Door lock with integrated door position sensor

Abstract

A door lock with integrated door position sensor includes rectangular magnets positioned behind the door strike to maximize magnetic field strength in available space limited by industry-standard dimensions for the door strike. A beveled or stepped mounting opening for the sensor is formed in a front plate of the door lock and behind a non-magnetic faceplate. The shape of the mounting opening allows the magnetic field to penetrate deeply through the faceplate and front plate to actuate the door position sensor. The sensor may be used in mortise locks or bored locks. In an alternative embodiment, the sensor is spring mounted to eliminate all mounting tolerances and ensure that the sensor is maximally forward and flush against the back of the non-magnetic faceplate.

Claims

1. A door lock mechanism comprising: a lock adapted for mounting to a door and having a latchbolt; a magnetically actuated door position sensor assembly comprising a sensor mount having a shaped opening and a magnetically actuated sensor, the shaped opening receiving and holding the magnetically actuated sensor; a front plate for the lock, the front plate having a front face, a back face, a mounting opening for the magnetically actuated door position sensor assembly, and a latchbolt opening for the latchbolt, the latchbolt opening and mounting opening extending through the front plate from the front face to the back face, wherein the mounting opening has a first end at the front face of the front plate and a second end at the back face of the front plate that define a space between said first and second ends that is larger at the first end than at the second end of the mounting opening, wherein the sensor mount of the magnetically actuated door position sensor assembly snaps into the mounting opening so that a portion of the magnetically actuated sensor, held in the shaped opening of the sensor mount, resides within and is surrounded by the space to allow a magnetic field to penetrate into the space within the mounting opening to actuate the magnetically actuated sensor; a non-magnetic faceplate covering the front plate, the non-magnetic faceplate having an opening for the latchbolt, at least a portion of the magnetically actuated sensor of the magnetically actuated door position sensor assembly contacting the non-magnetic faceplate; a non-magnetic strike adapted for mounting to a door frame, the strike having a strike opening for receiving the latchbolt; and a first magnet mounted to the strike for producing the magnetic field that actuates the magnetically actuated sensor, whereby the magnetic field penetrates into the space within the mounting opening, extending from the first end of the mounting opening to the second end of the mounting opening, and surrounds the portion of said magnetically actuated sensor within the space to actuate the magnetically actuated sensor.

2. The door lock mechanism according to claim 1 wherein the first magnet is a rectangular magnet.

3. The door lock mechanism according to claim 2 wherein the rectangular magnet is mounted to a corner of the strike only on a backside of the strike, the rectangular magnet has a width substantially corresponding to a distance from an edge of the strike to a mounting opening in the strike for mounting the strike to the door frame.

4. The door lock mechanism according to claim 1 wherein the first and second ends of the mounting opening are respectively first and second distal ends of said mounting opening.

5. The door lock mechanism according to claim 1 wherein the first magnet is mounted within a recess on a backside of the strike and has a thickness less than a thickness of the strike, when the first magnet is mounted in the recess on the backside of the strike, the first magnet contacts a planar surface of backside of the strike residing within said recess.

6. The door lock mechanism according to claim 1 wherein the magnet is a disc magnet.

7. The door lock mechanism according to claim 1 wherein the strike defines opposed ends about a horizontal centerline and the strike further includes a second magnet symmetrically mounted relative to the first magnet about the centerline of the strike to allow the strike to be mounted with either of the opposed ends above the other end with either of the first or second magnets aligned with the magnetically actuated door position sensor assembly when the latchbolt engages the strike, the first and second magnets residing within recesses on a backside of the strike.

8. The door lock mechanism according to claim 1 wherein: the lock further includes a deadbolt; and the front plate further includes a deadbolt opening for the deadbolt, the deadbolt opening extending through the front plate from the front face to the back face.

9. The door lock mechanism according to claim 1 wherein the non-magnetic faceplate covers the mounting opening for the magnetically actuated door position sensor assembly to prevent visual detection of the magnetically actuated door position sensor assembly when the door is open.

10. The door lock mechanism according to claim 1 wherein the mounting opening is a beveled opening defining the space as a beveled space, the beveled space surrounding said portion of said magnetically actuated sensor residing within said beveled space and allowing the magnetic field from the first magnet in the strike to penetrate through the non-magnetic faceplate and fill the beveled space of the mounting opening to actuate the magnetically actuated sensor.

11. The door lock mechanism according to claim 1 wherein the mounting opening is a stepped opening defining the space as a stepped space, the stepped opening surrounding said portion of said magnetically actuated sensor residing within said stepped space and allowing the magnetic field from the first magnet in the strike to penetrate through the non-magnetic faceplate and fill the stepped space of the mounting opening to actuate the magnetically actuated sensor.

12. The door lock mechanism according to claim 1 wherein the sensor mount is constructed of a non-magnetic material.

13. The door lock mechanism according to claim 1 wherein the sensor mount is shaped to fit within the mounting opening in the front plate.

14. The door lock mechanism according to claim 1 wherein the shaped opening of the sensor mount is shaped to receive and hold the magnetically actuated sensor only in a correct orientation such that the magnetically actuated sensor is actuated by the magnetic field.

15. The door lock mechanism according to claim 14 wherein the sensor mount is shaped to snap into the mounting opening in the front plate with a predetermined orientation corresponding to the magnetic field produced by the first magnet mounted to the strike.

16. The door lock mechanism according to claim 1 wherein the magnetically actuated door position sensor is a reed switch or a Hall effect sensor.

17. The door lock mechanism according to claim 1 wherein the lock having the latchbolt is a mortise lock or a bored lock.

18. The door lock mechanism according to claim 1 wherein at least a portion of the magnetically actuated sensor resides within the sensor mount.

19. The door lock mechanism according to claim 1 wherein at least one portion of the sensor mount and the at least one portion of the magnetically actuated sensor contact the faceplate.

20. A door lock mechanism comprising: a lock adapted for mounting to a door and having a latchbolt; a sensor mount having a shaped opening; a magnetically actuated sensor residing within the shaped opening of the sensor mount; a non-magnetic faceplate having an opening for the latchbolt; a front plate adjacent and contacting the non-magnetic faceplate, the front plate having a latchbolt opening for the latchbolt and a mounting opening for the magnetically actuated sensor, the mounting opening being larger at an end adjacent the faceplate than at a second end extending away from the faceplate, the sensor mount is shaped to fit within the mounting opening in the front plate such that a portion of the sensor mount and portion of the magnetically actuated sensor residing in the sensor mount both contact the non-magnetic faceplate; a non-magnetic strike adapted for mounting to a door frame, the strike having a strike opening for receiving the latchbolt; and a first magnet mounted to the strike for producing a magnetic field that actuates the magnetically actuated sensor, whereby the magnetic field penetrates into the mounting opening and the sensor mount and actuates the magnetically actuated sensor residing within the shaped opening of the sensor mount.

21. The door lock mechanism according to claim 20 wherein an end of the magnetically actuated sensor is planar with an end of the sensor mount.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

(2) FIG. 1 is an exploded perspective view of a mortise lock having a door position sensor and door strike having rectangular magnets according to one embodiment of the present invention.

(3) FIG. 2 is a right side elevational view of an assembled mortise lock having a door position sensor and door strike having rectangular magnets according to the embodiment of the invention seen in FIG. 1. The mortise lock is shown opposite the door strike, with a gap therebetween.

(4) FIG. 3 is a front elevational view of the lock seen in FIG. 2. The view is toward the lock from the door jamb and therefore shows the back side of the strike with the magnets in position.

(5) FIG. 4 is a cross sectional view taken along the line 4-4 in FIG. 2.

(6) FIG. 5 is a detail view of the area marked 5 in FIG. 4 showing details of the gap, the sensor and the magnet at an enlarged scale.

(7) FIG. 6 is a perspective view showing the door position sensor of FIG. 1.

(8) FIG. 7 is an exploded view of the door position sensor of FIG. 6.

(9) FIG. 8 shows magnetic field lines from the magnet in FIG. 1 to illustrate how the beveled recess in the front plate surrounding the door position sensor allows the magnetic field to better penetrate to the door position sensor. The faceplate and strike are not shown.

(10) FIG. 9 is only for the purpose of comparison to FIG. 8 to illustrate how a non-beveled design around the door position sensor would prevent deep penetration of the magnetic field lines to the sensor.

(11) FIG. 10 shows an alternative embodiment of the invention in which a stepped opening has replaced the beveled opening in the embodiment shown in FIG. 8.

(12) FIG. 11 shows another embodiment of the invention in which the sensor is spring mounted to ensure the sensor is as close to the back of the faceplate as possible to minimize the distance from the sensor to the magnet.

(13) FIG. 12 is a detail perspective view of the spring loaded sensor mount of the embodiment seen in FIG. 11.

(14) FIG. 13 is an exploded view of the spring loaded sensor mount seen in FIG. 12.

(15) FIG. 14 is a further embodiment of the invention in which the door position sensor is mounted into limited space available in a latchbolt for a bored in lock having a two-piece front plate surrounding the latchbolt.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(16) In describing the preferred embodiment of the present invention, reference will be made herein to FIGS. 1-14 of the drawings in which like numerals refer to like features of the invention.

(17) Referring to FIG. 1, a mortise lock 10 includes a front plate 12. A latchbolt 14, a guard bolt 15 and a deadbolt 16 are operable through corresponding openings in the faceplate. The faceplate 12 includes a beveled mounting hole 18 that receives a magnetically actuated door position sensor 20. Referring to FIGS. 6 and 7, the door position sensor 20 includes a sensor mount 22, preferably of plastic or other non-magnetic material, and a magnetically actuated sensor 24, which my be a reed switch, a Hall effect sensor or other magnetically operated sensor device.

(18) The sensor mount 22 is shaped to fit into the beveled mounting opening 18 in the faceplate 12. Preferably, the sensor mount 22 snaps into the beveled opening. The faceplate 12 may be of a magnetic material, which allows a conventional steel housing or case to be used for the mortise lock. The sensor mount 22 includes a shaped opening 26 that engages the sensor 24. Opening 26 is shaped to receive and hold the sensor only in the correct orientation to be actuated by a magnetic field from magnets 28 or 30 (see FIG. 1) mounted in corresponding recesses 32, 34 on the back side of a strike plate 36.

(19) The front plate 12 of the mortise lock is covered with a non-magnetic faceplate 38. The faceplate covers the door position sensor 20, preventing it from being seen. The magnets 28, 30 are also hidden on the back side of the strike, which is mounted on the door jamb (not shown).

(20) Openings 40, 42 in the faceplate allow the deadbolt and latchbolt to protrude through the faceplate. A corresponding opening 44 in the strike is large enough to receive the deadbolt and latchbolt. Individual openings for each may also be used. The two magnets 28, 30 in opposite corners of the strike allow it to be installed in either direction to accommodate both left and right swing doors.

(21) It will be particularly noted that the strike 36 has a standard size to match a standard mortise lock, installed in a standard mortise lock opening. The strike is made of a non-magnetic material and is provided with mounting holes 46, 48. The size of the strike and the standardized dimensions limit the space available for the magnets. Prior art designs have heretofore used disc magnets.

(22) Disc magnets are attractive as they are relatively inexpensive. Alignment problems are reduced with disc magnets. However, it has not previously been recognized that the disc shape acts as a limitation on the size of the magnet when the magnet must fit into a limited space constrained by standards, such as the standardized dimensions of a mortise lock strike.

(23) The present invention uses rectangular magnets for improved performance. These magnets allow additional magnet material to fit into the corners in the limited space available for an industry standard door prep. These corners of available space cannot be used by a the type of conventional disc magnet having a circular perimeter used in existing door sensor designs. In part, it is the use of the larger size of a rectangular magnet which permits the present invention to be used as a retrofit for existing door lock designs.

(24) More specifically, the edges of the industry standard strike and the position of the standard mounting hole 46 limit the size of recess 32. A disc magnet would be limited to a disc of the smallest dimension or the rectangular magnet 28. It has been found that approximately double the field strength can be obtained by using a rectangular magnet of the type shown.

(25) Although a rectangular magnet has a less symmetrical field shape than a disc magnet, the orientation of the sensor 24 can be controlled by controlling the mounting to optimize sensitivity of the sensor in the field produced by the rectangular magnet. However, even with a rectangular magnet, and optimized mounting orientations, very large gaps between the door and the jamb, i.e. between the faceplate and the strike can produce erratic operation.

(26) To improve performance, the present invention uses a specially shaped mounting opening 18 for the sensor. The mounting opening is larger at the front than in the back. In the preferred design, this is a beveled opening, however, as can be seen in FIG. 10, it can be a stepped opening. Referring to FIG. 8, it can be seen that the magnetic field line 50 from magnet 28 extends more deeply into mounting opening 18 to actuate sensor 24 if the opening 18 is beveled. FIG. 8 can be compared to FIG. 9 where a magnet 28 is shown producing a magnetic field line 50. A straight sided, conventionally drilled opening 18 is formed in a front plate 12, which is made of steel or other magnetic material. The field line 50 is less effective at actuating sensor 24 in FIG. 9 than field line 50 in FIG. 8 due to the shape of the mounting hole 18.

(27) Referring to FIG. 10, a stepped mounting opening 18 in front plate 12 allows field line 50 deeper access to sensor 24 than in the cylindrical hole of FIG. 9.

(28) By monitoring the door position sensor to detect when the lock is actually adjacent the strike it is possible to determine when the door is actually closed or opened. The mortise lock is preferably supplied with additional sensors to detect the position of the guard bolt, latchbolt, deadbolt, locked or unlocked status, etc. The combination of theses sensors can detect various conditions, faults, security issues, etc.

(29) FIG. 11 shows an alternative embodiment of the invention. The front plate 12 and faceplate 38 are unchanged. The beveled opening 18 is unchanged and operates as previously described. However, instead of permanently fixing the sensor 24 in a fixed mount, it is installed in a sliding spring mount 52. The purpose of the sliding spring mount 52 is to ensure that the sensor 24 is flush with and in perfect contact with the back surface of the faceplate 38. The faceplate 38 may even be provided with a recess to allow the sensor 24 to be slightly closer to the magnet in the strike plate 54.

(30) Strike plate 54 differs from the strike plate 36 in the previous embodiment in that it is provided with disc magnets 56, 58 mounted in corresponding recess openings 60, 62. As previously described, the size of disc magnets is limited by the positions of the strike plate mounting holes 46, 48. Thus, the spring mount 52 is used to eliminate all mounting tolerances which would keep a sensor on a fixed mount slightly farther away from the magnet.

(31) Referring to FIGS. 12 and 13, the sensor 24 is held in a carrier 66, which slides along a track 68 in spring mount 52. Spring 70 urges the carrier 66 and sensor 24 forward to the position seen in FIG. 12. The spring mount is installed in the lock with the sensor 24 projecting forward out of the beveled (or stepped) opening.

(32) The mortise lock is installed in the door mortise first, and the faceplate is then installed over it. The spring 70 holds the sensor 24 out from the front plate, and as the faceplate is installed, the back of the faceplate contacts the sensor 24 and compresses spring 70, sliding the sensor back into the lock mechanism slightly. This ensures that the sensor 24 is as far forward as possible.

(33) The spring mount 52 may also be used with the strike plate 36 and rectangular magnets as previously described.

(34) FIG. 14 shows a bored lock 100 that drives a latchbolt mechanism 102 having a sliding latchbolt 104 that extends through a conventional front plate 106 (typically made of steel or other magnetic material) and a non-magnetic faceplate 108. The latchbolt extends into a non-magnetic strike mounted in the door jamb. The strike 110 is provided with rectangular magnets 114, 116 (as previously described) that fit into recesses 116, 118. With the strike installed, the magnets are hidden.

(35) The faceplate 106 includes a beveled opening 120 that receives a sensor 20 as described and shown in FIGS. 6 and 7.

(36) While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.