US3535189A - Pressure-sensitive adhesive tape applicator - Google Patents

Description

Oct. 20, 1970 HA| EI'AL PRESSURE-SENSITIVE ADHESIVE TAPE APPLICATOR 4 Sheets-Sheet 1 Filed Feb. 17. 1967 L LP R #3 MMETOW INVE JasEp Jun A ATTORNEY RQ mm R 0 Q mm mm INVENTO S J0sEPHJ/54LL BY M07670 4 Sheets-Sheet 3 J. J. HALL 51' AL PRESSURE-SENSITIVE ADHESIVE TAPE APPLICATOR Filed Feb. 17. 1967 Oct. 20, 1970 ATTORNEY Oct. 20, 1970 L ET AL 3,535,189

V PRESSURE-SENSITIVE ADHESIVE TAPE APPLICATOR Filed Feb. 17. 1967 4 Sheets-Sheet 5 '74 q u: 44 7; 44 M '15 i H z 1 K INVEN 0R5 A BY,

ATTORNEY Patented Oct. 20, 1970 US. Cl. 156-486 16 Claims ABSTRACT OF THE DISCLOSURE This application discloses apparatus for applying normally tacky and pressure-sensitive adhesive tape to an object to be taped which comprises, feeding means for advancing a strip of the tape longitudinally beyond the feeding means, guide means for leading the end of the tape a substantial distance beyond the feeding means in a path extending alongside and spaced from the object to be taped, and applicator means for pressing the tape sideways into adhering contact with said object. The guide means has a first position adjacent the feeding means and is adapted, after engaging the tape, to move longitudinally in the same direction, and at a linear speed substantially the same as or somewhat greater than the tape, to a second position remote from the feeding means. Thus, the guide means is removed from the path of the applicator means which is adapted to press the tape onto and, if necessary, partially around the object to be taped to form a tape clip in the form of a C, or the like.

The present invention relates to apparatus for applying pressure-sensitive, or normally tacky, adhesive tape to an article, such as a carton, to be taped and, more particularly, to apparatus of this type which is adapted ot apply strips of such tape automatically to successive articles or objects.

In general, the prior art which has been proposed for this purpose has been adapted to attach one end of a strip of such tape to the article and then pull or drag the tape around a corner or segment of the article to draw it into adhesive contact therewith. This requires relative movement between the article and the tape applicator means and a rolling or wiping motion of the application from the attached end of the tape to the other extremity of the strip in order to assure its adherence to the article.

According to our invention, the tape first is positioned alongside the article to be taped in spaced relation therefrom with the adhesive side of the tape facing the article. Then, the tape is pressed sideways against the article and into the desired adhering relation therewith. To accom plish this, We provide feeding means for projecting a strip of pressure-sensitive adhesive tape longitudinally, guide means for leading the end of the tape a substantial dis tance beyond the feeding means in a path extending alongside and spaced from the article to be taped, and applicator means for pressing the tape sideways into adhering contact with the article, as described above. More specifically, the guide means assumes a first position adjacent the feeding means in which the guide means first enters into guiding relation with the tape and is adapted, after engaging the tape, to move longitudinally in the same direction and at substantially the same linear speed as the tape to a second position remote from the feeding means. The guide means remains in guiding relation with the leading end of the tape strip throughout its travel from its first to its second position with the result that the tape is positioned alongside the article to be taped in spaced relation therefrom. Preferably, the guide means moves longitudinally at a speed equal to or slightly greater than that of the tape so that the guide means, if anything, has the tendency to draw the tape out into the desired position, rather than to cause the tape to buckle because of its adherence to the guide means as it is advanced or projected by the feeding means.

In a preferred form of the invention, the applicator means is movable in a path across or generally normal to the path of the tape for pressing the tape into contact with the article. A pressing foot and a pair of rollers, one located at each end of the foot, may be used for this purpose. It also is preferred that the feeding means be adapted to cause the tape to assume a three-dimensional transverse cross-section to impart stiffness thereto as it is being fed and that the guide means be shaped accordingly to cause the tape to maintain its three-dimensional transverse cross-section. Since the tape normally is drawn from a supply roll by and through said feeding means, it normally is necessary that tape severing means be provided adjacent the feeding means for severing the tape strip from the supply roll after the guide means reaches its second position. To facilitate guidance of the tape alongside the article to be taped and to hold it in position after the tape strip has been severed, it is preferred that a fixed tape guide for the trailing end of the tape also be positioned adjacent the tape severing means.

Other and further advantages of this invention will appear to one skilled in the art from the following description and claims taken together with the drawings wherein:

FIG. 1 is a view partly in section and partly in front elevation of apparatus according to a preferred embodiment of this invention, broken away to show certain details of its construction.

FIG. 2a is a somewhat reduced schematic view in perspective showing a stack of sheets or boards having taped C-clips applied to its sides and ends in accordance with this invention.

FIG. 2b is a similar schematic view in perspective of a stack of boards having two pairs of C-clips applied in opposed sets to opposite sides of the stack.

FIG. 3 is a somewhat enlarged view partly in section and partly in elevation taken from the left end of FIG. 1 and partially broken away to show certain structural details.

FIG. 4 is a view similar to FIG. 3 taken from the opposite end of the apparatus of FIG. 1 with the tape roll and associated parts removed and with portions broken away for the sake of clarity.

FIG. 5 is a somewhat enlarged partial view partly in section and partly in elevation showing the relationship between the feeding means, the guide means and the tape applicator means just after the guide means reaches its second position and the applicator means is about to contact the tape to press it sideways against the stack of boards to be taped.

FIG. 6 is a view similar to that of FIG. 5 showing the relationship of the parts just after the tape has been pressed into contact with the sides of the boards and its ends are being rolled into contact with the top and bottom surfaces of the stack.

FIG. 7 is a further view similar to that of FIGS. 5 and 6 showing the relationship of the parts just after the tape has been completely pressed into contact with the side and the top and bottom surfaces of the stack of boards to form a C-clip.

FIG. 8 is another view similar to that of FIGS. 5, 6 and 7 showing the relationship of the parts after the applicator has been withdrawn and the guide means has returned to its first position adjacent the feeding means to receive the end of a new strip of tape just prior to beginning its longitudinal movement with the tape to its second position.

FIG. 9 is a still further enlarged view partly in section and partly in plan of the fixed tape applicator arm of the apparatus of the preceding figures.

FIG. 10 is a similarly enlarged elevational view of the arm of FIG. 9.

FIG. 11 is an end elevational view showing the rack for adjusting the height of the upper applicator arm of the apparatus of the preceding figures.

FIG. 12 is a similarly enlarged view partly in section and partly in elevation showing the feeding and tape severing means of this apparatus.

FIG. 13 is a view partly in section and partly in plan taken along the line 1313 of FIG. 12.

FIG. 14 is an enlarged top plan view of the tape guide means of the preceding figures.

FIG. 15 is a more greatly enlarged plan view taken from the line 1515 of FIG. 12 showing the feeding means of this embodiment, with certain portions in section for the sake of clarity.

Referring to the drawings, there is shown a preferred embodiment of apparatus according to this invention for applying normally tacky and pressure-sensitive adhesive tape 21 to an object, such as a stack 22 of panels or wall boards, to be taped, from a supply roll 23 of such tape wound upon itself in the form of a roll with the pressure-sensitive adhesive side of the tape facing inwardly. The stack 22 consists of a number of boards, say eight, piled one on top of the other in such a way that the stack has parallel sides and is generally rectangular. The stack rests upon a table 24 which may consist of a number of rollers, not shown, and the table is constructed in such a way that the tape may be applied in the form of a C-clip 25, such as shown in FIGS. 2a and 2b, transversely around one side of the stack without interfering with the table, in such a manner as Will be described more fully hereinafter. As indicated hereinbefore, FIG. 2a illustrates a stack of boards with a single C-clip 25 of tape applied at each end and each side of the stack, and FIG. 2b shows a stack with opposed pairs of C-clips 25 on each of its sides. Of course, the C-clip, referred to, is a piece of tape applied vertically against one side of the stack 22 with its ends folded down over the top and under the bottom of the stack and adhered thereto, as illustrated in FIGS. 2a, 2b, 7 and 8.

The stack 22 is held in position on the table 24 for taping by at least one pair of clamping pads 26 in the form of horizontal plates attached to the lower ends of plungers 27 integral with and normally urged downwardly by a corresponding pair of pneumatic clamping cylinders 28 mounted on a cantilever platform 29 extending horizontally from a vertical supporting column 30. The clamping cylinders 28 may be operated manually to depress the clamping pads 26 and hold the stack 22 in position, or means such as a limit switch, not shown, may be used to operate the clamping cylinders 28 in this manner when the stack reaches a given position on the table 24. The platform 29 comprises a horizontal plate 31, a vertical end plate 32, and a pair of vertical brackets 33 extending between the horizontal plate 31 and the end plate 32 to provide the necessary structural strength and rigidity. The platform 29 is slidably mounted on a pair of vertical guide rods 34 through top and bottom horizontal bushings 35 and 36, respectively, attached to the end plate 32, and the vertical guide rods 34 are attached to the supporting column through horizontal top and bottom brackets 37 and 38 spaced from one another. The platform 29 may be raised or lowered by operating a hand wheel 39 keyed to a vertical positioning screw 41 rotatably mounted in the top horizontal bracket 37 and threaded through the top horizontal bushing attached to the cantilever platform. As the hand wheel 39 is turned in one direction, the top bushing 35 and the platform 29 will be raised, or moved upward with respect to the column 30; whereas, if it is turned in the other direction, it will be lowered. A pointer 42 secured to the lower bushing 36 is adapted to be used in conjunction with a scale 43 attached to the supporting column to indicate the correct position of the platform for a given stack thickness. The supporting column 30 is in the form of a hollow rectangular structure having opposed vertical end and side walls extending upwardly from a base plate 44 and a horizontal cover 45. The hori zontal brackets 37 and 38, which support the vertical guide rods 34, are fixed to and extend outwardly from a front plate 46 which is slightly wider than the adjacent wall of the column 30, as indicated in FIG. 3, but cut away on one side to allow the pointer 42 to ride flat against the scale 43 fixed to one side of the column.

Also supported from the cantilever platform 29 above the stack 22 are the tape supply roll 23, a feeding unit 47 for advancing tape from the supply roll, and a tape severing knife 48 for severing the tape from the supply after it has been projected from the feeding unit. The supply roll 23 is mounted for rotation on an axle supported from a bracket 49 extending upwardly from a vertical supporting wall 51 which, in turn, is attached to an angle iron 52 bolted to one side of a horizontal casting 53 attached to the top surface of the platform 29.

The feeding unit 47 also is supported directly from the vertical wall 51 and is in the form of a pulling device 54 for drawing tape 21 from the supply roll and a feeding device 55 for projecting the tape in the direction of the stack 22. A guide roll 56 also is rotatably mounted from the vertical wall 51 to direct the tape around the pulling device 54. The pulling and feeding devices of this feeding unit 47 are described in full detail in Applicants copending application, Ser. No. 543,718. However, the feeding device 55 thereof is shown in some detail in FIGS. 12 and l5, and comprises inner and outer continuous belts 57 and 58, respectively, each driven longitudinally in a closed path having a forward flight and a return flight. The belts 57 and 58 are adapted to sandwich the tape 21 between them in their forward flights and thereby grip the tape sufficient to feed it through a guide track 59 which is adapted to impart a three-dimensional transverse cross-section to the tape. In the embodiment shown, the guide track presents concave arcuate surface portions 61 on each side of the belts to impart a correspondingly concave arcuate transverse cross-section to the tape. These concave arcuate surface portions of the track together with a pair of opposed shelf-like supports 62 therefor act as edge guide portions of the track which position the longitudinal edges of the tape 21 transversely with respect to the belts 57 and 58. The guide track 59 has a bell mouth or widened portion 63 at the leading end of the track to facilitate entrance of the tape into the track and between the belts 57 and 58. The inner belt 57 passes around an inner pair of spaced first and second pulleys 64 mounted on inner shafts journaled in the structure of the supports 62, and the outer belt 58 passes around a corresponding outer pair of spaced first and second pulleys 65 mounted for rotation outwardly of the guide track 59. The tape 21 is driven forward through the feeding device 55 only by the light pressure exerted between the forward flights of the two belts 57 and 58 and the relatively light adherence between the inner belt 57 and the adhesive side of the tape along the longitudinal centerline of the tape. Suflicient stiffness is imparted to the tape 21 by virtue of the three-dimensional transverse cross-section in which it is guided, that the belts may be separated and the inner belt 57 moved away from the adhesive side of the tape without distoring the tape or drawing it around the second inner pulley 64, all of which is described more fully in the aboveidentified application. The concave arcuate threedimensional transverse cross-section of the tape 21 also serves to impart sufficient stiffness or rigidity to the tape to allow the tape to be projected downwardly or advanced away from the feeding unit.

The tape next passes through an opening 66 in the knife or tape severing structure and then through a fixed guiding orifice 67 in the platform 29, as shown most clearly in FIGS. -7 and 12. The guiding orifice 67 in the platform has a circular perimeter, the arcuate dimension of which corresponds to that of the arcuate guiding surfaces 61 of the feeding unit so that the fixed orifice 67 cooperates with the guide track 59 of the feeding unit to maintain the concave arcuate transverse cross-section of the tape as it is projected below the platform.

Movable guide means in the form of a guide plate 68 defining a movable orifice 69 presenting a concave arouate guiding surface 71, which also corresponds in shape to that of the guide track 59 of the feeding unit, is positioned below the platform 29 in line with the fixed orifice 67 and the aforesaid guide track. The periphery of the movable orifice 69 is completed by bolting a cover 75 over the slot formed by the guiding surface 71 in the guide plate. The guiding surface 71 is semi-circular in general outline and tapered inwardly and downwardly from the top. The maximum cross-dimension of the movable orifice 69 is greater than the width of the tape 21 at the top of the orifice 69 and less than the tape width at the bottom of the orifice, thereby assuring that the tape will enter the movable orifice 69 smooth even if it has flattened somewhat from its initial concave cross-section. As shown most clearly in FIGS. 4 and 14, the guide plate 68 is arranged substantially parallel with the adjacent side of the stack 22 and supported at opposite ends by a movable plunger 72 of a pneumatic cylinder 73 and by a guide bar 74 adapted to move with the plunger. The pneumatic cylinder 73 extends through and is supported by a transverse bar 76 bolted to the base plate 44 of the apparatus. The guide bar 74 is attached to the guide plate 68, as indicated above, in such a way that it passes through and is guided by a hole in the transverse bar 76 thereby providing directional rigidity for the guide plate. Thus, the cylinder 73 may be operated to extend the plunger 72 and place the guide plate 68 in contact with the underside of the cantilever platform 29, as shown in phantom in FIGS. 1 and 8. This approximates the first position of the guide plate 68 Wherein it is adjacent the feeding unit 47 with its concave arcuate guiding surface 71 positioned directly under the corresponding concave surface of the fixed guiding orifice 67 in the platform. After tape is projected from the feeding unit 47 through the fixed orifice 67 and into guiding relation with the guiding surfaces of the movable orifice 69 of the guide plate 68, the pneumatic cylinder 73 may be operated to retract the plunger 72 and cause the guide plate to move from its first position to its second position below the stack 22, which is shown in full in FIGS. 1, 5, 6 and 7. The operation of the guide plate 68 in leading and guiding the tape as it is being advanced by the feeding unit will be described more fully hereinafter. Suffice it to say at this point, that the guide means leads the end of the tape a substantial distance beyond the feeding unit in a path extending alongside and spaced from one side of the stack 22 to which a C-clip is to be applied, as shown in dot-dash lines in FIG. 1.

On the opposite side of the tape from said stack 22, is applicator means comprising a pressing foot 79 and a pair of applicator rollers 81, one located above and the other below the foot 79. The pressing foot 79 and applicator rollers 81 are mounted for movement in a path substantially normal to the path of the tape, and that of the guide plate 68, to press the tape into adhering relation with the stack 22 and apply it thereto.

The pressing foot 79 comprises a vertical pressing member 82 which presents a surface substantially parallel with the side of the stack 22, and a layer 83 of resilient material such as a 30 or 40 druometer rubber sheet adhered thereto for pressing the tape into close contact with at least the central portion of the side of the stack 22. The vertical pressing member 82 is attached centrally to a transverse bar 84 which, in turn, is secured adjacent its ends to a pair of parallel driving rods 85 passing through and journaled in the structure of the supporting column 30. These rods 85 are bolted at their opposite ends to a connecting plate 86 which also is attached to the plunger 87 of a pneumatic pressing cylinder 88 mounted on the side of the supporting column 30. Thus, when the plunger 87 is retracted in the pressing cylinder, the pressing foot 79 is driven towards the tape 21 and then into contact with the side of the stack 22 to press the tape into contact with the stack. When the plunger 87 is extended from the pressing cylinder, the pressing foot is retracted to the position shown roughly in FIG. 1.

Each of the applicator rollers 81 is mounted on a stub shaft 89 journaled in the end of a horizontal applicator arm 91, and each of the applicator arms comprises a fixed horizontal segment 92 and a pivoted end segment 93 on which the roller 81 is mounted. Each of the pivoted end segments 93 is fixed to a short stub shaft 94 journaled in the end of the fixed segment 92 of the respective arm. The outer end of each of the pivoted segments 93 and, therefore, the respective applicator roller 81, is urged towards, or in the direction of, the pressing foot 79 by a coil spring 95 mounted on a portion of the stub shaft 94 which extends through the fixed segment 92 of the respective applicator arm. In each case, the coil spring 95 is attached to the fixed segment 92 of the arm and to a collar 96 keyed to the stub shaft 94, as illustrated in FIGS. 4 and 9, in such a way as to urge the stub shaft to pivot the end segment 93 of the arm towards the foot 79. An adjustable stop 97 is provided on the fixed segment 92 of each of the arms for contacting a corresponding shoulder 98 on the pivoted segment 93 of the arm to prevent the respective applicator roller 81 from contacting or jamming against the pressing foot 79. As shown in FIG. 1, and more clearly in FIG. 10, this stop 97 is in the form of a screw threaded through a boss 99 extending from the fixed segment 92 of the arm. As a result, when the applicator means is at rest at one side of the tape 21, as shown in FIG. 1, the applicator rollers 81 are retained in position immediately above and below the pressing foot 79 by the stops 97. However, when the foot 79 and the rollers 81 are moved into contact with the stack 22 to apply the tape thereto, the pivoted segments 93 of the arms are free to pivot away from the foot 79 against the resistance of the coil springs 95 to allow the rollers 81 to fit around the stack 22 and press the tape 21 downwardly (in the case of the top roller) and upwardly (in the case of the bottom roller) against the top and bottom surfaces of the stack, respectively.

The fixed segment 92 of the bottom applicator arm 91 is attached to an applicator housing 101 in such a way that it is fixed on the housing and is adapted to move therewith. The fixed segment 92 of the upper, or top, applicator arm 91 is attached to a boss 102 secured to the upper end of a vertical rack 103 mounted for vertical movement with respect to the applicator housing 101 and adjustable vertically therein. As illustrated most clearly in FIGS. 1, 9 and 10, the rack 103 passes through a vertical slot in the housing in such a way that its teeth engage the teeth of an adjusting pinion 104 mounted for rotation in the housing on a pinion shaft 105 to which it is fixed through a collar 106 integral with the pinion. The pinion 104 may be rotated to raise or lower the rack 103 and, therefore, raise or lower the upper applicator am to adjust its position with respect to the pressing foot and the lower applicator arm, merely by turning an adjusting wheel 107 fixed to the opposite end of the pinion shaft 105. To hold the pinion 104, and, therefore, the upper applicator arm, in a given position, a locking wheel 108 is provided on the pinion shaft 105 between the adjusting wheel 107 and the housing 101. The locking wheel 108 is threaded on the shaft in such a way that it may be tightened against the housing 101 to hold the pinion 104 in position.

The applicator housing 101 is mounted on the ends of a second pair of guide rods 109, mounted one above the other for horizontal slidable movement in and through supporting column 30. The housing 101 also is attached 7 centrally to the outer end of the plunger 110 of a pneumatic driving cylinder 111 for the applicator rollers 81. In this case, the plunger 110 is extended to move the rollers 81 into contact with the tape 21 and, together with the pressing foot 79, to apply the tape to the stack 22. As will be explained more fully hereinafter, the driving plunger 110 has a greater travel than the plunger 87 of the pressing cylinder 88 since the applicator rollers 81 continue to move over the top and under the bottom, respectively, of the stack 22 after the pressing foot 79 has been stopped in its motion by coming into contact with the side of the stack. When the applicator rollers 81 have completed their travel and the C-clip 25 is applied to the stack, the rollers are withdrawn to the position shown in FIG. 1 by retraction of the plunger 110 in the driving cylinder 111.

As indicated hereinbefore, the knife 48 for severing the tape 21 from its supply as it is about to be applied to the stack (after the tape has been projected from the feeding unit 47) is mounted on the cantilever platform 29 above the stack 22. The knife 48, which has a V-shaped cutting edge 112, is in the form of a flat plate bolted to the underside of a supporting bracket 114 which, in turn, is attached through a vertical bar 114 to the plunger 115 of a solenoid 116 for operating the knife. The knife 48 normally is urged away from the tape 21 by a compression spring 117 which presses against the vertical bar 114 and is adjustable with respect to the knife 48 through a collar 118 keyed to a supporting rod 119 which, in turn, is threaded through a nut 121 attached to a portion of the horizontal casting 53. The knife 48 is guided by slide portions 122 of the horizontal casting 53 and is held in position vertically by a positioning plate 123 which is clamped into resilient contact with the top surface of the knife 48 by a series of four bolts 124, two at each side of the knife, in such a way that the positioning plate 123 normally presses the knife 48 down into contact with the horizontal surfaces of the slide portions 122 but is capable of lifting slightly against the resistance of springs 125 which, in turn, are compressed between collars 126 attached to the bottom ends of the bolts 124, and the under-surfaces of the slide structure, The previously referred to opening 66 in the tape severing structure is located in the positioning plate 123 directly ahead of the cutting edge 112 of the knife. The pulling device 54 and the feeding device 55 are driven from a common source of power, not shown, the operation of which is controlled by a time delay relay, also not shown, which is adjustable to regulate the time of feeding and, therefore, the length of tape 21 projected from the feeding unit. By this means, the size and vertical centering of the C-clip 25 may be adjusted with respect to the thickness and vertical position of the stack 22.

In operation, the tape 21 is drawn from the supply roll 23 by the pulling device 54 and thence to the feeding device 55 of the feeding unit 47. As shown most clearly in FIG. and described hereinbefore, the tape 21 is caused to assume a concave arcuate three-dimensional transverse cross-section as it passes through the feeding device 55 and is projected cantilever fashion by the feeding device through the orifice 66 in the cutter structure and the fixed orifice 67 in the platform 29 and then into the movable orifice 69 of the guide plate 68 of the tape guiding means. At this time, the guide plate 68 is in its first position, shown in phantom in FIGS. 1 and 8, directly under the fixed orifice 67 in the platform. The fixed orifice 67 and the movable orifice 69 both are shaped, as indicated hereinbefore, to maintain the concave arcuate transverse cross-section of the tape, and therefore the rigidity of the tape, as the tape passes therethrough.

After the leading end of the tape 21 enters the movable orifice 69 of the guide plate and a short length of the tape passes through the movable orifice, the guiding cylinder 73 is actuated to cause the guide plate to move longitudinally downward with the tape at a speed slightly greater than that of the tape in such a way that it tends to draw the tape downwardly alongside the stack 22 of boards to be taped. However, the speed of the guide plate is such that the movable orifice 69 remains in guiding relation with the leading end of the tape 21 throughout its travel from the first position of the guide plate, referred to above, to its second position shown in full in FIGS. 1 and 5-7. At this point, a length of tape is positioned in a path extending more or less parallel with an alongside the stack 22 with its adhesive side facing the stack, as shown most clearly in FIGS. 1 and 5. The leading end of this tape still is held in the movable orifice 69 and its trailing end extends through the fixed orifice 67 and is attached to the tape supply through the feeding unit.

Almost simultaneously, the tape severing solenoid 116 and the pneumatic cylinders 88 and 111 are respectively operated to cause the tape severing knife 48 to move into the tape 21 and sever it from its supply and to cause the pressing foot 79 and applicator rollers 81 of the applicator means to move sideways into contact with the tape strip 21 extending alongside the stack 22 and push the tape into adhering contact with the stack, as shown in FIG. 6. At this point, the pressing foot 79 and the rollers 81 draw the leading and trailing ends of the severed tape strip out of the movable orifice 69 of the guide plate 68 and the fixed orifice 67 0f the platform 29. The rollers 81 then cause the ends of the tape strip to swing down into contact with the top and bottom surfaces of the stack 22 and then proceed over and under the stack and, by virtue of the fact that they are urged towards each other by the springs 95, roll the tape firmly into adhering contact with the top and bottom surfaces of the stack. In the meantime, the resilient surface 83 of the pressing foot 79 presses the intermediate portion of the tape into firm contact with the side surface of the stack 22. In this manner, the desired tape length is applied to the stack in the form of a C- clip 25. Then, the pressing foot 79 and the rollers 81 are retracted to the position shown in FIG. 8, the cylinder 73 is operated to move the guide plate 68 back to its first position, and the clamping pad 27 is lifted so that the taped stack 22 may be moved to another position. The apparatus then is ready for another taping cycle.

As indicated hereinbefore, the apparatus may be adjusted to accommodate the thickness of the stack 22 both by raising the platform 29 to elevate the feeding unit 47 and the clamps 26 which hold the stack in position on the table 24, and by operating the adjusting wheel 107 for the rack 103 to elevate the uppermost arm 92 for the applicator rollers 81. Since the lower roller 81 is fixed in position vertically, the span between the two rollers may be adjusted in this manner to accommodate stacks of different thickness for applying a C- clip thereto.

Having now described the invention in specific detail and exemplified the manner in which it may be carried into practice, it will be readily apparent to those skilled in the art that innumerable variations, applications, modifications, and extensions of the basic principles involved may be made without departing from its spirit or scope.

What is claimed is:

1. Apparatus for applying pressure-sensitive adhesive tape to an object to be taped which comprises, feeding means in contact with the tape and adapted to project a strip of said tape longitudinally beyond said feeding means, guide means for leading the end of the tape a substantial distance beyond said feeding means in a path extending alongside and spaced from said object and with the adhesive side of the tape facing said object, the tape end being unrestrained by said guide means for movement longitudinally in said path with respect to said guide means but being retained laterally in said path by said guide means, and applicator means movable in a path generlly normal to the path of the tape for pressing the tape into adhering contact with said object.

2. Apparatus according to claim 1, which comprises guide means having a first position adjacent the feeding means in which said guide means first enters into guiding relation with said tape and a second position remote from said feeding means in which said guide means remains in guiding relation with the leading end of said tape strip, said guide means in its second position being removed from the path of the applicator means.

3. Apparatus according to claim 2, wherein said guide means after engaging said tape moves longitudinally in the same direction and at substantially the same linear speed as said tape.

4. Appratus acording to claim 3, wherein said guide means moves longitudinally at a speed equal to or slightly greater than that of the tape.

5. Apparatus according to claim 3, wherein the guide means contacts only the longitudinal edges and the nonadhesive backside of the tape.

6. Apparatus according to claim 2, wherein said feeding means is adapted to cause the tape to assume a threedimensional transverse cross-section to impart stiffness thereto as it is being fed, and the guide means is shaped to cause the tape to maintain its three-dimensional transverse cross-section.

7. Apparatus according to claim 2, wherein the tape is drawn from a supply roll through said feeding means and which further comprises tape severing means adjacent the feeding means for severing the tape strip from the supply roll after said guide means reaches its second position, and a fixed tape guide positioned between said tape severing means and said guide means in its first position for guiding the trailing end of the tape strip.

8. Apparatus according to claim 7, wherein said applicator means comprises a pair of rollers adapted to roll the ends of the strip into adhering contact with the object to be taped.

9. Apparatus according to claim 8, wherein said applicator means also comprises a pressing foot located between said rollers, said rollers being spaced from one another longitudinally of the tape by a distance at least equal to the length of the foot, and said foot being adapted to press an intermediate portion of the tape strip into contact with the object to be taped.

10. Apparatus for applying pressure-sensitive adhesive tape to an object to be taped which comprises, feeding means in contact with the tape and adapted to project a strip of said tape at a given linear speed longitudinally beyond said feeding means, guide means for leading the end of the tape a substantial distance beyond said feeding means in a path extending alongside and spaced from said object and with the adhesive side of the tape facing said object, said guide means having a first position adjacent the feeding means in which said guide means first enters into guiding relation with said tape and being adapted after engaging said tape to move longitudinally in the same direction and at substantially the same linear speed as said tape to a second position remote from said feeding means, said guide means remaining in guiding relation with the leading end of the tape strip throughout its travel from its first to its second position, and applicator means for pressing the tape into adhering contact with said object.

11. Apparatus according to claim 10, wherein said guide means moves longitudinally at a speed equal to or slightly greater than that of the tape.

12. Apparatus according to claim 10, wherein said feeding means is adapted to cause the tape to assume a three-dimensional transverse cross-section to impart stitfness thereto as it is being fed, and the guide means is shaped to cause the tape to maintain its three-dimensional transverse cross-section.

13. Apparatus according to claim 10, wherein said guide means defines a guiding orifice adapted to receive said tape and the tape is free to slide longitudinally therein.

14. Apparatus according to claim 13, wherein said guide means contacts only the longitudinal edges and the non-adhesive backside of the tape.

15. Apparatus according to claim 10, wherein the tape is drawn from a supply roll through said feeding means and which further comprises tape severing means adjacent the feeding means for severing the tape strip from the supply roll after said guide means reaches its second position.

16. Apparatus according to claim 15, which further comprises a fixed tape guide positioned between said tape severing means and said guide means in its first position for guiding the trailing end of the tape strip.

References Cited UNITED STATES PATENTS 2,809,141 10/1957 Biddison 156-477 X 3,050,107 8/1962 Barry et a1 156486 3,420,723 1/1969 Thorp 156--477 X BENJAMIN A. BORCHELT, Primary Examiner J. I. DEVITI, Assistant Examiner US. Cl. X.R. 156-479

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