Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
  • B23D61/00—Tools for sawing machines or sawing devices; Clamping devices for these tools
  • B23D61/12—Straight saw blades; Strap saw blades
  • B23D61/121—Types of set; Variable teeth, e.g. variable in height or gullet depth; Varying pitch; Details of gullet
  • B23D61/1216—Repeating pattern of groups having three or more teeth
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
  • B23D61/00—Tools for sawing machines or sawing devices; Clamping devices for these tools
  • B23D61/12—Straight saw blades; Strap saw blades
  • B23D61/121—Types of set; Variable teeth, e.g. variable in height or gullet depth; Varying pitch; Details of gullet
  • B23D61/1214—Varying height
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T83/00—Cutting
  • Y10T83/929—Tool or tool with support
  • Y10T83/9317—Endless band or belt type

Definitions

• Well known such tooth arrangements include having some teeth straight and longer than others to guide the tooth edge laterally, and letting teeth with unequal edge shapes cut thick but narrow chips known as the "triple chip” method.
• Lateral forces on the toothed edge of the bandsaw may be minimized by letting such teeth that have large lateral forces occur in pairs with opposite setting. If the distance between teeth is small enough they will both be in the cut must of the time, and their individual lateral forces will cancel. However, small distance also means that a larger number of teeth will be cutting simultaneously, with a large feed force when cutting solid sections. which is not desirable, or small feed force on each tooth, which means inefficient cutting and excessive wear.
• the teeth should be arranged m recurrent groups, corresponding to the w idths of grinding, milling and setting tools Ver ⁇ long recurrent groups require large tools, large machines and large machining forces
• the present invention is a tooth aiTangement for metal handsa s which is equally useful for hard and soft materials which causes less vibrations than pieviously known designs with that usage, and which still is simple to manufacture with adequate precision
• figure 1 shows a bandsaw blade from the side
• figure 2 a cross-section through the same
• the first operation in manufacture of bandsaw teeth is cutting teeth in the edge of a steel strip by grinding or blanking
• the teeth can ha ⁇ e different height and different pitch distance According to the present inv ention, different height is important, different pitch is optional for special materials If the steel stnp is made of tw o alloys, as is commonh the case, the tips of the teeth will consist of a harder alloy such as high-speed steel, while the body and back of the strip is made of a tough crack-resistant steel alloy In many cases howev ei.
• the teeth are then set by knocking or pressing them to either side, or leaving some unset
• Many setting patterns include teeth set to different width which is very difficult to achieve in practice, but according to the invention only one setting width is used
• Many patterns combining different tooth heights, pitches and setting widths comp ⁇ se a large number of teeth in a recurrent group, which is one reason why it is difficult to do the setting with high precision, and also requires more expensive tooling
• the long recurrent group is achieved by combining a short group for height and pitch with another short group for setting, where the groups have incommensurable number of members The long group will then have as many members as the product of the members of the smaller groups
• Figure 1 sho s a part of a bandsaw blade according to the invention, where the teeth of a long recurrent group of six teeth are maiked (1 1-16)
• the group is the result of a tooth height and pitch group of two teeth, one high and one low (H-L), and a setting group of three teeth, one unset, one right and one left (O-R-L)
• the front rake face of every tooth is normal to the blade sides
• the first tooth in the group (1 1) is high and unset
• the second tooth (12) is low and set right
• the third tooth (13) is high and set left
• the fourth tooth (14) is low and unset
• the fifth tooth (15) is high and set right
• the sixth tooth (15) is low and set left
• the feed can be great enough to let all six teeth cut, although initially with smaller cutting depth for the low teeth. If the pitch distance is smaller in front of a high tooth, and larger in front of a low tooth, the cutting depth and tooth wear will soon become more equal between high and low teeth, with optimal durability for saw blades m this application
• the mv ention can be realized with other incommensurable tooth numbers, such as three/ four, and the height and pitch group need not be the one with lesser number of teeth.
• Examples of recurring tooth height groups are high-low or high-low-low or high- low-medium, and examples of setting groups are ORL, or OROL Excepting th e case mentioned with a tooth height group of two and a setting group of three, the number of teeth in the recurrent group my exceed the number of possible combinations of height and setting, and thus some teeth in the group will have the same combination, although with different sequence of neighbors However, the balance between right and left will always be maintained, whether the feed is so slow that only high teeth cut, or larger so that low teeth cut a depth which is a certain fi action of what the high teeth do
• the height difference should be enough to avoid any cutting action with set low teeth when cutting hard materials, which for most saw dimensions means that low teeth should be at least 0 1 mm lower than high teeth before setting It will also be possible within the invention to use a tooth height group with three levels, such as High-Low-Medium

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Component Parts Of Construction Machinery (AREA)
• Sawing (AREA)
• Crushing And Pulverization Processes (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Cited By (1)

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Citations (4)

Family Cites Families (4)

• 1997
  • 1997-06-26 SE SE9702459A patent/SE509398C2/sv not_active IP Right Cessation
• 1998
  • 1998-06-08 EP EP98929967A patent/EP1009600B1/en not_active Expired - Lifetime
  • 1998-06-08 JP JP50548199A patent/JP4447665B2/ja not_active Expired - Lifetime
  • 1998-06-08 AT AT98929967T patent/ATE235998T1/de active
  • 1998-06-08 WO PCT/SE1998/001097 patent/WO1999000228A1/en not_active Ceased
  • 1998-06-08 DE DE69812973T patent/DE69812973T2/de not_active Expired - Lifetime
  • 1998-06-08 CA CA002294304A patent/CA2294304A1/en not_active Abandoned
  • 1998-06-25 US US09/104,391 patent/US6269722B1/en not_active Expired - Lifetime

Patent Citations (5)

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