing of cartons conveyed in continuous forwardly travelling manner through the taping machine would not be satisfactory for applying tape in the aforementioned tape course on a shallow depth carton, since such machines do not embody features allowing for complete and continuous tape pressing or wipe down along the full course and more particularly at the wraparound part thereof extending at the carton rear end and forwardly a distance at the said carton other side. If such trailing part of the run is loose or not fully secured to the carton structure, it can in subsequent handling of the carton during shipping and delivery to the ultimate user cause the rest of the tape course to come loose, tear or otherwise suffer loss of integrity such that the carton may open and the contents of the carton spill out.

An object of the present invention is to provide an improved machine and method for tape sealing shallow depth cartons while the carton is travelling continuously in a forwardly moving direction in the machine.

In accordance with the invention there is provided a machine for tape sealing a carton of generally rectangular configuration, such carton having a relatively shallow depth between broad faced top and bottom sides and as compared to its longitudinal and transverse expanse, the sealing being effected with tape runs disposed longitudinally of the carton in wraparound from the carton top side to the bottom side at both the front and rear of the carton, said machine comprising, a conveyor for receiving a carton and carrying it forward at a predetermined speed along a fixed travel path, first and second movably mounted tape applicator means each having a normally extended position lying within said carton travel path, said first applicator means in extended position presenting a tape feed in carton confronting array with a tape feed initial length segment extending vertically beyond the carton travel path, said first applicator means when in extended position being engageable by the front end of a forwardly travelling carton to press the tape against said front end, continued forward travel of said carton moving said first applicator means to a retracted position thereof, said second applicator means being connected with said first applicator means to extend and retract in tandem therewith, both said applicator means in retracted position being disposed to engage one of said carton broad faces in tape pressing contact therewith, said second tape applicator means including an arm member and a tape pressing unit including a tape engaging member rotatably mounted to said arm member, the tape engaging member being located a distance from the point at which said unit is rotatably mounted to said arm member, said first and second applicator means extending from the retracted positions thereof when said carton one broad face travels forwardly beyond the point of said second applicator means tape pressing engagement therewith, said pressing unit being rotatable relative to said arm member to nest in close adjacency therewith at the forward side of said arm member when said second applicator means is retracted but opening away therefrom and following a movement path passing the tape engaging member thereof from the carton said one broad face onto the carton rear end and then onto the other broad face as the second applicator means extends from retracted position, engagement of said tape engaging member with the carton rear wall restraining return of the second applicator means to fully extended position, passage of the tape engaging member beyond the plane of the other broad face the carton releasing such restraint whereby said arm member in moving to fully extended position propels said tape engaging member forwardly along the said carton other broad face at a speed greater than that of said carton certain speed and until said second applicator means is fully extended, and means for urging said tape engaging member into tape pressing engagement with the said carton other broad face during the time said tape engaging member is being propelled forwardly.

The general constructional details of a preferred embodiment of the machine are similar to those of the carton sealing machine disclosed in U.S. Patent 4,061,526. Where necessary for proper understanding of the construction details in common with the machine of this invention and said '526 patent will be restated. However, particularized constructional details of the present machine which are already fully described in said patent need not be restated.

Thus, ail the details of construction of the tandemly operating later described first and second tape applicator means are not given herein. The machine includes first and second movably mounted tape applicator means carried in elevator head beam structure above the carton travel path and disposed normally in extended position into the travel course of the carton, the second such means being located forwardly of the first. Pressure sensitive tape feed from an endless stock thereof passes in front of the first applicator means and is thereby presented in carton confronting array so as to be engaged by the front end of a forwardly moving carton with a short initial length of such tape extending below the carton broad faced bottom side.As the forwardly travelling carton moves along, its front end or front vertically disposed carton wall strikes the tape and with ensuing forward travel, the first applicator means pressing the tape against the carton front end. Such action also initiates upwardly retracting rotative movement of the first applicator means.

Since the second applicator means is connected to the first to move in tandem therewith, it also starts to retract upwardly. As the first applicator means is moving upwardly, the tape pressing device, preferably a roller carried on the tip end of the applicator means wipes or presses the tape against the carton front end and after the first applicator means has fully retracted upwardly, passes onto the carton top side in tape pressing engagement therewith. As the carton continues to pass underthe now retracted first applicator means, tape is fed along its top side length and pressed thereagainst.By the time the trailing section ofthe carton top side is underthe first applicator means, the leading section thereof has arrived below the second applicator means, being engaged by the tape pressing device carried by such second means which performs a second wipe down of the tape at the carton top side.

The second tape applicator means includes an elongated arm member pivoted in the elevator head structure and having the tape pressing device thereof carried in a bracket which in turn is pivoted or articulated to the other end of said arm member. In such manner, the pressing device when the second applicator means is retracted nests in close adjacency forwardly alongside the lower part of the arm member while presenting a pressing roller thereon in carton top side tape pressing disposition. When the trailing section part cf the carton top side has passed beyond the first applicator means and arrives below the second applicator means, such first means does not start to return to extended position since it moves only in tandem with the second means which is still retracted.However such travel of the carton does free a thus far retracted tape knife which extends downwardly to sever the tape from the continuous stock thereof in the manner shown and described in U.S. Patent 4,061,526.

When the top side of the carton passes forwardly beyond the point of the engagement of the roller on the second applicator means therewith, the second applicator means pressing device opens in the forward direction away from its associated arm member following a trajectory keeping the roller carried thereon in contact with the carton and passing down the carton rear end vertical wall in pressing tape thereagainst. Such engagement of the second means roller with the carton rear end restrains return of the second applicator means to fully extended position until the roller passes down below the carton rear wall, i.e; below the carton bottom side at which point the restraint is released.

Upon such release, the second, and the first applicator means as well, complete return to fully extended position. However during the terminal travel stage of the second applicator means arm member to fully extended position, and due to the lever arm length and the geometry of the pressing device, the arm member propels the pressing device forwardly along the carton bottom side at a speed greater than that at which the carton is travelling. Bias means carried in the pressing device and normally operating to urge the presser device into nesting position alongside the arm member maintains the second applicator means roller in tape pressing contact with the carton bottom side during the time the pressing device is being propelled forwardly. Thus the sealing tape is applied in good sealing contact on the carton bottom side for a distance forwardly of the carton rear end, the course run of the tape from the front wall, along the top and in wraparound at the rear end having been applied with the pressing device in continuous contact with the tape.

During further forward travel of the carton in the machine and before it comes to the exit end thereof, a roller or like tape wiping device mounted at the bottom side of the travel path presses the short initial length tape segment at the carton front end and which up to this point was extending vertically downwardly of the carton into tape sealing contact with the carton bottom side and for some distance rearwardly of the front end.

A further aspect of the invention provides a method of tape sealing a shallow depth carton which includes applying tape in a wraparound course extending from a carton top side to the bottom side thereof at least at the rear end part of said carton and while it is travelling forwardly along a fixed path, the method comprising the steps of positioning a tape pressing member at a location in the path of carton travel, engaging one of said sides with said tape pressing member before the rear end of said travelling carton has reached said location, passing said tape ressing member onto the rear end of said carton in tape pressing engagement therewith when it reaches said location, and then and before the said carton rear end has travelled any appreciable distance beyond said location passing said tape pressing member onto the other side of said carton and forwardly in tape pressing engagement therewith at a speed greater than the forward travel speed of said carton.

The invention will be further described, by way of example, in conjunction with the accompanying drawings in which: Figure lisa perspective view of a shallow depth shipping carton of the type intended to be tape sealed with a machine of the present invention; Figure 2 is a bottom plan view of the carton shown in Figure 1; Figure 3 is a side elevational view of a tape sealing machine embodying the present invention, first and second tape applicator means being shown in their normally extended position, with a forwardly travel 1- ing carton moving toward engagement with a confronting tape and the first tape applicator means;; Figures 4 to 9 show the operation of the machine at successive travel positions of the carton, portions of the machine as depicted in Figure 3 being removed for sake of clarity and ease of illustration of the operating components; Figure 70 is side elevational view on enlarged scale of the second applicator means, with the pressing device being shown in opened out position as it appears when in tape pressing engagement with the bottom side of the carton as shown in Figure 8; and Figure 11 is a rear elevational view of Figure 10.

The machine and method of the present invention are intended mainly for tape sealing relatively shallow depth shipping cartons with a pressure sensitive type tape and is particularly characterized by the functioning of same to apply and press tape along longitudinal courses thereof at both the top and bottom of the carton while employing tape applicator means disposed in a location which is remote from at least one of said sides. Thus tape applicator means located at the top of the carton travel path apply and press tape against the carton top but such means is also operable to be positioned to apply and press tape against at least a portion of the remotely located carton bottom side.

Figures 1 and 2 depict a typical generally rectangularly configured, relatively shallow depth carton, e.g., a book mailer. The carton 10 has a bottom side 12, a front end wall 14, a rear end wall 16, lateral walls 18, 20 and a top side defined by infolded top closure flaps 22, 24. The carton can be fabricated in a number of ways, for example, from a blank, and as such also could have infolded flaps forming the front and rear end walls. But since the taping procedurefor closing such carton, and a one-piece folder as well, would be the same as for the depicted form, the carton is for convenience of illustration shown as having infolded flaps only at the top side. The carton is filled with contents such as a book with the top closure flaps 22, 24 open.The flaps are then infolded downwardly in long edge abutment thereof to close the carton and the same is then passed through the shortly to be described machine to tape seal same.

Figures 1 and 2 show the sealing course of the tape 30. Thus the tape course illustrated as being a continuous run thereof with end wraparound at both the carton front and rear, includes a segment 30-1 at the carton bottom side running forwardly from a point spaced rearwardly a distance from front end wall 14, a segment 30-2 running up the front end wall 14, a segment 30-3 running the full length of the carton on the top side thereof, a segment 30-4 passing down the carton rear wall 16 and a segment 30-5 running forwardly at the carton bottom 12 for a distance toward the front end.Such tape course which in the illustrated embodiment is laid along the longitudinal centerline of the carton provides for secure anchorage length at both ends to obviate loosening, peeling or other pullawayfrom the carton surfaces as might occur if the terminal ends were disposed only on the relatively shallow front and rear walls of the carton. Of particular importance is that from the outset of taping, starting with segment 30-2 and right up until completion of applying segment 30-5, there is uninterrupted or continuous pressing of the tape against the box surfaces with presser devices. It is undesirable that pressing contact be interrupted when taping a travelling carton inasmuch as laid out tape not immediately pressed against the carton surfaces can easily wrinkle or double over and seal on itself.

Referring now to Figure 3 of the drawings, the tape sealing machine 40 includes the same general constructional features of the machine disclosed in U.S. Patent 4,061,526. It has a base 42 mounting a vertical column 44 on which is adjustably vertically carried an elevator head beam structure 46 in which is housed the tape applicator means soon to be described. The head beam structure also supports an arm 48 a stock or roll of pressure sensitive tape 50, the tape passing around a guide roller 52 and disposing with its pressure sensitive face facing rearwardly, the first applicator means shown generally at 54 being extended down and just forwardly of the tape so that the tape is thus disposed in confronting array to a carton moving forwardly through the machine.The machine also includes endless belt means 56 comprised of two laterally spaced belts passing in driven course around end rolls 58,60 and employed to convey a carton through the machine along the fixed course defined by the upper belt run and at a certain travel speed.

The first applicator means is identical to the corresponding component described in the '526 patent and so is the second applicator means shown generally at 62 except as such second means is modified to the extent to be hereinafter described.

Thus both movably mounted applicator means 54, 62 are connected together by connecting bar 64 and move to retracted and extended positions thereof in tandem. The applicator means 54, 62 are shown in fully extended and normal position in Figure 3. A cutter knife 66 to sever tape from the stock thereof is provided and functions in the same manner and is of like construction to that disclosed in '526 patent.

Other machine elements such as side guide rails are not shown as being unnecessary for further understanding of the present construction.

Figures 4 to 9 show successive steps occurring in the tape sealing of a forwardly travelling carton.

After the carton 10 has been filled it is fed into the machine. The head beam can be of the type that will adjust to the carton depth in the manner described in the 4,061,526 patent. Soon after, the carton commences its conveyed forward travel in the machine, the carton front end 14 will strike the tape and the first application means 54, and more particularly the roller 70 rotatably mounted at the lower end thereof, will press the tape against the carton front end with an initial tape run as at 72 extending downwardly below the carton bottom side. The forwardly moving carton causes the first applicator means arm 74 pivoted at the top thereof as at 76 to rotate clockwise moving, e.g. to the position as shown in Figure 4 from that shown in Figure 3, the roller 70 wiping the tape uniformly against the carton front end wall from bottom to top.Concurrent with the clockwise rotation and hence initiation of retraction of tape applicator means 54 and because of their connection together with bar 64, the second applicator means 62, having arm 78 thereof pivoted as at 80 will rotate counterclockwise in moving to its retracted position such retraction operation being in opposition to the effect of a tension spring (not shown) that functions to normally urge the two means to extend positions.

Knife 66 will, as taught in the '526 patent, also start to retract.

With further forward travel of the carton, as for example to the Figure 5 position, itwill cause the first applicator means 54 and likewise second applicator means 62 to rotate, respectively, clockwise and counter-clockwise to their retracted position in which the respective rollers 70, 82 thereof dispose above the carton travel path in position to make tape pressing engagement with the carton top side.

During such forward travel tape is of course being led out from the stock and roller 70, now on top of the carton, is pressing the tape down against the top side infolded flaps to seal them together. Further, the carton is in a position in which it will soon arrive under the roller 82 to have a second tape pressing action applied to the tape already laid down on the carton top side.

Figure 6 shows the tape applying and pressing condition after the carton has travelled forwardly sufficiently to move the top side thereof beyond the contact of roller 70, but at which time tape pressing is being effected by roller 82 at the trailing or rear part of the carton top side and just prior to the point at which roller 82 will move down the carton rear wall 16. In the Figure 6 condition and while the first applicator means is no longer in contact with the carton, such means 54 will not start to move from retracted to extended condition in spite of the action of the tension spring (not shown but the same as described in the '526 patent) that tends to urge the tandem operated applicator means into normally extended position. The tandem coupling of such means and the engagement of roller 82 with the carton top side prevents initiation of extension.No such restraint however acts on the knife 66 which in the same manner described in the '526 patent will descend to sever the tape feed in the manner, e.g., shown in Figure 7 of the 4,061,526 patent, leaving a sufficient terminal length of tape to constitute the tape segments 30-4 and 30-5.

As soon as the carton travels forwardly beyond the point at which its rear wall is at the point of engagement with roller 82 of retracted means 62 and as shown in Figure 7, both applicator means will start to extend downwardly from their retracted positions. Second applicator means 62 it will be noted particularly from Figures 10 and 11, includes in addition to arm 78 which it will be understood is comprised of two spaced identical arm parts 78a and 78b, a right angle profiled bracket 90 pivoted to the lower end of the arm and in which is rotatably mounted roller 82, the roller being carried on a shaft 92. The bracket 90 includes spaced right angle profiled arm parts 94 and 96 joined at the front side by a web 81. The shaft 92 is received near the tip end of one leg 94 of the bracket, while the bracket in turn is pivoted as at 97 to arm 78 near the tip end of the other leg part 96.Bracket 90 being rotatable relative to arm 78 can move with respect to the arm 78 to nest in close alongside adiacency at the forward side of the arm 78 when the applicator means 62 is retracted as shown, for example, in Figure 4. Torsion springs 98 (Figures 10 and 11) enclose pivot 97 and are connected at one end to arm parts 78a and 78b as at 93 and at their other ends engage against web 81 of the bracket 90 as at 95 so as to apply a bias thereto tending to rotate the bracket clockwise about pivot 97 into nested position alongside arm 78. With reference again to Figure 7, it will be seen that as the second applicator means extends downwardly, the bracket 90 will, due to the fact that it is in contact with the travelling carton coupled with the extension movement of the second applicator means, be caused to rotate counterclockwise and open away from arm member 78 in opposition to the bias of spring 98 but following due to pivoting action of arm 78 and rotation of bracket 90, itself a path of movement which maintains roller 82 in constant tape pressing contact with the carton rear end wall 16. As roller 82 "walks" down the carton rear end wall there is caused a restraint in the complete extension of both applicator means so that, e.g., as shown in the Figure 7 depiction both arms 74 and 78 still have some distance of respective counterclockwise and clockwise rotative movement to make before they are fully extended.

As soon as the roller 82 clears engagement with the carton rear end wall, i.e., when the point of roller engagement is at the carton bottom side, the restraint on full extension of the applicator means is released. As shown in Figure 8, the clockwise rotation of arm 78 in returning to full extension position, "throws" or propels the bracket 90 and roller 82 carried therein forwardly at a speed greater than that at which the carton is travelling to wipe down tape at the carton bottom side, the roller 82 "walking" around the corner formed by carton rear end 16 and bottom 12 and never leaving pressing contact with the tape or carton structure.Roller 82 which is the tape engaging member, it will be noted, is located at a distance from pivot 97 with the distance between the point of engagement of the roller with the tape and the pivot 97 representing an effective lever distance through which the roller can be "thrown" as it passes from the carton rear onto the carton bottom side. Springs 98 tending to urge the bracket rotatably towards arm 78 are effective to maintain the roller 82 in tape pressing engagement with the carton underside to allow for wipe down of the tape segment 30-5 securely against the carton bottom side. As soon as the carton rear end wall travels forwardly beyond roller 82, the bracket 90 will rotate clockwise to nest alongside the fully extended now at rest arm 78.The application and pressing or wipe down of the tape on course segments 30-2, 30-3,30-4 and 30-5 has been accomplished with tape pressing means in continuous contact with the carton, there being no interruption of pressing contact at any point along such segments during the time the forwardly moving carton is being thus taped.

The tape course is now fully applied to the carton 10 except the segment 30-1 is still extending down wardly. As shown in Figure 9, a tape wiping component, e.g., a spring-biased wiper roller 102 is disposed along the travel path and as the carton nears the end of travel in the machine, the carton front wall engages roller 102, pivots itcounterclock- wise and it passes onto the carton bottom side to press segment 30-1 securely thereagainst. The fully sealed carton is then removed from the machine.

It will be appreciated that various modifications can be made in the machine. Thus the tape engaging or pressing devices are described and depicted as being rollers 70,82 and 102. They could obviously be shoes, tape pressing blades or the like and function in the same manner as the rollers. The applicator means 54, 62 are shown as overhead mounted units arranged at the top side of the carton travel path.

They could instead of being thus mounted, be reversed and mounted at the underside of the carton travel path in which case of course wipe down component 102 would be mounted at the top side.

Further, component 102 need not be a pivoted roller and it need not engage the carton front wall. It could be positioned simply to engage the carton bottom side. Component 102 also could be a simple obstruction such as a bar or blade fixed in the travel path at the level of the carton bottom side.

It will be seen that the present disclosure provides important improvement in machines and method for taping relatively shallow depth cartons. It effects taping of a forwardly travelling carton with continuous engagement of the tape by the pressing means during the application thereof from the front end, across the top and in wraparound at the rear end. It also can be used for taping more conventionally used cartons of greater depth where tape application and wipe down is not effected in a continuous course extending in wraparound from the carton top side to the bottom side. Where tape sealing is to be achieved in conventional cartons with the machine of the present invention, it would be adapted by insertion of a lower tape applicator cartridge to apply and wipe down tape at the carton bottom with devices located below the travel path and as, for example, described in U.S. Patent 4,041,675. Also it will be appreciated that while the machine is described as used in connection with the pressure sensitive tape, it can with simple modification be used with solvent activated adhesive tape, the machine otherwise being and operating identically with that as disclosed herein.

Claims (15)

1. A machine for tape sealing a carton of generally rectangular configuration, such carton having a relatively shallow depth between broad faced top and bottom sides and as compared to its longitudinal and transverse expanse, the sealing being effected with tape runs disposed longitudinally of the carton in wraparound from the carton top side to the bottom side at both the front and rear of the carton, said machine comprising a conveyor for receiving a carton and carrying it forward at a predetermined speed along a fixed travel path, first and second movably mounted tape applicator means each having a normally extended position lying with said carton travel path, said first applicator means in extended position presenting a tape feed in carton confronting array with a tape feed initial length segment extending vertically beyond the carton travel path, said first applicator means when in extended position being engageable by the front end of a forwardly travelling carton to press the tape against said front end, continued forward travel of said carton moving said first applicator rneans to a retracted position thereof, said second applicator means being connected with said first applicator means to extend and retract in tandem therewith, both said applicator means in retracted position being disposed to engage one of said carton broad faces in tape pressing contact therewith, said second tape applicator means including an arm member and a tape pressing unit including a tape engaging member rotatably mounted to said arm member, the tape engaging member being located a distance from the point at which said unit is rotatably mounted to said arm member, said first and second applicator means extending from the retracted posi tionsthereofwhen said carton one broad face travels forwardly beyond the point of said second applicator means tape pressing engagement therewith, said pressing unit being rotatable relative to said arm member to nest in close adjacency therewith at the forward side of said arm member when said second applicator means is retracted but 6pen- ing away therefrom and following a movement path passing the tape engaging member thereof from the carton said one broad face onto the carton rear end and then onto the other broad face as the second applicator means extends from retracted position, engagement of said tape engaging member with the carton rear wall restraining return ofthe second applicator means to fully extended position, passage of the tape engaging member beyond the plane of the other broad face of the carton releasing such restraint whereby said arm member in moving to fully extended position propels said tape engaging member forwardly along the said carton other broad face at a speed greater than that of said carton certain speed and until said second applicator means is fully extended, and means for urging said tape engaging member into tape pressing engagement with the said carton other broad face during the time said tape engaging member is being propelled forwardly.

2. A machine in accordance with claim 1, in which the means for urging the said pressing unit tape engaging member into engagement with the said carton other broad face is a bias member carried in said tape pressing unit and tending to rotate it into nested adjacency with said arm member.

3. A machine in accordance with claim 2, in which said second applicator means arm is elon gated and movably mounted at one end thereof on a pivot, said pressing unit being pivoted to the other end of said arm member.

4. A machine in accordance with claim 3, in which said bias member is a spring.

5. A machine in accordance with claim 4, in which the spring is a torsion spring encircling the pivot connecting the unit to said arm member and being in bias applying engagement with said unit.

6. A machine in accordance with claim 3,4 or 5, in which said pressing unit comprises an angularly profiled bracket having two leg parts, one leg part at its tip end being pivoted to said other end of said arm member, the tape engaging member being carried at the tip end of the other leg part.

7. A machine in accordance with claim 6, in which said tape engaging member is a roller.

8. A machine in accordance with any preceding claim, further comprising a tape pressing compo nent located forwardly of said second tape applicator means and operable to press said tape initial length segment against said carton other broad face along the frontal part thereof.

9. A machine for tape sealing a shallow depth carton with a tape course extending in wraparound from a carton top side to the bottom side thereof at least at the rear part of the carton, such machine including means for conveying the carton along a fixed travel path at a certain speed and tape pressing means comprising a retractable-extendible pressing unit mounted along the carton travel path, said unit including an arm member and a tape engageable component carried on the arm member, said tape engageable component disposing to engage one of said carton sides when said unit is in retracted position, said tape engageable component being pivoted to said arm member and nesting alongside said arm member when said unit is retracted, said unit moving to an extended position when the rear end of the forwardly travelling carton passes the point at which the tape engageable component is in engagement with said one side, said component opening away from said arm member as the latter is extending to pass said tape engageable component in tape pressing engagement onto the carton rear wall, the arm member being operable in moving to fully extended position to propel said tape engageable component forwardly along the other side of said carton when said component moves beyond the plane of said side at a speed greater than that at which said carton is travelling, said unit embodying means for urging said tape engageable component towards said arm member thereby to maintain said component in contact with said carton other side as said component is being propelled forwardly.

10. Atape sealing machine according to claim 9, in which said pressing unit in retracted position is disposed above the carton travel path, the arm member being mounted for pivoting movement at an upper end thereof, said tape pressing component being pivoted to the lower end of said arm member.

11. A tape sealing machine according to claim 9 or 10, in which said tape pressing component includes a roller.

12. A tape sealing machine according to claim 9, 10 or 11, in which said urging means is a spring.

13. A method of tape sealing a shallow depth carton which includes applying tape in a wraparound course extending from a carton top side to the bottom side thereof at least at the rear end part of said carton and while is is travelling forwardly along a fixed path, the method comprising the steps of positioning a tape pressing member at a location in the path of carton travel, engaging one of said sides with said tape pressing member before the rear end of said travelling carton has reached said location, passing said tape pressing member onto the rear end of said carton in tape pressing engagement therewith when it reaches said location, and then and before the said carton rear end has travelled any appreciable distance beyond said location passing said tape pressing member onto the other side of said carton and forward/ in tape pressing engagement therewith at a speed greater than the forward travel speed of said capon.

14. A method of tape sealing a shallow depth carton substantially as herein described with reference to and as illustrated in the accompanying drawings.

15. A tape seaiing machine constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.