US3442203A - Automatic strapping machine employing friction-fused joints - Google Patents

Automatic strapping machine employing friction-fused joints Download PDF

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Publication number
US3442203A
US3442203A US3442203DA US3442203A US 3442203 A US3442203 A US 3442203A US 3442203D A US3442203D A US 3442203DA US 3442203 A US3442203 A US 3442203A
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United States
Prior art keywords
strap
tension
vibrator
gripper
clutch
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English (en)
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Robert J Kobiella
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Signode Corp
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Signode Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B13/00—Bundling articles
    • B65B13/18—Details of, or auxiliary devices used in, bundling machines or bundling tools
    • B65B13/24—Securing ends of binding material
    • B65B13/32—Securing ends of binding material by welding, soldering, or heat-sealing; by applying adhesive
    • B65B13/322—Friction welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/06—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using friction, e.g. spin welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/05—Particular design of joint configurations
    • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/112—Single lapped joints
    • B29C66/1122—Single lap to lap joints, i.e. overlap joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B29C66/4322—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms by joining a single sheet to itself
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B29C66/4324—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms for making closed loops, e.g. belts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/49—Internally supporting the, e.g. tubular, article during joining
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/82—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps
    • B29C66/822—Transmission mechanisms
    • B29C66/8225—Crank mechanisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
    • B29C66/832—Reciprocating joining or pressing tools
    • B29C66/8322—Joining or pressing tools reciprocating along one axis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/71—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the composition of the plastics material of the parts to be joined

Definitions

  • ABSTRACT F THE DISCLOSURE This disclosure is directed to an automatic strapping machine wherein plastic strap is fed about a package at a high rate of speed into overlapping position with the trailing end of the strap.
  • the strap disposed about the article is tensioned and the overlapped ends are moved into engagement under pressure.
  • the straps are moved relative to each other at a high rate of speed to form a friction-fused joint at the interface regions.
  • the strap ends ⁇ are in tension during the formation of the fused joint with the result that the stress distribution existing in the strap during fusion and after the joint has been formed as part of the complete loop is similar.
  • the present invention relates to an automatic strapping machine wherein plastic strap is automatically fed around an article, tension drawn thereon, and the overlapped strap portions secured in place by a joint formed by frictionally fusing the interface regions together.
  • plastic strapping has been extensively used for strapping articles, but only recently has such strap been secured in place by fusing the overlapping strap ends by the generation of heat between the interface surfaces created by the friction forces resulting from the rapid relative movement of the Strap portions when biased together under substantial pressure.
  • Another obviously desirable feature in an automatic strapping machine is one in which the strap can be fed at a relatively high speed, yet tensioned at a low speed and proportionally higher torque by the use of a single motor and drive mechanism.
  • This desirable attribute while not limited in its application to an automatic strapping machine employing friction-fusion mechanism is also part of the present invention.
  • the mechanism hereinafter disclosed provides for highspeed, economical, substantially trouble-free operation.
  • a fully automatic strapping machine which will feed strap at a high rate of speed about an article, after which the leading end of the strap will be retained in place. The trailing end of the strap is then tensioned to tighten the strap about the article. After the strap has been tensioned about the article and the strap placed in overlapping relationship, the overlapping strap portions are squeezed together and moved relative to each other to form a friction-fused joint. When the friction-fused joint is being formed, there are no other members en- ACC gaging the strap, with the result that the tension previously imposed on the strap acts during the period that the joint is being formed.
  • the foregoing method of operation is accomplished by a mechanism, which, while appearing to be quite cornplex, employs simple mechanical components.
  • the feeding and tensioning of the strap, as well as the forming of the joint after the straps have been placed in abutting relationship under high pressure, is accomplished with but a single motor through suitable clutches and gears to sequentially operate the feeding, tensioning, and sealing mechanisms at the appropriate time.
  • the strap is fed at a high rate of speed about the article to be strapped.
  • the motor is reversed to draw tension on the strap, and thus form a tensioned loop about the article.
  • the motor is disengaged from the tensioning mechanism and acts to operate the sealing mechanism through a cam and plate arrangement which serves to move the overlapped strap portions into frictional engagement.
  • a vibrator contacting one of the straps is operated to move one of the straps relative to the other to fuse the interface region of the overlapped strap portions.
  • the strap loop Prior to the fusing of the overlapped sections, the strap loop has been severed from the strap roll by a suitable cut-olf mechanism located adjacent the strap gripping mechanisms. After the joint has been formed, the motor is then reversed and acts to operate the feeding mechanism and begin a new cycle.
  • FIGURE l is a schematic cross-sectional view 0f a strapping machine and associated strap guide with an article located therein to be strapped;
  • FIGURE 2 is an elevation view of the strapping machine shown partially broken away to illustrate various component parts
  • FIGURE 3 is a plan view partially broken away of the strapping apparatus shown in FIGURE 2;
  • FIGURE 4 is a sectional view taken along line 4-4 of FIGURE 2;
  • FIGURE 5 is a sectional View taken along line 5-5 of FIGURE 3;
  • FIGURE 6 is an elevation view of the tension clutch
  • FIGURE 7 is an end view of the tension clutch illustrated in FIGURE 6;
  • FIGURE 8 is a perspective view of the strap cutter
  • FIGURE 9 is an elevation view partially broken away showing the mechanism for gripping the overlapped stra-p sections and taken along line 9-9 of FIGURE 4;
  • FIGURE 10 is a perspective view of the carriage and associated gripper elements
  • FIGURE 11 is a sectional view of the face gate shown in the strap engaging and disengaging positions
  • FIGURE 12 is an exploded perspective view of the cam and clutch mechanisms employed to squeeze the straps together and drive the vibrator;
  • FIGURE 13 is a plan view of the clutch mechanism shown in FIGURE 12 in position prior to engagement to oscillate the vibrator;
  • FIGURE 14 is a perspective view of the cam face and associated vibrator plate.
  • FIGURES 15-19 are sequential views showing the positions of the various grippers starting from when the inner strap end is maintained in place against the vibrator by a temporary holding gripper through the various steps until the overlapped strap ends are pressed into tight frictional engagement between the vibrator and the main grippers free of any other holding members.
  • this invention is directed t0 a strapping machine for use with plastic strapping.
  • a strapping material that could be used is nylon.
  • the invention is not limited to this specific material as other plastics such as polypropylene could be employed.
  • FIGURE 1 there is illustrated in schematic form a motor 10 that is used to drive the feeding, tensioning, and sealing mechanisms through suitable drive mechanisms to be described in detail here inafter.
  • the feeding and tensioning mechanisms are operated by a belt 12 (FIGURE 3) driven by the motor 10.
  • the feeding mechanism pays off strap from a roll 21, past the feeding and tensioning wheels, through the joint forming mechanism and around a strap guide 14 to envelop the article 16 to be strapped located within the guide 14.
  • the guide 14 can be of any suitable design and the ⁇ details thereof are not important to an understanding of the present invention.
  • Strap feed mechanism Briey the feeding arrangement to be described hereinafter enables the strap to be fed at a very high rate, which is possible since there is essentially no impediment to its travel from the strap supply past the feeding and tensioning wheels, past the sealing mechanism, through 4 the strap guides, and back into overlapping relationship with the lead end of the strap.
  • the strap 20 fed from the roll 21 is directed into a lower guide 22 to between lower pinch rolls 24 and feed wheel 28 that is partially surrounded Eby a guide 26.
  • the strap is directed about the feed wheel by the guide 26 and is biased into engagement with the feed wheel by the upper pinch rolls 30, which provides the initial energizing force for the wrapping eiect.
  • the pinch rolls 24, 30 are biased into engagement with the feed wheel by a tension spring 31.
  • the angle of wrap around the feed wheel provides the pulling force for taking strap from the feed roll 21.
  • the strap After leaving the feed wheel 28, the strap enters a strap guide 32 disposed adjacent to and partially surrounding the tension wheel 34.
  • the resistance of the lead edge of the strap contacting the guide 32 tends to make the strap hug the curve of guide 32, keeping the strap from any appreciable contact pressure against the tension wheel. In this way, the tension wheel does not impede the high-speed feeding rate imposed on the strap by the feed wheel.
  • the tension wheel 34 After the strap leaves the tension wheel 34, it moves through an upper guide 38 past a gripper member 40, which, as described hereinafter, functions to hold the lead end of the strap in place about the package when tension is applied to the strap.
  • a stationary cutter 42 Located adjacent the gripper member 40 is a stationary cutter 42 which has an opening 44 through which the lead end of the strap passes (see FIGURE 8).
  • the strap then moves under a face gate 46 and into strap chutes 14 surrounding the package to be strapped.
  • the face gate 46 functions to separate the overlapping strap portions during feeding, thus facilitating the feeding operation.
  • the face gate 46 is subsequently moved out of the position shown in full lines in FIGURE 11 to that shown in dotted lines therein to permit the overlapped strap portions 20a, 2Gb to be placed in overlapping relationship under substantial pressure when the joint is to be formed.
  • the strap After leaving the chutes 14, the strap travels through the gate 48 and the space provided between the vibrator 50 and gripper 40.
  • the vibrator ⁇ 50 ⁇ functions to form the friction-fused joint between the overlapping strap portions 20a, 20b and will be discussed in detail in the portion of this application dealing with the sealing operation.
  • the strap is directed over the stationary cutter 42 and face gate 46 to where it engages a stop 52.
  • the stop 52 When the stop 52 is engaged, the strap which is being continuously fed by the motor expands outward into the chamber 53 located adjacent the tension wheel 34 against the action of a pivotally mounted drop-out arm 57.
  • the clockwise movement of the arm 57 brings it into contact with a switch 59 that stops the motor 10. Any overrunningr of the motor merely results in a further accumulation of strap in the chamber 53.
  • the dropout arm 57 is designed to initially provide substantial resistance against privotal movement, but once it starts swinging, the resistance substantially decreases.
  • the switch can be designed to be actuated after any given travel of the dropout arm.
  • the gripper 40 is energized (moved upward into engagement with strap end a) by solenod 54 which moves the linkage 55 to the left, as viewed in FIGURE 15.
  • the linkage 55 including the yoke 55a and spring 55h acts on a pin 57a that is secured to link 57.
  • the link 57 is connected to the gripper 40 through pin 61. With this arrangement movement of linkage 55 to the left results in spring 55h moving pin 57a to the left which moves link 57 in a clockwise direction about its pivot ⁇ 59.
  • This mechanism includes a clutch shaft 56y that is driven by the belt 12 connected to the motor 10 in clockwise direction in the illustrated embodiment.
  • the clutch shaft 56 is splined to a tensioner clutch 58, which tensioner clutch includes clutch ramps 60 that are engaged with pinion ramps 62 of the clutch pinion 64 during the feeding operation.
  • the clutch pinion 64 drives a tension gear 66 in a counterclockwise direction that rotates a slip clutch pinion 68 mounted on a shaft 29 to which the feed wheel 28 is con nected in a clockwise direction.
  • the feed ⁇ wheel shaft 29 is driven through clutch discs 70 and acts to rotate the feed wheel at the desired speed.
  • the motor 10 is reversed through suitable electrical circuitry to rotate in the illustrated embodiment in a counterclockwise direction.
  • the clutch shaft 56 now acts to rotate the tensioner clutch 58 counterclockwise, which rotates the clutch pinion 64, and through it the tension gear 66 clockwise and the slip clutch pinion 68 in a counterclockwise direction.
  • the slip clutch pinion 68 rotates the feed wheel shaft 29 and associated feed wheel 28 in a counterclockwise direction to take up the slack in the strap disposed about the article.
  • the strap pinched between the feed wheel 28 and the pinch rolls 24, 30, respectively, is caused to be removed in the direction of the counterclockwise direction of the feed wheel 28.
  • the strap 20 is now pulled back through the chute system 14 and tension is drawn thereon.
  • the strap is retained in position relative to the package bythe gripper 40, which holds the leading end of the strap against the vibrator 50 to keep the strap from being completely pulled back out of the chute and also to provide the necessary means to hold the strap tension reaction.
  • the strap which has been disposed about the tension wheel 34, but out of contact therewith, by sliding against the guide 32, now acts to wrap itself around the tension wheel 34.
  • the tension wheel 34 is positively attached to the tension shaft 36, but the tension shaft 36 receives its turning moment through an overrunning clutch 72, which is attached to the tension gear 66. Since in the instant embodiment the mechanisms are de- CII signed so that the feed wheel 28 rotates 3.3 times faster than the tension wheel 34, the tension wheel 34 and tension shaft 36 will overrun the tension gear and speed up to match the speed of the feed wheel 28. It is again noted that various mechanisms which can be used in this novel feeding and tensioning mechanism are illustrated in the copending application entitled Strap Feed and Tensioning Mechanism, filed in the name of the present inventor and assigned to the same assignee as the instant application.
  • the strap tension begins to increase.
  • the slip clutch pinion 68 will slip causing the feed wheel 28 to stall.
  • the tension gear 66 is positively driven, it continues to rotate Iand drives the tension shaft 36 through the overrunning clutch 72.
  • the tension shaft 36 rotates the tension wheel 34 clockwise at a slower speed and consequently higher torque for pulling the nal tension around the article being strapped.
  • the tension clutch 58 increases, ultimately all the torque required to pull the strap tight is transmitted through the inclined ramp 60 or the clutch pinion 64. This induces a reaction which ⁇ causes the tension clutch 58 to slide along the spline of the clutch shaft 56 in the direction of disengagement with the clutch pinion 64.
  • the tension setting on the clutch pinion 64 which in effect sets the amount of tension to be drawn on the strap, is determined by a toggle linkage 74 shown in detail in FIGURE 5.
  • the desired strap tension can be obtained. That is to say that the clutch pinion will disengage from the tensioner clutch 58 at the strap tension determined by the toggle linkage. After a certain distance of tensioner clutch disengagement, the spring-loaded toggle linkage 74 goes overcenter, thereby snapping the tensioner clutch 58 out of full engagement with the clutch pinion.
  • the feed and tension gear drive train at this point is fully disconnected from the driving motor and further strap tensioning will not take place.
  • the tension gear shaft 36 engages another overrunning clutch 80 to lock itself to a sprocket 82 tending to rotate the sprocket in ya counterclockwise direction.
  • the sprocket 82 acts on chain 84, which is disposed about a smaller sprocket 86 to rotate it in the counterclockwise direction.
  • the sprocket 86 is positively locked to the feed shaft 29 and would thus act to rotate the feed shaft 29 in a counterclockwise direction. Rotation of the feed shaft 29 rotates the feed wheel 28 counterclockwise, which is in the tension direction, thereby locking the feed shaft 29, which in turn locks the tension shaft 36 through the sprockets and chain.
  • the tension in the strap between the feed and tension wheels combined with the wrap effect of the strap around the tension wheel is sufficient to keep the strap from sliding around the wheels. Thus, the strap is locked in this state although the motor has ybeen disengaged therefrom.
  • the strapping machine After the tension has been drawn in the loop, the strapping machine operates to fuse the overlapped strap sections 20a, 20]; into a friction-fused joint.
  • the sealing cycle is accomplished by the motor 10 heretofore used for feeding and tensioning along with various gears, cams, clutches, vibrators, and other mechanisms to be subsequently described.
  • the present invention as illustrated in the present embodiment consists of holding the overlapped strap portions between horizontally parallel pressure members with the full loop tension acting on them.
  • the straps are moved relatively to each other to heat up the interface regions and fuse the overlapped sections together. Since the pressure loaded members are the only means acting on the straps during fusing, the stress distribution that exists in the strap at this time is similar to that which acts on the strap when the loop is completed and removed from the machine.
  • the apparatus disclosed herein is operated at a rate of vibration of approximately 4,000 cycles per minute for a period of approximately one second during which time the interface regions of the overlapped strap ends are melted. After the oscillation of the vibrator member has ceased the strap ends will begin to fuse together to form a joint.
  • the stress distribution across the joint in the overlapped strap ends runs from zero at each end of the strap to a maximum at the opposite end of the joint. The stresses in the overlapped strap ends thus run counter to each other which results in a wavy configuration of the joint when the joint is completed.
  • the vibrator cam 96 driven by the cam shaft 94 first acts to squeeze the overlapping strap portions 20a, Zib together. This is accomplished by the action of a cam follower 106 located in a cam track 98.
  • the cam follower 106 is connected to a toggle plate 104 that contains a pair of slots 112, 138, which guide the actions of toggle links that in turn funetion to move associated carrier members 126, 142, which carry grippers 128, 144 (FIG. 10), respectively, that engage the undersurface of strap portion 20b and move it and strap portion 20a by the application of substantial pressure against the undersurface of vibrator 50.
  • the toggle links 114, 116 for moving carriage 126 upwardly are pivotally connected by a pin ⁇ 108 that is disposed in the upper portion of slot 112.
  • the upper link 114 connects to a pin 124 that is secured in aligned openings in the carriage 126.
  • the carriage 126 contains a gripper 128 having teeth formed therein which engage the undersurface of strap portion 20h.
  • the right-hand carriage 142 containing toothed gripper 1-44 is controlled by the action of toggle links 132, 134 which are connected at their adjacent ends by a pin 130.
  • the pin 130 is located in the upper portion of slot 138 formed in the toggle plate 104.
  • the right-hand carriage 142 is connected to toggle link 134 by a pin 140 (FIG. 10).
  • the lower ends of toggle links 116, 132 have pins 109, 111, respectively, which are located in the lower portions of slots 112, 138, respectively.
  • the slots 112, 138 are designed so that during the upward movement of the toggle plate 104, the pin 108 is first positioned by the incline 110 of slot 112 to push the left-hand toggle links 114, 116 inwardly. During the upward movement of the plate 104, it engages a block 118 secured to a depending plate 46a connected to the face gate 46.
  • FIGURE 11 This relationship can best be seen by referring to FIGURE 11, wherein it is seen that the toggle plate moves the face gate out of engagement with overlapped strap portions to permit the carriage and associated grippers to squeeze the overlapped strap portions together.
  • the toggle links 132, 134 move the gripper 142 upwardly to move it into engagement with the overlapped strap portions.
  • the right-hand gripper 142 is provided with a sharp corner 146, which engages with the cutter 42 to sever the strap from the strap reel.
  • the strap having been retained in place by the left hand gripper 126, there is no problem of the strap previously tensioned becoming unwound.
  • FIGURE 15 The relative movements of the grippers 128, 144 during the gripping steps and after the strap has been tensioned can best be seen by referring to FIGURES 15-19.
  • the grippers 128, 144 are shown out of engagement with the strap ends 20a, 20b and the gripper in engagement with strap end 20a to maintain it against vibrator 50.
  • the toggle plate 104 moves upwardly the gripper 128 is first moved into engagement with strap end 20b to urge it and strap end 20a into clamping engagement between gripper 128 and vibrator 50 (see FIGURE 16).
  • Further movement of toggle plate 104 moves the gripper 144 into the position shown in FIGURE 17 wherein the gripper 144 in conjunction with cutter 42 severs the strap from strap end 20b.
  • gripper 40 is still in contact with strap end 20a. It is noted that the upward movement of gripper 144 has moved pin 142a out of engagement with rod 67.
  • toggle plate 104 brings sloped surface 142b thereof into engagement with rod 67 to move it to the right against the action of spring 63.
  • This movement of rod 67 carries 'with it pivot pin 59 which effectively acts to rotate link 57 and associated gripper ⁇ 40 in a counterclockwise direction out of engagement with strap end 20a.
  • the gripping action with the strap 20a prevents the gripper from moving to the right along with rod 67.
  • the solenoid 54 has been released prior to this action and the counterclockwise movement of link 57 and associated gripper 40 is enhanced by tension spring 69 interconnecting pins 57a and 65.
  • the stroke length imparted by the toggle links 114, 116 and 132, 134 is greater than the stroke needed for the gripper to contact the straps.
  • the overstroke of the toggle links is used to push anchor plate 152 downward, compressing springs 154.
  • the springs 154 thus control the amount of pressure acting on the overlapped straps.
  • the pressure exerted by the grippers 128 and 144 causes the strap portions 20a, 20b to be firmly squeezed together and strap portion 20a to be forced against a toothed surface on the vibrator 50.
  • the oscillating vibrator 50 moves the outside strap position 20a rlative to the inside strap portion 20b, which is held squeezed thereagainst by the toothed surfaces on the grippers 128 and 144. Therefore, the two strap surfaces in contact are being rapidly moved in relation to each other, which by friction produces the necessary heat at the interface regions to fuse the overlapping strap portions together. It is again noted that the strap is only gripped between the vibrator member ⁇ 50 and the gripper jaws 126, 142.
  • the tension in the loop is acting on the joint during the formation of the fused joint. It has been found that this results in a stronger joint than would otherwise be formed. Also, as previously mentioned, the stress distribution which exists in the strap during the fusion operation is substantially similar to that which acts vwhen the loop is completed.
  • the inner strap end 20a will have a stress gradient thereacross running from zero at the free end to a maximum at the end of the joint being formed which as shown in FIGURE 19 is immediately above the right hand corner of the gripper 144.
  • the stress gradient in the strap end 20b l will start ywith zero at the free end and increase to a maximum at the end of the joint which is immediately above the left hand end of the gripper 26.
  • the design of the cam 96 is such that the rubbing of the two straps relative to each other will cease, after a sufficient period of time, to allow the strap joint to cool, To this end, after a predetermined vibration period wherein the overlapped strap ends have been fused and the jo-int formed but not completely solidified, the inner race 158 will be cammed tout of engagement with the overlapped strap portions by the incline 176 on the inner race 158 and on the vibrator cam 96. The driving action between the races 156, 158 will thus be terminated and the 'vibration stopped.
  • the cam 96 is designed so that a brief period of time will then transpire to allow partial solidification of the joint. A further rotation of cam 96 moves cam follower 106 located in cam track 98 to move toggle plate 104 downwardly to retract grippers 126, 142 from the overlapped strap ends.
  • a notch 178 (see FIG. 3) on the vibrator cam 96 then comes to a position which allows the cam follower 180, attached to the vibrator 50 to swing inward about an axle 182. T-his rotation of the vibrator 50 pulls its toothed grip surface away from the joint, thereby allowing the tensioned strap to be snapped out of the machine.
  • the clutch shaft 56 now starts to rotate the tensioner clutch S8 in the clockwise direction.
  • the inclines of the tensioner clutch ramps 90 ⁇ are now tending to drive the clutch pinion 88.
  • Clutch pinion 88 starts to revolve idler gear 190 counterclockwise, but a back stopping clutch 192 prevents the counterclockwise rotation of the idler gear 190, which in turn prevents rotation 'of the clutch pinion '88.
  • the clutch pinion ramps 90 then force the tensioner clutch ramps to yslide out of engagement with each other.
  • the method of operation of the apparatus is as follows:
  • the motor 10 is started and through. various cams and gears the feed and tension wheelsI are actuated to first feed and then tension the strap.
  • the strap 20 is fed from the strap roll 21 into contact with the feed wheel 28 and is then led about, but out of contact with the tension wheel 34 from where it moves up past the motor ldropout arm 57.
  • the leading strap end then moves through an upper guide 38, aligned openings in gripper 40 and adjacent cutter 42, under the face gate v46, and through a guide chute 14 within which is located the article 16 to be strapped.
  • the strap reenters a gate ⁇ 48, moves past the top of the gripper ⁇ 40 and beneath the vibrator 50 into engagement with a stop 52.
  • the motor is then reversed through suitable electrical circuitry and through various cams and gears the tension wheel is driven to draw tension in the ⁇ loop.
  • the toggle linkage 74 is moved overcenter to disengage the motor from the tensioning means.
  • a chain and sprocket assembly 82, 84, 86 is provided to prevent the strap from unwinding when the motor has been disengaged from the tensioning mechanism.
  • the motor then acts, through the action of various clutches and gears, to drive the cam shaft 94 to which is connected the cam 96 that functions to sequentially move the overlapped strap ends against the vibrator member 50 under pressure, cut the strap from its supply, operate the vibrator member to fuse the overlapped strap ends, and move the vibrator out of the way to permit removal of the strapped package.
  • the cam 96 through the action of cam follower 106, moves toggle plate 104 to effect operation of the toggle links 1.14, 116 and 132, '134, to move carriages 126, 142, and associated grippers 128, 144, respectively, into engagement with the overlapping straps 20a, 20b to bias them under pressure against the vibrator member 50.
  • the face gate 46 which was provided to facilitate feeding of the strap about the package, is pivoted out of contact with the strap to permit the overlapping strap ends 20a, 20h to be moved into frictional engagement.
  • the carriage 142 disposed adjacent the stationary cutter 42 during its upward movement acts in conjunction with cutter 42 to sever the strap 20 leading from the strap roll 21.
  • the toggle links are designed so that the carriage 126 and associated gripper 128 are moved into engagement with the overlapping strap portions before the carriage 142 and gripper l1144 contact the cutter 42 to prevent unwinding of the strap.
  • the gripper 40 is released so that the tension in the loop is acting on the overlapped strap ends prior to the operation of the vibrator member to fuse the overlapped strap ends together.
  • the cam 96 has been moved to a position where the clutch jaws ⁇ 162, 164 are allowed to engage and drive the belt 168, which is connected to the vibrator eccentric 170.
  • the rotation of the vibrator eccentric 170 brings about the vibrating movement of the vibrator 50 ⁇ to effectuate the friction fusion.
  • the rubbing of the two straps ceases and after a brief period to allow solidi-cation, the cam follower 180 moves into a notch 184 to move the vibrator out of contact with the overlapped strap ends and thus allow the strapped package to be removed from the strapping machine.
  • a strapping machine for providing a tensioned loop of thermoplastic strap about a package comprising means for automatically feeding and tensioning the strap about a package and placing the overlapped strap ends in a substantially flat plane, means for urging and maintaining the overlapped strap ends together under pressure free of any external holding means whereby the tension in the loop acts on the overlapped strap ends, means for oscillating one strap relative to the other to fuse the overlapped strap sections together at their interface regions.
  • a strapping machine as set forth in claim :1 including motor operated means for rapidly feeding the strap about the package and for tensioning the strap about the package at a reduced rate to draw a high tension in the strap.
  • a strapping machine as set forth in claim 1 including single motor operated means for eifectuating feeding, tensioning, and fusing of the overlapped strap ends, said last mentioned means including mechanisms for effecting sequential operation of the strap feeding, tensioning, and fusing operations.
  • a strapping machine as set forth in claim 3 including means for retaining the strap under tension when the motor means is released from the tensioning means to oscillate the straps relative to each other to fuse the overlapped strap ends together to form the tensioned loop.
  • a strapping machine as set forth in claim 1 in which the means for maintaining the overlapped strap ends in contact under pressure consists of horizontally disposed grippers located adjacent a horizontally extending vibrator member, means for guiding the strap about the package and for holding it in place during tensioning, and means for biasing the grippers into engagement with the overlapped strap ends and against said vibrator and for releasing said holding means whereby the overlapped strap ends are exposed to the tension in the loop during the fusing operation.
  • a strapping machine as set forth in claim 5 including a gate means located adjacent the gripper means to facilitate feeding of the strap about the package, and means for moving the gate out of position during the closing movement of said gripper means.
  • a strapping machine for providing a tensioned loop of thermoplastic strap about a package comprising means for feeding a strap, means for guiding the strap about a package to place the leading end of the strap disposed thereabout in overlapping relationship with the trailing end, means for holding the leading end of the strap relative to the package, means for tensioning the strap disposed about said package, means for maintaining the strap ends in overlapping relationship under pressure, means for cutting the trailing end of the strap from its supply, means for releasing said holding means whereby the overlapped strap ends are in tension, means for moving the strap ends relative to each other to fuse the overlapped strap ends, and means for releasing the fused strap portions to permit'removal of the package from the strapping machine.
  • a strapping machine as set forth in claim 7 in which the means for maintaining the strap ends in overlapping relationship under pressure consists of a pair of adjacent gripper members wherein one gripper includes means for directing the strap into engagement with the cutter means, means for sequentially operating said grippers whereby the gripper effecting the cutting ofthe strap from its supply will not be positioned against the strap until the adjacent cutter Ihas engaged the strap ends to maintain them in position to prevent unwinding of the strap disposed about the package.
  • a strapping machine as set forth in claim 9 including a single motor operated gear and ca-m means for effecting feeding and tensioning of the strap and sealing of the overlapped strap ends into a friction-fused joint.
  • Apparatus for tensioning and sealing a loop of thermoplastic strap about an article said apparatus having means for tensioning the strap about the article to form a tensioned loop with overlapping strap portions, means including confronting substantially flat jaws for holding the loop under tension by maintaining said overlapping strap portions together under pressure whereby tension acts on said overlapping strap portions in a sense to establish a stress distribution pattern generally corresponding to the strap distribution pattern ultimately established by the completed loop, and means operable while said overlapping strap portions are held together under pressure to produce relative movement between said overlapping strap portions to fuse and unify the overlapping strap portions.
  • Apparatus as set forth in claim 11 in which the means for maintaining the overlapping strap portions under pressure consists of a vibrator member and a pair of flat jaws adapted to be moved into contact with the overlapping strap portions to bias the strap against the vibrator under pressure to maintain the friction contact and means for moving the vibrator member relative to the fiat jaws to produce relative movement between the overlapping strap portions to fuse and unify them.
  • Apparatus as set forth in claim 12 in which the at jaw members each consists of a carriage and a toothed gripper member secured in place relative to said carriage.
  • Apparatus as set forth in claim 12 including means for sequentially moving the grippers into engagement with the strap and adjacent vibrator member and for severing the strap from its supply comprising a cutter member disposed adjacent the gripper that is last to be moved into engagement with the overlapped strap portions.
  • Apparatus as set forth in claim 14 in which the means for sequentially moving the grippers includes a toggle plate assembly and toggle links connected to said gripper members, and motor driven cam means operably connected to said toggle plate and toggle links.
  • Apparatus for gripping and retaining strap ends in overlapping relationship including a pair of horizontally disposed gripper Imembers and a vibrator member, means for sequentially moving the grippers into engagement with the strap and against the vibrator member, and means for moving the vibrator relative to said grippers to effect fusion of the overlapped strap sections.
  • each gripper member includes a carriage and a toothed element aixed in position relative to its respective carriages.
  • Apparatus as set forth in claim 16 plus means for setting the gripping pressure and cutter means disposed adjacent one of said grippers and cooperating therewith for cutting the strap from its source.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Basic Packing Technique (AREA)
US3442203D 1967-04-10 1967-04-10 Automatic strapping machine employing friction-fused joints Expired - Lifetime US3442203A (en)

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US62979967A 1967-04-10 1967-04-10

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US (1) US3442203A (cs)
JP (1) JPS541239B1 (cs)
CH (1) CH492603A (cs)
DE (1) DE1761166A1 (cs)
FR (1) FR1551582A (cs)
GB (1) GB1225992A (cs)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3552305A (en) * 1967-08-16 1971-01-05 Power Ind Ltd Tensioning apparatus
US3561350A (en) * 1967-08-16 1971-02-09 Power Ind Ltd Package binding machine
US3841213A (en) * 1971-11-15 1974-10-15 Fmc Corp Strapping machine feed control
US3847071A (en) * 1971-11-15 1974-11-12 Fmc Corp Strapping machine feed
US4011807A (en) * 1976-01-21 1977-03-15 Signode Corporation Strap feeding and tensioning machine
US4050372A (en) * 1976-01-21 1977-09-27 Signode Corporation Automatic strapping machine
US4119449A (en) * 1974-11-25 1978-10-10 Signode Corporation Strapping joint and method and apparatus for forming same
US4227949A (en) * 1978-01-18 1980-10-14 Cyklop-Gesselschaft, Emil Hoffmann Method and device for welding superimposed strips of thermoplastic
US4265687A (en) * 1977-12-27 1981-05-05 The Boeing Company Ultrasonic tape tie strapping method and apparatus
US4313779A (en) * 1979-07-30 1982-02-02 Signode Corporation All electric friction fusion strapping tool
US4328742A (en) * 1980-02-25 1982-05-11 Cyklop Strapping Corp. Strapping apparatus feed and tension mechanism
US4383881A (en) * 1981-09-17 1983-05-17 Strapack Shimojima Co., Ltd. Strapping machine
US4409058A (en) * 1981-10-07 1983-10-11 Nichiro Kogyo Company, Ltd. Band type strapping machine
DE3444391A1 (de) * 1983-12-05 1985-06-13 Masaho Hirakata Osaka Takami Vorrichtung zum verschnueren von paeckchen oder paketen
US4661185A (en) * 1985-03-05 1987-04-28 Signode Corporation Method and apparatus for heat sealing strap in a strapping machine
US4707390A (en) * 1986-06-06 1987-11-17 Signode Corporation Thermoplastic strap weld with encapsulated cavities
US4776905A (en) * 1986-06-06 1988-10-11 Signode Corporation Method and apparatus for producing a welded joint in thermoplastic strap
US4892768A (en) * 1986-06-06 1990-01-09 Signode Corporation Thermoplastic strap with multiple material structure and weld produced therewith
EP0441514A1 (en) * 1990-02-08 1991-08-14 Signode Corporation Time-control circuit for pneumatically operable devices
US5141591A (en) * 1990-05-04 1992-08-25 Rmo Systempack Gmbh Verpackungssysteme Device for the connection of overlapping portion of a thermoplastic band
US5179892A (en) * 1991-03-18 1993-01-19 General Motors Corporation Strap feed assembly with floating back-up wheels
US5380393A (en) * 1992-03-10 1995-01-10 Signode Corporation Hand strapping tool
US20230131439A1 (en) * 2021-10-22 2023-04-27 Abb Schweiz Ag Automated cable tie installation tool with induction welding joining mechanism

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3118710A1 (de) * 1981-05-12 1982-12-09 Cyklop International Emil Hoffmann KG, 5000 Köln Vorrichtung zum spannen, verschliessen und abschneiden von kunststoffbaendern fuer packstueckumreifungen
DE19714309A1 (de) * 1997-04-08 1998-10-15 Signode Bernpak Gmbh Vorrichtung zum Umreifen von Packstücken
KR101613251B1 (ko) * 2008-04-23 2016-04-18 시그노드 인터내셔널 아이피 홀딩스 엘엘씨 전기 드라이브를 갖는 스트래핑 디바이스

Citations (5)

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Publication number Priority date Publication date Assignee Title
SU149296A1 (ru) * 1960-10-24 1961-11-30 В.Д. Вознесенский Способ сварки вибротрением
US3184354A (en) * 1962-02-28 1965-05-18 West Point Mfg Co Method of splicing multifilament yarns by vibratory treatment
US3183824A (en) * 1962-11-13 1965-05-18 Package Sealing Company Export Package binding machines
GB1014988A (en) * 1963-03-06 1965-12-31 Philips Electronic Associated Improvements in or relating to methods and devices for ultrasonic welding
US3269300A (en) * 1964-12-29 1966-08-30 Fmc Corp Strapping machine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU149296A1 (ru) * 1960-10-24 1961-11-30 В.Д. Вознесенский Способ сварки вибротрением
US3184354A (en) * 1962-02-28 1965-05-18 West Point Mfg Co Method of splicing multifilament yarns by vibratory treatment
US3183824A (en) * 1962-11-13 1965-05-18 Package Sealing Company Export Package binding machines
GB1014988A (en) * 1963-03-06 1965-12-31 Philips Electronic Associated Improvements in or relating to methods and devices for ultrasonic welding
US3269300A (en) * 1964-12-29 1966-08-30 Fmc Corp Strapping machine

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3552305A (en) * 1967-08-16 1971-01-05 Power Ind Ltd Tensioning apparatus
US3561350A (en) * 1967-08-16 1971-02-09 Power Ind Ltd Package binding machine
US3841213A (en) * 1971-11-15 1974-10-15 Fmc Corp Strapping machine feed control
US3847071A (en) * 1971-11-15 1974-11-12 Fmc Corp Strapping machine feed
US4119449A (en) * 1974-11-25 1978-10-10 Signode Corporation Strapping joint and method and apparatus for forming same
US4011807A (en) * 1976-01-21 1977-03-15 Signode Corporation Strap feeding and tensioning machine
US4050372A (en) * 1976-01-21 1977-09-27 Signode Corporation Automatic strapping machine
US4265687A (en) * 1977-12-27 1981-05-05 The Boeing Company Ultrasonic tape tie strapping method and apparatus
US4227949A (en) * 1978-01-18 1980-10-14 Cyklop-Gesselschaft, Emil Hoffmann Method and device for welding superimposed strips of thermoplastic
US4313779A (en) * 1979-07-30 1982-02-02 Signode Corporation All electric friction fusion strapping tool
US4328742A (en) * 1980-02-25 1982-05-11 Cyklop Strapping Corp. Strapping apparatus feed and tension mechanism
US4383881A (en) * 1981-09-17 1983-05-17 Strapack Shimojima Co., Ltd. Strapping machine
US4409058A (en) * 1981-10-07 1983-10-11 Nichiro Kogyo Company, Ltd. Band type strapping machine
DE3444391A1 (de) * 1983-12-05 1985-06-13 Masaho Hirakata Osaka Takami Vorrichtung zum verschnueren von paeckchen oder paketen
US4661185A (en) * 1985-03-05 1987-04-28 Signode Corporation Method and apparatus for heat sealing strap in a strapping machine
US4707390A (en) * 1986-06-06 1987-11-17 Signode Corporation Thermoplastic strap weld with encapsulated cavities
US4776905A (en) * 1986-06-06 1988-10-11 Signode Corporation Method and apparatus for producing a welded joint in thermoplastic strap
US4892768A (en) * 1986-06-06 1990-01-09 Signode Corporation Thermoplastic strap with multiple material structure and weld produced therewith
EP0441514A1 (en) * 1990-02-08 1991-08-14 Signode Corporation Time-control circuit for pneumatically operable devices
US5141591A (en) * 1990-05-04 1992-08-25 Rmo Systempack Gmbh Verpackungssysteme Device for the connection of overlapping portion of a thermoplastic band
US5179892A (en) * 1991-03-18 1993-01-19 General Motors Corporation Strap feed assembly with floating back-up wheels
US5380393A (en) * 1992-03-10 1995-01-10 Signode Corporation Hand strapping tool
US20230131439A1 (en) * 2021-10-22 2023-04-27 Abb Schweiz Ag Automated cable tie installation tool with induction welding joining mechanism

Also Published As

Publication number Publication date
DE1761166A1 (de) 1972-04-20
GB1225992A (cs) 1971-03-24
JPS541239B1 (cs) 1979-01-22
CH492603A (de) 1970-06-30
FR1551582A (cs) 1968-12-27

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