US3371466A

US3371466A - Wrapping machine

Info

Publication number: US3371466A
Application number: US426507A
Authority: US
Inventors: King L Klopfenstein
Original assignee: Triangle Package Machinery Co
Current assignee: Triangle Package Machinery Co
Priority date: 1965-01-19
Filing date: 1965-01-19
Publication date: 1968-03-05
Anticipated expiration: 1985-03-05

Description

March 5 1968 K. L. KLOPFENSTEIN 3,371,466

WRAPPING MACHINE Filed Jan. 19, 1965 6 Sheets-Sheet 1 INVENTOR: KING L. KLOPFENSTEIN ATT'YS March 5, 1968 K. KLOPFENSTEIN 3,

WRAPPING MACHINE Filed Jan. 19, 1965 6 Sheets-Sheet 2 INVENTOR. KING KLQPFENSTEIN I juh lfw'wdflm YA T' S Mam}! 1968 K. 1.. KLOPFENSTEIN 3,371,466

WRAPPING MACHINE Filed Jan. 19, 1965. 6 Sheets-Sheet 3 INVENTOR: KING L. KLOPFENSTEIN g qw zz Mam ATTYS March 1968 K. L. KLOPFENSTEIN 3,371,466

WRAPPING MACHINE Filed Jan. 19, 1965 6 Sheets-Sheet 5" Field F|G.|2.

INVENTOR: KING L. KLOPFENSTEIN flm azzzyaa ia fiw ATT'YS March 5, 1968 Filed Jan. 19, 1965 K. L. KLOPFENSTEIN WRAPPING MACHINE 6 Sheets-Sheet 6 I02 INVENTOR. KING L. KLOPFENSTEIN mm wyo@m wad ATT 'YS United States Patent 3,371,466 WRAPPENG MACHINE King L. Klopfenstein, Prospect Heights, ilk, assignor to Triangle Package Machinery Company, Chicago, 113., a corporation of Illinois Filed Jan. 19, 1965, Ser. No. 426,507 Claims. (Cl. 53-206) ABSTRAQT 0F TI-lE DISrTJLGSURE A package wrapping machine for applying a diamond wrap, wherein the package is manually prewrapped, then placed in the machine, and the extending ends of the wrap are folded downwardly and then inwardly under the bottom of the package and spot sealed thereto while the package is at rest in its intermittent movement.

This invention relates in general to wrapping machines which are particularly adapted for wrapping food and other such merchandise placed on a container having a relatively flat bottom and wherein the wrapping material is heat sensitive. More particularly, the invention is directed to a semiautomatic wrapping machine utilizing what is known as a diamond wrap.

The semi-automatic designation indicates that the first wrapping step of placing the wrapping material around the package is performed by hand and the diagonally opposed corners of the wrap are heat-sealed on the bottom of the package. The diamond wrap is one which provides for lateral and outwardly extending end wing portions extending from each end of the package after the initial hand seal is accomplished.

According to the invention, the package is moved through the machine in an intermittent step-by-step movement after the initial hand sealing has been accomplished and the diamond Wrap is in place around the package with the end wings of the wrapping material extending laterally outwardly from each end of the package. As is customary in machines of this type, front tuckers and rear tuckers are provided at each side of the machine which act to tuck the front and rear portions of each end wing against the end of the package. Thereafter, the downfolders located at each side of the machine move downwardly against the end wings so that they then assume a position over the front and rear tucks and extend downwardly for a distance below the bottom of the package.

Underfolders located at each side of the machine then move inwardly toward each other to fold the end wings upwardly against the bottom of the package. In the present invention these underfolders have fixed thereto heaters which spot-seal the end Wings to the heat sensitive material on the bottom of the package. In machines heretofore known, these underfolders and sealing means must move inwardly to spotseal the end wings and then return outwardly before the downfolders can return upwardly to their normal upper position. In the past it has been found on occasion that to achieve and maintain the necessary increased speed of the machine, the underfolders and sealers must move inwardly and outwardly so rapidly that an efficient spot-seal does not always result. When this occurs, the end wing may become loose and the resulting package is not properly sealed and does not have the proper appearance.

This problem has been overcome in the present machine by designing the downfolders and underfolders in such a way that the underfolders can remain in their innermost folding and sealing positions while the downfolders move upwardly, thus increasing the sealing time 3,371,466 Patented Mar. 5, 1968 and assuring a better package. The underfolders do not return to their outermost separated positions until after the downfolders are in the process of moving upwardly and returning to their uppermost positions.

Another feature of the present invention relates to the mechanism which pulls taut the end wings of the wrapping material over the top of the package, thereby to prevent the wrapper from being loosely wrapped around the merchandise. The present embodiment of this feature of the invention entails the use of a pincher member at each side of the machine and positioned inwardly of the end wing when it is in the downwardly extending position thereof. The pincher means is movable so that when the underfolder moves to fold the end wing against the bottom of the package, the Wing will be pinched between the underfolder and the pincher means for a sufficient length of time as the two members continue to move inwardly so as to effect a drawing movement of the wrapping material and make it taut. After this movement has been completed and the wing has been scaled along the bottom of the package after having been pulled taut, the pincher means then moves inwardly further to release the end wing and permit the package to be moved to its next position by the intermittently moving conveyor.

It is one of the primary objects of the present invention to provide an improved semi-automatic machine for wrapping merchandise in a heat-sensitive sheet of wrapping material.

Another object is to provide a wrapping machine which has embodied therein improved sealing means for heatsealing the wrapping material which improves the seal without decreasing the speed of the machine.

A further object is to provide a wrapping machine which will complete a diamond wrap in wrapping a heatsensitive wrapping material about a package and wherein the folding and sealing of the end wings of wrapping material against the bottom of the package takes place in an improved manner without decreasing the speed of the machine.

A still further and important object of the invention is to provide a wrapping machine which will complete a diamond wrap in wrapping a heat-sensitive wrapping material about a package wherein the underfolders and heat sealers which fold the end wings under the package and seal them along the package bottom are caused to remain in sealing position for a longer period of time than has heretofore been possible in other machines of this general type and still retain the feature of increased speed, thereby assuring an improved seal.

Still another object is to provide a wrapping machine which has embodied therein a mechanism for drawing the wrapping material taut over the top of the package as the end wings are folded and sealed at the underside thereof, thereby to produce an improved package.

Yet another object is to provide a wrapping machine wherein a pincher member at each side of the machine cooperates with the adjacent underfolder to pinch therebetween an end wing of wrapping material as the wing is folded under the package, thereby to draw the material taut over the top of the package.

Other objects and advantages of the invention will become apparent upon reading the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a top plan view of a wrapping machine embodying the present invention with a portion of the top cover plate broken away for the sake of clarity, and with certain of the moving parts shown in an intermediate position;

FIG. 2 is a perspective view from the underside of a partially wrapped package showing the end wing portions of the wrapper extending laterally outwardly from each end thereof;

FIG. 3 is a perspective view from the underside of the package of FIG. 2 which has been completely wrapped and sealed;

FIG. 4 is a side elevational view of the machine with parts of the side plates broken away for the sake of clarity, and showing certain parts in the positions which they assume before any wrapping operations have taken place;

FIG. 5 is a fragmentary side elevational view of certain parts of the machine shown in FIG. 4 but on an enlarged scale;

FIG. 5a is an enlarged fragmentary horizontal sectional view taken along the plane of line 5a-5a of FIG. 5;

FIG. 6 is an end elevational view of one side Only of the machine as seen in FIG. 5 and looking in the direction of the arrows 66;

FIG. 7 is a fragmentary sectional view through the machine with the various parts adjusted to accommodate the smallest package showing the right-hand side of the machine with the package moving away from the viewer and illustrating the downfolder in its lower position, the underfolder in its outermost or separated position, and the pincher plate in normal position with the end wings of the wrapper extending downwardly;

FIG. 8 is a view similar to FIG. 7 but with certain parts moved to show an end wing pinched between the inwardly movingunderfolder and the pincher plate;

FIG. 9 is a view similar to FIGS. 7 and 8 but with the underfolder moved all the way under the package and the pincher plate separated therefrom to allow the package to move to the front of the machine;

FIG. 10 is a schematic view in plan of the right-hand front tucker with the package and wrapper in dot-dash lines and in dotted lines, respectively, at the completion of the front tucking step;

FIG. 11 is a side elevational view of the parts as shown in FIG. 10;

FIG. 12 is a schematic view in plan of the right-hand downfolder means with the package in dot-dash lines and the wrapper in dotted lines, and with the downfolder moving downwardly to begin the down-folding step;

FIG. 13 is a schematic side elevational view similar to FIG. 12 showing also the rear tucker in its uppermost or tucking position;

FIG. 14 is a schematic view in plan similar to FIG. 12 but showing the downfolder in an intermediate position and still moving downwardly;

FIG. 15 is a schematic view in end elevation of the parts shown in FIGS. 14 and 16 and taken along the plane of line 1515 of FIG. 16, and in addition shows the corresponding underfolder beginning its inward movement toward the end wing of the wrapper and pincher plate;

FIG. 16 is a schematic side elevational view of the parts shown in FIG. 15 but omitting the underfolder and the pincher plate;

FIGS. 17, 18 and 19 are schematic fragmentary top, end, and side elevational views, respectively, showing the downfolder in its lowermost position and the underfolder and pincher plate in their initial contacting position; and

FIGS. 20, 21, and 22 are schematic fragmentary top, end, and side elevational views, respectively, showing the pincher plate separated from the underfolder at its innermost position, the downfolder returning to its upper position, and the rear tucker returned to its inactive position.

Referring now more particularly to the drawings and especially to FIGS. 1 and 4, the machine has a main stationary frame generally indicated by the numeral 1 and which includes spaced horizontally extending leftand right-

hand angle members

2 and 3 defining the top of the frame. Similar angle members form the lower part of the frame, one such angle member at the right-hand side l of the machine being indicated by the numeral 4. The frame may be supported by a suitable number of legs 5.

The sides of the frame may be suitably enclosed either completely or partially by suitable panels, the right-hand panel being shown in FIG. 4 and identified by the numeral 6. A top panel or work table 7 is positioned at the top of the frame and at the rear end of the machine where the package begins its movement through the machine for having the various wrapping operations performed thereon.

Within the main stationary frame 1 there is a pair of inner movable frames, one at each side of the machine, as generally indicated by the numeral 8. These inner movable frames are identical in construction and operation and a description of one will, therefore, suffice for both. The movable frame 8 illustrated in FIGS. 4 and 5 in the righthand frame looking toward the right in FIGS. 1, 4 and 5.

Each such movable frame 8 includes a front upright member 9 and a rear upright member 10. The various folding and operating devices to be described in greater detail hereinafter are mounted on these movable frames so that they can be adjusted to accommodate packages of different sizes. For example, the various folding operations such as the downfolders, underfolders, front and rear tuckers, and the like, must operate adjacent each end of the package as it passes through the machine. Thus, these various mechanisms at each side of the machine must be spaced farther apart for longer packages than they are for shorter packages.

This general type of adjustment is common in wrapping machines so that the details thereof need not be fully described here. It is sufiicient merely to point out that the front and

rear uprights

9 and 10 are mounted on front and rear shafts 11 and 12, respectively. These shafts 11 and 12 are oppositely threaded at their ends so that when they are rotated, the movable frames will move inwardly or outwardly depending upon the direction of rotation.

Sprockets 13 and 14 are mounted on the respective shafts 11 and 12 and are connected by a sprocket chain 15. Any suitable means, such as a crank (not shown) may be utilized to rotate one of the shafts 11 or 12, thereby to cause the threads on those shafts to move the frames inwardly or outwardly.

Support rails 16 and 17 are provided along which the package may be moved in its travel through the machine. in FIG. 1, 16 represents the left-hand package support rail and 17 represents the right-hand package support rail. These rails also move toward or away from each other with like movements of the inner movable frames. In FIG. 1 these frames, as well as the

rails

16 and 17, and the other mechanisms mounted thereon, are illustrated in an intermediate position, i.e. neither in the completely closed nor completely open position.

Referring now for a moment to FIGS. 2 and 3, the package itself is indicated by the letter P and may have thereon articles of food or other merchandise to be wrapped. The wrapping material is indicated by the letter W and is preferably formed of a transparent heatsensitive material. In the initial wrapping operation, which is performed by hand in such a semi-automatic machine, the wrapping material is placed around the package so that the diagonally opposed corners thereof overlap on the bottom of the package. When such a diamond wrap is used, there will result end wings of wrapping material which extend laterally outwardly from each end of the package. In FIG. 2 the right end wing of wrapping material is shown at 18 and the left end wing is shown at 19. The diagonally opposed corners of the wrap overlap at the bottom of the package, as shown by the numeral 20.

The tucking of the front and rear corners of each end wing is performed by suitable front and rear tuckers in the machine. Downfolders then operate to fold the end wings downwardly after which underfolders come into play having heat-sealing means thereon which fold the end wings upwardly against the bottom of the pack-.

age and spot-seal. When this operation is completed, the package then is moved by an intermittently moving conveyor into contact with suitable plows which urge the trailing or tip ends of the wings against the bottom of the package and a final heat-seal at the front end of the machine completes the package. The wrapped package then will appear as illustrated in FIG. 3.

The machine is provided with a hand heat-sealer 21 at the rear end thereof which is utilized to seal the overlapping corners on the bottom of the package when the initial wrap is placed around the package by hand. The package is then placed on the top panel between the leftand right-

hand guide members

22 and 23. As the conveyor moves the package through the machine, these guides will tend to center the package so that the ends thereof will be in proper relation with the various folding devices.

The conveyor chain and pusher members are of the normal type and may be seen more clearly in FIGS. 7, 8 and 9. A plurality of spaced pusher members 24 are mounted upon the conveyor chain 25 and push the packages through the machine in a step-by-step movement during each intermittent movement of the chain. The chain is positioned with a support member 25a which supports the chain as well as the package.

Referring now for a moment to FIG. 4, the machine is operated by a suitable drive motor (not shown) 'which has associated therewith a belt 26 which drives a speed reducer 27. A drive shaft 28 from the speed reducer has mounted thereon a sprocket 29 and drives a second sprocket 30 by means of a chain 31. Suitable rollers (not shown) on studs 32 on sprocket 30 cooperate with at Geneva drive member 33 mounted on shaft 34, thereby to rotate shaft 34 intermittently.

This latter shaft has a sprocket 35 thereon and drives a sprocket 36 by means of a chain 37. One of the sprockets for the conveyor chain is mounted on the same shaft as the sprocket 36 so that during each intermittent motion of the Geneva drive the conveyor chain will move and advance the package through the machine.

A guide rod 33 is mounted at each side of the machine on the respective inner movable frames 8 and supports and guides the downfolders and front tuckers in their respective movements.

The lower bracket 39 (FIG. is mounted for sliding movement along the vertical guide rod 38 at each side of the machine and has mounted thereon or formed integrally therewith the

front tucker members

40 and 41. These front tuckers remain stationary during the tucking operation and tuck the front corner of the wrapper against the end of the package. The upper tucker 40- is designed to take care of relatively high packages, whereas the lower tucker 41 performs its operation upon lower packages.

The upper bracket 42 also mounted for sliding movement along the guide rod 38 at each side of the machine, has mounted thereon or formed integrally therewith the downfolder assembly generally indicated by the numeral 43. This assembly consists of an upper arm 44 and a lower arm 45 spaced downwardly therefrom.

A bell crank generally indicated at 46 comprises a lower bell crank arm 47 and an upper bell crank arm 48 and is mounted for rotation on the stud shaft 49 which thus becomes the pivot for the bell crank 46. This stud 49 is mounted on and extends outwardly from the lower bracket 39 (see also FIG. 5a).

A link 50 is connected at its lower end by means of the pivot pin 51 to the outer end of bell crank arm 48. The upper end of link 50 is then connected to a stud 52 which is connected with and extends outwardly from the upper bracket 42. The stud 49 which forms the pivot for the bell crank lever 46 has rotatably mounted at the outer end thereof a roller 53. A similar roller 54 is mounted at the outer end of stud 52. These

rollers

53 and 54 are adapted to traverse a track 55 which extends lengthwise of an upright support member 56 mounted at its lower end to a suitable part of the inner movable frame 8, and which prevents

brackets

39 and 42 from rotating about guide rod 38. The operation of this mechanism will be described presently.

The step of tucking the rear portion of the laterally extending end wing of the wrapper is performed by the rear tucker assembly generally indicated by the numeral 57. The rear tucker itself is shown at 58 and is pivotally mounted on the pivot arm 59 which extends rearwardly from and is an integral part of the lower bracket 39. This pivotal connection between the rear tucker 58 and arm 59 includes a rod 60 supported in a bearing 60a. The tucker 58 is secured to the inner end of the rod 60 (FIGS. 1 and 5).

The rear tucker is caused to rotate upwardly to perform its tucking operation by longitudinal movement of the actuator link 61. This latter link is pivotally comiected as at 62 with the outer end of hell crank arm 47. The other end of the actuator link 61 is pivotally connected as at 63 to the tucker arm 64.

Thus far it will be evident that when the bell crank 46 is caused to rotate in a clockwise direction about its pivotal mounting 49, the lower arm 47 thereof will move toward the left, as viewed in FIG. 5, and will likewise rotate the tucker arm 64 in a clockwise direction. This arm 64 and the rear tucker 58 are both connected to the pivot rod 60 so that clockwise movement of the arm 64 will cause a similar clockwise movement of the rear tucker 58 and will raise it to its tucking position, such as that shown in FIGS. 15, 16 and 19.

As will presently by seen, the operation of the rear tucker and the downfolders are so coordinated that im mediately after the tucking operations take place, or substantially simultaneously therewith, the downfolders will move downwardly to effect the downfold of the end wings of the wrapping material.

There are two cams on the drive shaft 28. Cam 65 controls the operation of the downfolders and tuckers, while cam 66 controls the operation of the underfolders yet to be described.

With respect to the downfolders, they are caused to be operated by a series of elements which includes a cross member 67 which, according to FIGS. 4 and 5, is illustrated as being hollow and rectangular in cross section. An arm 68 extends downwardly from the cross member 67 and supports a cam follower 69 at the outer end thereof.

At each end of the cross member 67 there is an end plate 70 mounted for rotation at the left-hand end thereof on the main frame, as viewed in FIG. 4. Thus, as the cam 65 rotates, the cam follower 69 will hear thereagainst and will be caused to move outwardly and inwardly in accordance with the high and low contour of the cam. As viewed in FIG. 4, the cam follower 69 is approximately at the high point of the cam 65 so that in this position the assembly of arm 68, cross member 67, and end plates 70 will be in their elevated position to which they have been moved by reason of the pivotal mounting of the plates 70. At each side of the machine and mounted on the respective inner movable frames 8 there is a rocker arm 71 pivotally mounted as at 72 to said frame. The pivot mounting for the plates 70 is substantially in alignment with the pivot point 72 for rocker arm 71. The rocker arm 71 extends lengthwise of the machine and, as viewed in FIGS. 4 and 5, the righthand end thereof is indicated by the numeral 73. A vertically extending rod 74 is received within an opening through the end 73 of the rocker arm 71 and is threaded at its lower end to receive a nut 75. The nut 75 prevents upward withdrawal of the rod 74 and also may be adjusted to regulate the effective length of the rod. The upper end of rod 74 threadedly engages an opening in a yoke 76, which yoke has an opening therethrough to receive the stud 77 which extends outwardly from the up- 7 per bracket 42. A locknut Ida is utilized to lock the rod 74 against rotation and loosening thereof, which nut presses against the lower end of the yoke 76.

A coiled spring 78 surrounds the rod '74 bearing at its upper end against the locknut 7a and at its lower end against the right-hand end 73 of the rocker arm 71. From this description it will be evident that when the rocker arm 71 is caused to move downwardly about its pivot, the upper bracket 42 and the

downfolder arms

44 and 45 will also be pulled downwardly by the rod 74. The rod fits loosely through an opening in the end 73 of the rocker arm so that if during upward movement of the rocker arm 71, rod '74, and upper bracket 42, something should occur to jamb the device and prevent the bracket 42 from moving upwardly, or to stop it in its upward movement, the rocker arm 71 can, and will, continue its upward movement due to the driving cam action. In this event, the spring 78 will compress and the end 73 of the rocker arm will slide the desired distance along the rod 74 so that the machine may continue to function without jambing the other parts thereof.

The rocker arm 71 is provided intermediate the ends thereof with a roller 7% which rests upon the cross member 67. When the inner movable frames 8 are adjusted toward or away from each other to accommodate different sized packages, the roller 79 on each rocker arm will roll lengthwise of the cross member 67. It will be clear, of course, that the raising and lowering of the cross member 67 due to the action of the cam 65 will cause a similar raising and lowering of the rocker arm 71, the rod 74, and the upper bracket 42 connected therewith.

The rocker arm 71 is normally urged downwardly by means of a spring 80 which is connected at its upper end to the rocker arm at 81. The lower end of spring 80 is provided with a yoke 82 having an opening 83 therein to receive the horizontally extending end 34 of a rod 85 (FIGS. 4, and 6). The rod 85 extends upwardly and is secured, as at 86, to a suitable part of the inner movable frame 8. The spring 3 thus tends always to pull the rocker arm 71 downwardly so that the roller 79 thereon will always be in contact with the cross member 67.

A coiled tension spring 87 (FIG. 5) is secured at its upper end, as at 88, to the top bracket 42. The lower end of spring 87 is secured, as at 89, to the lower bracket 39. This spring 87 therefore tends to urge the upper and

lower brackets

42 and 39 toward each other.

A vertical rod t is threaded and is connected at its lower end by suitable means 1 to the lower bracket 39. Intermediate the ends of threaded rod 96 there is located at a suitable position a pair of locknuts 92. The upper end of rod 90, when all of the parts are in their elevated position, passes through an enlarged portion 93 of the upper bracket 42 (FIGS. 5 and 6). At its upper end the rod is provided with a head 94 and in its upper position bears against a bumper 95 extending downwardly from a stationary part of the main frame.

Since the end '73 of the rocker arm 71 will have a slightly arcuate movement as it reciprocates in a vertical plane, the bracket 96 on the main frame will have an opening therethrough sufiiciently large enough to accommodate any resulting lateral movement of the rod 74.

The operation of the downfolders and tuckers is controlled by the mechanism just described and the movements of the various parts, as well as their coordination with each other, will now be dealt with in greater detail.

rom the positions of the parts as shown in FIGS. 4, 5 and 6, continued rotation of the cam 65 will cause the low part thereof to be moved into position in contact with the cam follower 69 so that the cross member 67 and rocker arm 71 will move downwardly. Such downward movement will carry with it the rod 74 which will thereupon pull the upper bracket 42 and the downfolder arms connected therewith to a lower position. Since the stud or piv- 0t 52 is mounted on the bracket 42, it also moves downwardly therewith and causes a similar downward movement of the link 50 and its pivot connection 51 with the bell crank lever 46. Since spring 87 holds bracket 39 and the parts thereon in their upper position, this movement will in turn impart a clockwise rotation of the bell crank lever about its pivot 49, thereby causing the lower arm 47 thereof to move toward the left, as viewed in FIG. 5. This in turn causes a longitudinal movement of the actuator arm 61 toward the left and into the position thereof as shown in FIG. 19. The clockwise rotation of the tucker arm 64 will rotate the tucker member 58 up wardly to the position shown in FIG. 19.

It should also be noted here that whiie this action is taking place, the upper bracket 42 and the downfolders connected therewith will slide downwardly lengthwise of the rod until the enlargement 93 comes into contact with the locknut 92 on the rod 90. At this point, the package, having been moved against the stationary front tuckers ii) and 41, will have had the front portions of the end wings tucked against the ends thereof. Likewise, the upwardly rotating movement of the rear tucker 53 at each side of the machine will have tucked the rear corners of the end wings against the ends of the package. At this point the positions of the various parts will be like that shown in FIG. 13. The front and rear tucks having been accomplished, the

downfolders

44 and 45 attached to the upper bracket 42 will then continue the downward movement thereof, but since at this point the enlargement 93 will bear against the locknut 92 on rod 90, the lower bracket 39 will also be forced to move downwardly. When this occurs, all of the mechanism just described will move downwardly as a unit. This will include the bell crank lever 46, the front tuckers 40, 41, as well as the rear tucker 58 in its upper or tucking position.

The various parts then move from the position thereof shown in FIG. 13 through the position shown in FIG. 16 and into the position shown in FIG. 19. At this point the downfold has been completed and the end wings will be extending downwardly as illustrated in FIGS. 7 and 8. Also, the

downfolder arms

44 and 45 will be positioned as they appear in FIGS. 7, 8 and 9.

The underfold takes place while the parts just described are in this position but the detailed operation of the underfolders and pincher plate will be dealt with presently. In the meantime, however, after the underfold has been completed, the cam follower 69 will begin its movement toward the high point on cam 65, therebyv to raise the rocker arm 71 and move the connecting rod 74 upwardly. The upper bracket 42 is thus raised by its connection with the rod 74, but since it is also connected to the lower bracket 39 by the spring 87, such upward movement of the bracket 42 will carry with it the lower bracket 39 together with the parts connected therewith including the front tuckers 40, 41, the bell crank lever 46, the pivot arm 59, rear tucker 58, actuator arm 61, and tucker link 64. This upward movement will continue until the upper end of rod 90 comes against the bumper which thereupon will stop the upward movement of the lower bracket 39 and the parts connected therewith. The upper bracket 42 will, however, continue moving upwardly carrying with it the pivot stud 52 and link 50. Since this link 50 moves with respect to the pivot 49 of the bell crank lever 46, it will cause a counterclockwise rotation of the bell crank lever, thereupon reversing the movement of the rear tucker 58 and moving it back to its lower position, as shown in FIGS. 4, 5 and 22.

From the foregoing it will be evident that rotation of the cam 65 will cause a vertical reciprocating movement of the

downfolders

44, 45 and will actuate the rear tucker 58, where-by the tucking operations and the downfold are accomplished at each end of the package.

One of the main features of the invention as mentioned hereinabove resides in the construction and operation of the underfolder. By means of this novel arrangement, the

underfolders with the heat-sealer thereon are allowed to remain in sealing position a greater period of time than has heretofore been possible with other wrapping machines, thus to insure a good spot-seal. The over-all time consumed, however, for the completion of the entire wrapping operation will actually be decreased, thus increasing the output of the machine. This is made possible by reason of the fact that immediately upon completion of the downfold, the underfolder will move in to fold the end wing against the bottom of the package and spotseal it and will remain in that position until after'the downfolder mechanism has partially completed its upward movement.

As in the previous mechanisms described herein, there are two underfolder and pincher plate assemblies, one at each side of the machine. A description of one, therefore, will sufiice for both. The underfolder is identified by the numeral 97 in FIGS. 4 to 9, inclusive, as well as in the schematic views of FIGS. 15, 18 and 21. The underfolder constitutes an angle member extending lengthwise of the machine and has mounted on the top thereof a heater element identified as a spot-sealer 98. This spot-sealer may also be seen in the same figures above enumerated and in addition is shown in FIGS. 19 and 22.

The underfolder 97 together with its associated spotsealer 98 is mounted on the underfolder arm 99, which has at the upper end thereof an enlarged top portion 100 to Which the underfolder is actually secured. Intermediate the ends of the underfolder 97 there is secured a package retainer 101 consisting of a relatively small plate member adapted to retain the package in place while the folding operations are being performed thereon. As will be seen hereinafter, the underfolder arm 99 is mounted for arcuate movement from the outer normal position thereof shown in FIG. 7 to the inner position thereof shown in FIG. 9. Also, as maybe seen in FIG. 19, the underfolder, when moved to its inner position, passes between the

downfolder arms

44 and 45. At the completion of the underfold, as shown in FIG. 9, the downfolders are free to move upwardly While the underfolders remain in their innermost or sealing position.

Heretofore it has been necessary for the underfolders to move inwardly and then outwardly before the downfolders could begin their upward movement. Since the present construction allows the downfolders to move up wardly while the underfolders are still in the sealing position below the package, there is not only a saving in time but also the underfolders and spot-sealers may remain in sealing position for a greater period of time and still obtain increased speed of the wrapping operation.

The details of the mechanism for causing the inward and outward movement of the underfolder will be described presently, but in the meantime reference will be made briefly to another feature of the invention wherein the end wings are gripped to pull the wrapping material taut over the top of the package. To accomplish this there is provided at each side of the machine a pincher plate 102 mounted on a pincher plate arm 103. This pincher plate assembly may be seen in side elevation in FIGS. 4 and and the cooperative action between the pincher plate and the underfolder will be more readily understood by reference to FIGS. 7, 8 and 9.

In general it may be said that the pincher plate 102 is normally in an upright position below the package and spaced inwardly not only from the underfolder, but also from the downwardly extending end wing. When the underfolder moves inwardly it will first contact the outer surface of the end Wing and move it into contact with a friction member 103a on the pincher plate, thereby to pinch the end wing between the plate and underfolder. The continued inward movement of the underfolder will move the pincher plate with it for a short distance, thus to pull the wrapping material taut over the top of the package. Continued inward movement of the underfolder to its position shown in FIG. 9 where the spot-sealer 98 is activated, causes the pincher plate to move inwardly at a more rapid rate to release the end wing so that the package may then continue its movement through the machine after the spot-seal has been completed.

The operation of the underfolders and pincher plates is controlled by cam 66 on the drive shaft 28. An actuator bracket for the underfolders consists of two spaced-apart channel members 104, one at each side of the machine, each of which is mounted for pivotal movement at the rear end thereof about a pivot pin 104a (FIG. 4). The two channel members 104 are tied together by a cross member 195 to which is mounted intermediate the channel members a support arm 1%. The forward end of this support arm is provided with a cam follower 107 which follows the contour of the cam 66 as it is rotated. It will thus be evident that rotation of the cam 66 so that the cam follower 107 will follow the contour thereof, past thehigh and low points thereof, will cause the actuator bracket for the downfolders to be raised and lowered. The right-hand channel member 104 of this actuator bracket may be seen in cross section in FIGS. 7, 8 and 9. In FIG. 7 the channel member is in its lowermost position. FIG. 8 shows the channel member in an intermediate position elevated somewhat from FIG. 7. FIG. 9 shows the channel memher in its highest position with the underfolder and pincher plate at their innermost positions.

The underfolder at each side of the machine is actuated by means of an underfolder arm actuator plate 108 which is mounted for rotation about a pivot pin 109 secured to the inner movable frame 8. The outer end of plate 108 has mounted thereon a roller 110 which is adapted to rest upon the channel member 104. This roller 110 may also be seen in FIGS. 4 and 5.

Since the actuator bracket for the underfolders is mounted on the main frame, and the underfolders and pincher plates are mounted onthe movable frames, it is evident that when the movable frames are adjusted for different sized packages the underfolder and pincher plate assemblies will move with respect to the main frame. When this adjustment takes place, the roller 110 will move outwardly or inwardly and roll across the surface of the adjacent channel member 194. As shown in FIGS. 7, 8 and 9, the inner movable frames 8 have been adjusted to their innermost positions.

The underfolder arm 99 at its lower end is bifurcated and is angularly positioned to extend inwardly as may be seen at 111. The inner ends of the bifurcations 111 are adapted to receive a pivot pin 112 which also passes through a lug 113 integral with plate 108 at the inner end thereof.

A plate 114 extends upwardly from the actuator plate 168 adjacent the inner end thereof and has either extending transversely therethrough, or extending outwardly from each end thereof a pin 115. A lower pin 116 extends transversely of the arm 99 and through the flanges at each side thereof to which springs 117 are secured. There is a spring 117 at each side of the arm 99. The upper end of each spring is secured to a pin and the lower end of each spring is'secured to a pin 116. Thus, the springs 117 tend to urge the underfolder arm 99 inwardly toward the upstanding plate 114.

As the actuator plate 198 moves upwardly about its pivot 109 the plate 114 which is secured thereto or formed integrally therewith, as well as the arm 99, through its connection at 112, will likewise be moved inwardly as a unit. Arm 99, however, may also move with respect to

plates

108 and 114 when necessary.

Since the upward movement of the actuator plate 108 is controlled by the cam 66 it follows that springs 117 will prevent jambing of the machine in the event some object should prevent the arm 99 from moving all the way to its innermost position. Should this occur, plates 1118 and 114 will continue to move but the springs 117 will allow arm 99 to stop.

There is also a spring 1.18 below the plate 108 which is secured at its inner end to a pin 119 mounted on the frame 8. The outer end of spring 118 is secured to the downwardly extending pin 120 mounted on the underside of plate 108. This spring tends to urge the plate 108 and its connected elements downwardly so that the roller 110 will always be in contact with the channel memher 104.

The pincher plate arm 103 has either secured thereto or formed integrally therewith an actuator plate 12] extending angular-1y outwardly from the bottom thereof. A transversely extending boss 122 along the upper surface of actuator plate 121 has a pivot pin extending therethrough and mounted on the inner movable frame 8 about which the pincher plate 102, arm 103, and plate 121 may rotate.

The actuator plate 121 has mounted therein and extending downwardly therefrom a bolt 123 to which is secured at its lower end a bumper 124 Which may preferably be formed of a material such as nylon.

In its initial movement upwardly, the underfolder actuator plate 108 will mOVe to the position shown in FIG. 8 without any movement of the pincher plate taking place. At this point, however, the plate 108 will come against the undersurface of the bumper 124. Continued movement upwardly of the plate 108 will thereafter move the pincher plate 102, arm 103 and plate 121 upwardly with it.

An important feature of the invention resides in the relationship between the actuator plate 108 for the underfolder and the actuator plate 121 for the pincher. The radius of the are through which the plate 108 moves may be measured from the pivot pin 109 to the point of contact of bumper 124 therewith. The radius of the are through which the plate 121 rotates, however, may be measured from the axis of rotation or the pin which extends through the boss 122 to the same point of contact of bumper 124 with plate 108. Since the radius of the are through which the plate 121 moves is much shorter than the radius of the are through which the plate 108 moves, it is evident that for the same upward movement of the two plates at the point of contact of the bumper 124 with plate 108, the pincher plate arm 103 will move through a greater distance and at a greater rate of speed than the underfolder arm 99.

Thus, from the position of the arm 99 and pincher plate 102 in FIG. 8, where the end wing is pinched between these two elements, to their respective positions shown in FIG. 9, the pincher plate 102 and arm 99 have moved together for a short distance long enough to pull the wrapper taut and thereafter the pincher plate moves away from the downfolder to free the tip end of the wing so that the package may be moved after the bottom spotseal has taken place.

An adjustable stop member 125 threadedly engages an opening through a boss 126 formed on the under surface of plate 121. The inner end of member 125 normally bears against a portion of the frame 108 to limit the downward movement of the actuator plate 121 and the outward movement of the pincher plate 102 mounted thereon.

Behind the bolt 123 and adjusted stop member 125, as viewed in FIGS. 7, 8 and 9, there is provided an elongated pin 127 extending downwardly from the plate 121. The lower end of the pin 127 is adapted to have one end 128 of a spring secured thereto. The spring is not visible in these figures but is immediately behind the spring 118 and has its other end secured to a part of the frame 8. Thus, the pincher plate 102 and its actuator plate 121 are urged to an outer position at all times.

There is another adjusting screw for the arm 99 and this is identified by the numeral 129 in FIGS. 7, 8 and 9. This screw may be utilized to adjust the relative positions of the arm 99 and the upstanding plate 114.

Initially, therefore, the size of the package will be determined and the machine adjusted therefor by moving the inner frames 8 inwardly or outwardly as may be necessary. To facilitate this adjustment, plates 130 are secured to the guide members 22 and 23 (FIG. 1) which will move with the frames 8 as they are being adjusted. A chart 131 bearing suitable indicia thereon is mounted at each side of the machine to the top panel or work table 7 immediately below the adjacent plate 130. In each of the members 130 there is an opening 132 which has an indicator strip 133 extending across it. This strip extends across the opening and immediately above the chart 131 so that as the inner movable frames 8 are adjusted inwardly or outwardly, the indicator strip 133 will indicate on the chart 131 the proper setting for a given package.

As the package moves into the position where the folding operations are performed thereon as described above, the package is held down onto the support rails by means of a flexible hold-down member 134 (FIG. 4). This may be a narrow length of flexible material, such as rubber, and is preferably suspended from an arm 135 extending lengthwise of the machine and located thereabove. The arm 135 is mounted to a yoke 136 (FIGS. 1 and 4) pivotally secured at its outer ends to the stationary main frame as at 137. As the package moves through the machine, the hold-down member 134 keeps the package on the support rails as they are moved by the conveyor off of the rails and onto the plows 13$ and 139. As is well known, these plows fold the ends of the

end wings

19 and 20 from the positions thereof after they have been spotsealed, as in FIG. 9, to a position flat and in possibly overlapping relation against the bottom of the package. After the tip ends have been folded against the bottom, the package is then moved onto the heater plate 140 for the final complete seal of the wrapper.

From the foregoing description it will be evident that a machine has been provided which will effectively pull the wrapper taut around the package and that is certain to provide an clfective spot-seal on the bottom thereof before the package is moved to the final sealing position. The effective spot-seal is accomplished by an arrangement which permits the sealer on the underfolder to remain in contact with the bottom of the package for a longer period of time than has heretofore been possible. As has been seen above, the construction is such that the underfolder and sealer move under the package between the upper and lower downfolder arms and may remain in that position while the downfolder moves upwardly where the lower arm thereof is above the path of movement of the underfolder. While the downfolder continues its upward movement, the underfolder moves outwardly and thus not only increased efiiciency, but increased speed in the wrapping operation is accomplished.

While the invention has been disclosed as including a spot-sealing operation in connection with the underfolding step, it will be evident that this feature of the invention lends itself to merely underfolding without sealing, if desired, since the package moves to the heater plate through the plows immediately after the underfold is completed.

Changes may be made in the form, construction and arrangement of parts from those disclosed herein without in any way departing from the spirit of the invention or sacrificing any of the attendant advantages thereof, provided, however, that such changes fall within the scope of the claims appended hereto.

The invention is hereby claimed as follows:

1. A wrapping machine comprising (a) means for supporting a partially wrapped package having end wing portions of heat scalable wrapping film extending laterally outwardly from each end thereof,

(b) front and rear pairs of tuckers for tucking the front and rear sides of said wing portions,

(0) downfolder means at opposite sides of the machine mounted for movement from an upper to a lower 13 position for folding said wing portions downwardly to a poistion below the bottom of said package,

(d) underfolder means at opposite sides of the machine for folding the downwardly extending wing portions upwardly against the bottom of said package,

(e) means to move said underfolder means toward each other to Wing-folding position while said downfolder means are in a lower position,

(f) means to elevate said downfolder means while said underfolder means are in wing-folding position, and

(g) means to move said underfolder means away from each other to their normal separated position after said downfolder means have been elevated to a position above the path of movement of said underfolder means.

2. A wrapping machine as defined in claim 1 wherein said downfolder means each includes an upper arm and a lower arm movable together as a unit.

3. A wrapping machine as defined in claim 2 wherein said underfolder means at opposite sides of said machine move toward each other to wing-folding position between said upper and lower arms of said downfolder means.

4. A wrapping machine as defined in claim 2 wherein said underfolder means at opposite sides of said machine move toward each other to wing-folding position between said upper and lower arms of said downfolder means, and move away from each other to their normal separated positions below said lower arm.

5. A wrapping machine as defined in claim 1, wherein said underfolder means are mounted for pivotal movement to and from the wing-folding and sealing positions thereof.

6. A wrapping machine as defined in claim 1, wherein each said underfolder means is mounted on an arm, an actuator plate connected to said arm at the lower end thereof, means mounting said actuator plate and arm for pivotal movement, and means for moving said actuator plate and arm in a reciprocating pivotal movement, thereby to move said underfolder means to and from the wingfolding and sealing positions thereof.

7. A wrapping machine as defined in claim 1, wherein each said underfolder means is mounted on an arm, an actuator plate adjacent the lower end of said arm, means mounting said plate for pivotal movement, means mounting said arm on said plate for pivotal movement therewith and for pivotal movement with respect thereto, and means for moving said actuator plate and arm in a reciprocating pivotal movement, thereby to move said underfolder means to and from the wing-folding and sealing positions thereof.

8. A Wrapping machine comprising (a) a main outer stationary frame,

(b) a pair of inner frames adjustably mounted on said main frame for movement inwardly toward each other and outwardly away from each other,

(0) means on said inner frames for supporting a partially wrapped package having end wing portions of heat scalable wrapping film extending laterally outwardly from each end thereof,

(d) front and rear pairs of tuckers on said inner frames for tucking the front and rear sides of said wing portions,

(e) downfolder means on each of said inner frames and mounted thereon for movement from an upper to a lower position for folding said wing portions downwardly to a position below the bottom of said package,

(f) underfolder means mounted on said inner frames for folding the downwardly extending wing portions upwardly against the bottom of said package and for performing a spot-seal thereon,

(g) means to move said underfolder means toward each other to wing-folding position while said downfolder means are in a lower position,

(h) means to elevate said downfolder means while said underfolder means are in wing-folding position, and

(i) means to move said underfolder means away from each other to their normal separated position after said downfolder means have been elevated to a position above the path of movement of said underfolder means.

9. A wrapping machine as defined in claim 8, wherein said downfolder means each includes a lower arm for folding the end wing downwardly, and wherein the means to move the underfolder means to wing-folding position operates to so move the underfolder means above said lower arm, and the means to move said underfolder means away from each other operates to so move the underfolder means below said lower arm.

10. A wrapping machine as defined in claim 8, including a pincher member on each inner frame adapted to cooperate with the underfolder means thereon to pinch the downwardly extending end wing and draw the wrapper taut over the package as said underfolder means moves to wing-folding position.

References Cited TRAVIS S. MCGEHEE, Primary Examiner.

N. A. ABRAMS, Assistant Examiner.