Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23G—THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH
  • B23G5/00—Thread-cutting tools; Die-heads
  • B23G5/18—Milling cutters
  • B23G5/182—Milling cutters combined with other tools
  • B23G5/186—Milling cutters combined with other tools combined with chamfering tools
  • B23G5/188—Milling cutters combined with other tools combined with chamfering tools and with drills
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23G—THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH
  • B23G2200/00—Details of threading tools
  • B23G2200/50—Tools in which the pitch of the teeth is a multiple of the pitch of the thread being produced

Definitions

• This invention is in the field of cutting tools and processes for making a thread in or on a workpiece, and more particularly, to combined hole making, threading, and chamfering tools for making a hole, thread, and/or a thread in a workpiece.
• the tool comprises a straight body with a drill point at the forward end, a shank at the rearward end and a thread form mill between the drill pont and the shank.
• U.S. Pat. No. 5,429,459 incorporated herein by reference, relates to a method of and apparatus for thread mill drilling.
• Figure 1 is a prior art combined hole making and threading tool 100 having a shank 102 at one end, a drill point 104 at the forward end, and a thread form mill 108 intermediate the drill point 104 and the shank 102.
• Thread-form mill 108 is provided with a multiplicity of thread-form cutters 112 and one or more flutes 110 extending from the drill point 104 throughout the thread form mill 108 for the purpose of chip removal.
• Each thread-form cutter 112 comprises a number of cutter segments 114a and 114b circumferentially aligned and are separated by the intervening flute 110.
• Each of the thread-form cutters 112 is of annular configuration and the number of cutters segments is preferably equal to or greater than the number of threads to be cut.
• the thread cutting segments 114a and 114b are laterally displaced into the wall of said hole. As the tool rotates, threads (not shown) are cut in the wall, generating cutting forces that act on the tool 100, including thread-form mill 108.
• FIG. 1 shows a side view of a prior art combined hole making and threading tool.
• Figure 2 is a side view of a combined hole making, threading and chamfering tool with staggered thread cutting teeth according to the present invention.
• Figure 3 is a side view of a combined hole making, threading and chamfering tool with cutting inserts including staggered thread cutting teeth.
• Figure 4 is a side view of a combined hole making, threading chamfering tool staggered thread cutting teeth and coolant passage according to another aspect of the present invention.
• Figure 5 A is side view of a combined hole making, threading chamfering tool with staggered thread cutting and an end mill hole making geometry.
• Figure 5 B is a side view of a combined hole making, threading chamfering tool with staggered thread cutting teeth and an inverted hole making geometry.
• Figure 2 is a side view of a combined hole making, threading and chamfering tool with staggered thread cutting teeth according to the present invention.
• Figure 2 illustrates a combined hole making and threading tool 200 having shank a 202 for engagement in a holder (not shown) of a machine system (not shown); a hole making means 204 for making a hole in a workpiece (not shown), said hole having a wall.
• Flute 208 extending from said shank 202 to said hole making means 204 forming a first land 210.
• First land 210 having a thread cutting edge 212 between said shank 202 and said hold making means 204.
• Another flute extends from said shank 202 to said hole making means 204 forming a second land (not shown).
• Second having a thread cutting edge 214 between said shank 202 and said hole making means 204.
• Thread cutting edge 212 is offset by at least one pitch from thread cutting edge 214 to make staggered thread cutting teeth between shank 202 and hole making
• the staggered tooth doubles chip thickness and reduces side forces (less engagement), consequently allowing the feed rate to be increased and reducing the thread milling time, also reducing tool chatter providing a smoother surface finish in the thread.
• Staggered thread cutting teeth reduce number of engaged in a workpiece, during thread milling phase.
• Solid tungsten carbide is the popular material for these combination tools. High resultant side forces on the tool during the thread milling phase are caused by relatively high circumferentially engagement of the tool and a very low feed per tooth (chip thickness).
• a combined hole making, threading and chamfering tool with staggered thread cutting teeth doubles chip thickness and reduces side forces (less engagement) consequently allowing the feed rate to be increased and reducing thread milling time also reducing tool chatter providing a smoother surface finish in the thread.
• the chip removal v. force is a non-linear relationship. As the chip removal increases, the forces acting on the cutting edges increases at a lesser rate.
• the alternating (staggered) cutting teeth reduces the force acting on the thread milling portion of the cutting tool. This will reduce the force exerted on the thread portion of the cutting tool. Although each thread cutting tooth will remove additional workpiece material, the force acting on the tool does not increase by the same margin. Also, because the number of the thread cutting teeth is reduced, the forces acting on the thread portion had also been reduced.
• Chamfer 206 will chamfer the hole produce hole making 204.
• Chamfer cutting edge can also include forming a spot face. Coolant passages are discussed below for assisting in chip removal. Holder of the machine system call replace or augment the chamfer or coolant passage features in the cutting tool .
• Figure 3 is a side view of a combined hole making and threading tool with staggered thread cutting inserts according to another aspect of the present invention.
• Figure 3 shows a combined hole making, threading, and chamfering tool 300 having a shank 302 for engagement in a holder of a machine system (not shown) and a body 304 .extending from said shank 302.
• Body 304 having a first flute 310 and a corresponding cutting insert 306 attached by any suitable means, including screws 312 and 314.
• Body 304 further includes a second flute (not shown) having a corresponding cutting insert 308 attached by any suitable means, including screws (not shown).
• Body 304 may include, but is not required, one or more pockets (not shown) for receiving said cutting inserts 306 and 310.
• Cutting inserts 306 and 308 each include hole cutting edge (306c; 308c), thread cutting edge (306b; 308b), chamfering cutting edge (306a; 308a).
• Combined hole making, threading and chamfering tool 300 can have one or more flutes having a corresponding one or more cutting inserts.
• Each flute can have one or more corresponding cutting inserts, such as hole cutting insert, thread cutting insert or chamfering cutting insert. Flutes and corresponding cutting inserts can be disposed at any desirable angle, including helical and non-helical angles.
• Thread cutting inserts can have either standard or non- standard thread forms (e.g., staggered thread cutting teeth). Hole cutting inserts can also be used to form any desired geometry, including drill points, end mills, or inverted hole cutting edges.
• FIG. 4 is a side view of a combined hole making and threading tool 400 with staggered thread cutting teeth and coolant passage according to another aspect of the present invention.
• a combined hole making and threading tool 400 includes means for supplying coolant to remove chips.
• Combined hole making and threading tool having a shank 402, a hole making means 406, staggered thread cutting teeth 404 disposed between said shank 402, chamfer cutting means 408 disposed between said shank and said staggered thread cutting teeth 404.
• Main coolant passage 408 and with branch passages 410a and 410b for supply of liquid under pressure to the hole making means for cooling and to aid in the chip removal.
• Figure 5 A is a side view of a combined hole making, threading chamfering tool with staggered thread cutting and an end mill hole making geometry.
• Figure 5 B is a side view of a combined hole making, threading chamfering tool with staggered thread cutting teeth and an inverted hole making geometry.
• the hole making means may be a drill point (e.g., 204), end mill 506, or any other hole cutting geometry, including inverted hole cutting edge 524.
• Cutting edges can be coated with materials improve performance and increase tool life, including applying wear resistant, corrosion and erosion resistant materials, including ultra hard materials.
• wear resistant, corrosion and erosion resistant materials including ultra hard materials.
• diamond, diamond-like carbon, or CBN materials to the cutting edges for improved performance.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Milling Processes (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22255785

Family Applications (1)

Country Status (3)

Families Citing this family (6)

Family Cites Families (4)

• 1996
  • 1996-09-12 AU AU70721/96A patent/AU7072196A/en not_active Abandoned
  • 1996-09-12 WO PCT/US1996/014760 patent/WO1998010882A1/en not_active Ceased
  • 1996-09-12 EP EP96931583A patent/EP0912286A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events