GB2366450A

GB2366450A - A re-armable tripping device

Info

Publication number: GB2366450A
Application number: GB0121505A
Authority: GB
Inventors: Didier Lair; Manuel Francisco; Philippe Geneste
Original assignee: Legrand SNC
Current assignee: Legrand SNC
Priority date: 2000-09-05
Filing date: 2001-09-05
Publication date: 2002-03-06
Anticipated expiration: 2021-09-05
Also published as: DE10143284A1; FR2813704A1; FR2813704B1; GB2366450B8; GB2366450B; GB2366450A8; GB0121505D0

Abstract

A re-armable tripping device includes a case 2 in which there are disposed an actuator member 12 and a plate 30 elastically deformable between two stable positions, accessible via a first opening formed in a front face of the case, disposed over the actuator member 12 and preventing unintentional action thereon. A member 20 is pivotably mounted in the case so that a first part 44 of that member is mobile between a first position in which it is in contact with the plate in its first stable position and a second position in which it is in contact with the plate in its second stable position, a second part 46 of that member being used to re-arm the device.

Description

<Desc/Clms Page number 1> A re-armable tripping device The present invention relates to a re-armable manual tripping device as used in safety applications, for example, in particular in fire safety applications.

Providing manual tripping devices at various locations in premises, in particular in offices or places intended to receive the general public, is known in the art. When actuated, this kind of device trips an audible alarm, for example, to warn of a hazard (fire etc.). Once actuated, the device must remain in its contacted position until an operator takes positive action to break the electrical contact.

Some tripping devices include a case containing a push-button. A glass window forms a front face of the case and prevents access to the push-button. The glass window must therefore be broken to obtain access to the push-button.

The document FR-2 495 374 cites the drawbacks of this kind of device and proposes a tripping device in which a plate is disposed over a push-button. The plate has, at least locally, an outwardly curved shape in the armed position (before actuation) and an inwardly curved shape in the tripped position (af ter actuation) .

The above document also shows how it is possible to return the tripping device from its tripped position to its armed rest position. A lever is inserted into the case under the plate via a slot on a side wall -of the case. A relatively large free space must therefore be provided beside the device, on the side containing the access slot for the re-arming device. The tripping device must therefore not be installed near a corner of the premises or beside any other device that could impede rearming the tripping device. Also, the lever must be positioned correctly to locate the correct bearing point.

To adjust the lever correctly it is often necessary to proceed by trial and error.

An object of the present invention is to provide a membrane-type tripping device that is easier to re-arm than prior art devices. The device is advantageously such that there is no risk of it being impeded by a wall, a device or the like disposed near it.

To this end, it proposes a membrane-type re-armable manual tripping device, including a case in which there are disposed an actuator member and a plate elastically deformable between two stable positions, accessible via a first opening formed in a front face of the case, disposed over the actuator member and preventing unintentional action thereon.

According to the invention, a member is pivotably mounted in the case so that a first part of that member is mobile between a f irst position in which it is in contact with the plate in its first stable position and a second position in which it is in contact with the plate in its second stable position, a second part of that member being used to actuate it.

Accordingly, the case integrates a member for rearming the device by acting on the membrane. That member can be a cam that is caused to pivot or a lever or any other similar mechanical member. The pivoting member can be acted on either directly or via a mechanism (lock, lever, etc).

In a first embodiment of the tripping device in accordance with the invention, the pivoting member is a lever having a first branch adapted to come into contact with the plate and an actuator second branch. In this case, the first branch of the lever has at its free end a projection adapted to come into contact with the plate, so as to have virtually point contact with the membrane. The action of the lever on the membrane is then cleaner.

If - the pivoting member is a lever, its second branch is preferably accessible via a second opening formed in the front face of the case. This guarantees easy access to the lever because the front face of the device is always free as it must be possible to act on the plate without any difficulty. The second opening preferably has a specific shape so that only a tool of complementary shape can be passed through it. The second opening is a semi-circular slot, for example, so that a screwdriver cannot be passed through it.

In a preferred embodiment the first part of the pivoting member is disposed between the plate and the actuator member and the pivoting member acts on the actuator member. Compared to the prior art devices, there is no direct contact between the actuator member and the plate or membrane.

If the plate has a bending line, the pivoting member advantageously comes into contact with the plate at the level of the bending line because the maximum travel of the plate occurs there. Thus acting at this location reduces the force to be applied to re-arm the device. Moreover, if the pivoting member is a lever, it advantageously extends under the bending line of the plate and pivots about an axis substantially perpendicular to that line.

In a preferred embodiment the plate includes two arms extending in two substantially opposite directions, each arm having a base fastened to the plate and-a free end, in an armed position, the plate is plane and the arms extend in a plane inclined relative to the plane of the plate, the arms being on the same side of the plate, and the f ree ends of the arms are each disposed in a corresponding housing provided in the case.

In this preferred embodiment, the plate has a rectangular membrane, for example, with a transverse

median -bending groove and four arms, two on each longitudinal side of the membrane.

The following description, given with reference to the accompanying drawings, explains further the objects and advantages of the invention. It is clear that the description is given by way of example only and has no limiting character.

Figure 1 is a perspective view of a tripping device in accordance with the invention, Figure 2 is a view corresponding to figure 1 of the tripping device in accordance with the invention without its cover, Figure 3 is a bottom view of the cover, Figure 4 is a view in section taken along the line IV-IV in figure 3 in the armed position, Figure 5 corresponds to figure 4 in the tripped position, Figure 6 is a view of the device from figure 1 in the armed position and in cross section taken along the line VI-VI, and Figure 7 corresponds to figure 6 in the tripped position.

Generally speaking, a tripping device in accordance with the invention includes a case 2 having a base 4 and a cover 6.

In the embodiment shown in the drawing, the cover 6 is removably attached to the base 4. Attachment lugs 8 locate the cover correctly on the base and a screw 10 is provided to retain the cover 6. The base 4 and the cover 6 are substantially square.

The base 4 provides a housing for a push-button 12 (figures 6 and 7) associated with an electrical switch and with other components, for example electrical connecting terminals, an electrical circuit and possibly electronic components. Actuating the push-button 12 trips

an audible alarm, for example, to warn of a hazard such as a f ire.

The base 4 has a bottom 14 attached to side walls 16 and a cover plate 18. The latter is fixed by screws to the combination of the bottom 14 and the side walls 16, for example. Like the cover 6, the two component parts of the base 4 are injection-moulded from a plastics material, for example. The push-button 12 and the various components are disposed in the base 4 and held in position therein by the cover plate 18. The latter is substantially plane and square.

The cover plate 18 includes a plurality of openings providing access to the push-button 12 and to the connecting terminals in particular. The push-button 12 is actuated by means of a cranked lever 20 mounted to pivot about a spindle 22 supported by two bearings. Each bearing is formed at the end of a lug 23 whose end is slit longitudinally to define two elastic branches in each of which a housing is formed to receive the spindle 22. Accordingly, in a manner that is known in itself, the spindle 22 can be clipped onto the lugs 23 and pivot freely in its bearings, which are defined by the housings formed in the elastic branches.

The spindle 22 is substantially in the plane of the cover plate 18 and perpendicular to the cranked lever 20. An opening is provided in the plate at the location of the lever 20 and its spindle 22. The spindle 22 is disposed so that a free end of the lever 20 can come into contact with and actuate the push-button 12. The lever 20 is cranked so that when the first free end is in contact with the push-button 12 the branch including that free end is substantially in the plane of the coverlplate 18 and the branch including the other free end of the lever 20 projects outwards from the base 4.

The cover 6 has a front face 24 which is surrounded

by side walls 26 and in which a rectangular opening 28 is formed. The latter opening is closed by a plate 30 formed by a membrane 32 and four arms 34. The plate 30 is made from a synthetic material for example, such as polypropylene. This material is able to withstand bending, which is necessary in the present application.

In its "rest" position, i.e. before actuation of the tripping device in accordance with the invention, the membrane 32 is plane and rectangular. Its shape substantially corresponds to that of the rectangular opening 28, which it covers entirely. It fits inside the cover 6, i.e. between the side walls 26, and is therefore on the same side thereof as the base 4 when mounted in the device. The membrane 32 has on its inside face, i.e. on the same side as the base 4, a median transverse groove 36 dividing the membrane 32 into two equal parts and defining a bending axis.

The arms 34 extend longitudinally alongside the membrane 32. Each arm 34 has a base 38 and a free part 40. The base 38 is fastened to the membrane 32, to which it is attached at one longitudinal edge, i.e. one long edge, of the membrane 32, in the vicinity of the groove 36. The free part of each arm 34 is always at the end opposite the groove 36. All four free parts 40 of the arms 34 are inclined to the plane of the membrane in its "rest" position and oriented towards the interior of the device.

The free ends of the arms 34 are substantially level with a transverse edge of the membrane. Each is housed in a housing formed in the cover 6 and enabling the arms 34 to pivot in their housing. Each housing is defined by abutments that are formed when the cover 6 is injection moulded, for example.

The plate 30 therefore has two stable positions, shown in figures 4 and S. In a first position (figure 4),

referred- to as the rest or armed position, the membrane 32 is plane and the arms 34 are inclined so that their free parts 40 are farther inside the cover 6, and therefore the device, than the bases 38. The membrane 32 is then slightly stressed. In a second position (figure 5), referred to as the actuated or tripped position, the membrane 32 forms a dihedron whose ridge is inside the tripping device; the free edges of the dihedron are in contact with the front face 24. The arms 34 are inclined so that their bases 38 are farther inside the cover 6, and therefore the device, than their free parts 40. The membrane 32 is therefore unstressed. The inclination of the arms relative to the front face 24 is therefore reversed between the first position and the second position. The plate 30 passes through a bracing point corresponding to a maximum force applied by a user to the membrane 32 via the rectangular opening 28.

This is how the device works: The base 4 is f ixed to a wall or the like in premises such as an office. of course, the tripping device is electrically connected to an alarm system, for example a fire alarm. The plate 30 is in the rest position previously described. The rectangular opening 28 providing access to the membrane 32 is on the front face of the device, facing a user. If the user wishes to trip the alarm, it is suf f icient to press the membrane 32 in order to depress it into the interior of the case. The membrane 32 bends at the level of the groove 36 and the plate 30 takes up the actuated position shown in figures 5 and 7. The membrane 32 operates on the push-button 12 via a branch of the cranked lever 20, so tripping the alarm. The lever 20 is advantageously disposed parallel to and just below the ridge of the dihedron formed by the membrane 32 in its tripped position. The branch 44 of the lever acting on the push-button 12 is substantially in the plane of the

cover p-late 18. A projection 42 on this branch ensures that contact between the membrane 32 and the lever 20 occurs at the level of the projection 42, and not over the whole of the length of the corresponding branch; this achieves a cleaner contact.

As indicated above, in this tripped position the second branch 46 of the cranked lever 20 causes the cover plate 18 to project towards the cover 6 and the plate 30. To return the tripping device to its rest position, and therefore to return the membrane 32 to its plane configuration, it is sufficient to act on the second branch 46 of the cranked lever, which in turn acts on the membrane 32. An opening 48 is provided for this purpose in the front face 24 of the cover 6, just above the second branch 46. In the embodiment shown in the drawing, the opening 48 is semicircular. This shape is to restrict access to the cranked lever 20 by necessitating the use of a special tool or key. That tool, not shown, is inserted into the case 2 via the opening 48 until it comes into contact with the second branch 46 of the cranked lever 20 and causes the latter to pivot about the spindle 22. The projection 42 on the first branch 44 of the lever therefore pushes on the membrane 32, at the location of the transverse groove 36, to return it to its plane rest position. This re-arms the tripping device. The fact that the opening 48 providing access to the rearming lever is on the front face 24 of the device, immediately adjacent the opening 28 corresponding- to the membrane 32, guarantees easy access to the device for rearming it. Even if the case 2 is in the corner of a room or in contact with some other case, there is no problem of access for re-arming the device because, for safety reasons, its front face is always readily accessible. Also, there is no difficulty in reaching and acting on the lever 20. It suffices to insert the tool in the

corresponding opening. The lever pivots and acts on the membrane without trial and error. The positioning of the lever relative to the membrane is always correct.

The scope of the present invention is not limited to the details of the embodiment considered above by way of non-limiting example, but on the contrary extends to modifications that will be evident to the skilled person and are within the scope of the following claims.

Thus the lever could be replaced by a cam acting on the membrane, for example.

The means for acting on the cam or the lever can be of diverse and varied kinds. Direct action on the pivoting member as described above is preferred, but other solutions can be envisaged: action of a lever or a cam on the pivoting member, action by means of a lock, etc.

The position of the pivoting member, here a lever, can be modified. The lever described could be placed elsewhere, for example, and act on the membrane at a distance from the bend therein. Moreover, the pivoting member does not necessarily act on the push-button. The membrane can act directly on it.

Claims

CLAIMS 1. A membrane-type re-armable manual tripping device, including a case in which there are disposed an actuator member and a plate elastically deformable between two stable positions, accessible via a first opening formed in a front face of the case, disposed over the actuator member and preventing unintentional action thereon, wherein a member is pivotably mounted in the case so that a first part of that member is mobile between a first position in which it is in contact with the plate in its first stable position and a second position in which it is in contact with the plate in its second stable position, a second part of that member being used to actuate it.
2. A tripping device according to claim 1, wherein the pivoting member is a lever having a first branch adapted to come into contact with the plate and an actuator second branch.
3. A tripping device according to claim 2, wherein the first branch of the lever has at its free end a projection-adapted to come into contact with the plate.
4. A tripping device according to either claim 2 or claim 3, wherein the second branch of the lever is accessible via a second opening formed in the front face of the case.
5. A tripping device according to claim 4, wherein the second opening has a specific shape so that only a tool of complementary shape can pass through it. -
6. A tripping device according to any of claims 1 to 5, wherein the first part of the pivoting member is disposed between the plate and the actuator member and the pivoting member acts on that actuator members
7. A tripping device according to any of claims 1 to 6, wherein the plate incorporates a bending line and the pivoting member comes into contact with the plate at

<Desc/Clms Page number 11>

the location of the bending line.
8. A tripping device according to claim 7, wherein the pivoting member is a lever extending under the bending line of the plate and pivoting about a spindle substantially perpendicular to that line.
9. A membrane-type re-armable manual tripping device substantially as described herein and with reference to the drawings hereof.