Patent Grant
7237478
The present invention is directed to a strapping machine having an improved strap chute and release system. More particularly, the present invention is directed to an asymmetrical strap chute and release system to prevent debris from interfering with or damaging the strap chute and release system.
Strapping machines are in widespread use for securing straps around loads. One use for strapping machines is for loads of conglomerated objects that spontaneously yield multiple and sizable fragments. For example, bricks, cement blocks and the like can fragment (resulting in both large and small fragments) during the strapping operation. The fragments have been know to interfere with the proper operation of the strapping machine by clogging the strap chute and damaging the strap as it is pulled from the chute.
In one known strapping machine, the debris problem has been resolved by including a lower strap chute that is formed with a two-piece peaked guard that resembles a gable that covers the strap chute. The gabled structure opens as the strap is pulled from the chute between the guard sections or gates. In operation, as the strap is pulled from the chute the guard opens generally symmetrically, at the top, to allow the strap to pass. The guard gates are spring mounted so that they close once the strap had exited the chute. The chute includes openings at the bottom to allow debris to fall through so as to not interfere with operation of the chute. Such a guard design is disclosed in Powers, U.S. Pat. No. 6,990,895, which patent is commonly owned with the present application and is incorporate herein by reference.
Although this design works well, it has been found that debris can enter the guard and interfere with the chute when the guard is open. That is, it has been observed that debris fall into the guard (and thus to the chute) coincidentally with the guard opening to release the strap.
Accordingly, there is a need for an improved strap chute and release system that prevents the introduction of debris into the strap chute area. More desirably, such a system can be fitted onto existing strapping machines without excessive changes.
An asymmetrical chute system is for use in a strapping machine of the type for feeding a strapping material around a load, positioning, tensioning and sealing the strapping material around the load. The strapping machine has a feed head for feeding the strapping material into strapping machine, a strap chute defining a strap path through which the strapping material is passed and a sealing head to seal overlapping courses of the strapping material onto itself. The system prevents the introduction of debris into the strap chute area. Advantageously, the chute system can be fitted onto existing strapping machines without excessive changes.
The asymmetrical chute system includes a base, a stationary guard and a movable guard. The stationary guard has an inclined wall extending, at least in part, over the strap path. The stationary guard is stationary relative to the base and the movable guard. The movable guard is movable relative to the base and the stationary guard. The movable guard is movable into engagement with the stationary guard inclined wall to open and close the strap path. When the movable guard is open, the inclined wall extends over the strap path so as to form a blind portion intersecting a line normal to the strap path.
The stationary guard includes a reverse bend back over the line normal to the strap path. Preferably, the stationary guard includes a portion extending from the reverse bend that defines a stationary guard exit wall substantially parallel to the line normal to the strap path.
In a present system, a guide is mounted at about the base, spaced from the stationary guard and the movable guard is disposed between the stationary guard and the guide. The guide is fixedly mounted relative to the stationary guard and the base.
The guide includes at least one bend to define a guide exit wall substantially parallel to and spaced from the stationary guard exit wall. The guide exit wall and stationary guard exit wall define a strap exit parallel to and aligned with the strap path. To prevent the accumulation of debris, the guide is mounted at about the base, and is spaced from the base.
In a present system the movable guard is mounted to the base by a biasing element and is biased into engagement with the stationary wall. A preferred biasing element is a flat spring.
The movable guard can be configured with a path forming leg that, in conjunction with the base, defines a path for the strap through the strap chute. A strapping machine having an asymmetrical strap chute and release system is also disclosed.
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 figures 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 to the figures and in particular to
In a typical configuration, the strap S is fed into the strapper 10 at the feed head 16 and is directed downwardly through the near leg 22 of the strap chute 18. The strap S then traverses along the bottom leg 24 of the chute 18, up the opposite (far) vertical leg 26, across the top leg 28 and back down the near leg 22 to the sealing head 14.
Once the strap S reenters the sealing head 14, the free end of the strap S is held or secured, the feed end is tensioned around the load L, and the overlapping strap courses are sealed to one another as the feed end is severed from the supply. The load L is then discharged from the machine 10.
In the course of a cycle of machine operation, as the strap S is tensioned around the load L, it is pulled from the strap chute 18. The entirety of the strap “loop” does not exit the chute 18 at once; rather, it is pulled in a sequential manner from the chute 18 onto the load L. As such, as one portion of the chute 18 is opened by the strap s exiting (at that portion), because the chute 18 is formed from elongated elements, the entirety, or at least a substantial section of the chute 18 is also opened even though the strap S has yet to be pulled from that particular section or has already been pulled from that section. This results in sections or areas of the chute 18 being open when strap S is not being pulled. This can open the chute 18 for debris to enter.
The present asymmetrical chute and release system 12 provides an enhanced debris deflection function to prevent the ingress of debris by creating a diverted path for the debris as it falls from the load L. The system 12 is formed as part of the bottom leg 24 of the chute 18 and as part of the transitions 30 between the bottom leg 24 and the vertical legs 22, 26 adjacent to the bottom leg 24 (the transition sections 30 are radial track sections).
As seen in
In a present chute system 12, the movable guard 34 is mounted to a chute block 48 by a flat spring 50, such as a spring steel spring. Other biasing arrangements, such as coil springs or the like can also be used.
The movable guard 34 includes a path-forming leg 52 that defines the path 36 for the strap by between a wall 54 in opposing relation to the chute block 48. The movable guard 34 includes a step-like contact 56 with the chute block 48 to prevent over movement of the movable guard 34. A rounded or curved free end 58 provides a smooth surface over which the strap S traverses as it is pulled from the chute 18. The position of the movable guard 34 relative to the stationary guard 32 is such that the movable guard spring 50 is preloaded to close the chute 18.
The bottom leg 24 of the chute 18 also includes a guide 60 to re-center or re-orient the strap S as it exits the chute 18. It will be appreciated that because the chute guards 32, 34 are asymmetrical (with the stationary guard 32 extending over the center C36 of the strap path 36), when the strap S moves beyond the stationary guard 32 it is no longer at about the center C36 of the path 36. Accordingly, the guide 60 includes an angled leg portion 62 that redirects or reorients the exiting strap S back toward the center C36 of the strap path 36. In addition, the stationary guard 32 includes an upper extension 64 with the reverse bend 42 that, with the guide 60, defines an exit 68 for the strap S that is about centered (see C66) over the strap path 36. The guide angled leg portion 62 and the stationary guard upper extension 64 define a reorienting path (as indicated at 68) between them that angles back toward the strap path 36. The reorienting path 68 terminates in a pair of walls 70, 72 that are substantially parallel to the direction the strap moves (as indicated at 74) toward the load L.
It will be appreciated from a study of the figures and specifically
The guide 60 is mounted to the chute block 48 by fasteners 78, such as bolts that are spaced from one another to define gaps between the bolts 78. The guide 60 is also spaced from the chute block 48 (by, for example, spacers 80 on the bolts 78 between the guide 60 and the block 48) to provide sufficient space between the guide 60 and block 48 for debris to fall through. The guide 60 can also include an adjustable 82 stop to prevent over-flexing of the movable guard 34.
As seen in
Referring to
Another important advantage of the present chute system is that can be retrofitted to many presently known strapping machines. That is, the bottom chute systems and the transition sections of some known strapping machines can be readily replaced with the present asymmetrical strap chute system without averse effect to the machines and/or the systems and processes within which they are situated.
All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done 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 all such modifications as fall within the scope of the claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3179037 | Cranston, Jr. et al. | Apr 1965 | A |
| 3613557 | Coleman | Oct 1971 | A |
| 4697510 | Cranston et al. | Oct 1987 | A |
| 5251544 | Abrams | Oct 1993 | A |
| 6990895 | Powers et al. | Jan 2006 | B2 |
