US 11,719,497 B2
Determination of round count by hall switch encoding
Erin Czarnecki, Broomfield, CO (US); Jeffrey Holt, Austin, TX (US); Michael Leighton, Broomfield, CO (US); Donald McKelvey, Erie, CO (US); Steven Dunbar, Lafayette, CO (US); Timothy Eric Roberts, Broomfield, CO (US); Nicholas Kielsmeier, Denver, CO (US); and Eric Chow, Highlands Ranch, CO (US)
Assigned to Magpul Industries Corp., Austin, TX (US)
Filed by Magpul Industries Corp., Austin, TX (US)
Filed on Apr. 23, 2021, as Appl. No. 17/238,411.
Application 17/238,411 is a continuation in part of application No. 16/635,692, granted, now 11,015,890, previously published as PCT/US2019/057460, filed on Oct. 22, 2019.
Claims priority of provisional application 62/748,602, filed on Oct. 22, 2018.
Prior Publication US 2021/0254916 A1, Aug. 19, 2021
Int. Cl. F41A 19/01 (2006.01); F41A 9/62 (2006.01)
CPC F41A 19/01 (2013.01) [F41A 9/62 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A round counting system for a firearm, the system comprising:
a detachable magazine comprising a follower, the follower comprising one or more magnets, and the magazine comprising:
<N magnetic-field-sensing sensors arranged substantially along a path of the one or more magnets when the follower moves along a length of the magazine, where N is a maximum number of cartridges that can be loaded in the magazine, the sensors generating round count data based on a position of the one or more magnets relative to the <N magnetic-field-sensing sensors; and
a first antenna on the magazine arranged in a region of the magazine that is configured to fit at least partially within a magazine well of the firearm, the first antenna configured to wirelessly transmit a round count indication from the magazine to the firearm via a second antenna on the magazine well or a trigger guard of the firearm, the round count indication based on the round count data.