Interfering thread form

Claim 2

A male thread form member having crests of generally constant uniform diameter throughout the major portion of its length and for being received in a standard female V-shaped thread form, said male member comprised of three axial zones along its length including a first initial engagement zone, a second zone having a thread root of progressively increasing diameter from said first zone, and a third zone, said thread root in said second zone also having its radially innermost portion formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root, whereby cold working and deformation of said female thread form occurs in said second zone of said male member, the cross sectional shape of the crest of threads in said second zone being generally arcuate, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.

Claim 3

A male thread form member having crests of generally constant uniform diameter throughout the major portion of its length and for use in connection with a female threaded member having a generally standard female thread form of substantially V-shape cross section, said male thread form member being received in said female thread form and comprised of three axial zones along its lengTh, said zones including a first initial engagement zone, a second zone having a thread root of progressively increasing diameter from said first zone, and a third zone, said thread root in said second zone also being formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root whereby said root of said second zone is undulating in form at least during a portion of its length as it progressively increases from said first zone to said third zone, and cold working and deformation of said female thread form occurs in said second zone so that said female form fills the space between the threads of the male member in said third zone, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.

Claim 4

A male thread form member having crests of generally constant uniform diameter throughout the major portion of its length and for use in connection with a female threaded member having a generally standard female thread form of substantially V-shape cross section, said male thread form member being received in said female thread form and comprised of three axial zones along its lengTh, said zones including a first initial engagement zone, a second zone having a thread root of progressively increasing diameter from said first zone, and a third zone, said thread root in said second zone also being formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root whereby said root of said second zone is undulating in form at least during a portion of its length as it progressively increases from said first zone to said third zone, and cold working and deformation of said female thread form occurs in said second zone so that said female form fills the space between the threads of the male member in said third zone, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.

Claim 5

A member provided with a male thread form of substantially uniform axial pitch throughout the major portion of its length and also having crests of generally constant uniform diameter throughout the major portion of its length, said male thread form member being receivable in a female thread form, said male member comprised of three axial zones along its length, said zones including an initial engagement first zone with a root of substantially V-shape in cross section, a second zone having a root of generally progressively increasing diameter from said first zone, and a third zone, said thread root in said second zone also being formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root whereby said root of said second zone is undulating in form for at least a portion of its length as it progressively increases from said first zone to said third zone, and cold working and deformation of said female thread form occurs in said second zone so that said female thread form fills the space between the threads of the male member in said third zone, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.

Claim 6

A member provided with a male thread form of substantially uniform axial pitch throughout the major portion of its length and also having crests of generally constant uniform diameter throughout the major portion of its length, said male thread form member being receivable in a female thread form, said male member comprised of three axial zones along its length, said zones including an initial engagement first zone with a root of substantially V-shape in cross section, a second zone having a root of generally progressively increasing diameter from said first zone, and a third zone, said thread root in said second zone also being formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root whereby said root of said second zone is undulating in form for at least a portion of its length as it progressively increases from said first zone to said third zone, and cold working and deformation of said female thread form occurs in said second zone so that said female thread form fills the space between the threads of the male member in said third zone, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.

Claim 7

For use in connection with a threaded member having a generally standard female thread form of uniform axial pitch with roots and crests of substantially V-shape in cross section and having generally constant uniform diameter; a member provided with a male thread form of substantially corresponding uniform axial pitch throughout the major portion of its length and also having crests of generally constant uniform diameter throughout the major portion of its length, said male thread form being received in said female thread form and comprised of three axial zones along its length, said zones including an initial engagement firsT zone, with the root in said first zone being substantially V-shape in cross section, a second zone having a root of generally progressively increasing diameter from said first zone, and a third zone having a thread root generally corresponding to the diameter of the thread root at the terminal of the second zone, said thread root in said second zone also being flattened and formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root whereby said root of said second zone is undulating in form at least for a portion of its length as it progressively increases from said first zone to said third zone, and cold working and deformation of said female thread form occurs in said second zone so that said female thread form fills the space between the threads of the male member in said third zone, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.

Claim 8

For use in connection with a threaded member having a generally standard female thread form of uniform axial pitch with roots and crests of substantially V-shape in cross section and having generally constant uniform diameter; a member provided with a male thread form of substantially corresponding uniform axial pitch throughout the major portion of its length and also having crests of generally constant uniform diameter throughout the major portion of its length, said male thread form being received in said female thread form and comprised of three axial zones along its length, said zones including an initial engagement firsT zone, with the root in said first zone being substantially V-shape in cross section, a second zone having a root of generally progressively increasing diameter from said first zone, and a third zone having a thread root generally corresponding to the diameter of the thread root at the terminal of the second zone, said thread root in said second zone also being flattened and formed with a gentle and gradual wave pattern which rises and falls in a direction along the circumferential length of the root whereby said root of said second zone is undulating in form at least for a portion of its length as it progressively increases from said first zone to said third zone, and cold working and deformation of said female thread form occurs in said second zone so that said female thread form fills the space between the threads of the male member in said third zone, said third zone having a root diameter which is greater than its normal pitch diameter by a maximum amount determined by a percentage of the pitch of the threads as follows: (a) for a pitch of the threads of from about 4 to 19 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 5 per cent of the pitch of the threads; (b) for a pitch of the threads of from about 20 to 64 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 10 per cent of the pitch of the threads; and (c) for a pitch of the threads of from about 65 to 80 threads per inch, the maximum root diameter over its normal conventional pitch diameter is 13 per cent of the pitch of the threads.