Invalidity dossier
US 2152274
Stencil attachment for spray guns
Current assignee: Individual
Added 9/23/2026, 6:00:51 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 2,152,274
Title: Stencil attachment for spray guns
Inventor: Martin S. Papazian (Worcester, Mass.)
Assignee: Individual (original assignee listed as Individual; no corporate assignee shown)
Filing / Priority Date: August 26, 1936 (Application Serial No. 93,029)
Publication (grant) Date: March 28, 1939
Legal Status: Expired – Lifetime (anticipated expiration March 28, 1956)
Source: https://patents.google.com/patent/US2152274/en
Purpose: The patent addresses difficulty in permanently marking or numbering billets and other hard-surface objects. The customary practice used a steel die, but the die impression was small and shallow and became illegible through rust. The stated object is to provide stencil means for use with an ordinary spray gun so billets and the like may be quickly and effectively marked with stenciled identifications.
Plain-language scope: A standard spray gun carries a plate (preferably rectangular, with peripheral apertures) between the nozzle and handle. A light sheet-metal hood, shaped like the frustum of a rectangular pyramid, is removably screwed to that plate at its smaller end via aligned tapped apertures. A stencil plate fits in the bottom of the hood and is held by quickly releasable means such as hooks; apertures in the plate may themselves act as the stencil, or receive changeable stencils resting on supporting flanges for easy substitution. A cowl inside the hood receives the nozzle, shielding it from fouling by the spraying medium. The trigger has an extension arm; pressing the hood against the object to be marked depresses the arm to actuate the trigger automatically, allowing rapid marking, including of billets passing a fixed spray position. Seven claims are presented, including combinations with the hood, cowl, stencil, and automatic trigger-actuating means.
Not established by this excerpt: The excerpt does not establish the actual corporate owner of any rights, any assignment or ownership transfer, validity or enforceability, or the identity, content, or relevance of any prior art. It also does not establish the full text of the drawing description and claims, which are only partially reproduced in the supplied material.
Generated 10/1/2026, 9:43:04 PM
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Litigation summary
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Proceedings on file (0)
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.