Patent Application
20060175458
The present invention pertains to a strap dispenser. More particularly, the present invention pertains to a strap dispenser for use with a strapping machine that assists starting movement of the strap coil upon tensioning of the strap as it is pulled from the coil.
Coil dispensers are used as a source or supply of coil material for many operations. In one application, strapping material is supplied on a coil for use in a strapping machine. Various types of strapping machines are known in the art and will be recognized by those skilled in the art.
The strapping material is fed from the coil to the strapping machine. The coil is supported on a coil dispenser that provides a controlled source of the strapping material to the strapping machine. The dispenser must permit feeding the strapping material to the strapping machine when there is a demand (e.g., as-needed) with little resistance on the material. The dispenser must also, however, prevent the coil from free-rolling (free rotation) so that the strapping material does not continue to feed from the coil when there is no demand for strapping material. To this end, the dispenser must include provisions to slow or brake the coil from free rotation upon a drop in demand.
It will also be recognized that the dispenser coils, particularly when the coil is full, can be quite heavy. As such, a fairly significant force is needed to commence movement (rotation) of the coil, even though the coil is mounted to the dispenser using a low friction roller bearing. This in turn requires that the strapping machine be able to develop a tension in the feed system in order to commence coil rotation.
One known dispenser includes a shaft about which the coil is mounted for rotation. A dancer arm pivots about the coil shaft and a roller is positioned at an end of the dancer arm opposing the arm axis of rotation. A brake assembly is mounted to the dancer arm for movement into and out of engagement with the side plate. The dancer arm is biased such that the brake is in engagement with the side plate. Other known dispensers use an electric brake that is mounted to dispenser at about the shaft to slow or stop that coil upon receipt of a signal from the strapper. None of these known dispensers, however, include any arrangement or provision for starting the coil from a stop. Rather, these are all concerned with stopping the coil to prevent free-rolling or overfeeding.
It is believed that dispensers were configured that use a pneumatic arrangement to assist or to help “push” the coil to start the coil rolling. However, it is not known whether these were successful in use or whether continued use of such coil start devices has been made. Moreover, because of the external assist (i.e., the pneumatic systems), these devices were complex and could require maintenance and attention beyond the value of their commercial use.
Accordingly, there exists a need for a coil dispenser for dispensing strapping material from a coil. Preferably, such a dispenser includes a simple brake mechanism, in conjunction with a start-assist or auto-start mechanism. Desirably, such a dispenser is of a simple design. Most desirably, the start-assist uses mechanical energy and the tensioning of the strap to actuate the start-assist.
A dispenser for dispensing or feeding flexible material, such as strapping, from a coil has a start-assist for starting rotation of the coil. The dispenser includes a frame, a support, a shaft mounted to the support for supporting the coil and for rotation with the coil and an arm mounted about the shaft by a one-way element. The arm is operably connected to the shaft for rotation such that when the arm rotates in a one direction the one-way element engages the shaft to rotate the shaft and when the arm rotates in the opposite direction the one-way element is disengaged from the shaft to permit the shaft to freely rotate. In this manner, when the strap material is pulled (tensioned) from the coil the arm is rotated to begin rotation of the coil.
In addition, the present dispenser includes a brake mechanism, in conjunction with the start-assist. Advantageously, the dispenser is of a simple design and uses the mechanical energy in tensioning of the strap to actuate the start-assist.
A present dispenser includes a roller element disposed on the arm for directing the flexible material to rotate the arm. The one-way element is a one-way clutch that engages the shaft as it rotates in the first direction but allows the shaft to roll freely in the other direction.
The arm pivots between an at rest position and a dispensing position. The arm is biased to the at rest position and the clutch engages as the arm is pivots from the at rest to the dispensing position.
The dispenser can include a strap sensor and rollers disposed adjacent the sensor to maintain the strap moving in a straight line path through the sensor. A present dispenser includes a stop to limit rotation of the arm in the at rest position and a stop to limit rotation of the arm in the dispensing direction.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.
The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.
It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
Referring now to the figures there is shown an auto-start or start-assist strap dispenser 10 embodying the principles of the present invention. The illustrated dispenser 10 includes generally a frame 12 having a central upright or support 14. The dispenser 10 is configured to accommodate a coil 16 on which a flexible material, such as strapping material S, is stored and to feed the strapping material S from the coil 16 to, for example, a strapping machine (not shown). Those skilled in the art will recognize and appreciate the various types of strapping machines commercially available. The present dispenser 10 is intended for use with most any of these strapping machines and is most suitably used with an automatic type strapper, in which strapping material is fed by a drive assembly around a load, tensioned and sealed to itself. It will also be appreciated that in
The speeds at which these strapping machines operate is increasing. Likewise, the automation with which they operate is also increasing. To this end, dispensers 10 require operation at high speeds, and their design must take into consideration less operator attention. One way in which the dispenser can contribute to efficient operation of a strapping machine is to reduce the “pull” that the machine is required to exert on the coil 16 in order to start rotation of (and thus feeding from) the coil 16. The present dispenser 10 achieves this by providing an auto-start or start-assist to urge the coil 16 into rotation.
As set forth above, the present dispenser 10 includes a frame 12 having a base 18 and the upright support 14. A shaft 20 is mounted to the support 14 for supporting the coil 16. The shaft 20 is mounted in (through) the support 14 (as indicated at 22) at a roller bearing 24 to permit low friction or low resistance rotation of the coil 16. A nut 26 secures the coil 16 to the shaft 20.
A brake 28 is mounted to the shaft 20 on the exit or opposite side of the support 14. In a present embodiment, the brake 28 is an electric type brake, providing a positive stopping function arrangement. Such brakes will be recognized by those skilled in the art.
A dancer arm 30 is mounted to the dispenser 10 for pivoting about the shaft 20. The dancer arm 30 has a roller 32 mounted to a free end 34 of the arm 30. The arm 30 is biased to a near vertical position (with the roller 32 above the coil 16, as illustrated in
The dancer arm 30 is mounted to the shaft 20 by a one-way clutch 40. In this arrangement, the arm 30 grasps (or holds) the shaft 20 as the arm 30 pivots in one direction (against the bias, as indicated by the arrow at 42) and moves freely about the shaft 20 as the arm 30 pivots in the opposing direction (in the direction of the bias as indicated by the arrow at 44). In the illustrated embodiment, as the arm 30 rotates downward, away from the vertical, it rotates the coil 16 by action of the clutch 40, whereas the spring 36 returns the arm 30 to the near vertical position without effecting rotation of the coil 16 (by slipping of the clutch 40). Washers 41 are disposed on between the clutch 40 and the upright 14 and between the arm 30 and the coil 16, as seen in
In order to prevent over-rotation of the arm 30 in the at rest position, the arm 30 and support 14 include cooperating stop elements 46a,b that physically stop the arm 30 in the at-rest position. The dispenser 10 can also include stops 48a,b at the dispensing position to prevent over rotation of the arm 30 in that direction.
The illustrated dispenser 10 includes additional rollers and/or guides 50a,b and 52a,b to direct the strap S toward and over the dancer arm roller 32 and to maintain the strap S moving in a straight line direction when, for example, the strap S traverses through a sensor 54.
In use, strapping material S is fed through the sensor rollers 50a,b and 52a,b and through the sensor 54 and is looped over the dancer arm roller 32 (between the roller 32 and the guide 38) and is introduced to the strapping machine (not shown). As strapping material S is needed by the strapping machine, the material S is “pulled” from the coil 16. As the material S is pulled, the arm 30 begins to pivot from the at-rest position (
The present dispenser 10 arrangement provides a number of benefits, such as actuation of the start-assist feature by virtue of the demand (pull) on the strap S. Thus, no external sources (e.g., power such as pneumatics) are required to provide this assist. In addition, the present dispenser 10 design is relatively simple, and uses, for the start-assist, only a mechanical arrangement of elements. Although the brake 28 illustrated is of an electrical or electro-mechanical design, those skilled in the art will recognize the various brake configurations that can be used in the present dispenser 10.
All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically do so within the text of this disclosure.
In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.
