United States Patent [191 Zimmerman et a1.
[ FULLY AUTOMATIC WRAPPING MACHINE  Inventors: Thomas C. Zimmerman,
Franksville; Charles E. Michels, Racine, both of Wis.
 Assignee: Reliance Electric Company,
Cleveland, Ohio  Filed: Sept. 25, 1972  Appl. No.: 290,664
 US. Cl 53/66, 53/210, 53/389  Int. Cl B651) 11/22, B65b 59/00  Field of Search 53/64, 66, 182, 206, 210, 53/228, 389; 74/55  References Cited UNITED STATES PATENTS 3,196,591 7/1965 Guido et a1. 53/66 X 3,429,098 2/1969 Treiber 53/210 X 3,490,194 1/1970 Monaghan 53/182 X 3,503,175 3/1970 Marasso et al 1 53/182 X 3,505,780 4/1970 Hansen et al. 53/210 3,543,480 12/1970 Weeks 53/210 3,552,088 1/1971 Akiro Niwa. 53/182 X 3,559,367 2/1971 Misik 53/182 X 3,564,810 2/1971 Faletti 53/228 X 1 June 18, 1974 3,643,396 2/1972 Togashi et a1. 53/182 X Primary Examiner-Travis S. McGehee Assistant Examiner-John Sipos Attorney, Agent, or Firm-Wheeler, Morsell, House & Fuller [5 7] ABSTRACT A fully automatic article wrapping machine which first forms a fold from a continuous film web around and trailing the article, with film wings extending laterally beyond both sides of the article. The machine measures the length of the film web in accordance with the length of the article and then cuts the web off at the measured length. In the course of forming the first fold, the article is advanced against a vertically disposed film web and the article is pushed through the vertical plane thereof and onto an array of conveyors. The array includes inboard and outboard sets of double-decked conveyors with means to advance the par- 32 Claims, 25 Drawing Figures PATENTEDJun 1a 1924 3.816; 969
snw 5 BF 9 PATENTEUJUIHB m4 3316x969 sum 9 0f 9 I i I I Z3 E 3 W I! an I i l 6 E q m I l I 207 22 25 205 I! E i I I 2/4 26 n W f w i I hm I I, i ll lmll llnlm i I||| MHHHHIII'I [II "'HIWH BACKGROUND OF THEINVENTION This invention provides a fully automatic wrapping machine primarily for in-store wrapping of palleted food items, such as meat, fruit, etc. US. Pat. No. 2,917,885 is an example of a semi-automatic wrapping machine for in-store wrapping of similar products. However, in such semi-automatic machines, an operator was required to make the initial fold manually, from pre-cut discrete sheets of film wrapping material (typically cellophane).
US. Pat. No. 3,521,425 shows an improved semiautomatic machine adapted to utilize roll film, instead of pre-cut film sheets. In this machine the operator was still required to make an initial fold manually around thearticle. The formation of this fold was greatly facilitated by the apparatus of said patent and this machine has been highlysuccessful.
The present invention achieves full automation in the wrapping process and eliminates the need for the operator to make the initial fold manually.
SUMMARY OF THE INVENTION In accordance with the present invention, all the operator has to do is to place the unwrapped article on the infeed table of the machine. The machine will function automatically thereafter to make all folds and completely wrap the article. The first fold which leaves the article with laterally projecting film wings is effectuated by apparatus which disposes an uncut length of film web in an upright plane beyond the table where the article is deposited by the operator. Deposit by the operator actuates mechanism which advances the article against a midportion of the upright film web and pushes the article therebeyond and onto one of the conveyors of a subsequent conveyor system or array. Mechanism at the first fold forming station will respond to the length of the package, in order to automatically measure a length of film web material appropriate for the length of the package, and without regard to the arrival sequence of the packages. Packages of random length can be supplied to the table and the machine will automatically cut the film web to a length appropriate for the package size without intervention by the operator.
Beyond the infeed table there is a conveyor array including inboard and outboard sets of double-decked conveyors which will automatically serially advance the partially wrapped package with its extending wing prtions from one conveyor to the next. In the course of this advance, the tail end of the film web will be folded beneath the package and the extending wings will be folded inwardly and up against the bottom of the package in a neat wrap. The wrapped package is then dis charged to a heat seal belt, shrink tunnel, etc., which will complete the wrapping sequence.
Other objects, features and advantages of the invention will appear from the following disclosure.
DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary perspective view of the load ing station of the machine, certain positions of the article being illustrated diagrammatically.
FIG. 2 is another fragmentary perspective view and showing the article at another position in which it is being pushed against the wrappingfilm web.
FIG. 3 is a fragmentary perspectiveview from the other end of the machine. This view shows the article being pushed against the web, asin FIG. .2.
0 views showing the progress of a typical article in its various positions as it is advancedthrough the vertical web for the purpose of forming the'first fold thereabout.
F IG. 9 is a view similar to FIG."5, but illustrating an article of different size and different relation to the metering switch.
FIG. 10 is an enlarged fragmentary perspective view of the vacuum box and its actuating mechanism.
FIG. 11 is a fragmentary perspective view of the web cutoff knife and its co-acting nip blades.
FIG. 12 is a fragmentary diagrammaticview illustrating the inboard and outboard conveyor sets.
FIG. 13 is a view similar to FIG. 12 and showing the outboard conveyor set in elevated position.
FIG. 14 is an enlargedfragmentary perspective view showing the upper conveyor of the inboard conveyor set and the relationship therewith ofthefilm wing folding arms.
FIGS. 15, 16 and 17 are diagrammatic front views of the apparatus shownin FIG. 14 and illustrating successive positions of the wing folding arms as they tuck the film wings beneath the article.
FIG. 18 is an enlarged cross section taken through one of the wing folding arms and illustrating the vacuum nozzles therein.
FIG. 19 is an enlarged fragmentary perspective view showing details of one of the paired web folding fingers.
FIG. 25 is a cross section along the line 25-25 of FIG. 24.
DESCRIPTION OF THE PREFERRED EMBODIMENT Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.
The machine comprises an article input or loading table 25 which has a longitudinal recessed way 26 to receive and guide forward travel of the article 27 to be packaged. Article 27 is typically a palletized food item, such as fresh meat. Way 26 is defined by laterally movable way rails 24, the spacing of which is adjustable by turning control knob 23, thus to adjust the width of the way 26 to fit a particular size article 27. Pusher arms 28 are mounted in the way 26 for longitudinal movement toward the film web 31 which is disposed in a vertical plane at the end of the table 25. Arms 28 are driven by a drive lever 96 (FIG. 5). The film web 31 is supported and advanced and is folded about the article 27, as hereinafter described.
Beyond the end of table there is a gap 122 to receive the film web 31 and beyond the web 31 there is an inboard set 32 and an outboard set 33 (FIGS. 4, 12, 13), of conveyor tableswhich perform further folding operations on the web to snug it about the article. The inboard conveyor set 32 comprises a pair of doubledecked stationary conveyors stacked one over the other. The lowermost or input conveyor is 34 and uppermost or discharge conveyor is 35. The outboard conveyor set 33 also consists of double-decked conveyors stacked one over the other, namely, lowermost input conveyor 36 and uppermost discharge conveyor 37. The two sets 32, 33 constitute a conveyor array, the component parts of which co-act to complete the package wrap about the article.
Uppermost conveyor tables 35 and 37 are roller conveyors. Lowermost conveyors 34, 36 comprise endless belts 112 and 138 respectively about endmost rollers. The belts travel over support aprons and are driven to advance the article.
Uppermost discharge conveyor 37 of outboard set 33 is mounted on its lowermost input conveyor 36 by paired pedestal plates 42 and the outboard set 33 is mounted to swing up and down as a unit about the axis of shaft 41. Shaft 41 is fast to a pair of oppositely disposed swing arms 43 which are respectively pivotally connected to the tail end of conveyor 36 on pintles 44. Shaft 41 is fast to a crank arm 45 which is interconnected by link 46 to one arm 47 of a double arm bell crank 49 which partakes ofthe motion of cam 48 (FIG. 4). Bell crank 49 is pivotally mounted by pintle 52 on a frame member 51. Cam 48 is mounted on shaft 38 driven by chain 39 from gear box powered by motor 50.
Bell crank 49 has another arm 53 connected by link 54 to conveyor table 36 at the base of pedestal 42. The geometry of the arms 47, 53, 45, 43 is such that rotation of the cam 48 and its pressure against the cam follower roller 55 on the bell crank 49 will swing the outboard conveyor set 33 in a compound motion about shaft 41 and also about pintle 44. As the conveyor set 33 swings upwardly from its position shown in FIG. 12 to its position shown in FIG. 13, the tail end of the conveyors 36, 37 will lift to position conveyor 37 in an appropriate attitude for smooth gravity discharge of the wrapped package onto a fixed discharge roller conveyor 56, from which the wrapped package is discharged to a heated discharge belt 57 and thence optionally through a shrink tunnel 60 (FIG. 13).
The initial fold of the film about the article 27 is made automatically as the article is advanced from table 25 toward the conveyor sets 32, 33. Subsequent folds of the film about the article are made automatically as the partially folded article is moved sequentially from one conveyor to another on the sets 32, 33. Formation of the initial fold will be described first.
The transparent film web 31 is unwound from a parent roll 61 supported on elevated roll stand 59. Additional parent rolls 58 may be stored on stand 59 (FIG. 4). The film web 31 is trained through two sets 62 and 63 of guide and feed rollers, and around a dancer bar or roller 64. Roller sets 62, 63 are mounted on paired support arms 70. Roller set 62 is intermittently driven by chain 78 (FIG. 4), as hereinafter explained. Dancer roll 64 is mounted to swing on paired arms 65 which hang from arms and which are biased by gravity and/or spring tension to form a loop 98 in the web 31. Slack in the loop 98 is available to supply added web length as the web is formed around the article 27.
Inasmuch as the film web 31 is drawn from a continuous parent roll 61, it is necessary to cut appropriately measured lengths of film from the web to fit around each package. In in-store wrapping operations, the arti' cles 27 are typically supplied to the machine in different sizes and in random order. Accordingly, the machine of the present invention contains apparatus which will sense article size and will cut appropriate lengths of film from the web 31 which is measured to be the correct length to encircle the article. For the purpose of sensing the length of the article 27, table 25 is provided with a sensing switch 66 which is let into the bed 26 of the table 25 and which will respond to the package thereover of the forward edge of the article 27. In the disclosed embodiment, switch 66 comprises a photocell connected in the circuit shown in FIG. 20. A mechanical'switch could be substituted.
When a relatively short article 27 is placed by the operator on the table 25 ahead of the pusher arms 28, as shown in FIG. 5, the distance between the forward edge of article 27 and the photocell 66 is relatively great, as indicated by the dimension A. When a much longer article 27' is placed ahead of pusher arms 28, as shown in FIG. 9, this distance will be much shorter, as indicated by dimension B. The difference in the distances A and B is utilized to meter the correct amount of web material 31 to encircle the article, as will be hereinafter explained. I
Beneath the table 25 is a vacuum box 67 which has its front face 68 perforated to provide a multiplicity of vacuum nozzles 71 and against which the previously cut lower edge 72 of web 31 will be held under air pressure (FIGS. 5, 6 and 9). The rear of the vacuum box is connected to a flexible air duct 73 and thence to an exhaust fan or blower 74 (FIG. 4) which will maintain subatmospheric pressure within the box 67.
The vacuum box 67 is mounted for vertical movement in the plane of the web 31 by means of paired racks 75 (FIGS. 4 and 10). In one practical embodiment of the invention the box 67 has a maximum vertical movement of 2.5 inches. The racks 75 are actuated for vertical reciprocation by gear 76 and intermediate pinions 77. As best shown in FIG. 10, gear 76 is mounted on one end of shaft 80 which is biased by spring 81 to rotate gear 76 counterclockwise, as shown in FIG. 10, thus to normally maintain the vacuum box 67 in its uppermost position, as shown in FIG. 5.
However, there is a sleeve 82 about the shaft 80 which is coupled to the shaft through an electromagnetic clutch 83. Sleeve 82 also carries a crank arm 84 pivotally connected on pintle 85 to an actuating link 86 having at its lower end a cam follower roller 87 which rides on cam 88. The position of the roller 87 is guided by a swing link 91 which is pivotally connected to frame bracket 92 (FIG. 4). Crank arm 84 is also provided with a laterally extending finger 93 which co-acts with a peg 94 which projects from shaft 80 for purposes to be explained later.
The operation of the aforedescribed apparatus, to measure or meter an appropriate length of film, is as follows:
When the operator places a relatively short article 27 on the bed 26 of table 25 (FIG. 5), the article will depress a switch arm 95 which will close switch 101 in the circuit shown in FIG. 20, to start the motor or clutch which will start to move the drive lever 96 to which the pusher arms 28 are linked, and hence move the article 27 forward toward the film web 31. At the same time, the main shaft 97 on which cam 88 is mounted will be turning clockwise, as shown in FIG. 21. At this point the cam 88 is timed to have its high lobe uppermost with crank 84 also in its uppermost position. As cam 88 turns, cam follower roller 87 will follow down the cam surface 89 so that sleeve 82 will start to rotate (clockwise in FIG. with respect to shaft 80. However, if clutch 83 is not energized, the movement will not be transmitted to shaft 80 and vacuum box 67 will remain in its uppermost position.
When the front edge of the article 27 comes over the sensing switch 66 the circuit is closed to the electromagnetic clutch 83, thus connecting sleeve 82 to shaft 80, whereupon further downward movement of the crank arm 84 will cause rotation of gears 76, 77 and consequent downward motion of the rack 75 and attached vacuum box 67.
As the box moves downwardly, it will pull the film web 31 with it, thus to draw an additional length of film below the level of table 25. The amount of material drawn downwardly will depend upon the length of the article 27. For a short article, there will be little or no movement of the box, whereas for a long article 27' (FIG. 9), there will be a much longer movement of the box, because the period of energization of the clutch 83 will be longer. The crank 84 will have the same movement in each cycle, regardless of the size of the article. However, the time period of energization of the clutch 83 will be longer for a long article than for a short article and this will govern the amount of web material drawn down below the level of table 25.
In order to minimize resistance to downward movement of the web 31, considerable slack is introduced into the web, as shown in FIG. 5. For this purpose the web is trained over the dancer roll 64 and arms 65 are biased downwardly by gravity and/or spring pressure to a position in which a substantial loop 98 is formed between the parent roll 61 and its free end 72 adhered by vacuum or air pressure to the box 67. As the vacuum box 67 draws downwardly on the web 31, loop 98 will shorten, as indicated in FIG. 6, with very little resis tance to downward motion thereof. As loop 98 shortens, it will lift dancer roll 64 and swing arms 65 clock wise in FIG. 4. Near its pivot, one of arms 65 has a cam actuator for switch 160 which is in the circuit to an electromagnetic clutch-brake unit 161 (FIG. 4), which is driven by chain 162 from sprocket 163 on drive shaft 164. Chain 78 to roll set 62 is driven from clutch-brake unit 161 via chain 165. Any appreciable clockwise movement of dancer roll 64 will actuate switch 160 to close against contact 166 and energize the clutch of unit 161 and drive roll set 62 to draw film from supply roll 61 and replenish loop 98. As loop 98 is replenished and dancer roll 64 returns to its lowermost position switch 160 will open from contact 166 and close against contact 167 to energize the brake in unit 161 and discontinue drawing web from roll 61.
In the course of downward movement of vacuum box 67, a sufficient length of web 31 is drawn below the level of table 25 to form a web tail 99 below the table. Tail 99 has sufficient length so that it will substantially completely cover the bottom of the article.
Downward movement of vacuum box 67 also actuates roll set 63, through chain69 and at the same lineal rate so as to assist the box 67 in drawing web 31 downwardly. For this purpose, a soft rubber limit roll 170 of roll set 63 is coupled by a conventional mechanical one-way overrunning clutch 171 (FIG. 2) to its shaft which, in turn, is directly coupled to chain 69, which is driven from sprocket 172 on cross shaft 173, which interconnects pinions 77 (FIG. 10). Clutch 171 is mechanically engaged when chain 69 is driven on the downstroke of vacuum box 67, thus to turn roller 170 in a direction to feed web at the same rate as the vacuum box draws it downwardly. Clutch 171 also has a back-stopping feature which prevents it from rotating backwards, unless its shaft is driven backwards.
At the end of limit roller 170, opposite mechanical clutch 171, there is an electromagnetic one-way clutch 174 between the limit roller 170 and its shaft. Clutch 174 is actuated by switch 175 which is mounted on the vacuum box 67 (FIG. 2). Switch 175 responds to an actuating arm 176 mounted on the carriage 127 for sweep roller or bar 123. The functioning of clutch 174 in re sponse to switch 175 will be hereinafter explained.
FIG. 7 illustrates the box 67 in its lowermost position as determined by the time interval of actuation of clutch 83. Also in this view, the front edge of the package has engaged and pushed against the web 31 to start to form the web in a fold about the front edge of the package. This is also illustrated in FIGS. 2 and 3. To assist in the formation of an even, well defined fold 100 throughout the transverse width of the web, not only where the front edge of article 27 actually contacts the web, but also laterally thereof, the table 25 is desirably provided with a pair of forming fingers 103 which are pivotally mounted on the ends of way rails 24.
As best shown in FIG. 19, each finger 103 is pivotally mounted on a pin 104 which has a spring biasing the finger away from the film web 31 and toward contact with bumper 107. Fingers 103 have downtumed flanges 106 which provide contact of the finger with a substantial part of the web. Flanges 106 are also in the path of advance of the article 27. As the article 27 moves forward, the fingers 103 are picked up by the article and press against the web 31. Fingers 103 also swing laterally about pins 104 to sweep laterally toward the web margins and away from the direct path of the article. Fingers 103 have a hump 108 which smooths the web at fold or bight 100 as the article 27 advances to the point of direct contact with the web 31.
As the article 27 forces the web 31 across gap 122, the fingers 103 will prevent the web from collapsing where it is unsupported by the front edge of the article 27. In this manner the fold 100 will be smooth and unbroken throughout its length. After the article has advanced beyond the point where its sides contact finger flanges 106, spring 105 restores the fingers against the bumpers 107. In this position the fingers 103 are clear of the downward path of sweep bar 123.
As also shown in FIG. 7, as article 27 is pushed against the web 31 and across the gap 122, it is transferred onto the lowermost or input conveyor 34 of the inboard conveyor set 32. Conveyor 34 consists of end rollers 111 and an intermediate apron 110 encircled by an endless belt 112. One of the end rollers is provided with a laterally projecting shaft having a pulley 113 for belt 114 driven from pulley 115, mobilized by a chain covered, cam driven sector 178. Sector 178 pivots about shaft 52 and has an actuating crank arm 179 with a cam follower roller 180 which rides in the cam track 181 in cam 182 mounted on cam shaft 38. Sector 178 has a rack or chain 185 fast to its curved face. Chain 185 engages sprocket 186 on the shaft of pulley 115. Cam 182 causes sector 178 to oscillate about shaft 52, thus to alternately drive belt 114 in opposite directions.
Interposed between the pulley 113 and its roller 111 is a single directional clutch 117 (FIG. 3). When the pulley 115 is driven to move belt 114 in the direction of arrow 118, clutch 117 is engaged, thus to drive the conveyor belt 112 in the direction of arrow 121, when article 27 is transferred from conveyor 34 onto conveyor 36.
In the course of its movement beyond the point where the article 27 first contacts the web 31, tail 99 of the web will be stripped off of the vacuum box 67, as illustrated in FIG. 7, and will lay up beneath the article 27 and on top of belt 112, as shown in FIG. 8.
As soon as the article 27 has cleared the gap 122 between the discharge edge of table 25 and the input end of conveyor 34, the web 31 will be swept downwardly through the gap 122 to its position shown in FIG. 8, thus to completely form the first fold about the article. For this purpose the apparatus is provided with a cross sweep roller 123, mounted for vertical movement through gap 122. The ends of roller 123 are attached to carriage sleeves 127 slidable vertically on guide rods 133. Also attached at its ends to sleeves 127 is a veeshaped assembly 120 of spaced serrated knife blades 124, 125 and a fabric barrier panel 126. The sleeves 127 move up and down on the guide rods 133 as powered by the swing arm 130 (FIG. 4), which has a cam follower roller 131 engaged on cam 132. One end of the swing arm 132 is pivotally connected to frame bracket 92 and the other end is pivotally connected to a link 129 which is, in turn, pivotally connected to sleeve 127. Accordingly, the sleeve 127 is vertically reciprocated by action of cam 132. In the preferred embodiment, there is a link 129 connected to each sleeve 127.
As the sweep roller 123 descends, it will draw additional slack out of loop 98. At the same time, roll set 62 will be actuated to draw more film off of parent roll 61, as previously explained, thus to replenish slack withdrawn from loop 98.
The relationship of parts when the sweep roller 123 is in its lowermost position is illustrated in FIG. 8. The web 31 is then cut off by a swinging serrated knife blade 134 which is actuated by solenoid 135 (FIG. 8) to swing the blade 134 between the serrated nip blades 124, 125 and hence cut the web 31 transversely to leave another tail 136 depending therefrom. The new free end portion of the web 31 is, at the same time, attracted to the vacuum box 67.
In lieu of the serrated knife blade 134 and anvil blades 124, 125, a hot wire or comparable cutoff device could be used to sever the web 31.
The purpose of the fabric barrier panel 126 is to intervene between the severed film tail 136 and the film web 31 and prevent these film sheets from touching one another, inasmuch as they tend to adhere. The intervening panel 126 prevents contact of the film sheets and consequent jamming of succeeding operations by adherence of the two sheet lengths.
The severance of the film by knife 134 is facilitated by the functioning of electromagnetic clutch 174. The spacial relation of the switch 175 mounted on vacuum box 67 and switch actuator arm 176 mounted on the carriage for sweep roller 123 is such that switch 175 is actuated just before the sweep roller 123 reaches its lowermost position. In one practical embodiment, switch 175 is actuated when sweep roller 123 is onefourth of an inch from its lowermost position. The clutch 174 then locks the limit roller 170 to its shaft which is held against turning by chain 69, inasmuch as vacuum box 67 is already in its lowermost position. As the sweep roller 123 advances, an additional onefourth of an inch, the web curtain 31 becomes taut, so that the knife 134 will make a clean cut. Locking the limit roller 170 to its shaft will also prevent overfeeding the web curtain.
At this point in the cycle, the cam 88 is at its lowest point, as shown in FIG. 4. Shortly thereafter, the vacuum box 67 will be restored to its uppermost position as the cam 88 continues to move clockwise and lifts link 86 and crank arm 84 upwardly. Clutch 83 is deenergized and the tab 93 on the crank arm 84 picks up the peg 94 on shaft 80, thus to rotate the gear 76 counterclockwise in FIG. 10. Thus rack and vacuum box 67 are lifted to uppermost position, as shown in FIG. 5. Clutch 174 will remain engaged as vacuum box 67 lifts and returns to its starting position shown in FIG. 5. As the box 67 lifts, chain 69 rotates roll 170 to feed the web curtain upwardly.
During this upward movement of the vacuum box 67, the swing arms 65 and the dancer roll 64 will move from position shown in FIG. 8 to position shown in FIG. 5, thus to draw a new loop 98 in the film web 31. To increase the size of the loop the power driven rolls 62 continue to operate until the dancer roll 64 is in its lowermost position, where switch 160 will move to contact 167 to energize the brake in unit 161, as hereinbefore explained.
Partially wrapped article 27 is now in its condition illustrated in FIG. 1, in which it is supported entirely on the lowermost input conveyor 34 of inboard set 32 and in which film wings 137 extend laterally therefrom. The co-action of the forward edge of the article 27 and the folding blades or fingers 103 have formed the neat forward fold on the wings 137.
Cam driven sector 178, which drives belt 114, then begins to operate to transfer partially wrapped article 27 from lowermost input conveyor 34 of the inboard set 32 to the lowermost input conveyor 36 of the outboard set 33. This is illustrated in FIG. 12, where partially wrapped article 27 has been advanced onto conveyor 34, drawing film tail 136 up through the gap 122 and onto the conveyor 34. A previously processed article 27 is at the same time undergoing further processing on uppermost conveyor table 35 of inboard set 32, as hereinafter explained.
The next position of article 27 on conveyor table 34 results from its transfer to the lowermost input conveyor table 36 of outboard set 33, as illustrated in broken lines in FIG. 12. Conveyor 36 is provided with an endless belt 138 which encircles its end rollers 14].
The belt 138 is powered by belt 114 which is trained about pulley 142 at one end of arm 43 (FIG. 3). Pulley 142 carries a sprocket engaged with a chain 143 around a corresponding sprocket on end shaft 44 of roller conveyor 36. Accordingly, movement of belt 114 in the direction of arrow 118 will advance the package from conveyor table 34 to conveyor table 36, as indicated in broken lines in FIG. 12. Concurrently, the package 27 on top conveyor table 35 is pushed onto conveyor table 37 and to its broken line position shown in FIG. 12.
At this point in the cycle, cam 48 will rotate to its position shown in FIG. 13. This results in the lifting of the interconnected outboard set of conveyors 33 about the axis of shaft 41. This aligns lowermost input conveyor 36 of set 33 with the uppermost conveyor 35 of inboard set 32. At this point in the cycle, the drive to belt 114 is reversed so that it moves in the direction opposite arrow 118. Accordingly, belt 138 will be driven in the opposite direction to transfer the partially wrapped package 27 from its full line position on conveyor 36 (FIG. 13) to its broken line position on conveyor 35. Note that in the course of elevating conveyor set 33 from FIG. 12 position to FIG. 13 position, the film tail 136 is draped between the conveyors 35, 36. Accordingly, movement of the partially wrapped package 27 from conveyor 36 to conveyor 35 will fold and truck the film tail 136 beneath the article 27, as shown in broken lines in FIG. 13. Moreover, the package 27 on conveyor table 37, shown in broken lines in FIG. 12, is concurrently discharged by gravity from roller conveyor 37 to discharge belt 57, over discharge conveyor 56, as hereinafter explained.
Reversal of direction of movement of belt 114 will have no effect upon the conveyor 34 because the single directional clutch 117 will idle during this reverse direction movement of the belt 114. As soon as package 27 is conveyed onto conveyor 35, belt 114 will again be driven in the direction of arrow 118, thus to transfer a new package 27 from conveyor 34 onto conveyor 36, in the direction of arrow 121, as indicated in FIG. 12, after conveyor set 33 has been lowered to its bottom position.
Partly wrapped package 27 on uppermost discharge conveyor 35 of the inboard set 32 is now in its condition shown in FIG. 14. Film wings 137 still project laterally from the article 27 and overlie the interrupted undriven rollers 144 of conveyor 35. The construction of this conveyor is special, to provide for tucking the film wings 137 beneath the article 27, as indicated in FIGS. 1417. In the gap 145 of the interrupted rollers 144 there is an elevator blade or paddle 146 which is actuated to lift the partially wrapped package 27 (FIG. 16). Overlying the conveyor table 35 are paired tucking arms or blades 147. These blades are mounted for concurrent movement toward and away from each other on an oppositely threaded screw shaft 150 which is driven by chain 151. The base of each arm 147 is provided with a correspondingly oppositely threaded socket 152. The film wing tucking operation is as follows.
After the partially wrapped package 27 arrives on the conveyor 35, tucking arms 147 are pivoted about the axis of shaft 150 to swing them in the direction of arrows 148 to their position shownin FIG. in which they overlie film wings 137. Elevator arm 146 is also actuated to lift the article 27 (FIG. 16), whereupon the arms 147 are caused to move toward one another by virtue of rotation of the double leadscrew shaft 150. As the blades 147 sweep toward each other beneath the package 27, they will wipe the film wings 137 under the article 27 and against the layers 99, 136 of film already therebeneath. The final position of the parts is shown in FIG. 17. The initial lateral spacing of tucking arms 147 is adjusted concurrently with the adjustment of the lateral spacing of guide rails 24 (FIGS. 1 and 2) as knob 23 is turned. Knob 23 is coupled to the double lead screw 150 to effectuate this initial adjustment.
Novel apparatus to adjust the initial spacing of the tucking arms 147 and to actuate the arms 147 and lift arm 146 tucking sequence is illustrated in FIGS. 14 and 22. This apparatus includes mechanism for actuating a motion transmitting element selectively in an adjustment mode and in a driving mode. The hub 152 of each arm 147 is provided with a projecting crank sector having gear teeth 191 engaged with corresponding spline teeth 192 on cross shaft 193. The spline teeth 192 on shaft 193 also mesh with gear teeth 194 on a crank sector 195 which is pivotally mounted on pintle 197 and is connected by link 196 and lift crank 198 to elevator arm 146. Accordingly, rotation of the shaft 193, as hereinafter described, will concurrently raise and lower the tucking arms 147 and will raise and lower the elevator arm 146. If shaft 193 is held against rotation and the lead screw 150 is turned by chain 151, the geared crank sectors 190 will slide along the splined shaft 193 and will guide the tucking arms 147 for rectilinear movement toward and away from each other, depending on the direction of rotation of the chain 151.
FIGS. 3 and 22 illustrate the mechanism for actuating the chain 151. Control knob 23 is connected by its shaft 200 to a sprocket 201 for vertically oriented chain 202. Chain 202 is provided with a coupling 203 pivotally connected to one end of a swinging arm 204, the other end of which is pivotally mounted on shaft 205 which is fixed to the frame of the machine. Arm 204 carries at its respective ends sprockets 206, 207 for a chain 208. On the same shaft as sprocket 206 there is a rotor with gear teeth,'such as sprocket 211, having its teeth meshing with a rack such as :a length of chain 212 mounted on the curved face of sector 213, the radius or swing arm 214 of which is also pivoted about the shaft 205.
Sprocket 207 is fast to a parallel sprocket 215 engaged with chain 151. The upper end of chain 151 engages a sprocket 216 fast to the lead screw 150.
Accordingly, when the control knob 23 is turned to adjust the space between the guide rails 24, via the crossed chains or belts 217 (FIG. 2), chain 202 will concurrently be actuated to move coupling 203 up or down, depending upon the direction of rotation of knob 23. As coupling 203 moves up and down, sprocket 211 will walk along the rack 212 on the face of sector 213, thus to rotate the sprocket 211 and hence the motion transmitting elements, namely, the drive chain 208 and chain 151 in their adjustment mode. At this time in the cycle, the sector 213 is stationary and splined shaft 193 is also stationary. Accordingly, rotation of the lead screw 150 caused by movement of chain 151 will move the tucking arms 147 in and out, in step with the in and out movements of the guide rails 24, thus to adjust the tucking arms 147 to a proper spacing corresponding to the lateral width of the package.
Once the adjustment is made by turning the hand wheel 23, swing arm 204 will be retained in adjusted position by chain 202 and coupling 203. Accordingly, toothed rotor or sprocket 211 will have a fixed position. Swing arm 214 carrying sector 213 and rack 212 may now be actuated in the driving mode for the motion transmitting elements, such as chains 208 and 151, by causing swing arm 214 to oscillate up and down during operation of the machine. For this purpose arm 214 is provided with a cam follower roller 219 which follows cam 218 on shaft 97. As the sector 213 is oscillated, its chain or rack 212 will turn sprocket 211 to drive chains 208 and 151, thus to rotate the lead screw 150 to move the arms 147 toward and away from each other in the tucking sequence shown in FIGS. 15-17, as hereinbefore explained.
Splined shaft 193 is rotated at appropriate times in the cycle, thus to raise and lower the tucking arms 147 and the elevator arm 146, by reason of the actuation of link 222. Link 222 is connected to crank arm 223, which is fast to the sector 195, the gear teeth 194 of which mesh with the splines 192 on shaft 193. Link 222 is mounted on a crank arm 224 pivoted about pintle 221. Crank arm 224 has a cam follower roller 225 engaged by a cam 226 which is fast to the shaft 205 which is also fast to radius arm 214 of sector 213 so as to partake of the motion thereof and hence rotate the spline shaft 193 in time with the actuation of the chain 151.
In some embodiments, tucking arms 147 may be formed with a hollow interior 153, as shown in FIG. 18. The hollow 153 may be subjected to vacuum which is exposed to the film wings 137 through vacuum nozzles or openings 154 in the bottom face of the arms 147. This assists the arms 147 in picking up and capturing the film wings 137 and sweeping the film wings 137 under the package. The suction also imposes added drag or friction between the film wings and arms, thus to insure a tight wrap around the article. Control mechanism is desirably added to release the suction after the tucking arms 147 reach their position shown in FIG. 17, so that ejection of the article 27 oh of conveyor 35 by pusher arm 155 will not be impeded.
A modified form of tucking arm is shown in FIGS. 23, 24 and 25. In this embodiment, the arm 227 is formed of sheet metal which is folded into a channel or U- shaped configuration, as illustrated in FIG. 24. The channel flanges or face panels 228 are connected along corresponding edges by a web 229, the free ends of the flanges 228 being spaced apart to form a slot 232. Within the space between flanges 228 there is disposed a wiper blade 233 having a friction edge 231 of rubber, felt, etc. The innermost edge of the blade has upwardly projecting pegs 234. The pegs project upwardly through slots 235 formed in the uppermost flange 228 to limit and guide the wiper blade 233 in its sliding movement in and out of the channel 227. The midportion of a wire spring 236 passes around a peg 238 on the wiper blade 233. One end of the spring 236 is anchored at one end to a peg 237 fast to the arm 227. The other end of the spring 236 passes around another peg 239, also fast to the arm 227. The spring biases the wiper blade 233 to project its friction edge 231 outwardly through the opening 232 so that edge 231 will contact the film and insure a snug wrap of the film around the article.
Pegs 234 also carry an upstanding flange 242 which is movable with the wiper blade 233. Accordingly, as the tucking arms move toward one another far enough so that the flanges 242 embrace the article 27, the resultant outward pressure on the flanges 242 will withdraw the friction edges 231 of the blades 233 into the sheath and away from contact with the film. Accordingly, edges 231 will no longer contact the film, thus to facilitate easy discharge of the wrapped article from the conveyor 35 under pressure of the push-off arm 155.
After completion of the film wing tucking operation. as shown in FIG. 17, the wrapped package is in readiness for transfer from conveyor 35 onto uppermost discharge conveyor 37 of outboard set 33. For this purpose pusher arm connected to push link 156 is actuated, concurrently with reversal of direction of belt 114 to advance article from lowermost conveyor table 34 onto conveyor table 36 (FIG. 12), and cause the completely wrapped package 27 to move from its full line position on conveyor 35 (FIG. 12) to its broken line position on conveyor 37. Conveyor 37 consists of a series of rollers 157 (FIG. 3). Accordingly, the packages are concurrently moved from the conveyors of the inboard set to the conveyors of the outboard set.
Cam 48 then turns to its FIG. 13 position to lift the outboard set 33 of conveyors, whereupon the completely wrapped package 27 rolls off of the rollers 157 of conveyor 37 by gravity, across a stationary output roller conveyor 56 and onto a hot belt 57 which fuses the layers of film beneath the package one to another to seal the wrapper. Belt conveyor 57 may carry the package through an optional heat shrink tunnel 60 (FIG. 4) for the purpose of snugging the film about the article 27.
FIG. 12 illustrates the functioning of the conveyor array in which packages are concurrently transferred from both the upper 35 and lower 34 conveyors of the inboard set 32 of stationary conveyors to the upper 37 and lower 36 conveyors of the outboard set 33 when the outboard set is in lowermost position. FIG. 13 illustrates the functioning of the conveyor array when the outboard conveyor set 33 is elevated, at which time a new article 27 is loaded onto the lowermost input conveyor 34 of inboard set concurrently with the discharge of a completely wrapped package from the discharge conveyor 37 of the elevated outboard set 33 while at the same time a partially wrapped article 27 is transferred in the opposite direction from the elevated lowermost conveyor 36 of outboard set 33 to the uppermost conveyor 35 of inboard set 32. As outboard set 33 is moved between its positions shown in FIGS. 12 and 13, the swingable end of lowermost conveyor 36 is selectively aligned with the input conveyor 34 and the discharge conveyor 35 of the inboard set 32.
An electric circuit diagram for one embodiment of the invention is shown in FIG. 20. Main transformers 248, 249 and relays 250, 251 are connected to various terminals on terminal blocks 252, 253, 254, 255. When an article 27 is placed onto the machine bed 26, it will depress the package sensing paddle 95, thereby closing a package sensing switch 101 and energizing the motor 50. As the machine starts to operate, the article 27 is pushed from behind by pusher 28 on lever arm 96, thus to move the article toward the film curtain. This movement causes switch 258 to close. Cam 259, on a cam shaft such as 97, actuates cam follower roller 260 which actuates switch 261. Switches 258 and 261 are power switches which control power to the vacuum box clutch 83 and the cutoff knife solenoid 135. These switches must be actuated to condition the clutch 83 and solenoid to act during the packaging sequence.
Package sensing switch 101 is in parallel with a stop switch 242. As soon as the article moves off of the paddle 95, pawl 243 is actuated by pusher 28 and will rotate about its pivot shaft 244 to be removed from contact with stop switch 242 which will automatically close to hold the circuit closed to the motor 50. Thus, the machine will continue to operate, even though the article 27 is no longer exerting pressure on paddle 95. Pivot shaft 244 is timer controlled to return pawl 243 to rest position after the article is processed entirely through the machine. When pawl 243 returns to its rest position, switch 242 will open, thereby stopping the machine, unless another article is then on the article sensing paddle 95, in which case the machine continues to operate.
As the article 27 moves forward toward the film curtain, it will interrupt the beam of photocell 66 to activate the vacuum box transport clutch 83, as hereinbefore described. Accordingly, the vacuum box will move downwardly and the correct length of film web will be advanced below the level of the table for the underfold required by the particular article size being processed.
As the article moves into the film curtain, the sweep roller 123 will sweep behind the film as indicated in FlGS. 7 and 8 until the cutter bar anvil blades 125 are located in their FIG. 8 position, whereupon the solenoid 135 will be actuated by switch 246 and cut off the film. During movement of sweep roller 123, the dancer roller 64 actuates switch 160, to actuate the clutchbrake unit 161, as hereinbefore described, to draw an additional length of film from the parent roll 61. Limit roller 170 is energized by its clutch 174 under control of the micro-switch 175 mounted on the vacuum box 67, as hereinbefore described. Limit roller clutch 174 remains energized until the vacuum box 67 is returned to its uppermost position.
1. A wrapping machine comprising folding means for partially enfolding a wrapping film about an article with film wings extending beyond both sides of the article, a conveyor array including inboard and outboard sets of double-decked conveyors, means to advance the partially enfolded article serially from one conveyor to the next and tucking means associated with said conveyor array to tuck the film wings inwardly and against the article before the article is discharged from the conveyor array.
2. The machine of claim 1 in which the said inboard and outboard sets of conveyors respectively have input and discharge conveyors, said inboard set of conveyors being stationary, the outboard set being swingable to selectively align the swingable end of its input conveyor with the input and discharge conveyors of the inboard set, in the course of serially advancing the enfolded article.
3. The machine of claim 2 in which the input conveyor of the outboard set has reversible drive means to selectively advance the article in one direction when it is aligned with the input conveyor of the inboard set and to advance the article in the opposite direction when it is aligned with the discharge conveyor of the inboard set.
4. The machine of claim 3 in which the folding means leaves the article with a trailing film tail as the article arrives on said conveyor array, said tail depending downwardly between the adjacent ends of the discharge conveyor of the inboard set and the input conveyor of the outboard set as the input conveyor of the outboard set is reversed, whereby said tail is folded beneath the article as it is transferred to the discharge conveyor of the inboard set.
5. The machine of claim 4 in which the input conveyors of said sets are the lowermost conveyors thereof, the discharge conveyors of said sets being the uppermost conveyors thereof.
6. The machine of claim 1 in which the tucking means comprises paired tucking arms and means for advancing said arms concurrently toward each other and beneath the article supported. on one of said conveyors, thus to sweep the film wings beneath and against the article.
7. The machine of claim6 in combination with means to initially adjust the lateral spacing between said tucking arms in accordance with article width.
8. The machine of claim 7 in which the means to initially adjust the lateral spacing between said tucking armscomprises a splined shaft, a lead screw parallel to said shaft, said tucking arm having crank sectors with gear teeth engaged with said splined shaft whereby rotation of said splined shaft will pivot the tucking arms about the axis of the lead screw and rotation of the lead screw will advance the tucking arms along the splined shaft, and means to turn said lead screw in relation to the width of an article.
9. The machine of claim 6 in which the means for advancing said arms comprises a motion transmitting element and mechanism for actuating said element selectively in an adjustment mode and in a driving mode.
10. The machine of claim 9 in which said mechanism comprises a rotor having gear teeth, coupling means between said rotor and said motion transmitting element, a first swing arm upon which said rotor is mounted, a second swing arm having a sector face and a rack along said face and engaged with the rotor teeth, means for swinging the first swing arm with respect to the sector to cause the rotor to walk along the rack and actuate the motion transmitting element in one of said modes and means for swinging said second swing arm with respect to said first swing arm to swing the rack past the rotor to turn the rotor and] actuate the motion transmitting element in the other of said modes.
11. The machine of claim 6 in which said tucking arms have suction means to adhere the film wings thereto.
12. The machine of claim 6 in which said tucking arms have retractable wiper blades with friction surfaces whereby to tighten the film around the article when the blades are extended and release the film wings when the blades are retracted.
13. The machine of claim 6 in which said one conveyor has an elevator to lift the article as the tucking arms sweep the film wings therebeneath.
14. The machine of claim 13 in which the elevator comprises an arm, said one conveyor having a well in which the arm is retractable.
15. The machine of claim 1 in which the folding means comprises means for advancing a continuous film web and disposing it in an upright plane, means for advancing the article on a transverse plane and against a midportion of the upright web and within marginal portions of the web at both sides of the midportion of the web, said means advancing the article beyond said upright plane and onto the input conveyor of the inboard set, and sweep arm means for sweeping along said upright plane and behind the advanced article for partially enfolding the web about the article with laterally extending marginal film wings.
16. The machine of claim 15 in which said sweep arm means comprises a folding arm which contacts the film web and a barrier sheet non-adherent to the film web and which intervenes between adjacent runs of the film web formed by the sweep action of the sweep arm means.
17. The machine of claim 15 in which the means for advancing the continuous film web includes control means responsive to the length of the article to control the length of film advance.
18. The machine of claim 17 in which the control means comprises a package length sensor and a web driver intermittently actuated by said sensor.
19. Apparatus for making a first fold of wrapping film material about an article with film wings extending laterally beyond both sides of the article, said apparatus comprising a table, film advancing means for advancing a continuous signle web of film material and disposing it in upright plane beyond the end of the table, said film advancing means including shiftable web holding means below the table to draw the web downwardly in said upright plane, article advancing means for advancing the article along said table and against a midportion of the upright web and within marginal portions of the web at both sides of the midportion of the web, said article advancing means advancing the article beyond said upright plane, sweep arm means for sweeping along said upright plane and behind the advanced article for folding the web against the article and rearwardly thereof to leave laterally extending wings extending at both sides of the article and control means responsive to the size ofthe article to control the length of film advance, said control means comprising means to shift said web holding means downwardly through a distance sufficient to draw a length of film web appropriate for the size of the article.
20. Apparatus for folding wrapping film material about an article and comprising a table, means for disposing a single continuous film web in an upright plane beyond the end of the table, means for advancing the article along said table and against said web and beyond said upright plane, sweep arm means for sweeping along said upright plane and behind the advanced article and below the level of the table for folding the web against the article and rearwardly thereof and forming a loop of said material below said table, said sweep arm means comprising a fold arm which contacts the film web and a barrier panel above the fold arm which is nonadherent to the film web and which intervenes between adjacent runs of the film web loop below the table as formed by the sweep action of the sweep arm means.
21. The apparatus of claim 19 in which the control means comprises an article length sensor, said means to shift said web holding means being intermittently actuated by said sensor.
22. The apparatus of claim 19 in further combination with web fold shaping means movable with said article and which engages the bight of the web at both sides of the article to shape the film wings extending laterally therefrom.
23. Apparatus for making a first fold of wrapping film material about an article with film wings extending laterally beyond both sides of the article, said apparatus comprising means for advancing a continuous film web and disposing it in upright plane, means for advancing the article on a transverse plane and against a midportion of the upright web and within marginal portions of the web at both sides of the midportion of the web, said means advancing the article beyond said upright plane, sweep arm means for sweeping along said upright plane and behind the advanced article for folding the web against the article and rearwardly thereof to leave laterally extending wings extending at both sides of the article and control means responsive to the size of the article to control the length of film advance, said means for advancing the continuous film web comprising a vacuum box, said vacuum box having a perforated suction plate substantially in said upright plane and which will attract the leading edge of said film web, and means for moving said vacuum box in said plane to draw the web along said plane in order to advance the web a distance appropriate for the length of the article to be enfolded.
24. The apparatus of claim 23 in which the means for advancing the continuous film web also comprises a feed roller and means for driving said roller which is coordinated with the means for moving the vacuum box for concurrent action thereby on said web.
25. The apparatus of claim 19 in which the means for advancing the continuous film web further comprises a feed roller, and means for rotating said roller to advance the web in said plane in order to advance the web a distance appropriate for the length of the article to be enfolded.
26. The apparatus of claim 19 in which the continuous film web is trained in a loop over a dancer, the means for rotating the feed roller being responsive to said dancer whereby to replenish film to said loop.
27. Apparatus for making a first fold of wrapping film material about an article with film wings extending laterally beyond both sides of the article, said apparatus comprising means for advancing a continuous film web and disposing it in upright plane, means for advancing the article on a transverse plane and against a midportion of the upright web and within marginal portions of the web at both sides of the midportion of the web, said means advancing the article beyond said upright plane, sweep arm means for sweeping along said upright plane and behind the advanced article for folding the web against the article and rearwardly thereof to leave laterally extending wings extending at both sides of the article and control means responsive to the size of the article to control the length of film advance, said means for advancing the continuous film web comprising two drive roll sets, a dancer intermediate said sets, a vacuum box and means for moving the vacuum box, means for driving one drive roll set in response to movement of the dancer and means for driving the other roll set in response to movement of the vacuum box.
28. The apparatus of claim l9 in combination with a web cutoff means, and means for drawing the web taut while the web is being cut.
29. Mechanism for actuating a motion transmitting element selectively in an adjustment mode and in a driving mode, said mechanism comprising a rotor having gear teeth, coupling means between said rotor and said motion transmitting element, a first swing arm upon which said rotor is mounted, a second swing arm having a sector face and a rack along said face and engaged with the rotor teeth, means for swinging the first swing arm with respect to the sector to cause the rotor to walk along the rack and actuate the motion transmitting element in one of said modes and means for swinging said second swing arm .with respect to said first swing arm to swing the rack past the rotor to turnthe rotor and actuate the motion transmitting element in the other of said modes.
30. The mechanism of claim 29 in combination with an article wrapping machine having an article feed table with laterally adjustable article sizing means and an article wrapping station with laterally adjustable film tucking arms, said motion transmitting element being connected to said film tucking arms, one of the swing arm swinging means of said mechanism being connected to said sizing means for concurrent adjustment of the sizing means and said film tucking arms.
31. The mechanism of claim 30 in which said wrapping machine has a cam shaft and a cam engaged with the other of the swing arm swinging means, whereby to drive said arms in their driving mode.
32. The apparatus of claim 23 in which the control means comprises an article length sensor, the means for moving said vacuum box being responsive to said sen-