EP2521108A2

EP2521108A2 - Alarm unit and tool for alarm unit

Info

Publication number: EP2521108A2
Application number: EP12003236A
Authority: EP
Inventors: Keld Gade Andersen
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-04
Filing date: 2012-05-03
Publication date: 2012-11-07
Also published as: EP2521108A3; DK201100082U3

Abstract

The invention relates to a method of mounting an alarm unit (2) comprising a second connection arrangement (7) and a third connection arrangement (14) in a fixation base (3) comprising a fourth connection arrangement (15) by means of a tool (1) comprising a connection part (4) for connecting with a shaft (5), and a first connection arrangement (6) by engaging said first connection arrangement (6) with said second connection arrangement (7) so as to fixate said alarm unit (2) to said tool (1), putting into contact said alarm unit (2) with said fixation base (3), turning said tool (1) and said alarm unit (2) about a longitudinal direction (12) of said shaft (5) in a first direction (9) so as to engage said fourth connection arrangement (15) of said fixation base (3) with said third connection arrangement (14) of said alarm unit (2), exerting a force on said tool (1) in a direction towards said fixation base (3), and turning said tool (1) about a longitudinal direction (12) of said shaft (5) in the first or a second direction (10) so as to release said tool (1) from said alarm unit (2).

Description

Field of the invention

The present invention relates to a method of mounting an alarm unit, such as a smoke detector, in a fixation base and a tool for mounting said alarm unit in said fixation base according to said method.

Background of the invention

An alarm unit, such as a smoke detector, may be fixated in a fixation base, the fixation base itself being attached to the ceiling. Thereby, the alarm unit may be attached and detached from the fixation base, e.g. for service or changing the battery, or when changing from one alarm unit to another alarm unit. However, where the ceiling is out of reach of a normal person, such attachment and/or detachment of the alarm unit may require a ladder for the person installing the alarm unit. Instead, the person may use a tool extending his or her reach and allowing the person to attach and/or detach the alarm unit from the ground. Such tools may, however, be rather complex, an example of which is shown in United States Patent US 3,900,795 . Another example of such tools are shown in UK Patent Application GB 2 405 735 A , where a smoke alarm rests on fork-like extensions of a tool.

Brief description of the invention

It is therefore an object of the invention to provide a simple tool for safe mounting and/or dismounting an alarm unit from a fixation base, and a method for operating said tool.
The invention relates to a method of mounting an alarm unit in a fixation base for said alarm unit by means of a tool, said alarm unit comprising a second connection arrangement, and a third connection arrangement, said tool comprising a connection part for connecting with a shaft, and a first connection arrangement for engaging said second connection arrangement on said alarm unit so as to fixate said alarm unit with said tool when mounting said alarm unit, said fixation base comprising a fourth connection arrangement for engaging said third connection arrangement on said alarm unit, said method comprises the steps of engaging said first connection arrangement of said tool with said second connection arrangement on said alarm unit so as to fixate said alarm unit to said tool, putting into contact said alarm unit fixated to said tool with said fixation base, turning said tool fixated to said alarm unit about a longitudinal direction of said shaft in a first direction so as to engage said fourth connection arrangement of said fixation base with said third connection arrangement of said alarm unit, exerting a force on said tool in a direction towards said fixation base, and turning said tool about a longitudinal direction of said shaft in the first or a second direction so as to release said tool from said alarm unit.
By a first and a second direction of rotation about an axis is meant one direction and the other direction of rotation, i.e. one direction and the opposite direction of rotation. By exerting a force on said tool in a direction towards said fixation base is meant e.g. that for a fixation base on a horizontal ceiling such force is an upwards force, and for inclining ceilings, the force is towards the ceiling and perpendicular to said ceiling. By fixated is meant e.g. that for said tool being fixated to said alarm unit, the tool and alarm unit are locked together for any orientation of the tool and alarm unit, but that when applying forces in the correct directions as described in various embodiments, the tool and the alarm unit may be separated.
By turning said tool about the longitudinal axis of said shaft, the rotational movement is transferred to said alarm unit, such that said alarm unit perform a rotational movement. Furthermore, the alarm unit will then preferably rotate about a center axis of said alarm unit. Also, this center axis preferably corresponds to a center axis of said fixation base, said center axis of said fixation base being perpendicular to a surface to which said fixation base is fixed.
According to an embodiment of the invention the step of turning said tool fixated to said alarm unit about a longitudinal direction of said shaft in a first direction comprises turning said tool fixated to said alarm unit about a longitudinal direction of said shaft in a first direction to a predetermined position between of said alarm unit relative to said fixation base.
According to an advantageous embodiment of the invention, said step of turning said tool about a longitudinal direction of said shaft so as to release said tool from said alarm unit consists of turning said tool about a longitudinal direction of said shaft in a second direction.
According to an advantageous embodiment of the invention, said third connection arrangement comprises a first part, and said fourth connection arrangement comprises a first part, said first part of said third connection arrangement and said first part of said fourth connection arrangement constitutes a protrusion and a recess together forming a bard-like function such that said first part of said third connection arrangement can pass said first part of said fourth connection arrangement in one direction only.
By a bard-like function is meant that said protrusion and said recess engages each other such that they may be disengaged in one direction relatively easy, i.e. easy e.g, by hand, whereas in the other direction they do not disengage, at least not easily.
In one embodiment, the first part of the third connection arrangement is a protrusion and the first part of the fourth connection arrangement is a recess, however, in an alternative embodiment they may be opposite, An advantage of the above embodiment is that the alarm unit may be turned freely in one direction, while it may only be turned to a predetermined position when turned in the opposite direction. Thereby, the alarm unit may be accurately positioned or orientated relative to said fixation base. This is especially advantageous in embodiments where there is an electrical connection between said alarm unit and said fixation base, e.g. for supply of electrical power, because the electrical connections may require accurate positioning or orientation of the alarm unit relative to the fixation base, which is accomplished by the above embodiment.
According to an advantageous embodiment of the invention, said step of engaging said connection arrangement of said tool with said first connection arrangement on said alarm unit comprises the steps of putting into contact said connection arrangement of said tool with said alarm unit, and turning said tool in a first direction so as to engage a first part of said first connection arrangement with a first part of said second connection arrangement.
By said first part of said first connection arrangement engaging said first part of said second connection arrangement, said alarm unit is properly fixated to said tool and thereby restricted from rotational movement. Thereby, the person mounting and/or dismounting said alarm unit in said fixation base may operate the tool by a shaft. When doing so, this person may be out of reach from said alarm unit. Therefore, it is important that said alarm unit is fixated to said tool for any rotation of said alarm unit and tool, i.e. for e.g. a horizontal position of said shaft and/or said tool, or even when said alarm unit fixated to said tool is turned upside down. This is accomplished by said first parts of said first and second connection arrangement restricting the rotational movement of said alarm unit relative to said tool.
According to an advantageous embodiment of the invention, said first part of said first connection arrangement and said first part of said second connection arrangement constitute a protrusion and a recess.
In one embodiment, the first part of the first connection arrangement is a protrusion and the first part of the second connection arrangement is a recess, however, in another embodiment, the he first part of the first connection arrangement is a recess and the first part of the second connection arrangement is a protrusion.
According to an advantageous embodiment of the invention, a second part of said first connection arrangement engages a second part of said second connection arrangement by a sliding movement, where said second part of said first connection arrangement and said second part of said second connection arrangement constitute a recess and a protrusion.
In one embodiment, the second part of the first connection arrangement is protrusion and the second part of the second connection arrangement is a recess. However, in an alternative embodiment, the second part of the first connection arrangement is recess and the second part of the second connection arrangement is a protrusion. This recess may be an annular recess, or a recess extending over at least part of the circumference of said alarm unit, thereby allowing said recess to move in said recess. An advantage of the above embodiment is that said protrusion in said annular recess fixates the alarm unit such that its movement in a direction parallel to said longitudinal axis of said shaft is restricted. The recess is to be understood in a broad sense, it may be a narrow recess fitting said protrusion, or it may be at least one edge engaging the protrusion of said first connection arrangement.
Alternatively, said second part of said first connection arrangement is a recess, and said second part of said second connection arrangement is a protrusion.
An advantage of the above embodiment is that said protrusion in said annular recess fixates the alarm unit such that its movement in a direction parallel to said longitudinal axis of said shaft is restricted.
In one embodiment of the invention, the first and second connection arrangement comprise parts, which restrict movement perpendicular to the ceiling plane, i.e. the plane abutting the fixation base, and parts, which restrict movements parallel to the ceiling plane, i.e. the plane abutting the fixation base.
According to an advantageous embodiment of the invention, said tool comprises a flexible element adapted to exert a force on said alarm unit in a direction away from said tool when said tool is fixated to said alarm unit.
By said flexible element being adapted to exert a force on said alarm unit, the first part of the first connection arrangement, such as a protrusion, will be fixated to said first part of said second connection arrangement, such as a recess. Thereby the alarm unit is fixable to said tool, and the tool fixated to said alarm unit may be rotated into any orientation without said alarm unit detaching unintentionally from said tool.
In one embodiment of the invention, the step of turning said tool in a first direction so as to engage a first part of said first connection arrangement of said tool with a first part of said second connection arrangement of said alarm unit comprises exerting a force on said tool in towards said alarm unit so as to deform said flexible element before and during turning said tool and releasing said force after the tool is turned into a predetermined position so as to allow said flexible element to move said tool away from said alarm unit, said first part of said first connection arrangement thereby engaging said first part of said second connection arrangement. By deforming the flexible element, the first part of the first connection arrangement is allowed to pass under the second part of the second connection arrangement of the alarm unit.
According to an advantageous embodiment of the invention, said step of exerting a force on said tool releases said first part from said second part.
By exerting a force on said tool, the first part of said first connection arrangement is released from said first part of said second connection arrangement. This force may in one embodiment overcome a force from said flexible element
According to an advantageous embodiment of the invention, said step of turning said tool about a longitudinal direction of said shaft in a second direction comprises the step of maintaining said force on said tool while turning said tool in said second direction at least until said first part of said first connection arrangement is free from said first part of said second connection arrangement.
Thereby, it is secured that said first part of said first connection arrangement and said first part of said second connection arrangement are properly disengaged from each other.
According to an advantageous embodiment of the invention, said alarm unit comprises at least one first stopping element adapted to restrict rotational movement of said second part of said first connection arrangement when rotating said tool relative to said alarm unit.
An advantage of the above embodiment is that when fixating said tool to said alarm unit, the first stopping element defines a rotational interval over which the tool may rotate. This may be done such that e.g. during said step of turning said tool in said first direction so as to engage said first part of said first connection arrangement with said first part of said second connection arrangement, said tool may only be turning to a position where said first part of said first connection arrangement and said first part of said second connection arrangement are positioned opposite to each other, i.e. in the same rotational angle, and therefore ready to engage each other. Furthermore, during said step of turning said tool in said first direction to fixate said alarm unit in said fixation base, the first stopping element prevents the tool from rotating relative to said alarm unit. Finally, during when turning said tool in said second direction in order to release the tool from the alarm unit, second part of the first connection arrangement may engage the first stopping element and thereby the tool may rotate the alarm unit in a second direction until the first part of the third connection arrangement meets the first part of the fourth connection arrangement thereby preventing further rotation of the alarm unit relative to the fixation base. I.e. the first stopping element allows the tool to turn the alarm unit to a predetermined position or orientation relative to the fixation base, thereby facilitating e.g. electrical connection between the alarm unit and the fixation base.
According to one embodiment of the invention, said first connection arrangement of said tool comprises three arms for engaging three complimentary sections of said second connection arrangement of said alarm unit.
According to one embodiment of the invention, said tool comprises a second stopping element arrangement adapted to restrict the movement of said tool towards said alarm unit during said step of exerting a force on said tool.
By restricting the movement of the tool towards the alarm unit, the distance between the tool and the alarm unit is confined within an interval defined by the second stopping element and the flexible element.
According to an advantageous embodiment of the invention, wherein said tool furthermore comprises an elongated flexible part connecting said connection part and said connection arrangement.
An advantage of the above embodiment is that said first connection arrangement may bend relative to said shaft. This is a distinct advantage when mounting and/or dismounting an alarm unit to and/or from a fixation base on an inclined ceiling. If the user is positioned approximately under the fixation base during mounting of an alarm unit, the alarm unit will not meet the fixation base in a proper angle, i.e. there will be a non-zero angle between the bottom surface of the alarm unit and the top surface of the fixation base. However, when said tool comprises an elongated flexible part, it may bend when said alarm unit comes into contact with the fixation base and/or the ceiling, thereby bringing the alarm unit into proper orientation for mounting it in said fixation base. Also, when dismounting an alarm unit from a fixation base, the elongated flexible part may bend when the tool, e.g. a part of the first connection arrangement, comes into contact with the alarm unit.
In one embodiment length of the elongated flexible part may be adjusted. Thereby, the elongated element is adjusted, since a longer elongated part is more flexible than a short elongated part.
According to an advantageous embodiment of the invention, said alarm unit is a smoke detector unit.
Alternatively, the alarm unit may comprise other types of alarm units, such as e.g. temperature detector units, light detector units etc. or even work as a cover for e.g. such units already installed in a ceiling or other units, such as e.g. fire sprinkler units or fire sprinkler system units.
According to an advantageous embodiment of the invention, said fixation base comprises electrical contacts for connecting to said alarm unit and to an electric grid, such as an electric utility grid.
According to an embodiment of the invention, said alarm unit is an alarm unit housing comprising a base plate and a covering part, said covering part allowing flow of air to pass by means of at least one opening, preferably a plurality of openings.
According to an embodiment of the invention, said base plate comprises a fifth connection arrangement adapted for engaging a sixth connection arrangement of a smoke detector unit.
Thereby, the base plate is adapted to be connected to any smoke detector unit, such as commercial available smoke detector units.
According to an embodiment of the invention, the first connection arrangement of the tool comprises at least three arms, such as three symmetrically positioned arms. An advantage of having three arms and therefore at least three contact points to said alarm unit is that the tool is easily centered relative to said alarm unit when putting said tool into contact with said alarm unit.
According to an embodiment of the invention, the tool, the alarm unit and/or the fixation base may be made at least partly by a plastic material, preferably by injection molding.
According to an embodiment of the invention, the fixation between the fixation base and the alarm unit is stronger than the fixation between the tool and the alarm unit for a first direction of rotation, and wherein the fixation between the tool and the alarm unit is stronger than the fixation between the fixation base and the alarm unit for a second direction of rotation.
According to a further embodiment of the invention, any two connection arrangements and/or parts thereof adapted for engaging each other, may be have complimentary form, such that one connection arrangement and/or a part thereof fits into another connection arrangement and/or a part thereof. Furthermore, one connection arrangement and/ or a part thereof preferably comprise a recess, such as a point recess or an annular or at least partly annular recess, while the complimentary connection arrangement and/or a part thereof is a protrusion, or an annular or at least partly annular protrusion. Preferably, the protrusion and recess are designed such that they allow one-way pass only with respect to rotation, i.e. they allow one connection arrangement and/or a part thereof to pass when rotating relative to the other connection arrangement and/or a part thereof in a first direction, but prevents the two connection arrangement and/or a part thereof from passing each other when rotating in the opposite direction relative to each other. Such one-way passing mechanism could e.g. be a barb or a barb-like structure. The above describe embodiment could apply for e.g. the first and second connection arrangements and/or parts thereof, the third and fourth connection arrangements and/or parts thereof, or the fifth and sixth connection arrangements and/or parts thereof.
According to a further embodiment of the invention, a protective element for said tool 1 may be provided. This protective element is adapted for engaging the first connection arrangement of said tool, and thereby protecting said first connection arrangement from breaking, e.g. due to pressure or blows. This protective element may have any suitable shape. The protective element is especially suitable for being fixated to the tool during storage of the tool, where the above mentioned pressure and/or blows to said tool may occur.
According to one embodiment of the invention, a method of dismounting an alarm unit in a fixation base for said alarm unit is provided, said method comprising the steps of engaging into contact a first connection arrangement of said tool with a second connection arrangement of said alarm unit, and turning said tool in said first direction so as to release a third connection arrangement of said alarm unit from a fourth connection arrangement of said fixation base. This may be combines with any of the embodiments of the invention.
According to one embodiment of the invention, a tool for mounting and/or dismounting an alarm unit in a fixation base for said alarm unit is provided in accordance with the method of any of the above described embodiments, where said tool comprises a connection part for connecting with a shaft, and a first connection arrangement for engaging a second connection arrangement on said alarm unit so as to fixate said alarm unit to said tool when mounting and/or dismounting said alarm unit.
Said tool comprises a connection part for connecting with a shaft according to the above embodiment. However, in alternative embodiments said shaft may be integrated in said tool, e.g. by such a tool comprising a shaft being a one-piece tool.
The invention furthermore relates to an alarm unit configured for operation in accordance with the method of any of the above described embodiments, wherein said alarm unit comprises a first connection arrangement for engaging said connection arrangement of a tool according to the invention, and a second connection arrangement for engaging a connection arrangement of a fixation base according to the invention.
According to one embodiment of the invention, a fixation base configured for operation in accordance with the method of any of any of the above embodiments is provided, the fixation base comprising a connection arrangement for engaging said second connection arrangement of said alarm unit.
According to one embodiment of the invention, a kit comprising a fixation base according to any of the above embodiments, an alarm unit according to any of the above embodiments, and a tool according to any of the above embodiments for mounting and/or dismounting said alarm unit in said fixation base according to any of the above embodiments is provided.

Figures

The invention wilt now be described with reference to the drawings, where

figures 1A-1F illustrate step-by-step a method of installing an alarm unit in a fixation base using a tool,
figure 2A illustrates an alarm unit in a perspective view,
figure 2B illustrates an alarm unit in a bottom-up view,
figure 2C illustrates an alarm unit in a top-down view,
figure 3 illustrates a tool, an alarm unit, and a fixation base in a side view,
figure 4 illustrates a tool fixated to an alarm unit in a perspective view,
figure 5 illustrates a tool in a perspective view,
figure 6 illustrates a fixation base in a top-down view,
figure 7 illustrates an alarm unit in a bottom-up view,
figure 8 illustrates an enlarged part of an alarm unit, and
figure 9 illustrates a part of a tool in a cut-through view.

Description of the invention

Referring to figure 1A - IF, a method of mounting an alarm unit 2 in a fixation base 3 for the alarm unit 2 according to an embodiment of the invention is illustrated. According to this method the alarm unit 2, the alarm comprises a second connection arrangement 7, and a third connection arrangement 14. Furthermore, the tool 1 comprises a shaft 5, and a first connection arrangement 6 for engaging the second connection arrangement 7 on the alarm unit 2 so as to fixate the alarm unit 2 with the tool 1 when mounting the alarm unit 2. The fixation base 3 comprises a fourth connection arrangement 15 for engaging the third connection arrangement 14 on the alarm unit 2. The method of this embodiment comprises a number of steps, the first step being engaging S1 the first connection arrangement 6 of the tool 1 with the second connection arrangement 7 on the alarm unit 2 so as to fixate the alarm unit 2 to the tool 1. This step is illustrated on figure 1A. A later step is illustrated on figure 1B, where the alarm unit 2 fixated to the tool 1 is put into contact with the fixation base 3, here by moving S2 the alarm unit 2 in an upwards direction. A later step is illustrated on figure 1C, where the tool 1 fixated to the alarm unit 2 is turned S3 about a longitudinal direction 12 of the shaft 5 in a first direction 9 to a predetermined position between of the alarm unit 2 relative to the fixation base 3 thereby engaging the fourth connection arrangement 15 of the fixation base. 3 with the third connection arrangement 14 of the alarm unit 2. A later step is illustrated on figure 1D, where a force is exerted $4 on the tool 1 in a direction towards the fixation base 3. A later step is illustrated on figure IE, where the tool 1 is turned S5 about a longitudinal direction 12 of the shaft 5 in a second direction 10 so as to release the tool 1 from the alarm unit 2. Furthermore, in some embodiments, the force S4 is maintained while turning S5 the tool 1. Finally, the tool 1 is released from the alarm unit 2, and therefore, the tool 1 can be removed S6 from the alarm unit 2, which is now fixated to the fixation base 3. This is illustrated on figure 1F.
An embodiment is illustrated on figure 2A - 2C, where the alarm unit 2 is shown from different angles. On figure 2A, the alarm unit 2 is shown in a perspective view. The alarm comprises a plurality of openings 17. These openings 17 allows air to pass into the alarm unit 2, thereby allowing the alarm unit 2 to detect a characteristic of the air, such as smoke or particle content, temperature etc. Furthermore, the alarm unit 2 comprises first part 7a of second connection arrangements 7. According to the illustrated embodiment, these first parts 7a are recesses 7a. These are adapted for receiving a first part 6a of a first connection arrangement 6 of a tool 1, such first parts 6a being in one embodiment protrusions 6a. Also to be seen on figure 2A and 1C is a test button 19. This test button 19 is for testing if the alarm works correctly, e.g. if it is connected to a power source, and if such power source supplies the correct voltage. On figure 2B holes 20 for fixating said fixation base 3 to a ceiling with fixation means, such as screws or nails. However, the fixation base 3 may be connected to the ceiling any suitable way.
Referring now to figure 3, an embodiment of the invention is illustrated. On figure 3, a tool 1, an alarm unit 2, and a fixation base 3 is shown. The tool 1 comprises a connection part 4 for connection to a shaft 5, an elongated part 8, and a first connection arrangement 6. The first connection arrangement 6 comprises a first part 6a and a second part 6b. Furthermore, the tool 1 comprises a flexible element 22 supplying, when the tool 1 and the alarm unit 2 are fixated to each other, a force pushing the tool 1 away from the alarm unit 2. The alarm unit 2 comprises a second connection arrangement 7, a third connection arrangement 14, a first stopping element 11, a plurality of openings 17 allowing the surrounding atmosphere, including smoke particles, easy passage into the inner space of said alarm unit 2, and a plate 18, which may be separable from the rest of the alarm unit 2. The second connection arrangement 7 comprises a first part 7a and a second part 7b. The third connection arrangement 14 comprises a first part 14a and a second part 14b. The fixation base 3 comprises a fourth connection arrangement 15. The fourth connection arrangement 15 comprises a first part 15a and a second part 15b. According to one embodiment of the invention, the alarm unit 2 can be attached to a tool 1 by means of the first connection arrangement 6 engaging the second connection arrangement 7. More specifically, the first part 6a of the first connection arrangement 6, being e.g. a protrusion, engages the first part 7a of the second connection arrangement 7, such as a recess. Preferably, the protrusion 6a and the recess 7a engage each other, such that they prevent rotational movement of the tool 1 relative to the alarm unit 2. Also, they are preferably such that the can be disengaged by moving the tool 1 towards the alarm unit 2. In order to perform such a disengaging movement, the force from the flexible element 22 has to be overcome, e.g. by exerting a greater force in the opposite direction. Alternatively, the recess 6a and the protrusion 7a may be switched, such that the first part 7a of the second connection arrangement 7 is a protrusion 7a, and the first part 6a of the first connection arrangement 6 is a recess 6a. Moreover, the second part 6b of the first connection arrangement 6, being e.g. an at least partly annular rim, ledge or protrusion, engages the second part 7b of the second connection arrangement 7, being e.g. an at least partly annular recess or slot. Alternatively, the two second parts may be switched such that the second part 7a is a rim, ledge or protrusion and the second part 6a is a recess or slot. Thereby, the first and second connection arrangements 6, 7 interlocks such that first parts 6a, 7a of each 6, 7 rotational movement of the tool 1 relative to the alarm unit 2 while allowing movement of the tool 1 relative to the alarm unit 2 in at least one direction, while the second parts 6b, 7b prevents movement of the tool 1 relative to the alarm unit 2 in at least one direction.
Referring to figure 4, the tool 1 is fixated to the alarm unit 2, while at the same time, the tool 1 is fixated to the fixation base 3. A longitudinal axis 12 is shown as a longitudinal axis 12 of the elongated element 8. This longitudinal axis defines rotation movement of the tool 1 relative to the alarm unit 2 and rotational movement of the alarm unit 2 relative to the fixation base 3 as being rotation about this longitudinal axis 12.
Referring to figure 5, the tool 1 is illustrated according to an embodiment of the invention. In figure 5 the tool 1 is shown in a perspective view from the side an upwards. Of the tool 1 is shown a second stopping element 23. This second stopping element 23 is preferably implemented on all arms 24 of the tool 1. The second stopping element 23 performs its function when the tool 1 is pushed towards the alarm unit 2 thereby overcoming the force from the flexible element 22. In order to limit the distance over which the tool 1 may move towards the alarm unit 2 when supplying this force, the stopping elements 23 may be implements. These stopping elements 23 will, when the tool 1 is moved towards the alarm unit 2, come into contact with the alarm unit 2, thereby preventing further movement of the tool 1 relative to the alarm unit 2. Furthermore, a test button activator 21 can be seen on said tool 1. This test button activator 21 is adapted for engaging the testing button 19 on the alarm unit 2, thereby activating said alarm unit 2. I.e. the tool may allow the user to test the alarm unit 2 without removing the alarm unit 2 from the fixation base 3.
Referring to figure 6, the fixation base 3 is shown in a top-down view. According to an embodiment, the fourth connection arrangement 15 of the fixation base 3 comprises a first part 15a. The fixation base 3 furthermore comprises electrical contacts 25 for making electrical connection between the fixation base 3 and the alarm unit 2. Such electrical connection may e.g. be used if the fixation base is connection to an electrical power source, such as an electrical utility grid, and supplies at least partly the alarm unit 2 with electrical power. The first parts 15a of the fourth connection arrangement 15 may e.g. be a recess, such as a barb-like structure, i.e. a recess with one sharp edge and one edge with a soft transition, thereby allowing a complimentary protrusion 14a to engage the recess 15a, thereby preventing rotation of the alarm unit 2 relative to the fixation base 3 about a longitudinal axis 12 in a first direction, while allow rotation in the opposite direction.
On figure 7, an alarm unit 2 according to an embodiment of the invention is shown in a bottom-up view. The first parts 14a of the third connection arrangement 14 are shown as a barb-like structure. Furthermore, electrical contact elements 25 are shown, such electrical contact elements 25 being adapted to engage electrical contact elements 25 of a fixation base 3, thereby facilitating electrical connection between the fixation base 3 and the alarm unit 2 allowing an electrical power source in or connected to the fixation base 3 to supply electrical power to the alarm unit 2 via the electrical contact elements 25.
Referring to figure 8, an enlarged part 16 of the alarm unit 2 is shown illustrating the shape of the first part 14a of the third connection arrangement 14 being a barb-like structure allowing the alarm unit 2 to rotate relative to the fixation base 3 about the longitudinal axis 12.
On figure 9, a cross-sectional view of a part of a tool 1 according to an embodiment of the invention is illustrated. The first connection arrangement 6 is partly shown, while the elongated part 8 extends into the head of the tool 1 comprising the first connection arrangement 6. Also, the tool 1 comprises a connection part 4 for connecting the tool 1 with a shaft 5. On figure 9, the tool 1 is shown to be connected to a shaft by the shaft 5 extending into the connection part 4. In alternative embodiments, the shaft 5 may extend over the connection part 4, or the connection between the shaft 5 and the tool 1 may be facilitated in other ways. Also, the elongated part 8 may be a flexible part, i.e. being more flexible that the rest of the tool 1 and the shaft 5, and thereby allowing the user to stand directly below a fixation base 3 mounted on an inclined ceiling. The flexibility of the flexible elongated part 8 may in an embodiment be determined from the free length of the elongated part 8, i.e. the length between the head of the tool 1 and the connection part 4, longer lengths being more flexible and short lengths being less flexible. Therefore, by adjusting the free length of the elongated part 8, e.g. by moving the connection part 4 along the elongated part 8, the flexibility of the elongated part 8 may be adjusted.
According to the present invention the embodiments mentioned in the specification of this patent application may be combined to obtain further embodiments according to the present invention.

List of reference numerals

1. Tool
2. Alarm unit
3. Fixation base
4. Connection part of tool
5. Shaft
6. First connection arrangement of said tool
6a. First part of said first connection arrangement of said tool
6b. Second part of said first connection arrangement of said tool
7. Second connection arrangement of said alarm unit
7a. First part of second connection arrangement of said alarm unit
7b. Second part of second connection arrangement of said alarm unit
8. Elongated part
9. First direction
10. Second direction
11 First stopping element of said second connection arrangement
12. Longitudinal axis
13. Smoke detector unit
14. Third connection arrangement of said alarm unit
14a. First part of said third connection arrangement of said alarm unit
14b. Second part of said third connection arrangement of said alarm unit
15. Fourth connection arrangement of said fixation base
15a. First part of said fourth connection arrangement of said fixation base
15b. Second part of said fourth connection arrangement of said fixation base
16. Enlarged part
17. Openings
18. Plate
19. Test button
20. Hole for fixation means
21. Test button activator
22. Flexible element
23. Second stopping element of said tool
24. Arm of said first connection arrangement
25. Electrical contact element
S1. Engaging first connection arrangement with second connection arrangement
S2. Moving the tool and alarm unit upwards
S3. Turning about a longitudinal axis of the shaft in a first direction
S4. Exerting force towards the fixation base
S5, Turning about a longitudinal axis of the shaft in a second direction
S6. Removing the tool from the alarm unit

Claims

A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) by means of a tool (1),
said alarm unit (2) comprising
a second connection arrangement (7), and
a third connection arrangement (14),
said tool (1) comprising
a connection part (4) for connecting with a shaft (5), and
a first connection arrangement (6) for engaging said second connection arrangement (7) so as to fixate said alarm unit (2) with said tool (1) when mounting said alarm unit (2),
said fixation base (3) comprising
a fourth connection arrangement (15) for engaging said third connection arrangement (14),
said method comprises the steps of
- engaging said first connection arrangement (6) with said second connection arrangement (7) so as to fixate said alarm unit (2) to said tool (1),

- putting into contact said alarm unit (2) fixated to said tool (1) with said fixation base (3),

- turning said tool (1) fixated to said alarm unit (2) about a longitudinal direction (12) of said shaft (5) in a first direction (9) so as to engage said fourth connection arrangement (15) with said third connection arrangement (14),

- exerting a force on said tool (1) in a direction towards said fixation base (3), and

- turning said tool (1) about said longitudinal direction (12) of said shaft (5) in the first or a second direction (10) so as to release said tool (1) from said alarm unit (2).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to claim 1,
wherein said step of turning said tool (1) about a longitudinal direction (12) of said shaft (5) so as to release said tool (1) from said alarm unit (2) consists of turning said tool (1) about a longitudinal direction (12) of said shaft (5) in a second direction (10).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to claim 1 or 2,
wherein said third connection arrangement (14) comprises a first part (14a), and said fourth connection arrangement (15) comprises a first part (15a),
said first part (14a) of said third connection arrangement (14) and said first part (15a) of said fourth connection arrangement (15) constitutes a protrusion and a recess together forming a bard-like function such that said first part (14a) of said third connection arrangement (14) can pass said first part (15a) of said fourth connection arrangement in one direction only.
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein said step of engaging said connection arrangement (6) of said tool (1) with said first connection arrangement (7) on said alarm unit (2) comprises the steps of
- putting into contact said connection arrangement (6) of said tool (1) with said alarm unit (2), and

- turning said tool (1) in a first direction (9) so as to engage a first part (6a) of said first connection arrangement (6) with a first part (7a) of said second connection arrangement (7).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to claim 4,
wherein said first part (6a) of said first connection arrangement (6) and said first part (7a) of said second connection arrangement (7) constitute a protrusion (6a) and a recess (7a).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein a second part (6b) of said first connection arrangement (6) engages a second part (7b) of said second connection arrangement (7) by a sliding movement, said second part (6b) of said first connection arrangement (6) and said second part (7b) of said second connection arrangement (7) constitute a recess (7b) and a protrusion (6b).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein said tool (1) comprises a flexible element (22) adapted to exert a force on said alarm unit (2) in a direction away from said tool (1) when said tool (1) is fixated to said alarm unit (2).
A method of mounting an alarm unit (2) in a fixation base (3) for, said alarm unit (2) according to any of claims 4-7,
wherein said step of exerting a force on said tool (1) releases said first part (6a) from said second part (7a).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of claims 2-8,
wherein said step of turning said tool (1) about a longitudinal direction (12) of said shaft (5) in a second direction (10) comprises the step of
- maintaining said force on said tool (1) while turning said tool (1) in said second direction (10) at least until said first part (6a) of said first connection arrangement (6) is free from said first part (7a) of said second connection arrangement (7).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein said alarm unit (2) comprises at least one first stopping element (11) adapted to restrict rotational movement of said second part (6b) of said first connection arrangement (6) when rotating said tool (1) relative to said alarm unit (2).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein said tool (1) furthermore comprises an elongated flexible part (8) connecting said connection part (4) and said connection arrangement (6).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein said alarm unit (2) is a smoke detector unit (13).
A method of mounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) according to any of the preceding claims,
wherein said fixation base (3) comprises electrical contacts (25) for connecting to said alarm unit (2) and to an electric grid, such as an electric utility grid.
A tool (1) for mounting and/or dismounting an alarm unit (2) in a fixation base (3) for said alarm unit (2) in accordance with the method of any of claim 1-13, where said tool (1) comprises
- a connection part (4) for connecting with a shaft (5), and

- a first connection arrangement (6) for engaging a second connection arrangement (7) on said alarm unit (2) so as to fixate said alarm unit (2) to said tool (1) when mounting and/or dismounting said alarm unit (2).
An alarm unit (2) configured for operation in accordance with the method of any of claims 1-13, wherein said alarm unit (2) comprises a first connection arrangement (7) for engaging said connection arrangement (6) of said tool (1), and
a second connection arrangement (14) for engaging a connection arrangement (15) of said fixation base (3).