Tap and method of making a tap with selected size limits
OwnerTerrence C. Hawkeinventor
Life of this patent
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Abstract
A nib tap configuration in which the thread turns are of progressively increasing pitch diameter over a range of size limits associated with a standard basic pitch diameter. A particular size limit can be provided by grinding off the turns of a larger limit size. A family of taps covering an extended range of pitch diameter size limits allow selection over the extended range.
Claims8
A method of making a tap of a specific pitch diameter size limit in relation to a nominal tap size, comprising the steps of:
- forming a tap having a series of thread turns of a progressively increasing pitch diameter form, with a maximum pitch diameter at a thread turn nearest a shank end of said tap, said pitch diameters of said thread turn series defining a predetermined range of size limits with respect to said nominal pitch diameter, said range including said selected pitch diameter;
- grinding off as many turns as necessary to leave a thread form of a selected pitch diameter adjacent the shank end of said tap.
A method of making a tap of any given pitch diameter size limit in relation to a nominal pitch diameter size, comprising the steps of:
- forming a family of taps, each tap in said family having a series of thread turns of progressively increasing pitch diameter to a maximum pitch diameter adjacent a tap shank, each tap in said family having thread turns extending over a portion of a range of pitch diameter limit sizes from the same nominal pitch diameter;
- selecting a tap from said family having said given pitch diameter limit size;
- and,
- grinding off any thread turns over said given pitch diameter on said selected tap.
A method of making a nib tap for threading nuts of a desired pitch diameter size limit relative to a nominal pitch diameter, comprising the steps of:
- forming a nib tap having a series of thread turns of progressively increasing pitch diameter to the rear of said tap, including said desired size, said series encompassing a range of pitch diameter limit sizes;
- and,
- grinding off thread turns larger than said desired size.
A set of taps comprising:
- a plurality of taps;
- each tap related to a single nominal pitch diameter size, each tap having a series of thread turns of progressively increasing pitch diameter, with a maximum pitch diameter adjacent a shank portion of said tap;
- each tap in said set having a unique pitch diameter range of size limits associated with said nominal pitch diameter, whereby a desired pitch diameter tap can be selected from a tap in said series.
In a through tapping apparatus having a tap driver allowing nuts to progress onto said driver and a nib tap driven by said driver, the improvement comprising:
- progressively increasing pitch diameter of thread turns on said tap at the turns adjacent the shank of said tap, said increasing pitch diameter thread turns extending over a range of pitch diameter size limits.
A thread cutting tap comprising:
- an elongate body formed with a shank at a rear end, and a chamfered section at a front end;
- a series of full form cutting threads extending rearwardly from said chamfered section to said shank;
- said full form thread series of progressively increasing pitch diameter from said chamfer section to said shank, said pitch diameters of a size limit range relating to a standard basic pitch diameter size.
Dependencies are inferred from the claim text.