The present invention relates to embodiments of an apparatus and method for dispensing elongated material, such as tape, from a roll of the material.
Modern consumer and industrial packaging often includes reinforcing tapes or tear tapes as part of their construction. Various tape dispensers have been devised to dispense such tapes into corrugator and packaging equipment.
One such dispenser in disclosed in U.S. Pat. No. 4,914,327 to Asbury et al. The '327 application discloses a system for automatically splicing together the trailing end portion of a spool, or roll, of tape to the leading end portion of a new spool of tape without interrupting the dispensing process. To prevent the tape from breaking under the strain caused by the inertia of the new spool of tape (which is initially at rest), the tape path is provided with a tension-control mechanism. In response to an increase in tension in the tape, the tension-control mechanism moves to shorten the length of the tape path, thereby relieving the increased tension in the tape. As the new spool comes up to speed, the tension-control mechanism, under the influence of a biasing mechanism, returns to its initial position to increase the path of the tape length. An active brake assembly prevents the new spool from unduly accelerating in response to the lengthening of the tape path by the tension-control mechanism.
Despite the previous systems, there is a continuing need for new and improved systems for dispensing tape. For example, the productivity of downstream equipment (e.g., corrugator and packaging equipment) that receives tape from a dispensing system depends in part on the rate at which the dispensing system can dispense the tape. Hence, there is a particular need for dispensing systems that allows for splicing at dispensing rates greater than heretofore possible.
The present invention is directed to various embodiments of an apparatus and method for dispensing elongated material, such as tape, from a spool of such material.
According to one representative embodiment, an apparatus for dispensing elongated material from a roll of material includes at least one spindle for supporting the roll of material and a brake for applying a braking force to the spindle. A movable guide member defines a portion of the path the elongated material is to follow by moving in response to increased tension in the material to shorten the path of the material and by moving in response to decreased tension in the material to lengthen the path of the material. An elongated biasing member is coupled at one end to the guide member, and also is movably coupled to a mechanical linkage, such as a pivoted lever, which in turn is operatively connected to the brake.
The guide member, biasing member, mechanical linkage, and brake cooperate in a feedback system to provide a controlled braking force to the spindle in response to changes in tension in the material being dispensed. For example, when the guide member moves to shorten the path length in response to an increase in tension, the brake automatically reduces the braking force to permit acceleration of the spindle. Conversely, when the guide member moves to lengthen the path length in response to a decrease in tension, the brake automatically increases the braking force to retard rotation of the spindle.
In particular embodiments, a pulley is mounted on the mechanical linkage and the biasing member is reeved around the pulley. In this manner, the pulley serves as a force multiplier by increasing the force that is transferred to the mechanical linkage through the biasing member. The mechanical advantage provided by the pulley arrangement allows for the use of braking torques that prevent a spool from unduly accelerating at dispensing rates greater than 900 feet per minute.
In an illustrated embodiment, the guide member is mounted for movement on a rail. The guide member also has a pulley, or roller, around which the material is reeved. Thus, an increase in tension in the material causes movement of the guide member along the rail in a first direction against the bias of the biasing member. When there is a decrease in tension, the guide member is caused to move in a second direction along the rail under the influence of the biasing member.
According to another representative embodiment, an apparatus is provided for dispensing elongated material from a roll of material supported on a rotatable spindle. A tension-control mechanism for defining the path of the material being dispensed is movable in a first direction in response to an increase in tension in the material being dispensed. An elongated elastic member is reeved around a pulley and has a first end coupled to the tension-control mechanism and a second end secured at a position spaced from the pulley. The elastic member provides a biasing force for urging the tension-control mechanism in a second direction, which can be directly opposite the first direction, whenever there is a decrease in tension in the material being dispensed.
According to yet another representative embodiment, an apparatus allows for splicing the trailing end portion of an elongated material from a first roll to the leading end portion of an elongated material from a second roll to provide a continuous feed of material between the rolls. The apparatus includes a first rotatable spindle for supporting the first roll of material and a second rotatable spindle for supporting the second roll of material. A feedback mechanism is configured to prevent slack from forming in the second roll of material following splicing as material from the second roll is being dispensed at a rate of at least 900 feet per minute. In particular embodiments, the feedback mechanism comprises a brake mechanism for applying a braking torque to the first and second spindles, a mechanical linkage coupled to the brake mechanism, a tension-control mechanism operable to move in response to changes in tension in the material being dispensed, and a biasing element coupling the tension-control mechanism to the mechanical linkage. The brake mechanism, mechanical linkage, tension-control mechanism, and biasing element cooperate to provide a controlled braking torque in response to changes in tension in the material.
Methods for dispensing elongated material, such as tape, from a roll also are disclosed. In one embodiment, for example, material is dispensed from a first spool of material at a rate of at least 900 feet per minute. When the first spool is nearly depleted, the trailing end portion of the material from the first spool is spliced to the leading end portion of material from a second spool without decreasing the rate at which material is being dispensed. Following the splicing operation, material is dispensed from the second spool at a rate of at least 900 feet per minute.
In another embodiment, a method for dispensing material comprises applying a quiescent braking torque of at least 30 in-lbs to a rotatable spindle supporting a first spool of the material and removing at least a portion of the braking torque to allow material to be dispensed from the first spool. When the first spool is nearly depleted of material, the trailing end portion of the material from the first spool is spliced to the leading end portion of material from a second spool. Following splicing, material is dispensed from the second spool. In particular embodiments, material is dispensed from the first and second spools at a rate of at least 900 feet per minute.
The foregoing and other features and advantages of the invention will become more apparent from the following detailed description of several embodiments, which proceeds with reference to the accompanying figures.
Referring to
Apparatus 10 in the illustrated embodiment includes a frame 11. Mounted on the frame 11 for rotational movement are a first spindle 12 and a second spindle 14. The first spindle 12 supports a first spool of tape 16 and the second spindle 14 supports a second spool of tape 18. Tape T from one of the first and second spools 16, 18 is routed over a fixed roller 20, down to a tensioning roller 22 of a tension-control mechanism 24, and over a fixed roller 26, and then is fed to downstream equipment (e.g., corrugator or packaging equipment), as indicated by arrow A.
In the illustrated embodiment, apparatus 10 is shown dispensing tape from the first spool 16. When the tape from the first spool 16 is depleted, the trailing end portion of the tape from the first spool 16 can be spliced to the leading end portion of the tape from the second spool 18 to provide a continuous feed of tape. While tape is being dispensed from the second spool 18, another full spool of tape can be loaded onto the first spindle 12. The leading end portion of the tape from the new spool can then be spliced to the trailing end portion of tape from the second spool 18. This process can be repeated as necessary with any number of spools.
Any suitable splicing technique can be implemented in the embodiments of dispensing apparatus described herein to splice the trailing end portion of one spool of tape to the leading end portion of a succeeding spool of tape. For example, the automatic splicing technique described in the previously mentioned '327 patent to Asbury, which is incorporated herein by reference, can be used for splicing. As used herein, the phrase “automatic splicing” or “automatically splicing” refers to splicing operations in which the trailing end portion of a first spool is caused to splice to the leading end portion of a second spool while substantially maintaining the rate at which tape is supplied to downstream equipment.
The tension-control mechanism 24 (also referred to herein as a guide member in other embodiments) is movable in two directions (upwardly and downwardly, as indicated by double-headed arrow B, in the illustrated embodiment) along an upright rail 25 to vary the path length of the tape in response to changes in tension in the tape. The tension-control mechanism 24 is pulled downwardly by an elongated biasing member 28 and upwardly by the tension in the tape. Thus, when tape tension is high (i.e., when the current spool is providing tape slower than is required by downstream equipment, such as at the beginning of a spool), the tension-control mechanism is elevated. The upward movement of the tension-control mechanism 24 shortens the tape path so that tape can be fed to downstream equipment without requiring the spool to dispense a corresponding length contemporaneously. Conversely, when tape tension is low (i.e., when the current spool is providing tape faster than is required by downstream equipment), the biasing member 28 causes the tension-control mechanism 24 to assume a lower position (as shown in
In particular embodiments, the biasing member 28 is a piece of elastic material, such as an elastic hose (e.g., surgical tubing), although other elastic materials can be used, such as an elastic band or equivalent devices. The illustrated biasing member 28 is reeved around a pulley 32 of a pivoted lever 34, and has a first end 30 connected to the tension-control member 24 and a second end 36 secured to an extension 54 of frame 11. Lever 34 is mounted for pivoting movement about a pivot pin 56, as indicated by double-headed arrow C.
A brake assembly 38 applies a controlled braking force to the first and second spindles 12, 14, respectively. The brake assembly 38 in the illustrated configuration includes a brake band 40 that extends about portions of spindles 12, 14 and serves to retard their rotation. An upper end portion 42 of the band 40 is affixed to frame, as at 42a, and therefore is stationary. A lower end portion 44 of the band 40 is coupled to extension 54 of frame 11 by a spring 46. Spring 46 exerts a biasing force on band 40 that causes the band to apply a quiescent braking force to the spindles 12, 14. In the illustrated embodiment, for example, the spring 46 is a tension spring and is operable to pull upwardly on the lower end portion 44 of band 40 to cause the band 40 to tighten around spindles 12, 14. In alternative embodiments, such as the embodiment of
The lower end portion 44 of band 40 is coupled to a first end portion 48 of the lever 34 by a connecting member 50. The brake assembly 38, lever 34, tension-control mechanism 24, and biasing member 28 cooperate to form a feedback mechanism, by which the brake assembly 38 applies a controlled braking force in response to changes in the tension in the tape. More specifically, when tape tension is high, the tension-control mechanism 24 travels upwardly, which in turn causes a second end 52 of the lever 34 to move upwardly and the first end 48 of the lever 34 to move downwardly. This movement is coupled to the brake assembly 38 by connecting member 50, which pulls against the spring 46, thereby reducing tension in the brake band 40 and causing a decrease in braking force so that the dispensing of tape can be accelerated. Conversely, when tape tension is lowered, the tension-control mechanism 24 travels downwardly under the biasing force of biasing member 28, which in turn allows the first end 48 of the lever 34 to move upwardly. This motion permits the spring 46 to reapply more tensioning force to the brake band 40, thereby causing a corresponding increase in the braking force to reduce the rate at which tape is being dispensed.
When the first spool 12 becomes depleted of tape, splicing the trailing end of the tape from the first spool 12 to the leading end of the tape from the second spool 14 will automatically bring the second spool 14 into action. The feedback mechanism serves to control the braking force in response to tension spikes that can occur during and immediately following splicing. For example, since the second spool 14 cannot immediately supply tape at the rate required by downstream equipment (due to the inertia of the second spool 14), the tension in the tape suddenly increases. The increased tension causes the tension-control mechanism 24 to move upwardly, which in turn causes the brake assembly 38 to reduce the braking force to allow rotation of the second spool 18. Also, the upward movement of the tension-control mechanism 24 shortens the tape path, thereby providing tape to the downstream equipment without requiring the second spool 14 to dispense a corresponding length contemporaneously.
As the second spool 18 accelerates to the required speed, the tension in the tape decreases, thereby allowing the tension-control mechanism 24 to be pulled downwardly by the biasing member 28. This movement activates the brake band 40, which applies a gradually increasing braking force on the second spindle 14 in response to the decrease in tape tension until equilibrium is established.
As a spool is dispensing tape, the diameter of the tape on the spool decreases. The feedback mechanism provided by the brake assembly 38, lever 34, tension-control mechanism 24, and biasing mechanism 28 compensates for the diametrical change of the spool by gradually decreasing the braking force to ensure substantially uniform tension throughout an entire roll. Without such a feedback system, the tension in the tape would increase in proportion to the change in radius of the spool from which the tape is dispensed.
If, following a splicing operation, the second spool 18 accelerates beyond the rate at which tape is being pulled by the downstream equipment, slack can form in the second spool 18. The slack can become stuck to the spool, entangled with the tape path, and/or cause tape breakage, which then requires a stoppage in production to fix the problem. This phenomenon is known as “overrun.” Thus, to prevent such overrun of the second spool following a splice, the brake band must provide a braking torque sufficient to prevent the second spool 18 from accelerating beyond the rate at which tape is being pulled by the downstream equipment. It can be appreciated that increasing the rate at which tape is dispensed requires a corresponding increase in available braking torque to prevent over-acceleration of a spool following a splicing operation.
However, if the braking torque on a spindle is too high, the upward pulling force of the tension-control mechanism 24 (caused by an increase in tension) may not be sufficient to overcome the spring 46 to permit the spindle to accelerate to the required speed. Hence, the braking torque desirably should be great enough to prevent over-acceleration at a desired dispensing rate without adversely affecting the ability of the system to overcome the biasing mechanism (e.g., spring 46) that retards rotation of the spindles.
In the system disclosed in the '327 patent to Asbury, a maximum braking torque of about 21 in-lbs. typically is applied to the spindles, which is sufficient to permit splicing at dispensing rates of about 600 to 800 feet per minute while preventing overrun from occurring after a splicing.
The embodiments of dispensing apparatus described herein allow for splicing at greater dispensing rates than prior systems. In particular embodiments, the brake band (e.g., brake band 40) is configured to apply a maximum braking torque of about 30 to 100 in-lbs., with 40 in-lbs. being a specific example. Embodiments having a braking torque of up to 100 in-lbs. have been found to permit splicing at dispensing rates up to about 1500 feet per minute. The ability to provide an increased braking torque is a consequence of coupling the biasing member 28 to the lever 34 via the pulley 32. More specifically, biasing member 28 pulls upwardly on the second end 52 of lever 34 when the tension-control mechanism 24 is pulled upwardly in response to an increase in tape tension. Since biasing member 28 is reeved around pulley 32, the pulling force of biasing member 28 on the lever 34 is greater than the upward pulling force that the tape exerts on the tension-control mechanism 24. In this manner, pulley 32 serves as a force multiplier for increasing the force (by about a factor of two) that is transferred to the lever 34 from the tension-control mechanism 24 by the biasing member 28. Hence, the mechanical advantage provided by the pulley 32 can be used to compensate for an increase in braking torque over prior systems.
Referring now to
Components of dispensers 104′ that are identical to corresponding components of dispensers 104 are given the same respective reference numerals, except that the reference numerals for the components of dispensers 104′ are followed by an apostrophe ('). As shown in
Each dispenser 104, 104′ also includes a respective tension-control mechanism 114, 114′ that ride on respective upright rails 116, 116′ extending between the top and bottom portions of the frame 102. As shown in
As shown in
As best shown in
Biasing members 128, 128′ can be coupled to tension-control members 114, 114′, respectively, and to extension 138 in any suitable manner. As shown in
As shown in
As shown in
As best shown in
In use, tension spikes, which can occur following splicing, can transfer excessive forces to the spring 174, causing damage or failure of the spring due to over-actuation. A stop mechanism may be provided to prevent such over-actuation of the spring. As shown in
Each dispenser 104′ has a similarly configured brake assembly, which is shown partially in
As shown in
Dispensers 104, 104′ operate in a manner similar to the embodiment shown in
Using one of the dispensers 104 shown in
Comparatively, if the tape was dispensed from a similar system without a brake being operatively connected to a tension-control mechanism in a feedback system, the tension in the tape paths would have increased in proportion to the change in the radii of the spools. For example, a tape path being dispensed from the first spool, having an initial tension of 2.74 lbs., would have increased to about 10 lbs. near the end of the spool (2.74 lbs.×6.5″/1.8″).
The present invention has been shown in the described embodiments for illustrative purposes only. The present invention may be subject to many modifications and changes without departing from the spirit or essential characteristics thereof. We therefore claim as our invention all such modifications as come within the spirit and scope of the following claims.
The present application is a continuation of U.S. application Ser. No. 10/359,521, filed Feb. 5, 2003, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 10359521 | Feb 2003 | US |
Child | 11303227 | Dec 2005 | US |