The invention relates to an anti-theft device configured to be attached to merchandise to be protected, in particular textile products, comprising a housing and a locking mechanism, which
comprises a securing element, the securing element being adjustable between a securing position, in which it engages with the merchandise to be protected, and a release position, in which detachment and removal of the anti-theft device from the merchandise to be protected are permitted.
Anti-theft devices of this kind are well known and have been preferentially used for many years in the field of stores open to the public, as they provide sufficient protection against unauthorized removal from the store, or from or a demarcated sales area within said store, of merchandise sold therein. For this purpose, appropriate detector units are usually provided at all entrances and exits of the store, or of any demarcated sales areas therein, and these are designed and intended to emit an acoustic and/or visual warning signal if a customer attempts to remove from the store or sales area any protected merchandise to which an anti-theft device of this kind is attached.
A generic anti-theft device is disclosed in the applicant's German patent application with the official file reference 10 2019 204 779.3. The locking mechanism described therein comprises a slider that can be engaged with a needle-receiving element in order to lock the needle-receiving element, by a needle attached thereto, in the securing position. To transfer the needle-receiving element from the securing position to the release position, the slider is connected to a wire made of a shape-memory alloy (hereinafter sometimes referred to in short as an “SMA wire”), which can be heated by applying an electrical voltage. As a result, the SMA wire contracts, whereby the slider can be disengaged from the needle-receiving element and the needle-receiving element can be moved from the securing position to the release position.
Although this kind of embodiment of the locking mechanism is a reliable way of opening the generic anti-theft device, it has disadvantages in that a relatively long SMA wire has to be used to move the slider since the amount by which the length of a wire can shorten is usually only about 3-5% of the length of the SMA wire. However, using a long SMA wire is not only disadvantageous in terms of the necessary installation space, but it also results in increased power consumption, which entails frequent charging or replacement of the battery of an anti-theft device of this kind.
In addition, the generic anti-theft device in DE 10 2019 204 779.3 has a substantially circular shape, which can make it difficult to position the needle precisely when attaching the anti-theft device to textile products and can thus lead to unintentional damage to these textile products.
The object of the present invention is therefore to remedy this situation.
According to a first aspect of the present invention, this object is achieved by an anti-theft device of the type mentioned at the outset in which the locking mechanism further comprises at least two guide openings which are displaceable relative to one another and through which the securing element is guided, a guide element, in which at least one of the at least two guide openings is formed, the guide element having a first position, in which the at least two guide openings are positioned relative to one another in such a way that movement of the securing element from the securing position to the release position is prevented, and
a second position, in which the at least two guide openings are positioned relative to one another in such a way that movement of the securing element from the securing position to the release position is permitted, and a wire, which is made at least in part of a shape-memory alloy (hereinafter also “SMA wire”), is operatively connected to the guide element, and is configured to transfer the guide element from the first position to the second position.
Preferably, the securing element is in the form of a needle or a locking pin. In the first position, the positioning of the at least two guide openings relative to one another is preferably selected in such a way that a clamping action, i.e., a clamping force, is exerted on the securing element. In the second position, however, the relative position of the at least two guide openings is preferably selected in such a way that the securing element can move freely, in particular independently, from the securing position to the release position. As a result, the SMA wire only has to travel over a comparatively short actuation path to transfer the guide element to the second position and thus allow the securing element to move from the securing position to the release position. A comparatively short SMA wire can thus be used, resulting in reduced installation space requirements, lower power consumption, and reduced material costs for the SMA wire.
In principle, the at least one guide opening of the at least two guide openings may be formed on the guide element whereas another guide opening of the at least two guide openings may be formed on the housing or on a part connected thereto. To implement particularly precise needle guidance, according to an embodiment example of the invention it is proposed that, furthermore, at least one other guide opening of the at least two guide openings is formed on the guide element.
To be able to ensure that the guide element can independently return to the first position after being actuated by the SMA wire in order to allow the securing element to be locked back in the securing position, according to an embodiment example it is proposed that the guide element is preloaded, in particular spring-biased, into the first position. This can be achieved, for example, by the guide element itself simply having sufficient resilience.
According to a further embodiment example, the at least one guide opening of the at least two guide openings can have a substantially oval contour and/or at least one other guide opening of the at least two guide openings can have a substantially circular contour. As a result, the at least one guide opening having the substantially oval contour can be used primarily for blocking or releasing the movement of the securing element, whereas the at least one further guide opening having the substantially circular contour can be used primarily for guiding the securing element, in particular substantially transversely to its direction of movement.
Additionally or alternatively, the at least one guide opening of the at least two guide openings can be displaceable relative to the housing and/or at least one other guide opening of the at least two guide openings can be arranged immovably relative to the housing. Similarly, the at least one guide opening that is displaceable relative to the housing can be used primarily for blocking or releasing the movement of the securing element, whereas the at least one further guide opening that is arranged substantially immovably relative to the housing can be used primarily for guiding the securing element, in particular substantially transversely to its direction of movement.
If the at least one guide opening of the at least two guide openings has the substantially oval contour and the at least one other guide opening of the at least two guide openings has the substantially circular contour, it is additionally conceivable according to an embodiment example that the substantially circular guide opening is arranged immovably relative to the housing and the substantially oval guide opening is displaceable relative to the housing.
To be able to configure the guide element so as to be particularly compact and at the same time functionally reliable, the guide element can have a curved shape, preferably substantially a C-shape or an S-shape. If the guide element is S-shaped, three guide openings can accordingly be provided for guiding the securing element. By way of example, if three of the guide openings are provided, one of the three guide openings may have the substantially circular contour and two of the three guide openings may have the substantially oval contour.
In principle, the SMA wire can be connected to the housing, or to a part fastened thereto, at one end, and to the guide element, or to a part connected thereto, at the other end. For this purpose, however, the excitation circuit for heating the SMA wire must run through the guide element, as a result of which the securing element, and thus the merchandise to be protected, may also be energized. To counter this circumstance, in a development of this embodiment example it is proposed that both ends of the SMA wire are held in place immovably relative to the housing, a contact portion of the SMA wire in between said two ends being in contact with the guide element, or with a part connected thereto, in such a way that, upon shortening of the SMA wire, the guide element is transferred from the first position to the second position. As a result, the electrical excitation circuit can be established in a simple manner while at the same time preventing the guide element, and thus the securing element, from being necessarily energized.
According to a first alternative embodiment, the guide element may be made of an electrically conductive material, preferably sheet metal. However, in order to prevent electrical contact between the guide element and the SMA wire in this case, insulation can additionally be provided in a contact region between the guide element and the SMA wire.
If this insulation is to be omitted, in accordance with a second alternative embodiment the guide element can be made of an electrically non-conductive material. However, if the electrically non-conductive material should also have low thermal conductivity, it is then preferred if the electrically non-conductive material further has sufficient thermal resistance to provide the guide element with adequate resistance to the heat generated by the application of the voltage to the SMA wire.
In addition, to allow the anti-theft device to be removed from the merchandise to be protected particularly quickly and conveniently as soon as the guide element has assumed the second position and has thus released the movement of the securing element from the securing position to the release position, according to a further embodiment example it is proposed that the securing element is preloaded, in particular spring-biased, into the release position.
Moreover, in order for the anti-theft device to have a sufficient degree of freedom with respect to different methods and/or locations for being attached to merchandise to be protected, the housing may further have a cut-out that preferably extends substantially radially, the cut-out being configured to receive at least one part of the merchandise to be protected. By way of example, the cut-out may take the form of a slit along a sectional plane running substantially in parallel with a main plane of the housing. Preferably, however, in the extension direction running substantially orthogonally to the main plane of the housing, the cut-out is only so pronounced to the extent that it runs between two wall portions of the housing that are located above and below the main plane of the housing. In addition, in the radial direction the cut-out may have a predetermined extent that is, for example, only about half the radial extent of the housing or less.
In this context, it should also be noted that the securing element is preferably arranged in the region of this cut-out such that the securing element can pierce the part of the merchandise to be protected that is accommodated within said cut-out. A huge range of variants are conceivable with regard to the positioning of the securing element in relation to the cut-out. The securing element can, for example, be positioned centrally in relation to the cut-out or also at an outer edge region of the cut-out.
According to a second aspect of the present invention, which can preferably be combined with the first aspect, the object is achieved by an anti-theft device of the type mentioned at the outset in which the locking mechanism further comprises a wire, which is made at least in part of a shape-memory alloy (sometimes referred to in short as “SMA wire”), and a guide element, which can be releasably engaged with the securing element and has a first position, in which movement of the securing element from the securing position to the release position is prevented, and a second position, in which movement of the securing element from the securing position to the release position is permitted, both ends of the wire being held in place immovably relative to the housing and a contact portion of the wire in between said two ends being in contact with the guide element, or with a part connected thereto, in such a way that, upon shortening of the wire, the guide element is transferred from the first position to the second position.
It should be noted at this point that ail the advantages and effects described in connection with the anti-theft device according to the first aspect also apply to the anti-theft device according to the second aspect. Furthermore, according to the invention, the SMA wire can be contacted at its two ends in a simple manner to be able to establish the electrical excitation circuit.
Preferably, the SMA wire can be substantially V-shaped when in the installed state ready for operation. In this way, the actuation path of the guide element that can be achieved by the SMA wire can be increased compared with the generic anti-theft device.
According to a third aspect of the present invention, which can preferably be combined with the first and/or the second aspect, the object is achieved by an anti-theft device of the type mentioned at the outset in which the housing has a first end portion, which forms an engagement portion in which the locking mechanism is arranged, and a second end portion, which is opposite the first end portion and forms a handling portion provided for handling the anti-theft device, the housing having a width in the region of the first end portion that is less than a width of the housing in the region of the second end portion.
Preferably, the width of the housing corresponds to the extent of the housing in a direction running substantially orthogonally to a plane that contains the movement direction of the securing element.
Compared with generic anti-theft, devices, the anti-theft device according to the third aspect of the invention is characterized firstly in that the anti-theft device is easier to attach to merchandise to be protected, in particular textile products, since the housing has the smaller width in the region of the first end portion and the securing element can consequently be positioned more precisely on the merchandise to be protected. Secondly, the anti-theft device according to the second aspect of the invention is more secure against misuse since the leverage achievable in the first end portion in the region of the locking mechanism in the event of an attempt to open the anti-theft device by force, for example in the event of an attempt to bend the anti-theft device open by means of a screwdriver or the like, is reduced. Moreover, the second, wider end portion can ensure safe handling of the anti-theft, device and provide sufficient installation space for other functional elements of the anti-theft device that are to be accommodated in and/or attached to the housing.
In addition, to be able to ensure that, while attached to the merchandise to be protected, the anti-theft device does not tend to snag on the textile product itself or interfere with the wearing comfort to an unacceptable extent, for example when a potential customer or the like is trying said product on, according to an embodiment example the width of the housing may decrease substantially continuously and/or gradually from the second end portion toward the first end portion.
Additionally or alternatively, the housing may be substantially teardrop-shaped when viewed in plan view.
The invention will now be described with reference to a number of embodiment examples on the basis of the accompanying drawings, in which:
In
The anti-theft device 100 comprises a housing 102 which, in the embodiment example shown, is formed from an upper housing part 102a and a lower housing part 102b arranged opposite thereto. The housing 102 comprises a first end portion 104 and a second end portion 106 opposite thereto, which forms a handling portion of the housing 102, i.e., is provided for a user to handle the anti-theft device. To attach the anti-theft device 100 to merchandise to be protected, e.g., textile products, the anti-theft device 100 comprises a locking mechanism, which is denoted in general by 110 and is arranged in the region of the first end portion 104. The first end portion 104 thus forms an engagement portion, which is provided for engagement with merchandise to be protected.
With reference to
To engage with a part of an item of merchandise to be protected (not shown); such as a part of a textile product, the anti-theft device 100 further comprises a cut-out 108 that extends substantially radially. In the embodiment example shown, the cut-out is in the form of a slit along a sectional plane running substantially in parallel with a main plane E (see
In
To transfer the anti-theft device 100 from the locked state shown in
If the anti-theft device 100 is to be transferred back to the locked state shown in
Lastly,
Embodiment examples of the locking mechanism as able to be installed on the anti-theft device 100 according to the invention will now be described with reference to
In
In
To transfer the guide plate 120a to a second position, in which the two guide openings 124a, 126a are to be positioned relative to one another in such a way that movement of the needle 112a from the securing position to the release position is permitted, a wire 130 is provided, made of a shape-memory alloy (SMA wire). In the process, both ends 132a, 134a of the wire 130a are held in place immovably relative to the housing 102, or are fastened thereto, and a contact portion 136a of the wire 130a in between the two ends 132a, 134a is stretched over the upper end portion 128a of the guide plate 120a in such a way that the wire 130a is arranged substantially in an inverted V-shape. Connected to the two ends 132a, 134a of the wire 130a is a wire activation unit 138a, for example in the form of a switching unit, a chip unit, or the like, which may be accommodated in the housing 102 and is also only indicated schematically in
When a voltage is applied by the wire activation unit 138a, the SMA wire 130a is heated and contracts, causing the contact portion 136a, and thus the upper end portion 128a of the guide plate 120a, to move downward in the direction of the arrow, which in turn results in a corresponding displacement of the guide opening 124a, and thus in the release of the needle 112a such that it can be transferred from the securing position to the release position, preferably with assistance from a spring (not shown) connected to the needle 112a at one end and to the housing 102 at the other end.
Preferably, the voltage is applied whenever a signal receiving unit 142a operatively connected to the wire activation unit 138a receives a corresponding opening signal, for example in the form of a token or the like, but this is also only indicated schematically in
Once the wire 130a has cooled again, the guide plate 120a can return, preferably under its own spring action, to the first position, in which movement of the needle 112a from the securing position to the release position is prevented but movement of the needle 112a from the release position to the securing position is permitted, thus allowing the anti-theft device 100 to be fastened again to merchandise to be protected. In this case, the needle 112a can be transferred from the release position to the securing position by, for example, manually actuating the needle-receiving element 114 (described above with reference to
whereupon the needle 112a can remain in the securing position due to the damping force through the guide opening 124a.
A second embodiment example of a locking mechanism (denoted in general by 110b) for the anti-theft device 100 according to the invention is described with reference to
In particular, the locking mechanism 110b is distinguished on account of a different guide plate 120b, which is substantially S-shaped. Furthermore, the guide plate 120b has an additional guide hole 125b, which can improve the guidance of the needle 112b and increase the damping force acting on the needle 112b. Disadvantageously, however, the necessary installation space in the direction substantially parallel to the needle 112b within the housing 102 may be higher compared with the locking mechanism 110a.
It should be added that the anti-theft device 100 further comprises an electronic article surveillance (EAS) element (not shown), which is preferably also accommodated in the housing 102 and is configured to interact with an electronic article surveillance system (not shown either) so that when a customer attempts to remove, without authorization, protected merchandise to which the anti-theft device 100 is attached, for example from a store, an alarm signal is emitted as soon as the merchandise passes a detector unit associated with the electronic article surveillance system.
Number | Date | Country | Kind |
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10 2020 209 216.8 | Jul 2020 | DE | national |