3 ms·
I am really surprised people are calling this a story or narrative. I found factual statement made by the designers in their own patents that "throw-out" (their
by RobertRoberts 4y ago
I am really surprised people are calling this a story or narrative. I found factual statement made by the designers in their own patents that "throw-out" (their phrasing similar to cam-out) is intentional to protect against wrecking screws or tooling with use with clutched automatic screw drivers.
Sections 7.35 to 7.55 discuss this here:
https://pdfpiw.uspto.gov/.piw?PageNum=7&docid=02474994&IDKey=14D96AF311E8&HomeUrl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DPALL%2526S1%3D2474994.PN.%2526OS%3DPN%2F2474994%2526RS%3DPN%2F2474994 https://pdfpiw.uspto.gov/.piw?PageNum=7&docid=02474994&IDKey...
Edit: As a side note, they point out that _all_ screws have throw-out, and the only way to not is to have "zero vertical angle is used on all engaging driving faces or the friction between the driver and the recess walls is greater than the axial component of the driving torque." (Section 7.15 in the link above)
They acknowledge that it's possible, but it's not done in their design intentionally.
- DannyBee 4y agoThat isn't the original patent. That is a modified post-1940 version, as i mentioned. The original patent is the JP Thompson patent #19008081 (screw - 1932) and patent #2046840 (screwdriver - i forget when)
- RobertRoberts 4y agoI agree, here's their original patent: https://patents.google.com/patent/US1908081A/en https://patents.google.com/patent/US1908081A/en The designers own statements of requiring "zero vertical angle" to avoid cam-out/throw-out is proof Phillips was designed with it to begin with. The patent change later only added _more_ cam-out/throw-out, it did not introduce it in 1942. Also, the 1942 patent represents the modern Phillips (which is what everyone would acknowledge is the problem screw), where the original 1932 patent looks more like a Reed and Prince.
- RobertRoberts 4y agoEdit: Previous comment should read -- "...is proof Phillips was _NOT_ designed with it to begin with."