US2882814A

US2882814A - Box strapping machine

Info

Publication number: US2882814A
Application number: US284634A
Authority: US
Inventors: Alvin L Winkler; Robert E Hager; Kjell A Falck-Pedersen
Original assignee: Acme Steel Co
Current assignee: Acme Steel Co
Priority date: 1952-04-26
Filing date: 1952-04-26
Publication date: 1959-04-21
Anticipated expiration: 1976-04-21

Description

April 21, 1959 A. L. WINKLER ET AL 2,882,814

- I BOX STRAPPING MACHINE I Filed April 26, 1952 I 16 Sheets-Shet 1 I ,I l l I I I I ,I I I II ll lit II III I Mum v I I I W 1/ X IN- IIIIII? IN V EN TORS I CZZU znl. win/1977 April 1959 A. WINKLER ET AL 2,882,814

BOX STRAPPING MACHINE l6 Sheets-Sheet 2 Filed April 26, 1952 I l i 581) IN VEN TORS I CZlz/zlnll ZZ/nklen ZobertZYH April 21, 1959 A. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE Filed April 26, 1952 1s Sheets-Sheet 5 IN VEN TORSI- e iadgzg a April 21, 1959 A. L. WINKLER ET AL 2,882,814

ox STRAPPING MACHINE is Sheets-Sheet 4 Filed April 26. 1952 A. L. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE April 21, 1959 16 Sheets-Sheet 5 Filed April 26, 1952 I INVENTORSJ; I CZZz/L'n/Z. ZZ/L' jZaerZfi ZH April 1959 A. L. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE l6 Sheets-Sheet 6 Filed April 26, 1952 Illll l l l l l |||L|||| INVENTORSI A nl 21, 1959 A. L. WINKLER ET AL 2,882,314

' BOX STRAPPING MACHINE Filed April 26, 1952 l6 Sheets-Sheet 7 INVENTORS. I

(ZZZ/270i: Maia/def .EObfE figger 8 April 21, 1959 A. L. WlNKLER ETAL BOX STRAPPING MACHINE Filed April 26. 1952 QZZ/Ln/Z. Babe?" ZEH e77 @EMQFzZokJ 16 Sheets-Sheet 1O INVENTORSF- wen/dear April 21, 1959 A. L. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE 16 Sheets-Sheet 11 Filed April 26, 1952 IN VEN TORS 6212/07/17. ZZ/inkler; flaberifi 15%81; 5 T5872 April 21, 1959 i A. WINKLER ETAL 2,882,314

BOX STRAPPING MACHINE Filed April 26, 1952' 16 Sheets-Sheet 12 I l l INVENTORS. CZZz/L'nl ZZ/zLn/der flabert E17 827 April 21, 1959 A. WINKLER El'AL 2,8

BOX STRAPPING MACHINE Filed April 26, 1952 1s Sheets-Sheet 1s April 1959 A. L. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE Filed April 26, 1952 6 M r w t n e 6 m M. 7 -A 5 m H w I JJ U 5 WW My. e 1! 1, a & 0 g; t v, m I 5 in c W T q l- .L e

April 1959 A. L. WINKLER ETAL 2,882,814

BOX STRAPPING MACHINE Filed April 26, 1952 16 Sheets-Sheet 15 United States Patent i 2,882,814: BOX STRAPPING. MACHINE L2 Winkle'r', ChicagmRob'ert'E. Hager, Park Forest, and Kjell A. FalcloPedersen, Cicero, 111., assignorsto AcmetSteel Companygzchicago', 111., a corporation of Illinois.

AppIicationJApriH'G, 1952, Serial No. 284,634 STClaii'ns: (6.100e-25)- This" invention relates to box: strapping machines'and its'pu'rpose is to provide animproved machine for applyiug a flexible binder, such a's'a flat metal strap, about a-boxor package, drawing the binder taut, cutting it all from the'source-of supply and then uniting itsoverlapping ends. The primary object of the invention is to provide an improved machine in which all of the operations just mentioned," exceptfor an initial operation of'extending the .binderpartially around the box or package, are performed automatically in proper sequence and timed relation'without any attention: on the part of theoperator.

In the operation of the machine, the completion of one binding operation leaves 'a predetermined length of str'apin a positionsuch that it partially encircles a package when the package is placed in binding position. After placing the package in that position the operator pulls out the free end of the strap and completes the encirclemeut of the package with the free end of the strap in a position to be gripped by the mechanism, whereupon the automatic. operations are initiated and the free end of the strap is gripped, the slack in the strap then-taken up by reversing the strap feeding means, the strap then positively-drawn taut to a predetermined degree bythe movement of a strap gripping device engaging the supply portion of :the strap, the supply portion then held by a stationary gripping device, the supply portion then cutoff, a joint formed betweenthe ends of the tensioned strap, and the strap and package then released from the gripping mechanism.

One difliculty with the operation of prior box strapping machines hasbeen that the strap has generally been dr'awntaut about the box by pulling mechanism which depends upon the-slipping of a clutch or the like to terminate .the: tensioning 'operation and it has been found that'the straptisnot'thereby drawn taut to the same degree? when appliedzto different boxes. Itis one of the principal objects of the presentinvention to provide improved mechanism for positively gripping the strap and-'drawingittaut to' substantially the same degree in successive operations on different boxes or packages. A further objectof the: invention is to provide improved means'whereby' any desired degree of tension, withina wide range, may-be created with accuracy in the strap surrounding the package. Another objectisto provide means for insuring the operation of the strap tensioning mechanism only after the slack in the strap encircling the-package has-been. removed. Other objects relate to various features of-constructionand arrangement which will appear more fully hereinafter.

Thev nature-of the invention will be-understood from the following specificationtakenwith the accompanying drawings in which one-embodiment of the. invention .and' amodification of apart thereof are illustrated. In the drawings,

Figure 1 shows a perspective view of a; preferred:

embodiment ofthe invention;

'ice

which has been bound with the use of the machine illustrated in Fig. 1;

Fig. 3 shows a top plan view of the overlappingends of the strap which extends around thebox shown in Fig. 2 with th'eseends united by means of spot welds;

Fig. 4a is a somewhat diagrammatic view of-some of the principal parts of theboxv strapping machine; illustrated in Fig. 1, showing the relation of the binding strapto theqboxx'when thexbox'is first placedfin position to be bound and before the strap has been caused. to encircle thebox;

Fig; 4b is a diagrammatic view-similarito thattof Fig. 4a showing the condition after thefreeend of the strap: has been manually. moved about the box by the operator and its end inserted in a guide beneath the box;

Fig. 4c is. a diagrammatic view. similar to thoseof Figs; 4a and 4b illustrating the condition after the free endof the strap has .been gripped beneath the box and after the feeding mechanism has: started a reverse operation for the purpose of taking up the slack in the strap which" encircles the box;

Fig. 4d is a view similar to that ofFig; 4c showing the condition after theslack in the strap has been taken up so that the strap is in close contact with the box on three sides thereof and after the supply portion of the strap has been gripped by a movable gripping device which has started its movement for'drawing the strap taut around the box;

Fig. 4e is a diagrammatic view similar to, that of Fig. 4d showing the relative arrangement: of the parts after the movable gripping device has moved further to draw the strap taut and after astationary gripping device has started its movement toward a position: wherein it grips the supply portion of the strap;

Fig. 4, is a view similar to that of Fig. 42 showing the condition at a later stage when the movablegripping device has passed-out of engagement with the strap, a stationary gripping dog has moved into gripping engage. ment with the supply portion of the strap, the strap has been severed by shearing blades, and the welding device has started its movement toward the welding position;

Fig. 4g shows a diagrammatic view similar to that of Fig. 4 with the welding device in the position toweld the overlapping ends of the strap which is then held by the two, stationary gripping devices beneath the box;

Fig. 4h, shows a diagrammatic view similar to that of Fig. 4g, illustrating the condition after an ejecting: device has moved the bound box out ofengagement with the gripping devices, and the gripping dogs as .well as the welding device have been retracted so that the. parts are then in readiness for a new binding operation;

Fig. Sshows a front elevation of the machine-illus trated in Fig. 1 with the casing removed to reveal the internal mechanism;

Fig. 6 shows an end elevation of the machine illustrated in Fig. 5, looking-toward the right as viewed in Fig. 5;

Fig. 7 shows a top plan view of the machine illustrated in Fig. 5; 1

Fig. 8 shows apartial vertical section taken on the line 8'8 of Fig. 7' showing the stationary grippingdogs, the welding device, and other associated parts of the apparatus;

Fig. 9 shows a sectional view taken on the line 99 of Fig. 6;

Fig. 10 shows a sectional view taken on the line 10..-10. of Fig. 5;

Fig; 11 shows a sectional view taken on the line ll ll' of-Fig. 10;

Fig. 12 is .a view similarto thatofFig. 11 showingthe relative positions ofrthe parts of the, shearingymechanism when they are in the extended position wherein the shear- 14-14 of Fig.5;

Fig. 15 shows a sectional view taken on the line 15-45 of Fig. 14; p Fig. 16 shows a sectional viewtaken on the line 16 16 of Fig.

Fig. 17 shows a sectional view taken on the line 17 17 of Fig. 16;

Fig. 18 is a sectional view similar to that of Fig. 16 showing the strap tensioning mechanism when it is in its extreme tensioning position;

Fig. 19 shows a partial sectional view taken on the line 19-19 of Fig. 18; L'Fig. 20 shows a side elevation of the strap tensioning gripping dog and its associated parts at that time in the operating cycle when the strap tensioning mechanism is about to start its operation;

Fig. 21 is a view similar to that of Fig. 20 illustrating the relative positions of the parts a short interval after the strap tensioning operation has started;

Fig. 22 is a view similar to that of Fig. 21 illustrating the strap tensioning parts when they are in the elevated position corresponding to that shown in Fig. 16;

Fig. 23 shows the parts of the strap tensioning mechanism after the strap tensioning dog has gripped the strap and has started its downward movement as illustrated by dotted lines;

Fig. 24 shows the strap tensioning mechanism in its lowermost position after the strap has been drawn taut around the box or package;

Fig. 25 shows the parts of the strap tensioning mechanism illustrated in Fig. 24 after these parts have started to return to their normal upper positions;

Fig. 26 is a view similar to that of Fig. 16 showing a modified form of means for loading the strap tensioning mechanism;

Fig. 27 shows a top plan view of the modified mechanism illustrated in Fig. 26; and

Fig. 28 shows a schematic diagram of the electrical system by which various parts of the machine are operated and controlled.

As illustrated in the drawings, particularly in Fig. 1, the invention is embodied in a box strapping machine comprising a casing 30 which is made up of a sheet metal shell 31 surrounding an internal frame structure which supports the movable parts of the mechanism. This casing 30 is open at its top but is normally closed by a lid or cover 32 which is hinged at 33 on the casing so that it may be tilted upwardly to the position shown by dotted lines in order to gain access to the mechanism within the casing. The lid or cover 32 serves as a table on which the box strapping operations are carried on. For this purpose, the table is provided with a recess in which are mounted a series of rollers 34 extending for a considerable distance from one end of the table and, adjacent the other end, the table is recessed to accommodate a lesser number of rollers 35. All of these rollers project slightly above the top surface of the table and serve as conveyors over which the boxes or packages may be conveniently moved to and from the strapping position. Between the two series of rollers, there is mounted a welding device 36 which is adapted to unite the overlapping ends of a strap passed around the package. The table is provided with a groove 32a adapted to receive the strap which is passed around the package and, at the rear of the table, there is mounted a guide 37 having a vertical groove 37a therein which is adapted to receive the strap 40 when it is projected upwardly from the interior of the casing as shown in Fig. 1 and to permit the forward looping of this strap about the box or package which is positioned over the welding device 36 when the binding operation is carried on. At the forward side of the table 32, there is provided a panel 41 on which are mounted a series of

knobs

42, 43 and 44 for controlling the operation of various parts of the apparatus which are designated, respectively, by the

numerals

450, 445 and 528 in Fig. 28. Beneath this panel, there are mounted switches for controlling the operating circuit including a switch 45 by which each cycle of operations may be initiated. At the bottom of the-casing 31, there is mounted a foot pedal 46 adapted to be manipulated by the operator to control the feeding of the strap 40 from the-interior of the casing.

The strap 40 is adapted to be drawn taut around a box or package, such as the box 50 shown in Fig. 2, and after it has been drawn taut and its supply portion cut off, the overlapping ends are secured together to form an interlocking joint preferably by means of spot welds as shown at 51 in Figs. 2 and 3. Only one strap is shown as being applied around the box or package but, by shifting the position of the box or package on the table 32, any desired number of straps might be applied around a single package.

Before proceeding with a detailed description of the structure of the apparatus, reference will be made to the diagrammatic views of Figs. 4a to 4k, inclusive, which illustrate the sequence of the various operations which are performed from the time that the package is placed over the welding device until it has been completely bound and removed from the table of the machine. In these figures, certain primary parts of the apparatus are illustrated in their operative relationship looking toward the left-hand end of the machine as viewed in Fig. 1. Referring to Fig. 4a, the strap 40 is drawn from a supply reel (not shown) around a guide wheel 54 between the dogs of a movable gripping device 55 and then around a feed wheel 56 which is power driven and with which the strap is maintained in contact by a guide wheel 57. The feed wheel 56 is adapted to feed the strap through a guide channel 58a formed in a front gripping dog 58 which is pivoted at 59 on the frame structure and which is provided with a series of teeth 58b adapted to cooperate with a stationary gripping plate 60 in gripping the strap after it has been passed around the package 50. From the passage 58a of the front gripping dog 58, the strap extends through the lower guide channel 61a of a strap guide 61 which is positioned beneath the welding device 36. The strap then extends above a rear gripping dog 62 which is pivoted at 63 on the frame structure and which is provided with a series of teeth 62!) adapted to cooperate with a stationary gripping plate 64 located beneath the package 50. At the proper time, the rear gripping dog 62 is adapted to be moved upwardly to cooperate with the plate 64 in holding the supply portion of the strap after it has been drawn taut about the package.

At the conclusion of a strapping operation, the parts of the machine normally come to rest in the relative positions shown in Fig. 4a with the free end 40a of the strap curved upwardly and extending partially over the box 50 positioned on the table against the guide 37. In normal operation, a sufficient length of strap will extend upwardly over the box to permit it to be passed around the box by the operator but, if a suflicient length of strap does not extend in this manner, the operator may step on the foot pedal 46 and thereby actuate the feeding mechanism, including the feed wheel 56, to cause the required length of strap to be projected upwardly over the box. Assuming that the box has been placed in proper position on the table and that a sufficient length of strap is present, the operator then seizes this end of the strap and extends it forwardly and downwardly around the box until it extends between the forward gripping dog 58 and the stationary gripping plate 60 and into the upper channel 61b of'the guide member 61.

This channel is closed atits end so that when the strap has been thrust inwardly to the extent permitted by the depth of the channel 61b, the box has been completely encircled and the parts are in readiness for the cycle of automatic operations which is initiated by closing the switch 45 beneath the panel 41 at the front of the machine.

When the switch 45 is closed, the front gripping dog 58 is moved upwardly from the position shown in Fig. 4b to the position shown in Fig. 4c so that the free end of the strap is then gripped and held against the stationary gripping plate 60 and at the same time the rear gripping dog 62 begins an upward movement from the position shown in Fig. 4b to an intermediate position shown in Fig. 40. When the free end of the strap 40 has thus been gripped, the feeding mechanism is reversed so that the feed wheel 56 is then rotated in the direction shown by the arrow 65 in Fig. 40 with the result that the loop of strap extending around the box is contracted until all of the slack has been taken out of the strap and it lies in close contact with the box under moderate tension, as shown in Fig. 4d. At the conclusion of this slack take-up the movable gripping device 55 is actuated and its gripping dogs seize the strap beneath the feed wheel 56 and move downwardly to continue the pull on the strap as indicated by the arrow 66 in Fig. 4d.

In Fig. 4e the relative positions of the parts are illustrated at a somewhat later stage in the operation when the movable gripping device 55 has moved downwardly to a further extent and the rear gripping dog 62 has moved still further in an upward direction so that an arm 62a on the free end of this dog extends upwardly at the side of the supply portion of the strap 40 to guide the strap and keep it in alignment with the free end of the strap which is then held by the front gripping dog 58. At this stage, the welding head 67, which has previously occupied its lowermost position, begins an upward movement from the lower position which is illustrated by dotted lines. At this stage the strap shearing blades 68 have been moved to a position where they embrace the supply portion of the strap somewhat forwardly from the position occupied by the welding device 36. In Fig. 4f, the operation has continued to the point where the strap has been drawn taut around the package with a predetermined tension in it and the rear gripping dog 62 has moved upwardly to the point where it grips the supply portion of the strap against the plate 64 and the shearing blades 68 have been actuated to cut off the strap, leaving two ends of the strap overlapping beneath the contacts of the welding device 36. The welding head 67 then moves upwardly from the position shown in Fig. 4) to the position shown in Fig. 4g and is actuated to weld the overlapping ends of the strap together to form the type of joint which is illustrated in Figs. 2 and 3. While this welding operation is going on, the movable gripping dogs are moved out of engagement with the supply portion of the strap beneath the feed wheel 56 and, the box having been completely bound, an ejecting device 69. is then actuated to engage the strap and move it out of engagement with the gripping

plates

60 and 64 at the same time that the gripping

dogs

58 and 62 are moved downwardly to the position shown in Fig. 4h. At the same time, the welding head 67 is moved downwardly from the position shown by dotted lines in Fig. 4h to the position shown by full lines so that the parts are then in readiness for a new binding operation except for the final actuation of the feed wheel 56 which then takes place to project a length of strap through the guide channel 61a of the guide 61 and upwardly through the groove 37a of the guide 37 so that it then will curve over the welding device 56 in readiness for a new strapping operation.

Before proceeding with a detailed description of the operating mechanism of the machine, reference will be made to the frame structure which supports the outer shell of the cabinet 31 shown in Fig..1,. as well as the various parts of the operatingmechanism. .Asshdivh particularly in Figs. 5, 6 and 7, this frame structure comprises four upright frame members 75, -76, 77 and 78 which extend vertically at the corners of ,the cabinet and are provided at their lower ends with horizontally extending flanges 79 provided with apertures 79a adapted to be engaged by studs or bolts for the purpose .of securin g thecabinet to the floor or other support. Adjacent their lower ends, the

vertical frame members

75 and 76 are connected by a horizontal frame member 80 of angle bar form and, at the rear of the machine, the lower ends of the

vertical frame members

77 and 78 are similarly connected by a horizontal framemember 81 of angle bar cross section which has its top horizontal flange in the same plane as the top flange of the frame member 80. These

frame members

80 and 81 are connected by two angle bars 82 (see Fig. 5) on which there is mounted a plate 83 arranged to serve as a support for an electric motor 85 by which most of the movable parts of the machine are actuated.

Some distance above the

horizontal frame members

80 and 81 the

vertical frame members

75 and 76 are connected by a horizontal channel-shaped frame member 86 which has its flange directed outwardly and which is arranged in the same horizontal plane as the corresponding channel-shaped frame member 87 which extends between the

upright frame members

77 and 78 at the rear of the machine. The top end of the frame member 75 is connected to the top end of the frame member 77 by a bar 88 and the top end of the upright frame member 76 is similarly connected to the top end of the frame mem: ber 78 by an angle bar 89. r Adjacent the left-hand end of the machine, as viewed in Fig. 5, the front horizontal frame member 86 is con nected to the rear horizontal frame member 87 by two parallel channel-shaped members 90 which have their ends welded to the inner vertical facesfofthe

members

86 and 87. The upper horizontal flanges ofthese frame members 90 have welded thereto four blocks 91 to which are secured by bolts 92 the base flanges of a metal cast-. ing 93 which serves as a supporting frame for most of the movable parts of the mechanism. Toward the righthand end of the machine a pair of angle bars 94 are welded at their rear ends to the horizontal frame member 87 and these angle bars are supported toward their forward ends by upright frame members 95 which are welded thereto at their upper ends and which are welded at their lower ends of the plate 83 by which the motor 85 is supported. The bars 94 serve as supports for an electric transformer which is supported above the bars 94 by four bolts 101 which are threaded at both endsfor engagement with apertures in the frame of the trans: former and in the bars 94 and which are engaged bya series of nuts 102.

Somewhat to the right of its middle point, the front horizontal frame member86 has welded thereto an upright frame member 103 which is welded at its upper end to a horizontal frame member 104 secured at its right-hand end to the upright frame member 76. A plate 105 is Welded to the frame member 104 to extend downwardly therefrom and this plate serves as a support for a rotary switch 106 which is connected in the electric op: erating circuit as hereinafter described. At the rearof the machine, the horizontal frame member 87 has secured thereto an upstanding frame member 107 which is similar to the frame member 103 and which is secured at its upper end to a horizontal frame member 108 cx tending to the right-hand end of the machine whereit is welded to the upright frame member 78.

At the lower left-hand end of the frame structure, the frame member 75 is connected to the upright frame 'mem ber 77 by means of a horizontal frame member 109 which has bolted to the forward end thereof-a horizon tal plate 110 arranged to serve as .a-support foraxhys 1 d au i pu p 1.1.1 which s r an d to circulate un e p es ure the hydraulic fluid which is employed in the operatiouof .the machine. On the other side of the frame member 109, there is mounted a hydraulic cylinder 112 which serves in conjunction with the pump 111 to regulate the tension set up in the strap 40 by the tensioning mechanism 55, as more fully described hereinafter. At the left-hand rear corner of the cabinet, adjacent the upright frame member 77, there is mounted a hydraulic accumulator *114which is held in place by an encircling strap 11441 which is attached at one end to the frame member '77 by a stud 116 and secured at the other end to a bracket 117 which is welded to the horizontal frame member 87. The lower end of the accumulator 114 communicates with a T-connection 115 from which one conduit 118 extends to a port at the upper end of the pump 3111 while another conduit 119 extends to the end of the cylinder 112 which is adjacent the forward side of the machine.

A cam shaft 120, extending longitudinally of the machine, is journaled in bearings mounted in the cast metal frame '93 and this cam shaft has fixed thereon a series of

cams

121, 122, 123 and 124, shown particularly in Fig. 9, which serve to control various parts of the operating mechanism as the cam shaft is rotated. The cam 121 operates in conjunction with the control of the tension mechanism 55, the cam 122 serves to move the welding head 67 to and from its operating position and also to actuate the forward gripping dog 58, the cam 123 operates to actuate the strap ejector 69 and the rear gripping dog 62 as well as the strap end guide 61, and the cam 124 controls the actuation of the shearing mechanism 68.

The cam shaft 120 is driven by a belt 125 extending around a pulley 126 on the shaft 127 of the motor 85 and also around a pulley 128 which is rotatably mounted on the cam shaft as shown in Figs. 6 and 9. The

pulleys

126 and 128 are provided with a pair of V-shaped grooves which are engaged by the corresponding projections of 'V-shaped cross section which are formed on the inner side of the belt 125. At the left-hand end of the cam shaft, as viewed in Figs. 7 and 9, the shaft has fixed thereon a Sprocket gear 129 which meshes with a chain 130 having a driving engagement with a sprocket pinion 131 fixed on a feed shaft 135 which is journaled at one end in a ball bearing unit 136 mounted in a bearing member 137 attached to the frame 93, and at its other end in an over-running clutch 138 mounted in a bracket 139 of L-shaped form which is secured to the frame 93 as shown particularly in Fig. "7. The overrunning clutch 138 permits rotation of the shaft 135 in one direction but prevents rotation in the opposite direction. At an intermediate point the feed shaft 135 has mounted thereon the feed wheel 56 bywhich the strap 40 is fed from the source of supply, this mounting being effected by an elongated hub portion 56a, shown in Fig. 9, which is journaled in ball bearing units 140 and 141 mounted in the frame 93. The feed wheel 56 has a gear143 mounted on its hub and secured to the side thereof, as shown in Fig. 9, and this gear meshes with a pinion 144 secured upon a countersliaft 145 which is journaled in ball bearing units 146 and 147 mounted in the frame 93 and in the bracket 139, respectively. Thus, when the shaft 145 is actuated the pinion 144 drives the gear 143 and thereby actuates the strap feed wheel 56.

The cam shaft 120 also has rotatably mounted thereon a sprocket wheel 148 which rotates with the pulley 128 and meshes with sprocket belt 149 extending around a sprocket wheel 150 mounted to revolve about the feed shaft 135 and also about a sprocket pulley 151 which is rotatably mounted upon the countershaft 145. When the motor 85 is operated to drive the pulley 128, the connected sprocket pulley 148 is simultaneously rotated to drive the belt 149 so that both of the sprocket pulleys 148 and 151 are thereby actuated. Means are provided for Connecting these sprocket pulleys to the

shafts

135 and 145, respectively, in order to control the operation of the feed wheel 56 and the actuation of the cam shaft on which the

cams

121, 122, 123 and 124 are mounted.

The sprocket pulley 151 has a long hub 151a which is mounted to revolve about the shaft on ball hearing units 152 and 153 which are positioned against shoulders on an intermediate part of the shaft as shown in Fig. 9. One end of the hub 151a has secured thereon a ring 155 which is secured by studs 156, metal ring 157, and pins 158 to the casing of a ring-shaped electromagnet 160 which revolves with the sprocket gear 151 about the shaft. Adjacent to the magnet 160 which forms a part of an electromagnet clutch, there is mounted a complementary ring 161 which is secured upon the countershaft 145 by means of a key 162. This ring 161 is provided with an annular series of apertures 161a in which there are slidably mounted plungers 163 having enlarged heads which are fastened to an annular metallic ring made up of a member 165a of channel form and a connected flat disk 16512 which is adapted to coact with the radial face of the clutch magnet 160. Each of the plungers 163 is provided with a spring 164 which reacts between the ring 161 and the annular metallic ring 165 to urge it against the clutch magnet 160. Electric current is supplied to the clutch magnet 160 by means of slip rings 166 and wires 158 which are mounted upon the ring 155 and separated from each other by an anniilar insulating member 167. Brushes engaging these slip rings are connected in the electric circuit hereinafter described and when the clutch magnet 160 is energized, the magnetizable ring 165 is attracted and held by the magnet so that the magnet and the sprocket gear 151 then rotate the clutch member 161 with the result that the countershaft 145 is thereby actuated to operate the pinion 144 and thereby drive the feed wheel 56 through the gear 143 so that the metal strap 40 is thereby fed through the guide member 37 to the strapping position above the table 32 as heretofore described.

There is also mounted around the ,countershaft 145 an annular electromagnet 170 which is secured by a metal ring 171 and studs 172 to the bracket 139 carried by the frame 93. Since the magnet 170 is stationary, connec' tions to its electric winding may be made through stationary terminal posts in the usual manner. The elec tromagnet 174), when enerziged, attracts a metallic ring 173 made up of a flat ring 173a adapted to contact with the end face of the casing of the magnet 170 and another member 173b of channel-shaped cross section to which there is secured the enlarged ends of another series of plungers 174 which are slidably mounted in certain of the apertures 161a formed in the disk 161. The plungers 174 are arranged alternately with the plungers 163 around the outer portion of the disk 161 and coil springs 175 normally press the ring 173 into engagement with the end face of the clutch magnet 170 which serves as a brake to arrest the rotation of the shaft 145 when it is energized. When the shaft 145 is rotating, the plate 173a is pressed against the end face of the magnet by the springs 175 but, upon deenergization of the clutch magnet 160, the brake magnet 170 is energized by the operation of the electric circuit hereinafter described so that the brake ring 173 is thereby attracted and the shaft 145 is brought to rest. The connections of the electric circuit are such that the two

magnets

160 and 170 cannot be energized at the same time. At the right-hand end of the shaft 145, as viewed in Fig. 9, a gear 176 is fixed to rotate with the shaft and this gear meshes with another gear 177 mounted upon the shaft of the rotary switch 106, as shown in Fig. 5, so that this switch is operated to control certain parts of the electric control circuit each time that the countershaft 145 is rotated.

The pulley 128 and the sprocket pulley 148, which are rotated continuously when the motor 85 is in operation, operate through the belt 149 to effect a simultaneous rotation of the gear 150 which has a long hub 150a