US Patent: 125,823
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Improvement in Gauges
Butt Gage
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Patentee:
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| John A. Marden (exact or similar names) - Veazie, ME |
| USPTO Classifications: |
| 33/44 |
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Patent Dates:
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| Granted: |
Apr. 16, 1872 |
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Patent Pictures:
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1 | 2
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Ralph Brendler
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Description: |
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The Marden's Patent gage was the first one to really solve the
problem of hinge mortise layout. The key to this patent is a
sliding "tongue" attached to the face of the head, which moves a
marking point such that the distance from the end of the arm to
this point is a tiny bit greater than the distance from the head
to the fixed point. This difference will automatically make up
for the "gain" needed to keep the door from binding in its
rabbet.
This comparatively simple design dramatically simplified the
error-prone task of hinge layout, and almost all butt gages from
this point on used a variation of Marden's idea.
Chapin-Stevens showed two varieties of gage referred to as
Marden's Patent in one of their catalogs: one that looks almost
exactly like the patent drawing, and another with a sliding fence
on the back of the bar. Current research indicates that the
second gage is not in fact based on the Marden patent, but is
instead a Thompson's Patent of 1900 (658,881) which shares many
of the Marden features.
Another gage with very similar characteristics that is often
mis-identified as a Marden is the LeFrancois Patent
(435089). The LaFrancois gage adds a scribing point in the side
of the head, and also uses a solid brass head.
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