[0001] The subject of the invention is a buckle for electronic surveillance devices and
the method of opening it. The invention is intended for use in electronic surveillance
systems.
[0002] Overcrowded penal institutions in many countries have led to the introduction of
alternative, cheaper, and less-strict sentences of deprivation or restriction of freedom
using electronic surveillance systems. The person subject to electronic surveillance
may be detained in a less rigorous manner by changing the place of the sentence to
his or her residence, or other place of liberty as indicated by the court. This allows
for a relatively normal personal, professional, and family life for the person subject
to electronic surveillance. The freedom of the person subject to electronic surveillance
may be restricted at all times, or only at certain times, such as after or before
work. In order for the system to operate efficiently, an appropriate monitoring service
must be prepared to react to any undesirable activities on the part of the person
subject to electronic surveillance. In case of non-compliance by the person under
surveillance, the sentence may be intensified or extended.
[0003] Increasingly frequent use of this form of punishment as a substitute for imprisonment
has created the need for reliable monitoring systems. In order for such systems to
achieve their primary purpose - namely, to ensure that the person being monitored
is observing the rigors laid down by the judicial system - they must be fully credible
and resistant to manipulation attempts.
[0004] A typical example is a monitoring device with a security strap that attaches an electronic
module to the leg of the person being monitored. The strap contains a cable that closes
the electric circuit. The device can only be removed after the electric circuit has
been disconnected.
[0005] The ingenuity of monitored persons trying to outsmart surveillance devices based
solely on detection of impedance changes in the cables has led to various methods
of circumvention. One such method involves immersion of part of the strap in ionic
liquid, such as salt water, which enables strap removal without opening the electronic
circuit. Newer systems are based on measuring the reactance of the cables in the strap,
or the body characteristics of the monitored person, such as skin temperature, to
determine normal conditions of use. Any changes in the parameters being monitored
indicate manipulation. However, electrical measurements of body properties require
complex circuits, and may lead to unreliable results. That is why such electronic
devices must be properly constructed.
[0006] Brace locks are used in electronic surveillance devices such as GPS tracking bands.
GPS tracking bands are used in the penitentiary system for efficient enforcement of
sentences involving electronic surveillance, as well as for monitoring the sick and
elderly.
[0007] Known from U.S. Pat. No.
US5'497'149 is a monitoring device with anti-removal functions. The device is attached to a person's
limb using a strap. After activation, the device sends an encrypted signature by radio,
which allows it to be distinguished by the receiving station from other monitoring
devices. The receiving station receives information from the device both when the
location of the device is changed, as well as when the attached strap is tampered
with. In one embodiment, the device includes transducer housing that protects the
monitoring device from external factors, and a strap, one end of which is mounted
indirectly on the housing base and which is electrically connected to the transmitter
via a switch. In addition, the device includes a mounting element with a protrusion
designed to monitor the condition of the device and strap.
[0008] Known from U.S. Pat. No.
US4'736'196 is a system for monitoring the location of a person with an electronic surveillance
device strapped to their ankle or wrist. The unit also consists of a trigger, a transmitter,
and an antenna. The trigger controls the transmitter, and activation occurs using
the portable control unit. The trigger deactivates the transmitter under predetermined
conditions (such as removal of the strap), and reactivation requires the control device.
The strap is made of nylon or other thermoplastic material, and its length is adjusted
to the width of the wrist or ankle. Additionally, at each end of the strap is a fastener
with a conductive tip. Together they form an electrical circuit.
[0009] Known from U.S. Pat. No.
US2014124389 is housing for GPS devices used to locate children, which consists of a male and
female end locking device with adjustable sizing, a titanium cable band, and a special
key for the locking mechanism. The housing is locked around the child's ankle or wrist,
and may only be opened using a special key. A small GPS locator, which allows the
child to be located, can be placed inside the housing.
[0010] Known from U.S. Pat. No.
US9'129'504 is a device for monitoring the location of persons, which contains a main fastening
strap and at least one additional reinforcement strap. The strap can be reinforced
with cut-resistant, woven, knitted or braided material. This type of reinforced strap
is saw-resistant.
[0011] Known from U.S. Pat. No.
US2015332567 is a monitoring device equipped with housing that includes a locking mechanism, as
well as a strap and a tamper-detection system. The tamper-detection system has a power
source, a latch for fastening one part of the strap to the housing, a shape-memory
material connected to the latch, and a circuit that controls the heat of the shape-memory
material.
[0012] Known from U.S. Pat. No.
US5'471'197 is a monitoring device with a transmitter for transmitting decoded data, a strap
for attaching the transmitter, an emitter for emitting an optical signal, and a detector
for detecting an optical signal. The optical fiber is coupled with the strap to the
optical link between the emitter and the detector. The comparator compares the optical
signal and the reference signal, and the result of this comparison establishes the
value of the pre-determined data bit of the coded signals.
[0013] Known from U.S. Pat. No
US5'912'623 is a monitoring system wherein the transmitter module is connected to the monitored
person by a strap containing several cables. The module contains a microprocessor
that applies voltage to certain cables, and which establishes the voltage pattern
of the cables. Any change in the voltage pattern triggers an alarm signal. The system
is set for monitoring using an optical signal in order to prevent unauthorized disruption
in case the device is forcibly unfastened.
[0014] Unfastening the strap without damaging the housing, while also maintaining a tamper
signal, is known to be a technical problem.
[0015] The gist of the invention is a buckle equipped with a male connecting member and
female connecting member, with the female connecting member containing at least one
wedge-shaped element, and the male connecting member adapted to be inserted into the
female connecting member, which contains at least one flexible latching element for
locking the male connecting member in the female connecting member by latching at
least one latching element behind the locking element. The invention is also characterized
in that the locking element is fitted with a latch release channel, and the latching
element is adapted such that it can be titled to a position that enables release of
the male connecting member from the female connecting member by means of a tool inserted
through the latch release channel.
[0016] Furthermore, the buckle according to the invention, is characterized in that the
female connecting member contains at least two wedge-shaped locking elements that
are symmetrically arranged on opposite sides of the female connecting member, where
each locking element is fitted with a latch release channel.
[0017] Furthermore, the buckle according to the invention, is characterized in that the
male connecting member also has a flange that blocks access to the channels when the
male connecting member is latched into the female connecting member.
[0018] Furthermore, the buckle according to the invention, is characterized in that the
flange has at least one groove, which can be penetrated to gain access to the channel
when the male connecting member is latched into the female connecting member.
[0019] Furthermore, the buckle according to the invention, is characterized in that it is
made from non-fusible material.
[0020] Furthermore, the buckle according to the invention, is characterized in that the
flange is equipped with a pattern that facilitates identification of penetration attempts.
[0021] The essence of the invention is also the method of opening the buckle comprising
the following steps: first, the tool is used to penetrate the flange of the buckle;
then, the tool is inserted through channel into the latching elements; then, using
the tool, at least one latch element of the male connecting member is tilted to a
position allowing release of the male connecting member from the female connecting
member; finally, the male connecting member is pulled out of the female connecting
member.
[0022] Furthermore, the method according to the invention, is characterized in that if the
buckle contains at least two latching elements, all latching elements of the male
connecting member are tilted using the tool to a position allowing release of the
male connecting member from the female connecting member.
[0023] According to the invention, the main advantage of the buckle is its ability to release
the clamps without damaging the inner elements of the housing, while simultaneously
only allowing one-time use. The one-time use nature of the male connecting member
is important, as a damaged male connecting member can serve as proof of an unauthorized
removal attempt.
[0024] The subject of the invention has been depicted using an example scenario in the following
figures:
- Fig. 1
- shows the main elements of the monitoring device;
- Fig. 2a and 2b
- show the construction details of the buckle female connecting member;
- Fig. 3a and 3b
- show the construction details of the buckle.
[0025] Fig. 1 shows the monitoring device 1, its housing 10, the male connecting member
20, and the strap 30. The buckle is comprised of the female connecting member 11 and
the male connecting member 20. The housing 10 has a female connecting member 11 and
indicating elements 14. The shape of the housing 10 enables the device 1 to be secured
onto the leg or arm of the person being monitored. The edges of the housing are rounded
in order to eliminate discomfort while wearing and operating the device 1. Extrusions
are on two sides of the housing 10. One of these extrusions comprises the elements
that fasten the strap, and the other comprises the female connecting member 11 of
the buckle. It is also possible to have two buckles on either side of the housing.
The housing 10 can have signaling elements 12, which may be used to indicate the status
of the device 1. For example, they can indicate proper locking of the buckle, a lack
of GPS signal, or a low battery charge. The prong 20 has latching elements 21, elements
for fastening 22 the strap, and a flange 23. The latching elements 21 serve to lock
the male connecting member 20 in the socket 11 such that the flange 23 is also in
the female connecting member 11. The role of the flange 23 is to prevent outside access
to the latching elements 21 and the elements for fastening 22 the strap. The strap
30 may be connected with the male connecting member 20 when it is outside the socket
11 using the elements for fastening 22 the strap. After the buckle has been locked,
the elements for fastening 22 the strap become inaccessible from the outside, which
ensures the security of the connection between the strap 30 and the male connecting
member 20. This connection allows adjustment of the length of the strap 30 just before
locking the buckle.
[0026] If the housing 10 has two buckles, a strap 30 of predetermined length can be selected
from a number of available straps. The strap 30 can also be permanently attached to
the buckle male connecting member 20.
[0027] Fig. 2a and 2b show the construction details of the buckle female connecting member
11. Inside the female connecting member 11 are the locking elements 12. Inside the
locking elements 12 are the channels 13. The size of the locking elements 12 and the
depth of the channels 13 are adapted to the size of the latching elements 21 of the
male connecting member 20. The locking elements 12 should provide a secure connection
with the prong, whereas the depth of the channels 13 should allow access to the area
between the latching elements 21 and the inner wall of the socket 11.
[0028] Fig. 3a and 3b show the construction details of the buckle. The buckle is shown in
the locked position, as the latching elements 21 of the male connecting member 20
are clamped onto the locking elements 12 of the female connecting member 11, and the
flange 23 is in the female connecting member 11. In the flange are two grooves 24,
such that the flange is thin enough to be penetrated effortlessly using the appropriate
tool. At the same time, a properly selected groove diameter reduces the risk of accidental
damage to the flange during use of the device 1.
[0029] To open the buckle, a tool 40 such as a pin, rod, or other thin and rigid element
small enough to enter the channels 13 must be used. The tip 41 of the tool 40 must
have the shape of a sharpened cone or knife. Two tools 40 spaced a sufficient distance
away from one another, depending on the construction of the male connecting member
20 and female connecting member 11, may serve to open the buckles fitted with the
two latching elements 21. The tip 41 of the tool 40 has three functions. The first
is to penetrate the thin wall of the flange 23 at the groove 24 so that the tool 40
can be inserted into the hole thus formed. The second is that it allows the tool 40
to be inserted into the space between the wall of the socket 11 and the latching elements
21. The third is that it tilts the latching elements 21 with respect to the locking
elements 12 such that the connection between the male connecting member 20 and the
female connecting member 11 is released.
[0030] Because a damaged flange 23 is evidence of an attempt to open the buckle, it may
be necessary to take measures to make removal of such evidence impossible. In the
case of a male connecting member 20 made using an injection technique, and thus from
thermoplastic material, it is better to use a pattern that facilitates identification
of penetration attempts, and which can be placed on the flange 23 in the area of the
groove 24. This pattern can take the form of an extrusion, of a logo or a simple design.
The male connecting member 20 may also be made of non-fusible material, e.g. duromer,
epoxy plastic, polyester, polyurethane, or phenol-formaldehyde resins. The male connecting
member 20 may also be made of two different materials, with the latching elements
21 being made from flexible thermoplastic material, and the flange 23 from non-fusible
material.
1. A buckle fitted with a female connection member (11) and male connection member (20),
whereby
the female connection member (11) contains at least one wedge-shaped locking element
(12); and
the male connection member (20) is adapted to be inserted into the female connection
member (11), which contains at least one flexible latching element (21) for locking
the male connection member (20) in the female connection member (11) by latching at
least one latching element (21) behind the locking element (12);
characterized in that
the locking element (12) is fitted with a latch release channel (13);
and the latching element (21) is adapted such that it can be tilted to a position
that enables release of the male connection member (20) from the female connection
member (11) by means of a tool (40) inserted through the latch release channel (13).
2. The buckle as in claim 1, characterized in that the female connection member contains at least two wedge-shaped locking elements
(12) that are symmetrically arranged on opposite sides of the female connection member
(11), where each locking element (12) is fitted with a latch release channel (13).
3. The buckle as in claim 1 or 2, characterized in that the male connection member (20) also has a flange (23) that blocks access to the
channels (13) when the male connection member (20) is latched into the female connection
member (11).
4. The buckle as in claim 3, characterized in that the flange (23) has at least one groove (24), which can be penetrated to gain access
to the channel (12) when the male connection member (20) is latched into the female
connection member (11).
5. The buckle as in any of the claims 1 through 4, characterized in that it is made of non-fusible material.
6. The buckle as in any of the claims 1 through 5, characterized in that the flange (23) is equipped with a pattern that facilitates identification of penetration
attempts.
7. A method of opening the buckle comprising the following steps:
the tool (40) is used to penetrate the flange of the buckle; then,
the tool (40) is inserted through the channel (13) in latching elements (12); then,
using the tool (40), at least one latching element (21) of the male connecting member
(20) is tilted to a position allowing release of the prong (20) from the female connecting
member (11); and
the male connecting member (20) is pulled out of the female connecting member.
8. The method as in claim 6,
characterized in that if the buckle contains at least two latching elements (21),
all latching elements (21) of the male connecting member (20) are tilted using the
tool (40) to a position allowing release of the male connecting member (20) from the
female connecting member (11).