US3118367A

US3118367A - Strapping machine

Info

Publication number: US3118367A
Authority: US
Publication date: 1964-01-21
Anticipated expiration: 1981-01-21

Description

STRAPPING MACHINE 7 Sheets-Sheet l Filed Jan. 30, 1961 Jan. 2l, 1964 F. .1. LINDHOLM STRAPPING MACHINE '7 Sheets-Sheet 2 .Im/@1 7 wlw/w,

Filed Jan. 30, 1961 Jan. 21, 1964 F. J. LINDHOLM STRAPPING MACHINE- '7 Sheets-Sheet 3 Filed Jan. 50, 1961 I Inga/d0?? @ga/wmwm @mmm/awww 4.455 .I

Jan. 21, 1964- F. J. LINDHOLM STRAPPING MACHINE '7 Sheets-Sheet 4 Filed Jan. 30. 1961 'IMM E? '7 Sheets-Sheet 5 J luga: (if u@ ge/'MMM nafu/ Jan. 2l, 1964 F. J. LINDHOLM STRAPPING MACHINE Filed Jan. 30. 1961 F. J. LINDHOLM STRAPPING MACHINE Jan. 21, 1964 7 Sheets-Sheet 6 Filed Jan. 30, 1961 F. J. LINDHOLM STRAPPING MACHINE Jan. 21, 1964 '7 Sheets-Sheet '7 Filed Jan. 30, 1961 Y lllllllllllllllllllllllllllllll Il.

United States Patent Office ll? Patented dan. 2l, i964 Filed `lan. 30, i961, Ser, No. $5,913 14 Claims. (Cl. Mill-4) This invention relates to strapping apparatus, and is particularly concerned with apparatus capable of strapping an article as it is being moved along a longitudinal path of travel by a conveyor, without stopping or slowing the conveyor or the article carried thereby.

While embodiments of this invention have general utility and may be used in many environments, there is described herein an illustrative embodiment effective to perform a strapping operation for simultaneously strapping two oppositely disposed portions of a coil of material being moved by a conveyor.

In this embodiment of the invention, the strapping apparatus comprises a pair of strapping machines 'that are interconnected electrically and mechanically to enable them to be normally operated simultaneously on opposite sides of a coil of material that is moved longitudinally through a strapping zone. rlhe apparatus is normally automatic, but it also includes hand operated controls for operating different parts of the apparatus separately if so desired or in the event of any malfunction and to facilitate servicing.

The coils of material to be strapped are carried individually on hooks suspended from an overhead conveyor chain that is continuously driven in any suitable manner. A photo-electric system, generally referred to as an electric eye is disposed to observe the coils as they enter the strapping zone. lf any hook passes through the strapping Zone without a coil mounted on it, the light beam of the system is not interrupted, and the strapping apparatus is not operated.

A coil mounted on one of the hooks activates the strapping apparatus by interrupting the light beam to the photo-electric cell as the coil enters the strapping zone. The strapping apparatus is so timed that it starts the strapping operation as a coil of material breai s the light beam upon entrance of the coil into the strapping Zone, and completes the strapping operation and returns the mechanism to its starting or rest position before the next hook enters the strapping zone in the normal operation of the conveyor and strapping apparatus.

Each strapping machine is mounted on a movable carriage, and the carriages are interconnected mechanically by a common shaft coupled to the drive shaft of each cai riage to synchronize the longitudinal movement of both carriage The strapping machines face each other, and each is mounted on a cross slide that moves it inwardly toward the coil that is carried through the strapping zone between the two machines by the longitudinally moving conveyor. The machines strap an arcuate portion of the ring formed by the coil at each of two diametrically opposite positions and apply a metal seal to the strap as the coil passes through the strapping Zone.

When a coil breaks the light beam at the entrance to the strapping zone, a drive arm swings downwardly from each of the carriages into the longitudinal path of travel of the coil. Each drive arm has a positioning block secured thereto and projecting from the drive arm toward the entrance end of the strapping Zone. lf a coil mounted on one of the conveyor hooks hangs so that one edge of the coil strikes a positioning block before the other does, the forward edge of the coil engaging one positioning block is held stationary against its positioning block, and the conveyor hook continues to move the other edge of the coil until both edges of the coil are in Contact with the positioning blocks.

Each positioning block has a switch mounted thereon. The switches are in series so that both switches must be closed before the circuit is energized. When both switches are closed the head of each strapping machine moves inwardly, and other switches mounted on the strapping machine heads engage opposite edges of the coil and are closed thereby. The switch on each head swings a pair of chute arms inwardly to close the arms inside the coil. Each chute has a switch that is actuated by closing the chute, to start the strap feeding mechanism. The switches on the chutes are in series with the switches on the strapping machine head, so that the chutes must be closed before the strap can be fed. Each chute is provided with a gate that isl closed to confine the strap that is fed into the chute by each strapping machine. The chute is larger in circumference than the circumference of the circular portion of the coil, and therefore the strap forms a loose loop around said circular portion of the coil.

The carriages on which the strapping machines are mounted are each held against longitudinal movement by an air cylinder. When the conveyor hook strikes a switch on either drive arm the air cylinders are vented, and both carriages are released for longitudinal movement. Both carriages are moved longitudinally by the engagement of the conveyor hook with the drive arms, and, therefore, must move at the same speed as the hook. The strapping operation is continued as the hook moves the carriages toward the discharge end of the strapping zone. The electrical circuits are so interconnected that when the strap encircles a portion of the coil the strap feeding mechanism is stopped, the gates are opened, and the strap is pulled tight around the circular portion of the coil to tension it. The chutes are opened after the gates are opened to re-set them for the next coi1 to enter the strapping zone. When the strap has been tensioned, a metal seal is applied to seal two overlapping portions of the strap and the strap is cut off.

When the strap is cut olf the strapped coil is free to move out of the strapping zone. The cylinders for driving the carriages bach to their starting position are provided with air cushions to decelerate them as they approach the end of their movement to prevent an abrupt stop at the end of the longitudinal movement of the carriages.

An illustrative embodiment of the invention and a structure by means of which the above noted and other advantages of the invention are attained is described in detail inthe foliowin specification, taken in conjunction with the accompanying drawings, in which:

FIG. l is a fragmentary front elevational view of a strapping apparatus embodying the invention;

FIG. 2 is an end elevation, taken from the right hand side of FlG. l, with parts broken away to clarify the illustration;

FlG. 3 is an enlarged top plan View of the apparatus shown in FlG. l, with the vertical portion of the con,- veyor hook shown in section;

FlG. 4 is a cross sectional view, the line 4,-4 of FlG. 3;

FlG. 5 is a view, partly in elevation and partly in section showing one chute and its related structure;

FlG. 6 is a cross sectional view, taken along the line 6-6 of FlG. 5;

FlG. 7 is a cross sectional View, taken along the line 7-7 of FlG. 5;

FIG. 8 is a cross sectional View, taken along the line Sw?. of FlG. 5;

FIG. 9 is a cross sectional View, taken along the line 9--9 of FlG. 5;

FIG. lO is a cross sectional view, taken along the line lli-lll of FlG. 3;

taken generally along FIG. 1l is a pneumatic circuit diagram of the rear strapping apparatus remote from the operator; and

FIG. 12 is a view, similar to FIG. 1l, for the front strapping apparatus in front of which the operator normally stands.

The illustrative embodiment shown in the drawings comprises two

strapping machines

11, 12 mounted on longitudinally

movable carriages

13, 14. The strapping machines are essentially similar to the machine shown in the Crosby et al. Patent No. 2,915,003. It should be understood, however, that the present invention is not limited to use with any specific strapping machine, and that any suitable strapping machine may be used. It should also be appreciated that embodiments of the present invention may use a single strapping machine when it is not desired to apply a pair of straps simultaneously to an object. Each strapping machine has a head that contains mechanism for performing the various strapping operations, and a chute for guiding the strap around the article to be strapped. The strapping head is the same as that described in the above mentioned patent and, therefore, is not described in detail herein.

The

carriages

13, 14 are mounted in spaced relationship on opposite sides of a conveyor adapted to move a series of hooks 15 along a predetermined path of travel extending longitudinally in one direction through a strapping Zone between the

carriages

13, 14. The conveyor moves the hooks back to their initial position along a path of travel remote from said strapping machines. Each hook comprises a vertical section 16 that is secured to an overhead chain (not shown), and a horizontal section 17 adapted to carry a coil 18 of material to be strapped. The material of the coils may be bars, rods or strips of metal or any other material that can be iandled in coil form.

The

carriages

13, 14 are duplicates, and therefore only one of them will be described in detail, it being understood that the description applies to both carriages. The structure of the carriage is shown best in FIG. 4. The carriage is supported on a bed 19 having a pair of

side walls

20, 21 and corner posts 22. Leveling screws 23 are provided for each post to insure accurate leveling of the bed. A shaft 24 is journalled in bearings 25 mounted in each side wall. Suitable couplings 26 at one end of cach shaft 24 connect each of the shafts 24 to an intermediate shaft 27 axially aligned with the shafts 24. The coupled connection between the shafts synchronizes the rotational `tovemcnt of both shafts and the longitudinal movement of both carriages, as hereinafter described.

The bed 19 has two intermediate coplanar

horizontal plates

28, 29 extending inwardly from

side walls

20, 21, respectively. The inner edges of the

plates

28, 29 are spaced from each other to provide a space for a plate 30 for supporting an air cylinder 110 (FIG. 1) from which a piston rod 31 projects. After completion of each strapping operation the piston rod moves carriage 13 back to its initial position in a manner hereinafter described. A plurality of transversely disposed angle irons 32 support longitudinally extending plates 33 that support the inner edges of

plates

28, 29. Ears 34 projecting laterally from opposite edges of support plate 30 are secured to the inner edge portions of

plates

28, 29 by bolts 35.

The carriage 13 is provided with a ilat bed plate 36 movable longitudinally on the bed 19. The bed plate has a flange 37 depending from each longitudinal edge, and the flanges are provided with apertures 38 in each of which a tubular sleeve 39 is rigidly secured. A bearing 40 has a shaft 41 extending through the sleeve 39 and secured thereto by a nut 42. The bearings are rotatably mounted in longitudinally extending recesses 43 in the

side walls

20, 21. The bearings provide a rolling support for the carriage as it is moved longitudinally relative to the bed 19.

A longitudinally extending bar 44 secured to plate 29 by bolts 45 serves as a xed guide for the longitudinal movement of the carriage. A plate 46 depending from the bed plate 36 has a horizontal flange 47 extending therefrom to support a pair of laterally spaced vertically disposed bearing shafts 48 secured thereto by a nut 49. A roller 59 is rotatably mounted on the lower end portion of each bearing shaft 48. The rollers 50 engage opposite edges of guide bar 44 to provide rolling contact therewith as the carriage is moved longitudinally in either direction. Each roller is spaced from the underside of ilange 47 by a sleeve 51. The frictional Contact between the rollers 50 and the guide bar 44 is not suillcient to interfere with the longitudinal movement of thc carriage.

A carriage link 52 having its upper end secured to plate 46 by bolts 53 has an aperture through which the outer end of piston rod 31 extends. A nut 54 secures the piston rod to the carriage link. 'The lower end of the carriage link is secured to an endless chain 55 that extends around a sprocket 56 mounted on shaft 24 and another sprocket 57 (FIG. 1) spaced longitudinally therefrom. The sprocket 57 is mounted on an idler shaft 558 journalled in bearings (not shown) in

walls

20 and 21.

When the carriage is moved longitudinally in either direction the carriage link moves the chain 55 to rotate the shaft 24. The intermediate shaft 27 and couplings 26 rotate the other shaft 24 to synchronize the longitudinal movement of the

carriages

13, 14. The carriage is moved in the same direction as the movement of the coil through the strapping zone by the conveyor hook 15 in a manner hereinafter described. The carriage 13 moves the piston rod 31 outwardly as it is moved by the hook 15. The carriage is moved back to its initial position by the piston rod 31 after the hook has moved out of the strapping zone. The end of the return movement of the piston rod is deceleratcd by a valve 118 that is operatively connected thereto in any suitable manner. The valve 118 is enclosed in a housing 579 having an arm 60 projecting therefrom and terminating in a clevis 61. A lug 62 rigidly secured to the lower edge portion of the flange 37 by a bolt 63, depends into the clevis and is secured thereto.

The strapping machine is mounted on the bed 19 in a manner to permit transverse movement of the strapping mechanism relative to the bed. The head of thc strapping machine is secured to a cross slide 64 mounted on ball bearings 65, one of which is shown in FIG. 10. The ball bearings are housed in races 66 supported by plates 67 projecting upwardly from the bed. A piston rod projecting from a cylinder 111 moves the cross slide transversely of the bed.

A cover plate 68, supported in a suitable manner, extends over the bed 19 and moves longitudinally with respect to the bed plate 36. The outer end of the cover plate 63 is supported on an extension plate 69 (FIG. l) by rollers 70. The rollers 70 are each rotatably mounted in a bracket 71 secured to the underside of the cover plate.

Each carriage is provided with a drive arm 72 (FIG. 2) having a base section 73 and an upper section 74 pivotally mounted on the outer end of the base section, as indicated at 75. The pivotal connection 75 also secures a bell crank 76 to the drive arm. The lower end of the base section 73 is secured to the carriage adjacent the side that is remote from the entrance of the strapping zone and also remote from the conveyor. The base section is angular and its upper end extends toward the conveyor. A cylinder 112 mounted on the base section 73 has a piston rod '/'7 connected to one end of the bell crank. Another cylinder 78 mounted on the base section has a spring biased rod 79 connected to the opposite end of the bell crank.

When the apparatus is in its rest position the spring biased rod 79 holds the upper section of the drive arm upwardly out of the path of travel of the coils 18. The cylinder 112 is operated by an electric eye system, hercinafter described, to lower thc upper arm section into the attese? path of travel of the coils when the conveyor moves a coil into the strapping Zone. The upper end of the drive arm is engaged by the conveyor hook to move the carriage longitudinally a limited distance. When the carriage has reached the end of its normal movement a limit switch energizes an electrical circuit that is effective to exhaust the cylinder lil The spring biased rod 79 then moves the upper section of the drive arm upwardly out of the way of the coil which is carried past the drive arm to a discharge station.

A switch ltlSl is associated with the upper section of each drive arm. The switch may be mounted directly on the drive arm, but it is preferred to mount it on a positioning block Si) secured to the drive arm. The positioning block projects from the drive arm toward the entrance of the strapping zone so that the switch mounted thereon will be engaged by the coil before the coil engages the drive arm. The positioning block is slidable transversely of the drive arm, as indicated at Sti', FIG. 3. The positioning block slides the coil rearwardly on the conveyor hook until the conveyor hook i engages the drive arm. The engagement of the switch ltlS with the coil initiates the strapping cycle, as hereinafter described. Mounting the switch llilSl on the positioning block in spaced relationship to the drive arm allows more time for the strapping operation. l

A lswitch i251 is mounted on the outer end or the upper section of the drive arm in position to be engaged by the hook of the conveyor. When the conveyor hook engages switch i231 and closes it the rst result is that an air cylinder il@ is vented. The cylinder il@ normally holds die carriage i3 against longitudinal movement. The hook of the conveyor exerts pressure against the drive arm 72 to move the carriage longitudinally until the strapping operation is completed.

The chute assembly 82 shown in FlG. 5 has a pair of coacting chute arms @3, fili each of which is rigidly secured to a sleeve 35 that is pivotally mounted on a vertical post Se, 87. The

posts

83, 39 of a second chute assembly Eil are closely spaced, as shown in FIG. 3. rl`his difference in the post spacing is necessary because one strapping machine is reversed, and it is desirable to have both chute assemblies aligned with the coil so that they can encircle diametrically opposite portions of the coil simultaneously. The structure of chute assembly 9@ will not be described specifically, since the structural characteristics of both chute assemblies are essentially the same.

The lower end of each vertical post is lixed in a base support @l by a set screw 92., as shown in FlG. 1G. The base support 9i is mounted on the cross slide 64 and moves with the head of the strapping machine. The base support has an upstanding wall 93 to which a support bracnet 94 and a horizontally disposed channel 9S are secured. The upper end of the post is supported in vertical position by the support bracket 9d. The sleeve S5 ts over the post but is cut away, as indicated at 6, to permit the support bracket 94 to engage the peripheral surface of the post. The sleeve 35 may be made in two sections rigidly secured together by any suitable bridge member. The sleeve d5 has bearings 97, 93 adjacent its upper and lower ends. A pinion gear 99 projects laterally from the vertical sleeve 8S. The pinion gear is preferably integral with the sleeve, but may be a separate member rigidly secured thereto. A cover plate lull fits around the exposed portion of the pinion gear as a protective cover.

A rack 301 is slidably mounted in the channel 95 and meshes with the pinion gear 9. A cylinder 113 has a piston rod 362. Rack Sill is moved back and forth in the channel $5. The cylinder 113 is operated by an electrical circuit that includes the switches ltlSl, MS2. Limit switches SlA, SSlA mounted adjacent opposite ends of channel 95 are actuated by one end of rack 301 and by a collar or clamp 393 mounted on the opposite end of the rack, as the raclr is reciprocated in the channel 95. The reciprocation of the rack 301 oscillates the chute assembly by rotation of the pinion gear 99 in opposite directions.

As shown in FIG. 5, the sleeves S5 are positioned at opposite sides of the strapping machine head. Chute arms 83, Sd;- have straight sections 394, 3%, respectively, extending from each sleeve along diverging lines. The outer end of section Stil-l terminates in a curved section 3%, and the outer end of section 395 terminates in a curved section 367. A web 3% (Pi. l0) extending between each sleeve $5 and the adjacent curved section 3th?, Sii? provides a rigid reinforcement that helps to support the chute assembly. The curved sections of the chute arms cooperate to encircle a circular portion of a coil l in engagement with the switches ltlSll, 1082 on positioning blocks A strap gate Sil@ having an inverted Lshaped cross section is mounted on a ilat block Titti comprising two juxtaposed sections Sil., 312 secured to the cross slide ed. A limit finger 313 is secured to the end of the cross slide to overhang one edge of strap gate 369. The vertical flange of strap gate Citi@ is spaced from the edge of section Sil to provide a narrow gap 314 through which the strap is threaded. A strap gate Sie adjacent the other side of the strapping machine has a gap 31.6 through which the free end of the strap is threaded as it is pulled from a supply source. A Contact block 317 depends from section in position to be engaged by the strap being fed through the chute. When the contact block is engaged by the free end of the strap being fed through the chute it triggers a time relay which, after a predetermined time delay, reverses the current to stop a strap feeding motor. Stopping the motor stops the strap feeding movement.

The strap gate Sti@ is held against the upper surface of block Si@ by a cam 13 pivotally mounted in a carn guide .319 by means of a pin 32d. The cam guide is rigidly secured to the upper surface of the section 394 of chute arm 53 in any suitable manner. The cam is urged into position in which the strap gate is held down against the upper surface of block Edil by a spring 321. The spring 321 is seated in a recess 322 in section 3M and is secured to a guide pin 323 that is positioned in an aperture 3124i in the cam.

After the strap feeding movement is stopped it is necessary to open the strap gate to allow the strap to be tensioned around the portion of the coil which it encircles. An air cylinder 1li@ is mounted below an aperture 325 in the chute arm 83 and actuates a plunger 326 to move the gate upwardly to allow the tensioning mechanism of the strapping machine to pull the strap out of the chtite. When the gate is opened and the strap is pulled out of the chute, the pressure against plunger 326 is released, and the gate is pulled down by a spring 327 that is assisted by gravity.

The spring 327 is mounted on a bushing 328 and extends upwardly into a counterbored recess 329 in block Sill. A rod .i3-il having one end secured in the bushing 32S extends through the recess 329 and is threaded into an aperture in the strap gate, as indicated at 33t, FG. 7. The spring encircles the rod 336i andrat its upper end bears against a washer 332.

A clear understanding of the sequence of operations of the strapping mechanism may behad by reference to the schematic, electricpneumatic-mechanical illustrations shown in FiGS. ll and 12, inclusive. rl`hese iigures clearly show and fully disclose all of the pneumatic and electric wiring connections and the interrelations therebetween. Moreover, the elements of the electrical system are numeralled and lettered to indicate the correspondence thereof with each other. For example, the relays and the contacts thereof, respectively, have corresponding numerals and letters to identify the same. rl`he following discussion describes the operating relation of the electric, pneumatic and mechanical arrangements and functions with reference to the fully disclosed systems shown in the drawings which form a part of this specication.

The master control panel for the simultaneous operation of both strapping machines is located on the front of strapping machine 11 where it is easily accessible to the operator.

For automatic operation of the mechanism, a selector switch is turned to automatic position to energize the automatic circuits and to lock out the hand controlled circuits. It will be assumed that the strapping mechanism is in its starting position in the following description of the operation.

A coil 18 mounted on a conveyor hoolt is moved into the strapping zone by the conveyor. The coil breaks a light beam between a light and a photo-electric cell receiver to energize the solenoids D1, D2. The solenoids D1, D?. operate valves for the

cylinders

112, 212 and thereby cause the drive arms 72 to lower into the path of longitudinal travel of the coil. Switches 1281, 1282 are in series with the electric eye system and must be closed or the drive arms cannot move downwardly. The downward movement of the drive arms opens switches 581, 582.

A positioning block 80 is secured to each drive arm and is spaced from the drive arm toward the entrance of the strapping zone, so that as the coil is moved along with the hook of the conveyor longitudinally ofthe machine, it will engage the positioning blocks S before the hook engages the drive arms 72. Switches 1081, 1G82 are mounted on the positioning blocks and are closed by contact with the coil 18 being moved by the conveyor hook. The switches 1081, 1082 are in series, so nothing can happen until both switches are closed.

If one edge of the coil 13 engages one of the positioning blocks, said one edge will be held stationary in contact with said bloclt as the movement of the conveyor hook moves the other edge of the coil into engagement with the other positioning block so that the coil is properly positioned for the strapping operation. When the coil engages both positioning blocks it closes both switches 1081, 1082 and energizes the solenoids B1, B2, C1, C2. The solenoids C1, C2 operate the

cylinders

111, 211 to move the heads of the strapping machines inwardly into engagement with the edge portions of the coil. The engagement of the strapping machine heads with edge portions of the coil closes switches 381, 382. The solenoids B1, B2 operate the

cylinders

113, 114, 213 to close the

chutes

82, 90. As the chutes are closed they open switches 781, 781A, 782 and close switches 881, 381A, 882 to start the strap feeding operation. The switches 881, 881A are in series with switches 381 and 1081, and the switch 882 is in series with the switches 382 and 1082. Therefore, the chutes must be closed, and the head must be in engagement with the coil, before the strap feeding movement can start. The switches 1081, 1082 could be located on the drive arms, but it is preferred to mount them on the positioning blocks to start the strapping cycle sooner.

As the coil moves toward the drive arms, the strap is fed through the eye of the coil. A contact block 317 mounted on the chute is engaged by the strap being fed into the chute. The contact block triggers a time relay which, after a time delay, reverses the current to plug the motors to a stop, thereby stopping the strap feeding movement and de-energizing the solenoids El, E2. The deenergization of the solenoids E1, E2 operates the

cylinders

120, 220 to open the gates 315 and permit tensioning of the strap. When the gates are opened they close switches 981, 982 to de-energize the solenoids B1, B2 and operate the

cylinders

113, 114, 213. The

cylinders

113, 114, 213 open the

chutes

82, 90 and start the tensioning cycle.

As the conveyor continues to move the coil longitudinally through the strapping zone, the hook is moved into engagement with switches 1281, 1282 that are mounted on the drive arms 72. The hook closes the switches 1281, 1282 to de-energize the solenoids A1, A21 to vent the

cylinders

110, 210 so that the

carriages

12, 13 can be moved along with the conveyor. The carriages are moved by the engagement of the hook with the drive arms, and therefore must move at the same speed as the conveyor.

When the sealing operation is completed and the strap is cut, the switches 181, 182 are opened to fle-energize the solenoids C1, C2, D1, D2. The dc-energization of solcnoids C1, C2` operates

cylinders

111, 211 to withdraw the strapping machines from the sides of the coil 18. The de-energization of solenoids D1, D2 causes exhausting of the

cylinders

112, 212 to permit spring biased rods 79 to raise the drive arms 72 clear of the conveyor hook. Movement of the heads of strapping

machines

11, 12 away from the sides of the coil closes switches 481, 482. Upward movement of the drive arms closes switches 581, 582, opens switches 281, 2812, 1281, 1282, and encrgizes solenoids A1, A2 to operate

cylinders

110, 210 through thc valves 168, 208 to drive the carriages back to their starting positions.

As the carriages are driven back to their starting positions the

cylinders

110, 210 are exhausted through valves 105, 167, 236, 267. Cams 250, 251 mounted on the carriages close valves 118, 218 that are aligned with valves 1F36, 2&6 to close them to restrict the exhaust iiow, and thereby form an air cushion to decelerate the pistons in

cylinders

110, 219 as they approach the end of their movement as the carriages return to their starting position.

Normally the mechanism is operated automatically as a continuous process with a new cycle started every time a coil carried by a hooi: of the conveyor breaks thc beam to the electric eye. However, if any part of the mechanism malfunctions, the cause of the malfunction misst be corrected before normal operation can be resumed. lt is not practical to service parts of the mechanism while the automatic control is energized, and therefore hand operated control means has been provided for service and test purposes. The procedures for correcting the operation of the mechanism depends upon the nature of the malfunction.

lf the limit switches 381, 382 are not actuated by contact with the coil, or it the switches 881, 881A, 882 are not actuated because the chutes are unable to close, after a timed interval the chutes open, the drive arms raise, the strapping machines retract, and the carriages return to rest position. The coil that is not properly strapped is removed, and the loose coil signal is reset by pressing a signal reset button. The machine will strap the following coils.

If either strapping machine fails to function properly, the loose coil signal is actuated, but the other strapping machine will finish its strapping operation. The chutes open, the drive arms raise, the strapping machines retract, and the carriages return to their starting position. The loose coil signal cannot be reset until the malfunction is corrected and the start button is pressed to re-energize the machine. The machine will not strap the following coils until it is cleared and re-energized.

If the carriages are carried to within three inches of the end of travel, the limit switches 681, 682 are actuated to stop the conveyor and de-energize the control circuits. The chutes open, the drive arms raise, and the strapping machines retract. The malfunction must be cleared and the carriages moved off the limit switches before the circuit can be re-energized by pressing the start button.

In order to service the machine it is necessary to change from the automatic control to hand control. This is done by turning a selector from automatic position to hand position. This energizes the hand operation circuits and locks out the automatic circuits. The loose coil signal is activated and cannot be reset until the selector is turned back to automatic position. The conveyor stops when the automatic selector is turned to hand operation, but may be started again by turning the conveyor stop selector to ov-aride position. A pilot lamp on the panel board lights when the automatic selector is turned to hand operation, and remains lighted until the automatic selector is turned back to automatic position. A plurality of manually operated switches actuate each mechanism separately to facilitate locating and correcting any malfunction.

Although a preferred embodiment `of the invention is described in considerable detail, it will be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details may be modied or changed without departing from the spirit or scope of the invention. Accordingly, it is not intended to restrict the invention to the exact construction described.

l claim:

l. In combination for cooperative operation with a con veyor having a movable member adapted to carry an article to be strapped, a carriage movable along a line parallel to said conveyor, a strapping machine mounted on said carriage, said carriage being disposed in the path of and engageable by an article carried by said movable member to move said carriage and said strapping machine in the same direction as said article, means to limit the movement of said carriage in the direction of movement of said article, means for actuating said strapping machine to strap an article carried -by said movable member before said carriage reaches the limit of its movement in said direction, means to disengage said strapping machine from said article after the strapping operation is completed, and means to move said carriage back to its initial position.

2. ln combination for cooperative operation with a conveyor member adapted to move an article along a lixed path of travel, a strapping machine movably mounted adjacent the path of travel of said article, a pair of chute arms mounted on said strapping machine, means including a member engageable by said conveyor to move said strapping machine a limited distance in the same direction and at the same rate of speed as said article, means to actuate said chute arms to encircle said article and guide a strap around said article, said strapping machine being adapted to feed a strap through said chute yarms and to apply it to said article as said article and said strapping machine are being moved, said strapping machine being operated within predetermined travel limits to complete the strapping operation before it reaches the limit of its movement in said one direction.

3. ln combination for cooperative operation with a conveyor member adapted to move a coil of material in one direction, a pair of strapping machines positioned on opposite sides of the path of travel or" said coil, means to move both of said strapping machines a limited distance in the same direction and at the same rate of speed as said coil, means to operate said strapping machines simultaneously to apply straps to different portions of said coil as said coil and said strapping machines are being moved in the same direction, and means to insure completion of the strapping operation before said strapping machines reach the limit of their movement in the direction of the movement of said coil.

4. in combination for cooperative operation with a movable conveyormember adapted to move an 'article along a fixed path of travel, means including a drive arm for movably mounting a strapping machine adjacent said path of travel, means to move said drive arm into said path of travel as said conveyor member moves an article into proximity to said strapping machine, said drive arm moving said strapping machine in the direction of movement of said conveyor, and means to actuate said strapping machine to apply a strap to an article being moved along said path of travel by said conveyor member, said last mentioned means including a switch mounted on said drive arm, said switch being adapted to be closed by engagement with said article being moved by said conveyor member.

5. In combination for cooperative operation with a movable conveyor member adapted to move an article along a xed path of travel, means including a drive arm for movably mounting a strapping machine adjacent said path of travel, means to move said drive arm into said path of travel as said conveyor member moves an article into proximity to said strapping machine, said drive arm moving said strapping machine parallel to said article, and means to actuate said strapping machine to apply a strap to an article being moved along said path of travel by said conveyor member, said last mentioned means including a switch mounted on said drive arm, said switch being adapted to be closed by engagement with said article being moved by said conveyor member before said conveyor member moves into engagement with said drive arm.

6. In combination for cooperative operation with a conveyor member adapted to move a coil of material in one direction, a pair of strapping machines positioned on opposite sides of the path of travel of said coil, a pair of chute arms mounted on each of said strapping machines, means in engagement with said conveyor for supporting and moving both of said strapping machines a limited distance in the same direction and at the same rate of speed as the speed of said coil, and means to actuate said chute arms simultaneously to close each pair of them around a different portion or said coil, said strapping machines including means for 'feeding straps through said pairs of chute arms as said coil and said strapping machines are being moved in the same direction, and means for operating said strapping machines within predetermined limits to complete the strapping operation before they reach the limit of their movement in the direction of movement of said coil.

7. ln combination, two longitudinally movable carriages mounted in spaced relationship, a strapping machine mounted on each of said carriages, a conveyor member adapted to move a coil of material longitudinally lbetween said strapping machines, and means for actuating each ot' said strapping machines when a coil is moved between said strapping machines, said means including switches connected in series to be engaged by said coil to actuate both strapping machines substantially simultaneously.

8. ln combination, means mounting two strapping Inachines in spaced relationship including a drive arm disposed adjacent each of said strapping machines, a conveyor adapted to move a coil of material longitudinally between said strapping machines into engagement with said drive arms, and a positioning block projecting from each of said drive arms, said positioning blocks being adapted to hold one edge portion of a coil against longitudinal movement as said conveyor moves the opposite edge portion of said coil longitudinally, to center said coil relative to said strapping machines.

9. ln combination for cooperative operation with a conveyor member adapted to move an article along a lined path of travel, means including a drive arm for movably supporting a strapping machine adjacent said path of travel, said strapping machine having a pair of chute arms adapted to guide a strap around an article when the chute arms are in the closed position, a switch adapted to actuate movement of said chute arms to close them, said switch being positioned in said path of travel whereby it is engaged by said article and moved into closed position thereby, said conveyor member being engageable with said drive arm after said chute arms have been closed to move said strapping machine along with said article.

l0. ln combination for cooperative operation with a conveyor member adapted to move an article along a xed path of travel, means including a drive arm for movably supporting a strapping machine adjacent said path of travel, said strapping machine having a pair of chute arms adapted to guide strap around an article when in closed position, a switch adapted to actuate movement of said chute arms to close them, said switch being positioned in said path of travel whereby it is engaged by said article and moved into closed position thereby, said conveyor member being engageable with said drive arm after said chute arms have been closed to move said strapping machine along with said article, and means for operating said strapping machine to apply a strap to said article as said article and said strapping machine are being moved by said conveyor member.

l1. In combination, two carriages mounted in spaced relationship, a strapping machine mounted on each of said carriages, a conveyor member adapted to move a coil of material longitudinally between said strapping machines, a drive arm connected to each of said carriages, an electric eye system adapted to cast a beam of light across the path of travel of a coil carried yby said conveyor member, an electrical circuit energized by interruption of said beam of light to move said drive arms into the path of travel of said coil, and means including a switch to actuate said strapping machines, each of said switches being adapted to be closed by engagement with an edge portion of a coil being moved between said strapping machines.

12. In combination, two longitudinally movable carriages mounted in spaced relationship, a strapping machine mounted on each of said carriages, a conveyor member adapted to move a coil of material longitudinally between said strapping machines, a drive arm connected to each of said carriages, an electric eye system comprising means to cast a beam of light across the path of travel of a coil carried by said conveyor member and an electric eye responsive to said beam of light to generate signals upon decrease of luminosity upon interruption of said beam of light, an electrical circuit activated by said signals to cause movement of said drive arms into the path of travel of said coil, means for actuating said strapping machines, said means including a first and a second switch mounted on each of said drive arms, each of said first switches being adapted to be closed by engagement with an edge portion of a coil being moved between said strapping machines, means for holding said carriages against longitudinal movement, said second switches being engageable by said conveyor member when said drive arms are in the path of travel of said coil to release said holding means, said conveyor member being adapted to move said carriages in the same direction as said coil upon release of said holding means.

13. In combination, two carriages mounted in spaced relationship, a strapping machine mounted on each of said carriages, a conveyor member adapted to move a coil of material longitudinally between said strapping machines, a drive arm connected to each of said carriages, said conveyor member being engageable with said drive arms to move said carriages longitudinally, a fluid pressure operated cylinder for holding each of said carriages against longitudinal movement, a switch mounted on each of said drive arms, said switches being engageable by said conveyor member to actuate said cylinder to release said carriages for limited longitudinal movement by said conveyor member, and means for actuating said cylinders after said limited longitudinal movement to move said carriages back to their initial position.

14. In combination for cooperative operation with a conveyor having a movable member adapted to carry an article to be strapped, a carriage movable along a line parallel to said conveyor, a strapping machine mounted on said carriage, said movable member being engagcable with said carriage to move said carriage and said strapping machine in one direction along a line parallel to said conveyor, means to limit the normal movement of said carriage in said one direction, means for actuating said strapping machine, said strapping machine being timed to strap an article carried by said movable conveyor member before said carriage reaches the limit of its normal movement parallel to said conveyor in said one direction, and a switch in an area beyond the normal limit of movement of said carriage and in the path thereof, said switch being operable upon engagement by said carriage to stop said conveyor and to de-encrgize the strapping machine.

References Cited in the le of this patent UNITED STATES PATENTS 1,261,589 Mogan et al Apr. 2, 1918 2,901,966 Becher Sept. 1, 1959 2,905,078 Laine Sept. 22, 1959 2,915,003 Crosby et al Dec. 1, 1959 2,930,313 Bocher Mar. 29, 1960 FOREIGN PATENTS 744,176 Great Britain Feb. 1, 1956 OTHER REFERENCES German printed application 1,087,514, Aug. 18, 1960.

Claims

1. IN COMBINATION FOR COOPERATIVE OPERATION WITH A CONVEYOR HAVING A MOVABLE MEMBER ADAPTED TO CARRY AN ARTICLE TO BE STRAPPED, A CARRIAGE MOVABLE ALONG A LINE PARALLEL TO SAID CONVEYOR, A STRAPPING MACHINE MOUNTED ON SAID CARRIAGE, SAID CARRIAGE BEING DISPOSED IN THE PATH OF AND ENGAGEABLE BY AN ARTICLE CARRIED BY SAID MOVABLE MEMBER TO MOVE SAID CARRIAGE AND SAID STRAPPING MACHINE IN THE SAME DIRECTION AS SAID ARTICLE, MEANS TO LIMIT THE MOVEMENT OF SAID CARRIAGE IN THE DIRECTION OF MOVEMENT OF SAID ARTICLE, MEANS FOR ACTUATING SAID STRAPPING MACHINE TO STRAP AN ARTICLE CARRIED BY SAID MOVABLE MEMBER BEFORE SAID CARRIAGE REACHES THE LIMIT OF ITS MOVEMENT IN SAID DIRECTION, MEANS TO DISENGAGE SAID STRAPPING MACHINE FROM SAID ARTICLE AFTER THE STRAPPING OPERATION IS COMPLETED, AND MEANS TO MOVE SAID CARRIAGE BACK TO ITS INITIAL POSITION.