Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B13/00—Bundling articles
  • B65B13/18—Details of, or auxiliary devices used in, bundling machines or bundling tools
  • B65B13/24—Securing ends of binding material
  • B65B13/30—Securing ends of binding material by deforming the overlapping ends of the strip or band
  • B65B13/305—Hand tools

Definitions

• the present invention is directed to a jaw for use in a sealless strapping machine for forming a seal-less crimp. More particularly, the present invention is directed to a one-piece jaw for forming a seal-less crimp.
• Strapping machines are in widespread use. Typically, strapping machines are designed for use with metal (steel) or plastic strapping. In use, strapping is wrapped around the load, tensioned and sealed to itself.
• the seal can be formed by use of a separate seal that is positioned around the strap and crimped onto the overlapping courses of strap. The seal can also be formed by gripping the strap material sections between a punch and the strapping machine jaw and cutting portions of the over- and under-lying courses of strap material into one another to interlock the strap courses. Such a seal is referred to as a seal-less crimp.
• This action creates a locking action that provides additional strength to the strap, so that the tension in the band is maintained.
• the geometry of the jaw is highly engineered and does not lend itself to change.
• the jaws by the nature of the design, experiences extremely high fluctuating stresses, that can result in fatigue failure if the maximum tensile stresses at the shear section exceeds half the shear yield strength. There are tremendous gains to be had if the stresses stay at or below Vz the yield strength.
• Known punches e.g., bearing surfaces
• Each the fixed and movable punches include a plurality of punch heads.
• the punches are mounted to the jaw by fasteners to permit removing the punches for replacement, repair or maintenance.
• One drawback to this design is that the bearing surfaces (punches) are mounted to the jaw structure using fasteners, such as bolts.
• the bores or holes that are formed to secure the punches to the jaw structure also create areas that can be susceptible to failure.
• a jaw for a sealless strapping machine includes a jaw element having a body that defines a linkage portion, a hook portion and a base portion.
• the hook portion extends transverse to the leg portion.
• the linkage portion is contiguous with the hook portion which is contiguous with the base portion.
• the linkage, hook and base are formed from a single piece of material.
• the jaw element includes a plurality of punches, preferably three punches (three peaks with two, intermediate valleys), that extend upwardly from the base portion to defining a juncture.
• Each punch is defined by a peak and a valley between the peak and the peak of an adjacent punch.
• the juncture of the punches and the base is formed as a relieved area.
• the relived area defines a first transition between the punches and the base and second transition between the base and the support leg.
• the first and second transitions are formed having smooth radii, defining the relieved area.
• the transitions are formed parallel to a longitudinal direction of the jaw.
• the relieved area has a depth that is about equal to or greater than a depth of a valley as measured from its respective adjacent peaks to a base of the valley.
• the jaw can be configure such that the peaks have about equal heights and the valleys have about equal depths.
• FIG. 1 is a front view of a jaw assembly that has been formed, in part, in accordance with the principles of the present invention, the jaw assembly shown at a slight upward angle;
• FIG. 2 is a side view of the jaw assembly of FIG. 1 ;
• FIG. 3 is a front perspective view of the jaw assembly
• FIG. 4 is a side view of the jaw assembly
• FIG. 5 is another perspective view of the jaw of the present invention, similar to that shown in FIG. 3;
• FIGS. 6 is a front view showing the relationship of the punches (peaks and valleys) to the base and the jaw.
• the jaw assembly 10 having a relieved region 12 embodying the principles of the present invention.
• the jaw assembly 10 includes a body 14 having a linkage portion 16 (that portion that is operably connected to the strapping machine — not shown), a hook portion 18 that extends generally transverse to the linkage or leg portion 16 and a base portion 20.
• the hook 18 extends transverse, toward an opposing hook portion (not shown).
• the punches are defined by peaks 26 and valleys 28.
• the assembly 10 is a contiguous, unitary element. That is, unlike known jaws which use separate, attached punches, the present jaw assembly 10 uses a unitary jaw element with the punches 22 formed as part of the jaw 10. This precludes the need for holes or bores in the jaw structure (for mounting screws or bolts) that otherwise could weaken the jaw.
• the juncture (indicated at 24) of the punches 22 and the base 20 is formed in counter-intuitive manner. Rather than a build-up of material at the juncture 24, the material at the juncture 24 is relieved or removed and the transition from the punch 22 to the base 20 and the base 20 to the support leg 16 surfaces are formed having relatively large radii, thus forming the respective relieved areas 40, 42.
• the punches 22 are formed as raised areas or peaks 26 (for first contact with the strap), much like teeth, and root areas or valleys 28 between the raised areas 26.
• the root areas 28 extend transverse to the longitudinal direction of the jaw Ai o and essentially divide the peaks 26 from one another. In the illustrated embodiment, there are three peaks 26a,b,c. The peaks 26a,b,c are separated from the hook portion 18 at a transition area 30. The transition area 30 extends parallel to the direction Aio of the jaw 10 and transverse to the root areas 28.
• the faces of the punches e.g., 22a and 22b
• a present jaw 10 includes a one-piece body made of high strength high fatigue material such as high alloy steel, for example, D2 or DC53 heat treated to hardness in excess of 62 RC.
• the jaw 10 includes a maximum possible metallic section (indicated at 32 in FIG. 5), along the shear plane where shear stresses are highest and fatigue related failure occurs. This feature reduces the effective shear stress along the section.
• the strapping surface 22 dictates the strap strength and is formed by the peak and valley features 26, 28.
• a smooth radius, indicated at 34 blends in the peak 26 and valley 28 features to the back face 36 with a radius R that seamlessly blends these features of the geometry.
• a sand blasted or shot blasting process is used to establish a compressive stresses at the surface of the fillet area. This improves fatigue life.
• the depth of the undercut preferably closely matches the peak to valley height Ii 26 - This is established by thinning the section 32.
• the depth of the undercut d38 is more than or approximately equal to the peak to valley height. That is, the radius at 34 is formed to a depth d38 that is about at the valley 28 depth d 2 ⁇ to (relieve stresses and to) prevent failure of the jaw 10, while at the same time, retaining sufficient material to provide strength.
• the highest stresses are seen at the interface of the peaks 26 and the back face 36. By eliminating the point junctures (of the peaks 26 and face 36), and creating a line interface, (see at 40), the highest stress areas are eliminated.
• the present jaw can be used on, for example, an M400 strapping machine currently available from ITW Signode of Glenview, Illinois.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Basic Packing Technique (AREA)
• Package Frames And Binding Bands (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Publications (1)

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ID=38582308

Family Applications (1)

Country Status (5)

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Citations (1)

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• 2007
  • 2007-05-15 US US11/748,669 patent/US7900657B2/en not_active Expired - Fee Related
  • 2007-05-25 BR BRPI0711780-9A patent/BRPI0711780A2/pt not_active IP Right Cessation
  • 2007-05-25 MX MX2008015002A patent/MX2008015002A/es active IP Right Grant
  • 2007-05-25 JP JP2009513198A patent/JP5199247B2/ja not_active Expired - Fee Related
  • 2007-05-25 WO PCT/US2007/012479 patent/WO2007142875A1/en not_active Ceased

Patent Citations (1)

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