US2071548A - Wrapper control for wrapping machines - Google Patents

Description

N. \N. LYON WRAPPER CONTROL FOR WRAPPING MACHINES 0 Feb. 23, 1937.

5 Sheets Sheet 1 Filed Feb. 25, 1935 INVENTOR BY lVORMA/V M/L m/v W 71d ATTORNEYS Feb. 23, 1931. N L N 2,071,548

WRAPPER CONTROL FOR WRAPPING MACHINES Filed Feb. 25, 1935 3 Sheets-Sheet 2 INVENTOR A/ORMA/V l Vl ro/v ATTORNEYS Feb. 23, 1937. N. w. LYON WRAPPER CONTROL FOR WRAPPING MACHINES Filed Feb. 25, 1935 3 Sheets-Sheet 3 0 Z; I 46 X 70 AZ fl'aj 6 42 Z9 Hj INVENTOR NORM/Ml W LJ o/z/ ATTORNEYS Patented Feb. 23, 1937 UNITED STATES PAT FlC

WRAPPER CONTROL FOR WRAPPING MACHINES Application February 25, 1935, Serial No. 7,990

1'7 Claims.

In the wrapping of articles having a considerable size, such as cartons, or having an irregular contour as in the case of loaves of bread, it has been a serious problem to secure accurate alignment of the wrapper as it is being folded circumferentially around the article. The difliculty becomes more pronounced at high speeds, and has served both to reduce the output of wrapping machines and to mar the appearance of the wrapped articles. The best prior solution of the problem has involved the use of a pair of freely rotatable rolls between which the wrapper is drawn out as it is being wrapped circumferentially around the article. These rolls offer a greater resistance to slantwise motion of the wrapper than they do to its straight motion, and during their engagement with the wrapper insure that it follows a straight path as it is wound around the article. The wrapper is governed by the resistance to slantwise motion offered by the rolls to such an extent that it will follow a straight course even if the article about which it is being folded is unsymmetrical, as is frequently the case with loaves of bread. The rolls also serve to regulate the tension with which the wrapper is tightened around the article.

In prior constructions, however, the control of the unattached portion of the wrapper was discontinuous, leaving intervals in which the wrapper might shift laterally or lose its proper tension, and not maintaining a uniform effect as the machine was adjusted for articles of different heights. The present invention relates to mechanism for improving the continuity of the control of the wrapper, and for improving generally the mechanism by which this control is exercised. The invention may be applied to many different types of wrapping mechanisms. It will be described in a concrete embodiment in which the article is delivered together with a wrapper into a reciprocating carrier by which it is shifted into alignment with a delivery channel. In the case shown the wrapper is fed underneath the carrier towards the open side thereof, but it will be understood that the in- 5 vention could be applied equally well to wrapping mechanism having other types of wrapper feed, such for example as that shown in the Smith and Hoppe Patent 1,953,195, April 3, 1934.

The invention will now be described in the embodiment chosen for illustration, with reference to the accompanying drawings in which:

Fig. 1 is a fragmentary median. section of a wrapping machine with enough of its essential parts shown to illustrate a setting for the present invention;

Fig. 2 is a detail;

Figs. 3 to 9 are diagrammatic views showing the mode of operation of the wrapper control means; and

Fig. 10 is a diagrammatic view of a modification. 5

Before describing the device which is the particular subject of the invention, it is necessary to describe enough of one form of wrapping machine to furnish an environment in which the action of the wrapper control mechanism may be under- N stood. The machine is shown as mounted upon a frame l0 carrying an article feeding-in plate It and a delivery channel floor l2. An article carrier i3 is vertically reciprocable on guides l4, as by a link l5 connecting it to an arm IE on an oscillat- 15 I ing shaft I7; and carries a platform I 8 upon which the article is received when pushed from the feeding-in plate I I by a plunger 19.

The web 20 from which the wrappers are to be cut is shown in this instance as being delivered to 20 the machine according to the manner described more fully in the Hoppe Patent 2,043,376, dated June 9, 1936; although it will be apparent as the description proceeds that other modes of feeding the wrapper into position, such for example as 25 that shown in the Smith and Hoppe Patents Nos. 1,953,195 and 1,953,196 dated April 3, 1934, may be used if desired. .In the specific case chosen for illustration, the web is led from a roll 2|, passes over a floating roll 22 and under a roll 23 on the 30 frame, and is then received between rolls 24 on the carrier I3. These rolls 24 are preferably spring pressed together and are provided with a one way clutch such as a ratchet on one of them so that while the web can be drawn forward through them 35 with freedom, it cannot move back. This gives the rolls the power of drawing a length of web from around the roll 23 as the carrier moves up wardly. Beyond the rolls 24 the web lies on a guide plate 25 pivoted at 26 to the carrier, and is 40 guided at the end of the carrier by a roll 21.

The web is drawn out forwardly through the rolls 24 partly when the carrier is at the upper end of its stroke and partly when the carrier is descending, as will be explained below, and is sev- 45 ered to form a wrapper when the carrier is at about the lower limit of its movement. In its descent the plate 25 is tilted to bring the web adjacent a cutting block 29 on the carrier as shown in Fig. 1. A knife 30, preferably movable so as to increase the rapidity of the cutting action, coacts with the cutting block to sever a wrapper from the end of the web, leaving the end of the web projecting slightly from beyond the end of th 55 plate 25 so that it may be grasped by the web feeding grippers.

When the carrier is at the upper end of its travel in alignment with the delivery channel l2 a reciprocating gripper 3|, movable back and forth on a horizontal center line 32, engages the end of the web projecting beyond plate 25 as shown in Fig. 8. The descent of the carrier need be delayed only long enough to allow the gripperto move beyond its edge, the gripper continuing to draw out a length of web as the carrier descends. In the descent of the carrier the web is brought over the roll 33, and when the carrier is in its lowermost position the web is draped between the rolls 21 and 33 as shown in Fig. 1 ready to be engaged by the package a as the latter is pushed onto the carrier by the pusher l9, this occurring at about the same instant as the severance of the web by the cutter 30.

As the article moves onto the carrier it draws the short severed end of the wrapper 11; around the roll 21 and tucks it underneath the article as shown in Fig. 3. At the same time the portions of the wrapper extending beyond the ends of the article contact with tucking plates 35 on the carrier, turning down these parts of the wrapper to make the first end flaps. The second end flaps are here shown as made by stationary folders 36, the third by folders 31, and the last by the usual plow folders 38.

The carrier is also preferably fitted with a slide 40 frictionally mounted for back and forth movement and bearing a backing plunger 4| at its forward end. As the article is pushed onto the carrier (Figs. 1 and 3) the backing plunger acts to hold the wrapper firmly against the then leading face of the article and to prevent relative slip between them. The same backing plunger is used to eject the article from the carrier onto the delivery channel l2. For this purpose the slide 40 is provided with an abutment 42 adapted to be contacted by a roll 43 on a swinging arm 44. The arm 44 is moved by suitable means to shift the slide from the position of Fig. 6 to that of Figs. '7 and 8, leaving the circumferentially wrapped article in a position clear of the carrier and from which it may be carried through the delivery channel by the pressure of succeeding articles or by a suitable conveying mechanism.

In the wrapping of large articles, and particularly in the wrapping of irregular articles such as loaves of bread, there is a tendency for the wrapper to become displaced sidewise as it is being wrapped circumferentially around the article. It has heretofore been proposed, in order to control this sideways shifting of the wrapper, to grasp its trailing end between a pair of rolls through which it is drawn by the operation of encircling the wrapper around the article. In the present case an improved form of wrapper controlling means is shown, giving control of the wrapper throughout a much larger fraction of the complete machine cycle irrespective of the size of the article being wrapped.

A bar is carried at its ends by brackets 5| vertically adjustable on rods 52, the rods having as one form of adjusting means recesses 53 into which spring pressed plungers 54 on the brackets may fit to hold the bar in a definite position. The rods are preferably reciprocable vertically to raise the bar clear of the article as the latter is being fed onto the carrier. For this purpose the rods are reciprocable in brackets 55 and are pivoted at their lower ends to arms 5'! swinging on the frame and having rolls 58 resting upon cams 59 on the oscillating shaft I! previously mentioned. The bar 50 preferably has on its upper surface a flat spring 60 secured in place as by a screw SI, and being bent to provide wrapper contacting portions 62 spaced apart on opposite sides of the center of the bar. The bar 50 also carries at one side the roll 33 previously mentioned. Pivoted at 65 to each side of the carrier I3 is an arm 66; the two arms being connected by a roll 67 having a centrally disposed rubber covering 68. The arms swing freely, and are of such length that when the carrier is up the roll 6'! will be brought next to the roll 2! (Fig. 6) and when the carrier is at the level of the bar 50 the roll 6'! will ride over the spring 60 as in Fig. 4. To smooth out the action of the roll in striking the spring, and to limit the compression of the spring by the weight of the roll, a cam plate 69 is located at each end of the bar 50 in position to engage the ends of the roll.

The operation of the mechanism will now be described with particular reference to Figs. 1 and 3 to 9. The position of the wrapper in Fig. 1 is that which it assumes when an article is about to be pushed onto the carrier. It is held underneath the carrier since it is still connected to the body of the web. Above the carrier it passes around the roll 33 and is held between the spring 60 and the roll 67, which is pressed by gravity against the upper side of the web. The web is severed at about the time the carrier reaches its lowest point, but whether or not this time diifers from the time when the article contacts with the wrapper is of no particular moment since the length of wrapper below the web is in any case short and cannot become materially displaced. The part of the wrapper above the article is, however, a. diiferent matter. As soon as the article has clamped the wrapper between it and the backing plunger 4| the wrapper begins to be taken up from the length previously drawn out by the gripper; and it is this part, initially extending above the article to a length equal to almost the width of three sides of the article, that requires control. As the wrapper slides through between the spring 60 and the roll 61 it rotates the roll, which offers much less resistance to the straight passage of the wrapper than it does to slantwise motion.

This drawing out action of the free end of the wrapper continues throughout the motion of the carrier through the positions of Figs. 3 and 4 to the position of Fig. 5, the roll 6'! moving back and forth on the spring 60 in accordance with the position of the pivot 65 relative to the bar 50. In the latter position the pivot has risen to an elevation causing the roll 61 to move laterally a sufficient distance to clamp the wrapper against the roll 21. As will be apparent from Fig. 5, the shifting of control from between roll 61 and spring 60 to between rolls 6! and 21 is substantially instantaneous, so that the control of the wrapper is not lost. During the subsequent upward movement of the carrier from the position of Fig. 5 to that of Fig. 6, the roll 61 remains in contact with the roll 21, since the arms 66 which carry roll 61 are themselves pivoted to and movable with the carrier.

If a particularly tight wrap is desired a refinement of the invention makes it possible to press the rolls 6'! and 2'! together with something more than gravity pressure during the formation of the final flap. For this purpose a plate 10, having a curved end H, is fixed to the channel floor 12 at each side of the machines. As the carrier reaches its highest position these plates contact the ends of the roll 61 and cause it to be pressed firmly against the roll 21, the rubber covering of the roll 61 here affording the necessary resillence. Figs. 6, 7 and 8 show successive stages in the completion of the final flap. The last of these figures shows also the gripper 3| coming in underneath the carrier to pick up the leading end of the web preparatory to drawing out a fresh length of wrapper.

The same control of the wrapper is exercised during the downward travel of the carrier. During the first part of this travel the end of the wrapper is held by the gripper 3| and is therefore under no danger of displacement. Before the gripper relinquishes control the carrier has descended to a point shortly beyond that shown in Fig. 9, so that an intermediate portion of the wrapper will be gripped between the roll 61 and the spring 60. The gripper in this type of wrapping machine releases the end of the wrapper at different points in the descent of the carrier in accordance with the size of the article to be wrapped, and the construction described prevents the wrapper becoming temporarily out of control after its release by the gripper.

The lateral movement of the roll 61 on top of the spring 60, as indicated by a comparison of Figs. 9, 3, 4 and 5, has several useful functions. It will be apparent that as the roll moves over the spring in a direction away from the article it will tend to tighten up the paper around the package, provided that the resistance of the roll to turning is greater than the resistance offered by the spring 60 to the sliding of the wrapper. Due to the rubber surface 68 of the roll 61 the wrapper does not slip on the roll itself, the friction being much greater than any sliding friction between the wrapper and the spring. To regulate the resistance to turning of the roll a friction spring 15 (Fig. 2) is held to a lug l6 and bears on an extension of the steel part of roll 61. The friction offered by the spring can readily be adjusted to give any resistance desired to the turning of the roll. During the turning of the wrapper around the upper right hand corner of the article (as viewed in Fig. 3) the roll 51 is constantly moving away from the article, and at the same time the bar 50 is being lowered by the cam 59 turning out from under it. Both of these actions have a tendency to keep out any formation of slack and to turn the wrapper around the corner of the article with just the tension desired. As the article moves further up its speed of vertical travel is increasing, and the movement ofthe roll 61 back towards the carrier as in Figs. 6 and '7 keeps this increased speed from increasing the tension beyond the point desired.

The vertical motion of bar 50 has also another function of great utility in increasing the range of article sizes with which a given machine can deal; It will be seen from Fig. 1 that the bar 50 must be above the article when the latter is being pushed into the carrier. Were the bar to be fixed in this position enough space would have to be left between it and the channel floor l2 to permit the passage of the gripper as shown in Fig. 8. It is of course desirable to keep the vertical travel of the carrier down as much as possible in order to increase the speed of operation of the machine, and on the other hand it is equally desirable to increase the maximum size of article which can be handled on a machine with a given carrier travel. By moving the bar 50 upwardly as the package goes under it and downwardly as the gripper goes over it, the maximum height of the package that can be wrapped is materially increased. The height of the bar is adjusted for packages of different heights, in order to keep the slant of the paper as small as possible in the position of Fig. 3 and thus to avoid any tendency toward slack. formation as the carrier moves up. In any position of the bar other than that for packages of maximum height its vertical movement is not necessary for space saving purposes. It is preferred to retain the motion, however, as it assists in keeping the proper wrapping tension in the manner described.

The present construction has very material advantages with low packages, it being borne in mind that the bar 50 is set at a correspondingly low level. When the carrier in its upward movement reaches the level of the bar 50, control of the trailing end of the wrapper passes from the spring 60 to the roll 2'! and this latter control persists throughout the remainder of the carriers upward movement. This transfer occurs at different levels for articles of differing heights, and permits substantially uniform wrapper control irrespective of the height of the article,--an effect not previously attained as far as I am aware.

The use of a single roll 61 as described gives a sufiiciently complete control of the wrapper for most practical purposes. There however, a very slight period,not exceeding three or four degrees of the machine cycle,-in which the wrapper is not tightly gripped. This occurs during the transfer of control from spring 60 to roll 21 as in Fig. 5. As an additional refinement I have shown in Fig. 10 a modification in which the control is complete throughout the machine cycle. The only change made in this modification is to replace the single roll 6! by two smaller rolls and 8| set so that roll 80 can contact roll 21 at the same time that roll 8! contacts spring 60. In this construction there is an instantaneous transfer of control without any interference between the action of the two pairs of control elements. It will be apparent that many other changes can be made in the constructions described while remaining within the scope of the invention as defined by the following claims.

I claim:

1. A wrapping machine having, in combination, an article carrier movable between an article receiving and an article discharging station. wrapper feeding means, a wrapper contacting member independent of the carrier and a wrapper contacting member on the carrier, each positioned to contact with the same side of the wrapper, and a rotatable roll engageable with the second side of the wrapper and movable to press the wrapper by gravity first against one and then against the other of said wrapper contacting members.

2. A wrapping machine comprising article feeding and delivery stations located one above the other, an article carrier movable between said stations, wrapper feeding means, means for pushing an article from the feeding station into the carrier, a wrapper contacting member positioned between the two stations and adjacent both to the top of the article as it is pushed into the carrier and to the side of the article as' the carrier moves toward the delivery station, and a second wrapper contacting member having a lost motion connection with the carrier and engageable with the first contacting member when the carrier is at the article receiving station.

3. A wrapping machine comprising article feeding and delivery stations the latter of which is located above the former, an article carrier movable between said stations, wrapper feeding means, means for pushing an article from the feeding station into the carrier, a wrapper contacting member positioned between the two stations and adjacent both to the top of the article as it is pushed into the carrier and to the side of the article as the carrier moves toward the delivery station, a second wrapper contacting member on that edge of the carrier which comes next to the feeding and delivery stations, a pair of arms pivoted at the side of the carrier opposite its article receiving side, and a roll provided with a friction surface and carried by said arms in position to rest by gravity alternately against said wrapper contacting members.

4. A wrapping machine comprising article feeding and delivery stations the latter of which is located above the former, an article carrier movable between said stations, wrapper feeding means, means for pushing an article from the feeding station into the carrier, a wrapper contacting member positioned between the two stations and adjacent both to the top of the article as it is pushed into the carrier and to the side of the article as the carrier moves toward the delivery station, a second wrapper contacting member on that edge of the carrier which comes next to the feeding and delivery stations, a pair of arms pivoted at the sideof the carrier opposite its article receiving side, and a roll provided with a friction surface and carried by said arms in position to rest by gravity alternately against said wrapper contacting members, said first" named wrapper contacting member having a yielding substantially fiat surfaced member against which the friction-surfaced roll rests.

5. A wrapping machine comprising article feeding and delivery stations the latter of which is located above the former, an article carrier movable between said stations, wrapper feeding means, means for pushing an article from the feeding station into the carrier, a wrapper contacting member positioned between the two stations and adjacent both to the top of the article as it is pushed into the carrier and to the side of the article as the carrier moves toward the delivery station, a second wrapper contacting member on that edge of the carrier which comes next to the feeding and delivery stations, a pair of arms pivoted at the side of the carrier opposite its article receiving side, a roll provided with a friction surface and carried by said arms in position to rest by gravity alternately against said wrapper contacting members, said firstnamed wrapper contacting member having a yielding substantially fiat surfaced member against which the friction-surfaced roll rests, and means for limiting the amount of compres* sion given to said yielding member by the weight of the roll.

6. A wrapping machine comprising article feeding and delivery stations the latter of which is located above the former, an article carrier movable between said stations, wrapper feeding means, means for pushing an article from the feeding station into the carrier, a wrapper contacting member positioned between the two stations and adjacent both to the top of the article as it is pushed into the carrier and to the side of the article as the carrier moves toward the delivery station, a second wrapper contacting member on that edge of the carrier which comes next to the feeding and delivery stations, a pair of arms pivoted at the side of the carrier opposite its article receiving side, a roll provided with a friction surface and carried by said arms in position to rest by gravity alternately against said wrapper contacting members, and means for moving the first wrapper contacting member upwardly to permit the passage of an article under it and into the carrier.

7. A wrapping machine having, in combination, an article carrier movable between an article receiving and an article discharging station, wrapper feeding means, a wrapper contacting member independent of the carrier, a wrapper contacting member on the carrier, and mechanism operable to transfer control of the wrapper from the first to the second wrapper contacting member without substantial interruption and while the carrier is a substantial distance from the article discharging station.

8. A wrapping machine having, in combination, an article carrier movable between an article receiving and an article delivering station, a wrapper feeding gripper movable between the carrier and the article feeding station when the carrier is in article delivering position, wrapper control means engaging the wrapper drawn out by the gripper, and means for moving'said control means out of the path of an article as the article is being fed into the carrier and out of the path of the gripper when the latter is moved between the carrier and the article feeding station.

9. A wrapping machine having, in combination, an article carrier movable between an article receiving and an article discharging station, wrapper feeding means, wrapper control means located between said stations and adapted to grasp the trailing end of a wrapper with a greater resistance to sideways motion than to straight motion thereof, and means for adjusting the location of said wrapper control means between the stations in accordance with the size of the article to be wrapped so that the control means may be maintained near the adjacent side of the article as the article moves into the carrier.

10, A wrapping machine having, in combination, an article carrier movable between an article receiving and an article discharging station, wrapper feeding means, wrapper control means located between said stations and adapted to grasp the trailing end of a wrapper with a greater resistance to sideways motion than to straight motion thereof, means for adjusting the location of said wrapper control means between the stations in accordance with the size of the article to be wrapped so that the control means may be maintained near the adjacent side of the article as the article moves into the carrier, and means for moving the control means periodically in a direction counter to the direction of movement of the carrier.

11. A wrapping machine comprising article feeding and delivery stations the latter of which is located above the former, an article carrier movable between the stations, wrapper feeding means, a member extending adjacent the carrier between the stations and having a wrapper guiding surface, a member on the carrier having a wrapper guiding surface, one or more arms pivoted on the carrier upon an axis extending transversely thereto and located substantially above the article supporting surface of the carrier and remote from the article receiving side thereof, and a roll mounted on said arms in position to be supported by the first-named member when the carrier is lowered and to be supported by the member on the carrier when the carrier is elevated.

12. A wrapping machine comprising article feeding and delivery stations the latter of which is located above the former, an article carrier movable between the stations, wrapper feeding means, a member extending adjacent the carrier between the stations and having a wrapper guiding surface, means for adjusting the member vertically in accordance with the size of the article being wrapped, means for periodically reciprocating the member vertically and in a direction counter to the direction of movement of the carrier, one or more arms pivoted on the carrier upon an axis extending transversely thereto and located substantially above the article supporting surface of the carrier and remote from the article receiving side thereof, and a roll mounted on said arms in position to be supported by the first-named member when the carrier is lowered and to be supported by the member on the carrier when the carrier is elevated.

13. A wrapping machine comprising folding means, means for carrying an article past said folding means, and wrapper control means adapted to grasp a wrapper flap projecting from the article and to tension it during the action of said folding means, said wrapper control means comprising a flat surface and a roll pressing the wrapper flap thereagainst.

14. A wrapping machine comprising folding means, means for carrying an article past said folding means, and wrapper control means adapted to grasp a wrapper flap projecting from the article and to tension it during the action to force yielding of said surface.

16. A wrapping machine comprising folding means, means for carrying an article past said folding means, and wrapper control means adapted to grasp a wrapper flap projecting from the article and to tension it during the action of the folding means, said wrapper control means comprising a yielding flat surface, a roll pressing the Wrapper against the flat surface, means for offering resistance to the rotation of the roll, and

means for moving the roll back and forth across said surface to control the tautness of the wrapper between the roll and the article.

17. A wrapping machine having, in combination, an article carrier movable between an article receiving and an article delivering station, wrapper feeding means, a device located at the article receiving station to feed an article and a wrapper onto the carrier with a portion of the wrapper projecting from the article, mechanism normally positioned within the path of an article as it enters the carrier for engaging and controlling the wrapper prior to the contact of the article therewith and for continuing without interruption to engage and control the portion of the wrapper projecting from the article, and means for moving said mechanism out of the path of an article as the article is being fed into the carrier without losing .control of the wrapper.

NORMAN W. LYON.

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