US2820517A - Tape cut-off mechanism - Google Patents

Description

Jan. 21, 1958 P. w. JAcoBsEN TAPE CUT-OFF' MECHANISM 3 Sheets-Sheet 1 Filed Aug, 9, 1954 Engg aan: f Paul W c/Zzcoben Jan. 21,1958 P. w. JAcoBsl-:N

I TAPE CUT-OFF MECHANISM Filed'Aug. 9, 1954 s Smeets-sheet 2 Pau! MVr/620012.56@

Jan. 21, 1958 P. w. JAcoBsl-:N

TAPE CUT-OFF MECHANISM 3 Sheets-Sheet 5 Filed Aug. 9, 1954 u! Jacobsen W Z z 775 Si @DQ United TAPE CUTeFlF MECHANISM Application August 9, 1954, Serial No. 448,573 1 Claim. (Cl. 164-43) This invention relates to a method and means for controlling a work lstroke in timed relation to movement of each of a series of articles past a work station, and particularly to apparatus for successively cutting a continuous length of tape in the application of the tape to a succession of travelling articles.

The invention has particular `application to a tear strip applying machine for carton blanks. A feeding and take off mechanism suitable for delivering carton blanks to the cut-off mechanism of the present invention is illustrated in my cgi-pending application Serial No. 378,843, iiled September 8, 1953, now Patent No. 2,787,467.

`It is an object of the present invention to provide a cutoif mechanism for use with a tear strip applicator machine Where cut-oif is controlled automatically by travel of the carton blanks through the machine.

It is a further object of the present invention to provide a compact and rugged mechanically controlled cutoff system `for use in applying tape to a succession of traveling articles.

It is another object of the present invention to provide a cut-.olf mechanism and method for a tear strip applicator which accommodates precise adjustment of the cut-off stroke in relation to the trailing edge of a carton blank traveling through the mechanism.

lt is still another object of the present invention to provide a system and method for controlling a work operation in timed relation to a traveling article.

According to the features and objects of the present invention there is provided a cut-off system for a tape applying machine including means for placing the cut-off mechanism in readiness to execute a work stroke as each article enters the machine, and separate means cooperating with an article passing through the machine for determining the precise timing of the cut-off stroke in relation to the trailing edge of the article.

According to further features and objects of the present invention, there is provided means for lifting the entire tape cut-off mechanism away from the path of travel of the articles by means of a single control.

Other objects, features, and advantages of the present invention will be apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Figure l is a fragmentary side elevational view of a tape cut-off system according to the present invention incorporated in a tear strip applicator machine with certain parts inl section and showing the cutoif system in readiness to begin a cut-off cycle in relation to an article entering the machine;

Figure 2 is a `fragmentary the structure of Figure l;

Figure 3 is a fragmentary vertical sectional view taken generally along the line lll-lil of Figure l;

Figure 4 is a fragmentary longitudinal sectional view illustrating certain details of construction;

Figure 5 is a fragmentary side elevational view of the structure of Figure l, but showing the cutoff mechanism left end elevational view of atent ice after execution of a cut-olf stroke in relation to the trailing edge of an article traveling through the machine; and l Figure 6 is a diagrammatic electric circuit illustrating schematically the limit switches in a series circuit controlling the energizing circuit for the solenoid.

As shown on the drawings:

The cut-.off system of the present invention is adapted to form an integral part of a .tear strip applying mechanisrn for usein applying tear strips to carton blanks traveling through the machine. A tear strip applicator machine including a feeding and take-olf mechanism for delivering carton blanks to the tape applying mechanism isillustrated in my co-pending application Serial No. 37 8,843.

As illustrated in Figure l, the tape applying section of the machine may have means including upper and lower feed rolls 10 and ll. for moving carton blanks such as indicated at 12 along an applicator deck 15. The tape applying mechanism may be mounted on a support structure including a horizontal shaft 16 for adjustment transversely of the path of movement of the carton blanks.

The tape applying mechanism may utilize a continuous roll of normally tacky pressure-sensitive adhesive tape (not shown) from which `successive strips are drawn and applied to the successive carton blanks such as 12 traveling through the tape applying section of the machine. The tape when intended as a tear strip is preferably hooked around the leading edge of the carton blank with a free end of the tape on the underside of the blank serving as `a tab which will be disposed on the exterior of the assembled carton and which is pulled to tear open the carton.

In operation of the tape applying mechanism, a length of tape is drawn from the supply roll (manually in the first instance) and an end portion 20 thereof is tem porarily applied to a platen 21 lying slightly below the level of the deck plate 15. An unapplied portion of the tape indicated at 22, extends upwardly from the platen to and around an applying roller 26 and thence upwardly to the supply roll (not shown).

When a carton blank is fed into the tape applying section by means of the feed rollers 10 and 11, the leading end of the blank strikes a pilot roller 3i, whereby the pilot roller is raised and with it the trailing end of frame 33, thus turning the frame counter clockwise about a pivotal shaft 34 carried by the plate 15() against the pull of spring 36, and thereby causing the applying roller 2.6 at the leading end of the frame 33 to move downwardly into contact with the top surface of the blank. The tape is thus applied by the applying roller 26 to a leading edge surface of the blank and thence along the top surface of the blank to the point of contact of the applying roller 26 with the blank. The application of this length of tape on the front edge of the blank and along the top surface thereof is accomplished by the time the blank commences to pull or withdraw fresh tape.

Continued advancement of the blank peels off the portion 20 of the tape that was initially applied to the platen 21 and thus turns the tape back on itself so that it becomes applied to the bottom of the blank until all the portion 20 has been transferred from the platento the bottom of the blank. At the same time, the portion 22 becomes adhered to the top of the blank, since the applying roller 26 continues to bear down on the blank as long as the pilot roller 31 is held up by the blank.

After the trailing end of the blank has passed the pilot roller 31, the spring 36 returns the applying roller frame 33 to its normal position shown in Figure i with the applying roller 25 above the level of the path of travel of the blanks.

The tape applying mechanism may include a take-up device such as disclosed in my copending application entitled Mechanical Take-Up for Tear Strip Applicator, Serial No. 429,348, filed May l2, 1954.

The present application is an improvement over my copending application entitled Mechanical Cut-OE for Tear Strip Applicator, Serial No. 429,350, filed May 12, 1954.

The illustrated embodiment of the present invention is adapted to form an integral part of a tear strip applying machine for use in applying tear strips to carton blanks traveling through the machine, and corresponding reference numerals have been applied to certain of the corresponding parts in the two illustrated embodi` ments.

As indicated in Figure 1, before a carton blank enters the tape applying section of the machine, the tape cutoff assembly 37 is maintained in a raised position vabove the deck by means of a spring 151 connected between a bracket 152 carried by the tape carriage 230 and a bracket 153 secured to a pivot block 155 which transmits the spring raising force to the cut-off assembly 37 through upper arms 157 and 158, pivot shafts 159 and 160, and lower parallel arms 162 and 163 keyed to said pivot shafts 159 and 160 at the upper ends and pivotally connected to the cut-off assembly 37 at the lower ends by means of shafts 165 and 166. The lower arms 162 and 163 thus provide a parallelogram linkage for raising the cut-off assembly 37 in a fixed generally horizontal orientation.

For initiating the cut-off stroke of the cut-off assembly 37 in precise timed relation to the trailing edge of the carton blank 12 entering the machine, means is provided for exerting a downward force on the cut-off assembly as the carton blank travels under the cut-off assembly, and separate means is provided for engaging the upper surface of the carton blank as the cut-olf assembly is urged downwardly to prevent a Work stroke of the cut-0E mechanism until the trailing edge of the blank travels past the cut-off knife 39.

To this end, a pair of limit switches 170 and 171 are provided. The limit switch 170 has an actuating arm 172 which is secured to a shaft 173 and is pivoted as the leading edge of the carton blank enters the tape applying section, while the limit switch 171 has an actuating arm 175 which is secured to a shaft 176 and is pivoted by the carton blank as the leading edge thereof approaches the discharge feed rollers 177 and 178. The limit switches 170 and 171 are connected in an electric circuit in such a manner as to initiate cut off when the leading edge of the box blank has traveled under the actuating arm 175 of switch 171 and is being driven by discharge rollers 177 and 17S, while the trailing edge of the carton blank has moved past the forward actuating arm 172 of the forward sensing switch 170.

For example, as illustrated in Figure 6, limit switch 170 may be closed when its sensing arm 172 is resting on the applicator deck 15, while limit switch 171 may be closed when its sensing arm 175 is riding on the upper surface of a carton blank, and the switches may be connected in series in an electric circuit.

Thus with the front sensing arm 172 on the deck and the rear sensing arm 175 riding on the upper surface of a carton blank, an energizing circuit for a solenoid 184 is closed to energize the solenoid and retract the armature 185 thereof. Retraction of armature 185 stretches a spring 187 which acts on the block 155 through a bracket 188 to tend to urge the cut-off assembly in the downward direction; however a sensing roll 190 carried With the cut-olf assembly is disposed to engage the upper surface of the carton blank and ride thereon to hold the cut-off assembly out of the path of the carton blank as the carton blank travels thereunder. When the carton blank trailing edge has traveled past the sensing roll 190, the sensing roll is no longer operative to prevent cut-off stroke of the cut-olf assembly and the spring 187 is then operative to drive the cut-off assembly 37 and the sensing roll 190 downwardly into the cut-off position shown in Figure 5.

When a further carton blank enters the machine and CII actuates the arm 172 of limit switch 170, or after the trailing edge of the carton blank travels past the arm 175, the energizing circuit for the solenoid 184 will be interrupted, and the spring 151 will be operative to raise the cut-off assembly 37 to its upper position in readiness for a further cut-olf cycle. The limit switch 170 thus provides a safety feature for insuring that the cut-off assembly will be raised even though the carton blanks follow each other in close succession. As seen in Figure 1, a stroke adjustment screw 191 limits the upward movement of the cut-off assembly by spring 151. The screw 191 is threadedly carried by a sleeve 192 secured to a bracket 193 carried by the mounting plate 150.

It will be understood from the foregoing description f that the sensing roll 190 is not urged into engagement with a carton blank traveling through the machine until the trailing edge of the carton blank has passed through the front draw rolls 10 and 11, so that the blank cannot buckle as a result of the extra load placed thereon by the sensing roll 190. The blank at the time the sensing roll 190 moves into engagement therewith under the urging of the solenoid 184 is simply being pulled through the machine under the tension of the pull of the rear draw rolls 177 and 178. Further, the solenoid may be energized from an alternating current source indicated at 197 in Figure 6, since the spacing between the actuating arm 172 of sensing switch 170 and the sensing roll 190 is such, in relation to the speed of the carton blank through the machine, that regardless of in what portion of the alternating current cycle the switch 170 is actuated, the carton blank will still be under the sensing roll 190 after the armature 185 has been fully retracted by energization of the solenoid 184. Thus energization of the solenoid 184 will always simply stretch the spring 187 initially pressing the sensing roll 190 against the upper surface of the blank, and actual initiation of the cut-olf stroke will always be mechanically timed by the sensing roller 190 and unaffected by alternating current characteristics.

For connecting the sensing roll 190 to the cut-off assembly 37 and for accommodating relative horizontal and vertical adjustments of the sensing roll 190, a slotted bracket 194 is provided carrying the sensing roller 190 at the lower end thereof by means of a shaft 195 and connected at its upper end to a linkage block 196 secured to the parallel arms 162 and 163 by means of shafts 199 and 200. The bracket 194 s secured to the block 196 by means of a clamping screw 202 extending through the elongated slot 203 of the bracket and threadedly engaging the block 196, the clamping screw 202 being adapted to clamp a pinch plate 204 against the bracket to x the horizontal position thereof. For adjusting the vertical position of the bracket 194 and thus of the sensing roll 190, a pair of cam adjustment members 208 and 209 extend into the slot 203 and have cam portions 210 (Figure l) rotatable about the axes of set screws 212 threadedly connecting with the block 196. Thus, to adjust the vertical position of the sensing roll 190, the heads of the cam members 208 and 209 are rotated with the respective set screws 212 loosened, to secure the desired vertical position of the sensing roll, and the set screws 212 are then tightened. However, the length of the eccentric portion 210 is such that the heads of the cam member will accommodate horizontal siding movement of the bracket 194 even with the set screws 212 fully tightened. Thus, horizontal adjustment of the bracket 194 may be made simply by loosening of the clamp screw 202.

A bracket 220 mounting the tape lay down frame 33 by means of a depending flange 221 is horizontally and vertically adjustable relative to the mounting plate in a manner entirely similar to that just described for the bracket 194.

It will be observed that the limit switch is adjust- Iably mounted by means of a bracket 225 having an elongated slot 226 therein in conjunction with a clamp screw 227 extending through the elongated slot and securing the bracket to the tape carriage 230 which in turn is mounted on the shaft 16 for lateral adjustment of the entire tape applying mechanism. Similarly, the limit switch 171 is adjustably secured by means of brackets 232 having elongated slots 233 receiving clamping screws 234 threadedly engaging the carriage 230.

For accommodating lifting of the entire tape applying mechanism away from the deck plate 15 in case of a carton blank jam up, the mounting plate 150 is pivotally mounted to the carriage 230 by means of a pivot member 240, and a spring 241 is provided for constantly urging the mounting plate 150 to pivot upwardly about the member 240. The pivot member 240 and a further cap cap screw 242 are threadedly engaged with the carriage 230 and are constructed so as to closely hold the mounting plate 150 against the carriage to insure proper vertical positioning of the plate without preventing pivotal movement of the plate about member 240, the plate 150 having an elongated slot 245 accommodating pivotal movement of the plate relative to the cap screw 242.

The plate 150 is locked in operating position by an index lock knob 247 which cooperates with a cone nosed pin 248 which is constantly urged against the surface of the tape applicator carriage 230 by a spring 249 for registration with a cone shaped female index cavity 250 in the surface of the carriage, the cavity being located to index plate 1.50 in the proper operating location. The index lock knob 247 is fastened to the cone nosed index pin 248 so that when the knob 247 is pulled out, the cone nosed index pin is dislodged from its socket 250, Eand the plate 150 swings up due to the tension in spring 241, the plate 150 pivoting about the pivot member 240. Since the tape lay down frame 33 is carried by the bracket 220 which in turn is secured to the mounting plate 150, and since the bracket 255 receiving the bifurcated upper ends of the arms 162 and 163 is also carried by the mounting plate, both the tape applying frame 33 and tape cut oi assembly 37 will be raised away from the applicator deck 15.

The operation of the illustrated embodiment of the present invention will now be readily apparent. As a carton blank enters the tape applying section of the machine, the cut-olf assembly 37 is maintained in its upper position by means of the spring 151 until the carton blank has passed under the limit switch actuating arm 175 and between the discharge rollers 177 and 178, and until the trailing edge of the carton blank has passed the limit switch actuating arm 172. With the limit switch arm 172 on the deck and the limit switch riding on top of the carton blank, a solenoid 184 is energized to press the sensing roll against the upper surface of the carton blank traveling thereunder through the medium of spring 187. When the trailing edge of the carton blank passes beyond the sensing roll 190, the spring 187 is operative to snap the cut-off assembly 37 downwardly so that the cut-01T knife 39 severs the tape as indicated in Figure 5.

It will be apparent that many modications and variations may be effected Without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

In a tape cut-off mechanism, cutting means disposed along the path of travel of a series of articles and movable toward and away from said path of movement of said articles for severing a portion of a length of tape applied to each article in succession, sensing means operatively connected to said cutting means for movement therewith and disposed closer to said path of movement of said articles than said cutting means, a tension spring having one end operatively connected with said cutting means and the sensing means for urging said cutting means and sensing means toward the path of said articles upon tensioning thereof, solenoid means connected with the opposite end of said spring, said solenoid means being operative upon energization thereof to tension said spring to press said sensing means against an article traveling thereby with the sensing means being operative during engagement with the article to prevent cutting of the tape by said cutting means, and said solenoid means and said tension spring being operative upon movement of the article past said sensing means to move the cutting means to cut the tape, and means for energizing said solenoid means a predetermined time period in advance of the article traveling past said sensing means whereby the solenoid means is always fully actuated to tension the spring before the article has travelled past the sensing means.

References Cited in the le of this patent UNITED STATES PATENTS 2,052,903 Stagmeier Sept. 1, 1936 2,072,654 Stagmeier Mar. 2, 1937 2,083,257 Dyment June 8, 1937 2,298,360 Fitch Oct. 13, 1942 2,495,003 Haas Jan. 17, 1950 2,574,181 Hess Nov. 6, 1951 2,652,166 Johnson Sept. 15, 1953 2,721,669 Keely Oct. 25, 1955

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