4 ms·

I found the original designs that are part of the patent, it was designed to cam out. Edit: I guess the very original patent was edited to _add_ the cam out? I

I found the original designs that are part of the patent, it was designed to cam out. Edit: I guess the very original patent was edited to _add_ the cam out? I may be wrong on this, but my research showed that the automated screwdrivers on assembly lines did not have good torque controls and therefore were wrecking screws (early 1900s?) and so the cam-out feature was added to help with this problem.

DannyBee 4y ago
What you've found in your research is the common story, but there is not a lot of evidence to back it up, AFAIK. Like if you actually go read the references, there isn't a lot of history from the early 1900's that agrees with the narrative. Also, slotted screws (that they were using) actually cam out before phillips (and aren't self-centering). It's more likely the self-centering part was more useful to the automated screwdrivers back then.
- 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 ago
    That 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 ago
      I 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 ago
        Edit: Previous comment should read -- "...is proof Phillips was _NOT_ designed with it to begin with."

DannyBee 4y ago

What you've found in your research is the common story, but there is not a lot of evidence to back it up, AFAIK. Like if you actually go read the references, there isn't a lot of history from the early 1900's that agrees with the narrative. Also, slotted screws (that they were using) actually cam out before phillips (and aren't self-centering). It's more likely the self-centering part was more useful to the automated screwdrivers back then.

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 ago
  That 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 ago
    I 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 ago
      Edit: Previous comment should read -- "...is proof Phillips was _NOT_ designed with it to begin with."