IP Library › Granted Patent US 12,571,932
Granted Patent B2
US 12,571,932 · App. 18/553,522 · Granted Mar 10, 2026

Window locking device and system

Inventor: Michael Derham (Saffron Walden, GB)
Assignee: Mighton Products Limited
G01V3/081E05C3/004E05C3/045
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Quick Facts
Patent No.
US 12,571,932
App. No.
18/553,522
Granted
Mar 10, 2026
Kind
B2
Abstract

A locking device for a sash window having a window sash moveably mounted in a window frame, the locking device comprising a body and a locking element moveable between an unlocked position and a locked position. The device includes a sensor system to detect whether the window sash is in a closed position in the window frame and also to detect whether the locking element is in the locked position. The device includes a first sensor comprising a first lock sensor component mounted for movement with the locking element and a second lock sensor component mounted to the body. The device also includes a second sensor comprising a first window sensor component arranged to be mounted to the sash window and a second window sensor component mounted to the body. The device includes a detent mechanism which acts with the positional arrangement of the sensors to provide a reliable system.

Claims (63)

1 . A locking device for a sash window having a window sash moveably mounted in a window frame, the locking device comprising:

a body for mounting to the sash window;

a locking element moveable between an unlocked position and a locked position;

a sensor system to detect whether the window sash is in a closed position in the window frame and also to detect whether the locking element is in the locked position; and

a detent mechanism,

the sensor system comprising;

a first sensor and a second sensor;

the first sensor comprising a first lock sensor component mounted for movement with the locking element and a second lock sensor component mounted to the body; and

the second sensor comprising a first window sensor component arranged to be mounted to the sash window and a second window sensor component mounted to the body,

the detent mechanism arranged to releasably retain or detain locking element in the locked position or the unlocked position,

the detent mechanism comprising a biasing member such that a threshold force must be applied to overcome the detent mechanism in order to move the locking element away from the locked position or the unlocked position.

2 . A locking device for a sash window according to claim 1 in which the first lock sensor component is mounted to the locking element.

3 . A locking device for a sash window according to claim 1 in which the locking element comprises a bore into which the first lock sensor component is located.

4 . A locking device for a sash window according to claim 1 in which the first lock sensor component is integral with the locking element.

5 . A locking device for a sash window according to claim 1 in which the locking element is rotatably mounted in the body and the locking element comprises a peripheral engaging rim which is arranged to be rotated to locate within a keep to form a locked configuration and, in which, the peripheral engaging rim is arranged to be rotated through 180 degrees between an unlocked configuration and a locked configuration.

6 . A locking device for a sash window according to claim 1 in which the first lock sensor component comprises a magnet and the second lock sensor component comprises a reed switch.

7 . A locking device for a sash window according to claim 1 in which the first window sensor component comprises a magnet and the second window sensor component comprises a reed switch.

8 . A locking device for a sash window according to claim 1 in which the detent mechanism comprises first and second detent formations which are arranged to engage with one another in order to detain the locking element in the locked position or the unlocked position.

9 . A locking device for a sash window according to claim 1 in which the first detent formations are provided on the handle and the second detent formations are provided on the body.

10 . A locking device for a sash window according to claim 1 in which the detent mechanism comprises a pair of first detent formations and a corresponding pair of second detent formations which are circumferentially spaced apart by substantially 180 degrees, the detent formations comprising projections and corresponding recesses, wherein the handle is rotatable through 180 degrees from a retained locked position to a retained unlocked position and in which, in the retained locked position, a first projection engages in a first recess and a second projection engages in a second recess and in the retained unlocked position, the first projection engages in the second recess and the second projection engages in the first recess.

11 . A locking device for a sash window according to claim 1 in which the detent mechanism is in register with the first lock sensor and the second lock sensor such that when the detent mechanism engages the locking element in the locked position the first lock sensor locates directly above the second lock sensor.

12 . A locking device for a sash window according to claim 1 in which the detent mechanism is in register with the first lock sensor and the second lock sensor such that when the detent mechanism engages the locking element in the unlocked position the first lock sensor locates at a furthest point from the second lock sensor.

13 . A locking device for a sash window according to claim 12 in which the locking element is rotatably mounted in the body, the first lock sensor is mounted on the locking element for rotation therewith and wherein rotation of the locking element changes the separation distance between the first lock sensor and the second lock sensor.

14 . A locking device for a sash window according to claim 13 in which, in the locked position, the first lock sensor locates with a minimum possible separation distance relative to the second lock sensor and in the unlocked position the first lock sensor locates with a maximum possible separation distance relative to the second lock sensor.

15 . A locking device for a sash window according to claim 1 in which the first lock sensor rotates about an axis with a radius of travel and wherein in a planar view, the position of the first lock sensor coincides with the position of the second lock sensor and in the unlocked position, the first lock sensor is spaced from the second lock sensor by twice the radius of travel.

16 . A locking device for a sash window according to claim 1 in which the locking device comprises a keep which is arranged to be mounted to the sash window, the keep being arranged to retain the locking element in order to secure the window in the closed position and in which the keep may be separate from the body.

17 . A locking device for a sash window according to claim 16 in which the first window sensor component is mounted in the keep.

18 . A locking device for a sash window according to claim 1 in which the locking device comprises a communication module to communicate signals from each sensor to a remote unit.

19 . A locking device for a sash window according to claim 18 in which the communication module is arranged to be connected to a control hub and the control hub is connected to a router in order to further communicate the signals from the locking device.

20 . A locking device for a sash window according to claim 19 in which the control hub combines the signals from both sensors.

21 . A window assembly comprising a window sash, a window frame and a locking device, the locking device comprising:

a body for mounting to the sash window;

a locking element moveable between an unlocked position and a locked position;

a sensor system to detect whether the window sash is in a closed position in the window frame and also to detect whether the locking element is in the locked position; and

a detent mechanism,

the sensor system comprising;

a first sensor and a second sensor;

the first sensor comprising a first lock sensor component mounted for movement with the locking element and a second lock sensor component mounted to the body; and

the second sensor comprising a first window sensor component arranged to be mounted to the sash window and a second window sensor component mounted to the body,

the detent mechanism arranged to releasably retain or detain the locking element in the locked position or the unlocked position,

the detent mechanism comprising a biasing member such that a threshold force must be applied to overcome the detent mechanism in order to move the locking element away from the licked position or the unlocked position.

22 . A home automation system comprising a least one window status sensor system for monitoring a sash window having a window sash moveably mounted in a window frame and including a locking device comprising:

a body for mounting to the sash window;

a locking element moveable between an unlocked position and a locked position;

a sensor system to detect whether the window sash is in a closed position in the window frame and also to detect whether the locking element is in the locked position;

a detent mechanism,

the sensor system comprising;

a first sensor and a second sensor;

the first sensor comprising a first lock sensor component mounted for movement with the locking element and a second lock sensor component mounted to the body; and

the second sensor comprising a first window sensor component arranged to be mounted to the sash window and a second window sensor component mounted to the body,

the detent mechanism arranged to releasably retain or detain the locking element in the locked position or the unlocked position,

the detent mechanism comprising a biasing member such that a threshold force must be applied to overcome the detent mechanism in order to move the locking element away from the locked position or the unlocked position.

23 . A method of providing a window status sensor system, in which the window includes a locking device, the locking device comprising:

a body for mounting to the sash window;

a locking element moveable between an unlocked position and a locked position;

a sensor system to detect whether the window sash is in a closed position in the window frame and also to detect whether the locking element is in the locked position; and

a detent mechanism,

the sensor system comprising;

a first sensor and a second sensor;

the first sensor comprising a first lock sensor component mounted for movement with the locking element and a second lock sensor component mounted to the body; and

the second sensor comprising a first window sensor component arranged to be mounted to the sash window and a second window sensor component mounted to the body,

the detent mechanism arranged to releasably retain or detain the locking element in the locked position or the unlocked position,

the detent mechanism comprising a biasing member such that a threshold force must be applied to overcome the dent mechanism in order to move the locking element away from the locked position or the unlocked position.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 8, 2026
From: DERHAM, MICHAEL
To: MIGHTON PRODUCTS LIMITED
Reel/Frame 073725/0141 →
Priority Claims (1)
GB 2104492 · Mar 30, 2021 · national
Continuity (1)
Related Publication 20240192397A1 · Jun 13, 2024
References Cited (51)
US 7093392B2 · Derham · 2006 [cited by examiner]
US D581247S · Durrant · 2008 [cited by examiner]
US 8726572B2 · Derham · 2014 [cited by examiner]
US 8881461B2 · Derham · 2014 [cited by examiner]
US 9309711B2 · Derham · 2016 [cited by examiner]
US 9816300B2 · Derham · 2017 [cited by examiner]
US 9933243B2 · Thibault · 2018 [cited by examiner]
US 10228266B1 · McGruder · 2019 [cited by examiner]
US 10317247B1 · Wernlund · 2019 [cited by examiner]
US 10633897B2 · Liang · 2020 [cited by examiner]
US 11118376B1 · Liang · 2021 [cited by examiner]
US 11136797B2 · Derham · 2021 [cited by examiner]
US 11168492B1 · Liang · 2021 [cited by examiner]
US 11459794B2 · Derham · 2022 [cited by examiner]
US 11993964B2 · Derham · 2024 [cited by examiner]
US 12359477B1 · Liang · 2025 [cited by examiner]
US 12428886B1 · Liang · 2025 [cited by examiner]
US 20060087130A1 · Liang · 2006 [cited by examiner]
US 20080252451A1 · Buchhalter · 2008 [cited by examiner]
US 20090140858A1 · Gore · 2009 [cited by examiner]
US 20100026489A1 · Jordan · 2010 [cited by examiner]
US 20110113695A1 · Derham · 2011 [cited by examiner]
US 20130082469A1 · Derham · 2013 [cited by examiner]
US 20140026709A1 · Derham · 2014 [cited by examiner]
US 20140035297A1 · Kreuser · 2014 [cited by examiner]
US 20140062466A1 · Thibault · 2014 [cited by examiner]
US 20140239649A1 · Derham · 2014 [cited by examiner]
US 20150015000A1 · Derham · 2015 [cited by examiner]
US 20150252596A1 · Liang · 2015 [cited by examiner]
US 20150252600A1 · Liang · 2015 [cited by examiner]
US 20160060920A1 · Liang · 2016 [cited by examiner]
US 20160060921A1 · Liang · 2016 [cited by examiner]
US 20160069108A1 · Liang · 2016 [cited by examiner]
US 20160343227A1 · Shih · 2016 [cited by examiner]
US 20170152688A1 · Liang · 2017 [cited by examiner]
US 20170362862A1 · Derham · 2017 [cited by examiner]
US 20180230710A1 · Liang · 2018 [cited by examiner]
US 20180340355A1 · Liang · 2018 [cited by examiner]
US 20200354991A1 · Derham · 2020 [cited by examiner]
US 20210404228A1 · Derham · 2021 [cited by examiner]
US 20220270451A1 · Derham · 2022 [cited by examiner]
US 20220341229A1 · Derham · 2022 [cited by examiner]
US 20240141694A1 · Derham · 2024 [cited by examiner]
US 20240192397A1 · Derham · 2024 [cited by examiner]
GB 2529891 · 2016 [cited by applicant]
JP 2008274669 · 2008 [cited by applicant]
JP 2013044217 · 2013 [cited by applicant]
WO 2020234598 · 2020 [cited by applicant]
WO 2021053330 · 2021 [cited by applicant]
International Search Report and Written Opinion of the International Searching Authority from a corresponding International patent application (PCT/GB2022/050772) bearing a mailing date of Jul. 19, 2022. [cited by applicant]
UKIPO Search Report from a corresponding GB patent application (GB 2104492.0) bearing a mailing date of Sep. 28, 2021. [cited by applicant]