US3324789A - Apparatus for strapping packages - Google Patents

Description

June 13, 1967 ET R 3,324,789

APPARATUS FOR STRAPPING PACKAGES Filed Jan. 5, 1966 6 sheets sheet l INVENTOR HUGO BUE T 7' IVE plw M ML/ 4 7TOHNEYS June 13, 1967 H. BUETTNER 3,324,789

APPARATUS FOR ST RAPPING PACKAGES Filed Jan. 5,, 1966 G $heets-$heet 2 INVENTOR HUGU BUETT/VER A TTORNEYS June 13, 1967 H. BUETTNER APPARATUS FOR STRAPPING PACKAGES Sheets-Sheet :7

Filed Jan.

HVVE/V TOR HUGO BUETT/Vfl? vile MM ATTORNEYS June 13, 1967 v H. BUETTNER 3,324,789

APPARATUS FOR STRAPPING PACKAGES Filed Jan. 5, 1966 v 6 Sheets-Sheet INVENTOR HUGO BUETT/VER BY I.

A TTORNEYS June 13, 1967 H. BUETTNER 3,324,789

APPARATUS FOR STRAPPING PACKAGES Filed Jan. 5, 1966 6 Sheets-Sheet 5 INVE/V TOR HUGU EUETT/VEI? M MM Q/ A TTORMEXS June 13, 1967 Filed Jan. 5, 1966 H. BUETTNER 3,324,789

APPARATUS FOR STRAPPING PACKAGES 6 Sheets$heet 6 l/VVE/VTOR HUGO BUE T T IVER Br I m M M 1- 4 4 TTOR/VEY United States Patent 3,324,789 AE'PARATUS FOR STRAPPING PACKAGES Hugo Buettner, Gruiten, Rhineland, Germany, assignor to Ampag G.m.b.H. 8; 0mpany KG. Fiied 52111. 5, 1955, Ser. No. 518,939 Claims priority, application Germany, Jan. 9, 1365, A 43,085, A 48438,; Feb. 5, 1965, A 48,330 12 Claims. (Cl. 100-27) This invention relates to apparatus for tying packages and, more particularly, is concerned with an automatic or semi-automatic strapping machine for tying packages with a textile or plastic strap.

According to the prior art, automatic or semi-automatic strapping machines for packages are known where the strap unwinds from a drum positioned on a rotatable ring. In these arrangements, the package to be tied is inserted and supported at a location encircled by the ring with the free end of the tape being held by a free end gripper located at a position ahead of the strap sealing device. The ring is then driven through a full revolution about the package to wrap the strap into a tight loop configuration having opposite strap ends superposed for sealing. Until the time of the present invention, it has been diflicult to assure high speed operation of the rotary ring with packages of different types and configurations and it has been diflicult to provide a reliable arrangement for overlapping the strap ends prior to sealing.

In effecting high speed machine operation, the guiding ring is accelerated abruptly at the beginning of the loop and is stopped abruptly at the end of the loop. This rapid acceleration, the resultant high circumferential speed and the rapid deceleration acts upon the strap being unwound from the drum, tends to develop free Wheeling of the drum upon stoppage of the ring and subjects the strap to jerking forces and undesirably high tension. In addition, it is more difficult to assure alignment and superposition of the strap at opposite ends of the loop.

In the practice of the present invention, the supply drum from which the strap is fed as the drum moves around the package with the ring is acted upon by a brake arrangement to respond to increasing tension on the strap to reduce its holding function or even to eliminate it. As the strap leads from the drum, it is guided over one or more tension rollers carried on a spring loaded lever that applies a braking effect upon the drum. The tension buildup in the strap, acting through the rollers, shifts the lever against the spring action to reduce the brake effect. Initial shifting of the brake lever by strap tension effects direct drive of the drum in a sense to start the drum rotating in its unwinding directing. This avoids development of jerking actions and high tension forces in the strap.

More specifically, the invention provides for guiding and unwinding the strap from the payout drum like a block and tackle over several idler rollers that ride directly upon the guiding ring and over one or more loose rollers that ride on the pivotally mounted brake lever. Several storage loops of strap extend between these sets of rollers. In this Way, comparatively small strap tension values can effect the desired pivoting of the brake lever in order to reduce the braking effect. In this configuration, in the beginning of a strapping cycle there is slack strap available in the multi-roller system and ready for immediate payout. Additional slack strap for convenient initial payout is accommodated by providing a separate floating roller movable against a light spring over a relatively long path in the circumferential direction of the rotatable ring. Any excess of unwound strap is immediately taken up by the action of this roller in the event the ring is stopped suddenly.

An important feature provided in accordance with the practice of the invention is the use of a movable gripper Patented June 13, 1967 which is inactive when the strap is being wrapped into a loop while held in the free end gripper during the rotation of the ring. This movable gripper catches the strap at the feed end of the loop and is operable after the strap loop has been formed by the ring movement to effect final tensioning and alignment of the strap ends in superposed relationship to facilitate final sealing. In a particular movable gripper disclosed herein, the gripper is guided for movement in the plane of the loop of strap, with the gripper first moving slightly away from the package and then moving in a strap tensioning direction and then returning to adjacent the package to bring the strap ends into superposed relation. The movable gripper carries a cooperating clamping jaw that is operable to clamp the strap against a projecting nose on the gripper, the clamping jaw being actuated during displacement movement of the gripper by means of a stationary stop located in the gripper movement path. A sealer unit is timed to operate When the movable gripper brings the strap into overlapping relation.

The movable gripper also carries a knife for cutting off the supply end of the strap, the knife being actuated by a stationary stop in response to final movement of the gripper. In the strap cutting operation, one face of the projecting nose of the gripper nests against the strap loop while the supply section of strap is held against an opposite face of the nose to be cut through by the knife.

Upon completion and cutting of the strapping, the movable gripper returns to its original position and in so doing transports the newly formed free end of the strap into the free end gripper, with the operating lever for the clamping jaw thereafter engaging a stationary stop to free the strap end from the movable gripper in preparation for the next cycle of operation. The gripper movement as disclosed herein is guided by driving the gripper through a rod system which can be raised, lowered and displaced horizontally to execute the required gripper movement path.

One important advantage of the movable gripper arrangement for holding, guiding and overlapping the strap ends resides in the fact that the sealer unit may remain stationary. Any conventional type of sealer may be employed and in any event the actual sealer design will be simplified. In particular, where the sealer employs wrap around seals, feeding of the seals and the operation of the sealer jaws for applying the seals is facilitated where the sealer unit is stationary.

A further aspect of the invention relates to a rotating ring machine arranged to provide a package with a strap loop not only in one plane, but to form a second loop in a manner analogous to that in hand tying which embraces the package in a second plane perpendicular to the first. The invention provides for forming a single length of strap into a multi-l oop crosstie configuration requiring only a single seal. For this purpose, the rotating ring strapping machine is provided with deflection lever movable into the motion path of the feed end of the strap to deflect the same to the side of the sealing unit. When the guide ring for the strap comes to a stop after forming a first loop, the package is turned by and a further loop is formed in a plane at right angles. When the final strap loop is formed the deflection lever is in retracted position so that the feed end of the final loop of strap is brought into the sealer unit in overlapping relation with the free end of the first loop of strap.

The deflection lever may be selectively controlled to enable more than one strap loop to be formed in the first plane. In this event, the deflection lever will act at the end of each such loop and the package will then be turned 90 for information of one or more loops in a transverse plane, with the final loop being formed while the deflection lever is retracted to allow overlapping 3 of the start of the strap with the end of the strap in preparation for sealing.

Instead of guiding the package past the sealing unit for actuation of the deflection lever it is also contemplated temporarily to withdraw the sealing unit from the strap loop and after turning of the package, returning the sealing unit to receive the finish end of the final loop of strap.

Other features and advantages of the invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which show structure embodying preferred features of the present invention and the principles thereof, and what is now considered to be the best mode in which to apply these principles.

In the accompanying drawings forming a part of the specification, and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a front elevational view of a rotary guide ring strapping machine incorporating features in accordance with this invention;

FIG. 2 is an enlarged fragmentary elevational view illustrating a portion of the guide ring, a strap supply drum mounted thereon and a strap guiding and braking mechanism associated with the ring and drum;

FIG. 3 is a detailed sectional view of the drum and shows a brake lever pivotally mounted thereon;

FIG. 4 is an axial sectional view through the supply drum equipped with a pivotal brake lever shown in elevation;

FIGS. 5-8 are rear elevational views illustrating the strapping machine as a whole with portions thereof broken out to facilitate disclosure and with the successive views showing various positions in the operating sequence of a movable gripper;

FIG. 9 is a fragmentary enlarged elevational view further illustrating the movable gripper utilized in accordance with this invention;

FIG. 10 is a related and greatly enlarged view of the movable gripper to show it in approximately natural size;

FIG. 11 is a side elevational view of the gripper structure that is shown in FIG. 10;

FIG. 12 is a reduced transverse section through a rotating ring strapping machine illustrating a pivotally mounted deflection lever used for offsetting the feed end of a strap loop, with the lever shown in retracted position;

FIG. 13 corresponds to FIG. 12 and shows the lever in an' advanced position for deflecting the feed end of the strap; and

FIG. 14 is a related transverse cross sectional view illustrating the lever in retracted position during formation of a final strap loop in a plane perpendicular to the plane of the first strap loop.

Referring now to the drawings and particularly to FIG. 1 thereof, the machine is designated in its entirety at and it comprises main housing structure including a sectional working table 21 bordering a central opening 22 which receives the package P to be tied with strapping. A guide ring 23 is disposed within the housing of the machine 20 to encircle the package opening 22. The guide ring being supported on a pair of upper idler rollers 24 and a pair of lower drive rollers 25, which propel the ring 23 in the direction of the arrow in FIG. 1. At this point, it should be noted that whereas FIG. 1 is a front elevational view, FIGS. 5-8 are rear elevational views and the ring rotation appears counterclockwise in FIG. 1 and clockwise in FIGS. 5-8.

A foot switch 26 is shown in FIGS. 1 and 12-14 to effect turn-on and turn-off of a motor 27 that operates the drive rollers to rotate the ring v23 at high speed. A strap storage drum 28 is rotatably mounted outboard of the ring 23 by means of a bracket 29 (FIGS. 2 and 4). Thus, the strap drum 28 rides with the ring and unwinds to payout strap being wrapped about the package P.

4 The work table, as best seen in FIGS. 12-14, is divided into front and rear sections 21F and 21R to define a strap access way 21W in the plane of the strap loop.

Gripper facilities 30 for the free end of the strap are shown in FIG. 9 and normally underlie the work table and intercept the plane of the access way to receive and hold the free end of the strap until sealing and severing of the loop is completed. The gripper jaws 30 open and retract laterally to permit another free strap end to be moved into position, with the gripper jaws 3t returning to seize the new free strap end. Mechanism for controlling the free end gripper jaws 30 may be of any suitable type and is preferably integrated with the main power drive and control for the machine to be operated in automatically timed relation to the remaining mechanisms described herein.

The mechanism for controlling strap feed from the supply drum during the wrapping motion of the rotating ring is best shown in FIGS. 2, 3 and 4. The strap S as it leads from the drum 28 first runs over a movably mounted idler roller 31 carried at the free end of a lever 32 which is pivoted about an axis 32A located outboard of the ring periphery as determined by a stationary support arm 33. A slack take up spring 34 reacts between the ring .23 and the lever 32 normally to pull the roller 31 farther away from the supply drum 28.

In the particular embodiment illustrated herein, a set of four guide rollers 35 are rotatably carried by the ring in generally peripherally spaced relation and a cooperating pair of guide rollers 36 are carried on an extension arm 37A of a brake lever 37 which is mounted for rotation about the axis of the supply drum 28. The strap S is threaded back and forth between the rollers 35 and 36 to form a pair of storage loops of strap which apply strap tension forces in a direction to pivot the brake lever 37 clockwise as viewed in FIG. 2 against the action of the load spring 38 that normally biases the brake lever towards a position to apply brakin action against the drum. Thus, generally speaking, an increase in strap tension produces a decreased braking effect as is explained in more detail hereinafter.

The brake drum 28 is mounted to rotate on a shaft 39 that is fixedly carried by the outboard bracket 29. A pair of bearings 39B mount the sleeve portion of the drum for axial and rotary movement relative to the shaft 39. The drum end flange 28F is adjacent to the brake lever 37 and is provided with a friction ring 28R and correspondingly the brake lever 37 is provided with a mating friction ring 37R to engage the ring 28R for applying brake action on the drum. A compression spring 40 encircles the outboard end of the shaft 39 normally to bias the drum ring 28R towards the barake ring 37R. In the illustrated arrangement, the compression effect of the spring 40 is adjustable by varying the number of insert rings 41 on the outer end of t-he shaft 39, thereby varying the axial loading on the drum 23. A replaceable cap screw 42 retains the spring 40. An unloader spring 43 reacts against a fixed flange 39F immediately along the shaft 39 and at its other end acts against a mounting hub portion 37H of the brake lever normally to tend to separate the rings 28R and 37R. The bracket 29 is suitably socketed to mount a set of spacer balls 44 which cooperatively bear upon a cam ring 45 that is mounted on the brake lever 37. As illustrated in FIG. 4, the spacer balls 44 are riding against upraised flat regions on the cam ring 45. A series of recesses 45R are provided in the cam ring to receive the spacer balls 29 upon appropriate rotation of the brake lever 37.

When the spacer balls 44 act against the upraised fiat regions of the cam ring 45, pictured in FIG. 4, the braking force exerted on the supply drum 28 by the coacting friction rings 28R and 37R is a maximum and is determined by the spring 40 and by the number of insert rings 41. When the brake lever 37 rotates to receive the spacer balls 44 in the recesses 45R the unloader spring 43 shifts the brake lever 37 while the shaft flange 39F restrains further axial movement of the drum 28 to reduce the engagement of the brake rings and free the supply drum for easy payout of strap.

According to the invention, the shifting movement of the brake lever is determined by the tension in the strap storage loops existing between the rollers 35 and 36. When the tension in the strap increases, these strap storage loops tend to pivot the brake lever clockwise as viewed in FIG. 2 against the action of the spring 38. When this pivoting movement of the brake lever brings the spacer balls 44 into the cam ring recesses, the brake lever 37 is shifted towards the left as viewed in FIG. 4 to reduce or totally eliminate the braking action. It will be noted that the cam ring 45 is mounted to the brake lever 37 by means of screws 46 operating in arcuate slots 375 (see FIG. 3) to enable adjustment of the rotary position of the brake lever and hence of the length of the strap storage loops.

When the guide ring 23 is initially accelerated from the FIG. 1 position wherein the strap is already secured in the grippers 30, the strap tension increases instantaneously to shift the floating roller 31 towards the brake drum against the action of the spring 34. Simultaneously, the strap storage loops between the rollers 35 and 36 shorten and pivot the brake lever 37 clockwise as viewed in FIG. 2. Since the brake action is effective during this movement, the drum 28 rotates with the pivoting brake lever. Thus, the supply drum 28 is started in rotation in the strap unwinding direction by pivoting movement of the brake lever 37. Rapid and easy initial payout of strap is accomplished from the stored strap and is continued by reason of starting the drum rotation by the movement of the brake lever. As the brake force is reduced or eliminated by the pivoting movement of the brake lever 37 the continued rotation of the guide ring 23 and the wrapping of the package now allows unwinding of the drum with the tension in the strap being determined primarily by the springs 34 and 38.

When the aide ring 23 completes a full revolution and stops abruptly the brake lever 37 instantaneously returns to its braking position to take up excess strap and to engage the friction rings 28R and 37R for preventing free wheeling of the strap supply drum 28. Simultaneously, the movable roller 31 is retracted by the spring 34 also to take up any excess strap.

A movable gripper element designated generally at 50 is best disclosed in FIGS. -11, and cooperates with the brake regulated drum 28 in that the movable gripper accurately effects final tensioning and alignment of the strap ends in superposed relation. The movable gripper 50, receives the feed end of a strap loop which has been tightly wrapped about the package and makes corrections for any loop alignment variations associated with the wrapping action.

The sequence views of FIGS. 5 and 6 indicate that the movable gripper is at the same location after a loop of strap has been wrapped about the package, FIG. 6, as when the strap is initially inserted in the stationary gripper in preparation for the wrapping. As the rotating ring 23 carries the supply drum 25 beneath the package to complete a full wrapping cycle with more or less tension acting on the strap dependent on the predetermined machine adjustment, the strap is placed beneath the projecting nose 51 provided at the upper end of the movable gripper in the fashion illustrated in FIGS. and 11. At this point the movable gripper assembly moves downwardly from the position of FIG. 6 to the position of FIGURE 7 and then moves horizontally from the position of FIGURE 7 to the position of FIGURE 8, this movement pattern being controlled by a rod system illustrated d agrammatically and designated generally at 52 in FIGURES 5-8. The movable gripper 50 initially moves downwardly sufficiently to clear the gripper jaws 30 and the sealer jaws in preparation for the horizontal travel of the gripper which finally brings the strap end portions into overlapping relationship.

When the movable gripper reaches the FIGURE '7 position, a clamping jaw 53 is forced and held against the underface of the projecting nose 51 to seize the feed end of the strap. Subsequent horizontal and then vertical movement to the FIGURE 8 position draws the strap more more around the package and brings the opposite ends into superposed relationship.

A set of upper and lower sealer jaws 54 and 55, respectively, as best illustrated in FIG. 9 are provided to form and clamp a seal 56 about the strap ends after the movable gripper 50 brings them into overlapping relation beneath and within the seal 56. The sealer unit may be of a known type wherein the upper jaw 54 is laterally reciproca'ble to effect pick up and delivery of a seal of U- shaped outline. Normally, the upper jaw 54 intercepts the plane of the strap loop and holds the U-shaped seal in preparation for receiving the free end of the strap. The upper jaw remains in this position during the wrapping and tensioning of the strap loop and while the movable gripper brings the free end of strap up into the seal 56. The lower jaw is held laterally retracted during this time to enable entry of the strap ends into the seal and thereafter the lower jaw 55 moves laterally and then upwardly to deform the seal and wrap it in clamping relation about the strap ends before the strap is finally cut. The mechanism for timing the action of the sealer jaws may be integrated with the remaining elements and powered from the main drive system to enable high speed automatic operation.

Other sealer arrangements are also contemplated and other and diiferent techniques may be employed for effecting the seal. In any case, the seal operation is facilitated by the action of the movable gripper 59.

In the illustrated embodiment, as best seen in FIGS. 10 and 11, the movable gripper unit 5%} includes a rigid base 57 carrying a pair of upstanding arms 58 that merge at the top to present the projecting nose 51 which terminates in a widened guide wall 59. A cam 60 is pivoted on this base plate and presents an inclined cam face 60F and a pair of abutment shoulders 60A and 6013 at peripherally spaced locations. The cam 60 carries a lever arm extension 61 which is best shown in FIG. 9. The clamping jaw 53 nests between the upstanding arms 58 and carries a cross bolt 62 adjacent its upper end and having opposite extremities projecting through a matched pair of sloping slots 588 provided in the arms. A spring 63 is connected between the bolt 62 and the base plate 57 normally to urge the clamping jaw downwardly to the position illustrated in FIGS. 10 and 11. A transverse bolt 64 is anchored between the lower ends of the arms 58 and extends through a vertical slot 538 provided in the clamping jaw to guide the clamping jaw through a vertically sloping movement imparted by rotation of the cam 60. The jaw 53 presents a flat upper end face 53F that moves slopingly upwardly to grip the strap against the underside of the projecting nose 51 so that final strap tensioning is determined by the movement of the gripper.

The machine is provided with a stationary stop 65 located to intercept the cam shoulder 056A at an intermediate point along the horizontal travel path of the movable grippers 50 as illustrated in FIG. 7. Continued horizontal travel to the position of FIG. 9 causes the rotation of the cam that actuates the clamping jaw 53 to grip the strap, with the cam then remaining in its FIG. 9 position during subsequent horizontal and upward travel of the movable gripper 59. During such upward movement of the gripper 50 with the supply end of the strap, the nose 51 approaches and nests upon the start or free end of the strap to assure alignment of the strap ends in overlapping relation within the seal 56 which is being held in the upper jaw of the sealer unit. The bottom jaw 55 of the sealer unit is now moved laterally and upwardly toward the top jaw to fold the seal 56 about the overlapping strap ends in a conventional manner. This completes the strap loop and now it merely must be separated from the strap supply.

A cutting knife 66 is mounted alongside one of the upstanding arms 58 of the movable gripper 50 by means of a pivot pin 67 which extends through these arms and is engaged by a bias spring 68 anchored to the base plate 57 normally to hold the knife 66 in the position illustrated in FIGS. and 11. The knife 66 presents a cutting edge 6 6E arranged to sever the supply strap end after the seal 56 is applied under the control of an operating mechanism which is not shown and which is automatically controlled from the main power drive of the machine. A stop 665 is shown in FIG. 9 for actuating the knife 66 at the top of the upward stroke of the movable gripper. The widened guide wall 59 coacts with the cutting edge upon pivoting movement of the knife to accomplish severing of the strap end for freeing the package from the strap supply.

At this point, the tied package may be removed and it is to be noted that the newly formed free strap end is still gripped between the clamping jaw and the projecting nose 51 of the movable gripper. The movable gripper 50 is then actuated to retrace its movement path by first shifting downwardly, then horizontally and then upwardly to its start position. The free end gripper jaws 30 which were previously retracted from the plane of the strap loop now return to seize the free strap end during the approach of the movable gripper 50 to its start position. At this time, the abutment shoulder 603 on the cam strikes a stationary stop 67 provided in the reverse path of the movable gripper to return the cam and enable the bias spring 63 to retract the clamping jaw 53.

An important advantage associated with the action of the movable gripper St in aligning and tensioning the ends of the strap loop resides in the fact that the precise position of the supply drum 28 at the end of a strap wrapping cycle is not critical. For example, it is not necessary that the supply drum 28 be stopped exactly in the hori- Zontal plane of the work table 21. It may be slightly above or slightly below the plane as the movable gripper will see to the proper overlapping of the ends of the loop. If the guide ring 23 is operated at high speed during the strap wrapping cycle and suddenly stopped it is diflicult to assure precise final positioning of the supply drum. The action of the movable gripper in determining the final loop tension and strap overlap relationship makes high speed ring travel feasible.

Additional strap guiding mechanism is shown in FIGS. 12-14 to enable the machine to be controlled in a fashion for tying multiple strap loops in perpendicular planes by means of a single length of strap and with the use of only a single joint. If, at the end of a first strap loop wrapping operation, as already described, it is desired to form a second loop in a perpendicular plane, the mechanism designated generally at 70 in FIGS. 12-14 is rendered operative. The housing of the machine 20 incorporates internal support structure 71 underlying the work table 21 and including an angle bracket 72 which mounts a solenoid 73 to be controlled by a front panel mounted switch 74. The armature of the solenoid drives a link 75 connected to a bell crank 76 pivotally mounted on the angle bracket 72 and having a drive link 77 connecting to the lower end of a vertical deflection lever 78. The deflection lever has an intermediate pivot axis defined by the support structure 71 and in its retracted position illustrated in FIGS. 12 and 14 it is offset slightly from the plane of the strap loop as generated by normal operation of the rotating ring 23 and the movable gripper.

Where a package is to be tied in only a single lane, the deflection lever 78 is left in this retracted position. However, when a package is to be cross tied by multiple loops in perpendicular planes, the switch 74 is actuated to operate the links and bell crank and swing the deflection lever 78 to the position in FIG. 13 wherein it presents an inclined face intersecting the plane of the strap loop for deflecting the strap end laterally sufliciently to prevent it from entering the sealer jaws which are not shown in FIGS. 1214. After this first strap loop is drawn taut, the guide ring 23 is stopped and the package is turned 90 about a vertical axis. The start switch 26 is again actuated and a second loop of strap is formed about the package in perpendicular relation to the first loop. In the meantime, the deflection lever 78 has been retracted so that the end of the final strap loop may be guided into the sealer jaws in the usual fashion, there to be in overlapping relation to the start end of the first strap loop. The return of the deflection lever to enable completion of the final strap loop in the usual fashion may be controlled manually or automatically prior to or during the wrapping of the second loop. The sealing of the strap ends can be accomplished without any problem even though they relate to strap loops that are oriented in different planes. It will be appreciated that several loops of strap may be formed in the first plane by maintaining the deflection lever 78 projected, with the package then being turned 90 to receive several cross tie loops. Again the deflection lever 78 will be projected until the final loop is to be formed at which time the deflection lever is retracted.

Thus, while preferred constructional features of the invention are embodied in the structure illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

What is claimed is: v

1. In a package binding mechanism, package support means defining a strap access way, a rotary strap supply drum, first gripping means adjacent the package support means for gripping a strap end leading from said drum, means for transporting the rotary supply drum along a path that encircles said strap access way to unwind said drum and form a loop of strap about a package that is disposed on said support means, a brake transportable with and engageable with said drum to resist unwinding thereof, and means transportable with said drum and connected to respond to tension in the strap leading from said drum to reduce braking action between said brake and said drum.

2. In a package binding mechanism in accordance with claim 1 and wherein said brake is pivotally mounted adjacent said drum to exert a braking effect related to pivot position and said brake having an extending arm mounting first roller means, resilient means connected to bias said brake towards a pivot position of maximum braking effect, and said transporting means mounting second roller means adjacent and spaced from the first named roller means to receive strap leading from the drum in an expansible strap storage configuration trained between said roller means to apply strap tension in a sense to oppose said resilient means.

3. In a package binding mechanism in accordance with claim 1 and wherein said brake is pivotally mounted adjacent to and coaxially with said drum to exert a braking elfect related to pivot position and said brake having an extending arm mounting first roller means, resilient means connected to bias said brake in a drum Winding relation towards a pivot position of maximum braking effect, and said transporting means mounting second roller means adjacent and spaced from said first roller means to receive strap leading from the drum in an expansible strap storage configuration trained between said roller means to apply strap tension in a sense to oppose said resilient means and enable increased strap tension at the start of drum travel to effect pivoting of the brake for initiating unwinding movement of the drum.

4. In a package binding mechanism in accordance with claim 2 and wherein said transporting means includes said path towards and away from the drum, with strap leading from said drum and first running about said floating roller and then about said first and second roller means, and resilient means connected to bias said floating roller away from said drum and against the direction of said path to take up any excess unwound strap.

5. In a package binding mechanism in accordance with claim 1 and wherein said transporting means is a rotary guide ring having an outboard bracket equipped with a stationary shaft, bearing means on said shaft and mounting said drum for axial and rotary movement relative to said shaft, said brake being pivotally mounted on said shaft adjacent an end of said drum located near the bracket, a cam element mounted to rotate with said brake to react against said bracket and effect axial shifting of the brake towards said drum end in accordance with the brake position, spring means reacting axially between said shaft and said drum to bias the drum end towards engagement with the brake and spring means reacting axially between said shaft and said brake to bias the brake away from the drum end when the cam element permits.

6. In a package tying mechanism, package support means defining a strap access way immediately underlying a package located on said support means, sealing means adjacent the strap access way to receive and join overlapping strap portions, first gripping means adjacent the strap access way for gripping a free end of strap beneath the package to dispose a free end strap portion in the sealing means, strap wrapping means movable along a path that encircles the strap access way to form a loop of strap about the package, a movable gripper having a nose adjacent the strap access way to catch a feed end strap portion as the loop is being completed by the strap wrapping means, and means for moving the movable gripper to bring the feed end strap portion into over lapping relation to the free end strap portion.

7. In a package tying mechanism in accordance with claim 6 and wherein said strap wrapping means includes a rotary strap supply drum presenting a free end of strap engaged in said first gripping means to enable unwinding of said drum to pay out strap as said drum moves along a path encircling the package, a brake transportable with and engageable with said drum to resist unwinding thereof, and means transportable with said drum and connected to respond to tension in the strap leading from said drum to reduce braking action between said brake and said drum.

8. In a package tying mechanism in accordance with claim 6 and wherein said first gripping means is between said sealing means and said movable gripper when the strap wrapping means forms the loop of strap about the package and wherein said moving means thereafter transports said movable gripper to a location where the sealing means is between said first gripping means and said movable gripper.

9. In a package tying mechanism in accordance with claim 8 and wherein said moving means includes means for shifting the movable gripper generally downwardly, then generally horizontally beneath the first gripping means and the sealing means and then generally upwardly.

10. In a package tying mechanism in accordance with claim 9 and wherein said movable gripper has a clamping jaw shiftably mounted thereon and cam means carried on the movable gripper and responsive during horizontal movement thereof to actuate the clamping jaw to grip the free end strap portion against said nose during the remaining movement thereof.

11. In a package tying mechanism in accordance with claim 6 and wherein said movable gripper has a clamping jaw shiftably mounted thereon and normally biased away from said nose, cam means mounted on the movable gripper to actuate said jaw to grip strap against the nose, and a knife mounted on the gripper to sever strap held between said nose and jaw, and wherein said moving means reversibly shifts said movable gripper along a travel path between a loop wrapping position and a loop sealing position, said travel path leading generally downwardly, then generally horizontally and then generally upwardly, said first gripping means being between said sealing means and said loop wrapping position for the movable gripper and said sealing means being between said first gripping means and said loop sealing position for the gripper, and wherein a first stationary stop activates the cam means when the gripper is intermediate along its horizontal motion, a second stationary stop activates the knife as the movable gripper arrives at the sealing position, and a third stationary stop deactivates the cam means when the movable gripper arrives back at the wrapping position to free the new strap end to be held by said first gripping means.

12. In a package tying mechanism, package support means providing a strap access way immediately underlying a package located on said support means, sealing means adjacent the strap access way to receive and join overlapping strap portions, gripping means adjacent the strap access way for gripping a free end of strap beneath the package to dispose a free end strap portion in the sealing means, strap wrapping means movable along a path that encircles the strap access way to form a loop of strap about the package, a deflection lever adjacent the sealing means and active at an advanced position to deflect a feed end strap portion as the loop is being completed by the strap wrapping means, said sealing means and gripping means being stationary and cooperably holding the free end strap portion while the package is turned to rotate the first loop about means for shifting the deflection lever to a retracted position, and means for reactuating the strap wrapping means to form another loop of strap about the turned package to bring a feed end strap portion into the sealing means in overlapping relation to the free end strap portion.

References Cited UNITED STATES PATENTS 2,467,286 4/1949 Young et al. 53-203 2,469,544 5/1949 Bunn -27 2,608,150 8/1952 Cranston 100-27 2,614,487 10/1952 Cheesman 10027 2,696,778 12/1954 Ervin 10027 2,748,692 6/1956 Osgood et al. 10027 2,972,844 2/1961 Ripley 53198 3,126,686 3/1964 Kobylanski 53-198 3,247,781 4/ 1966 Meckler 10027 BILLY I WILHITE, Primary Examiner.

Claims (1)

1. IN A PACKAGE BINDING MECHANISM, PACKAGE SUPPORT MEANS DEFINING A STRAP ACCESS WAY, A ROTARY STRAP SUPPLY DRUM, FIRST GRIPPING MEANS ADJACENT THE PACKAGE SUPPORT MEANS FOR GRIPPING A STRAP END LEADING FROM SAID DRUM, MEANS FOR TRANSPORTING THE ROTARY SUPPLY DRUM ALONG A PATH THAT ENCIRCLES SAID STRAP ACCESS WAY TO UNWIND SAID DRUM AND FORM A LOOP OF STRAP ABOUT A PACKAGE THAT IS DISPOSED ON SAID SUPPORT MEANS, A BRAKE TRANSPORTABLE WITH AND ENGAGEABLE WITH SAID DRUM TO RESIST UNWINDING THEREOF, AND MEANS TRANSPORTABLE WITH SAID DRUM AND CONNECTED TO RESPOND TO TENSION IN THE STRAP LEADING FROM SAID DRUM TO REDUCE BRAKING ACTION BETWEEN SAID BRAKE AND SAID DRUM.

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