GB2501235A

GB2501235A - Door closer with magnetic holding mechanism

Info

Publication number: GB2501235A
Application number: GB1203874.1A
Authority: GB
Inventors: Nicholas Roger Charles Goddard
Original assignee: Stephenson Gobin Ltd
Current assignee: Stephenson Gobin Ltd
Priority date: 2012-03-06
Filing date: 2012-03-06
Publication date: 2013-10-23
Also published as: GB201203874D0

Abstract

A door closing mechanism 10 comprises a door closer 22, a latch mechanism 24 and a magnetic actuator 26, the closer including a body 28 containing a spring and damper arrangement, and an arm 30 which extends from the body, the actuator being movable between a first condition whereby it magnetically attracts a portion (52 Fig. 5) of the latch mechanism and a second condition where it doesnt. The door closer may include a rotatable axle connecting to the arm whilst the latch mechanism may include a pawl (44 Fig. 5) operable to maintain the axle in a first position when the magnetic actuator is in the first condition. The latch mechanism may include a latch arm which may be connected to the pawl such that movement of one results in corresponding movement of the other. A latch for a door locking mechanism is also claimed.

Description

Door Closing Mechanism The present invention relates to door closing mechanisms. In particular, the present invention relates to external door closing mechanisms which arc mounted between the door and a surface which surrounds the door aperture.

A known type of external door closing mechanism comprising a body containing a spring and damper arrangement, and an arm. The body is mounted to a door. The arm includes first and second arm sections which are articulated to one another at a pivot. The first arm section is provided with an end which is rotationally mounted to an axle which extends into the body of the door closing mechanism. The second arm section is provided with an end which is connected to a bracket mounted to a surface which surrounds the door aperture.

In use, opening of the door causes rotation of the axle, and thereby the storage of energy in the spring contained within the body. This energy is retained within the spring when the door is held open. When the door is released, the energy stored in the spring is released and the door closes. The damper within the body limits the closure speed of the door.

In order to hold the door open, it is necessary to counteract the closing force applied by the spring. This may, for example, be achieved by placing a wedge under the door.

This way of keeping the door open is unsuitable for fire doors which must be kept closed at all times.

According lo a Iirst aspccL ol ihe preseni invenlion there is provided a door closing mechanism comprising a door closer, a latch mechanism and a magnetic actuator, the door closer including a body contain a spring and damper arrangement, and an arm which extends from the body, the magnetic actuator being movable between a first position whereby the actuator magnetically attracts a portion of the latch mechanism, and a second position whereby the actuator does not magnetically attract a portion of the latch mechanism.

In a preferred embodiment the door closer includes a rotatable axle connected to the arm, the axle being rotatable between a first position corresponding to the open position of a door and a second position corresponding to the closed position of a door, the latch mechanism including a pawl operable to maintain the axle in the first position when the magnetic actuator is in the first position and portion of the latch mechanism which is attracted by the magnetic actuator contacts the magnetic actuator.

The pawl is preferably pivotably mounted to a base of the door closing mechanism.

The latch mechanism preferably includes a latch arm, the latch arm having said portion which is attractable by the magnetic actuator. The latch arm is preferably pivotably mounted to a base of the door closing mechanism. The latch arm and pawl are preferably connected to one another such that pivotable movement of the pawl results in corresponding pivotable movement of the latch arm and vice versa. The portion of the latch arm that is attractable by the magnetic actuator may be formed integrally with the latch arm. Alternatively, said portion of the latch arm that is attractable by the magnetic actuator may be defined by a separate member connected to or carried by the latch arm.

The latch arm preferably also includes a return spring which urges an end of the latch arm in the direction of the magnetic actuator.

The latch mechanism preferably also includes a cam ring, the cam ring being coupled for rotation with the axle of the door closer, the cam ring including a recess within which the pawl is received when the magnetic actuator is in the first position and portion of the latch mechanism which is attracted by the magnetic actuator is in contact with the magnetic actuator.

The magnetic actuator preferably includes a permanent magnet and two blocks comprised of a ferrous material. The blocks are provided with opposed recesses within which the permanent magnet is rotatably mounted. The magnet is rotatable between a first position and a second position. In the first position, the magnet is aligned such that one of the poles of the magnet is frilly received within the recess of one of thc blocks and the other of the poleis fully rcceived in the recess of the other of the blocks. In the second position, the magnet is aligned such that both poles are received partially in both recesses.

According to a second aspect of the present invention there is provided a latch for a door closing mechanism, the latch comprising a base having a latch mechanism a magnetic actuator and a space to which a door closer can be mounted, the magnetic actuator being movable between a first position whereby the actuator magnetically attracts a portion of the latch mechanism, and a second position whereby the actuator does not magnetically attract a portion of the latch mechanism.

In a preferred embodiment the latch mechanism including a pawl operable to maintain a door closer mounted to the base in a desired position when the magnetic actuator is in the first position and portion of the latch mechanism which is attracted by the magnetic actuator contacts the magnetic actuator. The pawl is preferably pivotably mounted to the base.

The latch mechanism preferably includes a latch arm, the latch arm having said portion which is attractable by the magnetic actuator. The latch arm is preferably pivotably mounted to the base. The latch arm and pawl arc preferably connected to one another such that pivotable movement of the pawl results in corresponding pivotable movement of the latch arm and vice versa. The portion of the latch arm that is attractable by the magnetic actuator may be formed integrally with the latch arm.

Alternatively, said portion of the latch arm that is attractable by the magnetic actuator may be defined by a separate member connected to or carried by the latch arm.

The latch mechanism preferably also includes a cam ring, the cam ring being coupleable for rotation with an axle of a door closer mounted to the base, the cam ring including a recess within which the pawl is received when the magnetic actuator is in the first position and portion of the latch mechanism which is attracted by the magnetic actuator is in contact with the magnetic actuator.

The magnetic actuator preferably includes a permanent magnet and two blocks comprised of a ferrous material. The blocks arc provided with opposed recesses within which the permanent magnet is rotatably mounted. The magnet is rotatable between a first position and a second position. In the first position, the magnet is aligned such that one of the poles of the magnet is filly received within the recess of one of the blocks and the other of the poleis thily received in the recess of the other of the blocks. In the second position, the magnet is aligned such that both poles are received partially in both recesses.

An embodiment of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a top plan view of a door and door closing mechanism according to the present invention, the door being held in a open position; Figure 2 shows the a top plan view of the door and door closing mechanism with the door in a closed position; Figure 3 shows a top plan view of the door closing mechanism in the open position; Figure 4 shows a top plan view of the door closing mechanism in the closed position; and Figure 5 shows an exploded view of the door closing mechanism.

Referring to the figures there is shown a door closing mechanism generally designated 10. The door closing mechanism 10 is operable to close a door 12. The mechanism is connected between a surface 14 of the door 12 and a surface 16 which surrounds the door aperture 18. The surface 16 may, for example, be part of the door frame 20 or a the wall surounding the door aperture 18.

The mechanism 10 includes a door closer generally designated 22, a latch arrangement 24 and a magnetic actuator generally designated 26. The door closer 22,

S

latch arrangement 24 and magnetic actuator 26 are mounted to a base plate 27 which, in turn, cam be mounted to a door surface 14.

The door closer 22 is of a conventional type comprising a body 28 containing a spring and damper arrangement, and an arm 30. The arm 30 includes first and second arm sections 32,34 which are articulated to one another at a pivot 36. The first aim section 32 is provided with an end 33 which is rotationally mounted to an axle 38 which extends into the body 28. The second arm section 34 is provided with an end 35 which is connected to a bracket 40 mounted to the surface 16 which surrounds the dooraperturel8.

In use, opening of the door 12 causes rotation of the axle 38, and thereby the storage of energy in the spring contained within the body 28. This energy is retained within the spring when the door 12 is held open. When the door 12 is released, the energy stored in the spring is released and the door closes. The damper within the body 28 limits the closure speed of the door 12.

The latch arrangement 24 includes a latch arm 42, a paw] 44, a cam ring 46 and a return spring 48. The latch arm 42 is pivotably connected at a first end 50 to the base plate 27. The second end 51 of the latch arm 42 is provided with a substantially circular plate 52. The plate 52 is formed from a ferrous material and, as will be described in greater detail below, may be attracted by the magnetic actuator 26. In the embodiment shown the plate 52 is formed separately to the latch arm 42 and is connected thereto by a fastener 54. In an alternative embodiment, the plate 52 may be formed integrally with the latch arm 42.

The pawl 44 is pivotably connected at a first end 56 to the base plate 27. The second end 58 of the pawl 44 is pivotably connected to a link 60. The link 60 is in turn pivotably connected to the latch arm 42. In the embodiment shown, the link 60 is comprised of two link members 60a,60b. The purpose of the link 60 is to couple the pawl 44 to the latch arm 42 such that pivoting of the latch arm 42 about its first end 50 results in corresponding pivoting of the paw] 44 about its first end 56. The pawl 44 is further provided at its first end with a tooth 62 for engagement with a formation of the cam ring 46.

The cam ring 46, in use, is mountable to the axle 38 of the door closer body 28 such that it is able to rotate with the axle 38. The cam ring 46 is formed from a planar body which is provided with a central aperture 64 through which a portion of the axle 38 is able to project, in use. The cam ring 46 is further provided with a pair of curved slots 66 which arc positioned radially outwardly of the central aperture 64, and which partially surround the central aperture 64. The slots 66 permit the cam ring 46 to be coupled for rotation with the axle 38. The radius of the curved slots 66 matches the pitch radius of a plurality of threaded holes 68 present upon a flange 70 of the axle 38.

The cam ring 46 is thus connectable to the axle 38 by the use of threaded fastener 72 which passes through one of the slots 66 and into a hole 68 and which clamps the cam ring 46 to the flange 70.

The outer periphery of the cam ring 46 is provided with a cam surface 74. The cam surface 74 is provided with a recess 76 within which the tooth 62 of the pawl 44 is receivable when the cam ring 46 at a specified rotational position corresponding to the open position of a door.

The return spring 48 extends between the base plate 27 and the latch arm 42.

The magnetic actuator 26 includes a substantially barrel shaped permanent magnet 78, a pair of blocks 80 formed from a ferrous material such as, for example, mild steel, a drive motor 82 and a power source 84. The blocks 80 are each provided with a part cylindrical recess 86 within which the permanent magnet 78 is received with sufficient clearance to allow the magnet 78 to rotate. The magnet 78 is rotatable between a first position shown in figures 1 and 3, and a second position shown in figures 2 and 4. In the first position, the magnet 78 is aligned such that one of the poles (N) of the magnet 78 is fully received within the recess 86 of one of the blocks 80 and the other of the poles (S) is fully received in the recess 86 of the other of the blocks 80. In the second position, the magnet 78 is aligned such that both poles (N,S) are received partially in both recesses.

In the first position, the alignment of the magnet 78 is such that the blocks 80 are magnetised, and are thus able to attract the plate 52 of the latch arm 42. In the second position, the alignment of the magnet 78 is such that the blocks 80 are not magnetised, and thus the plate 52 of the latch arm 42 is not attracted. The blocks 80 are each provided with a part cylindrical engagement surface 88 which, in use, abuts the plate 52.

The magnet 78 is movable between the first and second positions relative to the block 80 by the drive motor 82. In the embodiment shown and starting from one of the positions, rotation of the magnet 78 through approximately 90 degrees is sufficient to move the magnet 78 to the other of the positions.

Figures 1 and 3 show the door holding mechanism 10 in the position adopted when the door 12 is held open by the mechanism 10. The magnet 78 is in the first position, such that the plate 52 is attracted to, and abuts, the part cylindrical engagement surfaces 88 of the blocks 80. The cam ring 46 is in a rotational position whereby the tooth 62 of the pawl 44 is received in the recess 76 of the cam ring 46. The spring of the door closer 22 is in a state where energy is stored therewithin, however the spring is prevented from closing the door 12 by rotating the axle 38 due to the pawl 44 being held in the recess 76 by the magnet 78.

From the position shown in figures 1 and 3, the door 12 may be moved to the closed position in one of two ways. Firstly, the door 12 may be closed manually. In such an instance, a user may apply a closing force to the door 12. This causes movement of the door closer axle 38 which is sufficient to move the pawl tooth 62 out of the recess 76 on the cam ring 46. This in turn results in pivotal movement of the pawl 44 and, via the link 60, corresponding pivotal movement of the latch arm 42. This pivotal movement of the latch arm 42 disengages the plate 52 from the magnetised blocks 80.

The door 12 is thus able to close as a result of the force released by the door closer spring.

Alternatively, the door 12 may be closed due to operation of the magnetic actuator 26.

In order to close the door 12, the drive motor 82 is operated to move the magnet 78 from the first position to the second position. The blocks 80 are thus demagnetised as a result of the rotation of the magnet 78, and thus the plate 52 is no longer attracted to the blocks 80. The retaining force applied to the door closer axle 38 by the interengagement of the pawl 44 and recess 76 of the cam ring 46 is less than the closing force applied to the door 12 by the spring of the door closer 22. The pawl 44 is thus moved out of the recess 76 of the cam ring 46 by rotation of the axle 38, and the door 12 is thus able to close as a result of the force released by the door closer spring.

The magnetic actuator 26 may be configured to move the magnet 78 between the first and second positions relative to the blocks 80 by a number of different control methods. For example, the actuator 26 may be configured to move the magnet 78 as the result of receiving an instruction to do so. Such an instruction may be transmitted wirelessly to the actuator 26. Alternatively, the actuator 26 may be wired to a controller which is operable to send an instruction to move the magnet. The actuator 26 may alternatively be configured to move the magnet 26 in the absence of receiving an instruction, either wirelessly or non-wirelessly. in such an embodiment the actuator may receive a continuous or periodic instruction to maintain the magnet in a given position, and there after change the position of the magnet if the instruction is no longer received. The actuator 26 may be configured to move the magnet in response to receiving an acoustic instruction, for example the sounding of a fire alarm.

It will be appreciated that the permanent magnet 78 does not require any external power in order to magnetise the blocks 80. Accordingly, power is only required to rotate the magnet 78. As such, the size of the drive motor can be kept to a minimum, and it can be powered by self contained batteries within the power source 84.

In order to hold the door 12 in an open condition, the magnet 78 is either moved to, or maintained in, the first position. A user then moves the door 12 to the fully open position. Opening of the door causes the paw] tooth 62 to move over the cam surface 74 of the cam ring 46 until it is aligned with the recess 76. The return spring 48 ensures that thc tooth 62 is received within thc recess 76. The return spring 48 further assists in the pivotal movement of the latch arm 42, and hence the plate 52, in the direction of the blocks 80. The door 12 is thus held open by the combination of the magnetic attraction of the plate 52 to the blocks 80 and the force of the pawl tooth 62 S in the recess 76 countering the closing force applied to the door by the spring of the door closer 22.

Claims

Claims 1. A door closing mechanism comprising a door closcr, a latch mcchanism and a magnetic actuator, the door closer including a body contain a spring and damper arrangement, and an arm which extends from the body, the magnetic actuator being movable between a first condition whereby the actuator magnetically attracts a portion of the latch mechanism, and a second condition whereby the actuator does not magnetically attract a portion of the latch mechanism.
2. A door closing mechanism as claimed in claim I wherein thc door closer includes a rotatable axle connected to the arm, the axle being rotatable between a first position corresponding to the open position of a door and a second position corresponding to the closed position of a door, thc latch mechanism including a pawl operable to maintain the axle in the first position when the magnetic actuator is in the first position and portion of the latch mechanism which is attracted by the magnetic actuator contacts the magnetic actuator.
3. A door closing mechanism as claimed in claim 2 wherein the pawl is pivotably mounted to a base of the door closing mechanism.
4. A door closing mechanism as claimed in claim 2 or claim 3 wherein the latch mechanism includes a latch arm, the latch arm having said portion which is attractable by the magnetic actuator.
5. A door closing mechanism as claimed in claim 4 wherein the latch arm is pivotably mounted to a base of the door closing mechanism.
6. A door closing mechanism as claimed in any of claims 2 to 5 wherein the latch arm and pawl preferably connected to one another such that pivotable movement of the pawl results in corresponding pivotable movement of the latch arm and vice versa.
7. A door closing mechanism as claimed in any of claims 4 to 6 wherein the latch arm ineludcs a return spring which urges an end of the latch arm in the direction of the magnetic actuator.
8. A door closing mechanism as claimed in any of claims 2 to 7 wherein the latch mechanism includes a cam ring, the cam ring being coupled for rotation with the axle of the door closer, the cam ring including a recess within which the pawl is received when the magnetic actuator is in the first condition and the portion of thc latch mechanism which is attracted by the magnetic actuator is in contact with the magnetic actuator.
9. A door closing mechanism as claimed in any preceding claims wherein the magnetic actuator includes a permanent magnet and two blocks comprised of a ferrous material.
10. A door closing mechanism as claimed in claim 9 wherein the blocks are provided with opposed recesses within which the permanent magnet is rotatably mounted.
11. A door closing mechanism as claimed in claim 10 wherein the magnet is rotatable between a first position and a second position wherein, in the first position, the magnet is aligned such that one of the poles of the magnet is fully received within the recess of one of the blocks and the other of the poles is fully received in the recess of the other of the blocks, and wherein in the second position, the magnet is aligned such that both poles are received partially in both recesses.
12. A latch for a door closing mechanism, the latch comprising a base having a latch mechanism, a magnetic actuator and a space to which a door closer can be mounted, the magnetic actuator being movable between a first condition whereby the actuator magnetically attracts a portion of the latch mechanism, and a second condition whereby the actuator does not magnetically attract a portion of the latch mechanism.
13. A latch for a door closing mechanism as claimed in claim 12 wherein the latch mechanism includes a pawl operable to maintain a door closer mounted to the base in a desired position when the magnetic actuator is in the first condition and the portion of the latch mechanism which is attracted by the magnetic actuator contacts the magnetic actuator.
14. A latch for a door closing mechanism as claimed in claim 13 wherein the pawl is pivotably mounted to the base.
15. A latch for a door closing mechanism as claimed in claim 13 or claim 14 wherein the latch mechanism includes a latch arm, the latch arm having said portion which is attractable by the magnetic actuator.
16. A latch for a door closing mechanism as claimed in claim 15 wherein the latch arm is pivotably mounted to the base.
17. A latch for a door closing mechanism as claimed in any of claims 13 to 15 wherein the latch arm and pawl are connected to one another such that pivotable movement of the pawl results in corresponding pivotable movement of the latch arm and vice versa.
18. A latch for a door closing mechanism of any of claims 15 to 17 wherein the latch arm includes a return spring which urges an end of the latch arm in the direction of the magnetic actuator.
19. A latch for a door closing mechanism as claimed in any of claims 13 to 18 wherein the latch mechanism includes a cam ring, the cam ring being coupleable for rotation with an axle of a door closer mounted to the base, the cam ring including a recess within which the pawl is received when the magnetic actuator is in the first condition and the portion of the latch mechanism which is attracted by the magnetic actuator is in contact with the magnetic actuator.
20. A latch for a door closing mechanism as claimed in any of claims 12 to 19 wherein the magnetic actuator includes a permanent magnet and two blocks comprised of a ferrous material.
21. A latch for a door closing mechanism as claimed in claim 20 wherein the blocks are provided with opposed recesses within which the permanent magnet is rotatably mounted.
22. A latch for a door closing mechanism as claimed in claim 21 wherein the magnet is rotatable between a first position and a second position, wherein in the first position the magnet is aligned such that one of the poles of the magnet is fully received within the recess of one of the blocks and the other of the poleis fully received in the recess of the other of the blocks, and in the second position the magnet is aligned such that both poles are received partially in both recesses.