Antitheft device

FIELD OF THE INVENTION

The present invention relates to antitheft devices for use as attached to commodities for preventing the commodity from being stolen, and more particularly to antitheft devices comprising a tag performing the function of preventing theft occurring upon escaping from a control area, and a member for attaching the tag to the commodity.

BACKGROUND OF THE INVENTION

<figref idref="f0008 f0009 f0010 f0011">FIGS. 9 to 15</figref> show an antitheft device already proposed (<patcit id="pcit0001" dnum="JP2849048B"><text>Japanese Patent No. 2849048 B2</text></patcit>). The device comprises a tag 15 having a flat housing 16 composed of a lower half segment 17 and an upper half segment 18, and a member 2 for attaching the tag 15 to a garment or like commodity 9 as shown in <figref idref="f0008">FIG. 9</figref>.

With reference to <figref idref="f0008">FIG. 10</figref>, the housing 16 of the tag 15 has enclosed therein a sensor 40 which performs a specified theft preventing function when the tag 15 as affixed to the commodity is to be brought out of the store past a gate to actuate a theft alarm device installed in the gate.

With reference to <figref idref="f0011">FIG. 15</figref>, the attaching member 2 comprises a button 22 in the form of a disk, and a pin 21 projecting from the rear side of the button 22. A pinhole 18a is formed in the upper half segment 18 constituting the housing 16 for inserting therethrough the pin 21 of the attaching member 2 as shown in <figref idref="f0009">FIG. 11</figref>. As seen in <figref idref="f0009">FIG. 12</figref>, the lower half segment 17 constituting the housing 16 is provided with a cylindrical portion 17a for the outer end of the pin 21 of the attaching member 2 to fit in (see <figref idref="f0008">FIG. 10</figref>).

With reference to <figref idref="f0010">FIG. 14</figref>, a spring clamp member 3 made of sheet metal is disposed inside the housing 16 of the tag 15. As shown in <figref idref="f0010">FIG. 13</figref>, the spring clamp member 3 includes a main body 31 in the form of a flat plate and provided with a pair of clamp pieces 32, 32 for clamping the pin 21 of the attaching member 2 therebetween. The clamp pieces 32, 32 have outer end faces providing a clamp portion 34. The main body 31 has a circular hole 35 formed therein and a spring piece 36 projecting therefrom.

As shown in <figref idref="f0009">FIG. 12</figref>, the housing lower half segment 17 has a stepped cylindrical portion 17b positioned away from the cylindrical portion 17a. The spring clamp member 3 is rotatably supported on the housing lower half segment 17 by the stepped cylindrical portion 17b fitting in the circular hole 35 as seen in <figref idref="f0010">FIG. 14</figref>. The clamp member 3 has its spring piece 36 retained at the outer end thereof on the lower half segment 17 by engagement therewith. The spring piece 36 is elastically deformed by counterclockwise rotation of the main body 31, giving a clockwise repulsive force to the main body 31.

Referring to <figref idref="f0008">FIG. 9</figref>, a small opening 13 is formed in the housing 16 of the tag 15. The opening 13 communicates with the space wherein the clamp member 3 is installed through an inlet passage 14 formed in the housing lower half segment 17 as shown in <figref idref="f0010">FIG. 14</figref>. With the tag 15 attached to the commodity 9 by the attaching member 2 as seen in <figref idref="f0008">FIG. 9</figref>, the pin 21 of the attaching member 2 is clamped by the spring clamp member 3 (see <figref idref="f0008">FIG. 10</figref>), whereby the attaching member 2 is prevented from being pulled out.

If the tag 15 as attached to the commodity is to be brought out of the store past the gate, the sensor 40 incorporated in the tag 15 receives a radio signal (e.g., lines of magnetic force) from the theft alarm device installed in the gate, and transmits a radio signal (e.g., altered magnetic field) to a theft preventing system in response to the received signal. Consequently, an alarm incorporated in the system is actuated, notifying salesclerks of the theft. When the pin 21 is to be released from the clamp member 3 for the salesclerk to remove the tag 15 from the commodity, an unclamping probe 7 shown in <figref idref="f0008">FIG. 9</figref> is used.

With reference to <figref idref="f0011">FIG. 15</figref>, the forward end of the probe 7 is inserted into the clamp member accommodating space from the housing opening 13 through the inlet passage 14 to push the main body 31 of the clamp member 3 with the probe end against the elasticity of the spring piece 36. This rotates the clamp member 3 counterclockwise, thereby disengaging the clamp portion 34 of the clamp member 3 from the pin 21 of the attaching member 2 to unclamp the pin 21. As a result, the attaching member 2 can be removed.

However, since the pin 21 of the attaching member 2 clamped by the clamp member 3 as shown in <figref idref="f0008">FIG. 10</figref> can be cut at its base portion with a simple tool, the antitheft device has the problem of suffering an incident in that the tag 15 as attached to the commodity 9 is separated therefrom by cutting the pin 21 of the attaching member 2 to bring the commodity 9 only out of the store unlawfully.

Accordingly, it appears useful to take a countermeasure by providing a sensor on the tag 15 for detecting the separation of the tag 15 from the commodity by the cutting of the pin 21. Although it is required that the tag 15 for use as attached to the commodity be compacted to the greatest possible extent, there arises the problem that the provision of the sensor makes the tag 15 larger in size.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an antitheft device which is capable of reliably preventing the foregoing wrongful act and which is nevertheless made compact.

This is in particular achieved by an on-off switch comprising an actuator having an outer end projecting outward from the housing through a hole in the housing, and a cylindrical guide portion formed around a base end portion of the actuator and providing the pivot for the clamp member.

The present invention provides an antitheft device which comprises a tag 10 for performing a theft preventing function upon an escape from a specified control area, and an attaching member 2 for attaching the tag 10 to a commodity 9. The attaching member 2 comprises a button 22, and a pin 21 projecting from the button 22 and movable into a housing 1 of the tag 10 through a pinhole 12a formed in the housing 1.

Arranged inside the housing 1 of the tag 10 are a clamp member 3 for clamping the pin 21 of the attaching member 2 as moved in through the pinhole 12a, an on-off switch 8 to be depressed by the button 22 of the attaching member 2, and a theft alarm operable under the control of on-off signals from the on-off switch 8.

The clamp member 3 has a clamp portion 34 for the pin 21 of the attaching member 2 to be inserted therethrough for clamping the pin 21 unremovably. The clamp member 3 is rotatably supported by a pivot provided inside the housing 1, permits the clamp portion 34 to be disengaged from the pin 21 when rotated about the pivot in one direction and is given an elastic repulsive force against the rotation.

The housing 1 is provided with an inlet passage 14 for an unclamping probe 7 for pushing the clamp member 3 into rotation toward the above-mentioned one direction. The on-off switch 8 comprises an actuator 82 having an outer end projecting outward from the housing 1 through a hole 12b formed in the housing 1, and a cylindrical guide portion 83 formed around a base end portion of the actuator 82 and providing the pivot for the clamp member 3.

The stepped cylindrical portion 17b provided in the conventional antitheft device for rotatably supporting the clamp member 3 thereon is omitted from the antitheft device of the present invention, while the on-off switch 8 is disposed at the corresponding position for the cylindrical guide portion 83 of the switch 8 to rotatably support the clamp member 3. When the tag 10 as attached to the commodity 9 is to be brought out of the specified control area, the salesclerk is notified of the situation by the antitheft function of the tag 10 as is the case with the conventional device.

The unclamping probe 7 is used for the salesclerk to remove the tag 10 from the commodity 9 as in the prior art. Stated more specifically, the forward end of the probe 7 is inserted into the space wherein the clamp member 3 is provided by way of the inlet passage 14 of the housing 1 to push the clamp member 3 with the forward end against the elastic repulsive force, whereby the clamp member 3 is rotated in the above-mentioned one direction to thereby disengage the clamp portion 34 from the pin 21 of the attaching member 2 and unclamp the pin 21. Consequently, the attaching member 2 becomes removable.

If the pin 21 of the attaching member 2 is cut with the tag 10 affixed to the commodity 9, the removal of the button 22 of the attaching member 2 from the tag 10 frees the actuator 82 of the on-off switch 8 from the depression by the button 22, projecting the actuator 82 from the depressed position to a released position to turn off the switch which is closed. As a result, an on signal from the switch 8 is changed for an off signal, which is fed to the theft alarm, notifying salesclerks of the occurrence of theft. The signal is so processed as to hold the theft alarm out of operation when the attaching member 2 is removed by the salesclerk using the probe 7.

The cylindrical guide portion 83 of the on-off switch 8 is utilized in the antitheft device of the invention in place of the stepped cylindrical portion 17b provided in the conventional antitheft device for rotatably supporting the clamp member 3. The additional provision of the on-off switch 8 is therefore unlikely to make the housing 1 greater in size. Accordingly, the present device remaining as large as the conventional antitheft device is adapted to reliably prevent the commodity 9 from being stolen by cutting the pin 21 of the attaching member 2.

BRIEF DESCRIPTION OF THE DRAWINGS

<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a view in section of an antitheft device embodying the invention, with an attaching member affixed to a tag;</li><li><figref idref="f0002">FIG. 2</figref> is a view in section of the antitheft device, with the attaching member removed from the tag;</li><li><figref idref="f0003">FIG. 3</figref> is a perspective view of a housing upper half segment of the device;</li><li><figref idref="f0003">FIG. 4</figref> is a perspective view of a housing lower half segment of the device;</li><li><figref idref="f0004">FIG. 5</figref> is an enlarged perspective view of an on-off switch included in the device;</li><li><figref idref="f0005">FIG. 6</figref> is an enlarged perspective view showing a spring clamp member as mounted on the housing lower half segment of the device;</li><li><figref idref="f0006">FIG. 7</figref> is an enlarged perspective view of a probe as inserted into the housing of the device;</li><li><figref idref="f0007">FIG. 8</figref> is a block diagram showing the circuit construction of the antitheft device of the invention;</li><li><figref idref="f0008">FIG. 9</figref> is a perspective view showing the appearance of a conventional antitheft device;</li><li><figref idref="f0008">FIG. 10</figref> is a sectional view of the device;</li><li><figref idref="f0009">FIG. 11</figref> is a perspective view of a housing upper half segment of the device;</li><li><figref idref="f0009">FIG. 12</figref> is a perspective view of a housing lower half segment of the device;</li><li><figref idref="f0010">FIG. 13</figref> is an enlarged perspective view of a spring clamp member;</li><li><figref idref="f0010">FIG. 14</figref> is an enlarged perspective view showing the spring clamp member as mounted on the housing lower half segment of the device; and</li><li><figref idref="f0011">FIG. 15</figref> is an enlarged perspective view of a probe as inserted into the housing of the device.</li></ul>

DETAILED DESCRIPTION OF EMBODIMENT

An embodiment of the present invention will be described below in detail with reference to the drawings. The antitheft device of the present invention is an improvement over the conventional antitheft device shown in <figref idref="f0008 f0009 f0010 f0011">FIGS. 9 to 15</figref> (<patcit id="pcit0002" dnum="JP2849048B"><text>Japanese Patent No. 2849048</text></patcit>) and is not different from the conventional device in the appearance shown in <figref idref="f0008">FIG. 9</figref> and in the size of the device. Throughout the drawings, like parts are designated by like reference numerals and will not be described repeatedly when so desired.

With reference to <figref idref="f0001">FIG. 1</figref>, a tag 10 has a housing 1, which comprises a lower half segment 11 and an upper half segment 12. Enclosed in the housing 1 are a circuit board 4 to perform a specified theft preventing function, a buzzer 6 to be actuated in the event of the unlawful act of cutting a pin 21 of an attaching member 2, and a cell 5 serving as a power source. Also disposed inside the housing 1 is an on-off switch 8 for detecting the unlawful act, if any, of cutting the pin 21 of the attaching member 2.

With reference to <figref idref="f0004">FIG. 5</figref>, the on-off switch 8 comprises a rectangular parallelepipedal body 81, a cylindrical guide portion 83 provided on the top of the body 81, and an actuator 82 to be guided for an upward or downward sliding movement by the guide portion 83. A pair of terminals 84, 84 are provided on a side wall of the body 81 for delivering the on or off signal to be produced upon a change-over between a depressed position (on position) and a released position (off position) of the actuator 82.

As shown in <figref idref="f0007">FIG. 8</figref>, the on or off signal output from the on-off switch 8 is fed to a drive circuit 41 on the circuit board 4. When the switch 8 in the on state is turned off, the drive circuit 41 drives the buzzer 6, notifying salesclerks of an unlawful act. The cell 5 supplies power to the drive circuit 41. As seen in <figref idref="f0006">FIG. 7</figref>, the attaching member 2 comprises a button 22 in the form of a disk, and the pin 21 projecting from the rear side of the button 22.

With reference to <figref idref="f0003">FIG. 3</figref>, the upper half segment 12 constituting the housing 1 is provided, in the region thereof where the attaching member 2 is to be installed, with a pinhole 12a for inserting the pin 21 of the attaching member 2 therethrough and a hole 12b for inserting the actuator 82 of the on-off switch 8 therethrough. As shown in <figref idref="f0003">FIG. 4</figref>, the lower half segment 11 constituting the housing 1 is provided with a cylindrical portion 11a for the outer end of the pin 21 of the attaching member 2 to fit in, and a frame 11b for holding the body 81 of the on-off switch 8 therein (see <figref idref="f0004">FIG. 5</figref>).

With reference to <figref idref="f0005">FIG. 6</figref>, a spring clamp member 3 having the same construction as the conventional one is disposed inside the housing 1 of the tag 10. The clamp member 3 is rotatably supported on the housing lower half segment 11 by the cylindrical guide portion 83 of the switch 8 fitted in a circular hole 35 formed in the main body 31 of the clamp member 3 as seen in <figref idref="f0005">FIG. 6</figref>. The clamp member 3 has a spring piece 36 which is retained at its outer end on the lower half segment 11 by engagement therewith. The spring piece 36 is elastically deformed by counterclockwise rotation of the main body 31 to exert a clockwise repulsive force.

With the tag 10 attached to a commodity by the clamp member 2, the pin 21 of the attaching member 2 is clamped by the spring clamp member 3 as seen <figref idref="f0001">FIG. 1</figref>, whereby the attaching member 2 is prevented from being pulled out.

If the tag 10 as attached to the commodity is to be brought out of the store past a gate, the tag 10 receives a radio signal (e.g., lines of magnetic force) from a theft alarm device installed in the gate, and transmits a radio signal (e.g., altered magnetic field) to a theft preventing system in response to the received signal. Consequently, an alarm incorporated in the system is actuated, notifying salesclerks of the occurrence of theft.

When the pin 21 is to be released from the clamp member 3 for the salesclerk to remove the tag 10 from the commodity, an unclamping probe 7 shown in <figref idref="f0006">FIG. 7</figref> is used. The forward end of the probe 7 is inserted into the clamp member accommodating space from a housing opening 13 through an inlet passage 14 to push the main body 31 of the clamp member 3 with the probe end against the elasticity of the spring piece 36 as shown in the drawing. This rotates the clamp member 3 counterclockwise, thereby disengaging the clamp portion 34 of the clamp member 3 from the pin 21 of the attaching member 2 to unclamp the pin 21. As a result, the attaching member 2 can be removed.

If the pin 21 of the attaching member 2 is cut with the tag 10 affixed to a commodity, the removal of the button 22 of the attaching member 2 from the tag 10 frees the actuator 82 of the on-off switch 8 from the depression by the button 22, projecting the actuator 82 from the depressed position to a released position to turn off the switch 8 which is closed. As a result, an on signal from the switch 8 is changed over to an off signal, which is fed to the drive circuit 41 to drive the buzzer 6, notifying salesclerks of the occurrence of theft. The signal is so processed as to hold the drive circuit out of operation when the attaching member 2 is removed by the salesclerk using the probe 7.

A described above, the cylindrical guide portion 83 of the on-off switch 8 is utilized in the antitheft device of the invention in place of the stepped cylindrical portion 17b provided in the conventional antitheft device for rotatably supporting the clamp member 3. The additional provision of the on-off switch 8 is therefore unlikely to make the housing 1 greater in size. Accordingly, the present device remaining as large as the conventional antitheft device is adapted to reliably prevent the commodity from being stolen by cutting the pin 21 of the attaching member 2.

The device of the present invention is not limited to the foregoing embodiment in construction but can be modified variously without departing from the spirit of the invention as set forth in the appended claims. For example, the theft preventing system installed in the gate is adapted to produce an alarm when the tag 10 as attached to a commodity 9 is moved past the gate according to the foregoing embodiment, whereas the buzzer 6 incorporated in the tag 10 can be actuated in response to a radio signal from the theft preventing system installed in the gate.