US 3101663 A
Description (OCR text may contain errors)
Aug. 27, 1963 M. B. HALL ETAL 3,101,663
AUTOMATIC Box STRAPPING MACHINE Filed Feb. 14, 1957 16 Sheets-Sheet 1 al, H?
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AUTOMATIC Box STRAPPING MACHINE Filed Feb. 14, 1957 16 Sl'xeeizs-Sl'xee'I 6 INVENTORS. fzrcandbzl, BY Edu/@rd hm erzger Aug. 27, 1963 M. B. HALL ETAL AUTOMATIC Box STRAPPING MACHINE 16 Sheets-Sheet 7 Filed Feb. 14, 1957 INVENTORS. ffrcaml Hzl, BY kgm I jer www? l Aug. 27, 1963 M. B. HALL ETAL v 3,101,663
AUTOMATIC BOX STRAPPING MACHINE Filed Feb. 14, 1957 16 Sheets-Sheet 8 .jf Edward SZZzrom w @gil/52997;
Aug. v27, 1963 M. B. HALL ETAL AUTOMATIC BOX STRAPPING MACHINE 1e sheetssheet 9 Filed Feb. 14, 1957 Aug. 27, 1963 M. B. HALL ETAL AUTOMATIC Box sTR'APPING MACHINE 16 Sheets-Sheet 10 Filed Feb. 14, 1957 Allg '27, 1963 M. B; HALL ETAL 3,101,663
AUTOMATIC BOX STRAPPING MACHINE Filed Feb. 14, 1957 16 Sheets-Sheet 11 Aug. '27, 1963 M. B. HALL ETAL 3,101,663
AUTOMATIC Box STRAPPING MACHINE Filed Feb. 14, 1957 16 Sheets-Sheet 12 INVENTORS.
Aug. 27, 1963 M. B. HALL ETAL AUTOMATIC Box STRAPPING MACHINE 16 Sheets-Sheet 13 Filed Feb. 14, 1957 VENTORS. gdffal,
. Aug. v27, 1963 M. B. HALL. ETAL 3,101,653
AUTOMATIC Box STRAPPING MACHINE Filed Feb. 14, 1957 1e sheets-sheet 14 Aug. 27, 1963 M. B. HALL ETAL 3,101,663
AUTOMATIC Box STRAPPING MACHINE Filed Feb. 14, 1957 16 sheets-sheet 15 i l (a) i 206 i P01/ I 230 jl 203) 28g $042661 202 Q i /l 1 206 20j 230. e/ E 202 2C/l? g3 2,042051 (d/1T Li/206 INVENTORS.
Aug. 27, 1963 M. B. HALL l-:TAL
AUTOMATIC Box STRAPPING MACHINE 16 Sheets-Sheet 16 Filed Feb. 14, 1957 5 Q w mw 1 d om b 3 7 3 d/ f ,y a .0 3 w@ m 3 d f 2 a7 @w/d M3 M, a 6 6 Q 6 3 3 d w 6 R M, w @im mgm@ 2 2, 2 wBE- FMM/ mdd nvr?. Mm Jw. 6 m w, ,Mm/ Mw 9; 2 7 ,o 2V y wu d @New A 3v I MLV/- im 3,; y 3, 4 3 @u a@ d la "drawings in which one embodiment is illustrated.
United States Patent() This invention relates to improvements in machines for applying metal :binding straps around boxes, packages or other objects, and its purpose is to provid-e Ian improved machine which .may be efficiently employed for this purpose and which is fully automatic in its operation except for the initial step of looping the strap about the object to 'be bound.
'I'he present improvements are particularly adapted for use in a machine of the type in which a metal seal is caused to enclose the overlapping strap ends and which 'is deformed together with the enclosed strap ends, after the strap has been drawn taut about the object being lbound, to provide an interlocking joint.
The principal object of the invention is to provide a machine capable of performing Aall of the steps of feeding seal stock and automatically forming a channel shaped seal therefrom, moving a seal to the sealing position, feeding a binding strap :from a source of supply through the channel shaped seal to provide a length of strap suflicient to he looped around the box or other object to he bound with its free end extending through said seal in overlapping relation to said supply portion, then gripping the free end of the strap, then reversing the feeding means to draw the `strap taut, then operating a sealing device to form a joint lbetween the seal 'and the enclosed strap portions, cutting Ioff the supply portionl of the strap as the joint is completed while at the same time forming la new seal for the next sealing operation, then ejecting y the seal joint from the sealing device, and then feeding the seal which has just Ibeen formed to the sealing position in readiness for a new operation.
Another object 'of the invention is to provide improved mechanism for performing each of the steps of the operation which have fbeen referred to above. A further object is to provide an improved machine of the type referred to comprising power driven mechanism having la single operating shaft which operates through novel connected devices to feed the seal stock and partially form a seal from a portion cut from the seal stock, to grip the 'free -end of the strap while it is being drawn taut around the package, to form a sealed joint after the seal has been moved to the sealing position, and then to eject the seal joint rfrom the sealing means. Still another object is to provide improved means for forming a seal from seal stock and for advancing the formed seal from the seal forming position to the strap sealing position. A fur-` ther object of the invention is to provide a novel pneu- A`matic -system and a novel electric system for automatically causing the operations referred to above to he peri formed in proper sequence and timed relation. `Other objects relate to various features of construction and arrangement which will appear more fully hereinafter.
The nature yof the invention will he understood from the rfollowing specification taken with the accompanying In the drawings,
FIGURE 1 is a diagrammatic side elevation of the primary parts of the machine showing them in the relative positions which they occupy lat the commencement of a strapping operation with the binding strap being fed from the source through -a partially clo-sed channel shaped seal which acts as a guide;
FIG. 2 is a view similar to that of FIG. 1, showing a 3d@ 1,663 Patented Aug. 27, 1963 "ice the relative positions of the parts :at a 'later stage of the operation after the free end of the lstrap has been gripped and rheld 4by gripping dogs and afterthe 4strap feeding device has Ibeen reversed to draw the strap taut around the 'b-ox; 1
FIG. 4 is a view similar to that of FIG. 3, showing the relative positions of the parts at a still later stage of the operation when. the sealing device has heen operated to form a joint, the shearing blade has been actuated to cut off the supply portion of the strap and the seal former has rbeen operated to form another seal over the forming anvil; fr
FIG. 5 is a view simi-lar to FIG. 4, showing the parts at a later stage of the operation when the seal former has been retracted leaving a new seal on the anvil, the gripping dogsV have been withdrawn, the shearing fblade and the sealing device have been -retracted and the ejector has been operated to eject the completed joint from the sealing device;
FIG. 6 is a view similar to the preceding ones showing the parts after the Ibound box has lbeen `removed from its support, and the fanvil has been actuated to move the new seal to the open jaws of the sea-ling device;
' FIG. 7 shows the parts at a stilllaterfstageafter the sealer has been operated to for-m partially the new seal delivered .by the anvil;
FIG. 8 is a view similar to FIG. 7, showing the anvil being retracted and the strap feedingldevice feeding a new length of stra-p through the partially formed seal;
. FIG. 9 shows the parts illustrated in FIG. 7 in readiness for a new strapping cycle;
FIG. 10. is a perspective 'View of la box which has been lbound 'by the use of the strapping machine of the present invention with two pairs of straps extending in right angular directions;
FIG. 11 is a perspective view on an enlarged scale of one of the strap joints formed by the machine of the .present invention;
FIG. 12 shows an end elevation of what may be regarded as the left hand end of a machine lembodying the invention, including the parts which are diagrammatically illustrated in FIGS. 1 to 9, inclusive;
FIG. 13 shows an elevation of the right-hand end of the machine shown in FIG. 12 with certain portions broken away Ifor clarity;
FIG. 14 shows :a front elevation of the machine illustrated in FIG. 12 with the fbox supporting tahle removed,
the section being taken on the line 14-14 of FIG. 13;
l17--17' of FIG. 12; Y
FIG. 17A is a fragmentary plan View of the portion of the machine illustrated in iFIG. 17;
FIG. 18 shows `an enlarged fragmentary section taken on the line 1-8-18 of FIG. 12; I
FIG. 19 shows ran enlarged section taken on the line 19-19 of FIG. i13; v
FIG. 20 shows a sectional view taken on the line 2li-2t) of FIG. 13;
FIG. 2l .shows an elevation on the line ZI-Zl of FIG. with parts of the machine illustrated in section;
FIG. 22 shows Kan end elevation of the structure shown in FIG. 2l, the view being taken lalong the line 22-22 of FIG. 2l with 4the seal stock feeding mechanism removed;
FIG. 23 shows a sectional view taken on the line 23--23 of FIG. 2l
FIG. 24 shows `a sectional view through the seal stock v illustrating the engagement with lan aperture in the device of the stock `feeding arm;
FIG. 25 shows an` enlarged sectional view taken on the line 25-25 of FIG. 23;
FIG. 26 shows a section taken 4on the line 25-26 of FIG. 21, illustrating the sealing jaws and other parts of the sealing device in elevation, with the jaws in open position;
FIG. 27 is a View similar Ito FIG. 26, showing the jaws partially closed;
FIG. 28 is a view similar to those of FIGS. 26 `and 27, showing the sealing jaws 'fully closed;
FIG. 29 is a horizontal section taken on the line 29-29 of FIG. 27;
FIG. 30 is a sectional view taken on the line liti-30 of FIG. 29, showing an elevation of the shearing blade and cooperating parts;
FIG. 3l lis `a Sectional view taken on the line 3l*3l of FIG. 30;
FIG. 32 is a view similar to FIG. 30, showing the shearing blade `in its extended position;
FIG. 33 is Ia sectional view similar to .but more eX- tensive than FIG. 3l, showing the `shearing lblade in its `forward position Kand the joint ejectorretracted;
FIG. 34 is a sectional view taken on the line 34-34 of FIG. 21, illustrating the mechanism for gripping and holding the free end of the strap, the gripping jaws being shown in open position;
FIG. 35 is a View similar to that of FIG. 34, but with the jaws in partially closed position;
FIG. 36 is a view similar to those of FIGS. 34 and 35 but with the jaws in fully closed position;
FIG. 37 is an enlarged front elevation of the upper part of Ithe machine shown in FIGS. 12 and 14;
FIG. 38 shows a vertical 'section taken on the line 33-38 of FIG. 37;
FIG. 39 is a diagrammatic view of the pneumatic system by which various parts of -the machine are actuated and controlled;
FIG. 40 is fa diagrammatic sectional view showing different positions of the pistons `and the double cylinder by which various parts of the machine are actuated by the pneumatic system shown in FIG. 39; and
FIG. 4l is a circuit diagram of the electrical system Iby which the sequence and time relation of lthe operation ofthe different parts of the machine are controlled.
In FIGS. -l to 9, inclusive, of the accompanying drawings, the principal parts of the machine and the sequence of their operation Iare somewhat diagrammatioally illustrated `and lthese views will be described in a general way before proceeding with the detailed description of the actual structure of the machine.
The relationship of the parts preliminary to placing a `box on the machine to Ibe bound is shown in FIG. l where the metal `binding strap 50 is shown passing upwardly past the box supporting table 51 and through a partially formed channel lshaped seal 52 having converging side walls which is being held by the sealing device 53. The strap is withdrawn from a supply and moved endwise by a power driven -feed roll 54 which presses the ystrap against an idler roll 55. Above the sealing device in an anvil 56 about which the seal 52 is formed by a seal former 57. The seal 52 is formed from metal stock which is advanced intermittently to the forming position by `feeding means not shown. A shearing blade 58 is mounted below the sealing device 53 yand is `adapted to be actuated to cut oit the strap when ithe joint has been formed. f
In FIG. 2 there is shown the relative positions of the parts referred to `after a box 6d has been placed on the table 5I and the strap 50 has been looped manually around the box while being Ifed endwise by the feed roll 54 as indicated lby the arrows 6l. After being looped yaround the box the yfree end Sila of the strap is manually threaded through the seal 52 so that it overlaps the supply portion 50h of the strap.
The next stage of the operation is shown in FIG. 3
`where gripping dogs 62 have been actuated to grip and hold the free end 50a of the strap while the feed roll S4 has been reversed to move the supply portion 50b of Ithe strap in the direction of the arrows 63 and thereby draw the strap taut around the box.
The machine then reaches the stage shown in FIG. 4 Where the sealing device is shown as having been operated to deform the seal 52 and the enclosed strap ends 4while the shearing blade 58 has been operated at the conclusion of the joint forming operation to sever the supply portion of the strap beneath and adjacent to the seal. At the same time the seal dormer 57 is actuated to form a new seal 52a about the lower end of the anvil 56 in readiness for the next strapping operation.
The next step of the machine operation is shown in FIG. 5 Where the shearing blade 58` and the seal former 57 have been retracted and an ejector 53a, associated with the sealing device, has been actuated to eject the seal joint from the jaws of the sealing device.
After the ejector 53a and the jaws of the sealing device are fully retracted, the anvil 56 is then actuated as shown in FIG. 6 to move, the new seal 52a downwardly and iorwardly to a position to be operated upon by the sealing device 53, the ejector 53a having by that time been Withdrawn.
In FIG. 7 the new seal has been engaged by the sealing device 53 and its walls partially bent about the anvil 56. The anvil is then withdrawn from the seal 52a, as shown in FIG. 8, and the feed roll 54 is actuated to feed the lfree strap end upwardly through the seal 52a, the side walls of the seal 52a guiding the strap as it is fed upwardly therethrough. The parts are then in the relative positions shown in FIG. 9, like FIG. y1, from which positions a new length of strap VSil may be looped around a box as a part of the next strapping operation.
The box 60* may have two straps Sllclooped around it in 'planes at right angles to the planes of two other straps extending around the box, as shown in FIG. 10, and the joints between the overlapping ends of the straps may have the form shown particularly in FIG. ll where the seal 52 and the enclosed strap ends Sita and Stlb are partially sheared transversely at the edges thereof where the seal is Ifolded around the overlapping strap ends and the metal between each pair of cuts 52e is deflected transversely as shown at `52d so that abutting shoulders are formed which prevent relative endwise movement of the seal and the strap ends. The box Gil [may be turned on the supporting table 51 to permit the convenient application of the binding straps as shown in FIG. 10.
As shown particularly in FIGS. l2, v13, 14 and l5, the machine comprises a frame 65 which includes a heavy rectangular vertical plate 65a secured to downwardly extending frame tmembers 65C which are secured to channel-shaped horizontal frame members 65d.
At the forward end of the machine, the frame 65 carries the box supporting table `51 which comprises a front vertical plate `66, a rear plate 67 and a series of cylindrical rollers 68 which have their trunnions 68a journaled in the plates '66 and '67 so that the boxes oil may be readily passed to and from the strapping position while allowing the binding strap to be passed downwardly between two adjacent rollers when looping the strap around a box. rThe front plate 66 is supported by an inverted channel shaped brace member 69 which has its lower end secured El to the frame members 65C and which is inclined upwardly and forwardly therefrom with its forward end secured to the plate 66 as shown in FIG. `12.
The member 69 supports a strap guide 70, shown in FIGS. 12, 17 and 18, which guides the binding strap Si) as it is looped around the box. This guide 7) comprises a downwardly and forwardly inclined curved portion 70a which communicates with an upwardly and forwardly inclined straight portion 7Gb arranged to terminate adjacent to the upper part of the plate y66 to which it is secured. The plate y66 is provided with a rectangular slot 66a (see FIGS. 12 and 17) through which the free end of the strap may be passed as it is |looped around the box. A pair of lguide plates 72b is provided on the straight portion 7Gb, the outer ends of the plates 72b also passing through openings in the plate y66 and being directed outwardly from each other as at 72c (see FIG. 17A). The outer edges of the slot `66a may be beveled as at 66b to avoid sharp corners and to aid in directing the strap through the slot 66a onto top of the guide portion 70h and between the guide plates 72b. lIhe curved portion 70a of the strap guide directs the strap upwardly so that the strap end may be thrust through the seal 52. The portion 70a of the strap guide 7d comprises a bar 71 (see FIG. 18) having side plates 72 which have their upper edge portions 72a converging inwardly to overlap the` strap passing between them. The side plates 72 are normally held against the bar 71 by coil springs 735l which are mounted on bolts 74 extending through apertures 71a formed in the bar 71, only one bolt 74 and associated parts being shown in FIG. 1l8. Each bolt 74 carries two washers 75 and a nut 76 and the two springs 73 on each bolt seat in cup-shaped retaining members 77 which lit in the aperture 71a and in apertures formed in the plates 72 with their annular flanges overlapping these plates. The side plates 72 are thus permitted to yield alway .from each other to any extent necessary to permit the strap to be subsequently removed from the guide.
Since the seal 5-2 serves as a guide for the binding strap, the means for forming the seal from the seal stock and placing it in the guiding position will now be described. The seal stock 80 the form of a coiled strip is provided at equally spaced intervals with centrally located Iround holes 80a (see FIGS. 12 and 24), which are employed in the feeding of the stock to the forming position, and the stock is supplied in the form of a spiral coil Stb adapted tof be mounted on a rotary cup-shaped drum 81. 'Ilhis drum has an annular 81a over which the stock is withdrawn and it has a central hub "8119 which centers the coil Sllb and this hub is mounted to rotate about a spindle 82 fixed in a plate 83 mounted on a pedestal 84 which extends upwardly from the frame 6'5 (FIG. 12).
As the seal stock 80- passes from fthe reel 81 (FIG. 12) it moves into a curved guideS .(PIG.' 23) which is mounted in fixed position ion the upper part of the frame of the machine `and which is provided with a longitudinal curved passage 85a through which the seal stock 80 passes in the direction of [the arrow 86. The stock 80 passes from the discharge end of the guide 85 through an opening 87a formed in a member -87 secured to the frame and the stock then extends outwardly opposite the lower end of the anvil 56 which will have been moved downwardly to the position shown in FIG. 23 by the mechanism hereinafter described. The seal former 57, previously described, comprises twxo blades 57a and 57b which are mounted on opposite sides of a block 88 secured to the frame midway between the member 87 and another similar lmember 89 which is also secured to the frame. When the former 57 is moved toward the left, as viewed in IFIG. 23, rthe upper blade `57a thereof oooperates Ywith the member 87 to cut off the seal stock from the source of supply and at the same time to bend the end of the cut-off portion to form a wall 52e of a channel-shaped seal. At the same time the other blade 5711 of the former moves beneath the anvil 56 to bend v the other end of the cut-off portion of the seal stock to form .the other side wall 52) of the seal 52 which has previously been described. The member 89 is provided with a threaded apenture engaged by a plug 90 which may be adjusted to vary the position of the blade 57a of the former with respect to the part 87.
The inner end 'of the former `57 is pivotally connected (by a pin 91 to a 'link 92 which, in turn, is pivoted at 93 upon a crank arm 94 secured upon a shaft 9S which is the main shaft of the machine, serving not only to actuate the seal stock feeder and the seal stock former but also the means by which the joint is :formed between the seal and the overlapping ends `of the binding strap and the means for rejecting the joint from the jaws of the sealing device. The main shaft 95 is rotated intermittently in the manner hereinafter described and it -is adaptcdto control the actuation of the seal stock feeding means through another crank arm 96 which fixed thereon. rThe seal stock feeding means comprises a dog 100 which is pivoted at .101 upon the stock feeding lever E102. The
dog 100 is provided at its outer end with a projecting tooth 101m, shown in FIG. 24, which is adapted to enter one of the apertures ySila which are formed in the seal stock 8d. rlhe dog 100' is maintained in: contact with the lower face of the seal stock =8tl through a slot in the guide `85 by mems of a coil spring i103 which .is mounted on the pivot pin i101 and which has one arm engaging the lever 102 yand the other arm engaging the dog. When the lever 102,*which is pivioted at W4 on the frame of the machine is move-d in a counterclockwise direction, as shown in FIG. 23, the seal stock 86 is advanced by the dog 10b tow-and the anvil 56. The stroke of the feeding dog 1li@ may be regulated by a stop screw 105 which threadedly enga-ges the lever .102 and which is adapted to abut againstthe upper side of the stationary member 87. This stop scr-ew 105` may be secured in adjusted position by a lock nut i106.
The actuation of the seal stock feeding lever I1(12 during its feeding stroke is effected by a coil spring 107 which is mounted on a piu 168 carried by that lever and which spring .1117 extends outwardly into engagement with a thimble W9 having a screw threaded engagement with a clamping device 110 mounted on the frame of the machine. Y The thimble 199 may be adjusted endwise to vary the compression of the spring 107 and thereby vary the pressure with which the feeding lever y102 is actuated.
The movement of the lever 1102 in the reverse direction to retract the feeding dog 100 is effected by the lateral extension 102a of the lever 102 which is provided at its :lower end with -a pin 1111 having a sliding engagement with a slot 112a formed in a link 112. link is pivotally connected by la pin 1.13` with the crank arm 96 Xed on the shaft f'and, when the crank arm 96 is moved in a clockwise direction as viewed in FIG. 23, a roller 114 mounted von the pin 1111 engages a stop` screw 1|15 which is adjustably mounted in a threaded aperture formed the `end of the link and which is held in adjusted position by a lock nut 116. The engagement of the stop screw 1'15 with the roller 114- causes fthe lever arm- 102a to be actuated in a clockwise direction and the same motion lis thereby imparted to the lever 10l t so that the feeding dog 101) is lretracted and moved outwardly along the guideway 85. During this reverse movement of the feeding dog 160, the seal stock 80 is held in adjusted position by means lof a detent .1,118 which has a tooth 11-8a arranged to engage another of the apertures 80a in the seal stock under the influence of a coil spring :119 by which it is pivotally mounted upon an arm 120l secuned at 121 on the frame of the machine. In this manner, the rotary motion of the main shaft 95 is utilized to control the movement of the seal stock to the seal forming position and also to actuate the seal former 57 by which the channel-shaped seal is formed on the anvil 56.
After the seal stock 80 has been moved in a horizontal `plane through the guideway S and the seal 52. has been formed on the lower end of the anvil S6, to produce a channel-shaped seal as shown in FIG. 23, the anvil 5o is moved downwardly `from `the position shown in FIGS. 2l `and 23 until the seal 52 has been positioned between the jaws of the sealing device 53 which will be described more fully later. For this purpose, the enlarged upper end 56a of the anvil, shown particularly in FIGS. 13, 2l and 22, is pivotally connected to a link 124 and a lever 125. This link is pivoted at 126 to a bracket 127 carried by lthe frame of the machine and the lever 125 is pivoted at 128 to another bracket 129 iixed on the frame of the machine. The lever 125 extends rearwardly from its pivot 12S and has a downturned extremity which is pivoted at 139 to a piston rod 131 mounted in a cylinder 132,.' Upon admission of compressed iluid to this cylinder the piston connected to the piston rod 131 is actuated to operate the lever 125 and thereby move the anvil 56 in a general vertical direction. As the anvil 56 moves downwardly from thel position shown in FIG. 2l, it also moves forwardly and away from the block 88' (see also FIG. 23). When the seal 52 is formed against the anvil 56, as shown in FIGS. 23, 25 and 38, it is held in Contact with the anvil by a plunger 133 (see FIG. 38) which is mounted in a bore formed in the block SS and actuated by a coil spring 134i (see FIG. 25) to press its tip against the back wall of the seal. ilhe compression of this spring is regulated by a plug 135 which threadedly engages the end or" the bore and the movement of the plunger away from the plug is limited by a ange 13311 (see FIG. 25) on the plunger which engages an annular shoulder in the wall of the bore. As the anvil 56 moves downwardly and forwardly from the position shown by full lines in FlG. 2l to the position shown by dotted lines in that figure, the seal 52 which is being pressed against the anvil by the plunger 133 slides downwardly and forwardly over the inclined face 13761 of a head 137 on `a plunger 133 slidably mounted in a bore 139 formed in the yframe of the` machine. A coil spring Mtl is mounted in this bore between a shoulder at the end ofthe bore and the Ihead 137 so that the head is normally moved toward the left as viewed in FIGS. 25 and 38 but is retracted by the pressure of the anvil and the seal as their downward vmovement proceeds. The upper edge of the back wall of the seal finally snaps beneath a shoulder 13% formed on the head of the plunger so that the seal is then held in a position frictioually between the jaws of the sealing device 53, as shown in FIG. 38, when the anvil 56- is then moved upwardly. When positioned between the jaws of the sealing device 53, the frictional engagement of the seal with the sealing jaws holds the seal against downward movement until it has been operated Iupon by the sealing jaws.
The sealing device `53 is shown particularly in FIGS.
14, 26 to 33, inclusive,`and FIG. 38 and comprises rela-v tively movable bending jaws 145 which are pivoted on pins 146 extending between the plates 147 (see PEG. 29) carried by the frame and'which have inwardly turned extremities 145a adapted to move toward each other 'to bend the side Iwalls 52e and 521 of the seal toward each other to embrace the overlapping strap ends. in so doing, the jaws extend into a notch 14E-ia formed in a plate 144 which is secured to the ifront edge of the frame members 65e (see FIGS. 26, ,27 and 28). The jaws have inwardly extending arms 14511 which are pivotaily connected by pins 145e to the links 1-t and 1119. The other ends of these links are pivotally connected by pins 151i to the arms 151a and 151!) of a three armed lever 151 secured on the main shaft 95 by a key 152. The turning or the lever 151 in a counterclockwise direction is adapted to actuate the jaws 145 to cause ,their tips 145e to close upon the side walls of the seal 52' and bend them inwardly toward each other from the positions shown in PEG. 26. '.Ilhe lower end of the anvil 56 is then between the jaws, as shown in FIGS. 26 and 27, and when the jaws reach the positions shown in FlG. 27, the side walls of the seal have been bent inwardly toward each other in conformity with the tapered sides of the anvil.
When the side walls of the seal thus converge as shown in FlG. 27, the anvil 56 is withdrawn from the seal and the strap-Sti` is threaded twice through the seal as it is looped around the box 6l?, as previously described. The jaws of the sealer are then moved to the positions where they are fully closed as shown in FIG. 28 to provide an interlocking joint between the seal and the enclosed strap ends', having the form` shown in FIG. ll.
The sealing jaws operate in conjunction with a pair of bridges or shearing dies 153 which extend transversely to the sealing head in contact with the sides of the jaws and which are provided with parallel slots 153a engaged by the pivot pins 146. Each jaw 145' carries a pin 1511 upon which is mounted a roller 1155 (see FIG. These rollers engage the rear edges 153b of the bridges or dies 153 and as tihe jaws are closed upon each other these rollers ride on the inclined end portions 153C of these edges and force the bridges or dies forwardly against the seal so that lthe dies cooperate with the jaw portions 145a to effect the shearing of the edges of the strap and seal and the de-ilection of the intervening portions of metal to form the interlocking joint.
During the last stage of .the joint forming movement of the jaws v1415, the shearing blade S is actuated to sever the supply portion of the strap in proximity to the seal. This shearing blade (FIG. 30") has an inclined cutting edge 58a and is provided with slots 585 which are engaged by the pins 146. As the jaws 145 approach their nal closed positions, the inclined surfaces 58e on the ends of the rear portion of the shearing blade are engaged by rollers 156 mounted on the jaws and the shearing blade is thereby forced lforwardly to shear the supply portion of the strap. After its shearing .Inovement, the blade is returned by pins 157 mounted on the sealing jaws 145 `of the sealing head as the sealing jaws 145 are returned during the normal return stroke thereof.
In shearing the strap, `the shearing blade 53` operates in conjunction with a stationary shearing blade 141 (FIG. 29) which Ais secured to the fron-t plate 144 and ysupported by projections 1451i on the jaws 145. The joint is almost completely formed when the shearing takes place so that there is no slipping of the overlapping strap ends during the shearing opera-tion.
The rsealed joint ejector, which constitutes the part 53a of the sealing device (see FIG. 5), comprises a joint engaging member 16d having three fingers 160:1, :which extend on opposite sides of the bridges lor dies 153 (FIGS. 29 Iand 33) to bear against the completed joint and force it away lfrom the sealing mechanism. The inner end of the ejector 16@ is provided with a slot 1606 through which ya pin "161 extends with a roller 162 mounted thereon. This roller i-s embraced by the yoke-shaped extremity 164g of a lever 164 which is pivotally mounted on 4a pin 165 mounted in the fname. The lever `164 has a coil spring 166 connected thereto :and extending to Ithe free end of a link 167 which is pivoted at 168 on the frame.
An arm 174B is privo-ted at 171 on the arm 151C of the 151 and extends upwardly over a roller 172 mounte on the frame. As the lever 151 is moved in `a clockwise direction by the rotation of Ithe main shaft 95, the arm 17d rides up on the roller 172 and its hooked extremity 179e is disengaged from r.the extremity of the extension 1641? of the lever 16d so that the lever 164i is free to move in a countericlockwise direction, thereby retracting the ejector 16d. instead of relying entirely on the spring 1615 to retract the ejector, the rollers 155 carried by the sealing jaws for actuating the dies 153 are also arranged to engage inclined comming surfaces 160e on