Patent Publication Number: US-6217501-B1

Title: Cushioning conversion machine

Description:
TECHNICAL FIELD 
     This invention relates generally to a transfer device and, more particularly, to a system for transferring a pad from a cushioning conversion machine along a curved path to a work platform for use by an operator. 
     BACKGROUND OF THE INVENTION 
     In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping case, or box, to fill any voids and/or to cushion the item during the shipping process. Some conventional protective packaging materials are plastic foam peanuts and plastic bubble pack. While these conventional plastic materials seem to perform adequately as cushioning products, they are not without disadvantages. Perhaps the most serious drawback of plastic bubble wrap and/or plastic foam peanuts is their effect on our environment. Quite simply, these plastic packaging materials are not biodegradable and thus they cannot avoid further multiplying our planet&#39;s already critical waste disposal problems. The non-biodegradability of these packaging materials has become increasingly important in light of many industries adopting more progressive policies in terms of environmental responsibility. 
     The foregoing and other disadvantages of conventional plastic packaging materials have made paper protective packaging material a very popular alternative. Paper is biodegradable, recyclable and renewable, making it an environmentally responsible choice for conscientious industries. Furthermore, paper protective dunnage material is particularly advantageous for use with particle-sensitive merchandise, as its clean, dust-free surface is resistant to electrostatic buildup. 
     While paper in sheet form could possibly be used as a protective packaging material, it is usually preferable to convert the sheets of paper into a pad-like or other relatively low density dunnage product. This conversion may be accomplished by a cushioning conversion machine, such as those disclosed in commonly assigned U.S. Pat. Nos. 4,968,291 and 5,123,889. The therein disclosed cushioning conversion machines convert sheet-like stock material, such as paper in multi-ply form, into a pad-like dunnage product having longitudinally extending pillow-like portions that are connected together along a stitched central portion of the product. The stock material preferably consists of two or three superimposed webs or layers of biodegradable, recyclable and reusable thirty-pound Kraft paper or the like rolled onto a hollow cylindrical tube. A thirty-inch wide roll of this paper, which is approximately 450 feet long, will weigh about 35 pounds and will provide cushioning equal to approximately four fifteen cubic foot bags of plastic foam peanuts while at the same time requiring less than one-thirtieth the storage space. 
     Specifically, these machines convert the stock material into a continuous strip having lateral pillow-like portions separated by a thin central band. This strip is connected or coined along the central band to form a coined strip which is severed or cut into sections of a desired length. The cut sections each include lateral pillow-like portions separated by a thin central band and provide an excellent relatively low density pad-like product which may be used in place of conventional plastic protective packaging material. 
     As shown in U.S. patent application Ser. Nos. 08/109,124 and 08/155,931, a cushioning conversion machine may be situated below the work platform of a dispensing table. In such an arrangement, the cushioning product, or pad, travels from the generally horizontal machine through an output chute where the pad is directed upwardly to emerge through an opening in the work platform. In this manner, the pad is deposited on the work platform during operation of the machine. Consequently, an operator can conveniently grab the pad and place it in a shipping box to fill any voids and/or to cushion an item in the shipping box. 
     While such a device works well for a number of pads or where sufficiently long pads are being produced, if only a small number of short pads are desired, these short pads may not fully emerge from the output chute and thus cannot be conveniently retrieved by the operator. 
     It would be desirable for a cushioning conversion device, which is situated beneath a work platform, to deposit pads on or at the platform for use by an operator without regard to the length or number of pads produced. 
     SUMMARY OF THE INVENTION 
     The present invention provides a powered output drive system which drives a pad from a machine exit portion upwardly to a work platform. The output chute includes a number of rollers which cooperatively engage the pad as it is being produced and urge the pad upwardly toward the work platform. 
     In accordance with one aspect of the invention, a system for transferring a pad from a cushioning conversion machine includes an upper series of drive elements arranged in a generally arcuate path, a lower series of drive elements arranged in a generally arcuate path, and a motor for powering the rotation of the upper and lower series of drive elements, the upper and the lower series of drive elements being spaced to accommodate a pad therebetween and transfer it along a path defined by the upper and lower series of drive elements. 
     In accordance with another aspect of the present invention, a cushioning conversion machine, located below a work table, includes a stock supply assembly, a conversion assembly for converting the stock material into a cushioning product and providing it through a machine exit, and a cushioning product transferring system including an upper series of rollers arranged in a path, a lower series of rollers arranged in a path and a motor for powering the rotation of the rollers, the upper and the lower series of rollers defining a path therebetween leading from the machine exit to a passage in the work table. 
     In accordance with a further aspect of the present invention, a method of transferring a cushioning product from a cushioning conversion machine includes the steps of engaging a portion of the cushioning product between opposed drive elements and transferring the cushioning product along an at least partially curved path based on movement of the drive elements, sensing the cushioning product reaching an exit location and, after a delay adequate for the cushioning product to continue its progress past the exit location to partially emerge from the path adequate to be grasped for removal by an operator, ceasing the movement of the drive elements, and providing a signal to the cushioning conversion machine to produce a further cushioning product after the cushioning product at the exit location has been removed. 
     The foregoing and other features of the invention are hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principles of the invention may be employed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a cushioning conversion machine and a curved output drive system for transferring a pad from the machine to a work platform in accordance with one embodiment of the present invention; 
     FIG. 2 is a front elevational view of the cushioning conversion machine and output drive system of FIG. 1; 
     FIG. 3 is an enlarged side view of the output drive system; 
     FIG. 4 is an enlarged front view of the output drive system; 
     FIG. 5 is an illustration of the output drive system depicting the direction of rotation of the drive rollers; and 
     FIGS. 6A and 6B are illustrations of a pad being transferred through the output drive system. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings in detail and initially to FIGS. 1 and 2, there is shown a cushioning conversion machine  10  for producing low density cushioning product with a curved output drive system  12  for transferring pads upwardly from the exit  14  of the machine to a work platform  16  of a dispensing table  18 . 
     The machine  10  includes a frame  20  to which are mounted a supply assembly  22  at the upstream end  24  of the frame for supplying stock material to be converted into a cushioning product, a conversion assembly  26  for converting the stock material into a continuous strip of cushioning product and a severing or cutting assembly  28  located generally between the conversion assembly and output drive system  12  at the downstream end  30  of the machine  10  for severing the strip into cushioning pads of the desired length. (The terms “upstream” and “downstream” in this context are characteristic of the direction of flow of the stock material through the machine  10 .) 
     The stock supply assembly  22  preferably includes a shaft  32  for supporting a roll of sheet-like stock material (not shown) and a number of rollers  34  for providing the stock material to the conversion assembly  26 . The stock material may consist of three superimposed webs of biodegradable, recyclable and reusable thirty-pound Kraft paper or the like rolled onto a hollow cylindrical tube. The conversion assembly  26  includes a forming assembly  36 , such as a cooperating three dimensional wire former  38  and converging chute  40  as is shown in FIG. 1, and a feed assembly  42  including a pair of gears  44  for pulling the stock material through the forming assembly and feeding it through an outlet to the cutting assembly  28  and the curved output drive system  12 . The severing or cutting assembly  28  may include one or more blades or other means acting to sever the continuous strip of padding at the appropriate times. 
     The machine frame  20  is supported on a cart  46  including a plurality of vertical support members or legs  48 , each ending in a caster  50  to permit the machine  10  to be moved with relative ease. Preferably, the support members  48  include a fixed upper portion  52  and a telescoping lower portion  54  which moves in and out of the interior of the fixed portion to permit vertical adjustment of the machine  10  and output drive system  12  under the dispensing table  18  and accurate alignment between the exit  56  of the output drive system and the passage  58  through the work platform  16  of the dispensing table  18 . Preferably the legs  60  of the dispensing table  18  are also adjustable to facilitate alignment with and more preferably a connection between the curved output drive system  12  and the dispensing table. 
     The output drive system  12 , as discussed more fully below, forms the connection between the cushioning conversion machine  10  and the dispensing table  18  and includes a series of upper and lower rotating drive rollers  66 ,  67 , respectively, spaced in an arc along a curved guide path  68  for engaging and transferring a pad from the machine exit  14  along the guide path and upwardly and through the passage  58  in the work platform  16  to present the formed and cut pad at or on the work platform. The upper and lower series of drive rollers  66 ,  67  are powered through a connection to a motor  70  and an assembly of gears  72 . 
     During operation of the machine  10  and output drive system  12 , the stock supply assembly  22  supplies the stock material to the forming assembly  36 . The wire former  38  and converging conical chute  40  of the forming assembly  36  cause inward rolling of the lateral edges of the sheet-like stock material to form a continuous strip having lateral pillow-like portions. The gears  44  of the feed assembly  42  pull the stock material downstream through the machine and also coin the central band of the continuous strip to form the coined strip. As the coined strip travels downstream from the feed assembly  42  it passes through the cutting assembly  28  to the output drive system  12  where it is frictionally engaged on its opposed upper and lower surfaces by the rotating upper and lower series of drive rollers  66 ,  67  which transfer the pad along the guide in the direction of the work platform  16 . Once a pad of the desired length has been cut by the cutting assembly  28 , the series of drive rollers  66 ,  67  will continue to transfer the cut pad upwardly through the passage  58  in the work platform to deposit the formed and cut pad on the work platform for use as needed by the operator. 
     As shown in greater detail in FIGS. 3 through 5, the curved output drive system  12  includes a frame  80  having parallel side walls  82 ,  84  and a bottom wall  86 . Extending perpendicular to and between the side walls  82  and  84  are a pair of curved guide walls  88 ,  90  defining the arcuate guide path  68  therebetween. Each guide wall  88  and  90  includes a number of openings  92  through which a circumferential portion of a drive roller protrudes into the guide path  68  to engage the surface of the pad. Each drive roller of the upper and lower series of drive rollers  66 ,  67  extends laterally for substantially the entire distance between the side walls  82  and  84  on a shaft  94  extending through each side wall and further includes a number of axially separated circumferential channels or grooves each serving to retain an elastomeric O-ring  93  for improving the ability of a drive roller to frictionally engage a pad. The shafts  94  are positioned and the rollers are sized so that an appropriate section of each drive roller protrudes through a corresponding opening  92  in the guide walls  88  and  90  to effectively engage and transfer a pad through the guide path  68 . It should be understood that the distances between the outer peripheries of the opposed upper and lower series of drive roller  66 ,  67  are less than the thickness of the pad passing therebetween, thereby sufficiently compressing the pad to permit the transfer thereof. The shaft  94  of the first drive roller  96  in the lower series of drive rollers  67  extends through the side wall  82  to a clutch mechanism  98  for selectively coupling the first drive roller  96  with the motor  70 . Rotational motion is transferred from the motor  70  mounted to the bottom wall  86  to the first drive roller  96  through a drive pulley  102  connected to the motor shaft  104  and a belt  106  extending between the drive pulley and a pulley  100  connected to the clutch mechanism  98 . Consequently, when engaged the clutch mechanism  98  transfers rotational movement from the motor  70  to the first drive roller  96  through the shaft  94 . When disengaged, the clutch mechanism conversely prevents the transfer of rotational movement from the motor  70  to the first drive roller  96 . 
     Opposite the pulley  100 , a pair of gears  108  and  110  are connected to the distal end of the shaft  94  of the first drive roller  96  extending through side wall  84 . The shaft  94  of the second drive roller  114  of the lower series of drive rollers  67  extends through side wall  84  for connection to a gear  116  in communication with the gear  110  of the first drive roller  96  through a transfer gear  118  rotatably mounted on a shaft  120  extending from the side wall  84 . Consequently, rotation of the first drive roller  96  causes rotation of the second drive roller  114  in the same direction through common connection with the transfer gear  118 . Similarly, rotational motion is transferred from drive roller  114  to the next drive roller, drive roller  122 , and so on for all of the drive rollers of the lower series  67 . 
     Rotational motion is transferred to the upper series of drive rollers  66  by an enmeshed connection between the gear  108  associated with the first drive roller  96  of the lower series of drive rollers  67  and a gear  124  adapted to drive the first drive roller  132  of the upper series of rollers  66  through the shaft  94 . Rotational motion is transferred to the second drive roller  138  though a transfer gear  126  rotatably mounted on a shaft  128  extending from the side wall  84  and enmeshed with the gear  125  of the drive roller  132  and gear  134  connected to drive roller  138  through an associated shaft  94 . The drive roller  138  causes rotation of the drive roller  140  through the transfer gear  142  in the same manner. Since the gear  108  transfers rotation from the first drive roller  96  of the lower series of drive rollers  67  to the drive roller  136  of the upper series of drive rollers  66  directly through the gear  124  connected to the drive roller  136 , the direction of rotation of the upper series of drive rollers  66  is opposite that of the lower series of drive rollers  67  (see directional arrows in FIG.  5 ). Therefore, the upper and lower series of drive rollers  66 ,  67  will act cooperatively in urging a pad compressed therebetween in the same direction through the guide path  68 , namely a direction away from the cushioning conversion machine to the dispensing table  18 . 
     Operation of the curved output drive system  12  and assisted operation of the cushioning conversion machine  10  is accomplished through one or more sensors  146  and  148 . Each of the sensors  146  and  148  may be conventional sensors for detecting the presence or absence of a pad adjacent the sensor. An example of a suitable sensor would be an optical sensor with a corresponding retro-reflector positioned at an opposite side of the path  68  from the optical sensor. 
     The sensor  146  is positioned near the exit portion  56  of the system  12  and senses the presence or absence of a pad at the exit portion  56 . The output of the sensor  146  controls the clutch mechanism  98 , preferably in combination with a timer or delay circuit (hereinafter the timer and sensor  146  are collectively referenced by the reference numeral  146 ), so that once a pad is sensed at the exit portion  56  by the sensor  146 , transfer of the pad will continue for a short period of time, as controlled by the timer, sufficient to permit an adequate amount of pad to emerge from the passage  58  in the work platform  16  that an operator can easily access and remove the pad. Once such time has elapsed, the clutch mechanism  98  is disengaged, thereby discontinuing movement of the upper and lower series of drive rollers  66  and  67  and ceasing movement of the pad. The clutch mechanism  98  will remain disengaged until an operator removes the pad from the output drive system  12 , and such removal is detected by the sensor  146 . The output of the sensor  146  may also be provided to the machine  10  which can use the information to control production of pads such that when a pad is removed from the output drive system  12 , as detected by the sensor  146 , the machine will automatically produce another pad. The automatically produced pad will be conveyed by the output drive system  12  (as the clutch mechanism  98  is engaged since the sensor  146  is not blocked by a pad) to begin to emerge from the work platform  16  whereupon the sensor will detect the pad and the clutch mechanism  98  will be disengaged (after a short time period) and the machine will again wait for the partially emerged pad to be removed by an operator before producing another pad. 
     When the output of the sensor  146  is used by the machine  10  in controlling the automatic production of a pad as a pad is used by an operator, and especially when the pad length may be short, in relation to the length of the guide path  68 , it is preferable to locate the sensor  148  midway between the machine exit  14  and the exit portion  56  of the output drive system  12  and to provide the output of the sensor  146  to the machine  10 . As a pad progresses past the sensor  148 , the sensor  148  detects the presence of the pad and reports the fact to the machine  10 . The machine  10  examines the output of the sensor  148 , when the sensor  146  has reported that a pad has been removed, to ensure that another pad is not already in the output drive system  12  before producing a further pad. The sensor  148  is also provided with a timer or delay circuit so that the timer  148  will continue to indicate the presence of another pad in the output drive system, even after the pad has progressed past the sensor  148  to give the pad adequate time to reach the sensor  146  located at the output. This ensures that the machine will not produce a pad when a short pad is in the output drive system, but located wholly within the “blindspot” between the sensors  146  and  148 . 
     In some instances the motor  70  or clutch mechanism  98  may be controlled by a process controller or similar circuity in the cushioning conversion machine  10  to cause the upper and lower drive rollers  66  and  67  to operate either continuously or only while a pad is being produced and a short period thereafter adequate to transfer the pad to the dispensing table  18 . The motor  70  or clutch mechanism  98  may also be controlled to pause movement of the drive rollers during a cutting operation by the cutting assembly  28 . In an instance where pads are to be produced which may be of the same length or longer than the guide path  68 , it is desirable that the process controller of the cushioning conversion machine cause the clutch mechanism  98  to remain engaged whenever the feed assembly  42  is operating. 
     As an example of the operation of the curved output drive system  12 , attention is directed to the pad  150  shown in FIGS. 6A and 6B. Once the pad  150  leaves the machine exit  14  it enters the curved output drive system  12  at entry portion  152  and is compressed and engaged by opposed drive rollers  96  and  136  (see FIG.  6 A). The rotation of the drive rollers  96  and  136  causes the pad  150  to move through the guide path  68  in the direction of arrow  154  (see FIG.  6 B). Continued rotation of the drive rollers in the upper and lower series of drive rollers  66 ,  67  moves the pad  150  further along the curved guide path  68 , past the sensor  148 , and causing pad  150  to pass the sensor  146 . For a short period of time after the sensor  146  has detected the pad  150 , as determined by the timer associated with the sensor  146 , the clutch mechanism  98  will remain engaged to further drive the pad  150  to emerge from the exit port  156  for a distance sufficient to allow an operator to grasp the pad and remove it, when needed, from the output drive system  12 . After that short duration, the clutch is disengaged and the pad  150  remains partially emerged from the output drive system  12  and the work platform  16  of the dispensing table  18  to present the pad to the operator at the work platform (FIG.  1 ). 
     Although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications, and is limited only by the scope of the following claims. Furthermore, the corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or acts for performing the functions in combination with other claimed elements as specifically claimed.