Winding Device

Abstract

A winding device generally includes a spool, which includes a shaft, a sleeve rotatably coupled to the shaft such that the sleeve and the shaft are capable of partial independent rotation relative to one another, with the sleeve adapted to receive thereon a core onto which a web of material may be wound, and one or more gripping members, which are adapted to engage the core upon relative rotation of the shaft in a first direction, and disengage the core upon relative rotation of the shaft in a second direction.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a winding device for winding a web of material onto a core and, more particularly, to an improved winding device for webs comprising inflated cushioning material.

Various machines for forming inflated cushioning material are known, which produce inflated cushioning from a web of un-inflated material by inflating and sealing closed gas-containing chambers within the material. Such cushioning is used to package items, by wrapping the items in the cushions and placing the wrapped items in a shipping carton, or simply placing one or more inflated cushions inside of a shipping carton along with an item to be shipped. The cushions protect the packaged item by absorbing impacts that may otherwise be fully transmitted to the packaged item during transit, and also restrict movement of the packaged item within the carton to further reduce the likelihood of damage to the item. At the same time, the end-user can inflate and use as desired, without having to store large volumes of pre-inflated cushioning material.

In many instances, it is desired to inflate cushioning material, and store small quantities of the material for subsequent use, typically by winding the inflated material into a roll. Existing winding devices for this purpose are not as efficient or convenient as would otherwise be desired.

Accordingly, there remains a need in the art for improved web-winding devices, which are more effective and easier for operators to use.

SUMMARY OF THE INVENTION

Those needs are met by the present invention, which, in one aspect, provides a winding device comprising a spool, the spool comprising:

a. a shaft;

b. a sleeve rotatably coupled to the shaft such that the sleeve and the shaft are capable of partial independent rotation relative to one another, the sleeve enclosing at least a portion of the shaft and adapted to receive thereon a core, onto which a web of material may be wound; and

c. one or more gripping members, which are adapted to engage the core upon relative rotation of the shaft in a first direction, whereby the core rotates with the shaft to allow the web to be wound onto the core, the gripping members being further adapted to disengage the core upon relative rotation of the shaft in a second direction, whereby the core may be removed from the sleeve.

A further aspect of the invention is directed to a winding device comprising a spool, said spool comprising:

a. a shaft;

b. a sleeve rotatably coupled to the shaft such that the sleeve and the shaft are capable of partial independent rotation relative to one another, the sleeve enclosing at least a portion of the shaft and adapted to receive thereon a web of material such that the web may be wound onto the sleeve; and

c. one or more gripping members, which are adapted to engage the web upon relative rotation of the shaft in a first direction, whereby the web rotates with the shaft and is thereby wound into a roll on the sleeve, the gripping members being further adapted to disengage the web upon relative rotation of the shaft in a second direction, whereby the roll may be removed from the sleeve.

Yet another aspect of the invention is directed to a winding device, comprising:

a. a spool adapted to receive thereon a core, onto which a web of material may be wound, the web being supplied to the spool at a predetermined speed;

b. a drive mechanism coupled to the spool to drive the rotation thereof at a predetermined rotational speed;

c. a sensor, which monitors the rotational speed of the spool and generates a signal indicative of the rotational speed; and

d. a controller in communication with the sensor to receive the signal as a first input, the controller also receiving, as a second input, an indication of the speed at which the web is supplied to the spool, wherein, the controller calculates a diameter of the web as it is wound onto the core.

These and other aspects and features of the invention may be better understood with reference to the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a system having an inflation/sealing apparatus that produces a web of inflated cushioning material, and a winding device in accordance with the present invention for winding the web onto a core;

FIG. 2 is a partial perspective view of the winding device shown in FIG. 1, featuring a spool and a core that may be received on the spool;

FIG. 3 is a partially-exploded perspective view of the spool shown in FIG. 2;

FIG. 4 is a cross-sectional view of the spool shown in FIG. 2;

FIG. 5 is a frontal, elevational view of the spool, showing the gripping members of the spool moving from a disengagement position to an engagement position;

FIG. 6 is similar to FIG. 5, except taken along lines 6-6 in FIG. 4 to show the gripping members in the engagement position;

FIG. 7 is similar to FIG. 6, except showing the gripping members moving from the engagement position to the disengagement position;

FIG. 8 is a schematic view of a control system for the winding device; and

FIG. 9 is a plan view of the inflated cushioning material as shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a system 10 for inflating, sealing, and winding a web 12 of material into a roll 14. Roll 14 is shown in phantom for clarity. System 10 generally includes an inflation and sealing apparatus 16 and a winding device 18. The inflation/sealing apparatus 16 may be any suitable device for producing a web, e.g., of inflated cushioning material, as described, e.g., in U.S. Pat. No. 7,220,476 or in U.S. Publication No. US 2010-0251665 A1, the disclosures of which are hereby incorporated herein by reference thereto. As further described in the foregoing references and illustrated in FIG. 9, the web 12 produced by apparatus 16 may be an inflated cushioning material 20. Inflated cushioning material 20 may be formed from two superposed film sheets 19, and may include rows of inflated chambers 22, wherein each of the chambers 22 has at least one change in width over their length, e.g., with two inflatable sections of relatively large width 24 connected by relatively narrow inflatable passageways 26. As shown, the large sections 24 may be substantially spherical or hemispherical in shape, e.g., resembling bubbles or the like. Cushioning material 20 may further include inflation ports 28 located at a proximal end of each chamber 22, with the inflation ports being formed by intermittent seals 30 between the sheets 19. As each chamber 22 is inflated, apparatus 16 continuously forms a seal line 31 at the corresponding inflation port 28 to enclose the inflation gas within each chamber. As shown in FIG. 1, un-inflated web 32 may be supplied to the inflation/sealing apparatus 16 in the form of a roll 34, which is then conveyed through the apparatus via suitable drive rollers or the like, wherein the chambers 22 are sequentially and continuously inflated and sealed closed, to produce the inflated cushioning material 20 as shown in FIG. 9.

It should be understood that the present invention is not limited to inflatable webs of the type as described above, but may be used with any web that can be wound onto a core, e.g., thermoplastic film, paper, etc.

Winding device 18 may include a base 36, a stanchion 38, and a spool 40, extending in cantilevered fashion from stanchion 38. In some embodiments, a drive mechanism, e.g., a motor (not shown), may be housed in base 36, with suitable mechanical linkage (not shown) in stanchion 38 to join the drive mechanism to the spool 40, e.g., a belt, chain, gear train, etc. In such embodiments, an on/off switch 42 for the motor may be provided, e.g., on stanchion 38 (see FIG. 2).

As shown in FIGS. 2-4, spool 40 may include a shaft 44, a sleeve 46, and one or more gripping members 48. In the illustrated embodiment, four (4) such gripping members 48 are included in spool 40. As will be explained in further detail below, sleeve 46 is rotatably coupled to shaft 44, such that the sleeve and shaft are capable of partial independent rotation relative to one another. Further, sleeve 46 encloses at least a portion of the shaft 44, and is adapted to receive thereon a core 50, onto which web 12, e.g., comprising inflated cushioning material 20, may be wound (see also FIG. 1). As shown, shaft 44 may be coupled to sleeve 46 via a rotary mounting bracket 52. As also shown, a sleeve extension member 53 may be affixed to spool 40, e.g., at rotary mounting bracket 52. Such extension member 53 may be included as necessary to accommodate the length of core 50, e.g., such that the resultant sleeve-length of the spool 40 may approximate that of the core 50. In this manner, cores of various lengths, corresponding to webs 12 of various widths, may be accommodated by winding device 18. The extension member 53 may further include an end-cap 55, which may have a rounded outer surface in order to facilitate the placement of a core 50 on sleeve 46, as extended by member 53, as shown in FIG. 2.

Referring now to FIGS. 5-7, the operation of spool 40 will be described in further detail. As noted above, sleeve 46 is rotatably coupled to shaft 44, such that the sleeve and shaft are capable of partial independent rotation relative to one another. Moreover, gripping members 48 are adapted to engage a core 50 received on sleeve 46, upon relative rotation of shaft 44 in a first direction. FIGS. 5-6 illustrate these features. In FIG. 5, a core 50 (shown in phantom) has been placed over sleeve 46 as shown in FIG. 2. FIGS. 5-6 illustrate a sequence of events by which the gripping members 48 engage the core upon relative rotation of shaft 44 in first direction 54, whereby the core 50 rotates with shaft 44, i.e., also in first direction 54, to allow the web 12 to be wound onto the core, e.g., as shown in FIG. 1. As shown in FIG. 7, gripping members 48 are further adapted to disengage the core 50 upon relative rotation of shaft 44 in a second direction 56, whereby the core 50 may be removed from sleeve 46, e.g., when roll 14 of web 12 has reached a desired size.

Gripping members 48 are adapted, i.e., structured and arranged, to both engage and disengage the core, based on the coupled relationship between the shaft 44 and sleeve 46, wherein the shaft and sleeve are capable of partial independent rotation relative to one another. In some embodiments, this may be achieved when shaft 44 is rotatably mounted in rotary mounting bracket 52, and the bracket 52 is affixed to sleeve 46, e.g., via fasteners 58 (FIGS. 3-4). Fasteners 58 may be in the form of screws (as illustrated), welded joints, etc. Shaft 44 may include a bushing 60 or the like to facilitate rotational movement of the shaft against the bracket 52, e.g., against an inner surface of the bracket as illustrated.

The gripping members 48 may be attached to shaft 44, e.g., at the distal end 62 thereof. In the illustrated embodiment, distal end 62 of shaft 44 is relatively wide to accommodate four (4) gripping members 48, and is in the form of a platform, which is affixed to an end region 64 of shaft 44. Other arrangements are, of course, also possible, such as a widened distal end 62 being integral with shaft 44; the distal end 62 not being widened, e.g., the same diameter as the rest of shaft 44; a greater or lesser number of gripping members 48; etc.

As shown in FIG. 5, the gripping members 48 may have a proximal end 67 and a distal end 68, wherein the proximal end 67 is attached to shaft 44, e.g., at the distal end 62 thereof. The attachment of the gripping members 48 to shaft 44 may be a pivotal attachment, i.e., such that the gripping members 48 are pivotally attached at proximal end 67 to the shaft, e.g., via pivotal fasteners 69.

Accordingly, a part, e.g., distal end 68, of each gripping member 48 may move in the direction of arrow 66 (FIG. 5) away from shaft 44 and into an engagement position (FIG. 6), in which the gripping members engage the core 50, when shaft 44 rotates in first direction 54. Such movement 66 may generally be a rotation-to-translation type of movement, as will be described in further detail below, as produced by the rotation of shaft 44 in first direction 54, and facilitated by the pivotal attachment of gripping members 48 to shaft 44. Similarly, as shown in FIG. 7, the part, e.g., distal end 68, of the gripping members 48 that are in the engagement position of FIG. 6, may also move in the direction of arrow 70 towards the shaft 44 and into a disengagement position, in which the gripping members disengage the core 50, when the shaft 44 rotates in second direction 56.

As shown in FIGS. 3-7, rotary mounting bracket 52 may include one or more guide slots 72. Further, each of the gripping members 48 may include a guide pin 74, which is movable within a corresponding one of the guide slots 72. As will be explained in further detail below, the guide slots and guide pins cooperate to facilitate movement of the gripping members 48 into the engagement position shown in FIG. 6, and also the return movement of the gripping members into the disengagement position shown in FIG. 7.

In the illustrated embodiment, slots 72 provide a substantially linear path, and are positioned at an angle relative to a radial direction extending from the center of shaft 44 and outwards towards sleeve 46. Further, the gripping members 48 are pivotally attached at their proximal end 67 to shaft 44, with guide pins 74 being spaced from pivotal fasteners 69 and moving within a corresponding one the guide slots 72. With such an arrangement, it may be seen from FIGS. 5-7 that the rotational movement of shaft 44 is converted into translational movement by the distal ends 68 of the gripping members 48. Thus, distal ends 68 of the gripping members move away from shaft 44 in direction 66, and into the engagement position shown in FIG. 6, when the shaft rotates in first direction 54, as guide pins 74 move translationally in guide slots 72 in the direction of arrow 76 (FIG. 5). In the reverse situation, i.e., when it is desired to remove roll 14 from spool 40, distal ends 68 of the gripping members move towards shaft 44 in the return direction 70, and into the disengagement position shown in FIG. 7, when the shaft rotates in opposing second direction 56, as guide pins 74 move translationally in guide slots 72 in the direction of arrow 78 (FIG. 7), which is the reverse of direction 76 (FIG. 5).

As noted above, sleeve 46 is rotatably coupled to shaft 44, such that the sleeve and shaft are capable of partial independent rotation relative to one another. The partial nature of such relative rotation is perhaps best shown in FIG. 6, wherein the guide pins 74 have reached the outer ends 80 of the guide slots 72. As shown, the outer ends 80 serve to prevent further outward travel of the pins 74 in slots 72, and thus also further outward movement of the distal ends 68 of gripping members 48. Because the gripping members are attached to shaft 44 (at proximal ends 67), at the point where the pins 74 reach the outer ends 80 of the slots 72, shaft 44 can no longer rotate in first direction 54 independently of sleeve 46. Instead, if/when pins 74 reach ends 80 of slots 72 as shown in FIG. 6, the sleeve 46 is forced to rotate with shaft 44 in direction 54, such that the shaft 44 and sleeve 46 thereafter rotate together in direction 54 for the remainder of the winding operation for the roll 14 then being made. Similarly, the inner ends 82 of guide slots 72 delimit the extent to which shaft 44 can rotate in second direction 56 independently of sleeve 46 (FIG. 7).

More significantly, the extension of gripping members 48 into the engagement position shown in FIG. 6 enables them to engage the core 50 and cause the core to rotate with shaft 44, thereby allowing web 12 to be wound onto the core. In some instances, the gripping members 48 will need to extend fully to engage the core 50, i.e., with pins 74 reaching the ends 80 of slots 72. In other instances, e.g., when the inner diameter of core 50 is just larger than the outer diameter of sleeve 46, the gripping members 48 will not extend fully when engaged with core 50. In such instances the pins 74 will not reach the ends 80 of slots 72; rotation of sleeve 46 will then be caused by the force of the pins 74 against the side walls of the slots 72.

In some embodiments, the distal ends 68 of the gripping members 48 may have a roughened or knurled surface, and/or be made to have acute edges as shown, in order to facilitate the ability of the distal ends 68 to engage, i.e., grip, the inner diameter of the roll 50.

In various embodiments of the invention, the distal ends 68 of the gripping members 48 will be within the diameter of sleeve 46 when the gripping members are in the disengagement position (FIG. 5), and will extend beyond the diameter of sleeve 46 when the gripping members are in the engagement position (FIG. 6). In FIGS. 5-7, the diameter of sleeve 46 is indicated as “D1.” As also shown, the distal ends 68 of gripping members 48 together form a diameter, which is indicated as D2. In FIG. 5, the gripping members 48 are in the disengagement position—in this configuration, it may be seen that D2 is less than D1. In FIG. 6, on the other hand, the gripping members 48 are in the engagement position, wherein D2 is greater than D1, such that the distal ends 68 extend beyond D1 to engage the core 50.

In FIG. 7, the gripping members 48 are in the process of returning to the disengagement position (D2<D1) via relative rotation of shaft 44 in second direction 56, whereby core 50 may be removed from sleeve 46, e.g., when web roll 14 has reached a desired size. The operator of system 10 may cause this to occur, for example, by simply pressing on/off switch 42, which cuts drive power to shaft 44. The rotational inertia of roll 14 will cause it to continue to rotate in direction 54 as shown. Because shaft 44 will then no longer be driven, the inertial rotation of roll 14 will cause its rotational speed to exceed that of the shaft, such that independent rotation of the shaft 44, relative to sleeve 46, in second direction 56 will occur, thereby causing the gripping members 48 to retract to the disengagement position as shown in FIG. 7.

In some embodiments of the invention, web 12 may be wound onto sleeve 46 without a core 50, thereby forming a ‘core-less’ roll 14. In such embodiments, sleeve 46 may be adapted to receive thereon web 12 such that the web may be wound directly onto the sleeve. The sleeve may be adapted in this regard, e.g., by being constructed of a material that provides sufficient friction with the web to allow at least the initial process of winding to begin, in some cases with some assistance by the operator, e.g., by holding the leading edge of the web against the sleeve with a flat piece of wood or the like until the first few overlapped windings of the web have been created. At that point, the gripping members 48 will have moved into the engagement position to engage the web directly, i.e., upon relative rotation of shaft 44 in first direction 54, whereby the web 12 rotates with the shaft and is thereby wound into a roll on sleeve 46. As with the previously-described embodiments, the gripping members 48 subsequently disengage the web, i.e., move into the disengagement position, upon relative rotation of shaft 44 in second direction 56, e.g., when the thusly-formed roll has reached a desired size, whereby the roll may be removed from the sleeve.

Referring now to FIG. 8, additional features of the present invention will be described. Winding device 18 may further include a drive mechanism 84, which is schematically indicated as “D” in FIG. 8. Drive mechanism 84 is coupled to shaft 44, schematically indicated at 85, e.g., a mechanical coupling, in order to drive the rotation of the shaft at a predetermined rotational speed. In many embodiments, such speed is selected by the operator of system 10 such that the wind-up rate of winding device 18 approximates the rate at which the inflated web 12 is supplied by inflation/sealing apparatus 16, e.g., such that the web remains relatively taut during its transit from apparatus 16 to winding device 18. As the size of roll 14 increases on spool 40/core 50, the rotational speed of the shaft 44 will, of necessity, decrease, for a given web feed-rate from apparatus 16.

The drive mechanism 84 can be any conventional device capable of producing rotational power, such as a pneumatic, hydraulic, or electric motor, e.g., an AC or DC motor. In some embodiments, the drive mechanism may be an electric motor contained in base 36, and supplied with power via power cord 86, which supplies electric power to both the inflation/sealing apparatus 16 and winding device 18.

Winding device 18 may further include a controller 88 and a sensor 90, as represented schematically in FIG. 8 as “C” and “S,” respectively. The sensor 90 monitors the rotational speed of shaft 44, and generates and sends a corresponding signal 92 to controller 88, which is indicative of such rotational speed. Based, at least in part, on signal 92, controller 88 calculates a diameter of the web 12 as it is wound into roll 14 on core 50. For example, when web 12 is supplied to spool 40 from apparatus 16 at a predetermined web speed “W”, controller 88 may calculate the diameter of roll 14 (Dia₁₄) by dividing the web speed “W” by the rotational speed “R” of shaft 44, as determined by sensor 90, and dividing the result by pi (π), so that:

Dia₁₄=W/R·π

For example, if the web speed W of web 12 from apparatus 16 is 60 feet/minute, and the detected rotational speed “R” of shaft 44 is 2.5 revolutions/minute, 24 feet of web 12 is added to roll 14 for every revolution of shaft 44 (W/R=60/2.5=24), which means that the circumference of roll 14 at that instant is 24 feet. When this number is divided by pi (π), the diameter of roll 14 may be determined by controller 88 to be 7.6 feet (diameter=circumference/π).

Thus, in accordance with an embodiment of the present invention, controller 88 may be in communication with sensor 90 to receive signal 92 as a first input. System 10 may be configured such that controller 88 also receives, as a second input, an indication of the speed at which web 12 is supplied to spool 40. Such indication may be in the form of a signal 98, which may be transmitted to controller 88 by a web speed indicator 100, schematically shown as “W” in FIG. 8. Web speed indicator 100 may be a web speed sensor, which physically measures the speed of web 12 as it moves from apparatus 16 to winding device 18. Alternatively, web speed indicator 100 may be supplied by the operator of system 10, e.g., via a key pad or other operator interface device; may be a fixed, e.g., pre-programmed, value; or may be communicated in real time by apparatus 16, e.g., via suitable wiring so that apparatus 16 communicates with controller 88 to supply signal 98 as an indication of the speed at which web 12 is being produced and supplied to spool 40. In this manner, controller 88 calculates a diameter of web 12 as it is wound onto core 50 to form roll 14.

Controller 88 may be in the form of a printed circuit assembly, and include a control unit, e.g., an electronic control unit, such as a microcontroller, which stores pre-programmed operating codes; a programmable logic controller (PLC); a programmable automation controller (PAC); a personal computer (PC); or other such control device. Commands may be supplied to the controller 88 via an operator interface or the like, or may be supplied remotely or substantially completely via pre-programming, i.e., to operate system 10 in a substantially fully-automated fashion.

Sensor 90 may be any conventional device for detecting and counting the rotations of an object, such as shaft 44, and generating a corresponding electronic signal 92. The detection of the rotation of shaft 44 is represented by arrow 96. A suitable device for sensor 90 is one that uses mechanical contact to detect rotation, such as an encoder or tachometer, or one that uses non-mechanical detection means, such as an optical sensor, e.g., a laser-based optical sensor.

The foregoing ability of controller 88 to continuously determine the diameter of roll 14 as the roll is being produced allows winding device 18 to provide a number of beneficial features in a system, such as system 10.

For example, the controller 88 may be made operative, e.g., via suitable programming, to stop the rotation of shaft 44, e.g., via signal 94 to drive mechanism 84, when the diameter of the web 12 as roll 14 on core 50 reaches a predetermined value. This frees the operator of system 10 to perform other tasks, i.e., instead of idly monitoring system 10 to press on/off switch 42 when the diameter reaches the predetermined value. For instance, if a roll diameter of 8 feet is desired, the controller will send signal 94 to drive mechanism 84, causing the drive mechanism to cease driving the rotation of shaft 44, e.g., via a suitable electronic switch (transistor or the like), which acts as an on/off switch for the supply of power to the drive mechanism. Such signal 94 would preferably also cause apparatus 16 to cease operation, e.g., via the same electronic switch as for drive mechanism 84, through which power supplied by power cord 86 may flow to both the apparatus 16 and winding device 18. When convenient, the operator can then remove the roll 14, insert another core 50 on spool 40, attach the end of a web 12 to the core, and then cause power to once again be supplied to apparatus 16 and winding device 18 to begin the production of a new roll 14.

As another example, the controller 88 may be operative to vary the output of drive mechanism 84 in order to maintain a substantially constant tensional force on the web 12 as it is wound onto core 50. That is, in order to wind web 12 onto spool 40/core 50, the drive mechanism 84 applies torque to the spool 40, thereby producing a tensional force 102 on web 12 as it is wound onto the core 50. One of the challenges of making large rolls 14, e.g., having diameters in excess of about four feet, e.g., 6 or even 8 feet, from inflated cushioning material 20, is that such rolls tend to be uneven and/or loosen, which leads to difficulty in handling the rolls for storage and subsequent use, e.g., often resulting in the material 20 falling off of the roll. The inventors have found that large rolls 14 of inflated cushioning material 20 can be can be successfully made when the web 12 remains under a substantially constant tensional force. This results in a uniform, tightly-wound roll 14.

However, the torque required of drive mechanism 84 to provide a constant tensional force on web 12 changes continuously as the diameter of the roll 14 increases. In order to solve this problem in accordance with another embodiment of the invention, controller 88 may be operative to cause the drive mechanism 84 to increase the torque applied to spool 40 in proportion to the increase in the diameter of web 12 on core 50 as roll 14 is being formed. This allows the tensional force 102 of web 12 to be controlled, even as the diameter of roll 14 continuously increases.

As an example, if an operator of system 10 determines that a tensional force 102 of 3 pounds produces a roll 14 of desired tightness and uniformity, and apparatus 16 produces web 12 at a web speed W of 60 feet/minute, the initial rotational speed R of shaft 44, as determined by sensor 90, may be 20 revolutions/minute. Applying the formula Dia₁₄=W/R·π, the diameter of the roll 14 at that time will be 0.95 feet. Given that:

Torque(“T”)=Force(“F”)·Length(“L”),

and that “L” in this case is the radius of the roll 14, which is found by dividing Dia₁₄ by 2, resulting in a radius (L) of 0.47 feet. Thus, in order to achieve a tensional force (F) of 3 pounds when the roll diameter is 0.95 feet, the above formula, T=F·L, is applied to result in a torque (T) of 1.4 foot-pounds (T=3 pounds·0.47 feet=1.4 foot-pounds). Accordingly, controller 88, which has made the foregoing calculation, will command drive mechanism 84 to apply a torque of 1.4 foot-pounds during the instant that the calculated diameter of roll 14 is 0.95 feet, thereby achieving a tensional force 102 on web 12 of 3 pounds.

Later, as roll 14 has grown, sensor 90 may detect a rotational speed R of shaft 44 of 2.5 revolutions/minute. With apparatus 16 continuing to supply web 12 at a rate of 60 feet/minute, according to the formula, Dia₁₄=W/R·π, this rotational speed corresponds to a roll diameter of 7.6 feet, or a radius of 3.8 feet. Applying the formula, T=F·L, the torque required of drive mechanism 84 to achieve a tensional force in the web of 3 pounds is 14.25 foot-pounds, which controller 88 will command the drive mechanism to provide.

Accordingly, the tensional force 102 of web 12 may be controlled at a desired value, even as the diameter of roll 14 continuously increases.

A further feature of the invention is that the controller 88 may be adapted, e.g., programmed, to cause the drive mechanism 84 to stop the rotation of shaft 44, e.g., via signal 94 to drive mechanism 84, when the detected rotational speed “R” of shaft 44/spool 40 exceeds, or decreases below, a predetermined value. For example, a sudden increase in R could result from the breakage of web 12. As another example, a sudden decrease in R could result from a web jam or other malfunction, in either the inflation/sealing apparatus 16 or in winding device 18. Thus, the predetermined value to be programmed into controller 88 could be, e.g., a change in R of 20% or more, which occurs over a period of, e.g, 5 seconds or less.

The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention.

Claims

1. A winding device comprising a spool, said spool comprising: a. a shaft;b. a sleeve rotatably coupled to said shaft such that said sleeve and said shaft are capable of partial independent rotation relative to one another, said sleeve enclosing at least a portion of said shaft and adapted to receive thereon a core, onto which a web of material may be wound; andc. one or more gripping members, which are adapted to engage the core upon relative rotation of said shaft in a first direction, whereby the core rotates with said shaft to allow the web to be wound onto the core, said gripping members being further adapted to disengage the core upon relative rotation of said shaft in a second direction, whereby said core may be removed from said sleeve.

2. The device of claim 1, wherein said shaft is coupled to said sleeve via a rotary mounting bracket.

3. The device of claim 2, wherein said shaft is rotatably mounted in said bracket; andsaid bracket is affixed to sleeve.

4. The device of claim 3, wherein said gripping members are attached to said shaft; andpart of each gripping member moves away from said shaft and into an engagement position, in which said gripping members engage the core, when said shaft rotates in said first direction.

5. The device of claim 4, wherein said gripping members are pivotally attached to said shaft;said bracket includes one or more guide slots; andeach of said gripping members includes a guide pin, which is movable within one of said guide slots to facilitate movement of said gripping members into said engagement position.

6. The device of claim 4, wherein said part of said gripping members that are in said engagement position move towards said shaft and into a disengagement position, in which said gripping members disengage the core, when said shaft rotates in said second direction.

7. The device of claim 4, wherein said gripping members have a proximal end and a distal end;said proximal end is attached to said shaft;said distal end moves away from said shaft and into said engagement position when said shaft rotates in said first direction; andsaid distal end moves towards said shaft and into said disengagement position when said shaft rotates in said second direction.

8. The device of claim 7, wherein said sleeve has a diameter D1;said distal ends of said gripping members together form a diameter D2;D2 is greater than D1 when the distal ends of said gripping members are in said engagement position; andD2 is less than D1 when the distal ends of said gripping members are in said disengagement position.

9. The device of claim 1, further including a drive mechanism coupled to said shaft to drive the rotation thereof at a predetermined rotational speed.

10. The device of claim 9, further including a controller and a sensor, wherein said sensor monitors the rotational speed of said shaft and sends a corresponding signal to said controller; andbased, at least in part, on said signal, said controller calculates a diameter of the web as it is wound onto the core.

11. The device of claim 10, wherein said controller is operative to stop the rotation of said shaft upon the occurrence of at least one of the following events: a. said diameter of the web on the core reaches a predetermined value; andb. the rotational speed of said shaft exceeds, or falls below, a predetermined value.

12. The device of claim 10, wherein said controller is operative to vary the output of said drive mechanism in order to maintain a substantially constant tensional force on the web as it is wound onto the core.

13. The device of claim 10, wherein said device is adapted to wind a web comprising an inflated cushioning material onto the core.

14. A winding device, comprising: a. a spool adapted to receive thereon a core, onto which a web of material may be wound, the web being supplied to said spool at a predetermined speed;b. a drive mechanism coupled to said spool to drive the rotation thereof at a predetermined rotational speed;c. a sensor, which monitors the rotational speed of said spool and generates a signal indicative of said rotational speed; andd. a controller in communication with said sensor to receive said signal as a first input, said controller also receiving, as a second input, an indication of the speed at which the web is supplied to said spool, wherein, said controller calculates a diameter of the web as it is wound onto the core.

15. The device of claim 14, wherein said controller is operative to stop the rotation of said spool upon the occurrence of at least one of the following events: a. said diameter of the web on the core reaches a predetermined value; andb. the rotational speed of said spool exceeds, or falls below, a predetermined value.

16. The device of claim 14, wherein said drive mechanism applies torque to said spool, thereby producing a tensional force on the web as it is wound onto the core; andsaid controller is operative to cause said drive mechanism to increase said torque in proportion to an increase in the diameter of the web on the core to thereby control said tensional force.

17. A winding device comprising a spool, said spool comprising: a. a shaft;b. a sleeve rotatably coupled to said shaft such that said sleeve and said shaft are capable of partial independent rotation relative to one another, said sleeve enclosing at least a portion of said shaft and adapted to receive thereon a web of material such that the web may be wound onto said sleeve; andc. one or more gripping members, which are adapted to engage the web upon relative rotation of said shaft in a first direction, whereby the web rotates with said shaft and is thereby wound into a roll on said sleeve, said gripping members being further adapted to disengage the web upon relative rotation of said shaft in a second direction, whereby the roll may be removed from said sleeve.